[PATCH 3/4] perf tools: Check libunwind for availability of dwarf parsing feature

[Jean Pihet]

The newly added dwarf unwinding feature [1] requires:
. a recent version (>= 1.1) of libunwind,
. libunwind to be configured with --enable-debug-frame.

[1] http://www.spinics.net/lists/kernel/msg1598951.html

Add the corresponding API tests in the feature check list.

Signed-off-by: Jean Pihet <jean.pihet at linaro.org>
---
 tools/perf/config/Makefile          |  6 +++++-
 tools/perf/config/feature-tests.mak | 21 ++++++++++++++++++++-
 2 files changed, 25 insertions(+), 2 deletions(-)

diff --git a/tools/perf/config/Makefile b/tools/perf/config/Makefile
index 4b65710..bbaeb04 100644
--- a/tools/perf/config/Makefile
+++ b/tools/perf/config/Makefile
@@ -223,9 +223,13 @@ endif
 
 FLAGS_UNWIND=$(LIBUNWIND_CFLAGS) $(CFLAGS) $(LIBUNWIND_LDFLAGS) $(LDFLAGS) $(EXTLIBS) $(LIBUNWIND_LIBS)
 ifneq ($(call try-cc,$(SOURCE_LIBUNWIND),$(FLAGS_UNWIND),libunwind),y)
-  msg := $(warning No libunwind found, disabling post unwind support. Please install libunwind-dev[el] >= 0.99);
+  msg := $(warning No libunwind found, disabling post unwind support. Please install libunwind-dev[el] >= 1.1);
   NO_LIBUNWIND := 1
 endif # Libunwind support
+ifneq ($(call try-cc,$(SOURCE_LIBUNWIND_DEBUG_FRAME),$(FLAGS_UNWIND),libunwind debug_frame),y)
+  msg := $(warning No debug_frame support found in libunwind);
+CFLAGS += -DNO_LIBUNWIND_DEBUG_FRAME
+endif # debug_frame support in libunwind
 endif # NO_LIBUNWIND
 
 ifndef NO_LIBUNWIND
diff --git a/tools/perf/config/feature-tests.mak b/tools/perf/config/feature-tests.mak
index 708fb8e..cde75f5 100644
--- a/tools/perf/config/feature-tests.mak
+++ b/tools/perf/config/feature-tests.mak
@@ -176,7 +176,6 @@ extern int UNW_OBJ(dwarf_search_unwind_table) (unw_addr_space_t as,
                                       unw_proc_info_t *pi,
                                       int need_unwind_info, void *arg);
 
-
 #define dwarf_search_unwind_table UNW_OBJ(dwarf_search_unwind_table)
 
 int main(void)
@@ -188,6 +187,26 @@ int main(void)
 	return 0;
 }
 endef
+
+define SOURCE_LIBUNWIND_DEBUG_FRAME
+#include <libunwind.h>
+#include <stdlib.h>
+
+extern int
+UNW_OBJ(dwarf_find_debug_frame) (int found, unw_dyn_info_t *di_debug,
+				 unw_word_t ip, unw_word_t segbase,
+				 const char *obj_name, unw_word_t start,
+				 unw_word_t end);
+
+#define dwarf_find_debug_frame UNW_OBJ(dwarf_find_debug_frame)
+
+int main(void)
+{
+	dwarf_find_debug_frame(0, NULL, 0, 0, NULL, 0, 0);
+	return 0;
+}
+endef
+
 endif
 
 ifndef NO_BACKTRACE
-- 
1.7.11.7