collect2.c

GCC编译器源代码

  /* If we look for a program in the compiler directories, we just use
     the short name, since these directories are already system-specific.
     But it we look for a took in the system directories, we need to
     qualify the program name with the target machine.  */

  full_ld_suffix
    = xcalloc (strlen (ld_suffix) + strlen (target_machine) + 2, 1);
  strcpy (full_ld_suffix, target_machine);
  strcat (full_ld_suffix, "-");
  strcat (full_ld_suffix, ld_suffix);

  full_real_ld_suffix
    = xcalloc (strlen (real_ld_suffix) + strlen (target_machine) + 2, 1);
  strcpy (full_real_ld_suffix, target_machine);
  strcat (full_real_ld_suffix, "-");
  strcat (full_real_ld_suffix, real_ld_suffix);

#if 0
  full_gld_suffix
    = xcalloc (strlen (gld_suffix) + strlen (target_machine) + 2, 1);
  strcpy (full_gld_suffix, target_machine);
  strcat (full_gld_suffix, "-");
  strcat (full_gld_suffix, gld_suffix);
#endif

  full_nm_suffix
    = xcalloc (strlen (nm_suffix) + strlen (target_machine) + 2, 1);
  strcpy (full_nm_suffix, target_machine);
  strcat (full_nm_suffix, "-");
  strcat (full_nm_suffix, nm_suffix);

  full_gnm_suffix
    = xcalloc (strlen (gnm_suffix) + strlen (target_machine) + 2, 1);
  strcpy (full_gnm_suffix, target_machine);
  strcat (full_gnm_suffix, "-");
  strcat (full_gnm_suffix, gnm_suffix);

#ifdef LDD_SUFFIX
  full_ldd_suffix
    = xcalloc (strlen (ldd_suffix) + strlen (target_machine) + 2, 1);
  strcpy (full_ldd_suffix, target_machine);
  strcat (full_ldd_suffix, "-");
  strcat (full_ldd_suffix, ldd_suffix);
#endif

  full_strip_suffix
    = xcalloc (strlen (strip_suffix) + strlen (target_machine) + 2, 1);
  strcpy (full_strip_suffix, target_machine);
  strcat (full_strip_suffix, "-");
  strcat (full_strip_suffix, strip_suffix);
  
  full_gstrip_suffix
    = xcalloc (strlen (gstrip_suffix) + strlen (target_machine) + 2, 1);
  strcpy (full_gstrip_suffix, target_machine);
  strcat (full_gstrip_suffix, "-");
  strcat (full_gstrip_suffix, gstrip_suffix);
#endif /* CROSS_COMPILE */

  /* Try to discover a valid linker/nm/strip to use.  */

  /* Maybe we know the right file to use (if not cross).  */
#ifdef REAL_LD_FILE_NAME
  ld_file_name = find_a_file (&path, REAL_LD_FILE_NAME);
  if (ld_file_name == 0)
#endif
  /* Search the (target-specific) compiler dirs for ld'.  */
  ld_file_name = find_a_file (&cpath, real_ld_suffix);
  /* Likewise for `collect-ld'.  */
  if (ld_file_name == 0)
    ld_file_name = find_a_file (&cpath, collect_ld_suffix);
  /* Search the compiler directories for `ld'.  We have protection against
     recursive calls in find_a_file.  */
  if (ld_file_name == 0)
    ld_file_name = find_a_file (&cpath, ld_suffix);
  /* Search the ordinary system bin directories
     for `ld' (if native linking) or `TARGET-ld' (if cross).  */
  if (ld_file_name == 0)
    ld_file_name = find_a_file (&path, full_ld_suffix);

  /* If we've invoked ourselves, try again with LD_FILE_NAME.  */

  if (collect_names != 0)
    {
      if (ld_file_name != 0)
	{
	  argv[0] = ld_file_name;
	  execvp (argv[0], argv);
	}
      fatal ("cannot find `ld'");
    }

#ifdef REAL_NM_FILE_NAME
  nm_file_name = find_a_file (&path, REAL_NM_FILE_NAME);
  if (nm_file_name == 0)
#endif
  nm_file_name = find_a_file (&cpath, gnm_suffix);
  if (nm_file_name == 0)
    nm_file_name = find_a_file (&path, full_gnm_suffix);
  if (nm_file_name == 0)
    nm_file_name = find_a_file (&cpath, nm_suffix);
  if (nm_file_name == 0)
    nm_file_name = find_a_file (&path, full_nm_suffix);

