22 files changed, 615 insertions, 63 deletions

diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config
index 8a493d46fab9..09c2a9874f2f 100644
--- a/tools/perf/Makefile.config
+++ b/tools/perf/Makefile.config
@@ -136,6 +136,7 @@ endif
 # Treat warnings as errors unless directed not to
 ifneq ($(WERROR),0)
   CFLAGS += -Werror
+  CXXFLAGS += -Werror
 endif
 
 ifndef DEBUG
@@ -182,6 +183,13 @@ CFLAGS += -Wall
 CFLAGS += -Wextra
 CFLAGS += -std=gnu99
 
+CXXFLAGS += -std=gnu++11 -fno-exceptions -fno-rtti
+CXXFLAGS += -Wall
+CXXFLAGS += -fno-omit-frame-pointer
+CXXFLAGS += -ggdb3
+CXXFLAGS += -funwind-tables
+CXXFLAGS += -Wno-strict-aliasing
+
 # Enforce a non-executable stack, as we may regress (again) in the future by
 # adding assembler files missing the .GNU-stack linker note.
 LDFLAGS += -Wl,-z,noexecstack
@@ -204,24 +212,27 @@ ifeq ($(DEBUG),0)
   endif
 endif
 
-CFLAGS += -I$(src-perf)/util/include
-CFLAGS += -I$(src-perf)/arch/$(ARCH)/include
-CFLAGS += -I$(srctree)/tools/include/uapi
-CFLAGS += -I$(srctree)/tools/include/
-CFLAGS += -I$(srctree)/tools/arch/$(ARCH)/include/uapi
-CFLAGS += -I$(srctree)/tools/arch/$(ARCH)/include/
-CFLAGS += -I$(srctree)/tools/arch/$(ARCH)/
+INC_FLAGS += -I$(src-perf)/util/include
+INC_FLAGS += -I$(src-perf)/arch/$(ARCH)/include
+INC_FLAGS += -I$(srctree)/tools/include/uapi
+INC_FLAGS += -I$(srctree)/tools/include/
+INC_FLAGS += -I$(srctree)/tools/arch/$(ARCH)/include/uapi
+INC_FLAGS += -I$(srctree)/tools/arch/$(ARCH)/include/
+INC_FLAGS += -I$(srctree)/tools/arch/$(ARCH)/
 
 # $(obj-perf)      for generated common-cmds.h
 # $(obj-perf)/util for generated bison/flex headers
 ifneq ($(OUTPUT),)
-CFLAGS += -I$(obj-perf)/util
-CFLAGS += -I$(obj-perf)
+INC_FLAGS += -I$(obj-perf)/util
+INC_FLAGS += -I$(obj-perf)
 endif
 
-CFLAGS += -I$(src-perf)/util
-CFLAGS += -I$(src-perf)
-CFLAGS += -I$(srctree)/tools/lib/
+INC_FLAGS += -I$(src-perf)/util
+INC_FLAGS += -I$(src-perf)
+INC_FLAGS += -I$(srctree)/tools/lib/
+
+CFLAGS   += $(INC_FLAGS)
+CXXFLAGS += $(INC_FLAGS)
 
