* readelf.c (byte_get_little_endian): Comment typo fix.
[binutils.git] / libiberty / pexecute.c
blob347c4db10924737cfebd0cd52c6c37982be4b4d4
1 /* Utilities to execute a program in a subprocess (possibly linked by pipes
2 with other subprocesses), and wait for it.
3 Copyright (C) 1996-2000 Free Software Foundation, Inc.
5 This file is part of the libiberty library.
6 Libiberty is free software; you can redistribute it and/or
7 modify it under the terms of the GNU Library General Public
8 License as published by the Free Software Foundation; either
9 version 2 of the License, or (at your option) any later version.
11 Libiberty is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 Library General Public License for more details.
16 You should have received a copy of the GNU Library General Public
17 License along with libiberty; see the file COPYING.LIB. If not,
18 write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
19 Boston, MA 02111-1307, USA. */
21 /* This file exports two functions: pexecute and pwait. */
23 /* This file lives in at least two places: libiberty and gcc.
24 Don't change one without the other. */
26 #ifdef HAVE_CONFIG_H
27 #include "config.h"
28 #endif
30 #include <stdio.h>
31 #include <errno.h>
32 #ifdef NEED_DECLARATION_ERRNO
33 extern int errno;
34 #endif
35 #ifdef HAVE_STRING_H
36 #include <string.h>
37 #endif
38 #ifdef HAVE_UNISTD_H
39 #include <unistd.h>
40 #endif
41 #ifdef HAVE_STDLIB_H
42 #include <stdlib.h>
43 #endif
44 #ifdef HAVE_SYS_WAIT_H
45 #include <sys/wait.h>
46 #endif
48 #include "libiberty.h"
49 #include "safe-ctype.h"
51 /* stdin file number. */
52 #define STDIN_FILE_NO 0
54 /* stdout file number. */
55 #define STDOUT_FILE_NO 1
57 /* value of `pipe': port index for reading. */
58 #define READ_PORT 0
60 /* value of `pipe': port index for writing. */
61 #define WRITE_PORT 1
63 static char *install_error_msg = "installation problem, cannot exec `%s'";
65 /* pexecute: execute a program.
67 @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)
69 Executes a program.
71 @var{program} and @var{argv} are the arguments to
72 @code{execv}/@code{execvp}.
74 @var{this_pname} is name of the calling program (i.e., @code{argv[0]}).
76 @var{temp_base} is the path name, sans suffix, of a temporary file to
77 use if needed. This is currently only needed for MS-DOS ports that
78 don't use @code{go32} (do any still exist?). Ports that don't need it
79 can pass @code{NULL}.
81 (@code{@var{flags} & PEXECUTE_SEARCH}) is non-zero if @env{PATH} should be searched
82 (??? It's not clear that GCC passes this flag correctly). (@code{@var{flags} &
83 PEXECUTE_FIRST}) is nonzero for the first process in chain.
84 (@code{@var{flags} & PEXECUTE_FIRST}) is nonzero for the last process
85 in chain. The first/last flags could be simplified to only mark the
86 last of a chain of processes but that requires the caller to always
87 mark the last one (and not give up early if some error occurs).
88 It's more robust to require the caller to mark both ends of the chain.
90 The result is the pid on systems like Unix where we
91 @code{fork}/@code{exec} and on systems like WIN32 and OS/2 where we
92 use @code{spawn}. It is up to the caller to wait for the child.
94 The result is the @code{WEXITSTATUS} on systems like MS-DOS where we
95 @code{spawn} and wait for the child here.
97 Upon failure, @var{errmsg_fmt} and @var{errmsg_arg} are set to the
98 text of the error message with an optional argument (if not needed,
99 @var{errmsg_arg} is set to @code{NULL}), and @minus{}1 is returned.
100 @code{errno} is available to the caller to use.