#ifdef LDD_SUFFIX
  ldd_file_name = find_a_file (&cpath, ldd_suffix);
  if (ldd_file_name == 0)
    ldd_file_name = find_a_file (&path, full_ldd_suffix);
#endif

#ifdef REAL_STRIP_FILE_NAME
  strip_file_name = find_a_file (&path, REAL_STRIP_FILE_NAME);
  if (strip_file_name == 0)
#endif
  strip_file_name = find_a_file (&cpath, gstrip_suffix);
  if (strip_file_name == 0)
    strip_file_name = find_a_file (&path, full_gstrip_suffix);
  if (strip_file_name == 0)
    strip_file_name = find_a_file (&cpath, strip_suffix);
  if (strip_file_name == 0)
    strip_file_name = find_a_file (&path, full_strip_suffix);

  /* Determine the full path name of the C compiler to use.  */
  c_file_name = getenv ("COLLECT_GCC");
  if (c_file_name == 0)
    {
#ifdef CROSS_COMPILE
      c_file_name = xcalloc (sizeof ("gcc-") + strlen (target_machine) + 1, 1);
      strcpy (c_file_name, target_machine);
      strcat (c_file_name, "-gcc");
#else
      c_file_name = "gcc";
#endif
    }

  p = find_a_file (&cpath, c_file_name);

  /* Here it should be safe to use the system search path since we should have
     already qualified the name of the compiler when it is needed.  */
  if (p == 0)
    p = find_a_file (&path, c_file_name);

  if (p)
    c_file_name = p;

  *ld1++ = *ld2++ = ld_file_name;

  /* Make temp file names.  */
  temp_filename = choose_temp_base ();
  temp_filename_length = strlen (temp_filename);
  c_file = xcalloc (temp_filename_length + sizeof (".c"), 1);
  o_file = xcalloc (temp_filename_length + sizeof (".o"), 1);
  export_file = xmalloc (temp_filename_length + sizeof (".x"));
  ldout = xmalloc (temp_filename_length + sizeof (".ld"));
  sprintf (ldout, "%s.ld", temp_filename);
  sprintf (c_file, "%s.c", temp_filename);
  sprintf (o_file, "%s.o", temp_filename);
  sprintf (export_file, "%s.x", temp_filename);
  *c_ptr++ = c_file_name;
  *c_ptr++ = "-c";
  *c_ptr++ = "-o";
  *c_ptr++ = o_file;

  /* !!! When GCC calls collect2,
     it does not know whether it is calling collect2 or ld.
     So collect2 cannot meaningfully understand any options
     except those ld understands.
     If you propose to make GCC pass some other option,
     just imagine what will happen if ld is really ld!!!  */

  /* Parse arguments.  Remember output file spec, pass the rest to ld.  */
  /* After the first file, put in the c++ rt0.  */

  first_file = 1;
  while ((arg = *++argv) != (char *) 0)
    {
      *ld1++ = *ld2++ = arg;

      if (arg[0] == '-')
	{
	  switch (arg[1])
	    {
	    case 'd':
	      if (!strcmp (arg, "-debug"))
		{
		  debug = 1;
		  vflag = 1;
		  ld1--;
		  ld2--;
		}
	      break;

	    case 'l':
	      if (first_file)
		{
		  /* place o_file BEFORE this argument! */
		  first_file = 0;
		  ld2--;
		  *ld2++ = o_file;
		  *ld2++ = arg;
		}
	      break;

	    case 'o':
	      if (arg[2] == '\0')
		output_file = *ld1++ = *ld2++ = *++argv;
	      else
		output_file = &arg[2];
	      break;

	    case 'r':
	      if (arg[2] == '\0')
		rflag = 1;
	      break;

	    case 's':
	      if (arg[2] == '\0' && do_collecting)
		{
		  /* We must strip after the nm run, otherwise C++ linking
		     won't work.  Thus we strip in the second ld run, or
		     else with strip if there is no second ld run.  */
		  strip_flag = 1;
		  ld1--;
		}
	      break;

	    case 'v':
	      if (arg[2] == '\0')
		vflag = 1;
	      break;
	    }
	}
      else if ((p = rindex (arg, '.')) != (char *) 0
	       && (strcmp (p, ".o") == 0 || strcmp (p, ".a") == 0))
	{
	  if (first_file)
	    {
	      first_file = 0;
	      if (p[1] == 'o')
		*ld2++ = o_file;
	      else
		{
		  /* place o_file BEFORE this argument! */
		  ld2--;
		  *ld2++ = o_file;
		  *ld2++ = arg;
		}
	    }
	  if (p[1] == 'o')
	    *object++ = arg;
	}
    }

