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

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-FGmpkydfwqlkaw7yy8ewjpza@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

tools/perf/config/Makefile

@@ -115,6 +115,7 @@ FEATURE_TESTS =				\
 	libelf-getphdrnum		\
 	libunwind			\
 	libaudit			\
+	libslang			\
 	libnuma
 
 $(foreach test,$(FEATURE_TESTS),$(call feature_check,$(test),$(test)))
@@ -280,8 +281,7 @@ ifdef NO_NEWT
 endif
 
 ifndef NO_SLANG
-  FLAGS_SLANG=$(CFLAGS) $(LDFLAGS) $(EXTLIBS) -I/usr/include/slang -lslang
-  ifneq ($(call try-cc,$(SOURCE_SLANG),$(FLAGS_SLANG),libslang),y)
+  ifneq ($(feature-libslang), 1)
     msg := $(warning slang not found, disables TUI support. Please install slang-devel or libslang-dev);
     NO_SLANG := 1
   else

tools/perf/config/feature-checks/Makefile

@@ -13,6 +13,7 @@ FILES=					\
 	test-libelf-getphdrnum		\
 	test-libunwind			\
 	test-libaudit			\
+	test-libslang			\
 	test-libnuma
 
 CC := $(CC) -MD
@@ -65,6 +66,9 @@ test-libunwind:
 test-libaudit:
 	$(BUILD) -laudit
 
+test-libslang:
+	$(BUILD) -I/usr/include/slang -lslang
+
 -include *.d */*.d
 
 ###############################

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

@@ -0,0 +1,6 @@
+#include <slang.h>
+
+int main(void)
+{
+	return SLsmg_init_smg();
+}