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authorRichard Henderson <rth@redhat.com>1999-05-03 07:29:06 +0000
committerRichard Henderson <rth@redhat.com>1999-05-03 07:29:06 +0000
commit860acaebec6b57ce27e244cc02a58e6651a4b6c3 (patch)
treeeff5420756a4bd56b40b74c2b828b261f327610b /bfd/coff-i386.c
parentf9c53ad2d7cb541cbe821d645b90437ac063e5db (diff)
downloadgdb-860acaebec6b57ce27e244cc02a58e6651a4b6c3.tar.gz
Initial revision
Diffstat (limited to 'bfd/coff-i386.c')
-rw-r--r--bfd/coff-i386.c637
1 files changed, 637 insertions, 0 deletions
diff --git a/bfd/coff-i386.c b/bfd/coff-i386.c
new file mode 100644
index 00000000000..7898cc159ca
--- /dev/null
+++ b/bfd/coff-i386.c
@@ -0,0 +1,637 @@
+/* BFD back-end for Intel 386 COFF files.
+ Copyright 1990, 91, 92, 93, 94, 95, 96, 97, 1998
+ Free Software Foundation, Inc.
+ Written by Cygnus Support.
+
+This file is part of BFD, the Binary File Descriptor library.
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program; if not, write to the Free Software
+Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
+
+#include "bfd.h"
+#include "sysdep.h"
+#include "libbfd.h"
+
+#include "coff/i386.h"
+
+#include "coff/internal.h"
+
+#ifdef COFF_WITH_PE
+#include "coff/pe.h"
+#endif
+
+#ifdef COFF_GO32_EXE
+#include "coff/go32exe.h"
+#endif
+
+#include "libcoff.h"
+
+static bfd_reloc_status_type coff_i386_reloc
+ PARAMS ((bfd *, arelent *, asymbol *, PTR, asection *, bfd *, char **));
+static reloc_howto_type *coff_i386_rtype_to_howto
+ PARAMS ((bfd *, asection *, struct internal_reloc *,
+ struct coff_link_hash_entry *, struct internal_syment *,
+
+ bfd_vma *));
+
+#define COFF_DEFAULT_SECTION_ALIGNMENT_POWER (2)
+/* The page size is a guess based on ELF. */
+
+#define COFF_PAGE_SIZE 0x1000
+
+/* For some reason when using i386 COFF the value stored in the .text
+ section for a reference to a common symbol is the value itself plus
+ any desired offset. Ian Taylor, Cygnus Support. */
+
+/* If we are producing relocateable output, we need to do some
+ adjustments to the object file that are not done by the
+ bfd_perform_relocation function. This function is called by every
+ reloc type to make any required adjustments. */
+
+static bfd_reloc_status_type
+coff_i386_reloc (abfd, reloc_entry, symbol, data, input_section, output_bfd,
+ error_message)
+ bfd *abfd;
+ arelent *reloc_entry;
+ asymbol *symbol;
+ PTR data;
+ asection *input_section;
+ bfd *output_bfd;
+ char **error_message;
+{
+ symvalue diff;
+
+ if (output_bfd == (bfd *) NULL)
+ return bfd_reloc_continue;
+
+ if (bfd_is_com_section (symbol->section))
+ {
+#ifndef COFF_WITH_PE
+ /* We are relocating a common symbol. The current value in the
+ object file is ORIG + OFFSET, where ORIG is the value of the
+ common symbol as seen by the object file when it was compiled
+ (this may be zero if the symbol was undefined) and OFFSET is
+ the offset into the common symbol (normally zero, but may be
+ non-zero when referring to a field in a common structure).