102 @end deftypefn
104 @deftypefn Extension int pwait (int @var{pid}, int *@var{status}, int @var{flags})
106 Waits for a program started by @code{pexecute} to finish.
108 @var{pid} is the process id of the task to wait for. @var{status} is
109 the `status' argument to wait. @var{flags} is currently unused (allows
110 future enhancement without breaking upward compatibility). Pass 0 for now.
112 The result is the pid of the child reaped, or -1 for failure
113 (@code{errno} says why).
115 On systems that don't support waiting for a particular child, @var{pid} is
116 ignored. On systems like MS-DOS that don't really multitask @code{pwait}
117 is just a mechanism to provide a consistent interface for the caller.
119 @end deftypefn
121 @undocumented pfinish
123 pfinish: finish generation of script
125 pfinish is necessary for systems like MPW where a script is generated that
126 runs the requested programs. */
128 #ifdef __MSDOS__
130 /* MSDOS doesn't multitask, but for the sake of a consistent interface
131 the code behaves like it does. pexecute runs the program, tucks the
132 exit code away, and returns a "pid". pwait must be called to fetch the
133 exit code. */
135 #include <process.h>
137 /* For communicating information from pexecute to pwait. */
138 static int last_pid = 0;
139 static int last_status = 0;
140 static int last_reaped = 0;
143 pexecute (program, argv, this_pname, temp_base, errmsg_fmt, errmsg_arg, flags)
144 const char *program;
145 char * const *argv;
146 const char *this_pname;
147 const char *temp_base;
148 char **errmsg_fmt, **errmsg_arg;
149 int flags;
151 int rc;
153 last_pid++;
154 if (last_pid < 0)
155 last_pid = 1;
157 if ((flags & PEXECUTE_ONE) != PEXECUTE_ONE)
158 abort ();
160 #ifdef __DJGPP__
161 /* ??? What are the possible return values from spawnv? */
162 rc = (flags & PEXECUTE_SEARCH ? spawnvp : spawnv) (P_WAIT, program, argv);
163 #else
164 char *scmd, *rf;
165 FILE *argfile;
166 int i, el = flags & PEXECUTE_SEARCH ? 4 : 0;
168 if (temp_base == 0)
169 temp_base = choose_temp_base ();
170 scmd = (char *) xmalloc (strlen (program) + strlen (temp_base) + 6 + el);
171 rf = scmd + strlen(program) + 2 + el;
172 sprintf (scmd, "%s%s @%s.gp", program,
173 (flags & PEXECUTE_SEARCH ? ".exe" : ""), temp_base);
174 argfile = fopen (rf, "w");
175 if (argfile == 0)
177 int errno_save = errno;
178 free (scmd);
179 errno = errno_save;
180 *errmsg_fmt = "cannot open `%s.gp'";
181 *errmsg_arg = temp_base;
182 return -1;
185 for (i=1; argv[i]; i++)
187 char *cp;
188 for (cp = argv[i]; *cp; cp++)
190 if (*cp == '"' || *cp == '\'' || *cp == '\\' || ISSPACE (*cp))
191 fputc ('\\', argfile);
192 fputc (*cp, argfile);
194 fputc ('\n', argfile);
196 fclose (argfile);
198 rc = system (scmd);
201 int errno_save = errno;
202 remove (rf);
203 free (scmd);
204 errno = errno_save;
206 #endif
208 if (rc == -1)
210 *errmsg_fmt = install_error_msg;
211 *errmsg_arg = (char *)program;
212 return -1;
215 /* Tuck the status away for pwait, and return a "pid". */
216 last_status = rc << 8;
217 return last_pid;
220 /* Use ECHILD if available, otherwise use EINVAL. */
221 #ifdef ECHILD
222 #define PWAIT_ERROR ECHILD
223 #else
224 #define PWAIT_ERROR EINVAL
225 #endif
228 pwait (pid, status, flags)
229 int pid;
230 int *status;
231 int flags;
233 /* On MSDOS each pexecute must be followed by it's associated pwait. */
234 if (pid != last_pid
235 /* Called twice for the same child? */
236 || pid == last_reaped)
238 errno = PWAIT_ERROR;
239 return -1;
241 /* ??? Here's an opportunity to canonicalize the values in STATUS.
