# [PATCH] gettext.c: only work around the vsnprintf bug on glibc < 2.17 12 messages from 2013-11-30 to 2013-12-02. Participants: Nguyễn Thái Ngọc Duy, Andreas Schwab, Torsten Bögershausen, Duy Nguyen, Trần Ngọc Quân. Thread: https://gitlist.dev/t/35441 ## Nguyễn Thái Ngọc Duy, 2013-11-30 01:51 Subject: [PATCH] gettext.c: only work around the vsnprintf bug on glibc < 2.17 Message-ID: <1385776291-21006-1-git-send-email-pclouds@gmail.com> URL: https://gitlist.dev/e/1385776291-21006-1-git-send-email-pclouds%40gmail.com ``` Bug 6530 [1] causes "git show v0.99.6~1" to fail with error "your vsnprintf is broken". The workaround avoids that, but it corrupts system error messages in non-C locales. The bug has been fixed since 2.17. If git is built with glibc, it can know running libc version with gnu_get_libc_version() and avoid the workaround on fixed versions. As a side effect, the workaround is dropped for all non-glibc systems. Tested on Gentoo Linux, glibc 2.17, amd64. [1] http://sourceware.org/bugzilla/show_bug.cgi?id=6530 Signed-off-by: Nguyễn Thái Ngọc Duy --- We could even dlopen and look for gnu_get_libc_version at runtime and drop USE_GLIBC define. But there may be other problems with dl* on other platforms.. Somebody should test for the other two "USE_GLIBC = YesPlease" I added. I don't have Debian/FreeBSD nor any non-Linux GNU systems. Makefile | 5 +++++ config.mak.uname | 3 +++ gettext.c | 34 ++++++++++++++++++++++++++++------ 3 files changed, 36 insertions(+), 6 deletions(-) diff --git a/Makefile b/Makefile index af847f8..8df6d6d 100644 --- a/Makefile +++ b/Makefile @@ -66,6 +66,8 @@ all:: # Define LIBC_CONTAINS_LIBINTL if your gettext implementation doesn't # need -lintl when linking. # +# Define USE_GLIBC if your libc version is glibc >= 2.1. +# # Define NO_MSGFMT_EXTENDED_OPTIONS if your implementation of msgfmt # doesn't support GNU extensions like --check and --statistics # @@ -1203,6 +1205,9 @@ ifndef NO_GETTEXT ifndef LIBC_CONTAINS_LIBINTL EXTLIBS += -lintl endif +ifdef USE_GLIBC + BASIC_CFLAGS += -DUSE_GLIBC +endif endif ifdef NEEDS_SOCKET EXTLIBS += -lsocket diff --git a/config.mak.uname b/config.mak.uname index 82d549e..ffb01e0 100644 --- a/config.mak.uname +++ b/config.mak.uname @@ -33,6 +33,7 @@ ifeq ($(uname_S),Linux) HAVE_PATHS_H = YesPlease LIBC_CONTAINS_LIBINTL = YesPlease HAVE_DEV_TTY = YesPlease + USE_GLIBC = YesPlease endif ifeq ($(uname_S),GNU/kFreeBSD) NO_STRLCPY = YesPlease @@ -40,6 +41,7 @@ ifeq ($(uname_S),GNU/kFreeBSD) HAVE_PATHS_H = YesPlease DIR_HAS_BSD_GROUP_SEMANTICS = YesPlease LIBC_CONTAINS_LIBINTL = YesPlease + USE_GLIBC = YesPlease endif ifeq ($(uname_S),UnixWare) CC = cc @@ -236,6 +238,7 @@ ifeq ($(uname_S),GNU) NO_MKSTEMPS = YesPlease HAVE_PATHS_H = YesPlease LIBC_CONTAINS_LIBINTL = YesPlease + USE_GLIBC = YesPlease endif ifeq ($(uname_S),IRIX) NO_SETENV = YesPlease diff --git a/gettext.c b/gettext.c index 71e9545..91e679d 100644 --- a/gettext.c +++ b/gettext.c @@ -18,6 +18,13 @@ # endif #endif +#ifdef USE_GLIBC +#ifndef _GNU_SOURCE +#define _GNU_SOURCE +#endif +#include +#endif + #ifdef GETTEXT_POISON int use_gettext_poison(void) { @@ -30,6 +37,7 @@ int use_gettext_poison(void) #ifndef NO_GETTEXT static const char *charset; +static int vsnprintf_workaround; static void init_gettext_charset(const char *domain) { /* @@ -99,9 +107,7 @@ static void init_gettext_charset(const char *domain) $ LANGUAGE= LANG=de_DE.utf8 ./test test: Kein passendes Ger?t gefunden - In the long term we should probably see about getting that - vsnprintf bug in glibc fixed, and audit our code so it won't - fall apart