text: /* Read the export table symbols from a portable executable and
     convert to internal format, for GDB. Used as a last resort if no
     debugging symbols recognized.
  
     Copyright (C) 2003, 2007-2012 Free Software Foundation, Inc.
  
     This file is part of GDB.
  
     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, see <http://www.gnu.org/licenses/>.
  
     Contributed by Raoul M. Gough (RaoulGough@yahoo.co.uk).  */
  
  #include "coff-pe-read.h"
  
  #include "defs.h"
  #include "bfd.h"
  #include "gdbtypes.h"
  
  #include "symtab.h"
  #include "symfile.h"
  #include "objfiles.h"
  
  /* Internal section information */
  
  struct read_pe_section_data
  {
    CORE_ADDR vma_offset;		/* Offset to loaded address of section.  */
    unsigned long rva_start;	/* Start offset within the pe.  */
    unsigned long rva_end;	/* End offset within the pe.  */
    enum minimal_symbol_type ms_type;	/* Type to assign symbols in
  					   section.  */
  };
  
  #define PE_SECTION_INDEX_TEXT     0
  #define PE_SECTION_INDEX_DATA     1
  #define PE_SECTION_INDEX_BSS      2
  #define PE_SECTION_TABLE_SIZE     3
  #define PE_SECTION_INDEX_INVALID -1
  
  /* Get the index of the named section in our own array, which contains
     text, data and bss in that order.  Return PE_SECTION_INDEX_INVALID
     if passed an unrecognised section name.  */
  
  static int
  read_pe_section_index (const char *section_name)
  {
    if (strcmp (section_name, ".text") == 0)
      {
        return PE_SECTION_INDEX_TEXT;
      }
  
    else if (strcmp (section_name, ".data") == 0)
      {
        return PE_SECTION_INDEX_DATA;
      }
  
    else if (strcmp (section_name, ".bss") == 0)
      {
        return PE_SECTION_INDEX_BSS;
      }
  
    else
      {
        return PE_SECTION_INDEX_INVALID;
      }
  }
  
  /* Record the virtual memory address of a section.  */
  
  static void
  get_section_vmas (bfd *abfd, asection *sectp, void *context)
  {
    struct read_pe_section_data *sections = context;
    int sectix = read_pe_section_index (sectp->name);
  
    if (sectix != PE_SECTION_INDEX_INVALID)
      {
        /* Data within the section start at rva_start in the pe and at
           bfd_get_section_vma() within memory.  Store the offset.  */
  
        sections[sectix].vma_offset
  	= bfd_get_section_vma (abfd, sectp) - sections[sectix].rva_start;
      }
  }
  
  /* Create a minimal symbol entry for an exported symbol.  */
  
  static void
  add_pe_exported_sym (char *sym_name,
  		     unsigned long func_rva,
  		     const struct read_pe_section_data *section_data,
  		     const char *dll_name, struct objfile *objfile)
  {
    /* Add the stored offset to get the loaded address of the symbol.  */
  
    CORE_ADDR vma = func_rva + section_data->vma_offset;
  
    char *qualified_name = 0;
    int dll_name_len = strlen (dll_name);
  
    /* Generate a (hopefully unique) qualified name using the first part
       of the dll name, e.g. KERNEL32!AddAtomA.  This matches the style
       used by windbg from the "Microsoft Debugging Tools for Windows".  */
  
    qualified_name = xmalloc (dll_name_len + strlen (sym_name) + 2);
  
    strncpy (qualified_name, dll_name, dll_name_len);
    qualified_name[dll_name_len] = '!';
    strcpy (qualified_name + dll_name_len + 1, sym_name);
  
    prim_record_minimal_symbol (qualified_name,
  			      vma, section_data->ms_type, objfile);
  
    xfree (qualified_name);
  
    /* Enter the plain name as well, which might not be unique.  */
    prim_record_minimal_symbol (sym_name, vma, 
  			      section_data->ms_type, objfile);
  }
  
