build: merge the great pkg/ rename into dev.power64

This also removes pkg/runtime/traceback_lr.c, which was ported
to Go in an earlier commit and then moved to
runtime/traceback.go.

Reviewer: rsc@golang.org
          rsc: LGTM

58 files changed, 11086 insertions, 0 deletions

diff --git a/src/debug/dwarf/buf.go b/src/debug/dwarf/buf.go
new file mode 100644
index 000000000..53c46eb4b
--- /dev/null
+++ b/src/debug/dwarf/buf.go
@@ -0,0 +1,181 @@
+// Copyright 2009 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Buffered reading and decoding of DWARF data streams.
+
+package dwarf
+
+import (
+	"encoding/binary"
+	"strconv"
+)
+
+// Data buffer being decoded.
+type buf struct {
+	dwarf  *Data
+	order  binary.ByteOrder
+	format dataFormat
+	name   string
+	off    Offset
+	data   []byte
+	err    error
+}
+
+// Data format, other than byte order.  This affects the handling of
+// certain field formats.
+type dataFormat interface {
+	// DWARF version number.  Zero means unknown.
+	version() int
+
+	// 64-bit DWARF format?
+	dwarf64() (dwarf64 bool, isKnown bool)
+
+	// Size of an address, in bytes.  Zero means unknown.
+	addrsize() int
+}
+
+// Some parts of DWARF have no data format, e.g., abbrevs.
+type unknownFormat struct{}
+
+func (u unknownFormat) version() int {
+	return 0
+}
+
+func (u unknownFormat) dwarf64() (bool, bool) {
+	return false, false
+}
+
+func (u unknownFormat) addrsize() int {
+	return 0
+}
+
+func makeBuf(d *Data, format dataFormat, name string, off Offset, data []byte) buf {
+	return buf{d, d.order, format, name, off, data, nil}
+}
+
+func (b *buf) uint8() uint8 {
+	if len(b.data) < 1 {
+		b.error("underflow")
+		return 0
+	}
+	val := b.data[0]
+	b.data = b.data[1:]
+	b.off++
+	return val
+}
+
+func (b *buf) bytes(n int) []byte {
+	if len(b.data) < n {
+		b.error("underflow")
+		return nil
+	}
+	data := b.data[0:n]
+	b.data = b.data[n:]
+	b.off += Offset(n)
+	return data
+}
+
+func (b *buf) skip(n int) { b.bytes(n) }
+
+func (b *buf) string() string {
+	for i := 0; i < len(b.data); i++ {
+		if b.data[i] == 0 {
+			s := string(b.data[0:i])
+			b.data = b.data[i+1:]
+			b.off += Offset(i + 1)
+			return s
+		}
+	}
+	b.error("underflow")
+	return ""
+}
+
+func (b *buf) uint16() uint16 {
+	a := b.bytes(2)
+	if a == nil {
+		return 0
+	}
+	return b.order.Uint16(a)
+}
+
+func (b *buf) uint32() uint32 {
+	a := b.bytes(4)
+	if a == nil {
+		return 0
+	}
+	return b.order.Uint32(a)
+}
+
+func (b *buf) uint64() uint64 {
+	a := b.bytes(8)
+	if a == nil {
+		return 0
+	}
+	return b.order.Uint64(a)
+}
+
+// Read a varint, which is 7 bits per byte, little endian.
+// the 0x80 bit means read another byte.
+func (b *buf) varint() (c uint64, bits uint) {
+	for i := 0; i < len(b.data); i++ {
+		byte := b.data[i]
+		c |= uint64(byte&0x7F) << bits
+		bits += 7
+		if byte&0x80 == 0 {
+			b.off += Offset(i + 1)
+			b.data = b.data[i+1:]
+			return c, bits
+		}
+	}
+	return 0, 0
+}
+
+// Unsigned int is just a varint.
+func (b *buf) uint() uint64 {
+	x, _ := b.varint()
+	return x
+}
+
+// Signed int is a sign-extended varint.
+func (b *buf) int() int64 {
+	ux, bits := b.varint()
+	x := int64(ux)
+	if x&(1<<(bits-1)) != 0 {
+		x |= -1 << bits
+	}
+	return x
+}
+
+// Address-sized uint.
+func (b *buf) addr() uint64 {
+	switch b.format.addrsize() {
+	case 1:
+		return uint64(b.uint8())
+	case 2:
+		return uint64(b.uint16())
+	case 4:
+		return uint64(b.uint32())
+	case 8:
+		return uint64(b.uint64())
+	}
+	b.error("unknown address size")
+	return 0
+}
+
+func (b *buf) error(s string) {
+	if b.err == nil {
+		b.data = nil
+		b.err = DecodeError{b.name, b.off, s}
+	}
+}
+
+type DecodeError struct {
+	Name   string
+	Offset Offset
+	Err    string
+}
+
+func (e DecodeError) Error() string {
+	return "decoding dwarf section " + e.Name + " at offset 0x" + strconv.FormatInt(int64(e.Offset), 16) + ": " + e.Err
+}
diff --git a/src/debug/dwarf/const.go b/src/debug/dwarf/const.go
new file mode 100644
index 000000000..93c68881a
--- /dev/null
+++ b/src/debug/dwarf/const.go
@@ -0,0 +1,454 @@
+// Copyright 2009 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Constants
+
+package dwarf
+
+import "strconv"
+
+// An Attr identifies the attribute type in a DWARF Entry's Field.
+type Attr uint32
+
+const (
+	AttrSibling        Attr = 0x01
+	AttrLocation       Attr = 0x02
+	AttrName           Attr = 0x03
+	AttrOrdering       Attr = 0x09
+	AttrByteSize       Attr = 0x0B
+	AttrBitOffset      Attr = 0x0C
+	AttrBitSize        Attr = 0x0D
+	AttrStmtList       Attr = 0x10
+	AttrLowpc          Attr = 0x11
+	AttrHighpc         Attr = 0x12
+	AttrLanguage       Attr = 0x13
+	AttrDiscr          Attr = 0x15
+	AttrDiscrValue     Attr = 0x16
+	AttrVisibility     Attr = 0x17
+	AttrImport         Attr = 0x18
+	AttrStringLength   Attr = 0x19
+	AttrCommonRef      Attr = 0x1A
+	AttrCompDir        Attr = 0x1B
+	AttrConstValue     Attr = 0x1C
+	AttrContainingType Attr = 0x1D
+	AttrDefaultValue   Attr = 0x1E
+	AttrInline         Attr = 0x20
+	AttrIsOptional     Attr = 0x21
+	AttrLowerBound     Attr = 0x22
+	AttrProducer       Attr = 0x25
+	AttrPrototyped     Attr = 0x27
+	AttrReturnAddr     Attr = 0x2A
+	AttrStartScope     Attr = 0x2C
+	AttrStrideSize     Attr = 0x2E
+	AttrUpperBound     Attr = 0x2F
+	AttrAbstractOrigin Attr = 0x31
+	AttrAccessibility  Attr = 0x32
+	AttrAddrClass      Attr = 0x33
+	AttrArtificial     Attr = 0x34
+	AttrBaseTypes      Attr = 0x35
+	AttrCalling        Attr = 0x36
+	AttrCount          Attr = 0x37
+	AttrDataMemberLoc  Attr = 0x38
+	AttrDeclColumn     Attr = 0x39
+	AttrDeclFile       Attr = 0x3A
+	AttrDeclLine       Attr = 0x3B
+	AttrDeclaration    Attr = 0x3C
+	AttrDiscrList      Attr = 0x3D
+	AttrEncoding       Attr = 0x3E
+	AttrExternal       Attr = 0x3F
+	AttrFrameBase      Attr = 0x40
+	AttrFriend         Attr = 0x41
+	AttrIdentifierCase Attr = 0x42
+	AttrMacroInfo      Attr = 0x43
+	AttrNamelistItem   Attr = 0x44
+	AttrPriority       Attr = 0x45
+	AttrSegment        Attr = 0x46
+	AttrSpecification  Attr = 0x47
+	AttrStaticLink     Attr = 0x48
+	AttrType           Attr = 0x49
+	AttrUseLocation    Attr = 0x4A
+	AttrVarParam       Attr = 0x4B
+	AttrVirtuality     Attr = 0x4C
+	AttrVtableElemLoc  Attr = 0x4D
+	AttrAllocated      Attr = 0x4E
+	AttrAssociated     Attr = 0x4F
+	AttrDataLocation   Attr = 0x50
+	AttrStride         Attr = 0x51
+	AttrEntrypc        Attr = 0x52
+	AttrUseUTF8        Attr = 0x53
+	AttrExtension      Attr = 0x54
+	AttrRanges         Attr = 0x55
+	AttrTrampoline     Attr = 0x56
+	AttrCallColumn     Attr = 0x57
+	AttrCallFile       Attr = 0x58
+	AttrCallLine       Attr = 0x59
+	AttrDescription    Attr = 0x5A
+)
+
+var attrNames = [...]string{
+	AttrSibling:        "Sibling",
+	AttrLocation:       "Location",
+	AttrName:           "Name",
+	AttrOrdering:       "Ordering",
+	AttrByteSize:       "ByteSize",
+	AttrBitOffset:      "BitOffset",
+	AttrBitSize:        "BitSize",
+	AttrStmtList:       "StmtList",
+	AttrLowpc:          "Lowpc",
+	AttrHighpc:         "Highpc",
+	AttrLanguage:       "Language",
+	AttrDiscr:          "Discr",
+	AttrDiscrValue:     "DiscrValue",
+	AttrVisibility:     "Visibility",
+	AttrImport:         "Import",
+	AttrStringLength:   "StringLength",
+	AttrCommonRef:      "CommonRef",
+	AttrCompDir:        "CompDir",
+	AttrConstValue:     "ConstValue",
+	AttrContainingType: "ContainingType",
+	AttrDefaultValue:   "DefaultValue",
+	AttrInline:         "Inline",
+	AttrIsOptional:     "IsOptional",
+	AttrLowerBound:     "LowerBound",
+	AttrProducer:       "Producer",
+	AttrPrototyped:     "Prototyped",
+	AttrReturnAddr:     "ReturnAddr",
+	AttrStartScope:     "StartScope",
+	AttrStrideSize:     "StrideSize",
+	AttrUpperBound:     "UpperBound",
+	AttrAbstractOrigin: "AbstractOrigin",
+	AttrAccessibility:  "Accessibility",
+	AttrAddrClass:      "AddrClass",
+	AttrArtificial:     "Artificial",
+	AttrBaseTypes:      "BaseTypes",
+	AttrCalling:        "Calling",
+	AttrCount:          "Count",
+	AttrDataMemberLoc:  "DataMemberLoc",
+	AttrDeclColumn:     "DeclColumn",
+	AttrDeclFile:       "DeclFile",
+	AttrDeclLine:       "DeclLine",
+	AttrDeclaration:    "Declaration",
+	AttrDiscrList:      "DiscrList",
+	AttrEncoding:       "Encoding",
+	AttrExternal:       "External",
+	AttrFrameBase:      "FrameBase",
+	AttrFriend:         "Friend",
+	AttrIdentifierCase: "IdentifierCase",
+	AttrMacroInfo:      "MacroInfo",
+	AttrNamelistItem:   "NamelistItem",
+	AttrPriority:       "Priority",
+	AttrSegment:        "Segment",
+	AttrSpecification:  "Specification",
+	AttrStaticLink:     "StaticLink",
+	AttrType:           "Type",
+	AttrUseLocation:    "UseLocation",
+	AttrVarParam:       "VarParam",
+	AttrVirtuality:     "Virtuality",
+	AttrVtableElemLoc:  "VtableElemLoc",
+	AttrAllocated:      "Allocated",
+	AttrAssociated:     "Associated",
+	AttrDataLocation:   "DataLocation",
+	AttrStride:         "Stride",
+	AttrEntrypc:        "Entrypc",
+	AttrUseUTF8:        "UseUTF8",
+	AttrExtension:      "Extension",
+	AttrRanges:         "Ranges",
+	AttrTrampoline:     "Trampoline",
+	AttrCallColumn:     "CallColumn",
+	AttrCallFile:       "CallFile",
+	AttrCallLine:       "CallLine",
+	AttrDescription:    "Description",
+}
+
+func (a Attr) String() string {
+	if int(a) < len(attrNames) {
+		s := attrNames[a]
+		if s != "" {
+			return s
+		}
+	}
+	return strconv.Itoa(int(a))
+}
+
+func (a Attr) GoString() string {
+	if int(a) < len(attrNames) {
+		s := attrNames[a]
+		if s != "" {
+			return "dwarf.Attr" + s
+		}
+	}
+	return "dwarf.Attr(" + strconv.FormatInt(int64(a), 10) + ")"
+}
+
+// A format is a DWARF data encoding format.
+type format uint32
+
+const (
+	// value formats
+	formAddr        format = 0x01
+	formDwarfBlock2 format = 0x03
+	formDwarfBlock4 format = 0x04
+	formData2       format = 0x05
+	formData4       format = 0x06
+	formData8       format = 0x07
+	formString      format = 0x08
+	formDwarfBlock  format = 0x09
+	formDwarfBlock1 format = 0x0A
+	formData1       format = 0x0B
+	formFlag        format = 0x0C
+	formSdata       format = 0x0D
+	formStrp        format = 0x0E
+	formUdata       format = 0x0F
+	formRefAddr     format = 0x10
+	formRef1        format = 0x11
+	formRef2        format = 0x12
+	formRef4        format = 0x13
+	formRef8        format = 0x14
+	formRefUdata    format = 0x15
+	formIndirect    format = 0x16
+	// The following are new in DWARF 4.
+	formSecOffset   format = 0x17
+	formExprloc     format = 0x18
+	formFlagPresent format = 0x19
+	formRefSig8     format = 0x20
+	// Extensions for multi-file compression (.dwz)
+	// http://www.dwarfstd.org/ShowIssue.php?issue=120604.1
+	formGnuRefAlt  format = 0x1f20
+	formGnuStrpAlt format = 0x1f21
+)
+
+// A Tag is the classification (the type) of an Entry.
+type Tag uint32
+
+const (
+	TagArrayType              Tag = 0x01
+	TagClassType              Tag = 0x02
+	TagEntryPoint             Tag = 0x03
+	TagEnumerationType        Tag = 0x04
+	TagFormalParameter        Tag = 0x05
+	TagImportedDeclaration    Tag = 0x08
+	TagLabel                  Tag = 0x0A
+	TagLexDwarfBlock          Tag = 0x0B
+	TagMember                 Tag = 0x0D
+	TagPointerType            Tag = 0x0F
+	TagReferenceType          Tag = 0x10
+	TagCompileUnit            Tag = 0x11
+	TagStringType             Tag = 0x12
+	TagStructType             Tag = 0x13
+	TagSubroutineType         Tag = 0x15
+	TagTypedef                Tag = 0x16
+	TagUnionType              Tag = 0x17
+	TagUnspecifiedParameters  Tag = 0x18
+	TagVariant                Tag = 0x19
+	TagCommonDwarfBlock       Tag = 0x1A
+	TagCommonInclusion        Tag = 0x1B
+	TagInheritance            Tag = 0x1C
+	TagInlinedSubroutine      Tag = 0x1D
+	TagModule                 Tag = 0x1E
+	TagPtrToMemberType        Tag = 0x1F
+	TagSetType                Tag = 0x20
+	TagSubrangeType           Tag = 0x21
+	TagWithStmt               Tag = 0x22
+	TagAccessDeclaration      Tag = 0x23
+	TagBaseType               Tag = 0x24
+	TagCatchDwarfBlock        Tag = 0x25
+	TagConstType              Tag = 0x26
+	TagConstant               Tag = 0x27
+	TagEnumerator             Tag = 0x28
+	TagFileType               Tag = 0x29
+	TagFriend                 Tag = 0x2A
+	TagNamelist               Tag = 0x2B
+	TagNamelistItem           Tag = 0x2C
+	TagPackedType             Tag = 0x2D
+	TagSubprogram             Tag = 0x2E
+	TagTemplateTypeParameter  Tag = 0x2F
+	TagTemplateValueParameter Tag = 0x30
+	TagThrownType             Tag = 0x31
+	TagTryDwarfBlock          Tag = 0x32
+	TagVariantPart            Tag = 0x33
+	TagVariable               Tag = 0x34
+	TagVolatileType           Tag = 0x35
+	// The following are new in DWARF 3.
+	TagDwarfProcedure  Tag = 0x36
+	TagRestrictType    Tag = 0x37
+	TagInterfaceType   Tag = 0x38
+	TagNamespace       Tag = 0x39
+	TagImportedModule  Tag = 0x3A
+	TagUnspecifiedType Tag = 0x3B
+	TagPartialUnit     Tag = 0x3C
+	TagImportedUnit    Tag = 0x3D
+	TagMutableType     Tag = 0x3E // Later removed from DWARF.
+	TagCondition       Tag = 0x3F
+	TagSharedType      Tag = 0x40
+	// The following are new in DWARF 4.
+	TagTypeUnit            Tag = 0x41
+	TagRvalueReferenceType Tag = 0x42
+	TagTemplateAlias       Tag = 0x43
+)
+
+var tagNames = [...]string{
+	TagArrayType:              "ArrayType",
+	TagClassType:              "ClassType",
+	TagEntryPoint:             "EntryPoint",
+	TagEnumerationType:        "EnumerationType",
+	TagFormalParameter:        "FormalParameter",
+	TagImportedDeclaration:    "ImportedDeclaration",
+	TagLabel:                  "Label",
+	TagLexDwarfBlock:          "LexDwarfBlock",
+	TagMember:                 "Member",
+	TagPointerType:            "PointerType",
+	TagReferenceType:          "ReferenceType",
+	TagCompileUnit:            "CompileUnit",
+	TagStringType:             "StringType",
+	TagStructType:             "StructType",
+	TagSubroutineType:         "SubroutineType",
+	TagTypedef:                "Typedef",
+	TagUnionType:              "UnionType",
+	TagUnspecifiedParameters:  "UnspecifiedParameters",
+	TagVariant:                "Variant",
+	TagCommonDwarfBlock:       "CommonDwarfBlock",
+	TagCommonInclusion:        "CommonInclusion",
+	TagInheritance:            "Inheritance",
+	TagInlinedSubroutine:      "InlinedSubroutine",
+	TagModule:                 "Module",
+	TagPtrToMemberType:        "PtrToMemberType",
+	TagSetType:                "SetType",
+	TagSubrangeType:           "SubrangeType",
+	TagWithStmt:               "WithStmt",
+	TagAccessDeclaration:      "AccessDeclaration",
+	TagBaseType:               "BaseType",
+	TagCatchDwarfBlock:        "CatchDwarfBlock",
+	TagConstType:              "ConstType",
+	TagConstant:               "Constant",
+	TagEnumerator:             "Enumerator",
+	TagFileType:               "FileType",
+	TagFriend:                 "Friend",
+	TagNamelist:               "Namelist",
+	TagNamelistItem:           "NamelistItem",
+	TagPackedType:             "PackedType",
+	TagSubprogram:             "Subprogram",
+	TagTemplateTypeParameter:  "TemplateTypeParameter",
+	TagTemplateValueParameter: "TemplateValueParameter",
+	TagThrownType:             "ThrownType",
+	TagTryDwarfBlock:          "TryDwarfBlock",
+	TagVariantPart:            "VariantPart",
+	TagVariable:               "Variable",
+	TagVolatileType:           "VolatileType",
+	TagDwarfProcedure:         "DwarfProcedure",
+	TagRestrictType:           "RestrictType",
+	TagInterfaceType:          "InterfaceType",
+	TagNamespace:              "Namespace",
+	TagImportedModule:         "ImportedModule",
+	TagUnspecifiedType:        "UnspecifiedType",
+	TagPartialUnit:            "PartialUnit",
+	TagImportedUnit:           "ImportedUnit",
+	TagMutableType:            "MutableType",
+	TagCondition:              "Condition",
+	TagSharedType:             "SharedType",
+	TagTypeUnit:               "TypeUnit",
+	TagRvalueReferenceType:    "RvalueReferenceType",
+	TagTemplateAlias:          "TemplateAlias",
+}
+
+func (t Tag) String() string {
+	if int(t) < len(tagNames) {
+		s := tagNames[t]
+		if s != "" {
+			return s
+		}
+	}
+	return strconv.Itoa(int(t))
+}
+
+func (t Tag) GoString() string {
+	if int(t) < len(tagNames) {
+		s := tagNames[t]
+		if s != "" {
+			return "dwarf.Tag" + s
+		}
+	}
+	return "dwarf.Tag(" + strconv.FormatInt(int64(t), 10) + ")"
+}
+
+// Location expression operators.
+// The debug info encodes value locations like 8(R3)
+// as a sequence of these op codes.
+// This package does not implement full expressions;
+// the opPlusUconst operator is expected by the type parser.
+const (
+	opAddr       = 0x03 /* 1 op, const addr */
+	opDeref      = 0x06
+	opConst1u    = 0x08 /* 1 op, 1 byte const */
+	opConst1s    = 0x09 /*	" signed */
+	opConst2u    = 0x0A /* 1 op, 2 byte const  */
+	opConst2s    = 0x0B /*	" signed */
+	opConst4u    = 0x0C /* 1 op, 4 byte const */
+	opConst4s    = 0x0D /*	" signed */
+	opConst8u    = 0x0E /* 1 op, 8 byte const */
+	opConst8s    = 0x0F /*	" signed */
+	opConstu     = 0x10 /* 1 op, LEB128 const */
+	opConsts     = 0x11 /*	" signed */
+	opDup        = 0x12
+	opDrop       = 0x13
+	opOver       = 0x14
+	opPick       = 0x15 /* 1 op, 1 byte stack index */
+	opSwap       = 0x16
+	opRot        = 0x17
+	opXderef     = 0x18
+	opAbs        = 0x19
+	opAnd        = 0x1A
+	opDiv        = 0x1B
+	opMinus      = 0x1C
+	opMod        = 0x1D
+	opMul        = 0x1E
+	opNeg        = 0x1F
+	opNot        = 0x20
+	opOr         = 0x21
+	opPlus       = 0x22
+	opPlusUconst = 0x23 /* 1 op, ULEB128 addend */
+	opShl        = 0x24
+	opShr        = 0x25
+	opShra       = 0x26
+	opXor        = 0x27
+	opSkip       = 0x2F /* 1 op, signed 2-byte constant */
+	opBra        = 0x28 /* 1 op, signed 2-byte constant */
+	opEq         = 0x29
+	opGe         = 0x2A
+	opGt         = 0x2B
+	opLe         = 0x2C
+	opLt         = 0x2D
+	opNe         = 0x2E
+	opLit0       = 0x30
+	/* OpLitN = OpLit0 + N for N = 0..31 */
+	opReg0 = 0x50
+	/* OpRegN = OpReg0 + N for N = 0..31 */
+	opBreg0 = 0x70 /* 1 op, signed LEB128 constant */
+	/* OpBregN = OpBreg0 + N for N = 0..31 */
+	opRegx       = 0x90 /* 1 op, ULEB128 register */
+	opFbreg      = 0x91 /* 1 op, SLEB128 offset */
+	opBregx      = 0x92 /* 2 op, ULEB128 reg; SLEB128 off */
+	opPiece      = 0x93 /* 1 op, ULEB128 size of piece */
+	opDerefSize  = 0x94 /* 1-byte size of data retrieved */
+	opXderefSize = 0x95 /* 1-byte size of data retrieved */
+	opNop        = 0x96
+	/* next four new in Dwarf v3 */
+	opPushObjAddr = 0x97
+	opCall2       = 0x98 /* 2-byte offset of DIE */
+	opCall4       = 0x99 /* 4-byte offset of DIE */
+	opCallRef     = 0x9A /* 4- or 8- byte offset of DIE */
+	/* 0xE0-0xFF reserved for user-specific */
+)
+
+// Basic type encodings -- the value for AttrEncoding in a TagBaseType Entry.
+const (
+	encAddress        = 0x01
+	encBoolean        = 0x02
+	encComplexFloat   = 0x03
+	encFloat          = 0x04
+	encSigned         = 0x05
+	encSignedChar     = 0x06
+	encUnsigned       = 0x07
+	encUnsignedChar   = 0x08
+	encImaginaryFloat = 0x09
+)
diff --git a/src/debug/dwarf/entry.go b/src/debug/dwarf/entry.go
new file mode 100644
index 000000000..665c6840d
--- /dev/null
+++ b/src/debug/dwarf/entry.go
@@ -0,0 +1,401 @@
+// Copyright 2009 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// DWARF debug information entry parser.
+// An entry is a sequence of data items of a given format.
+// The first word in the entry is an index into what DWARF
+// calls the ``abbreviation table.''  An abbreviation is really
+// just a type descriptor: it's an array of attribute tag/value format pairs.
+
+package dwarf
+
+import (
+	"errors"
+	"strconv"
+)
+
+// a single entry's description: a sequence of attributes
+type abbrev struct {
+	tag      Tag
+	children bool
+	field    []afield
+}
+
+type afield struct {
+	attr Attr
+	fmt  format
+}
+
+// a map from entry format ids to their descriptions
+type abbrevTable map[uint32]abbrev
+
+// ParseAbbrev returns the abbreviation table that starts at byte off
+// in the .debug_abbrev section.
+func (d *Data) parseAbbrev(off uint32) (abbrevTable, error) {
+	if m, ok := d.abbrevCache[off]; ok {
+		return m, nil
+	}
+
+	data := d.abbrev
+	if off > uint32(len(data)) {
+		data = nil
+	} else {
+		data = data[off:]
+	}
+	b := makeBuf(d, unknownFormat{}, "abbrev", 0, data)
+
+	// Error handling is simplified by the buf getters
+	// returning an endless stream of 0s after an error.
+	m := make(abbrevTable)
+	for {
+		// Table ends with id == 0.
+		id := uint32(b.uint())
+		if id == 0 {
+			break
+		}
+
+		// Walk over attributes, counting.
+		n := 0
+		b1 := b // Read from copy of b.
+		b1.uint()
+		b1.uint8()
+		for {
+			tag := b1.uint()
+			fmt := b1.uint()
+			if tag == 0 && fmt == 0 {
+				break
+			}
+			n++
+		}
+		if b1.err != nil {
+			return nil, b1.err
+		}
+
+		// Walk over attributes again, this time writing them down.
+		var a abbrev
+		a.tag = Tag(b.uint())
+		a.children = b.uint8() != 0
+		a.field = make([]afield, n)
+		for i := range a.field {
+			a.field[i].attr = Attr(b.uint())
+			a.field[i].fmt = format(b.uint())
+		}
+		b.uint()
+		b.uint()
+
+		m[id] = a
+	}
+	if b.err != nil {
+		return nil, b.err
+	}
+	d.abbrevCache[off] = m
+	return m, nil
+}
+
+// An entry is a sequence of attribute/value pairs.
+type Entry struct {
+	Offset   Offset // offset of Entry in DWARF info
+	Tag      Tag    // tag (kind of Entry)
+	Children bool   // whether Entry is followed by children
+	Field    []Field
+}
+
+// A Field is a single attribute/value pair in an Entry.
+type Field struct {
+	Attr Attr
+	Val  interface{}
+}
+
+// Val returns the value associated with attribute Attr in Entry,
+// or nil if there is no such attribute.
+//
+// A common idiom is to merge the check for nil return with
+// the check that the value has the expected dynamic type, as in:
+//	v, ok := e.Val(AttrSibling).(int64);
+//
+func (e *Entry) Val(a Attr) interface{} {
+	for _, f := range e.Field {
+		if f.Attr == a {
+			return f.Val
+		}
+	}
+	return nil
+}
+
+// An Offset represents the location of an Entry within the DWARF info.
+// (See Reader.Seek.)
+type Offset uint32
+
+// Entry reads a single entry from buf, decoding
+// according to the given abbreviation table.
+func (b *buf) entry(atab abbrevTable, ubase Offset) *Entry {
+	off := b.off
+	id := uint32(b.uint())
+	if id == 0 {
+		return &Entry{}
+	}
+	a, ok := atab[id]
+	if !ok {
+		b.error("unknown abbreviation table index")
+		return nil
+	}
+	e := &Entry{
+		Offset:   off,
+		Tag:      a.tag,
+		Children: a.children,
+		Field:    make([]Field, len(a.field)),
+	}
+	for i := range e.Field {
+		e.Field[i].Attr = a.field[i].attr
+		fmt := a.field[i].fmt
+		if fmt == formIndirect {
+			fmt = format(b.uint())
+		}
+		var val interface{}
+		switch fmt {
+		default:
+			b.error("unknown entry attr format 0x" + strconv.FormatInt(int64(fmt), 16))
+
+		// address
+		case formAddr:
+			val = b.addr()
+
+		// block
+		case formDwarfBlock1:
+			val = b.bytes(int(b.uint8()))
+		case formDwarfBlock2:
+			val = b.bytes(int(b.uint16()))
+		case formDwarfBlock4:
+			val = b.bytes(int(b.uint32()))
+		case formDwarfBlock:
+			val = b.bytes(int(b.uint()))
+
+		// constant
+		case formData1:
+			val = int64(b.uint8())
+		case formData2:
+			val = int64(b.uint16())
+		case formData4:
+			val = int64(b.uint32())
+		case formData8:
+			val = int64(b.uint64())
+		case formSdata:
+			val = int64(b.int())
+		case formUdata:
+			val = int64(b.uint())
+
+		// flag
+		case formFlag:
+			val = b.uint8() == 1
+		// New in DWARF 4.
+		case formFlagPresent:
+			// The attribute is implicitly indicated as present, and no value is
+			// encoded in the debugging information entry itself.
+			val = true
+
+		// reference to other entry
+		case formRefAddr:
+			vers := b.format.version()
+			if vers == 0 {
+				b.error("unknown version for DW_FORM_ref_addr")
+			} else if vers == 2 {
+				val = Offset(b.addr())
+			} else {
+				is64, known := b.format.dwarf64()
+				if !known {
+					b.error("unknown size for DW_FORM_ref_addr")
+				} else if is64 {
+					val = Offset(b.uint64())
+				} else {
+					val = Offset(b.uint32())
+				}
+			}
+		case formRef1:
+			val = Offset(b.uint8()) + ubase
+		case formRef2:
+			val = Offset(b.uint16()) + ubase
+		case formRef4:
+			val = Offset(b.uint32()) + ubase
+		case formRef8:
+			val = Offset(b.uint64()) + ubase
+		case formRefUdata:
+			val = Offset(b.uint()) + ubase
+
+		// string
+		case formString:
+			val = b.string()
+		case formStrp:
+			off := b.uint32() // offset into .debug_str
+			if b.err != nil {
+				return nil
+			}
+			b1 := makeBuf(b.dwarf, unknownFormat{}, "str", 0, b.dwarf.str)
+			b1.skip(int(off))
+			val = b1.string()
+			if b1.err != nil {
+				b.err = b1.err
+				return nil
+			}
+
+		// lineptr, loclistptr, macptr, rangelistptr
+		// New in DWARF 4, but clang can generate them with -gdwarf-2.
+		// Section reference, replacing use of formData4 and formData8.
+		case formSecOffset, formGnuRefAlt, formGnuStrpAlt:
+			is64, known := b.format.dwarf64()
+			if !known {
+				b.error("unknown size for form 0x" + strconv.FormatInt(int64(fmt), 16))
+			} else if is64 {
+				val = int64(b.uint64())
+			} else {
+				val = int64(b.uint32())
+			}
+
+		// exprloc
+		// New in DWARF 4.
+		case formExprloc:
+			val = b.bytes(int(b.uint()))
+
+		// reference
+		// New in DWARF 4.
+		case formRefSig8:
+			// 64-bit type signature.
+			val = b.uint64()
+		}
+		e.Field[i].Val = val
+	}
+	if b.err != nil {
+		return nil
+	}
+	return e
+}
+
+// A Reader allows reading Entry structures from a DWARF ``info'' section.
+// The Entry structures are arranged in a tree.  The Reader's Next function
+// return successive entries from a pre-order traversal of the tree.
+// If an entry has children, its Children field will be true, and the children
+// follow, terminated by an Entry with Tag 0.
+type Reader struct {
+	b            buf
+	d            *Data
+	err          error
+	unit         int
+	lastChildren bool   // .Children of last entry returned by Next
+	lastSibling  Offset // .Val(AttrSibling) of last entry returned by Next
+}
+
+// Reader returns a new Reader for Data.
+// The reader is positioned at byte offset 0 in the DWARF ``info'' section.
+func (d *Data) Reader() *Reader {
+	r := &Reader{d: d}
+	r.Seek(0)
+	return r
+}
+
+// Seek positions the Reader at offset off in the encoded entry stream.
+// Offset 0 can be used to denote the first entry.
+func (r *Reader) Seek(off Offset) {
+	d := r.d
+	r.err = nil
+	r.lastChildren = false
+	if off == 0 {
+		if len(d.unit) == 0 {
+			return
+		}
+		u := &d.unit[0]
+		r.unit = 0
+		r.b = makeBuf(r.d, u, "info", u.off, u.data)
+		return
+	}
+
+	// TODO(rsc): binary search (maybe a new package)
+	var i int
+	var u *unit
+	for i = range d.unit {
+		u = &d.unit[i]
+		if u.off <= off && off < u.off+Offset(len(u.data)) {
+			r.unit = i
+			r.b = makeBuf(r.d, u, "info", off, u.data[off-u.off:])
+			return
+		}
+	}
+	r.err = errors.New("offset out of range")
+}
+
+// maybeNextUnit advances to the next unit if this one is finished.
+func (r *Reader) maybeNextUnit() {
+	for len(r.b.data) == 0 && r.unit+1 < len(r.d.unit) {
+		r.unit++
+		u := &r.d.unit[r.unit]
+		r.b = makeBuf(r.d, u, "info", u.off, u.data)
+	}
+}
+
+// Next reads the next entry from the encoded entry stream.
+// It returns nil, nil when it reaches the end of the section.
+// It returns an error if the current offset is invalid or the data at the
+// offset cannot be decoded as a valid Entry.
+func (r *Reader) Next() (*Entry, error) {
+	if r.err != nil {
+		return nil, r.err
+	}
+	r.maybeNextUnit()
+	if len(r.b.data) == 0 {
+		return nil, nil
+	}
+	u := &r.d.unit[r.unit]
+	e := r.b.entry(u.atable, u.base)
+	if r.b.err != nil {
+		r.err = r.b.err
+		return nil, r.err
+	}
+	if e != nil {
+		r.lastChildren = e.Children
+		if r.lastChildren {
+			r.lastSibling, _ = e.Val(AttrSibling).(Offset)
+		}
+	} else {
+		r.lastChildren = false
+	}
+	return e, nil
+}
+
+// SkipChildren skips over the child entries associated with
+// the last Entry returned by Next.  If that Entry did not have
+// children or Next has not been called, SkipChildren is a no-op.
+func (r *Reader) SkipChildren() {
+	if r.err != nil || !r.lastChildren {
+		return
+	}
+
+	// If the last entry had a sibling attribute,
+	// that attribute gives the offset of the next
+	// sibling, so we can avoid decoding the
+	// child subtrees.
+	if r.lastSibling >= r.b.off {
+		r.Seek(r.lastSibling)
+		return
+	}
+
+	for {
+		e, err := r.Next()
+		if err != nil || e == nil || e.Tag == 0 {
+			break
+		}
+		if e.Children {
+			r.SkipChildren()
+		}
+	}
+}
+
+// clone returns a copy of the reader.  This is used by the typeReader
+// interface.
+func (r *Reader) clone() typeReader {
+	return r.d.Reader()
+}
+
+// offset returns the current buffer offset.  This is used by the
+// typeReader interface.
+func (r *Reader) offset() Offset {
+	return r.b.off
+}
diff --git a/src/debug/dwarf/open.go b/src/debug/dwarf/open.go
new file mode 100644
index 000000000..c1b3f37ac
--- /dev/null
+++ b/src/debug/dwarf/open.go
@@ -0,0 +1,87 @@
+// Copyright 2009 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package dwarf provides access to DWARF debugging information loaded from
+// executable files, as defined in the DWARF 2.0 Standard at
+// http://dwarfstd.org/doc/dwarf-2.0.0.pdf
+package dwarf
+
+import "encoding/binary"
+
+// Data represents the DWARF debugging information
+// loaded from an executable file (for example, an ELF or Mach-O executable).
+type Data struct {
+	// raw data
+	abbrev   []byte
+	aranges  []byte
+	frame    []byte
+	info     []byte
+	line     []byte
+	pubnames []byte
+	ranges   []byte
+	str      []byte
+
+	// parsed data
+	abbrevCache map[uint32]abbrevTable
+	order       binary.ByteOrder
+	typeCache   map[Offset]Type
+	typeSigs    map[uint64]*typeUnit
+	unit        []unit
+}
+
+// New returns a new Data object initialized from the given parameters.
+// Rather than calling this function directly, clients should typically use
+// the DWARF method of the File type of the appropriate package debug/elf,
+// debug/macho, or debug/pe.
+//
+// The []byte arguments are the data from the corresponding debug section
+// in the object file; for example, for an ELF object, abbrev is the contents of
+// the ".debug_abbrev" section.
+func New(abbrev, aranges, frame, info, line, pubnames, ranges, str []byte) (*Data, error) {
+	d := &Data{
+		abbrev:      abbrev,
+		aranges:     aranges,
+		frame:       frame,
+		info:        info,
+		line:        line,
+		pubnames:    pubnames,
+		ranges:      ranges,
+		str:         str,
+		abbrevCache: make(map[uint32]abbrevTable),
+		typeCache:   make(map[Offset]Type),
+		typeSigs:    make(map[uint64]*typeUnit),
+	}
+
+	// Sniff .debug_info to figure out byte order.
+	// bytes 4:6 are the version, a tiny 16-bit number (1, 2, 3).
+	if len(d.info) < 6 {
+		return nil, DecodeError{"info", Offset(len(d.info)), "too short"}
+	}
+	x, y := d.info[4], d.info[5]
+	switch {
+	case x == 0 && y == 0:
+		return nil, DecodeError{"info", 4, "unsupported version 0"}
+	case x == 0:
+		d.order = binary.BigEndian
+	case y == 0:
+		d.order = binary.LittleEndian
+	default:
+		return nil, DecodeError{"info", 4, "cannot determine byte order"}
+	}
+
+	u, err := d.parseUnits()
+	if err != nil {
+		return nil, err
+	}
+	d.unit = u
+	return d, nil
+}
+
+// AddTypes will add one .debug_types section to the DWARF data.  A
+// typical object with DWARF version 4 debug info will have multiple
+// .debug_types sections.  The name is used for error reporting only,
+// and serves to distinguish one .debug_types section from another.
+func (d *Data) AddTypes(name string, types []byte) error {
+	return d.parseTypes(name, types)
+}
diff --git a/src/debug/dwarf/testdata/typedef.c b/src/debug/dwarf/testdata/typedef.c
new file mode 100644
index 000000000..f05f01564
--- /dev/null
+++ b/src/debug/dwarf/testdata/typedef.c
@@ -0,0 +1,85 @@
+// Copyright 2009 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+/*
+Linux ELF:
+gcc -gdwarf-2 -m64 -c typedef.c && gcc -gdwarf-2 -m64 -o typedef.elf typedef.o
+
+OS X Mach-O:
+gcc -gdwarf-2 -m64 -c typedef.c -o typedef.macho
+*/
+#include <complex.h>
+
+typedef volatile int* t_ptr_volatile_int;
+typedef const char *t_ptr_const_char;
+typedef long t_long;
+typedef unsigned short t_ushort;
+typedef int t_func_int_of_float_double(float, double);
+typedef int (*t_ptr_func_int_of_float_double)(float, double);
+typedef int (*t_ptr_func_int_of_float_complex)(float complex);
+typedef int (*t_ptr_func_int_of_double_complex)(double complex);
+typedef int (*t_ptr_func_int_of_long_double_complex)(long double complex);
+typedef int *t_func_ptr_int_of_char_schar_uchar(char, signed char, unsigned char);
+typedef void t_func_void_of_char(char);
+typedef void t_func_void_of_void(void);
+typedef void t_func_void_of_ptr_char_dots(char*, ...);
+typedef struct my_struct {
+	volatile int vi;
+	char x : 1;
+	int y : 4;
+	int z[0];
+	long long array[40];
+	int zz[0];
+} t_my_struct;
+typedef struct my_struct1 {
+	int zz [1];
+} t_my_struct1;
+typedef union my_union {
+	volatile int vi;
+	char x : 1;
+	int y : 4;
+	long long array[40];
+} t_my_union;
+typedef enum my_enum {
+	e1 = 1,
+	e2 = 2,
+	e3 = -5,
+	e4 = 1000000000000000LL,
+} t_my_enum;
+
+typedef struct list t_my_list;
+struct list {
+	short val;
+	t_my_list *next;
+};
+
+typedef struct tree {
+	struct tree *left, *right;
+	unsigned long long val;
+} t_my_tree;
+
+t_ptr_volatile_int *a2;
+t_ptr_const_char **a3a;
+t_long *a4;
+t_ushort *a5;
+t_func_int_of_float_double *a6;
+t_ptr_func_int_of_float_double *a7;
+t_func_ptr_int_of_char_schar_uchar *a8;
+t_func_void_of_char *a9;
+t_func_void_of_void *a10;
+t_func_void_of_ptr_char_dots *a11;
+t_my_struct *a12;
+t_my_struct1 *a12a;
+t_my_union *a12b;
+t_my_enum *a13;
+t_my_list *a14;
+t_my_tree *a15;
+t_ptr_func_int_of_float_complex *a16;
+t_ptr_func_int_of_double_complex *a17;
+t_ptr_func_int_of_long_double_complex *a18;
+
+int main()
+{
+	return 0;
+}
diff --git a/src/debug/dwarf/testdata/typedef.elf b/src/debug/dwarf/testdata/typedef.elf
new file mode 100755
index 000000000..b2062d2c4
--- /dev/null
+++ b/src/debug/dwarf/testdata/typedef.elf
diff --git a/src/debug/dwarf/testdata/typedef.elf4 b/src/debug/dwarf/testdata/typedef.elf4
new file mode 100644
index 000000000..3d5a5a1b1
--- /dev/null
+++ b/src/debug/dwarf/testdata/typedef.elf4
diff --git a/src/debug/dwarf/testdata/typedef.macho b/src/debug/dwarf/testdata/typedef.macho
new file mode 100644
index 000000000..f75afcccb
--- /dev/null
+++ b/src/debug/dwarf/testdata/typedef.macho
diff --git a/src/debug/dwarf/type.go b/src/debug/dwarf/type.go
new file mode 100644
index 000000000..fa40b2bef
--- /dev/null
+++ b/src/debug/dwarf/type.go
@@ -0,0 +1,685 @@
+// Copyright 2009 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// DWARF type information structures.
+// The format is heavily biased toward C, but for simplicity
+// the String methods use a pseudo-Go syntax.
+
+package dwarf
+
+import "strconv"
+
+// A Type conventionally represents a pointer to any of the
+// specific Type structures (CharType, StructType, etc.).
+type Type interface {
+	Common() *CommonType
+	String() string
+	Size() int64
+}
+
+// A CommonType holds fields common to multiple types.
+// If a field is not known or not applicable for a given type,
+// the zero value is used.
+type CommonType struct {
+	ByteSize int64  // size of value of this type, in bytes
+	Name     string // name that can be used to refer to type
+}
+
+func (c *CommonType) Common() *CommonType { return c }
+
+func (c *CommonType) Size() int64 { return c.ByteSize }
+
+// Basic types
+
+// A BasicType holds fields common to all basic types.
+type BasicType struct {
+	CommonType
+	BitSize   int64
+	BitOffset int64
+}
+
+func (b *BasicType) Basic() *BasicType { return b }
+
+func (t *BasicType) String() string {
+	if t.Name != "" {
+		return t.Name
+	}
+	return "?"
+}
+
+// A CharType represents a signed character type.
+type CharType struct {
+	BasicType
+}
+
+// A UcharType represents an unsigned character type.
+type UcharType struct {
+	BasicType
+}
+
+// An IntType represents a signed integer type.
+type IntType struct {
+	BasicType
+}
+
+// A UintType represents an unsigned integer type.
+type UintType struct {
+	BasicType
+}
+
+// A FloatType represents a floating point type.
+type FloatType struct {
+	BasicType
+}
+
+// A ComplexType represents a complex floating point type.
+type ComplexType struct {
+	BasicType
+}
+
+// A BoolType represents a boolean type.
+type BoolType struct {
+	BasicType
+}
+
+// An AddrType represents a machine address type.
+type AddrType struct {
+	BasicType
+}
+
+// An UnspecifiedType represents an implicit, unknown, ambiguous or nonexistent type.
+type UnspecifiedType struct {
+	BasicType
+}
+
+// qualifiers
+
+// A QualType represents a type that has the C/C++ "const", "restrict", or "volatile" qualifier.
+type QualType struct {
+	CommonType
+	Qual string
+	Type Type
+}
+
+func (t *QualType) String() string { return t.Qual + " " + t.Type.String() }
+
+func (t *QualType) Size() int64 { return t.Type.Size() }
+
+// An ArrayType represents a fixed size array type.
+type ArrayType struct {
+	CommonType
+	Type          Type
+	StrideBitSize int64 // if > 0, number of bits to hold each element
+	Count         int64 // if == -1, an incomplete array, like char x[].
+}
+
+func (t *ArrayType) String() string {
+	return "[" + strconv.FormatInt(t.Count, 10) + "]" + t.Type.String()
+}
+
+func (t *ArrayType) Size() int64 {
+	if t.Count == -1 {
+		return 0
+	}
+	return t.Count * t.Type.Size()
+}
+
+// A VoidType represents the C void type.
+type VoidType struct {
+	CommonType
+}
+
+func (t *VoidType) String() string { return "void" }
+
+// A PtrType represents a pointer type.
+type PtrType struct {
+	CommonType
+	Type Type
+}
+
+func (t *PtrType) String() string { return "*" + t.Type.String() }
+
+// A StructType represents a struct, union, or C++ class type.
+type StructType struct {
+	CommonType
+	StructName string
+	Kind       string // "struct", "union", or "class".
+	Field      []*StructField
+	Incomplete bool // if true, struct, union, class is declared but not defined
+}
+
+// A StructField represents a field in a struct, union, or C++ class type.
+type StructField struct {
+	Name       string
+	Type       Type
+	ByteOffset int64
+	ByteSize   int64
+	BitOffset  int64 // within the ByteSize bytes at ByteOffset
+	BitSize    int64 // zero if not a bit field
+}
+
+func (t *StructType) String() string {
+	if t.StructName != "" {
+		return t.Kind + " " + t.StructName
+	}
+	return t.Defn()
+}
+
+func (t *StructType) Defn() string {
+	s := t.Kind
+	if t.StructName != "" {
+		s += " " + t.StructName
+	}
+	if t.Incomplete {
+		s += " /*incomplete*/"
+		return s
+	}
+	s += " {"
+	for i, f := range t.Field {
+		if i > 0 {
+			s += "; "
+		}
+		s += f.Name + " " + f.Type.String()
+		s += "@" + strconv.FormatInt(f.ByteOffset, 10)
+		if f.BitSize > 0 {
+			s += " : " + strconv.FormatInt(f.BitSize, 10)
+			s += "@" + strconv.FormatInt(f.BitOffset, 10)
+		}
+	}
+	s += "}"
+	return s
+}
+
+// An EnumType represents an enumerated type.
+// The only indication of its native integer type is its ByteSize
+// (inside CommonType).
+type EnumType struct {
+	CommonType
+	EnumName string
+	Val      []*EnumValue
+}
+
+// An EnumValue represents a single enumeration value.
+type EnumValue struct {
+	Name string
+	Val  int64
+}
+
+func (t *EnumType) String() string {
+	s := "enum"
+	if t.EnumName != "" {
+		s += " " + t.EnumName
+	}
+	s += " {"
+	for i, v := range t.Val {
+		if i > 0 {
+			s += "; "
+		}
+		s += v.Name + "=" + strconv.FormatInt(v.Val, 10)
+	}
+	s += "}"
+	return s
+}
+
+// A FuncType represents a function type.
+type FuncType struct {
+	CommonType
+	ReturnType Type
+	ParamType  []Type
+}
+
+func (t *FuncType) String() string {
+	s := "func("
+	for i, t := range t.ParamType {
+		if i > 0 {
+			s += ", "
+		}
+		s += t.String()
+	}
+	s += ")"
+	if t.ReturnType != nil {
+		s += " " + t.ReturnType.String()
+	}
+	return s
+}
+
+// A DotDotDotType represents the variadic ... function parameter.
+type DotDotDotType struct {
+	CommonType
+}
+
+func (t *DotDotDotType) String() string { return "..." }
+
+// A TypedefType represents a named type.
+type TypedefType struct {
+	CommonType
+	Type Type
+}
+
+func (t *TypedefType) String() string { return t.Name }
+
+func (t *TypedefType) Size() int64 { return t.Type.Size() }
+
+// typeReader is used to read from either the info section or the
+// types section.
+type typeReader interface {
+	Seek(Offset)
+	Next() (*Entry, error)
+	clone() typeReader
+	offset() Offset
+}
+
+// Type reads the type at off in the DWARF ``info'' section.
+func (d *Data) Type(off Offset) (Type, error) {
+	return d.readType("info", d.Reader(), off, d.typeCache)
+}
+
+// readType reads a type from r at off of name using and updating a
+// type cache.
+func (d *Data) readType(name string, r typeReader, off Offset, typeCache map[Offset]Type) (Type, error) {
+	if t, ok := typeCache[off]; ok {
+		return t, nil
+	}
+	r.Seek(off)
+	e, err := r.Next()
+	if err != nil {
+		return nil, err
+	}
+	if e == nil || e.Offset != off {
+		return nil, DecodeError{name, off, "no type at offset"}
+	}
+
+	// Parse type from Entry.
+	// Must always set typeCache[off] before calling
+	// d.Type recursively, to handle circular types correctly.
+	var typ Type
+
+	nextDepth := 0
+
+	// Get next child; set err if error happens.
+	next := func() *Entry {
+		if !e.Children {
+			return nil
+		}
+		// Only return direct children.
+		// Skip over composite entries that happen to be nested
+		// inside this one. Most DWARF generators wouldn't generate
+		// such a thing, but clang does.
+		// See golang.org/issue/6472.
+		for {
+			kid, err1 := r.Next()
+			if err1 != nil {
+				err = err1
+				return nil
+			}
+			if kid == nil {
+				err = DecodeError{name, r.offset(), "unexpected end of DWARF entries"}
+				return nil
+			}
+			if kid.Tag == 0 {
+				if nextDepth > 0 {
+					nextDepth--
+					continue
+				}
+				return nil
+			}
+			if kid.Children {
+				nextDepth++
+			}
+			if nextDepth > 0 {
+				continue
+			}
+			return kid
+		}
+	}
+
+	// Get Type referred to by Entry's AttrType field.
+	// Set err if error happens.  Not having a type is an error.
+	typeOf := func(e *Entry) Type {
+		tval := e.Val(AttrType)
+		var t Type
+		switch toff := tval.(type) {
+		case Offset:
+			if t, err = d.readType(name, r.clone(), toff, typeCache); err != nil {
+				return nil
+			}
+		case uint64:
+			if t, err = d.sigToType(toff); err != nil {
+				return nil
+			}
+		default:
+			// It appears that no Type means "void".
+			return new(VoidType)
+		}
+		return t
+	}
+
+	switch e.Tag {
+	case TagArrayType:
+		// Multi-dimensional array.  (DWARF v2 §5.4)
+		// Attributes:
+		//	AttrType:subtype [required]
+		//	AttrStrideSize: size in bits of each element of the array
+		//	AttrByteSize: size of entire array
+		// Children:
+		//	TagSubrangeType or TagEnumerationType giving one dimension.
+		//	dimensions are in left to right order.
+		t := new(ArrayType)
+		typ = t
+		typeCache[off] = t
+		if t.Type = typeOf(e); err != nil {
+			goto Error
+		}
+		t.StrideBitSize, _ = e.Val(AttrStrideSize).(int64)
+
+		// Accumulate dimensions,
+		var dims []int64
+		for kid := next(); kid != nil; kid = next() {
+			// TODO(rsc): Can also be TagEnumerationType
+			// but haven't seen that in the wild yet.
+			switch kid.Tag {
+			case TagSubrangeType:
+				count, ok := kid.Val(AttrCount).(int64)
+				if !ok {
+					// Old binaries may have an upper bound instead.
+					count, ok = kid.Val(AttrUpperBound).(int64)
+					if ok {
+						count++ // Length is one more than upper bound.
+					} else if len(dims) == 0 {
+						count = -1 // As in x[].
+					}
+				}
+				dims = append(dims, count)
+			case TagEnumerationType:
+				err = DecodeError{name, kid.Offset, "cannot handle enumeration type as array bound"}
+				goto Error
+			}
+		}
+		if len(dims) == 0 {
+			// LLVM generates this for x[].
+			dims = []int64{-1}
+		}
+
+		t.Count = dims[0]
+		for i := len(dims) - 1; i >= 1; i-- {
+			t.Type = &ArrayType{Type: t.Type, Count: dims[i]}
+		}
+
+	case TagBaseType:
+		// Basic type.  (DWARF v2 §5.1)
+		// Attributes:
+		//	AttrName: name of base type in programming language of the compilation unit [required]
+		//	AttrEncoding: encoding value for type (encFloat etc) [required]
+		//	AttrByteSize: size of type in bytes [required]
+		//	AttrBitOffset: for sub-byte types, size in bits
+		//	AttrBitSize: for sub-byte types, bit offset of high order bit in the AttrByteSize bytes
+		name, _ := e.Val(AttrName).(string)
+		enc, ok := e.Val(AttrEncoding).(int64)
+		if !ok {
+			err = DecodeError{name, e.Offset, "missing encoding attribute for " + name}
+			goto Error
+		}
+		switch enc {
+		default:
+			err = DecodeError{name, e.Offset, "unrecognized encoding attribute value"}
+			goto Error
+
+		case encAddress:
+			typ = new(AddrType)
+		case encBoolean:
+			typ = new(BoolType)
+		case encComplexFloat:
+			typ = new(ComplexType)
+		case encFloat:
+			typ = new(FloatType)
+		case encSigned:
+			typ = new(IntType)
+		case encUnsigned:
+			typ = new(UintType)
+		case encSignedChar:
+			typ = new(CharType)
+		case encUnsignedChar:
+			typ = new(UcharType)
+		}
+		typeCache[off] = typ
+		t := typ.(interface {
+			Basic() *BasicType
+		}).Basic()
+		t.Name = name
+		t.BitSize, _ = e.Val(AttrBitSize).(int64)
+		t.BitOffset, _ = e.Val(AttrBitOffset).(int64)
+
+	case TagClassType, TagStructType, TagUnionType:
+		// Structure, union, or class type.  (DWARF v2 §5.5)
+		// Attributes:
+		//	AttrName: name of struct, union, or class
+		//	AttrByteSize: byte size [required]
+		//	AttrDeclaration: if true, struct/union/class is incomplete
+		// Children:
+		//	TagMember to describe one member.
