tools/perf/build: Split out feature check: 'glibc'

Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/n/tip-nqnnsptw7ivOzhzbNjiun7ds@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

tools/perf/config/Makefile

@@ -109,6 +109,7 @@ FEATURE_TESTS =				\
 	fortify-source			\
 	bionic				\
 	libelf				\
+	glibc				\
 	libnuma
 
 $(foreach test,$(FEATURE_TESTS),$(call feature_check,$(test),$(test)))
@@ -166,8 +167,7 @@ ifdef NO_LIBELF
   NO_LIBUNWIND := 1
 else
   ifeq ($(feature-libelf), 0)
-    FLAGS_GLIBC=$(CFLAGS) $(LDFLAGS)
-    ifeq ($(call try-cc,$(SOURCE_GLIBC),$(FLAGS_GLIBC),glibc),y)
+    ifeq ($(feature-glibc), 1)
       LIBC_SUPPORT := 1
     endif
     ifeq ($(BIONIC),1)

tools/perf/config/feature-checks/Makefile

@@ -7,6 +7,7 @@ FILES=					\
 	test-fortify-source		\
 	test-bionic			\
 	test-libelf			\
+	test-glibc			\
 	test-libnuma
 
 CC := $(CC) -MD
@@ -38,6 +39,9 @@ test-bionic:
 test-libelf:
 	$(BUILD) -lelf
 
+test-glibc:
+	$(BUILD)
+
 test-libnuma:
 	$(BUILD) -lnuma
 

tools/perf/config/feature-checks/test-glibc.c

@@ -0,0 +1,8 @@
+#include <gnu/libc-version.h>
+
+int main(void)
+{
+	const char *version = gnu_get_libc_version();
+	return (long)version;
+}
+