Daily bump.
[official-gcc.git] / libiberty / pex-unix.c
blob21d5606ce496b397629e9713651d24ca6333cdf1
1 /* Utilities to execute a program in a subprocess (possibly linked by pipes
2 with other subprocesses), and wait for it. Generic Unix version
3 (also used for UWIN and VMS).
4 Copyright (C) 1996-2018 Free Software Foundation, Inc.
6 This file is part of the libiberty library.
7 Libiberty is free software; you can redistribute it and/or
8 modify it under the terms of the GNU Library General Public
9 License as published by the Free Software Foundation; either
10 version 2 of the License, or (at your option) any later version.
12 Libiberty is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 Library General Public License for more details.
17 You should have received a copy of the GNU Library General Public
18 License along with libiberty; see the file COPYING.LIB. If not,
19 write to the Free Software Foundation, Inc., 51 Franklin Street - Fifth Floor,
20 Boston, MA 02110-1301, USA. */
22 #include "config.h"
23 #include "libiberty.h"
24 #include "pex-common.h"
25 #include "environ.h"
27 #include <stdio.h>
28 #include <signal.h>
29 #include <errno.h>
30 #ifdef NEED_DECLARATION_ERRNO
31 extern int errno;
32 #endif
33 #ifdef HAVE_STDLIB_H
34 #include <stdlib.h>
35 #endif
36 #ifdef HAVE_STRING_H
37 #include <string.h>
38 #endif
39 #ifdef HAVE_UNISTD_H
40 #include <unistd.h>
41 #endif
43 #include <sys/types.h>
45 #ifdef HAVE_FCNTL_H
46 #include <fcntl.h>
47 #endif
48 #ifdef HAVE_SYS_WAIT_H
49 #include <sys/wait.h>
50 #endif
51 #ifdef HAVE_GETRUSAGE
52 #include <sys/time.h>
53 #include <sys/resource.h>
54 #endif
55 #ifdef HAVE_SYS_STAT_H
56 #include <sys/stat.h>
57 #endif
58 #ifdef HAVE_PROCESS_H
59 #include <process.h>
60 #endif
62 #ifdef vfork /* Autoconf may define this to fork for us. */
63 # define VFORK_STRING "fork"
64 #else
65 # define VFORK_STRING "vfork"
66 #endif
67 #ifdef HAVE_VFORK_H
68 #include <vfork.h>
69 #endif
70 #if defined(VMS) && defined (__LONG_POINTERS)
71 #ifndef __CHAR_PTR32
72 typedef char * __char_ptr32
73 __attribute__ ((mode (SI)));
74 #endif
76 typedef __char_ptr32 *__char_ptr_char_ptr32
77 __attribute__ ((mode (SI)));
79 /* Return a 32 bit pointer to an array of 32 bit pointers
80 given a 64 bit pointer to an array of 64 bit pointers. */
82 static __char_ptr_char_ptr32
83 to_ptr32 (char **ptr64)
85 int argc;
86 __char_ptr_char_ptr32 short_argv;
88 /* Count number of arguments. */
89 for (argc = 0; ptr64[argc] != NULL; argc++)
92 /* Reallocate argv with 32 bit pointers. */
93 short_argv = (__char_ptr_char_ptr32) decc$malloc
94 (sizeof (__char_ptr32) * (argc + 1));
96 for (argc = 0; ptr64[argc] != NULL; argc++)
97 short_argv[argc] = (__char_ptr32) decc$strdup (ptr64[argc]);
99 short_argv[argc] = (__char_ptr32) 0;
100 return short_argv;
103 #else
104 #define to_ptr32(argv) argv
105 #endif
107 /* File mode to use for private and world-readable files. */
109 #if defined (S_IRUSR) && defined (S_IWUSR) && defined (S_IRGRP) && defined (S_IWGRP) && defined (S_IROTH) && defined (S_IWOTH)
110 #define PUBLIC_MODE \
111 (S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH)
112 #else
113 #define PUBLIC_MODE 0666
