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/* Routines to help build PEI-format DLLs (Win32 etc)

   Copyright 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007,

   2008, 2009, 2010, 2011, 2012 Free Software Foundation, Inc.

   Written by DJ Delorie <dj@cygnus.com>

   This file is part of the GNU Binutils.

   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 3 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., 51 Franklin Street - Fifth Floor, Boston,

   MA 02110-1301, USA.  */

#include "sysdep.h"

#include "bfd.h"

#include "bfdlink.h"

#include "libiberty.h"

#include "filenames.h"

#include "safe-ctype.h"

#include <time.h>

#include "ld.h"

#include "ldexp.h"

#include "ldlang.h"

#include "ldwrite.h"

#include "ldmisc.h"

#include <ldgram.h>

#include "ldmain.h"

#include "ldfile.h"

#include "ldemul.h"

#include "coff/internal.h"

#include "../bfd/libcoff.h"

#include "deffile.h"

#ifdef pe_use_x86_64

#define PE_IDATA4_SIZE  8

#define PE_IDATA5_SIZE  8

#include "pep-dll.h"

#undef  AOUTSZ

#define AOUTSZ          PEPAOUTSZ

#define PEAOUTHDR       PEPAOUTHDR

#else

#include "pe-dll.h"

#endif

#ifndef PE_IDATA4_SIZE

#define PE_IDATA4_SIZE  4

#endif

#ifndef PE_IDATA5_SIZE

#define PE_IDATA5_SIZE  4

#endif

/*  This file turns a regular Windows PE image into a DLL.  Because of

    the complexity of this operation, it has been broken down into a

    number of separate modules which are all called by the main function

    at the end of this file.  This function is not re-entrant and is

    normally only called once, so static variables are used to reduce

    the number of parameters and return values required.

    See also: ld/emultempl/pe.em and ld/emultempl/pep.em.  */

/*  Auto-import feature by Paul Sokolovsky

    Quick facts:

    1. With this feature on, DLL clients can import variables from DLL

    without any concern from their side (for example, without any source

    code modifications).

    2. This is done completely in bounds of the PE specification (to be fair,

    there's a place where it pokes nose out of, but in practice it works).

    So, resulting module can be used with any other PE compiler/linker.

    3. Auto-import is fully compatible with standard import method and they

    can be mixed together.

    4. Overheads: space: 8 bytes per imported symbol, plus 20 for each

    reference to it; load time: negligible; virtual/physical memory: should be

    less than effect of DLL relocation, and I sincerely hope it doesn't affect

    DLL sharability (too much).

    Idea

    The obvious and only way to get rid of dllimport insanity is to make client

    access variable directly in the DLL, bypassing extra dereference. I.e.,

    whenever client contains something like

    mov dll_var,%eax,

    address of dll_var in the command should be relocated to point into loaded

    DLL. The aim is to make OS loader do so, and than make ld help with that.

    Import section of PE made following way: there's a vector of structures

    each describing imports from particular DLL. Each such structure points

    to two other parallel vectors: one holding imported names, and one which

    will hold address of corresponding imported name. So, the solution is

    de-vectorize these structures, making import locations be sparse and

    pointing directly into code. Before continuing, it is worth a note that,

    while authors strives to make PE act ELF-like, there're some other people

    make ELF act PE-like: elfvector, ;-) .

