1 /* Common code for executing a program in a sub-process.
2 Copyright (C) 2005-2023 Free Software Foundation, Inc.
3 Written by Ian Lance Taylor <ian@airs.com>.
4
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.
10
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.
15
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., 51 Franklin Street - Fifth Floor,
19 Boston, MA 02110-1301, USA. */
20
21 #include "config.h"
22 #include "libiberty.h"
23 #include "pex-common.h"
24
25 #include <stdio.h>
26 #include <errno.h>
27 #ifdef NEED_DECLARATION_ERRNO
28 extern int errno;
29 #endif
30 #ifdef HAVE_STDLIB_H
31 #include <stdlib.h>
32 #endif
33 #ifdef HAVE_STRING_H
34 #include <string.h>
35 #endif
36 #ifdef HAVE_UNISTD_H
37 #include <unistd.h>
38 #endif
39
40 extern int mkstemps (char *, int);
41
42 /* This file contains subroutines for the program execution routines
43 (pex_init, pex_run, etc.). This file is compiled on all
44 systems. */
45
46 static void pex_add_remove (struct pex_obj *, const char *, int);
47 static int pex_get_status_and_time (struct pex_obj *, int, const char **,
48 int *);
49
50 /* Initialize a pex_obj structure. */
51
52 struct pex_obj *
53 pex_init_common (int flags, const char *pname, const char *tempbase,
54 const struct pex_funcs *funcs)
55 {
56 struct pex_obj *obj;
57
58 obj = XNEW (struct pex_obj);
59 obj->flags = flags;
60 obj->pname = pname;
61 obj->tempbase = tempbase;
62 obj->next_input = STDIN_FILE_NO;
63 obj->next_input_name = NULL;
64 obj->next_input_name_allocated = 0;
65 obj->stderr_pipe = -1;
66 obj->count = 0;
67 obj->children = NULL;
68 obj->status = NULL;
69 obj->time = NULL;
70 obj->number_waited = 0;
71 obj->input_file = NULL;
72 obj->read_output = NULL;
73 obj->read_err = NULL;
74 obj->remove_count = 0;
75 obj->remove = NULL;
76 obj->funcs = funcs;
77 obj->sysdep = NULL;
78 return obj;
79 }
80
81 /* Add a file to be removed when we are done. */
82
83 static void
84 pex_add_remove (struct pex_obj *obj, const char *name, int allocated)
85 {
86 char *add;
87
88 ++obj->remove_count;
89 obj->remove = XRESIZEVEC (char *, obj->remove, obj->remove_count);
90 if (allocated)
91 add = (char *) name;
92 else
93 add = xstrdup (name);
94 obj->remove[obj->remove_count - 1] = add;
95 }
96
97 /* Generate a temporary file name based on OBJ, FLAGS, and NAME.
98 Return NULL if we were unable to reserve a temporary filename.
99
100 If non-NULL, the result is either allocated with malloc, or the
101 same pointer as NAME. */
102 static char *
103 temp_file (struct pex_obj *obj, int flags, char *name)
104 {
105 if (name == NULL)
106 {
107 if (obj->tempbase == NULL)
108 {
109 name = make_temp_file (NULL);
110 }
111 else
112 {
113 int len = strlen (obj->tempbase);
114 int out;
115
116 if (len >= 6
117 && strcmp (obj->tempbase + len - 6, "XXXXXX") == 0)
118 name = xstrdup (obj->tempbase);
119 else
120 name = concat (obj->tempbase, "XXXXXX", NULL);
121
122 out = mkstemps (name, 0);
123 if (out < 0)
124 {
125 free (name);
126 return NULL;
127 }
128
129 /* This isn't obj->funcs->close because we got the
130 descriptor from mkstemps, not from a function in
131 obj->funcs. Calling close here is just like what
132 make_temp_file does. */
133 close (out);
134 }
135 }
136 else if ((flags & PEX_SUFFIX) != 0)
137 {
138 if (obj->tempbase == NULL)
139 name = make_temp_file (name);
140 else
141 name = concat (obj->tempbase, name, NULL);
142 }
143
144 return name;
145 }
146
147
148 /* As for pex_run (), but permits the environment for the child process
149 to be specified. */
150
151 const char *
152 pex_run_in_environment (struct pex_obj *obj, int flags, const char *executable,
153 char * const * argv, char * const * env,
154 const char *orig_outname, const char *errname,
155 int *err)
156 {
157 const char *errmsg;
158 int in, out, errdes;
