[bison.git] / djgpp / subpipe.c

/* Subprocesses with pipes.

   Copyright (C) 2005, 2006, 2007, 2008 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 3 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, see <http://www.gnu.org/licenses/>.  */

/* Written by Juan Manuel Guerrero <juan.guerrero@gmx.de>. */


#include <config.h>

#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)
{
  char *tmpdir;
  int fd;

  tmpdir = getenv("TMPDIR");
  if (tmpdir == NULL)
    tmpdir = getenv("TMP");
  if (tmpdir == NULL)
    tmpdir = getenv("TEMP");
  if (access(tmpdir, D_OK))
    tmpdir = ".";

  strcpy(tmp_file_name[0], tmpdir);
  strcat(tmp_file_name[0], "/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], tmpdir);
  strcat(tmp_file_name[1], "/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);
}
Commit	Line	Data
6bebb373 JMG	1	/* Subprocesses with pipes.
6bebb373 JMG	2
988a9d67	3	Copyright (C) 2005, 2006, 2007, 2008 Free Software Foundation, Inc.
6bebb373	4
f16b0819	5	This program is free software: you can redistribute it and/or modify
6bebb373	6	it under the terms of the GNU General Public License as published by
f16b0819 PE	7	the Free Software Foundation, either version 3 of the License, or
f16b0819 PE	8	(at your option) any later version.
6bebb373 JMG	9
	10	This program is distributed in the hope that it will be useful,
	11	but WITHOUT ANY WARRANTY; without even the implied warranty of
	12	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	13	GNU General Public License for more details.
	14
	15	You should have received a copy of the GNU General Public License
f16b0819	16	along with this program. If not, see <http://www.gnu.org/licenses/>. */
6bebb373 JMG	17
	18	/* Written by Juan Manuel Guerrero <juan.guerrero@gmx.de>. */
	19
	20
231ed89a	21	#include <config.h>
6bebb373 JMG	22
	23	#include "subpipe.h"
	24
	25	#include <errno.h>
	26	#include <fcntl.h>
	27	#include <sys/stat.h>
	28	#include <process.h>
	29	#include <signal.h>
	30	#include <stdio.h>
	31	#include <stdlib.h>
	32	#include <string.h>
	33	#include <unistd.h>
	34	#include "xalloc.h"
	35
	36
	37	#ifndef STDIN_FILENO
	38	# define STDIN_FILENO 0
	39	#endif
	40	#ifndef STDOUT_FILENO
	41	# define STDOUT_FILENO 1
	42	#endif
	43
	44
	45	#include "error.h"
	46
	47	#include "gettext.h"
	48	#define _(Msgid) gettext (Msgid)
	49
	50
	51	/* Initialize this module. */
	52
	53
	54	static int old_stdin;
	55	static int old_stdout;
	56	static char **arguments;
	57	static char tmp_file_name[2][L_tmpnam];
	58
	59	#define remove_tmp_file(fd, name) \
	60	do { \
	61	close ((fd)); \
	62	if (unlink ((name))) \
	63	error (EXIT_FAILURE, 0, _("removing of `%s' failed"), (name)); \
	64	} while (0)
	65
	66
	67	void
	68	init_subpipe(void)
	69	{
988a9d67	70	char *tmpdir;
6bebb373 JMG	71	int fd;
6bebb373 JMG	72
988a9d67 JMG	73	tmpdir = getenv("TMPDIR");
	74	if (tmpdir == NULL)
	75	tmpdir = getenv("TMP");
	76	if (tmpdir == NULL)
	77	tmpdir = getenv("TEMP");
	78	if (access(tmpdir, D_OK))
	79	tmpdir = ".";
	80
	81	strcpy(tmp_file_name[0], tmpdir);
	82	strcat(tmp_file_name[0], "/bnXXXXXX");
6bebb373 JMG	83	fd = mkstemp(tmp_file_name[0]);
	84	if (fd < 0)
	85	error(EXIT_FAILURE, 0, _("creation of a temporary file failed"));
