diff --git a/configure.ac b/configure.ac index 4aba1afad0b0f70bcc2e08564bcbb01bd5cb67b6..05eb82a149246f770e60c6179e09d5e6bbd54563 100644 --- a/configure.ac +++ b/configure.ac @@ -45,6 +45,7 @@ dnl Check for tools dnl AC_PROG_CC_C99 AC_USE_SYSTEM_EXTENSIONS +VLC_PROG_CC_C11 AC_DEFINE([_FORTIFY_SOURCE], 2, [Define to 2 to get glibc warnings.]) AC_DEFINE([_FILE_OFFSET_BITS], 64, [Define to 64 for large files support.]) AH_TOP([ diff --git a/m4/c11.m4 b/m4/c11.m4 new file mode 100644 index 0000000000000000000000000000000000000000..228860280561943811fac131726621965fdff519 --- /dev/null +++ b/m4/c11.m4 @@ -0,0 +1,44 @@ +# Copyright © 2015 Rémi Denis-Courmont +# This file (c11.m4) is free software; unlimited permission to +# copy and/or distribute it , with or without modifications, as long +# as this notice is preserved. + +# This program is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY, to the extent permitted by law; without +# even the implied warranty of MERCHANTABILITY or FITNESS FOR A +# PARTICULAR PURPOSE. + + +AC_DEFUN([VLC_PROG_CC_C11], [ + AC_LANG_ASSERT(C) + + for opt in "" -std=gnu11 -std=c11 -c11 + do + cachevar=AS_TR_SH([ax_cv_c_compile_c11_$opt]) + AC_CACHE_CHECK([whether $CC $opt supports C11], [$cachevar], [ + CFLAGS_save="$CFLAGS" + CFLAGS="$CFLAGS $opt" + dnl PREPROC is not enough due to CFLAGS usage + AC_COMPILE_IFELSE([AC_LANG_SOURCE([ +[#ifndef __STDC_VERSION__ +# error Not a C compiler! +#endif +#if (__STDC_VERSION__ < 201112L) +# error Too old C compiler! +#endif +_Static_assert(1, "Not C11!"); +const int varname = _Generic(1, int: 1, default: 0); +]])], [ + eval $cachevar="yes" + ], [ + eval $cachevar="no" + ]) + CFLAGS="$CFLAGS_save" + ]) + if eval test "\$$cachevar" = "yes" + then + CFLAGS="$CFLAGS $opt" + break + fi + done +])