    Implementation

    For each reference of data symbol to be imported from DLL (to set of which

    belong symbols with name <sym>, if __imp_<sym> is found in implib), the

    import fixup entry is generated. That entry is of type

    IMAGE_IMPORT_DESCRIPTOR and stored in .idata$2 subsection. Each

    fixup entry contains pointer to symbol's address within .text section

    (marked with __fuN_<sym> symbol, where N is integer), pointer to DLL name

    (so, DLL name is referenced by multiple entries), and pointer to symbol

    name thunk. Symbol name thunk is singleton vector (__nm_th_<symbol>)

    pointing to IMAGE_IMPORT_BY_NAME structure (__nm_<symbol>) directly

    containing imported name. Here comes that "on the edge" problem mentioned

    above: PE specification rambles that name vector (OriginalFirstThunk)

    should run in parallel with addresses vector (FirstThunk), i.e. that they

    should have same number of elements and terminated with zero. We violate

    this, since FirstThunk points directly into machine code. But in practice,

    OS loader implemented the sane way: it goes thru OriginalFirstThunk and

    puts addresses to FirstThunk, not something else. It once again should be

    noted that dll and symbol name structures are reused across fixup entries

    and should be there anyway to support standard import stuff, so sustained

    overhead is 20 bytes per reference. Other question is whether having several

    IMAGE_IMPORT_DESCRIPTORS for the same DLL is possible. Answer is yes, it is

    done even by native compiler/linker (libth32's functions are in fact reside

    in windows9x kernel32.dll, so if you use it, you have two

    IMAGE_IMPORT_DESCRIPTORS for kernel32.dll). Yet other question is whether

    referencing the same PE structures several times is valid. The answer is why

    not, prohibiting that (detecting violation) would require more work on

    behalf of loader than not doing it.

    See also: ld/emultempl/pe.em and ld/emultempl/pep.em.  */

static void add_bfd_to_link (bfd *, const char *, struct bfd_link_info *);

/* For emultempl/pe.em.  */

def_file * pe_def_file = 0;

int pe_dll_export_everything = 0;

int pe_dll_exclude_all_symbols = 0;

int pe_dll_do_default_excludes = 1;

int pe_dll_kill_ats = 0;

int pe_dll_stdcall_aliases = 0;

int pe_dll_warn_dup_exports = 0;

int pe_dll_compat_implib = 0;

int pe_dll_extra_pe_debug = 0;

int pe_use_nul_prefixed_import_tables = 0;

int pe_use_coff_long_section_names = -1;

int pe_leading_underscore = -1;

/* Static variables and types.  */

static bfd_vma image_base;

static bfd *filler_bfd;

static struct bfd_section *edata_s, *reloc_s;

static unsigned char *edata_d, *reloc_d;

static size_t edata_sz, reloc_sz;

static int runtime_pseudo_relocs_created = 0;

static int runtime_pseudp_reloc_v2_init = 0;

typedef struct

{

  const char *name;

  int len;

}

autofilter_entry_type;

typedef struct

{

  const char *target_name;

  const char *object_target;

  unsigned int imagebase_reloc;

  int pe_arch;

  int bfd_arch;

  bfd_boolean underscored;

  const autofilter_entry_type* autofilter_symbollist;

}

pe_details_type;

static const autofilter_entry_type autofilter_symbollist_generic[] =

{

  { STRING_COMMA_LEN ("_NULL_IMPORT_DESCRIPTOR") },

  /* Entry point symbols.  */

  { STRING_COMMA_LEN ("DllMain") },

  { STRING_COMMA_LEN ("DllMainCRTStartup") },

  { STRING_COMMA_LEN ("_DllMainCRTStartup") },

  /* Runtime pseudo-reloc.  */

  { STRING_COMMA_LEN ("_pei386_runtime_relocator") },

  { STRING_COMMA_LEN ("do_pseudo_reloc") },

  { NULL, 0 }

};