242 Needed? */
243 #ifdef __DJGPP__
244 *status = (last_status >> 8);
245 #else
246 *status = last_status;
247 #endif
248 last_reaped = last_pid;
249 return last_pid;
252 #endif /* MSDOS */
254 #if defined (_WIN32) && ! defined (_UWIN)
256 #include <process.h>
258 #ifdef __CYGWIN__
260 #define fix_argv(argvec) (argvec)
262 extern int _spawnv ();
263 extern int _spawnvp ();
265 #else /* ! __CYGWIN__ */
267 /* This is a kludge to get around the Microsoft C spawn functions' propensity
268 to remove the outermost set of double quotes from all arguments. */
270 static const char * const *
271 fix_argv (argvec)
272 char **argvec;
274 int i;
276 for (i = 1; argvec[i] != 0; i++)
278 int len, j;
279 char *temp, *newtemp;
281 temp = argvec[i];
282 len = strlen (temp);
283 for (j = 0; j < len; j++)
285 if (temp[j] == '"')
287 newtemp = xmalloc (len + 2);
288 strncpy (newtemp, temp, j);
289 newtemp [j] = '\\';
290 strncpy (&newtemp [j+1], &temp [j], len-j);
291 newtemp [len+1] = 0;
292 temp = newtemp;
293 len++;
294 j++;
298 argvec[i] = temp;
301 for (i = 0; argvec[i] != 0; i++)
303 if (strpbrk (argvec[i], " \t"))
305 int len, trailing_backslash;
306 char *temp;
308 len = strlen (argvec[i]);
309 trailing_backslash = 0;
311 /* There is an added complication when an arg with embedded white
312 space ends in a backslash (such as in the case of -iprefix arg
313 passed to cpp). The resulting quoted strings gets misinterpreted
314 by the command interpreter -- it thinks that the ending quote
315 is escaped by the trailing backslash and things get confused.
316 We handle this case by escaping the trailing backslash, provided
317 it was not escaped in the first place. */
318 if (len > 1
319 && argvec[i][len-1] == '\\'
320 && argvec[i][len-2] != '\\')
322 trailing_backslash = 1;
323 ++len; /* to escape the final backslash. */
326 len += 2; /* and for the enclosing quotes. */
328 temp = xmalloc (len + 1);
329 temp[0] = '"';
330 strcpy (temp + 1, argvec[i]);
331 if (trailing_backslash)
332 temp[len-2] = '\\';
333 temp[len-1] = '"';
334 temp[len] = '\0';
336 argvec[i] = temp;
340 return (const char * const *) argvec;
342 #endif /* __CYGWIN__ */
344 #include <io.h>
345 #include <fcntl.h>
346 #include <signal.h>
348 /* mingw32 headers may not define the following. */
350 #ifndef _P_WAIT
351 # define _P_WAIT 0
352 # define _P_NOWAIT 1
353 # define _P_OVERLAY 2
354 # define _P_NOWAITO 3
355 # define _P_DETACH 4
357 # define WAIT_CHILD 0
358 # define WAIT_GRANDCHILD 1
359 #endif
361 /* Win32 supports pipes */
363 pexecute (program, argv, this_pname, temp_base, errmsg_fmt, errmsg_arg, flags)
364 const char *program;
365 char * const *argv;
366 const char *this_pname;
367 const char *temp_base;
368 char **errmsg_fmt, **errmsg_arg;
369 int flags;
371 int pid;
372 int pdes[2], org_stdin, org_stdout;
373 int input_desc, output_desc;
374 int retries, sleep_interval;
376 /* Pipe waiting from last process, to be used as input for the next one.
