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