static const autofilter_entry_type autofilter_symbollist_i386[] =

{

  { STRING_COMMA_LEN ("_NULL_IMPORT_DESCRIPTOR") },

  /* Entry point symbols, and entry hooks.  */

  { STRING_COMMA_LEN ("cygwin_crt0") },

#ifdef pe_use_x86_64

  { STRING_COMMA_LEN ("DllMain") },

  { STRING_COMMA_LEN ("DllEntryPoint") },

  { STRING_COMMA_LEN ("DllMainCRTStartup") },

  { STRING_COMMA_LEN ("_cygwin_dll_entry") },

  { STRING_COMMA_LEN ("_cygwin_crt0_common") },

  { STRING_COMMA_LEN ("_cygwin_noncygwin_dll_entry") },

#else

  { STRING_COMMA_LEN ("DllMain@12") },

  { STRING_COMMA_LEN ("DllEntryPoint@0") },

  { STRING_COMMA_LEN ("DllMainCRTStartup@12") },

  { STRING_COMMA_LEN ("_cygwin_dll_entry@12") },

  { STRING_COMMA_LEN ("_cygwin_crt0_common@8") },

  { STRING_COMMA_LEN ("_cygwin_noncygwin_dll_entry@12") },

  { STRING_COMMA_LEN ("cygwin_attach_dll") },

#endif

  { STRING_COMMA_LEN ("cygwin_premain0") },

  { STRING_COMMA_LEN ("cygwin_premain1") },

  { STRING_COMMA_LEN ("cygwin_premain2") },

  { STRING_COMMA_LEN ("cygwin_premain3") },

  /* Runtime pseudo-reloc.  */

  { STRING_COMMA_LEN ("_pei386_runtime_relocator") },

  { STRING_COMMA_LEN ("do_pseudo_reloc") },

  /* Global vars that should not be exported.  */

  { STRING_COMMA_LEN ("impure_ptr") },

  { STRING_COMMA_LEN ("_impure_ptr") },

  { STRING_COMMA_LEN ("_fmode") },

  { STRING_COMMA_LEN ("environ") },

  { NULL, 0 }

};

#define PE_ARCH_i386     1

#define PE_ARCH_sh       2

#define PE_ARCH_mips     3

#define PE_ARCH_arm      4

#define PE_ARCH_arm_epoc 5

#define PE_ARCH_arm_wince 6

/* Don't make it constant as underscore mode gets possibly overriden

   by target or -(no-)leading-underscore option.  */

static pe_details_type pe_detail_list[] =

{

  {

#ifdef pe_use_x86_64

    "pei-x86-64",

    "pe-x86-64",

    3 /* R_IMAGEBASE */,

#else

    "pei-i386",

    "pe-i386",

    7 /* R_IMAGEBASE */,

#endif

    PE_ARCH_i386,

    bfd_arch_i386,

#ifdef pe_use_x86_64

    FALSE,

#else

    TRUE,

#endif

    autofilter_symbollist_i386

  },

  {

    "pei-shl",

    "pe-shl",

    16 /* R_SH_IMAGEBASE */,

    PE_ARCH_sh,

    bfd_arch_sh,

    TRUE,

    autofilter_symbollist_generic

  },

  {

    "pei-mips",

    "pe-mips",

    34 /* MIPS_R_RVA */,

    PE_ARCH_mips,

    bfd_arch_mips,

    FALSE,

    autofilter_symbollist_generic

  },

  {

    "pei-arm-little",

    "pe-arm-little",

    11 /* ARM_RVA32 */,

    PE_ARCH_arm,

    bfd_arch_arm,

    TRUE,

    autofilter_symbollist_generic

  },

  {

    "epoc-pei-arm-little",

    "epoc-pe-arm-little",

    11 /* ARM_RVA32 */,

    PE_ARCH_arm_epoc,

    bfd_arch_arm,

    FALSE,

    autofilter_symbollist_generic

  },

  {

    "pei-arm-wince-little",

    "pe-arm-wince-little",

    2,  /* ARM_RVA32 on Windows CE, see bfd/coff-arm.c.  */

    PE_ARCH_arm_wince,

    bfd_arch_arm,

    FALSE,

    autofilter_symbollist_generic

  },

  { NULL, NULL, 0, 0, 0, FALSE, NULL }

};

static const pe_details_type *pe_details;

