collect2.c

GCC编译器源代码

	fprintf (stderr, "[cannot find %s]", prog);

      for (p_argv = &argv[1]; (str = *p_argv) != (char *) 0; p_argv++)
	fprintf (stderr, " %s", str);

      fprintf (stderr, "\n");
    }

  fflush (stdout);
  fflush (stderr);

  /* If we can't find a program we need, complain error.  Do this here
     since we might not end up needing something that we couldn't find.  */

  if (argv[0] == 0)
    fatal ("cannot find `%s'", prog);

  pid = vfork ();
  if (pid == -1)
    {
#ifdef vfork
      fatal_perror ("fork");
#else
      fatal_perror ("vfork");
#endif
    }

  if (pid == 0)			/* child context */
    {
      if (redir)
	{
	  unlink (redir);
	  if (freopen (redir, "a", stdout) == NULL)
	    fatal_perror ("redirecting stdout: %s", redir);
	  if (freopen (redir, "a", stderr) == NULL)
	    fatal_perror ("redirecting stderr: %s", redir);
	}

      execvp (argv[0], argv);
      fatal_perror ("executing %s", prog);
    }
}

static void
fork_execute (prog, argv)
     char *prog;
     char **argv;
{
  collect_execute (prog, argv, NULL);
  do_wait (prog);
}

/* Unlink a file unless we are debugging.  */

static void
maybe_unlink (file)
     char *file;
{
  if (!debug)
    unlink (file);
  else
    fprintf (stderr, "[Leaving %s]\n", file);
}


/* Add a name to a linked list.  */

static void
add_to_list (head_ptr, name)
     struct head *head_ptr;
     char *name;
{
  struct id *newid
    = (struct id *) xcalloc (sizeof (struct id) + strlen (name), 1);
  struct id *p;
  static long sequence_number = 0;
  strcpy (newid->name, name);

  if (head_ptr->first)
    head_ptr->last->next = newid;
  else
    head_ptr->first = newid;

  /* Check for duplicate symbols.  */
  for (p = head_ptr->first;
       strcmp (name, p->name) != 0;
       p = p->next)
    ;
  if (p != newid)
    {
      head_ptr->last->next = 0;
      free (newid);
      return;
    }

  newid->sequence = ++sequence_number;
  head_ptr->last = newid;
  head_ptr->number++;
}

/* Write: `prefix', the names on list LIST, `suffix'.  */

static void
write_list (stream, prefix, list)
     FILE *stream;
     char *prefix;
     struct id *list;
{
  while (list)
    {
      fprintf (stream, "%sx%d,\n", prefix, list->sequence);
      list = list->next;
    }
}

static void
write_list_with_asm (stream, prefix, list)
     FILE *stream;
     char *prefix;
     struct id *list;
{
  while (list)
    {
      fprintf (stream, "%sx%d __asm__ (\"%s\");\n",
	       prefix, list->sequence, list->name);
      list = list->next;
    }
}

/* Write out the constructor and destructor tables statically (for a shared
   object), along with the functions to execute them.  */

static void
write_c_file_stat (stream, name)
     FILE *stream;
     char *name;
{
  char *prefix, *p, *q;
  int frames = (frame_tables.number > 0);

  /* Figure out name of output_file, stripping off .so version.  */
  p = rindex (output_file, '/');
  if (p == 0)
    p = (char *) output_file;
  else
    p++;
  q = p;
  while (q)
    {
      q = index (q,'.');
      if (q == 0)
	{
	  q = p + strlen (p);
	  break;
	}
      else
	{
	  if (strncmp (q, ".so", 3) == 0)
	    {
	      q += 3;
	      break;
	    }
	  else
	    q++;
	}
    }
  /* q points to null at end of the string (or . of the .so version) */
  prefix = xmalloc (q - p + 1);
  strncpy (prefix, p, q - p);
  prefix[q - p] = 0;
  for (q = prefix; *q; q++)
    if (!isalnum (*q))
      *q = '_';
  if (debug)
    fprintf (stderr, "\nwrite_c_file - output name is %s, prefix is %s\n",
	     output_file, prefix);

