ld/emultempl/armelf.em

   1 # This shell script emits a C file. -*- C -*-
   2 # It does some substitutions.
   3 ELFSIZE=32
   4 cat >e${EMULATION_NAME}.c <<EOF
   5 /* This file is is generated by a shell script.  DO NOT EDIT! */
   6
   7 /* emulate the original gld for the given ${EMULATION_NAME}
   8    Copyright (C) 1991, 93, 96, 97, 98, 99, 2000
   9    Free Software Foundation, Inc.
  10    Written by Steve Chamberlain steve@cygnus.com
  11
  12 This file is part of GLD, the Gnu Linker.
  13
  14 This program is free software; you can redistribute it and/or modify
  15 it under the terms of the GNU General Public License as published by
  16 the Free Software Foundation; either version 2 of the License, or
  17 (at your option) any later version.
  18
  19 This program is distributed in the hope that it will be useful,
  20 but WITHOUT ANY WARRANTY; without even the implied warranty of
  21 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22 GNU General Public License for more details.
  23
  24 You should have received a copy of the GNU General Public License
  25 along with this program; if not, write to the Free Software
  26 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
  27
  28 #define TARGET_IS_${EMULATION_NAME}
  29
  30 #include "bfd.h"
  31 #include "sysdep.h"
  32
  33 #include <ctype.h>
  34
  35 #include "bfdlink.h"
  36 #include "getopt.h"
  37
  38 #include "ld.h"
  39 #include "ldmain.h"
  40 #include "ldmisc.h"
  41
  42 #include "ldexp.h"
  43 #include "ldlang.h"
  44 #include "ldfile.h"
  45 #include "ldemul.h"
  46 #include "ldgram.h"
  47
  48 static boolean gld${EMULATION_NAME}_open_dynamic_archive
  49   PARAMS ((const char *, search_dirs_type *, lang_input_statement_type *));
  50 static void gld${EMULATION_NAME}_after_open PARAMS ((void));
  51 static void gld${EMULATION_NAME}_check_needed
  52   PARAMS ((lang_input_statement_type *));
  53 static void gld${EMULATION_NAME}_stat_needed
  54   PARAMS ((lang_input_statement_type *));
  55 static boolean gld${EMULATION_NAME}_search_needed
  56   PARAMS ((const char *, const char *, int));
  57 static boolean gld${EMULATION_NAME}_try_needed PARAMS ((const char *, int));
  58 static void gld${EMULATION_NAME}_vercheck
  59   PARAMS ((lang_input_statement_type *));
  60 static void gld${EMULATION_NAME}_find_statement_assignment
  61   PARAMS ((lang_statement_union_type *));
  62 static void gld${EMULATION_NAME}_find_exp_assignment PARAMS ((etree_type *));
  63 static boolean gld${EMULATION_NAME}_place_orphan
  64   PARAMS ((lang_input_statement_type *, asection *));
  65 static lang_output_section_statement_type *output_rel_find PARAMS ((void));
  66 static void gld${EMULATION_NAME}_before_parse PARAMS ((void));
  67 static void gld${EMULATION_NAME}_before_allocation PARAMS ((void));
  68 static char *gld${EMULATION_NAME}_get_script PARAMS ((int *isfile));
  69 static int  gld${EMULATION_NAME}_parse_args PARAMS((int, char **));
  70 static void gld${EMULATION_NAME}_list_options PARAMS ((FILE *));
  71 static void gld${EMULATION_NAME}_finish PARAMS ((void));
  72
  73 \f
  74 static int no_pipeline_knowledge = 0;
  75 static char * thumb_entry_symbol = NULL;
  76
  77 #define OPTION_THUMB_ENTRY              301
  78
  79 static struct option longopts[] =
  80 {
  81   { "no-pipeline-knowledge", no_argument, NULL, 'p'},
  82   { "thumb-entry", required_argument, NULL, OPTION_THUMB_ENTRY},
  83   { NULL, no_argument, NULL, 0 }
  84 };
  85
  86 static void
  87 gld${EMULATION_NAME}_list_options (file)
  88      FILE * file;
  89 {
  90   fprintf (file, _("  -p --no-pipeline-knowledge  Stop the linker knowing about the pipeline length\n"));
  91   fprintf (file, _("     --thumb-entry=<sym>      Set the entry point to be Thumb symbol <sym>\n"));
  92 }
  93
  94 static int
  95 gld${EMULATION_NAME}_parse_args (argc, argv)
  96      int     argc;
  97      char ** argv;
  98 {
  99   int        longind;
 100   int        optc;
 101   int        prevoptind = optind;
 102   int        prevopterr = opterr;
 103   int        wanterror;
 104   static int lastoptind = -1;
 105
 106   if (lastoptind != optind)
 107     opterr = 0;
 108
 109   wanterror  = opterr;
 110   lastoptind = optind;
 111
 112   optc   = getopt_long_only (argc, argv, "-p", longopts, & longind);
 113   opterr = prevopterr;
 114
 115   switch (optc)
 116     {
 117     default:
 118       if (wanterror)
 119         xexit (1);
 120       optind =  prevoptind;
 121       return 0;
 122
 123     case 'p':
 124       no_pipeline_knowledge = 1;
 125       break;
 126
 127     case OPTION_THUMB_ENTRY:
 128       thumb_entry_symbol = optarg;
 129       break;
 130     }
 131
 132   return 1;
 133 }
 134 \f
 135
 136 static void
 137 gld${EMULATION_NAME}_before_parse ()
 138 {
 139 #ifndef TARGET_                 /* I.e., if not generic.  */
 140   ldfile_set_output_arch ("`echo ${ARCH}`");
 141 #endif /* not TARGET_ */
 142   config.dynamic_link = ${DYNAMIC_LINK-true};
 143   config.has_shared = `if test -n "$GENERATE_SHLIB_SCRIPT" ; then echo true ; else echo false ; fi`;
 144 }
 145
 146 /* Try to open a dynamic archive.  This is where we know that ELF
 147    dynamic libraries have an extension of .so.  */
 148
 149 static boolean
 150 gld${EMULATION_NAME}_open_dynamic_archive (arch, search, entry)
 151      const char *arch;
 152      search_dirs_type *search;
 153      lang_input_statement_type *entry;
 154 {
 155   const char *filename;
 156   char *string;
 157
 158   if (! entry->is_archive)
 159     return false;
 160
 161   filename = entry->filename;
 162
 163   string = (char *) xmalloc (strlen (search->name)
 164                              + strlen (filename)
 165                              + strlen (arch)
 166                              + sizeof "/lib.so");
 167
 168   sprintf (string, "%s/lib%s%s.so", search->name, filename, arch);
 169
 170   if (! ldfile_try_open_bfd (string, entry))
 171     {
 172       free (string);
 173       return false;
 174     }
 175
 176   entry->filename = string;
 177
 178   /* We have found a dynamic object to include in the link.  The ELF
 179      backend linker will create a DT_NEEDED entry in the .dynamic
 180      section naming this file.  If this file includes a DT_SONAME
 181      entry, it will be used.  Otherwise, the ELF linker will just use
 182      the name of the file.  For an archive found by searching, like
 183      this one, the DT_NEEDED entry should consist of just the name of
 184      the file, without the path information used to find it.  Note
 185      that we only need to do this if we have a dynamic object; an
 186      archive will never be referenced by a DT_NEEDED entry.
