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      1 // incremental.cc -- incremental linking test/debug tool
      2 
      3 // Copyright (C) 2009-2016 Free Software Foundation, Inc.
      4 // Written by Rafael Avila de Espindola <rafael.espindola (at) gmail.com>
      5 
      6 // This file is part of gold.
      7 
      8 // This program is free software; you can redistribute it and/or modify
      9 // it under the terms of the GNU General Public License as published by
     10 // the Free Software Foundation; either version 3 of the License, or
     11 // (at your option) any later version.
     12 
     13 // This program is distributed in the hope that it will be useful,
     14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
     15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
     16 // GNU General Public License for more details.
     17 
     18 // You should have received a copy of the GNU General Public License
     19 // along with this program; if not, write to the Free Software
     20 // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
     21 // MA 02110-1301, USA.
     22 
     23 
     24 // This file is a (still incomplete) test/debug tool that should display
     25 // all information available in the incremental linking sections in a
     26 // format that is easy to read.
     27 // Once the format is a bit more stable, this should probably be moved to
     28 // readelf. Because of that, the use of gold's data structures and functions
     29 // is just a short term convenience and not a design decision.
     30 
     31 #include "gold.h"
     32 
     33 #include <stdio.h>
     34 #include <errno.h>
     35 #include <time.h>
     36 
     37 #include "incremental.h"
     38 
     39 namespace gold
     40 {
     41   class Output_file;
     42 }
     43 
     44 using namespace gold;
     45 
     46 template<int size, bool big_endian>
     47 static typename Incremental_inputs_reader<size, big_endian>::
     48     Incremental_input_entry_reader
     49 find_input_containing_global(
     50     Incremental_inputs_reader<size, big_endian>& incremental_inputs,
     51     unsigned int offset,
     52     unsigned int* symndx)
     53 {
     54   typedef Incremental_inputs_reader<size, big_endian> Inputs_reader;
     55   static const unsigned int global_sym_entry_size =
     56       Incremental_inputs_reader<size, big_endian>::global_sym_entry_size;
     57 
     58   for (unsigned int i = 0; i < incremental_inputs.input_file_count(); ++i)
     59     {
     60       typename Inputs_reader::Incremental_input_entry_reader input_file =
     61 	  incremental_inputs.input_file(i);
     62       if (input_file.type() != INCREMENTAL_INPUT_OBJECT
     63           && input_file.type() != INCREMENTAL_INPUT_ARCHIVE_MEMBER)
     64         continue;
     65       unsigned int nsyms = input_file.get_global_symbol_count();
     66       if (offset >= input_file.get_symbol_offset(0)
     67           && offset < input_file.get_symbol_offset(nsyms))
     68 	{
     69 	  *symndx = ((offset - input_file.get_symbol_offset(0))
     70 		     / global_sym_entry_size);
     71 	  return input_file;
     72 	}
     73     }
     74   gold_unreachable();
     75 }
     76 
     77 template<int size, bool big_endian>
     78 static void
     79 dump_incremental_inputs(const char* argv0, const char* filename,
     80 			Sized_incremental_binary<size, big_endian>* inc)
     81 {
     82   typedef Incremental_binary::Location Location;
     83   typedef Incremental_binary::View View;
     84   typedef Incremental_inputs_reader<size, big_endian> Inputs_reader;
     85   typedef typename Inputs_reader::Incremental_input_entry_reader Entry_reader;
     86 
     87   if (!inc->has_incremental_info())
     88     {
     89       fprintf(stderr, "%s: %s: no .gnu_incremental_inputs section\n", argv0,
     90               filename);
     91       exit(1);
     92     }
     93 
     94   // Create a reader object for the .gnu_incremental_inputs section.
