Ben Pfaff wrote:
> This works around a bug in the glibc 2.7 macro implementation of
> strtok_r described here:
> http://sources.redhat.com/bugzilla/show_bug.cgi?id=5614.
Thanks. I've done the following modifications to your patch:
- Choose a macro name that is more similar to the current gnulib idioms.
For a long time already, HAVE_<some negative connotation> is deprecated;
we use HAVE_* macros to denote positive features.
- Prepare not only for undefining the macro, but also for replacing it
(although it's not used yet).
- Change the test so that it detects the broken macro also when configuring
without -O and compiling with -O later.
- Provide a better cross-compilation default for the test.
- Fix the quoting style: The general rule is that both arguments to
AC_LANG_PROGRAM must be doubly quoted: [[ ... ]].
- In the documentation, list specifically the affected glibc version.
Committed as follows:
2009-09-06 Ben Pfaff <b...@gnu.org>
Bruno Haible <br...@clisp.org>
Work around a glibc bug in strtok_r.
* lib/string.in.h (strtok_r): Replace if REPLACE_STRTOK_R is set.
Undefine if UNDEFINE_STRTOK_R is set.
* lib/strtok_r.c (strtok_r, __strtok_r) [!_LIBC]: Don't undefine.
* m4/string_h.m4 (gl_HEADER_STRING_H_DEFAULTS): Initialize
REPLACE_STRTOK_R and UNDEFINE_STRTOK_R.
* m4/strtok_r.m4 (gl_FUNC_STRTOK_R): Check against the glibc bug.
* modules/string (Makefile.am): Substitute REPLACE_STRTOK_R,
UNDEFINE_STRTOK_R.
* doc/posix-functions/strtok_r.texi: Mention the glibc 2.7 bug.
--- doc/posix-functions/strtok_r.texi.orig 2009-09-06 17:17:03.000000000
+0200
+++ doc/posix-functions/strtok_r.texi 2009-09-06 16:48:37.000000000 +0200
@@ -11,6 +11,10 @@
@item
This function is missing on some platforms:
mingw.
+...@item
+This function crashes when invoked from code compiled with optimization enabled
+on some platforms:
+glibc 2.7.
@end itemize
Portability problems not fixed by Gnulib:
--- lib/string.in.h.orig 2009-09-06 17:17:03.000000000 +0200
+++ lib/string.in.h 2009-09-06 16:55:35.000000000 +0200
@@ -399,7 +399,13 @@
See also strsep(). */
#if @GNULIB_STRTOK_R@
-# if ! @HAVE_DECL_STRTOK_R@
+# if @REPLACE_STRTOK_R@
+# undef strtok_r
+# define strtok_r rpl_strtok_r
+# elif @UNDEFINE_STRTOK_R@
+# undef strtok_r
+# endif
+# if ! @HAVE_DECL_STRTOK_R@ || @REPLACE_STRTOK_R@
extern char *strtok_r (char *restrict s, char const *restrict delim,
char **restrict save_ptr);
# endif
--- lib/strtok_r.c.orig 2009-09-06 17:18:39.000000000 +0200
+++ lib/strtok_r.c 2009-09-06 16:45:07.000000000 +0200
@@ -1,5 +1,5 @@
/* Reentrant string tokenizer. Generic version.
- Copyright (C) 1991,1996-1999,2001,2004,2007 Free Software Foundation, Inc.
+ Copyright (C) 1991,1996-1999,2001,2004,2007,2009 Free Software Foundation,
Inc.
This file is part of the GNU C Library.
