Re: [PATCH v3] gettext.c: detect the vsnprintf bug at runtime

From: Duy Nguyen <pclouds@gmail.com>
Date: Dec 2, 2013, 09:00 UTC
Message-ID: <CACsJy8BqzH7G4yyXMnhgA6kH25eipt9ubqL1S2OdM-ke8GnvJA@mail.gmail.com>
In-Reply-To: <529C3987.7070708@gmail.com>

On Mon, Dec 2, 2013 at 2:40 PM, Trần Ngọc Quân <vnwildman@gmail.com> wrote:

Show 13 quoted lines

> 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.

Show 27 quoted lines

>
>
> AC_LANG_CONFTEST(
> [AC_LANG_PROGRAM([[
> #include <stdio.h>
> #include <locale.h>
> #include <gnu/libc-version.h>
>
> #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