 187
 188      FIXME: This approach--using bfd_elf_set_dt_needed_name--is not
 189      very pretty.  I haven't been able to think of anything that is
 190      pretty, though.  */
 191   if (bfd_check_format (entry->the_bfd, bfd_object)
 192       && (entry->the_bfd->flags & DYNAMIC) != 0)
 193     {
 194       char *needed_name;
 195
 196       ASSERT (entry->is_archive && entry->search_dirs_flag);
 197       needed_name = (char *) xmalloc (strlen (filename)
 198                                       + strlen (arch)
 199                                       + sizeof "lib.so");
 200       sprintf (needed_name, "lib%s%s.so", filename, arch);
 201       bfd_elf_set_dt_needed_name (entry->the_bfd, needed_name);
 202     }
 203
 204   return true;
 205 }
 206
 207 EOF
 208 if [ "x${host}" = "x${target}" ] ; then
 209   case " ${EMULATION_LIBPATH} " in
 210   *" ${EMULATION_NAME} "*)
 211 cat >>e${EMULATION_NAME}.c <<EOF
 212
 213 /* For a native linker, check the file /etc/ld.so.conf for directories
 214    in which we may find shared libraries.  /etc/ld.so.conf is really
 215    only meaningful on Linux, but we check it on other systems anyhow.  */
 216
 217 static boolean gld${EMULATION_NAME}_check_ld_so_conf
 218   PARAMS ((const char *, int));
 219
 220 static boolean
 221 gld${EMULATION_NAME}_check_ld_so_conf (name, force)
 222      const char *name;
 223      int force;
 224 {
 225   static boolean initialized;
 226   static char *ld_so_conf;
 227
 228   if (! initialized)
 229     {
 230       FILE *f;
 231
 232       f = fopen ("/etc/ld.so.conf", FOPEN_RT);
 233       if (f != NULL)
 234         {
 235           char *b;
 236           size_t len, alloc;
 237           int c;
 238
 239           len = 0;
 240           alloc = 100;
 241           b = (char *) xmalloc (alloc);
 242
 243           while ((c = getc (f)) != EOF)
 244             {
 245               if (len + 1 >= alloc)
 246                 {
 247                   alloc *= 2;
 248                   b = (char *) xrealloc (b, alloc);
 249                 }
 250               if (c != ':'
 251                   && c != ' '
 252                   && c != '\t'
 253                   && c != '\n'
 254                   && c != ',')
 255                 {
 256                   b[len] = c;
 257                   ++len;
 258                 }
 259               else
 260                 {
 261                   if (len > 0 && b[len - 1] != ':')
 262                     {
 263                       b[len] = ':';
 264                       ++len;
 265                     }
 266                 }
 267             }
 268
 269           if (len > 0 && b[len - 1] == ':')
 270             --len;
 271
 272           if (len > 0)
 273             b[len] = '\0';
 274           else
 275             {
 276               free (b);
 277               b = NULL;
 278             }
 279
 280           fclose (f);
 281
 282           ld_so_conf = b;
 283         }
 284
 285       initialized = true;
 286     }
 287
 288   if (ld_so_conf == NULL)
 289     return false;
 290
 291   return gld${EMULATION_NAME}_search_needed (ld_so_conf, name, force);
 292 }
 293
 294 EOF
 295   ;;
 296   esac
 297 fi
 298 cat >>e${EMULATION_NAME}.c <<EOF
 299
 300 /* These variables are required to pass information back and forth
 301    between after_open and check_needed and stat_needed and vercheck.  */
 302
 303 static struct bfd_link_needed_list *global_needed;
 304 static struct stat global_stat;
 305 static boolean global_found;
 306 static struct bfd_link_needed_list *global_vercheck_needed;
 307 static boolean global_vercheck_failed;
 308
 309 static void
 310 gld${EMULATION_NAME}_after_open ()
 311 {
 312   struct bfd_link_needed_list *needed, *l;
 313
 314   if (strstr (bfd_get_target (output_bfd), "arm") == NULL)
 315     {
 316       /* The arm backend needs special fields in the output hash structure.
 317          These will only be created if the output format is an arm format,
 318          hence we do not support linking and changing output formats at the
 319          same time.  Use a link followed by objcopy to change output formats.  */
 320       einfo ("%F%X%P: error: cannot change output format whilst linking ARM binaries\n");
 321       return;
 322     }
 323
 324   {
 325     LANG_FOR_EACH_INPUT_STATEMENT (is)
 326       {
 327         /* The interworking bfd must be the last one to be processed */
 328         if (!is->next)
 329           bfd_elf32_arm_get_bfd_for_interworking (is->the_bfd, & link_info);
 330       }
 331   }
 332
 333   /* We only need to worry about this when doing a final link.  */
 334   if (link_info.relocateable || link_info.shared)
 335     return;
 336
 337   /* Get the list of files which appear in DT_NEEDED entries in
 338      dynamic objects included in the link (often there will be none).
