--- /dev/null
+/* Subprocesses with pipes.
+
+ Copyright (C) 2005 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 Juan Manuel Guerrero <juan.guerrero@gmx.de>. */
+
+
+#if HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include "subpipe.h"
+
+#include <errno.h>
+#include <fcntl.h>
+#include <sys/stat.h>
+#include <process.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include "xalloc.h"
+
+
+#ifndef STDIN_FILENO
+# define STDIN_FILENO 0
+#endif
+#ifndef STDOUT_FILENO
+# define STDOUT_FILENO 1
+#endif
+
+
+#include "error.h"
+
+#include "gettext.h"
+#define _(Msgid) gettext (Msgid)
+
+
+/* Initialize this module. */
+
+
+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 a temporary file 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 a temporary file 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 temporary files. First bison's
+ stdout is redirected to a temporary 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 temporary 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 temporary 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 the temporary file 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
+end_of_output_subpipe(pid_t pid, 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 the temporary file failed"));
+ }
+ close(from_out_fd);
+
+ /*
+ * All m4's output will be gathered in this temporary 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 a temporary file 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 a temporary file 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 the temporary file 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);
+}
projects / bison.git / commitdiff