114 #endif
116 /* Get the exit status of a particular process, and optionally get the
117 time that it took. This is simple if we have wait4, slightly
118 harder if we have waitpid, and is a pain if we only have wait. */
120 static pid_t pex_wait (struct pex_obj *, pid_t, int *, struct pex_time *);
122 #ifdef HAVE_WAIT4
124 static pid_t
125 pex_wait (struct pex_obj *obj ATTRIBUTE_UNUSED, pid_t pid, int *status,
126 struct pex_time *time)
128 pid_t ret;
129 struct rusage r;
131 #ifdef HAVE_WAITPID
132 if (time == NULL)
133 return waitpid (pid, status, 0);
134 #endif
136 ret = wait4 (pid, status, 0, &r);
138 if (time != NULL)
140 time->user_seconds = r.ru_utime.tv_sec;
141 time->user_microseconds= r.ru_utime.tv_usec;
142 time->system_seconds = r.ru_stime.tv_sec;
143 time->system_microseconds= r.ru_stime.tv_usec;
146 return ret;
149 #else /* ! defined (HAVE_WAIT4) */
151 #ifdef HAVE_WAITPID
153 #ifndef HAVE_GETRUSAGE
155 static pid_t
156 pex_wait (struct pex_obj *obj ATTRIBUTE_UNUSED, pid_t pid, int *status,
157 struct pex_time *time)
159 if (time != NULL)
160 memset (time, 0, sizeof (struct pex_time));
161 return waitpid (pid, status, 0);
164 #else /* defined (HAVE_GETRUSAGE) */
166 static pid_t
167 pex_wait (struct pex_obj *obj ATTRIBUTE_UNUSED, pid_t pid, int *status,
168 struct pex_time *time)
170 struct rusage r1, r2;
171 pid_t ret;
173 if (time == NULL)
174 return waitpid (pid, status, 0);
176 getrusage (RUSAGE_CHILDREN, &r1);
178 ret = waitpid (pid, status, 0);
179 if (ret < 0)
180 return ret;
182 getrusage (RUSAGE_CHILDREN, &r2);
184 time->user_seconds = r2.ru_utime.tv_sec - r1.ru_utime.tv_sec;
185 time->user_microseconds = r2.ru_utime.tv_usec - r1.ru_utime.tv_usec;
186 if (r2.ru_utime.tv_usec < r1.ru_utime.tv_usec)
188 --time->user_seconds;
189 time->user_microseconds += 1000000;
192 time->system_seconds = r2.ru_stime.tv_sec - r1.ru_stime.tv_sec;
193 time->system_microseconds = r2.ru_stime.tv_usec - r1.ru_stime.tv_usec;
194 if (r2.ru_stime.tv_usec < r1.ru_stime.tv_usec)
196 --time->system_seconds;
197 time->system_microseconds += 1000000;
200 return ret;
203 #endif /* defined (HAVE_GETRUSAGE) */
205 #else /* ! defined (HAVE_WAITPID) */
207 struct status_list
209 struct status_list *next;
210 pid_t pid;
211 int status;
212 struct pex_time time;
215 static pid_t
216 pex_wait (struct pex_obj *obj, pid_t pid, int *status, struct pex_time *time)
218 struct status_list **pp;
220 for (pp = (struct status_list **) &obj->sysdep;
221 *pp != NULL;
222 pp = &(*pp)->next)
224 if ((*pp)->pid == pid)
226 struct status_list *p;
228 p = *pp;
229 *status = p->status;
230 if (time != NULL)
231 *time = p->time;
232 *pp = p->next;
233 free (p);
234 return pid;
238 while (1)
240 pid_t cpid;
241 struct status_list *psl;
242 struct pex_time pt;
243 #ifdef HAVE_GETRUSAGE
244 struct rusage r1, r2;
245 #endif
247 if (time != NULL)
249 #ifdef HAVE_GETRUSAGE
250 getrusage (RUSAGE_CHILDREN, &r1);
251 #else
252 memset (&pt, 0, sizeof (struct pex_time));
253 #endif
256 cpid = wait (status);
258 #ifdef HAVE_GETRUSAGE
259 if (time != NULL && cpid >= 0)
261 getrusage (RUSAGE_CHILDREN, &r2);
263 pt.user_seconds = r2.ru_utime.tv_sec - r1.ru_utime.tv_sec;