/* Do not specify library suffix explicitly, to allow for dllized versions.  */

static const autofilter_entry_type autofilter_liblist[] =

{

  { STRING_COMMA_LEN ("libcegcc") },

  { STRING_COMMA_LEN ("libcygwin") },

  { STRING_COMMA_LEN ("libgcc") },

  { STRING_COMMA_LEN ("libgcc_s") },

  { STRING_COMMA_LEN ("libstdc++") },

  { STRING_COMMA_LEN ("libmingw32") },

  { STRING_COMMA_LEN ("libmingwex") },

  { STRING_COMMA_LEN ("libg2c") },

  { STRING_COMMA_LEN ("libsupc++") },

  { STRING_COMMA_LEN ("libobjc") },

  { STRING_COMMA_LEN ("libgcj") },

  { NULL, 0 }

};

/* Regardless of the suffix issue mentioned above, we must ensure that

  we do not falsely match on a leading substring, such as when libtool

  builds libstdc++ as a DLL using libsupc++convenience.a as an intermediate.

  This routine ensures that the leading part of the name matches and that

  it is followed by only an optional version suffix and a file extension,

  returning zero if so or -1 if not.  */

static int libnamencmp (const char *libname, const autofilter_entry_type *afptr)

{

  if (filename_ncmp (libname, afptr->name, afptr->len))

    return -1;

  libname += afptr->len;

  /* Be liberal in interpreting what counts as a version suffix; we

    accept anything that has a dash to separate it from the name and

    begins with a digit.  */

  if (libname[0] == '-')

    {

      if (!ISDIGIT (*++libname))

        return -1;

      /* Ensure the filename has an extension.  */

      while (*++libname != '.')

        if (!*libname)

          return -1;

    }

  else if (libname[0] != '.')

    return -1;

  return 0;

}

static const autofilter_entry_type autofilter_objlist[] =

{

  { STRING_COMMA_LEN ("crt0.o") },

  { STRING_COMMA_LEN ("crt1.o") },

  { STRING_COMMA_LEN ("crt2.o") },

  { STRING_COMMA_LEN ("dllcrt1.o") },

  { STRING_COMMA_LEN ("dllcrt2.o") },

  { STRING_COMMA_LEN ("gcrt0.o") },

  { STRING_COMMA_LEN ("gcrt1.o") },

  { STRING_COMMA_LEN ("gcrt2.o") },

  { STRING_COMMA_LEN ("crtbegin.o") },

  { STRING_COMMA_LEN ("crtend.o") },

  { NULL, 0 }

};

static const autofilter_entry_type autofilter_symbolprefixlist[] =

{

  /* _imp_ is treated specially, as it is always underscored.  */

  /* { STRING_COMMA_LEN ("_imp_") },  */

  /* Don't export some c++ symbols.  */

  { STRING_COMMA_LEN ("__rtti_") },

  { STRING_COMMA_LEN ("__builtin_") },

  /* Don't re-export auto-imported symbols.  */

  { STRING_COMMA_LEN ("__nm_") },

  /* Don't export symbols specifying internal DLL layout.  */

  { STRING_COMMA_LEN ("_head_") },

  { STRING_COMMA_LEN ("_IMPORT_DESCRIPTOR_") },

  /* Don't export section labels or artificial symbols

  (eg ".weak.foo".  */

  { STRING_COMMA_LEN (".") },

  { NULL, 0 }

};

static const autofilter_entry_type autofilter_symbolsuffixlist[] =

{

  { STRING_COMMA_LEN ("_iname") },

  { STRING_COMMA_LEN ("_NULL_THUNK_DATA") },

  { NULL, 0 }

};

#define U(str) (pe_details->underscored ? "_" str : str)

void

pe_dll_id_target (const char *target)

{

  int i;

  for (i = 0; pe_detail_list[i].target_name; i++)

    if (strcmp (pe_detail_list[i].target_name, target) == 0

        || strcmp (pe_detail_list[i].object_target, target) == 0)

