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/* Support for the generic parts of most COFF variants, for BFD.

   Copyright 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,

   2000, 2001, 2002

   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.  */

/*

Most of this hacked by  Steve Chamberlain,

                        sac@cygnus.com

*/

/*

SECTION

        coff backends

        BFD supports a number of different flavours of coff format.

        The major differences between formats are the sizes and

        alignments of fields in structures on disk, and the occasional

        extra field.

        Coff in all its varieties is implemented with a few common

        files and a number of implementation specific files. For

        example, The 88k bcs coff format is implemented in the file

        @file{coff-m88k.c}. This file @code{#include}s

        @file{coff/m88k.h} which defines the external structure of the

        coff format for the 88k, and @file{coff/internal.h} which

        defines the internal structure. @file{coff-m88k.c} also

        defines the relocations used by the 88k format

        @xref{Relocations}.

        The Intel i960 processor version of coff is implemented in

        @file{coff-i960.c}. This file has the same structure as

        @file{coff-m88k.c}, except that it includes @file{coff/i960.h}

        rather than @file{coff-m88k.h}.

SUBSECTION

        Porting to a new version of coff

        The recommended method is to select from the existing

        implementations the version of coff which is most like the one

        you want to use.  For example, we'll say that i386 coff is

        the one you select, and that your coff flavour is called foo.

        Copy @file{i386coff.c} to @file{foocoff.c}, copy

        @file{../include/coff/i386.h} to @file{../include/coff/foo.h},

        and add the lines to @file{targets.c} and @file{Makefile.in}

        so that your new back end is used. Alter the shapes of the

        structures in @file{../include/coff/foo.h} so that they match

        what you need. You will probably also have to add

        @code{#ifdef}s to the code in @file{coff/internal.h} and

        @file{coffcode.h} if your version of coff is too wild.

        You can verify that your new BFD backend works quite simply by

        building @file{objdump} from the @file{binutils} directory,

        and making sure that its version of what's going on and your

        host system's idea (assuming it has the pretty standard coff

        dump utility, usually called @code{att-dump} or just

        @code{dump}) are the same.  Then clean up your code, and send

        what you've done to Cygnus. Then your stuff will be in the

        next release, and you won't have to keep integrating it.

SUBSECTION

        How the coff backend works

SUBSUBSECTION

        File layout

        The Coff backend is split into generic routines that are

        applicable to any Coff target and routines that are specific

        to a particular target.  The target-specific routines are

        further split into ones which are basically the same for all

        Coff targets except that they use the external symbol format

        or use different values for certain constants.

        The generic routines are in @file{coffgen.c}.  These routines

        work for any Coff target.  They use some hooks into the target

        specific code; the hooks are in a @code{bfd_coff_backend_data}

        structure, one of which exists for each target.

        The essentially similar target-specific routines are in

        @file{coffcode.h}.  This header file includes executable C code.

        The various Coff targets first include the appropriate Coff

        header file, make any special defines that are needed, and

        then include @file{coffcode.h}.

        Some of the Coff targets then also have additional routines in

        the target source file itself.

        For example, @file{coff-i960.c} includes

        @file{coff/internal.h} and @file{coff/i960.h}.  It then

        defines a few constants, such as @code{I960}, and includes

        @file{coffcode.h}.  Since the i960 has complex relocation

        types, @file{coff-i960.c} also includes some code to

        manipulate the i960 relocs.  This code is not in

        @file{coffcode.h} because it would not be used by any other

        target.

SUBSUBSECTION

        Bit twiddling

        Each flavour of coff supported in BFD has its own header file

        describing the external layout of the structures. There is also

        an internal description of the coff layout, in

        @file{coff/internal.h}. A major function of the

        coff backend is swapping the bytes and twiddling the bits to

        translate the external form of the structures into the normal

        internal form. This is all performed in the

        @code{bfd_swap}_@i{thing}_@i{direction} routines. Some

        elements are different sizes between different versions of

        coff; it is the duty of the coff version specific include file

        to override the definitions of various packing routines in

        @file{coffcode.h}. E.g., the size of line number entry in coff is

        sometimes 16 bits, and sometimes 32 bits. @code{#define}ing

        @code{PUT_LNSZ_LNNO} and @code{GET_LNSZ_LNNO} will select the

        correct one. No doubt, some day someone will find a version of

        coff which has a varying field size not catered to at the

        moment. To port BFD, that person will have to add more @code{#defines}.

