Finally ``revert'' to the recent pexecute interface, now that we do not need

to support gcc 2.95. Tested on gcc 3 and gcc 4 platforms, riding on the
major bump.

2 files changed, 325 insertions, 772 deletions

diff --git a/gnu/lib/libiberty/src/pexecute.c b/gnu/lib/libiberty/src/pexecute.c
index 347c4db1092..97f157447b7 100644
--- a/gnu/lib/libiberty/src/pexecute.c
+++ b/gnu/lib/libiberty/src/pexecute.c
@@ -1,6 +1,6 @@
 /* Utilities to execute a program in a subprocess (possibly linked by pipes
    with other subprocesses), and wait for it.
-   Copyright (C) 1996-2000 Free Software Foundation, Inc.
+   Copyright (C) 2004 Free Software Foundation, Inc.
 
 This file is part of the libiberty library.
 Libiberty is free software; you can redistribute it and/or
@@ -15,778 +15,110 @@ Library General Public License for more details.
 
 You should have received a copy of the GNU Library General Public
 License along with libiberty; see the file COPYING.LIB.  If not,
-write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
-Boston, MA 02111-1307, USA.  */
+write to the Free Software Foundation, Inc., 51 Franklin Street - Fifth Floor,
+Boston, MA 02110-1301, USA.  */
 
-/* This file exports two functions: pexecute and pwait.  */
+/* pexecute is an old routine.  This implementation uses the newer
+   pex_init/pex_run/pex_get_status/pex_free routines.  Don't use
+   pexecute in new code.  Use the newer routines instead.  */
 
-/* This file lives in at least two places: libiberty and gcc.
-   Don't change one without the other.  */
-
-#ifdef HAVE_CONFIG_H
 #include "config.h"
-#endif
+#include "libiberty.h"
 
-#include <stdio.h>
-#include <errno.h>
-#ifdef NEED_DECLARATION_ERRNO
-extern int errno;
-#endif
-#ifdef HAVE_STRING_H
-#include <string.h>
-#endif
-#ifdef HAVE_UNISTD_H
-#include <unistd.h>
-#endif
 #ifdef HAVE_STDLIB_H
 #include <stdlib.h>
 #endif
-#ifdef HAVE_SYS_WAIT_H
-#include <sys/wait.h>
-#endif
-
-#include "libiberty.h"
-#include "safe-ctype.h"
-
-/* stdin file number.  */
-#define STDIN_FILE_NO 0
-
-/* stdout file number.  */
-#define STDOUT_FILE_NO 1
-
-/* value of `pipe': port index for reading.  */
-#define READ_PORT 0
-
-/* value of `pipe': port index for writing.  */
-#define WRITE_PORT 1
-
-static char *install_error_msg = "installation problem, cannot exec `%s'";
-
-/* pexecute: execute a program.
-
-@deftypefn Extension int pexecute (const char *@var{program}, char * const *@var{argv}, const char *@var{this_pname}, const char *@var{temp_base}, char **@var{errmsg_fmt}, char **@var{errmsg_arg}, int flags)
-
-Executes a program.
-
-@var{program} and @var{argv} are the arguments to
-@code{execv}/@code{execvp}.
-
-@var{this_pname} is name of the calling program (i.e., @code{argv[0]}).
-
-@var{temp_base} is the path name, sans suffix, of a temporary file to
-use if needed.  This is currently only needed for MS-DOS ports that
-don't use @code{go32} (do any still exist?).  Ports that don't need it
-can pass @code{NULL}.
-
-(@code{@var{flags} & PEXECUTE_SEARCH}) is non-zero if @env{PATH} should be searched
-(??? It's not clear that GCC passes this flag correctly).  (@code{@var{flags} &
-PEXECUTE_FIRST}) is nonzero for the first process in chain.
-(@code{@var{flags} & PEXECUTE_FIRST}) is nonzero for the last process
-in chain.  The first/last flags could be simplified to only mark the
-last of a chain of processes but that requires the caller to always
-mark the last one (and not give up early if some error occurs).
-It's more robust to require the caller to mark both ends of the chain.
-
-The result is the pid on systems like Unix where we
-@code{fork}/@code{exec} and on systems like WIN32 and OS/2 where we
-use @code{spawn}.  It is up to the caller to wait for the child.
-
-The result is the @code{WEXITSTATUS} on systems like MS-DOS where we
-@code{spawn} and wait for the child here.
-
-Upon failure, @var{errmsg_fmt} and @var{errmsg_arg} are set to the
-text of the error message with an optional argument (if not needed,
-@var{errmsg_arg} is set to @code{NULL}), and @minus{}1 is returned.
-@code{errno} is available to the caller to use.
-
-@end deftypefn
-
-@deftypefn Extension int pwait (int @var{pid}, int *@var{status}, int @var{flags})
 
-Waits for a program started by @code{pexecute} to finish.
+/* We only permit a single pexecute chain to execute at a time.  This
+   was always true anyhow, though it wasn't documented.  */
 
