From 08d9d985daf51644755c77185996501c1b386574 Mon Sep 17 00:00:00 2001 From: Amitay Isaacs Date: Tue, 10 Jul 2018 14:38:50 +1000 Subject: [PATCH] Add m4 macro to check for C __attribute__ features Signed-off-by: Amitay Isaacs --- m4/c_attribute.m4 | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) create mode 100644 m4/c_attribute.m4 diff --git a/m4/c_attribute.m4 b/m4/c_attribute.m4 new file mode 100644 index 00000000..48aa6223 --- /dev/null +++ b/m4/c_attribute.m4 @@ -0,0 +1,18 @@ +# +# Check for supported __attribute__ features +# +# AC_C_ATTRIBUTE(FEATURE, [ACTION-IF-FOUND], [ACTION-IF-NOT-FOUND]) +# +AC_DEFUN([AC_C_ATTRIBUTE], +[AS_VAR_PUSHDEF([CACHEVAR], [ax_cv_c_attribute_$1])dnl +AC_CACHE_CHECK([for __attribute__ (($1))], + CACHEVAR,[ + AC_COMPILE_IFELSE([AC_LANG_PROGRAM([], + [[ void foo(void) __attribute__ (($1)); ]])], + [AS_VAR_SET(CACHEVAR, [yes])], + [AS_VAR_SET(CACHEVAR, [no])])]) +AS_VAR_IF(CACHEVAR,yes, + [m4_default([$2], :)], + [m4_default([$3], :)]) +AS_VAR_POPDEF([CACHEVAR])dnl +])dnl