under a non-C locale. + The vsnprintf bug has been fixed since 2.17. Then we could simply set LC_CTYPE from the environment, which would make things like the external perror(3) messages work. @@ -112,20 +118,36 @@ static void init_gettext_charset(const char *domain) 1. http://sourceware.org/bugzilla/show_bug.cgi?id=6530 2. E.g. "Content-Type: text/plain; charset=UTF-8\n" in po/is.po */ - setlocale(LC_CTYPE, ""); + if (vsnprintf_workaround) + setlocale(LC_CTYPE, ""); charset = locale_charset(); bind_textdomain_codeset(domain, charset); - setlocale(LC_CTYPE, "C"); + if (vsnprintf_workaround) + setlocale(LC_CTYPE, "C"); } void git_setup_gettext(void) { const char *podir = getenv("GIT_TEXTDOMAINDIR"); +#ifdef USE_GLIBC + int major, minor; + const char *version = gnu_get_libc_version(); + + if (version && sscanf(version, "%d.%d", &major, &minor) == 2 && + (major > 2 || (major == 2 && minor >= 17))) + vsnprintf_workaround = 0; + else + vsnprintf_workaround = 1; +#endif + if (!podir) podir = GIT_LOCALE_PATH; bindtextdomain("git", podir); - setlocale(LC_MESSAGES, ""); + if (vsnprintf_workaround) + setlocale(LC_MESSAGES, ""); + else + setlocale(LC_ALL, ""); init_gettext_charset("git"); textdomain("git"); } -- 1.8.2.83.gc99314b ``` ## Andreas Schwab, 2013-11-30 09:51 Subject: Re: [PATCH] gettext.c: only work around the vsnprintf bug on glibc < 2.17 Message-ID: URL: https://gitlist.dev/e/m2y546b4ka.fsf%40linux-m68k.org In-Reply-To: <1385776291-21006-1-git-send-email-pclouds@gmail.com> ``` Nguyễn Thái Ngọc Duy writes: > diff --git a/gettext.c b/gettext.c > index 71e9545..91e679d 100644 > --- a/gettext.c > +++ b/gettext.c > @@ -18,6 +18,13 @@ > # endif > #endif > > +#ifdef USE_GLIBC > +#ifndef _GNU_SOURCE > +#define _GNU_SOURCE > +#endif Defining a feature test macro after any system header is included is undefined. Andreas. -- Andreas Schwab, schwab@linux-m68k.org GPG Key fingerprint = 58CA 54C7 6D53 942B 1756 01D3 44D5 214B 8276 4ED5 "And now for something completely different." ``` ## Nguyễn Thái Ngọc Duy, 2013-11-30 12:01 Subject: [PATCH v2] gettext.c: only work around the vsnprintf bug on glibc < 2.17 Message-ID: <1385812884-23776-1-git-send-email-pclouds@gmail.com> URL: https://gitlist.dev/e/1385812884-23776-1-git-send-email-pclouds%40gmail.com In-Reply-To: <1385776291-21006-1-git-send-email-pclouds@gmail.com> ``` Bug 6530 [1] causes "git show v0.99.6~1" to fail with error "your vsnprintf is broken". The workaround avoids that, but it corrupts system error messages in non-C locales. The bug has been fixed since 2.17. If git is built with glibc, it can know running libc version with gnu_get_libc_version() and avoid the workaround on fixed versions. The workaround is also dropped for all non-glibc systems. Tested on Gentoo Linux, glibc 2.17, amd64. [1] http://sourceware.org/bugzilla/show_bug.cgi?id=6530 Signed-off-by: Nguyễn Thái Ngọc Duy --- v2 removes USE_GLIBC and lets git-compat-util.h do the detection gettext.c | 24 ++++++++++++++++-------- git-compat-util.h | 11 +++++++++++ 2 files changed, 27 insertions(+), 8 deletions(-) diff --git a/gettext.c b/gettext.c index 71e9545..772ab92 100644 --- a/gettext.c +++ b/gettext.c @@ -30,7 +30,7 @@ int use_gettext_poison(void) #ifndef NO_GETTEXT static const char *charset; -static void init_gettext_charset(const char *domain) +static void init_gettext_charset(const char *domain, int vsnprintf_broken) { /* This trick arranges for messages to be emitted in the user's @@ -99,9 +99,7 @@ static void init_gettext_charset(const char *domain) $ LANGUAGE= LANG=de_DE.utf8 ./test test: Kein passendes