2 files changed, 53 insertions, 1 deletions

diff --git a/tools/perf/Makefile b/tools/perf/Makefile
index 27ae84bb5e4c..0aee6a916493 100644
--- a/tools/perf/Makefile
+++ b/tools/perf/Makefile
@@ -43,6 +43,8 @@ include config/utilities.mak
 #
 # Define NO_LIBELF if you do not want libelf dependency (e.g. cross-builds)
 #
+# Define NO_LIBUNWIND if you do not want libunwind dependency for dwarf
+# backtrace post unwind.
 
 $(OUTPUT)PERF-VERSION-FILE: .FORCE-PERF-VERSION-FILE
         @$(SHELL_PATH) util/PERF-VERSION-GEN $(OUTPUT)
@@ -64,6 +66,7 @@ AR = $(CROSS_COMPILE)ar
 ifeq ($(ARCH),i386)
         ARCH := x86
         NO_PERF_REGS := 0
+        LIBUNWIND_LIBS = -lunwind -lunwind-x86
 endif
 ifeq ($(ARCH),x86_64)
         ARCH := x86
@@ -77,6 +80,7 @@ ifeq ($(ARCH),x86_64)
                 ARCH_INCLUDE = ../../arch/x86/lib/memcpy_64.S ../../arch/x86/lib/memset_64.S
         endif
         NO_PERF_REGS := 0
+        LIBUNWIND_LIBS = -lunwind -lunwind-x86_64
 endif
 
 # Treat warnings as errors unless directed not to
@@ -97,7 +101,7 @@ ifdef PARSER_DEBUG
         PARSER_DEBUG_CFLAGS := -DPARSER_DEBUG
 endif
 
-CFLAGS = -fno-omit-frame-pointer -ggdb3 -Wall -Wextra -std=gnu99 $(CFLAGS_WERROR) $(CFLAGS_OPTIMIZE) $(EXTRA_WARNINGS) $(EXTRA_CFLAGS) $(PARSER_DEBUG_CFLAGS)
+CFLAGS = -fno-omit-frame-pointer -ggdb3 -funwind-tables -Wall -Wextra -std=gnu99 $(CFLAGS_WERROR) $(CFLAGS_OPTIMIZE) $(EXTRA_WARNINGS) $(EXTRA_CFLAGS) $(PARSER_DEBUG_CFLAGS)
 EXTLIBS = -lpthread -lrt -lelf -lm
 ALL_CFLAGS = $(CFLAGS) -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 -D_GNU_SOURCE
 ALL_LDFLAGS = $(LDFLAGS)
@@ -476,6 +480,21 @@ ifneq ($(call try-cc,$(SOURCE_LIBELF),$(FLAGS_LIBELF)),y)
 endif
 endif # NO_LIBELF
 
+ifndef NO_LIBUNWIND
+# for linking with debug library, run like:
+# make DEBUG=1 LIBUNWIND_DIR=/opt/libunwind/
+ifdef LIBUNWIND_DIR
+        LIBUNWIND_CFLAGS  := -I$(LIBUNWIND_DIR)/include
+        LIBUNWIND_LDFLAGS := -L$(LIBUNWIND_DIR)/lib
+endif
+
+FLAGS_UNWIND=$(LIBUNWIND_CFLAGS) $(ALL_CFLAGS) $(LIBUNWIND_LDFLAGS) $(ALL_LDFLAGS) $(EXTLIBS) $(LIBUNWIND_LIBS)
+ifneq ($(call try-cc,$(SOURCE_LIBUNWIND),$(FLAGS_UNWIND)),y)
+        msg := $(warning No libunwind found. Please install libunwind >= 0.99);
+        NO_LIBUNWIND := 1
+endif # Libunwind support
+endif # NO_LIBUNWIND
+
 -include arch/$(ARCH)/Makefile
 
 ifneq ($(OUTPUT),)
@@ -522,6 +541,14 @@ endif # PERF_HAVE_DWARF_REGS
 endif # NO_DWARF
 endif # NO_LIBELF
 
+ifdef NO_LIBUNWIND
+        BASIC_CFLAGS += -DNO_LIBUNWIND_SUPPORT
+else
+        EXTLIBS += $(LIBUNWIND_LIBS)
+        BASIC_CFLAGS := $(LIBUNWIND_CFLAGS) $(BASIC_CFLAGS)
+        BASIC_LDFLAGS := $(LIBUNWIND_LDFLAGS) $(BASIC_LDFLAGS)
+endif
+
 ifdef NO_NEWT
         BASIC_CFLAGS += -DNO_NEWT_SUPPORT
 else
diff --git a/tools/perf/config/feature-tests.mak b/tools/perf/config/feature-tests.mak
index 6c18785a6417..2f1156a62ab7 100644
--- a/tools/perf/config/feature-tests.mak
+++ b/tools/perf/config/feature-tests.mak
@@ -154,3 +154,28 @@ int main(void)
         return 0;
 }
 endef
+
+ifndef NO_LIBUNWIND
+define SOURCE_LIBUNWIND
+#include <libunwind.h>
+#include <stdlib.h>
+
+extern int UNW_OBJ(dwarf_search_unwind_table) (unw_addr_space_t as,
+                                      unw_word_t ip,
+                                      unw_dyn_info_t *di,
+                                      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)
+{
+        unw_addr_space_t addr_space;
+        addr_space = unw_create_addr_space(NULL, 0);
+        unw_init_remote(NULL, addr_space, NULL);
+        dwarf_search_unwind_table(addr_space, 0, NULL, NULL, 0, NULL);
+        return 0;
+}
+endef
+endif