      {

        int u = pe_leading_underscore; /* Underscoring mode. -1 for use default.  */

        if (u == -1)

          bfd_get_target_info (target, NULL, NULL, &u, NULL);

        if (u == -1)

          abort ();

        pe_detail_list[i].underscored = (u != 0 ? TRUE : FALSE);

        pe_details = pe_detail_list + i;

        pe_leading_underscore = (u != 0 ? 1 : 0);

        return;

      }

  einfo (_("%XUnsupported PEI architecture: %s\n"), target);

  exit (1);

}

/* Helper functions for qsort.  Relocs must be sorted so that we can write

   them out by pages.  */

typedef struct

  {

    bfd_vma vma;

    char type;

    short extra;

  }

reloc_data_type;

static int

reloc_sort (const void *va, const void *vb)

{

  bfd_vma a = ((const reloc_data_type *) va)->vma;

  bfd_vma b = ((const reloc_data_type *) vb)->vma;

  return (a > b) ? 1 : ((a < b) ? -1 : 0);

}

static int

pe_export_sort (const void *va, const void *vb)

{

  const def_file_export *a = va;

  const def_file_export *b = vb;

  char *an = a->name;

  char *bn = b->name;

  if (a->its_name)

    an = a->its_name;

  if (b->its_name)

    bn = b->its_name;

  return strcmp (an, bn);

}

/* Read and process the .DEF file.  */

/* These correspond to the entries in pe_def_file->exports[].  I use

   exported_symbol_sections[i] to tag whether or not the symbol was

   defined, since we can't export symbols we don't have.  */

static bfd_vma *exported_symbol_offsets;

static struct bfd_section **exported_symbol_sections;

static int export_table_size;

static int count_exported;

static int count_exported_byname;

static int count_with_ordinals;

static const char *dll_name;

static int min_ordinal, max_ordinal;

static int *exported_symbols;

typedef struct exclude_list_struct

  {

    char *string;

    struct exclude_list_struct *next;

    exclude_type type;

  }

exclude_list_struct;

static struct exclude_list_struct *excludes = 0;

void

pe_dll_add_excludes (const char *new_excludes, const exclude_type type)

{

  char *local_copy;

  char *exclude_string;

  local_copy = xstrdup (new_excludes);

  exclude_string = strtok (local_copy, ",:");

  for (; exclude_string; exclude_string = strtok (NULL, ",:"))

    {

      struct exclude_list_struct *new_exclude;

      new_exclude = xmalloc (sizeof (struct exclude_list_struct));

      new_exclude->string = xmalloc (strlen (exclude_string) + 1);

      strcpy (new_exclude->string, exclude_string);

      new_exclude->type = type;

      new_exclude->next = excludes;

      excludes = new_exclude;

    }

  free (local_copy);

}

static bfd_boolean

is_import (const char* n)

{

  return (CONST_STRNEQ (n, "__imp_"));

}

/* abfd is a bfd containing n (or NULL)

   It can be used for contextual checks.  */

static int

auto_export (bfd *abfd, def_file *d, const char *n)

{

  def_file_export key;

  struct exclude_list_struct *ex;

  const autofilter_entry_type *afptr;

  const char * libname = NULL;

  if (abfd && abfd->my_archive)

    libname = lbasename (abfd->my_archive->filename);

  key.name = key.its_name = (char *) n;

  /* Return false if n is in the d->exports table.  */

  if (bsearch (&key, d->exports, d->num_exports,

               sizeof (pe_def_file->exports[0]), pe_export_sort))

    return 0;

  if (pe_dll_do_default_excludes)

    {

      const char * p;

      int    len;

      if (pe_dll_extra_pe_debug)

        printf ("considering exporting: %s, abfd=%p, abfd->my_arc=%p\n",

                n, abfd, abfd->my_archive);

      /* First of all, make context checks:

         Don't export anything from standard libs.  */

      if (libname)

        {

          afptr = autofilter_liblist;

          while (afptr->name)