     95 
     96   Incremental_inputs_reader<size, big_endian>
     97       incremental_inputs(inc->inputs_reader());
     98 
     99   if (incremental_inputs.version() != 2)
    100     {
    101       fprintf(stderr, "%s: %s: unknown incremental version %d\n", argv0,
    102               filename, incremental_inputs.version());
    103       exit(1);
    104     }
    105 
    106   const char* command_line = incremental_inputs.command_line();
    107   if (command_line == NULL)
    108     {
    109       fprintf(stderr,
    110               "%s: %s: failed to get link command line\n",
    111               argv0, filename);
    112       exit(1);
    113     }
    114   printf("Link command line: %s\n", command_line);
    115 
    116   printf("\nInput files:\n");
    117   for (unsigned int i = 0; i < incremental_inputs.input_file_count(); ++i)
    118     {
    119       Entry_reader input_file = incremental_inputs.input_file(i);
    120 
    121       const char* objname = input_file.filename();
    122       if (objname == NULL)
    123 	{
    124 	  fprintf(stderr,"%s: %s: failed to get file name for object %u\n",
    125 		  argv0, filename, i);
    126 	  exit(1);
    127 	}
    128       printf("[%d] %s\n", i, objname);
    129 
    130       Timespec mtime = input_file.get_mtime();
    131       printf("    Timestamp: %llu.%09d  %s",
    132 	     static_cast<unsigned long long>(mtime.seconds),
    133 	     mtime.nanoseconds,
    134 	     ctime(&mtime.seconds));
    135 
    136       printf("    Serial Number: %d\n", input_file.arg_serial());
    137       printf("    In System Directory: %s\n",
    138 	     input_file.is_in_system_directory() ? "true" : "false");
    139 
    140       Incremental_input_type input_type = input_file.type();
    141       printf("    Type: ");
    142       switch (input_type)
    143 	{
    144 	case INCREMENTAL_INPUT_OBJECT:
    145 	case INCREMENTAL_INPUT_ARCHIVE_MEMBER:
    146 	  printf("%s\n", (input_type == INCREMENTAL_INPUT_OBJECT
    147 			  ? "Object" : "Archive member"));
    148 	  printf("    Input section count: %d\n",
    149 		 input_file.get_input_section_count());
    150 	  printf("    Global symbol count: %d\n",
    151 		 input_file.get_global_symbol_count());
    152 	  printf("    Local symbol offset: %d\n",
    153 		 input_file.get_local_symbol_offset());
    154 	  printf("    Local symbol count: %d\n",
    155 		 input_file.get_local_symbol_count());
    156 	  printf("    First dynamic reloc: %d\n",
    157 		 input_file.get_first_dyn_reloc());
    158 	  printf("    Dynamic reloc count: %d\n",
    159 		 input_file.get_dyn_reloc_count());
    160 	  printf("    COMDAT group count: %d\n",
    161 		 input_file.get_comdat_group_count());
    162 	  break;
    163 	case INCREMENTAL_INPUT_ARCHIVE:
    164 	  printf("Archive\n");
    165 	  printf("    Member count: %d\n", input_file.get_member_count());
    166 	  printf("    Unused symbol count: %d\n",
    167 		 input_file.get_unused_symbol_count());
    168 	  break;
    169 	case INCREMENTAL_INPUT_SHARED_LIBRARY:
    170 	  printf("Shared library\n");
    171 	  printf("    As needed: %s\n",
    172 		 input_file.as_needed() ? "true" : "false");
    173 	  printf("    soname: %s\n",
    174 		 input_file.get_soname());
    175 	  printf("    Symbol count: %d\n",
    176 		 input_file.get_global_symbol_count());
    177 	  break;
    178 	case INCREMENTAL_INPUT_SCRIPT:
    179 	  printf("Linker script\n");
    180 	  printf("    Object count: %d\n", input_file.get_object_count());
    181 	  break;
    182 	default:
    183 	  fprintf(stderr, "%s: invalid file type for object %u: %d\n",
    184 		  argv0, i, input_type);
    185 	  exit(1);
    186 	}
    187     }
    188 
    189   printf("\nInput sections:\n");
    190   for (unsigned int i = 0; i < incremental_inputs.input_file_count(); ++i)
    191     {
    192       Entry_reader input_file(incremental_inputs.input_file(i));
    193 
    194       if (input_file.type() != INCREMENTAL_INPUT_OBJECT
    195 	  && input_file.type() != INCREMENTAL_INPUT_ARCHIVE_MEMBER)
    196 	continue;
    197 
    198       const char* objname = input_file.filename();
    199       if (objname == NULL)
    200 	{
    201 	  fprintf(stderr,"%s: %s: failed to get file name for object %u\n",
    202 		  argv0, filename, i);
    203 	  exit(1);
    204 	}
    205 
    206       printf("[%d] %s\n", i, objname);
    207 
    208       printf("    %3s  %6s  %8s  %8s  %s\n",
    209 	     "n", "outndx", "offset", "size", "name");
    210       unsigned int nsections = input_file.get_input_section_count();
    211       for (unsigned int shndx = 0; shndx < nsections; ++shndx)
    212 	{
    213 	  typename Entry_reader::Input_section_info info(
    214 	      input_file.get_input_section(shndx));
    215 	  printf("    %3d  %6d  %8lld  %8lld  %s\n", shndx + 1,
    216 		 info.output_shndx,
    217 		 static_cast<long long>(info.sh_offset),
    218 		 static_cast<long long>(info.sh_size),
    219 		 info.name);
    220 	}
    221 
    222       unsigned int ncomdat = input_file.get_comdat_group_count();
    223       for (unsigned int i = 0; i < ncomdat; ++i)
    224 	printf("    Comdat group: %s\n",
    225 	       input_file.get_comdat_group_signature(i));
    226     }
    227 
    228   // Get a view of the .symtab section.
