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 = xmalloc (sizeof (*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->read_output = NULL;
  71   obj->remove_count = 0;
  72   obj->remove = NULL;
  73   obj->funcs = funcs;
  74   obj->sysdep = NULL;
  75   return obj;
  76 }
  77
  78 /* Add a file to be removed when we are done.  */
  79
  80 static void
  81 pex_add_remove (struct pex_obj *obj, const char *name, int allocated)
  82 {
  83   char *add;
  84
  85   ++obj->remove_count;
  86   obj->remove = xrealloc (obj->remove, obj->remove_count * sizeof (char *));
  87   if (allocated)
  88     add = (char *) name;
  89   else
  90     add = xstrdup (name);
  91   obj->remove[obj->remove_count - 1] = add;
  92 }
  93
  94 /* Run a program.  */
  95
  96 const char *
  97 pex_run (struct pex_obj *obj, int flags, const char *executable,
  98          char * const * argv, const char *orig_outname, const char *errname,
  99          int *err)
 100 {
 101   const char *errmsg;
 102   int in, out, errdes;
 103   char *outname;
 104   int outname_allocated;
 105   int p[2];
 106   long pid;
 107
 108   in = -1;
 109   out = -1;
 110   errdes = -1;
 111   outname = (char *) orig_outname;
 112   outname_allocated = 0;
 113
 114   /* Set IN.  */
 115
 116   if (obj->next_input_name != NULL)
 117     {
 118       /* We have to make sure that the previous process has completed
 119          before we try to read the file.  */
 120       if (!pex_get_status_and_time (obj, 0, &errmsg, err))
 121         goto error_exit;
 122
 123       in = obj->funcs->open_read (obj, obj->next_input_name,
 124                                   (flags & PEX_BINARY_INPUT) != 0);
 125       if (in < 0)
 126         {
 127           *err = errno;
 128           errmsg = "open temporary file";
 129           goto error_exit;
 130         }
 131       if (obj->next_input_name_allocated)
 132         {
 133           free (obj->next_input_name);
 134           obj->next_input_name_allocated = 0;
 135         }
 136       obj->next_input_name = NULL;
 137     }
 138   else
 139     {
 140       in = obj->next_input;
 141       if (in < 0)
 142         {
 143           *err = 0;
 144           errmsg = "pipeline already complete";
 145           goto error_exit;
 146         }
 147     }
 148
 149   /* Set OUT and OBJ->NEXT_INPUT/OBJ->NEXT_INPUT_NAME.  */
 150
 151   if ((flags & PEX_LAST) != 0)
 152     {
 153       if (outname == NULL)
 154         out = STDOUT_FILE_NO;
 155       else if ((flags & PEX_SUFFIX) != 0)
 156         {
 157           outname = concat (obj->tempbase, outname, NULL);
 158           outname_allocated = 1;
 159         }
 160       obj->next_input = -1;
 161     }
 162   else if ((obj->flags & PEX_USE_PIPES) == 0)
 163     {
 164       if (outname == NULL)
 165         {
 166           if (obj->tempbase == NULL)
 167             {
 168               outname = make_temp_file (NULL);
 169               outname_allocated = 1;
 170             }
 171           else
 172             {
 173               int len = strlen (obj->tempbase);
 174
 175               if (len >= 6
 176                   && strcmp (obj->tempbase + len - 6, "XXXXXX") == 0)
 177                 outname = xstrdup (obj->tempbase);
 178               else
 179                 outname = concat (obj->tempbase, "XXXXXX", NULL);
 180
 181               outname_allocated = 1;
 182
 183               out = mkstemps (outname, 0);
 184               if (out < 0)
 185                 {
 186                   *err = 0;
 187                   errmsg = "could not create temporary output file";
 188                   goto error_exit;
 189                 }
 190
 191               /* This isn't obj->funcs->close because we got the
 192                  descriptor from mkstemps, not from a function in
 193                  obj->funcs.  Calling close here is just like what