            {

              if (libnamencmp (libname, afptr) == 0 )

                return 0;

              afptr++;

            }

        }

      /* Next, exclude symbols from certain startup objects.  */

      if (abfd && (p = lbasename (abfd->filename)))

        {

          afptr = autofilter_objlist;

          while (afptr->name)

            {

              if (strcmp (p, afptr->name) == 0)

                return 0;

              afptr++;

            }

        }

      /* Don't try to blindly exclude all symbols

         that begin with '__'; this was tried and

         it is too restrictive.  Instead we have

         a target specific list to use:  */

      afptr = pe_details->autofilter_symbollist;

      while (afptr->name)

        {

          if (strcmp (n, afptr->name) == 0)

            return 0;

          afptr++;

        }

      /* Next, exclude symbols starting with ...  */

      afptr = autofilter_symbolprefixlist;

      while (afptr->name)

        {

          if (strncmp (n, afptr->name, afptr->len) == 0)

            return 0;

          afptr++;

        }

      /* Finally, exclude symbols ending with ...  */

      len = strlen (n);

      afptr = autofilter_symbolsuffixlist;

      while (afptr->name)

        {

          if ((len >= afptr->len)

              /* Add 1 to insure match with trailing '\0'.  */

              && strncmp (n + len - afptr->len, afptr->name,

                          afptr->len + 1) == 0)

            return 0;

          afptr++;

        }

    }

  for (ex = excludes; ex; ex = ex->next)

    {

      if (ex->type == EXCLUDELIBS)

        {

          if (libname

              && ((filename_cmp (libname, ex->string) == 0)

                   || (strcasecmp ("ALL", ex->string) == 0)))

            return 0;

        }

      else if (ex->type == EXCLUDEFORIMPLIB)

        {

          if (filename_cmp (abfd->filename, ex->string) == 0)

            return 0;

        }

      else if (strcmp (n, ex->string) == 0)

        return 0;

    }

  return 1;

}

static void

process_def_file_and_drectve (bfd *abfd ATTRIBUTE_UNUSED, struct bfd_link_info *info)

{

  int i, j;

  struct bfd_link_hash_entry *blhe;

  bfd *b;

  struct bfd_section *s;

  def_file_export *e = 0;

  bfd_boolean resort_needed;

  if (!pe_def_file)

    pe_def_file = def_file_empty ();

  /* First, run around to all the objects looking for the .drectve

     sections, and push those into the def file too.  */

  for (b = info->input_bfds; b; b = b->link_next)

    {

      s = bfd_get_section_by_name (b, ".drectve");

      if (s)

        {

          long size = s->size;

          char *buf = xmalloc (size);

          bfd_get_section_contents (b, s, buf, 0, size);

          def_file_add_directive (pe_def_file, buf, size);

          free (buf);

        }

    }

  /* Process aligned common symbol information from the

     .drectve sections now; common symbol allocation is

     done before final link, so it will be too late to

     process them in process_embedded_commands() called

     from _bfd_coff_link_input_bfd().  */

  if (pe_def_file->aligncomms)

    {

      def_file_aligncomm *ac = pe_def_file->aligncomms;

      while (ac)

        {

          struct coff_link_hash_entry *sym_hash;

          sym_hash = coff_link_hash_lookup (coff_hash_table (info),

                ac->symbol_name, FALSE, FALSE, FALSE);

          if (sym_hash && sym_hash->root.type == bfd_link_hash_common

            && sym_hash->root.u.c.p->alignment_power < (unsigned) ac->alignment)

            {

              sym_hash->root.u.c.p->alignment_power = (unsigned) ac->alignment;

            }

          ac = ac->next;

        }

    }

  /* If we are building an executable and there is nothing

     to export, we do not build an export table at all.  */

  if (info->executable && pe_def_file->num_exports == 0

      && (!pe_dll_export_everything || pe_dll_exclude_all_symbols))