+ ORIG is the negative of reloc_entry->addend, which is set by
+ the CALC_ADDEND macro below. We want to replace the value in
+ the object file with NEW + OFFSET, where NEW is the value of
+ the common symbol which we are going to put in the final
+ object file. NEW is symbol->value. */
+ diff = symbol->value + reloc_entry->addend;
+#else
+ /* In PE mode, we do not offset the common symbol. */
+ diff = reloc_entry->addend;
+#endif
+ }
+ else
+ {
+ /* For some reason bfd_perform_relocation always effectively
+ ignores the addend for a COFF target when producing
+ relocateable output. This seems to be always wrong for 386
+ COFF, so we handle the addend here instead. */
+ diff = reloc_entry->addend;
+ }
+
+#ifdef COFF_WITH_PE
+ /* FIXME: How should this case be handled? */
+ if (reloc_entry->howto->type == R_IMAGEBASE && diff != 0)
+ abort ();
+#endif
+
+#define DOIT(x) \
+ x = ((x & ~howto->dst_mask) | (((x & howto->src_mask) + diff) & howto->dst_mask))
+
+ if (diff != 0)
+ {
+ reloc_howto_type *howto = reloc_entry->howto;
+ unsigned char *addr = (unsigned char *) data + reloc_entry->address;
+
+ switch (howto->size)
+ {
+ case 0:
+ {
+ char x = bfd_get_8 (abfd, addr);
+ DOIT (x);
+ bfd_put_8 (abfd, x, addr);
+ }
+ break;
+
+ case 1:
+ {
+ short x = bfd_get_16 (abfd, addr);
+ DOIT (x);
+ bfd_put_16 (abfd, x, addr);
+ }
+ break;
+
+ case 2:
+ {
+ long x = bfd_get_32 (abfd, addr);
+ DOIT (x);
+ bfd_put_32 (abfd, x, addr);
+ }
+ break;
+
+ default:
+ abort ();
+ }
+ }
+
+ /* Now let bfd_perform_relocation finish everything up. */
+ return bfd_reloc_continue;
+}
+
+#ifdef COFF_WITH_PE
+/* Return true if this relocation should
+ appear in the output .reloc section. */
+
+static boolean in_reloc_p(abfd, howto)
+ bfd * abfd;
+ reloc_howto_type *howto;
+{
+ return ! howto->pc_relative && howto->type != R_IMAGEBASE;
+}
+#endif
+
+#ifndef PCRELOFFSET
+#define PCRELOFFSET false
+#endif
+
+static reloc_howto_type howto_table[] =
+{
+ {0},
+ {1},
+ {2},
+ {3},
+ {4},
+ {5},
+ HOWTO (R_DIR32, /* type */
+ 0, /* rightshift */
+ 2, /* size (0 = byte, 1 = short, 2 = long) */
+ 32, /* bitsize */
+ false, /* pc_relative */
+ 0, /* bitpos */
+ complain_overflow_bitfield, /* complain_on_overflow */
+ coff_i386_reloc, /* special_function */
+ "dir32", /* name */
+ true, /* partial_inplace */
+ 0xffffffff, /* src_mask */
+ 0xffffffff, /* dst_mask */
+ true), /* pcrel_offset */
+ /* {7}, */
+ HOWTO (R_IMAGEBASE, /* type */
+ 0, /* rightshift */
+ 2, /* size (0 = byte, 1 = short, 2 = long) */
+ 32, /* bitsize */
+ false, /* pc_relative */
+ 0, /* bitpos */
+ complain_overflow_bitfield, /* complain_on_overflow */
+ coff_i386_reloc, /* special_function */
+ "rva32", /* name */
+ true, /* partial_inplace */
+ 0xffffffff, /* src_mask */
+ 0xffffffff, /* dst_mask */
+ false), /* pcrel_offset */
+ {010},
+ {011},
+ {012},
+ {013},
+ {014},
+ {015},
+ {016},
+ HOWTO (R_RELBYTE, /* type */
+ 0, /* rightshift */
+ 0, /* size (0 = byte, 1 = short, 2 = long) */
+ 8, /* bitsize */
+ false, /* pc_relative */
+ 0, /* bitpos */
+ complain_overflow_bitfield, /* complain_on_overflow */
+ coff_i386_reloc, /* special_function */
+ "8", /* name */
+ true, /* partial_inplace */
+ 0x000000ff, /* src_mask */