+		//		AttrName: name of member [required]
+		//		AttrType: type of member [required]
+		//		AttrByteSize: size in bytes
+		//		AttrBitOffset: bit offset within bytes for bit fields
+		//		AttrBitSize: bit size for bit fields
+		//		AttrDataMemberLoc: location within struct [required for struct, class]
+		// There is much more to handle C++, all ignored for now.
+		t := new(StructType)
+		typ = t
+		typeCache[off] = t
+		switch e.Tag {
+		case TagClassType:
+			t.Kind = "class"
+		case TagStructType:
+			t.Kind = "struct"
+		case TagUnionType:
+			t.Kind = "union"
+		}
+		t.StructName, _ = e.Val(AttrName).(string)
+		t.Incomplete = e.Val(AttrDeclaration) != nil
+		t.Field = make([]*StructField, 0, 8)
+		var lastFieldType *Type
+		var lastFieldBitOffset int64
+		for kid := next(); kid != nil; kid = next() {
+			if kid.Tag == TagMember {
+				f := new(StructField)
+				if f.Type = typeOf(kid); err != nil {
+					goto Error
+				}
+				switch loc := kid.Val(AttrDataMemberLoc).(type) {
+				case []byte:
+					// TODO: Should have original compilation
+					// unit here, not unknownFormat.
+					b := makeBuf(d, unknownFormat{}, "location", 0, loc)
+					if b.uint8() != opPlusUconst {
+						err = DecodeError{name, kid.Offset, "unexpected opcode"}
+						goto Error
+					}
+					f.ByteOffset = int64(b.uint())
+					if b.err != nil {
+						err = b.err
+						goto Error
+					}
+				case int64:
+					f.ByteOffset = loc
+				}
+
+				haveBitOffset := false
+				f.Name, _ = kid.Val(AttrName).(string)
+				f.ByteSize, _ = kid.Val(AttrByteSize).(int64)
+				f.BitOffset, haveBitOffset = kid.Val(AttrBitOffset).(int64)
+				f.BitSize, _ = kid.Val(AttrBitSize).(int64)
+				t.Field = append(t.Field, f)
+
+				bito := f.BitOffset
+				if !haveBitOffset {
+					bito = f.ByteOffset * 8
+				}
+				if bito == lastFieldBitOffset && t.Kind != "union" {
+					// Last field was zero width.  Fix array length.
+					// (DWARF writes out 0-length arrays as if they were 1-length arrays.)
+					zeroArray(lastFieldType)
+				}
+				lastFieldType = &f.Type
+				lastFieldBitOffset = bito
+			}
+		}
+		if t.Kind != "union" {
+			b, ok := e.Val(AttrByteSize).(int64)
+			if ok && b*8 == lastFieldBitOffset {
+				// Final field must be zero width.  Fix array length.
+				zeroArray(lastFieldType)
+			}
+		}
+
+	case TagConstType, TagVolatileType, TagRestrictType:
+		// Type modifier (DWARF v2 §5.2)
+		// Attributes:
+		//	AttrType: subtype
+		t := new(QualType)
+		typ = t
+		typeCache[off] = t
+		if t.Type = typeOf(e); err != nil {
+			goto Error
+		}
+		switch e.Tag {
+		case TagConstType:
+			t.Qual = "const"
+		case TagRestrictType:
+			t.Qual = "restrict"
+		case TagVolatileType:
+			t.Qual = "volatile"
+		}
+
+	case TagEnumerationType:
+		// Enumeration type (DWARF v2 §5.6)
+		// Attributes:
+		//	AttrName: enum name if any
+		//	AttrByteSize: bytes required to represent largest value
+		// Children:
+		//	TagEnumerator:
+		//		AttrName: name of constant
+		//		AttrConstValue: value of constant
+		t := new(EnumType)
+		typ = t
+		typeCache[off] = t
+		t.EnumName, _ = e.Val(AttrName).(string)
+		t.Val = make([]*EnumValue, 0, 8)
+		for kid := next(); kid != nil; kid = next() {
+			if kid.Tag == TagEnumerator {
+				f := new(EnumValue)
+				f.Name, _ = kid.Val(AttrName).(string)
+				f.Val, _ = kid.Val(AttrConstValue).(int64)
+				n := len(t.Val)
+				if n >= cap(t.Val) {
+					val := make([]*EnumValue, n, n*2)
+					copy(val, t.Val)
+					t.Val = val
+				}
+				t.Val = t.Val[0 : n+1]
+				t.Val[n] = f
+			}
+		}
+
+	case TagPointerType:
+		// Type modifier (DWARF v2 §5.2)
+		// Attributes:
+		//	AttrType: subtype [not required!  void* has no AttrType]
+		//	AttrAddrClass: address class [ignored]
+		t := new(PtrType)
+		typ = t
+		typeCache[off] = t
+		if e.Val(AttrType) == nil {
+			t.Type = &VoidType{}
+			break
+		}
+		t.Type = typeOf(e)
+
+	case TagSubroutineType:
+		// Subroutine type.  (DWARF v2 §5.7)
+		// Attributes:
+		//	AttrType: type of return value if any
+		//	AttrName: possible name of type [ignored]
+		//	AttrPrototyped: whether used ANSI C prototype [ignored]
+		// Children:
+		//	TagFormalParameter: typed parameter
+		//		AttrType: type of parameter
+		//	TagUnspecifiedParameter: final ...
+		t := new(FuncType)
+		typ = t
+		typeCache[off] = t
+		if t.ReturnType = typeOf(e); err != nil {
+			goto Error
+		}
+		t.ParamType = make([]Type, 0, 8)
+		for kid := next(); kid != nil; kid = next() {
+			var tkid Type
+			switch kid.Tag {
+			default:
+				continue
+			case TagFormalParameter:
+				if tkid = typeOf(kid); err != nil {
+					goto Error
+				}
+			case TagUnspecifiedParameters:
+				tkid = &DotDotDotType{}
+			}
+			t.ParamType = append(t.ParamType, tkid)
+		}
+
+	case TagTypedef:
+		// Typedef (DWARF v2 §5.3)
+		// Attributes:
+		//	AttrName: name [required]
+		//	AttrType: type definition [required]
+		t := new(TypedefType)
+		typ = t
+		typeCache[off] = t
+		t.Name, _ = e.Val(AttrName).(string)
+		t.Type = typeOf(e)
+
+	case TagUnspecifiedType:
+		// Unspecified type (DWARF v3 §5.2)
+		// Attributes:
+		//	AttrName: name
+		t := new(UnspecifiedType)
+		typ = t
+		typeCache[off] = t
+		t.Name, _ = e.Val(AttrName).(string)
+	}
+
+	if err != nil {
+		goto Error
+	}
+
+	{
+		b, ok := e.Val(AttrByteSize).(int64)
+		if !ok {
+			b = -1
+		}
+		typ.Common().ByteSize = b
+	}
+	return typ, nil
+
+Error:
+	// If the parse fails, take the type out of the cache
+	// so that the next call with this offset doesn't hit
+	// the cache and return success.
+	delete(typeCache, off)
+	return nil, err
+}
+
+func zeroArray(t *Type) {
+	if t == nil {
+		return
+	}
+	at, ok := (*t).(*ArrayType)
+	if !ok || at.Type.Size() == 0 {
+		return
+	}
+	// Make a copy to avoid invalidating typeCache.
+	tt := *at
+	tt.Count = 0
+	*t = &tt
+}
diff --git a/src/debug/dwarf/type_test.go b/src/debug/dwarf/type_test.go
new file mode 100644
index 000000000..2cb85e74b
--- /dev/null
+++ b/src/debug/dwarf/type_test.go
@@ -0,0 +1,122 @@
+// Copyright 2009 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package dwarf_test
+
+import (
+	. "debug/dwarf"
+	"debug/elf"
+	"debug/macho"
+	"testing"
+)
+
+var typedefTests = map[string]string{
+	"t_ptr_volatile_int":                    "*volatile int",
+	"t_ptr_const_char":                      "*const char",
+	"t_long":                                "long int",
+	"t_ushort":                              "short unsigned int",
+	"t_func_int_of_float_double":            "func(float, double) int",
+	"t_ptr_func_int_of_float_double":        "*func(float, double) int",
+	"t_ptr_func_int_of_float_complex":       "*func(complex float) int",
+	"t_ptr_func_int_of_double_complex":      "*func(complex double) int",
+	"t_ptr_func_int_of_long_double_complex": "*func(complex long double) int",
+	"t_func_ptr_int_of_char_schar_uchar":    "func(char, signed char, unsigned char) *int",
+	"t_func_void_of_char":                   "func(char) void",
+	"t_func_void_of_void":                   "func() void",
+	"t_func_void_of_ptr_char_dots":          "func(*char, ...) void",
+	"t_my_struct":                           "struct my_struct {vi volatile int@0; x char@4 : 1@7; y int@4 : 4@27; z [0]int@8; array [40]long long int@8; zz [0]int@328}",
+	"t_my_struct1":                          "struct my_struct1 {zz [1]int@0}",
+	"t_my_union":                            "union my_union {vi volatile int@0; x char@0 : 1@7; y int@0 : 4@28; array [40]long long int@0}",
+	"t_my_enum":                             "enum my_enum {e1=1; e2=2; e3=-5; e4=1000000000000000}",
+	"t_my_list":                             "struct list {val short int@0; next *t_my_list@8}",
+	"t_my_tree":                             "struct tree {left *struct tree@0; right *struct tree@8; val long long unsigned int@16}",
+}
+
+// As Apple converts gcc to a clang-based front end
+// they keep breaking the DWARF output.  This map lists the
+// conversion from real answer to Apple answer.
+var machoBug = map[string]string{
+	"func(*char, ...) void":                                 "func(*char) void",
+	"enum my_enum {e1=1; e2=2; e3=-5; e4=1000000000000000}": "enum my_enum {e1=1; e2=2; e3=-5; e4=-1530494976}",
+}
+
+func elfData(t *testing.T, name string) *Data {
+	f, err := elf.Open(name)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	d, err := f.DWARF()
+	if err != nil {
+		t.Fatal(err)
+	}
+	return d
+}
+
+func machoData(t *testing.T, name string) *Data {
+	f, err := macho.Open(name)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	d, err := f.DWARF()
+	if err != nil {
+		t.Fatal(err)
+	}
+	return d
+}
+
+func TestTypedefsELF(t *testing.T) { testTypedefs(t, elfData(t, "testdata/typedef.elf"), "elf") }
+
+func TestTypedefsMachO(t *testing.T) {
+	testTypedefs(t, machoData(t, "testdata/typedef.macho"), "macho")
+}
+
+func TestTypedefsELFDwarf4(t *testing.T) { testTypedefs(t, elfData(t, "testdata/typedef.elf4"), "elf") }
+
+func testTypedefs(t *testing.T, d *Data, kind string) {
+	r := d.Reader()
+	seen := make(map[string]bool)
+	for {
+		e, err := r.Next()
+		if err != nil {
+			t.Fatal("r.Next:", err)
+		}
+		if e == nil {
+			break
+		}
+		if e.Tag == TagTypedef {
+			typ, err := d.Type(e.Offset)
+			if err != nil {
+				t.Fatal("d.Type:", err)
+			}
+			t1 := typ.(*TypedefType)
+			var typstr string
+			if ts, ok := t1.Type.(*StructType); ok {
+				typstr = ts.Defn()
+			} else {
+				typstr = t1.Type.String()
+			}
+
+			if want, ok := typedefTests[t1.Name]; ok {
+				if seen[t1.Name] {
+					t.Errorf("multiple definitions for %s", t1.Name)
+				}
+				seen[t1.Name] = true
+				if typstr != want && (kind != "macho" || typstr != machoBug[want]) {
+					t.Errorf("%s:\n\thave %s\n\twant %s", t1.Name, typstr, want)
+				}
+			}
+		}
+		if e.Tag != TagCompileUnit {
+			r.SkipChildren()
+		}
+	}
+
+	for k := range typedefTests {
+		if !seen[k] {
+			t.Errorf("missing %s", k)
+		}
+	}
+}
diff --git a/src/debug/dwarf/typeunit.go b/src/debug/dwarf/typeunit.go
new file mode 100644
index 000000000..3fd1c9973
--- /dev/null
+++ b/src/debug/dwarf/typeunit.go
@@ -0,0 +1,166 @@
+// Copyright 2012 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package dwarf
+
+import (
+	"fmt"
+	"strconv"
+)
+
+// Parse the type units stored in a DWARF4 .debug_types section.  Each
+// type unit defines a single primary type and an 8-byte signature.
+// Other sections may then use formRefSig8 to refer to the type.
+
+// The typeUnit format is a single type with a signature.  It holds
+// the same data as a compilation unit.
+type typeUnit struct {
+	unit
+	toff  Offset // Offset to signature type within data.
+	name  string // Name of .debug_type section.
+	cache Type   // Cache the type, nil to start.
+}
+
+// Parse a .debug_types section.
+func (d *Data) parseTypes(name string, types []byte) error {
+	b := makeBuf(d, unknownFormat{}, name, 0, types)
+	for len(b.data) > 0 {
+		base := b.off
+		dwarf64 := false
+		n := b.uint32()
+		if n == 0xffffffff {
+			n64 := b.uint64()
+			if n64 != uint64(uint32(n64)) {
+				b.error("type unit length overflow")
+				return b.err
+			}
+			n = uint32(n64)
+			dwarf64 = true
+		}
+		hdroff := b.off
+		vers := b.uint16()
+		if vers != 4 {
+			b.error("unsupported DWARF version " + strconv.Itoa(int(vers)))
+			return b.err
+		}
+		var ao uint32
+		if !dwarf64 {
+			ao = b.uint32()
+		} else {
+			ao64 := b.uint64()
+			if ao64 != uint64(uint32(ao64)) {
+				b.error("type unit abbrev offset overflow")
+				return b.err
+			}
+			ao = uint32(ao64)
+		}
+		atable, err := d.parseAbbrev(ao)
+		if err != nil {
+			return err
+		}
+		asize := b.uint8()
+		sig := b.uint64()
+
+		var toff uint32
+		if !dwarf64 {
+			toff = b.uint32()
+		} else {
+			to64 := b.uint64()
+			if to64 != uint64(uint32(to64)) {
+				b.error("type unit type offset overflow")
+				return b.err
+			}
+			toff = uint32(to64)
+		}
+
+		boff := b.off
+		d.typeSigs[sig] = &typeUnit{
+			unit: unit{
+				base:   base,
+				off:    boff,
+				data:   b.bytes(int(Offset(n) - (b.off - hdroff))),
+				atable: atable,
+				asize:  int(asize),
+				vers:   int(vers),
+				is64:   dwarf64,
+			},
+			toff: Offset(toff),
+			name: name,
+		}
+		if b.err != nil {
+			return b.err
+		}
+	}
+	return nil
+}
+
+// Return the type for a type signature.
+func (d *Data) sigToType(sig uint64) (Type, error) {
+	tu := d.typeSigs[sig]
+	if tu == nil {
+		return nil, fmt.Errorf("no type unit with signature %v", sig)
+	}
+	if tu.cache != nil {
+		return tu.cache, nil
+	}
+
+	b := makeBuf(d, tu, tu.name, tu.off, tu.data)
+	r := &typeUnitReader{d: d, tu: tu, b: b}
+	t, err := d.readType(tu.name, r, Offset(tu.toff), make(map[Offset]Type))
+	if err != nil {
+		return nil, err
+	}
+
+	tu.cache = t
+	return t, nil
+}
+
+// typeUnitReader is a typeReader for a tagTypeUnit.
+type typeUnitReader struct {
+	d   *Data
+	tu  *typeUnit
+	b   buf
+	err error
+}
+
+// Seek to a new position in the type unit.
+func (tur *typeUnitReader) Seek(off Offset) {
+	tur.err = nil
+	doff := off - tur.tu.off
+	if doff < 0 || doff >= Offset(len(tur.tu.data)) {
+		tur.err = fmt.Errorf("%s: offset %d out of range; max %d", tur.tu.name, doff, len(tur.tu.data))
+		return
+	}
+	tur.b = makeBuf(tur.d, tur.tu, tur.tu.name, off, tur.tu.data[doff:])
+}
+
+// Next reads the next Entry from the type unit.
+func (tur *typeUnitReader) Next() (*Entry, error) {
+	if tur.err != nil {
+		return nil, tur.err
+	}
+	if len(tur.tu.data) == 0 {
+		return nil, nil
+	}
+	e := tur.b.entry(tur.tu.atable, tur.tu.base)
+	if tur.b.err != nil {
+		tur.err = tur.b.err
+		return nil, tur.err
+	}
+	return e, nil
+}
+
+// clone returns a new reader for the type unit.
+func (tur *typeUnitReader) clone() typeReader {
+	return &typeUnitReader{
+		d:  tur.d,
+		tu: tur.tu,
+		b:  makeBuf(tur.d, tur.tu, tur.tu.name, tur.tu.off, tur.tu.data),
+	}
+}
+
+// offset returns the current offset.
+func (tur *typeUnitReader) offset() Offset {
+	return tur.b.off
+}
diff --git a/src/debug/dwarf/unit.go b/src/debug/dwarf/unit.go
new file mode 100644
index 000000000..0fbc8e082
--- /dev/null
+++ b/src/debug/dwarf/unit.go
@@ -0,0 +1,90 @@
+// Copyright 2009 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package dwarf
+
+import "strconv"
+
+// DWARF debug info is split into a sequence of compilation units.
+// Each unit has its own abbreviation table and address size.
+
+type unit struct {
+	base   Offset // byte offset of header within the aggregate info
+	off    Offset // byte offset of data within the aggregate info
+	data   []byte
+	atable abbrevTable
+	asize  int
+	vers   int
+	is64   bool // True for 64-bit DWARF format
+}
+
+// Implement the dataFormat interface.
+
+func (u *unit) version() int {
+	return u.vers
+}
+
+func (u *unit) dwarf64() (bool, bool) {
+	return u.is64, true
+}
+
+func (u *unit) addrsize() int {
+	return u.asize
+}
+
+func (d *Data) parseUnits() ([]unit, error) {
+	// Count units.
+	nunit := 0
+	b := makeBuf(d, unknownFormat{}, "info", 0, d.info)
+	for len(b.data) > 0 {
+		len := b.uint32()
+		if len == 0xffffffff {
+			len64 := b.uint64()
+			if len64 != uint64(uint32(len64)) {
+				b.error("unit length overflow")
+				break
+			}
+			len = uint32(len64)
+		}
+		b.skip(int(len))
+		nunit++
+	}
+	if b.err != nil {
+		return nil, b.err
+	}
+
+	// Again, this time writing them down.
+	b = makeBuf(d, unknownFormat{}, "info", 0, d.info)
+	units := make([]unit, nunit)
+	for i := range units {
+		u := &units[i]
+		u.base = b.off
+		n := b.uint32()
+		if n == 0xffffffff {
+			u.is64 = true
+			n = uint32(b.uint64())
+		}
+		vers := b.uint16()
+		if vers != 2 && vers != 3 && vers != 4 {
+			b.error("unsupported DWARF version " + strconv.Itoa(int(vers)))
+			break
+		}
+		u.vers = int(vers)
+		atable, err := d.parseAbbrev(b.uint32())
+		if err != nil {
+			if b.err == nil {
+				b.err = err
+			}
+			break
+		}
+		u.atable = atable
+		u.asize = int(b.uint8())
+		u.off = b.off
+		u.data = b.bytes(int(n - (2 + 4 + 1)))
+	}
+	if b.err != nil {
+		return nil, b.err
+	}
+	return units, nil
+}
diff --git a/src/debug/elf/elf.go b/src/debug/elf/elf.go
new file mode 100644
index 000000000..46e9d5735
--- /dev/null
+++ b/src/debug/elf/elf.go
@@ -0,0 +1,1951 @@
+/*
+ * ELF constants and data structures
+ *
+ * Derived from:
+ * $FreeBSD: src/sys/sys/elf32.h,v 1.8.14.1 2005/12/30 22:13:58 marcel Exp $
+ * $FreeBSD: src/sys/sys/elf64.h,v 1.10.14.1 2005/12/30 22:13:58 marcel Exp $
+ * $FreeBSD: src/sys/sys/elf_common.h,v 1.15.8.1 2005/12/30 22:13:58 marcel Exp $
+ * $FreeBSD: src/sys/alpha/include/elf.h,v 1.14 2003/09/25 01:10:22 peter Exp $
+ * $FreeBSD: src/sys/amd64/include/elf.h,v 1.18 2004/08/03 08:21:48 dfr Exp $
+ * $FreeBSD: src/sys/arm/include/elf.h,v 1.5.2.1 2006/06/30 21:42:52 cognet Exp $
+ * $FreeBSD: src/sys/i386/include/elf.h,v 1.16 2004/08/02 19:12:17 dfr Exp $
+ * $FreeBSD: src/sys/powerpc/include/elf.h,v 1.7 2004/11/02 09:47:01 ssouhlal Exp $
+ * $FreeBSD: src/sys/sparc64/include/elf.h,v 1.12 2003/09/25 01:10:26 peter Exp $
+ * "ELF for the ARM® 64-bit Architecture (AArch64)" (ARM IHI 0056B)
+ *
+ * Copyright (c) 1996-1998 John D. Polstra.  All rights reserved.
+ * Copyright (c) 2001 David E. O'Brien
+ * Portions Copyright 2009 The Go Authors.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+package elf
+
+import "strconv"
+
+/*
+ * Constants
+ */
+
+// Indexes into the Header.Ident array.
+const (
+	EI_CLASS      = 4  /* Class of machine. */
+	EI_DATA       = 5  /* Data format. */
+	EI_VERSION    = 6  /* ELF format version. */
+	EI_OSABI      = 7  /* Operating system / ABI identification */
+	EI_ABIVERSION = 8  /* ABI version */
+	EI_PAD        = 9  /* Start of padding (per SVR4 ABI). */
+	EI_NIDENT     = 16 /* Size of e_ident array. */
+)
+
+// Initial magic number for ELF files.
+const ELFMAG = "\177ELF"
+
+// Version is found in Header.Ident[EI_VERSION] and Header.Version.
+type Version byte
+
+const (
+	EV_NONE    Version = 0
+	EV_CURRENT Version = 1
+)
+
+var versionStrings = []intName{
+	{0, "EV_NONE"},
+	{1, "EV_CURRENT"},
+}
+
+func (i Version) String() string   { return stringName(uint32(i), versionStrings, false) }
+func (i Version) GoString() string { return stringName(uint32(i), versionStrings, true) }
+
+// Class is found in Header.Ident[EI_CLASS] and Header.Class.
+type Class byte
+
+const (
+	ELFCLASSNONE Class = 0 /* Unknown class. */
+	ELFCLASS32   Class = 1 /* 32-bit architecture. */
+	ELFCLASS64   Class = 2 /* 64-bit architecture. */
+)
+
+var classStrings = []intName{
+	{0, "ELFCLASSNONE"},
+	{1, "ELFCLASS32"},
+	{2, "ELFCLASS64"},
+}
+
+func (i Class) String() string   { return stringName(uint32(i), classStrings, false) }
+func (i Class) GoString() string { return stringName(uint32(i), classStrings, true) }
+
+// Data is found in Header.Ident[EI_DATA] and Header.Data.
+type Data byte
+
+const (
+	ELFDATANONE Data = 0 /* Unknown data format. */
+	ELFDATA2LSB Data = 1 /* 2's complement little-endian. */
+	ELFDATA2MSB Data = 2 /* 2's complement big-endian. */
+)
+
+var dataStrings = []intName{
+	{0, "ELFDATANONE"},
+	{1, "ELFDATA2LSB"},
+	{2, "ELFDATA2MSB"},
+}
+
+func (i Data) String() string   { return stringName(uint32(i), dataStrings, false) }
+func (i Data) GoString() string { return stringName(uint32(i), dataStrings, true) }
+
+// OSABI is found in Header.Ident[EI_OSABI] and Header.OSABI.
+type OSABI byte
+
+const (
+	ELFOSABI_NONE       OSABI = 0   /* UNIX System V ABI */
+	ELFOSABI_HPUX       OSABI = 1   /* HP-UX operating system */
+	ELFOSABI_NETBSD     OSABI = 2   /* NetBSD */
+	ELFOSABI_LINUX      OSABI = 3   /* GNU/Linux */
+	ELFOSABI_HURD       OSABI = 4   /* GNU/Hurd */
+	ELFOSABI_86OPEN     OSABI = 5   /* 86Open common IA32 ABI */
+	ELFOSABI_SOLARIS    OSABI = 6   /* Solaris */
+	ELFOSABI_AIX        OSABI = 7   /* AIX */
+	ELFOSABI_IRIX       OSABI = 8   /* IRIX */
+	ELFOSABI_FREEBSD    OSABI = 9   /* FreeBSD */
+	ELFOSABI_TRU64      OSABI = 10  /* TRU64 UNIX */
+	ELFOSABI_MODESTO    OSABI = 11  /* Novell Modesto */
+	ELFOSABI_OPENBSD    OSABI = 12  /* OpenBSD */
+	ELFOSABI_OPENVMS    OSABI = 13  /* Open VMS */
+	ELFOSABI_NSK        OSABI = 14  /* HP Non-Stop Kernel */
+	ELFOSABI_ARM        OSABI = 97  /* ARM */
+	ELFOSABI_STANDALONE OSABI = 255 /* Standalone (embedded) application */
+)
+
+var osabiStrings = []intName{
+	{0, "ELFOSABI_NONE"},
+	{1, "ELFOSABI_HPUX"},
+	{2, "ELFOSABI_NETBSD"},
+	{3, "ELFOSABI_LINUX"},
+	{4, "ELFOSABI_HURD"},
+	{5, "ELFOSABI_86OPEN"},
+	{6, "ELFOSABI_SOLARIS"},
+	{7, "ELFOSABI_AIX"},
+	{8, "ELFOSABI_IRIX"},
+	{9, "ELFOSABI_FREEBSD"},
+	{10, "ELFOSABI_TRU64"},
+	{11, "ELFOSABI_MODESTO"},
+	{12, "ELFOSABI_OPENBSD"},
+	{13, "ELFOSABI_OPENVMS"},
+	{14, "ELFOSABI_NSK"},
+	{97, "ELFOSABI_ARM"},
+	{255, "ELFOSABI_STANDALONE"},
+}
+
+func (i OSABI) String() string   { return stringName(uint32(i), osabiStrings, false) }
+func (i OSABI) GoString() string { return stringName(uint32(i), osabiStrings, true) }
+
+// Type is found in Header.Type.
+type Type uint16
+
+const (
+	ET_NONE   Type = 0      /* Unknown type. */
+	ET_REL    Type = 1      /* Relocatable. */
+	ET_EXEC   Type = 2      /* Executable. */
+	ET_DYN    Type = 3      /* Shared object. */
+	ET_CORE   Type = 4      /* Core file. */
+	ET_LOOS   Type = 0xfe00 /* First operating system specific. */
+	ET_HIOS   Type = 0xfeff /* Last operating system-specific. */
+	ET_LOPROC Type = 0xff00 /* First processor-specific. */
+	ET_HIPROC Type = 0xffff /* Last processor-specific. */
+)
+
+var typeStrings = []intName{
+	{0, "ET_NONE"},
+	{1, "ET_REL"},
+	{2, "ET_EXEC"},
+	{3, "ET_DYN"},
+	{4, "ET_CORE"},
+	{0xfe00, "ET_LOOS"},
+	{0xfeff, "ET_HIOS"},
+	{0xff00, "ET_LOPROC"},
+	{0xffff, "ET_HIPROC"},
+}
+
+func (i Type) String() string   { return stringName(uint32(i), typeStrings, false) }
+func (i Type) GoString() string { return stringName(uint32(i), typeStrings, true) }
+
+// Machine is found in Header.Machine.
+type Machine uint16
+
+const (
+	EM_NONE        Machine = 0   /* Unknown machine. */
+	EM_M32         Machine = 1   /* AT&T WE32100. */
+	EM_SPARC       Machine = 2   /* Sun SPARC. */
+	EM_386         Machine = 3   /* Intel i386. */
+	EM_68K         Machine = 4   /* Motorola 68000. */
+	EM_88K         Machine = 5   /* Motorola 88000. */
+	EM_860         Machine = 7   /* Intel i860. */
+	EM_MIPS        Machine = 8   /* MIPS R3000 Big-Endian only. */
+	EM_S370        Machine = 9   /* IBM System/370. */
+	EM_MIPS_RS3_LE Machine = 10  /* MIPS R3000 Little-Endian. */
+	EM_PARISC      Machine = 15  /* HP PA-RISC. */
+	EM_VPP500      Machine = 17  /* Fujitsu VPP500. */
+	EM_SPARC32PLUS Machine = 18  /* SPARC v8plus. */
+	EM_960         Machine = 19  /* Intel 80960. */
+	EM_PPC         Machine = 20  /* PowerPC 32-bit. */
+	EM_PPC64       Machine = 21  /* PowerPC 64-bit. */
+	EM_S390        Machine = 22  /* IBM System/390. */
+	EM_V800        Machine = 36  /* NEC V800. */
+	EM_FR20        Machine = 37  /* Fujitsu FR20. */
+	EM_RH32        Machine = 38  /* TRW RH-32. */
+	EM_RCE         Machine = 39  /* Motorola RCE. */
+	EM_ARM         Machine = 40  /* ARM. */
+	EM_SH          Machine = 42  /* Hitachi SH. */
+	EM_SPARCV9     Machine = 43  /* SPARC v9 64-bit. */
+	EM_TRICORE     Machine = 44  /* Siemens TriCore embedded processor. */
+	EM_ARC         Machine = 45  /* Argonaut RISC Core. */
+	EM_H8_300      Machine = 46  /* Hitachi H8/300. */
+	EM_H8_300H     Machine = 47  /* Hitachi H8/300H. */
+	EM_H8S         Machine = 48  /* Hitachi H8S. */
+	EM_H8_500      Machine = 49  /* Hitachi H8/500. */
+	EM_IA_64       Machine = 50  /* Intel IA-64 Processor. */
+	EM_MIPS_X      Machine = 51  /* Stanford MIPS-X. */
+	EM_COLDFIRE    Machine = 52  /* Motorola ColdFire. */
+	EM_68HC12      Machine = 53  /* Motorola M68HC12. */
+	EM_MMA         Machine = 54  /* Fujitsu MMA. */
+	EM_PCP         Machine = 55  /* Siemens PCP. */
+	EM_NCPU        Machine = 56  /* Sony nCPU. */
+	EM_NDR1        Machine = 57  /* Denso NDR1 microprocessor. */
+	EM_STARCORE    Machine = 58  /* Motorola Star*Core processor. */
+	EM_ME16        Machine = 59  /* Toyota ME16 processor. */
+	EM_ST100       Machine = 60  /* STMicroelectronics ST100 processor. */
+	EM_TINYJ       Machine = 61  /* Advanced Logic Corp. TinyJ processor. */
+	EM_X86_64      Machine = 62  /* Advanced Micro Devices x86-64 */
+	EM_AARCH64     Machine = 183 /* ARM 64-bit Architecture (AArch64) */
+
+	/* Non-standard or deprecated. */
+	EM_486         Machine = 6      /* Intel i486. */
+	EM_MIPS_RS4_BE Machine = 10     /* MIPS R4000 Big-Endian */
+	EM_ALPHA_STD   Machine = 41     /* Digital Alpha (standard value). */
+	EM_ALPHA       Machine = 0x9026 /* Alpha (written in the absence of an ABI) */
+)
+
+var machineStrings = []intName{
+	{0, "EM_NONE"},
+	{1, "EM_M32"},
+	{2, "EM_SPARC"},
+	{3, "EM_386"},
+	{4, "EM_68K"},
+	{5, "EM_88K"},
+	{7, "EM_860"},
+	{8, "EM_MIPS"},
+	{9, "EM_S370"},
+	{10, "EM_MIPS_RS3_LE"},
+	{15, "EM_PARISC"},
+	{17, "EM_VPP500"},
+	{18, "EM_SPARC32PLUS"},
+	{19, "EM_960"},
+	{20, "EM_PPC"},
+	{21, "EM_PPC64"},
+	{22, "EM_S390"},
+	{36, "EM_V800"},
+	{37, "EM_FR20"},
+	{38, "EM_RH32"},
+	{39, "EM_RCE"},
+	{40, "EM_ARM"},
+	{42, "EM_SH"},
+	{43, "EM_SPARCV9"},
+	{44, "EM_TRICORE"},
+	{45, "EM_ARC"},
+	{46, "EM_H8_300"},
+	{47, "EM_H8_300H"},
+	{48, "EM_H8S"},
+	{49, "EM_H8_500"},
+	{50, "EM_IA_64"},
+	{51, "EM_MIPS_X"},
+	{52, "EM_COLDFIRE"},
+	{53, "EM_68HC12"},
+	{54, "EM_MMA"},
+	{55, "EM_PCP"},
+	{56, "EM_NCPU"},
+	{57, "EM_NDR1"},
+	{58, "EM_STARCORE"},
+	{59, "EM_ME16"},
+	{60, "EM_ST100"},
+	{61, "EM_TINYJ"},
+	{62, "EM_X86_64"},
+
+	/* Non-standard or deprecated. */
+	{6, "EM_486"},
+	{10, "EM_MIPS_RS4_BE"},
+	{41, "EM_ALPHA_STD"},
+	{0x9026, "EM_ALPHA"},
+}
+
+func (i Machine) String() string   { return stringName(uint32(i), machineStrings, false) }
+func (i Machine) GoString() string { return stringName(uint32(i), machineStrings, true) }
+
+// Special section indices.
+type SectionIndex int
+
+const (
+	SHN_UNDEF     SectionIndex = 0      /* Undefined, missing, irrelevant. */
+	SHN_LORESERVE SectionIndex = 0xff00 /* First of reserved range. */
+	SHN_LOPROC    SectionIndex = 0xff00 /* First processor-specific. */
+	SHN_HIPROC    SectionIndex = 0xff1f /* Last processor-specific. */
+	SHN_LOOS      SectionIndex = 0xff20 /* First operating system-specific. */
+	SHN_HIOS      SectionIndex = 0xff3f /* Last operating system-specific. */
+	SHN_ABS       SectionIndex = 0xfff1 /* Absolute values. */
+	SHN_COMMON    SectionIndex = 0xfff2 /* Common data. */
+	SHN_XINDEX    SectionIndex = 0xffff /* Escape -- index stored elsewhere. */
+	SHN_HIRESERVE SectionIndex = 0xffff /* Last of reserved range. */
+)
+
+var shnStrings = []intName{
+	{0, "SHN_UNDEF"},
+	{0xff00, "SHN_LOPROC"},
+	{0xff20, "SHN_LOOS"},
+	{0xfff1, "SHN_ABS"},
+	{0xfff2, "SHN_COMMON"},
+	{0xffff, "SHN_XINDEX"},
+}
+
+func (i SectionIndex) String() string   { return stringName(uint32(i), shnStrings, false) }
+func (i SectionIndex) GoString() string { return stringName(uint32(i), shnStrings, true) }
+
+// Section type.
+type SectionType uint32
+
+const (
+	SHT_NULL           SectionType = 0          /* inactive */
+	SHT_PROGBITS       SectionType = 1          /* program defined information */
+	SHT_SYMTAB         SectionType = 2          /* symbol table section */
+	SHT_STRTAB         SectionType = 3          /* string table section */
+	SHT_RELA           SectionType = 4          /* relocation section with addends */
+	SHT_HASH           SectionType = 5          /* symbol hash table section */
+	SHT_DYNAMIC        SectionType = 6          /* dynamic section */
+	SHT_NOTE           SectionType = 7          /* note section */
+	SHT_NOBITS         SectionType = 8          /* no space section */
+	SHT_REL            SectionType = 9          /* relocation section - no addends */
+	SHT_SHLIB          SectionType = 10         /* reserved - purpose unknown */
+	SHT_DYNSYM         SectionType = 11         /* dynamic symbol table section */
+	SHT_INIT_ARRAY     SectionType = 14         /* Initialization function pointers. */
+	SHT_FINI_ARRAY     SectionType = 15         /* Termination function pointers. */
+	SHT_PREINIT_ARRAY  SectionType = 16         /* Pre-initialization function ptrs. */
+	SHT_GROUP          SectionType = 17         /* Section group. */
+	SHT_SYMTAB_SHNDX   SectionType = 18         /* Section indexes (see SHN_XINDEX). */
+	SHT_LOOS           SectionType = 0x60000000 /* First of OS specific semantics */
+	SHT_GNU_ATTRIBUTES SectionType = 0x6ffffff5 /* GNU object attributes */
+	SHT_GNU_HASH       SectionType = 0x6ffffff6 /* GNU hash table */
+	SHT_GNU_LIBLIST    SectionType = 0x6ffffff7 /* GNU prelink library list */
+	SHT_GNU_VERDEF     SectionType = 0x6ffffffd /* GNU version definition section */
+	SHT_GNU_VERNEED    SectionType = 0x6ffffffe /* GNU version needs section */
+	SHT_GNU_VERSYM     SectionType = 0x6fffffff /* GNU version symbol table */
+	SHT_HIOS           SectionType = 0x6fffffff /* Last of OS specific semantics */
+	SHT_LOPROC         SectionType = 0x70000000 /* reserved range for processor */
+	SHT_HIPROC         SectionType = 0x7fffffff /* specific section header types */
+	SHT_LOUSER         SectionType = 0x80000000 /* reserved range for application */
+	SHT_HIUSER         SectionType = 0xffffffff /* specific indexes */
+)
+
+var shtStrings = []intName{
+	{0, "SHT_NULL"},
+	{1, "SHT_PROGBITS"},
+	{2, "SHT_SYMTAB"},
+	{3, "SHT_STRTAB"},
+	{4, "SHT_RELA"},
+	{5, "SHT_HASH"},
+	{6, "SHT_DYNAMIC"},
+	{7, "SHT_NOTE"},
+	{8, "SHT_NOBITS"},
+	{9, "SHT_REL"},
+	{10, "SHT_SHLIB"},
+	{11, "SHT_DYNSYM"},
+	{14, "SHT_INIT_ARRAY"},
+	{15, "SHT_FINI_ARRAY"},
+	{16, "SHT_PREINIT_ARRAY"},
+	{17, "SHT_GROUP"},
+	{18, "SHT_SYMTAB_SHNDX"},
+	{0x60000000, "SHT_LOOS"},
+	{0x6ffffff5, "SHT_GNU_ATTRIBUTES"},
+	{0x6ffffff6, "SHT_GNU_HASH"},
+	{0x6ffffff7, "SHT_GNU_LIBLIST"},
+	{0x6ffffffd, "SHT_GNU_VERDEF"},
+	{0x6ffffffe, "SHT_GNU_VERNEED"},
+	{0x6fffffff, "SHT_GNU_VERSYM"},
+	{0x70000000, "SHT_LOPROC"},
+	{0x7fffffff, "SHT_HIPROC"},
+	{0x80000000, "SHT_LOUSER"},
+	{0xffffffff, "SHT_HIUSER"},
+}
+
+func (i SectionType) String() string   { return stringName(uint32(i), shtStrings, false) }
+func (i SectionType) GoString() string { return stringName(uint32(i), shtStrings, true) }
+
+// Section flags.
+type SectionFlag uint32
+
+const (
+	SHF_WRITE            SectionFlag = 0x1        /* Section contains writable data. */
+	SHF_ALLOC            SectionFlag = 0x2        /* Section occupies memory. */
+	SHF_EXECINSTR        SectionFlag = 0x4        /* Section contains instructions. */
+	SHF_MERGE            SectionFlag = 0x10       /* Section may be merged. */
+	SHF_STRINGS          SectionFlag = 0x20       /* Section contains strings. */
+	SHF_INFO_LINK        SectionFlag = 0x40       /* sh_info holds section index. */
+	SHF_LINK_ORDER       SectionFlag = 0x80       /* Special ordering requirements. */
+	SHF_OS_NONCONFORMING SectionFlag = 0x100      /* OS-specific processing required. */
+	SHF_GROUP            SectionFlag = 0x200      /* Member of section group. */
+	SHF_TLS              SectionFlag = 0x400      /* Section contains TLS data. */
+	SHF_MASKOS           SectionFlag = 0x0ff00000 /* OS-specific semantics. */
+	SHF_MASKPROC         SectionFlag = 0xf0000000 /* Processor-specific semantics. */
+)
+
+var shfStrings = []intName{
+	{0x1, "SHF_WRITE"},
+	{0x2, "SHF_ALLOC"},
+	{0x4, "SHF_EXECINSTR"},
+	{0x10, "SHF_MERGE"},
+	{0x20, "SHF_STRINGS"},
+	{0x40, "SHF_INFO_LINK"},
+	{0x80, "SHF_LINK_ORDER"},
+	{0x100, "SHF_OS_NONCONFORMING"},
+	{0x200, "SHF_GROUP"},
+	{0x400, "SHF_TLS"},
+}
+
+func (i SectionFlag) String() string   { return flagName(uint32(i), shfStrings, false) }
+func (i SectionFlag) GoString() string { return flagName(uint32(i), shfStrings, true) }
+
+// Prog.Type
+type ProgType int
+
+const (
+	PT_NULL    ProgType = 0          /* Unused entry. */
+	PT_LOAD    ProgType = 1          /* Loadable segment. */
+	PT_DYNAMIC ProgType = 2          /* Dynamic linking information segment. */
+	PT_INTERP  ProgType = 3          /* Pathname of interpreter. */
+	PT_NOTE    ProgType = 4          /* Auxiliary information. */
+	PT_SHLIB   ProgType = 5          /* Reserved (not used). */
+	PT_PHDR    ProgType = 6          /* Location of program header itself. */
+	PT_TLS     ProgType = 7          /* Thread local storage segment */
+	PT_LOOS    ProgType = 0x60000000 /* First OS-specific. */
+	PT_HIOS    ProgType = 0x6fffffff /* Last OS-specific. */
+	PT_LOPROC  ProgType = 0x70000000 /* First processor-specific type. */
+	PT_HIPROC  ProgType = 0x7fffffff /* Last processor-specific type. */
+)
+
+var ptStrings = []intName{
+	{0, "PT_NULL"},
+	{1, "PT_LOAD"},
+	{2, "PT_DYNAMIC"},
+	{3, "PT_INTERP"},
+	{4, "PT_NOTE"},
+	{5, "PT_SHLIB"},
+	{6, "PT_PHDR"},
+	{7, "PT_TLS"},
+	{0x60000000, "PT_LOOS"},
+	{0x6fffffff, "PT_HIOS"},
+	{0x70000000, "PT_LOPROC"},
+	{0x7fffffff, "PT_HIPROC"},
+}
+
+func (i ProgType) String() string   { return stringName(uint32(i), ptStrings, false) }
+func (i ProgType) GoString() string { return stringName(uint32(i), ptStrings, true) }
+
+// Prog.Flag
+type ProgFlag uint32
+
+const (
+	PF_X        ProgFlag = 0x1        /* Executable. */
+	PF_W        ProgFlag = 0x2        /* Writable. */
+	PF_R        ProgFlag = 0x4        /* Readable. */
+	PF_MASKOS   ProgFlag = 0x0ff00000 /* Operating system-specific. */
+	PF_MASKPROC ProgFlag = 0xf0000000 /* Processor-specific. */
+)
+
+var pfStrings = []intName{
+	{0x1, "PF_X"},
+	{0x2, "PF_W"},
+	{0x4, "PF_R"},
+}
+
+func (i ProgFlag) String() string   { return flagName(uint32(i), pfStrings, false) }
+func (i ProgFlag) GoString() string { return flagName(uint32(i), pfStrings, true) }
+
+// Dyn.Tag
+type DynTag int
+
+const (
+	DT_NULL         DynTag = 0  /* Terminating entry. */
+	DT_NEEDED       DynTag = 1  /* String table offset of a needed shared library. */
+	DT_PLTRELSZ     DynTag = 2  /* Total size in bytes of PLT relocations. */
+	DT_PLTGOT       DynTag = 3  /* Processor-dependent address. */
+	DT_HASH         DynTag = 4  /* Address of symbol hash table. */
+	DT_STRTAB       DynTag = 5  /* Address of string table. */
+	DT_SYMTAB       DynTag = 6  /* Address of symbol table. */
+	DT_RELA         DynTag = 7  /* Address of ElfNN_Rela relocations. */
+	DT_RELASZ       DynTag = 8  /* Total size of ElfNN_Rela relocations. */
+	DT_RELAENT      DynTag = 9  /* Size of each ElfNN_Rela relocation entry. */
+	DT_STRSZ        DynTag = 10 /* Size of string table. */
+	DT_SYMENT       DynTag = 11 /* Size of each symbol table entry. */
+	DT_INIT         DynTag = 12 /* Address of initialization function. */
+	DT_FINI         DynTag = 13 /* Address of finalization function. */
+	DT_SONAME       DynTag = 14 /* String table offset of shared object name. */
+	DT_RPATH        DynTag = 15 /* String table offset of library path. [sup] */
+	DT_SYMBOLIC     DynTag = 16 /* Indicates "symbolic" linking. [sup] */
+	DT_REL          DynTag = 17 /* Address of ElfNN_Rel relocations. */
+	DT_RELSZ        DynTag = 18 /* Total size of ElfNN_Rel relocations. */
+	DT_RELENT       DynTag = 19 /* Size of each ElfNN_Rel relocation. */
+	DT_PLTREL       DynTag = 20 /* Type of relocation used for PLT. */
+	DT_DEBUG        DynTag = 21 /* Reserved (not used). */
+	DT_TEXTREL      DynTag = 22 /* Indicates there may be relocations in non-writable segments. [sup] */
+	DT_JMPREL       DynTag = 23 /* Address of PLT relocations. */
+	DT_BIND_NOW     DynTag = 24 /* [sup] */
+	DT_INIT_ARRAY   DynTag = 25 /* Address of the array of pointers to initialization functions */
+	DT_FINI_ARRAY   DynTag = 26 /* Address of the array of pointers to termination functions */
+	DT_INIT_ARRAYSZ DynTag = 27 /* Size in bytes of the array of initialization functions. */
+	DT_FINI_ARRAYSZ DynTag = 28 /* Size in bytes of the array of termination functions. */
+	DT_RUNPATH      DynTag = 29 /* String table offset of a null-terminated library search path string. */
+	DT_FLAGS        DynTag = 30 /* Object specific flag values. */
+	DT_ENCODING     DynTag = 32 /* Values greater than or equal to DT_ENCODING
+	   and less than DT_LOOS follow the rules for
+	   the interpretation of the d_un union
+	   as follows: even == 'd_ptr', even == 'd_val'
+	   or none */
+	DT_PREINIT_ARRAY   DynTag = 32         /* Address of the array of pointers to pre-initialization functions. */
+	DT_PREINIT_ARRAYSZ DynTag = 33         /* Size in bytes of the array of pre-initialization functions. */
+	DT_LOOS            DynTag = 0x6000000d /* First OS-specific */
+	DT_HIOS            DynTag = 0x6ffff000 /* Last OS-specific */
+	DT_VERSYM          DynTag = 0x6ffffff0
+	DT_VERNEED         DynTag = 0x6ffffffe
+	DT_VERNEEDNUM      DynTag = 0x6fffffff
+	DT_LOPROC          DynTag = 0x70000000 /* First processor-specific type. */
+	DT_HIPROC          DynTag = 0x7fffffff /* Last processor-specific type. */
+)
+
+var dtStrings = []intName{
+	{0, "DT_NULL"},
+	{1, "DT_NEEDED"},
+	{2, "DT_PLTRELSZ"},
+	{3, "DT_PLTGOT"},
+	{4, "DT_HASH"},
+	{5, "DT_STRTAB"},
+	{6, "DT_SYMTAB"},
+	{7, "DT_RELA"},
+	{8, "DT_RELASZ"},
+	{9, "DT_RELAENT"},
+	{10, "DT_STRSZ"},
+	{11, "DT_SYMENT"},
+	{12, "DT_INIT"},
+	{13, "DT_FINI"},
+	{14, "DT_SONAME"},
+	{15, "DT_RPATH"},
+	{16, "DT_SYMBOLIC"},
+	{17, "DT_REL"},
+	{18, "DT_RELSZ"},
+	{19, "DT_RELENT"},
+	{20, "DT_PLTREL"},
+	{21, "DT_DEBUG"},
+	{22, "DT_TEXTREL"},
+	{23, "DT_JMPREL"},
+	{24, "DT_BIND_NOW"},
+	{25, "DT_INIT_ARRAY"},
+	{26, "DT_FINI_ARRAY"},
+	{27, "DT_INIT_ARRAYSZ"},
+	{28, "DT_FINI_ARRAYSZ"},
+	{29, "DT_RUNPATH"},
+	{30, "DT_FLAGS"},
+	{32, "DT_ENCODING"},
+	{32, "DT_PREINIT_ARRAY"},
+	{33, "DT_PREINIT_ARRAYSZ"},
+	{0x6000000d, "DT_LOOS"},
+	{0x6ffff000, "DT_HIOS"},
+	{0x6ffffff0, "DT_VERSYM"},
+	{0x6ffffffe, "DT_VERNEED"},
+	{0x6fffffff, "DT_VERNEEDNUM"},
+	{0x70000000, "DT_LOPROC"},
+	{0x7fffffff, "DT_HIPROC"},
+}
+
+func (i DynTag) String() string   { return stringName(uint32(i), dtStrings, false) }
+func (i DynTag) GoString() string { return stringName(uint32(i), dtStrings, true) }
+
+// DT_FLAGS values.
+type DynFlag int
+
+const (
+	DF_ORIGIN DynFlag = 0x0001 /* Indicates that the object being loaded may
+	   make reference to the
+	   $ORIGIN substitution string */
+	DF_SYMBOLIC DynFlag = 0x0002 /* Indicates "symbolic" linking. */
+	DF_TEXTREL  DynFlag = 0x0004 /* Indicates there may be relocations in non-writable segments. */
+	DF_BIND_NOW DynFlag = 0x0008 /* Indicates that the dynamic linker should
+	   process all relocations for the object
+	   containing this entry before transferring
+	   control to the program. */
+	DF_STATIC_TLS DynFlag = 0x0010 /* Indicates that the shared object or
+	   executable contains code using a static
+	   thread-local storage scheme. */
+)
+
+var dflagStrings = []intName{
+	{0x0001, "DF_ORIGIN"},
+	{0x0002, "DF_SYMBOLIC"},
+	{0x0004, "DF_TEXTREL"},
+	{0x0008, "DF_BIND_NOW"},
+	{0x0010, "DF_STATIC_TLS"},
+}
+
+func (i DynFlag) String() string   { return flagName(uint32(i), dflagStrings, false) }
+func (i DynFlag) GoString() string { return flagName(uint32(i), dflagStrings, true) }
+
+// NType values; used in core files.
+type NType int
+
+const (
+	NT_PRSTATUS NType = 1 /* Process status. */
+	NT_FPREGSET NType = 2 /* Floating point registers. */
+	NT_PRPSINFO NType = 3 /* Process state info. */
+)
+
+var ntypeStrings = []intName{
+	{1, "NT_PRSTATUS"},
+	{2, "NT_FPREGSET"},
+	{3, "NT_PRPSINFO"},
+}
+
+func (i NType) String() string   { return stringName(uint32(i), ntypeStrings, false) }
+func (i NType) GoString() string { return stringName(uint32(i), ntypeStrings, true) }
+
+/* Symbol Binding - ELFNN_ST_BIND - st_info */
+type SymBind int
+
+const (
+	STB_LOCAL  SymBind = 0  /* Local symbol */
+	STB_GLOBAL SymBind = 1  /* Global symbol */
+	STB_WEAK   SymBind = 2  /* like global - lower precedence */
+	STB_LOOS   SymBind = 10 /* Reserved range for operating system */
+	STB_HIOS   SymBind = 12 /*   specific semantics. */
+	STB_LOPROC SymBind = 13 /* reserved range for processor */
+	STB_HIPROC SymBind = 15 /*   specific semantics. */
+)
+
+var stbStrings = []intName{
+	{0, "STB_LOCAL"},
+	{1, "STB_GLOBAL"},
+	{2, "STB_WEAK"},
+	{10, "STB_LOOS"},
+	{12, "STB_HIOS"},
+	{13, "STB_LOPROC"},
+	{15, "STB_HIPROC"},
+}
+
+func (i SymBind) String() string   { return stringName(uint32(i), stbStrings, false) }
+func (i SymBind) GoString() string { return stringName(uint32(i), stbStrings, true) }
+
+/* Symbol type - ELFNN_ST_TYPE - st_info */
+type SymType int
+
+const (
+	STT_NOTYPE  SymType = 0  /* Unspecified type. */
+	STT_OBJECT  SymType = 1  /* Data object. */
+	STT_FUNC    SymType = 2  /* Function. */
+	STT_SECTION SymType = 3  /* Section. */
+	STT_FILE    SymType = 4  /* Source file. */
+	STT_COMMON  SymType = 5  /* Uninitialized common block. */
+	STT_TLS     SymType = 6  /* TLS object. */
+	STT_LOOS    SymType = 10 /* Reserved range for operating system */
+	STT_HIOS    SymType = 12 /*   specific semantics. */
+	STT_LOPROC  SymType = 13 /* reserved range for processor */
+	STT_HIPROC  SymType = 15 /*   specific semantics. */
+)
+
+var sttStrings = []intName{
+	{0, "STT_NOTYPE"},
+	{1, "STT_OBJECT"},
+	{2, "STT_FUNC"},
+	{3, "STT_SECTION"},
+	{4, "STT_FILE"},
+	{5, "STT_COMMON"},
+	{6, "STT_TLS"},
+	{10, "STT_LOOS"},
+	{12, "STT_HIOS"},
+	{13, "STT_LOPROC"},
+	{15, "STT_HIPROC"},
+}
+
+func (i SymType) String() string   { return stringName(uint32(i), sttStrings, false) }
+func (i SymType) GoString() string { return stringName(uint32(i), sttStrings, true) }
+
+/* Symbol visibility - ELFNN_ST_VISIBILITY - st_other */
+type SymVis int
+
+const (
+	STV_DEFAULT   SymVis = 0x0 /* Default visibility (see binding). */
+	STV_INTERNAL  SymVis = 0x1 /* Special meaning in relocatable objects. */
+	STV_HIDDEN    SymVis = 0x2 /* Not visible. */
+	STV_PROTECTED SymVis = 0x3 /* Visible but not preemptible. */
+)
+
+var stvStrings = []intName{
+	{0x0, "STV_DEFAULT"},
+	{0x1, "STV_INTERNAL"},
+	{0x2, "STV_HIDDEN"},
+	{0x3, "STV_PROTECTED"},
+}
+
+func (i SymVis) String() string   { return stringName(uint32(i), stvStrings, false) }
+func (i SymVis) GoString() string { return stringName(uint32(i), stvStrings, true) }
+
+/*
+ * Relocation types.
