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portability: fix several issues with M4 subprocess.

Browse Source 
M4's output pipe was not being drained upon fatal errors during
scan_skel.  As a result, broken-pipe messages from M4 were seen
on at least AIX, HP-UX, Solaris, and RHEL4, and this caused a
failure in the test suite.  The problem was that, on platforms
where the default disposition for SIGPIPE is ignore instead of
terminate, M4 sometimes saw fwrite fail with errno=EPIPE and
then reported it.  However, there's some sort of race condition,
because the new test group occasionally succeeded.
Reported by Albert Chin at
<http://lists.gnu.org/archive/html/bug-bison/2010-02/msg00004.html>.

There were also problems with the test suite livelocking on
Tru64 5.1b.  Reported by Didier Godefroy at
<http://lists.gnu.org/archive/html/bug-bison/2009-05/msg00005.html>.
Switching to create_pipe_bidi suggested by Akim Demaille.

To attempt to solve both of these problems, switch to gnulib's
create_pipe_bidi and register M4 process as a slave.  Along the
way, clean up file name conflict handling, which was affected by
the broken-pipe problem before the switch.
* NEWS (2.4.2): Document.
* THANKS (Didier Godefroy): Add.
* bootstrap.conf (gnulib_modules): Add pipe.
* gnulib: Update to latest to make sure we have all the latest
fixes.
* lib/Makefile.am (libbison_a_SOURCES): Remove subpipe.h and
subpipe.c.
* po/POTFILES.in (lib/subpipe.c): Remove.
* src/files.c (compute_output_file_names): Update invocations
of output_file_name_check.
(output_file_name_check): In the case that the grammar file
would be overwritten, use complain instead of fatal, but replace
the output file name with /dev/null.  Use the /dev/null solution
for the case of two conflicting output files as well because it
seems safer in case Bison one day tries to open both files at
the same time.
* src/files.h (output_file_name_check): Update prototype.
* src/output.c (output_skeleton): Use create_pipe_bidi and
wait_subprocess.  Assert that scan_skel completely drains the
pipe.
* src/scan-skel.l (at_directive_perform): Update
output_file_name_check invocation.
* tests/output.at (AT_CHECK_CONFLICTING_OUTPUT): Check that the
grammar file actually isn't overwritten.
(Conflicting output files: -o foo.y): Update expected output.
* tests/skeletons.at (Fatal errors but M4 continues producing
output): New test group.
(cherry picked from commit 22cc8d813e)

Conflicts:

	NEWS
	bootstrap.conf
	lib/.cvsignore
	lib/.gitignore
	m4/.cvsignore
	m4/.gitignore
	src/output.c
This commit is contained in:
Joel E. Denny
2010-02-22 18:09:19 -05:00
parent d67e37a74b
commit 47fa574761
19 changed files with 298 additions and 239 deletions
Download Patch File Download Diff File Expand all files Collapse all files