This program is free software: you can redistribute it and/or modify
@@ -21,10 +21,10 @@
#include <string.h>
-#undef strtok_r
-#undef __strtok_r
-
-#ifndef _LIBC
+#ifdef _LIBC
+# undef strtok_r
+# undef __strtok_r
+#else
# define __strtok_r strtok_r
# define __rawmemchr strchr
#endif
--- m4/string_h.m4.orig 2009-09-06 17:17:03.000000000 +0200
+++ m4/string_h.m4 2009-09-06 16:56:27.000000000 +0200
@@ -5,7 +5,7 @@
# gives unlimited permission to copy and/or distribute it,
# with or without modifications, as long as this notice is preserved.
-# serial 7
+# serial 8
# Written by Paul Eggert.
@@ -91,4 +91,6 @@
REPLACE_STRCASESTR=0; AC_SUBST([REPLACE_STRCASESTR])
REPLACE_STRERROR=0; AC_SUBST([REPLACE_STRERROR])
REPLACE_STRSIGNAL=0; AC_SUBST([REPLACE_STRSIGNAL])
+ REPLACE_STRTOK_R=0; AC_SUBST([REPLACE_STRTOK_R])
+ UNDEFINE_STRTOK_R=0; AC_SUBST([UNDEFINE_STRTOK_R])
])
--- m4/strtok_r.m4.orig 2009-09-06 17:17:03.000000000 +0200
+++ m4/strtok_r.m4 2009-09-06 17:16:36.000000000 +0200
@@ -1,4 +1,4 @@
-# strtok_r.m4 serial 8
+# strtok_r.m4 serial 9
dnl Copyright (C) 2002, 2003, 2004, 2007, 2009 Free Software Foundation, Inc.
dnl This file is free software; the Free Software Foundation
dnl gives unlimited permission to copy and/or distribute it,
@@ -10,7 +10,55 @@
AC_REQUIRE([AC_C_RESTRICT])
AC_REQUIRE([gl_HEADER_STRING_H_DEFAULTS])
- AC_REPLACE_FUNCS([strtok_r])
+ AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
+ AC_CHECK_FUNCS([strtok_r])
+ if test $ac_cv_func_strtok_r = yes; then
+ dnl glibc 2.7 has a bug in strtok_r that causes a segmentation fault
+ dnl when the second argument to strtok_r is a constant string that has
+ dnl exactly one byte and compiling with optimization. This bug is, for
+ dnl example, present in the glibc 2.7-18 package in Debian "lenny".
+ dnl See <http://sources.redhat.com/bugzilla/show_bug.cgi?id=5614>.
+ AC_CACHE_CHECK([whether strtok_r works], [gl_cv_func_strtok_r_works],
+ [AC_RUN_IFELSE(
+ [AC_LANG_PROGRAM([[
+ #ifndef __OPTIMIZE__
+ # define __OPTIMIZE__ 1
+ #endif
+ #undef __OPTIMIZE_SIZE__
+ #undef __NO_INLINE__
+ #include <stdio.h>
+ #include <string.h>
+ ]],
+ [[char delimiters[] = "xxxxxxxx";
+ char *save_ptr = (char *) 0xd0d0;
+ strtok_r (delimiters, "x", &save_ptr);
+ strtok_r (NULL, "x", &save_ptr);
+ return 0;
+ ]])
+ ],
+ [gl_cv_func_strtok_r_works=yes],
+ [gl_cv_func_strtok_r_works=no],
+ [
+changequote(,)dnl
+ case "$host_os" in
+ # Guess no on glibc systems.
+ *-gnu*) gl_cv_func_strtok_r_works="guessing no";;
+ *) gl_cv_func_strtok_r_works="guessing yes";;
+ esac
+changequote([,])dnl
+ ])
+ ])
+ case "$gl_cv_func_strtok_r_works" in
+ *no)
+ dnl We could set REPLACE_STRTOK_R=1 and AC_LIBOBJ([strtok_r]) here,
+ dnl but it's only the macro version in <bits/string2.h> which is wrong.
+ dnl The code compiled into libc is fine.
+ UNDEFINE_STRTOK_R=1
+ ;;
+ esac
+ else
+ AC_LIBOBJ([strtok_r])
+ fi
AC_CHECK_DECLS_ONCE([strtok_r])
if test $ac_cv_have_decl_strtok_r = no; then
HAVE_DECL_STRTOK_R=0
--- modules/string.orig 2009-09-06 17:17:03.000000000 +0200
+++ modules/string 2009-09-06 17:12:56.000000000 +0200
@@ -83,6 +83,8 @@
-e 's|@''REPLACE_STRSTR''@|$(REPLACE_STRSTR)|g' \
-e 's|@''REPLACE_STRERROR''@|$(REPLACE_STRERROR)|g' \
-e 's|@''REPLACE_STRSIGNAL''@|$(REPLACE_STRSIGNAL)|g' \
+ -e 's|@''REPLACE_STRTOK_R''@|$(REPLACE_STRTOK_R)|g' \
+ -e 's|@''UNDEFINE_STRTOK_R''@|$(UNDEFINE_STRTOK_R)|g' \
-e '/definition of GL_LINK_WARNING/r $(LINK_WARNING_H)' \
< $(srcdir)/string.in.h; \
} > $...@-t && \