-@var{pid} is the process id of the task to wait for. @var{status} is
-the `status' argument to wait. @var{flags} is currently unused (allows
-future enhancement without breaking upward compatibility).  Pass 0 for now.
-
-The result is the pid of the child reaped, or -1 for failure
-(@code{errno} says why).
-
-On systems that don't support waiting for a particular child, @var{pid} is
-ignored.  On systems like MS-DOS that don't really multitask @code{pwait}
-is just a mechanism to provide a consistent interface for the caller.
-
-@end deftypefn
-
-@undocumented pfinish
-
-   pfinish: finish generation of script
-
-   pfinish is necessary for systems like MPW where a script is generated that
-   runs the requested programs.  */
-
-#ifdef __MSDOS__
-
-/* MSDOS doesn't multitask, but for the sake of a consistent interface
-   the code behaves like it does.  pexecute runs the program, tucks the
-   exit code away, and returns a "pid".  pwait must be called to fetch the
-   exit code.  */
-
-#include <process.h>
-
-/* For communicating information from pexecute to pwait.  */
-static int last_pid = 0;
-static int last_status = 0;
-static int last_reaped = 0;
+static struct pex_obj *pex;
+static int idx;
 
 int
-pexecute (program, argv, this_pname, temp_base, errmsg_fmt, errmsg_arg, flags)
-     const char *program;
-     char * const *argv;
-     const char *this_pname;
-     const char *temp_base;
-     char **errmsg_fmt, **errmsg_arg;
-     int flags;
+pexecute (const char *program, char * const *argv, const char *pname,
+	  const char *temp_base, char **errmsg_fmt, char **errmsg_arg,
+	  int flags)
 {
-  int rc;
-
-  last_pid++;
-  if (last_pid < 0)
-    last_pid = 1;
-
-  if ((flags & PEXECUTE_ONE) != PEXECUTE_ONE)
-    abort ();
-
-#ifdef __DJGPP__
-  /* ??? What are the possible return values from spawnv?  */
-  rc = (flags & PEXECUTE_SEARCH ? spawnvp : spawnv) (P_WAIT, program, argv);
-#else
-  char *scmd, *rf;
-  FILE *argfile;
-  int i, el = flags & PEXECUTE_SEARCH ? 4 : 0;
+  const char *errmsg;
+  int err;
 
