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, 2004, 2005
   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 (char **argvec)
  57 {
  58   int i;
  59   char * command0 = argvec[0];
  60
  61   /* Ensure that the executable pathname uses Win32 backslashes. This
  62      is not necessary on NT, but on W9x, forward slashes causes failure
  63      of spawn* and exec* functions (and probably any function that
  64      calls CreateProcess) *iff* the executable pathname (argvec[0]) is
  65      a quoted string.  And quoting is necessary in case a pathname
  66      contains  embedded white space. You can't win.  */
  67   for (; *command0 != '\0'; command0++)
  68     if (*command0 == '/')
  69       *command0 = '\\';
  70
  71   for (i = 1; argvec[i] != 0; i++)
  72     {
  73       int len, j;
  74       char *temp, *newtemp;
  75
  76       temp = argvec[i];
  77       len = strlen (temp);
  78       for (j = 0; j < len; j++)
  79         {
  80           if (temp[j] == '"')
  81             {
  82               newtemp = xmalloc (len + 2);
  83               strncpy (newtemp, temp, j);
  84               newtemp [j] = '\\';
  85               strncpy (&newtemp [j+1], &temp [j], len-j);
  86               newtemp [len+1] = 0;
  87               temp = newtemp;
  88               len++;
  89               j++;
  90             }
  91         }
  92
  93         argvec[i] = temp;
  94       }
  95
  96   for (i = 0; argvec[i] != 0; i++)
  97     {
  98       if (strpbrk (argvec[i], " \t"))
  99         {
 100           int len, trailing_backslash;
 101           char *temp;
 102
 103           len = strlen (argvec[i]);
 104           trailing_backslash = 0;
 105
 106           /* There is an added complication when an arg with embedded white
 107              space ends in a backslash (such as in the case of -iprefix arg
 108              passed to cpp). The resulting quoted strings gets misinterpreted
 109              by the command interpreter -- it thinks that the ending quote
 110              is escaped by the trailing backslash and things get confused.
 111              We handle this case by escaping the trailing backslash, provided
 112              it was not escaped in the first place.  */
 113           if (len > 1
 114               && argvec[i][len-1] == '\\'
 115               && argvec[i][len-2] != '\\')
 116             {
 117               trailing_backslash = 1;
 118               ++len;                    /* to escape the final backslash. */
 119             }
 120
 121           len += 2;                     /* and for the enclosing quotes. */
 122
 123           temp = xmalloc (len + 1);
 124           temp[0] = '"';
 125           strcpy (temp + 1, argvec[i]);
 126           if (trailing_backslash)
 127             temp[len-2] = '\\';
 128           temp[len-1] = '"';
 129           temp[len] = '\0';
 130
 131           argvec[i] = temp;
 132         }
 133     }
 134
 135   return (const char * const *) argvec;
 136 }
 137
 138 /* Win32 supports pipes */
 139 int
 140 pexecute (const char *program, char * const *argv,
 141           const char *this_pname ATTRIBUTE_UNUSED,
 142           const char *temp_base ATTRIBUTE_UNUSED,
 143           char **errmsg_fmt, char **errmsg_arg, int flags)
 144 {
 145   int pid;
 146   int pdes[2];
 147   int org_stdin = -1;
 148   int org_stdout = -1;
 149   int input_desc, output_desc;
 150
 151   /* Pipe waiting from last process, to be used as input for the next one.
 152      Value is STDIN_FILE_NO if no pipe is waiting
 153      (i.e. the next command is the first of a group).  */
 154   static int last_pipe_input;
 155
 156   /* If this is the first process, initialize.  */
 157   if (flags & PEXECUTE_FIRST)
 158     last_pipe_input = STDIN_FILE_NO;
 159
 160   input_desc = last_pipe_input;
 161
 162   /* If this isn't the last process, make a pipe for its output,
 163      and record it as waiting to be the input to the next process.  */
 164   if (! (flags & PEXECUTE_LAST))
 165     {
 166       if (_pipe (pdes, 256, O_BINARY) < 0)
 167         {
 168           *errmsg_fmt = "pipe";
 169           *errmsg_arg = NULL;
 170           return -1;
 171         }
 172       output_desc = pdes[WRITE_PORT];
 173       last_pipe_input = pdes[READ_PORT];
 174     }
 175   else
 176     {
 177       /* Last process.  */
 178       output_desc = STDOUT_FILE_NO;
 179       last_pipe_input = STDIN_FILE_NO;
 180     }
 181
 182   if (input_desc != STDIN_FILE_NO)
 183     {
 184       org_stdin = dup (STDIN_FILE_NO);
 185       dup2 (input_desc, STDIN_FILE_NO);
 186       close (input_desc);
 187     }
 188
 189   if (output_desc != STDOUT_FILE_NO)
 190     {
 191       org_stdout = dup (STDOUT_FILE_NO);
 192       dup2 (output_desc, STDOUT_FILE_NO);
 193       close (output_desc);
 194     }
 195
 196   pid = (flags & PEXECUTE_SEARCH ? _spawnvp : _spawnv)
 197     (_P_NOWAIT, program, fix_argv(argv));
 198
 199   if (input_desc != STDIN_FILE_NO)
 200     {
 201       dup2 (org_stdin, STDIN_FILE_NO);
 202       close (org_stdin);
 203     }
 204
 205   if (output_desc != STDOUT_FILE_NO)
 206     {
 207       dup2 (org_stdout, STDOUT_FILE_NO);
 208       close (org_stdout);
 209     }
 210
 211   if (pid == -1)
 212     {
 213       *errmsg_fmt = install_error_msg;
 214       *errmsg_arg = (char*) program;
 215       return -1;
 216     }
 217
 218   return pid;
 219 }
 220
 221 /* MS CRTDLL doesn't return enough information in status to decide if the
 222    child exited due to a signal or not, rather it simply returns an
 223    integer with the exit code of the child; eg., if the child exited with
 224    an abort() call and didn't have a handler for SIGABRT, it simply returns
 225    with status = 3. We fix the status code to conform to the usual WIF*
 226    macros. Note that WIFSIGNALED will never be true under CRTDLL. */
 227
 228 int
 229 pwait (int pid, int *status, int flags ATTRIBUTE_UNUSED)
 230 {
 231   int termstat;
 232
 233   pid = _cwait (&termstat, pid, WAIT_CHILD);
 234
 235   /* ??? Here's an opportunity to canonicalize the values in STATUS.
 236      Needed?  */
 237
 238   /* cwait returns the child process exit code in termstat.
 239      A value of 3 indicates that the child caught a signal, but not
 240      which one.  Since only SIGABRT, SIGFPE and SIGINT do anything, we
 241      report SIGABRT.  */
 242   if (termstat == 3)
 243     *status = SIGABRT;
 244   else
 245     *status = (((termstat) & 0xff) << 8);
 246
 247   return pid;
 248 }