Ger?t gefunden - In the long term we should probably see about getting that - vsnprintf bug in glibc fixed, and audit our code so it won't - fall apart under a non-C locale. + The vsnprintf bug has been fixed since 2.17. Then we could simply set LC_CTYPE from the environment, which would make things like the external perror(3) messages work. @@ -112,21 +110,31 @@ static void init_gettext_charset(const char *domain) 1. http://sourceware.org/bugzilla/show_bug.cgi?id=6530 2. E.g. "Content-Type: text/plain; charset=UTF-8\n" in po/is.po */ - setlocale(LC_CTYPE, ""); + if (vsnprintf_broken) + setlocale(LC_CTYPE, ""); charset = locale_charset(); bind_textdomain_codeset(domain, charset); - setlocale(LC_CTYPE, "C"); + if (vsnprintf_broken) + setlocale(LC_CTYPE, "C"); } void git_setup_gettext(void) { const char *podir = getenv("GIT_TEXTDOMAINDIR"); + const char *version = glibc_version(); + int major, minor, vsnprintf_broken; + + if (version && sscanf(version, "%d.%d", &major, &minor) == 2 && + (major > 2 || (major == 2 && minor >= 17))) + vsnprintf_broken = 0; + else + vsnprintf_broken = 1; if (!podir) podir = GIT_LOCALE_PATH; bindtextdomain("git", podir); - setlocale(LC_MESSAGES, ""); - init_gettext_charset("git"); + setlocale(vsnprintf_broken ? LC_MESSAGES : LC_ALL, ""); + init_gettext_charset("git", vsnprintf_broken); textdomain("git"); } diff --git a/git-compat-util.h b/git-compat-util.h index 7776f12..967f452 100644 --- a/git-compat-util.h +++ b/git-compat-util.h @@ -488,11 +488,22 @@ extern int git_vsnprintf(char *str, size_t maxsize, #ifdef __GLIBC_PREREQ #if __GLIBC_PREREQ(2, 1) +#include +#define glibc_version() gnu_get_libc_version() #define HAVE_STRCHRNUL #define HAVE_MEMPCPY #endif #endif +#ifndef glibc_version +#ifdef __GNU_LIBRARY__ +#define glibc_version() NULL +#else +/* non-glibc platforms, see git_setup_gettext() for "2.17" */ +#define glibc_version() "2.17" +#endif +#endif + #ifndef HAVE_STRCHRNUL #define strchrnul gitstrchrnul static inline char *gitstrchrnul(const char *s, int c) -- 1.8.2.83.gc99314b ``` ## Torsten Bögershausen, 2013-11-30 23:01 Subject: Re: [PATCH v2] gettext.c: only work around the vsnprintf bug on glibc < 2.17 Message-ID: <529A6E48.4050001@web.de> URL: https://gitlist.dev/e/529A6E48.4050001%40web.de In-Reply-To: <1385812884-23776-1-git-send-email-pclouds@gmail.com> ``` On 2013-11-30 13.01, Nguyễn Thái Ngọc Duy wrote: > Bug 6530 [1] causes "git show v0.99.6~1" to fail with error "your causes or caused (as we have a work around?) > vsnprintf is broken". The workaround avoids that, but it corrupts > system error messages in non-C locales. [snip] > The bug in glibc has been fixed since 2.17. If git is built with glibc, it can ^^^^^^ (Should we name glibc ?) [snip] > - setlocale(LC_MESSAGES, ""); > - init_gettext_charset("git"); > + setlocale(vsnprintf_broken ? LC_MESSAGES : LC_ALL, ""); 1) One thing I don't understand: Why do we need to set LC_ALL ? The old patch didn't do it, or what do I miss ? See https://wiki.debian.org/Locale : Using LC_ALL is strongly discouraged as it overrides everything. Please use it only when testing and never set it in a startup file. 2) I stole the code partly from here: http://sourceware.org/bugzilla/show_bug.cgi?id=6530 ---------------------- #include #include #include #define STR "²éľÂíɱ²¡¶¾£¬ÖܺèµtÄúµÄ360²»×¨Òµ£¡" int main(void) { char buf[200]; setlocale(LC_ALL, ""); printf("gnu_glibc_version()=%s\n", gnu_get_libc_version()); printf("ret(snprintf)=%d\n", snprintf(buf, 150, "%.50s", STR)); return 0; } ---------------------- Then I run it on different machines: gnu_glibc_version()=2.11.3 /* Ubuntu 10.4, no updates */ gnu_glibc_version()=2.11.3 /* Debian Squeze ?