+ */
+
+// Relocation types for x86-64.
+type R_X86_64 int
+
+const (
+	R_X86_64_NONE     R_X86_64 = 0  /* No relocation. */
+	R_X86_64_64       R_X86_64 = 1  /* Add 64 bit symbol value. */
+	R_X86_64_PC32     R_X86_64 = 2  /* PC-relative 32 bit signed sym value. */
+	R_X86_64_GOT32    R_X86_64 = 3  /* PC-relative 32 bit GOT offset. */
+	R_X86_64_PLT32    R_X86_64 = 4  /* PC-relative 32 bit PLT offset. */
+	R_X86_64_COPY     R_X86_64 = 5  /* Copy data from shared object. */
+	R_X86_64_GLOB_DAT R_X86_64 = 6  /* Set GOT entry to data address. */
+	R_X86_64_JMP_SLOT R_X86_64 = 7  /* Set GOT entry to code address. */
+	R_X86_64_RELATIVE R_X86_64 = 8  /* Add load address of shared object. */
+	R_X86_64_GOTPCREL R_X86_64 = 9  /* Add 32 bit signed pcrel offset to GOT. */
+	R_X86_64_32       R_X86_64 = 10 /* Add 32 bit zero extended symbol value */
+	R_X86_64_32S      R_X86_64 = 11 /* Add 32 bit sign extended symbol value */
+	R_X86_64_16       R_X86_64 = 12 /* Add 16 bit zero extended symbol value */
+	R_X86_64_PC16     R_X86_64 = 13 /* Add 16 bit signed extended pc relative symbol value */
+	R_X86_64_8        R_X86_64 = 14 /* Add 8 bit zero extended symbol value */
+	R_X86_64_PC8      R_X86_64 = 15 /* Add 8 bit signed extended pc relative symbol value */
+	R_X86_64_DTPMOD64 R_X86_64 = 16 /* ID of module containing symbol */
+	R_X86_64_DTPOFF64 R_X86_64 = 17 /* Offset in TLS block */
+	R_X86_64_TPOFF64  R_X86_64 = 18 /* Offset in static TLS block */
+	R_X86_64_TLSGD    R_X86_64 = 19 /* PC relative offset to GD GOT entry */
+	R_X86_64_TLSLD    R_X86_64 = 20 /* PC relative offset to LD GOT entry */
+	R_X86_64_DTPOFF32 R_X86_64 = 21 /* Offset in TLS block */
+	R_X86_64_GOTTPOFF R_X86_64 = 22 /* PC relative offset to IE GOT entry */
+	R_X86_64_TPOFF32  R_X86_64 = 23 /* Offset in static TLS block */
+)
+
+var rx86_64Strings = []intName{
+	{0, "R_X86_64_NONE"},
+	{1, "R_X86_64_64"},
+	{2, "R_X86_64_PC32"},
+	{3, "R_X86_64_GOT32"},
+	{4, "R_X86_64_PLT32"},
+	{5, "R_X86_64_COPY"},
+	{6, "R_X86_64_GLOB_DAT"},
+	{7, "R_X86_64_JMP_SLOT"},
+	{8, "R_X86_64_RELATIVE"},
+	{9, "R_X86_64_GOTPCREL"},
+	{10, "R_X86_64_32"},
+	{11, "R_X86_64_32S"},
+	{12, "R_X86_64_16"},
+	{13, "R_X86_64_PC16"},
+	{14, "R_X86_64_8"},
+	{15, "R_X86_64_PC8"},
+	{16, "R_X86_64_DTPMOD64"},
+	{17, "R_X86_64_DTPOFF64"},
+	{18, "R_X86_64_TPOFF64"},
+	{19, "R_X86_64_TLSGD"},
+	{20, "R_X86_64_TLSLD"},
+	{21, "R_X86_64_DTPOFF32"},
+	{22, "R_X86_64_GOTTPOFF"},
+	{23, "R_X86_64_TPOFF32"},
+}
+
+func (i R_X86_64) String() string   { return stringName(uint32(i), rx86_64Strings, false) }
+func (i R_X86_64) GoString() string { return stringName(uint32(i), rx86_64Strings, true) }
+
+// Relocation types for AArch64 (aka arm64)
+type R_AARCH64 int
+
+const (
+	R_AARCH64_NONE                            R_AARCH64 = 0
+	R_AARCH64_P32_ABS32                       R_AARCH64 = 1
+	R_AARCH64_P32_ABS16                       R_AARCH64 = 2
+	R_AARCH64_P32_PREL32                      R_AARCH64 = 3
+	R_AARCH64_P32_PREL16                      R_AARCH64 = 4
+	R_AARCH64_P32_MOVW_UABS_G0                R_AARCH64 = 5
+	R_AARCH64_P32_MOVW_UABS_G0_NC             R_AARCH64 = 6
+	R_AARCH64_P32_MOVW_UABS_G1                R_AARCH64 = 7
+	R_AARCH64_P32_MOVW_SABS_G0                R_AARCH64 = 8
+	R_AARCH64_P32_LD_PREL_LO19                R_AARCH64 = 9
+	R_AARCH64_P32_ADR_PREL_LO21               R_AARCH64 = 10
+	R_AARCH64_P32_ADR_PREL_PG_HI21            R_AARCH64 = 11
+	R_AARCH64_P32_ADD_ABS_LO12_NC             R_AARCH64 = 12
+	R_AARCH64_P32_LDST8_ABS_LO12_NC           R_AARCH64 = 13
+	R_AARCH64_P32_LDST16_ABS_LO12_NC          R_AARCH64 = 14
+	R_AARCH64_P32_LDST32_ABS_LO12_NC          R_AARCH64 = 15
+	R_AARCH64_P32_LDST64_ABS_LO12_NC          R_AARCH64 = 16
+	R_AARCH64_P32_LDST128_ABS_LO12_NC         R_AARCH64 = 17
+	R_AARCH64_P32_TSTBR14                     R_AARCH64 = 18
+	R_AARCH64_P32_CONDBR19                    R_AARCH64 = 19
+	R_AARCH64_P32_JUMP26                      R_AARCH64 = 20
+	R_AARCH64_P32_CALL26                      R_AARCH64 = 21
+	R_AARCH64_P32_GOT_LD_PREL19               R_AARCH64 = 25
+	R_AARCH64_P32_ADR_GOT_PAGE                R_AARCH64 = 26
+	R_AARCH64_P32_LD32_GOT_LO12_NC            R_AARCH64 = 27
+	R_AARCH64_P32_TLSGD_ADR_PAGE21            R_AARCH64 = 81
+	R_AARCH64_P32_TLSGD_ADD_LO12_NC           R_AARCH64 = 82
+	R_AARCH64_P32_TLSIE_ADR_GOTTPREL_PAGE21   R_AARCH64 = 103
+	R_AARCH64_P32_TLSIE_LD32_GOTTPREL_LO12_NC R_AARCH64 = 104
+	R_AARCH64_P32_TLSIE_LD_GOTTPREL_PREL19    R_AARCH64 = 105
+	R_AARCH64_P32_TLSLE_MOVW_TPREL_G1         R_AARCH64 = 106
+	R_AARCH64_P32_TLSLE_MOVW_TPREL_G0         R_AARCH64 = 107
+	R_AARCH64_P32_TLSLE_MOVW_TPREL_G0_NC      R_AARCH64 = 108
+	R_AARCH64_P32_TLSLE_ADD_TPREL_HI12        R_AARCH64 = 109
+	R_AARCH64_P32_TLSLE_ADD_TPREL_LO12        R_AARCH64 = 110
+	R_AARCH64_P32_TLSLE_ADD_TPREL_LO12_NC     R_AARCH64 = 111
+	R_AARCH64_P32_TLSDESC_LD_PREL19           R_AARCH64 = 122
+	R_AARCH64_P32_TLSDESC_ADR_PREL21          R_AARCH64 = 123
+	R_AARCH64_P32_TLSDESC_ADR_PAGE21          R_AARCH64 = 124
+	R_AARCH64_P32_TLSDESC_LD32_LO12_NC        R_AARCH64 = 125
+	R_AARCH64_P32_TLSDESC_ADD_LO12_NC         R_AARCH64 = 126
+	R_AARCH64_P32_TLSDESC_CALL                R_AARCH64 = 127
+	R_AARCH64_P32_COPY                        R_AARCH64 = 180
+	R_AARCH64_P32_GLOB_DAT                    R_AARCH64 = 181
+	R_AARCH64_P32_JUMP_SLOT                   R_AARCH64 = 182
+	R_AARCH64_P32_RELATIVE                    R_AARCH64 = 183
+	R_AARCH64_P32_TLS_DTPMOD                  R_AARCH64 = 184
+	R_AARCH64_P32_TLS_DTPREL                  R_AARCH64 = 185
+	R_AARCH64_P32_TLS_TPREL                   R_AARCH64 = 186
+	R_AARCH64_P32_TLSDESC                     R_AARCH64 = 187
+	R_AARCH64_P32_IRELATIVE                   R_AARCH64 = 188
+	R_AARCH64_NULL                            R_AARCH64 = 256
+	R_AARCH64_ABS64                           R_AARCH64 = 257
+	R_AARCH64_ABS32                           R_AARCH64 = 258
+	R_AARCH64_ABS16                           R_AARCH64 = 259
+	R_AARCH64_PREL64                          R_AARCH64 = 260
+	R_AARCH64_PREL32                          R_AARCH64 = 261
+	R_AARCH64_PREL16                          R_AARCH64 = 262
+	R_AARCH64_MOVW_UABS_G0                    R_AARCH64 = 263
+	R_AARCH64_MOVW_UABS_G0_NC                 R_AARCH64 = 264
+	R_AARCH64_MOVW_UABS_G1                    R_AARCH64 = 265
+	R_AARCH64_MOVW_UABS_G1_NC                 R_AARCH64 = 266
+	R_AARCH64_MOVW_UABS_G2                    R_AARCH64 = 267
+	R_AARCH64_MOVW_UABS_G2_NC                 R_AARCH64 = 268
+	R_AARCH64_MOVW_UABS_G3                    R_AARCH64 = 269
+	R_AARCH64_MOVW_SABS_G0                    R_AARCH64 = 270
+	R_AARCH64_MOVW_SABS_G1                    R_AARCH64 = 271
+	R_AARCH64_MOVW_SABS_G2                    R_AARCH64 = 272
+	R_AARCH64_LD_PREL_LO19                    R_AARCH64 = 273
+	R_AARCH64_ADR_PREL_LO21                   R_AARCH64 = 274
+	R_AARCH64_ADR_PREL_PG_HI21                R_AARCH64 = 275
+	R_AARCH64_ADR_PREL_PG_HI21_NC             R_AARCH64 = 276
+	R_AARCH64_ADD_ABS_LO12_NC                 R_AARCH64 = 277
+	R_AARCH64_LDST8_ABS_LO12_NC               R_AARCH64 = 278
+	R_AARCH64_TSTBR14                         R_AARCH64 = 279
+	R_AARCH64_CONDBR19                        R_AARCH64 = 280
+	R_AARCH64_JUMP26                          R_AARCH64 = 282
+	R_AARCH64_CALL26                          R_AARCH64 = 283
+	R_AARCH64_LDST16_ABS_LO12_NC              R_AARCH64 = 284
+	R_AARCH64_LDST32_ABS_LO12_NC              R_AARCH64 = 285
+	R_AARCH64_LDST64_ABS_LO12_NC              R_AARCH64 = 286
+	R_AARCH64_LDST128_ABS_LO12_NC             R_AARCH64 = 299
+	R_AARCH64_GOT_LD_PREL19                   R_AARCH64 = 309
+	R_AARCH64_ADR_GOT_PAGE                    R_AARCH64 = 311
+	R_AARCH64_LD64_GOT_LO12_NC                R_AARCH64 = 312
+	R_AARCH64_TLSGD_ADR_PAGE21                R_AARCH64 = 513
+	R_AARCH64_TLSGD_ADD_LO12_NC               R_AARCH64 = 514
+	R_AARCH64_TLSIE_MOVW_GOTTPREL_G1          R_AARCH64 = 539
+	R_AARCH64_TLSIE_MOVW_GOTTPREL_G0_NC       R_AARCH64 = 540
+	R_AARCH64_TLSIE_ADR_GOTTPREL_PAGE21       R_AARCH64 = 541
+	R_AARCH64_TLSIE_LD64_GOTTPREL_LO12_NC     R_AARCH64 = 542
+	R_AARCH64_TLSIE_LD_GOTTPREL_PREL19        R_AARCH64 = 543
+	R_AARCH64_TLSLE_MOVW_TPREL_G2             R_AARCH64 = 544
+	R_AARCH64_TLSLE_MOVW_TPREL_G1             R_AARCH64 = 545
+	R_AARCH64_TLSLE_MOVW_TPREL_G1_NC          R_AARCH64 = 546
+	R_AARCH64_TLSLE_MOVW_TPREL_G0             R_AARCH64 = 547
+	R_AARCH64_TLSLE_MOVW_TPREL_G0_NC          R_AARCH64 = 548
+	R_AARCH64_TLSLE_ADD_TPREL_HI12            R_AARCH64 = 549
+	R_AARCH64_TLSLE_ADD_TPREL_LO12            R_AARCH64 = 550
+	R_AARCH64_TLSLE_ADD_TPREL_LO12_NC         R_AARCH64 = 551
+	R_AARCH64_TLSDESC_LD_PREL19               R_AARCH64 = 560
+	R_AARCH64_TLSDESC_ADR_PREL21              R_AARCH64 = 561
+	R_AARCH64_TLSDESC_ADR_PAGE21              R_AARCH64 = 562
+	R_AARCH64_TLSDESC_LD64_LO12_NC            R_AARCH64 = 563
+	R_AARCH64_TLSDESC_ADD_LO12_NC             R_AARCH64 = 564
+	R_AARCH64_TLSDESC_OFF_G1                  R_AARCH64 = 565
+	R_AARCH64_TLSDESC_OFF_G0_NC               R_AARCH64 = 566
+	R_AARCH64_TLSDESC_LDR                     R_AARCH64 = 567
+	R_AARCH64_TLSDESC_ADD                     R_AARCH64 = 568
+	R_AARCH64_TLSDESC_CALL                    R_AARCH64 = 569
+	R_AARCH64_COPY                            R_AARCH64 = 1024
+	R_AARCH64_GLOB_DAT                        R_AARCH64 = 1025
+	R_AARCH64_JUMP_SLOT                       R_AARCH64 = 1026
+	R_AARCH64_RELATIVE                        R_AARCH64 = 1027
+	R_AARCH64_TLS_DTPMOD64                    R_AARCH64 = 1028
+	R_AARCH64_TLS_DTPREL64                    R_AARCH64 = 1029
+	R_AARCH64_TLS_TPREL64                     R_AARCH64 = 1030
+	R_AARCH64_TLSDESC                         R_AARCH64 = 1031
+	R_AARCH64_IRELATIVE                       R_AARCH64 = 1032
+)
+
+var raarch64Strings = []intName{
+	{0, "R_AARCH64_NONE"},
+	{1, "R_AARCH64_P32_ABS32"},
+	{2, "R_AARCH64_P32_ABS16"},
+	{3, "R_AARCH64_P32_PREL32"},
+	{4, "R_AARCH64_P32_PREL16"},
+	{5, "R_AARCH64_P32_MOVW_UABS_G0"},
+	{6, "R_AARCH64_P32_MOVW_UABS_G0_NC"},
+	{7, "R_AARCH64_P32_MOVW_UABS_G1"},
+	{8, "R_AARCH64_P32_MOVW_SABS_G0"},
+	{9, "R_AARCH64_P32_LD_PREL_LO19"},
+	{10, "R_AARCH64_P32_ADR_PREL_LO21"},
+	{11, "R_AARCH64_P32_ADR_PREL_PG_HI21"},
+	{12, "R_AARCH64_P32_ADD_ABS_LO12_NC"},
+	{13, "R_AARCH64_P32_LDST8_ABS_LO12_NC"},
+	{14, "R_AARCH64_P32_LDST16_ABS_LO12_NC"},
+	{15, "R_AARCH64_P32_LDST32_ABS_LO12_NC"},
+	{16, "R_AARCH64_P32_LDST64_ABS_LO12_NC"},
+	{17, "R_AARCH64_P32_LDST128_ABS_LO12_NC"},
+	{18, "R_AARCH64_P32_TSTBR14"},
+	{19, "R_AARCH64_P32_CONDBR19"},
+	{20, "R_AARCH64_P32_JUMP26"},
+	{21, "R_AARCH64_P32_CALL26"},
+	{25, "R_AARCH64_P32_GOT_LD_PREL19"},
+	{26, "R_AARCH64_P32_ADR_GOT_PAGE"},
+	{27, "R_AARCH64_P32_LD32_GOT_LO12_NC"},
+	{81, "R_AARCH64_P32_TLSGD_ADR_PAGE21"},
+	{82, "R_AARCH64_P32_TLSGD_ADD_LO12_NC"},
+	{103, "R_AARCH64_P32_TLSIE_ADR_GOTTPREL_PAGE21"},
+	{104, "R_AARCH64_P32_TLSIE_LD32_GOTTPREL_LO12_NC"},
+	{105, "R_AARCH64_P32_TLSIE_LD_GOTTPREL_PREL19"},
+	{106, "R_AARCH64_P32_TLSLE_MOVW_TPREL_G1"},
+	{107, "R_AARCH64_P32_TLSLE_MOVW_TPREL_G0"},
+	{108, "R_AARCH64_P32_TLSLE_MOVW_TPREL_G0_NC"},
+	{109, "R_AARCH64_P32_TLSLE_ADD_TPREL_HI12"},
+	{110, "R_AARCH64_P32_TLSLE_ADD_TPREL_LO12"},
+	{111, "R_AARCH64_P32_TLSLE_ADD_TPREL_LO12_NC"},
+	{122, "R_AARCH64_P32_TLSDESC_LD_PREL19"},
+	{123, "R_AARCH64_P32_TLSDESC_ADR_PREL21"},
+	{124, "R_AARCH64_P32_TLSDESC_ADR_PAGE21"},
+	{125, "R_AARCH64_P32_TLSDESC_LD32_LO12_NC"},
+	{126, "R_AARCH64_P32_TLSDESC_ADD_LO12_NC"},
+	{127, "R_AARCH64_P32_TLSDESC_CALL"},
+	{180, "R_AARCH64_P32_COPY"},
+	{181, "R_AARCH64_P32_GLOB_DAT"},
+	{182, "R_AARCH64_P32_JUMP_SLOT"},
+	{183, "R_AARCH64_P32_RELATIVE"},
+	{184, "R_AARCH64_P32_TLS_DTPMOD"},
+	{185, "R_AARCH64_P32_TLS_DTPREL"},
+	{186, "R_AARCH64_P32_TLS_TPREL"},
+	{187, "R_AARCH64_P32_TLSDESC"},
+	{188, "R_AARCH64_P32_IRELATIVE"},
+	{256, "R_AARCH64_NULL"},
+	{257, "R_AARCH64_ABS64"},
+	{258, "R_AARCH64_ABS32"},
+	{259, "R_AARCH64_ABS16"},
+	{260, "R_AARCH64_PREL64"},
+	{261, "R_AARCH64_PREL32"},
+	{262, "R_AARCH64_PREL16"},
+	{263, "R_AARCH64_MOVW_UABS_G0"},
+	{264, "R_AARCH64_MOVW_UABS_G0_NC"},
+	{265, "R_AARCH64_MOVW_UABS_G1"},
+	{266, "R_AARCH64_MOVW_UABS_G1_NC"},
+	{267, "R_AARCH64_MOVW_UABS_G2"},
+	{268, "R_AARCH64_MOVW_UABS_G2_NC"},
+	{269, "R_AARCH64_MOVW_UABS_G3"},
+	{270, "R_AARCH64_MOVW_SABS_G0"},
+	{271, "R_AARCH64_MOVW_SABS_G1"},
+	{272, "R_AARCH64_MOVW_SABS_G2"},
+	{273, "R_AARCH64_LD_PREL_LO19"},
+	{274, "R_AARCH64_ADR_PREL_LO21"},
+	{275, "R_AARCH64_ADR_PREL_PG_HI21"},
+	{276, "R_AARCH64_ADR_PREL_PG_HI21_NC"},
+	{277, "R_AARCH64_ADD_ABS_LO12_NC"},
+	{278, "R_AARCH64_LDST8_ABS_LO12_NC"},
+	{279, "R_AARCH64_TSTBR14"},
+	{280, "R_AARCH64_CONDBR19"},
+	{282, "R_AARCH64_JUMP26"},
+	{283, "R_AARCH64_CALL26"},
+	{284, "R_AARCH64_LDST16_ABS_LO12_NC"},
+	{285, "R_AARCH64_LDST32_ABS_LO12_NC"},
+	{286, "R_AARCH64_LDST64_ABS_LO12_NC"},
+	{299, "R_AARCH64_LDST128_ABS_LO12_NC"},
+	{309, "R_AARCH64_GOT_LD_PREL19"},
+	{311, "R_AARCH64_ADR_GOT_PAGE"},
+	{312, "R_AARCH64_LD64_GOT_LO12_NC"},
+	{513, "R_AARCH64_TLSGD_ADR_PAGE21"},
+	{514, "R_AARCH64_TLSGD_ADD_LO12_NC"},
+	{539, "R_AARCH64_TLSIE_MOVW_GOTTPREL_G1"},
+	{540, "R_AARCH64_TLSIE_MOVW_GOTTPREL_G0_NC"},
+	{541, "R_AARCH64_TLSIE_ADR_GOTTPREL_PAGE21"},
+	{542, "R_AARCH64_TLSIE_LD64_GOTTPREL_LO12_NC"},
+	{543, "R_AARCH64_TLSIE_LD_GOTTPREL_PREL19"},
+	{544, "R_AARCH64_TLSLE_MOVW_TPREL_G2"},
+	{545, "R_AARCH64_TLSLE_MOVW_TPREL_G1"},
+	{546, "R_AARCH64_TLSLE_MOVW_TPREL_G1_NC"},
+	{547, "R_AARCH64_TLSLE_MOVW_TPREL_G0"},
+	{548, "R_AARCH64_TLSLE_MOVW_TPREL_G0_NC"},
+	{549, "R_AARCH64_TLSLE_ADD_TPREL_HI12"},
+	{550, "R_AARCH64_TLSLE_ADD_TPREL_LO12"},
+	{551, "R_AARCH64_TLSLE_ADD_TPREL_LO12_NC"},
+	{560, "R_AARCH64_TLSDESC_LD_PREL19"},
+	{561, "R_AARCH64_TLSDESC_ADR_PREL21"},
+	{562, "R_AARCH64_TLSDESC_ADR_PAGE21"},
+	{563, "R_AARCH64_TLSDESC_LD64_LO12_NC"},
+	{564, "R_AARCH64_TLSDESC_ADD_LO12_NC"},
+	{565, "R_AARCH64_TLSDESC_OFF_G1"},
+	{566, "R_AARCH64_TLSDESC_OFF_G0_NC"},
+	{567, "R_AARCH64_TLSDESC_LDR"},
+	{568, "R_AARCH64_TLSDESC_ADD"},
+	{569, "R_AARCH64_TLSDESC_CALL"},
+	{1024, "R_AARCH64_COPY"},
+	{1025, "R_AARCH64_GLOB_DAT"},
+	{1026, "R_AARCH64_JUMP_SLOT"},
+	{1027, "R_AARCH64_RELATIVE"},
+	{1028, "R_AARCH64_TLS_DTPMOD64"},
+	{1029, "R_AARCH64_TLS_DTPREL64"},
+	{1030, "R_AARCH64_TLS_TPREL64"},
+	{1031, "R_AARCH64_TLSDESC"},
+	{1032, "R_AARCH64_IRELATIVE"},
+}
+
+func (i R_AARCH64) String() string   { return stringName(uint32(i), raarch64Strings, false) }
+func (i R_AARCH64) GoString() string { return stringName(uint32(i), raarch64Strings, true) }
+
+// Relocation types for Alpha.
+type R_ALPHA int
+
+const (
+	R_ALPHA_NONE           R_ALPHA = 0  /* No reloc */
+	R_ALPHA_REFLONG        R_ALPHA = 1  /* Direct 32 bit */
+	R_ALPHA_REFQUAD        R_ALPHA = 2  /* Direct 64 bit */
+	R_ALPHA_GPREL32        R_ALPHA = 3  /* GP relative 32 bit */
+	R_ALPHA_LITERAL        R_ALPHA = 4  /* GP relative 16 bit w/optimization */
+	R_ALPHA_LITUSE         R_ALPHA = 5  /* Optimization hint for LITERAL */
+	R_ALPHA_GPDISP         R_ALPHA = 6  /* Add displacement to GP */
+	R_ALPHA_BRADDR         R_ALPHA = 7  /* PC+4 relative 23 bit shifted */
+	R_ALPHA_HINT           R_ALPHA = 8  /* PC+4 relative 16 bit shifted */
+	R_ALPHA_SREL16         R_ALPHA = 9  /* PC relative 16 bit */
+	R_ALPHA_SREL32         R_ALPHA = 10 /* PC relative 32 bit */
+	R_ALPHA_SREL64         R_ALPHA = 11 /* PC relative 64 bit */
+	R_ALPHA_OP_PUSH        R_ALPHA = 12 /* OP stack push */
+	R_ALPHA_OP_STORE       R_ALPHA = 13 /* OP stack pop and store */
+	R_ALPHA_OP_PSUB        R_ALPHA = 14 /* OP stack subtract */
+	R_ALPHA_OP_PRSHIFT     R_ALPHA = 15 /* OP stack right shift */
+	R_ALPHA_GPVALUE        R_ALPHA = 16
+	R_ALPHA_GPRELHIGH      R_ALPHA = 17
+	R_ALPHA_GPRELLOW       R_ALPHA = 18
+	R_ALPHA_IMMED_GP_16    R_ALPHA = 19
+	R_ALPHA_IMMED_GP_HI32  R_ALPHA = 20
+	R_ALPHA_IMMED_SCN_HI32 R_ALPHA = 21
+	R_ALPHA_IMMED_BR_HI32  R_ALPHA = 22
+	R_ALPHA_IMMED_LO32     R_ALPHA = 23
+	R_ALPHA_COPY           R_ALPHA = 24 /* Copy symbol at runtime */
+	R_ALPHA_GLOB_DAT       R_ALPHA = 25 /* Create GOT entry */
+	R_ALPHA_JMP_SLOT       R_ALPHA = 26 /* Create PLT entry */
+	R_ALPHA_RELATIVE       R_ALPHA = 27 /* Adjust by program base */
+)
+
+var ralphaStrings = []intName{
+	{0, "R_ALPHA_NONE"},
+	{1, "R_ALPHA_REFLONG"},
+	{2, "R_ALPHA_REFQUAD"},
+	{3, "R_ALPHA_GPREL32"},
+	{4, "R_ALPHA_LITERAL"},
+	{5, "R_ALPHA_LITUSE"},
+	{6, "R_ALPHA_GPDISP"},
+	{7, "R_ALPHA_BRADDR"},
+	{8, "R_ALPHA_HINT"},
+	{9, "R_ALPHA_SREL16"},
+	{10, "R_ALPHA_SREL32"},
+	{11, "R_ALPHA_SREL64"},
+	{12, "R_ALPHA_OP_PUSH"},
+	{13, "R_ALPHA_OP_STORE"},
+	{14, "R_ALPHA_OP_PSUB"},
+	{15, "R_ALPHA_OP_PRSHIFT"},
+	{16, "R_ALPHA_GPVALUE"},
+	{17, "R_ALPHA_GPRELHIGH"},
+	{18, "R_ALPHA_GPRELLOW"},
+	{19, "R_ALPHA_IMMED_GP_16"},
+	{20, "R_ALPHA_IMMED_GP_HI32"},
+	{21, "R_ALPHA_IMMED_SCN_HI32"},
+	{22, "R_ALPHA_IMMED_BR_HI32"},
+	{23, "R_ALPHA_IMMED_LO32"},
+	{24, "R_ALPHA_COPY"},
+	{25, "R_ALPHA_GLOB_DAT"},
+	{26, "R_ALPHA_JMP_SLOT"},
+	{27, "R_ALPHA_RELATIVE"},
+}
+
+func (i R_ALPHA) String() string   { return stringName(uint32(i), ralphaStrings, false) }
+func (i R_ALPHA) GoString() string { return stringName(uint32(i), ralphaStrings, true) }
+
+// Relocation types for ARM.
+type R_ARM int
+
+const (
+	R_ARM_NONE          R_ARM = 0 /* No relocation. */
+	R_ARM_PC24          R_ARM = 1
+	R_ARM_ABS32         R_ARM = 2
+	R_ARM_REL32         R_ARM = 3
+	R_ARM_PC13          R_ARM = 4
+	R_ARM_ABS16         R_ARM = 5
+	R_ARM_ABS12         R_ARM = 6
+	R_ARM_THM_ABS5      R_ARM = 7
+	R_ARM_ABS8          R_ARM = 8
+	R_ARM_SBREL32       R_ARM = 9
+	R_ARM_THM_PC22      R_ARM = 10
+	R_ARM_THM_PC8       R_ARM = 11
+	R_ARM_AMP_VCALL9    R_ARM = 12
+	R_ARM_SWI24         R_ARM = 13
+	R_ARM_THM_SWI8      R_ARM = 14
+	R_ARM_XPC25         R_ARM = 15
+	R_ARM_THM_XPC22     R_ARM = 16
+	R_ARM_COPY          R_ARM = 20 /* Copy data from shared object. */
+	R_ARM_GLOB_DAT      R_ARM = 21 /* Set GOT entry to data address. */
+	R_ARM_JUMP_SLOT     R_ARM = 22 /* Set GOT entry to code address. */
+	R_ARM_RELATIVE      R_ARM = 23 /* Add load address of shared object. */
+	R_ARM_GOTOFF        R_ARM = 24 /* Add GOT-relative symbol address. */
+	R_ARM_GOTPC         R_ARM = 25 /* Add PC-relative GOT table address. */
+	R_ARM_GOT32         R_ARM = 26 /* Add PC-relative GOT offset. */
+	R_ARM_PLT32         R_ARM = 27 /* Add PC-relative PLT offset. */
+	R_ARM_GNU_VTENTRY   R_ARM = 100
+	R_ARM_GNU_VTINHERIT R_ARM = 101
+	R_ARM_RSBREL32      R_ARM = 250
+	R_ARM_THM_RPC22     R_ARM = 251
+	R_ARM_RREL32        R_ARM = 252
+	R_ARM_RABS32        R_ARM = 253
+	R_ARM_RPC24         R_ARM = 254
+	R_ARM_RBASE         R_ARM = 255
+)
+
+var rarmStrings = []intName{
+	{0, "R_ARM_NONE"},
+	{1, "R_ARM_PC24"},
+	{2, "R_ARM_ABS32"},
+	{3, "R_ARM_REL32"},
+	{4, "R_ARM_PC13"},
+	{5, "R_ARM_ABS16"},
+	{6, "R_ARM_ABS12"},
+	{7, "R_ARM_THM_ABS5"},
+	{8, "R_ARM_ABS8"},
+	{9, "R_ARM_SBREL32"},
+	{10, "R_ARM_THM_PC22"},
+	{11, "R_ARM_THM_PC8"},
+	{12, "R_ARM_AMP_VCALL9"},
+	{13, "R_ARM_SWI24"},
+	{14, "R_ARM_THM_SWI8"},
+	{15, "R_ARM_XPC25"},
+	{16, "R_ARM_THM_XPC22"},
+	{20, "R_ARM_COPY"},
+	{21, "R_ARM_GLOB_DAT"},
+	{22, "R_ARM_JUMP_SLOT"},
+	{23, "R_ARM_RELATIVE"},
+	{24, "R_ARM_GOTOFF"},
+	{25, "R_ARM_GOTPC"},
+	{26, "R_ARM_GOT32"},
+	{27, "R_ARM_PLT32"},
+	{100, "R_ARM_GNU_VTENTRY"},
+	{101, "R_ARM_GNU_VTINHERIT"},
+	{250, "R_ARM_RSBREL32"},
+	{251, "R_ARM_THM_RPC22"},
+	{252, "R_ARM_RREL32"},
+	{253, "R_ARM_RABS32"},
+	{254, "R_ARM_RPC24"},
+	{255, "R_ARM_RBASE"},
+}
+
+func (i R_ARM) String() string   { return stringName(uint32(i), rarmStrings, false) }
+func (i R_ARM) GoString() string { return stringName(uint32(i), rarmStrings, true) }
+
+// Relocation types for 386.
+type R_386 int
+
+const (
+	R_386_NONE         R_386 = 0  /* No relocation. */
+	R_386_32           R_386 = 1  /* Add symbol value. */
+	R_386_PC32         R_386 = 2  /* Add PC-relative symbol value. */
+	R_386_GOT32        R_386 = 3  /* Add PC-relative GOT offset. */
+	R_386_PLT32        R_386 = 4  /* Add PC-relative PLT offset. */
+	R_386_COPY         R_386 = 5  /* Copy data from shared object. */
+	R_386_GLOB_DAT     R_386 = 6  /* Set GOT entry to data address. */
+	R_386_JMP_SLOT     R_386 = 7  /* Set GOT entry to code address. */
+	R_386_RELATIVE     R_386 = 8  /* Add load address of shared object. */
+	R_386_GOTOFF       R_386 = 9  /* Add GOT-relative symbol address. */
+	R_386_GOTPC        R_386 = 10 /* Add PC-relative GOT table address. */
+	R_386_TLS_TPOFF    R_386 = 14 /* Negative offset in static TLS block */
+	R_386_TLS_IE       R_386 = 15 /* Absolute address of GOT for -ve static TLS */
+	R_386_TLS_GOTIE    R_386 = 16 /* GOT entry for negative static TLS block */
+	R_386_TLS_LE       R_386 = 17 /* Negative offset relative to static TLS */
+	R_386_TLS_GD       R_386 = 18 /* 32 bit offset to GOT (index,off) pair */
+	R_386_TLS_LDM      R_386 = 19 /* 32 bit offset to GOT (index,zero) pair */
+	R_386_TLS_GD_32    R_386 = 24 /* 32 bit offset to GOT (index,off) pair */
+	R_386_TLS_GD_PUSH  R_386 = 25 /* pushl instruction for Sun ABI GD sequence */
+	R_386_TLS_GD_CALL  R_386 = 26 /* call instruction for Sun ABI GD sequence */
+	R_386_TLS_GD_POP   R_386 = 27 /* popl instruction for Sun ABI GD sequence */
+	R_386_TLS_LDM_32   R_386 = 28 /* 32 bit offset to GOT (index,zero) pair */
+	R_386_TLS_LDM_PUSH R_386 = 29 /* pushl instruction for Sun ABI LD sequence */
+	R_386_TLS_LDM_CALL R_386 = 30 /* call instruction for Sun ABI LD sequence */
+	R_386_TLS_LDM_POP  R_386 = 31 /* popl instruction for Sun ABI LD sequence */
+	R_386_TLS_LDO_32   R_386 = 32 /* 32 bit offset from start of TLS block */
+	R_386_TLS_IE_32    R_386 = 33 /* 32 bit offset to GOT static TLS offset entry */
+	R_386_TLS_LE_32    R_386 = 34 /* 32 bit offset within static TLS block */
+	R_386_TLS_DTPMOD32 R_386 = 35 /* GOT entry containing TLS index */
+	R_386_TLS_DTPOFF32 R_386 = 36 /* GOT entry containing TLS offset */
+	R_386_TLS_TPOFF32  R_386 = 37 /* GOT entry of -ve static TLS offset */
+)
+
+var r386Strings = []intName{
+	{0, "R_386_NONE"},
+	{1, "R_386_32"},
+	{2, "R_386_PC32"},
+	{3, "R_386_GOT32"},
+	{4, "R_386_PLT32"},
+	{5, "R_386_COPY"},
+	{6, "R_386_GLOB_DAT"},
+	{7, "R_386_JMP_SLOT"},
+	{8, "R_386_RELATIVE"},
+	{9, "R_386_GOTOFF"},
+	{10, "R_386_GOTPC"},
+	{14, "R_386_TLS_TPOFF"},
+	{15, "R_386_TLS_IE"},
+	{16, "R_386_TLS_GOTIE"},
+	{17, "R_386_TLS_LE"},
+	{18, "R_386_TLS_GD"},
+	{19, "R_386_TLS_LDM"},
+	{24, "R_386_TLS_GD_32"},
+	{25, "R_386_TLS_GD_PUSH"},
+	{26, "R_386_TLS_GD_CALL"},
+	{27, "R_386_TLS_GD_POP"},
+	{28, "R_386_TLS_LDM_32"},
+	{29, "R_386_TLS_LDM_PUSH"},
+	{30, "R_386_TLS_LDM_CALL"},
+	{31, "R_386_TLS_LDM_POP"},
+	{32, "R_386_TLS_LDO_32"},
+	{33, "R_386_TLS_IE_32"},
+	{34, "R_386_TLS_LE_32"},
+	{35, "R_386_TLS_DTPMOD32"},
+	{36, "R_386_TLS_DTPOFF32"},
+	{37, "R_386_TLS_TPOFF32"},
+}
+
+func (i R_386) String() string   { return stringName(uint32(i), r386Strings, false) }
+func (i R_386) GoString() string { return stringName(uint32(i), r386Strings, true) }
+
+// Relocation types for PowerPC.
+type R_PPC int
+
+const (
+	R_PPC_NONE            R_PPC = 0 /* No relocation. */
+	R_PPC_ADDR32          R_PPC = 1
+	R_PPC_ADDR24          R_PPC = 2
+	R_PPC_ADDR16          R_PPC = 3
+	R_PPC_ADDR16_LO       R_PPC = 4
+	R_PPC_ADDR16_HI       R_PPC = 5
+	R_PPC_ADDR16_HA       R_PPC = 6
+	R_PPC_ADDR14          R_PPC = 7
+	R_PPC_ADDR14_BRTAKEN  R_PPC = 8
+	R_PPC_ADDR14_BRNTAKEN R_PPC = 9
+	R_PPC_REL24           R_PPC = 10
+	R_PPC_REL14           R_PPC = 11
+	R_PPC_REL14_BRTAKEN   R_PPC = 12
+	R_PPC_REL14_BRNTAKEN  R_PPC = 13
+	R_PPC_GOT16           R_PPC = 14
+	R_PPC_GOT16_LO        R_PPC = 15
+	R_PPC_GOT16_HI        R_PPC = 16
+	R_PPC_GOT16_HA        R_PPC = 17
+	R_PPC_PLTREL24        R_PPC = 18
+	R_PPC_COPY            R_PPC = 19
+	R_PPC_GLOB_DAT        R_PPC = 20
+	R_PPC_JMP_SLOT        R_PPC = 21
+	R_PPC_RELATIVE        R_PPC = 22
+	R_PPC_LOCAL24PC       R_PPC = 23
+	R_PPC_UADDR32         R_PPC = 24
+	R_PPC_UADDR16         R_PPC = 25
+	R_PPC_REL32           R_PPC = 26
+	R_PPC_PLT32           R_PPC = 27
+	R_PPC_PLTREL32        R_PPC = 28
+	R_PPC_PLT16_LO        R_PPC = 29
+	R_PPC_PLT16_HI        R_PPC = 30
+	R_PPC_PLT16_HA        R_PPC = 31
+	R_PPC_SDAREL16        R_PPC = 32
+	R_PPC_SECTOFF         R_PPC = 33
+	R_PPC_SECTOFF_LO      R_PPC = 34
+	R_PPC_SECTOFF_HI      R_PPC = 35
+	R_PPC_SECTOFF_HA      R_PPC = 36
+	R_PPC_TLS             R_PPC = 67
+	R_PPC_DTPMOD32        R_PPC = 68
+	R_PPC_TPREL16         R_PPC = 69
+	R_PPC_TPREL16_LO      R_PPC = 70
+	R_PPC_TPREL16_HI      R_PPC = 71
+	R_PPC_TPREL16_HA      R_PPC = 72
+	R_PPC_TPREL32         R_PPC = 73
+	R_PPC_DTPREL16        R_PPC = 74
+	R_PPC_DTPREL16_LO     R_PPC = 75
+	R_PPC_DTPREL16_HI     R_PPC = 76
+	R_PPC_DTPREL16_HA     R_PPC = 77
+	R_PPC_DTPREL32        R_PPC = 78
+	R_PPC_GOT_TLSGD16     R_PPC = 79
+	R_PPC_GOT_TLSGD16_LO  R_PPC = 80
+	R_PPC_GOT_TLSGD16_HI  R_PPC = 81
+	R_PPC_GOT_TLSGD16_HA  R_PPC = 82
+	R_PPC_GOT_TLSLD16     R_PPC = 83
+	R_PPC_GOT_TLSLD16_LO  R_PPC = 84
+	R_PPC_GOT_TLSLD16_HI  R_PPC = 85
+	R_PPC_GOT_TLSLD16_HA  R_PPC = 86
+	R_PPC_GOT_TPREL16     R_PPC = 87
+	R_PPC_GOT_TPREL16_LO  R_PPC = 88
+	R_PPC_GOT_TPREL16_HI  R_PPC = 89
+	R_PPC_GOT_TPREL16_HA  R_PPC = 90
+	R_PPC_EMB_NADDR32     R_PPC = 101
+	R_PPC_EMB_NADDR16     R_PPC = 102
+	R_PPC_EMB_NADDR16_LO  R_PPC = 103
+	R_PPC_EMB_NADDR16_HI  R_PPC = 104
+	R_PPC_EMB_NADDR16_HA  R_PPC = 105
+	R_PPC_EMB_SDAI16      R_PPC = 106
+	R_PPC_EMB_SDA2I16     R_PPC = 107
+	R_PPC_EMB_SDA2REL     R_PPC = 108
+	R_PPC_EMB_SDA21       R_PPC = 109
+	R_PPC_EMB_MRKREF      R_PPC = 110
+	R_PPC_EMB_RELSEC16    R_PPC = 111
+	R_PPC_EMB_RELST_LO    R_PPC = 112
+	R_PPC_EMB_RELST_HI    R_PPC = 113
+	R_PPC_EMB_RELST_HA    R_PPC = 114
+	R_PPC_EMB_BIT_FLD     R_PPC = 115
+	R_PPC_EMB_RELSDA      R_PPC = 116
+)
+
+var rppcStrings = []intName{
+	{0, "R_PPC_NONE"},
+	{1, "R_PPC_ADDR32"},
+	{2, "R_PPC_ADDR24"},
+	{3, "R_PPC_ADDR16"},
+	{4, "R_PPC_ADDR16_LO"},
+	{5, "R_PPC_ADDR16_HI"},
+	{6, "R_PPC_ADDR16_HA"},
+	{7, "R_PPC_ADDR14"},
+	{8, "R_PPC_ADDR14_BRTAKEN"},
+	{9, "R_PPC_ADDR14_BRNTAKEN"},
+	{10, "R_PPC_REL24"},
+	{11, "R_PPC_REL14"},
+	{12, "R_PPC_REL14_BRTAKEN"},
+	{13, "R_PPC_REL14_BRNTAKEN"},
+	{14, "R_PPC_GOT16"},
+	{15, "R_PPC_GOT16_LO"},
+	{16, "R_PPC_GOT16_HI"},
+	{17, "R_PPC_GOT16_HA"},
+	{18, "R_PPC_PLTREL24"},
+	{19, "R_PPC_COPY"},
+	{20, "R_PPC_GLOB_DAT"},
+	{21, "R_PPC_JMP_SLOT"},
+	{22, "R_PPC_RELATIVE"},
+	{23, "R_PPC_LOCAL24PC"},
+	{24, "R_PPC_UADDR32"},
+	{25, "R_PPC_UADDR16"},
+	{26, "R_PPC_REL32"},
+	{27, "R_PPC_PLT32"},
+	{28, "R_PPC_PLTREL32"},
+	{29, "R_PPC_PLT16_LO"},
+	{30, "R_PPC_PLT16_HI"},
+	{31, "R_PPC_PLT16_HA"},
+	{32, "R_PPC_SDAREL16"},
+	{33, "R_PPC_SECTOFF"},
+	{34, "R_PPC_SECTOFF_LO"},
+	{35, "R_PPC_SECTOFF_HI"},
+	{36, "R_PPC_SECTOFF_HA"},
+
+	{67, "R_PPC_TLS"},
+	{68, "R_PPC_DTPMOD32"},
+	{69, "R_PPC_TPREL16"},
+	{70, "R_PPC_TPREL16_LO"},
+	{71, "R_PPC_TPREL16_HI"},
+	{72, "R_PPC_TPREL16_HA"},
+	{73, "R_PPC_TPREL32"},
+	{74, "R_PPC_DTPREL16"},
+	{75, "R_PPC_DTPREL16_LO"},
+	{76, "R_PPC_DTPREL16_HI"},
+	{77, "R_PPC_DTPREL16_HA"},
+	{78, "R_PPC_DTPREL32"},
+	{79, "R_PPC_GOT_TLSGD16"},
+	{80, "R_PPC_GOT_TLSGD16_LO"},
+	{81, "R_PPC_GOT_TLSGD16_HI"},
+	{82, "R_PPC_GOT_TLSGD16_HA"},
+	{83, "R_PPC_GOT_TLSLD16"},
+	{84, "R_PPC_GOT_TLSLD16_LO"},
+	{85, "R_PPC_GOT_TLSLD16_HI"},
+	{86, "R_PPC_GOT_TLSLD16_HA"},
+	{87, "R_PPC_GOT_TPREL16"},
+	{88, "R_PPC_GOT_TPREL16_LO"},
+	{89, "R_PPC_GOT_TPREL16_HI"},
+	{90, "R_PPC_GOT_TPREL16_HA"},
+
+	{101, "R_PPC_EMB_NADDR32"},
+	{102, "R_PPC_EMB_NADDR16"},
+	{103, "R_PPC_EMB_NADDR16_LO"},
+	{104, "R_PPC_EMB_NADDR16_HI"},
+	{105, "R_PPC_EMB_NADDR16_HA"},
+	{106, "R_PPC_EMB_SDAI16"},
+	{107, "R_PPC_EMB_SDA2I16"},
+	{108, "R_PPC_EMB_SDA2REL"},
+	{109, "R_PPC_EMB_SDA21"},
+	{110, "R_PPC_EMB_MRKREF"},
+	{111, "R_PPC_EMB_RELSEC16"},
+	{112, "R_PPC_EMB_RELST_LO"},
+	{113, "R_PPC_EMB_RELST_HI"},
+	{114, "R_PPC_EMB_RELST_HA"},
+	{115, "R_PPC_EMB_BIT_FLD"},
+	{116, "R_PPC_EMB_RELSDA"},
+}
+
+func (i R_PPC) String() string   { return stringName(uint32(i), rppcStrings, false) }
+func (i R_PPC) GoString() string { return stringName(uint32(i), rppcStrings, true) }
+
+// Relocation types for PowerPC 64.