+ 0x000000ff, /* dst_mask */
+ PCRELOFFSET), /* pcrel_offset */
+ HOWTO (R_RELWORD, /* type */
+ 0, /* rightshift */
+ 1, /* size (0 = byte, 1 = short, 2 = long) */
+ 16, /* bitsize */
+ false, /* pc_relative */
+ 0, /* bitpos */
+ complain_overflow_bitfield, /* complain_on_overflow */
+ coff_i386_reloc, /* special_function */
+ "16", /* name */
+ true, /* partial_inplace */
+ 0x0000ffff, /* src_mask */
+ 0x0000ffff, /* dst_mask */
+ PCRELOFFSET), /* pcrel_offset */
+ HOWTO (R_RELLONG, /* type */
+ 0, /* rightshift */
+ 2, /* size (0 = byte, 1 = short, 2 = long) */
+ 32, /* bitsize */
+ false, /* pc_relative */
+ 0, /* bitpos */
+ complain_overflow_bitfield, /* complain_on_overflow */
+ coff_i386_reloc, /* special_function */
+ "32", /* name */
+ true, /* partial_inplace */
+ 0xffffffff, /* src_mask */
+ 0xffffffff, /* dst_mask */
+ PCRELOFFSET), /* pcrel_offset */
+ HOWTO (R_PCRBYTE, /* type */
+ 0, /* rightshift */
+ 0, /* size (0 = byte, 1 = short, 2 = long) */
+ 8, /* bitsize */
+ true, /* pc_relative */
+ 0, /* bitpos */
+ complain_overflow_signed, /* complain_on_overflow */
+ coff_i386_reloc, /* special_function */
+ "DISP8", /* name */
+ true, /* partial_inplace */
+ 0x000000ff, /* src_mask */
+ 0x000000ff, /* dst_mask */
+ PCRELOFFSET), /* pcrel_offset */
+ HOWTO (R_PCRWORD, /* type */
+ 0, /* rightshift */
+ 1, /* size (0 = byte, 1 = short, 2 = long) */
+ 16, /* bitsize */
+ true, /* pc_relative */
+ 0, /* bitpos */
+ complain_overflow_signed, /* complain_on_overflow */
+ coff_i386_reloc, /* special_function */
+ "DISP16", /* name */
+ true, /* partial_inplace */
+ 0x0000ffff, /* src_mask */
+ 0x0000ffff, /* dst_mask */
+ PCRELOFFSET), /* pcrel_offset */
+ HOWTO (R_PCRLONG, /* type */
+ 0, /* rightshift */
+ 2, /* size (0 = byte, 1 = short, 2 = long) */
+ 32, /* bitsize */
+ true, /* pc_relative */
+ 0, /* bitpos */
+ complain_overflow_signed, /* complain_on_overflow */
+ coff_i386_reloc, /* special_function */
+ "DISP32", /* name */
+ true, /* partial_inplace */
+ 0xffffffff, /* src_mask */
+ 0xffffffff, /* dst_mask */
+ PCRELOFFSET) /* pcrel_offset */
+};
+
+/* Turn a howto into a reloc nunmber */
+
+#define SELECT_RELOC(x,howto) { x.r_type = howto->type; }
+#define BADMAG(x) I386BADMAG(x)
+#define I386 1 /* Customize coffcode.h */
+
+#define RTYPE2HOWTO(cache_ptr, dst) \
+ (cache_ptr)->howto = howto_table + (dst)->r_type;
+
+/* For 386 COFF a STYP_NOLOAD | STYP_BSS section is part of a shared
+ library. On some other COFF targets STYP_BSS is normally
+ STYP_NOLOAD. */
+#define BSS_NOLOAD_IS_SHARED_LIBRARY
+
+/* Compute the addend of a reloc. If the reloc is to a common symbol,
+ the object file contains the value of the common symbol. By the
+ time this is called, the linker may be using a different symbol
+ from a different object file with a different value. Therefore, we
+ hack wildly to locate the original symbol from this file so that we
+ can make the correct adjustment. This macro sets coffsym to the
+ symbol from the original file, and uses it to set the addend value
+ correctly. If this is not a common symbol, the usual addend
+ calculation is done, except that an additional tweak is needed for
+ PC relative relocs.