377 Value is STDIN_FILE_NO if no pipe is waiting
378 (i.e. the next command is the first of a group). */
379 static int last_pipe_input;
381 /* If this is the first process, initialize. */
382 if (flags & PEXECUTE_FIRST)
383 last_pipe_input = STDIN_FILE_NO;
385 input_desc = last_pipe_input;
387 /* If this isn't the last process, make a pipe for its output,
388 and record it as waiting to be the input to the next process. */
389 if (! (flags & PEXECUTE_LAST))
391 if (_pipe (pdes, 256, O_BINARY) < 0)
393 *errmsg_fmt = "pipe";
394 *errmsg_arg = NULL;
395 return -1;
397 output_desc = pdes[WRITE_PORT];
398 last_pipe_input = pdes[READ_PORT];
400 else
402 /* Last process. */
403 output_desc = STDOUT_FILE_NO;
404 last_pipe_input = STDIN_FILE_NO;
407 if (input_desc != STDIN_FILE_NO)
409 org_stdin = dup (STDIN_FILE_NO);
410 dup2 (input_desc, STDIN_FILE_NO);
411 close (input_desc);
414 if (output_desc != STDOUT_FILE_NO)
416 org_stdout = dup (STDOUT_FILE_NO);
417 dup2 (output_desc, STDOUT_FILE_NO);
418 close (output_desc);
421 pid = (flags & PEXECUTE_SEARCH ? _spawnvp : _spawnv)
422 (_P_NOWAIT, program, fix_argv(argv));
424 if (input_desc != STDIN_FILE_NO)
426 dup2 (org_stdin, STDIN_FILE_NO);
427 close (org_stdin);
430 if (output_desc != STDOUT_FILE_NO)
432 dup2 (org_stdout, STDOUT_FILE_NO);
433 close (org_stdout);
436 if (pid == -1)
438 *errmsg_fmt = install_error_msg;
439 *errmsg_arg = program;
440 return -1;
443 return pid;
446 /* MS CRTDLL doesn't return enough information in status to decide if the
447 child exited due to a signal or not, rather it simply returns an
448 integer with the exit code of the child; eg., if the child exited with
449 an abort() call and didn't have a handler for SIGABRT, it simply returns
450 with status = 3. We fix the status code to conform to the usual WIF*
451 macros. Note that WIFSIGNALED will never be true under CRTDLL. */
454 pwait (pid, status, flags)
455 int pid;
456 int *status;
457 int flags;
459 #ifdef __CYGWIN__
460 return wait (status);
461 #else
462 int termstat;
464 pid = _cwait (&termstat, pid, WAIT_CHILD);
466 /* ??? Here's an opportunity to canonicalize the values in STATUS.
467 Needed? */
469 /* cwait returns the child process exit code in termstat.
470 A value of 3 indicates that the child caught a signal, but not
471 which one. Since only SIGABRT, SIGFPE and SIGINT do anything, we
472 report SIGABRT. */
473 if (termstat == 3)
474 *status = SIGABRT;
475 else
476 *status = (((termstat) & 0xff) << 8);
478 return pid;
479 #endif /* __CYGWIN__ */
482 #endif /* _WIN32 && ! _UWIN */
484 #ifdef OS2
486 /* ??? Does OS2 have process.h? */
487 extern int spawnv ();
488 extern int spawnvp ();
491 pexecute (program, argv, this_pname, temp_base, errmsg_fmt, errmsg_arg, flags)
492 const char *program;
493 char * const *argv;
494 const char *this_pname;
495 const char *temp_base;
496 char **errmsg_fmt, **errmsg_arg;
497 int flags;
499 int pid;
501 if ((flags & PEXECUTE_ONE) != PEXECUTE_ONE)
502 abort ();
503 /* ??? Presumably 1 == _P_NOWAIT. */
504 pid = (flags & PEXECUTE_SEARCH ? spawnvp : spawnv) (1, program, argv);
505 if (pid == -1)
507 *errmsg_fmt = install_error_msg;
508 *errmsg_arg = program;
509 return -1;
511 return pid;
515 pwait (pid, status, flags)
516 int pid;
517 int *status;
518 int flags;
520 /* ??? Here's an opportunity to canonicalize the values in STATUS.