159 char *outname;
160 int outname_allocated;
161 int p[2];
162 int toclose;
163 pid_t pid;
164
165 in = -1;
166 out = -1;
167 errdes = -1;
168 outname = (char *) orig_outname;
169 outname_allocated = 0;
170
171 /* If the user called pex_input_file, close the file now. */
172 if (obj->input_file)
173 {
174 if (fclose (obj->input_file) == EOF)
175 {
176 errmsg = "closing pipeline input file";
177 goto error_exit;
178 }
179 obj->input_file = NULL;
180 }
181
182 /* Set IN. */
183
184 if (obj->next_input_name != NULL)
185 {
186 /* We have to make sure that the previous process has completed
187 before we try to read the file. */
188 if (!pex_get_status_and_time (obj, 0, &errmsg, err))
189 goto error_exit;
190
191 in = obj->funcs->open_read (obj, obj->next_input_name,
192 (flags & PEX_BINARY_INPUT) != 0);
193 if (in < 0)
194 {
195 *err = errno;
196 errmsg = "open temporary file";
197 goto error_exit;
198 }
199 if (obj->next_input_name_allocated)
200 {
201 free (obj->next_input_name);
202 obj->next_input_name_allocated = 0;
203 }
204 obj->next_input_name = NULL;
205 }
206 else
207 {
208 in = obj->next_input;
209 if (in < 0)
210 {
211 *err = 0;
212 errmsg = "pipeline already complete";
213 goto error_exit;
214 }
215 }
216
217 /* Set OUT and OBJ->NEXT_INPUT/OBJ->NEXT_INPUT_NAME. */
218
219 if ((flags & PEX_LAST) != 0)
220 {
221 if (outname == NULL)
222 out = STDOUT_FILE_NO;
223 else if ((flags & PEX_SUFFIX) != 0)
224 {
225 outname = concat (obj->tempbase, outname, NULL);
226 outname_allocated = 1;
227 }
228 obj->next_input = -1;
229 }
230 else if ((obj->flags & PEX_USE_PIPES) == 0)
231 {
232 outname = temp_file (obj, flags, outname);
233 if (! outname)
234 {
235 *err = 0;
236 errmsg = "could not create temporary file";
237 goto error_exit;
238 }
239
240 if (outname != orig_outname)
241 outname_allocated = 1;
242
243 if ((obj->flags & PEX_SAVE_TEMPS) == 0)
244 {
245 pex_add_remove (obj, outname, outname_allocated);
246 outname_allocated = 0;
247 }
248
249 /* Hand off ownership of outname to the next stage. */
250 obj->next_input_name = outname;
251 obj->next_input_name_allocated = outname_allocated;
252 outname_allocated = 0;
253 }
254 else
255 {
256 if (obj->funcs->pipe (obj, p, (flags & PEX_BINARY_OUTPUT) != 0) < 0)
257 {
258 *err = errno;
259 errmsg = "pipe";
260 goto error_exit;
261 }
262
263 out = p[WRITE_PORT];
264 obj->next_input = p[READ_PORT];
265 }
266
267 if (out < 0)
268 {
269 out = obj->funcs->open_write (obj, outname,
270 (flags & PEX_BINARY_OUTPUT) != 0,
271 (flags & PEX_STDOUT_APPEND) != 0);
272 if (out < 0)
273 {
274 *err = errno;
275 errmsg = "open temporary output file";
276 goto error_exit;
277 }
278 }
279
280 if (outname_allocated)
281 {
282 free (outname);
283 outname_allocated = 0;
284 }
285
286 /* Set ERRDES. */
287
288 if (errname != NULL && (flags & PEX_STDERR_TO_PIPE) != 0)
289 {
290 *err = 0;
291 errmsg = "both ERRNAME and PEX_STDERR_TO_PIPE specified.";
292 goto error_exit;
293 }
294
295 if (obj->stderr_pipe != -1)
296 {
297 *err = 0;
298 errmsg = "PEX_STDERR_TO_PIPE used in the middle of pipeline";
299 goto error_exit;
300 }
301
302 if (errname == NULL)
303 {
304 if (flags & PEX_STDERR_TO_PIPE)
305 {
306 if (obj->funcs->pipe (obj, p, (flags & PEX_BINARY_ERROR) != 0) < 0)
307 {
308 *err = errno;
309 errmsg = "pipe";
310 goto error_exit;
311 }
312
313 errdes = p[WRITE_PORT];
314 obj->stderr_pipe = p[READ_PORT];
315 }
316 else
317 {
318 errdes = STDERR_FILE_NO;
319 }
320 }
321 else
322 {
323 errdes = obj->funcs->open_write (obj, errname,
324 (flags & PEX_BINARY_ERROR) != 0,
325 (flags & PEX_STDERR_APPEND) != 0);
326 if (errdes < 0)
327 {
328 *err = errno;
329 errmsg = "open error file";
330 goto error_exit;
331 }
332 }
333
334 /* If we are using pipes, the child process has to close the next
335 input pipe. */
336
