2004-12-06  Guerrero, Juan Manuel  <st001906@hrz1.hrz.tu-darmstadt.de>

	* src/system.h [MSDOS]: __DJGPP__ conditional added.  Use pathconf
	  to choose POSIX or DOS file extensions at run time.
	* lib/subpipe.c: Use conditionals HAVE_WORKING_VFORK and
	  HAVE_WORKING_FORK to select the appropriate versions of the functions
	  init_subpipe, create_subpipe and reap_subpipe.
	  lib/subpipe.c [HAVE_WORKING_VFORK, HAVE_WORKING_FORK]: DJGPP specific
	  versions of init_subpipe, create_subpipe, reap_subpipe and run_m4
	  to emulate the missing fork/pipe functionality on MSDOS.
	* src/output.c (output_skeleton) [!HAVE_WORKING_VFORK, !HAVE_WORKING_FORK]:
	  Call function run_m4 to generate parser output file on non posix systems. 
	* lib/subpipe.h [!HAVE_WORKING_VFORK, !HAVE_WORKING_FORK]: Add run_m4
	  declaration on non posix systems.
	* lib/subpipe.c [HAVE_WORKING_VFORK, HAVE_WORKING_FORK]: Add function
	  signal_catcher.



diff -apruNU5 bison-1.875.orig/lib/subpipe.c bison-1.875/lib/subpipe.c
--- bison-1.875.orig/lib/subpipe.c	2002-10-20 06:28:22.000000000 +0000
+++ bison-1.875/lib/subpipe.c	2004-12-06 02:55:40.000000000 +0000
@@ -87,10 +87,12 @@ extern int errno;
 #define _(Msgid)  gettext (Msgid)
 
 #include "subpipe.h"
 