 339      For each such file, we want to track down the corresponding
 340      library, and include the symbol table in the link.  This is what
 341      the runtime dynamic linker will do.  Tracking the files down here
 342      permits one dynamic object to include another without requiring
 343      special action by the person doing the link.  Note that the
 344      needed list can actually grow while we are stepping through this
 345      loop.  */
 346   needed = bfd_elf_get_needed_list (output_bfd, &link_info);
 347   for (l = needed; l != NULL; l = l->next)
 348     {
 349       struct bfd_link_needed_list *ll;
 350       int force;
 351
 352       /* If we've already seen this file, skip it.  */
 353       for (ll = needed; ll != l; ll = ll->next)
 354         if (strcmp (ll->name, l->name) == 0)
 355           break;
 356       if (ll != l)
 357         continue;
 358
 359       /* See if this file was included in the link explicitly.  */
 360       global_needed = l;
 361       global_found = false;
 362       lang_for_each_input_file (gld${EMULATION_NAME}_check_needed);
 363       if (global_found)
 364         continue;
 365
 366       /* We need to find this file and include the symbol table.  We
 367          want to search for the file in the same way that the dynamic
 368          linker will search.  That means that we want to use
 369          rpath_link, rpath, then the environment variable
 370          LD_LIBRARY_PATH (native only), then the linker script
 371          LIB_SEARCH_DIRS.  We do not search using the -L arguments.
 372
 373          We search twice.  The first time, we skip objects which may
 374          introduce version mismatches.  The second time, we force
 375          their use.  See gld${EMULATION_NAME}_vercheck comment.  */
 376       for (force = 0; force < 2; force++)
 377         {
 378           const char *lib_path;
 379           size_t len;
 380           search_dirs_type *search;
 381
 382           if (gld${EMULATION_NAME}_search_needed (command_line.rpath_link,
 383                                                   l->name, force))
 384             break;
 385           if (gld${EMULATION_NAME}_search_needed (command_line.rpath,
 386                                                   l->name, force))
 387             break;
 388           if (command_line.rpath_link == NULL
 389               && command_line.rpath == NULL)
 390             {
 391               lib_path = (const char *) getenv ("LD_RUN_PATH");
 392               if (gld${EMULATION_NAME}_search_needed (lib_path, l->name,
 393                                                       force))
 394                 break;
 395             }
 396 EOF
 397 if [ "x${host}" = "x${target}" ] ; then
 398   case " ${EMULATION_LIBPATH} " in
 399   *" ${EMULATION_NAME} "*)
 400 cat >>e${EMULATION_NAME}.c <<EOF
 401           lib_path = (const char *) getenv ("LD_LIBRARY_PATH");
 402           if (gld${EMULATION_NAME}_search_needed (lib_path, l->name, force))
 403             break;
 404 EOF
 405   ;;
 406   esac
 407 fi
 408 cat >>e${EMULATION_NAME}.c <<EOF
 409           len = strlen (l->name);
 410           for (search = search_head; search != NULL; search = search->next)
 411             {
 412               char *filename;
 413
 414               if (search->cmdline)
 415                 continue;
 416               filename = (char *) xmalloc (strlen (search->name) + len + 2);
 417               sprintf (filename, "%s/%s", search->name, l->name);
 418               if (gld${EMULATION_NAME}_try_needed (filename, force))
 419                 break;
 420               free (filename);
 421             }
 422           if (search != NULL)
 423             break;
 424 EOF
 425 if [ "x${host}" = "x${target}" ] ; then
 426   case " ${EMULATION_LIBPATH} " in
 427   *" ${EMULATION_NAME} "*)
 428 cat >>e${EMULATION_NAME}.c <<EOF
 429           if (gld${EMULATION_NAME}_check_ld_so_conf (l->name, force))
 430             break;
 431 EOF
 432   ;;
 433   esac
 434 fi
 435 cat >>e${EMULATION_NAME}.c <<EOF
 436         }
 437
 438       if (force < 2)
 439         continue;
 440
 441       einfo ("%P: warning: %s, needed by %B, not found (try using --rpath)\n",
 442              l->name, l->by);
 443     }
 444 }
 445
 446 /* Search for a needed file in a path.  */
 447
 448 static boolean
 449 gld${EMULATION_NAME}_search_needed (path, name, force)
 450      const char *path;
 451      const char *name;
 452      int force;
 453 {
 454   const char *s;
 455   size_t len;
 456
 457   if (path == NULL || *path == '\0')
 458     return false;
 459   len = strlen (name);
 460   while (1)
 461     {
 462       char *filename, *sset;
 463
 464       s = strchr (path, ':');
 465       if (s == NULL)
 466         s = path + strlen (path);
 467
 468       filename = (char *) xmalloc (s - path + len + 2);
 469       if (s == path)
 470         sset = filename;
 471       else
 472         {
 473           memcpy (filename, path, s - path);
 474           filename[s - path] = '/';
 475           sset = filename + (s - path) + 1;
 476         }
 477       strcpy (sset, name);
 478
 479       if (gld${EMULATION_NAME}_try_needed (filename, force))
 480         return true;
 481
 482       free (filename);
 483
 484       if (*s == '\0')
 485         break;
 486       path = s + 1;
 487     }
 488
 489   return false;
 490 }
 491
 492 /* This function is called for each possible name for a dynamic object
 493    named by a DT_NEEDED entry.  The FORCE parameter indicates whether
 494    to skip the check for a conflicting version.  */
 495
 496 static boolean
 497 gld${EMULATION_NAME}_try_needed (name, force)
 498      const char *name;
 499      int force;
 500 {
 501   bfd *abfd;
 502
 503   abfd = bfd_openr (name, bfd_get_target (output_bfd));
 504   if (abfd == NULL)
 505     return false;
 506   if (! bfd_check_format (abfd, bfd_object))
 507     {
 508       (void) bfd_close (abfd);
 509       return false;
 510     }
 511   if ((bfd_get_file_flags (abfd) & DYNAMIC) == 0)
 512     {
 513       (void) bfd_close (abfd);
 514       return false;
 515     }
 516
 517   /* Check whether this object would include any conflicting library
 518      versions.  If FORCE is set, then we skip this check; we use this
 519      the second time around, if we couldn't find any compatible
 520      instance of the shared library.  */
 521
 522   if (! force)
 523     {
 524       struct bfd_link_needed_list *needed;