-  if (temp_base == 0)
-    temp_base = choose_temp_base ();
-  scmd = (char *) xmalloc (strlen (program) + strlen (temp_base) + 6 + el);
-  rf = scmd + strlen(program) + 2 + el;
-  sprintf (scmd, "%s%s @%s.gp", program,
-	   (flags & PEXECUTE_SEARCH ? ".exe" : ""), temp_base);
-  argfile = fopen (rf, "w");
-  if (argfile == 0)
+  if ((flags & PEXECUTE_FIRST) != 0)
     {
-      int errno_save = errno;
-      free (scmd);
-      errno = errno_save;
-      *errmsg_fmt = "cannot open `%s.gp'";
-      *errmsg_arg = temp_base;
-      return -1;
-    }
-
-  for (i=1; argv[i]; i++)
-    {
-      char *cp;
-      for (cp = argv[i]; *cp; cp++)
+      if (pex != NULL)
 	{
-	  if (*cp == '"' || *cp == '\'' || *cp == '\\' || ISSPACE (*cp))
-	    fputc ('\\', argfile);
-	  fputc (*cp, argfile);
-	}
-      fputc ('\n', argfile);
-    }
-  fclose (argfile);
-
-  rc = system (scmd);
-
-  {
-    int errno_save = errno;
-    remove (rf);
-    free (scmd);
-    errno = errno_save;
-  }
-#endif
-
-  if (rc == -1)
-    {
-      *errmsg_fmt = install_error_msg;
-      *errmsg_arg = (char *)program;
-      return -1;
-    }
-
-  /* Tuck the status away for pwait, and return a "pid".  */
-  last_status = rc << 8;
-  return last_pid;
-}
-
-/* Use ECHILD if available, otherwise use EINVAL.  */
-#ifdef ECHILD
-#define PWAIT_ERROR ECHILD
-#else
-#define PWAIT_ERROR EINVAL
-#endif
-
-int
-pwait (pid, status, flags)
-     int pid;
-     int *status;
-     int flags;
-{
-  /* On MSDOS each pexecute must be followed by it's associated pwait.  */
-  if (pid != last_pid
-      /* Called twice for the same child?  */
-      || pid == last_reaped)
-    {
-      errno = PWAIT_ERROR;
-      return -1;
-    }
-  /* ??? Here's an opportunity to canonicalize the values in STATUS.
-     Needed?  */
-#ifdef __DJGPP__
-  *status = (last_status >> 8);
-#else
-  *status = last_status;
-#endif
-  last_reaped = last_pid;
-  return last_pid;
-}
-
-#endif /* MSDOS */
-
-#if defined (_WIN32) && ! defined (_UWIN)
-
-#include <process.h>
-
-#ifdef __CYGWIN__
-
-#define fix_argv(argvec) (argvec)
-
-extern int _spawnv ();
-extern int _spawnvp ();
-
-#else /* ! __CYGWIN__ */
-
-/* This is a kludge to get around the Microsoft C spawn functions' propensity
-   to remove the outermost set of double quotes from all arguments.  */
-
-static const char * const *
-fix_argv (argvec)
-     char **argvec;
-{
-  int i;
-
-  for (i = 1; argvec[i] != 0; i++)
-    {
-      int len, j;
-      char *temp, *newtemp;
-
-      temp = argvec[i];
-      len = strlen (temp);
-      for (j = 0; j < len; j++)
-        {
-          if (temp[j] == '"')
-            {
-              newtemp = xmalloc (len + 2);
-              strncpy (newtemp, temp, j);
-              newtemp [j] = '\\';
-              strncpy (&newtemp [j+1], &temp [j], len-j);
-              newtemp [len+1] = 0;
-              temp = newtemp;
-              len++;
-              j++;
-            }
-        }
-
-        argvec[i] = temp;
-      }
-
-  for (i = 0; argvec[i] != 0; i++)
-    {
-      if (strpbrk (argvec[i], " \t"))
-        {
-	  int len, trailing_backslash;
-	  char *temp;
-
-	  len = strlen (argvec[i]);
-	  trailing_backslash = 0;
-
-	  /* There is an added complication when an arg with embedded white
-	     space ends in a backslash (such as in the case of -iprefix arg
-	     passed to cpp). The resulting quoted strings gets misinterpreted
-	     by the command interpreter -- it thinks that the ending quote
-	     is escaped by the trailing backslash and things get confused. 
-	     We handle this case by escaping the trailing backslash, provided
-	     it was not escaped in the first place.  */
-	  if (len > 1 
-	      && argvec[i][len-1] == '\\' 
-	      && argvec[i][len-2] != '\\')
-	    {
-	      trailing_backslash = 1;
-	      ++len;			/* to escape the final backslash. */
-	    }
-
-	  len += 2;			/* and for the enclosing quotes. */
-
-	  temp = xmalloc (len + 1);
-	  temp[0] = '"';
-	  strcpy (temp + 1, argvec[i]);
-	  if (trailing_backslash)
-	    temp[len-2] = '\\';
-	  temp[len-1] = '"';
-	  temp[len] = '\0';
-
-	  argvec[i] = temp;
+	  *errmsg_fmt = (char *) "pexecute already in progress";
+	  *errmsg_arg = NULL;
+	  return -1;
 	}
+      pex = pex_init (PEX_USE_PIPES, pname, temp_base);
+      idx = 0;
     }
-
-  return (const char * const *) argvec;
-}
-#endif /* __CYGWIN__ */
-
-#include <io.h>
-#include <fcntl.h>
-#include <signal.h>
-
-/* mingw32 headers may not define the following.  */
-
-#ifndef _P_WAIT
-#  define _P_WAIT	0
-#  define _P_NOWAIT	1
-#  define _P_OVERLAY	2
-#  define _P_NOWAITO	3
-#  define _P_DETACH	4
-
-#  define WAIT_CHILD	0
-#  define WAIT_GRANDCHILD	1
-#endif
-
-/* Win32 supports pipes */
-int
-pexecute (program, argv, this_pname, temp_base, errmsg_fmt, errmsg_arg, flags)
-     const char *program;
-     char * const *argv;
-     const char *this_pname;
-     const char *temp_base;
-     char **errmsg_fmt, **errmsg_arg;
-     int flags;
-{
-  int pid;
-  int pdes[2], org_stdin, org_stdout;
-  int input_desc, output_desc;
-  int retries, sleep_interval;
-
-  /* Pipe waiting from last process, to be used as input for the next one.
-     Value is STDIN_FILE_NO if no pipe is waiting
-     (i.e. the next command is the first of a group).  */
-  static int last_pipe_input;
-
-  /* If this is the first process, initialize.  */
-  if (flags & PEXECUTE_FIRST)
-    last_pipe_input = STDIN_FILE_NO;
-
-  input_desc = last_pipe_input;
-
-  /* If this isn't the last process, make a pipe for its output,
-     and record it as waiting to be the input to the next process.  */
-  if (! (flags & PEXECUTE_LAST))
+  else
     {
-      if (_pipe (pdes, 256, O_BINARY) < 0)
+      if (pex == NULL)
 	{
-	  *errmsg_fmt = "pipe";
+	  *errmsg_fmt = (char *) "pexecute not in progress";
 	  *errmsg_arg = NULL;
 	  return -1;
 	}
-      output_desc = pdes[WRITE_PORT];
-      last_pipe_input = pdes[READ_PORT];
     }
-  else
-    {
-      /* Last process.  */
-      output_desc = STDOUT_FILE_NO;
-      last_pipe_input = STDIN_FILE_NO;
-    }
-
-  if (input_desc != STDIN_FILE_NO)
-    {
-      org_stdin = dup (STDIN_FILE_NO);
-      dup2 (input_desc, STDIN_FILE_NO);
-      close (input_desc); 
-    }
-
-  if (output_desc != STDOUT_FILE_NO)
-    {
-      org_stdout = dup (STDOUT_FILE_NO);
-      dup2 (output_desc, STDOUT_FILE_NO);
-      close (output_desc);
-    }
-
-  pid = (flags & PEXECUTE_SEARCH ? _spawnvp : _spawnv)
-    (_P_NOWAIT, program, fix_argv(argv));
-
-  if (input_desc != STDIN_FILE_NO)
-    {
-      dup2 (org_stdin, STDIN_FILE_NO);
-      close (org_stdin);
-    }
-
-  if (output_desc != STDOUT_FILE_NO)
-    {
-      dup2 (org_stdout, STDOUT_FILE_NO);
-      close (org_stdout);
-    }
-
-  if (pid == -1)
-    {
-      *errmsg_fmt = install_error_msg;
-      *errmsg_arg = program;
-      return -1;
-    }
-
-  return pid;
-}
-
-/* MS CRTDLL doesn't return enough information in status to decide if the
-   child exited due to a signal or not, rather it simply returns an
-   integer with the exit code of the child; eg., if the child exited with 
-   an abort() call and didn't have a handler for SIGABRT, it simply returns
-   with status = 3. We fix the status code to conform to the usual WIF*
-   macros. Note that WIFSIGNALED will never be true under CRTDLL. */
-
-int
-pwait (pid, status, flags)
-     int pid;
-     int *status;
-     int flags;
-{
-#ifdef __CYGWIN__
-  return wait (status);
-#else
-  int termstat;
-
-  pid = _cwait (&termstat, pid, WAIT_CHILD);
-
-  /* ??? Here's an opportunity to canonicalize the values in STATUS.
-     Needed?  */
 
