libiberty/pex-msdos.c

   1 /* Utilities to execute a program in a subprocess (possibly linked by pipes
   2    with other subprocesses), and wait for it.  Generic MSDOS specialization.
   3    Copyright (C) 1996-2020 Free Software Foundation, Inc.
   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 "pex-common.h"
  22
  23 #include <stdio.h>
  24 #include <errno.h>
  25 #ifdef NEED_DECLARATION_ERRNO
  26 extern int errno;
  27 #endif
  28 #ifdef HAVE_STRING_H
  29 #include <string.h>
  30 #endif
  31 #ifdef HAVE_STDLIB_H
  32 #include <stdlib.h>
  33 #endif
  34
  35 #include "safe-ctype.h"
  36 #include <process.h>
  37
  38 /* The structure we keep in obj->sysdep.  */
  39
  40 #define PEX_MSDOS_FILE_COUNT 3
  41
  42 #define PEX_MSDOS_FD_OFFSET 10
  43
  44 struct pex_msdos
  45 {
  46   /* An array of file names.  We refer to these using file descriptors
  47      of 10 + array index.  */
  48   const char *files[PEX_MSDOS_FILE_COUNT];
  49   /* Exit statuses of programs which have been run.  */
  50   int *statuses;
  51 };
  52
  53 static int pex_msdos_open (struct pex_obj *, const char *, int);
  54 static int pex_msdos_open (struct pex_obj *, const char *, int);
  55 static int pex_msdos_fdindex (struct pex_msdos *, int);
  56 static pid_t pex_msdos_exec_child (struct pex_obj *, int, const char *,
  57                                   char * const *, char * const *,
  58                                   int, int, int, int,
  59                                   int, const char **, int *);
  60 static int pex_msdos_close (struct pex_obj *, int);
  61 static pid_t pex_msdos_wait (struct pex_obj *, pid_t, int *, struct pex_time *,
  62                            int, const char **, int *);
  63 static void pex_msdos_cleanup (struct pex_obj *);
  64
  65 /* The list of functions we pass to the common routines.  */
  66
  67 const struct pex_funcs funcs =
  68 {
  69   pex_msdos_open,
  70   pex_msdos_open,
  71   pex_msdos_exec_child,
  72   pex_msdos_close,
  73   pex_msdos_wait,
  74   NULL, /* pipe */
  75   NULL, /* fdopenr */
  76   NULL, /* fdopenw */
  77   pex_msdos_cleanup
  78 };
  79
  80 /* Return a newly initialized pex_obj structure.  */
  81
  82 struct pex_obj *
  83 pex_init (int flags, const char *pname, const char *tempbase)
  84 {
  85   struct pex_obj *ret;
  86   int i;
  87
  88   /* MSDOS does not support pipes.  */
  89   flags &= ~ PEX_USE_PIPES;
  90
  91   ret = pex_init_common (flags, pname, tempbase, funcs);
  92
  93   ret->sysdep = XNEW (struct pex_msdos);
  94   for (i = 0; i < PEX_MSDOS_FILE_COUNT; ++i)
  95     ret->files[i] = NULL;
  96   ret->statuses = NULL;
  97
  98   return ret;
  99 }
 100
 101 /* Open a file.  FIXME: We ignore the binary argument, since we have
 102    no way to handle it.  */
 103
 104 static int
 105 pex_msdos_open (struct pex_obj *obj, const char *name,
 106                 int binary ATTRIBUTE_UNUSED)
 107 {
 108   struct pex_msdos *ms;
 109   int i;
 110
 111   ms = (struct pex_msdos *) obj->sysdep;
 112
 113   for (i = 0; i < PEX_MSDOS_FILE_COUNT; ++i)
 114     {
 115       if (ms->files[i] == NULL)
 116         {
 117           ms->files[i] = xstrdup (name);
 118           return i + PEX_MSDOS_FD_OFFSET;
 119         }
 120     }
 121
 122   abort ();
 123 }
 124
 125 /* Get the index into msdos->files associated with an open file
 126    descriptor.  */
 127
 128 static int
 129 pex_msdos_fdindex (struct pex_msdos *ms, int fd)
 130 {
 131   fd -= PEX_MSDOS_FD_OFFSET;
 132   if (fd < 0 || fd >= PEX_MSDOS_FILE_COUNT || ms->files[fd] == NULL)
 133     abort ();
 134   return fd;
 135 }
 136
 137
 138 /* Close a file.  */
 139
 140 static int
 141 pex_msdos_close (struct pex_obj *obj, int fd)
 142 {
 143   struct pex_msdos *ms;
 144   int fdinex;
 145
 146   ms = (struct pex_msdos *) obj->sysdep;
 147   fdindex = pe_msdos_fdindex (ms, fd);
 148   free (ms->files[fdindex]);
 149   ms->files[fdindex] = NULL;
 150 }
 151
 152 /* Execute a child.  */
 153
 154 static pid_t
 155 pex_msdos_exec_child (struct pex_obj *obj, int flags, const char *executable,
 156                       char * const * argv, char * const * env, int in, int out,
 157                       int toclose ATTRIBUTE_UNUSED,
