[FFmpeg-devel] [PATCH] configure: add check_feature_test_macro for exp10, exp10f

[Ganesh Ajjanagadde]

exp10 and exp10f need _GNU_SOURCE. check_mathfunc only tests if the
function is available, and not whether it is locked or unlocked via
_GNU_SOURCE.

This adds some support to configure to test for _GNU_SOURCE and
accordingly report the existence of exp10, exp10f.

Signed-off-by: Ganesh Ajjanagadde <gajjanagadde at gmail.com>
---
 configure | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/configure b/configure
index 67baa5d..3797c4b 100755
--- a/configure
+++ b/configure
@@ -1134,6 +1134,17 @@ check_class_headers_cpp(){
     } | check_ld "cxx" "$@" && enable $funcs && enable_safe $headers
 }
 
+check_feature_test_macro(){
+    log check_feature_test_macro "$@"
+    macro=$1
+    shift 1
+    check_cc "$@" <<EOF
+#if !defined($macro)
+#error "feature test macro not enabled: $macro"
+#endif
+EOF
+}
+
 check_cpp_condition(){
     log check_cpp_condition "$@"
     header=$1
@@ -6026,6 +6037,8 @@ done
 
 enabled zlib && add_cppflags -DZLIB_CONST
 
+check_feature_test_macro "_GNU_SOURCE" || disable "exp10 exp10f"
+
 # conditional library dependencies, in linking order
 enabled amovie_filter       && prepend avfilter_deps "avformat avcodec"
 enabled aresample_filter    && prepend avfilter_deps "swresample"
-- 
2.6.4