  /* Truncate a dll_name at the first dot character.  */
  
  static void
  read_pe_truncate_name (char *dll_name)
  {
    while (*dll_name)
      {
        if ((*dll_name) == '.')
  	{
  	  *dll_name = '\0';	/* truncates and causes loop exit.  */
  	}
  
        else
  	{
  	  ++dll_name;
  	}
      }
  }
  
  /* Low-level support functions, direct from the ld module pe-dll.c.  */
  static unsigned int
  pe_get16 (bfd *abfd, int where)
  {
    unsigned char b[2];
  
    bfd_seek (abfd, (file_ptr) where, SEEK_SET);
    bfd_bread (b, (bfd_size_type) 2, abfd);
    return b[0] + (b[1] << 8);
  }
  
  static unsigned int
  pe_get32 (bfd *abfd, int where)
  {
    unsigned char b[4];
  
    bfd_seek (abfd, (file_ptr) where, SEEK_SET);
    bfd_bread (b, (bfd_size_type) 4, abfd);
    return b[0] + (b[1] << 8) + (b[2] << 16) + (b[3] << 24);
  }
  
  static unsigned int
  pe_as32 (void *ptr)
  {
    unsigned char *b = ptr;
  
    return b[0] + (b[1] << 8) + (b[2] << 16) + (b[3] << 24);
  }
  
  /* Read the (non-debug) export symbol table from a portable
     executable.  Code originally lifted from the ld function
     pe_implied_import_dll in pe-dll.c.  */
  
  void
  read_pe_exported_syms (struct objfile *objfile)
  {
    bfd *dll = objfile->obfd;
    unsigned long pe_header_offset, opthdr_ofs, num_entries, i;
    unsigned long export_rva, export_size, nsections, secptr, expptr;
    unsigned long exp_funcbase;
    unsigned char *expdata, *erva;
    unsigned long name_rvas, ordinals, nexp, ordbase;
    char *dll_name;
    int is_pe64 = 0;
    int is_pe32 = 0;
  
    /* Array elements are for text, data and bss in that order
       Initialization with start_rva > end_rva guarantees that
       unused sections won't be matched.  */
    struct read_pe_section_data section_data[PE_SECTION_TABLE_SIZE]
      = { {0, 1, 0, mst_text},
    {0, 1, 0, mst_data},
    {0, 1, 0, mst_bss}
    };
  
    struct cleanup *back_to = 0;
  
    char const *target = bfd_get_target (objfile->obfd);
  
    is_pe64 = (strcmp (target, "pe-x86-64") == 0
  	     || strcmp (target, "pei-x86-64") == 0);
    is_pe32 = (strcmp (target, "pe-i386") == 0
  	     || strcmp (target, "pei-i386") == 0
  	     || strcmp (target, "pe-arm-wince-little") == 0
  	     || strcmp (target, "pei-arm-wince-little") == 0);
  
    if (!is_pe32 && !is_pe64)
      {
        /* This is not a recognized PE format file.  Abort now, because
  	 the code is untested on anything else.  *FIXME* test on
  	 further architectures and loosen or remove this test.  */
        return;
      }
  
    /* Get pe_header, optional header and numbers of export entries.  */
    pe_header_offset = pe_get32 (dll, 0x3c);
    opthdr_ofs = pe_header_offset + 4 + 20;
    if (is_pe64)
      num_entries = pe_get32 (dll, opthdr_ofs + 108);
    else
      num_entries = pe_get32 (dll, opthdr_ofs + 92);
  
    if (num_entries < 1)		/* No exports.  */
      {
        return;
      }
  
    if (is_pe64)
      {
        export_rva = pe_get32 (dll, opthdr_ofs + 112);
        export_size = pe_get32 (dll, opthdr_ofs + 116);
      }
    else
      {
        export_rva = pe_get32 (dll, opthdr_ofs + 96);
        export_size = pe_get32 (dll, opthdr_ofs + 100);
      }
    nsections = pe_get16 (dll, pe_header_offset + 4 + 2);
    secptr = (pe_header_offset + 4 + 20 +
  	    pe_get16 (dll, pe_header_offset + 4 + 16));
    expptr = 0;
  