337 if ((obj->flags & PEX_USE_PIPES) == 0)
338 toclose = -1;
339 else
340 toclose = obj->next_input;
341
342 /* Run the program. */
343
344 pid = obj->funcs->exec_child (obj, flags, executable, argv, env,
345 in, out, errdes, toclose, &errmsg, err);
346 if (pid < 0)
347 goto error_exit;
348
349 ++obj->count;
350 obj->children = XRESIZEVEC (pid_t, obj->children, obj->count);
351 obj->children[obj->count - 1] = pid;
352
353 return NULL;
354
355 error_exit:
356 if (in >= 0 && in != STDIN_FILE_NO)
357 obj->funcs->close (obj, in);
358 if (out >= 0 && out != STDOUT_FILE_NO)
359 obj->funcs->close (obj, out);
360 if (errdes >= 0 && errdes != STDERR_FILE_NO)
361 obj->funcs->close (obj, errdes);
362 if (outname_allocated)
363 free (outname);
364 return errmsg;
365 }
366
367 /* Run a program. */
368
369 const char *
370 pex_run (struct pex_obj *obj, int flags, const char *executable,
371 char * const * argv, const char *orig_outname, const char *errname,
372 int *err)
373 {
374 return pex_run_in_environment (obj, flags, executable, argv, NULL,
375 orig_outname, errname, err);
376 }
377
378 /* Return a FILE pointer for a temporary file to fill with input for
379 the pipeline. */
380 FILE *
381 pex_input_file (struct pex_obj *obj, int flags, const char *in_name)
382 {
383 char *name = (char *) in_name;
384 FILE *f;
385
386 /* This must be called before the first pipeline stage is run, and
387 there must not have been any other input selected. */
388 if (obj->count != 0
389 || (obj->next_input >= 0 && obj->next_input != STDIN_FILE_NO)
390 || obj->next_input_name)
391 {
392 errno = EINVAL;
393 return NULL;
394 }
395
396 name = temp_file (obj, flags, name);
397 if (! name)
398 return NULL;
399
400 f = fopen (name, (flags & PEX_BINARY_OUTPUT) ? "wb" : "w");
401 if (! f)
402 {
403 free (name);
404 return NULL;
405 }
406
407 obj->input_file = f;
408 obj->next_input_name = name;
409 obj->next_input_name_allocated = (name != in_name);
410
411 return f;
412 }
413
414 /* Return a stream for a pipe connected to the standard input of the
415 first stage of the pipeline. */
416 FILE *
417 pex_input_pipe (struct pex_obj *obj, int binary)
418 {
419 int p[2];
420 FILE *f;
421
422 /* You must call pex_input_pipe before the first pex_run or pex_one. */
423 if (obj->count > 0)
424 goto usage_error;
425
426 /* You must be using pipes. Implementations that don't support
427 pipes clear this flag before calling pex_init_common. */
428 if (! (obj->flags & PEX_USE_PIPES))
429 goto usage_error;
430
431 /* If we have somehow already selected other input, that's a
432 mistake. */
433 if ((obj->next_input >= 0 && obj->next_input != STDIN_FILE_NO)
434 || obj->next_input_name)
435 goto usage_error;
436
437 if (obj->funcs->pipe (obj, p, binary != 0) < 0)
438 return NULL;
439
440 f = obj->funcs->fdopenw (obj, p[WRITE_PORT], binary != 0);
441 if (! f)
442 {
443 int saved_errno = errno;
444 obj->funcs->close (obj, p[READ_PORT]);
445 obj->funcs->close (obj, p[WRITE_PORT]);
446 errno = saved_errno;
447 return NULL;
448 }
449
450 obj->next_input = p[READ_PORT];
451
452 return f;
453
454 usage_error:
455 errno = EINVAL;
456 return NULL;
457 }
458
459 /* Return a FILE pointer for the output of the last program
460 executed. */
461
462 FILE *
463 pex_read_output (struct pex_obj *obj, int binary)
464 {
465 if (obj->next_input_name != NULL)
466 {
467 const char *errmsg;
468 int err;
469
470 /* We have to make sure that the process has completed before we
471 try to read the file. */
472 if (!pex_get_status_and_time (obj, 0, &errmsg, &err))
473 {
474 errno = err;
475 return NULL;
476 }
477
478 obj->read_output = fopen (obj->next_input_name, binary ? "rb" : "r");
479
480 if (obj->next_input_name_allocated)
481 {
482 free (obj->next_input_name);
483 obj->next_input_name_allocated = 0;
484 }