 194                  make_temp_file does.  */
 195               close (out);
 196               out = -1;
 197             }
 198         }
 199       else if ((flags & PEX_SUFFIX) != 0)
 200         {
 201           if (obj->tempbase == NULL)
 202             outname = make_temp_file (outname);
 203           else
 204             outname = concat (obj->tempbase, outname, NULL);
 205           outname_allocated = 1;
 206         }
 207
 208       if ((obj->flags & PEX_SAVE_TEMPS) == 0)
 209         {
 210           pex_add_remove (obj, outname, outname_allocated);
 211           outname_allocated = 0;
 212         }
 213
 214       if (!outname_allocated)
 215         {
 216           obj->next_input_name = outname;
 217           obj->next_input_name_allocated = 0;
 218         }
 219       else
 220         {
 221           obj->next_input_name = outname;
 222           outname_allocated = 0;
 223           obj->next_input_name_allocated = 1;
 224         }
 225     }
 226   else
 227     {
 228       if (obj->funcs->pipe (obj, p, (flags & PEX_BINARY_OUTPUT) != 0) < 0)
 229         {
 230           *err = errno;
 231           errmsg = "pipe";
 232           goto error_exit;
 233         }
 234
 235       out = p[WRITE_PORT];
 236       obj->next_input = p[READ_PORT];
 237     }
 238
 239   if (out < 0)
 240     {
 241       out = obj->funcs->open_write (obj, outname,
 242                                     (flags & PEX_BINARY_OUTPUT) != 0);
 243       if (out < 0)
 244         {
 245           *err = errno;
 246           errmsg = "open temporary output file";
 247           goto error_exit;
 248         }
 249     }
 250
 251   if (outname_allocated)
 252     {
 253       free (outname);
 254       outname_allocated = 0;
 255     }
 256
 257   /* Set ERRDES.  */
 258
 259   if (errname == NULL)
 260     errdes = STDERR_FILE_NO;
 261   else
 262     {
 263       /* We assume that stderr is in text mode--it certainly shouldn't
 264          be controlled by PEX_BINARY_OUTPUT.  If necessary, we can add
 265          a PEX_BINARY_STDERR flag.  */
 266       errdes = obj->funcs->open_write (obj, errname, 0);
 267       if (errdes < 0)
 268         {
 269           *err = errno;
 270           errmsg = "open error file";
 271           goto error_exit;
 272         }
 273     }
 274
 275   /* Run the program.  */
 276
 277   pid = obj->funcs->exec_child (obj, flags, executable, argv, in, out, errdes,
 278                                 &errmsg, err);
 279   if (pid < 0)
 280     goto error_exit;
 281
 282   ++obj->count;
 283   obj->children = xrealloc (obj->children, obj->count * sizeof (long));
 284   obj->children[obj->count - 1] = pid;
 285
 286   return NULL;
 287
 288  error_exit:
 289   if (in >= 0 && in != STDIN_FILE_NO)
 290     obj->funcs->close (obj, in);
 291   if (out >= 0 && out != STDOUT_FILE_NO)
 292     obj->funcs->close (obj, out);
 293   if (errdes >= 0 && errdes != STDERR_FILE_NO)
 294     obj->funcs->close (obj, errdes);
 295   if (outname_allocated)
 296     free (outname);
 297   return errmsg;
 298 }
 299
 300 /* Return a FILE pointer for the output of the last program
 301    executed.  */
 302
 303 FILE *
 304 pex_read_output (struct pex_obj *obj, int binary)
 305 {
 306   if (obj->next_input_name != NULL)
 307     {
 308       const char *errmsg;
 309       int err;
 310
 311       /* We have to make sure that the process has completed before we
 312          try to read the file.  */
 313       if (!pex_get_status_and_time (obj, 0, &errmsg, &err))
 314         {
 315           errno = err;
 316           return NULL;
 317         }
 318
 319       obj->read_output = fopen (obj->next_input_name, binary ? "rb" : "r");
 320
 321       if (obj->next_input_name_allocated)
 322         {
 323           free (obj->next_input_name);
 324           obj->next_input_name_allocated = 0;
 325         }
 326       obj->next_input_name = NULL;