521 Needed? */
522 int pid = wait (status);
523 return pid;
526 #endif /* OS2 */
528 #ifdef MPW
530 /* MPW pexecute doesn't actually run anything; instead, it writes out
531 script commands that, when run, will do the actual executing.
533 For example, in GCC's case, GCC will write out several script commands:
535 cpp ...
536 cc1 ...
537 as ...
538 ld ...
540 and then exit. None of the above programs will have run yet. The task
541 that called GCC will then execute the script and cause cpp,etc. to run.
542 The caller must invoke pfinish before calling exit. This adds
543 the finishing touches to the generated script. */
545 static int first_time = 1;
548 pexecute (program, argv, this_pname, temp_base, errmsg_fmt, errmsg_arg, flags)
549 const char *program;
550 char * const *argv;
551 const char *this_pname;
552 const char *temp_base;
553 char **errmsg_fmt, **errmsg_arg;
554 int flags;
556 char tmpprogram[255];
557 char *cp, *tmpname;
558 int i;
560 mpwify_filename (program, tmpprogram);
561 if (first_time)
563 printf ("Set Failed 0\n");
564 first_time = 0;
567 fputs ("If {Failed} == 0\n", stdout);
568 /* If being verbose, output a copy of the command. It should be
569 accurate enough and escaped enough to be "clickable". */
570 if (flags & PEXECUTE_VERBOSE)
572 fputs ("\tEcho ", stdout);
573 fputc ('\'', stdout);
574 fputs (tmpprogram, stdout);
575 fputc ('\'', stdout);
576 fputc (' ', stdout);
577 for (i=1; argv[i]; i++)
579 fputc ('\'', stdout);
580 /* See if we have an argument that needs fixing. */
581 if (strchr(argv[i], '/'))
583 tmpname = (char *) xmalloc (256);
584 mpwify_filename (argv[i], tmpname);
585 argv[i] = tmpname;
587 for (cp = argv[i]; *cp; cp++)
589 /* Write an Option-d escape char in front of special chars. */
590 if (strchr("'+", *cp))
591 fputc ('\266', stdout);
592 fputc (*cp, stdout);
594 fputc ('\'', stdout);
595 fputc (' ', stdout);
597 fputs ("\n", stdout);
599 fputs ("\t", stdout);
600 fputs (tmpprogram, stdout);
601 fputc (' ', stdout);
603 for (i=1; argv[i]; i++)
605 /* See if we have an argument that needs fixing. */
606 if (strchr(argv[i], '/'))
608 tmpname = (char *) xmalloc (256);
609 mpwify_filename (argv[i], tmpname);
610 argv[i] = tmpname;
612 if (strchr (argv[i], ' '))
613 fputc ('\'', stdout);
614 for (cp = argv[i]; *cp; cp++)
616 /* Write an Option-d escape char in front of special chars. */
617 if (strchr("'+", *cp))
618 fputc ('\266', stdout);
619 fputc (*cp, stdout);
621 if (strchr (argv[i], ' '))
622 fputc ('\'', stdout);
623 fputc (' ', stdout);
626 fputs ("\n", stdout);
628 /* Output commands that arrange to clean up and exit if a failure occurs.
