coffcode.h

来自「基于4个mips核的noc设计」· C头文件 代码 · 共 2,097 行 · 第 1/5 页

      styp_flags = STYP_DEBUG_INFO;
    }
#endif
#ifdef RS6000COFF_C
  else if (!strcmp (sec_name, _PAD))
    {
      styp_flags = STYP_PAD;
    }
  else if (!strcmp (sec_name, _LOADER))
    {
      styp_flags = STYP_LOADER;
    }
#endif
  /* Try and figure out what it should be */
  else if (sec_flags & SEC_CODE)
    {
      styp_flags = STYP_TEXT;
    }
  else if (sec_flags & SEC_DATA)
    {
      styp_flags = STYP_DATA;
    }
  else if (sec_flags & SEC_READONLY)
    {
#ifdef STYP_LIT			/* 29k readonly text/data section */
      styp_flags = STYP_LIT;
#else
      styp_flags = STYP_TEXT;
#endif /* STYP_LIT */
    }
  else if (sec_flags & SEC_LOAD)
    {
      styp_flags = STYP_TEXT;
    }
  else if (sec_flags & SEC_ALLOC)
    {
      styp_flags = STYP_BSS;
    }

#ifdef STYP_CLINK
  if (sec_flags & SEC_CLINK)
    styp_flags |= STYP_CLINK;
#endif

#ifdef STYP_BLOCK
  if (sec_flags & SEC_BLOCK)
    styp_flags |= STYP_BLOCK;
#endif

#ifdef STYP_NOLOAD
  if ((sec_flags & (SEC_NEVER_LOAD | SEC_COFF_SHARED_LIBRARY)) != 0)
    styp_flags |= STYP_NOLOAD;
#endif

  return styp_flags;
}

#else /* COFF_WITH_PE */

/* The PE version; see above for the general comments.  The non-PE
   case seems to be more guessing, and breaks PE format; specifically,
   .rdata is readonly, but it sure ain't text.  Really, all this
   should be set up properly in gas (or whatever assembler is in use),
   and honor whatever objcopy/strip, etc. sent us as input.  */

static long
sec_to_styp_flags (sec_name, sec_flags)
     const char *sec_name ATTRIBUTE_UNUSED;
     flagword sec_flags;
{
  long styp_flags = 0;

  /* caution: there are at least three groups of symbols that have
     very similar bits and meanings: IMAGE_SCN*, SEC_*, and STYP_*.
     SEC_* are the BFD internal flags, used for generic BFD
     information.  STYP_* are the COFF section flags which appear in
     COFF files.  IMAGE_SCN_* are the PE section flags which appear in
     PE files.  The STYP_* flags and the IMAGE_SCN_* flags overlap,
     but there are more IMAGE_SCN_* flags.  */

  /* skip LOAD */
  /* READONLY later */
  /* skip RELOC */
  if ((sec_flags & SEC_CODE) != 0)
    styp_flags |= IMAGE_SCN_CNT_CODE;
  if ((sec_flags & SEC_DATA) != 0)
    styp_flags |= IMAGE_SCN_CNT_INITIALIZED_DATA;
  if ((sec_flags & SEC_ALLOC) != 0 && (sec_flags & SEC_LOAD) == 0)
    styp_flags |= IMAGE_SCN_CNT_UNINITIALIZED_DATA;  /* ==STYP_BSS */
  /* skip ROM */
  /* skip CONSTRUCTOR */
  /* skip CONTENTS */
#ifdef STYP_NOLOAD
  if ((sec_flags & (SEC_NEVER_LOAD | SEC_COFF_SHARED_LIBRARY)) != 0)
    styp_flags |= STYP_NOLOAD;
#endif
  if ((sec_flags & SEC_IS_COMMON) != 0)
    styp_flags |= IMAGE_SCN_LNK_COMDAT;
  if ((sec_flags & SEC_DEBUGGING) != 0)
    styp_flags |= IMAGE_SCN_MEM_DISCARDABLE;
  if ((sec_flags & SEC_EXCLUDE) != 0)
    styp_flags |= IMAGE_SCN_LNK_REMOVE;
  if ((sec_flags & SEC_NEVER_LOAD) != 0)
    styp_flags |= IMAGE_SCN_LNK_REMOVE;
  /* skip IN_MEMORY */
  /* skip SORT */
  if (sec_flags & SEC_LINK_ONCE)
    styp_flags |= IMAGE_SCN_LNK_COMDAT;
  /* skip LINK_DUPLICATES */
  /* skip LINKER_CREATED */

