coff-i386.c

来自「基于4个mips核的noc设计」· C语言 代码 · 共 624 行 · 第 1/2 页

	 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 =							\
   ((dst)->r_type < sizeof (howto_table) / sizeof (howto_table[0])	\
    ? howto_table + (dst)->r_type					\
    : NULL))

/* 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 ATTRIBUTE_UNUSED;
     asection *sec;
     struct internal_reloc *rel;
     struct coff_link_hash_entry *h;
     struct internal_syment *sym;
     bfd_vma *addendp;
{
  reloc_howto_type *howto;

  if (rel->r_type > sizeof (howto_table) / sizeof (howto_table[0]))
    {
      bfd_set_error (bfd_error_bad_value);
      return NULL;
    }

  howto = howto_table + rel->r_type;

#ifdef COFF_WITH_PE
  /* Cancel out code in _bfd_coff_generic_relocate_section.  */
  *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
      && (bfd_get_flavour(sec->output_section->owner)
	  == bfd_target_coff_flavour))
    {
      *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 ATTRIBUTE_UNUSED;
     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;
    case BFD_RELOC_16:
      return howto_table + R_RELWORD;
    case BFD_RELOC_16_PCREL:
      return howto_table + R_PCRWORD;
    case BFD_RELOC_8:
      return howto_table + R_RELBYTE;
    case BFD_RELOC_8_PCREL:
      return howto_table + R_PCRBYTE;
    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"

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),

  (SEC_HAS_CONTENTS | SEC_ALLOC | SEC_LOAD | SEC_RELOC /* section flags */
#ifdef COFF_WITH_PE
   | SEC_LINK_ONCE | SEC_LINK_DUPLICATES | SEC_READONLY
#endif
   | SEC_CODE | SEC_DATA),

#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, coff_object_p, /* bfd_check_format */
       bfd_generic_archive_p, coff_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),

  NULL,

  COFF_SWAP_TABLE
};