	86	close (fd);
02650b7f	87
988a9d67 JMG	88	strcpy(tmp_file_name[1], tmpdir);
988a9d67 JMG	89	strcat(tmp_file_name[1], "/bnXXXXXX");
6bebb373 JMG	90	fd = mkstemp(tmp_file_name[1]);
	91	if (fd < 0)
	92	error(EXIT_FAILURE, 0, _("creation of a temporary file failed"));
	93	close (fd);
	94	}
	95
	96
	97	/* Create a subprocess that is run as a filter. ARGV is the
	98	NULL-terminated argument vector for the subprocess. Store read and
	99	write file descriptors for communication with the subprocess into
	100	FD[0] and FD[1]: input meant for the process can be written into
	101	FD[0], and output from the process can be read from FD[1]. Return
	102	the subprocess id.
	103
	104	Because DOS has neither fork nor pipe functionality to run the subprocess
	105	as a filter, the filter is reproduced using temporary files. First bison's
	106	stdout is redirected to a temporary file. After bison has produced all of
	107	is output, this file is closed and connected to m4's stdin. All m4's output
	108	is redirected from m4's stdout to a second temporary file and reopened as
	109	bison's stdin. */
	110
	111	pid_t
	112	create_subpipe(char const const argv, int fd[2])
	113	{
	114	int argc;
	115	int from_in_fd; /* pipe from bison to m4. */
	116	pid_t pid;
	117
	118
	119	pid = getpid();
	120
	121	/*
	122	* Save original stdin and stdout
	123	* for later restauration.
	124	*/
	125	old_stdin = dup(STDIN_FILENO);
	126	if (old_stdin < 0)
	127	error(EXIT_FAILURE, 0, _("saving stdin failed"));
	128
	129	old_stdout = dup(STDOUT_FILENO);
	130	if (old_stdout < 0)
	131	error(EXIT_FAILURE, 0, _("saving stdout failed"));
	132
	133	/*
	134	* Save argv for later use.
	135	*/
	136	for (argc = 0; argv[argc]; argc++)
	137	;
	138	argc++;
	139	arguments = xmalloc(argc * sizeof(arguments[0]));
	140	for (argc = 0; argv[argc]; argc++)
	141	{
	142	arguments[argc] = xmalloc((strlen(argv[argc]) + 1) * sizeof(arguments[0][0]));
	143	strcpy(arguments[argc], argv[argc]);
	144	}
	145	arguments[argc] = NULL;
	146
	147	/*
	148	* All bison's output will be gathered in this temporary file
	149	* and will be redirected to m4's stdin.
	150	*/
	151	from_in_fd = open(tmp_file_name[0], O_WRONLY \| O_CREAT \| O_TRUNC, S_IWUSR);
	152	if (from_in_fd < 0)
	153	error(EXIT_FAILURE, 0, _("opening of tmpfile failed"));
154	if (dup2(from_in_fd, STDOUT_FILENO) < 0)
155	{
156	remove_tmp_file(from_in_fd, tmp_file_name[0]);
157	error(EXIT_FAILURE, 0, _("redirecting bison's stdout to the temporary file failed"));
158	}
159	close(from_in_fd);
160
161
162	fd[0] = STDOUT_FILENO;
163	return pid;
164	}
165
166
167	/* A signal handler that just records that a signal has happened. */
168	static int child_interrupted;
169
170	static void
171	signal_catcher(int signo)
172	{
173	child_interrupted++;
174	}
175
176
177	void
178	end_of_output_subpipe(pid_t pid, int fd[2])
179	{
180	char *program;
181	int from_out_fd = open(tmp_file_name[0], O_RDONLY, S_IRUSR); /* pipe from bison to m4. */
182	int to_in_fd = open(tmp_file_name[1], O_WRONLY \| O_CREAT \| O_TRUNC, S_IWUSR); /* pipe from m4 to bison. */
183	int status;
184	void (*previous_handler)(int);
185
186
187	program = strrchr(arguments[0], '/');
188	if (program)
189	program++;
190	else