52
ChangeLog
View File

@@ -1,3 +1,55 @@
2010-02-22 Joel E. Denny <jdenny@ces.clemson.edu>
portability: fix several issues with M4 subprocess.
M4's output pipe was not being drained upon fatal errors during
scan_skel. As a result, broken-pipe messages from M4 were seen
on at least AIX, HP-UX, Solaris, and RHEL4, and this caused a
failure in the test suite. The problem was that, on platforms
where the default disposition for SIGPIPE is ignore instead of
terminate, M4 sometimes saw fwrite fail with errno=EPIPE and
then reported it. However, there's some sort of race condition,
because the new test group occasionally succeeded.
Reported by Albert Chin at
<http://lists.gnu.org/archive/html/bug-bison/2010-02/msg00004.html>.
There were also problems with the test suite livelocking on
Tru64 5.1b. Reported by Didier Godefroy at
<http://lists.gnu.org/archive/html/bug-bison/2009-05/msg00005.html>.
Switching to create_pipe_bidi suggested by Akim Demaille.
To attempt to solve both of these problems, switch to gnulib's
create_pipe_bidi and register M4 process as a slave. Along the
way, clean up file name conflict handling, which was affected by
the broken-pipe problem before the switch.
* NEWS (2.4.2): Document.
* THANKS (Didier Godefroy): Add.
* bootstrap.conf (gnulib_modules): Add pipe.
* gnulib: Update to latest to make sure we have all the latest
fixes.
* lib/Makefile.am (libbison_a_SOURCES): Remove subpipe.h and
subpipe.c.
* po/POTFILES.in (lib/subpipe.c): Remove.
* src/files.c (compute_output_file_names): Update invocations
of output_file_name_check.
(output_file_name_check): In the case that the grammar file
would be overwritten, use complain instead of fatal, but replace
the output file name with /dev/null. Use the /dev/null solution
for the case of two conflicting output files as well because it
seems safer in case Bison one day tries to open both files at
the same time.
* src/files.h (output_file_name_check): Update prototype.
* src/output.c (output_skeleton): Use create_pipe_bidi and
wait_subprocess. Assert that scan_skel completely drains the
pipe.
* src/scan-skel.l (at_directive_perform): Update
output_file_name_check invocation.
* tests/output.at (AT_CHECK_CONFLICTING_OUTPUT): Check that the
grammar file actually isn't overwritten.
(Conflicting output files: -o foo.y): Update expected output.
* tests/skeletons.at (Fatal errors but M4 continues producing
output): New test group.
2010-02-04 Joel E. Denny <jdenny@ces.clemson.edu>
Update POTFILES.

6
NEWS
View File

@@ -188,6 +188,12 @@ Bison News
* Changes in version 2.4.2 (????-??-??):
** Some portability problems that resulted in failures and livelocks
in the test suite on some versions of at least Solaris, AIX, HP-UX,
RHEL4, and Tru64 have been fixed. As part of those fixes, fatal
Bison errors no longer cause M4 to report a broken pipe on the
affected platforms.
** `%prec IDENTIFIER' requires IDENTIFIER to be defined separately.
POSIX specifies that an error be reported for any identifier that does

1
THANKS
View File

@@ -29,6 +29,7 @@ David J. MacKenzie djm@gnu.org
Derek M. Jones derek@knosof.co.uk
Di-an Jan dianj@freeshell.org
Dick Streefland dick.streefland@altium.nl
Didier Godefroy dg@ulysium.net
Enrico Scholz enrico.scholz@informatik.tu-chemnitz.de
Eric Blake ebb9@byu.net
Evgeny Stambulchik fnevgeny@plasma-gate.weizmann.ac.il

2
bootstrap.conf
View File

@@ -20,7 +20,7 @@ gnulib_modules='
announce-gen argmatch assert config-h c-strcase configmake dirname
error extensions fopen-safer gendocs getopt-gnu gettext
git-version-gen hash inttypes javacomp-script javaexec-script
maintainer-makefile malloc mbswidth obstack quote quotearg
maintainer-makefile malloc mbswidth obstack pipe quote quotearg
realloc-posix stdbool stpcpy strerror strtoul strverscmp unistd
unistd-safer unlocked-io update-copyright unsetenv verify warnings
xalloc xalloc-die xstrndup