264 pt.user_microseconds = r2.ru_utime.tv_usec - r1.ru_utime.tv_usec;
265 if (pt.user_microseconds < 0)
267 --pt.user_seconds;
268 pt.user_microseconds += 1000000;
271 pt.system_seconds = r2.ru_stime.tv_sec - r1.ru_stime.tv_sec;
272 pt.system_microseconds = r2.ru_stime.tv_usec - r1.ru_stime.tv_usec;
273 if (pt.system_microseconds < 0)
275 --pt.system_seconds;
276 pt.system_microseconds += 1000000;
279 #endif
281 if (cpid < 0 || cpid == pid)
283 if (time != NULL)
284 *time = pt;
285 return cpid;
288 psl = XNEW (struct status_list);
289 psl->pid = cpid;
290 psl->status = *status;
291 if (time != NULL)
292 psl->time = pt;
293 psl->next = (struct status_list *) obj->sysdep;
294 obj->sysdep = (void *) psl;
298 #endif /* ! defined (HAVE_WAITPID) */
299 #endif /* ! defined (HAVE_WAIT4) */
301 static void pex_child_error (struct pex_obj *, const char *, const char *, int)
302 ATTRIBUTE_NORETURN;
303 static int pex_unix_open_read (struct pex_obj *, const char *, int);
304 static int pex_unix_open_write (struct pex_obj *, const char *, int, int);
305 static pid_t pex_unix_exec_child (struct pex_obj *, int, const char *,
306 char * const *, char * const *,
307 int, int, int, int,
308 const char **, int *);
309 static int pex_unix_close (struct pex_obj *, int);
310 static int pex_unix_wait (struct pex_obj *, pid_t, int *, struct pex_time *,
311 int, const char **, int *);
312 static int pex_unix_pipe (struct pex_obj *, int *, int);
313 static FILE *pex_unix_fdopenr (struct pex_obj *, int, int);
314 static FILE *pex_unix_fdopenw (struct pex_obj *, int, int);
315 static void pex_unix_cleanup (struct pex_obj *);
317 /* The list of functions we pass to the common routines. */
319 const struct pex_funcs funcs =
321 pex_unix_open_read,
322 pex_unix_open_write,
323 pex_unix_exec_child,
324 pex_unix_close,
325 pex_unix_wait,
326 pex_unix_pipe,
327 pex_unix_fdopenr,
328 pex_unix_fdopenw,
329 pex_unix_cleanup
332 /* Return a newly initialized pex_obj structure. */
334 struct pex_obj *
335 pex_init (int flags, const char *pname, const char *tempbase)
337 return pex_init_common (flags, pname, tempbase, &funcs);
340 /* Open a file for reading. */
342 static int
343 pex_unix_open_read (struct pex_obj *obj ATTRIBUTE_UNUSED, const char *name,
344 int binary ATTRIBUTE_UNUSED)
346 return open (name, O_RDONLY);
349 /* Open a file for writing. */
351 static int
352 pex_unix_open_write (struct pex_obj *obj ATTRIBUTE_UNUSED, const char *name,
353 int binary ATTRIBUTE_UNUSED, int append)
355 /* Note that we can't use O_EXCL here because gcc may have already
356 created the temporary file via make_temp_file. */
357 return open (name, O_WRONLY | O_CREAT
358 | (append ? O_APPEND : O_TRUNC), PUBLIC_MODE);
361 /* Close a file. */
363 static int
364 pex_unix_close (struct pex_obj *obj ATTRIBUTE_UNUSED, int fd)
366 return close (fd);
369 /* Report an error from a child process. We don't use stdio routines,
370 because we might be here due to a vfork call. */
372 static void
373 pex_child_error (struct pex_obj *obj, const char *executable,
374 const char *errmsg, int err)
376 int retval = 0;
377 #define writeerr(s) retval |= (write (STDERR_FILE_NO, s, strlen (s)) < 0)