+type R_PPC64 int
+
+const (
+	R_PPC64_NONE               R_PPC64 = 0
+	R_PPC64_ADDR32             R_PPC64 = 1
+	R_PPC64_ADDR24             R_PPC64 = 2
+	R_PPC64_ADDR16             R_PPC64 = 3
+	R_PPC64_ADDR16_LO          R_PPC64 = 4
+	R_PPC64_ADDR16_HI          R_PPC64 = 5
+	R_PPC64_ADDR16_HA          R_PPC64 = 6
+	R_PPC64_ADDR14             R_PPC64 = 7
+	R_PPC64_ADDR14_BRTAKEN     R_PPC64 = 8
+	R_PPC64_ADDR14_BRNTAKEN    R_PPC64 = 9
+	R_PPC64_REL24              R_PPC64 = 10
+	R_PPC64_REL14              R_PPC64 = 11
+	R_PPC64_REL14_BRTAKEN      R_PPC64 = 12
+	R_PPC64_REL14_BRNTAKEN     R_PPC64 = 13
+	R_PPC64_GOT16              R_PPC64 = 14
+	R_PPC64_GOT16_LO           R_PPC64 = 15
+	R_PPC64_GOT16_HI           R_PPC64 = 16
+	R_PPC64_GOT16_HA           R_PPC64 = 17
+	R_PPC64_JMP_SLOT           R_PPC64 = 21
+	R_PPC64_REL32              R_PPC64 = 26
+	R_PPC64_ADDR64             R_PPC64 = 38
+	R_PPC64_ADDR16_HIGHER      R_PPC64 = 39
+	R_PPC64_ADDR16_HIGHERA     R_PPC64 = 40
+	R_PPC64_ADDR16_HIGHEST     R_PPC64 = 41
+	R_PPC64_ADDR16_HIGHESTA    R_PPC64 = 42
+	R_PPC64_REL64              R_PPC64 = 44
+	R_PPC64_TOC16              R_PPC64 = 47
+	R_PPC64_TOC16_LO           R_PPC64 = 48
+	R_PPC64_TOC16_HI           R_PPC64 = 49
+	R_PPC64_TOC16_HA           R_PPC64 = 50
+	R_PPC64_TOC                R_PPC64 = 51
+	R_PPC64_ADDR16_DS          R_PPC64 = 56
+	R_PPC64_ADDR16_LO_DS       R_PPC64 = 57
+	R_PPC64_GOT16_DS           R_PPC64 = 58
+	R_PPC64_GOT16_LO_DS        R_PPC64 = 59
+	R_PPC64_TOC16_DS           R_PPC64 = 63
+	R_PPC64_TOC16_LO_DS        R_PPC64 = 64
+	R_PPC64_TLS                R_PPC64 = 67
+	R_PPC64_DTPMOD64           R_PPC64 = 68
+	R_PPC64_TPREL16            R_PPC64 = 69
+	R_PPC64_TPREL16_LO         R_PPC64 = 70
+	R_PPC64_TPREL16_HI         R_PPC64 = 71
+	R_PPC64_TPREL16_HA         R_PPC64 = 72
+	R_PPC64_TPREL64            R_PPC64 = 73
+	R_PPC64_DTPREL16           R_PPC64 = 74
+	R_PPC64_DTPREL16_LO        R_PPC64 = 75
+	R_PPC64_DTPREL16_HI        R_PPC64 = 76
+	R_PPC64_DTPREL16_HA        R_PPC64 = 77
+	R_PPC64_DTPREL64           R_PPC64 = 78
+	R_PPC64_GOT_TLSGD16        R_PPC64 = 79
+	R_PPC64_GOT_TLSGD16_LO     R_PPC64 = 80
+	R_PPC64_GOT_TLSGD16_HI     R_PPC64 = 81
+	R_PPC64_GOT_TLSGD16_HA     R_PPC64 = 82
+	R_PPC64_GOT_TLSLD16        R_PPC64 = 83
+	R_PPC64_GOT_TLSLD16_LO     R_PPC64 = 84
+	R_PPC64_GOT_TLSLD16_HI     R_PPC64 = 85
+	R_PPC64_GOT_TLSLD16_HA     R_PPC64 = 86
+	R_PPC64_GOT_TPREL16_DS     R_PPC64 = 87
+	R_PPC64_GOT_TPREL16_LO_DS  R_PPC64 = 88
+	R_PPC64_GOT_TPREL16_HI     R_PPC64 = 89
+	R_PPC64_GOT_TPREL16_HA     R_PPC64 = 90
+	R_PPC64_GOT_DTPREL16_DS    R_PPC64 = 91
+	R_PPC64_GOT_DTPREL16_LO_DS R_PPC64 = 92
+	R_PPC64_GOT_DTPREL16_HI    R_PPC64 = 93
+	R_PPC64_GOT_DTPREL16_HA    R_PPC64 = 94
+	R_PPC64_TPREL16_DS         R_PPC64 = 95
+	R_PPC64_TPREL16_LO_DS      R_PPC64 = 96
+	R_PPC64_TPREL16_HIGHER     R_PPC64 = 97
+	R_PPC64_TPREL16_HIGHERA    R_PPC64 = 98
+	R_PPC64_TPREL16_HIGHEST    R_PPC64 = 99
+	R_PPC64_TPREL16_HIGHESTA   R_PPC64 = 100
+	R_PPC64_DTPREL16_DS        R_PPC64 = 101
+	R_PPC64_DTPREL16_LO_DS     R_PPC64 = 102
+	R_PPC64_DTPREL16_HIGHER    R_PPC64 = 103
+	R_PPC64_DTPREL16_HIGHERA   R_PPC64 = 104
+	R_PPC64_DTPREL16_HIGHEST   R_PPC64 = 105
+	R_PPC64_DTPREL16_HIGHESTA  R_PPC64 = 106
+	R_PPC64_TLSGD              R_PPC64 = 107
+	R_PPC64_TLSLD              R_PPC64 = 108
+	R_PPC64_REL16              R_PPC64 = 249
+	R_PPC64_REL16_LO           R_PPC64 = 250
+	R_PPC64_REL16_HI           R_PPC64 = 251
+	R_PPC64_REL16_HA           R_PPC64 = 252
+)
+
+var rppc64Strings = []intName{
+	{0, "R_PPC64_NONE"},
+	{1, "R_PPC64_ADDR32"},
+	{2, "R_PPC64_ADDR24"},
+	{3, "R_PPC64_ADDR16"},
+	{4, "R_PPC64_ADDR16_LO"},
+	{5, "R_PPC64_ADDR16_HI"},
+	{6, "R_PPC64_ADDR16_HA"},
+	{7, "R_PPC64_ADDR14"},
+	{8, "R_PPC64_ADDR14_BRTAKEN"},
+	{9, "R_PPC64_ADDR14_BRNTAKEN"},
+	{10, "R_PPC64_REL24"},
+	{11, "R_PPC64_REL14"},
+	{12, "R_PPC64_REL14_BRTAKEN"},
+	{13, "R_PPC64_REL14_BRNTAKEN"},
+	{14, "R_PPC64_GOT16"},
+	{15, "R_PPC64_GOT16_LO"},
+	{16, "R_PPC64_GOT16_HI"},
+	{17, "R_PPC64_GOT16_HA"},
+	{21, "R_PPC64_JMP_SLOT"},
+	{26, "R_PPC64_REL32"},
+	{38, "R_PPC64_ADDR64"},
+	{39, "R_PPC64_ADDR16_HIGHER"},
+	{40, "R_PPC64_ADDR16_HIGHERA"},
+	{41, "R_PPC64_ADDR16_HIGHEST"},
+	{42, "R_PPC64_ADDR16_HIGHESTA"},
+	{44, "R_PPC64_REL64"},
+	{47, "R_PPC64_TOC16"},
+	{48, "R_PPC64_TOC16_LO"},
+	{49, "R_PPC64_TOC16_HI"},
+	{50, "R_PPC64_TOC16_HA"},
+	{51, "R_PPC64_TOC"},
+	{56, "R_PPC64_ADDR16_DS"},
+	{57, "R_PPC64_ADDR16_LO_DS"},
+	{58, "R_PPC64_GOT16_DS"},
+	{59, "R_PPC64_GOT16_LO_DS"},
+	{63, "R_PPC64_TOC16_DS"},
+	{64, "R_PPC64_TOC16_LO_DS"},
+	{67, "R_PPC64_TLS"},
+	{68, "R_PPC64_DTPMOD64"},
+	{69, "R_PPC64_TPREL16"},
+	{70, "R_PPC64_TPREL16_LO"},
+	{71, "R_PPC64_TPREL16_HI"},
+	{72, "R_PPC64_TPREL16_HA"},
+	{73, "R_PPC64_TPREL64"},
+	{74, "R_PPC64_DTPREL16"},
+	{75, "R_PPC64_DTPREL16_LO"},
+	{76, "R_PPC64_DTPREL16_HI"},
+	{77, "R_PPC64_DTPREL16_HA"},
+	{78, "R_PPC64_DTPREL64"},
+	{79, "R_PPC64_GOT_TLSGD16"},
+	{80, "R_PPC64_GOT_TLSGD16_LO"},
+	{81, "R_PPC64_GOT_TLSGD16_HI"},
+	{82, "R_PPC64_GOT_TLSGD16_HA"},
+	{83, "R_PPC64_GOT_TLSLD16"},
+	{84, "R_PPC64_GOT_TLSLD16_LO"},
+	{85, "R_PPC64_GOT_TLSLD16_HI"},
+	{86, "R_PPC64_GOT_TLSLD16_HA"},
+	{87, "R_PPC64_GOT_TPREL16_DS"},
+	{88, "R_PPC64_GOT_TPREL16_LO_DS"},
+	{89, "R_PPC64_GOT_TPREL16_HI"},
+	{90, "R_PPC64_GOT_TPREL16_HA"},
+	{91, "R_PPC64_GOT_DTPREL16_DS"},
+	{92, "R_PPC64_GOT_DTPREL16_LO_DS"},
+	{93, "R_PPC64_GOT_DTPREL16_HI"},
+	{94, "R_PPC64_GOT_DTPREL16_HA"},
+	{95, "R_PPC64_TPREL16_DS"},
+	{96, "R_PPC64_TPREL16_LO_DS"},
+	{97, "R_PPC64_TPREL16_HIGHER"},
+	{98, "R_PPC64_TPREL16_HIGHERA"},
+	{99, "R_PPC64_TPREL16_HIGHEST"},
+	{100, "R_PPC64_TPREL16_HIGHESTA"},
+	{101, "R_PPC64_DTPREL16_DS"},
+	{102, "R_PPC64_DTPREL16_LO_DS"},
+	{103, "R_PPC64_DTPREL16_HIGHER"},
+	{104, "R_PPC64_DTPREL16_HIGHERA"},
+	{105, "R_PPC64_DTPREL16_HIGHEST"},
+	{106, "R_PPC64_DTPREL16_HIGHESTA"},
+	{107, "R_PPC64_TLSGD"},
+	{108, "R_PPC64_TLSLD"},
+	{249, "R_PPC64_REL16"},
+	{250, "R_PPC64_REL16_LO"},
+	{251, "R_PPC64_REL16_HI"},
+	{252, "R_PPC64_REL16_HA"},
+}
+
+func (i R_PPC64) String() string   { return stringName(uint32(i), rppc64Strings, false) }
+func (i R_PPC64) GoString() string { return stringName(uint32(i), rppc64Strings, true) }
+
+// Relocation types for SPARC.
+type R_SPARC int
+
+const (
+	R_SPARC_NONE     R_SPARC = 0
+	R_SPARC_8        R_SPARC = 1
+	R_SPARC_16       R_SPARC = 2
+	R_SPARC_32       R_SPARC = 3
+	R_SPARC_DISP8    R_SPARC = 4
+	R_SPARC_DISP16   R_SPARC = 5
+	R_SPARC_DISP32   R_SPARC = 6
+	R_SPARC_WDISP30  R_SPARC = 7
+	R_SPARC_WDISP22  R_SPARC = 8
+	R_SPARC_HI22     R_SPARC = 9
+	R_SPARC_22       R_SPARC = 10
+	R_SPARC_13       R_SPARC = 11
+	R_SPARC_LO10     R_SPARC = 12
+	R_SPARC_GOT10    R_SPARC = 13
+	R_SPARC_GOT13    R_SPARC = 14
+	R_SPARC_GOT22    R_SPARC = 15
+	R_SPARC_PC10     R_SPARC = 16
+	R_SPARC_PC22     R_SPARC = 17
+	R_SPARC_WPLT30   R_SPARC = 18
+	R_SPARC_COPY     R_SPARC = 19
+	R_SPARC_GLOB_DAT R_SPARC = 20
+	R_SPARC_JMP_SLOT R_SPARC = 21
+	R_SPARC_RELATIVE R_SPARC = 22
+	R_SPARC_UA32     R_SPARC = 23
+	R_SPARC_PLT32    R_SPARC = 24
+	R_SPARC_HIPLT22  R_SPARC = 25
+	R_SPARC_LOPLT10  R_SPARC = 26
+	R_SPARC_PCPLT32  R_SPARC = 27
+	R_SPARC_PCPLT22  R_SPARC = 28
+	R_SPARC_PCPLT10  R_SPARC = 29
+	R_SPARC_10       R_SPARC = 30
+	R_SPARC_11       R_SPARC = 31
+	R_SPARC_64       R_SPARC = 32
+	R_SPARC_OLO10    R_SPARC = 33
+	R_SPARC_HH22     R_SPARC = 34
+	R_SPARC_HM10     R_SPARC = 35
+	R_SPARC_LM22     R_SPARC = 36
+	R_SPARC_PC_HH22  R_SPARC = 37
+	R_SPARC_PC_HM10  R_SPARC = 38
+	R_SPARC_PC_LM22  R_SPARC = 39
+	R_SPARC_WDISP16  R_SPARC = 40
+	R_SPARC_WDISP19  R_SPARC = 41
+	R_SPARC_GLOB_JMP R_SPARC = 42
+	R_SPARC_7        R_SPARC = 43
+	R_SPARC_5        R_SPARC = 44
+	R_SPARC_6        R_SPARC = 45
+	R_SPARC_DISP64   R_SPARC = 46
+	R_SPARC_PLT64    R_SPARC = 47
+	R_SPARC_HIX22    R_SPARC = 48
+	R_SPARC_LOX10    R_SPARC = 49
+	R_SPARC_H44      R_SPARC = 50
+	R_SPARC_M44      R_SPARC = 51
+	R_SPARC_L44      R_SPARC = 52
+	R_SPARC_REGISTER R_SPARC = 53
+	R_SPARC_UA64     R_SPARC = 54
+	R_SPARC_UA16     R_SPARC = 55
+)
+
+var rsparcStrings = []intName{
+	{0, "R_SPARC_NONE"},
+	{1, "R_SPARC_8"},
+	{2, "R_SPARC_16"},
+	{3, "R_SPARC_32"},
+	{4, "R_SPARC_DISP8"},
+	{5, "R_SPARC_DISP16"},
+	{6, "R_SPARC_DISP32"},
+	{7, "R_SPARC_WDISP30"},
+	{8, "R_SPARC_WDISP22"},
+	{9, "R_SPARC_HI22"},
+	{10, "R_SPARC_22"},
+	{11, "R_SPARC_13"},
+	{12, "R_SPARC_LO10"},
+	{13, "R_SPARC_GOT10"},
+	{14, "R_SPARC_GOT13"},
+	{15, "R_SPARC_GOT22"},
+	{16, "R_SPARC_PC10"},
+	{17, "R_SPARC_PC22"},
+	{18, "R_SPARC_WPLT30"},
+	{19, "R_SPARC_COPY"},
+	{20, "R_SPARC_GLOB_DAT"},
+	{21, "R_SPARC_JMP_SLOT"},
+	{22, "R_SPARC_RELATIVE"},
+	{23, "R_SPARC_UA32"},
+	{24, "R_SPARC_PLT32"},
+	{25, "R_SPARC_HIPLT22"},
+	{26, "R_SPARC_LOPLT10"},
+	{27, "R_SPARC_PCPLT32"},
+	{28, "R_SPARC_PCPLT22"},
+	{29, "R_SPARC_PCPLT10"},
+	{30, "R_SPARC_10"},
+	{31, "R_SPARC_11"},
+	{32, "R_SPARC_64"},
+	{33, "R_SPARC_OLO10"},
+	{34, "R_SPARC_HH22"},
+	{35, "R_SPARC_HM10"},
+	{36, "R_SPARC_LM22"},
+	{37, "R_SPARC_PC_HH22"},
+	{38, "R_SPARC_PC_HM10"},
+	{39, "R_SPARC_PC_LM22"},
+	{40, "R_SPARC_WDISP16"},
+	{41, "R_SPARC_WDISP19"},
+	{42, "R_SPARC_GLOB_JMP"},
+	{43, "R_SPARC_7"},
+	{44, "R_SPARC_5"},
+	{45, "R_SPARC_6"},
+	{46, "R_SPARC_DISP64"},
+	{47, "R_SPARC_PLT64"},
+	{48, "R_SPARC_HIX22"},
+	{49, "R_SPARC_LOX10"},
+	{50, "R_SPARC_H44"},
+	{51, "R_SPARC_M44"},
+	{52, "R_SPARC_L44"},
+	{53, "R_SPARC_REGISTER"},
+	{54, "R_SPARC_UA64"},
+	{55, "R_SPARC_UA16"},
+}
+
+func (i R_SPARC) String() string   { return stringName(uint32(i), rsparcStrings, false) }
+func (i R_SPARC) GoString() string { return stringName(uint32(i), rsparcStrings, true) }
+
+// Magic number for the elf trampoline, chosen wisely to be an immediate value.
+const ARM_MAGIC_TRAMP_NUMBER = 0x5c000003
+
+// ELF32 File header.
+type Header32 struct {
+	Ident     [EI_NIDENT]byte /* File identification. */
+	Type      uint16          /* File type. */
+	Machine   uint16          /* Machine architecture. */
+	Version   uint32          /* ELF format version. */
+	Entry     uint32          /* Entry point. */
+	Phoff     uint32          /* Program header file offset. */
+	Shoff     uint32          /* Section header file offset. */
+	Flags     uint32          /* Architecture-specific flags. */
+	Ehsize    uint16          /* Size of ELF header in bytes. */
+	Phentsize uint16          /* Size of program header entry. */
+	Phnum     uint16          /* Number of program header entries. */
+	Shentsize uint16          /* Size of section header entry. */
+	Shnum     uint16          /* Number of section header entries. */
+	Shstrndx  uint16          /* Section name strings section. */
+}
+
+// ELF32 Section header.
+type Section32 struct {
+	Name      uint32 /* Section name (index into the section header string table). */
+	Type      uint32 /* Section type. */
+	Flags     uint32 /* Section flags. */
+	Addr      uint32 /* Address in memory image. */
+	Off       uint32 /* Offset in file. */
+	Size      uint32 /* Size in bytes. */
+	Link      uint32 /* Index of a related section. */
+	Info      uint32 /* Depends on section type. */
+	Addralign uint32 /* Alignment in bytes. */
+	Entsize   uint32 /* Size of each entry in section. */
+}
+
+// ELF32 Program header.
+type Prog32 struct {
+	Type   uint32 /* Entry type. */
+	Off    uint32 /* File offset of contents. */
+	Vaddr  uint32 /* Virtual address in memory image. */
+	Paddr  uint32 /* Physical address (not used). */
+	Filesz uint32 /* Size of contents in file. */
+	Memsz  uint32 /* Size of contents in memory. */
+	Flags  uint32 /* Access permission flags. */
+	Align  uint32 /* Alignment in memory and file. */
+}
+
+// ELF32 Dynamic structure.  The ".dynamic" section contains an array of them.
+type Dyn32 struct {
+	Tag int32  /* Entry type. */
+	Val uint32 /* Integer/Address value. */
+}
+
+/*
+ * Relocation entries.
+ */
+
+// ELF32 Relocations that don't need an addend field.
+type Rel32 struct {
+	Off  uint32 /* Location to be relocated. */
+	Info uint32 /* Relocation type and symbol index. */
+}
+
+// ELF32 Relocations that need an addend field.
+type Rela32 struct {
+	Off    uint32 /* Location to be relocated. */
+	Info   uint32 /* Relocation type and symbol index. */
+	Addend int32  /* Addend. */
+}
+
+func R_SYM32(info uint32) uint32      { return uint32(info >> 8) }
+func R_TYPE32(info uint32) uint32     { return uint32(info & 0xff) }
+func R_INFO32(sym, typ uint32) uint32 { return sym<<8 | typ }
+
+// ELF32 Symbol.
+type Sym32 struct {
+	Name  uint32
+	Value uint32
+	Size  uint32
+	Info  uint8
+	Other uint8
+	Shndx uint16
+}
+
+const Sym32Size = 16
+
+func ST_BIND(info uint8) SymBind { return SymBind(info >> 4) }
+func ST_TYPE(info uint8) SymType { return SymType(info & 0xF) }
+func ST_INFO(bind SymBind, typ SymType) uint8 {
+	return uint8(bind)<<4 | uint8(typ)&0xf
+}
+func ST_VISIBILITY(other uint8) SymVis { return SymVis(other & 3) }
+
+/*
+ * ELF64
+ */
+
+// ELF64 file header.
+type Header64 struct {
+	Ident     [EI_NIDENT]byte /* File identification. */
+	Type      uint16          /* File type. */
+	Machine   uint16          /* Machine architecture. */
+	Version   uint32          /* ELF format version. */
+	Entry     uint64          /* Entry point. */
+	Phoff     uint64          /* Program header file offset. */
+	Shoff     uint64          /* Section header file offset. */
+	Flags     uint32          /* Architecture-specific flags. */
+	Ehsize    uint16          /* Size of ELF header in bytes. */
+	Phentsize uint16          /* Size of program header entry. */
+	Phnum     uint16          /* Number of program header entries. */
+	Shentsize uint16          /* Size of section header entry. */
+	Shnum     uint16          /* Number of section header entries. */
+	Shstrndx  uint16          /* Section name strings section. */
+}
+
+// ELF64 Section header.
+type Section64 struct {
+	Name      uint32 /* Section name (index into the section header string table). */
+	Type      uint32 /* Section type. */
+	Flags     uint64 /* Section flags. */
+	Addr      uint64 /* Address in memory image. */
+	Off       uint64 /* Offset in file. */
+	Size      uint64 /* Size in bytes. */
+	Link      uint32 /* Index of a related section. */
+	Info      uint32 /* Depends on section type. */
+	Addralign uint64 /* Alignment in bytes. */
+	Entsize   uint64 /* Size of each entry in section. */
+}
+
+// ELF64 Program header.
+type Prog64 struct {
+	Type   uint32 /* Entry type. */
+	Flags  uint32 /* Access permission flags. */
+	Off    uint64 /* File offset of contents. */
+	Vaddr  uint64 /* Virtual address in memory image. */
+	Paddr  uint64 /* Physical address (not used). */
+	Filesz uint64 /* Size of contents in file. */
+	Memsz  uint64 /* Size of contents in memory. */
+	Align  uint64 /* Alignment in memory and file. */
+}
+
+// ELF64 Dynamic structure.  The ".dynamic" section contains an array of them.
+type Dyn64 struct {
+	Tag int64  /* Entry type. */
+	Val uint64 /* Integer/address value */
+}
+
+/*
+ * Relocation entries.
+ */
+
+/* ELF64 relocations that don't need an addend field. */
+type Rel64 struct {
+	Off  uint64 /* Location to be relocated. */
+	Info uint64 /* Relocation type and symbol index. */
+}
+
+/* ELF64 relocations that need an addend field. */
+type Rela64 struct {
+	Off    uint64 /* Location to be relocated. */
+	Info   uint64 /* Relocation type and symbol index. */
+	Addend int64  /* Addend. */
+}
+
+func R_SYM64(info uint64) uint32    { return uint32(info >> 32) }
+func R_TYPE64(info uint64) uint32   { return uint32(info) }
+func R_INFO(sym, typ uint32) uint64 { return uint64(sym)<<32 | uint64(typ) }
+
+// ELF64 symbol table entries.
+type Sym64 struct {
+	Name  uint32 /* String table index of name. */
+	Info  uint8  /* Type and binding information. */
+	Other uint8  /* Reserved (not used). */
+	Shndx uint16 /* Section index of symbol. */
+	Value uint64 /* Symbol value. */
+	Size  uint64 /* Size of associated object. */
+}
+
+const Sym64Size = 24
+
+type intName struct {
+	i uint32
+	s string
+}
+
+func stringName(i uint32, names []intName, goSyntax bool) string {
+	for _, n := range names {
+		if n.i == i {
+			if goSyntax {
+				return "elf." + n.s
+			}
+			return n.s
+		}
+	}
+
+	// second pass - look for smaller to add with.
+	// assume sorted already
+	for j := len(names) - 1; j >= 0; j-- {
+		n := names[j]
+		if n.i < i {
+			s := n.s
+			if goSyntax {
+				s = "elf." + s
+			}
+			return s + "+" + strconv.FormatUint(uint64(i-n.i), 10)
+		}
+	}
+
+	return strconv.FormatUint(uint64(i), 10)
+}
+
+func flagName(i uint32, names []intName, goSyntax bool) string {
+	s := ""
+	for _, n := range names {
+		if n.i&i == n.i {
+			if len(s) > 0 {
+				s += "+"
+			}
+			if goSyntax {
+				s += "elf."
+			}
+			s += n.s
+			i -= n.i
+		}
+	}
+	if len(s) == 0 {
+		return "0x" + strconv.FormatUint(uint64(i), 16)
+	}
+	if i != 0 {
+		s += "+0x" + strconv.FormatUint(uint64(i), 16)
+	}
+	return s
+}
diff --git a/src/debug/elf/elf_test.go b/src/debug/elf/elf_test.go
new file mode 100644
index 000000000..e3c51bb71
--- /dev/null
+++ b/src/debug/elf/elf_test.go
@@ -0,0 +1,49 @@
+// Copyright 2009 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package elf
+
+import (
+	"fmt"
+	"testing"
+)
+
+type nameTest struct {
+	val interface{}
+	str string
+}
+
+var nameTests = []nameTest{
+	{ELFOSABI_LINUX, "ELFOSABI_LINUX"},
+	{ET_EXEC, "ET_EXEC"},
+	{EM_860, "EM_860"},
+	{SHN_LOPROC, "SHN_LOPROC"},
+	{SHT_PROGBITS, "SHT_PROGBITS"},
+	{SHF_MERGE + SHF_TLS, "SHF_MERGE+SHF_TLS"},
+	{PT_LOAD, "PT_LOAD"},
+	{PF_W + PF_R + 0x50, "PF_W+PF_R+0x50"},
+	{DT_SYMBOLIC, "DT_SYMBOLIC"},
+	{DF_BIND_NOW, "DF_BIND_NOW"},
+	{NT_FPREGSET, "NT_FPREGSET"},
+	{STB_GLOBAL, "STB_GLOBAL"},
+	{STT_COMMON, "STT_COMMON"},
+	{STV_HIDDEN, "STV_HIDDEN"},
+	{R_X86_64_PC32, "R_X86_64_PC32"},
+	{R_ALPHA_OP_PUSH, "R_ALPHA_OP_PUSH"},
+	{R_ARM_THM_ABS5, "R_ARM_THM_ABS5"},
+	{R_386_GOT32, "R_386_GOT32"},
+	{R_PPC_GOT16_HI, "R_PPC_GOT16_HI"},
+	{R_SPARC_GOT22, "R_SPARC_GOT22"},
+	{ET_LOOS + 5, "ET_LOOS+5"},
+	{ProgFlag(0x50), "0x50"},
+}
+
+func TestNames(t *testing.T) {
+	for i, tt := range nameTests {
+		s := fmt.Sprint(tt.val)
+		if s != tt.str {
+			t.Errorf("#%d: Sprint(%d) = %q, want %q", i, tt.val, s, tt.str)
+		}
+	}
+}
diff --git a/src/debug/elf/file.go b/src/debug/elf/file.go
new file mode 100644
index 000000000..49060b735
--- /dev/null
+++ b/src/debug/elf/file.go
@@ -0,0 +1,993 @@
+// Copyright 2009 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package elf implements access to ELF object files.
+package elf
+
+import (
+	"bytes"
+	"debug/dwarf"
+	"encoding/binary"
+	"errors"
+	"fmt"
+	"io"
+	"os"
+)
+
+// TODO: error reporting detail
+
+/*
+ * Internal ELF representation
+ */
+
+// A FileHeader represents an ELF file header.
+type FileHeader struct {
+	Class      Class
+	Data       Data
+	Version    Version
+	OSABI      OSABI
+	ABIVersion uint8
+	ByteOrder  binary.ByteOrder
+	Type       Type
+	Machine    Machine
+	Entry      uint64
+}
+
+// A File represents an open ELF file.
+type File struct {
+	FileHeader
+	Sections  []*Section
+	Progs     []*Prog
+	closer    io.Closer
+	gnuNeed   []verneed
+	gnuVersym []byte
+}
+
+// A SectionHeader represents a single ELF section header.
+type SectionHeader struct {
+	Name      string
+	Type      SectionType
+	Flags     SectionFlag
+	Addr      uint64
+	Offset    uint64
+	Size      uint64
+	Link      uint32
+	Info      uint32
+	Addralign uint64
+	Entsize   uint64
+}
+
+// A Section represents a single section in an ELF file.
+type Section struct {
+	SectionHeader
+
+	// Embed ReaderAt for ReadAt method.
+	// Do not embed SectionReader directly
+	// to avoid having Read and Seek.
+	// If a client wants Read and Seek it must use
+	// Open() to avoid fighting over the seek offset
+	// with other clients.
+	io.ReaderAt
+	sr *io.SectionReader
+}
+
+// Data reads and returns the contents of the ELF section.
+func (s *Section) Data() ([]byte, error) {
+	dat := make([]byte, s.sr.Size())
+	n, err := s.sr.ReadAt(dat, 0)
+	if n == len(dat) {
+		err = nil
+	}
+	return dat[0:n], err
+}
+
+// stringTable reads and returns the string table given by the
+// specified link value.
+func (f *File) stringTable(link uint32) ([]byte, error) {
+	if link <= 0 || link >= uint32(len(f.Sections)) {
+		return nil, errors.New("section has invalid string table link")
+	}
+	return f.Sections[link].Data()
+}
+
+// Open returns a new ReadSeeker reading the ELF section.
+func (s *Section) Open() io.ReadSeeker { return io.NewSectionReader(s.sr, 0, 1<<63-1) }
+
+// A ProgHeader represents a single ELF program header.
+type ProgHeader struct {
+	Type   ProgType
+	Flags  ProgFlag
+	Off    uint64
+	Vaddr  uint64
+	Paddr  uint64
+	Filesz uint64
+	Memsz  uint64
+	Align  uint64
+}
+
+// A Prog represents a single ELF program header in an ELF binary.
+type Prog struct {
+	ProgHeader
+
+	// Embed ReaderAt for ReadAt method.
+	// Do not embed SectionReader directly
+	// to avoid having Read and Seek.
+	// If a client wants Read and Seek it must use
+	// Open() to avoid fighting over the seek offset
+	// with other clients.
+	io.ReaderAt
+	sr *io.SectionReader
+}
+
+// Open returns a new ReadSeeker reading the ELF program body.
+func (p *Prog) Open() io.ReadSeeker { return io.NewSectionReader(p.sr, 0, 1<<63-1) }
+
+// A Symbol represents an entry in an ELF symbol table section.
+type Symbol struct {
+	Name        string
+	Info, Other byte
+	Section     SectionIndex
+	Value, Size uint64
+}
+
+/*
+ * ELF reader
+ */
+
+type FormatError struct {
+	off int64
+	msg string
+	val interface{}
+}
+
+func (e *FormatError) Error() string {
+	msg := e.msg
+	if e.val != nil {
+		msg += fmt.Sprintf(" '%v' ", e.val)
+	}
+	msg += fmt.Sprintf("in record at byte %#x", e.off)
+	return msg
+}
+
+// Open opens the named file using os.Open and prepares it for use as an ELF binary.
+func Open(name string) (*File, error) {
+	f, err := os.Open(name)
+	if err != nil {
+		return nil, err
+	}
+	ff, err := NewFile(f)
+	if err != nil {
+		f.Close()
+		return nil, err
+	}
+	ff.closer = f
+	return ff, nil
+}
+
+// Close closes the File.
+// If the File was created using NewFile directly instead of Open,
+// Close has no effect.
+func (f *File) Close() error {
+	var err error
+	if f.closer != nil {
+		err = f.closer.Close()
+		f.closer = nil
+	}
+	return err
+}
+
+// SectionByType returns the first section in f with the
+// given type, or nil if there is no such section.
+func (f *File) SectionByType(typ SectionType) *Section {
+	for _, s := range f.Sections {
+		if s.Type == typ {
+			return s
+		}
+	}
+	return nil
+}
+
+// NewFile creates a new File for accessing an ELF binary in an underlying reader.
+// The ELF binary is expected to start at position 0 in the ReaderAt.
+func NewFile(r io.ReaderAt) (*File, error) {
+	sr := io.NewSectionReader(r, 0, 1<<63-1)
+	// Read and decode ELF identifier
+	var ident [16]uint8
+	if _, err := r.ReadAt(ident[0:], 0); err != nil {
+		return nil, err
+	}
+	if ident[0] != '\x7f' || ident[1] != 'E' || ident[2] != 'L' || ident[3] != 'F' {
+		return nil, &FormatError{0, "bad magic number", ident[0:4]}
+	}
+
+	f := new(File)
+	f.Class = Class(ident[EI_CLASS])
+	switch f.Class {
+	case ELFCLASS32:
+	case ELFCLASS64:
+		// ok
+	default:
+		return nil, &FormatError{0, "unknown ELF class", f.Class}
+	}
+
+	f.Data = Data(ident[EI_DATA])
+	switch f.Data {
+	case ELFDATA2LSB:
+		f.ByteOrder = binary.LittleEndian
+	case ELFDATA2MSB:
+		f.ByteOrder = binary.BigEndian
+	default:
+		return nil, &FormatError{0, "unknown ELF data encoding", f.Data}
+	}
+
+	f.Version = Version(ident[EI_VERSION])
+	if f.Version != EV_CURRENT {
+		return nil, &FormatError{0, "unknown ELF version", f.Version}
+	}
+
+	f.OSABI = OSABI(ident[EI_OSABI])
+	f.ABIVersion = ident[EI_ABIVERSION]
+
+	// Read ELF file header
+	var phoff int64
+	var phentsize, phnum int
+	var shoff int64
+	var shentsize, shnum, shstrndx int
+	shstrndx = -1
+	switch f.Class {
+	case ELFCLASS32:
+		hdr := new(Header32)
+		sr.Seek(0, os.SEEK_SET)
+		if err := binary.Read(sr, f.ByteOrder, hdr); err != nil {
+			return nil, err
+		}
+		f.Type = Type(hdr.Type)
+		f.Machine = Machine(hdr.Machine)
+		f.Entry = uint64(hdr.Entry)
+		if v := Version(hdr.Version); v != f.Version {
+			return nil, &FormatError{0, "mismatched ELF version", v}
+		}
+		phoff = int64(hdr.Phoff)
+		phentsize = int(hdr.Phentsize)
+		phnum = int(hdr.Phnum)
+		shoff = int64(hdr.Shoff)
+		shentsize = int(hdr.Shentsize)
+		shnum = int(hdr.Shnum)
+		shstrndx = int(hdr.Shstrndx)
+	case ELFCLASS64:
+		hdr := new(Header64)
+		sr.Seek(0, os.SEEK_SET)
+		if err := binary.Read(sr, f.ByteOrder, hdr); err != nil {
+			return nil, err
+		}
+		f.Type = Type(hdr.Type)
+		f.Machine = Machine(hdr.Machine)
+		f.Entry = uint64(hdr.Entry)
+		if v := Version(hdr.Version); v != f.Version {
+			return nil, &FormatError{0, "mismatched ELF version", v}
+		}
+		phoff = int64(hdr.Phoff)
+		phentsize = int(hdr.Phentsize)
+		phnum = int(hdr.Phnum)
+		shoff = int64(hdr.Shoff)
+		shentsize = int(hdr.Shentsize)
+		shnum = int(hdr.Shnum)
+		shstrndx = int(hdr.Shstrndx)
+	}
+
+	if shnum > 0 && shoff > 0 && (shstrndx < 0 || shstrndx >= shnum) {
+		return nil, &FormatError{0, "invalid ELF shstrndx", shstrndx}
+	}
+
+	// Read program headers
+	f.Progs = make([]*Prog, phnum)
+	for i := 0; i < phnum; i++ {
+		off := phoff + int64(i)*int64(phentsize)
+		sr.Seek(off, os.SEEK_SET)
+		p := new(Prog)
+		switch f.Class {
+		case ELFCLASS32:
+			ph := new(Prog32)
+			if err := binary.Read(sr, f.ByteOrder, ph); err != nil {
+				return nil, err
+			}
+			p.ProgHeader = ProgHeader{
+				Type:   ProgType(ph.Type),
+				Flags:  ProgFlag(ph.Flags),
+				Off:    uint64(ph.Off),
+				Vaddr:  uint64(ph.Vaddr),
+				Paddr:  uint64(ph.Paddr),
+				Filesz: uint64(ph.Filesz),
+				Memsz:  uint64(ph.Memsz),
+				Align:  uint64(ph.Align),
+			}
+		case ELFCLASS64:
+			ph := new(Prog64)
+			if err := binary.Read(sr, f.ByteOrder, ph); err != nil {
+				return nil, err
+			}
+			p.ProgHeader = ProgHeader{
+				Type:   ProgType(ph.Type),
+				Flags:  ProgFlag(ph.Flags),
+				Off:    uint64(ph.Off),
+				Vaddr:  uint64(ph.Vaddr),
+				Paddr:  uint64(ph.Paddr),
+				Filesz: uint64(ph.Filesz),
+				Memsz:  uint64(ph.Memsz),
+				Align:  uint64(ph.Align),
+			}
+		}
+		p.sr = io.NewSectionReader(r, int64(p.Off), int64(p.Filesz))
+		p.ReaderAt = p.sr
+		f.Progs[i] = p
+	}
+
+	// Read section headers
+	f.Sections = make([]*Section, shnum)
+	names := make([]uint32, shnum)
+	for i := 0; i < shnum; i++ {
+		off := shoff + int64(i)*int64(shentsize)
+		sr.Seek(off, os.SEEK_SET)
+		s := new(Section)
+		switch f.Class {
+		case ELFCLASS32:
+			sh := new(Section32)
+			if err := binary.Read(sr, f.ByteOrder, sh); err != nil {
+				return nil, err
+			}
+			names[i] = sh.Name
+			s.SectionHeader = SectionHeader{
+				Type:      SectionType(sh.Type),
+				Flags:     SectionFlag(sh.Flags),
+				Addr:      uint64(sh.Addr),
+				Offset:    uint64(sh.Off),
+				Size:      uint64(sh.Size),
+				Link:      uint32(sh.Link),
+				Info:      uint32(sh.Info),
+				Addralign: uint64(sh.Addralign),
+				Entsize:   uint64(sh.Entsize),
+			}
+		case ELFCLASS64:
+			sh := new(Section64)
+			if err := binary.Read(sr, f.ByteOrder, sh); err != nil {
+				return nil, err
+			}
+			names[i] = sh.Name
+			s.SectionHeader = SectionHeader{
+				Type:      SectionType(sh.Type),
+				Flags:     SectionFlag(sh.Flags),
+				Offset:    uint64(sh.Off),
+				Size:      uint64(sh.Size),
+				Addr:      uint64(sh.Addr),
+				Link:      uint32(sh.Link),
+				Info:      uint32(sh.Info),
+				Addralign: uint64(sh.Addralign),
+				Entsize:   uint64(sh.Entsize),
+			}
+		}
+		s.sr = io.NewSectionReader(r, int64(s.Offset), int64(s.Size))
+		s.ReaderAt = s.sr
+		f.Sections[i] = s
+	}
+
+	if len(f.Sections) == 0 {
+		return f, nil
+	}
+
+	// Load section header string table.
+	shstrtab, err := f.Sections[shstrndx].Data()
+	if err != nil {
+		return nil, err
+	}
+	for i, s := range f.Sections {
+		var ok bool
+		s.Name, ok = getString(shstrtab, int(names[i]))
+		if !ok {
+			return nil, &FormatError{shoff + int64(i*shentsize), "bad section name index", names[i]}
+		}
+	}
+
+	return f, nil
+}
+
+// getSymbols returns a slice of Symbols from parsing the symbol table
+// with the given type, along with the associated string table.
+func (f *File) getSymbols(typ SectionType) ([]Symbol, []byte, error) {
+	switch f.Class {
+	case ELFCLASS64:
+		return f.getSymbols64(typ)
+
+	case ELFCLASS32:
+		return f.getSymbols32(typ)
+	}
+
+	return nil, nil, errors.New("not implemented")
+}
+
+// ErrNoSymbols is returned by File.Symbols and File.DynamicSymbols
+// if there is no such section in the File.
+var ErrNoSymbols = errors.New("no symbol section")
+
+func (f *File) getSymbols32(typ SectionType) ([]Symbol, []byte, error) {
+	symtabSection := f.SectionByType(typ)
+	if symtabSection == nil {
+		return nil, nil, ErrNoSymbols
+	}
+
+	data, err := symtabSection.Data()
+	if err != nil {
+		return nil, nil, errors.New("cannot load symbol section")
+	}
+	symtab := bytes.NewReader(data)
+	if symtab.Len()%Sym32Size != 0 {
+		return nil, nil, errors.New("length of symbol section is not a multiple of SymSize")
+	}
+
+	strdata, err := f.stringTable(symtabSection.Link)
+	if err != nil {
+		return nil, nil, errors.New("cannot load string table section")
+	}
+
+	// The first entry is all zeros.
+	var skip [Sym32Size]byte
+	symtab.Read(skip[:])
+
+	symbols := make([]Symbol, symtab.Len()/Sym32Size)
+
+	i := 0
+	var sym Sym32
+	for symtab.Len() > 0 {
+		binary.Read(symtab, f.ByteOrder, &sym)
+		str, _ := getString(strdata, int(sym.Name))
+		symbols[i].Name = str
+		symbols[i].Info = sym.Info
+		symbols[i].Other = sym.Other
+		symbols[i].Section = SectionIndex(sym.Shndx)
+		symbols[i].Value = uint64(sym.Value)
+		symbols[i].Size = uint64(sym.Size)
+		i++
+	}
+
+	return symbols, strdata, nil
+}
+
+func (f *File) getSymbols64(typ SectionType) ([]Symbol, []byte, error) {
+	symtabSection := f.SectionByType(typ)
+	if symtabSection == nil {
+		return nil, nil, ErrNoSymbols
+	}
+
+	data, err := symtabSection.Data()
+	if err != nil {
+		return nil, nil, errors.New("cannot load symbol section")
+	}
+	symtab := bytes.NewReader(data)
+	if symtab.Len()%Sym64Size != 0 {
+		return nil, nil, errors.New("length of symbol section is not a multiple of Sym64Size")
+	}
+
+	strdata, err := f.stringTable(symtabSection.Link)
+	if err != nil {
+		return nil, nil, errors.New("cannot load string table section")
+	}
+
+	// The first entry is all zeros.
+	var skip [Sym64Size]byte
+	symtab.Read(skip[:])
+
+	symbols := make([]Symbol, symtab.Len()/Sym64Size)
+
+	i := 0
+	var sym Sym64
+	for symtab.Len() > 0 {
+		binary.Read(symtab, f.ByteOrder, &sym)
+		str, _ := getString(strdata, int(sym.Name))
+		symbols[i].Name = str
+		symbols[i].Info = sym.Info
+		symbols[i].Other = sym.Other
+		symbols[i].Section = SectionIndex(sym.Shndx)
+		symbols[i].Value = sym.Value
+		symbols[i].Size = sym.Size
+		i++
+	}
+
+	return symbols, strdata, nil
+}
+
+// getString extracts a string from an ELF string table.
+func getString(section []byte, start int) (string, bool) {
+	if start < 0 || start >= len(section) {
+		return "", false
+	}
+
+	for end := start; end < len(section); end++ {
+		if section[end] == 0 {
+			return string(section[start:end]), true
+		}
+	}
+	return "", false
+}
+
+// Section returns a section with the given name, or nil if no such
+// section exists.
+func (f *File) Section(name string) *Section {
+	for _, s := range f.Sections {
+		if s.Name == name {
+			return s
+		}
+	}
+	return nil
+}
+
+// applyRelocations applies relocations to dst. rels is a relocations section
+// in RELA format.
+func (f *File) applyRelocations(dst []byte, rels []byte) error {
+	if f.Class == ELFCLASS64 && f.Machine == EM_X86_64 {
+		return f.applyRelocationsAMD64(dst, rels)
+	}
+	if f.Class == ELFCLASS32 && f.Machine == EM_386 {
+		return f.applyRelocations386(dst, rels)
+	}
+	if f.Class == ELFCLASS64 && f.Machine == EM_AARCH64 {
+		return f.applyRelocationsARM64(dst, rels)
+	}
+	if f.Class == ELFCLASS64 && f.Machine == EM_PPC64 {
+		return f.applyRelocationsPPC64(dst, rels)
+	}
+
+	return errors.New("not implemented")
+}
+
+func (f *File) applyRelocationsAMD64(dst []byte, rels []byte) error {
+	// 24 is the size of Rela64.
+	if len(rels)%24 != 0 {
+		return errors.New("length of relocation section is not a multiple of 24")
+	}
+
+	symbols, _, err := f.getSymbols(SHT_SYMTAB)
+	if err != nil {
+		return err
+	}
+
+	b := bytes.NewReader(rels)
+	var rela Rela64
+
+	for b.Len() > 0 {
+		binary.Read(b, f.ByteOrder, &rela)
+		symNo := rela.Info >> 32
+		t := R_X86_64(rela.Info & 0xffff)
+
+		if symNo == 0 || symNo > uint64(len(symbols)) {
+			continue
+		}
+		sym := &symbols[symNo-1]
+		if SymType(sym.Info&0xf) != STT_SECTION {
+			// We don't handle non-section relocations for now.
+			continue
+		}
+
+		switch t {
+		case R_X86_64_64:
+			if rela.Off+8 >= uint64(len(dst)) || rela.Addend < 0 {
+				continue
+			}
+			f.ByteOrder.PutUint64(dst[rela.Off:rela.Off+8], uint64(rela.Addend))
+		case R_X86_64_32:
+			if rela.Off+4 >= uint64(len(dst)) || rela.Addend < 0 {
+				continue
+			}
+			f.ByteOrder.PutUint32(dst[rela.Off:rela.Off+4], uint32(rela.Addend))
+		}
+	}
+
+	return nil
+}
+
+func (f *File) applyRelocations386(dst []byte, rels []byte) error {
+	// 8 is the size of Rel32.
+	if len(rels)%8 != 0 {
+		return errors.New("length of relocation section is not a multiple of 8")
+	}
+
+	symbols, _, err := f.getSymbols(SHT_SYMTAB)
+	if err != nil {
+		return err
+	}
+
+	b := bytes.NewReader(rels)
+	var rel Rel32
+
+	for b.Len() > 0 {
+		binary.Read(b, f.ByteOrder, &rel)
+		symNo := rel.Info >> 8
+		t := R_386(rel.Info & 0xff)
+
+		if symNo == 0 || symNo > uint32(len(symbols)) {
+			continue
+		}
+		sym := &symbols[symNo-1]
+
+		if t == R_386_32 {
+			if rel.Off+4 >= uint32(len(dst)) {
+				continue
+			}
+			val := f.ByteOrder.Uint32(dst[rel.Off : rel.Off+4])
+			val += uint32(sym.Value)
+			f.ByteOrder.PutUint32(dst[rel.Off:rel.Off+4], val)
+		}
+	}
+
+	return nil
+}
+
+func (f *File) applyRelocationsARM64(dst []byte, rels []byte) error {
+	// 24 is the size of Rela64.
+	if len(rels)%24 != 0 {
+		return errors.New("length of relocation section is not a multiple of 24")
+	}
+
+	symbols, _, err := f.getSymbols(SHT_SYMTAB)
+	if err != nil {
+		return err
+	}
+
+	b := bytes.NewReader(rels)
+	var rela Rela64
+
+	for b.Len() > 0 {
+		binary.Read(b, f.ByteOrder, &rela)
+		symNo := rela.Info >> 32
+		t := R_AARCH64(rela.Info & 0xffff)
+
+		if symNo == 0 || symNo > uint64(len(symbols)) {
+			continue
+		}
+		sym := &symbols[symNo-1]
+		if SymType(sym.Info&0xf) != STT_SECTION {
+			// We don't handle non-section relocations for now.
+			continue
+		}
+
+		switch t {
+		case R_AARCH64_ABS64:
+			if rela.Off+8 >= uint64(len(dst)) || rela.Addend < 0 {
+				continue
+			}
+			f.ByteOrder.PutUint64(dst[rela.Off:rela.Off+8], uint64(rela.Addend))
+		case R_AARCH64_ABS32:
+			if rela.Off+4 >= uint64(len(dst)) || rela.Addend < 0 {
+				continue
+			}
+			f.ByteOrder.PutUint32(dst[rela.Off:rela.Off+4], uint32(rela.Addend))
+		}
+	}
+
+	return nil
+}
+
+func (f *File) applyRelocationsPPC64(dst []byte, rels []byte) error {
+	// 24 is the size of Rela64.
+	if len(rels)%24 != 0 {
+		return errors.New("length of relocation section is not a multiple of 24")
+	}
+
+	symbols, _, err := f.getSymbols(SHT_SYMTAB)
+	if err != nil {
+		return err
+	}
+
+	b := bytes.NewReader(rels)
+	var rela Rela64
+
+	for b.Len() > 0 {
+		binary.Read(b, f.ByteOrder, &rela)
+		symNo := rela.Info >> 32
+		t := R_PPC64(rela.Info & 0xffff)
+
+		if symNo == 0 || symNo > uint64(len(symbols)) {
+			continue
+		}
+		sym := &symbols[symNo-1]
+		if SymType(sym.Info&0xf) != STT_SECTION {
+			// We don't handle non-section relocations for now.
+			continue
+		}
+
+		switch t {
+		case R_PPC64_ADDR64:
+			if rela.Off+8 >= uint64(len(dst)) || rela.Addend < 0 {
+				continue
+			}
+			f.ByteOrder.PutUint64(dst[rela.Off:rela.Off+8], uint64(rela.Addend))
+		case R_PPC64_ADDR32:
+			if rela.Off+4 >= uint64(len(dst)) || rela.Addend < 0 {
+				continue
+			}
+			f.ByteOrder.PutUint32(dst[rela.Off:rela.Off+4], uint32(rela.Addend))
+		}
+	}
+
+	return nil
+}
+
+func (f *File) DWARF() (*dwarf.Data, error) {
+	// There are many other DWARF sections, but these
+	// are the required ones, and the debug/dwarf package
+	// does not use the others, so don't bother loading them.
+	var names = [...]string{"abbrev", "info", "str"}
+	var dat [len(names)][]byte
+	for i, name := range names {
+		name = ".debug_" + name
+		s := f.Section(name)
+		if s == nil {
+			continue
+		}
+		b, err := s.Data()
+		if err != nil && uint64(len(b)) < s.Size {
+			return nil, err
+		}
+		dat[i] = b
+	}
+
+	// If there's a relocation table for .debug_info, we have to process it
+	// now otherwise the data in .debug_info is invalid for x86-64 objects.
+	rela := f.Section(".rela.debug_info")
+	if rela != nil && rela.Type == SHT_RELA && (f.Machine == EM_X86_64 || f.Machine == EM_AARCH64 || f.Machine == EM_PPC64) {
+		data, err := rela.Data()
+		if err != nil {
+			return nil, err
+		}
+		err = f.applyRelocations(dat[1], data)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	// When using clang we need to process relocations even for 386.
+	rel := f.Section(".rel.debug_info")
+	if rel != nil && rel.Type == SHT_REL && f.Machine == EM_386 {
+		data, err := rel.Data()
+		if err != nil {
+			return nil, err
+		}
+		err = f.applyRelocations(dat[1], data)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	abbrev, info, str := dat[0], dat[1], dat[2]
+	d, err := dwarf.New(abbrev, nil, nil, info, nil, nil, nil, str)
+	if err != nil {
+		return nil, err
+	}
+
+	// Look for DWARF4 .debug_types sections.
+	for i, s := range f.Sections {
+		if s.Name == ".debug_types" {
+			b, err := s.Data()
+			if err != nil && uint64(len(b)) < s.Size {
+				return nil, err
+			}
+
+			for _, r := range f.Sections {
+				if r.Type != SHT_RELA && r.Type != SHT_REL {
+					continue
+				}
+				if int(r.Info) != i {
+					continue
+				}
+				rd, err := r.Data()
+				if err != nil {
+					return nil, err
+				}
+				err = f.applyRelocations(b, rd)
+				if err != nil {
+					return nil, err
+				}
+			}
+
+			err = d.AddTypes(fmt.Sprintf("types-%d", i), b)
+			if err != nil {
+				return nil, err
+			}
+		}
+	}
+
+	return d, nil
+}
+
+// Symbols returns the symbol table for f. The symbols will be listed in the order
+// they appear in f.
+//
+// For compatibility with Go 1.0, Symbols omits the null symbol at index 0.
+// After retrieving the symbols as symtab, an externally supplied index x
+// corresponds to symtab[x-1], not symtab[x].
+func (f *File) Symbols() ([]Symbol, error) {
+	sym, _, err := f.getSymbols(SHT_SYMTAB)
+	return sym, err
+}
+
+// DynamicSymbols returns the dynamic symbol table for f. The symbols
+// will be listed in the order they appear in f.
+//
+// For compatibility with Symbols, DynamicSymbols omits the null symbol at index 0.
+// After retrieving the symbols as symtab, an externally supplied index x
+// corresponds to symtab[x-1], not symtab[x].
+func (f *File) DynamicSymbols() ([]Symbol, error) {
+	sym, _, err := f.getSymbols(SHT_DYNSYM)
+	return sym, err
+}
+
+type ImportedSymbol struct {
+	Name    string
+	Version string
+	Library string
+}
+
+// ImportedSymbols returns the names of all symbols
+// referred to by the binary f that are expected to be
+// satisfied by other libraries at dynamic load time.
+// It does not return weak symbols.
+func (f *File) ImportedSymbols() ([]ImportedSymbol, error) {
+	sym, str, err := f.getSymbols(SHT_DYNSYM)
+	if err != nil {
+		return nil, err
+	}
+	f.gnuVersionInit(str)
+	var all []ImportedSymbol
+	for i, s := range sym {
+		if ST_BIND(s.Info) == STB_GLOBAL && s.Section == SHN_UNDEF {
+			all = append(all, ImportedSymbol{Name: s.Name})
+			f.gnuVersion(i, &all[len(all)-1])
+		}
+	}
+	return all, nil
+}
+
+type verneed struct {
+	File string
+	Name string
+}
+
+// gnuVersionInit parses the GNU version tables
+// for use by calls to gnuVersion.
+func (f *File) gnuVersionInit(str []byte) {
+	// Accumulate verneed information.
+	vn := f.SectionByType(SHT_GNU_VERNEED)
+	if vn == nil {
+		return
+	}
+	d, _ := vn.Data()
+
+	var need []verneed
+	i := 0
+	for {
+		if i+16 > len(d) {
+			break
+		}
+		vers := f.ByteOrder.Uint16(d[i : i+2])
+		if vers != 1 {
+			break
+		}
+		cnt := f.ByteOrder.Uint16(d[i+2 : i+4])
+		fileoff := f.ByteOrder.Uint32(d[i+4 : i+8])
+		aux := f.ByteOrder.Uint32(d[i+8 : i+12])
+		next := f.ByteOrder.Uint32(d[i+12 : i+16])
+		file, _ := getString(str, int(fileoff))
+
+		var name string
+		j := i + int(aux)
+		for c := 0; c < int(cnt); c++ {
+			if j+16 > len(d) {
+				break
+			}
+			// hash := f.ByteOrder.Uint32(d[j:j+4])
+			// flags := f.ByteOrder.Uint16(d[j+4:j+6])
+			other := f.ByteOrder.Uint16(d[j+6 : j+8])
+			nameoff := f.ByteOrder.Uint32(d[j+8 : j+12])
+			next := f.ByteOrder.Uint32(d[j+12 : j+16])
+			name, _ = getString(str, int(nameoff))
+			ndx := int(other)
+			if ndx >= len(need) {
+				a := make([]verneed, 2*(ndx+1))
+				copy(a, need)
+				need = a
+			}
+
+			need[ndx] = verneed{file, name}
+			if next == 0 {
+				break
+			}
+			j += int(next)
+		}
+
+		if next == 0 {
+			break
+		}
+		i += int(next)
+	}
+
+	// Versym parallels symbol table, indexing into verneed.
+	vs := f.SectionByType(SHT_GNU_VERSYM)
+	if vs == nil {
+		return
+	}
+	d, _ = vs.Data()
+
+	f.gnuNeed = need
+	f.gnuVersym = d
+}
+
+// gnuVersion adds Library and Version information to sym,
+// which came from offset i of the symbol table.
+func (f *File) gnuVersion(i int, sym *ImportedSymbol) {
+	// Each entry is two bytes.
+	i = (i + 1) * 2
+	if i >= len(f.gnuVersym) {
+		return
+	}
+	j := int(f.ByteOrder.Uint16(f.gnuVersym[i:]))
+	if j < 2 || j >= len(f.gnuNeed) {
+		return
+	}
+	n := &f.gnuNeed[j]
+	sym.Library = n.File
+	sym.Version = n.Name
+}
+
+// ImportedLibraries returns the names of all libraries
+// referred to by the binary f that are expected to be
+// linked with the binary at dynamic link time.
+func (f *File) ImportedLibraries() ([]string, error) {
+	return f.DynString(DT_NEEDED)
+}
+
+// DynString returns the strings listed for the given tag in the file's dynamic
+// section.
+//
+// The tag must be one that takes string values: DT_NEEDED, DT_SONAME, DT_RPATH, or
+// DT_RUNPATH.