 327     }
 328   else
 329     {
 330       int o;
 331
 332       o = obj->next_input;
 333       if (o < 0 || o == STDIN_FILE_NO)
 334         return NULL;
 335       obj->read_output = obj->funcs->fdopenr (obj, o, binary);
 336       obj->next_input = -1;
 337     }
 338
 339   return obj->read_output;
 340 }
 341
 342 /* Get the exit status and, if requested, the resource time for all
 343    the child processes.  Return 0 on failure, 1 on success.  */
 344
 345 static int
 346 pex_get_status_and_time (struct pex_obj *obj, int done, const char **errmsg,
 347                          int *err)
 348 {
 349   int ret;
 350   int i;
 351
 352   if (obj->number_waited == obj->count)
 353     return 1;
 354
 355   obj->status = xrealloc (obj->status, obj->count * sizeof (int));
 356   if ((obj->flags & PEX_RECORD_TIMES) != 0)
 357     obj->time = xrealloc (obj->time, obj->count * sizeof (struct pex_time));
 358
 359   ret = 1;
 360   for (i = obj->number_waited; i < obj->count; ++i)
 361     {
 362       if (obj->funcs->wait (obj, obj->children[i], &obj->status[i],
 363                             obj->time == NULL ? NULL : &obj->time[i],
 364                             done, errmsg, err) < 0)
 365         ret = 0;
 366     }
 367   obj->number_waited = i;
 368
 369   return ret;
 370 }
 371
 372 /* Get exit status of executed programs.  */
 373
 374 int
 375 pex_get_status (struct pex_obj *obj, int count, int *vector)
 376 {
 377   if (obj->status == NULL)
 378     {
 379       const char *errmsg;
 380       int err;
 381
 382       if (!pex_get_status_and_time (obj, 0, &errmsg, &err))
 383         return 0;
 384     }
 385
 386   if (count > obj->count)
 387     {
 388       memset (vector + obj->count, 0, (count - obj->count) * sizeof (int));
 389       count = obj->count;
 390     }
 391
 392   memcpy (vector, obj->status, count * sizeof (int));
 393
 394   return 1;
 395 }
 396
 397 /* Get process times of executed programs.  */
 398
 399 int
 400 pex_get_times (struct pex_obj *obj, int count, struct pex_time *vector)
 401 {
 402   if (obj->status == NULL)
 403     {
 404       const char *errmsg;
 405       int err;
 406
 407       if (!pex_get_status_and_time (obj, 0, &errmsg, &err))
 408         return 0;
 409     }
 410
 411   if (obj->time == NULL)
 412     return 0;
 413
 414   if (count > obj->count)
 415     {
 416       memset (vector + obj->count, 0,
 417               (count - obj->count) * sizeof (struct pex_time));
 418       count = obj->count;
 419     }
 420
 421   memcpy (vector, obj->time, count * sizeof (struct pex_time));
 422
 423   return 1;
 424 }
 425
 426 /* Free a pex_obj structure.  */
 427
 428 void
 429 pex_free (struct pex_obj *obj)
 430 {
 431   if (obj->next_input >= 0 && obj->next_input != STDIN_FILE_NO)
 432     obj->funcs->close (obj, obj->next_input);
 433
 434   /* If the caller forgot to wait for the children, we do it here, to
 435      avoid zombies.  */
 436   if (obj->status == NULL)
 437     {
 438       const char *errmsg;
 439       int err;
 440
 441       obj->flags &= ~ PEX_RECORD_TIMES;
 442       pex_get_status_and_time (obj, 1, &errmsg, &err);
 443     }
 444
 445   if (obj->next_input_name_allocated)
 446     free (obj->next_input_name);
 447   if (obj->children != NULL)
 448     free (obj->children);
 449   if (obj->status != NULL)
 450     free (obj->status);
 451   if (obj->time != NULL)
 452     free (obj->time);
 453   if (obj->read_output != NULL)
 454     fclose (obj->read_output);
 455
 456   if (obj->remove_count > 0)
 457     {
 458       int i;
 459
 460       for (i = 0; i < obj->remove_count; ++i)
 461         {
 462           remove (obj->remove[i]);
 463           free (obj->remove[i]);
 464         }
 465       free (obj->remove);
 466     }
 467
 468   if (obj->funcs->cleanup != NULL)
 469     obj->funcs->cleanup (obj);
 470
 471   free (obj);
 472 }