    229 
    230   elfcpp::Elf_file<size, big_endian, Incremental_binary> elf_file(inc);
    231 
    232   unsigned int symtab_shndx = elf_file.find_section_by_type(elfcpp::SHT_SYMTAB);
    233   if (symtab_shndx == elfcpp::SHN_UNDEF)  // Not found.
    234     {
    235       fprintf(stderr, "%s: %s: no symbol table section\n", argv0, filename);
    236       exit(1);
    237     }
    238   Location symtab_location(elf_file.section_contents(symtab_shndx));
    239   View symtab_view(inc->view(symtab_location));
    240 
    241   // Get a view of the .strtab section.
    242 
    243   unsigned int strtab_shndx = elf_file.section_link(symtab_shndx);
    244   if (strtab_shndx == elfcpp::SHN_UNDEF
    245       || strtab_shndx > elf_file.shnum()
    246       || elf_file.section_type(strtab_shndx) != elfcpp::SHT_STRTAB)
    247     {
    248       fprintf(stderr, "%s: %s: no string table section\n", argv0, filename);
    249       exit(1);
    250     }
    251   Location strtab_location(elf_file.section_contents(strtab_shndx));
    252   View strtab_view(inc->view(strtab_location));
    253   elfcpp::Elf_strtab strtab(strtab_view.data(), strtab_location.data_size);
    254 
    255   // The .gnu_incremental_symtab section contains entries that parallel
    256   // the global symbols of the main symbol table.  The sh_info field
    257   // of the main symbol table's section header tells us how many global
    258   // symbols there are, but that count does not include any global
    259   // symbols that were forced local during the link.  Therefore, we
    260   // use the size of the .gnu_incremental_symtab section to deduce
    261   // the number of global symbols + forced-local symbols there are
    262   // in the symbol table.
    263   Incremental_symtab_reader<big_endian> isymtab(inc->symtab_reader());
    264   Incremental_relocs_reader<size, big_endian> irelocs(inc->relocs_reader());
    265   unsigned int sym_size = elfcpp::Elf_sizes<size>::sym_size;
    266   unsigned int nsyms = symtab_location.data_size / sym_size;
    267   unsigned int nglobals = isymtab.symbol_count();
    268   unsigned int first_global = nsyms - nglobals;
    269   unsigned const char* sym_p;
    270 
    271   printf("\nGlobal symbols per input file:\n");
    272   for (unsigned int i = 0; i < incremental_inputs.input_file_count(); ++i)
    273     {
    274       Entry_reader input_file(incremental_inputs.input_file(i));
    275 
    276       if (input_file.type() != INCREMENTAL_INPUT_OBJECT
    277 	  && input_file.type() != INCREMENTAL_INPUT_ARCHIVE_MEMBER
    278 	  && input_file.type() != INCREMENTAL_INPUT_SHARED_LIBRARY)
    279 	continue;
    280 
    281       const char* objname = input_file.filename();
    282       if (objname == NULL)
    283 	{
    284 	  fprintf(stderr,"%s: %s: failed to get file name for object %u\n",
    285 		  argv0, filename, i);
    286 	  exit(1);
    287 	}
    288 
    289       printf("[%d] %s\n", i, objname);
    290 
    291       unsigned int nsyms = input_file.get_global_symbol_count();
    292       if (nsyms > 0)
    293 	printf("    %6s  %6s  %8s  %8s  %8s  %8s\n",
    294 	       "outndx", "shndx", "offset", "chain", "#relocs", "rbase");
    295       if (input_file.type() == INCREMENTAL_INPUT_SHARED_LIBRARY)
    296 	{
    297 	  for (unsigned int symndx = 0; symndx < nsyms; ++symndx)
    298 	    {
    299 	      bool is_def;
    300 	      bool is_copy;
    301 	      unsigned int output_symndx =
    302 		  input_file.get_output_symbol_index(symndx, &is_def, &is_copy);
    303 	      sym_p = symtab_view.data() + output_symndx * sym_size;
    304 	      elfcpp::Sym<size, big_endian> sym(sym_p);
    305 	      const char* symname;
    306 	      if (!strtab.get_c_string(sym.get_st_name(), &symname))
    307 		symname = "<unknown>";
    308 	      printf("    %6d  %6s  %8s  %8s  %8s  %8s  %-5s  %s\n",
    309 		     output_symndx,
    310 		     "", "", "", "", "",