    /* Get the rva and size of the export section.  */
    for (i = 0; i < nsections; i++)
      {
        char sname[8];
        unsigned long secptr1 = secptr + 40 * i;
        unsigned long vaddr = pe_get32 (dll, secptr1 + 12);
        unsigned long vsize = pe_get32 (dll, secptr1 + 16);
        unsigned long fptr = pe_get32 (dll, secptr1 + 20);
  
        bfd_seek (dll, (file_ptr) secptr1, SEEK_SET);
        bfd_bread (sname, (bfd_size_type) 8, dll);
  
        if (vaddr <= export_rva && vaddr + vsize > export_rva)
  	{
  	  expptr = fptr + (export_rva - vaddr);
  	  if (export_rva + export_size > vaddr + vsize)
  	    export_size = vsize - (export_rva - vaddr);
  	  break;
  	}
      }
  
    if (export_size == 0)
      {
        /* Empty export table.  */
        return;
      }
  
    /* Scan sections and store the base and size of the relevant
       sections.  */
    for (i = 0; i < nsections; i++)
      {
        unsigned long secptr1 = secptr + 40 * i;
        unsigned long vsize = pe_get32 (dll, secptr1 + 8);
        unsigned long vaddr = pe_get32 (dll, secptr1 + 12);
        char sec_name[9];
        int sectix;
  
        sec_name[8] = '\0';
        bfd_seek (dll, (file_ptr) secptr1 + 0, SEEK_SET);
        bfd_bread (sec_name, (bfd_size_type) 8, dll);
  
        sectix = read_pe_section_index (sec_name);
  
        if (sectix != PE_SECTION_INDEX_INVALID)
  	{
  	  section_data[sectix].rva_start = vaddr;
  	  section_data[sectix].rva_end = vaddr + vsize;
  	}
      }
  
    expdata = (unsigned char *) xmalloc (export_size);
    back_to = make_cleanup (xfree, expdata);
  
    bfd_seek (dll, (file_ptr) expptr, SEEK_SET);
    bfd_bread (expdata, (bfd_size_type) export_size, dll);
    erva = expdata - export_rva;
  
    nexp = pe_as32 (expdata + 24);
    name_rvas = pe_as32 (expdata + 32);
    ordinals = pe_as32 (expdata + 36);
    ordbase = pe_as32 (expdata + 16);
    exp_funcbase = pe_as32 (expdata + 28);
  
    /* Use internal dll name instead of full pathname.  */
    dll_name = pe_as32 (expdata + 12) + erva;
  
    bfd_map_over_sections (dll, get_section_vmas, section_data);
  
    /* Adjust the vma_offsets in case this PE got relocated. This
       assumes that *all* sections share the same relocation offset
       as the text section.  */
    for (i = 0; i < PE_SECTION_TABLE_SIZE; i++)
      {
        section_data[i].vma_offset
  	+= ANOFFSET (objfile->section_offsets, SECT_OFF_TEXT (objfile));
      }
  
    /* Truncate name at first dot. Should maybe also convert to all
       lower case for convenience on Windows.  */
    read_pe_truncate_name (dll_name);
  
    /* Iterate through the list of symbols.  */
    for (i = 0; i < nexp; i++)
      {
        /* Pointer to the names vector.  */
        unsigned long name_rva = pe_as32 (erva + name_rvas + i * 4);
  
        /* Pointer to the function address vector.  */
        unsigned long func_rva = pe_as32 (erva + exp_funcbase + i * 4);
  
        /* Find this symbol's section in our own array.  */
        int sectix = 0;
  
        for (sectix = 0; sectix < PE_SECTION_TABLE_SIZE; ++sectix)
  	{
  	  if ((func_rva >= section_data[sectix].rva_start)
  	      && (func_rva < section_data[sectix].rva_end))
  	    {
  	      add_pe_exported_sym (erva + name_rva,
  				   func_rva,
  				   section_data + sectix, dll_name, objfile);
  	      break;
  	    }
  	}
      }
  
    /* Discard expdata.  */
    do_cleanups (back_to);
  }
  