 
+#if HAVE_WORKING_VFORK || HAVE_WORKING_FORK
+
 /* Initialize this module.  */
 
 void
 init_subpipe (void)
 {
@@ -192,5 +194,250 @@ reap_subpipe (pid_t pid, char const *pro
 		 : "subsidiary program `%s' failed (exit status %d)"),
 	       program, status);
     }
 #endif
 }
+#else /* !HAVE_WORKING_VFORK and !HAVE_WORKING_FORK */
+# if __DJGPP__
+/* Initialize this module.  */
+
+#include <fcntl.h>
+#include <sys/stat.h>
+#include <process.h>
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+#include "xalloc.h"
+
+static int old_stdin;
+static int old_stdout;
+static char **arguments;
+static char tmp_file_name[2][L_tmpnam];
+
+#define remove_tmp_file(fd, name)                                     \
+  do {                                                                \
+    close ((fd));                                                     \
+    if (unlink ((name)))                                              \
+      error (EXIT_FAILURE, 0, _("removing of `%s' failed"), (name));  \
+  } while (0)
+
+
+void
+init_subpipe (void)
+{
+  int fd;
+
+  strcpy (tmp_file_name[0], "/dev/env/TMPDIR/bnXXXXXX");
+  fd = mkstemp (tmp_file_name[0]);
+  if (fd < 0)
+    error (EXIT_FAILURE, 0, _("creation of tmpfile failed"));
+  close (fd);
+  
+  strcpy (tmp_file_name[1], "/dev/env/TMPDIR/bnXXXXXX");
+  fd = mkstemp (tmp_file_name[1]);
+  if (fd < 0)
+    error (EXIT_FAILURE, 0, _("creation of tmpfile failed"));
+  close (fd);
+}
+
+
+/* Create a subprocess that is run as a filter.  ARGV is the
+   NULL-terminated argument vector for the subprocess.  Store read and
+   write file descriptors for communication with the subprocess into
+   FD[0] and FD[1]: input meant for the process can be written into
+   FD[0], and output from the process can be read from FD[1].  Return
+   the subprocess id.
+
+   Because DOS has neither fork nor pipe functionality to run the subprocess
+   as a filter, the filter is reproduced using tmeporary files. First bison's
+   stdout is redirected to a temp. file. After bison has produced all of is
+   output, this file is closed and connected to m4's stdin. All m4's output
+   is redirected from m4's stdout to a second temp. file and reopened as
+   bison's stdin.  */
+
+pid_t
+create_subpipe (char const * const *argv, int fd[2])
+{
+  int argc;
+  int from_in_fd;  /* pipe from bison to m4. */
+  pid_t pid;
+
+
+  pid = getpid ();
+
+  /*
+   *  Save original stdin and stdout
+   *  for later restauration.
+   */
+  old_stdin = dup (STDIN_FILENO);
+  if (old_stdin < 0)
+    error (EXIT_FAILURE, 0, _("saving stdin failed"));
+
+  old_stdout = dup (STDOUT_FILENO);
+  if (old_stdout < 0)
+    error (EXIT_FAILURE, 0, _("saving stdout failed"));
+
+  /*
+   *  Save argv for later use.
+   */
+  for (argc = 0; argv[argc]; argc++)
+    ;
+  argc++;
+  arguments = xmalloc (argc * sizeof(arguments[0]));
+  for (argc = 0; argv[argc]; argc++)
+  {
+    arguments[argc] = xmalloc ((strlen (argv[argc]) + 1) * sizeof(arguments[0][0]));
+    strcpy (arguments[argc], argv[argc]);
+  }
+  arguments[argc] = NULL;
+
+  /*
+   *  All bison's output will be gathered in this temp. file
+   *  and will be redirected to m4's stdin.
+   */
+  from_in_fd = open (tmp_file_name[0], O_WRONLY | O_CREAT | O_TRUNC, S_IWUSR);
+  if (from_in_fd < 0)
+    error (EXIT_FAILURE, 0, _("opening of tmpfile failed"));
+  if (dup2 (from_in_fd, STDOUT_FILENO) < 0)
+  {
+    remove_tmp_file (from_in_fd, tmp_file_name[0]);
+    error (EXIT_FAILURE, 0, _("redirecting bison's stdout to tmpfile failed"));
+  }
+  close (from_in_fd);
+
+
+  fd[0] = STDOUT_FILENO;
+  return pid;
+}
+
+
+/* A signal handler that just records that a signal has happened.  */
+static int child_interrupted;
+
+static void
+signal_catcher (int signo)
+{
+  child_interrupted++;
+}
+
+
+void
+run_m4 (int fd[2])
+{
+  char *program;
+  int from_out_fd = open (tmp_file_name[0], O_RDONLY, S_IRUSR);                   /* pipe from bison to m4. */
+  int to_in_fd = open (tmp_file_name[1], O_WRONLY | O_CREAT | O_TRUNC, S_IWUSR);  /* pipe from m4 to bison. */
+  int status;
+  void (*previous_handler)(int);
+
+
+  program = strrchr (arguments[0], '/');
+  if (program)
+    program++;
+  else
+    program = arguments[0];
+
+  /*
+   *  Redirect bison's output to m4's stdin.
+   */
+  if (from_out_fd < 0)
+    error (EXIT_FAILURE, 0, _("opening of tmpfile failed"));
+  if (dup2 (from_out_fd, STDIN_FILENO) < 0)
+  {
+    remove_tmp_file (from_out_fd, tmp_file_name[0]);
+    error (EXIT_FAILURE, 0, _("redirecting m4's stdin from tmpfile failed"));
+  }
+  close (from_out_fd);
+
+  /*
+   *  All m4's output will be gathered in this temp. file
+   *  and will be redirected to bison's stdin.
+   */
+  if (to_in_fd < 0)
+  {
+    remove_tmp_file (STDIN_FILENO, tmp_file_name[0]);
+    error (EXIT_FAILURE, 0, _("opening of tmpfile failed"));
+  }
+  if (dup2 (to_in_fd, STDOUT_FILENO) < 0)
+  {
+    remove_tmp_file (STDIN_FILENO, tmp_file_name[0]);
+    remove_tmp_file (to_in_fd, tmp_file_name[1]);
+    error (EXIT_FAILURE, 0, _("redirecting m4's stdout to tmpfile failed"));
+  }
+  close (to_in_fd);
+
+  /*
+   *  Run m4.
+   */
+  child_interrupted = 0;
+  errno = 0;
+  previous_handler = signal (SIGINT, signal_catcher);
+  status = spawnvp (P_WAIT, program, arguments);
+  signal (SIGINT, previous_handler);
+  if (child_interrupted)
+  {
+    remove_tmp_file (STDIN_FILENO, tmp_file_name[0]);
+    remove_tmp_file (STDOUT_FILENO, tmp_file_name[1]);
+    error (EXIT_FAILURE, 0, _("subsidiary program `%s' interrupted"), program);
+  }
+  if (status)
+  {
+    remove_tmp_file (STDIN_FILENO, tmp_file_name[0]);
+    remove_tmp_file (STDOUT_FILENO, tmp_file_name[1]);
+    error (EXIT_FAILURE, 0, _(errno == ENOENT
+                              ? "subsidiary program `%s' not found"
+                              : status < 1
+                              ? "subsidiary program `%s' failed"
+                              : "subsidiary program `%s' failed (status=%i, errno=%i)"), program, status, errno);
+  }
+
+
+  /*
+   *  Redirect m4's output to bison's stdin.
+   */
+  if (dup2 (old_stdout, STDOUT_FILENO) < 0)
+    error (EXIT_FAILURE, 0, "restore of bison's stdout failed");
+  close (old_stdout);
+  to_in_fd = open (tmp_file_name[1], O_RDONLY, S_IRUSR);  /* pipe from m4 to bison. */
+  if (to_in_fd < 0)
+  {
+    remove_tmp_file (STDIN_FILENO, tmp_file_name[0]);
+    error (EXIT_FAILURE, 0, _("opening of tmpfile failed"));
+  }
+  if (dup2 (to_in_fd, STDIN_FILENO) < 0)
+  {
+    remove_tmp_file (STDIN_FILENO, tmp_file_name[0]);
+    remove_tmp_file (to_in_fd, tmp_file_name[1]);
+    error (EXIT_FAILURE, -1, "dup2");
+    error (EXIT_FAILURE, 0, _("redirecting bison's stdin from tmpfile failed"));
+  }
+  close (to_in_fd);
+
+
+  fd[1] = STDIN_FILENO;
+}
+
+
+/* Free resources, unlink temporary files and restore stdin and stdout.  */
+
+void
+reap_subpipe (pid_t pid, char const *program)
+{
+  int argc;
+
+  for (argc = 0; arguments[argc]; argc++)
+    free (arguments[argc]);
+  free (arguments);
+
+  if (unlink (tmp_file_name[0]))
+    error (EXIT_FAILURE, 0, _("removing of `%s' failed"), tmp_file_name[0]);
+  if (unlink (tmp_file_name[1]))
+    error (EXIT_FAILURE, 0, _("removing of `%s' failed"), tmp_file_name[1]);
+
+  if (dup2 (old_stdin, STDIN_FILENO) < 0)
+    error (EXIT_FAILURE, 0, "restore of bison's stdin failed");
+  close (old_stdin);
+}
+# elif /* !__DJGPP__ */
+#  error "vfork, fork or an emulation is required."
+# endif /* !__DJGPP__ */
+#endif /* !HAVE_WORKING_VFORK and !HAVE_WORKING_FORK */
diff -apruNU5 bison-1.875.orig/lib/subpipe.h bison-1.875/lib/subpipe.h
--- bison-1.875.orig/lib/subpipe.h	2002-10-20 06:28:10.000000000 +0000
+++ bison-1.875/lib/subpipe.h	2004-12-06 02:55:40.000000000 +0000
@@ -22,5 +22,9 @@
    and Florian Krohm <florian@edamail.fishkill.ibm.com>.  */
 