 525
 526       if (! bfd_elf_get_bfd_needed_list (abfd, &needed))
 527         einfo ("%F%P:%B: bfd_elf_get_bfd_needed_list failed: %E\n", abfd);
 528
 529       if (needed != NULL)
 530         {
 531           global_vercheck_needed = needed;
 532           global_vercheck_failed = false;
 533           lang_for_each_input_file (gld${EMULATION_NAME}_vercheck);
 534           if (global_vercheck_failed)
 535             {
 536               (void) bfd_close (abfd);
 537               /* Return false to force the caller to move on to try
 538                  another file on the search path.  */
 539               return false;
 540             }
 541
 542           /* But wait!  It gets much worse.  On Linux, if a shared
 543              library does not use libc at all, we are supposed to skip
 544              it the first time around in case we encounter a shared
 545              library later on with the same name which does use the
 546              version of libc that we want.  This is much too horrible
 547              to use on any system other than Linux.  */
 548
 549 EOF
 550 case ${target} in
 551   *-*-linux-gnu*)
 552     cat >>e${EMULATION_NAME}.c <<EOF
 553           {
 554             struct bfd_link_needed_list *l;
 555
 556             for (l = needed; l != NULL; l = l->next)
 557               if (strncmp (l->name, "libc.so", 7) == 0)
 558                 break;
 559             if (l == NULL)
 560               {
 561                 (void) bfd_close (abfd);
 562                 return false;
 563               }
 564           }
 565
 566 EOF
 567     ;;
 568 esac
 569 cat >>e${EMULATION_NAME}.c <<EOF
 570         }
 571     }
 572
 573   /* We've found a dynamic object matching the DT_NEEDED entry.  */
 574
 575   /* We have already checked that there is no other input file of the
 576      same name.  We must now check again that we are not including the
 577      same file twice.  We need to do this because on many systems
 578      libc.so is a symlink to, e.g., libc.so.1.  The SONAME entry will
 579      reference libc.so.1.  If we have already included libc.so, we
 580      don't want to include libc.so.1 if they are the same file, and we
 581      can only check that using stat.  */
 582
 583   if (bfd_stat (abfd, &global_stat) != 0)
 584     einfo ("%F%P:%B: bfd_stat failed: %E\n", abfd);
 585   global_found = false;
 586   lang_for_each_input_file (gld${EMULATION_NAME}_stat_needed);
 587   if (global_found)
 588     {
 589       /* Return true to indicate that we found the file, even though
 590          we aren't going to do anything with it.  */
 591       return true;
 592     }
 593
 594   /* Tell the ELF backend that don't want the output file to have a
 595      DT_NEEDED entry for this file.  */
 596   bfd_elf_set_dt_needed_name (abfd, "");
 597
 598   /* Add this file into the symbol table.  */
 599   if (! bfd_link_add_symbols (abfd, &link_info))
 600     einfo ("%F%B: could not read symbols: %E\n", abfd);
 601
 602   return true;
 603 }
 604
 605 /* See if an input file matches a DT_NEEDED entry by name.  */
 606
 607 static void
 608 gld${EMULATION_NAME}_check_needed (s)
 609      lang_input_statement_type *s;
 610 {
 611   if (global_found)
 612     return;
 613
 614   if (s->filename != NULL
 615       && strcmp (s->filename, global_needed->name) == 0)
 616     {
 617       global_found = true;
 618       return;
 619     }
 620
 621   if (s->the_bfd != NULL)
 622     {
 623       const char *soname;
 624
 625       soname = bfd_elf_get_dt_soname (s->the_bfd);
 626       if (soname != NULL
 627           && strcmp (soname, global_needed->name) == 0)
 628         {
 629           global_found = true;
 630           return;
 631         }
 632     }
 633
 634   if (s->search_dirs_flag
 635       && s->filename != NULL
 636       && strchr (global_needed->name, '/') == NULL)
 637     {
 638       const char *f;
 639
 640       f = strrchr (s->filename, '/');
 641       if (f != NULL
 642           && strcmp (f + 1, global_needed->name) == 0)
 643         {
 644           global_found = true;
 645           return;
 646         }
 647     }
 648 }
 649
 650 /* See if an input file matches a DT_NEEDED entry by running stat on
 651    the file.  */
 652
 653 static void
 654 gld${EMULATION_NAME}_stat_needed (s)
 655      lang_input_statement_type *s;
 656 {
 657   struct stat st;
 658   const char *suffix;
 659   const char *soname;
 660   const char *f;
 661
 662   if (global_found)
 663     return;
 664   if (s->the_bfd == NULL)
 665     return;
 666
 667   if (bfd_stat (s->the_bfd, &st) != 0)
 668     {
 669       einfo ("%P:%B: bfd_stat failed: %E\n", s->the_bfd);
 670       return;
 671     }
 672
 673   if (st.st_dev == global_stat.st_dev
 674       && st.st_ino == global_stat.st_ino)
 675     {
 676       global_found = true;
 677       return;
 678     }
 679
 680   /* We issue a warning if it looks like we are including two
 681      different versions of the same shared library.  For example,
 682      there may be a problem if -lc picks up libc.so.6 but some other
 683      shared library has a DT_NEEDED entry of libc.so.5.  This is a
 684      hueristic test, and it will only work if the name looks like
 685      NAME.so.VERSION.  FIXME: Depending on file names is error-prone.
 686      If we really want to issue warnings about mixing version numbers
 687      of shared libraries, we need to find a better way.  */
 688
 689   if (strchr (global_needed->name, '/') != NULL)
 690     return;
 691   suffix = strstr (global_needed->name, ".so.");
 692   if (suffix == NULL)
 693     return;
 694   suffix += sizeof ".so." - 1;
 695
 696   soname = bfd_elf_get_dt_soname (s->the_bfd);
 697   if (soname == NULL)
 698     soname = s->filename;
 699
 700   f = strrchr (soname, '/');
 701   if (f != NULL)
 702     ++f;
 703   else
 704     f = soname;
 705
 706   if (strncmp (f, global_needed->name, suffix - global_needed->name) == 0)
 707     einfo ("%P: warning: %s, needed by %B, may conflict with %s\n",
 708            global_needed->name, global_needed->by, f);
 709 }
 710
 711 /* On Linux, it's possible to have different versions of the same
 712    shared library linked against different versions of libc.  The
 713    dynamic linker somehow tags which libc version to use in
 714    /etc/ld.so.cache, and, based on the libc that it sees in the
 715    executable, chooses which version of the shared library to use.
