libiberty/pex-win32.c

   1 /* Utilities to execute a program in a subprocess (possibly linked by pipes
   2    with other subprocesses), and wait for it.  Generic Win32 specialization.
   3    Copyright (C) 1996, 1997, 1998, 1999, 2000, 2001, 2003
   4    Free Software Foundation, Inc.
   5
   6 This file is part of the libiberty library.
   7 Libiberty is free software; you can redistribute it and/or
   8 modify it under the terms of the GNU Library General Public
   9 License as published by the Free Software Foundation; either
  10 version 2 of the License, or (at your option) any later version.
  11
  12 Libiberty is distributed in the hope that it will be useful,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15 Library General Public License for more details.
  16
  17 You should have received a copy of the GNU Library General Public
  18 License along with libiberty; see the file COPYING.LIB.  If not,
  19 write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  20 Boston, MA 02111-1307, USA.  */
  21
  22 #include "pex-common.h"
  23
  24 #ifdef HAVE_STRING_H
  25 #include <string.h>
  26 #endif
  27 #ifdef HAVE_UNISTD_H
  28 #include <unistd.h>
  29 #endif
  30 #ifdef HAVE_SYS_WAIT_H
  31 #include <sys/wait.h>
  32 #endif
  33
  34 #include <process.h>
  35 #include <io.h>
  36 #include <fcntl.h>
  37 #include <signal.h>
  38
  39 /* mingw32 headers may not define the following.  */
  40
  41 #ifndef _P_WAIT
  42 #  define _P_WAIT       0
  43 #  define _P_NOWAIT     1
  44 #  define _P_OVERLAY    2
  45 #  define _P_NOWAITO    3
  46 #  define _P_DETACH     4
  47
  48 #  define WAIT_CHILD            0
  49 #  define WAIT_GRANDCHILD       1
  50 #endif
  51
  52 /* This is a kludge to get around the Microsoft C spawn functions' propensity
  53    to remove the outermost set of double quotes from all arguments.  */
  54
  55 static const char * const *
  56 fix_argv (argvec)
  57      char **argvec;
  58 {
  59   int i;
  60   char * command0 = argvec[0];
  61
  62   /* Ensure that the executable pathname uses Win32 backslashes. This
  63      is not necessary on NT, but on W9x, forward slashes causes failure
  64      of spawn* and exec* functions (and probably any function that
  65      calls CreateProcess) *iff* the executable pathname (argvec[0]) is
  66      a quoted string.  And quoting is necessary in case a pathname
  67      contains  embedded white space. You can't win.  */
  68   for (; *command0 != '\0'; command0++)
  69     if (*command0 == '/')
  70       *command0 = '\\';
  71
  72   for (i = 1; argvec[i] != 0; i++)
  73     {
  74       int len, j;
  75       char *temp, *newtemp;
  76
  77       temp = argvec[i];
  78       len = strlen (temp);
  79       for (j = 0; j < len; j++)
  80         {
  81           if (temp[j] == '"')
  82             {
  83               newtemp = xmalloc (len + 2);
  84               strncpy (newtemp, temp, j);
  85               newtemp [j] = '\\';
  86               strncpy (&newtemp [j+1], &temp [j], len-j);
  87               newtemp [len+1] = 0;
  88               temp = newtemp;
  89               len++;
  90               j++;
  91             }
  92         }
  93
  94         argvec[i] = temp;
  95       }
  96
  97   for (i = 0; argvec[i] != 0; i++)
  98     {
  99       if (strpbrk (argvec[i], " \t"))
 100         {
 101           int len, trailing_backslash;
 102           char *temp;
 103
 104           len = strlen (argvec[i]);
 105           trailing_backslash = 0;
 106
 107           /* There is an added complication when an arg with embedded white
 108              space ends in a backslash (such as in the case of -iprefix arg
 109              passed to cpp). The resulting quoted strings gets misinterpreted
 110              by the command interpreter -- it thinks that the ending quote
 111              is escaped by the trailing backslash and things get confused.