378 writeerr (obj->pname);
379 writeerr (": error trying to exec '");
380 writeerr (executable);
381 writeerr ("': ");
382 writeerr (errmsg);
383 writeerr (": ");
384 writeerr (xstrerror (err));
385 writeerr ("\n");
386 #undef writeerr
387 /* Exit with -2 if the error output failed, too. */
388 _exit (retval == 0 ? -1 : -2);
391 /* Execute a child. */
393 #if defined(HAVE_SPAWNVE) && defined(HAVE_SPAWNVPE)
394 /* Implementation of pex->exec_child using the Cygwin spawn operation. */
396 /* Subroutine of pex_unix_exec_child. Move OLD_FD to a new file descriptor
397 to be stored in *PNEW_FD, save the flags in *PFLAGS, and arrange for the
398 saved copy to be close-on-exec. Move CHILD_FD into OLD_FD. If CHILD_FD
399 is -1, OLD_FD is to be closed. Return -1 on error. */
401 static int
402 save_and_install_fd(int *pnew_fd, int *pflags, int old_fd, int child_fd)
404 int new_fd, flags;
406 flags = fcntl (old_fd, F_GETFD);
408 /* If we could not retrieve the flags, then OLD_FD was not open. */
409 if (flags < 0)
411 new_fd = -1, flags = 0;
412 if (child_fd >= 0 && dup2 (child_fd, old_fd) < 0)
413 return -1;
415 /* If we wish to close OLD_FD, just mark it CLOEXEC. */
416 else if (child_fd == -1)
418 new_fd = old_fd;
419 if ((flags & FD_CLOEXEC) == 0 && fcntl (old_fd, F_SETFD, FD_CLOEXEC) < 0)
420 return -1;
422 /* Otherwise we need to save a copy of OLD_FD before installing CHILD_FD. */
423 else
425 #ifdef F_DUPFD_CLOEXEC
426 new_fd = fcntl (old_fd, F_DUPFD_CLOEXEC, 3);
427 if (new_fd < 0)
428 return -1;
429 #else
430 /* Prefer F_DUPFD over dup in order to avoid getting a new fd
431 in the range 0-2, right where a new stderr fd might get put. */
432 new_fd = fcntl (old_fd, F_DUPFD, 3);
433 if (new_fd < 0)
434 return -1;
435 if (fcntl (new_fd, F_SETFD, FD_CLOEXEC) < 0)
436 return -1;
437 #endif
438 if (dup2 (child_fd, old_fd) < 0)
439 return -1;
442 *pflags = flags;
443 if (pnew_fd)
444 *pnew_fd = new_fd;
445 else if (new_fd != old_fd)
446 abort ();
448 return 0;
451 /* Subroutine of pex_unix_exec_child. Move SAVE_FD back to OLD_FD
452 restoring FLAGS. If SAVE_FD < 0, OLD_FD is to be closed. */
454 static int
455 restore_fd(int old_fd, int save_fd, int flags)
457 /* For SAVE_FD < 0, all we have to do is restore the
458 "closed-ness" of the original. */
459 if (save_fd < 0)
460 return close (old_fd);
462 /* For SAVE_FD == OLD_FD, all we have to do is restore the
463 original setting of the CLOEXEC flag. */
464 if (save_fd == old_fd)
466 if (flags & FD_CLOEXEC)
467 return 0;
468 return fcntl (old_fd, F_SETFD, flags);
471 /* Otherwise we have to move the descriptor back, restore the flags,
472 and close the saved copy. */
473 #ifdef HAVE_DUP3
474 if (flags == FD_CLOEXEC)
476 if (dup3 (save_fd, old_fd, O_CLOEXEC) < 0)
477 return -1;
479 else
480 #endif
482 if (dup2 (save_fd, old_fd) < 0)
483 return -1;
484 if (flags != 0 && fcntl (old_fd, F_SETFD, flags) < 0)
485 return -1;
487 return close (save_fd);
490 static pid_t
491 pex_unix_exec_child (struct pex_obj *obj ATTRIBUTE_UNUSED,
492 int flags, const char *executable,
493 char * const * argv, char * const * env,
494 int in, int out, int errdes, int toclose,