2
gnulib

Submodule gnulib updated: 102c411be0...9d0ad652de

49
lib/.cvsignore
View File

@@ -8,6 +8,7 @@ argmatch.h
asnprintf.c
basename-lgpl.c
basename.c
binary-io.h
bitrotate.h
c-ctype.c
c-ctype.h
@@ -15,6 +16,8 @@ c-strcase.h
c-strcasecmp.c
c-strncasecmp.c
charset.alias
cloexec.c
cloexec.h
config.charset
config.h
config.hin
@@ -22,6 +25,7 @@ configmake.h
dirname-lgpl.c
dirname.c
dirname.h
dup-safer-flag.c
dup-safer.c
dup2.c
errno.h
@@ -30,9 +34,12 @@ error.c
error.h
exitfail.c
exitfail.h
fatal-signal.c
fatal-signal.h
fcntl.c
fcntl.h
fcntl.in.h
fd-safer-flag.c
fd-safer.c
float+.h
float.h
@@ -45,6 +52,7 @@ frexp.c
frexpl.c
fseterr.c
fseterr.h
getdtablesize.c
getopt.c
getopt.h
getopt.in.h
@@ -80,7 +88,12 @@ memchr.c
memchr.valgrind
obstack.c
obstack.h
open.c
pipe-safer.c
pipe.c
pipe.h
pipe2-safer.c
pipe2.c
printf-args.c
printf-args.h
printf-frexp.c
@@ -94,18 +107,42 @@ quote.c
quote.h
quotearg.c
quotearg.h
rawmemchr.c
rawmemchr.valgrind
realloc.c
ref-add.sed
ref-add.sin
ref-del.sed
ref-del.sin
sched.h
sched.in.h
sig-handler.h
sigaction.c
signal.h
signal.in.h
signbitd.c
signbitf.c
signbitl.c
sigprocmask.c
size_max.h
snprintf.c
spawn.h
spawn.in.h
spawn_faction_addclose.c
spawn_faction_adddup2.c
spawn_faction_addopen.c
spawn_faction_destroy.c
spawn_faction_init.c
spawn_int.h
spawnattr_destroy.c
spawnattr_init.c
spawnattr_setflags.c
spawnattr_setsigmask.c
spawni.c
spawnp.c
sprintf.c
stamp-h1
stat.c
stdbool.h
stdbool.in.h
stdbool_.h
@@ -124,6 +161,8 @@ stdlib.h
stdlib.in.h
stdlib_.h
stpcpy.c
strchrnul.c
strchrnul.valgrind
streq.h
strerror.c
string.h
@@ -136,6 +175,13 @@ strtol.c
strtoul.c
strverscmp.c
strverscmp.h
sys
sys_stat.h
sys_stat.in.h
sys_wait.h
sys_wait.in.h
time.h
time.in.h
unistd--.h
unistd-safer.h
unistd.h
@@ -152,6 +198,9 @@ verify.h
vfprintf.c
vsnprintf.c
vsprintf.c
w32spawn.h
wait-process.c
wait-process.h
wchar.h
wchar.in.h
wchar_.h

49
lib/.gitignore vendored
View File

@@ -11,6 +11,7 @@
/asnprintf.c
/basename-lgpl.c
/basename.c
/binary-io.h
/bitrotate.h
/c-ctype.c
/c-ctype.h
@@ -18,6 +19,8 @@
/c-strcasecmp.c
/c-strncasecmp.c
/charset.alias
/cloexec.c
/cloexec.h
/config.charset
/config.h
/config.hin
@@ -25,6 +28,7 @@
/dirname-lgpl.c
/dirname.c
/dirname.h
/dup-safer-flag.c
/dup-safer.c
/dup2.c
/errno.h
@@ -33,9 +37,12 @@
/error.h
/exitfail.c
/exitfail.h
/fatal-signal.c
/fatal-signal.h
/fcntl.c
/fcntl.h
/fcntl.in.h
/fd-safer-flag.c
/fd-safer.c
/float+.h
/float.h
@@ -48,6 +55,7 @@
/frexpl.c
/fseterr.c
/fseterr.h
/getdtablesize.c
/getopt.c
/getopt.h
/getopt.in.h
@@ -83,7 +91,12 @@
/memchr.valgrind
/obstack.c
/obstack.h
/open.c
/pipe-safer.c
/pipe.c
/pipe.h
/pipe2-safer.c
/pipe2.c
/printf-args.c
/printf-args.h
/printf-frexp.c
@@ -97,18 +110,42 @@
/quote.h
/quotearg.c
/quotearg.h
/rawmemchr.c
/rawmemchr.valgrind
/realloc.c
/ref-add.sed
/ref-add.sin
/ref-del.sed
/ref-del.sin
/sched.h
/sched.in.h
/sig-handler.h
/sigaction.c
/signal.h
/signal.in.h
/signbitd.c
/signbitf.c
/signbitl.c
/sigprocmask.c
/size_max.h
/snprintf.c
/spawn.h
/spawn.in.h
/spawn_faction_addclose.c
/spawn_faction_adddup2.c
/spawn_faction_addopen.c
/spawn_faction_destroy.c
/spawn_faction_init.c
/spawn_int.h
/spawnattr_destroy.c
/spawnattr_init.c
/spawnattr_setflags.c
/spawnattr_setsigmask.c
/spawni.c
/spawnp.c
/sprintf.c
/stamp-h1
/stat.c
/stdbool.h
/stdbool.in.h
/stdbool_.h
@@ -127,6 +164,8 @@
/stdlib.in.h
/stdlib_.h
/stpcpy.c
/strchrnul.c
/strchrnul.valgrind
/streq.h
/strerror.c
/string.h
@@ -139,6 +178,13 @@
/strtoul.c
/strverscmp.c
/strverscmp.h
/sys
/sys_stat.h
/sys_stat.in.h
/sys_wait.h
/sys_wait.in.h
/time.h
/time.in.h
/unistd--.h
/unistd-safer.h
/unistd.h
@@ -155,6 +201,9 @@
/vfprintf.c
/vsnprintf.c
/vsprintf.c
/w32spawn.h
/wait-process.c
/wait-process.h
/wchar.h
/wchar.in.h
/wchar_.h

