Default CFLAGS fail with gcc-4.9

[Gottox]

gcc-4.9 does not use c99 by default, so the compilation fails with

cc -c -specs=/void-packages/common/environment/configure/gccspecs/hardened-cc1  -fstack-protector-strong -D_FORTIFY_SOURCE=2 -mtune=generic -O2 -pipe    -DDCADEC_SHARED -DDCADEC_INTERNAL -fPIC -fvisibility=hidden -o libdcadec/interpolator_fixed.o libdcadec/interpolator_fixed.c
In file included from libdcadec/idct_fixed.c:21:0:
libdcadec/idct.h:67:64: error: expected ';', ',' or ')' before 'idct'
 void idct_perform32_float(const struct idct_context * restrict idct,
                                                                ^
...

adding -std=gnu99 to the CFLAGS fixes this issue.

EDIT: replaced c99 with gnu99 as c99 neither defines __USE_MISC or __USE_XOPEN nor __USE_GNU which is needed to define M_PI when including math.h.

[jamrial]

Are you using a custom build script? Those cflags don't look like the ones in Makefile, which add -std=gnu99 and work just fine with gcc 4.9

[Gottox]

I'm using void-packages to build dcadec. void-packages sets its own CFLAGS which overwrite the ones in the Makefile, I guess.