libiberty/pex-common.c

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