#define INIT_NAME_FORMAT "_GLOBAL__FI_%s"
  initname = xmalloc (strlen (prefix) + sizeof (INIT_NAME_FORMAT) - 2);
  sprintf (initname, INIT_NAME_FORMAT, prefix);

#define FINI_NAME_FORMAT "_GLOBAL__FD_%s"
  fininame = xmalloc (strlen (prefix) + sizeof (FINI_NAME_FORMAT) - 2);
  sprintf (fininame, FINI_NAME_FORMAT, prefix);

  free (prefix);

  /* Write the tables as C code  */

  fprintf (stream, "static int count;\n");
  fprintf (stream, "typedef void entry_pt();\n");
  write_list_with_asm (stream, "extern entry_pt ", constructors.first);

  if (frames)
    {
      write_list_with_asm (stream, "extern void *", frame_tables.first);

      fprintf (stream, "\tstatic void *frame_table[] = {\n");
      write_list (stream, "\t\t&", frame_tables.first);
      fprintf (stream, "\t0\n};\n");

      /* This must match what's in frame.h.  */
      fprintf (stream, "struct object {\n");
      fprintf (stream, "  void *pc_begin;\n");
      fprintf (stream, "  void *pc_end;\n");
      fprintf (stream, "  void *fde_begin;\n");
      fprintf (stream, "  void *fde_array;\n");
      fprintf (stream, "  __SIZE_TYPE__ count;\n");
      fprintf (stream, "  struct object *next;\n");
      fprintf (stream, "};\n");

      fprintf (stream, "extern void __register_frame_info_table (void *, struct object *);\n");
      fprintf (stream, "extern void __deregister_frame_info (void *);\n");

      fprintf (stream, "static void reg_frame () {\n");
      fprintf (stream, "\tstatic struct object ob;\n");
      fprintf (stream, "\t__register_frame_info_table (frame_table, &ob);\n");
      fprintf (stream, "\t}\n");

      fprintf (stream, "static void dereg_frame () {\n");
      fprintf (stream, "\t__deregister_frame_info (frame_table);\n");
      fprintf (stream, "\t}\n");
    }

  fprintf (stream, "void %s() {\n", initname);
  if (constructors.number > 0 || frames)
    {
      fprintf (stream, "\tstatic entry_pt *ctors[] = {\n");
      write_list (stream, "\t\t", constructors.first);
      if (frames)
	fprintf (stream, "\treg_frame,\n");
      fprintf (stream, "\t};\n");
      fprintf (stream, "\tentry_pt **p;\n");
      fprintf (stream, "\tif (count++ != 0) return;\n");
      fprintf (stream, "\tp = ctors + %d;\n", constructors.number + frames);
      fprintf (stream, "\twhile (p > ctors) (*--p)();\n");
    }
  else
    fprintf (stream, "\t++count;\n");
  fprintf (stream, "}\n");
  write_list_with_asm (stream, "extern entry_pt ", destructors.first);
  fprintf (stream, "void %s() {\n", fininame);
  if (destructors.number > 0 || frames)
    {
      fprintf (stream, "\tstatic entry_pt *dtors[] = {\n");
      write_list (stream, "\t\t", destructors.first);
      if (frames)
	fprintf (stream, "\tdereg_frame,\n");
      fprintf (stream, "\t};\n");
      fprintf (stream, "\tentry_pt **p;\n");
      fprintf (stream, "\tif (--count != 0) return;\n");
      fprintf (stream, "\tp = dtors;\n");
      fprintf (stream, "\twhile (p < dtors + %d) (*p++)();\n",
	       destructors.number + frames);
    }
  fprintf (stream, "}\n");

  if (shared_obj)
    {
      fprintf (stream, "void _GLOBAL__DI() {\n\t%s();\n}\n", initname);
      fprintf (stream, "void _GLOBAL__DD() {\n\t%s();\n}\n", fininame);
    }
}