-  /* cwait returns the child process exit code in termstat.
-     A value of 3 indicates that the child caught a signal, but not
-     which one.  Since only SIGABRT, SIGFPE and SIGINT do anything, we
-     report SIGABRT.  */
-  if (termstat == 3)
-    *status = SIGABRT;
-  else
-    *status = (((termstat) & 0xff) << 8);
-
-  return pid;
-#endif /* __CYGWIN__ */
-}
-
-#endif /* _WIN32 && ! _UWIN */
-
-#ifdef OS2
-
-/* ??? Does OS2 have process.h?  */
-extern int spawnv ();
-extern int spawnvp ();
-
-int
-pexecute (program, argv, this_pname, temp_base, errmsg_fmt, errmsg_arg, flags)
-     const char *program;
-     char * const *argv;
-     const char *this_pname;
-     const char *temp_base;
-     char **errmsg_fmt, **errmsg_arg;
-     int flags;
-{
-  int pid;
-
-  if ((flags & PEXECUTE_ONE) != PEXECUTE_ONE)
-    abort ();
-  /* ??? Presumably 1 == _P_NOWAIT.  */
-  pid = (flags & PEXECUTE_SEARCH ? spawnvp : spawnv) (1, program, argv);
-  if (pid == -1)
+  errmsg = pex_run (pex,
+		    (((flags & PEXECUTE_LAST) != 0 ? PEX_LAST : 0)
+		     | ((flags & PEXECUTE_SEARCH) != 0 ? PEX_SEARCH : 0)),
+		    program, argv, NULL, NULL, &err);
+  if (errmsg != NULL)
     {
-      *errmsg_fmt = install_error_msg;
-      *errmsg_arg = program;
+      *errmsg_fmt = (char *) errmsg;
+      *errmsg_arg = NULL;
       return -1;
     }
-  return pid;
-}
 
-int
-pwait (pid, status, flags)
-     int pid;
-     int *status;
-     int flags;
-{
-  /* ??? Here's an opportunity to canonicalize the values in STATUS.
-     Needed?  */
-  int pid = wait (status);
-  return pid;
+  /* Instead of a PID, we just return a one-based index into the
+     status values.  We avoid zero just because the old pexecute would
+     never return it.  */
+  return ++idx;
 }
 
-#endif /* OS2 */
-
-#ifdef MPW
-
-/* MPW pexecute doesn't actually run anything; instead, it writes out
-   script commands that, when run, will do the actual executing.
-
-   For example, in GCC's case, GCC will write out several script commands:
-
-   cpp ...
-   cc1 ...
-   as ...
-   ld ...
-
-   and then exit.  None of the above programs will have run yet.  The task
-   that called GCC will then execute the script and cause cpp,etc. to run.
-   The caller must invoke pfinish before calling exit.  This adds
-   the finishing touches to the generated script.  */
-
-static int first_time = 1;
-
 int
-pexecute (program, argv, this_pname, temp_base, errmsg_fmt, errmsg_arg, flags)
-     const char *program;
-     char * const *argv;
-     const char *this_pname;
-     const char *temp_base;
-     char **errmsg_fmt, **errmsg_arg;
-     int flags;
+pwait (int pid, int *status, int flags ATTRIBUTE_UNUSED)
 {
-  char tmpprogram[255];
-  char *cp, *tmpname;
-  int i;
+  /* The PID returned by pexecute is one-based.  */
+  --pid;
 
-  mpwify_filename (program, tmpprogram);
-  if (first_time)
-    {
-      printf ("Set Failed 0\n");
-      first_time = 0;
-    }
+  if (pex == NULL || pid < 0 || pid >= idx)
+    return -1;
 