+ FIXME: This macro refers to symbols and asect; these are from the
+ calling function, not the macro arguments. */
+
+#define CALC_ADDEND(abfd, ptr, reloc, cache_ptr) \
+ { \
+ coff_symbol_type *coffsym = (coff_symbol_type *) NULL; \
+ if (ptr && bfd_asymbol_bfd (ptr) != abfd) \
+ coffsym = (obj_symbols (abfd) \
+ + (cache_ptr->sym_ptr_ptr - symbols)); \
+ else if (ptr) \
+ coffsym = coff_symbol_from (abfd, ptr); \
+ if (coffsym != (coff_symbol_type *) NULL \
+ && coffsym->native->u.syment.n_scnum == 0) \
+ cache_ptr->addend = - coffsym->native->u.syment.n_value; \
+ else if (ptr && bfd_asymbol_bfd (ptr) == abfd \
+ && ptr->section != (asection *) NULL) \
+ cache_ptr->addend = - (ptr->section->vma + ptr->value); \
+ else \
+ cache_ptr->addend = 0; \
+ if (ptr && howto_table[reloc.r_type].pc_relative) \
+ cache_ptr->addend += asect->vma; \
+ }
+
+/* We use the special COFF backend linker. For normal i386 COFF, we
+ can use the generic relocate_section routine. For PE, we need our
+ own routine. */
+
+#ifndef COFF_WITH_PE
+
+#define coff_relocate_section _bfd_coff_generic_relocate_section
+
+#else /* COFF_WITH_PE */
+
+/* The PE relocate section routine. The only difference between this
+ and the regular routine is that we don't want to do anything for a
+ relocateable link. */
+
+static boolean coff_pe_i386_relocate_section
+ PARAMS ((bfd *, struct bfd_link_info *, bfd *, asection *, bfd_byte *,
+ struct internal_reloc *, struct internal_syment *, asection **));
+
+static boolean
+coff_pe_i386_relocate_section (output_bfd, info, input_bfd,
+ input_section, contents, relocs, syms,
+ sections)
+ bfd *output_bfd;
+ struct bfd_link_info *info;
+ bfd *input_bfd;
+ asection *input_section;
+ bfd_byte *contents;
+ struct internal_reloc *relocs;
+ struct internal_syment *syms;
+ asection **sections;
+{
+ if (info->relocateable)
+ return true;
+
+ return _bfd_coff_generic_relocate_section (output_bfd, info, input_bfd,
+ input_section, contents,
+ relocs, syms, sections);
+}
+
+#define coff_relocate_section coff_pe_i386_relocate_section
+
+#endif /* COFF_WITH_PE */
+
+/* Convert an rtype to howto for the COFF backend linker. */
+
+static reloc_howto_type *
+coff_i386_rtype_to_howto (abfd, sec, rel, h, sym, addendp)
+ bfd *abfd;
+ asection *sec;
+ struct internal_reloc *rel;
+ struct coff_link_hash_entry *h;
+ struct internal_syment *sym;
+ bfd_vma *addendp;
+{
+
+ reloc_howto_type *howto;
+
+ howto = howto_table + rel->r_type;
+
+#ifdef COFF_WITH_PE
+ *addendp = 0;
+#endif
+
+ if (howto->pc_relative)
+ *addendp += sec->vma;
+
+ if (sym != NULL && sym->n_scnum == 0 && sym->n_value != 0)
+ {
+ /* This is a common symbol. The section contents include the
+ size (sym->n_value) as an addend. The relocate_section
+ function will be adding in the final value of the symbol. We
+ need to subtract out the current size in order to get the
+ correct result. */
+
+ BFD_ASSERT (h != NULL);
+
+#ifndef COFF_WITH_PE
+ /* I think we *do* want to bypass this. If we don't, I have
+ seen some data parameters get the wrong relocation address.