*/ gnu_glibc_version()=2.13 /* Debian Wheezy */ ret(snprintf)=50 /* All the 3 above */ ------------- So could it be that libc is patched in Debian/Ubuntu, and we can do a runtime check (rather than looking at the version number), similar to the code above ? ------------ 3) The patch didn't break anything here (Debian, Mac OS). 4) Could it be good to have a test case ? Is t0204 good for inspiration ? 5) I can do more testing if needed. /Torsten ``` ## Torsten Bögershausen, 2013-11-30 23:06 Subject: Re: [PATCH v2] gettext.c: only work around the vsnprintf bug on glibc < 2.17 Message-ID: <529A6F72.9030909@web.de> URL: https://gitlist.dev/e/529A6F72.9030909%40web.de In-Reply-To: <529A6E48.4050001@web.de> ``` > gnu_glibc_version()=2.11.3 /* Ubuntu 10.4, no updates */ Sorry, Copy-paste error: 2.11.1 ``` ## Duy Nguyen, 2013-12-01 01:33 Subject: Re: [PATCH v2] gettext.c: only work around the vsnprintf bug on glibc < 2.17 Message-ID: URL: https://gitlist.dev/e/CACsJy8BdFst0ZRpvMwUxby88YMJdiY4h386kTVP57h6XfgLLgg%40mail.gmail.com In-Reply-To: <529A6E48.4050001@web.de> ``` On Sun, Dec 1, 2013 at 6:01 AM, Torsten Bögershausen wrote: > On 2013-11-30 13.01, Nguyễn Thái Ngọc Duy wrote: >> Bug 6530 [1] causes "git show v0.99.6~1" to fail with error "your > causes or caused (as we have a work around?) >> vsnprintf is broken". The workaround avoids that, but it corrupts >> system error messages in non-C locales. > [snip] >> The bug in glibc has been fixed since 2.17. If git is built with glibc, it can > ^^^^^^ (Should we name glibc ?) No, probably leftover from editing. > [snip] >> - setlocale(LC_MESSAGES, ""); >> - init_gettext_charset("git"); >> + setlocale(vsnprintf_broken ? LC_MESSAGES : LC_ALL, ""); > 1) One thing I don't understand: Why do we need to set LC_ALL ? > The old patch didn't do it, or what do I miss ? > See https://wiki.debian.org/Locale : > Using LC_ALL is strongly discouraged as it overrides everything. Please use it only when testing and never set it in a startup file. I'm fine with changing it back to LC_MESSAGES+LC_TYPE. For the record, all gtk+ apps do setlocale(LC_ALL, ""); > 2) I stole the code partly from here: > http://sourceware.org/bugzilla/show_bug.cgi?id=6530 > ---------------------- > #include > #include > #include > > #define STR "²éľÂíɱ²¡¶¾£¬ÖܺèµtÄúµÄ360²»×¨Òµ£¡" > > int main(void) { > char buf[200]; > setlocale(LC_ALL, ""); > printf("gnu_glibc_version()=%s\n", gnu_get_libc_version()); > printf("ret(snprintf)=%d\n", snprintf(buf, 150, "%.50s", STR)); > return 0; > } > > ---------------------- > Then I run it on different machines: > > gnu_glibc_version()=2.11.3 /* Ubuntu 10.4, no updates */ > gnu_glibc_version()=2.11.3 /* Debian Squeze ?*/ > gnu_glibc_version()=2.13 /* Debian Wheezy */ > ret(snprintf)=50 /* All the 3 above */ > ------------- > So could it be that libc is patched in Debian/Ubuntu, and we > can do a runtime check (rather than looking at the version number), > similar to the code above ? Good idea. Now I need to install 2.16 for reproducing it :( > ------------ > > 3) The patch didn't break anything here (Debian, Mac OS). > > 4) Could it be good to have a test case ? Is t0204 good for inspiration ? > > 5) I can do more testing if needed. > > /Torsten > > > -- Duy ``` ## Nguyễn Thái Ngọc Duy, 2013-12-01 02:45 Subject: [PATCH v3] gettext.c: detect the vsnprintf bug at runtime Message-ID: <1385865938-16392-1-git-send-email-pclouds@gmail.com> URL: https://gitlist.dev/e/1385865938-16392-1-git-send-email-pclouds%40gmail.com