        Three of the bit twiddling routines are exported to

        @code{gdb}; @code{coff_swap_aux_in}, @code{coff_swap_sym_in}

        and @code{coff_swap_lineno_in}. @code{GDB} reads the symbol

        table on its own, but uses BFD to fix things up.  More of the

        bit twiddlers are exported for @code{gas};

        @code{coff_swap_aux_out}, @code{coff_swap_sym_out},

        @code{coff_swap_lineno_out}, @code{coff_swap_reloc_out},

        @code{coff_swap_filehdr_out}, @code{coff_swap_aouthdr_out},

        @code{coff_swap_scnhdr_out}. @code{Gas} currently keeps track

        of all the symbol table and reloc drudgery itself, thereby

        saving the internal BFD overhead, but uses BFD to swap things

        on the way out, making cross ports much safer.  Doing so also

        allows BFD (and thus the linker) to use the same header files

        as @code{gas}, which makes one avenue to disaster disappear.

SUBSUBSECTION

        Symbol reading

        The simple canonical form for symbols used by BFD is not rich

        enough to keep all the information available in a coff symbol

        table. The back end gets around this problem by keeping the original

        symbol table around, "behind the scenes".

        When a symbol table is requested (through a call to

        @code{bfd_canonicalize_symtab}), a request gets through to

        @code{coff_get_normalized_symtab}. This reads the symbol table from

        the coff file and swaps all the structures inside into the

        internal form. It also fixes up all the pointers in the table

        (represented in the file by offsets from the first symbol in

        the table) into physical pointers to elements in the new

        internal table. This involves some work since the meanings of

        fields change depending upon context: a field that is a

        pointer to another structure in the symbol table at one moment

        may be the size in bytes of a structure at the next.  Another

        pass is made over the table. All symbols which mark file names

        (<<C_FILE>> symbols) are modified so that the internal

        string points to the value in the auxent (the real filename)

        rather than the normal text associated with the symbol

        (@code{".file"}).

        At this time the symbol names are moved around. Coff stores

        all symbols less than nine characters long physically

        within the symbol table; longer strings are kept at the end of

        the file in the string  table. This pass moves all strings

        into memory and replaces them with pointers to the strings.

        The symbol table is massaged once again, this time to create

        the canonical table used by the BFD application. Each symbol

        is inspected in turn, and a decision made (using the

        @code{sclass} field) about the various flags to set in the

        @code{asymbol}.  @xref{Symbols}. The generated canonical table

        shares strings with the hidden internal symbol table.

        Any linenumbers are read from the coff file too, and attached

        to the symbols which own the functions the linenumbers belong to.

SUBSUBSECTION

        Symbol writing

        Writing a symbol to a coff file which didn't come from a coff

        file will lose any debugging information. The @code{asymbol}

        structure remembers the BFD from which the symbol was taken, and on

        output the back end makes sure that the same destination target as

        source target is present.

        When the symbols have come from a coff file then all the

        debugging information is preserved.

        Symbol tables are provided for writing to the back end in a

        vector of pointers to pointers. This allows applications like

        the linker to accumulate and output large symbol tables

        without having to do too much byte copying.

        This function runs through the provided symbol table and

        patches each symbol marked as a file place holder

        (@code{C_FILE}) to point to the next file place holder in the

        list. It also marks each @code{offset} field in the list with

        the offset from the first symbol of the current symbol.