 716
 717    We try to do a similar check here by checking whether this shared
 718    library needs any other shared libraries which may conflict with
 719    libraries we have already included in the link.  If it does, we
 720    skip it, and try to find another shared library farther on down the
 721    link path.
 722
 723    This is called via lang_for_each_input_file.
 724    GLOBAL_VERCHECK_NEEDED is the list of objects needed by the object
 725    which we ar checking.  This sets GLOBAL_VERCHECK_FAILED if we find
 726    a conflicting version.  */
 727
 728 static void
 729 gld${EMULATION_NAME}_vercheck (s)
 730      lang_input_statement_type *s;
 731 {
 732   const char *soname, *f;
 733   struct bfd_link_needed_list *l;
 734
 735   if (global_vercheck_failed)
 736     return;
 737   if (s->the_bfd == NULL
 738       || (bfd_get_file_flags (s->the_bfd) & DYNAMIC) == 0)
 739     return;
 740
 741   soname = bfd_elf_get_dt_soname (s->the_bfd);
 742   if (soname == NULL)
 743     soname = bfd_get_filename (s->the_bfd);
 744
 745   f = strrchr (soname, '/');
 746   if (f != NULL)
 747     ++f;
 748   else
 749     f = soname;
 750
 751   for (l = global_vercheck_needed; l != NULL; l = l->next)
 752     {
 753       const char *suffix;
 754
 755       if (strcmp (f, l->name) == 0)
 756         {
 757           /* Probably can't happen, but it's an easy check.  */
 758           continue;
 759         }
 760
 761       if (strchr (l->name, '/') != NULL)
 762         continue;
 763
 764       suffix = strstr (l->name, ".so.");
 765       if (suffix == NULL)
 766         continue;
 767
 768       suffix += sizeof ".so." - 1;
 769
 770       if (strncmp (f, l->name, suffix - l->name) == 0)
 771         {
 772           /* Here we know that S is a dynamic object FOO.SO.VER1, and
 773              the object we are considering needs a dynamic object
 774              FOO.SO.VER2, and VER1 and VER2 are different.  This
 775              appears to be a version mismatch, so we tell the caller
 776              to try a different version of this library.  */
 777           global_vercheck_failed = true;
 778           return;
 779         }
 780     }
 781 }
 782
 783 /* Place an orphan section.  We use this to put random SHF_ALLOC
 784    sections in the right segment.  */
 785
 786 struct orphan_save
 787 {
 788   lang_output_section_statement_type *os;
 789   asection **section;
 790   lang_statement_union_type **stmt;
 791 };
 792
 793 /*ARGSUSED*/
 794 static boolean
 795 gld${EMULATION_NAME}_place_orphan (file, s)
 796      lang_input_statement_type *file;
 797      asection *s;
 798 {
 799   static struct orphan_save hold_text;
 800   static struct orphan_save hold_rodata;
 801   static struct orphan_save hold_data;
 802   static struct orphan_save hold_bss;
 803   static struct orphan_save hold_rel;
 804   static struct orphan_save hold_interp;
 805   struct orphan_save *place;
 806   lang_statement_list_type *old;
 807   lang_statement_list_type add;
 808   etree_type *address;
 809   const char *secname, *ps;
 810   const char *outsecname;
 811   lang_output_section_statement_type *os;
 812
 813   secname = bfd_get_section_name (s->owner, s);
 814
 815   /* Look through the script to see where to place this section.  */
 816   os = lang_output_section_find (secname);
 817
 818   if (os != NULL
 819       && os->bfd_section != NULL
 820       && ((s->flags ^ os->bfd_section->flags) & (SEC_LOAD | SEC_ALLOC)) == 0)
 821     {
 822       /* We have already placed a section with this name.  */
 823       wild_doit (&os->children, s, os, file);
 824       return true;
 825     }
 826
 827   if (hold_text.os == NULL)
 828     hold_text.os = lang_output_section_find (".text");
 829
 830   /* If this is a final link, then always put .gnu.warning.SYMBOL
 831      sections into the .text section to get them out of the way.  */
 832   if (! link_info.shared
 833       && ! link_info.relocateable
 834       && strncmp (secname, ".gnu.warning.", sizeof ".gnu.warning." - 1) == 0
 835       && hold_text.os != NULL)
 836     {
 837       wild_doit (&hold_text.os->children, s, hold_text.os, file);
 838       return true;
 839     }
 840
 841   /* Decide which segment the section should go in based on the
 842      section name and section flags.  We put loadable .note sections
 843      right after the .interp section, so that the PT_NOTE segment is
 844      stored right after the program headers where the OS can read it
 845      in the first page.  */
 846 #define HAVE_SECTION(hold, name) \
 847 (hold.os != NULL || (hold.os = lang_output_section_find (name)) != NULL)
 848
 849   if (s->flags & SEC_EXCLUDE)
 850     return false;
 851   else if ((s->flags & SEC_ALLOC) == 0)
 852     place = NULL;
 853   else if ((s->flags & SEC_LOAD) != 0
 854            && strncmp (secname, ".note", 4) == 0
 855            && HAVE_SECTION (hold_interp, ".interp"))
 856     place = &hold_interp;
 857   else if ((s->flags & SEC_HAS_CONTENTS) == 0
 858            && HAVE_SECTION (hold_bss, ".bss"))
 859     place = &hold_bss;
 860   else if ((s->flags & SEC_READONLY) == 0
 861            && HAVE_SECTION (hold_data, ".data"))
 862     place = &hold_data;
 863   else if (strncmp (secname, ".rel", 4) == 0
 864            && (hold_rel.os != NULL
 865                || (hold_rel.os = output_rel_find ()) != NULL))
 866     place = &hold_rel;
 867   else if ((s->flags & SEC_CODE) == 0
 868            && (s->flags & SEC_READONLY) != 0
 869            && HAVE_SECTION (hold_rodata, ".rodata"))
 870     place = &hold_rodata;
 871   else if ((s->flags & SEC_READONLY) != 0
 872            && hold_text.os != NULL)
 873     place = &hold_text;
 874   else
 875     place = NULL;
 876
 877 #undef HAVE_SECTION
 878
 879   /* Choose a unique name for the section.  This will be needed if the
 880      same section name appears in the input file with different
 881      loadable or allocateable characteristics.  */
 882   outsecname = secname;
