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.  */
  63   for (; *command0 != '\0'; command0++)
  64     if (*command0 == '/')
  65       *command0 = '\\';
  66
  67   for (i = 1; argvec[i] != 0; i++)
  68     {
  69       int len, j;
  70       char *temp, *newtemp;
  71
  72       temp = argvec[i];
  73       len = strlen (temp);
  74       for (j = 0; j < len; j++)
  75         {
  76           if (temp[j] == '"')
  77             {
  78               newtemp = xmalloc (len + 2);
  79               strncpy (newtemp, temp, j);
  80               newtemp [j] = '\\';
  81               strncpy (&newtemp [j+1], &temp [j], len-j);
  82               newtemp [len+1] = 0;
  83               temp = newtemp;
  84               len++;
  85               j++;
  86             }
  87         }
  88
  89         argvec[i] = temp;
  90       }
  91
  92   for (i = 0; argvec[i] != 0; i++)
  93     {
  94       if (strpbrk (argvec[i], " \t"))
  95         {
  96           int len, trailing_backslash;
  97           char *temp;
  98
  99           len = strlen (argvec[i]);
 100           trailing_backslash = 0;
 101
 102           /* There is an added complication when an arg with embedded white
 103              space ends in a backslash (such as in the case of -iprefix arg
 104              passed to cpp). The resulting quoted strings gets misinterpreted
 105              by the command interpreter -- it thinks that the ending quote
 106              is escaped by the trailing backslash and things get confused.
 107              We handle this case by escaping the trailing backslash, provided
 108              it was not escaped in the first place.  */
 109           if (len > 1
 110               && argvec[i][len-1] == '\\'
 111               && argvec[i][len-2] != '\\')
 112             {
 113               trailing_backslash = 1;
 114               ++len;                    /* to escape the final backslash. */
 115             }
 116
 117           len += 2;                     /* and for the enclosing quotes. */
 118
 119           temp = xmalloc (len + 1);
 120           temp[0] = '"';
 121           strcpy (temp + 1, argvec[i]);
 122           if (trailing_backslash)
 123             temp[len-2] = '\\';
 124           temp[len-1] = '"';
 125           temp[len] = '\0';
 126
 127           argvec[i] = temp;
 128         }
 129     }
 130
 131   return (const char * const *) argvec;
 132 }
 133
 134 /* Win32 supports pipes */
 135 int
 136 pexecute (program, argv, this_pname, temp_base, errmsg_fmt, errmsg_arg, flags)
 137      const char *program;
 138      char * const *argv;
 139      const char *this_pname;
 140      const char *temp_base;
 141      char **errmsg_fmt, **errmsg_arg;
 142      int flags;
 143 {
 144   int pid;
 145   int pdes[2], org_stdin, org_stdout;
 146   int input_desc, output_desc;
 147   int retries, sleep_interval;
 148
 149   /* Pipe waiting from last process, to be used as input for the next one.
 150      Value is STDIN_FILE_NO if no pipe is waiting
 151      (i.e. the next command is the first of a group).  */
 152   static int last_pipe_input;
 153
 154   /* If this is the first process, initialize.  */
 155   if (flags & PEXECUTE_FIRST)
 156     last_pipe_input = STDIN_FILE_NO;
 157
 158   input_desc = last_pipe_input;
 159
 160   /* If this isn't the last process, make a pipe for its output,
 161      and record it as waiting to be the input to the next process.  */
 162   if (! (flags & PEXECUTE_LAST))
 163     {
 164       if (_pipe (pdes, 256, O_BINARY) < 0)
 165         {
 166           *errmsg_fmt = "pipe";
 167           *errmsg_arg = NULL;
 168           return -1;
 169         }
 170       output_desc = pdes[WRITE_PORT];
 171       last_pipe_input = pdes[READ_PORT];
 172     }
 173   else
 174     {
 175       /* Last process.  */
 176       output_desc = STDOUT_FILE_NO;
 177       last_pipe_input = STDIN_FILE_NO;
 178     }
 179
 180   if (input_desc != STDIN_FILE_NO)
 181     {
 182       org_stdin = dup (STDIN_FILE_NO);
 183       dup2 (input_desc, STDIN_FILE_NO);
 184       close (input_desc);
 185     }
 186
 187   if (output_desc != STDOUT_FILE_NO)
 188     {
 189       org_stdout = dup (STDOUT_FILE_NO);
 190       dup2 (output_desc, STDOUT_FILE_NO);
 191       close (output_desc);
 192     }
 193
 194   pid = (flags & PEXECUTE_SEARCH ? _spawnvp : _spawnv)
 195     (_P_NOWAIT, program, fix_argv(argv));
 196
 197   if (input_desc != STDIN_FILE_NO)
 198     {
 199       dup2 (org_stdin, STDIN_FILE_NO);
 200       close (org_stdin);
 201     }
 202
 203   if (output_desc != STDOUT_FILE_NO)
 204     {
 205       dup2 (org_stdout, STDOUT_FILE_NO);
 206       close (org_stdout);
 207     }
 208
 209   if (pid == -1)
 210     {
 211       *errmsg_fmt = install_error_msg;
 212       *errmsg_arg = (char*) program;
 213       return -1;
 214     }
 215
 216   return pid;
 217 }
 218
 219 /* MS CRTDLL doesn't return enough information in status to decide if the
 220    child exited due to a signal or not, rather it simply returns an
 221    integer with the exit code of the child; eg., if the child exited with
 222    an abort() call and didn't have a handler for SIGABRT, it simply returns
 223    with status = 3. We fix the status code to conform to the usual WIF*
 224    macros. Note that WIFSIGNALED will never be true under CRTDLL. */
 225
 226 int
 227 pwait (pid, status, flags)
 228      int pid;
 229      int *status;
 230      int flags;
 231 {
 232   int termstat;
 233
 234   pid = _cwait (&termstat, pid, WAIT_CHILD);
 235
 236   /* ??? Here's an opportunity to canonicalize the values in STATUS.
 237      Needed?  */
 238
 239   /* cwait returns the child process exit code in termstat.
 240      A value of 3 indicates that the child caught a signal, but not
 241      which one.  Since only SIGABRT, SIGFPE and SIGINT do anything, we
 242      report SIGABRT.  */
 243   if (termstat == 3)
 244     *status = SIGABRT;
 245   else
 246     *status = (((termstat) & 0xff) << 8);
 247
 248   return pid;
 249 }