+ If I link two versions with and without this section bypassed
+ and then do a binary comparison, the addresses which are
+ different can be looked up in the map. The case in which
+ this section has been bypassed has addresses which correspond
+ to values I can find in the map. */
+ *addendp -= sym->n_value;
+#endif
+ }
+
+#ifndef COFF_WITH_PE
+ /* If the output symbol is common (in which case this must be a
+ relocateable link), we need to add in the final size of the
+ common symbol. */
+ if (h != NULL && h->root.type == bfd_link_hash_common)
+ *addendp += h->root.u.c.size;
+#endif
+
+#ifdef COFF_WITH_PE
+ if (howto->pc_relative)
+ {
+ *addendp -= 4;
+
+ /* If the symbol is defined, then the generic code is going to
+ add back the symbol value in order to cancel out an
+ adjustment it made to the addend. However, we set the addend
+ to 0 at the start of this function. We need to adjust here,
+ to avoid the adjustment the generic code will make. FIXME:
+ This is getting a bit hackish. */
+ if (sym != NULL && sym->n_scnum != 0)
+ *addendp -= sym->n_value;
+ }
+
+ if (rel->r_type == R_IMAGEBASE)
+ {
+ *addendp -= pe_data(sec->output_section->owner)->pe_opthdr.ImageBase;
+ }
+#endif
+
+ return howto;
+}
+
+
+#define coff_bfd_reloc_type_lookup coff_i386_reloc_type_lookup
+
+
+static reloc_howto_type *
+coff_i386_reloc_type_lookup (abfd, code)
+ bfd *abfd;
+ bfd_reloc_code_real_type code;
+{
+ switch (code)
+ {
+ case BFD_RELOC_RVA:
+ return howto_table +R_IMAGEBASE;
+ case BFD_RELOC_32:
+ return howto_table + R_DIR32;
+ case BFD_RELOC_32_PCREL:
+ return howto_table + R_PCRLONG;
+ default:
+ BFD_FAIL ();
+ return 0;
+ }
+}
+
+#define coff_rtype_to_howto coff_i386_rtype_to_howto
+
+#ifdef TARGET_UNDERSCORE
+
+/* If i386 gcc uses underscores for symbol names, then it does not use
+ a leading dot for local labels, so if TARGET_UNDERSCORE is defined
+ we treat all symbols starting with L as local. */
+
+static boolean coff_i386_is_local_label_name PARAMS ((bfd *, const char *));
+
+static boolean
+coff_i386_is_local_label_name (abfd, name)
+ bfd *abfd;
+ const char *name;
+{
+ if (name[0] == 'L')
+ return true;
+
+ return _bfd_coff_is_local_label_name (abfd, name);
+}
+
+#define coff_bfd_is_local_label_name coff_i386_is_local_label_name
+
+#endif /* TARGET_UNDERSCORE */
+
+#include "coffcode.h"
+
+static const bfd_target *
+i3coff_object_p (abfd)
+ bfd *abfd;
+{
+#ifdef COFF_IMAGE_WITH_PE
+ /* We need to hack badly to handle a PE image correctly. In PE
+ images created by the GNU linker, the offset to the COFF header
+ is always the size. However, this is not the case in images
+ generated by other PE linkers. The PE format stores a four byte
+ offset to the PE signature just before the COFF header at
+ location 0x3c of the file. We pick up that offset, verify that
+ the PE signature is there, and then set ourselves up to read in
+ the COFF header. */
+ {
+ bfd_byte ext_offset[4];
+ file_ptr offset;
+ bfd_byte ext_signature[4];