 883   if (bfd_get_section_by_name (output_bfd, outsecname) != NULL)
 884     {
 885       unsigned int len;
 886       char *newname;
 887       unsigned int i;
 888
 889       len = strlen (outsecname);
 890       newname = xmalloc (len + 5);
 891       strcpy (newname, outsecname);
 892       i = 0;
 893       do
 894         {
 895           sprintf (newname + len, "%d", i);
 896           ++i;
 897         }
 898       while (bfd_get_section_by_name (output_bfd, newname) != NULL);
 899
 900       outsecname = newname;
 901     }
 902
 903   if (place != NULL)
 904     {
 905       /* Start building a list of statements for this section.  */
 906       old = stat_ptr;
 907       stat_ptr = &add;
 908       lang_list_init (stat_ptr);
 909
 910       /* If the name of the section is representable in C, then create
 911          symbols to mark the start and the end of the section.  */
 912       for (ps = outsecname; *ps != '\0'; ps++)
 913         if (! isalnum ((unsigned char) *ps) && *ps != '_')
 914           break;
 915       if (*ps == '\0' && config.build_constructors)
 916         {
 917           char *symname;
 918           etree_type *e_align;
 919
 920           symname = (char *) xmalloc (ps - outsecname + sizeof "__start_");
 921           sprintf (symname, "__start_%s", outsecname);
 922           e_align = exp_unop (ALIGN_K,
 923                               exp_intop ((bfd_vma) 1 << s->alignment_power));
 924           lang_add_assignment (exp_assop ('=', symname, e_align));
 925         }
 926     }
 927
 928   if (link_info.relocateable || (s->flags & (SEC_LOAD | SEC_ALLOC)) == 0)
 929     address = exp_intop ((bfd_vma) 0);
 930   else
 931     address = NULL;
 932
 933   os = lang_enter_output_section_statement (outsecname, address, 0,
 934                                             (bfd_vma) 0,
 935                                             (etree_type *) NULL,
 936                                             (etree_type *) NULL,
 937                                             (etree_type *) NULL);
 938
 939   wild_doit (&os->children, s, os, file);
 940
 941   lang_leave_output_section_statement
 942     ((bfd_vma) 0, "*default*",
 943      (struct lang_output_section_phdr_list *) NULL, "*default*");
 944
 945   if (place != NULL)
 946     {
 947       asection *snew, **pps;
 948
 949       stat_ptr = &add;
 950
 951       if (*ps == '\0' && config.build_constructors)
 952         {
 953           char *symname;
 954
 955           symname = (char *) xmalloc (ps - outsecname + sizeof "__stop_");
 956           sprintf (symname, "__stop_%s", outsecname);
 957           lang_add_assignment (exp_assop ('=', symname,
 958                                           exp_nameop (NAME, ".")));
 959         }
 960       stat_ptr = old;
 961
 962       snew = os->bfd_section;
 963       if (place->os->bfd_section != NULL || place->section != NULL)
 964         {
 965           /* Shuffle the section to make the output file look neater.  */
 966           if (place->section == NULL)
 967             {
 968 #if 0
 969               /* Finding the end of the list is a little tricky.  We
 970                  make a wild stab at it by comparing section flags.  */
 971               flagword first_flags = place->os->bfd_section->flags;
 972               for (pps = &place->os->bfd_section->next;
 973                    *pps != NULL && (*pps)->flags == first_flags;
 974                    pps = &(*pps)->next)
 975                 ;
 976               place->section = pps;
 977 #else
 978               /* Put orphans after the first section on the list.  */
 979               place->section = &place->os->bfd_section->next;
 980 #endif
 981             }
 982
 983           /*  Unlink the section.  */
 984           for (pps = &output_bfd->sections; *pps != snew; pps = &(*pps)->next)
 985             ;
 986           *pps = snew->next;
 987
 988           /* Now tack it on to the "place->os" section list.  */
 989           snew->next = *place->section;
 990           *place->section = snew;
 991         }
 992       place->section = &snew->next;     /* Save the end of this list.  */
 993
 994       if (place->stmt == NULL)
 995         {
 996           /* Put the new statement list right at the head.  */
 997           *add.tail = place->os->header.next;
 998           place->os->header.next = add.head;
 999         }
1000       else
1001         {
1002           /* Put it after the last orphan statement we added.  */
1003           *add.tail = *place->stmt;
1004           *place->stmt = add.head;
1005         }
1006       place->stmt = add.tail;           /* Save the end of this list.  */
1007     }
1008
1009   return true;
1010 }
1011
1012 /* A variant of lang_output_section_find.  */
1013 static lang_output_section_statement_type *
1014 output_rel_find ()
1015 {
1016   lang_statement_union_type *u;
1017   lang_output_section_statement_type *lookup;
1018
1019   for (u = lang_output_section_statement.head;
1020        u != (lang_statement_union_type *) NULL;
1021        u = lookup->next)
1022     {
1023       lookup = &u->output_section_statement;
1024       if (strncmp (".rel", lookup->name, 4) == 0
1025           && lookup->bfd_section != NULL
1026           && (lookup->bfd_section->flags & SEC_ALLOC) != 0)
1027         {
1028           return lookup;
1029         }
1030     }
1031   return (lang_output_section_statement_type *) NULL;
1032 }
1033
1034 /* Look through an expression for an assignment statement.  */
1035
1036 static void
1037 gld${EMULATION_NAME}_find_exp_assignment (exp)
1038      etree_type *exp;
1039 {
1040   struct bfd_link_hash_entry *h;
1041
1042   switch (exp->type.node_class)
1043     {
1044     case etree_provide:
1045       h = bfd_link_hash_lookup (link_info.hash, exp->assign.dst,
1046                                 false, false, false);
1047       if (h == NULL)
1048         break;
1049
1050       /* We call record_link_assignment even if the symbol is defined.