485 obj->next_input_name = NULL;
486 }
487 else
488 {
489 int o;
490
491 o = obj->next_input;
492 if (o < 0 || o == STDIN_FILE_NO)
493 return NULL;
494 obj->read_output = obj->funcs->fdopenr (obj, o, binary);
495 obj->next_input = -1;
496 }
497
498 return obj->read_output;
499 }
500
501 FILE *
502 pex_read_err (struct pex_obj *obj, int binary)
503 {
504 int o;
505
506 o = obj->stderr_pipe;
507 if (o < 0 || o == STDIN_FILE_NO)
508 return NULL;
509 obj->read_err = obj->funcs->fdopenr (obj, o, binary);
510 obj->stderr_pipe = -1;
511 return obj->read_err;
512 }
513
514 /* Get the exit status and, if requested, the resource time for all
515 the child processes. Return 0 on failure, 1 on success. */
516
517 static int
518 pex_get_status_and_time (struct pex_obj *obj, int done, const char **errmsg,
519 int *err)
520 {
521 int ret;
522 int i;
523
524 if (obj->number_waited == obj->count)
525 return 1;
526
527 obj->status = XRESIZEVEC (int, obj->status, obj->count);
528 if ((obj->flags & PEX_RECORD_TIMES) != 0)
529 obj->time = XRESIZEVEC (struct pex_time, obj->time, obj->count);
530
531 ret = 1;
532 for (i = obj->number_waited; i < obj->count; ++i)
533 {
534 if (obj->funcs->wait (obj, obj->children[i], &obj->status[i],
535 obj->time == NULL ? NULL : &obj->time[i],
536 done, errmsg, err) < 0)
537 ret = 0;
538 }
539 obj->number_waited = i;
540
541 return ret;
542 }
543
544 /* Get exit status of executed programs. */
545
546 int
547 pex_get_status (struct pex_obj *obj, int count, int *vector)
548 {
549 if (obj->status == NULL)
550 {
551 const char *errmsg;
552 int err;
553
554 if (!pex_get_status_and_time (obj, 0, &errmsg, &err))
555 return 0;
556 }
557
558 if (count > obj->count)
559 {
560 memset (vector + obj->count, 0, (count - obj->count) * sizeof (int));
561 count = obj->count;
562 }
563
564 memcpy (vector, obj->status, count * sizeof (int));
565
566 return 1;
567 }
568
569 /* Get process times of executed programs. */
570
571 int
572 pex_get_times (struct pex_obj *obj, int count, struct pex_time *vector)
573 {
574 if (obj->status == NULL)
575 {
576 const char *errmsg;
577 int err;
578
579 if (!pex_get_status_and_time (obj, 0, &errmsg, &err))
580 return 0;
581 }
582
583 if (obj->time == NULL)
584 return 0;
585
586 if (count > obj->count)
587 {
588 memset (vector + obj->count, 0,
589 (count - obj->count) * sizeof (struct pex_time));
590 count = obj->count;
591 }
592
593 memcpy (vector, obj->time, count * sizeof (struct pex_time));
594
595 return 1;
596 }
597
598 /* Free a pex_obj structure. */
599
600 void
601 pex_free (struct pex_obj *obj)
602 {
603 /* Close pipe file descriptors corresponding to child's stdout and
604 stderr so that the child does not hang trying to output something
605 while we're waiting for it. */
606 if (obj->next_input >= 0 && obj->next_input != STDIN_FILE_NO)
607 obj->funcs->close (obj, obj->next_input);
608 if (obj->stderr_pipe >= 0 && obj->stderr_pipe != STDIN_FILE_NO)
609 obj->funcs->close (obj, obj->stderr_pipe);
610 if (obj->read_output != NULL)
611 fclose (obj->read_output);
612 if (obj->read_err != NULL)
613 fclose (obj->read_err);
614
615 /* If the caller forgot to wait for the children, we do it here, to
616 avoid zombies. */
617 if (obj->status == NULL)
618 {
619 const char *errmsg;
620 int err;
621
622 obj->flags &= ~ PEX_RECORD_TIMES;
623 pex_get_status_and_time (obj, 1, &errmsg, &err);
624 }
625
626 if (obj->next_input_name_allocated)
627 free (obj->next_input_name);
628 free (obj->children);
629 free (obj->status);
630 free (obj->time);
631
632 if (obj->remove_count > 0)
633 {
634 int i;
635
636 for (i = 0; i < obj->remove_count; ++i)
637 {
638 remove (obj->remove[i]);
639 free (obj->remove[i]);
640 }
641 free (obj->remove);
642 }
643
644 if (obj->funcs->cleanup != NULL)
645 obj->funcs->cleanup (obj);
646
647 free (obj);
648 }