        Another function of this procedure is to turn the canonical

        value form of BFD into the form used by coff. Internally, BFD

        expects symbol values to be offsets from a section base; so a

        symbol physically at 0x120, but in a section starting at

        0x100, would have the value 0x20. Coff expects symbols to

        contain their final value, so symbols have their values

        changed at this point to reflect their sum with their owning

        section.  This transformation uses the

        <<output_section>> field of the @code{asymbol}'s

        @code{asection} @xref{Sections}.

        o <<coff_mangle_symbols>>

        This routine runs though the provided symbol table and uses

        the offsets generated by the previous pass and the pointers

        generated when the symbol table was read in to create the

        structured hierachy required by coff. It changes each pointer

        to a symbol into the index into the symbol table of the asymbol.

        o <<coff_write_symbols>>

        This routine runs through the symbol table and patches up the

        symbols from their internal form into the coff way, calls the

        bit twiddlers, and writes out the table to the file.

*/

/*

INTERNAL_DEFINITION

        coff_symbol_type

DESCRIPTION

        The hidden information for an <<asymbol>> is described in a

        <<combined_entry_type>>:

CODE_FRAGMENT

.

.typedef struct coff_ptr_struct

.{

.  {* Remembers the offset from the first symbol in the file for

.     this symbol. Generated by coff_renumber_symbols. *}

.  unsigned int offset;

.

.  {* Should the value of this symbol be renumbered.  Used for

.     XCOFF C_BSTAT symbols.  Set by coff_slurp_symbol_table.  *}

.  unsigned int fix_value : 1;

.

.  {* Should the tag field of this symbol be renumbered.

.     Created by coff_pointerize_aux. *}

.  unsigned int fix_tag : 1;

.

.  {* Should the endidx field of this symbol be renumbered.

.     Created by coff_pointerize_aux. *}

.  unsigned int fix_end : 1;

.

.  {* Should the x_csect.x_scnlen field be renumbered.

.     Created by coff_pointerize_aux. *}

.  unsigned int fix_scnlen : 1;

.

.  {* Fix up an XCOFF C_BINCL/C_EINCL symbol.  The value is the

.     index into the line number entries.  Set by coff_slurp_symbol_table.  *}

.  unsigned int fix_line : 1;

.

.  {* The container for the symbol structure as read and translated

.     from the file. *}

.  union

.  {

.    union internal_auxent auxent;

.    struct internal_syment syment;

.  } u;

.} combined_entry_type;

.

.

.{* Each canonical asymbol really looks like this: *}

.

.typedef struct coff_symbol_struct

.{

.  {* The actual symbol which the rest of BFD works with *}

.  asymbol symbol;

.

.  {* A pointer to the hidden information for this symbol *}

.  combined_entry_type *native;

.

.  {* A pointer to the linenumber information for this symbol *}

.  struct lineno_cache_entry *lineno;

.

.  {* Have the line numbers been relocated yet ? *}

.  boolean done_lineno;

.} coff_symbol_type;

*/

#ifdef COFF_WITH_PE

#include "peicode.h"

#else

#include "coffswap.h"

#endif

#define STRING_SIZE_SIZE (4)

static long sec_to_styp_flags PARAMS ((const char *, flagword));

static boolean styp_to_sec_flags

  PARAMS ((bfd *, PTR, const char *, asection *, flagword *));

static boolean coff_bad_format_hook PARAMS ((bfd *, PTR));

static void coff_set_custom_section_alignment

  PARAMS ((bfd *, asection *, const struct coff_section_alignment_entry *,

           const unsigned int));

static boolean coff_new_section_hook PARAMS ((bfd *, asection *));

static boolean coff_set_arch_mach_hook PARAMS ((bfd *, PTR));

static boolean coff_write_relocs PARAMS ((bfd *, int));

static boolean coff_set_flags

  PARAMS ((bfd *, unsigned int *, unsigned short *));

static boolean coff_set_arch_mach

  PARAMS ((bfd *, enum bfd_architecture, unsigned long)) ATTRIBUTE_UNUSED;

static boolean coff_compute_section_file_positions PARAMS ((bfd *));

static boolean coff_write_object_contents PARAMS ((bfd *)) ATTRIBUTE_UNUSED;

static boolean coff_set_section_contents

  PARAMS ((bfd *, asection *, PTR, file_ptr, bfd_size_type));

static PTR buy_and_read PARAMS ((bfd *, file_ptr, bfd_size_type));

static boolean coff_slurp_line_table PARAMS ((bfd *, asection *));

static boolean coff_slurp_symbol_table PARAMS ((bfd *));

static enum coff_symbol_classification coff_classify_symbol

  PARAMS ((bfd *, struct internal_syment *));

static boolean coff_slurp_reloc_table PARAMS ((bfd *, asection *, asymbol **));

static long coff_canonicalize_reloc

  PARAMS ((bfd *, asection *, arelent **, asymbol **));