1
lib/Makefile.am
View File

@@ -37,7 +37,6 @@ timevars_sources = \
# Non-gnulib sources in Bison's internal library.
libbison_a_SOURCES += \
get-errno.h get-errno.c \
subpipe.h subpipe.c \
$(bitsets_sources) $(additional_bitsets_sources) $(timevars_sources)
# The Yacc compatibility library.

177
lib/subpipe.c
View File

@@ -1,177 +0,0 @@
/* Subprocesses with pipes.
Copyright (C) 2002, 2004-2006, 2009-2010 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 Paul Eggert <eggert@twinsun.com>
and Florian Krohm <florian@edamail.fishkill.ibm.com>. */
#include <config.h>
#include "subpipe.h"
#include <errno.h>
#include <signal.h>
#if ! defined SIGCHLD && defined SIGCLD
# define SIGCHLD SIGCLD
#endif
#include <stdlib.h>
#include <unistd.h>
#ifndef STDIN_FILENO
# define STDIN_FILENO 0
#endif
#ifndef STDOUT_FILENO
# define STDOUT_FILENO 1
#endif
#if ! HAVE_DUP2 && ! defined dup2
# include <fcntl.h>
# 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 "unistd-safer.h"
#include "gettext.h"
#define _(Msgid) gettext (Msgid)
#ifndef __attribute__
/* This feature is available in gcc versions 2.5 and later. */
# if ! defined __GNUC__ || __GNUC__ < 2 || \
(__GNUC__ == 2 && __GNUC_MINOR__ < 5) || __STRICT_ANSI__
# define __attribute__(Spec) /* empty */
# endif
#endif
#ifndef ATTRIBUTE_UNUSED
# define ATTRIBUTE_UNUSED __attribute__ ((__unused__))
#endif
/* 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 child_fd[2];
pid_t pid;
if (pipe_safer (child_fd) != 0 || pipe_safer (pipe_fd) != 0)
error (EXIT_FAILURE, errno, "pipe");
fd[0] = child_fd[1];
fd[1] = pipe_fd[0];
child_fd[1] = pipe_fd[1];
pid = vfork ();
if (pid < 0)
error (EXIT_FAILURE, errno, "fork");
if (! pid)
{
/* Child. */
close (fd[0]);
close (fd[1]);
dup2 (child_fd[0], STDIN_FILENO);
close (child_fd[0]);
dup2 (child_fd[1], STDOUT_FILENO);
close (child_fd[1]);
/* 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 (child_fd[0]);
close (child_fd[1]);
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
}
void
end_of_output_subpipe (pid_t pid ATTRIBUTE_UNUSED,
int fd[2] ATTRIBUTE_UNUSED)
{
}

28
lib/subpipe.h
View File

@@ -1,28 +0,0 @@
/* Subprocesses with pipes.
Copyright (C) 2002, 2004-2005, 2009-2010 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 Paul Eggert <eggert@twinsun.com>
and Florian Krohm <florian@edamail.fishkill.ibm.com>. */
#if HAVE_SYS_TYPES_H
# include <sys/types.h>
#endif
void init_subpipe (void);
pid_t create_subpipe (char const * const *, int[2]);
void end_of_output_subpipe (pid_t, int[2]);
void reap_subpipe (pid_t, char const *);