495 const char **errmsg, int *err)
497 int fl_in = 0, fl_out = 0, fl_err = 0, fl_tc = 0;
498 int save_in = -1, save_out = -1, save_err = -1;
499 int max, retries;
500 pid_t pid;
502 if (flags & PEX_STDERR_TO_STDOUT)
503 errdes = out;
505 /* We need the three standard file descriptors to be set up as for
506 the child before we perform the spawn. The file descriptors for
507 the parent need to be moved and marked for close-on-exec. */
508 if (in != STDIN_FILE_NO
509 && save_and_install_fd (&save_in, &fl_in, STDIN_FILE_NO, in) < 0)
510 goto error_dup2;
511 if (out != STDOUT_FILE_NO
512 && save_and_install_fd (&save_out, &fl_out, STDOUT_FILE_NO, out) < 0)
513 goto error_dup2;
514 if (errdes != STDERR_FILE_NO
515 && save_and_install_fd (&save_err, &fl_err, STDERR_FILE_NO, errdes) < 0)
516 goto error_dup2;
517 if (toclose >= 0
518 && save_and_install_fd (NULL, &fl_tc, toclose, -1) < 0)
519 goto error_dup2;
521 /* Now that we've moved the file descriptors for the child into place,
522 close the originals. Be careful not to close any of the standard
523 file descriptors that we just set up. */
524 max = -1;
525 if (errdes >= 0)
526 max = STDERR_FILE_NO;
527 else if (out >= 0)
528 max = STDOUT_FILE_NO;
529 else if (in >= 0)
530 max = STDIN_FILE_NO;
531 if (in > max)
532 close (in);
533 if (out > max)
534 close (out);
535 if (errdes > max && errdes != out)
536 close (errdes);
538 /* If we were not given an environment, use the global environment. */
539 if (env == NULL)
540 env = environ;
542 /* Launch the program. If we get EAGAIN (normally out of pid's), try
543 again a few times with increasing backoff times. */
544 retries = 0;
545 while (1)
547 typedef const char * const *cc_cp;
549 if (flags & PEX_SEARCH)
550 pid = spawnvpe (_P_NOWAITO, executable, (cc_cp)argv, (cc_cp)env);
551 else
552 pid = spawnve (_P_NOWAITO, executable, (cc_cp)argv, (cc_cp)env);
554 if (pid > 0)
555 break;
557 *err = errno;
558 *errmsg = "spawn";
559 if (errno != EAGAIN || ++retries == 4)
560 return (pid_t) -1;
561 sleep (1 << retries);
564 /* Success. Restore the parent's file descriptors that we saved above. */
565 if (toclose >= 0
566 && restore_fd (toclose, toclose, fl_tc) < 0)
567 goto error_dup2;
568 if (in != STDIN_FILE_NO
569 && restore_fd (STDIN_FILE_NO, save_in, fl_in) < 0)
570 goto error_dup2;
571 if (out != STDOUT_FILE_NO
572 && restore_fd (STDOUT_FILE_NO, save_out, fl_out) < 0)
573 goto error_dup2;
574 if (errdes != STDERR_FILE_NO
575 && restore_fd (STDERR_FILE_NO, save_err, fl_err) < 0)
576 goto error_dup2;
578 return pid;
580 error_dup2:
581 *err = errno;
582 *errmsg = "dup2";
583 return (pid_t) -1;
586 #else
587 /* Implementation of pex->exec_child using standard vfork + exec. */
589 static pid_t
590 pex_unix_exec_child (struct pex_obj *obj, int flags, const char *executable,
591 char * const * argv, char * const * env,
592 int in, int out, int errdes,
593 int toclose, const char **errmsg, int *err)
595 pid_t pid;
597 /* We declare these to be volatile to avoid warnings from gcc about
598 them being clobbered by vfork. */
599 volatile int sleep_interval;
600 volatile int retries;
602 /* We vfork and then set environ in the child before calling execvp.
