synctex_parser: fix vasprintf() not exists in non-GNU environment

[sunlin7]

The vasprintf() is a GNU extension function, missed in non-GNU build environment, so we define it.

Without this change, there will have error message when build with clang:

./autogen.sh
./configure CC=clang
make

Will get errors:

synctex_parser.c:8448:13: error: call to undeclared function 'vasprintf'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
        if (vasprintf(&buffer, format, va) < 0) {

[vedang]

Thanks, I've merged the change in.

[sunlin7]

@vedang Thank you !

[vedang]

Please note that I have reverted the change since it broke compilation on Mac OS. I will look into the problem later once I have some time, for the moment I have fixed the master branch by reverting the change.

[sunlin7]

Sorry for the disturb, and look forward for the better solution. Thanks.

[cyrilarnould]

FYI, I found that I can build v1.1.0 with the following in MSYS2's clang environment:

./autogen.sh
CFLAGS='-g -O2 -D_GNU_SOURCE' ./configure
make

Not sure if this also works in your environment, however.

[sunlin7]

According #141 , the vasprintf should no be static in the synctex_parser.c while stdio.h:381 defined it as external.

synctex_parser.c:8421:12: error: static declaration of 'vasprintf' follows non-static declaration
static int vasprintf(char **ret,
^
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.14.sdk/usr/include/stdio.h:381:6: note:
previous declaration is here
int vasprintf(char ** __restrict, const char * __restrict, va_list) __printflike(2, 0);
^

[LinuxUserGD]

According #141 , the vasprintf should no be static in the synctex_parser.c while stdio.h:381 defined it as external.

Upstream defines _GNU_SOURCE to fix the error
https://www.tug.org/svn/texlive/trunk/Build/source/texk/web2c/synctexdir/synctex_parser.c?view=markup#l89