 CFLAGS += -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 -D_GNU_SOURCE
 
@@ -783,6 +794,33 @@ ifndef NO_JVMTI
   endif
 endif
 
+USE_CXX = 0
+USE_CLANGLLVM = 0
+ifdef LIBCLANGLLVM
+  $(call feature_check,cxx)
+  ifneq ($(feature-cxx), 1)
+    msg := $(warning No g++ found, disable clang and llvm support. Please install g++)
+  else
+    $(call feature_check,llvm)
+    ifneq ($(feature-llvm), 1)
+      msg := $(warning No libLLVM found, disable clang and llvm support. Please install llvm-dev)
+    else
+      $(call feature_check,clang)
+      ifneq ($(feature-clang), 1)
+        msg := $(warning No libclang found, disable clang and llvm support. Please install libclang-dev)
+      else
+        CFLAGS += -DHAVE_LIBCLANGLLVM_SUPPORT
+        CXXFLAGS += -DHAVE_LIBCLANGLLVM_SUPPORT -I$(shell $(LLVM_CONFIG) --includedir)
+        $(call detected,CONFIG_CXX)
+        $(call detected,CONFIG_CLANGLLVM)
+	USE_CXX = 1
+	USE_LLVM = 1
+	USE_CLANG = 1
+      endif
+    endif
+  endif
+endif
+
 # Among the variables below, these:
 #   perfexecdir
 #   template_dir
diff --git a/tools/perf/Makefile.perf b/tools/perf/Makefile.perf
index 3cb1df43ad3e..10495c9dbe71 100644
--- a/tools/perf/Makefile.perf
+++ b/tools/perf/Makefile.perf
@@ -88,6 +88,10 @@ include ../scripts/utilities.mak
 # and bypass the feature detection
 #
 # Define NO_JVMTI if you do not want jvmti agent built
+#
+# Define LIBCLANGLLVM if you DO want builtin clang and llvm support.
+# When selected, pass LLVM_CONFIG=/path/to/llvm-config to `make' if
+# llvm-config is not in $PATH.
 
 # As per kernel Makefile, avoid funny character set dependencies
 unexport LC_ALL
@@ -143,6 +147,7 @@ endef
 $(call allow-override,CC,$(CROSS_COMPILE)gcc)
 $(call allow-override,AR,$(CROSS_COMPILE)ar)
 $(call allow-override,LD,$(CROSS_COMPILE)ld)
+$(call allow-override,CXX,$(CROSS_COMPILE)g++)
 
 LD += $(EXTRA_LDFLAGS)
 
@@ -151,6 +156,7 @@ HOSTLD  ?= ld
 HOSTAR  ?= ar
 
 PKG_CONFIG = $(CROSS_COMPILE)pkg-config
+LLVM_CONFIG ?= llvm-config
 
 RM      = rm -f
 LN      = ln -f
@@ -171,7 +177,7 @@ SUBCMD_DIR	= $(srctree)/tools/lib/subcmd/
 # non-config cases
 config := 1
 
-NON_CONFIG_TARGETS := clean TAGS tags cscope help install-doc
+NON_CONFIG_TARGETS := clean TAGS tags cscope help install-doc install-man install-html install-info install-pdf doc man html info pdf
 
 ifdef MAKECMDGOALS
 ifeq ($(filter-out $(NON_CONFIG_TARGETS),$(MAKECMDGOALS)),)
@@ -262,17 +268,6 @@ python-clean := $(call QUIET_CLEAN, python) $(RM) -r $(PYTHON_EXTBUILD) $(OUTPUT
 PYTHON_EXT_SRCS := $(shell grep -v ^\# util/python-ext-sources)
 PYTHON_EXT_DEPS := util/python-ext-sources util/setup.py $(LIBTRACEEVENT) $(LIBAPI)
 
-$(OUTPUT)python/perf.so: $(PYTHON_EXT_SRCS) $(PYTHON_EXT_DEPS) $(LIBTRACEEVENT_DYNAMIC_LIST)
-	$(QUIET_GEN)LDSHARED="$(CC) -pthread -shared" \
-        CFLAGS='$(CFLAGS)' LDFLAGS='$(LDFLAGS) $(LIBTRACEEVENT_DYNAMIC_LIST_LDFLAGS)' \
-	  $(PYTHON_WORD) util/setup.py \
-	  --quiet build_ext; \
-	mkdir -p $(OUTPUT)python && \
-	cp $(PYTHON_EXTBUILD_LIB)perf.so $(OUTPUT)python/
-#
-# No Perl scripts right now:
-#
-
 SCRIPTS = $(patsubst %.sh,%,$(SCRIPT_SH))
 
