Mercurial > hg > octave-lyh > gnulib-hg
changeset 12478:0c2e471e00e6
wchar: Diagnose broken combination of glibc and gcc versions and flags.
author | Bruno Haible <bruno@clisp.org> |
---|---|
date | Wed, 23 Dec 2009 03:41:34 +0100 |
parents | 72b9e03189fd |
children | 3607500d4523 |
files | ChangeLog doc/posix-headers/wchar.texi m4/btowc.m4 m4/wchar.m4 |
diffstat | 4 files changed, 70 insertions(+), 2 deletions(-) [+] |
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--- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,12 @@ +2009-12-22 Bruno Haible <bruno@clisp.org> + + wchar: Diagnose broken combination of glibc and gcc versions and flags. + * m4/wchar.m4 (gl_WCHAR_H_INLINE_OK): New macro. + (gl_WCHAR_H): Invoke it. + * m4/btowc.m4 (gl_FUNC_BTOWC): Require it. + * doc/posix-headers/wchar.texi: Mention the interoperability problem. + Reported by Karl Berry <karl@freefriends.org>. + 2009-12-22 Eric Blake <ebb9@byu.net> math, unistd: avoid redundant includes
--- a/doc/posix-headers/wchar.texi +++ b/doc/posix-headers/wchar.texi @@ -25,4 +25,9 @@ Portability problems not fixed by Gnulib: @itemize +@item +This header file leads to link errors and endless recursions or endless loops +on some platforms: +glibc version 2.5 or older, together with gcc version 4.3 or newer and the +option @samp{-std=c99} or @samp{-std=gnu99}. @end itemize
--- a/m4/btowc.m4 +++ b/m4/btowc.m4 @@ -1,4 +1,4 @@ -# btowc.m4 serial 4 +# btowc.m4 serial 5 dnl Copyright (C) 2008-2009 Free Software Foundation, Inc. dnl This file is free software; the Free Software Foundation dnl gives unlimited permission to copy and/or distribute it, @@ -8,6 +8,11 @@ [ AC_REQUIRE([gl_WCHAR_H_DEFAULTS]) + dnl Check whether <wchar.h> is usable at all, first. Otherwise the test + dnl program below may lead to an endless loop. See + dnl <http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42440>. + AC_REQUIRE([gl_WCHAR_H_INLINE_OK]) + AC_CHECK_FUNCS_ONCE([btowc]) if test $ac_cv_func_btowc = no; then HAVE_BTOWC=0
--- a/m4/wchar.m4 +++ b/m4/wchar.m4 @@ -7,11 +7,12 @@ dnl Written by Eric Blake. -# wchar.m4 serial 26 +# wchar.m4 serial 27 AC_DEFUN([gl_WCHAR_H], [ AC_REQUIRE([gl_WCHAR_H_DEFAULTS]) + AC_REQUIRE([gl_WCHAR_H_INLINE_OK]) AC_CACHE_CHECK([whether <wchar.h> is standalone], [gl_cv_header_wchar_h_standalone], [AC_COMPILE_IFELSE([[#include <wchar.h> @@ -50,6 +51,54 @@ gl_CHECK_NEXT_HEADERS([wchar.h]) ]) +dnl Check whether <wchar.h> is usable at all. +AC_DEFUN([gl_WCHAR_H_INLINE_OK], +[ + dnl Test whether <wchar.h> suffers due to the transition from '__inline' to + dnl 'gnu_inline'. See <http://sourceware.org/bugzilla/show_bug.cgi?id=4022> + dnl and <http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42440>. In summary, + dnl glibc version 2.5 or older, together with gcc version 4.3 or newer and + dnl the option -std=c99 or -std=gnu99, leads to a broken <wchar.h>. + AC_CACHE_CHECK([whether <wchar.h> uses 'inline' correctly], + [gl_cv_header_wchar_h_correct_inline], + [gl_cv_header_wchar_h_correct_inline=yes + AC_LANG_CONFTEST([ + AC_LANG_SOURCE([[#define wcstod renamed_wcstod +#include <wchar.h> +extern int zero (void); +int main () { return zero(); } +]])]) + if AC_TRY_EVAL([ac_compile]); then + mv conftest.$ac_objext conftest1.$ac_objext + AC_LANG_CONFTEST([ + AC_LANG_SOURCE([[#define wcstod renamed_wcstod +#include <wchar.h> +int zero (void) { return 0; } +]])]) + if AC_TRY_EVAL([ac_compile]); then + mv conftest.$ac_objext conftest2.$ac_objext + if $CC -o conftest$ac_exeext $CFLAGS $LDFLAGS conftest1.$ac_objext conftest2.$ac_objext $LIBS >&AS_MESSAGE_LOG_FD 2>&1; then + : + else + gl_cv_header_wchar_h_correct_inline=no + fi + fi + fi + rm -f conftest1.$ac_objext conftest2.$ac_objext conftest$ac_exeext + ]) + if test $gl_cv_header_wchar_h_correct_inline = no; then + AC_MSG_ERROR([<wchar.h> cannot be used with this compiler ($CC $CFLAGS $CPPFLAGS). +This is a known interoperability problem of glibc <= 2.5 with gcc >= 4.3 in +C99 mode. You have four options: + - Add the flag -fgnu89-inline to CC and reconfigure, or + - Fix your include files, using parts of + <http://sourceware.org/git/?p=glibc.git;a=commitdiff;h=b037a293a48718af30d706c2e18c929d0e69a621>, or + - Use a gcc version older than 4.3, or + - Don't use the flags -std=c99 or -std=gnu99. +Configuration aborted.]) + fi +]) + dnl Unconditionally enables the replacement of <wchar.h>. AC_DEFUN([gl_REPLACE_WCHAR_H], [