Initial version.

diff --git a/lib/subpipe.c b/lib/subpipe.c
new file mode 100644 (file)
index 0000000..7bb520a
--- /dev/null
+++ b/lib/subpipe.c
@@ -0,0 +1,196 @@
+/* Subprocesses with pipes.
+
+   Copyright (C) 2002 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
+
+/* Written by Paul Eggert <eggert@twinsun.com>
+   and Florian Krohm <florian@edamail.fishkill.ibm.com>.  */
+
+#if HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#if HAVE_SYS_TYPES_H
+# include <sys/types.h>
+#endif
+
+#include <errno.h>
+#ifndef errno
+extern int errno;
+#endif
+
+#include <signal.h>
+#if ! defined SIGCHLD && defined SIGCLD
+# define SIGCHLD SIGCLD
+#endif
+
+#if HAVE_STDLIB_H
+# include <stdlib.h>
+#endif
+/* The following test is to work around the gross typo in
+   systems like Sony NEWS-OS Release 4.0C, whereby EXIT_FAILURE
+   is defined to 0, not 1.  */
+#if ! EXIT_FAILURE
+# undef EXIT_FAILURE
+# define EXIT_FAILURE 1
+#endif
+
+#if HAVE_UNISTD_H
+# include <unistd.h>
+#endif
+#ifndef STDIN_FILENO
+# define STDIN_FILENO 0
+#endif
+#ifndef STDOUT_FILENO
+# define STDOUT_FILENO 1
+#endif
+#if ! HAVE_DUP2 && ! defined dup2
+# if HAVE_FCNTL_H
+#  include <fcntl.h>
+# endif
+# define dup2(f, t) (close (t), fcntl (f, F_DUPFD, t))
+#endif
+
+#if HAVE_SYS_WAIT_H
+# include <sys/wait.h>
+#endif
+#ifndef WEXITSTATUS
+# define WEXITSTATUS(stat_val) ((unsigned int) (stat_val) >> 8)
+#endif
+#ifndef WIFEXITED
+# define WIFEXITED(stat_val) (((stat_val) & 255) == 0)
+#endif
+
+#if HAVE_VFORK_H
+# include <vfork.h>
+#endif
+#if ! HAVE_WORKING_VFORK
+# define vfork fork
+#endif
+
+#include "error.h"
+
+#include "gettext.h"
+#define _(Msgid)  gettext (Msgid)
+
+#include "subpipe.h"
+
+
+/* Initialize this module.  */
+
+void
+init_subpipe (void)
+{
+#ifdef SIGCHLD
+  /* System V fork+wait does not work if SIGCHLD is ignored.  */
+  signal (SIGCHLD, SIG_DFL);
+#endif
+}
+
+
+/* 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.
+
+   To avoid deadlock, the invoker must not let incoming data pile up
+   in FD[1] while writing data to FD[0].  */
+
+pid_t
+create_subpipe (char const * const *argv, int fd[2])
+{
+  int pipe_fd[2];
+  int from_in_fd;
+  int from_out_fd;
+  int to_in_fd;
+  int to_out_fd;
+  pid_t pid;
+
+  if (pipe (pipe_fd) != 0)
+    error (EXIT_FAILURE, errno, "pipe");
+  to_in_fd = pipe_fd[0];
+  to_out_fd = pipe_fd[1];
+
+  if (pipe (pipe_fd) != 0)
+    error (EXIT_FAILURE, errno, "pipe");
+  from_in_fd = pipe_fd[0];
+  from_out_fd = pipe_fd[1];
+
+  pid = vfork ();
+  if (pid < 0)
+    error (EXIT_FAILURE, errno, "fork");
+
+  if (! pid)
+    {
+      /* Child.  */
+      close (to_out_fd);
+      close (from_in_fd);
+
+      if (to_in_fd != STDIN_FILENO)
+       {
+         dup2 (to_in_fd, STDIN_FILENO);
+         close (to_in_fd);
+       }
+      if (from_out_fd != STDOUT_FILENO)
+       {
+         dup2 (from_out_fd, STDOUT_FILENO);
+         close (from_out_fd);
+       }
+
+      /* The cast to (char **) rather than (char * const *) is needed
+        for portability to older hosts with a nonstandard prototype
+        for execvp.  */
+      execvp (argv[0], (char **) argv);
+    
+      _exit (errno == ENOENT ? 127 : 126);
+    }
+
+  /* Parent.  */
+  close (to_in_fd);
+  close (from_out_fd);
+  fd[0] = to_out_fd;
+  fd[1] = from_in_fd;
+  return pid;
+}
+
+
+/* Wait for the subprocess to exit.  */
+
+void
+reap_subpipe (pid_t pid, char const *program)
+{
+#if HAVE_WAITPID || defined waitpid
+  int wstatus;
+  if (waitpid (pid, &wstatus, 0) < 0)
+    error (EXIT_FAILURE, errno, "waitpid");
+  else
+    {
+      int status = WIFEXITED (wstatus) ? WEXITSTATUS (wstatus) : -1;
+      if (status)
+       error (EXIT_FAILURE, 0,
+              _(status == 126
+                ? "subsidiary program `%s' could not be invoked"
+                : status == 127
+                ? "subsidiary program `%s' not found"
+                : status < 0
+                ? "subsidiary program `%s' failed"
+                : "subsidiary program `%s' failed (exit status %d)"),
+              program, status);
+    }
+#endif
+}

diff --git a/lib/subpipe.h b/lib/subpipe.h
new file mode 100644 (file)
index 0000000..6f4a592
--- /dev/null
+++ b/lib/subpipe.h
@@ -0,0 +1,26 @@
+/* Subprocesses with pipes.
+   Copyright (C) 2002 Free Software Foundation, Inc.
+
+   This file is part of Bison, the GNU Compiler Compiler.
+
+   Bison is free software; you can redistribute it and/or modify it
+   under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   Bison is distributed in the hope that it will be useful, but WITHOUT
+   ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+   or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
+   License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with Bison; see the file COPYING.  If not, write to the Free
+   Software Foundation, 59 Temple Place - Suite 330, Boston, MA
+   02111-1307, USA.  */
+
+/* Written by Paul Eggert <eggert@twinsun.com>
+   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 *);

diff --git a/m4/subpipe.m4 b/m4/subpipe.m4
new file mode 100644 (file)
index 0000000..d05bd77
--- /dev/null
+++ b/m4/subpipe.m4
@@ -0,0 +1,30 @@
+# -*- Autoconf -*-
+# Checks required to run `subpipe'.
+#
+# Copyright (C) 2002 Free Software Foundation, Inc.
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+# 02111-1307  USA
+
+# Written by Paul Eggert <eggert@twinsun.com>.
+
+AC_DEFUN([BISON_PREREQ_SUBPIPE],
+[
+ AC_TYPE_PID_T
+ AC_CHECK_HEADERS([fcntl.h sys/wait.h])
+ AC_HEADER_SYS_WAIT
+ AC_CHECK_FUNCS(dup2 waitpid)
+ AC_FUNC_FORK
+])