/* Write the constructor/destructor tables.  */

static void
write_c_file_glob (stream, name)
     FILE *stream;
     char *name;
{
  /* Write the tables as C code  */

  int frames = (frame_tables.number > 0);

  fprintf (stream, "typedef void entry_pt();\n\n");
    
  write_list_with_asm (stream, "extern entry_pt ", constructors.first);

  if (frames)
    {
      write_list_with_asm (stream, "extern void *", frame_tables.first);

      fprintf (stream, "\tstatic void *frame_table[] = {\n");
      write_list (stream, "\t\t&", frame_tables.first);
      fprintf (stream, "\t0\n};\n");

      /* This must match what's in frame.h.  */
      fprintf (stream, "struct object {\n");
      fprintf (stream, "  void *pc_begin;\n");
      fprintf (stream, "  void *pc_end;\n");
      fprintf (stream, "  void *fde_begin;\n");
      fprintf (stream, "  void *fde_array;\n");
      fprintf (stream, "  __SIZE_TYPE__ count;\n");
      fprintf (stream, "  struct object *next;\n");
      fprintf (stream, "};\n");

      fprintf (stream, "extern void __register_frame_info_table (void *, struct object *);\n");
      fprintf (stream, "extern void __deregister_frame_info (void *);\n");

      fprintf (stream, "static void reg_frame () {\n");
      fprintf (stream, "\tstatic struct object ob;\n");
      fprintf (stream, "\t__register_frame_info_table (frame_table, &ob);\n");
      fprintf (stream, "\t}\n");

      fprintf (stream, "static void dereg_frame () {\n");
      fprintf (stream, "\t__deregister_frame_info (frame_table);\n");
      fprintf (stream, "\t}\n");
    }

  fprintf (stream, "\nentry_pt * __CTOR_LIST__[] = {\n");
  fprintf (stream, "\t(entry_pt *) %d,\n", constructors.number + frames);
  write_list (stream, "\t", constructors.first);
  if (frames)
    fprintf (stream, "\treg_frame,\n");
  fprintf (stream, "\t0\n};\n\n");

  write_list_with_asm (stream, "extern entry_pt ", destructors.first);

  fprintf (stream, "\nentry_pt * __DTOR_LIST__[] = {\n");
  fprintf (stream, "\t(entry_pt *) %d,\n", destructors.number + frames);
  write_list (stream, "\t", destructors.first);
  if (frames)
    fprintf (stream, "\tdereg_frame,\n");
  fprintf (stream, "\t0\n};\n\n");

  fprintf (stream, "extern entry_pt %s;\n", NAME__MAIN);
  fprintf (stream, "entry_pt *__main_reference = %s;\n\n", NAME__MAIN);
}

static void
write_c_file (stream, name)
     FILE *stream;
     char *name;
{
  fprintf (stream, "#ifdef __cplusplus\nextern \"C\" {\n#endif\n");
#ifndef LD_INIT_SWITCH
  if (! shared_obj)
    write_c_file_glob (stream, name);
  else
#endif
    write_c_file_stat (stream, name);
  fprintf (stream, "#ifdef __cplusplus\n}\n#endif\n");
}

static void
write_export_file (stream)
     FILE *stream;
{
  struct id *list = exports.first;
  for (; list; list = list->next)
    fprintf (stream, "%s\n", list->name);
}

#ifdef OBJECT_FORMAT_NONE

/* Generic version to scan the name list of the loaded program for
   the symbols g++ uses for static constructors and destructors.

   The constructor table begins at __CTOR_LIST__ and contains a count
   of the number of pointers (or -1 if the constructors are built in a
   separate section by the linker), followed by the pointers to the
   constructor functions, terminated with a null pointer.  The
   destructor table has the same format, and begins at __DTOR_LIST__.  */

static void
scan_prog_file (prog_name, which_pass)
     char *prog_name;
     enum pass which_pass;
{
  void (*int_handler) ();
  void (*quit_handler) ();
  char *nm_argv[4];
  int pid;
  int argc = 0;
  int pipe_fd[2];
  char *p, buf[1024];
  FILE *inf;

  if (which_pass == PASS_SECOND)
    return;