629 We have to be careful to collect the status from the program that was
630 run, rather than some other script command. Also, we don't exit
631 immediately, since necessary cleanups are at the end of the script. */
632 fputs ("\tSet TmpStatus {Status}\n", stdout);
633 fputs ("\tIf {TmpStatus} != 0\n", stdout);
634 fputs ("\t\tSet Failed {TmpStatus}\n", stdout);
635 fputs ("\tEnd\n", stdout);
636 fputs ("End\n", stdout);
638 /* We're just composing a script, can't fail here. */
639 return 0;
643 pwait (pid, status, flags)
644 int pid;
645 int *status;
646 int flags;
648 *status = 0;
649 return 0;
652 /* Write out commands that will exit with the correct error code
653 if something in the script failed. */
655 void
656 pfinish ()
658 printf ("\tExit \"{Failed}\"\n");
661 #endif /* MPW */
663 /* include for Unix-like environments but not for Dos-like environments */
664 #if ! defined (__MSDOS__) && ! defined (OS2) && ! defined (MPW) \
665 && ! (defined (_WIN32) && ! defined (_UWIN))
667 extern int execv ();
668 extern int execvp ();
671 pexecute (program, argv, this_pname, temp_base, errmsg_fmt, errmsg_arg, flags)
672 const char *program;
673 char * const *argv;
674 const char *this_pname;
675 const char *temp_base ATTRIBUTE_UNUSED;
676 char **errmsg_fmt, **errmsg_arg;
677 int flags;
679 int (*func)() = (flags & PEXECUTE_SEARCH ? execvp : execv);
680 int pid;
681 int pdes[2];
682 int input_desc, output_desc;
683 int retries, sleep_interval;
684 /* Pipe waiting from last process, to be used as input for the next one.
685 Value is STDIN_FILE_NO if no pipe is waiting
686 (i.e. the next command is the first of a group). */
687 static int last_pipe_input;
689 /* If this is the first process, initialize. */
690 if (flags & PEXECUTE_FIRST)
691 last_pipe_input = STDIN_FILE_NO;
693 input_desc = last_pipe_input;
695 /* If this isn't the last process, make a pipe for its output,
696 and record it as waiting to be the input to the next process. */
697 if (! (flags & PEXECUTE_LAST))
699 if (pipe (pdes) < 0)
701 *errmsg_fmt = "pipe";
702 *errmsg_arg = NULL;
703 return -1;
705 output_desc = pdes[WRITE_PORT];
706 last_pipe_input = pdes[READ_PORT];
708 else
710 /* Last process. */
711 output_desc = STDOUT_FILE_NO;
712 last_pipe_input = STDIN_FILE_NO;
715 /* Fork a subprocess; wait and retry if it fails. */
716 sleep_interval = 1;
717 pid = -1;
718 for (retries = 0; retries < 4; retries++)
720 pid = fork ();
721 if (pid >= 0)
722 break;
723 sleep (sleep_interval);
724 sleep_interval *= 2;
727 switch (pid)
729 case -1:
730 *errmsg_fmt = "fork";
731 *errmsg_arg = NULL;
732 return -1;
734 case 0: /* child */
735 /* Move the input and output pipes into place, if necessary. */
736 if (input_desc != STDIN_FILE_NO)
738 close (STDIN_FILE_NO);
739 dup (input_desc);
740 close (input_desc);
742 if (output_desc != STDOUT_FILE_NO)
744 close (STDOUT_FILE_NO);
745 dup (output_desc);
746 close (output_desc);
749 /* Close the parent's descs that aren't wanted here. */
750 if (last_pipe_input != STDIN_FILE_NO)
751 close (last_pipe_input);
753 /* Exec the program. */
754 (*func) (program, argv);
756 fprintf (stderr, "%s: ", this_pname);
757 fprintf (stderr, install_error_msg, program);
758 fprintf (stderr, ": %s\n", xstrerror (errno));
759 exit (-1);
760 /* NOTREACHED */
761 return 0;
763 default:
764 /* In the parent, after forking.
765 Close the descriptors that we made for this child. */
766 if (input_desc != STDIN_FILE_NO)
767 close (input_desc);
768 if (output_desc != STDOUT_FILE_NO)
769 close (output_desc);
771 /* Return child's process number. */
772 return pid;
777 pwait (pid, status, flags)
778 int pid;
779 int *status;
780 int flags ATTRIBUTE_UNUSED;
782 /* ??? Here's an opportunity to canonicalize the values in STATUS.
783 Needed? */
784 #ifdef VMS
785 pid = waitpid (-1, status, 0);
786 #else
787 pid = wait (status);
788 #endif
789 return pid;
792 #endif /* ! __MSDOS__ && ! OS2 && ! MPW && ! (_WIN32 && ! _UWIN) */