21
m4/.cvsignore
View File

@@ -3,6 +3,7 @@ absolute-header.m4
alloca.m4
argmatch.m4
assert.m4
cloexec.m4
config-h.m4
dirname.m4
dos.m4
@@ -16,6 +17,7 @@ exponentd.m4
exponentf.m4
exponentl.m4
extensions.m4
fatal-signal.m4
fcntl-o.m4
fcntl.m4
fcntl_h.m4
@@ -25,6 +27,7 @@ fpieee.m4
fprintf-posix.m4
frexp.m4
frexpl.m4
getdtablesize.m4
getopt.m4
getpagesize.m4
gettext.m4
@@ -63,10 +66,15 @@ mbstate_t.m4
mbswidth.m4
memchr.m4
mmap-anon.m4
mode_t.m4
multiarch.m4
nls.m4
nocrash.m4
open.m4
pipe.m4
pipe2.m4
po.m4
posix_spawn.m4
printf-frexp.m4
printf-frexpl.m4
printf-posix-rpl.m4
@@ -75,12 +83,20 @@ printf.m4
progtest.m4
quote.m4
quotearg.m4
rawmemchr.m4
realloc.m4
sched_h.m4
setenv.m4
sig_atomic_t.m4
sigaction.m4
signal_h.m4
signalblocking.m4
signbit.m4
snprintf-posix.m4
snprintf.m4
spawn_h.m4
sprintf-posix.m4
stat.m4
stdbool.m4
stddef_h.m4
stdint.m4
@@ -89,6 +105,7 @@ stdio-safer.m4
stdio_h.m4
stdlib_h.m4
stpcpy.m4
strchrnul.m4
strerror.m4
string_h.m4
strndup.m4
@@ -96,7 +113,10 @@ strnlen.m4
strtol.m4
strtoul.m4
strverscmp.m4
sys_stat_h.m4
sys_wait_h.m4
threadlib.m4
time_h.m4
unistd-safer.m4
unistd_h.m4
unlocked-io.m4
@@ -105,6 +125,7 @@ vfprintf-posix.m4
vsnprintf-posix.m4
vsnprintf.m4
vsprintf-posix.m4
wait-process.m4
warn-on-use.m4
warning.m4
warnings.m4

21
m4/.gitignore vendored
View File

@@ -3,6 +3,7 @@
/alloca.m4
/argmatch.m4
/assert.m4
/cloexec.m4
/config-h.m4
/dirname.m4
/dos.m4
@@ -16,6 +17,7 @@
/exponentf.m4
/exponentl.m4
/extensions.m4
/fatal-signal.m4
/fcntl-o.m4
/fcntl.m4
/fcntl_h.m4
@@ -25,6 +27,7 @@
/fprintf-posix.m4
/frexp.m4
/frexpl.m4
/getdtablesize.m4
/getopt.m4
/getpagesize.m4
/gettext.m4
@@ -63,10 +66,15 @@
/mbswidth.m4
/memchr.m4
/mmap-anon.m4
/mode_t.m4
/multiarch.m4
/nls.m4
/nocrash.m4
/open.m4
/pipe.m4
/pipe2.m4
/po.m4
/posix_spawn.m4
/printf-frexp.m4
/printf-frexpl.m4
/printf-posix-rpl.m4
@@ -75,12 +83,20 @@
/progtest.m4
/quote.m4
/quotearg.m4
/rawmemchr.m4
/realloc.m4
/sched_h.m4
/setenv.m4
/sig_atomic_t.m4
/sigaction.m4
/signal_h.m4
/signalblocking.m4
/signbit.m4
/snprintf-posix.m4
/snprintf.m4
/spawn_h.m4
/sprintf-posix.m4
/stat.m4
/stdbool.m4
/stddef_h.m4
/stdint.m4
@@ -89,6 +105,7 @@
/stdio_h.m4
/stdlib_h.m4
/stpcpy.m4
/strchrnul.m4
/strerror.m4
/string_h.m4
/strndup.m4
@@ -96,7 +113,10 @@
/strtol.m4
/strtoul.m4
/strverscmp.m4
/sys_stat_h.m4
/sys_wait_h.m4
/threadlib.m4
/time_h.m4
/unistd-safer.m4
/unistd_h.m4
/unlocked-io.m4
@@ -105,6 +125,7 @@
/vsnprintf-posix.m4
/vsnprintf.m4
/vsprintf-posix.m4
/wait-process.m4
/warn-on-use.m4
/warning.m4
/warnings.m4