    311 		     is_copy ? "COPY" : (is_def ? "DEF" : "UNDEF"),
    312 		     symname);
    313 	    }
    314 	}
    315       else
    316 	{
    317 	  for (unsigned int symndx = 0; symndx < nsyms; ++symndx)
    318 	    {
    319 	      Incremental_global_symbol_reader<big_endian> info(
    320 		  input_file.get_global_symbol_reader(symndx));
    321 	      unsigned int output_symndx = info.output_symndx();
    322 	      sym_p = symtab_view.data() + output_symndx * sym_size;
    323 	      elfcpp::Sym<size, big_endian> sym(sym_p);
    324 	      const char* symname;
    325 	      if (!strtab.get_c_string(sym.get_st_name(), &symname))
    326 		symname = "<unknown>";
    327 	      printf("    %6d  %6d  %8d  %8d  %8d  %8d  %-5s  %s\n",
    328 		     output_symndx,
    329 		     info.shndx() == -1U ? -1 : info.shndx(),
    330 		     input_file.get_symbol_offset(symndx),
    331 		     info.next_offset(),
    332 		     info.reloc_count(),
    333 		     info.reloc_offset(),
    334 		     (info.shndx() == -1U
    335 		      ? "BASE"
    336 		      : info.shndx() == 0 ? "UNDEF" : "DEF"),
    337 		     symname);
    338 	    }
    339 	}
    340     }
    341 
    342   sym_p = symtab_view.data() + first_global * sym_size;
    343   printf("\nGlobal symbol table:\n");
    344   for (unsigned int i = 0; i < nglobals; i++)
    345     {
    346       elfcpp::Sym<size, big_endian> sym(sym_p);
    347       const char* symname;
    348       if (!strtab.get_c_string(sym.get_st_name(), &symname))
    349 	symname = "<unknown>";
    350       printf("[%d] %s\n", first_global + i, symname);
    351       unsigned int offset = isymtab.get_list_head(i);
    352       while (offset > 0)
    353         {
    354 	  unsigned int sym_ndx;
    355 	  Entry_reader input_file =
    356 	      find_input_containing_global<size, big_endian>(incremental_inputs,
    357 							     offset, &sym_ndx);
    358 	  Incremental_global_symbol_reader<big_endian> sym_info(
    359 	      input_file.get_global_symbol_reader(sym_ndx));
    360 	  printf("    %s (first reloc: %d, reloc count: %d)",
    361 		 input_file.filename(), sym_info.reloc_offset(),
    362 		 sym_info.reloc_count());
    363 	  if (sym_info.output_symndx() != first_global + i)
    364 	    printf(" ** wrong output symndx (%d) **", sym_info.output_symndx());
    365 	  printf("\n");
    366 	  // Dump the relocations from this input file for this symbol.
    367 	  unsigned int r_off = sym_info.reloc_offset();
    368 	  for (unsigned int j = 0; j < sym_info.reloc_count(); j++)
    369 	    {
    370 	      printf("      %4d  relocation type %3d  shndx %2d"
    371 		     "  offset %016llx  addend %016llx  %s\n",
    372 		     r_off,
    373 		     irelocs.get_r_type(r_off),
    374 		     irelocs.get_r_shndx(r_off),
    375 		     static_cast<long long>(irelocs.get_r_offset(r_off)),
    376 		     static_cast<long long>(irelocs.get_r_addend(r_off)),
    377 		     symname);
    378 	      r_off += irelocs.reloc_size;
    379 	    }
    380 	  offset = sym_info.next_offset();
    381 	}
    382       sym_p += sym_size;
    383     }
    384 
    385   Incremental_got_plt_reader<big_endian> igot_plt(inc->got_plt_reader());
    386   unsigned int ngot = igot_plt.get_got_entry_count();
    387   unsigned int nplt = igot_plt.get_plt_entry_count();
    388 
    389   printf("\nGOT entries:\n");
    390   for (unsigned int i = 0; i < ngot; ++i)
    391     {
    392       unsigned int got_type = igot_plt.get_got_type(i);
    393       unsigned int got_symndx = igot_plt.get_got_symndx(i);
    394       unsigned int got_input_index = igot_plt.get_got_input_index(i);
    395       printf("[%d] type %02x, ", i, got_type & 0x7f);
    396       if ((got_type & 0x7f) == 0x7f)
    397 	printf("reserved");
    398       else if (got_type & 0x80)
    399 	{
    400 	  Entry_reader input_file =
    401 	      incremental_inputs.input_file(got_input_index);
    402 	  const char* objname = input_file.filename();
