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Diffstat (limited to 'm4/ac_c__generic.m4')
-rw-r--r-- | m4/ac_c__generic.m4 | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/m4/ac_c__generic.m4 b/m4/ac_c__generic.m4 new file mode 100644 index 0000000000..0c4dd52c6a --- /dev/null +++ b/m4/ac_c__generic.m4 @@ -0,0 +1,28 @@ +# https://lists.gnu.org/archive/html/autoconf-commit/2012-12/msg00004.html +# AC_C__GENERIC +# ------------- +# Define HAVE_C__GENERIC if _Generic works, a la C11. +AN_IDENTIFIER([_Generic], [AC_C__GENERIC]) +AC_DEFUN([AC_C__GENERIC], +[AC_CACHE_CHECK([for _Generic], ac_cv_c__Generic, +[AC_COMPILE_IFELSE( + [AC_LANG_SOURCE( + [[int + main (int argc, char **argv) + { + int a = _Generic (argc, int: argc = 1); + int *b = &_Generic (argc, default: argc); + char ***c = _Generic (argv, int: argc, default: argv ? &argv : 0); + _Generic (1 ? 0 : b, int: a, default: b) = &argc; + _Generic (a = 1, default: a) = 3; + return a + !b + !c; + } + ]])], + [ac_cv_c__Generic=yes], + [ac_cv_c__Generic=no])]) +if test $ac_cv_c__Generic = yes; then + AC_DEFINE([HAVE_C__GENERIC], 1, + [Define to 1 if C11-style _Generic works.]) +fi +])# AC_C__GENERIC + |