 void init_subpipe (void);
 pid_t create_subpipe (char const * const *, int[2]);
 void reap_subpipe (pid_t, char const *);
+#if !HAVE_WORKING_VFORK && !HAVE_WORKING_FORK
+void run_m4 (int[2]);
+#endif
+
diff -apruNU5 bison-1.875.orig/src/output.c bison-1.875/src/output.c
--- bison-1.875.orig/src/output.c	2002-12-26 08:25:56.000000000 +0000
+++ bison-1.875/src/output.c	2004-12-06 02:58:48.000000000 +0000
@@ -581,10 +581,15 @@ output_skeleton (void)
   fputs ("m4_divert_push(0)dnl\n", out);
   xfclose (out);
 
   /* Read and process m4's output.  */
   timevar_push (TV_M4);
+#if !HAVE_WORKING_VFORK && !HAVE_WORKING_FORK
+  /* On non posix systems that lack vfork or vork
+     m4 must be explicitly spwaned to process bison output. */
+  run_m4 (filter_fd);
+#endif
   in = fdopen (filter_fd[1], "r");
   if (! in)
     error (EXIT_FAILURE, get_errno (), "fdopen");
   scan_skel (in);
   xfclose (in);
diff -apruNU5 bison-1.875.orig/src/system.h bison-1.875/src/system.h
--- bison-1.875.orig/src/system.h	2002-12-13 08:44:28.000000000 +0000
+++ bison-1.875/src/system.h	2004-12-06 02:55:40.000000000 +0000
@@ -239,12 +239,19 @@ do {								\
 # define TAB_EXT	"_tab"
 # define OUTPUT_EXT	".output"
 #else /* ! VMS */
 # ifdef MSDOS
    /* MS DOS. */
-#  define TAB_EXT	"_tab"
-#  define OUTPUT_EXT	".out"
+#  ifdef __DJGPP__
+    /* DJGPP. */
+#   include <unistd.h>
+#   define TAB_EXT	((pathconf(NULL, _PC_NAME_MAX) > 12) ? ".tab" : "_tab")
+#   define OUTPUT_EXT	((pathconf(NULL, _PC_NAME_MAX) > 12) ? ".output" : ".out")
+#  else /* ! __DJGPP__ */
+#   define TAB_EXT	"_tab"
+#   define OUTPUT_EXT	".out"
+#  endif /* ! __DJGPP__ */
 # else /* ! MSDOS */
   /* Standard. */
 #  define TAB_EXT	".tab"
 #  define OUTPUT_EXT	".output"
 # endif /* ! MSDOS */