    403 	  printf("local: %s (%d)", objname, got_symndx);
    404 	}
    405       else
    406 	{
    407 	  sym_p = symtab_view.data() + got_symndx * sym_size;
    408 	  elfcpp::Sym<size, big_endian> sym(sym_p);
    409 	  const char* symname;
    410 	  if (!strtab.get_c_string(sym.get_st_name(), &symname))
    411 	    symname = "<unknown>";
    412 	  printf("global %s (%d)", symname, got_symndx);
    413 	}
    414       printf("\n");
    415     }
    416 
    417   printf("\nPLT entries:\n");
    418   for (unsigned int i = 0; i < nplt; ++i)
    419     {
    420       unsigned int plt_desc = igot_plt.get_plt_desc(i);
    421       printf("[%d] ", i);
    422       sym_p = symtab_view.data() + plt_desc * sym_size;
    423       elfcpp::Sym<size, big_endian> sym(sym_p);
    424       const char* symname;
    425       if (!strtab.get_c_string(sym.get_st_name(), &symname))
    426 	symname = "<unknown>";
    427       printf("%s (%d)\n", symname, plt_desc);
    428     }
    429 
    430   printf("\nUnused archive symbols:\n");
    431   for (unsigned int i = 0; i < incremental_inputs.input_file_count(); ++i)
    432     {
    433       Entry_reader input_file(incremental_inputs.input_file(i));
    434 
    435       if (input_file.type() != INCREMENTAL_INPUT_ARCHIVE)
    436 	continue;
    437 
    438       const char* objname = input_file.filename();
    439       if (objname == NULL)
    440 	{
    441 	  fprintf(stderr,"%s: %s: failed to get file name for object %u\n",
    442 		  argv0, filename, i);
    443 	  exit(1);
    444 	}
    445 
    446       printf("[%d] %s\n", i, objname);
    447       unsigned int nsyms = input_file.get_unused_symbol_count();
    448       for (unsigned int symndx = 0; symndx < nsyms; ++symndx)
    449         printf("    %s\n", input_file.get_unused_symbol(symndx));
    450     }
    451 
    452 }
    453 
    454 int
    455 main(int argc, char** argv)
    456 {
    457   if (argc != 2)
    458     {
    459       fprintf(stderr, "Usage: %s <file>\n", argv[0]);
    460       return 1;
    461     }
    462   const char* filename = argv[1];
    463 
    464   Output_file* file = new Output_file(filename);
    465 
    466   bool t = file->open_base_file(NULL, false);
    467   if (!t)
    468     {
    469       fprintf(stderr, "%s: open_base_file(%s): %s\n", argv[0], filename,
    470               strerror(errno));
    471       return 1;
    472     }
    473 
    474   Incremental_binary* inc = open_incremental_binary(file);
    475 
    476   if (inc == NULL)
    477     {
    478       fprintf(stderr, "%s: open_incremental_binary(%s): %s\n", argv[0],
    479               filename, strerror(errno));
    480       return 1;
    481     }
    482 
    483   switch (parameters->size_and_endianness())
    484     {
    485 #ifdef HAVE_TARGET_32_LITTLE
    486     case Parameters::TARGET_32_LITTLE:
    487       dump_incremental_inputs<32, false>(
    488           argv[0], filename,
    489           static_cast<Sized_incremental_binary<32, false>*>(inc));
    490       break;
    491 #endif
    492 #ifdef HAVE_TARGET_32_BIG
    493     case Parameters::TARGET_32_BIG:
    494       dump_incremental_inputs<32, true>(
    495 	  argv[0], filename,
    496           static_cast<Sized_incremental_binary<32, true>*>(inc));
    497       break;
    498 #endif
    499 #ifdef HAVE_TARGET_64_LITTLE
    500     case Parameters::TARGET_64_LITTLE:
    501       dump_incremental_inputs<64, false>(
    502 	  argv[0], filename,
    503           static_cast<Sized_incremental_binary<64, false>*>(inc));
    504       break;
    505 #endif
    506 #ifdef HAVE_TARGET_64_BIG
    507     case Parameters::TARGET_64_BIG:
    508       dump_incremental_inputs<64, true>(
    509 	  argv[0], filename,
    510           static_cast<Sized_incremental_binary<64, true>*>(inc));
    511       break;
    512 #endif
    513     default:
    514       gold_unreachable();
    515     }
    516 
    517   return 0;
    518 }
    519