  /* Get any options that the upper GCC wants to pass to the sub-GCC.  */
  p = (char *) getenv ("COLLECT_GCC_OPTIONS");
  while (p && *p)
    {
      char *q = extract_string (&p);
      if (*q == '-' && (q[1] == 'm' || q[1] == 'f'))
	*c_ptr++ = obstack_copy0 (&permanent_obstack, q, strlen (q));
      if (strncmp (q, "-shared", sizeof ("shared") - 1) == 0)
	shared_obj = 1;
    }
  obstack_free (&temporary_obstack, temporary_firstobj);
  *c_ptr++ = "-fno-exceptions";

#ifdef COLLECT_EXPORT_LIST
  /* The AIX linker will discard static constructors in object files if
     nothing else in the file is referenced, so look at them first.  */
  while (object_lst < object)
    scan_prog_file (*object_lst++, PASS_OBJ);

  {
    char *buf = alloca (strlen (export_file) + 5);
    sprintf (buf, "-bE:%s", export_file);
    *ld1++ = buf;
    *ld2++ = buf;
    exportf = fopen (export_file, "w");
    if (exportf == (FILE *) 0)
      fatal_perror ("%s", export_file);
    write_export_file (exportf);
    if (fclose (exportf))
      fatal_perror ("closing %s", export_file);
  }
#endif

  *c_ptr++ = c_file;
  *object = *c_ptr = *ld1 = (char *) 0;

  if (vflag)
    {
      fprintf (stderr, "collect2 version %s", version_string);
#ifdef TARGET_VERSION
      TARGET_VERSION;
#endif
      fprintf (stderr, "\n");
    }

  if (debug)
    {
      char *ptr;
      fprintf (stderr, "ld_file_name        = %s\n",
	       (ld_file_name ? ld_file_name : "not found"));
      fprintf (stderr, "c_file_name         = %s\n",
	       (c_file_name ? c_file_name : "not found"));
      fprintf (stderr, "nm_file_name        = %s\n",
	       (nm_file_name ? nm_file_name : "not found"));
#ifdef LDD_SUFFIX
      fprintf (stderr, "ldd_file_name       = %s\n",
	       (ldd_file_name ? ldd_file_name : "not found"));
#endif
      fprintf (stderr, "strip_file_name     = %s\n",
	       (strip_file_name ? strip_file_name : "not found"));
      fprintf (stderr, "c_file              = %s\n",
	       (c_file ? c_file : "not found"));
      fprintf (stderr, "o_file              = %s\n",
	       (o_file ? o_file : "not found"));

      ptr = getenv ("COLLECT_NAMES");
      if (ptr)
	fprintf (stderr, "COLLECT_NAMES       = %s\n", ptr);

      ptr = getenv ("COLLECT_GCC_OPTIONS");
      if (ptr)
	fprintf (stderr, "COLLECT_GCC_OPTIONS = %s\n", ptr);

      ptr = getenv ("COLLECT_GCC");
      if (ptr)
	fprintf (stderr, "COLLECT_GCC         = %s\n", ptr);

      ptr = getenv ("COMPILER_PATH");
      if (ptr)
	fprintf (stderr, "COMPILER_PATH       = %s\n", ptr);

      ptr = getenv ("LIBRARY_PATH");
      if (ptr)
	fprintf (stderr, "LIBRARY_PATH        = %s\n", ptr);

      fprintf (stderr, "\n");
    }

  /* Load the program, searching all libraries.  */

  collect_execute ("ld", ld1_argv, ldout);
  do_wait ("ld");
  dump_file (ldout);
  unlink (ldout);

  /* If -r or they'll be run via some other method, don't build the
     constructor or destructor list, just return now.  */
  if (rflag || ! do_collecting)
    return 0;

  /* Examine the namelist with nm and search it for static constructors
     and destructors to call.
     Write the constructor and destructor tables to a .s file and reload.  */

  scan_prog_file (output_file, PASS_FIRST);