#ifndef coff_mkobject_hook

static PTR coff_mkobject_hook PARAMS ((bfd *, PTR,  PTR));

#endif

#ifdef COFF_WITH_PE

static flagword handle_COMDAT PARAMS ((bfd *, flagword, PTR, const char *, asection *));

#endif

#ifdef COFF_IMAGE_WITH_PE

static boolean coff_read_word PARAMS ((bfd *, unsigned int *));

static unsigned int coff_compute_checksum PARAMS ((bfd *));

static boolean coff_apply_checksum PARAMS ((bfd *));

#endif

/* void warning(); */

/* Return a word with STYP_* (scnhdr.s_flags) flags set to represent

   the incoming SEC_* flags.  The inverse of this function is

   styp_to_sec_flags().  NOTE: If you add to/change this routine, you

   should probably mirror the changes in styp_to_sec_flags().  */

#ifndef COFF_WITH_PE

/* Macros for setting debugging flags.  */

#ifdef STYP_DEBUG

#define STYP_XCOFF_DEBUG STYP_DEBUG

#else

#define STYP_XCOFF_DEBUG STYP_INFO

#endif

#ifdef COFF_ALIGN_IN_S_FLAGS

#define STYP_DEBUG_INFO STYP_DSECT

#else

#define STYP_DEBUG_INFO STYP_INFO

#endif

static long

sec_to_styp_flags (sec_name, sec_flags)

     const char *sec_name;

     flagword sec_flags;

{

  long styp_flags = 0;

  if (!strcmp (sec_name, _TEXT))

    {

      styp_flags = STYP_TEXT;

    }

  else if (!strcmp (sec_name, _DATA))

    {

      styp_flags = STYP_DATA;

    }

  else if (!strcmp (sec_name, _BSS))

    {

      styp_flags = STYP_BSS;

#ifdef _COMMENT

    }

  else if (!strcmp (sec_name, _COMMENT))

    {

      styp_flags = STYP_INFO;

#endif /* _COMMENT */

#ifdef _LIB

    }

  else if (!strcmp (sec_name, _LIB))

    {

      styp_flags = STYP_LIB;

#endif /* _LIB */

#ifdef _LIT

    }

  else if (!strcmp (sec_name, _LIT))

    {

      styp_flags = STYP_LIT;

#endif /* _LIT */

    }

  else if (!strncmp (sec_name, ".debug", 6))

    {

      /* Handle the XCOFF debug section and DWARF2 debug sections.  */

      if (!sec_name[6])

        styp_flags = STYP_XCOFF_DEBUG;

      else

        styp_flags = STYP_DEBUG_INFO;

    }

  else if (!strncmp (sec_name, ".stab", 5))

    {

      styp_flags = STYP_DEBUG_INFO;

    }

#ifdef COFF_LONG_SECTION_NAMES

  else if (!strncmp (sec_name, ".gnu.linkonce.wi.", 17))

    {

      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;

    }

  else if (!strcmp (sec_name, _EXCEPT))

    {

      styp_flags = STYP_EXCEPT;

    }

  else if (!strcmp (sec_name, _TYPCHK))

    {

      styp_flags = STYP_TYPCHK;

    }

#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 boolean

styp_to_sec_flags (abfd, hdr, name, section, flags_ptr)

     bfd *abfd ATTRIBUTE_UNUSED;

     PTR hdr;

     const char *name;

     asection *section ATTRIBUTE_UNUSED;

     flagword *flags_ptr;

{

  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

  if (flags_ptr == NULL)

    return false;

  * flags_ptr = sec_flags;

  return true;

}

#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.