+func (f *File) DynString(tag DynTag) ([]string, error) {
+	switch tag {
+	case DT_NEEDED, DT_SONAME, DT_RPATH, DT_RUNPATH:
+	default:
+		return nil, fmt.Errorf("non-string-valued tag %v", tag)
+	}
+	ds := f.SectionByType(SHT_DYNAMIC)
+	if ds == nil {
+		// not dynamic, so no libraries
+		return nil, nil
+	}
+	d, err := ds.Data()
+	if err != nil {
+		return nil, err
+	}
+	str, err := f.stringTable(ds.Link)
+	if err != nil {
+		return nil, err
+	}
+	var all []string
+	for len(d) > 0 {
+		var t DynTag
+		var v uint64
+		switch f.Class {
+		case ELFCLASS32:
+			t = DynTag(f.ByteOrder.Uint32(d[0:4]))
+			v = uint64(f.ByteOrder.Uint32(d[4:8]))
+			d = d[8:]
+		case ELFCLASS64:
+			t = DynTag(f.ByteOrder.Uint64(d[0:8]))
+			v = f.ByteOrder.Uint64(d[8:16])
+			d = d[16:]
+		}
+		if t == tag {
+			s, ok := getString(str, int(v))
+			if ok {
+				all = append(all, s)
+			}
+		}
+	}
+	return all, nil
+}
diff --git a/src/debug/elf/file_test.go b/src/debug/elf/file_test.go
new file mode 100644
index 000000000..d57aaab0e
--- /dev/null
+++ b/src/debug/elf/file_test.go
@@ -0,0 +1,351 @@
+// Copyright 2009 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package elf
+
+import (
+	"bytes"
+	"compress/gzip"
+	"debug/dwarf"
+	"encoding/binary"
+	"io"
+	"net"
+	"os"
+	"path"
+	"reflect"
+	"runtime"
+	"testing"
+)
+
+type fileTest struct {
+	file     string
+	hdr      FileHeader
+	sections []SectionHeader
+	progs    []ProgHeader
+	needed   []string
+}
+
+var fileTests = []fileTest{
+	{
+		"testdata/gcc-386-freebsd-exec",
+		FileHeader{ELFCLASS32, ELFDATA2LSB, EV_CURRENT, ELFOSABI_FREEBSD, 0, binary.LittleEndian, ET_EXEC, EM_386, 0x80483cc},
+		[]SectionHeader{
+			{"", SHT_NULL, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0},
+			{".interp", SHT_PROGBITS, SHF_ALLOC, 0x80480d4, 0xd4, 0x15, 0x0, 0x0, 0x1, 0x0},
+			{".hash", SHT_HASH, SHF_ALLOC, 0x80480ec, 0xec, 0x90, 0x3, 0x0, 0x4, 0x4},
+			{".dynsym", SHT_DYNSYM, SHF_ALLOC, 0x804817c, 0x17c, 0x110, 0x4, 0x1, 0x4, 0x10},
+			{".dynstr", SHT_STRTAB, SHF_ALLOC, 0x804828c, 0x28c, 0xbb, 0x0, 0x0, 0x1, 0x0},
+			{".rel.plt", SHT_REL, SHF_ALLOC, 0x8048348, 0x348, 0x20, 0x3, 0x7, 0x4, 0x8},
+			{".init", SHT_PROGBITS, SHF_ALLOC + SHF_EXECINSTR, 0x8048368, 0x368, 0x11, 0x0, 0x0, 0x4, 0x0},
+			{".plt", SHT_PROGBITS, SHF_ALLOC + SHF_EXECINSTR, 0x804837c, 0x37c, 0x50, 0x0, 0x0, 0x4, 0x4},
+			{".text", SHT_PROGBITS, SHF_ALLOC + SHF_EXECINSTR, 0x80483cc, 0x3cc, 0x180, 0x0, 0x0, 0x4, 0x0},
+			{".fini", SHT_PROGBITS, SHF_ALLOC + SHF_EXECINSTR, 0x804854c, 0x54c, 0xc, 0x0, 0x0, 0x4, 0x0},
+			{".rodata", SHT_PROGBITS, SHF_ALLOC, 0x8048558, 0x558, 0xa3, 0x0, 0x0, 0x1, 0x0},
+			{".data", SHT_PROGBITS, SHF_WRITE + SHF_ALLOC, 0x80495fc, 0x5fc, 0xc, 0x0, 0x0, 0x4, 0x0},
+			{".eh_frame", SHT_PROGBITS, SHF_ALLOC, 0x8049608, 0x608, 0x4, 0x0, 0x0, 0x4, 0x0},
+			{".dynamic", SHT_DYNAMIC, SHF_WRITE + SHF_ALLOC, 0x804960c, 0x60c, 0x98, 0x4, 0x0, 0x4, 0x8},
+			{".ctors", SHT_PROGBITS, SHF_WRITE + SHF_ALLOC, 0x80496a4, 0x6a4, 0x8, 0x0, 0x0, 0x4, 0x0},
+			{".dtors", SHT_PROGBITS, SHF_WRITE + SHF_ALLOC, 0x80496ac, 0x6ac, 0x8, 0x0, 0x0, 0x4, 0x0},
+			{".jcr", SHT_PROGBITS, SHF_WRITE + SHF_ALLOC, 0x80496b4, 0x6b4, 0x4, 0x0, 0x0, 0x4, 0x0},
+			{".got", SHT_PROGBITS, SHF_WRITE + SHF_ALLOC, 0x80496b8, 0x6b8, 0x1c, 0x0, 0x0, 0x4, 0x4},
+			{".bss", SHT_NOBITS, SHF_WRITE + SHF_ALLOC, 0x80496d4, 0x6d4, 0x20, 0x0, 0x0, 0x4, 0x0},
+			{".comment", SHT_PROGBITS, 0x0, 0x0, 0x6d4, 0x12d, 0x0, 0x0, 0x1, 0x0},
+			{".debug_aranges", SHT_PROGBITS, 0x0, 0x0, 0x801, 0x20, 0x0, 0x0, 0x1, 0x0},
+			{".debug_pubnames", SHT_PROGBITS, 0x0, 0x0, 0x821, 0x1b, 0x0, 0x0, 0x1, 0x0},
+			{".debug_info", SHT_PROGBITS, 0x0, 0x0, 0x83c, 0x11d, 0x0, 0x0, 0x1, 0x0},
+			{".debug_abbrev", SHT_PROGBITS, 0x0, 0x0, 0x959, 0x41, 0x0, 0x0, 0x1, 0x0},
+			{".debug_line", SHT_PROGBITS, 0x0, 0x0, 0x99a, 0x35, 0x0, 0x0, 0x1, 0x0},
+			{".debug_frame", SHT_PROGBITS, 0x0, 0x0, 0x9d0, 0x30, 0x0, 0x0, 0x4, 0x0},
+			{".debug_str", SHT_PROGBITS, 0x0, 0x0, 0xa00, 0xd, 0x0, 0x0, 0x1, 0x0},
+			{".shstrtab", SHT_STRTAB, 0x0, 0x0, 0xa0d, 0xf8, 0x0, 0x0, 0x1, 0x0},
+			{".symtab", SHT_SYMTAB, 0x0, 0x0, 0xfb8, 0x4b0, 0x1d, 0x38, 0x4, 0x10},
+			{".strtab", SHT_STRTAB, 0x0, 0x0, 0x1468, 0x206, 0x0, 0x0, 0x1, 0x0},
+		},
+		[]ProgHeader{
+			{PT_PHDR, PF_R + PF_X, 0x34, 0x8048034, 0x8048034, 0xa0, 0xa0, 0x4},
+			{PT_INTERP, PF_R, 0xd4, 0x80480d4, 0x80480d4, 0x15, 0x15, 0x1},
+			{PT_LOAD, PF_R + PF_X, 0x0, 0x8048000, 0x8048000, 0x5fb, 0x5fb, 0x1000},
+			{PT_LOAD, PF_R + PF_W, 0x5fc, 0x80495fc, 0x80495fc, 0xd8, 0xf8, 0x1000},
+			{PT_DYNAMIC, PF_R + PF_W, 0x60c, 0x804960c, 0x804960c, 0x98, 0x98, 0x4},
+		},
+		[]string{"libc.so.6"},
+	},
+	{
+		"testdata/gcc-amd64-linux-exec",
+		FileHeader{ELFCLASS64, ELFDATA2LSB, EV_CURRENT, ELFOSABI_NONE, 0, binary.LittleEndian, ET_EXEC, EM_X86_64, 0x4003e0},
+		[]SectionHeader{
+			{"", SHT_NULL, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0},
+			{".interp", SHT_PROGBITS, SHF_ALLOC, 0x400200, 0x200, 0x1c, 0x0, 0x0, 0x1, 0x0},
+			{".note.ABI-tag", SHT_NOTE, SHF_ALLOC, 0x40021c, 0x21c, 0x20, 0x0, 0x0, 0x4, 0x0},
+			{".hash", SHT_HASH, SHF_ALLOC, 0x400240, 0x240, 0x24, 0x5, 0x0, 0x8, 0x4},
+			{".gnu.hash", SHT_LOOS + 268435446, SHF_ALLOC, 0x400268, 0x268, 0x1c, 0x5, 0x0, 0x8, 0x0},
+			{".dynsym", SHT_DYNSYM, SHF_ALLOC, 0x400288, 0x288, 0x60, 0x6, 0x1, 0x8, 0x18},
+			{".dynstr", SHT_STRTAB, SHF_ALLOC, 0x4002e8, 0x2e8, 0x3d, 0x0, 0x0, 0x1, 0x0},
+			{".gnu.version", SHT_HIOS, SHF_ALLOC, 0x400326, 0x326, 0x8, 0x5, 0x0, 0x2, 0x2},
+			{".gnu.version_r", SHT_LOOS + 268435454, SHF_ALLOC, 0x400330, 0x330, 0x20, 0x6, 0x1, 0x8, 0x0},
+			{".rela.dyn", SHT_RELA, SHF_ALLOC, 0x400350, 0x350, 0x18, 0x5, 0x0, 0x8, 0x18},
+			{".rela.plt", SHT_RELA, SHF_ALLOC, 0x400368, 0x368, 0x30, 0x5, 0xc, 0x8, 0x18},
+			{".init", SHT_PROGBITS, SHF_ALLOC + SHF_EXECINSTR, 0x400398, 0x398, 0x18, 0x0, 0x0, 0x4, 0x0},
+			{".plt", SHT_PROGBITS, SHF_ALLOC + SHF_EXECINSTR, 0x4003b0, 0x3b0, 0x30, 0x0, 0x0, 0x4, 0x10},
+			{".text", SHT_PROGBITS, SHF_ALLOC + SHF_EXECINSTR, 0x4003e0, 0x3e0, 0x1b4, 0x0, 0x0, 0x10, 0x0},
+			{".fini", SHT_PROGBITS, SHF_ALLOC + SHF_EXECINSTR, 0x400594, 0x594, 0xe, 0x0, 0x0, 0x4, 0x0},
+			{".rodata", SHT_PROGBITS, SHF_ALLOC, 0x4005a4, 0x5a4, 0x11, 0x0, 0x0, 0x4, 0x0},
+			{".eh_frame_hdr", SHT_PROGBITS, SHF_ALLOC, 0x4005b8, 0x5b8, 0x24, 0x0, 0x0, 0x4, 0x0},
+			{".eh_frame", SHT_PROGBITS, SHF_ALLOC, 0x4005e0, 0x5e0, 0xa4, 0x0, 0x0, 0x8, 0x0},
+			{".ctors", SHT_PROGBITS, SHF_WRITE + SHF_ALLOC, 0x600688, 0x688, 0x10, 0x0, 0x0, 0x8, 0x0},
+			{".dtors", SHT_PROGBITS, SHF_WRITE + SHF_ALLOC, 0x600698, 0x698, 0x10, 0x0, 0x0, 0x8, 0x0},
+			{".jcr", SHT_PROGBITS, SHF_WRITE + SHF_ALLOC, 0x6006a8, 0x6a8, 0x8, 0x0, 0x0, 0x8, 0x0},
+			{".dynamic", SHT_DYNAMIC, SHF_WRITE + SHF_ALLOC, 0x6006b0, 0x6b0, 0x1a0, 0x6, 0x0, 0x8, 0x10},
+			{".got", SHT_PROGBITS, SHF_WRITE + SHF_ALLOC, 0x600850, 0x850, 0x8, 0x0, 0x0, 0x8, 0x8},
+			{".got.plt", SHT_PROGBITS, SHF_WRITE + SHF_ALLOC, 0x600858, 0x858, 0x28, 0x0, 0x0, 0x8, 0x8},
+			{".data", SHT_PROGBITS, SHF_WRITE + SHF_ALLOC, 0x600880, 0x880, 0x18, 0x0, 0x0, 0x8, 0x0},
+			{".bss", SHT_NOBITS, SHF_WRITE + SHF_ALLOC, 0x600898, 0x898, 0x8, 0x0, 0x0, 0x4, 0x0},
+			{".comment", SHT_PROGBITS, 0x0, 0x0, 0x898, 0x126, 0x0, 0x0, 0x1, 0x0},
+			{".debug_aranges", SHT_PROGBITS, 0x0, 0x0, 0x9c0, 0x90, 0x0, 0x0, 0x10, 0x0},
+			{".debug_pubnames", SHT_PROGBITS, 0x0, 0x0, 0xa50, 0x25, 0x0, 0x0, 0x1, 0x0},
+			{".debug_info", SHT_PROGBITS, 0x0, 0x0, 0xa75, 0x1a7, 0x0, 0x0, 0x1, 0x0},
+			{".debug_abbrev", SHT_PROGBITS, 0x0, 0x0, 0xc1c, 0x6f, 0x0, 0x0, 0x1, 0x0},
+			{".debug_line", SHT_PROGBITS, 0x0, 0x0, 0xc8b, 0x13f, 0x0, 0x0, 0x1, 0x0},
+			{".debug_str", SHT_PROGBITS, SHF_MERGE + SHF_STRINGS, 0x0, 0xdca, 0xb1, 0x0, 0x0, 0x1, 0x1},
+			{".debug_ranges", SHT_PROGBITS, 0x0, 0x0, 0xe80, 0x90, 0x0, 0x0, 0x10, 0x0},
+			{".shstrtab", SHT_STRTAB, 0x0, 0x0, 0xf10, 0x149, 0x0, 0x0, 0x1, 0x0},
+			{".symtab", SHT_SYMTAB, 0x0, 0x0, 0x19a0, 0x6f0, 0x24, 0x39, 0x8, 0x18},
+			{".strtab", SHT_STRTAB, 0x0, 0x0, 0x2090, 0x1fc, 0x0, 0x0, 0x1, 0x0},
+		},
+		[]ProgHeader{
+			{PT_PHDR, PF_R + PF_X, 0x40, 0x400040, 0x400040, 0x1c0, 0x1c0, 0x8},
+			{PT_INTERP, PF_R, 0x200, 0x400200, 0x400200, 0x1c, 0x1c, 1},
+			{PT_LOAD, PF_R + PF_X, 0x0, 0x400000, 0x400000, 0x684, 0x684, 0x200000},
+			{PT_LOAD, PF_R + PF_W, 0x688, 0x600688, 0x600688, 0x210, 0x218, 0x200000},
+			{PT_DYNAMIC, PF_R + PF_W, 0x6b0, 0x6006b0, 0x6006b0, 0x1a0, 0x1a0, 0x8},
+			{PT_NOTE, PF_R, 0x21c, 0x40021c, 0x40021c, 0x20, 0x20, 0x4},
+			{PT_LOOS + 0x474E550, PF_R, 0x5b8, 0x4005b8, 0x4005b8, 0x24, 0x24, 0x4},
+			{PT_LOOS + 0x474E551, PF_R + PF_W, 0x0, 0x0, 0x0, 0x0, 0x0, 0x8},
+		},
+		[]string{"libc.so.6"},
+	},
+	{
+		"testdata/hello-world-core.gz",
+		FileHeader{ELFCLASS64, ELFDATA2LSB, EV_CURRENT, ELFOSABI_NONE, 0x0, binary.LittleEndian, ET_CORE, EM_X86_64, 0x0},
+		[]SectionHeader{},
+		[]ProgHeader{
+			{Type: PT_NOTE, Flags: 0x0, Off: 0x3f8, Vaddr: 0x0, Paddr: 0x0, Filesz: 0x8ac, Memsz: 0x0, Align: 0x0},
+			{Type: PT_LOAD, Flags: PF_X + PF_R, Off: 0x1000, Vaddr: 0x400000, Paddr: 0x0, Filesz: 0x0, Memsz: 0x1000, Align: 0x1000},
+			{Type: PT_LOAD, Flags: PF_R, Off: 0x1000, Vaddr: 0x401000, Paddr: 0x0, Filesz: 0x1000, Memsz: 0x1000, Align: 0x1000},
+			{Type: PT_LOAD, Flags: PF_W + PF_R, Off: 0x2000, Vaddr: 0x402000, Paddr: 0x0, Filesz: 0x1000, Memsz: 0x1000, Align: 0x1000},
+			{Type: PT_LOAD, Flags: PF_X + PF_R, Off: 0x3000, Vaddr: 0x7f54078b8000, Paddr: 0x0, Filesz: 0x0, Memsz: 0x1b5000, Align: 0x1000},
+			{Type: PT_LOAD, Flags: 0x0, Off: 0x3000, Vaddr: 0x7f5407a6d000, Paddr: 0x0, Filesz: 0x0, Memsz: 0x1ff000, Align: 0x1000},
+			{Type: PT_LOAD, Flags: PF_R, Off: 0x3000, Vaddr: 0x7f5407c6c000, Paddr: 0x0, Filesz: 0x4000, Memsz: 0x4000, Align: 0x1000},
+			{Type: PT_LOAD, Flags: PF_W + PF_R, Off: 0x7000, Vaddr: 0x7f5407c70000, Paddr: 0x0, Filesz: 0x2000, Memsz: 0x2000, Align: 0x1000},
+			{Type: PT_LOAD, Flags: PF_W + PF_R, Off: 0x9000, Vaddr: 0x7f5407c72000, Paddr: 0x0, Filesz: 0x5000, Memsz: 0x5000, Align: 0x1000},
+			{Type: PT_LOAD, Flags: PF_X + PF_R, Off: 0xe000, Vaddr: 0x7f5407c77000, Paddr: 0x0, Filesz: 0x0, Memsz: 0x22000, Align: 0x1000},
+			{Type: PT_LOAD, Flags: PF_W + PF_R, Off: 0xe000, Vaddr: 0x7f5407e81000, Paddr: 0x0, Filesz: 0x3000, Memsz: 0x3000, Align: 0x1000},
+			{Type: PT_LOAD, Flags: PF_W + PF_R, Off: 0x11000, Vaddr: 0x7f5407e96000, Paddr: 0x0, Filesz: 0x3000, Memsz: 0x3000, Align: 0x1000},
+			{Type: PT_LOAD, Flags: PF_R, Off: 0x14000, Vaddr: 0x7f5407e99000, Paddr: 0x0, Filesz: 0x1000, Memsz: 0x1000, Align: 0x1000},
+			{Type: PT_LOAD, Flags: PF_W + PF_R, Off: 0x15000, Vaddr: 0x7f5407e9a000, Paddr: 0x0, Filesz: 0x2000, Memsz: 0x2000, Align: 0x1000},
+			{Type: PT_LOAD, Flags: PF_W + PF_R, Off: 0x17000, Vaddr: 0x7fff79972000, Paddr: 0x0, Filesz: 0x23000, Memsz: 0x23000, Align: 0x1000},
+			{Type: PT_LOAD, Flags: PF_X + PF_R, Off: 0x3a000, Vaddr: 0x7fff799f8000, Paddr: 0x0, Filesz: 0x1000, Memsz: 0x1000, Align: 0x1000},
+			{Type: PT_LOAD, Flags: PF_X + PF_R, Off: 0x3b000, Vaddr: 0xffffffffff600000, Paddr: 0x0, Filesz: 0x1000, Memsz: 0x1000, Align: 0x1000},
+		},
+		nil,
+	},
+}
+
+func TestOpen(t *testing.T) {
+	for i := range fileTests {
+		tt := &fileTests[i]
+
+		var f *File
+		var err error
+		if path.Ext(tt.file) == ".gz" {
+			var r io.ReaderAt
+			if r, err = decompress(tt.file); err == nil {
+				f, err = NewFile(r)
+			}
+		} else {
+			f, err = Open(tt.file)
+		}
+		if err != nil {
+			t.Errorf("cannot open file %s: %v", tt.file, err)
+			continue
+		}
+		defer f.Close()
+		if !reflect.DeepEqual(f.FileHeader, tt.hdr) {
+			t.Errorf("open %s:\n\thave %#v\n\twant %#v\n", tt.file, f.FileHeader, tt.hdr)
+			continue
+		}
+		for i, s := range f.Sections {
+			if i >= len(tt.sections) {
+				break
+			}
+			sh := &tt.sections[i]
+			if !reflect.DeepEqual(&s.SectionHeader, sh) {
+				t.Errorf("open %s, section %d:\n\thave %#v\n\twant %#v\n", tt.file, i, &s.SectionHeader, sh)
+			}
+		}
+		for i, p := range f.Progs {
+			if i >= len(tt.progs) {
+				break
+			}
+			ph := &tt.progs[i]
+			if !reflect.DeepEqual(&p.ProgHeader, ph) {
+				t.Errorf("open %s, program %d:\n\thave %#v\n\twant %#v\n", tt.file, i, &p.ProgHeader, ph)
+			}
+		}
+		tn := len(tt.sections)
+		fn := len(f.Sections)
+		if tn != fn {
+			t.Errorf("open %s: len(Sections) = %d, want %d", tt.file, fn, tn)
+		}
+		tn = len(tt.progs)
+		fn = len(f.Progs)
+		if tn != fn {
+			t.Errorf("open %s: len(Progs) = %d, want %d", tt.file, fn, tn)
+		}
+		tl := tt.needed
+		fl, err := f.ImportedLibraries()
+		if err != nil {
+			t.Error(err)
+		}
+		if !reflect.DeepEqual(tl, fl) {
+			t.Errorf("open %s: DT_NEEDED = %v, want %v", tt.file, tl, fl)
+		}
+	}
+}
+
+// elf.NewFile requires io.ReaderAt, which compress/gzip cannot
+// provide. Decompress the file to a bytes.Reader.
+func decompress(gz string) (io.ReaderAt, error) {
+	in, err := os.Open(gz)
+	if err != nil {
+		return nil, err
+	}
+	defer in.Close()
+	r, err := gzip.NewReader(in)
+	if err != nil {
+		return nil, err
+	}
+	var out bytes.Buffer
+	_, err = io.Copy(&out, r)
+	return bytes.NewReader(out.Bytes()), err
+}
+
+type relocationTestEntry struct {
+	entryNumber int
+	entry       *dwarf.Entry
+}
+
+type relocationTest struct {
+	file    string
+	entries []relocationTestEntry
+}
+
+var relocationTests = []relocationTest{
+	{
+		"testdata/go-relocation-test-gcc441-x86-64.obj",
+		[]relocationTestEntry{
+			{0, &dwarf.Entry{Offset: 0xb, Tag: dwarf.TagCompileUnit, Children: true, Field: []dwarf.Field{{Attr: dwarf.AttrProducer, Val: "GNU C 4.4.1"}, {Attr: dwarf.AttrLanguage, Val: int64(1)}, {Attr: dwarf.AttrName, Val: "go-relocation-test.c"}, {Attr: dwarf.AttrCompDir, Val: "/tmp"}, {Attr: dwarf.AttrLowpc, Val: uint64(0x0)}, {Attr: dwarf.AttrHighpc, Val: uint64(0x6)}, {Attr: dwarf.AttrStmtList, Val: int64(0)}}}},
+		},
+	},
+	{
+		"testdata/go-relocation-test-gcc441-x86.obj",
+		[]relocationTestEntry{
+			{0, &dwarf.Entry{Offset: 0xb, Tag: dwarf.TagCompileUnit, Children: true, Field: []dwarf.Field{{Attr: dwarf.AttrProducer, Val: "GNU C 4.4.1"}, {Attr: dwarf.AttrLanguage, Val: int64(1)}, {Attr: dwarf.AttrName, Val: "t.c"}, {Attr: dwarf.AttrCompDir, Val: "/tmp"}, {Attr: dwarf.AttrLowpc, Val: uint64(0x0)}, {Attr: dwarf.AttrHighpc, Val: uint64(0x5)}, {Attr: dwarf.AttrStmtList, Val: int64(0)}}}},
+		},
+	},
+	{
+		"testdata/go-relocation-test-gcc424-x86-64.obj",
+		[]relocationTestEntry{
+			{0, &dwarf.Entry{Offset: 0xb, Tag: dwarf.TagCompileUnit, Children: true, Field: []dwarf.Field{{Attr: dwarf.AttrProducer, Val: "GNU C 4.2.4 (Ubuntu 4.2.4-1ubuntu4)"}, {Attr: dwarf.AttrLanguage, Val: int64(1)}, {Attr: dwarf.AttrName, Val: "go-relocation-test-gcc424.c"}, {Attr: dwarf.AttrCompDir, Val: "/tmp"}, {Attr: dwarf.AttrLowpc, Val: uint64(0x0)}, {Attr: dwarf.AttrHighpc, Val: uint64(0x6)}, {Attr: dwarf.AttrStmtList, Val: int64(0)}}}},
+		},
+	},
+	{
+		"testdata/go-relocation-test-gcc482-aarch64.obj",
+		[]relocationTestEntry{
+			{0, &dwarf.Entry{Offset: 0xb, Tag: dwarf.TagCompileUnit, Children: true, Field: []dwarf.Field{{Attr: dwarf.AttrProducer, Val: "GNU C 4.8.2 -g -fstack-protector"}, {Attr: dwarf.AttrLanguage, Val: int64(1)}, {Attr: dwarf.AttrName, Val: "go-relocation-test-gcc482.c"}, {Attr: dwarf.AttrCompDir, Val: "/tmp"}, {Attr: dwarf.AttrLowpc, Val: uint64(0x0)}, {Attr: dwarf.AttrHighpc, Val: int64(0x24)}, {Attr: dwarf.AttrStmtList, Val: int64(0)}}}},
+		},
+	},
+	{
+		"testdata/go-relocation-test-gcc482-ppc64le.obj",
+		[]relocationTestEntry{
+			{0, &dwarf.Entry{Offset: 0xb, Tag: dwarf.TagCompileUnit, Children: true, Field: []dwarf.Field{dwarf.Field{Attr: dwarf.AttrProducer, Val: "GNU C 4.8.2 -Asystem=linux -Asystem=unix -Asystem=posix -msecure-plt -mtune=power8 -mcpu=power7 -gdwarf-2 -fstack-protector"}, dwarf.Field{Attr: dwarf.AttrLanguage, Val: int64(1)}, dwarf.Field{Attr: dwarf.AttrName, Val: "go-relocation-test-gcc482-ppc64le.c"}, dwarf.Field{Attr: dwarf.AttrCompDir, Val: "/tmp"}, dwarf.Field{Attr: dwarf.AttrLowpc, Val: uint64(0x0)}, dwarf.Field{Attr: dwarf.AttrHighpc, Val: uint64(0x24)}, dwarf.Field{Attr: dwarf.AttrStmtList, Val: int64(0)}}}},
+		},
+	},
+	{
+		"testdata/go-relocation-test-clang-x86.obj",
+		[]relocationTestEntry{
+			{0, &dwarf.Entry{Offset: 0xb, Tag: dwarf.TagCompileUnit, Children: true, Field: []dwarf.Field{{Attr: dwarf.AttrProducer, Val: "clang version google3-trunk (trunk r209387)"}, {Attr: dwarf.AttrLanguage, Val: int64(12)}, {Attr: dwarf.AttrName, Val: "go-relocation-test-clang.c"}, {Attr: dwarf.AttrStmtList, Val: int64(0)}, {Attr: dwarf.AttrCompDir, Val: "/tmp"}}}},
+		},
+	},
+	{
+		"testdata/gcc-amd64-openbsd-debug-with-rela.obj",
+		[]relocationTestEntry{
+			{203, &dwarf.Entry{Offset: 0xc62, Tag: dwarf.TagMember, Children: false, Field: []dwarf.Field{{Attr: dwarf.AttrName, Val: "it_interval"}, {Attr: dwarf.AttrDeclFile, Val: int64(7)}, {Attr: dwarf.AttrDeclLine, Val: int64(236)}, {Attr: dwarf.AttrType, Val: dwarf.Offset(0xb7f)}, {Attr: dwarf.AttrDataMemberLoc, Val: []byte{0x23, 0x0}}}}},
+			{204, &dwarf.Entry{Offset: 0xc70, Tag: dwarf.TagMember, Children: false, Field: []dwarf.Field{{Attr: dwarf.AttrName, Val: "it_value"}, {Attr: dwarf.AttrDeclFile, Val: int64(7)}, {Attr: dwarf.AttrDeclLine, Val: int64(237)}, {Attr: dwarf.AttrType, Val: dwarf.Offset(0xb7f)}, {Attr: dwarf.AttrDataMemberLoc, Val: []byte{0x23, 0x10}}}}},
+		},
+	},
+}
+
+func TestDWARFRelocations(t *testing.T) {
+	for i, test := range relocationTests {
+		f, err := Open(test.file)
+		if err != nil {
+			t.Error(err)
+			continue
+		}
+		dwarf, err := f.DWARF()
+		if err != nil {
+			t.Error(err)
+			continue
+		}
+		for _, testEntry := range test.entries {
+			reader := dwarf.Reader()
+			for j := 0; j < testEntry.entryNumber; j++ {
+				entry, err := reader.Next()
+				if entry == nil || err != nil {
+					t.Errorf("Failed to skip to entry %d: %v", testEntry.entryNumber, err)
+					continue
+				}
+			}
+			entry, err := reader.Next()
+			if err != nil {
+				t.Error(err)
+				continue
+			}
+			if !reflect.DeepEqual(testEntry.entry, entry) {
+				t.Errorf("#%d/%d: mismatch: got:%#v want:%#v", i, testEntry.entryNumber, entry, testEntry.entry)
+				continue
+			}
+		}
+	}
+}
+
+func TestNoSectionOverlaps(t *testing.T) {
+	// Ensure 6l outputs sections without overlaps.
+	if runtime.GOOS != "linux" && runtime.GOOS != "freebsd" {
+		return // not ELF
+	}
+	_ = net.ResolveIPAddr // force dynamic linkage
+	f, err := Open(os.Args[0])
+	if err != nil {
+		t.Error(err)
+		return
+	}
+	for i, si := range f.Sections {
+		sih := si.SectionHeader
+		if sih.Type == SHT_NOBITS {
+			continue
+		}
+		for j, sj := range f.Sections {
+			sjh := sj.SectionHeader
+			if i == j || sjh.Type == SHT_NOBITS || sih.Offset == sjh.Offset && sih.Size == 0 {
+				continue
+			}
+			if sih.Offset >= sjh.Offset && sih.Offset < sjh.Offset+sjh.Size {
+				t.Errorf("ld produced ELF with section %s within %s: 0x%x <= 0x%x..0x%x < 0x%x",
+					sih.Name, sjh.Name, sjh.Offset, sih.Offset, sih.Offset+sih.Size, sjh.Offset+sjh.Size)
+			}
+		}
+	}
+}
diff --git a/src/debug/elf/symbols_test.go b/src/debug/elf/symbols_test.go
new file mode 100644
index 000000000..1b79520e3
--- /dev/null
+++ b/src/debug/elf/symbols_test.go
@@ -0,0 +1,834 @@
+// Copyright 2014 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package elf
+
+import (
+	"io"
+	"path"
+	"reflect"
+	"testing"
+)
+
+// TODO: remove duplicate code
+func TestSymbols(t *testing.T) {
+	do := func(file string, ts []Symbol, getfunc func(*File) ([]Symbol, error)) {
+		var f *File
+		var err error
+		if path.Ext(file) == ".gz" {
+			var r io.ReaderAt
+			if r, err = decompress(file); err == nil {
+				f, err = NewFile(r)
+			}
+		} else {
+			f, err = Open(file)
+		}
+		if err != nil {
+			t.Errorf("TestSymbols: cannot open file %s: %v", file, err)
+			return
+		}
+		defer f.Close()
+		fs, err := getfunc(f)
+		if err != nil && err != ErrNoSymbols {
+			t.Error(err)
+			return
+		} else if err == ErrNoSymbols {
+			fs = []Symbol{}
+		}
+		if !reflect.DeepEqual(ts, fs) {
+			t.Errorf("%s: Symbols = %v, want %v", file, ts, fs)
+		}
+	}
+	for file, ts := range symbolsGolden {
+		do(file, ts, (*File).Symbols)
+	}
+	for file, ts := range dynamicSymbolsGolden {
+		do(file, ts, (*File).DynamicSymbols)
+	}
+}
+
+// golden symbol table data generated by testdata/getgoldsym.c
+
+var symbolsGolden = map[string][]Symbol{
+	"testdata/gcc-amd64-linux-exec": {
+		Symbol{
+			Name:    "",
+			Info:    0x3,
+			Other:   0x0,
+			Section: 0x1,
+			Value:   0x400200,
+			Size:    0x0,
+		},
+		Symbol{
+			Name:    "",
+			Info:    0x3,
+			Other:   0x0,
+			Section: 0x2,
+			Value:   0x40021C,
+			Size:    0x0,
+		},
+		Symbol{
+			Name:    "",
+			Info:    0x3,
+			Other:   0x0,
+			Section: 0x3,
+			Value:   0x400240,
+			Size:    0x0,
+		},
+		Symbol{
+			Name:    "",
+			Info:    0x3,
+			Other:   0x0,
+			Section: 0x4,
+			Value:   0x400268,
+			Size:    0x0,
+		},
+		Symbol{
+			Name:    "",
+			Info:    0x3,
+			Other:   0x0,
+			Section: 0x5,
+			Value:   0x400288,
+			Size:    0x0,
+		},
+		Symbol{
+			Name:    "",
+			Info:    0x3,
+			Other:   0x0,
+			Section: 0x6,
+			Value:   0x4002E8,
+			Size:    0x0,
+		},
+		Symbol{
+			Name:    "",
+			Info:    0x3,
+			Other:   0x0,
+			Section: 0x7,
+			Value:   0x400326,
+			Size:    0x0,
+		},
+		Symbol{
+			Name:    "",
+			Info:    0x3,
+			Other:   0x0,
+			Section: 0x8,
+			Value:   0x400330,
+			Size:    0x0,
+		},
+		Symbol{
+			Name:    "",
+			Info:    0x3,
+			Other:   0x0,
+			Section: 0x9,
+			Value:   0x400350,
+			Size:    0x0,
+		},
+		Symbol{
+			Name:    "",
+			Info:    0x3,
+			Other:   0x0,
+			Section: 0xA,
+			Value:   0x400368,
+			Size:    0x0,
+		},
+		Symbol{
+			Name:    "",
+			Info:    0x3,
+			Other:   0x0,
+			Section: 0xB,
+			Value:   0x400398,
+			Size:    0x0,
+		},
+		Symbol{
+			Name:    "",
+			Info:    0x3,
+			Other:   0x0,
+			Section: 0xC,
+			Value:   0x4003B0,
+			Size:    0x0,
+		},
+		Symbol{
+			Name:    "",
+			Info:    0x3,
+			Other:   0x0,
+			Section: 0xD,
+			Value:   0x4003E0,
+			Size:    0x0,
+		},
+		Symbol{
+			Name:    "",
+			Info:    0x3,
+			Other:   0x0,
+			Section: 0xE,
+			Value:   0x400594,
+			Size:    0x0,
+		},
+		Symbol{
+			Name:    "",
+			Info:    0x3,
+			Other:   0x0,
+			Section: 0xF,
+			Value:   0x4005A4,
+			Size:    0x0,
+		},
+		Symbol{
+			Name:    "",
+			Info:    0x3,
+			Other:   0x0,
+			Section: 0x10,
+			Value:   0x4005B8,
+			Size:    0x0,
+		},
+		Symbol{
+			Name:    "",
+			Info:    0x3,
+			Other:   0x0,
+			Section: 0x11,
+			Value:   0x4005E0,
+			Size:    0x0,
+		},
+		Symbol{
+			Name:    "",
+			Info:    0x3,
+			Other:   0x0,
+			Section: 0x12,
+			Value:   0x600688,
+			Size:    0x0,
+		},
+		Symbol{
+			Name:    "",
+			Info:    0x3,
+			Other:   0x0,
+			Section: 0x13,
+			Value:   0x600698,
+			Size:    0x0,
+		},
+		Symbol{
+			Name:    "",
+			Info:    0x3,
+			Other:   0x0,
+			Section: 0x14,
+			Value:   0x6006A8,
+			Size:    0x0,
+		},
+		Symbol{
+			Name:    "",
+			Info:    0x3,
+			Other:   0x0,
+			Section: 0x15,
+			Value:   0x6006B0,
+			Size:    0x0,
+		},
+		Symbol{
+			Name:    "",
+			Info:    0x3,
+			Other:   0x0,
+			Section: 0x16,
+			Value:   0x600850,
+			Size:    0x0,
+		},
+		Symbol{
+			Name:    "",
+			Info:    0x3,
+			Other:   0x0,
+			Section: 0x17,
+			Value:   0x600858,
+			Size:    0x0,
+		},
+		Symbol{
+			Name:    "",
+			Info:    0x3,
+			Other:   0x0,
+			Section: 0x18,
+			Value:   0x600880,
+			Size:    0x0,
+		},
+		Symbol{
+			Name:    "",
+			Info:    0x3,
+			Other:   0x0,
+			Section: 0x19,
+			Value:   0x600898,
+			Size:    0x0,
+		},
+		Symbol{
+			Name:    "",
+			Info:    0x3,
+			Other:   0x0,
+			Section: 0x1A,
+			Value:   0x0,
+			Size:    0x0,
+		},
+		Symbol{
+			Name:    "",
+			Info:    0x3,
+			Other:   0x0,
+			Section: 0x1B,
+			Value:   0x0,
+			Size:    0x0,
+		},
+		Symbol{
+			Name:    "",
+			Info:    0x3,
+			Other:   0x0,
+			Section: 0x1C,
+			Value:   0x0,
+			Size:    0x0,
+		},
+		Symbol{
+			Name:    "",
+			Info:    0x3,
+			Other:   0x0,
+			Section: 0x1D,
+			Value:   0x0,
+			Size:    0x0,
+		},
+		Symbol{
+			Name:    "",
+			Info:    0x3,
+			Other:   0x0,
+			Section: 0x1E,
+			Value:   0x0,
+			Size:    0x0,
+		},
+		Symbol{
+			Name:    "",
+			Info:    0x3,
+			Other:   0x0,
+			Section: 0x1F,
+			Value:   0x0,
+			Size:    0x0,
+		},
+		Symbol{
+			Name:    "",
+			Info:    0x3,
+			Other:   0x0,
+			Section: 0x20,
+			Value:   0x0,
+			Size:    0x0,
+		},
+		Symbol{
+			Name:    "",
+			Info:    0x3,
+			Other:   0x0,
+			Section: 0x21,
+			Value:   0x0,
+			Size:    0x0,
+		},
+		Symbol{
+			Name:    "init.c",
+			Info:    0x4,
+			Other:   0x0,
+			Section: 0xFFF1,
+			Value:   0x0,
+			Size:    0x0,
+		},
+		Symbol{
+			Name:    "initfini.c",
+			Info:    0x4,
+			Other:   0x0,
+			Section: 0xFFF1,
+			Value:   0x0,
+			Size:    0x0,
+		},
+		Symbol{
+			Name:    "call_gmon_start",
+			Info:    0x2,
+			Other:   0x0,
+			Section: 0xD,
+			Value:   0x40040C,
+			Size:    0x0,
+		},
+		Symbol{
+			Name:    "crtstuff.c",
+			Info:    0x4,
+			Other:   0x0,
+			Section: 0xFFF1,
+			Value:   0x0,
+			Size:    0x0,
+		},
+		Symbol{
+			Name:    "__CTOR_LIST__",
+			Info:    0x1,
+			Other:   0x0,
+			Section: 0x12,
+			Value:   0x600688,
+			Size:    0x0,
+		},
+		Symbol{
+			Name:    "__DTOR_LIST__",
+			Info:    0x1,
+			Other:   0x0,
+			Section: 0x13,
+			Value:   0x600698,
+			Size:    0x0,
+		},
+		Symbol{
+			Name:    "__JCR_LIST__",
+			Info:    0x1,
+			Other:   0x0,
+			Section: 0x14,
+			Value:   0x6006A8,
+			Size:    0x0,
+		},
+		Symbol{
+			Name:    "__do_global_dtors_aux",
+			Info:    0x2,
+			Other:   0x0,
+			Section: 0xD,
+			Value:   0x400430,
+			Size:    0x0,
+		},
+		Symbol{
+			Name:    "completed.6183",
+			Info:    0x1,
+			Other:   0x0,
+			Section: 0x19,
+			Value:   0x600898,
+			Size:    0x1,
+		},
+		Symbol{
+			Name:    "p.6181",
+			Info:    0x1,
+			Other:   0x0,
+			Section: 0x18,
+			Value:   0x600890,
+			Size:    0x0,
+		},
+		Symbol{
+			Name:    "frame_dummy",
+			Info:    0x2,
+			Other:   0x0,
+			Section: 0xD,
+			Value:   0x400470,
+			Size:    0x0,
+		},
+		Symbol{
+			Name:    "crtstuff.c",
+			Info:    0x4,
+			Other:   0x0,
+			Section: 0xFFF1,
+			Value:   0x0,
+			Size:    0x0,
+		},
+		Symbol{
+			Name:    "__CTOR_END__",
+			Info:    0x1,
+			Other:   0x0,
+			Section: 0x12,
+			Value:   0x600690,
+			Size:    0x0,
+		},
+		Symbol{
+			Name:    "__DTOR_END__",
+			Info:    0x1,
+			Other:   0x0,
+			Section: 0x13,
+			Value:   0x6006A0,
+			Size:    0x0,
+		},
+		Symbol{
+			Name:    "__FRAME_END__",
+			Info:    0x1,
+			Other:   0x0,
+			Section: 0x11,
+			Value:   0x400680,
+			Size:    0x0,
+		},
+		Symbol{
+			Name:    "__JCR_END__",
+			Info:    0x1,
+			Other:   0x0,
+			Section: 0x14,
+			Value:   0x6006A8,
+			Size:    0x0,
+		},
+		Symbol{
+			Name:    "__do_global_ctors_aux",
+			Info:    0x2,
+			Other:   0x0,
+			Section: 0xD,
+			Value:   0x400560,
+			Size:    0x0,
+		},
+		Symbol{
+			Name:    "initfini.c",
+			Info:    0x4,
+			Other:   0x0,
+			Section: 0xFFF1,
+			Value:   0x0,
+			Size:    0x0,
+		},
+		Symbol{
+			Name:    "hello.c",
+			Info:    0x4,
+			Other:   0x0,
+			Section: 0xFFF1,
+			Value:   0x0,
+			Size:    0x0,
+		},
+		Symbol{
+			Name:    "_GLOBAL_OFFSET_TABLE_",
+			Info:    0x1,
+			Other:   0x2,
+			Section: 0x17,
+			Value:   0x600858,
+			Size:    0x0,
+		},
+		Symbol{
+			Name:    "__init_array_end",
+			Info:    0x0,
+			Other:   0x2,
+			Section: 0x12,
+			Value:   0x600684,
+			Size:    0x0,
+		},
+		Symbol{
+			Name:    "__init_array_start",
+			Info:    0x0,
+			Other:   0x2,
+			Section: 0x12,
+			Value:   0x600684,
+			Size:    0x0,
+		},
+		Symbol{
+			Name:    "_DYNAMIC",
+			Info:    0x1,
+			Other:   0x2,
+			Section: 0x15,
+			Value:   0x6006B0,
+			Size:    0x0,
+		},
+		Symbol{
+			Name:    "data_start",
+			Info:    0x20,
+			Other:   0x0,
+			Section: 0x18,
+			Value:   0x600880,
+			Size:    0x0,
+		},
+		Symbol{
+			Name:    "__libc_csu_fini",
+			Info:    0x12,
+			Other:   0x0,
+			Section: 0xD,
+			Value:   0x4004C0,
+			Size:    0x2,
+		},
+		Symbol{
+			Name:    "_start",
+			Info:    0x12,
+			Other:   0x0,
+			Section: 0xD,
+			Value:   0x4003E0,
+			Size:    0x0,
+		},
+		Symbol{
+			Name:    "__gmon_start__",
+			Info:    0x20,
+			Other:   0x0,
+			Section: 0x0,
+			Value:   0x0,
+			Size:    0x0,
+		},
+		Symbol{
+			Name:    "_Jv_RegisterClasses",
+			Info:    0x20,
+			Other:   0x0,
+			Section: 0x0,
+			Value:   0x0,
+			Size:    0x0,
+		},
+		Symbol{
+			Name:    "puts@@GLIBC_2.2.5",
+			Info:    0x12,
+			Other:   0x0,
+			Section: 0x0,
+			Value:   0x0,
+			Size:    0x18C,
+		},
+		Symbol{
+			Name:    "_fini",
+			Info:    0x12,
+			Other:   0x0,
+			Section: 0xE,
+			Value:   0x400594,
+			Size:    0x0,
+		},
+		Symbol{
+			Name:    "__libc_start_main@@GLIBC_2.2.5",
+			Info:    0x12,
+			Other:   0x0,
+			Section: 0x0,
+			Value:   0x0,
+			Size:    0x1C2,
+		},
+		Symbol{
+			Name:    "_IO_stdin_used",
+			Info:    0x11,
+			Other:   0x0,
+			Section: 0xF,
+			Value:   0x4005A4,
+			Size:    0x4,
+		},
+		Symbol{
+			Name:    "__data_start",
+			Info:    0x10,
+			Other:   0x0,
+			Section: 0x18,
+			Value:   0x600880,
+			Size:    0x0,
+		},
+		Symbol{
+			Name:    "__dso_handle",
+			Info:    0x11,
+			Other:   0x2,
+			Section: 0x18,
+			Value:   0x600888,
+			Size:    0x0,
+		},
+		Symbol{
+			Name:    "__libc_csu_init",
+			Info:    0x12,
+			Other:   0x0,
+			Section: 0xD,
+			Value:   0x4004D0,
+			Size:    0x89,
+		},
+		Symbol{
+			Name:    "__bss_start",
+			Info:    0x10,
+			Other:   0x0,
+			Section: 0xFFF1,
+			Value:   0x600898,
+			Size:    0x0,
+		},
+		Symbol{
+			Name:    "_end",
+			Info:    0x10,
+			Other:   0x0,
+			Section: 0xFFF1,
+			Value:   0x6008A0,
+			Size:    0x0,
+		},
+		Symbol{
+			Name:    "_edata",
+			Info:    0x10,
+			Other:   0x0,
+			Section: 0xFFF1,
+			Value:   0x600898,
+			Size:    0x0,
+		},
+		Symbol{
+			Name:    "main",
+			Info:    0x12,
+			Other:   0x0,
+			Section: 0xD,
+			Value:   0x400498,
+			Size:    0x1B,
+		},
+		Symbol{
+			Name:    "_init",
+			Info:    0x12,
+			Other:   0x0,
+			Section: 0xB,
+			Value:   0x400398,
+			Size:    0x0,
+		},
+	},
+	"testdata/go-relocation-test-clang-x86.obj": {
+		Symbol{
+			Name:    "go-relocation-test-clang.c",
+			Info:    0x4,
+			Other:   0x0,
+			Section: 0xFFF1,
+			Value:   0x0,
+			Size:    0x0,
+		},
+		Symbol{
+			Name:    ".Linfo_string0",
+			Info:    0x0,
+			Other:   0x0,
+			Section: 0xC,
+			Value:   0x0,
+			Size:    0x0,
+		},
+		Symbol{
+			Name:    ".Linfo_string1",
+			Info:    0x0,
+			Other:   0x0,
+			Section: 0xC,
+			Value:   0x2C,
+			Size:    0x0,
+		},
+		Symbol{
+			Name:    ".Linfo_string2",
+			Info:    0x0,
+			Other:   0x0,
+			Section: 0xC,
+			Value:   0x47,
+			Size:    0x0,
+		},
+		Symbol{
+			Name:    ".Linfo_string3",
+			Info:    0x0,
+			Other:   0x0,
+			Section: 0xC,
+			Value:   0x4C,
+			Size:    0x0,
+		},
+		Symbol{
+			Name:    ".Linfo_string4",
+			Info:    0x0,
+			Other:   0x0,
+			Section: 0xC,
+			Value:   0x4E,
+			Size:    0x0,
+		},
+		Symbol{
+			Name:    "",
+			Info:    0x3,
+			Other:   0x0,
+			Section: 0x1,
+			Value:   0x0,
+			Size:    0x0,
+		},
+		Symbol{
+			Name:    "",
+			Info:    0x3,
+			Other:   0x0,
+			Section: 0x2,
+			Value:   0x0,
+			Size:    0x0,
+		},
+		Symbol{
+			Name:    "",
+			Info:    0x3,
+			Other:   0x0,
+			Section: 0x3,
+			Value:   0x0,
+			Size:    0x0,
+		},
+		Symbol{
+			Name:    "",
+			Info:    0x3,
+			Other:   0x0,
+			Section: 0x4,
+			Value:   0x0,
+			Size:    0x0,
+		},
+		Symbol{
+			Name:    "",
+			Info:    0x3,
+			Other:   0x0,
+			Section: 0x6,
+			Value:   0x0,
+			Size:    0x0,
+		},
+		Symbol{
+			Name:    "",
+			Info:    0x3,
+			Other:   0x0,
+			Section: 0x7,
+			Value:   0x0,
+			Size:    0x0,
+		},
+		Symbol{
+			Name:    "",
+			Info:    0x3,
+			Other:   0x0,
+			Section: 0x8,
+			Value:   0x0,
+			Size:    0x0,
+		},
+		Symbol{
+			Name:    "",
+			Info:    0x3,
+			Other:   0x0,
+			Section: 0xA,
+			Value:   0x0,
+			Size:    0x0,
+		},
+		Symbol{
+			Name:    "",
+			Info:    0x3,
+			Other:   0x0,
+			Section: 0xC,
+			Value:   0x0,
+			Size:    0x0,
+		},
+		Symbol{
+			Name:    "",
+			Info:    0x3,
+			Other:   0x0,
+			Section: 0xD,
+			Value:   0x0,
+			Size:    0x0,
+		},
+		Symbol{
+			Name:    "",
+			Info:    0x3,
+			Other:   0x0,
+			Section: 0xE,
+			Value:   0x0,
+			Size:    0x0,
+		},
+		Symbol{
+			Name:    "",
+			Info:    0x3,
+			Other:   0x0,
+			Section: 0xF,
+			Value:   0x0,
+			Size:    0x0,
+		},
+		Symbol{
+			Name:    "",
+			Info:    0x3,
+			Other:   0x0,
+			Section: 0x10,
+			Value:   0x0,
+			Size:    0x0,
+		},
+		Symbol{
+			Name:    "v",
+			Info:    0x11,
+			Other:   0x0,
+			Section: 0xFFF2,
+			Value:   0x4,
+			Size:    0x4,
+		},
+	},
+	"testdata/hello-world-core.gz": {},
+}
+
+var dynamicSymbolsGolden = map[string][]Symbol{
+	"testdata/gcc-amd64-linux-exec": {
+		Symbol{
+			Name:    "__gmon_start__",
+			Info:    0x20,
+			Other:   0x0,
+			Section: 0x0,
+			Value:   0x0,
+			Size:    0x0,
+		},
+		Symbol{
+			Name:    "puts",
+			Info:    0x12,
+			Other:   0x0,
+			Section: 0x0,
+			Value:   0x0,
+			Size:    0x18C,
+		},
+		Symbol{
+			Name:    "__libc_start_main",
+			Info:    0x12,
+			Other:   0x0,
+			Section: 0x0,
+			Value:   0x0,
+			Size:    0x1C2,
+		},
+	},
+	"testdata/go-relocation-test-clang-x86.obj": {},
+	"testdata/hello-world-core.gz":              {},
+}
diff --git a/src/debug/elf/testdata/gcc-386-freebsd-exec b/src/debug/elf/testdata/gcc-386-freebsd-exec
new file mode 100755
index 000000000..7af9c58ca
--- /dev/null
+++ b/src/debug/elf/testdata/gcc-386-freebsd-exec
diff --git a/src/debug/elf/testdata/gcc-amd64-linux-exec b/src/debug/elf/testdata/gcc-amd64-linux-exec
new file mode 100755
index 000000000..c6cb1de28
--- /dev/null
+++ b/src/debug/elf/testdata/gcc-amd64-linux-exec
diff --git a/src/debug/elf/testdata/gcc-amd64-openbsd-debug-with-rela.obj b/src/debug/elf/testdata/gcc-amd64-openbsd-debug-with-rela.obj
new file mode 100644
index 000000000..f62b1ea1c
--- /dev/null
+++ b/src/debug/elf/testdata/gcc-amd64-openbsd-debug-with-rela.obj
diff --git a/src/debug/elf/testdata/go-relocation-test-clang-x86.obj b/src/debug/elf/testdata/go-relocation-test-clang-x86.obj
new file mode 100644
index 000000000..e909cf4e6
--- /dev/null
+++ b/src/debug/elf/testdata/go-relocation-test-clang-x86.obj
diff --git a/src/debug/elf/testdata/go-relocation-test-gcc424-x86-64.obj b/src/debug/elf/testdata/go-relocation-test-gcc424-x86-64.obj
new file mode 100644
index 000000000..a7c6d6e56
--- /dev/null
+++ b/src/debug/elf/testdata/go-relocation-test-gcc424-x86-64.obj
diff --git a/src/debug/elf/testdata/go-relocation-test-gcc441-x86-64.obj b/src/debug/elf/testdata/go-relocation-test-gcc441-x86-64.obj
new file mode 100644
index 000000000..2d37ab6e6
--- /dev/null
+++ b/src/debug/elf/testdata/go-relocation-test-gcc441-x86-64.obj
diff --git a/src/debug/elf/testdata/go-relocation-test-gcc441-x86.obj b/src/debug/elf/testdata/go-relocation-test-gcc441-x86.obj
new file mode 100644
index 000000000..0d59fe303
--- /dev/null
+++ b/src/debug/elf/testdata/go-relocation-test-gcc441-x86.obj
diff --git a/src/debug/elf/testdata/go-relocation-test-gcc482-aarch64.obj b/src/debug/elf/testdata/go-relocation-test-gcc482-aarch64.obj
new file mode 100644
index 000000000..849e2644e
--- /dev/null
+++ b/src/debug/elf/testdata/go-relocation-test-gcc482-aarch64.obj
diff --git a/src/debug/elf/testdata/go-relocation-test-gcc482-ppc64le.obj b/src/debug/elf/testdata/go-relocation-test-gcc482-ppc64le.obj
new file mode 100644
index 000000000..dad744548
--- /dev/null
+++ b/src/debug/elf/testdata/go-relocation-test-gcc482-ppc64le.obj
diff --git a/src/debug/elf/testdata/hello-world-core.gz b/src/debug/elf/testdata/hello-world-core.gz
new file mode 100644
index 000000000..806af6edb
--- /dev/null
+++ b/src/debug/elf/testdata/hello-world-core.gz
diff --git a/src/debug/elf/testdata/hello.c b/src/debug/elf/testdata/hello.c
new file mode 100644
index 000000000..34d9ee792
--- /dev/null
+++ b/src/debug/elf/testdata/hello.c
@@ -0,0 +1,7 @@
+#include <stdio.h>
+
+void
+main(int argc, char *argv[])
+{
+	printf("hello, world\n");
+}
diff --git a/src/debug/goobj/read.go b/src/debug/goobj/read.go
new file mode 100644
index 000000000..79a83e59a
--- /dev/null
+++ b/src/debug/goobj/read.go
@@ -0,0 +1,666 @@
+// Copyright 2013 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package goobj implements reading of Go object files and archives.
