collect2.c

GUN开源阻止下的编译器GCC

      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");
	  if (freopen (redir, "a", stderr) == NULL)
	    fatal_perror ("redirecting stderr");
	}

      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;

  /* 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);
  fprintf (stream, "void %s() {\n", initname);
  if (constructors.number > 0)
    {
      fprintf (stream, "\tstatic entry_pt *ctors[] = {\n");
      write_list (stream, "\t\t", constructors.first);
      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);
      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)
    {
      fprintf (stream, "\tstatic entry_pt *dtors[] = {\n");
      write_list (stream, "\t\t", destructors.first);
      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);
    }
  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  */

  fprintf (stream, "typedef void entry_pt();\n\n");
    
  write_list_with_asm (stream, "extern entry_pt ", constructors.first);
    
  fprintf (stream, "\nentry_pt * __CTOR_LIST__[] = {\n");
  fprintf (stream, "\t(entry_pt *) %d,\n", constructors.number);
  write_list (stream, "\t", constructors.first);
  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);
  write_list (stream, "\t", destructors.first);
  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;
{
#ifndef LD_INIT_SWITCH
  if (! shared_obj)
    write_c_file_glob (stream, name);
  else
#endif
    write_c_file_stat (stream, name);
}

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;

	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);

  signal (SIGINT,  int_handler);
#ifdef SIGQUIT
  signal (SIGQUIT, quit_handler);
#endif
}

#if SUNOS4_SHARED_LIBRARIES

/* Routines to scan the SunOS 4 _DYNAMIC structure to find shared libraries
   that the output file depends upon and their initialization/finalization
   routines, if any.  */

#include <a.out.h>
#include <fcntl.h>
#include <link.h>
#include <sys/mman.h>
#include <sys/param.h>
#include <sys/unistd.h>
#include <sys/dir.h>

/* pointers to the object file */
unsigned object;    	/* address of memory mapped file */
unsigned objsize;    	/* size of memory mapped to file */
char * code;		/* pointer to code segment */
char * data;		/* pointer to data segment */
struct nlist *symtab;	/* pointer to symbol table */
struct link_dynamic *ld;
struct link_dynamic_2 *ld_2;
struct head libraries;

/* Map the file indicated by NAME into memory and store its address.  */

static void
mapfile (name)
     char *name;
{
  int fp;
  struct stat s;
  if ((fp = open (name, O_RDONLY)) == -1)
    fatal ("unable to open file '%s'", name);
  if (fstat (fp, &s) == -1)
    fatal ("unable to stat file '%s'", name);

  objsize = s.st_size;
  object = (unsigned) mmap (0, objsize, PROT_READ|PROT_WRITE, MAP_PRIVATE,
			    fp, 0);
  if (object == -1)
    fatal ("unable to mmap file '%s'", name);

  close (fp);
}

/* Helpers for locatelib.  */

static char *libname;

static int
libselect (d)
     struct direct *d;
{
  return (strncmp (libname, d->d_name, strlen (libname)) == 0);
}

/* If one file has an additional numeric extension past LIBNAME, then put
   that one first in the sort.  If both files have additional numeric
   extensions, then put the one with the higher number first in the sort.

   We must verify that the extension is numeric, because Sun saves the
   original versions of patched libraries with a .FCS extension.  Files with
   invalid extensions must go last in the sort, so that they won't be used.  */

static int
libcompare (d1, d2)
     struct direct **d1, **d2;
{
  int i1, i2 = strlen (libname);
  char *e1 = (*d1)->d_name + i2;
  char *e2 = (*d2)->d_name + i2;

  while (*e1 && *e2 && *e1 == '.' && *e2 == '.'
	 && e1[1] && isdigit (e1[1]) && e2[1] && isdigit (e2[1]))
    {
      ++e1;
      ++e2;
      i1 = strtol (e1, &e1, 10);
      i2 = strtol (e2, &e2, 10);
      if (i1 != i2)
	return i1 - i2;
    }

  if (*e1)
    {
      /* It has a valid numeric extension, prefer this one.  */
      if (*e1 == '.' && e1[1] && isdigit (e1[1]))
	return 1;
      /* It has a invalid numeric extension, must prefer the other one.  */
      else
	return -1;
    }
  else if (*e2)
    {
      /* It has a valid numeric extension, prefer this one.  */
      if (*e2 == '.' && e2[1] && isdigit (e2[1]))
	return -1;
      /* It has a invalid numeric extension, must prefer the other one.  */
      else
	return 1;
    }