cmd/addr2line: accept optional "0x" prefix for addresses.

LGTM=rsc
R=rsc
CC=golang-codereviews
https://codereview.appspot.com/91250043

1 files changed, 42 insertions, 10 deletions

diff --git a/src/cmd/addr2line/main.go b/src/cmd/addr2line/main.go
index c09b2616e..d6d14a733 100644
--- a/src/cmd/addr2line/main.go
+++ b/src/cmd/addr2line/main.go
@@ -8,7 +8,7 @@
 // Usage:
 //	go tool addr2line binary
 //
-// Addr2line reads hexadecimal addresses, one per line and without a 0x prefix,
+// Addr2line reads hexadecimal addresses, one per line and with optional 0x prefix,
 // from standard input. For each input address, addr2line prints two output lines,
 // first the name of the function containing the address and second the file:line
 // of the source code corresponding to that address.
@@ -88,7 +88,7 @@ func main() {
 			fmt.Fprintf(stdout, "!reverse translation not implemented\n")
 			continue
 		}
-		pc, _ := strconv.ParseUint(p, 16, 64)
+		pc, _ := strconv.ParseUint(strings.TrimPrefix(p, "0x"), 16, 64)
 		file, line, fn := tab.PCToLine(pc)
 		name := "?"
 		if fn != nil {
@@ -141,18 +141,50 @@ func loadTables(f *os.File) (textStart uint64, symtab, pclntab []byte, err error
 		if sect := obj.Section(".text"); sect != nil {
 			textStart = uint64(sect.VirtualAddress)
 		}
-		if sect := obj.Section(".gosymtab"); sect != nil {
-			if symtab, err = sect.Data(); err != nil {
-				return 0, nil, nil, err
-			}
+		if pclntab, err = loadPETable(obj, "pclntab", "epclntab"); err != nil {
+			return 0, nil, nil, err
 		}
-		if sect := obj.Section(".gopclntab"); sect != nil {
-			if pclntab, err = sect.Data(); err != nil {
-				return 0, nil, nil, err
-			}
+		if symtab, err = loadPETable(obj, "symtab", "esymtab"); err != nil {
+			return 0, nil, nil, err
 		}
 		return textStart, symtab, pclntab, nil
 	}
 
 	return 0, nil, nil, fmt.Errorf("unrecognized binary format")
 }
+
+func findPESymbol(f *pe.File, name string) (*pe.Symbol, error) {
+	for _, s := range f.Symbols {
+		if s.Name != name {
+			continue
+		}
+		if s.SectionNumber <= 0 {
+			return nil, fmt.Errorf("symbol %s: invalid section number %d", name, s.SectionNumber)
+		}
+		if len(f.Sections) < int(s.SectionNumber) {
+			return nil, fmt.Errorf("symbol %s: section number %d is larger than max %d", name, s.SectionNumber, len(f.Sections))
+		}
+		return s, nil
+	}
+	return nil, fmt.Errorf("no %s symbol found", name)
+}
+
+func loadPETable(f *pe.File, sname, ename string) ([]byte, error) {
+	ssym, err := findPESymbol(f, sname)
+	if err != nil {
+		return nil, err
+	}
+	esym, err := findPESymbol(f, ename)
+	if err != nil {
+		return nil, err
+	}
+	if ssym.SectionNumber != esym.SectionNumber {
+		return nil, fmt.Errorf("%s and %s symbols must be in the same section", sname, ename)
+	}
+	sect := f.Sections[ssym.SectionNumber-1]
+	data, err := sect.Data()
+	if err != nil {
+		return nil, err
+	}
+	return data[ssym.Value:esym.Value], nil
+}