603 This clobbers the parent's environ so we need to restore it.
604 It would be nice to use one of the exec* functions that takes an
605 environment as a parameter, but that may have portability issues. */
606 char **save_environ = environ;
608 sleep_interval = 1;
609 pid = -1;
610 for (retries = 0; retries < 4; ++retries)
612 pid = vfork ();
613 if (pid >= 0)
614 break;
615 sleep (sleep_interval);
616 sleep_interval *= 2;
619 switch (pid)
621 case -1:
622 *err = errno;
623 *errmsg = VFORK_STRING;
624 return (pid_t) -1;
626 case 0:
627 /* Child process. */
628 if (in != STDIN_FILE_NO)
630 if (dup2 (in, STDIN_FILE_NO) < 0)
631 pex_child_error (obj, executable, "dup2", errno);
632 if (close (in) < 0)
633 pex_child_error (obj, executable, "close", errno);
635 if (out != STDOUT_FILE_NO)
637 if (dup2 (out, STDOUT_FILE_NO) < 0)
638 pex_child_error (obj, executable, "dup2", errno);
639 if (close (out) < 0)
640 pex_child_error (obj, executable, "close", errno);
642 if (errdes != STDERR_FILE_NO)
644 if (dup2 (errdes, STDERR_FILE_NO) < 0)
645 pex_child_error (obj, executable, "dup2", errno);
646 if (close (errdes) < 0)
647 pex_child_error (obj, executable, "close", errno);
649 if (toclose >= 0)
651 if (close (toclose) < 0)
652 pex_child_error (obj, executable, "close", errno);
654 if ((flags & PEX_STDERR_TO_STDOUT) != 0)
656 if (dup2 (STDOUT_FILE_NO, STDERR_FILE_NO) < 0)
657 pex_child_error (obj, executable, "dup2", errno);
660 if (env)
662 /* NOTE: In a standard vfork implementation this clobbers the
663 parent's copy of environ "too" (in reality there's only one copy).
664 This is ok as we restore it below. */
665 environ = (char**) env;
668 if ((flags & PEX_SEARCH) != 0)
670 execvp (executable, to_ptr32 (argv));
671 pex_child_error (obj, executable, "execvp", errno);
673 else
675 execv (executable, to_ptr32 (argv));
676 pex_child_error (obj, executable, "execv", errno);
679 /* NOTREACHED */
680 return (pid_t) -1;
682 default:
683 /* Parent process. */
685 /* Restore environ.
686 Note that the parent either doesn't run until the child execs/exits
687 (standard vfork behaviour), or if it does run then vfork is behaving
688 more like fork. In either case we needn't worry about clobbering
689 the child's copy of environ. */
690 environ = save_environ;
692 if (in != STDIN_FILE_NO)
694 if (close (in) < 0)
696 *err = errno;
697 *errmsg = "close";
698 return (pid_t) -1;
701 if (out != STDOUT_FILE_NO)
703 if (close (out) < 0)
705 *err = errno;
706 *errmsg = "close";
707 return (pid_t) -1;
710 if (errdes != STDERR_FILE_NO)
712 if (close (errdes) < 0)
714 *err = errno;
715 *errmsg = "close";
716 return (pid_t) -1;
720 return pid;
723 #endif /* SPAWN */
725 /* Wait for a child process to complete. */
727 static int
728 pex_unix_wait (struct pex_obj *obj, pid_t pid, int *status,
729 struct pex_time *time, int done, const char **errmsg,
730 int *err)
732 /* If we are cleaning up when the caller didn't retrieve process
733 status for some reason, encourage the process to go away. */
734 if (done)
735 kill (pid, SIGTERM);
737 if (pex_wait (obj, pid, status, time) < 0)
739 *err = errno;
740 *errmsg = "wait";
741 return -1;
744 return 0;
747 /* Create a pipe. */
749 static int
750 pex_unix_pipe (struct pex_obj *obj ATTRIBUTE_UNUSED, int *p,
751 int binary ATTRIBUTE_UNUSED)
753 return pipe (p);
756 /* Get a FILE pointer to read from a file descriptor. */
758 static FILE *
759 pex_unix_fdopenr (struct pex_obj *obj ATTRIBUTE_UNUSED, int fd,
760 int binary ATTRIBUTE_UNUSED)
762 return fdopen (fd, "r");
765 static FILE *
766 pex_unix_fdopenw (struct pex_obj *obj ATTRIBUTE_UNUSED, int fd,
767 int binary ATTRIBUTE_UNUSED)
769 if (fcntl (fd, F_SETFD, FD_CLOEXEC) < 0)
770 return NULL;
771 return fdopen (fd, "w");
774 static void
775 pex_unix_cleanup (struct pex_obj *obj ATTRIBUTE_UNUSED)
777 #if !defined (HAVE_WAIT4) && !defined (HAVE_WAITPID)
778 while (obj->sysdep != NULL)
780 struct status_list *this;
781 struct status_list *next;
783 this = (struct status_list *) obj->sysdep;
784 next = this->next;
785 free (this);
786 obj->sysdep = (void *) next;
788 #endif