+ unsigned long signature;
+
+ if (bfd_seek (abfd, 0x3c, SEEK_SET) != 0
+ || bfd_read (ext_offset, 1, 4, abfd) != 4)
+ {
+ if (bfd_get_error () != bfd_error_system_call)
+ bfd_set_error (bfd_error_wrong_format);
+ return NULL;
+ }
+ offset = bfd_h_get_32 (abfd, ext_offset);
+ if (bfd_seek (abfd, offset, SEEK_SET) != 0
+ || bfd_read (ext_signature, 1, 4, abfd) != 4)
+ {
+ if (bfd_get_error () != bfd_error_system_call)
+ bfd_set_error (bfd_error_wrong_format);
+ return NULL;
+ }
+ signature = bfd_h_get_32 (abfd, ext_signature);
+
+ if (signature != 0x4550)
+ {
+ bfd_set_error (bfd_error_wrong_format);
+ return NULL;
+ }
+
+ /* Here is the hack. coff_object_p wants to read filhsz bytes to
+ pick up the COFF header. We adjust so that that will work. 20
+ is the size of the i386 COFF filehdr. */
+
+ if (bfd_seek (abfd,
+ (bfd_tell (abfd)
+ - bfd_coff_filhsz (abfd)
+ + 20),
+ SEEK_SET)
+ != 0)
+ {
+ if (bfd_get_error () != bfd_error_system_call)
+ bfd_set_error (bfd_error_wrong_format);
+ return NULL;
+ }
+ }
+#endif
+
+ return coff_object_p (abfd);
+}
+
+const bfd_target
+#ifdef TARGET_SYM
+ TARGET_SYM =
+#else
+ i386coff_vec =
+#endif
+{
+#ifdef TARGET_NAME
+ TARGET_NAME,
+#else
+ "coff-i386", /* name */
+#endif
+ bfd_target_coff_flavour,
+ BFD_ENDIAN_LITTLE, /* data byte order is little */
+ BFD_ENDIAN_LITTLE, /* header byte order is little */
+
+ (HAS_RELOC | EXEC_P | /* object flags */
+ HAS_LINENO | HAS_DEBUG |
+ HAS_SYMS | HAS_LOCALS | WP_TEXT | D_PAGED),
+
+#ifndef COFF_WITH_PE
+ (SEC_HAS_CONTENTS | SEC_ALLOC | SEC_LOAD | SEC_RELOC /* section flags */
+ | SEC_CODE | SEC_DATA),
+#else
+ (SEC_HAS_CONTENTS | SEC_ALLOC | SEC_LOAD | SEC_RELOC /* section flags */
+ | SEC_CODE | SEC_DATA
+ | SEC_LINK_ONCE | SEC_LINK_DUPLICATES),
+#endif
+
+#ifdef TARGET_UNDERSCORE
+ TARGET_UNDERSCORE, /* leading underscore */
+#else
+ 0, /* leading underscore */
+#endif
+ '/', /* ar_pad_char */
+ 15, /* ar_max_namelen */
+
+ bfd_getl64, bfd_getl_signed_64, bfd_putl64,
+ bfd_getl32, bfd_getl_signed_32, bfd_putl32,
+ bfd_getl16, bfd_getl_signed_16, bfd_putl16, /* data */
+ bfd_getl64, bfd_getl_signed_64, bfd_putl64,
+ bfd_getl32, bfd_getl_signed_32, bfd_putl32,
+ bfd_getl16, bfd_getl_signed_16, bfd_putl16, /* hdrs */
+
+/* Note that we allow an object file to be treated as a core file as well. */
+ {_bfd_dummy_target, i3coff_object_p, /* bfd_check_format */
+ bfd_generic_archive_p, i3coff_object_p},
+ {bfd_false, coff_mkobject, _bfd_generic_mkarchive, /* bfd_set_format */
+ bfd_false},
+ {bfd_false, coff_write_object_contents, /* bfd_write_contents */
+ _bfd_write_archive_contents, bfd_false},
+
+ BFD_JUMP_TABLE_GENERIC (coff),
+ BFD_JUMP_TABLE_COPY (coff),
+ BFD_JUMP_TABLE_CORE (_bfd_nocore),
+ BFD_JUMP_TABLE_ARCHIVE (_bfd_archive_coff),
+ BFD_JUMP_TABLE_SYMBOLS (coff),
+ BFD_JUMP_TABLE_RELOCS (coff),
+ BFD_JUMP_TABLE_WRITE (coff),
+ BFD_JUMP_TABLE_LINK (coff),
+ BFD_JUMP_TABLE_DYNAMIC (_bfd_nodynamic),
+
+ COFF_SWAP_TABLE,
+};