-  fputs ("If {Failed} == 0\n", stdout);
-  /* If being verbose, output a copy of the command.  It should be
-     accurate enough and escaped enough to be "clickable".  */
-  if (flags & PEXECUTE_VERBOSE)
+  if (pid == 0 && idx == 1)
     {
-      fputs ("\tEcho ", stdout);
-      fputc ('\'', stdout);
-      fputs (tmpprogram, stdout);
-      fputc ('\'', stdout);
-      fputc (' ', stdout);
-      for (i=1; argv[i]; i++)
-	{
-	  fputc ('\'', stdout);
-	  /* See if we have an argument that needs fixing.  */
-	  if (strchr(argv[i], '/'))
-	    {
-	      tmpname = (char *) xmalloc (256);
-	      mpwify_filename (argv[i], tmpname);
-	      argv[i] = tmpname;
-	    }
-	  for (cp = argv[i]; *cp; cp++)
-	    {
-	      /* Write an Option-d escape char in front of special chars.  */
-	      if (strchr("'+", *cp))
-		fputc ('\266', stdout);
-	      fputc (*cp, stdout);
-	    }
-	  fputc ('\'', stdout);
-	  fputc (' ', stdout);
-	}
-      fputs ("\n", stdout);
+      if (!pex_get_status (pex, 1, status))
+	return -1;
     }
-  fputs ("\t", stdout);
-  fputs (tmpprogram, stdout);
-  fputc (' ', stdout);
-
-  for (i=1; argv[i]; i++)
+  else
     {
-      /* See if we have an argument that needs fixing.  */
-      if (strchr(argv[i], '/'))
-	{
-	  tmpname = (char *) xmalloc (256);
-	  mpwify_filename (argv[i], tmpname);
-	  argv[i] = tmpname;
-	}
-      if (strchr (argv[i], ' '))
-	fputc ('\'', stdout);
-      for (cp = argv[i]; *cp; cp++)
-	{
-	  /* Write an Option-d escape char in front of special chars.  */
-	  if (strchr("'+", *cp))
-	    fputc ('\266', stdout);
-	  fputc (*cp, stdout);
-	}
-      if (strchr (argv[i], ' '))
-	fputc ('\'', stdout);
-      fputc (' ', stdout);
-    }
-
-  fputs ("\n", stdout);
-
-  /* Output commands that arrange to clean up and exit if a failure occurs.
-     We have to be careful to collect the status from the program that was
-     run, rather than some other script command.  Also, we don't exit
-     immediately, since necessary cleanups are at the end of the script.  */
-  fputs ("\tSet TmpStatus {Status}\n", stdout);
-  fputs ("\tIf {TmpStatus} != 0\n", stdout);
-  fputs ("\t\tSet Failed {TmpStatus}\n", stdout);
-  fputs ("\tEnd\n", stdout);
-  fputs ("End\n", stdout);
-
-  /* We're just composing a script, can't fail here.  */
-  return 0;
-}
-
-int
-pwait (pid, status, flags)
-     int pid;
-     int *status;
-     int flags;
-{
-  *status = 0;
-  return 0;
-}
-
-/* Write out commands that will exit with the correct error code
-   if something in the script failed.  */
-
-void
-pfinish ()
-{
-  printf ("\tExit \"{Failed}\"\n");
-}
-
-#endif /* MPW */
-
-/* include for Unix-like environments but not for Dos-like environments */
-#if ! defined (__MSDOS__) && ! defined (OS2) && ! defined (MPW) \
-    && ! (defined (_WIN32) && ! defined (_UWIN))
-
-extern int execv ();
-extern int execvp ();
-
-int
-pexecute (program, argv, this_pname, temp_base, errmsg_fmt, errmsg_arg, flags)
-     const char *program;
-     char * const *argv;
-     const char *this_pname;
-     const char *temp_base ATTRIBUTE_UNUSED;
-     char **errmsg_fmt, **errmsg_arg;
-     int flags;
-{
-  int (*func)() = (flags & PEXECUTE_SEARCH ? execvp : execv);
-  int pid;
-  int pdes[2];
-  int input_desc, output_desc;
-  int retries, sleep_interval;
-  /* Pipe waiting from last process, to be used as input for the next one.
-     Value is STDIN_FILE_NO if no pipe is waiting
-     (i.e. the next command is the first of a group).  */
-  static int last_pipe_input;
-
-  /* If this is the first process, initialize.  */
-  if (flags & PEXECUTE_FIRST)
-    last_pipe_input = STDIN_FILE_NO;
-
-  input_desc = last_pipe_input;
+      int *vector;
 
-  /* If this isn't the last process, make a pipe for its output,
-     and record it as waiting to be the input to the next process.  */
-  if (! (flags & PEXECUTE_LAST))
-    {
-      if (pipe (pdes) < 0)
+      vector = XNEWVEC (int, idx);
+      if (!pex_get_status (pex, idx, vector))
 	{
-	  *errmsg_fmt = "pipe";
-	  *errmsg_arg = NULL;
+	  free (vector);
 	  return -1;
 	}
-      output_desc = pdes[WRITE_PORT];
-      last_pipe_input = pdes[READ_PORT];
-    }
-  else
-    {
-      /* Last process.  */
-      output_desc = STDOUT_FILE_NO;
-      last_pipe_input = STDIN_FILE_NO;
+      *status = vector[pid];
+      free (vector);
     }
 
-  /* Fork a subprocess; wait and retry if it fails.  */
-  sleep_interval = 1;
-  pid = -1;
-  for (retries = 0; retries < 4; retries++)
+  /* Assume that we are done after the caller has retrieved the last
+     exit status.  The original implementation did not require that
+     the exit statuses be retrieved in order, but this implementation
+     does.  */
+  if (pid + 1 == idx)
     {
-      pid = fork ();
-      if (pid >= 0)
-	break;
-      sleep (sleep_interval);
-      sleep_interval *= 2;
+      pex_free (pex);
+      pex = NULL;
+      idx = 0;
     }
 