In-Reply-To: <1385812884-23776-1-git-send-email-pclouds@gmail.com> ``` Bug 6530 [1] in glibc causes "git show v0.99.6~1" to fail with error "your vsnprintf is broken". The workaround avoids that, but it corrupts system error messages in non-C locales. The bug has been fixed since 2.17. We could know running glibc version with gnu_get_libc_version(). But version is not a sure way to detect the bug because downstream may back port the fix to older versions. Do a runtime test that immitates the call flow that leads to "your vsnprintf is broken". Only enable the workaround if the test fails. Tested on Gentoo Linux, glibc 2.16.0 and 2.17, amd64. [1] http://sourceware.org/bugzilla/show_bug.cgi?id=6530 Signed-off-by: Nguyễn Thái Ngọc Duy --- v3 goes with runtime test instead of version check. gettext.c | 19 +++++++++++++++---- 1 file changed, 15 insertions(+), 4 deletions(-) diff --git a/gettext.c b/gettext.c index 71e9545..eed7c7f 100644 --- a/gettext.c +++ b/gettext.c @@ -29,6 +29,17 @@ int use_gettext_poison(void) #endif #ifndef NO_GETTEXT +static int test_vsnprintf(const char *fmt, ...) +{ + char buf[26]; + int ret; + va_list ap; + va_start(ap, fmt); + ret = vsnprintf(buf, sizeof(buf), fmt, ap); + va_end(ap); + return ret; +} + static const char *charset; static void init_gettext_charset(const char *domain) { @@ -99,9 +110,7 @@ static void init_gettext_charset(const char *domain) $ LANGUAGE= LANG=de_DE.utf8 ./test test: Kein passendes Ger?t gefunden - In the long term we should probably see about getting that - vsnprintf bug in glibc fixed, and audit our code so it won't - fall apart under a non-C locale. + The vsnprintf bug has been fixed since glibc 2.17. Then we could simply set LC_CTYPE from the environment, which would make things like the external perror(3) messages work. @@ -115,7 +124,9 @@ static void init_gettext_charset(const char *domain) setlocale(LC_CTYPE, ""); charset = locale_charset(); bind_textdomain_codeset(domain, charset); - setlocale(LC_CTYPE, "C"); + /* the string is taken from v0.99.6~1 */ + if (test_vsnprintf("%.*s", 13, "David_K\345gedal") < 0) + setlocale(LC_CTYPE, "C"); } void git_setup_gettext(void) -- 1.8.2.83.gc99314b ``` ## Trần Ngọc Quân, 2013-12-02 00:31 Subject: Re: [PATCH v3] gettext.c: detect the vsnprintf bug at runtime Message-ID: <529BD4E1.8040408@gmail.com> URL: https://gitlist.dev/e/529BD4E1.8040408%40gmail.com In-Reply-To: <1385865938-16392-1-git-send-email-pclouds@gmail.com> ``` On 01/12/2013 09:45, Nguyễn Thái Ngọc Duy wrote: > Bug 6530 [1] in glibc causes "git show v0.99.6~1" to fail with error > "your vsnprintf is broken". The workaround avoids that, but it > corrupts system error messages in non-C locales. > > The bug has been fixed since 2.17. We could know running glibc version > with gnu_get_libc_version(). But version is not a sure way to detect > the bug because downstream may back port the fix to older versions. Do > a runtime test that immitates the call flow that leads to "your > vsnprintf is broken". Only enable the workaround if the test fails. > > Tested on Gentoo Linux, glibc 2.16.0 and 2.17, amd64. > > [1] http://sourceware.org/bugzilla/show_bug.cgi?id=6530 > > Signed-off-by: Nguyễn Thái Ngọc Duy > --- > v3 goes with runtime test instead of version check. > > gettext.c | 19 +++++++++++++++---- > 1 file changed, 15 insertions(+), 4 deletions(-) > > diff --git a/gettext.c b/gettext.c > index 71e9545..eed7c7f 100644 > --- a/gettext.c > +++ b/gettext.c > @@ -29,6 +29,17 @@ int use_gettext_poison(void) > #endif > > #ifndef NO_GETTEXT > +static int test_vsnprintf(const char *fmt, ...) > +{ > + char buf[26]; > + int ret; > + va_list ap; > + va_start(ap, fmt); > + ret = vsnprintf(buf, sizeof(buf), fmt, ap); > + va_end(ap); > + return ret; > +} > + this function alway run each time we run git commad while libc is static. It is waste. > + /* the string is taken from v0.99.6~1 */ > + if (test_vsnprintf("%.