+//
+// TODO(rsc): Decide where this package should live. (golang.org/issue/6932)
+// TODO(rsc): Decide the appropriate integer types for various fields.
+// TODO(rsc): Write tests. (File format still up in the air a little.)
+package goobj
+
+import (
+	"bufio"
+	"bytes"
+	"errors"
+	"fmt"
+	"io"
+	"strconv"
+	"strings"
+)
+
+// A SymKind describes the kind of memory represented by a symbol.
+type SymKind int
+
+// This list is taken from include/link.h.
+
+// Defined SymKind values.
+// TODO(rsc): Give idiomatic Go names.
+// TODO(rsc): Reduce the number of symbol types in the object files.
+const (
+	_ SymKind = iota
+
+	// readonly, executable
+	STEXT
+	SELFRXSECT
+
+	// readonly, non-executable
+	STYPE
+	SSTRING
+	SGOSTRING
+	SGOFUNC
+	SRODATA
+	SFUNCTAB
+	STYPELINK
+	SSYMTAB // TODO: move to unmapped section
+	SPCLNTAB
+	SELFROSECT
+
+	// writable, non-executable
+	SMACHOPLT
+	SELFSECT
+	SMACHO // Mach-O __nl_symbol_ptr
+	SMACHOGOT
+	SNOPTRDATA
+	SINITARR
+	SDATA
+	SWINDOWS
+	SBSS
+	SNOPTRBSS
+	STLSBSS
+
+	// not mapped
+	SXREF
+	SMACHOSYMSTR
+	SMACHOSYMTAB
+	SMACHOINDIRECTPLT
+	SMACHOINDIRECTGOT
+	SFILE
+	SFILEPATH
+	SCONST
+	SDYNIMPORT
+	SHOSTOBJ
+)
+
+var symKindStrings = []string{
+	SBSS:              "SBSS",
+	SCONST:            "SCONST",
+	SDATA:             "SDATA",
+	SDYNIMPORT:        "SDYNIMPORT",
+	SELFROSECT:        "SELFROSECT",
+	SELFRXSECT:        "SELFRXSECT",
+	SELFSECT:          "SELFSECT",
+	SFILE:             "SFILE",
+	SFILEPATH:         "SFILEPATH",
+	SFUNCTAB:          "SFUNCTAB",
+	SGOFUNC:           "SGOFUNC",
+	SGOSTRING:         "SGOSTRING",
+	SHOSTOBJ:          "SHOSTOBJ",
+	SINITARR:          "SINITARR",
+	SMACHO:            "SMACHO",
+	SMACHOGOT:         "SMACHOGOT",
+	SMACHOINDIRECTGOT: "SMACHOINDIRECTGOT",
+	SMACHOINDIRECTPLT: "SMACHOINDIRECTPLT",
+	SMACHOPLT:         "SMACHOPLT",
+	SMACHOSYMSTR:      "SMACHOSYMSTR",
+	SMACHOSYMTAB:      "SMACHOSYMTAB",
+	SNOPTRBSS:         "SNOPTRBSS",
+	SNOPTRDATA:        "SNOPTRDATA",
+	SPCLNTAB:          "SPCLNTAB",
+	SRODATA:           "SRODATA",
+	SSTRING:           "SSTRING",
+	SSYMTAB:           "SSYMTAB",
+	STEXT:             "STEXT",
+	STLSBSS:           "STLSBSS",
+	STYPE:             "STYPE",
+	STYPELINK:         "STYPELINK",
+	SWINDOWS:          "SWINDOWS",
+	SXREF:             "SXREF",
+}
+
+func (k SymKind) String() string {
+	if k < 0 || int(k) >= len(symKindStrings) {
+		return fmt.Sprintf("SymKind(%d)", k)
+	}
+	return symKindStrings[k]
+}
+
+// A Sym is a named symbol in an object file.
+type Sym struct {
+	SymID         // symbol identifier (name and version)
+	Kind  SymKind // kind of symbol
+	DupOK bool    // are duplicate definitions okay?
+	Size  int     // size of corresponding data
+	Type  SymID   // symbol for Go type information
+	Data  Data    // memory image of symbol
+	Reloc []Reloc // relocations to apply to Data
+	Func  *Func   // additional data for functions
+}
+
+// A SymID - the combination of Name and Version - uniquely identifies
+// a symbol within a package.
+type SymID struct {
+	// Name is the name of a symbol.
+	Name string
+
+	// Version is zero for symbols with global visibility.
+	// Symbols with only file visibility (such as file-level static
+	// declarations in C) have a non-zero version distinguishing
+	// a symbol in one file from a symbol of the same name
+	// in another file
+	Version int
+}
+
+func (s SymID) String() string {
+	if s.Version == 0 {
+		return s.Name
+	}
+	return fmt.Sprintf("%s<%d>", s.Name, s.Version)
+}
+
+// A Data is a reference to data stored in an object file.
+// It records the offset and size of the data, so that a client can
+// read the data only if necessary.
+type Data struct {
+	Offset int64
+	Size   int64
+}
+
+// A Reloc describes a relocation applied to a memory image to refer
+// to an address within a particular symbol.
+type Reloc struct {
+	// The bytes at [Offset, Offset+Size) within the memory image
+	// should be updated to refer to the address Add bytes after the start
+	// of the symbol Sym.
+	Offset int
+	Size   int
+	Sym    SymID
+	Add    int
+
+	// The Type records the form of address expected in the bytes
+	// described by the previous fields: absolute, PC-relative, and so on.
+	// TODO(rsc): The interpretation of Type is not exposed by this package.
+	Type int
+}
+
+// A Var describes a variable in a function stack frame: a declared
+// local variable, an input argument, or an output result.
+type Var struct {
+	// The combination of Name, Kind, and Offset uniquely
+	// identifies a variable in a function stack frame.
+	// Using fewer of these - in particular, using only Name - does not.
+	Name   string // Name of variable.
+	Kind   int    // TODO(rsc): Define meaning.
+	Offset int    // Frame offset. TODO(rsc): Define meaning.
+
+	Type SymID // Go type for variable.
+}
+
+// Func contains additional per-symbol information specific to functions.
+type Func struct {
+	Args     int        // size in bytes of argument frame: inputs and outputs
+	Frame    int        // size in bytes of local variable frame
+	Leaf     bool       // function omits save of link register (ARM)
+	NoSplit  bool       // function omits stack split prologue
+	Var      []Var      // detail about local variables
+	PCSP     Data       // PC → SP offset map
+	PCFile   Data       // PC → file number map (index into File)
+	PCLine   Data       // PC → line number map
+	PCData   []Data     // PC → runtime support data map
+	FuncData []FuncData // non-PC-specific runtime support data
+	File     []string   // paths indexed by PCFile
+}
+
+// TODO: Add PCData []byte and PCDataIter (similar to liblink).
+
+// A FuncData is a single function-specific data value.
+type FuncData struct {
+	Sym    SymID // symbol holding data
+	Offset int64 // offset into symbol for funcdata pointer
+}
+
+// A Package is a parsed Go object file or archive defining a Go package.
+type Package struct {
+	ImportPath string   // import path denoting this package
+	Imports    []string // packages imported by this package
+	Syms       []*Sym   // symbols defined by this package
+	MaxVersion int      // maximum Version in any SymID in Syms
+}
+
+var (
+	archiveHeader = []byte("!<arch>\n")
+	archiveMagic  = []byte("`\n")
+	goobjHeader   = []byte("go objec") // truncated to size of archiveHeader
+
+	errCorruptArchive   = errors.New("corrupt archive")
+	errTruncatedArchive = errors.New("truncated archive")
+	errNotArchive       = errors.New("unrecognized archive format")
+
+	errCorruptObject   = errors.New("corrupt object file")
+	errTruncatedObject = errors.New("truncated object file")
+	errNotObject       = errors.New("unrecognized object file format")
+)
+
+// An objReader is an object file reader.
+type objReader struct {
+	p         *Package
+	b         *bufio.Reader
+	f         io.ReadSeeker
+	err       error
+	offset    int64
+	limit     int64
+	tmp       [256]byte
+	pkg       string
+	pkgprefix string
+}
+
+// importPathToPrefix returns the prefix that will be used in the
+// final symbol table for the given import path.
+// We escape '%', '"', all control characters and non-ASCII bytes,
+// and any '.' after the final slash.
+//
+// See ../../../cmd/ld/lib.c:/^pathtoprefix and
+// ../../../cmd/gc/subr.c:/^pathtoprefix.
+func importPathToPrefix(s string) string {
+	// find index of last slash, if any, or else -1.
+	// used for determining whether an index is after the last slash.
+	slash := strings.LastIndex(s, "/")
+
+	// check for chars that need escaping
+	n := 0
+	for r := 0; r < len(s); r++ {
+		if c := s[r]; c <= ' ' || (c == '.' && r > slash) || c == '%' || c == '"' || c >= 0x7F {
+			n++
+		}
+	}
+
+	// quick exit
+	if n == 0 {
+		return s
+	}
+
+	// escape
+	const hex = "0123456789abcdef"
+	p := make([]byte, 0, len(s)+2*n)
+	for r := 0; r < len(s); r++ {
+		if c := s[r]; c <= ' ' || (c == '.' && r > slash) || c == '%' || c == '"' || c >= 0x7F {
+			p = append(p, '%', hex[c>>4], hex[c&0xF])
+		} else {
+			p = append(p, c)
+		}
+	}
+
+	return string(p)
+}
+
+// init initializes r to read package p from f.
+func (r *objReader) init(f io.ReadSeeker, p *Package) {
+	r.f = f
+	r.p = p
+	r.offset, _ = f.Seek(0, 1)
+	r.limit, _ = f.Seek(0, 2)
+	f.Seek(r.offset, 0)
+	r.b = bufio.NewReader(f)
+	r.pkgprefix = importPathToPrefix(p.ImportPath) + "."
+}
+
+// error records that an error occurred.
+// It returns only the first error, so that an error
+// caused by an earlier error does not discard information
+// about the earlier error.
+func (r *objReader) error(err error) error {
+	if r.err == nil {
+		if err == io.EOF {
+			err = io.ErrUnexpectedEOF
+		}
+		r.err = err
+	}
+	// panic("corrupt") // useful for debugging
+	return r.err
+}
+
+// readByte reads and returns a byte from the input file.
+// On I/O error or EOF, it records the error but returns byte 0.
+// A sequence of 0 bytes will eventually terminate any
+// parsing state in the object file. In particular, it ends the
+// reading of a varint.
+func (r *objReader) readByte() byte {
+	if r.err != nil {
+		return 0
+	}
+	if r.offset >= r.limit {
+		r.error(io.ErrUnexpectedEOF)
+		return 0
+	}
+	b, err := r.b.ReadByte()
+	if err != nil {
+		if err == io.EOF {
+			err = io.ErrUnexpectedEOF
+		}
+		r.error(err)
+		b = 0
+	} else {
+		r.offset++
+	}
+	return b
+}
+
+// read reads exactly len(b) bytes from the input file.
+// If an error occurs, read returns the error but also
+// records it, so it is safe for callers to ignore the result
+// as long as delaying the report is not a problem.
+func (r *objReader) readFull(b []byte) error {
+	if r.err != nil {
+		return r.err
+	}
+	if r.offset+int64(len(b)) > r.limit {
+		return r.error(io.ErrUnexpectedEOF)
+	}
+	n, err := io.ReadFull(r.b, b)
+	r.offset += int64(n)
+	if err != nil {
+		return r.error(err)
+	}
+	return nil
+}
+
+// readInt reads a zigzag varint from the input file.
+func (r *objReader) readInt() int {
+	var u uint64
+
+	for shift := uint(0); ; shift += 7 {
+		if shift >= 64 {
+			r.error(errCorruptObject)
+			return 0
+		}
+		c := r.readByte()
+		u |= uint64(c&0x7F) << shift
+		if c&0x80 == 0 {
+			break
+		}
+	}
+
+	v := int64(u>>1) ^ (int64(u) << 63 >> 63)
+	if int64(int(v)) != v {
+		r.error(errCorruptObject) // TODO
+		return 0
+	}
+	return int(v)
+}
+
+// readString reads a length-delimited string from the input file.
+func (r *objReader) readString() string {
+	n := r.readInt()
+	buf := make([]byte, n)
+	r.readFull(buf)
+	return string(buf)
+}
+
+// readSymID reads a SymID from the input file.
+func (r *objReader) readSymID() SymID {
+	name, vers := r.readString(), r.readInt()
+
+	// In a symbol name in an object file, "". denotes the
+	// prefix for the package in which the object file has been found.
+	// Expand it.
+	name = strings.Replace(name, `"".`, r.pkgprefix, -1)
+
+	// An individual object file only records version 0 (extern) or 1 (static).
+	// To make static symbols unique across all files being read, we
+	// replace version 1 with the version corresponding to the current
+	// file number. The number is incremented on each call to parseObject.
+	if vers != 0 {
+		vers = r.p.MaxVersion
+	}
+
+	return SymID{name, vers}
+}
+
+// readData reads a data reference from the input file.
+func (r *objReader) readData() Data {
+	n := r.readInt()
+	d := Data{Offset: r.offset, Size: int64(n)}
+	r.skip(int64(n))
+	return d
+}
+
+// skip skips n bytes in the input.
+func (r *objReader) skip(n int64) {
+	if n < 0 {
+		r.error(fmt.Errorf("debug/goobj: internal error: misuse of skip"))
+	}
+	if n < int64(len(r.tmp)) {
+		// Since the data is so small, a just reading from the buffered
+		// reader is better than flushing the buffer and seeking.
+		r.readFull(r.tmp[:n])
+	} else if n <= int64(r.b.Buffered()) {
+		// Even though the data is not small, it has already been read.
+		// Advance the buffer instead of seeking.
+		for n > int64(len(r.tmp)) {
+			r.readFull(r.tmp[:])
+			n -= int64(len(r.tmp))
+		}
+		r.readFull(r.tmp[:n])
+	} else {
+		// Seek, giving up buffered data.
+		_, err := r.f.Seek(r.offset+n, 0)
+		if err != nil {
+			r.error(err)
+		}
+		r.offset += n
+		r.b.Reset(r.f)
+	}
+}
+
+// Parse parses an object file or archive from r,
+// assuming that its import path is pkgpath.
+func Parse(r io.ReadSeeker, pkgpath string) (*Package, error) {
+	if pkgpath == "" {
+		pkgpath = `""`
+	}
+	p := new(Package)
+	p.ImportPath = pkgpath
+
+	var rd objReader
+	rd.init(r, p)
+	err := rd.readFull(rd.tmp[:8])
+	if err != nil {
+		if err == io.EOF {
+			err = io.ErrUnexpectedEOF
+		}
+		return nil, err
+	}
+
+	switch {
+	default:
+		return nil, errNotObject
+
+	case bytes.Equal(rd.tmp[:8], archiveHeader):
+		if err := rd.parseArchive(); err != nil {
+			return nil, err
+		}
+	case bytes.Equal(rd.tmp[:8], goobjHeader):
+		if err := rd.parseObject(goobjHeader); err != nil {
+			return nil, err
+		}
+	}
+
+	return p, nil
+}
+
+// trimSpace removes trailing spaces from b and returns the corresponding string.
+// This effectively parses the form used in archive headers.
+func trimSpace(b []byte) string {
+	return string(bytes.TrimRight(b, " "))
+}
+
+// parseArchive parses a Unix archive of Go object files.
+// TODO(rsc): Need to skip non-Go object files.
+// TODO(rsc): Maybe record table of contents in r.p so that
+// linker can avoid having code to parse archives too.
+func (r *objReader) parseArchive() error {
+	for r.offset < r.limit {
+		if err := r.readFull(r.tmp[:60]); err != nil {
+			return err
+		}
+		data := r.tmp[:60]
+
+		// Each file is preceded by this text header (slice indices in first column):
+		//	 0:16	name
+		//	16:28 date
+		//	28:34 uid
+		//	34:40 gid
+		//	40:48 mode
+		//	48:58 size
+		//	58:60 magic - `\n
+		// We only care about name, size, and magic.
+		// The fields are space-padded on the right.
+		// The size is in decimal.
+		// The file data - size bytes - follows the header.
+		// Headers are 2-byte aligned, so if size is odd, an extra padding
+		// byte sits between the file data and the next header.
+		// The file data that follows is padded to an even number of bytes:
+		// if size is odd, an extra padding byte is inserted betw the next header.
+		if len(data) < 60 {
+			return errTruncatedArchive
+		}
+		if !bytes.Equal(data[58:60], archiveMagic) {
+			return errCorruptArchive
+		}
+		name := trimSpace(data[0:16])
+		size, err := strconv.ParseInt(trimSpace(data[48:58]), 10, 64)
+		if err != nil {
+			return errCorruptArchive
+		}
+		data = data[60:]
+		fsize := size + size&1
+		if fsize < 0 || fsize < size {
+			return errCorruptArchive
+		}
+		switch name {
+		case "__.SYMDEF", "__.GOSYMDEF", "__.PKGDEF":
+			r.skip(size)
+		default:
+			oldLimit := r.limit
+			r.limit = r.offset + size
+			if err := r.parseObject(nil); err != nil {
+				return fmt.Errorf("parsing archive member %q: %v", name, err)
+			}
+			r.skip(r.limit - r.offset)
+			r.limit = oldLimit
+		}
+		if size&1 != 0 {
+			r.skip(1)
+		}
+	}
+	return nil
+}
+
+// parseObject parses a single Go object file.
+// The prefix is the bytes already read from the file,
+// typically in order to detect that this is an object file.
+// The object file consists of a textual header ending in "\n!\n"
+// and then the part we want to parse begins.
+// The format of that part is defined in a comment at the top
+// of src/liblink/objfile.c.
+func (r *objReader) parseObject(prefix []byte) error {
+	// TODO(rsc): Maybe use prefix and the initial input to
+	// record the header line from the file, which would
+	// give the architecture and other version information.
+
+	r.p.MaxVersion++
+	var c1, c2, c3 byte
+	for {
+		c1, c2, c3 = c2, c3, r.readByte()
+		if c3 == 0 { // NUL or EOF, either is bad
+			return errCorruptObject
+		}
+		if c1 == '\n' && c2 == '!' && c3 == '\n' {
+			break
+		}
+	}
+
+	r.readFull(r.tmp[:8])
+	if !bytes.Equal(r.tmp[:8], []byte("\x00\x00go13ld")) {
+		return r.error(errCorruptObject)
+	}
+
+	b := r.readByte()
+	if b != 1 {
+		return r.error(errCorruptObject)
+	}
+
+	// Direct package dependencies.
+	for {
+		s := r.readString()
+		if s == "" {
+			break
+		}
+		r.p.Imports = append(r.p.Imports, s)
+	}
+
+	// Symbols.
+	for {
+		if b := r.readByte(); b != 0xfe {
+			if b != 0xff {
+				return r.error(errCorruptObject)
+			}
+			break
+		}
+
+		typ := r.readInt()
+		s := &Sym{SymID: r.readSymID()}
+		r.p.Syms = append(r.p.Syms, s)
+		s.Kind = SymKind(typ)
+		flags := r.readInt()
+		s.DupOK = flags&1 != 0
+		s.Size = r.readInt()
+		s.Type = r.readSymID()
+		s.Data = r.readData()
+		s.Reloc = make([]Reloc, r.readInt())
+		for i := range s.Reloc {
+			rel := &s.Reloc[i]
+			rel.Offset = r.readInt()
+			rel.Size = r.readInt()
+			rel.Type = r.readInt()
+			rel.Add = r.readInt()
+			r.readInt() // Xadd - ignored
+			rel.Sym = r.readSymID()
+			r.readSymID() // Xsym - ignored
+		}
+
+		if s.Kind == STEXT {
+			f := new(Func)
+			s.Func = f
+			f.Args = r.readInt()
+			f.Frame = r.readInt()
+			flags := r.readInt()
+			f.Leaf = flags&1 != 0
+			f.NoSplit = r.readInt() != 0
+			f.Var = make([]Var, r.readInt())
+			for i := range f.Var {
+				v := &f.Var[i]
+				v.Name = r.readSymID().Name
+				v.Offset = r.readInt()
+				v.Kind = r.readInt()
+				v.Type = r.readSymID()
+			}
+
+			f.PCSP = r.readData()
+			f.PCFile = r.readData()
+			f.PCLine = r.readData()
+			f.PCData = make([]Data, r.readInt())
+			for i := range f.PCData {
+				f.PCData[i] = r.readData()
+			}
+			f.FuncData = make([]FuncData, r.readInt())
+			for i := range f.FuncData {
+				f.FuncData[i].Sym = r.readSymID()
+			}
+			for i := range f.FuncData {
+				f.FuncData[i].Offset = int64(r.readInt()) // TODO
+			}
+			f.File = make([]string, r.readInt())
+			for i := range f.File {
+				f.File[i] = r.readSymID().Name
+			}
+		}
+	}
+
+	r.readFull(r.tmp[:7])
+	if !bytes.Equal(r.tmp[:7], []byte("\xffgo13ld")) {
+		return r.error(errCorruptObject)
+	}
+
+	return nil
+}
diff --git a/src/debug/goobj/read_test.go b/src/debug/goobj/read_test.go
new file mode 100644
index 000000000..dee140533
--- /dev/null
+++ b/src/debug/goobj/read_test.go
@@ -0,0 +1,28 @@
+// Copyright 2013 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package goobj
+
+import "testing"
+
+var importPathToPrefixTests = []struct {
+	in  string
+	out string
+}{
+	{"runtime", "runtime"},
+	{"sync/atomic", "sync/atomic"},
+	{"code.google.com/p/go.tools/godoc", "code.google.com/p/go.tools/godoc"},
+	{"foo.bar/baz.quux", "foo.bar/baz%2equux"},
+	{"", ""},
+	{"%foo%bar", "%25foo%25bar"},
+	{"\x01\x00\x7F☺", "%01%00%7f%e2%98%ba"},
+}
+
+func TestImportPathToPrefix(t *testing.T) {
+	for _, tt := range importPathToPrefixTests {
+		if out := importPathToPrefix(tt.in); out != tt.out {
+			t.Errorf("importPathToPrefix(%q) = %q, want %q", tt.in, out, tt.out)
+		}
+	}
+}
diff --git a/src/debug/gosym/pclinetest.asm b/src/debug/gosym/pclinetest.asm
new file mode 100644
index 000000000..b9ee9c0a5
--- /dev/null
+++ b/src/debug/gosym/pclinetest.asm
@@ -0,0 +1,58 @@
+TEXT linefrompc(SB),4,$0	// Each byte stores its line delta
+BYTE $2;
+BYTE $1;
+BYTE $1; BYTE $0;
+BYTE $1; BYTE $0; BYTE $0;
+BYTE $1; BYTE $0; BYTE $0; BYTE $0; BYTE $0;
+BYTE $1; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0;
+BYTE $1; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0;
+BYTE $1; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0;
+BYTE $1; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0;
+BYTE $1; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0;
+BYTE $1; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0;
+BYTE $1; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0;
+BYTE $1; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0;
+BYTE $1; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0;
+BYTE $1;
+BYTE $1;
+BYTE $1; BYTE $0;
+BYTE $1; BYTE $0; BYTE $0;
+BYTE $1; BYTE $0; BYTE $0; BYTE $0; BYTE $0;
+BYTE $1; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0;
+BYTE $1; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0;
+BYTE $1; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0;
+BYTE $1; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0; BYTE $0;
+#include "pclinetest.h"
+BYTE $2;
+#include "pclinetest.h"
+BYTE $2;
+BYTE $255;
+
+TEXT pcfromline(SB),4,$0	// Each record stores its line delta, then n, then n more bytes
+BYTE $32; BYTE $0;
+BYTE $1; BYTE $1; BYTE $0;
+BYTE $1; BYTE $0;
+
+BYTE $2; BYTE $4; BYTE $0; BYTE $0; BYTE $0; BYTE $0;
+
+
+#include "pclinetest.h"
+BYTE $4; BYTE $0;
+
+
+BYTE $3; BYTE $3; BYTE $0; BYTE $0; BYTE $0;
+#include "pclinetest.h"
+
+
+BYTE $4; BYTE $3; BYTE $0; BYTE $0; BYTE $0;
+BYTE $255;
+
+// Keep the linker happy
+TEXT main·main(SB),4,$0
+	RET
+
+TEXT main·init(SB),4,$0
+	// Prevent GC of our test symbols
+	CALL linefrompc(SB)
+	CALL pcfromline(SB)
+	RET
diff --git a/src/debug/gosym/pclinetest.h b/src/debug/gosym/pclinetest.h
new file mode 100644
index 000000000..156c0b87b
--- /dev/null
+++ b/src/debug/gosym/pclinetest.h
@@ -0,0 +1,9 @@
+// +build ignore
+
+// Empty include file to generate z symbols
+
+
+
+
+
+// EOF
diff --git a/src/debug/gosym/pclntab.go b/src/debug/gosym/pclntab.go
new file mode 100644
index 000000000..6620aefb0
--- /dev/null
+++ b/src/debug/gosym/pclntab.go
@@ -0,0 +1,453 @@
+// Copyright 2009 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+/*
+ * Line tables
+ */
+
+package gosym
+
+import (
+	"encoding/binary"
+	"sync"
+)
+
+// A LineTable is a data structure mapping program counters to line numbers.
+//
+// In Go 1.1 and earlier, each function (represented by a Func) had its own LineTable,
+// and the line number corresponded to a numbering of all source lines in the
+// program, across all files. That absolute line number would then have to be
+// converted separately to a file name and line number within the file.
+//
+// In Go 1.2, the format of the data changed so that there is a single LineTable
+// for the entire program, shared by all Funcs, and there are no absolute line
+// numbers, just line numbers within specific files.
+//
+// For the most part, LineTable's methods should be treated as an internal
+// detail of the package; callers should use the methods on Table instead.
+type LineTable struct {
+	Data []byte
+	PC   uint64
+	Line int
+
+	// Go 1.2 state
+	mu       sync.Mutex
+	go12     int // is this in Go 1.2 format? -1 no, 0 unknown, 1 yes
+	binary   binary.ByteOrder
+	quantum  uint32
+	ptrsize  uint32
+	functab  []byte
+	nfunctab uint32
+	filetab  []byte
+	nfiletab uint32
+	fileMap  map[string]uint32
+}
+
+// NOTE(rsc): This is wrong for GOARCH=arm, which uses a quantum of 4,
+// but we have no idea whether we're using arm or not. This only
+// matters in the old (pre-Go 1.2) symbol table format, so it's not worth
+// fixing.
+const oldQuantum = 1
+
+func (t *LineTable) parse(targetPC uint64, targetLine int) (b []byte, pc uint64, line int) {
+	// The PC/line table can be thought of as a sequence of
+	//  <pc update>* <line update>
+	// batches.  Each update batch results in a (pc, line) pair,
+	// where line applies to every PC from pc up to but not
+	// including the pc of the next pair.
+	//
+	// Here we process each update individually, which simplifies
+	// the code, but makes the corner cases more confusing.
+	b, pc, line = t.Data, t.PC, t.Line
+	for pc <= targetPC && line != targetLine && len(b) > 0 {
+		code := b[0]
+		b = b[1:]
+		switch {
+		case code == 0:
+			if len(b) < 4 {
+				b = b[0:0]
+				break
+			}
+			val := binary.BigEndian.Uint32(b)
+			b = b[4:]
+			line += int(val)
+		case code <= 64:
+			line += int(code)
+		case code <= 128:
+			line -= int(code - 64)
+		default:
+			pc += oldQuantum * uint64(code-128)
+			continue
+		}
+		pc += oldQuantum
+	}
+	return b, pc, line
+}
+
+func (t *LineTable) slice(pc uint64) *LineTable {
+	data, pc, line := t.parse(pc, -1)
+	return &LineTable{Data: data, PC: pc, Line: line}
+}
+
+// PCToLine returns the line number for the given program counter.
+// Callers should use Table's PCToLine method instead.
+func (t *LineTable) PCToLine(pc uint64) int {
+	if t.isGo12() {
+		return t.go12PCToLine(pc)
+	}
+	_, _, line := t.parse(pc, -1)
+	return line
+}
+
+// LineToPC returns the program counter for the given line number,
+// considering only program counters before maxpc.
+// Callers should use Table's LineToPC method instead.
+func (t *LineTable) LineToPC(line int, maxpc uint64) uint64 {
+	if t.isGo12() {
+		return 0
+	}
+	_, pc, line1 := t.parse(maxpc, line)
+	if line1 != line {
+		return 0
+	}
+	// Subtract quantum from PC to account for post-line increment
+	return pc - oldQuantum
+}
+
+// NewLineTable returns a new PC/line table
+// corresponding to the encoded data.
+// Text must be the start address of the
+// corresponding text segment.
+func NewLineTable(data []byte, text uint64) *LineTable {
+	return &LineTable{Data: data, PC: text, Line: 0}
+}
+
+// Go 1.2 symbol table format.
+// See golang.org/s/go12symtab.
+//
+// A general note about the methods here: rather than try to avoid
+// index out of bounds errors, we trust Go to detect them, and then
+// we recover from the panics and treat them as indicative of a malformed
+// or incomplete table.
+//
+// The methods called by symtab.go, which begin with "go12" prefixes,
+// are expected to have that recovery logic.
+
+// isGo12 reports whether this is a Go 1.2 (or later) symbol table.
+func (t *LineTable) isGo12() bool {
+	t.go12Init()
+	return t.go12 == 1
+}
+
+const go12magic = 0xfffffffb
+
+// uintptr returns the pointer-sized value encoded at b.
+// The pointer size is dictated by the table being read.
+func (t *LineTable) uintptr(b []byte) uint64 {
+	if t.ptrsize == 4 {
+		return uint64(t.binary.Uint32(b))
+	}
+	return t.binary.Uint64(b)
+}
+
+// go12init initializes the Go 1.2 metadata if t is a Go 1.2 symbol table.
+func (t *LineTable) go12Init() {
+	t.mu.Lock()
+	defer t.mu.Unlock()
+	if t.go12 != 0 {
+		return
+	}
+
+	defer func() {
+		// If we panic parsing, assume it's not a Go 1.2 symbol table.
+		recover()
+	}()
+
+	// Check header: 4-byte magic, two zeros, pc quantum, pointer size.
+	t.go12 = -1 // not Go 1.2 until proven otherwise
+	if len(t.Data) < 16 || t.Data[4] != 0 || t.Data[5] != 0 ||
+		(t.Data[6] != 1 && t.Data[6] != 4) || // pc quantum
+		(t.Data[7] != 4 && t.Data[7] != 8) { // pointer size
+		return
+	}
+
+	switch uint32(go12magic) {
+	case binary.LittleEndian.Uint32(t.Data):
+		t.binary = binary.LittleEndian
+	case binary.BigEndian.Uint32(t.Data):
+		t.binary = binary.BigEndian
+	default:
+		return
+	}
+
+	t.quantum = uint32(t.Data[6])
+	t.ptrsize = uint32(t.Data[7])
+
+	t.nfunctab = uint32(t.uintptr(t.Data[8:]))
+	t.functab = t.Data[8+t.ptrsize:]
+	functabsize := t.nfunctab*2*t.ptrsize + t.ptrsize
+	fileoff := t.binary.Uint32(t.functab[functabsize:])
+	t.functab = t.functab[:functabsize]
+	t.filetab = t.Data[fileoff:]
+	t.nfiletab = t.binary.Uint32(t.filetab)
+	t.filetab = t.filetab[:t.nfiletab*4]
+
+	t.go12 = 1 // so far so good
+}
+
+// go12Funcs returns a slice of Funcs derived from the Go 1.2 pcln table.
+func (t *LineTable) go12Funcs() []Func {
+	// Assume it is malformed and return nil on error.
+	defer func() {
+		recover()
+	}()
+
+	n := len(t.functab) / int(t.ptrsize) / 2
+	funcs := make([]Func, n)
+	for i := range funcs {
+		f := &funcs[i]
+		f.Entry = uint64(t.uintptr(t.functab[2*i*int(t.ptrsize):]))
+		f.End = uint64(t.uintptr(t.functab[(2*i+2)*int(t.ptrsize):]))
+		info := t.Data[t.uintptr(t.functab[(2*i+1)*int(t.ptrsize):]):]
+		f.LineTable = t
+		f.FrameSize = int(t.binary.Uint32(info[t.ptrsize+2*4:]))
+		f.Sym = &Sym{
+			Value:  f.Entry,
+			Type:   'T',
+			Name:   t.string(t.binary.Uint32(info[t.ptrsize:])),
+			GoType: 0,
+			Func:   f,
+		}
+	}
+	return funcs
+}
+
+// findFunc returns the func corresponding to the given program counter.
+func (t *LineTable) findFunc(pc uint64) []byte {
+	if pc < t.uintptr(t.functab) || pc >= t.uintptr(t.functab[len(t.functab)-int(t.ptrsize):]) {
+		return nil
+	}
+
+	// The function table is a list of 2*nfunctab+1 uintptrs,
+	// alternating program counters and offsets to func structures.
+	f := t.functab
+	nf := t.nfunctab
+	for nf > 0 {
+		m := nf / 2
+		fm := f[2*t.ptrsize*m:]
+		if t.uintptr(fm) <= pc && pc < t.uintptr(fm[2*t.ptrsize:]) {
+			return t.Data[t.uintptr(fm[t.ptrsize:]):]
+		} else if pc < t.uintptr(fm) {
+			nf = m
+		} else {
+			f = f[(m+1)*2*t.ptrsize:]
+			nf -= m + 1
+		}
+	}
+	return nil
+}
+
+// readvarint reads, removes, and returns a varint from *pp.
+func (t *LineTable) readvarint(pp *[]byte) uint32 {
+	var v, shift uint32
+	p := *pp
+	for shift = 0; ; shift += 7 {
+		b := p[0]
+		p = p[1:]
+		v |= (uint32(b) & 0x7F) << shift
+		if b&0x80 == 0 {
+			break
+		}
+	}
+	*pp = p
+	return v
+}
+
+// string returns a Go string found at off.
+func (t *LineTable) string(off uint32) string {
+	for i := off; ; i++ {
+		if t.Data[i] == 0 {
+			return string(t.Data[off:i])
+		}
+	}
+}
+
+// step advances to the next pc, value pair in the encoded table.
+func (t *LineTable) step(p *[]byte, pc *uint64, val *int32, first bool) bool {
+	uvdelta := t.readvarint(p)
+	if uvdelta == 0 && !first {
+		return false
+	}
+	if uvdelta&1 != 0 {
+		uvdelta = ^(uvdelta >> 1)
+	} else {
+		uvdelta >>= 1
+	}
+	vdelta := int32(uvdelta)
+	pcdelta := t.readvarint(p) * t.quantum
+	*pc += uint64(pcdelta)
+	*val += vdelta
+	return true
+}
+
+// pcvalue reports the value associated with the target pc.
+// off is the offset to the beginning of the pc-value table,
+// and entry is the start PC for the corresponding function.
+func (t *LineTable) pcvalue(off uint32, entry, targetpc uint64) int32 {
+	if off == 0 {
+		return -1
+	}
+	p := t.Data[off:]
+
+	val := int32(-1)
+	pc := entry
+	for t.step(&p, &pc, &val, pc == entry) {
+		if targetpc < pc {
+			return val
+		}
+	}
+	return -1
+}
+
+// findFileLine scans one function in the binary looking for a
+// program counter in the given file on the given line.
+// It does so by running the pc-value tables mapping program counter
+// to file number. Since most functions come from a single file, these
+// are usually short and quick to scan. If a file match is found, then the
+// code goes to the expense of looking for a simultaneous line number match.
+func (t *LineTable) findFileLine(entry uint64, filetab, linetab uint32, filenum, line int32) uint64 {
+	if filetab == 0 || linetab == 0 {
+		return 0
+	}
+
+	fp := t.Data[filetab:]
+	fl := t.Data[linetab:]
+	fileVal := int32(-1)
+	filePC := entry
+	lineVal := int32(-1)
+	linePC := entry
+	fileStartPC := filePC
+	for t.step(&fp, &filePC, &fileVal, filePC == entry) {
+		if fileVal == filenum && fileStartPC < filePC {
+			// fileVal is in effect starting at fileStartPC up to
+			// but not including filePC, and it's the file we want.
+			// Run the PC table looking for a matching line number
+			// or until we reach filePC.
+			lineStartPC := linePC
+			for linePC < filePC && t.step(&fl, &linePC, &lineVal, linePC == entry) {
+				// lineVal is in effect until linePC, and lineStartPC < filePC.
+				if lineVal == line {
+					if fileStartPC <= lineStartPC {
+						return lineStartPC
+					}
+					if fileStartPC < linePC {
+						return fileStartPC
+					}
+				}
+				lineStartPC = linePC
+			}
+		}
+		fileStartPC = filePC
+	}
+	return 0
+}
+
+// go12PCToLine maps program counter to line number for the Go 1.2 pcln table.
+func (t *LineTable) go12PCToLine(pc uint64) (line int) {
+	defer func() {
+		if recover() != nil {
+			line = -1
+		}
+	}()
+
+	f := t.findFunc(pc)
+	if f == nil {
+		return -1
+	}
+	entry := t.uintptr(f)
+	linetab := t.binary.Uint32(f[t.ptrsize+5*4:])
+	return int(t.pcvalue(linetab, entry, pc))
+}
+
+// go12PCToFile maps program counter to file name for the Go 1.2 pcln table.
+func (t *LineTable) go12PCToFile(pc uint64) (file string) {
+	defer func() {
+		if recover() != nil {
+			file = ""
+		}
+	}()
+
+	f := t.findFunc(pc)
+	if f == nil {
+		return ""
+	}
+	entry := t.uintptr(f)
+	filetab := t.binary.Uint32(f[t.ptrsize+4*4:])
+	fno := t.pcvalue(filetab, entry, pc)
+	if fno <= 0 {
+		return ""
+	}
+	return t.string(t.binary.Uint32(t.filetab[4*fno:]))
+}
+
+// go12LineToPC maps a (file, line) pair to a program counter for the Go 1.2 pcln table.
+func (t *LineTable) go12LineToPC(file string, line int) (pc uint64) {
+	defer func() {
+		if recover() != nil {
+			pc = 0
+		}
+	}()
+
+	t.initFileMap()
+	filenum := t.fileMap[file]
+	if filenum == 0 {
+		return 0
+	}
+
+	// Scan all functions.
+	// If this turns out to be a bottleneck, we could build a map[int32][]int32
+	// mapping file number to a list of functions with code from that file.
+	for i := uint32(0); i < t.nfunctab; i++ {
+		f := t.Data[t.uintptr(t.functab[2*t.ptrsize*i+t.ptrsize:]):]
+		entry := t.uintptr(f)
+		filetab := t.binary.Uint32(f[t.ptrsize+4*4:])
+		linetab := t.binary.Uint32(f[t.ptrsize+5*4:])
+		pc := t.findFileLine(entry, filetab, linetab, int32(filenum), int32(line))
+		if pc != 0 {
+			return pc
+		}
+	}
+	return 0
+}
+
+// initFileMap initializes the map from file name to file number.
+func (t *LineTable) initFileMap() {
+	t.mu.Lock()
+	defer t.mu.Unlock()
+
+	if t.fileMap != nil {
+		return
+	}
+	m := make(map[string]uint32)
+
+	for i := uint32(1); i < t.nfiletab; i++ {
+		s := t.string(t.binary.Uint32(t.filetab[4*i:]))
+		m[s] = i
+	}
+	t.fileMap = m
+}
+
+// go12MapFiles adds to m a key for every file in the Go 1.2 LineTable.
+// Every key maps to obj. That's not a very interesting map, but it provides
+// a way for callers to obtain the list of files in the program.
+func (t *LineTable) go12MapFiles(m map[string]*Obj, obj *Obj) {
+	defer func() {
+		recover()
+	}()
+
+	t.initFileMap()
+	for file := range t.fileMap {
+		m[file] = obj
+	}
+}
diff --git a/src/debug/gosym/pclntab_test.go b/src/debug/gosym/pclntab_test.go
new file mode 100644
index 000000000..35502e8c3
--- /dev/null
+++ b/src/debug/gosym/pclntab_test.go
@@ -0,0 +1,274 @@
+// Copyright 2009 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package gosym
+
+import (
+	"debug/elf"
+	"fmt"
+	"io/ioutil"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"runtime"
+	"strings"
+	"testing"
+)
+
+var (
+	pclineTempDir    string
+	pclinetestBinary string
+)
+
+func dotest(self bool) bool {
+	// For now, only works on amd64 platforms.
+	if runtime.GOARCH != "amd64" {
+		return false
+	}
+	// Self test reads test binary; only works on Linux.
+	if self && runtime.GOOS != "linux" {
+		return false
+	}
+	// Command below expects "sh", so Unix.
+	if runtime.GOOS == "windows" || runtime.GOOS == "plan9" {
+		return false
+	}
+	if pclinetestBinary != "" {
+		return true
+	}
+	var err error
+	pclineTempDir, err = ioutil.TempDir("", "pclinetest")
+	if err != nil {
+		panic(err)
+	}
+	if strings.Contains(pclineTempDir, " ") {
+		panic("unexpected space in tempdir")
+	}
+	// This command builds pclinetest from pclinetest.asm;
+	// the resulting binary looks like it was built from pclinetest.s,
+	// but we have renamed it to keep it away from the go tool.
+	pclinetestBinary = filepath.Join(pclineTempDir, "pclinetest")
+	command := fmt.Sprintf("go tool 6a -o %s.6 pclinetest.asm && go tool 6l -H linux -E main -o %s %s.6",
+		pclinetestBinary, pclinetestBinary, pclinetestBinary)
+	cmd := exec.Command("sh", "-c", command)
+	cmd.Stdout = os.Stdout
+	cmd.Stderr = os.Stderr
+	if err := cmd.Run(); err != nil {
+		panic(err)
+	}
+	return true
+}
+
+func endtest() {
+	if pclineTempDir != "" {
+		os.RemoveAll(pclineTempDir)
+		pclineTempDir = ""
+		pclinetestBinary = ""
+	}
+}
+
+func getTable(t *testing.T) *Table {
+	f, tab := crack(os.Args[0], t)
+	f.Close()
+	return tab
+}
+
+func crack(file string, t *testing.T) (*elf.File, *Table) {
+	// Open self
+	f, err := elf.Open(file)
+	if err != nil {
+		t.Fatal(err)
+	}
+	return parse(file, f, t)
+}
+
+func parse(file string, f *elf.File, t *testing.T) (*elf.File, *Table) {
+	symdat, err := f.Section(".gosymtab").Data()
+	if err != nil {
+		f.Close()
+		t.Fatalf("reading %s gosymtab: %v", file, err)
+	}
+	pclndat, err := f.Section(".gopclntab").Data()
+	if err != nil {
+		f.Close()
+		t.Fatalf("reading %s gopclntab: %v", file, err)
+	}
+
+	pcln := NewLineTable(pclndat, f.Section(".text").Addr)
+	tab, err := NewTable(symdat, pcln)
+	if err != nil {
+		f.Close()
+		t.Fatalf("parsing %s gosymtab: %v", file, err)
+	}
+
+	return f, tab
+}
+
+var goarch = os.Getenv("O")
+
+func TestLineFromAline(t *testing.T) {
+	if !dotest(true) {
+		return
+	}
+	defer endtest()
+
+	tab := getTable(t)
+	if tab.go12line != nil {
+		// aline's don't exist in the Go 1.2 table.
+		t.Skip("not relevant to Go 1.2 symbol table")
+	}
+
+	// Find the sym package
+	pkg := tab.LookupFunc("debug/gosym.TestLineFromAline").Obj
+	if pkg == nil {
+		t.Fatalf("nil pkg")
+	}
+
+	// Walk every absolute line and ensure that we hit every
+	// source line monotonically
+	lastline := make(map[string]int)
+	final := -1
+	for i := 0; i < 10000; i++ {
+		path, line := pkg.lineFromAline(i)
+		// Check for end of object
+		if path == "" {
+			if final == -1 {
+				final = i - 1
+			}
+			continue
+		} else if final != -1 {
+			t.Fatalf("reached end of package at absolute line %d, but absolute line %d mapped to %s:%d", final, i, path, line)
+		}
+		// It's okay to see files multiple times (e.g., sys.a)
+		if line == 1 {
+			lastline[path] = 1
+			continue
+		}
+		// Check that the is the next line in path
+		ll, ok := lastline[path]
+		if !ok {
+			t.Errorf("file %s starts on line %d", path, line)
+		} else if line != ll+1 {
+			t.Fatalf("expected next line of file %s to be %d, got %d", path, ll+1, line)
+		}
+		lastline[path] = line
+	}
+	if final == -1 {
+		t.Errorf("never reached end of object")
+	}
+}
+
+func TestLineAline(t *testing.T) {
+	if !dotest(true) {
+		return
+	}
+	defer endtest()
+
+	tab := getTable(t)
+	if tab.go12line != nil {
+		// aline's don't exist in the Go 1.2 table.
+		t.Skip("not relevant to Go 1.2 symbol table")
+	}
+
+	for _, o := range tab.Files {
+		// A source file can appear multiple times in a
+		// object.  alineFromLine will always return alines in
+		// the first file, so track which lines we've seen.
+		found := make(map[string]int)
+		for i := 0; i < 1000; i++ {
+			path, line := o.lineFromAline(i)
+			if path == "" {
+				break
+			}
+
+			// cgo files are full of 'Z' symbols, which we don't handle
+			if len(path) > 4 && path[len(path)-4:] == ".cgo" {
+				continue
+			}
+
+			if minline, ok := found[path]; path != "" && ok {
+				if minline >= line {
+					// We've already covered this file
+					continue
+				}
+			}
+			found[path] = line
+
+			a, err := o.alineFromLine(path, line)
+			if err != nil {
+				t.Errorf("absolute line %d in object %s maps to %s:%d, but mapping that back gives error %s", i, o.Paths[0].Name, path, line, err)
+			} else if a != i {
+				t.Errorf("absolute line %d in object %s maps to %s:%d, which maps back to absolute line %d\n", i, o.Paths[0].Name, path, line, a)
+			}
+		}
+	}
+}
+
+func TestPCLine(t *testing.T) {
+	if !dotest(false) {
+		return
+	}
+	defer endtest()
+
+	f, tab := crack(pclinetestBinary, t)
+	text := f.Section(".text")
+	textdat, err := text.Data()
+	if err != nil {
+		t.Fatalf("reading .text: %v", err)
+	}
+
+	// Test PCToLine
+	sym := tab.LookupFunc("linefrompc")
+	wantLine := 0
+	for pc := sym.Entry; pc < sym.End; pc++ {
+		off := pc - text.Addr // TODO(rsc): should not need off; bug in 8g
+		if textdat[off] == 255 {
+			break
+		}
+		wantLine += int(textdat[off])
+		t.Logf("off is %d %#x (max %d)", off, textdat[off], sym.End-pc)
+		file, line, fn := tab.PCToLine(pc)
+		if fn == nil {
+			t.Errorf("failed to get line of PC %#x", pc)
+		} else if !strings.HasSuffix(file, "pclinetest.asm") || line != wantLine || fn != sym {
+			t.Errorf("PCToLine(%#x) = %s:%d (%s), want %s:%d (%s)", pc, file, line, fn.Name, "pclinetest.asm", wantLine, sym.Name)
+		}
+	}
+
+	// Test LineToPC
+	sym = tab.LookupFunc("pcfromline")
+	lookupline := -1
+	wantLine = 0
+	off := uint64(0) // TODO(rsc): should not need off; bug in 8g
+	for pc := sym.Value; pc < sym.End; pc += 2 + uint64(textdat[off]) {
+		file, line, fn := tab.PCToLine(pc)
+		off = pc - text.Addr
+		if textdat[off] == 255 {
+			break
+		}
+		wantLine += int(textdat[off])
+		if line != wantLine {
+			t.Errorf("expected line %d at PC %#x in pcfromline, got %d", wantLine, pc, line)
+			off = pc + 1 - text.Addr
+			continue
+		}
+		if lookupline == -1 {
+			lookupline = line
+		}
+		for ; lookupline <= line; lookupline++ {
+			pc2, fn2, err := tab.LineToPC(file, lookupline)
+			if lookupline != line {
+				// Should be nothing on this line
+				if err == nil {
+					t.Errorf("expected no PC at line %d, got %#x (%s)", lookupline, pc2, fn2.Name)
+				}
+			} else if err != nil {
+				t.Errorf("failed to get PC of line %d: %s", lookupline, err)
+			} else if pc != pc2 {
+				t.Errorf("expected PC %#x (%s) at line %d, got PC %#x (%s)", pc, fn.Name, line, pc2, fn2.Name)
+			}
+		}
+		off = pc + 1 - text.Addr
+	}
+}
diff --git a/src/debug/gosym/symtab.go b/src/debug/gosym/symtab.go
new file mode 100644
index 000000000..ee18499d1
--- /dev/null
+++ b/src/debug/gosym/symtab.go
@@ -0,0 +1,710 @@
+// Copyright 2009 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package gosym implements access to the Go symbol
+// and line number tables embedded in Go binaries generated
+// by the gc compilers.
+package gosym
+
+// The table format is a variant of the format used in Plan 9's a.out
+// format, documented at http://plan9.bell-labs.com/magic/man2html/6/a.out.
+// The best reference for the differences between the Plan 9 format
+// and the Go format is the runtime source, specifically ../../runtime/symtab.c.
+
+import (
+	"bytes"
+	"encoding/binary"
+	"fmt"
+	"strconv"
+	"strings"
+)
+
+/*
+ * Symbols
+ */
+
+// A Sym represents a single symbol table entry.
+type Sym struct {
+	Value  uint64
+	Type   byte
+	Name   string
+	GoType uint64
+	// If this symbol if a function symbol, the corresponding Func
+	Func *Func
+}
+
+// Static reports whether this symbol is static (not visible outside its file).
+func (s *Sym) Static() bool { return s.Type >= 'a' }
+
+// PackageName returns the package part of the symbol name,
+// or the empty string if there is none.
+func (s *Sym) PackageName() string {
+	if i := strings.Index(s.Name, "."); i != -1 {
+		return s.Name[0:i]
+	}
+	return ""
+}
+
+// ReceiverName returns the receiver type name of this symbol,
+// or the empty string if there is none.
+func (s *Sym) ReceiverName() string {
+	l := strings.Index(s.Name, ".")
+	r := strings.LastIndex(s.Name, ".")
+	if l == -1 || r == -1 || l == r {
+		return ""
+	}
+	return s.Name[l+1 : r]
+}
+
+// BaseName returns the symbol name without the package or receiver name.
+func (s *Sym) BaseName() string {
+	if i := strings.LastIndex(s.Name, "."); i != -1 {
+		return s.Name[i+1:]
+	}
+	return s.Name
+}
+
+// A Func collects information about a single function.
+type Func struct {
+	Entry uint64
+	*Sym
+	End       uint64
+	Params    []*Sym
+	Locals    []*Sym
+	FrameSize int
+	LineTable *LineTable
+	Obj       *Obj
+}
+
+// An Obj represents a collection of functions in a symbol table.
+//
+// The exact method of division of a binary into separate Objs is an internal detail
+// of the symbol table format.
+//
+// In early versions of Go each source file became a different Obj.
+//
+// In Go 1 and Go 1.1, each package produced one Obj for all Go sources
+// and one Obj per C source file.
+//
+// In Go 1.2, there is a single Obj for the entire program.
+type Obj struct {
+	// Funcs is a list of functions in the Obj.
+	Funcs []Func
+
+	// In Go 1.1 and earlier, Paths is a list of symbols corresponding
+	// to the source file names that produced the Obj.
+	// In Go 1.2, Paths is nil.
+	// Use the keys of Table.Files to obtain a list of source files.
+	Paths []Sym // meta
+}
+
+/*
+ * Symbol tables
+ */
+
+// Table represents a Go symbol table.  It stores all of the
+// symbols decoded from the program and provides methods to translate
+// between symbols, names, and addresses.
+type Table struct {
+	Syms  []Sym
+	Funcs []Func
+	Files map[string]*Obj // nil for Go 1.2 and later binaries
+	Objs  []Obj           // nil for Go 1.2 and later binaries
+
+	go12line *LineTable // Go 1.2 line number table
+}
+
+type sym struct {
+	value  uint64
+	gotype uint64
+	typ    byte
+	name   []byte
+}
+
+var (
+	littleEndianSymtab    = []byte{0xFD, 0xFF, 0xFF, 0xFF, 0x00, 0x00, 0x00}
+	bigEndianSymtab       = []byte{0xFF, 0xFF, 0xFF, 0xFD, 0x00, 0x00, 0x00}
+	oldLittleEndianSymtab = []byte{0xFE, 0xFF, 0xFF, 0xFF, 0x00, 0x00}
+)
+
+func walksymtab(data []byte, fn func(sym) error) error {
+	if len(data) == 0 { // missing symtab is okay
+		return nil
+	}
+	var order binary.ByteOrder = binary.BigEndian
+	newTable := false
+	switch {
+	case bytes.HasPrefix(data, oldLittleEndianSymtab):
+		// Same as Go 1.0, but little endian.