-  switch (pid)
-    {
-    case -1:
-      *errmsg_fmt = "fork";
-      *errmsg_arg = NULL;
-      return -1;
-
-    case 0: /* child */
-      /* Move the input and output pipes into place, if necessary.  */
-      if (input_desc != STDIN_FILE_NO)
-	{
-	  close (STDIN_FILE_NO);
-	  dup (input_desc);
-	  close (input_desc);
-	}
-      if (output_desc != STDOUT_FILE_NO)
-	{
-	  close (STDOUT_FILE_NO);
-	  dup (output_desc);
-	  close (output_desc);
-	}
-
-      /* Close the parent's descs that aren't wanted here.  */
-      if (last_pipe_input != STDIN_FILE_NO)
-	close (last_pipe_input);
-
-      /* Exec the program.  */
-      (*func) (program, argv);
-
-      fprintf (stderr, "%s: ", this_pname);
-      fprintf (stderr, install_error_msg, program);
-      fprintf (stderr, ": %s\n", xstrerror (errno));
-      exit (-1);
-      /* NOTREACHED */
-      return 0;
-
-    default:
-      /* In the parent, after forking.
-	 Close the descriptors that we made for this child.  */
-      if (input_desc != STDIN_FILE_NO)
-	close (input_desc);
-      if (output_desc != STDOUT_FILE_NO)
-	close (output_desc);
-
-      /* Return child's process number.  */
-      return pid;
-    }
+  return pid + 1;
 }
-
-int
-pwait (pid, status, flags)
-     int pid;
-     int *status;
-     int flags ATTRIBUTE_UNUSED;
-{
-  /* ??? Here's an opportunity to canonicalize the values in STATUS.
-     Needed?  */
-#ifdef VMS
-  pid = waitpid (-1, status, 0);
-#else
-  pid = wait (status);
-#endif
-  return pid;
-}
-
-#endif /* ! __MSDOS__ && ! OS2 && ! MPW && ! (_WIN32 && ! _UWIN) */
diff --git a/gnu/lib/libiberty/src/pexecute.txh b/gnu/lib/libiberty/src/pexecute.txh
index 269f031cc72..ee50de33789 100644
--- a/gnu/lib/libiberty/src/pexecute.txh
+++ b/gnu/lib/libiberty/src/pexecute.txh
@@ -1,63 +1,284 @@
-@deftypefn Extension int pexecute (const char *@var{program}, char * const *@var{argv}, const char *@var{this_pname}, const char *@var{temp_base}, char **@var{errmsg_fmt}, char **@var{errmsg_arg}, int flags)
+@c -*- mode: texinfo -*-
+@deftypefn Extension {struct pex_obj *} pex_init (int @var{flags}, const char *@var{pname}, const char *@var{tempbase})
 
-Executes a program.
+Prepare to execute one or more programs, with standard output of each
+program fed to standard input of the next.  This is a system
+independent interface to execute a pipeline.
 
-@var{program} and @var{argv} are the arguments to
-@code{execv}/@code{execvp}.
+@var{flags} is a bitwise combination of the following:
 
-@var{this_pname} is name of the calling program (i.e., @code{argv[0]}).
+@table @code
 
-@var{temp_base} is the path name, sans suffix, of a temporary file to
-use if needed.  This is currently only needed for MS-DOS ports that
-don't use @code{go32} (do any still exist?).  Ports that don't need it
-can pass @code{NULL}.
+@vindex PEX_RECORD_TIMES
+@item PEX_RECORD_TIMES
+Record subprocess times if possible.
 
-(@code{@var{flags} & PEXECUTE_SEARCH}) is non-zero if @env{PATH}
-should be searched (??? It's not clear that GCC passes this flag
-correctly).  (@code{@var{flags} & PEXECUTE_FIRST}) is nonzero for the
-first process in chain.  (@code{@var{flags} & PEXECUTE_FIRST}) is
-nonzero for the last process in chain.  The first/last flags could be
-simplified to only mark the last of a chain of processes but that
-requires the caller to always mark the last one (and not give up
-early if some error occurs).  It's more robust to require the caller
-to mark both ends of the chain.
+@vindex PEX_USE_PIPES
+@item PEX_USE_PIPES
+Use pipes for communication between processes, if possible.
 
-The result is the pid on systems like Unix where we
-@code{fork}/@code{exec} and on systems like WIN32 and OS/2 where we
-use @code{spawn}.  It is up to the caller to wait for the child.
+@vindex PEX_SAVE_TEMPS
+@item PEX_SAVE_TEMPS
+Don't delete temporary files used for communication between
+processes.
 
-The result is the @code{WEXITSTATUS} on systems like MS-DOS where we
-@code{spawn} and wait for the child here.
+@end table
 