1
po/POTFILES.in
View File

@@ -22,6 +22,5 @@ lib/error.c
lib/getopt.c
lib/obstack.c
lib/quotearg.c
lib/subpipe.c
lib/timevar.c
lib/xalloc-die.c

39
src/files.c
View File

@@ -319,21 +319,21 @@ compute_output_file_names (void)
{
if (! spec_graph_file)
spec_graph_file = concat2 (all_but_tab_ext, ".dot");
output_file_name_check (spec_graph_file);
output_file_name_check (&spec_graph_file);
}
if (xml_flag)
{
if (! spec_xml_file)
spec_xml_file = concat2 (all_but_tab_ext, ".xml");
output_file_name_check (spec_xml_file);
output_file_name_check (&spec_xml_file);
}
if (report_flag)
{
if (!spec_verbose_file)
spec_verbose_file = concat2 (all_but_tab_ext, OUTPUT_EXT);
output_file_name_check (spec_verbose_file);
output_file_name_check (&spec_verbose_file);
}
free (all_but_tab_ext);
@@ -342,18 +342,37 @@ compute_output_file_names (void)
}
void
output_file_name_check (char const *file_name)
output_file_name_check (char **file_name)
{
if (0 == strcmp (file_name, grammar_file))
fatal (_("refusing to overwrite the input file %s"), quote (file_name));
bool conflict = false;
if (0 == strcmp (*file_name, grammar_file))
{
complain (_("refusing to overwrite the input file %s"),
quote (*file_name));
conflict = true;
}
else
{
int i;
for (i = 0; i < file_names_count; i++)
if (0 == strcmp (file_names[i], file_name))
warn (_("conflicting outputs to file %s"), quote (file_name));
if (0 == strcmp (file_names[i], *file_name))
{
warn (_("conflicting outputs to file %s"),
quote (*file_name));
conflict = true;
}
}
if (conflict)
{
free (*file_name);
*file_name = strdup ("/dev/null");
}
else
{
file_names = xnrealloc (file_names, ++file_names_count,
sizeof *file_names);
file_names[file_names_count-1] = xstrdup (*file_name);
}
file_names = xnrealloc (file_names, ++file_names_count, sizeof *file_names);
file_names[file_names_count-1] = xstrdup (file_name);
}
void

2
src/files.h
View File

@@ -63,7 +63,7 @@ extern char *all_but_ext;
void compute_output_file_names (void);
void output_file_names_free (void);
void output_file_name_check (char const *file_name);
void output_file_name_check (char **file_name);
FILE *xfopen (const char *name, const char *mode);
void xfclose (FILE *ptr);

20
src/output.c
View File

@@ -24,9 +24,10 @@
#include <configmake.h>
#include <error.h>
#include <get-errno.h>
#include <pipe.h>
#include <quotearg.h>
#include <subpipe.h>
#include <timevar.h>
#include <wait-process.h>
#include "complain.h"
#include "files.h"
@@ -568,17 +569,17 @@ output_skeleton (void)
aver (i <= ARRAY_CARDINALITY (argv));
}
init_subpipe ();
pid = create_subpipe (argv, filter_fd);
/* The ugly cast is because gnulib gets the const-ness wrong. */
pid = create_pipe_bidi ("m4", m4, (char **)(void*)argv, false, true,
true, filter_fd);
free (full_m4sugar);
free (full_m4bison);
free (full_skeleton);
if (trace_flag & trace_muscles)
muscles_output (stderr);
{
FILE *out = fdopen (filter_fd[0], "w");
FILE *out = fdopen (filter_fd[1], "w");
if (! out)
error (EXIT_FAILURE, get_errno (),
"fdopen");
@@ -588,14 +589,17 @@ output_skeleton (void)
/* Read and process m4's output. */
timevar_push (TV_M4);
end_of_output_subpipe (pid, filter_fd);
in = fdopen (filter_fd[1], "r");
in = fdopen (filter_fd[0], "r");
if (! in)
error (EXIT_FAILURE, get_errno (),
"fdopen");
scan_skel (in);
/* scan_skel should have read all of M4's output. Otherwise, when we
close the pipe, we risk letting M4 report a broken-pipe to the
Bison user. */
aver (feof (in));
xfclose (in);
reap_subpipe (pid, m4);
wait_subprocess (pid, "m4", false, false, true, true, NULL);
timevar_pop (TV_M4);
}