 PROGRAMS += $(OUTPUT)perf
@@ -325,11 +320,6 @@ endif
 ifndef NO_GTK2
   ALL_PROGRAMS += $(OUTPUT)libperf-gtk.so
   GTK_IN := $(OUTPUT)gtk-in.o
-
-install-gtk: $(OUTPUT)libperf-gtk.so
-	$(call QUIET_INSTALL, 'GTK UI') \
-		$(INSTALL) -d -m 755 '$(DESTDIR_SQ)$(libdir_SQ)'; \
-		$(INSTALL) $(OUTPUT)libperf-gtk.so '$(DESTDIR_SQ)$(libdir_SQ)'
 endif
 
 ifdef ASCIIDOC8
@@ -338,6 +328,21 @@ endif
 
 LIBS = -Wl,--whole-archive $(PERFLIBS) -Wl,--no-whole-archive -Wl,--start-group $(EXTLIBS) -Wl,--end-group
 
+ifeq ($(USE_CLANG), 1)
+  CLANGLIBS_LIST = AST Basic CodeGen Driver Frontend Lex Tooling Edit Sema Analysis Parse Serialization
+  LIBCLANG = $(foreach l,$(CLANGLIBS_LIST),$(wildcard $(shell $(LLVM_CONFIG) --libdir)/libclang$(l).a))
+  LIBS += -Wl,--start-group $(LIBCLANG) -Wl,--end-group
+endif
+
+ifeq ($(USE_LLVM), 1)
+  LIBLLVM = $(shell $(LLVM_CONFIG) --libs all) $(shell $(LLVM_CONFIG) --system-libs)
+  LIBS += -L$(shell $(LLVM_CONFIG) --libdir) $(LIBLLVM)
+endif
+
+ifeq ($(USE_CXX), 1)
+  LIBS += -lstdc++
+endif
+
 export INSTALL SHELL_PATH
 
 ### Build rules
@@ -346,6 +351,14 @@ SHELL = $(SHELL_PATH)
 
 all: shell_compatibility_test $(ALL_PROGRAMS) $(LANG_BINDINGS) $(OTHER_PROGRAMS)
 
+$(OUTPUT)python/perf.so: $(PYTHON_EXT_SRCS) $(PYTHON_EXT_DEPS) $(LIBTRACEEVENT_DYNAMIC_LIST)
+	$(QUIET_GEN)LDSHARED="$(CC) -pthread -shared" \
+        CFLAGS='$(CFLAGS)' LDFLAGS='$(LDFLAGS) $(LIBTRACEEVENT_DYNAMIC_LIST_LDFLAGS)' \
+	  $(PYTHON_WORD) util/setup.py \
+	  --quiet build_ext; \
+	mkdir -p $(OUTPUT)python && \
+	cp $(PYTHON_EXTBUILD_LIB)perf.so $(OUTPUT)python/
+
 please_set_SHELL_PATH_to_a_more_modern_shell:
 	$(Q)$$(:)
 
@@ -356,7 +369,7 @@ strip: $(PROGRAMS) $(OUTPUT)perf
 
 PERF_IN := $(OUTPUT)perf-in.o
 
-export srctree OUTPUT RM CC LD AR CFLAGS V BISON FLEX AWK
+export srctree OUTPUT RM CC CXX LD AR CFLAGS CXXFLAGS V BISON FLEX AWK
 export HOSTCC HOSTLD HOSTAR
 include $(srctree)/tools/build/Makefile.include
 
@@ -691,7 +704,14 @@ check: $(OUTPUT)common-cmds.h
 
 ### Installation rules
 
+ifndef NO_GTK2
+install-gtk: $(OUTPUT)libperf-gtk.so
+	$(call QUIET_INSTALL, 'GTK UI') \
+		$(INSTALL) -d -m 755 '$(DESTDIR_SQ)$(libdir_SQ)'; \
+		$(INSTALL) $(OUTPUT)libperf-gtk.so '$(DESTDIR_SQ)$(libdir_SQ)'
+else
 install-gtk:
+endif
 
 install-tools: all install-gtk
 	$(call QUIET_INSTALL, binaries) \
diff --git a/tools/perf/tests/Build b/tools/perf/tests/Build
index af3ec94869aa..6676c2dd6dcb 100644
--- a/tools/perf/tests/Build
+++ b/tools/perf/tests/Build
@@ -43,6 +43,7 @@ perf-y += sdt.o
 perf-y += is_printable_array.o
 perf-y += bitmap.o
 perf-y += perf-hooks.o
+perf-y += clang.o
 