+		// Format was used during interim development between Go 1.0 and Go 1.1.
+		// Should not be widespread, but easy to support.
+		data = data[6:]
+		order = binary.LittleEndian
+	case bytes.HasPrefix(data, bigEndianSymtab):
+		newTable = true
+	case bytes.HasPrefix(data, littleEndianSymtab):
+		newTable = true
+		order = binary.LittleEndian
+	}
+	var ptrsz int
+	if newTable {
+		if len(data) < 8 {
+			return &DecodingError{len(data), "unexpected EOF", nil}
+		}
+		ptrsz = int(data[7])
+		if ptrsz != 4 && ptrsz != 8 {
+			return &DecodingError{7, "invalid pointer size", ptrsz}
+		}
+		data = data[8:]
+	}
+	var s sym
+	p := data
+	for len(p) >= 4 {
+		var typ byte
+		if newTable {
+			// Symbol type, value, Go type.
+			typ = p[0] & 0x3F
+			wideValue := p[0]&0x40 != 0
+			goType := p[0]&0x80 != 0
+			if typ < 26 {
+				typ += 'A'
+			} else {
+				typ += 'a' - 26
+			}
+			s.typ = typ
+			p = p[1:]
+			if wideValue {
+				if len(p) < ptrsz {
+					return &DecodingError{len(data), "unexpected EOF", nil}
+				}
+				// fixed-width value
+				if ptrsz == 8 {
+					s.value = order.Uint64(p[0:8])
+					p = p[8:]
+				} else {
+					s.value = uint64(order.Uint32(p[0:4]))
+					p = p[4:]
+				}
+			} else {
+				// varint value
+				s.value = 0
+				shift := uint(0)
+				for len(p) > 0 && p[0]&0x80 != 0 {
+					s.value |= uint64(p[0]&0x7F) << shift
+					shift += 7
+					p = p[1:]
+				}
+				if len(p) == 0 {
+					return &DecodingError{len(data), "unexpected EOF", nil}
+				}
+				s.value |= uint64(p[0]) << shift
+				p = p[1:]
+			}
+			if goType {
+				if len(p) < ptrsz {
+					return &DecodingError{len(data), "unexpected EOF", nil}
+				}
+				// fixed-width go type
+				if ptrsz == 8 {
+					s.gotype = order.Uint64(p[0:8])
+					p = p[8:]
+				} else {
+					s.gotype = uint64(order.Uint32(p[0:4]))
+					p = p[4:]
+				}
+			}
+		} else {
+			// Value, symbol type.
+			s.value = uint64(order.Uint32(p[0:4]))
+			if len(p) < 5 {
+				return &DecodingError{len(data), "unexpected EOF", nil}
+			}
+			typ = p[4]
+			if typ&0x80 == 0 {
+				return &DecodingError{len(data) - len(p) + 4, "bad symbol type", typ}
+			}
+			typ &^= 0x80
+			s.typ = typ
+			p = p[5:]
+		}
+
+		// Name.
+		var i int
+		var nnul int
+		for i = 0; i < len(p); i++ {
+			if p[i] == 0 {
+				nnul = 1
+				break
+			}
+		}
+		switch typ {
+		case 'z', 'Z':
+			p = p[i+nnul:]
+			for i = 0; i+2 <= len(p); i += 2 {
+				if p[i] == 0 && p[i+1] == 0 {
+					nnul = 2
+					break
+				}
+			}
+		}
+		if len(p) < i+nnul {
+			return &DecodingError{len(data), "unexpected EOF", nil}
+		}
+		s.name = p[0:i]
+		i += nnul
+		p = p[i:]
+
+		if !newTable {
+			if len(p) < 4 {
+				return &DecodingError{len(data), "unexpected EOF", nil}
+			}
+			// Go type.
+			s.gotype = uint64(order.Uint32(p[:4]))
+			p = p[4:]
+		}
+		fn(s)
+	}
+	return nil
+}
+
+// NewTable decodes the Go symbol table in data,
+// returning an in-memory representation.
+func NewTable(symtab []byte, pcln *LineTable) (*Table, error) {
+	var n int
+	err := walksymtab(symtab, func(s sym) error {
+		n++
+		return nil
+	})
+	if err != nil {
+		return nil, err
+	}
+
+	var t Table
+	if pcln.isGo12() {
+		t.go12line = pcln
+	}
+	fname := make(map[uint16]string)
+	t.Syms = make([]Sym, 0, n)
+	nf := 0
+	nz := 0
+	lasttyp := uint8(0)
+	err = walksymtab(symtab, func(s sym) error {
+		n := len(t.Syms)
+		t.Syms = t.Syms[0 : n+1]
+		ts := &t.Syms[n]
+		ts.Type = s.typ
+		ts.Value = uint64(s.value)
+		ts.GoType = uint64(s.gotype)
+		switch s.typ {
+		default:
+			// rewrite name to use . instead of · (c2 b7)
+			w := 0
+			b := s.name
+			for i := 0; i < len(b); i++ {
+				if b[i] == 0xc2 && i+1 < len(b) && b[i+1] == 0xb7 {
+					i++
+					b[i] = '.'
+				}
+				b[w] = b[i]
+				w++
+			}
+			ts.Name = string(s.name[0:w])
+		case 'z', 'Z':
+			if lasttyp != 'z' && lasttyp != 'Z' {
+				nz++
+			}
+			for i := 0; i < len(s.name); i += 2 {
+				eltIdx := binary.BigEndian.Uint16(s.name[i : i+2])
+				elt, ok := fname[eltIdx]
+				if !ok {
+					return &DecodingError{-1, "bad filename code", eltIdx}
+				}
+				if n := len(ts.Name); n > 0 && ts.Name[n-1] != '/' {
+					ts.Name += "/"
+				}
+				ts.Name += elt
+			}
+		}
+		switch s.typ {
+		case 'T', 't', 'L', 'l':
+			nf++
+		case 'f':
+			fname[uint16(s.value)] = ts.Name
+		}
+		lasttyp = s.typ
+		return nil
+	})
+	if err != nil {
+		return nil, err
+	}
+
+	t.Funcs = make([]Func, 0, nf)
+	t.Files = make(map[string]*Obj)
+
+	var obj *Obj
+	if t.go12line != nil {
+		// Put all functions into one Obj.
+		t.Objs = make([]Obj, 1)
+		obj = &t.Objs[0]
+		t.go12line.go12MapFiles(t.Files, obj)
+	} else {
+		t.Objs = make([]Obj, 0, nz)
+	}
+
+	// Count text symbols and attach frame sizes, parameters, and
+	// locals to them.  Also, find object file boundaries.
+	lastf := 0
+	for i := 0; i < len(t.Syms); i++ {
+		sym := &t.Syms[i]
+		switch sym.Type {
+		case 'Z', 'z': // path symbol
+			if t.go12line != nil {
+				// Go 1.2 binaries have the file information elsewhere. Ignore.
+				break
+			}
+			// Finish the current object
+			if obj != nil {
+				obj.Funcs = t.Funcs[lastf:]
+			}
+			lastf = len(t.Funcs)
+
+			// Start new object
+			n := len(t.Objs)
+			t.Objs = t.Objs[0 : n+1]
+			obj = &t.Objs[n]
+
+			// Count & copy path symbols
+			var end int
+			for end = i + 1; end < len(t.Syms); end++ {
+				if c := t.Syms[end].Type; c != 'Z' && c != 'z' {
+					break
+				}
+			}
+			obj.Paths = t.Syms[i:end]
+			i = end - 1 // loop will i++
+
+			// Record file names
+			depth := 0
+			for j := range obj.Paths {
+				s := &obj.Paths[j]
+				if s.Name == "" {
+					depth--
+				} else {
+					if depth == 0 {
+						t.Files[s.Name] = obj
+					}
+					depth++
+				}
+			}
+
+		case 'T', 't', 'L', 'l': // text symbol
+			if n := len(t.Funcs); n > 0 {
+				t.Funcs[n-1].End = sym.Value
+			}
+			if sym.Name == "runtime.etext" || sym.Name == "etext" {
+				continue
+			}
+
+			// Count parameter and local (auto) syms
+			var np, na int
+			var end int
+		countloop:
+			for end = i + 1; end < len(t.Syms); end++ {
+				switch t.Syms[end].Type {
+				case 'T', 't', 'L', 'l', 'Z', 'z':
+					break countloop
+				case 'p':
+					np++
+				case 'a':
+					na++
+				}
+			}
+
+			// Fill in the function symbol
+			n := len(t.Funcs)
+			t.Funcs = t.Funcs[0 : n+1]
+			fn := &t.Funcs[n]
+			sym.Func = fn
+			fn.Params = make([]*Sym, 0, np)
+			fn.Locals = make([]*Sym, 0, na)
+			fn.Sym = sym
+			fn.Entry = sym.Value
+			fn.Obj = obj
+			if t.go12line != nil {
+				// All functions share the same line table.
+				// It knows how to narrow down to a specific
+				// function quickly.
+				fn.LineTable = t.go12line
+			} else if pcln != nil {
+				fn.LineTable = pcln.slice(fn.Entry)
+				pcln = fn.LineTable
+			}
+			for j := i; j < end; j++ {
+				s := &t.Syms[j]
+				switch s.Type {
+				case 'm':
+					fn.FrameSize = int(s.Value)
+				case 'p':
+					n := len(fn.Params)
+					fn.Params = fn.Params[0 : n+1]
+					fn.Params[n] = s
+				case 'a':
+					n := len(fn.Locals)
+					fn.Locals = fn.Locals[0 : n+1]
+					fn.Locals[n] = s
+				}
+			}
+			i = end - 1 // loop will i++
+		}
+	}
+
+	if t.go12line != nil && nf == 0 {
+		t.Funcs = t.go12line.go12Funcs()
+	}
+	if obj != nil {
+		obj.Funcs = t.Funcs[lastf:]
+	}
+	return &t, nil
+}
+
+// PCToFunc returns the function containing the program counter pc,
+// or nil if there is no such function.
+func (t *Table) PCToFunc(pc uint64) *Func {
+	funcs := t.Funcs
+	for len(funcs) > 0 {
+		m := len(funcs) / 2
+		fn := &funcs[m]
+		switch {
+		case pc < fn.Entry:
+			funcs = funcs[0:m]
+		case fn.Entry <= pc && pc < fn.End:
+			return fn
+		default:
+			funcs = funcs[m+1:]
+		}
+	}
+	return nil
+}
+
+// PCToLine looks up line number information for a program counter.
+// If there is no information, it returns fn == nil.
+func (t *Table) PCToLine(pc uint64) (file string, line int, fn *Func) {
+	if fn = t.PCToFunc(pc); fn == nil {
+		return
+	}
+	if t.go12line != nil {
+		file = t.go12line.go12PCToFile(pc)
+		line = t.go12line.go12PCToLine(pc)
+	} else {
+		file, line = fn.Obj.lineFromAline(fn.LineTable.PCToLine(pc))
+	}
+	return
+}
+
+// LineToPC looks up the first program counter on the given line in
+// the named file.  It returns UnknownPathError or UnknownLineError if
+// there is an error looking up this line.
+func (t *Table) LineToPC(file string, line int) (pc uint64, fn *Func, err error) {
+	obj, ok := t.Files[file]
+	if !ok {
+		return 0, nil, UnknownFileError(file)
+	}
+
+	if t.go12line != nil {
+		pc := t.go12line.go12LineToPC(file, line)
+		if pc == 0 {
+			return 0, nil, &UnknownLineError{file, line}
+		}
+		return pc, t.PCToFunc(pc), nil
+	}
+
+	abs, err := obj.alineFromLine(file, line)
+	if err != nil {
+		return
+	}
+	for i := range obj.Funcs {
+		f := &obj.Funcs[i]
+		pc := f.LineTable.LineToPC(abs, f.End)
+		if pc != 0 {
+			return pc, f, nil
+		}
+	}
+	return 0, nil, &UnknownLineError{file, line}
+}
+
+// LookupSym returns the text, data, or bss symbol with the given name,
+// or nil if no such symbol is found.
+func (t *Table) LookupSym(name string) *Sym {
+	// TODO(austin) Maybe make a map
+	for i := range t.Syms {
+		s := &t.Syms[i]
+		switch s.Type {
+		case 'T', 't', 'L', 'l', 'D', 'd', 'B', 'b':
+			if s.Name == name {
+				return s
+			}
+		}
+	}
+	return nil
+}
+
+// LookupFunc returns the text, data, or bss symbol with the given name,
+// or nil if no such symbol is found.
+func (t *Table) LookupFunc(name string) *Func {
+	for i := range t.Funcs {
+		f := &t.Funcs[i]
+		if f.Sym.Name == name {
+			return f
+		}
+	}
+	return nil
+}
+
+// SymByAddr returns the text, data, or bss symbol starting at the given address.
+func (t *Table) SymByAddr(addr uint64) *Sym {
+	for i := range t.Syms {
+		s := &t.Syms[i]
+		switch s.Type {
+		case 'T', 't', 'L', 'l', 'D', 'd', 'B', 'b':
+			if s.Value == addr {
+				return s
+			}
+		}
+	}
+	return nil
+}
+
+/*
+ * Object files
+ */
+
+// This is legacy code for Go 1.1 and earlier, which used the
+// Plan 9 format for pc-line tables. This code was never quite
+// correct. It's probably very close, and it's usually correct, but
+// we never quite found all the corner cases.
+//
+// Go 1.2 and later use a simpler format, documented at golang.org/s/go12symtab.
+
+func (o *Obj) lineFromAline(aline int) (string, int) {
+	type stackEnt struct {
+		path   string
+		start  int
+		offset int
+		prev   *stackEnt
+	}
+
+	noPath := &stackEnt{"", 0, 0, nil}
+	tos := noPath
+
+pathloop:
+	for _, s := range o.Paths {
+		val := int(s.Value)
+		switch {
+		case val > aline:
+			break pathloop
+
+		case val == 1:
+			// Start a new stack
+			tos = &stackEnt{s.Name, val, 0, noPath}
+
+		case s.Name == "":
+			// Pop
+			if tos == noPath {
+				return "<malformed symbol table>", 0
+			}
+			tos.prev.offset += val - tos.start
+			tos = tos.prev
+
+		default:
+			// Push
+			tos = &stackEnt{s.Name, val, 0, tos}
+		}
+	}
+
+	if tos == noPath {
+		return "", 0
+	}
+	return tos.path, aline - tos.start - tos.offset + 1
+}
+
+func (o *Obj) alineFromLine(path string, line int) (int, error) {
+	if line < 1 {
+		return 0, &UnknownLineError{path, line}
+	}
+
+	for i, s := range o.Paths {
+		// Find this path
+		if s.Name != path {
+			continue
+		}
+
+		// Find this line at this stack level
+		depth := 0
+		var incstart int
+		line += int(s.Value)
+	pathloop:
+		for _, s := range o.Paths[i:] {
+			val := int(s.Value)
+			switch {
+			case depth == 1 && val >= line:
+				return line - 1, nil
+
+			case s.Name == "":
+				depth--
+				if depth == 0 {
+					break pathloop
+				} else if depth == 1 {
+					line += val - incstart
+				}
+
+			default:
+				if depth == 1 {
+					incstart = val
+				}
+				depth++
+			}
+		}
+		return 0, &UnknownLineError{path, line}
+	}
+	return 0, UnknownFileError(path)
+}
+
+/*
+ * Errors
+ */
+
+// UnknownFileError represents a failure to find the specific file in
+// the symbol table.
+type UnknownFileError string
+
+func (e UnknownFileError) Error() string { return "unknown file: " + string(e) }
+
+// UnknownLineError represents a failure to map a line to a program
+// counter, either because the line is beyond the bounds of the file
+// or because there is no code on the given line.
+type UnknownLineError struct {
+	File string
+	Line int
+}
+
+func (e *UnknownLineError) Error() string {
+	return "no code at " + e.File + ":" + strconv.Itoa(e.Line)
+}
+
+// DecodingError represents an error during the decoding of
+// the symbol table.
+type DecodingError struct {
+	off int
+	msg string
+	val interface{}
+}
+
+func (e *DecodingError) Error() string {
+	msg := e.msg
+	if e.val != nil {
+		msg += fmt.Sprintf(" '%v'", e.val)
+	}
+	msg += fmt.Sprintf(" at byte %#x", e.off)
+	return msg
+}
diff --git a/src/debug/macho/fat.go b/src/debug/macho/fat.go
new file mode 100644
index 000000000..93b831526
--- /dev/null
+++ b/src/debug/macho/fat.go
@@ -0,0 +1,146 @@
+// Copyright 2014 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package macho
+
+import (
+	"encoding/binary"
+	"fmt"
+	"io"
+	"os"
+)
+
+// A FatFile is a Mach-O universal binary that contains at least one architecture.
+type FatFile struct {
+	Magic  uint32
+	Arches []FatArch
+	closer io.Closer
+}
+
+// A FatArchHeader represents a fat header for a specific image architecture.
+type FatArchHeader struct {
+	Cpu    Cpu
+	SubCpu uint32
+	Offset uint32
+	Size   uint32
+	Align  uint32
+}
+
+const fatArchHeaderSize = 5 * 4
+
+// A FatArch is a Mach-O File inside a FatFile.
+type FatArch struct {
+	FatArchHeader
+	*File
+}
+
+// ErrNotFat is returned from NewFatFile or OpenFat when the file is not a
+// universal binary but may be a thin binary, based on its magic number.
+var ErrNotFat = &FormatError{0, "not a fat Mach-O file", nil}
+
+// NewFatFile creates a new FatFile for accessing all the Mach-O images in a
+// universal binary. The Mach-O binary is expected to start at position 0 in
+// the ReaderAt.
+func NewFatFile(r io.ReaderAt) (*FatFile, error) {
+	var ff FatFile
+	sr := io.NewSectionReader(r, 0, 1<<63-1)
+
+	// Read the fat_header struct, which is always in big endian.
+	// Start with the magic number.
+	err := binary.Read(sr, binary.BigEndian, &ff.Magic)
+	if err != nil {
+		return nil, &FormatError{0, "error reading magic number", nil}
+	} else if ff.Magic != MagicFat {
+		// See if this is a Mach-O file via its magic number. The magic
+		// must be converted to little endian first though.
+		var buf [4]byte
+		binary.BigEndian.PutUint32(buf[:], ff.Magic)
+		leMagic := binary.LittleEndian.Uint32(buf[:])
+		if leMagic == Magic32 || leMagic == Magic64 {
+			return nil, ErrNotFat
+		} else {
+			return nil, &FormatError{0, "invalid magic number", nil}
+		}
+	}
+	offset := int64(4)
+
+	// Read the number of FatArchHeaders that come after the fat_header.
+	var narch uint32
+	err = binary.Read(sr, binary.BigEndian, &narch)
+	if err != nil {
+		return nil, &FormatError{offset, "invalid fat_header", nil}
+	}
+	offset += 4
+
+	if narch < 1 {
+		return nil, &FormatError{offset, "file contains no images", nil}
+	}
+
+	// Combine the Cpu and SubCpu (both uint32) into a uint64 to make sure
+	// there are not duplicate architectures.
+	seenArches := make(map[uint64]bool, narch)
+	// Make sure that all images are for the same MH_ type.
+	var machoType Type
+
+	// Following the fat_header comes narch fat_arch structs that index
+	// Mach-O images further in the file.
+	ff.Arches = make([]FatArch, narch)
+	for i := uint32(0); i < narch; i++ {
+		fa := &ff.Arches[i]
+		err = binary.Read(sr, binary.BigEndian, &fa.FatArchHeader)
+		if err != nil {
+			return nil, &FormatError{offset, "invalid fat_arch header", nil}
+		}
+		offset += fatArchHeaderSize
+
+		fr := io.NewSectionReader(r, int64(fa.Offset), int64(fa.Size))
+		fa.File, err = NewFile(fr)
+		if err != nil {
+			return nil, err
+		}
+
+		// Make sure the architecture for this image is not duplicate.
+		seenArch := (uint64(fa.Cpu) << 32) | uint64(fa.SubCpu)
+		if o, k := seenArches[seenArch]; o || k {
+			return nil, &FormatError{offset, fmt.Sprintf("duplicate architecture cpu=%v, subcpu=%#x", fa.Cpu, fa.SubCpu), nil}
+		}
+		seenArches[seenArch] = true
+
+		// Make sure the Mach-O type matches that of the first image.
+		if i == 0 {
+			machoType = fa.Type
+		} else {
+			if fa.Type != machoType {
+				return nil, &FormatError{offset, fmt.Sprintf("Mach-O type for architecture #%d (type=%#x) does not match first (type=%#x)", i, fa.Type, machoType), nil}
+			}
+		}
+	}
+
+	return &ff, nil
+}
+
+// OpenFat opens the named file using os.Open and prepares it for use as a Mach-O
+// universal binary.
+func OpenFat(name string) (ff *FatFile, err error) {
+	f, err := os.Open(name)
+	if err != nil {
+		return nil, err
+	}
+	ff, err = NewFatFile(f)
+	if err != nil {
+		f.Close()
+		return nil, err
+	}
+	ff.closer = f
+	return
+}
+
+func (ff *FatFile) Close() error {
+	var err error
+	if ff.closer != nil {
+		err = ff.closer.Close()
+		ff.closer = nil
+	}
+	return err
+}
diff --git a/src/debug/macho/file.go b/src/debug/macho/file.go
new file mode 100644
index 000000000..eefb74444
--- /dev/null
+++ b/src/debug/macho/file.go
@@ -0,0 +1,524 @@
+// Copyright 2009 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package macho implements access to Mach-O object files.
+package macho
+
+// High level access to low level data structures.
+
+import (
+	"bytes"
+	"debug/dwarf"
+	"encoding/binary"
+	"fmt"
+	"io"
+	"os"
+)
+
+// A File represents an open Mach-O file.
+type File struct {
+	FileHeader
+	ByteOrder binary.ByteOrder
+	Loads     []Load
+	Sections  []*Section
+
+	Symtab   *Symtab
+	Dysymtab *Dysymtab
+
+	closer io.Closer
+}
+
+// A Load represents any Mach-O load command.
+type Load interface {
+	Raw() []byte
+}
+
+// A LoadBytes is the uninterpreted bytes of a Mach-O load command.
+type LoadBytes []byte
+
+func (b LoadBytes) Raw() []byte { return b }
+
+// A SegmentHeader is the header for a Mach-O 32-bit or 64-bit load segment command.
+type SegmentHeader struct {
+	Cmd     LoadCmd
+	Len     uint32
+	Name    string
+	Addr    uint64
+	Memsz   uint64
+	Offset  uint64
+	Filesz  uint64
+	Maxprot uint32
+	Prot    uint32
+	Nsect   uint32
+	Flag    uint32
+}
+
+// A Segment represents a Mach-O 32-bit or 64-bit load segment command.
+type Segment struct {
+	LoadBytes
+	SegmentHeader
+
+	// Embed ReaderAt for ReadAt method.
+	// Do not embed SectionReader directly
+	// to avoid having Read and Seek.
+	// If a client wants Read and Seek it must use
+	// Open() to avoid fighting over the seek offset
+	// with other clients.
+	io.ReaderAt
+	sr *io.SectionReader
+}
+
+// Data reads and returns the contents of the segment.
+func (s *Segment) Data() ([]byte, error) {
+	dat := make([]byte, s.sr.Size())
+	n, err := s.sr.ReadAt(dat, 0)
+	if n == len(dat) {
+		err = nil
+	}
+	return dat[0:n], err
+}
+
+// Open returns a new ReadSeeker reading the segment.
+func (s *Segment) Open() io.ReadSeeker { return io.NewSectionReader(s.sr, 0, 1<<63-1) }
+
+type SectionHeader struct {
+	Name   string
+	Seg    string
+	Addr   uint64
+	Size   uint64
+	Offset uint32
+	Align  uint32
+	Reloff uint32
+	Nreloc uint32
+	Flags  uint32
+}
+
+type Section struct {
+	SectionHeader
+
+	// Embed ReaderAt for ReadAt method.
+	// Do not embed SectionReader directly
+	// to avoid having Read and Seek.
+	// If a client wants Read and Seek it must use
+	// Open() to avoid fighting over the seek offset
+	// with other clients.
+	io.ReaderAt
+	sr *io.SectionReader
+}
+
+// Data reads and returns the contents of the Mach-O section.
+func (s *Section) Data() ([]byte, error) {
+	dat := make([]byte, s.sr.Size())
+	n, err := s.sr.ReadAt(dat, 0)
+	if n == len(dat) {
+		err = nil
+	}
+	return dat[0:n], err
+}
+
+// Open returns a new ReadSeeker reading the Mach-O section.
+func (s *Section) Open() io.ReadSeeker { return io.NewSectionReader(s.sr, 0, 1<<63-1) }
+
+// A Dylib represents a Mach-O load dynamic library command.
+type Dylib struct {
+	LoadBytes
+	Name           string
+	Time           uint32
+	CurrentVersion uint32
+	CompatVersion  uint32
+}
+
+// A Symtab represents a Mach-O symbol table command.
+type Symtab struct {
+	LoadBytes
+	SymtabCmd
+	Syms []Symbol
+}
+
+// A Dysymtab represents a Mach-O dynamic symbol table command.
+type Dysymtab struct {
+	LoadBytes
+	DysymtabCmd
+	IndirectSyms []uint32 // indices into Symtab.Syms
+}
+
+/*
+ * Mach-O reader
+ */
+
+// FormatError is returned by some operations if the data does
+// not have the correct format for an object file.
+type FormatError struct {
+	off int64
+	msg string
+	val interface{}
+}
+
+func (e *FormatError) Error() string {
+	msg := e.msg
+	if e.val != nil {
+		msg += fmt.Sprintf(" '%v'", e.val)
+	}
+	msg += fmt.Sprintf(" in record at byte %#x", e.off)
+	return msg
+}
+
+// Open opens the named file using os.Open and prepares it for use as a Mach-O binary.
+func Open(name string) (*File, error) {
+	f, err := os.Open(name)
+	if err != nil {
+		return nil, err
+	}
+	ff, err := NewFile(f)
+	if err != nil {
+		f.Close()
+		return nil, err
+	}
+	ff.closer = f
+	return ff, nil
+}
+
+// Close closes the File.
+// If the File was created using NewFile directly instead of Open,
+// Close has no effect.
+func (f *File) Close() error {
+	var err error
+	if f.closer != nil {
+		err = f.closer.Close()
+		f.closer = nil
+	}
+	return err
+}
+
+// NewFile creates a new File for accessing a Mach-O binary in an underlying reader.
+// The Mach-O binary is expected to start at position 0 in the ReaderAt.
+func NewFile(r io.ReaderAt) (*File, error) {
+	f := new(File)
+	sr := io.NewSectionReader(r, 0, 1<<63-1)
+
+	// Read and decode Mach magic to determine byte order, size.
+	// Magic32 and Magic64 differ only in the bottom bit.
+	var ident [4]byte
+	if _, err := r.ReadAt(ident[0:], 0); err != nil {
+		return nil, err
+	}
+	be := binary.BigEndian.Uint32(ident[0:])
+	le := binary.LittleEndian.Uint32(ident[0:])
+	switch Magic32 &^ 1 {
+	case be &^ 1:
+		f.ByteOrder = binary.BigEndian
+		f.Magic = be
+	case le &^ 1:
+		f.ByteOrder = binary.LittleEndian
+		f.Magic = le
+	default:
+		return nil, &FormatError{0, "invalid magic number", nil}
+	}
+
+	// Read entire file header.
+	if err := binary.Read(sr, f.ByteOrder, &f.FileHeader); err != nil {
+		return nil, err
+	}
+
+	// Then load commands.
+	offset := int64(fileHeaderSize32)
+	if f.Magic == Magic64 {
+		offset = fileHeaderSize64
+	}
+	dat := make([]byte, f.Cmdsz)
+	if _, err := r.ReadAt(dat, offset); err != nil {
+		return nil, err
+	}
+	f.Loads = make([]Load, f.Ncmd)
+	bo := f.ByteOrder
+	for i := range f.Loads {
+		// Each load command begins with uint32 command and length.
+		if len(dat) < 8 {
+			return nil, &FormatError{offset, "command block too small", nil}
+		}
+		cmd, siz := LoadCmd(bo.Uint32(dat[0:4])), bo.Uint32(dat[4:8])
+		if siz < 8 || siz > uint32(len(dat)) {
+			return nil, &FormatError{offset, "invalid command block size", nil}
+		}
+		var cmddat []byte
+		cmddat, dat = dat[0:siz], dat[siz:]
+		offset += int64(siz)
+		var s *Segment
+		switch cmd {
+		default:
+			f.Loads[i] = LoadBytes(cmddat)
+
+		case LoadCmdDylib:
+			var hdr DylibCmd
+			b := bytes.NewReader(cmddat)
+			if err := binary.Read(b, bo, &hdr); err != nil {
+				return nil, err
+			}
+			l := new(Dylib)
+			if hdr.Name >= uint32(len(cmddat)) {
+				return nil, &FormatError{offset, "invalid name in dynamic library command", hdr.Name}
+			}
+			l.Name = cstring(cmddat[hdr.Name:])
+			l.Time = hdr.Time
+			l.CurrentVersion = hdr.CurrentVersion
+			l.CompatVersion = hdr.CompatVersion
+			l.LoadBytes = LoadBytes(cmddat)
+			f.Loads[i] = l
+
+		case LoadCmdSymtab:
+			var hdr SymtabCmd
+			b := bytes.NewReader(cmddat)
+			if err := binary.Read(b, bo, &hdr); err != nil {
+				return nil, err
+			}
+			strtab := make([]byte, hdr.Strsize)
+			if _, err := r.ReadAt(strtab, int64(hdr.Stroff)); err != nil {
+				return nil, err
+			}
+			var symsz int
+			if f.Magic == Magic64 {
+				symsz = 16
+			} else {
+				symsz = 12
+			}
+			symdat := make([]byte, int(hdr.Nsyms)*symsz)
+			if _, err := r.ReadAt(symdat, int64(hdr.Symoff)); err != nil {
+				return nil, err
+			}
+			st, err := f.parseSymtab(symdat, strtab, cmddat, &hdr, offset)
+			if err != nil {
+				return nil, err
+			}
+			f.Loads[i] = st
+			f.Symtab = st
+
+		case LoadCmdDysymtab:
+			var hdr DysymtabCmd
+			b := bytes.NewReader(cmddat)
+			if err := binary.Read(b, bo, &hdr); err != nil {
+				return nil, err
+			}
+			dat := make([]byte, hdr.Nindirectsyms*4)
+			if _, err := r.ReadAt(dat, int64(hdr.Indirectsymoff)); err != nil {
+				return nil, err
+			}
+			x := make([]uint32, hdr.Nindirectsyms)
+			if err := binary.Read(bytes.NewReader(dat), bo, x); err != nil {
+				return nil, err
+			}
+			st := new(Dysymtab)
+			st.LoadBytes = LoadBytes(cmddat)
+			st.DysymtabCmd = hdr
+			st.IndirectSyms = x
+			f.Loads[i] = st
+			f.Dysymtab = st
+
+		case LoadCmdSegment:
+			var seg32 Segment32
+			b := bytes.NewReader(cmddat)
+			if err := binary.Read(b, bo, &seg32); err != nil {
+				return nil, err
+			}
+			s = new(Segment)
+			s.LoadBytes = cmddat
+			s.Cmd = cmd
+			s.Len = siz
+			s.Name = cstring(seg32.Name[0:])
+			s.Addr = uint64(seg32.Addr)
+			s.Memsz = uint64(seg32.Memsz)
+			s.Offset = uint64(seg32.Offset)
+			s.Filesz = uint64(seg32.Filesz)
+			s.Maxprot = seg32.Maxprot
+			s.Prot = seg32.Prot
+			s.Nsect = seg32.Nsect
+			s.Flag = seg32.Flag
+			f.Loads[i] = s
+			for i := 0; i < int(s.Nsect); i++ {
+				var sh32 Section32
+				if err := binary.Read(b, bo, &sh32); err != nil {
+					return nil, err
+				}
+				sh := new(Section)
+				sh.Name = cstring(sh32.Name[0:])
+				sh.Seg = cstring(sh32.Seg[0:])
+				sh.Addr = uint64(sh32.Addr)
+				sh.Size = uint64(sh32.Size)
+				sh.Offset = sh32.Offset
+				sh.Align = sh32.Align
+				sh.Reloff = sh32.Reloff
+				sh.Nreloc = sh32.Nreloc
+				sh.Flags = sh32.Flags
+				f.pushSection(sh, r)
+			}
+
+		case LoadCmdSegment64:
+			var seg64 Segment64
+			b := bytes.NewReader(cmddat)
+			if err := binary.Read(b, bo, &seg64); err != nil {
+				return nil, err
+			}
+			s = new(Segment)
+			s.LoadBytes = cmddat
+			s.Cmd = cmd
+			s.Len = siz
+			s.Name = cstring(seg64.Name[0:])
+			s.Addr = seg64.Addr
+			s.Memsz = seg64.Memsz
+			s.Offset = seg64.Offset
+			s.Filesz = seg64.Filesz
+			s.Maxprot = seg64.Maxprot
+			s.Prot = seg64.Prot
+			s.Nsect = seg64.Nsect
+			s.Flag = seg64.Flag
+			f.Loads[i] = s
+			for i := 0; i < int(s.Nsect); i++ {
+				var sh64 Section64
+				if err := binary.Read(b, bo, &sh64); err != nil {
+					return nil, err
+				}
+				sh := new(Section)
+				sh.Name = cstring(sh64.Name[0:])
+				sh.Seg = cstring(sh64.Seg[0:])
+				sh.Addr = sh64.Addr
+				sh.Size = sh64.Size
+				sh.Offset = sh64.Offset
+				sh.Align = sh64.Align
+				sh.Reloff = sh64.Reloff
+				sh.Nreloc = sh64.Nreloc
+				sh.Flags = sh64.Flags
+				f.pushSection(sh, r)
+			}
+		}
+		if s != nil {
+			s.sr = io.NewSectionReader(r, int64(s.Offset), int64(s.Filesz))
+			s.ReaderAt = s.sr
+		}
+	}
+	return f, nil
+}
+
+func (f *File) parseSymtab(symdat, strtab, cmddat []byte, hdr *SymtabCmd, offset int64) (*Symtab, error) {
+	bo := f.ByteOrder
+	symtab := make([]Symbol, hdr.Nsyms)
+	b := bytes.NewReader(symdat)
+	for i := range symtab {
+		var n Nlist64
+		if f.Magic == Magic64 {
+			if err := binary.Read(b, bo, &n); err != nil {
+				return nil, err
+			}
+		} else {
+			var n32 Nlist32
+			if err := binary.Read(b, bo, &n32); err != nil {
+				return nil, err
+			}
+			n.Name = n32.Name
+			n.Type = n32.Type
+			n.Sect = n32.Sect
+			n.Desc = n32.Desc
+			n.Value = uint64(n32.Value)
+		}
+		sym := &symtab[i]
+		if n.Name >= uint32(len(strtab)) {
+			return nil, &FormatError{offset, "invalid name in symbol table", n.Name}
+		}
+		sym.Name = cstring(strtab[n.Name:])
+		sym.Type = n.Type
+		sym.Sect = n.Sect
+		sym.Desc = n.Desc
+		sym.Value = n.Value
+	}
+	st := new(Symtab)
+	st.LoadBytes = LoadBytes(cmddat)
+	st.Syms = symtab
+	return st, nil
+}
+
+func (f *File) pushSection(sh *Section, r io.ReaderAt) {
+	f.Sections = append(f.Sections, sh)
+	sh.sr = io.NewSectionReader(r, int64(sh.Offset), int64(sh.Size))
+	sh.ReaderAt = sh.sr
+}
+
+func cstring(b []byte) string {
+	var i int
+	for i = 0; i < len(b) && b[i] != 0; i++ {
+	}
+	return string(b[0:i])
+}
+
+// Segment returns the first Segment with the given name, or nil if no such segment exists.
+func (f *File) Segment(name string) *Segment {
+	for _, l := range f.Loads {
+		if s, ok := l.(*Segment); ok && s.Name == name {
+			return s
+		}
+	}
+	return nil
+}
+
+// Section returns the first section with the given name, or nil if no such
+// section exists.
+func (f *File) Section(name string) *Section {
+	for _, s := range f.Sections {
+		if s.Name == name {
+			return s
+		}
+	}
+	return nil
+}
+
+// DWARF returns the DWARF debug information for the Mach-O file.
+func (f *File) DWARF() (*dwarf.Data, error) {
+	// There are many other DWARF sections, but these
+	// are the required ones, and the debug/dwarf package
+	// does not use the others, so don't bother loading them.
+	var names = [...]string{"abbrev", "info", "str"}
+	var dat [len(names)][]byte
+	for i, name := range names {
+		name = "__debug_" + name
+		s := f.Section(name)
+		if s == nil {
+			continue
+		}
+		b, err := s.Data()
+		if err != nil && uint64(len(b)) < s.Size {
+			return nil, err
+		}
+		dat[i] = b
+	}
+
+	abbrev, info, str := dat[0], dat[1], dat[2]
+	return dwarf.New(abbrev, nil, nil, info, nil, nil, nil, str)
+}
+
+// ImportedSymbols returns the names of all symbols
+// referred to by the binary f that are expected to be
+// satisfied by other libraries at dynamic load time.
+func (f *File) ImportedSymbols() ([]string, error) {
+	if f.Dysymtab == nil || f.Symtab == nil {
+		return nil, &FormatError{0, "missing symbol table", nil}
+	}
+
+	st := f.Symtab
+	dt := f.Dysymtab
+	var all []string
+	for _, s := range st.Syms[dt.Iundefsym : dt.Iundefsym+dt.Nundefsym] {
+		all = append(all, s.Name)
+	}
+	return all, nil
+}
+
+// ImportedLibraries returns the paths of all libraries
+// referred to by the binary f that are expected to be
+// linked with the binary at dynamic link time.
+func (f *File) ImportedLibraries() ([]string, error) {
+	var all []string
+	for _, l := range f.Loads {
+		if lib, ok := l.(*Dylib); ok {
+			all = append(all, lib.Name)
+		}
+	}
+	return all, nil
+}
diff --git a/src/debug/macho/file_test.go b/src/debug/macho/file_test.go
new file mode 100644
index 000000000..4797780ce
--- /dev/null
+++ b/src/debug/macho/file_test.go
@@ -0,0 +1,210 @@
+// Copyright 2009 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package macho
+
+import (
+	"reflect"
+	"testing"
+)
+
+type fileTest struct {
+	file     string
+	hdr      FileHeader
+	segments []*SegmentHeader
+	sections []*SectionHeader
+}
+
+var fileTests = []fileTest{
+	{
+		"testdata/gcc-386-darwin-exec",
+		FileHeader{0xfeedface, Cpu386, 0x3, 0x2, 0xc, 0x3c0, 0x85},
+		[]*SegmentHeader{
+			{LoadCmdSegment, 0x38, "__PAGEZERO", 0x0, 0x1000, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0},
+			{LoadCmdSegment, 0xc0, "__TEXT", 0x1000, 0x1000, 0x0, 0x1000, 0x7, 0x5, 0x2, 0x0},
+			{LoadCmdSegment, 0xc0, "__DATA", 0x2000, 0x1000, 0x1000, 0x1000, 0x7, 0x3, 0x2, 0x0},
+			{LoadCmdSegment, 0x7c, "__IMPORT", 0x3000, 0x1000, 0x2000, 0x1000, 0x7, 0x7, 0x1, 0x0},
+			{LoadCmdSegment, 0x38, "__LINKEDIT", 0x4000, 0x1000, 0x3000, 0x12c, 0x7, 0x1, 0x0, 0x0},
+			nil,
+			nil,
+			nil,
+			nil,
+			nil,
+			nil,
+			nil,
+		},
+		[]*SectionHeader{
+			{"__text", "__TEXT", 0x1f68, 0x88, 0xf68, 0x2, 0x0, 0x0, 0x80000400},
+			{"__cstring", "__TEXT", 0x1ff0, 0xd, 0xff0, 0x0, 0x0, 0x0, 0x2},
+			{"__data", "__DATA", 0x2000, 0x14, 0x1000, 0x2, 0x0, 0x0, 0x0},
+			{"__dyld", "__DATA", 0x2014, 0x1c, 0x1014, 0x2, 0x0, 0x0, 0x0},
+			{"__jump_table", "__IMPORT", 0x3000, 0xa, 0x2000, 0x6, 0x0, 0x0, 0x4000008},
+		},
+	},
+	{
+		"testdata/gcc-amd64-darwin-exec",
+		FileHeader{0xfeedfacf, CpuAmd64, 0x80000003, 0x2, 0xb, 0x568, 0x85},
+		[]*SegmentHeader{
+			{LoadCmdSegment64, 0x48, "__PAGEZERO", 0x0, 0x100000000, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0},
+			{LoadCmdSegment64, 0x1d8, "__TEXT", 0x100000000, 0x1000, 0x0, 0x1000, 0x7, 0x5, 0x5, 0x0},
+			{LoadCmdSegment64, 0x138, "__DATA", 0x100001000, 0x1000, 0x1000, 0x1000, 0x7, 0x3, 0x3, 0x0},
+			{LoadCmdSegment64, 0x48, "__LINKEDIT", 0x100002000, 0x1000, 0x2000, 0x140, 0x7, 0x1, 0x0, 0x0},
+			nil,
+			nil,
+			nil,
+			nil,
+			nil,
+			nil,
+			nil,
+		},
+		[]*SectionHeader{
+			{"__text", "__TEXT", 0x100000f14, 0x6d, 0xf14, 0x2, 0x0, 0x0, 0x80000400},
+			{"__symbol_stub1", "__TEXT", 0x100000f81, 0xc, 0xf81, 0x0, 0x0, 0x0, 0x80000408},
+			{"__stub_helper", "__TEXT", 0x100000f90, 0x18, 0xf90, 0x2, 0x0, 0x0, 0x0},
+			{"__cstring", "__TEXT", 0x100000fa8, 0xd, 0xfa8, 0x0, 0x0, 0x0, 0x2},
+			{"__eh_frame", "__TEXT", 0x100000fb8, 0x48, 0xfb8, 0x3, 0x0, 0x0, 0x6000000b},
+			{"__data", "__DATA", 0x100001000, 0x1c, 0x1000, 0x3, 0x0, 0x0, 0x0},
+			{"__dyld", "__DATA", 0x100001020, 0x38, 0x1020, 0x3, 0x0, 0x0, 0x0},
+			{"__la_symbol_ptr", "__DATA", 0x100001058, 0x10, 0x1058, 0x2, 0x0, 0x0, 0x7},
+		},
+	},
+	{
+		"testdata/gcc-amd64-darwin-exec-debug",
+		FileHeader{0xfeedfacf, CpuAmd64, 0x80000003, 0xa, 0x4, 0x5a0, 0},
+		[]*SegmentHeader{
+			nil,
+			{LoadCmdSegment64, 0x1d8, "__TEXT", 0x100000000, 0x1000, 0x0, 0x0, 0x7, 0x5, 0x5, 0x0},
+			{LoadCmdSegment64, 0x138, "__DATA", 0x100001000, 0x1000, 0x0, 0x0, 0x7, 0x3, 0x3, 0x0},
+			{LoadCmdSegment64, 0x278, "__DWARF", 0x100002000, 0x1000, 0x1000, 0x1bc, 0x7, 0x3, 0x7, 0x0},
+		},
+		[]*SectionHeader{
+			{"__text", "__TEXT", 0x100000f14, 0x0, 0x0, 0x2, 0x0, 0x0, 0x80000400},
+			{"__symbol_stub1", "__TEXT", 0x100000f81, 0x0, 0x0, 0x0, 0x0, 0x0, 0x80000408},
+			{"__stub_helper", "__TEXT", 0x100000f90, 0x0, 0x0, 0x2, 0x0, 0x0, 0x0},
+			{"__cstring", "__TEXT", 0x100000fa8, 0x0, 0x0, 0x0, 0x0, 0x0, 0x2},
+			{"__eh_frame", "__TEXT", 0x100000fb8, 0x0, 0x0, 0x3, 0x0, 0x0, 0x6000000b},
+			{"__data", "__DATA", 0x100001000, 0x0, 0x0, 0x3, 0x0, 0x0, 0x0},
+			{"__dyld", "__DATA", 0x100001020, 0x0, 0x0, 0x3, 0x0, 0x0, 0x0},
+			{"__la_symbol_ptr", "__DATA", 0x100001058, 0x0, 0x0, 0x2, 0x0, 0x0, 0x7},
+			{"__debug_abbrev", "__DWARF", 0x100002000, 0x36, 0x1000, 0x0, 0x0, 0x0, 0x0},
+			{"__debug_aranges", "__DWARF", 0x100002036, 0x30, 0x1036, 0x0, 0x0, 0x0, 0x0},
+			{"__debug_frame", "__DWARF", 0x100002066, 0x40, 0x1066, 0x0, 0x0, 0x0, 0x0},
+			{"__debug_info", "__DWARF", 0x1000020a6, 0x54, 0x10a6, 0x0, 0x0, 0x0, 0x0},
+			{"__debug_line", "__DWARF", 0x1000020fa, 0x47, 0x10fa, 0x0, 0x0, 0x0, 0x0},
+			{"__debug_pubnames", "__DWARF", 0x100002141, 0x1b, 0x1141, 0x0, 0x0, 0x0, 0x0},
+			{"__debug_str", "__DWARF", 0x10000215c, 0x60, 0x115c, 0x0, 0x0, 0x0, 0x0},
+		},
+	},
+}
+
+func TestOpen(t *testing.T) {
+	for i := range fileTests {
+		tt := &fileTests[i]
+
+		f, err := Open(tt.file)
+		if err != nil {
+			t.Error(err)
+			continue
+		}
+		if !reflect.DeepEqual(f.FileHeader, tt.hdr) {
+			t.Errorf("open %s:\n\thave %#v\n\twant %#v\n", tt.file, f.FileHeader, tt.hdr)
+			continue
+		}
+		for i, l := range f.Loads {
+			if i >= len(tt.segments) {
+				break
+			}
+			sh := tt.segments[i]
+			s, ok := l.(*Segment)
+			if sh == nil {
+				if ok {
+					t.Errorf("open %s, section %d: skipping %#v\n", tt.file, i, &s.SegmentHeader)
+				}
+				continue
+			}
+			if !ok {
+				t.Errorf("open %s, section %d: not *Segment\n", tt.file, i)
+				continue
+			}
+			have := &s.SegmentHeader
+			want := sh
+			if !reflect.DeepEqual(have, want) {
+				t.Errorf("open %s, segment %d:\n\thave %#v\n\twant %#v\n", tt.file, i, have, want)
+			}
+		}
+		tn := len(tt.segments)
+		fn := len(f.Loads)
+		if tn != fn {
+			t.Errorf("open %s: len(Loads) = %d, want %d", tt.file, fn, tn)
+		}
+
+		for i, sh := range f.Sections {
+			if i >= len(tt.sections) {
+				break
+			}
+			have := &sh.SectionHeader
+			want := tt.sections[i]
+			if !reflect.DeepEqual(have, want) {
+				t.Errorf("open %s, section %d:\n\thave %#v\n\twant %#v\n", tt.file, i, have, want)
+			}
+		}
+		tn = len(tt.sections)
+		fn = len(f.Sections)
+		if tn != fn {
+			t.Errorf("open %s: len(Sections) = %d, want %d", tt.file, fn, tn)
+		}
+
+	}
+}
+
+func TestOpenFailure(t *testing.T) {
+	filename := "file.go"    // not a Mach-O file
+	_, err := Open(filename) // don't crash
+	if err == nil {
+		t.Errorf("open %s: succeeded unexpectedly", filename)
+	}
+}
+
+func TestOpenFat(t *testing.T) {
+	ff, err := OpenFat("testdata/fat-gcc-386-amd64-darwin-exec")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if ff.Magic != MagicFat {
+		t.Errorf("OpenFat: got magic number %#x, want %#x", ff.Magic, MagicFat)
+	}
+	if len(ff.Arches) != 2 {
+		t.Errorf("OpenFat: got %d architectures, want 2", len(ff.Arches))
+	}
+
+	for i := range ff.Arches {
+		arch := &ff.Arches[i]
+		ftArch := &fileTests[i]
+
+		if arch.Cpu != ftArch.hdr.Cpu || arch.SubCpu != ftArch.hdr.SubCpu {
+			t.Errorf("OpenFat: architecture #%d got cpu=%#x subtype=%#x, expected cpu=%#x, subtype=%#x", i, arch.Cpu, arch.SubCpu, ftArch.hdr.Cpu, ftArch.hdr.SubCpu)
+		}
+
+		if !reflect.DeepEqual(arch.FileHeader, ftArch.hdr) {
+			t.Errorf("OpenFat header:\n\tgot %#v\n\twant %#v\n", arch.FileHeader, ftArch.hdr)
+		}
+	}
+}
+
+func TestOpenFatFailure(t *testing.T) {
+	filename := "file.go" // not a Mach-O file
+	if _, err := OpenFat(filename); err == nil {
+		t.Errorf("OpenFat %s: succeeded unexpectedly", filename)
+	}
+
+	filename = "testdata/gcc-386-darwin-exec" // not a fat Mach-O
+	ff, err := OpenFat(filename)
+	if err != ErrNotFat {
+		t.Errorf("OpenFat %s: got %v, want ErrNotFat", filename, err)
+	}
+	if ff != nil {
+		t.Errorf("OpenFat %s: got %v, want nil", filename, ff)
+	}
+}
diff --git a/src/debug/macho/macho.go b/src/debug/macho/macho.go
new file mode 100644
index 000000000..d9678c8ed
--- /dev/null
+++ b/src/debug/macho/macho.go
@@ -0,0 +1,316 @@
+// Copyright 2009 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Mach-O header data structures
+// http://developer.apple.com/mac/library/documentation/DeveloperTools/Conceptual/MachORuntime/Reference/reference.html
+
+package macho
+
+import "strconv"
+
+// A FileHeader represents a Mach-O file header.
+type FileHeader struct {
+	Magic  uint32
+	Cpu    Cpu
+	SubCpu uint32
+	Type   Type
+	Ncmd   uint32
+	Cmdsz  uint32
+	Flags  uint32
+}
+
+const (
+	fileHeaderSize32 = 7 * 4
+	fileHeaderSize64 = 8 * 4
+)
+
+const (
+	Magic32  uint32 = 0xfeedface
+	Magic64  uint32 = 0xfeedfacf
+	MagicFat uint32 = 0xcafebabe
+)
+
+// A Type is the Mach-O file type, e.g. an object file, executable, or dynamic library.
+type Type uint32
+
+const (
+	TypeObj    Type = 1
+	TypeExec   Type = 2
+	TypeDylib  Type = 6
+	TypeBundle Type = 8
+)
+
+// A Cpu is a Mach-O cpu type.
+type Cpu uint32
+
+const cpuArch64 = 0x01000000
+
+const (
+	Cpu386   Cpu = 7
+	CpuAmd64 Cpu = Cpu386 | cpuArch64
+	CpuArm   Cpu = 12
+	CpuPpc   Cpu = 18
+	CpuPpc64 Cpu = CpuPpc | cpuArch64
+)
+
+var cpuStrings = []intName{
+	{uint32(Cpu386), "Cpu386"},
+	{uint32(CpuAmd64), "CpuAmd64"},
+	{uint32(CpuArm), "CpuArm"},
+	{uint32(CpuPpc), "CpuPpc"},
+	{uint32(CpuPpc64), "CpuPpc64"},
+}
+
+func (i Cpu) String() string   { return stringName(uint32(i), cpuStrings, false) }
+func (i Cpu) GoString() string { return stringName(uint32(i), cpuStrings, true) }
+
+// A LoadCmd is a Mach-O load command.
+type LoadCmd uint32
+
+const (
+	LoadCmdSegment    LoadCmd = 1
+	LoadCmdSymtab     LoadCmd = 2
+	LoadCmdThread     LoadCmd = 4
+	LoadCmdUnixThread LoadCmd = 5 // thread+stack
+	LoadCmdDysymtab   LoadCmd = 11
+	LoadCmdDylib      LoadCmd = 12
+	LoadCmdDylinker   LoadCmd = 15
+	LoadCmdSegment64  LoadCmd = 25
+)
+
+var cmdStrings = []intName{
+	{uint32(LoadCmdSegment), "LoadCmdSegment"},
+	{uint32(LoadCmdThread), "LoadCmdThread"},
+	{uint32(LoadCmdUnixThread), "LoadCmdUnixThread"},
+	{uint32(LoadCmdDylib), "LoadCmdDylib"},
+	{uint32(LoadCmdSegment64), "LoadCmdSegment64"},
+}
+
+func (i LoadCmd) String() string   { return stringName(uint32(i), cmdStrings, false) }
+func (i LoadCmd) GoString() string { return stringName(uint32(i), cmdStrings, true) }
+
+// A Segment64 is a 64-bit Mach-O segment load command.
+type Segment64 struct {
+	Cmd     LoadCmd
+	Len     uint32
+	Name    [16]byte
+	Addr    uint64
+	Memsz   uint64
+	Offset  uint64
+	Filesz  uint64
+	Maxprot uint32
+	Prot    uint32
+	Nsect   uint32
+	Flag    uint32
+}
+
+// A Segment32 is a 32-bit Mach-O segment load command.
+type Segment32 struct {
+	Cmd     LoadCmd
+	Len     uint32
+	Name    [16]byte
+	Addr    uint32
+	Memsz   uint32
+	Offset  uint32
+	Filesz  uint32
+	Maxprot uint32
+	Prot    uint32
+	Nsect   uint32
+	Flag    uint32
+}
+
+// A DylibCmd is a Mach-O load dynamic library command.
+type DylibCmd struct {
+	Cmd            LoadCmd
+	Len            uint32
+	Name           uint32
+	Time           uint32
+	CurrentVersion uint32
+	CompatVersion  uint32
+}
+
+// A Section32 is a 32-bit Mach-O section header.