*s", 13, "David_K\345gedal") < 0) > + setlocale(LC_CTYPE, "C"); > } > > void git_setup_gettext(void) I suggest use C preprocessor instead. The person who complete git (make debian, rpm etc. package) decide enable it or not (disable by default). Most of people use git from distribution instead of complete it from source. #ifndef VSNPRINTF_OK setlocale(LC_CTYPE, "C"); #endif -- Trần Ngọc Quân. ``` ## Duy Nguyen, 2013-12-02 05:57 Subject: Re: [PATCH v3] gettext.c: detect the vsnprintf bug at runtime Message-ID: URL: https://gitlist.dev/e/CACsJy8B5aBGnm%3D04y60W1XVovHVryP1Co0_mmgV0f7Ox13aGjw%40mail.gmail.com In-Reply-To: <529BD4E1.8040408@gmail.com> ``` On Mon, Dec 2, 2013 at 7:31 AM, Trần Ngọc Quân wrote: >> --- a/gettext.c >> +++ b/gettext.c >> @@ -29,6 +29,17 @@ int use_gettext_poison(void) >> #endif >> >> #ifndef NO_GETTEXT >> +static int test_vsnprintf(const char *fmt, ...) >> +{ >> + char buf[26]; >> + int ret; >> + va_list ap; >> + va_start(ap, fmt); >> + ret = vsnprintf(buf, sizeof(buf), fmt, ap); >> + va_end(ap); >> + return ret; >> +} >> + > this function alway run each time we run git commad while libc is > static. It is waste. >> + /* the string is taken from v0.99.6~1 */ >> + if (test_vsnprintf("%.*s", 13, "David_K\345gedal") < 0) >> + setlocale(LC_CTYPE, "C"); >> } >> >> void git_setup_gettext(void) > > I suggest use C preprocessor instead. The person who complete git (make debian, rpm etc. package) decide enable it or not (disable by default). Most of people use git from distribution instead of complete it from source. > > #ifndef VSNPRINTF_OK > setlocale(LC_CTYPE, "C"); > #endif > A single vsnprintf is cheap enough that I would not worry about performance impact. Given a choice between this and distro maintainers, some of them do check release notes, some not so much, I'd rather go with this. -- Duy ``` ## Trần Ngọc Quân, 2013-12-02 07:40 Subject: Re: [PATCH v3] gettext.c: detect the vsnprintf bug at runtime Message-ID: <529C3987.7070708@gmail.com> URL: https://gitlist.dev/e/529C3987.7070708%40gmail.com In-Reply-To: ``` On 02/12/2013 12:57, Duy Nguyen wrote: >> I suggest use C preprocessor instead. The person who complete git (make debian, rpm etc. package) decide enable it or not (disable by default). Most of people use git from distribution instead of complete it from source. >> >> #ifndef VSNPRINTF_OK >> setlocale(LC_CTYPE, "C"); >> #endif >> > A single vsnprintf is cheap enough that I would not worry about > performance impact. Given a choice between this and distro > maintainers, some of them do check release notes, some not so much, > I'd rather go with this. We can set this macro automatically by using autoconf. Add following code in configure.ac AC_LANG_CONFTEST( [AC_LANG_PROGRAM([[ #include #include #include #define STR "David_K\345gedal" ]],[[ char buf[20]; setlocale(LC_ALL, "en_US.UTF-8"); if (snprintf(buf, 13, "%.13s", STR) < 0){ printf("0"); }else{ printf("1"); } ]])]) gcc -o conftest conftest.c AC_DEFINE([VSNPRINTF_OK], [m4_esyscmd([./conftest])], [Enable l10n libc if vnsprintf OK]) You can change c code here! -- Trần Ngọc Quân. ``` ## Trần Ngọc Quân, 2013-12-02 08:49 Subject: Re: [PATCH v3] gettext.c: detect the vsnprintf bug at runtime Message-ID: <529C49B2.6050402@gmail.com> URL: https://gitlist.dev/e/529C49B2.6050402%40gmail.com In-Reply-To: <529C3987.7070708@gmail.com> ``` On 02/12/2013 14:40, Trần Ngọc Quân wrote: > On 02/12/2013 12:57, Duy Nguyen wrote: >>> I suggest use C preprocessor instead. The person who complete git (make debian, rpm etc. package) decide enable it or not (disable by default). Most of people use git from distribution instead of complete it from source. >>> >>> #ifndef VSNPRINTF_OK >>> setlocale(LC_CTYPE, "C"); >>> #endif >>> >> A single vsnprintf is cheap enough that I would not worry about >> performance impact. Given a choice between this and distro >> maintainers, some of them do check release notes, some not so much, >> I'd rather go with this. > We can set this macro automatically by using autoconf. > Add following code in configure.ac > > > AC_LANG_CONFTEST( > [AC_LANG_PROGRAM([[ > #include > #include > #include > > #define STR "David_K\345gedal" > ]],[[ > char buf[20]; > setlocale(LC_ALL, "en_US.UTF-8"); > if (snprintf(buf, 13, "%.13s", STR) < 0){ > printf("0"); > }else{ > printf("1"); > } > ]])]) > gcc -o conftest conftest.c > AC_DEFINE([VSNPRINTF_OK], [m4_esyscmd([./conftest])], [Enable l10n libc > if vnsprintf OK]) > > You can change c code here! > Sorry I'm wrong, m4_esyscmd don't work as I spect Change to: AC_LANG_CONFTEST( [AC_LANG_PROGRAM([[ #include #include #include #define STR "David_K\345gedal" ]],[[ char buf[20]; setlocale(LC_CTYPE, "en_US.UTF-8"); if (snprintf(buf, 13, "%.13s", STR) < 0){ printf("0"); }else{ printf("1"); } ]])]) gcc -o conftest conftest.c VSNPRINTF=$(./conftest) AC_DEFINE_UNQUOTED([VSNPRINTF_OK], [ $VSNPRINTF ], [Enable libc if vnsprintf OK]) don't missing run this: $ autoconf && autoheader My os (ubuntu 12.04) don't pass this test (libc6:i386 2.15-0ubuntu) $ grep VSNPRINTF_OK config.h #define VSNPRINTF_OK 0 -- Trần Ngọc Quân. ``` ## Duy Nguyen, 2013-12-02 09:00 Subject: Re: [PATCH v3] gettext.c: detect the vsnprintf bug at runtime Message-ID: URL: https://gitlist.dev/e/CACsJy8BqzH7G4yyXMnhgA6kH25eipt9ubqL1S2OdM-ke8GnvJA%40mail.gmail.com In-Reply-To: <529C3987.7070708@gmail.com> ``` On Mon, Dec 2, 2013 at 2:40 PM, Trần Ngọc Quân wrote: > On 02/12/2013 12:57, Duy Nguyen wrote: >>> I suggest use C preprocessor instead. The person who complete git (make debian, rpm etc. package) decide enable it or not (disable by default). Most of people use git from distribution instead of complete it from source. >>> >>> #ifndef VSNPRINTF_OK >>> setlocale(LC_CTYPE, "C"); >>> #endif >>> >> A single vsnprintf is cheap enough that I would not worry about >> performance impact. Given a choice between this and distro >> maintainers, some of them do check release notes, some not so much, >> I'd rather go with this. > We can set this macro automatically by using autoconf. > Add following code in configure.ac Except that most git devs do not use autoconf. I don't know about other but Gentoo also packages git without autoconf. And this test only means that at build time we detect this. glibc version at runtime could be different, as long as they are binary compatible with the build-time one. > > > AC_LANG_CONFTEST( > [AC_LANG_PROGRAM([[ > #include > #include > #include > > #define STR "David_K\345gedal" > ]],[[ > char buf[20]; > setlocale(LC_ALL, "en_US.UTF-8"); > if (snprintf(buf, 13, "%.13s", STR) < 0){ > printf("0"); > }else{ > printf("1"); > } > ]])]) > gcc -o conftest conftest.c > AC_DEFINE([VSNPRINTF_OK], [m4_esyscmd([./conftest])], [Enable l10n libc > if vnsprintf OK]) > > You can change c code here! > > -- > Trần Ngọc Quân. > -- Duy ```