-Upon failure, @var{errmsg_fmt} and @var{errmsg_arg} are set to the
-text of the error message with an optional argument (if not needed,
-@var{errmsg_arg} is set to @code{NULL}), and @minus{}1 is returned.
-@code{errno} is available to the caller to use.
+@var{pname} is the name of program to be executed, used in error
+messages.  @var{tempbase} is a base name to use for any required
+temporary files; it may be @code{NULL} to use a randomly chosen name.
+
+@end deftypefn
+
+@deftypefn Extension {const char *} pex_run (struct pex_obj *@var{obj}, int @var{flags}, const char *@var{executable}, char * const *@var{argv}, const char *@var{outname}, const char *@var{errname}, int *@var{err})
+
+Execute one program in a pipeline.  On success this returns
+@code{NULL}.  On failure it returns an error message, a statically
+allocated string.
+
+@var{obj} is returned by a previous call to @code{pex_init}.
+
+@var{flags} is a bitwise combination of the following:
+
+@table @code
+
+@vindex PEX_LAST
+@item PEX_LAST
+This must be set on the last program in the pipeline.  In particular,
+it should be set when executing a single program.  The standard output
+of the program will be sent to @var{outname}, or, if @var{outname} is
+@code{NULL}, to the standard output of the calling program.  Do @emph{not}
+set this bit if you want to call @code{pex_read_output}
+(described below).  After a call to @code{pex_run} with this bit set,
+@var{pex_run} may no longer be called with the same @var{obj}.
+
+@vindex PEX_SEARCH
+@item PEX_SEARCH
+Search for the program using the user's executable search path.
+
+@vindex PEX_SUFFIX
+@item PEX_SUFFIX
+@var{outname} is a suffix.  See the description of @var{outname},
+below.
+
+@vindex PEX_STDERR_TO_STDOUT
+@item PEX_STDERR_TO_STDOUT
+Send the program's standard error to standard output, if possible.
+
+@vindex PEX_BINARY_INPUT
+@vindex PEX_BINARY_OUTPUT
+@vindex PEX_BINARY_ERROR
+@item PEX_BINARY_INPUT
+@itemx PEX_BINARY_OUTPUT
+@itemx PEX_BINARY_ERROR
+The standard input (output or error) of the program should be read (written) in
+binary mode rather than text mode.  These flags are ignored on systems
+which do not distinguish binary mode and text mode, such as Unix.  For
+proper behavior these flags should match appropriately---a call to
+@code{pex_run} using @code{PEX_BINARY_OUTPUT} should be followed by a
+call using @code{PEX_BINARY_INPUT}.
+
+@vindex PEX_STDERR_TO_PIPE
+@item PEX_STDERR_TO_PIPE
+Send the program's standard error to a pipe, if possible.  This flag
+cannot be specified together with @code{PEX_STDERR_TO_STDOUT}.  This
+flag can be specified only on the last program in pipeline.
+
+@end table
+
+@var{executable} is the program to execute.  @var{argv} is the set of
+arguments to pass to the program; normally @code{@var{argv}[0]} will
+be a copy of @var{executable}.
+
+@var{outname} is used to set the name of the file to use for standard
+output.  There are two cases in which no output file will be used:
+
+@enumerate
+@item
+if @code{PEX_LAST} is not set in @var{flags}, and @code{PEX_USE_PIPES}
+was set in the call to @code{pex_init}, and the system supports pipes
+
+@item
+if @code{PEX_LAST} is set in @var{flags}, and @var{outname} is
+@code{NULL}
+@end enumerate
+
+@noindent
+Otherwise the code will use a file to hold standard
+output.  If @code{PEX_LAST} is not set, this file is considered to be
+a temporary file, and it will be removed when no longer needed, unless
+@code{PEX_SAVE_TEMPS} was set in the call to @code{pex_init}.
+
+There are two cases to consider when setting the name of the file to
+hold standard output.
+
+@enumerate
+@item
+@code{PEX_SUFFIX} is set in @var{flags}.  In this case
+@var{outname} may not be @code{NULL}.  If the @var{tempbase} parameter
+to @code{pex_init} was not @code{NULL}, then the output file name is
+the concatenation of @var{tempbase} and @var{outname}.  If
+@var{tempbase} was @code{NULL}, then the output file name is a random
+file name ending in @var{outname}.
+
+@item
+@code{PEX_SUFFIX} was not set in @var{flags}.  In this
+case, if @var{outname} is not @code{NULL}, it is used as the output
+file name.  If @var{outname} is @code{NULL}, and @var{tempbase} was
+not NULL, the output file name is randomly chosen using
+@var{tempbase}.  Otherwise the output file name is chosen completely
+at random.
+@end enumerate
+
+@var{errname} is the file name to use for standard error output.  If
+it is @code{NULL}, standard error is the same as the caller's.
+Otherwise, standard error is written to the named file.
+
+On an error return, the code sets @code{*@var{err}} to an @code{errno}
+value, or to 0 if there is no relevant @code{errno}.
+
+@end deftypefn
+
+@deftypefn Extension {const char *} pex_run_in_environment (struct pex_obj *@var{obj}, int @var{flags}, const char *@var{executable}, char * const *@var{argv}, char * const *@var{env}, int @var{env_size}, const char *@var{outname}, const char *@var{errname}, int *@var{err})
+
+Execute one program in a pipeline, permitting the environment for the
+program to be specified.  Behaviour and parameters not listed below are
+as for @code{pex_run}.
+
+@var{env} is the environment for the child process, specified as an array of
+character pointers.  Each element of the array should point to a string of the
+form @code{VAR=VALUE}, with the exception of the last element that must be
+@code{NULL}.
+
+@end deftypefn
+
+@deftypefn Extension {FILE *} pex_input_file (struct pex_obj *@var{obj}, int @var{flags}, const char *@var{in_name})
+
+Return a stream for a temporary file to pass to the first program in
+the pipeline as input.
+
+The name of the input file is chosen according to the same rules
+@code{pex_run} uses to choose output file names, based on
+@var{in_name}, @var{obj} and the @code{PEX_SUFFIX} bit in @var{flags}.
+
+Don't call @code{fclose} on the returned stream; the first call to
+@code{pex_run} closes it automatically.
+
+If @var{flags} includes @code{PEX_BINARY_OUTPUT}, open the stream in
+binary mode; otherwise, open it in the default mode.  Including
+@code{PEX_BINARY_OUTPUT} in @var{flags} has no effect on Unix.
+@end deftypefn
+
+@deftypefn Extension {FILE *} pex_input_pipe (struct pex_obj *@var{obj}, int @var{binary})
+
+Return a stream @var{fp} for a pipe connected to the standard input of
+the first program in the pipeline; @var{fp} is opened for writing.
+You must have passed @code{PEX_USE_PIPES} to the @code{pex_init} call
+that returned @var{obj}.
+
+You must close @var{fp} using @code{fclose} yourself when you have
+finished writing data to the pipeline.
+
+The file descriptor underlying @var{fp} is marked not to be inherited
+by child processes.
+
+On systems that do not support pipes, this function returns
+@code{NULL}, and sets @code{errno} to @code{EINVAL}.  If you would
+like to write code that is portable to all systems the @code{pex}
+functions support, consider using @code{pex_input_file} instead.
+
+There are two opportunities for deadlock using
+@code{pex_input_pipe}:
+
+@itemize @bullet
+@item
+Most systems' pipes can buffer only a fixed amount of data; a process
+that writes to a full pipe blocks.  Thus, if you write to @file{fp}
+before starting the first process, you run the risk of blocking when
+there is no child process yet to read the data and allow you to
+continue.  @code{pex_input_pipe} makes no promises about the
+size of the pipe's buffer, so if you need to write any data at all
+before starting the first process in the pipeline, consider using
+@code{pex_input_file} instead.
+
+@item
+Using @code{pex_input_pipe} and @code{pex_read_output} together
+may also cause deadlock.  If the output pipe fills up, so that each
+program in the pipeline is waiting for the next to read more data, and
+you fill the input pipe by writing more data to @var{fp}, then there
+is no way to make progress: the only process that could read data from
+the output pipe is you, but you are blocked on the input pipe.
+
+@end itemize
+
+@end deftypefn
+
+@deftypefn Extension {FILE *} pex_read_output (struct pex_obj *@var{obj}, int @var{binary})
+
+Returns a @code{FILE} pointer which may be used to read the standard
+output of the last program in the pipeline.  When this is used,
+@code{PEX_LAST} should not be used in a call to @code{pex_run}.  After
+this is called, @code{pex_run} may no longer be called with the same
+@var{obj}.  @var{binary} should be non-zero if the file should be
+opened in binary mode.  Don't call @code{fclose} on the returned file;
+it will be closed by @code{pex_free}.
 
