tools/perf/build: Split out feature check: 'libelf-getphdrnum'

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-wa9qstb8erbjreLxiHepzjfw@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

tools/perf/config/Makefile

@@ -112,6 +112,7 @@ FEATURE_TESTS =				\
 	glibc				\
 	dwarf				\
 	libelf-mmap			\
+	libelf-getphdrnum		\
 	libnuma
 
 $(foreach test,$(FEATURE_TESTS),$(call feature_check,$(test),$(test)))
@@ -207,7 +208,7 @@ ifndef NO_LIBELF
     CFLAGS += -DHAVE_LIBELF_MMAP_SUPPORT
   endif
 
-  ifeq ($(call try-cc,$(SOURCE_ELF_GETPHDRNUM),$(FLAGS_LIBELF),-DHAVE_ELF_GETPHDRNUM_SUPPORT),y)
+  ifeq ($(feature-libelf-getphdrnum), 1)
     CFLAGS += -DHAVE_ELF_GETPHDRNUM_SUPPORT
   endif
 
@@ -230,7 +231,7 @@ ifndef NO_LIBELF
   CFLAGS += -DHAVE_LIBELF_SUPPORT
   ifeq ($(feature-libelf-mmap), 1)
     CFLAGS += -DHAVE_LIBELF_MMAP_SUPPORT
-  endif # try-cc
+  endif
 endif # NO_LIBELF
 
 # There's only x86 (both 32 and 64) support for CFI unwind so far

tools/perf/config/feature-checks/Makefile

@@ -10,6 +10,7 @@ FILES=					\
 	test-glibc			\
 	test-dwarf			\
 	test-libelf-mmap		\
+	test-libelf-getphdrnum		\
 	test-libnuma
 
 CC := $(CC) -MD
@@ -50,6 +51,9 @@ test-dwarf:
 test-libelf-mmap:
 	$(BUILD) -lelf
 
+test-libelf-getphdrnum:
+	$(BUILD) -lelf
+
 test-libnuma:
 	$(BUILD) -lnuma
 

tools/perf/config/feature-checks/test-libelf-getphdrnum.c

@@ -0,0 +1,7 @@
+#include <libelf.h>
+#
+int main(void)
+{
+	size_t dst;
+	return elf_getphdrnum(0, &dst);
+}