  /* For now, the read/write bits are mapped onto SEC_READONLY, even
     though the semantics don't quite match.  The bits from the input
     are retained in pei_section_data(abfd, section)->pe_flags */

  styp_flags |= IMAGE_SCN_MEM_READ;       /* always readable.  */
  if ((sec_flags & SEC_READONLY) == 0)
    styp_flags |= IMAGE_SCN_MEM_WRITE;    /* Invert READONLY for write */
  if (sec_flags & SEC_CODE)
    styp_flags |= IMAGE_SCN_MEM_EXECUTE;  /* CODE->EXECUTE */
  if (sec_flags & SEC_SHARED)
    styp_flags |= IMAGE_SCN_MEM_SHARED;   /* Shared remains meaningful */

  return styp_flags;
}

#endif /* COFF_WITH_PE */

/* Return a word with SEC_* flags set to represent the incoming STYP_*
   flags (from scnhdr.s_flags).  The inverse of this function is
   sec_to_styp_flags().  NOTE: If you add to/change this routine, you
   should probably mirror the changes in sec_to_styp_flags().  */

#ifndef COFF_WITH_PE

static flagword
styp_to_sec_flags (abfd, hdr, name, section)
     bfd *abfd ATTRIBUTE_UNUSED;
     PTR hdr;
     const char *name;
     asection *section ATTRIBUTE_UNUSED;
{
  struct internal_scnhdr *internal_s = (struct internal_scnhdr *) hdr;
  long styp_flags = internal_s->s_flags;
  flagword sec_flags = 0;

#ifdef STYP_BLOCK
  if (styp_flags & STYP_BLOCK)
      sec_flags |= SEC_BLOCK;
#endif

#ifdef STYP_CLINK
  if (styp_flags & STYP_CLINK)
      sec_flags |= SEC_CLINK;
#endif

#ifdef STYP_NOLOAD
  if (styp_flags & STYP_NOLOAD)
    {
      sec_flags |= SEC_NEVER_LOAD;
    }
#endif /* STYP_NOLOAD */