#ifdef SCAN_LIBRARIES
  scan_libraries (output_file);
#endif

  if (debug)
    {
      fprintf (stderr, "%d constructor(s) found\n", constructors.number);
      fprintf (stderr, "%d destructor(s)  found\n", destructors.number);
    }

  if (constructors.number == 0 && destructors.number == 0
      && frame_tables.number == 0
#ifdef SCAN_LIBRARIES
      /* If we will be running these functions ourselves, we want to emit
	 stubs into the shared library so that we don't have to relink
	 dependent programs when we add static objects.  */
      && ! shared_obj
#endif
      )
    {
      /* Strip now if it was requested on the command line.  */
      if (strip_flag)
	{
	  char **strip_argv = (char **) xcalloc (sizeof (char *), 3);
	  strip_argv[0] = strip_file_name;
	  strip_argv[1] = output_file;
	  strip_argv[2] = (char *) 0;
	  fork_execute ("strip", strip_argv);
	}

#ifdef COLLECT_EXPORT_LIST
      maybe_unlink (export_file);
#endif
      return 0;
    }

  maybe_unlink(output_file);
  outf = fopen (c_file, "w");
  if (outf == (FILE *) 0)
    fatal_perror ("%s", c_file);

  write_c_file (outf, c_file);

  if (fclose (outf))
    fatal_perror ("closing %s", c_file);

  /* Tell the linker that we have initializer and finalizer functions.  */
#ifdef LD_INIT_SWITCH
  *ld2++ = LD_INIT_SWITCH;
  *ld2++ = initname;
  *ld2++ = LD_FINI_SWITCH;
  *ld2++ = fininame;
#endif
  *ld2 = (char*) 0;

#ifdef COLLECT_EXPORT_LIST
  if (shared_obj)
    {
      add_to_list (&exports, initname);
      add_to_list (&exports, fininame);
      add_to_list (&exports, "_GLOBAL__DI");
      add_to_list (&exports, "_GLOBAL__DD");
      exportf = fopen (export_file, "w");
      if (exportf == (FILE *) 0)
	fatal_perror ("%s", export_file);
      write_export_file (exportf);
      if (fclose (exportf))
	fatal_perror ("closing %s", export_file);
    }
#endif

  if (debug)
    {
      fprintf (stderr, "\n========== output_file = %s, c_file = %s\n",
	       output_file, c_file);
      write_c_file (stderr, "stderr");
      fprintf (stderr, "========== end of c_file\n\n");
#ifdef COLLECT_EXPORT_LIST
      fprintf (stderr, "\n========== export_file = %s\n", export_file);
      write_export_file (stderr);
      fprintf (stderr, "========== end of export_file\n\n");
#endif
    }

  /* Assemble the constructor and destructor tables.
     Link the tables in with the rest of the program.  */

  fork_execute ("gcc",  c_argv);
  fork_execute ("ld", ld2_argv);

  /* Let scan_prog_file do any final mods (OSF/rose needs this for
     constructors/destructors in shared libraries.  */
  scan_prog_file (output_file, PASS_SECOND);

  maybe_unlink (c_file);
  maybe_unlink (o_file);
  maybe_unlink (export_file);
  return 0;
}


/* Wait for a process to finish, and exit if a non-zero status is found.  */

int
collect_wait (prog)
     char *prog;
{
  int status;

  wait (&status);
  if (status)
    {
      if (WIFSIGNALED (status))
	{
	  int sig = WTERMSIG (status);
#ifdef NO_SYS_SIGLIST
	  error ("%s terminated with signal %d %s",
		 prog,
		 sig,
		 (status & 0200) ? ", core dumped" : "");
#else
	  error ("%s terminated with signal %d [%s]%s",
		 prog,
		 sig,
		 sys_siglist[sig],
		 (status & 0200) ? ", core dumped" : "");
#endif

	  collect_exit (FATAL_EXIT_CODE);
	}

      if (WIFEXITED (status))
	return WEXITSTATUS (status);
    }
  return 0;
}

static void
do_wait (prog)
     char *prog;
{
  int ret = collect_wait (prog);
  if (ret != 0)
    {
      error ("%s returned %d exit status", prog, ret);
      collect_exit (ret);
    }
}


/* Fork and execute a program, and wait for the reply.  */

void
collect_execute (prog, argv, redir)
     char *prog;
     char **argv;
     char *redir;
{
  int pid;

  if (vflag || debug)
    {
      char **p_argv;
      char *str;

      if (argv[0])
	fprintf (stderr, "%s", argv[0]);
      else