8
src/scan-skel.l
View File

@@ -107,7 +107,7 @@ static void fail_for_invalid_at (char const *at);
"@@" { obstack_1grow (&obstack_for_string, '@'); }
"@{" { obstack_1grow (&obstack_for_string, '['); }
"@}" { obstack_1grow (&obstack_for_string, ']'); }
"@`" /* Emtpy. Useful for starting an argument
"@`" /* Empty. Useful for starting an argument
that begins with whitespace. */
@\n /* Empty. */
@@ -174,8 +174,8 @@ skel_scanner_free (void)
yylex_destroy ();
}
static
void at_directive_perform (int at_directive_argc,
static void
at_directive_perform (int at_directive_argc,
char *at_directive_argv[],
char **outnamep, int *out_linenop)
{
@@ -276,7 +276,7 @@ void at_directive_perform (int at_directive_argc,
xfclose (yyout);
}
*outnamep = xstrdup (at_directive_argv[1]);
output_file_name_check (*outnamep);
output_file_name_check (outnamep);
yyout = xfopen (*outnamep, "w");
*out_linenop = 1;
}

4
tests/output.at
View File

@@ -137,7 +137,9 @@ AT_DATA([$1],
foo: {};
]])
[cp ]$1[ expout]
AT_BISON_CHECK([$3 $1], $5, [], [$4])
AT_CHECK([[cat $1]], [[0]], [expout])
AT_CLEANUP
])
@@ -157,7 +159,7 @@ AT_CHECK_CONFLICTING_OUTPUT([foo.y],
])
AT_CHECK_CONFLICTING_OUTPUT([foo.y], [], [-o foo.y],
[foo.y: fatal error: refusing to overwrite the input file `foo.y'
[foo.y: refusing to overwrite the input file `foo.y'
], 1)

42
tests/skeletons.at
View File

@@ -288,3 +288,45 @@ foo.y:1.5-6: fatal error: M4 should exit immediately here
]])
AT_CLEANUP
## ------------------------------------------------ ##
## Fatal errors but M4 continues producing output. ##
## ------------------------------------------------ ##
# At one time, if Bison encountered a fatal error during M4 processing,
# Bison failed to drain M4's output pipe. The result was a SIGPIPE.
# On some platforms, the default disposition for SIGPIPE is terminate,
# which was fine. On others, it's ignore, which caused M4 to report
# the broken pipe to the user, but we don't want to bother the user with
# that.
# There is a race condition somewhere. That is, before the associated
# fix, running this test group many times in a row would occasionally
# produce a pass among all the failures.
AT_SETUP([[Fatal errors but M4 continues producing output]])
AT_DATA([[gen-skel.pl]],
[[use warnings;
use strict;
my $M4 = "m4";
my $DNL = "d"."nl";
print "${M4}_divert_push(0)$DNL\n";
print '@output(@,@)', "\n";
(print "garbage"x10, "\n") for (1..1000);
print "${M4}_divert_pop(0)\n";
]])
AT_CHECK([[perl gen-skel.pl > skel.c || exit 77]])
AT_DATA([[input.y]],
[[%skeleton "./skel.c"
%%
start: ;
]])
AT_BISON_CHECK([[input.y]], [[1]], [[]],
[[input.y: fatal error: too many arguments for @output directive in skeleton
]])
AT_CLEANUP