 @end deftypefn
 
-@deftypefn Extension int pwait (int @var{pid}, int *@var{status}, int @var{flags})
 
-Waits for a program started by @code{pexecute} to finish.
+@deftypefn Extension int pex_get_status (struct pex_obj *@var{obj}, int @var{count}, int *@var{vector})
 
-@var{pid} is the process id of the task to wait for. @var{status} is
-the `status' argument to wait. @var{flags} is currently unused
-(allows future enhancement without breaking upward compatibility).
-Pass 0 for now.
+Returns the exit status of all programs run using @var{obj}.
+@var{count} is the number of results expected.  The results will be
+placed into @var{vector}.  The results are in the order of the calls
+to @code{pex_run}.  Returns 0 on error, 1 on success.
 
-The result is the pid of the child reaped, or -1 for failure
-(@code{errno} says why).
+@end deftypefn
+
+@deftypefn Extension int pex_get_times (struct pex_obj *@var{obj}, int @var{count}, struct pex_time *@var{vector})
+
+Returns the process execution times of all programs run using
+@var{obj}.  @var{count} is the number of results expected.  The
+results will be placed into @var{vector}.  The results are in the
+order of the calls to @code{pex_run}.  Returns 0 on error, 1 on
+success.
 
-On systems that don't support waiting for a particular child,
-@var{pid} is ignored.  On systems like MS-DOS that don't really
-multitask @code{pwait} is just a mechanism to provide a consistent
-interface for the caller.
+@code{struct pex_time} has the following fields of the type
+@code{unsigned long}: @code{user_seconds},
+@code{user_microseconds}, @code{system_seconds},
+@code{system_microseconds}.  On systems which do not support reporting
+process times, all the fields will be set to @code{0}.
 
 @end deftypefn
 
-@undocumented pfinish
+@deftypefn Extension void pex_free (struct pex_obj @var{obj})
 
-pfinish: finish generation of script
+Clean up and free all data associated with @var{obj}.
+
+@end deftypefn
+
+@deftypefn Extension {const char *} pex_one (int @var{flags}, const char *@var{executable}, char * const *@var{argv}, const char *@var{pname}, const char *@var{outname}, const char *@var{errname}, int *@var{status}, int *@var{err})
+
+An interface to permit the easy execution of a
+single program.  The return value and most of the parameters are as
+for a call to @code{pex_run}.  @var{flags} is restricted to a
+combination of @code{PEX_SEARCH}, @code{PEX_STDERR_TO_STDOUT}, and
+@code{PEX_BINARY_OUTPUT}.  @var{outname} is interpreted as if
+@code{PEX_LAST} were set.  On a successful return, @code{*@var{status}} will
+be set to the exit status of the program.
+
+@end deftypefn
 
-pfinish is necessary for systems like MPW where a script is generated
-that runs the requested programs.
+@deftypefn Extension int pexecute (const char *@var{program}, char * const *@var{argv}, const char *@var{this_pname}, const char *@var{temp_base}, char **@var{errmsg_fmt}, char **@var{errmsg_arg}, int @var{flags})
+
+This is the old interface to execute one or more programs.  It is
+still supported for compatibility purposes, but is no longer
+documented.
+
+@end deftypefn
+
+@deftypefn Extension int pwait (int @var{pid}, int *@var{status}, int @var{flags})
+
+Another part of the old execution interface.
+
+@end deftypefn