  /* For 386 COFF, at least, an unloadable text or data section is
     actually a shared library section.  */
  if (styp_flags & STYP_TEXT)
    {
      if (sec_flags & SEC_NEVER_LOAD)
	sec_flags |= SEC_CODE | SEC_COFF_SHARED_LIBRARY;
      else
	sec_flags |= SEC_CODE | SEC_LOAD | SEC_ALLOC;
    }
  else if (styp_flags & STYP_DATA)
    {
      if (sec_flags & SEC_NEVER_LOAD)
	sec_flags |= SEC_DATA | SEC_COFF_SHARED_LIBRARY;
      else
	sec_flags |= SEC_DATA | SEC_LOAD | SEC_ALLOC;
    }
  else if (styp_flags & STYP_BSS)
    {
#ifdef BSS_NOLOAD_IS_SHARED_LIBRARY
      if (sec_flags & SEC_NEVER_LOAD)
	sec_flags |= SEC_ALLOC | SEC_COFF_SHARED_LIBRARY;
      else
#endif
	sec_flags |= SEC_ALLOC;
    }
  else if (styp_flags & STYP_INFO)
    {
      /* We mark these as SEC_DEBUGGING, but only if COFF_PAGE_SIZE is
	 defined.  coff_compute_section_file_positions uses
	 COFF_PAGE_SIZE to ensure that the low order bits of the
	 section VMA and the file offset match.  If we don't know
	 COFF_PAGE_SIZE, we can't ensure the correct correspondence,
	 and demand page loading of the file will fail.  */
#if defined (COFF_PAGE_SIZE) && !defined (COFF_ALIGN_IN_S_FLAGS)
      sec_flags |= SEC_DEBUGGING;
#endif
    }
  else if (styp_flags & STYP_PAD)
    {
      sec_flags = 0;
    }
  else if (strcmp (name, _TEXT) == 0)
    {
      if (sec_flags & SEC_NEVER_LOAD)
	sec_flags |= SEC_CODE | SEC_COFF_SHARED_LIBRARY;
      else
	sec_flags |= SEC_CODE | SEC_LOAD | SEC_ALLOC;
    }
  else if (strcmp (name, _DATA) == 0)
    {
      if (sec_flags & SEC_NEVER_LOAD)
	sec_flags |= SEC_DATA | SEC_COFF_SHARED_LIBRARY;
      else
	sec_flags |= SEC_DATA | SEC_LOAD | SEC_ALLOC;
    }
  else if (strcmp (name, _BSS) == 0)
    {
#ifdef BSS_NOLOAD_IS_SHARED_LIBRARY
      if (sec_flags & SEC_NEVER_LOAD)
	sec_flags |= SEC_ALLOC | SEC_COFF_SHARED_LIBRARY;
      else
#endif
	sec_flags |= SEC_ALLOC;
    }
  else if (strncmp (name, ".debug", 6) == 0
#ifdef _COMMENT
	   || strcmp (name, _COMMENT) == 0
#endif
#ifdef COFF_LONG_SECTION_NAMES
	   || strncmp (name, ".gnu.linkonce.wi.", 17) == 0
#endif
	   || strncmp (name, ".stab", 5) == 0)
    {
#ifdef COFF_PAGE_SIZE
      sec_flags |= SEC_DEBUGGING;
#endif
    }
#ifdef _LIB
  else if (strcmp (name, _LIB) == 0)
    ;
#endif
#ifdef _LIT
  else if (strcmp (name, _LIT) == 0)
    {
      sec_flags = SEC_LOAD | SEC_ALLOC | SEC_READONLY;
    }
#endif
  else
    {
      sec_flags |= SEC_ALLOC | SEC_LOAD;
    }

#ifdef STYP_LIT			/* A29k readonly text/data section type */
  if ((styp_flags & STYP_LIT) == STYP_LIT)
    {
      sec_flags = (SEC_LOAD | SEC_ALLOC | SEC_READONLY);
    }
#endif /* STYP_LIT */
#ifdef STYP_OTHER_LOAD		/* Other loaded sections */
  if (styp_flags & STYP_OTHER_LOAD)
    {
      sec_flags = (SEC_LOAD | SEC_ALLOC);
    }
#endif /* STYP_SDATA */

#if defined (COFF_LONG_SECTION_NAMES) && defined (COFF_SUPPORT_GNU_LINKONCE)
  /* As a GNU extension, if the name begins with .gnu.linkonce, we
     only link a single copy of the section.  This is used to support
     g++.  g++ will emit each template expansion in its own section.
     The symbols will be defined as weak, so that multiple definitions
     are permitted.  The GNU linker extension is to actually discard
     all but one of the sections.  */
  if (strncmp (name, ".gnu.linkonce", sizeof ".gnu.linkonce" - 1) == 0)
    sec_flags |= SEC_LINK_ONCE | SEC_LINK_DUPLICATES_DISCARD;
#endif

  return sec_flags;
}

#else /* COFF_WITH_PE */

static flagword
handle_COMDAT (abfd, sec_flags, hdr, name, section)
     bfd * abfd;
     flagword sec_flags;
     PTR hdr;
     const char *name;
     asection *section;
{
  struct internal_scnhdr *internal_s = (struct internal_scnhdr *) hdr;
  bfd_byte *esymstart, *esym, *esymend;
  int seen_state = 0;
  char *target_name = NULL;

  sec_flags |= SEC_LINK_ONCE;