1051          This is because if it is defined by a dynamic object, we
1052          actually want to use the value defined by the linker script,
1053          not the value from the dynamic object (because we are setting
1054          symbols like etext).  If the symbol is defined by a regular
1055          object, then, as it happens, calling record_link_assignment
1056          will do no harm.  */
1057
1058       /* Fall through.  */
1059     case etree_assign:
1060       if (strcmp (exp->assign.dst, ".") != 0)
1061         {
1062           if (! (bfd_elf${ELFSIZE}_record_link_assignment
1063                  (output_bfd, &link_info, exp->assign.dst,
1064                   exp->type.node_class == etree_provide ? true : false)))
1065             einfo ("%P%F: failed to record assignment to %s: %E\n",
1066                    exp->assign.dst);
1067         }
1068       gld${EMULATION_NAME}_find_exp_assignment (exp->assign.src);
1069       break;
1070
1071     case etree_binary:
1072       gld${EMULATION_NAME}_find_exp_assignment (exp->binary.lhs);
1073       gld${EMULATION_NAME}_find_exp_assignment (exp->binary.rhs);
1074       break;
1075
1076     case etree_trinary:
1077       gld${EMULATION_NAME}_find_exp_assignment (exp->trinary.cond);
1078       gld${EMULATION_NAME}_find_exp_assignment (exp->trinary.lhs);
1079       gld${EMULATION_NAME}_find_exp_assignment (exp->trinary.rhs);
1080       break;
1081
1082     case etree_unary:
1083       gld${EMULATION_NAME}_find_exp_assignment (exp->unary.child);
1084       break;
1085
1086     default:
1087       break;
1088     }
1089 }
1090
1091 /* This is called by the before_allocation routine via
1092    lang_for_each_statement.  It locates any assignment statements, and
1093    tells the ELF backend about them, in case they are assignments to
1094    symbols which are referred to by dynamic objects.  */
1095
1096 static void
1097 gld${EMULATION_NAME}_find_statement_assignment (s)
1098      lang_statement_union_type *s;
1099 {
1100   if (s->header.type == lang_assignment_statement_enum)
1101     gld${EMULATION_NAME}_find_exp_assignment (s->assignment_statement.exp);
1102 }
1103
1104 /* This is called after the sections have been attached to output
1105    sections, but before any sizes or addresses have been set.  */
1106
1107 static void
1108 gld${EMULATION_NAME}_before_allocation ()
1109 {
1110   const char *rpath;
1111   asection *sinterp;
1112
1113   /* If we are going to make any variable assignments, we need to let
1114      the ELF backend know about them in case the variables are
1115      referred to by dynamic objects.  */
1116   lang_for_each_statement (gld${EMULATION_NAME}_find_statement_assignment);
1117
1118   /* Let the ELF backend work out the sizes of any sections required
1119      by dynamic linking.  */
1120   rpath = command_line.rpath;
1121   if (rpath == NULL)
1122     rpath = (const char *) getenv ("LD_RUN_PATH");
1123   if (! (bfd_elf${ELFSIZE}_size_dynamic_sections
1124          (output_bfd, command_line.soname, rpath,
1125           command_line.export_dynamic, command_line.filter_shlib,
1126           (const char * const *) command_line.auxiliary_filters,
1127           &link_info, &sinterp, lang_elf_version_info)))
1128     einfo ("%P%F: failed to set dynamic section sizes: %E\n");
1129
1130   /* Let the user override the dynamic linker we are using.  */
1131   if (command_line.interpreter != NULL
1132       && sinterp != NULL)
1133     {
1134       sinterp->contents = (bfd_byte *) command_line.interpreter;
1135       sinterp->_raw_size = strlen (command_line.interpreter) + 1;
1136     }
1137
1138   /* Look for any sections named .gnu.warning.  As a GNU extensions,
1139      we treat such sections as containing warning messages.  We print
1140      out the warning message, and then zero out the section size so
1141      that it does not get copied into the output file.  */
1142
1143   {
1144     LANG_FOR_EACH_INPUT_STATEMENT (is)
1145       {
1146         asection *s;
1147         bfd_size_type sz;
1148         char *msg;
1149         boolean ret;
1150
1151         if (is->just_syms_flag)
1152           continue;
1153
1154         s = bfd_get_section_by_name (is->the_bfd, ".gnu.warning");
1155         if (s == NULL)
1156           continue;
1157
1158         sz = bfd_section_size (is->the_bfd, s);
1159         msg = xmalloc ((size_t) sz + 1);
1160         if (! bfd_get_section_contents (is->the_bfd, s, msg, (file_ptr) 0, sz))
1161           einfo ("%F%B: Can't read contents of section .gnu.warning: %E\n",
1162                  is->the_bfd);
1163         msg[sz] = '\0';
1164         ret = link_info.callbacks->warning (&link_info, msg,
1165                                             (const char *) NULL,
1166                                             is->the_bfd, (asection *) NULL,
1167                                             (bfd_vma) 0);
1168         ASSERT (ret);
1169         free (msg);
1170
1171         /* Clobber the section size, so that we don't waste copying the
1172            warning into the output file.  */
1173         s->_raw_size = 0;
1174       }
1175   }
1176
1177   /* we should be able to set the size of the interworking stub section */
1178
1179   /* Here we rummage through the found bfds to collect glue information */