+type Section32 struct {
+	Name     [16]byte
+	Seg      [16]byte
+	Addr     uint32
+	Size     uint32
+	Offset   uint32
+	Align    uint32
+	Reloff   uint32
+	Nreloc   uint32
+	Flags    uint32
+	Reserve1 uint32
+	Reserve2 uint32
+}
+
+// A Section32 is a 64-bit Mach-O section header.
+type Section64 struct {
+	Name     [16]byte
+	Seg      [16]byte
+	Addr     uint64
+	Size     uint64
+	Offset   uint32
+	Align    uint32
+	Reloff   uint32
+	Nreloc   uint32
+	Flags    uint32
+	Reserve1 uint32
+	Reserve2 uint32
+	Reserve3 uint32
+}
+
+// A SymtabCmd is a Mach-O symbol table command.
+type SymtabCmd struct {
+	Cmd     LoadCmd
+	Len     uint32
+	Symoff  uint32
+	Nsyms   uint32
+	Stroff  uint32
+	Strsize uint32
+}
+
+// A DysymtabCmd is a Mach-O dynamic symbol table command.
+type DysymtabCmd struct {
+	Cmd            LoadCmd
+	Len            uint32
+	Ilocalsym      uint32
+	Nlocalsym      uint32
+	Iextdefsym     uint32
+	Nextdefsym     uint32
+	Iundefsym      uint32
+	Nundefsym      uint32
+	Tocoffset      uint32
+	Ntoc           uint32
+	Modtaboff      uint32
+	Nmodtab        uint32
+	Extrefsymoff   uint32
+	Nextrefsyms    uint32
+	Indirectsymoff uint32
+	Nindirectsyms  uint32
+	Extreloff      uint32
+	Nextrel        uint32
+	Locreloff      uint32
+	Nlocrel        uint32
+}
+
+// An Nlist32 is a Mach-O 32-bit symbol table entry.
+type Nlist32 struct {
+	Name  uint32
+	Type  uint8
+	Sect  uint8
+	Desc  uint16
+	Value uint32
+}
+
+// An Nlist64 is a Mach-O 64-bit symbol table entry.
+type Nlist64 struct {
+	Name  uint32
+	Type  uint8
+	Sect  uint8
+	Desc  uint16
+	Value uint64
+}
+
+// A Symbol is a Mach-O 32-bit or 64-bit symbol table entry.
+type Symbol struct {
+	Name  string
+	Type  uint8
+	Sect  uint8
+	Desc  uint16
+	Value uint64
+}
+
+// A Thread is a Mach-O thread state command.
+type Thread struct {
+	Cmd  LoadCmd
+	Len  uint32
+	Type uint32
+	Data []uint32
+}
+
+// Regs386 is the Mach-O 386 register structure.
+type Regs386 struct {
+	AX    uint32
+	BX    uint32
+	CX    uint32
+	DX    uint32
+	DI    uint32
+	SI    uint32
+	BP    uint32
+	SP    uint32
+	SS    uint32
+	FLAGS uint32
+	IP    uint32
+	CS    uint32
+	DS    uint32
+	ES    uint32
+	FS    uint32
+	GS    uint32
+}
+
+// RegsAMD64 is the Mach-O AMD64 register structure.
+type RegsAMD64 struct {
+	AX    uint64
+	BX    uint64
+	CX    uint64
+	DX    uint64
+	DI    uint64
+	SI    uint64
+	BP    uint64
+	SP    uint64
+	R8    uint64
+	R9    uint64
+	R10   uint64
+	R11   uint64
+	R12   uint64
+	R13   uint64
+	R14   uint64
+	R15   uint64
+	IP    uint64
+	FLAGS uint64
+	CS    uint64
+	FS    uint64
+	GS    uint64
+}
+
+type intName struct {
+	i uint32
+	s string
+}
+
+func stringName(i uint32, names []intName, goSyntax bool) string {
+	for _, n := range names {
+		if n.i == i {
+			if goSyntax {
+				return "macho." + n.s
+			}
+			return n.s
+		}
+	}
+	return strconv.FormatUint(uint64(i), 10)
+}
+
+func flagName(i uint32, names []intName, goSyntax bool) string {
+	s := ""
+	for _, n := range names {
+		if n.i&i == n.i {
+			if len(s) > 0 {
+				s += "+"
+			}
+			if goSyntax {
+				s += "macho."
+			}
+			s += n.s
+			i -= n.i
+		}
+	}
+	if len(s) == 0 {
+		return "0x" + strconv.FormatUint(uint64(i), 16)
+	}
+	if i != 0 {
+		s += "+0x" + strconv.FormatUint(uint64(i), 16)
+	}
+	return s
+}
diff --git a/src/debug/macho/testdata/fat-gcc-386-amd64-darwin-exec b/src/debug/macho/testdata/fat-gcc-386-amd64-darwin-exec
new file mode 100644
index 000000000..7efd19300
--- /dev/null
+++ b/src/debug/macho/testdata/fat-gcc-386-amd64-darwin-exec
diff --git a/src/debug/macho/testdata/gcc-386-darwin-exec b/src/debug/macho/testdata/gcc-386-darwin-exec
new file mode 100755
index 000000000..03ba1bafa
--- /dev/null
+++ b/src/debug/macho/testdata/gcc-386-darwin-exec
diff --git a/src/debug/macho/testdata/gcc-amd64-darwin-exec b/src/debug/macho/testdata/gcc-amd64-darwin-exec
new file mode 100755
index 000000000..5155a5a26
--- /dev/null
+++ b/src/debug/macho/testdata/gcc-amd64-darwin-exec
diff --git a/src/debug/macho/testdata/gcc-amd64-darwin-exec-debug b/src/debug/macho/testdata/gcc-amd64-darwin-exec-debug
new file mode 100644
index 000000000..a47d3aef7
--- /dev/null
+++ b/src/debug/macho/testdata/gcc-amd64-darwin-exec-debug
diff --git a/src/debug/macho/testdata/hello.c b/src/debug/macho/testdata/hello.c
new file mode 100644
index 000000000..a689d3644
--- /dev/null
+++ b/src/debug/macho/testdata/hello.c
@@ -0,0 +1,8 @@
+#include <stdio.h>
+
+int
+main(void)
+{
+	printf("hello, world\n");
+	return 0;
+}
diff --git a/src/debug/pe/file.go b/src/debug/pe/file.go
new file mode 100644
index 000000000..ce6f1408f
--- /dev/null
+++ b/src/debug/pe/file.go
@@ -0,0 +1,390 @@
+// Copyright 2009 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package pe implements access to PE (Microsoft Windows Portable Executable) files.
+package pe
+
+import (
+	"debug/dwarf"
+	"encoding/binary"
+	"errors"
+	"fmt"
+	"io"
+	"os"
+	"strconv"
+	"unsafe"
+)
+
+// A File represents an open PE file.
+type File struct {
+	FileHeader
+	OptionalHeader interface{} // of type *OptionalHeader32 or *OptionalHeader64
+	Sections       []*Section
+	Symbols        []*Symbol
+
+	closer io.Closer
+}
+
+type SectionHeader struct {
+	Name                 string
+	VirtualSize          uint32
+	VirtualAddress       uint32
+	Size                 uint32
+	Offset               uint32
+	PointerToRelocations uint32
+	PointerToLineNumbers uint32
+	NumberOfRelocations  uint16
+	NumberOfLineNumbers  uint16
+	Characteristics      uint32
+}
+
+type Section struct {
+	SectionHeader
+
+	// Embed ReaderAt for ReadAt method.
+	// Do not embed SectionReader directly
+	// to avoid having Read and Seek.
+	// If a client wants Read and Seek it must use
+	// Open() to avoid fighting over the seek offset
+	// with other clients.
+	io.ReaderAt
+	sr *io.SectionReader
+}
+
+type Symbol struct {
+	Name          string
+	Value         uint32
+	SectionNumber int16
+	Type          uint16
+	StorageClass  uint8
+}
+
+type ImportDirectory struct {
+	OriginalFirstThunk uint32
+	TimeDateStamp      uint32
+	ForwarderChain     uint32
+	Name               uint32
+	FirstThunk         uint32
+
+	dll string
+}
+
+// Data reads and returns the contents of the PE section.
+func (s *Section) Data() ([]byte, error) {
+	dat := make([]byte, s.sr.Size())
+	n, err := s.sr.ReadAt(dat, 0)
+	if n == len(dat) {
+		err = nil
+	}
+	return dat[0:n], err
+}
+
+// Open returns a new ReadSeeker reading the PE section.
+func (s *Section) Open() io.ReadSeeker { return io.NewSectionReader(s.sr, 0, 1<<63-1) }
+
+type FormatError struct {
+	off int64
+	msg string
+	val interface{}
+}
+
+func (e *FormatError) Error() string {
+	msg := e.msg
+	if e.val != nil {
+		msg += fmt.Sprintf(" '%v'", e.val)
+	}
+	msg += fmt.Sprintf(" in record at byte %#x", e.off)
+	return msg
+}
+
+// Open opens the named file using os.Open and prepares it for use as a PE binary.
+func Open(name string) (*File, error) {
+	f, err := os.Open(name)
+	if err != nil {
+		return nil, err
+	}
+	ff, err := NewFile(f)
+	if err != nil {
+		f.Close()
+		return nil, err
+	}
+	ff.closer = f
+	return ff, nil
+}
+
+// Close closes the File.
+// If the File was created using NewFile directly instead of Open,
+// Close has no effect.
+func (f *File) Close() error {
+	var err error
+	if f.closer != nil {
+		err = f.closer.Close()
+		f.closer = nil
+	}
+	return err
+}
+
+// NewFile creates a new File for accessing a PE binary in an underlying reader.
+func NewFile(r io.ReaderAt) (*File, error) {
+	f := new(File)
+	sr := io.NewSectionReader(r, 0, 1<<63-1)
+
+	var dosheader [96]byte
+	if _, err := r.ReadAt(dosheader[0:], 0); err != nil {
+		return nil, err
+	}
+	var base int64
+	if dosheader[0] == 'M' && dosheader[1] == 'Z' {
+		signoff := int64(binary.LittleEndian.Uint32(dosheader[0x3c:]))
+		var sign [4]byte
+		r.ReadAt(sign[:], signoff)
+		if !(sign[0] == 'P' && sign[1] == 'E' && sign[2] == 0 && sign[3] == 0) {
+			return nil, errors.New("Invalid PE File Format.")
+		}
+		base = signoff + 4
+	} else {
+		base = int64(0)
+	}
+	sr.Seek(base, os.SEEK_SET)
+	if err := binary.Read(sr, binary.LittleEndian, &f.FileHeader); err != nil {
+		return nil, err
+	}
+	if f.FileHeader.Machine != IMAGE_FILE_MACHINE_UNKNOWN && f.FileHeader.Machine != IMAGE_FILE_MACHINE_AMD64 && f.FileHeader.Machine != IMAGE_FILE_MACHINE_I386 {
+		return nil, errors.New("Invalid PE File Format.")
+	}
+
+	var ss []byte
+	if f.FileHeader.NumberOfSymbols > 0 {
+		// Get COFF string table, which is located at the end of the COFF symbol table.
+		sr.Seek(int64(f.FileHeader.PointerToSymbolTable+COFFSymbolSize*f.FileHeader.NumberOfSymbols), os.SEEK_SET)
+		var l uint32
+		if err := binary.Read(sr, binary.LittleEndian, &l); err != nil {
+			return nil, err
+		}
+		ss = make([]byte, l)
+		if _, err := r.ReadAt(ss, int64(f.FileHeader.PointerToSymbolTable+COFFSymbolSize*f.FileHeader.NumberOfSymbols)); err != nil {
+			return nil, err
+		}
+
+		// Process COFF symbol table.
+		sr.Seek(int64(f.FileHeader.PointerToSymbolTable), os.SEEK_SET)
+		aux := uint8(0)
+		for i := 0; i < int(f.FileHeader.NumberOfSymbols); i++ {
+			cs := new(COFFSymbol)
+			if err := binary.Read(sr, binary.LittleEndian, cs); err != nil {
+				return nil, err
+			}
+			if aux > 0 {
+				aux--
+				continue
+			}
+			var name string
+			if cs.Name[0] == 0 && cs.Name[1] == 0 && cs.Name[2] == 0 && cs.Name[3] == 0 {
+				si := int(binary.LittleEndian.Uint32(cs.Name[4:]))
+				name, _ = getString(ss, si)
+			} else {
+				name = cstring(cs.Name[:])
+			}
+			aux = cs.NumberOfAuxSymbols
+			s := &Symbol{
+				Name:          name,
+				Value:         cs.Value,
+				SectionNumber: cs.SectionNumber,
+				Type:          cs.Type,
+				StorageClass:  cs.StorageClass,
+			}
+			f.Symbols = append(f.Symbols, s)
+		}
+	}
+
+	// Read optional header.
+	sr.Seek(base, os.SEEK_SET)
+	if err := binary.Read(sr, binary.LittleEndian, &f.FileHeader); err != nil {
+		return nil, err
+	}
+	var oh32 OptionalHeader32
+	var oh64 OptionalHeader64
+	switch uintptr(f.FileHeader.SizeOfOptionalHeader) {
+	case unsafe.Sizeof(oh32):
+		if err := binary.Read(sr, binary.LittleEndian, &oh32); err != nil {
+			return nil, err
+		}
+		if oh32.Magic != 0x10b { // PE32
+			return nil, fmt.Errorf("pe32 optional header has unexpected Magic of 0x%x", oh32.Magic)
+		}
+		f.OptionalHeader = &oh32
+	case unsafe.Sizeof(oh64):
+		if err := binary.Read(sr, binary.LittleEndian, &oh64); err != nil {
+			return nil, err
+		}
+		if oh64.Magic != 0x20b { // PE32+
+			return nil, fmt.Errorf("pe32+ optional header has unexpected Magic of 0x%x", oh64.Magic)
+		}
+		f.OptionalHeader = &oh64
+	}
+
+	// Process sections.
+	f.Sections = make([]*Section, f.FileHeader.NumberOfSections)
+	for i := 0; i < int(f.FileHeader.NumberOfSections); i++ {
+		sh := new(SectionHeader32)
+		if err := binary.Read(sr, binary.LittleEndian, sh); err != nil {
+			return nil, err
+		}
+		var name string
+		if sh.Name[0] == '\x2F' {
+			si, _ := strconv.Atoi(cstring(sh.Name[1:]))
+			name, _ = getString(ss, si)
+		} else {
+			name = cstring(sh.Name[0:])
+		}
+		s := new(Section)
+		s.SectionHeader = SectionHeader{
+			Name:                 name,
+			VirtualSize:          sh.VirtualSize,
+			VirtualAddress:       sh.VirtualAddress,
+			Size:                 sh.SizeOfRawData,
+			Offset:               sh.PointerToRawData,
+			PointerToRelocations: sh.PointerToRelocations,
+			PointerToLineNumbers: sh.PointerToLineNumbers,
+			NumberOfRelocations:  sh.NumberOfRelocations,
+			NumberOfLineNumbers:  sh.NumberOfLineNumbers,
+			Characteristics:      sh.Characteristics,
+		}
+		s.sr = io.NewSectionReader(r, int64(s.SectionHeader.Offset), int64(s.SectionHeader.Size))
+		s.ReaderAt = s.sr
+		f.Sections[i] = s
+	}
+	return f, nil
+}
+
+func cstring(b []byte) string {
+	var i int
+	for i = 0; i < len(b) && b[i] != 0; i++ {
+	}
+	return string(b[0:i])
+}
+
+// getString extracts a string from symbol string table.
+func getString(section []byte, start int) (string, bool) {
+	if start < 0 || start >= len(section) {
+		return "", false
+	}
+
+	for end := start; end < len(section); end++ {
+		if section[end] == 0 {
+			return string(section[start:end]), true
+		}
+	}
+	return "", false
+}
+
+// Section returns the first section with the given name, or nil if no such
+// section exists.
+func (f *File) Section(name string) *Section {
+	for _, s := range f.Sections {
+		if s.Name == name {
+			return s
+		}
+	}
+	return nil
+}
+
+func (f *File) DWARF() (*dwarf.Data, error) {
+	// There are many other DWARF sections, but these
+	// are the required ones, and the debug/dwarf package
+	// does not use the others, so don't bother loading them.
+	var names = [...]string{"abbrev", "info", "str"}
+	var dat [len(names)][]byte
+	for i, name := range names {
+		name = ".debug_" + name
+		s := f.Section(name)
+		if s == nil {
+			continue
+		}
+		b, err := s.Data()
+		if err != nil && uint32(len(b)) < s.Size {
+			return nil, err
+		}
+		dat[i] = b
+	}
+
+	abbrev, info, str := dat[0], dat[1], dat[2]
+	return dwarf.New(abbrev, nil, nil, info, nil, nil, nil, str)
+}
+
+// ImportedSymbols returns the names of all symbols
+// referred to by the binary f that are expected to be
+// satisfied by other libraries at dynamic load time.
+// It does not return weak symbols.
+func (f *File) ImportedSymbols() ([]string, error) {
+	pe64 := f.Machine == IMAGE_FILE_MACHINE_AMD64
+	ds := f.Section(".idata")
+	if ds == nil {
+		// not dynamic, so no libraries
+		return nil, nil
+	}
+	d, err := ds.Data()
+	if err != nil {
+		return nil, err
+	}
+	var ida []ImportDirectory
+	for len(d) > 0 {
+		var dt ImportDirectory
+		dt.OriginalFirstThunk = binary.LittleEndian.Uint32(d[0:4])
+		dt.Name = binary.LittleEndian.Uint32(d[12:16])
+		dt.FirstThunk = binary.LittleEndian.Uint32(d[16:20])
+		d = d[20:]
+		if dt.OriginalFirstThunk == 0 {
+			break
+		}
+		ida = append(ida, dt)
+	}
+	names, _ := ds.Data()
+	var all []string
+	for _, dt := range ida {
+		dt.dll, _ = getString(names, int(dt.Name-ds.VirtualAddress))
+		d, _ = ds.Data()
+		// seek to OriginalFirstThunk
+		d = d[dt.OriginalFirstThunk-ds.VirtualAddress:]
+		for len(d) > 0 {
+			if pe64 { // 64bit
+				va := binary.LittleEndian.Uint64(d[0:8])
+				d = d[8:]
+				if va == 0 {
+					break
+				}
+				if va&0x8000000000000000 > 0 { // is Ordinal
+					// TODO add dynimport ordinal support.
+				} else {
+					fn, _ := getString(names, int(uint32(va)-ds.VirtualAddress+2))
+					all = append(all, fn+":"+dt.dll)
+				}
+			} else { // 32bit
+				va := binary.LittleEndian.Uint32(d[0:4])
+				d = d[4:]
+				if va == 0 {
+					break
+				}
+				if va&0x80000000 > 0 { // is Ordinal
+					// TODO add dynimport ordinal support.
+					//ord := va&0x0000FFFF
+				} else {
+					fn, _ := getString(names, int(va-ds.VirtualAddress+2))
+					all = append(all, fn+":"+dt.dll)
+				}
+			}
+		}
+	}
+
+	return all, nil
+}
+
+// ImportedLibraries returns the names of all libraries
+// referred to by the binary f that are expected to be
+// linked with the binary at dynamic link time.
+func (f *File) ImportedLibraries() ([]string, error) {
+	// TODO
+	// cgo -dynimport don't use this for windows PE, so just return.
+	return nil, nil
+}
diff --git a/src/debug/pe/file_test.go b/src/debug/pe/file_test.go
new file mode 100644
index 000000000..0d73969bc
--- /dev/null
+++ b/src/debug/pe/file_test.go
@@ -0,0 +1,243 @@
+// Copyright 2009 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package pe
+
+import (
+	"reflect"
+	"testing"
+)
+
+type fileTest struct {
+	file     string
+	hdr      FileHeader
+	opthdr   interface{}
+	sections []*SectionHeader
+	symbols  []*Symbol
+}
+
+var fileTests = []fileTest{
+	{
+		"testdata/gcc-386-mingw-obj",
+		FileHeader{0x014c, 0x000c, 0x0, 0x64a, 0x1e, 0x0, 0x104},
+		nil,
+		[]*SectionHeader{
+			{".text", 0, 0, 36, 500, 1440, 0, 3, 0, 0x60300020},
+			{".data", 0, 0, 0, 0, 0, 0, 0, 0, 3224371264},
+			{".bss", 0, 0, 0, 0, 0, 0, 0, 0, 3224371328},
+			{".debug_abbrev", 0, 0, 137, 536, 0, 0, 0, 0, 0x42100000},
+			{".debug_info", 0, 0, 418, 673, 1470, 0, 7, 0, 1108344832},
+			{".debug_line", 0, 0, 128, 1091, 1540, 0, 1, 0, 1108344832},
+			{".rdata", 0, 0, 16, 1219, 0, 0, 0, 0, 1076887616},
+			{".debug_frame", 0, 0, 52, 1235, 1550, 0, 2, 0, 1110441984},
+			{".debug_loc", 0, 0, 56, 1287, 0, 0, 0, 0, 1108344832},
+			{".debug_pubnames", 0, 0, 27, 1343, 1570, 0, 1, 0, 1108344832},
+			{".debug_pubtypes", 0, 0, 38, 1370, 1580, 0, 1, 0, 1108344832},
+			{".debug_aranges", 0, 0, 32, 1408, 1590, 0, 2, 0, 1108344832},
+		},
+		[]*Symbol{
+			{".file", 0x0, -2, 0x0, 0x67},
+			{"_main", 0x0, 1, 0x20, 0x2},
+			{".text", 0x0, 1, 0x0, 0x3},
+			{".data", 0x0, 2, 0x0, 0x3},
+			{".bss", 0x0, 3, 0x0, 0x3},
+			{".debug_abbrev", 0x0, 4, 0x0, 0x3},
+			{".debug_info", 0x0, 5, 0x0, 0x3},
+			{".debug_line", 0x0, 6, 0x0, 0x3},
+			{".rdata", 0x0, 7, 0x0, 0x3},
+			{".debug_frame", 0x0, 8, 0x0, 0x3},
+			{".debug_loc", 0x0, 9, 0x0, 0x3},
+			{".debug_pubnames", 0x0, 10, 0x0, 0x3},
+			{".debug_pubtypes", 0x0, 11, 0x0, 0x3},
+			{".debug_aranges", 0x0, 12, 0x0, 0x3},
+			{"___main", 0x0, 0, 0x20, 0x2},
+			{"_puts", 0x0, 0, 0x20, 0x2},
+		},
+	},
+	{
+		"testdata/gcc-386-mingw-exec",
+		FileHeader{0x014c, 0x000f, 0x4c6a1b60, 0x3c00, 0x282, 0xe0, 0x107},
+		&OptionalHeader32{
+			0x10b, 0x2, 0x38, 0xe00, 0x1a00, 0x200, 0x1160, 0x1000, 0x2000, 0x400000, 0x1000, 0x200, 0x4, 0x0, 0x1, 0x0, 0x4, 0x0, 0x0, 0x10000, 0x400, 0x14abb, 0x3, 0x0, 0x200000, 0x1000, 0x100000, 0x1000, 0x0, 0x10,
+			[16]DataDirectory{
+				{0x0, 0x0},
+				{0x5000, 0x3c8},
+				{0x0, 0x0},
+				{0x0, 0x0},
+				{0x0, 0x0},
+				{0x0, 0x0},
+				{0x0, 0x0},
+				{0x0, 0x0},
+				{0x0, 0x0},
+				{0x7000, 0x18},
+				{0x0, 0x0},
+				{0x0, 0x0},
+				{0x0, 0x0},
+				{0x0, 0x0},
+				{0x0, 0x0},
+				{0x0, 0x0},
+			},
+		},
+		[]*SectionHeader{
+			{".text", 0xcd8, 0x1000, 0xe00, 0x400, 0x0, 0x0, 0x0, 0x0, 0x60500060},
+			{".data", 0x10, 0x2000, 0x200, 0x1200, 0x0, 0x0, 0x0, 0x0, 0xc0300040},
+			{".rdata", 0x120, 0x3000, 0x200, 0x1400, 0x0, 0x0, 0x0, 0x0, 0x40300040},
+			{".bss", 0xdc, 0x4000, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0xc0400080},
+			{".idata", 0x3c8, 0x5000, 0x400, 0x1600, 0x0, 0x0, 0x0, 0x0, 0xc0300040},
+			{".CRT", 0x18, 0x6000, 0x200, 0x1a00, 0x0, 0x0, 0x0, 0x0, 0xc0300040},
+			{".tls", 0x20, 0x7000, 0x200, 0x1c00, 0x0, 0x0, 0x0, 0x0, 0xc0300040},
+			{".debug_aranges", 0x20, 0x8000, 0x200, 0x1e00, 0x0, 0x0, 0x0, 0x0, 0x42100000},
+			{".debug_pubnames", 0x51, 0x9000, 0x200, 0x2000, 0x0, 0x0, 0x0, 0x0, 0x42100000},
+			{".debug_pubtypes", 0x91, 0xa000, 0x200, 0x2200, 0x0, 0x0, 0x0, 0x0, 0x42100000},
+			{".debug_info", 0xe22, 0xb000, 0x1000, 0x2400, 0x0, 0x0, 0x0, 0x0, 0x42100000},
+			{".debug_abbrev", 0x157, 0xc000, 0x200, 0x3400, 0x0, 0x0, 0x0, 0x0, 0x42100000},
+			{".debug_line", 0x144, 0xd000, 0x200, 0x3600, 0x0, 0x0, 0x0, 0x0, 0x42100000},
+			{".debug_frame", 0x34, 0xe000, 0x200, 0x3800, 0x0, 0x0, 0x0, 0x0, 0x42300000},
+			{".debug_loc", 0x38, 0xf000, 0x200, 0x3a00, 0x0, 0x0, 0x0, 0x0, 0x42100000},
+		},
+		[]*Symbol{},
+	},
+	{
+		"testdata/gcc-amd64-mingw-obj",
+		FileHeader{0x8664, 0x6, 0x0, 0x198, 0x12, 0x0, 0x4},
+		nil,
+		[]*SectionHeader{
+			{".text", 0x0, 0x0, 0x30, 0x104, 0x15c, 0x0, 0x3, 0x0, 0x60500020},
+			{".data", 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0xc0500040},
+			{".bss", 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0xc0500080},
+			{".rdata", 0x0, 0x0, 0x10, 0x134, 0x0, 0x0, 0x0, 0x0, 0x40500040},
+			{".xdata", 0x0, 0x0, 0xc, 0x144, 0x0, 0x0, 0x0, 0x0, 0x40300040},
+			{".pdata", 0x0, 0x0, 0xc, 0x150, 0x17a, 0x0, 0x3, 0x0, 0x40300040},
+		},
+		[]*Symbol{
+			{".file", 0x0, -2, 0x0, 0x67},
+			{"main", 0x0, 1, 0x20, 0x2},
+			{".text", 0x0, 1, 0x0, 0x3},
+			{".data", 0x0, 2, 0x0, 0x3},
+			{".bss", 0x0, 3, 0x0, 0x3},
+			{".rdata", 0x0, 4, 0x0, 0x3},
+			{".xdata", 0x0, 5, 0x0, 0x3},
+			{".pdata", 0x0, 6, 0x0, 0x3},
+			{"__main", 0x0, 0, 0x20, 0x2},
+			{"puts", 0x0, 0, 0x20, 0x2},
+		},
+	},
+	{
+		"testdata/gcc-amd64-mingw-exec",
+		FileHeader{0x8664, 0x11, 0x53e4364f, 0x39600, 0x6fc, 0xf0, 0x27},
+		&OptionalHeader64{
+			0x20b, 0x2, 0x16, 0x6a00, 0x2400, 0x1600, 0x14e0, 0x1000, 0x400000, 0x1000, 0x200, 0x4, 0x0, 0x0, 0x0, 0x5, 0x2, 0x0, 0x45000, 0x600, 0x46f19, 0x3, 0x0, 0x200000, 0x1000, 0x100000, 0x1000, 0x0, 0x10,
+			[16]DataDirectory{
+				{0x0, 0x0},
+				{0xe000, 0x990},
+				{0x0, 0x0},
+				{0xa000, 0x498},
+				{0x0, 0x0},
+				{0x0, 0x0},
+				{0x0, 0x0},
+				{0x0, 0x0},
+				{0x0, 0x0},
+				{0x10000, 0x28},
+				{0x0, 0x0},
+				{0x0, 0x0},
+				{0xe254, 0x218},
+				{0x0, 0x0},
+				{0x0, 0x0},
+				{0x0, 0x0},
+			}},
+		[]*SectionHeader{
+			{".text", 0x6860, 0x1000, 0x6a00, 0x600, 0x0, 0x0, 0x0, 0x0, 0x60500020},
+			{".data", 0xe0, 0x8000, 0x200, 0x7000, 0x0, 0x0, 0x0, 0x0, 0xc0500040},
+			{".rdata", 0x6b0, 0x9000, 0x800, 0x7200, 0x0, 0x0, 0x0, 0x0, 0x40600040},
+			{".pdata", 0x498, 0xa000, 0x600, 0x7a00, 0x0, 0x0, 0x0, 0x0, 0x40300040},
+			{".xdata", 0x488, 0xb000, 0x600, 0x8000, 0x0, 0x0, 0x0, 0x0, 0x40300040},
+			{".bss", 0x1410, 0xc000, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0xc0600080},
+			{".idata", 0x990, 0xe000, 0xa00, 0x8600, 0x0, 0x0, 0x0, 0x0, 0xc0300040},
+			{".CRT", 0x68, 0xf000, 0x200, 0x9000, 0x0, 0x0, 0x0, 0x0, 0xc0400040},
+			{".tls", 0x48, 0x10000, 0x200, 0x9200, 0x0, 0x0, 0x0, 0x0, 0xc0600040},
+			{".debug_aranges", 0x600, 0x11000, 0x600, 0x9400, 0x0, 0x0, 0x0, 0x0, 0x42500040},
+			{".debug_info", 0x1316e, 0x12000, 0x13200, 0x9a00, 0x0, 0x0, 0x0, 0x0, 0x42100040},
+			{".debug_abbrev", 0x2ccb, 0x26000, 0x2e00, 0x1cc00, 0x0, 0x0, 0x0, 0x0, 0x42100040},
+			{".debug_line", 0x3c4d, 0x29000, 0x3e00, 0x1fa00, 0x0, 0x0, 0x0, 0x0, 0x42100040},
+			{".debug_frame", 0x18b8, 0x2d000, 0x1a00, 0x23800, 0x0, 0x0, 0x0, 0x0, 0x42400040},
+			{".debug_str", 0x396, 0x2f000, 0x400, 0x25200, 0x0, 0x0, 0x0, 0x0, 0x42100040},
+			{".debug_loc", 0x13240, 0x30000, 0x13400, 0x25600, 0x0, 0x0, 0x0, 0x0, 0x42100040},
+			{".debug_ranges", 0xa70, 0x44000, 0xc00, 0x38a00, 0x0, 0x0, 0x0, 0x0, 0x42100040},
+		},
+		[]*Symbol{},
+	},
+}
+
+func isOptHdrEq(a, b interface{}) bool {
+	switch va := a.(type) {
+	case *OptionalHeader32:
+		vb, ok := b.(*OptionalHeader32)
+		if !ok {
+			return false
+		}
+		return *vb == *va
+	case *OptionalHeader64:
+		vb, ok := b.(*OptionalHeader64)
+		if !ok {
+			return false
+		}
+		return *vb == *va
+	case nil:
+		return b == nil
+	}
+	return false
+}
+
+func TestOpen(t *testing.T) {
+	for i := range fileTests {
+		tt := &fileTests[i]
+
+		f, err := Open(tt.file)
+		if err != nil {
+			t.Error(err)
+			continue
+		}
+		if !reflect.DeepEqual(f.FileHeader, tt.hdr) {
+			t.Errorf("open %s:\n\thave %#v\n\twant %#v\n", tt.file, f.FileHeader, tt.hdr)
+			continue
+		}
+		if !isOptHdrEq(tt.opthdr, f.OptionalHeader) {
+			t.Errorf("open %s:\n\thave %#v\n\twant %#v\n", tt.file, f.OptionalHeader, tt.opthdr)
+			continue
+		}
+
+		for i, sh := range f.Sections {
+			if i >= len(tt.sections) {
+				break
+			}
+			have := &sh.SectionHeader
+			want := tt.sections[i]
+			if !reflect.DeepEqual(have, want) {
+				t.Errorf("open %s, section %d:\n\thave %#v\n\twant %#v\n", tt.file, i, have, want)
+			}
+		}
+		tn := len(tt.sections)
+		fn := len(f.Sections)
+		if tn != fn {
+			t.Errorf("open %s: len(Sections) = %d, want %d", tt.file, fn, tn)
+		}
+		for i, have := range f.Symbols {
+			if i >= len(tt.symbols) {
+				break
+			}
+			want := tt.symbols[i]
+			if !reflect.DeepEqual(have, want) {
+				t.Errorf("open %s, symbol %d:\n\thave %#v\n\twant %#v\n", tt.file, i, have, want)
+			}
+		}
+	}
+}
+
+func TestOpenFailure(t *testing.T) {
+	filename := "file.go"    // not a PE file
+	_, err := Open(filename) // don't crash
+	if err == nil {
+		t.Errorf("open %s: succeeded unexpectedly", filename)
+	}
+}
diff --git a/src/debug/pe/pe.go b/src/debug/pe/pe.go
new file mode 100644
index 000000000..8e90b1b51
--- /dev/null
+++ b/src/debug/pe/pe.go
@@ -0,0 +1,134 @@
+// Copyright 2009 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package pe
+
+type FileHeader struct {
+	Machine              uint16
+	NumberOfSections     uint16
+	TimeDateStamp        uint32
+	PointerToSymbolTable uint32
+	NumberOfSymbols      uint32
+	SizeOfOptionalHeader uint16
+	Characteristics      uint16
+}
+
+type DataDirectory struct {
+	VirtualAddress uint32
+	Size           uint32
+}
+
+type OptionalHeader32 struct {
+	Magic                       uint16
+	MajorLinkerVersion          uint8
+	MinorLinkerVersion          uint8
+	SizeOfCode                  uint32
+	SizeOfInitializedData       uint32
+	SizeOfUninitializedData     uint32
+	AddressOfEntryPoint         uint32
+	BaseOfCode                  uint32
+	BaseOfData                  uint32
+	ImageBase                   uint32
+	SectionAlignment            uint32
+	FileAlignment               uint32
+	MajorOperatingSystemVersion uint16
+	MinorOperatingSystemVersion uint16
+	MajorImageVersion           uint16
+	MinorImageVersion           uint16
+	MajorSubsystemVersion       uint16
+	MinorSubsystemVersion       uint16
+	Win32VersionValue           uint32
+	SizeOfImage                 uint32
+	SizeOfHeaders               uint32
+	CheckSum                    uint32
+	Subsystem                   uint16
+	DllCharacteristics          uint16
+	SizeOfStackReserve          uint32
+	SizeOfStackCommit           uint32
+	SizeOfHeapReserve           uint32
+	SizeOfHeapCommit            uint32
+	LoaderFlags                 uint32
+	NumberOfRvaAndSizes         uint32
+	DataDirectory               [16]DataDirectory
+}
+
+type OptionalHeader64 struct {
+	Magic                       uint16
+	MajorLinkerVersion          uint8
+	MinorLinkerVersion          uint8
+	SizeOfCode                  uint32
+	SizeOfInitializedData       uint32
+	SizeOfUninitializedData     uint32
+	AddressOfEntryPoint         uint32
+	BaseOfCode                  uint32
+	ImageBase                   uint64
+	SectionAlignment            uint32
+	FileAlignment               uint32
+	MajorOperatingSystemVersion uint16
+	MinorOperatingSystemVersion uint16
+	MajorImageVersion           uint16
+	MinorImageVersion           uint16
+	MajorSubsystemVersion       uint16
+	MinorSubsystemVersion       uint16
+	Win32VersionValue           uint32
+	SizeOfImage                 uint32
+	SizeOfHeaders               uint32
+	CheckSum                    uint32
+	Subsystem                   uint16
+	DllCharacteristics          uint16
+	SizeOfStackReserve          uint64
+	SizeOfStackCommit           uint64
+	SizeOfHeapReserve           uint64
+	SizeOfHeapCommit            uint64
+	LoaderFlags                 uint32
+	NumberOfRvaAndSizes         uint32
+	DataDirectory               [16]DataDirectory
+}
+
+type SectionHeader32 struct {
+	Name                 [8]uint8
+	VirtualSize          uint32
+	VirtualAddress       uint32
+	SizeOfRawData        uint32
+	PointerToRawData     uint32
+	PointerToRelocations uint32
+	PointerToLineNumbers uint32
+	NumberOfRelocations  uint16
+	NumberOfLineNumbers  uint16
+	Characteristics      uint32
+}
+
+const COFFSymbolSize = 18
+
+type COFFSymbol struct {
+	Name               [8]uint8
+	Value              uint32
+	SectionNumber      int16
+	Type               uint16
+	StorageClass       uint8
+	NumberOfAuxSymbols uint8
+}
+
+const (
+	IMAGE_FILE_MACHINE_UNKNOWN   = 0x0
+	IMAGE_FILE_MACHINE_AM33      = 0x1d3
+	IMAGE_FILE_MACHINE_AMD64     = 0x8664
+	IMAGE_FILE_MACHINE_ARM       = 0x1c0
+	IMAGE_FILE_MACHINE_EBC       = 0xebc
+	IMAGE_FILE_MACHINE_I386      = 0x14c
+	IMAGE_FILE_MACHINE_IA64      = 0x200
+	IMAGE_FILE_MACHINE_M32R      = 0x9041
+	IMAGE_FILE_MACHINE_MIPS16    = 0x266
+	IMAGE_FILE_MACHINE_MIPSFPU   = 0x366
+	IMAGE_FILE_MACHINE_MIPSFPU16 = 0x466
+	IMAGE_FILE_MACHINE_POWERPC   = 0x1f0
+	IMAGE_FILE_MACHINE_POWERPCFP = 0x1f1
+	IMAGE_FILE_MACHINE_R4000     = 0x166
+	IMAGE_FILE_MACHINE_SH3       = 0x1a2
+	IMAGE_FILE_MACHINE_SH3DSP    = 0x1a3
+	IMAGE_FILE_MACHINE_SH4       = 0x1a6
+	IMAGE_FILE_MACHINE_SH5       = 0x1a8
+	IMAGE_FILE_MACHINE_THUMB     = 0x1c2
+	IMAGE_FILE_MACHINE_WCEMIPSV2 = 0x169
+)
diff --git a/src/debug/pe/testdata/gcc-386-mingw-exec b/src/debug/pe/testdata/gcc-386-mingw-exec
new file mode 100644
index 000000000..4b808d043
--- /dev/null
+++ b/src/debug/pe/testdata/gcc-386-mingw-exec
diff --git a/src/debug/pe/testdata/gcc-386-mingw-obj b/src/debug/pe/testdata/gcc-386-mingw-obj
new file mode 100644
index 000000000..0c84d898d
--- /dev/null
+++ b/src/debug/pe/testdata/gcc-386-mingw-obj
diff --git a/src/debug/pe/testdata/gcc-amd64-mingw-exec b/src/debug/pe/testdata/gcc-amd64-mingw-exec
new file mode 100644
index 000000000..ce6feb6b7
--- /dev/null
+++ b/src/debug/pe/testdata/gcc-amd64-mingw-exec
diff --git a/src/debug/pe/testdata/gcc-amd64-mingw-obj b/src/debug/pe/testdata/gcc-amd64-mingw-obj
new file mode 100644
index 000000000..48ae7921f
--- /dev/null
+++ b/src/debug/pe/testdata/gcc-amd64-mingw-obj
diff --git a/src/debug/pe/testdata/hello.c b/src/debug/pe/testdata/hello.c
new file mode 100644
index 000000000..a689d3644
--- /dev/null
+++ b/src/debug/pe/testdata/hello.c
@@ -0,0 +1,8 @@
+#include <stdio.h>
+
+int
+main(void)
+{
+	printf("hello, world\n");
+	return 0;
+}
diff --git a/src/debug/plan9obj/file.go b/src/debug/plan9obj/file.go
new file mode 100644
index 000000000..b11ed86f1
--- /dev/null
+++ b/src/debug/plan9obj/file.go
@@ -0,0 +1,328 @@
+// Copyright 2014 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package plan9obj implements access to Plan 9 a.out object files.
+package plan9obj
+
+import (
+	"encoding/binary"
+	"errors"
+	"fmt"
+	"io"
+	"os"
+)
+
+// A FileHeader represents a Plan 9 a.out file header.
+type FileHeader struct {
+	Magic       uint32
+	Bss         uint32
+	Entry       uint64
+	PtrSize     int
+	LoadAddress uint64
+	HdrSize     uint64
+}
+
+// A File represents an open Plan 9 a.out file.
+type File struct {
+	FileHeader
+	Sections []*Section
+	closer   io.Closer
+}
+
+// A SectionHeader represents a single Plan 9 a.out section header.
+// This structure doesn't exist on-disk, but eases navigation
+// through the object file.
+type SectionHeader struct {
+	Name   string
+	Size   uint32
+	Offset uint32
+}
+
+// A Section represents a single section in a Plan 9 a.out file.
+type Section struct {
+	SectionHeader
+
+	// Embed ReaderAt for ReadAt method.
+	// Do not embed SectionReader directly
+	// to avoid having Read and Seek.
+	// If a client wants Read and Seek it must use
+	// Open() to avoid fighting over the seek offset
+	// with other clients.
+	io.ReaderAt
+	sr *io.SectionReader
+}
+
+// Data reads and returns the contents of the Plan 9 a.out section.
+func (s *Section) Data() ([]byte, error) {
+	dat := make([]byte, s.sr.Size())
+	n, err := s.sr.ReadAt(dat, 0)
+	if n == len(dat) {
+		err = nil
+	}
+	return dat[0:n], err
+}
+
+// Open returns a new ReadSeeker reading the Plan 9 a.out section.
+func (s *Section) Open() io.ReadSeeker { return io.NewSectionReader(s.sr, 0, 1<<63-1) }
+
+// A Symbol represents an entry in a Plan 9 a.out symbol table section.
+type Sym struct {
+	Value uint64
+	Type  rune
+	Name  string
+}
+
+/*
+ * Plan 9 a.out reader
+ */
+
+// formatError is returned by some operations if the data does
+// not have the correct format for an object file.
+type formatError struct {
+	off int
+	msg string
+	val interface{}
+}
+
+func (e *formatError) Error() string {
+	msg := e.msg
+	if e.val != nil {
+		msg += fmt.Sprintf(" '%v'", e.val)
+	}
+	msg += fmt.Sprintf(" in record at byte %#x", e.off)
+	return msg
+}
+
+// Open opens the named file using os.Open and prepares it for use as a Plan 9 a.out binary.
+func Open(name string) (*File, error) {
+	f, err := os.Open(name)
+	if err != nil {
+		return nil, err
+	}
+	ff, err := NewFile(f)
+	if err != nil {
+		f.Close()
+		return nil, err
+	}
+	ff.closer = f
+	return ff, nil
+}
+
+// Close closes the File.
+// If the File was created using NewFile directly instead of Open,
+// Close has no effect.
+func (f *File) Close() error {
+	var err error
+	if f.closer != nil {
+		err = f.closer.Close()
+		f.closer = nil
+	}
+	return err
+}
+
+func parseMagic(magic []byte) (uint32, error) {
+	m := binary.BigEndian.Uint32(magic)
+	switch m {
+	case Magic386, MagicAMD64, MagicARM:
+		return m, nil
+	}
+	return 0, &formatError{0, "bad magic number", magic}
+}
+
+// NewFile creates a new File for accessing a Plan 9 binary in an underlying reader.
+// The Plan 9 binary is expected to start at position 0 in the ReaderAt.
+func NewFile(r io.ReaderAt) (*File, error) {
+	sr := io.NewSectionReader(r, 0, 1<<63-1)
+	// Read and decode Plan 9 magic
+	var magic [4]byte
+	if _, err := r.ReadAt(magic[:], 0); err != nil {
+		return nil, err
+	}
+	_, err := parseMagic(magic[:])
+	if err != nil {
+		return nil, err
+	}
+
+	ph := new(prog)
+	if err := binary.Read(sr, binary.BigEndian, ph); err != nil {
+		return nil, err
+	}
+
+	f := &File{FileHeader: FileHeader{
+		Magic:       ph.Magic,
+		Bss:         ph.Bss,
+		Entry:       uint64(ph.Entry),
+		PtrSize:     4,
+		LoadAddress: 0x1000,
+		HdrSize:     4 * 8,
+	}}
+
+	if ph.Magic&Magic64 != 0 {
+		if err := binary.Read(sr, binary.BigEndian, &f.Entry); err != nil {
+			return nil, err
+		}
+		f.PtrSize = 8
+		f.LoadAddress = 0x200000
+		f.HdrSize += 8
+	}
+
+	var sects = []struct {
+		name string
+		size uint32
+	}{
+		{"text", ph.Text},
+		{"data", ph.Data},
+		{"syms", ph.Syms},
+		{"spsz", ph.Spsz},
+		{"pcsz", ph.Pcsz},
+	}
+
+	f.Sections = make([]*Section, 5)
+
+	off := uint32(f.HdrSize)
+
+	for i, sect := range sects {
+		s := new(Section)
+		s.SectionHeader = SectionHeader{
+			Name:   sect.name,
+			Size:   sect.size,
+			Offset: off,
+		}
+		off += sect.size
+		s.sr = io.NewSectionReader(r, int64(s.Offset), int64(s.Size))
+		s.ReaderAt = s.sr
+		f.Sections[i] = s
+	}
+
+	return f, nil
+}
+
+func walksymtab(data []byte, ptrsz int, fn func(sym) error) error {
+	var order binary.ByteOrder = binary.BigEndian
+	var s sym
+	p := data
+	for len(p) >= 4 {
+		// Symbol type, value.
+		if len(p) < ptrsz {
+			return &formatError{len(data), "unexpected EOF", nil}
+		}
+		// fixed-width value
+		if ptrsz == 8 {
+			s.value = order.Uint64(p[0:8])
+			p = p[8:]
+		} else {
+			s.value = uint64(order.Uint32(p[0:4]))
+			p = p[4:]
+		}
+
+		var typ byte
+		typ = p[0] & 0x7F
+		s.typ = typ
+		p = p[1:]
+
+		// Name.
+		var i int
+		var nnul int
+		for i = 0; i < len(p); i++ {
+			if p[i] == 0 {
+				nnul = 1
+				break
+			}
+		}
+		switch typ {
+		case 'z', 'Z':
+			p = p[i+nnul:]
+			for i = 0; i+2 <= len(p); i += 2 {
+				if p[i] == 0 && p[i+1] == 0 {
+					nnul = 2
+					break
+				}
+			}
+		}
+		if len(p) < i+nnul {
+			return &formatError{len(data), "unexpected EOF", nil}
+		}
+		s.name = p[0:i]
+		i += nnul
+		p = p[i:]
+
+		fn(s)
+	}
+	return nil
+}
+
+// NewTable decodes the Go symbol table in data,
+// returning an in-memory representation.
+func newTable(symtab []byte, ptrsz int) ([]Sym, error) {
+	var n int
+	err := walksymtab(symtab, ptrsz, func(s sym) error {
+		n++
+		return nil
+	})
+	if err != nil {
+		return nil, err
+	}
+
+	fname := make(map[uint16]string)
+	syms := make([]Sym, 0, n)
+	err = walksymtab(symtab, ptrsz, func(s sym) error {
+		n := len(syms)
+		syms = syms[0 : n+1]
+		ts := &syms[n]
+		ts.Type = rune(s.typ)
+		ts.Value = s.value
+		switch s.typ {
+		default:
+			ts.Name = string(s.name[:])
+		case 'z', 'Z':
+			for i := 0; i < len(s.name); i += 2 {
+				eltIdx := binary.BigEndian.Uint16(s.name[i : i+2])
+				elt, ok := fname[eltIdx]
+				if !ok {
+					return &formatError{-1, "bad filename code", eltIdx}
+				}
+				if n := len(ts.Name); n > 0 && ts.Name[n-1] != '/' {
+					ts.Name += "/"
+				}
+				ts.Name += elt
+			}
+		}
+		switch s.typ {
+		case 'f':
+			fname[uint16(s.value)] = ts.Name
+		}
+		return nil
+	})
+	if err != nil {
+		return nil, err
+	}
+
+	return syms, nil
+}
+
+// Symbols returns the symbol table for f.
+func (f *File) Symbols() ([]Sym, error) {
+	symtabSection := f.Section("syms")
+	if symtabSection == nil {
+		return nil, errors.New("no symbol section")
+	}
+
+	symtab, err := symtabSection.Data()
+	if err != nil {
+		return nil, errors.New("cannot load symbol section")
+	}
+
+	return newTable(symtab, f.PtrSize)
+}
+
+// Section returns a section with the given name, or nil if no such
+// section exists.
+func (f *File) Section(name string) *Section {
+	for _, s := range f.Sections {
+		if s.Name == name {
+			return s
+		}
+	}
+	return nil
+}
diff --git a/src/debug/plan9obj/file_test.go b/src/debug/plan9obj/file_test.go
new file mode 100644
index 000000000..cfd7a61d1
--- /dev/null
+++ b/src/debug/plan9obj/file_test.go
@@ -0,0 +1,81 @@
+// Copyright 2014 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package plan9obj
+
+import (
+	"reflect"
+	"testing"
+)
+
+type fileTest struct {
+	file     string
+	hdr      FileHeader
+	sections []*SectionHeader
+}
+
+var fileTests = []fileTest{
+	{
+		"testdata/386-plan9-exec",
+		FileHeader{Magic386, 0x324, 0x14, 4, 0x1000, 32},
+		[]*SectionHeader{
+			{"text", 0x4c5f, 0x20},
+			{"data", 0x94c, 0x4c7f},
+			{"syms", 0x2c2b, 0x55cb},
+			{"spsz", 0x0, 0x81f6},
+			{"pcsz", 0xf7a, 0x81f6},
+		},
+	},
+	{
+		"testdata/amd64-plan9-exec",
+		FileHeader{MagicAMD64, 0x618, 0x13, 8, 0x200000, 40},
+		[]*SectionHeader{
+			{"text", 0x4213, 0x28},
+			{"data", 0xa80, 0x423b},
+			{"syms", 0x2c8c, 0x4cbb},
+			{"spsz", 0x0, 0x7947},
+			{"pcsz", 0xca0, 0x7947},
+		},
+	},
+}
+
+func TestOpen(t *testing.T) {
+	for i := range fileTests {
+		tt := &fileTests[i]
+
+		f, err := Open(tt.file)
+		if err != nil {
+			t.Error(err)
+			continue
+		}
+		if !reflect.DeepEqual(f.FileHeader, tt.hdr) {
+			t.Errorf("open %s:\n\thave %#v\n\twant %#v\n", tt.file, f.FileHeader, tt.hdr)
+			continue
+		}
+
+		for i, sh := range f.Sections {
+			if i >= len(tt.sections) {
+				break
+			}
+			have := &sh.SectionHeader
+			want := tt.sections[i]
+			if !reflect.DeepEqual(have, want) {
+				t.Errorf("open %s, section %d:\n\thave %#v\n\twant %#v\n", tt.file, i, have, want)
+			}
+		}
+		tn := len(tt.sections)
+		fn := len(f.Sections)
+		if tn != fn {
+			t.Errorf("open %s: len(Sections) = %d, want %d", tt.file, fn, tn)
+		}
+	}
+}
+
+func TestOpenFailure(t *testing.T) {
+	filename := "file.go"    // not a Plan 9 a.out file
+	_, err := Open(filename) // don't crash
+	if err == nil {
+		t.Errorf("open %s: succeeded unexpectedly", filename)
+	}
+}
diff --git a/src/debug/plan9obj/plan9obj.go b/src/debug/plan9obj/plan9obj.go
new file mode 100644
index 000000000..af9858562
--- /dev/null
+++ b/src/debug/plan9obj/plan9obj.go
@@ -0,0 +1,36 @@
+// Copyright 2014 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+/*
+ * Plan 9 a.out constants and data structures
+ */
+
+package plan9obj
+
+// Plan 9 Program header.
+type prog struct {
+	Magic uint32 /* magic number */
+	Text  uint32 /* size of text segment */
+	Data  uint32 /* size of initialized data */
+	Bss   uint32 /* size of uninitialized data */
+	Syms  uint32 /* size of symbol table */
+	Entry uint32 /* entry point */
+	Spsz  uint32 /* size of pc/sp offset table */
+	Pcsz  uint32 /* size of pc/line number table */
+}
+
+// Plan 9 symbol table entries.
+type sym struct {
+	value uint64
+	typ   byte
+	name  []byte
+}
+
+const (
+	Magic64 = 0x8000 // 64-bit expanded header
+
+	Magic386   = (4*11+0)*11 + 7
+	MagicAMD64 = (4*26+0)*26 + 7 + Magic64
+	MagicARM   = (4*20+0)*20 + 7
+)
diff --git a/src/debug/plan9obj/testdata/386-plan9-exec b/src/debug/plan9obj/testdata/386-plan9-exec
new file mode 100755
index 000000000..748e83f8e
--- /dev/null
+++ b/src/debug/plan9obj/testdata/386-plan9-exec
diff --git a/src/debug/plan9obj/testdata/amd64-plan9-exec b/src/debug/plan9obj/testdata/amd64-plan9-exec
new file mode 100755
index 000000000..3e257dd8f
--- /dev/null
+++ b/src/debug/plan9obj/testdata/amd64-plan9-exec
diff --git a/src/debug/plan9obj/testdata/hello.c b/src/debug/plan9obj/testdata/hello.c
new file mode 100644
index 000000000..c0d633e29
--- /dev/null
+++ b/src/debug/plan9obj/testdata/hello.c
@@ -0,0 +1,8 @@
+#include <u.h>
+#include <libc.h>
+
+void
+main(void)
+{
+	print("hello, world\n");
+}