  /* Unfortunately, the PE format stores essential information in
     the symbol table, of all places.  We need to extract that
     information now, so that objdump and the linker will know how
     to handle the section without worrying about the symbols.  We
     can't call slurp_symtab, because the linker doesn't want the
     swapped symbols.  */

  /* COMDAT sections are special.  The first symbol is the section
     symbol, which tells what kind of COMDAT section it is.  The
     second symbol is the "comdat symbol" - the one with the
     unique name.  GNU uses the section symbol for the unique
     name; MS uses ".text" for every comdat section.  Sigh.  - DJ */

  /* This is not mirrored in sec_to_styp_flags(), but there
     doesn't seem to be a need to, either, and it would at best be
     rather messy.  */

  if (! _bfd_coff_get_external_symbols (abfd))
    return sec_flags;
  
  esymstart = esym = (bfd_byte *) obj_coff_external_syms (abfd);
  esymend = esym + obj_raw_syment_count (abfd) * bfd_coff_symesz (abfd);

  while (esym < esymend)
    {
      struct internal_syment isym;
      char buf[SYMNMLEN + 1];
      const char *symname;

      bfd_coff_swap_sym_in (abfd, (PTR) esym, (PTR) &isym);

      if (sizeof (internal_s->s_name) > SYMNMLEN)
	{
	  /* This case implies that the matching
	     symbol name will be in the string table.  */
	  abort ();
	}

      if (isym.n_scnum == section->target_index)
	{
	  /* According to the MSVC documentation, the first
	     TWO entries with the section # are both of
	     interest to us.  The first one is the "section
	     symbol" (section name).  The second is the comdat
	     symbol name.  Here, we've found the first
	     qualifying entry; we distinguish it from the
	     second with a state flag.

	     In the case of gas-generated (at least until that
	     is fixed) .o files, it isn't necessarily the
	     second one.  It may be some other later symbol.

	     Since gas also doesn't follow MS conventions and
	     emits the section similar to .text$<name>, where
	     <something> is the name we're looking for, we
	     distinguish the two as follows:

	     If the section name is simply a section name (no
	     $) we presume it's MS-generated, and look at
	     precisely the second symbol for the comdat name.
	     If the section name has a $, we assume it's
	     gas-generated, and look for <something> (whatever
	     follows the $) as the comdat symbol.  */

	  /* All 3 branches use this */
	  symname = _bfd_coff_internal_syment_name (abfd, &isym, buf);

	  if (symname == NULL)
	    abort ();

	  switch (seen_state)
	    {
	    case 0:
	      {
		/* The first time we've seen the symbol.  */
		union internal_auxent aux;

		seen_state = 1;

		/* If it isn't the stuff we're expecting, die;
		   The MS documentation is vague, but it
		   appears that the second entry serves BOTH
		   as the comdat symbol and the defining
		   symbol record (either C_STAT or C_EXT,
		   possibly with an aux entry with debug
		   information if it's a function.)  It
		   appears the only way to find the second one
		   is to count.  (On Intel, they appear to be
		   adjacent, but on Alpha, they have been
		   found separated.)

		   Here, we think we've found the first one,
		   but there's some checking we can do to be
		   sure.  */

		if (! (isym.n_sclass == C_STAT
		       && isym.n_type == T_NULL
		       && isym.n_value == 0))
		  abort ();

		/* FIXME LATER: MSVC generates section names
		   like .text for comdats.  Gas generates
		   names like .text$foo__Fv (in the case of a
		   function).  See comment above for more.  */

		if (strcmp (name, symname) != 0)
		  abort ();

		/* This is the section symbol.  */
		bfd_coff_swap_aux_in (abfd, (PTR) (esym + bfd_coff_symesz (abfd)),
				      isym.n_type, isym.n_sclass,
				      0, isym.n_numaux, (PTR) &aux);

		target_name = strchr (name, '$');
		if (target_name != NULL)
		  {
		    /* Gas mode.  */
		    seen_state = 2;
		    /* Skip the `$'.  */
		    target_name += 1;
		  }