 112              We handle this case by escaping the trailing backslash, provided
 113              it was not escaped in the first place.  */
 114           if (len > 1
 115               && argvec[i][len-1] == '\\'
 116               && argvec[i][len-2] != '\\')
 117             {
 118               trailing_backslash = 1;
 119               ++len;                    /* to escape the final backslash. */
 120             }
 121
 122           len += 2;                     /* and for the enclosing quotes. */
 123
 124           temp = xmalloc (len + 1);
 125           temp[0] = '"';
 126           strcpy (temp + 1, argvec[i]);
 127           if (trailing_backslash)
 128             temp[len-2] = '\\';
 129           temp[len-1] = '"';
 130           temp[len] = '\0';
 131
 132           argvec[i] = temp;
 133         }
 134     }
 135
 136   return (const char * const *) argvec;
 137 }
 138
 139 /* Win32 supports pipes */
 140 int
 141 pexecute (program, argv, this_pname, temp_base, errmsg_fmt, errmsg_arg, flags)
 142      const char *program;
 143      char * const *argv;
 144      const char *this_pname ATTRIBUTE_UNUSED;
 145      const char *temp_base ATTRIBUTE_UNUSED;
 146      char **errmsg_fmt, **errmsg_arg;
 147      int flags;
 148 {
 149   int pid;
 150   int pdes[2];
 151   int org_stdin = -1;
 152   int org_stdout = -1;
 153   int input_desc, output_desc;
 154
 155   /* Pipe waiting from last process, to be used as input for the next one.
 156      Value is STDIN_FILE_NO if no pipe is waiting
 157      (i.e. the next command is the first of a group).  */
 158   static int last_pipe_input;
 159
 160   /* If this is the first process, initialize.  */
 161   if (flags & PEXECUTE_FIRST)
 162     last_pipe_input = STDIN_FILE_NO;
 163
 164   input_desc = last_pipe_input;
 165
 166   /* If this isn't the last process, make a pipe for its output,
 167      and record it as waiting to be the input to the next process.  */
 168   if (! (flags & PEXECUTE_LAST))
 169     {
 170       if (_pipe (pdes, 256, O_BINARY) < 0)
 171         {
 172           *errmsg_fmt = "pipe";
 173           *errmsg_arg = NULL;
 174           return -1;
 175         }
 176       output_desc = pdes[WRITE_PORT];
 177       last_pipe_input = pdes[READ_PORT];
 178     }
 179   else
 180     {
 181       /* Last process.  */
 182       output_desc = STDOUT_FILE_NO;
 183       last_pipe_input = STDIN_FILE_NO;
 184     }
 185
 186   if (input_desc != STDIN_FILE_NO)
 187     {
 188       org_stdin = dup (STDIN_FILE_NO);
 189       dup2 (input_desc, STDIN_FILE_NO);
 190       close (input_desc);
 191     }
 192
 193   if (output_desc != STDOUT_FILE_NO)
 194     {
 195       org_stdout = dup (STDOUT_FILE_NO);
 196       dup2 (output_desc, STDOUT_FILE_NO);
 197       close (output_desc);
 198     }
 199
 200   pid = (flags & PEXECUTE_SEARCH ? _spawnvp : _spawnv)
 201     (_P_NOWAIT, program, fix_argv(argv));
 202
 203   if (input_desc != STDIN_FILE_NO)
 204     {
 205       dup2 (org_stdin, STDIN_FILE_NO);
 206       close (org_stdin);
 207     }
 208
 209   if (output_desc != STDOUT_FILE_NO)
 210     {
 211       dup2 (org_stdout, STDOUT_FILE_NO);
 212       close (org_stdout);
 213     }
 214
 215   if (pid == -1)
 216     {
 217       *errmsg_fmt = install_error_msg;
 218       *errmsg_arg = (char*) program;
 219       return -1;
 220     }
 221
 222   return pid;
 223 }
 224
 225 /* MS CRTDLL doesn't return enough information in status to decide if the
 226    child exited due to a signal or not, rather it simply returns an
 227    integer with the exit code of the child; eg., if the child exited with
 228    an abort() call and didn't have a handler for SIGABRT, it simply returns
 229    with status = 3. We fix the status code to conform to the usual WIF*
 230    macros. Note that WIFSIGNALED will never be true under CRTDLL. */
 231
 232 int
 233 pwait (pid, status, flags)
 234      int pid;
 235      int *status;
 236      int flags ATTRIBUTE_UNUSED;
 237 {
 238   int termstat;
 239
 240   pid = _cwait (&termstat, pid, WAIT_CHILD);
 241
 242   /* ??? Here's an opportunity to canonicalize the values in STATUS.
 243      Needed?  */
 244
 245   /* cwait returns the child process exit code in termstat.
 246      A value of 3 indicates that the child caught a signal, but not
 247      which one.  Since only SIGABRT, SIGFPE and SIGINT do anything, we
 248      report SIGABRT.  */
 249   if (termstat == 3)
 250     *status = SIGABRT;
 251   else
 252     *status = (((termstat) & 0xff) << 8);
 253
 254   return pid;
 255 }