191	program = arguments[0];
192
193	/*
194	* Redirect bison's output to m4's stdin.
195	*/
196	if (from_out_fd < 0)
197	error(EXIT_FAILURE, 0, _("opening of tmpfile failed"));
198	if (dup2(from_out_fd, STDIN_FILENO) < 0)
199	{
200	remove_tmp_file(from_out_fd, tmp_file_name[0]);
201	error(EXIT_FAILURE, 0, _("redirecting m4's stdin from the temporary file failed"));
202	}
203	close(from_out_fd);
204
205	/*
206	* All m4's output will be gathered in this temporary file
207	* and will be redirected to bison's stdin.
208	*/
209	if (to_in_fd < 0)
210	{
211	remove_tmp_file(STDIN_FILENO, tmp_file_name[0]);
212	error(EXIT_FAILURE, 0, _("opening of a temporary file failed"));
213	}
214	if (dup2(to_in_fd, STDOUT_FILENO) < 0)
215	{
216	remove_tmp_file(STDIN_FILENO, tmp_file_name[0]);
217	remove_tmp_file(to_in_fd, tmp_file_name[1]);
218	error(EXIT_FAILURE, 0, _("redirecting m4's stdout to a temporary file failed"));
219	}
220	close(to_in_fd);
221
222	/*
223	* Run m4.
224	*/
225	child_interrupted = 0;
226	errno = 0;
227	previous_handler = signal(SIGINT, signal_catcher);
228	status = spawnvp(P_WAIT, program, arguments);
229	signal(SIGINT, previous_handler);
230	if (child_interrupted)
231	{
232	remove_tmp_file(STDIN_FILENO, tmp_file_name[0]);
233	remove_tmp_file(STDOUT_FILENO, tmp_file_name[1]);
234	error(EXIT_FAILURE, 0, _("subsidiary program `%s' interrupted"), program);
235	}
236	if (status)
237	{
238	remove_tmp_file(STDIN_FILENO, tmp_file_name[0]);
239	remove_tmp_file(STDOUT_FILENO, tmp_file_name[1]);
240	error(EXIT_FAILURE, 0, _(errno == ENOENT
02650b7f PE	241	? "subsidiary program `%s' not found"
	242	: status < 1
	243	? "subsidiary program `%s' failed"
	244	: "subsidiary program `%s' failed (status=%i, errno=%i)"), program, status, errno);
6bebb373 JMG	245	}
	246
	247
	248	/*
	249	* Redirect m4's output to bison's stdin.
	250	*/
	251	if (dup2(old_stdout, STDOUT_FILENO) < 0)
	252	error(EXIT_FAILURE, 0, "restore of bison's stdout failed");
	253	close(old_stdout);
	254	to_in_fd = open(tmp_file_name[1], O_RDONLY, S_IRUSR); /* pipe from m4 to bison. */
	255	if (to_in_fd < 0)
	256	{
	257	remove_tmp_file(STDIN_FILENO, tmp_file_name[0]);
	258	error(EXIT_FAILURE, 0, _("opening of tmpfile failed"));
	259	}
	260	if (dup2(to_in_fd, STDIN_FILENO) < 0)
	261	{
	262	remove_tmp_file(STDIN_FILENO, tmp_file_name[0]);
	263	remove_tmp_file(to_in_fd, tmp_file_name[1]);
	264	error(EXIT_FAILURE, -1, "dup2");
	265	error(EXIT_FAILURE, 0, _("redirecting bison's stdin from the temporary file failed"));
	266	}
	267	close(to_in_fd);
	268
	269
	270	fd[1] = STDIN_FILENO;
	271	}
	272
	273
	274	/* Free resources, unlink temporary files and restore stdin and stdout. */
	275
	276	void
	277	reap_subpipe(pid_t pid, char const *program)
	278	{
	279	int argc;
	280
	281	for (argc = 0; arguments[argc]; argc++)
	282	free(arguments[argc]);
	283	free(arguments);
	284
	285	if (unlink(tmp_file_name[0]))
	286	error(EXIT_FAILURE, 0, _("removing of `%s' failed"), tmp_file_name[0]);
	287	if (unlink(tmp_file_name[1]))
	288	error(EXIT_FAILURE, 0, _("removing of `%s' failed"), tmp_file_name[1]);
	289
	290	if (dup2(old_stdin, STDIN_FILENO) < 0)
	291	error(EXIT_FAILURE, 0, "restore of bison's stdin failed");
	292	close(old_stdin);
	293	}