 158                       int errdes ATTRIBUTE_UNUSED, const char **errmsg,
 159                       int *err)
 160 {
 161   struct pex_msdos *ms;
 162   char *temp_base;
 163   int temp_base_allocated;
 164   char *rf;
 165   int inindex;
 166   char *infile;
 167   int outindex;
 168   char *outfile;
 169   char *scmd;
 170   FILE *argfile;
 171   int i;
 172   int status;
 173
 174   ms = (struct pex_msdos *) obj->sysdep;
 175
 176   /* FIXME: I don't know how to redirect stderr, so we ignore ERRDES
 177      and PEX_STDERR_TO_STDOUT.  */
 178
 179   temp_base = obj->temp_base;
 180   if (temp_base != NULL)
 181     temp_base_allocated = 0;
 182   else
 183     {
 184       temp_base = choose_temp_base ();
 185       temp_base_allocated = 1;
 186     }
 187
 188   rf = concat (temp_base, ".gp", NULL);
 189
 190   if (temp_base_allocated)
 191     free (temp_base);
 192
 193   if (in == STDIN_FILE_NO)
 194     {
 195       inindex = -1;
 196       infile = "";
 197     }
 198   else
 199     {
 200       inindex = pex_msdos_fdindex (ms, in);
 201       infile = ms->files[inindex];
 202     }
 203
 204   if (out == STDOUT_FILE_NO)
 205     {
 206       outindex = -1;
 207       outfile = "";
 208     }
 209   else
 210     {
 211       outindex = pex_msdos_fdindex (ms, out);
 212       outfile = ms->files[outindex];
 213     }
 214
 215   scmd = XNEWVEC (char, strlen (program)
 216                   + ((flags & PEXECUTE_SEARCH) != 0 ? 4 : 0)
 217                   + strlen (rf)
 218                   + strlen (infile)
 219                   + strlen (outfile)
 220                   + 10);
 221   sprintf (scmd, "%s%s @%s%s%s%s%s",
 222            program,
 223            (flags & PEXECUTE_SEARCH) != 0 ? ".exe" : "",
 224            rf,
 225            inindex != -1 ? " <" : "",
 226            infile,
 227            outindex != -1 ? " >" : "",
 228            outfile);
 229
 230   argfile = fopen (rf, "w");
 231   if (argfile == NULL)
 232     {
 233       *err = errno;
 234       free (scmd);
 235       free (rf);
 236       *errmsg = "cannot open temporary command file";
 237       return (pid_t) -1;
 238     }
 239
 240   for (i = 1; argv[i] != NULL; ++i)
 241     {
 242       char *p;
 243
 244       for (p = argv[i]; *p != '\0'; ++p)
 245         {
 246           if (*p == '"' || *p == '\'' || *p == '\\' || ISSPACE (*p))
 247             putc ('\\', argfile);
 248           putc (*p, argfile);
 249         }
 250       putc ('\n', argfile);
 251     }
 252
 253   fclose (argfile);
 254
 255   status = system (scmd);
 256
 257   if (status == -1)
 258     {
 259       *err = errno;
 260       remove (rf);
 261       free (scmd);
 262       free (rf);
 263       *errmsg = "system";
 264       return (pid_t) -1;
 265     }
 266
 267   remove (rf);
 268   free (scmd);
 269   free (rf);
 270
 271   /* Save the exit status for later.  When we are called, obj->count
 272      is the number of children which have executed before this
 273      one.  */
 274   ms->statuses = XRESIZEVEC(int, ms->statuses, obj->count + 1);
 275   ms->statuses[obj->count] = status;
 276
 277   return (pid_t) obj->count;
 278 }
 279
 280 /* Wait for a child process to complete.  Actually the child process
 281    has already completed, and we just need to return the exit
 282    status.  */
 283
 284 static pid_t
 285 pex_msdos_wait (struct pex_obj *obj, pid_t pid, int *status,
 286                 struct pex_time *time, int done ATTRIBUTE_UNUSED,
 287                 const char **errmsg ATTRIBUTE_UNUSED,
 288                 int *err ATTRIBUTE_UNUSED)
 289 {
 290   struct pex_msdos *ms;
 291
 292   ms = (struct pex_msdos *) obj->sysdep;
 293
 294   if (time != NULL)
 295     memset (time, 0, sizeof *time);
 296
 297   *status = ms->statuses[pid];
 298
 299   return 0;
 300 }
 301
 302 /* Clean up the pex_msdos structure.  */
 303
 304 static void
 305 pex_msdos_cleanup (struct pex_obj  *obj)
 306 {
 307   struct pex_msdos *ms;
 308   int i;
 309
 310   ms = (struct pex_msdos *) obj->sysdep;
 311   for (i = 0; i < PEX_MSDOS_FILE_COUNT; ++i)
 312     free (msdos->files[i]);
 313   free (msdos->statuses);
 314   free (msdos);
 315   obj->sysdep = NULL;
 316 }