  /* If we don't have an `nm', complain.  */
  if (nm_file_name == 0)
    fatal ("cannot find `nm'");

  nm_argv[argc++] = nm_file_name;
  if (NM_FLAGS[0] != '\0')
    nm_argv[argc++] = NM_FLAGS;

  nm_argv[argc++] = prog_name;
  nm_argv[argc++] = (char *) 0;

  if (pipe (pipe_fd) < 0)
    fatal_perror ("pipe");

  inf = fdopen (pipe_fd[0], "r");
  if (inf == (FILE *) 0)
    fatal_perror ("fdopen");

  /* Trace if needed.  */
  if (vflag)
    {
      char **p_argv;
      char *str;

      for (p_argv = &nm_argv[0]; (str = *p_argv) != (char *) 0; p_argv++)
	fprintf (stderr, " %s", str);

      fprintf (stderr, "\n");
    }

  fflush (stdout);
  fflush (stderr);

  /* Spawn child nm on pipe */
  pid = vfork ();
  if (pid == -1)
    {
#ifdef vfork
      fatal_perror ("fork");
#else
      fatal_perror ("vfork");
#endif
    }

  if (pid == 0)			/* child context */
    {
      /* setup stdout */
      if (dup2 (pipe_fd[1], 1) < 0)
	fatal_perror ("dup2 (%d, 1)", pipe_fd[1]);

      if (close (pipe_fd[0]) < 0)
	fatal_perror ("close (%d)", pipe_fd[0]);

      if (close (pipe_fd[1]) < 0)
	fatal_perror ("close (%d)", pipe_fd[1]);

      execv (nm_file_name, nm_argv);
      fatal_perror ("executing %s", nm_file_name);
    }

  /* Parent context from here on.  */
  int_handler  = (void (*) ())signal (SIGINT,  SIG_IGN);
#ifdef SIGQUIT
  quit_handler = (void (*) ())signal (SIGQUIT, SIG_IGN);
#endif

  if (close (pipe_fd[1]) < 0)
    fatal_perror ("close (%d)", pipe_fd[1]);

  if (debug)
    fprintf (stderr, "\nnm output with constructors/destructors.\n");

  /* Read each line of nm output.  */
  while (fgets (buf, sizeof buf, inf) != (char *) 0)
    {
      int ch, ch2;
      char *name, *end;

      /* If it contains a constructor or destructor name, add the name
	 to the appropriate list.  */

      for (p = buf; (ch = *p) != '\0' && ch != '\n' && ch != '_'; p++)
	if (ch == ' ' && p[1] == 'U' && p[2] == ' ')
	  break;

      if (ch != '_')
	continue;
  
      name = p;
      /* Find the end of the symbol name.
	 Don't include `|', because Encore nm can tack that on the end.  */
      for (end = p; (ch2 = *end) != '\0' && !isspace (ch2) && ch2 != '|';
	   end++)
	continue;


      *end = '\0';
      switch (is_ctor_dtor (name))
	{
	case 1:
	  if (which_pass != PASS_LIB)
	    add_to_list (&constructors, name);
	  break;

	case 2:
	  if (which_pass != PASS_LIB)
	    add_to_list (&destructors, name);
	  break;

	case 3:
	  if (which_pass != PASS_LIB)
	    fatal ("init function found in object %s", prog_name);
#ifndef LD_INIT_SWITCH
	  add_to_list (&constructors, name);
#endif
	  break;

	case 4:
	  if (which_pass != PASS_LIB)
	    fatal ("fini function found in object %s", prog_name);
#ifndef LD_FINI_SWITCH
	  add_to_list (&destructors, name);
#endif
	  break;

	case 5:
	  if (which_pass != PASS_LIB)
	    add_to_list (&frame_tables, name);

	default:		/* not a constructor or destructor */
	  continue;
	}

      if (debug)
	fprintf (stderr, "\t%s\n", buf);
    }

  if (debug)
    fprintf (stderr, "\n");

  if (fclose (inf) != 0)
    fatal_perror ("fclose of pipe");

  do_wait (nm_file_name);