1180   /* FIXME: should this be based on a command line option? krk@cygnus.com */
1181   {
1182     LANG_FOR_EACH_INPUT_STATEMENT (is)
1183       {
1184         if (!bfd_elf32_arm_process_before_allocation (is->the_bfd, & link_info,
1185                                                       no_pipeline_knowledge))
1186           {
1187             /* xgettext:c-format */
1188             einfo (_("Errors encountered processing file %s"), is->filename);
1189           }
1190       }
1191   }
1192
1193   /* We have seen it all. Allocate it, and carry on */
1194   bfd_elf32_arm_allocate_interworking_sections (& link_info);
1195 }
1196
1197 static void
1198 gld${EMULATION_NAME}_finish PARAMS((void))
1199 {
1200   struct bfd_link_hash_entry * h;
1201
1202   if (thumb_entry_symbol == NULL)
1203     return;
1204
1205   h = bfd_link_hash_lookup (link_info.hash, thumb_entry_symbol, false, false, true);
1206
1207   if (h != (struct bfd_link_hash_entry *) NULL
1208       && (h->type == bfd_link_hash_defined
1209           || h->type == bfd_link_hash_defweak)
1210       && h->u.def.section->output_section != NULL)
1211     {
1212       static char buffer[32];
1213       bfd_vma val;
1214
1215       /* Special procesing is required for a Thumb entry symbol.  The
1216          bottom bit of its address must be set.  */
1217       val = (h->u.def.value
1218              + bfd_get_section_vma (output_bfd,
1219                                     h->u.def.section->output_section)
1220              + h->u.def.section->output_offset);
1221
1222       val |= 1;
1223
1224       /* Now convert this value into a string and store it in entry_symbol
1225          where the lang_finish() function will pick it up.  */
1226       buffer[0] = '0';
1227       buffer[1] = 'x';
1228
1229       sprintf_vma (buffer + 2, val);
1230
1231       if (entry_symbol != NULL && entry_from_cmdline)
1232         einfo (_("%P: warning: '--thumb-entry %s' is overriding '-e %s'\n"),
1233                thumb_entry_symbol, entry_symbol);
1234       entry_symbol = buffer;
1235     }
1236   else
1237     einfo (_("%P: warning: connot find thumb start symbol %s\n"), thumb_entry_symbol);
1238 }
1239
1240 static char *
1241 gld${EMULATION_NAME}_get_script (isfile)
1242      int *isfile;
1243 EOF
1244
1245 if test -n "$COMPILE_IN"
1246 then
1247 # Scripts compiled in.
1248
1249 # sed commands to quote an ld script as a C string.
1250 sc="-f stringify.sed"
1251
1252 cat >>e${EMULATION_NAME}.c <<EOF
1253 {
1254   *isfile = 0;
1255
1256   if (link_info.relocateable == true && config.build_constructors == true)
1257     return
1258 EOF
1259 sed $sc ldscripts/${EMULATION_NAME}.xu                     >> e${EMULATION_NAME}.c
1260 echo '  ; else if (link_info.relocateable == true) return' >> e${EMULATION_NAME}.c
1261 sed $sc ldscripts/${EMULATION_NAME}.xr                     >> e${EMULATION_NAME}.c
1262 echo '  ; else if (!config.text_read_only) return'         >> e${EMULATION_NAME}.c
1263 sed $sc ldscripts/${EMULATION_NAME}.xbn                    >> e${EMULATION_NAME}.c
1264 echo '  ; else if (!config.magic_demand_paged) return'     >> e${EMULATION_NAME}.c
1265 sed $sc ldscripts/${EMULATION_NAME}.xn                     >> e${EMULATION_NAME}.c
1266 if test -n "$GENERATE_SHLIB_SCRIPT" ; then
1267         echo '  ; else if (link_info.shared) return'       >> e${EMULATION_NAME}.c
1268         sed $sc ldscripts/${EMULATION_NAME}.xs             >> e${EMULATION_NAME}.c
1269 fi
1270 echo '  ; else return'                                     >> e${EMULATION_NAME}.c
1271 sed $sc ldscripts/${EMULATION_NAME}.x                      >> e${EMULATION_NAME}.c
1272 echo '; }'                                                 >> e${EMULATION_NAME}.c
1273
1274 else
1275 # Scripts read from the filesystem.
1276
1277 cat >>e${EMULATION_NAME}.c <<EOF
1278 {
1279   *isfile = 1;
1280
1281   if (link_info.relocateable == true && config.build_constructors == true)
1282     return "ldscripts/${EMULATION_NAME}.xu";
1283   else if (link_info.relocateable == true)
1284     return "ldscripts/${EMULATION_NAME}.xr";
1285   else if (!config.text_read_only)
1286     return "ldscripts/${EMULATION_NAME}.xbn";
1287   else if (!config.magic_demand_paged)
1288     return "ldscripts/${EMULATION_NAME}.xn";
1289   else if (link_info.shared)
1290     return "ldscripts/${EMULATION_NAME}.xs";
1291   else
1292     return "ldscripts/${EMULATION_NAME}.x";
1293 }
1294 EOF
1295
1296 fi
1297
1298 cat >>e${EMULATION_NAME}.c <<EOF
1299
1300 struct ld_emulation_xfer_struct ld_${EMULATION_NAME}_emulation =
1301 {
1302   gld${EMULATION_NAME}_before_parse,
1303   syslib_default,
1304   hll_default,
1305   after_parse_default,
1306   gld${EMULATION_NAME}_after_open,
1307   after_allocation_default,
1308   set_output_arch_default,
1309   ldemul_default_target,
1310   gld${EMULATION_NAME}_before_allocation,
1311   gld${EMULATION_NAME}_get_script,
1312   "${EMULATION_NAME}",
1313   "${OUTPUT_FORMAT}",
1314   gld${EMULATION_NAME}_finish,
1315   NULL, /* create output section statements */
1316   gld${EMULATION_NAME}_open_dynamic_archive,
1317   gld${EMULATION_NAME}_place_orphan,
1318   NULL, /* set symbols */
1319   gld${EMULATION_NAME}_parse_args,
1320   NULL, /* unrecognized file */
1321   gld${EMULATION_NAME}_list_options,
1322   NULL, /* recognized file */
1323   NULL  /* find_potential_libraries */
1324 };
1325 EOF