 $(OUTPUT)tests/llvm-src-base.c: tests/bpf-script-example.c tests/Build
 	$(call rule_mkdir)
diff --git a/tools/perf/tests/builtin-test.c b/tools/perf/tests/builtin-test.c
index d1bec0444be7..23605202d4a1 100644
--- a/tools/perf/tests/builtin-test.c
+++ b/tools/perf/tests/builtin-test.c
@@ -234,6 +234,15 @@ static struct test generic_tests[] = {
 		.func = test__perf_hooks,
 	},
 	{
+		.desc = "builtin clang support",
+		.func = test__clang,
+		.subtest = {
+			.skip_if_fail	= true,
+			.get_nr		= test__clang_subtest_get_nr,
+			.get_desc	= test__clang_subtest_get_desc,
+		}
+	},
+	{
 		.func = NULL,
 	},
 };
diff --git a/tools/perf/tests/clang.c b/tools/perf/tests/clang.c
new file mode 100644
index 000000000000..f853e242a86c
--- /dev/null
+++ b/tools/perf/tests/clang.c
@@ -0,0 +1,46 @@
+#include "tests.h"
+#include "debug.h"
+#include "util.h"
+#include "c++/clang-c.h"
+
+static struct {
+	int (*func)(void);
+	const char *desc;
+} clang_testcase_table[] = {
+#ifdef HAVE_LIBCLANGLLVM_SUPPORT
+	{
+		.func = test__clang_to_IR,
+		.desc = "builtin clang compile C source to IR",
+	},
+	{
+		.func = test__clang_to_obj,
+		.desc = "builtin clang compile C source to ELF object",
+	},
+#endif
+};
+
+int test__clang_subtest_get_nr(void)
+{
+	return (int)ARRAY_SIZE(clang_testcase_table);
+}
+
+const char *test__clang_subtest_get_desc(int i)
+{
+	if (i < 0 || i >= (int)ARRAY_SIZE(clang_testcase_table))
+		return NULL;
+	return clang_testcase_table[i].desc;
+}
+
+#ifndef HAVE_LIBCLANGLLVM_SUPPORT
+int test__clang(int i __maybe_unused)
+{
+	return TEST_SKIP;
+}
+#else
+int test__clang(int i)
+{
+	if (i < 0 || i >= (int)ARRAY_SIZE(clang_testcase_table))
+		return TEST_FAIL;
+	return clang_testcase_table[i].func();
+}
+#endif
diff --git a/tools/perf/tests/llvm.h b/tools/perf/tests/llvm.h
index 0eaa604be99d..b83571758d83 100644
--- a/tools/perf/tests/llvm.h
+++ b/tools/perf/tests/llvm.h
@@ -1,6 +1,10 @@
 #ifndef PERF_TEST_LLVM_H
 #define PERF_TEST_LLVM_H
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 #include <stddef.h> /* for size_t */
 #include <stdbool.h> /* for bool */
 
@@ -20,4 +24,7 @@ enum test_llvm__testcase {
 int test_llvm__fetch_bpf_obj(void **p_obj_buf, size_t *p_obj_buf_sz,
 			     enum test_llvm__testcase index, bool force,
 			     bool *should_load_fail);
+#ifdef __cplusplus
+}
+#endif
 #endif
diff --git a/tools/perf/tests/make b/tools/perf/tests/make
index 08ed7f12cc37..0784748f1670 100644
--- a/tools/perf/tests/make
+++ b/tools/perf/tests/make
@@ -83,6 +83,7 @@ make_no_libbpf	    := NO_LIBBPF=1
 make_no_libcrypto   := NO_LIBCRYPTO=1
 make_with_babeltrace:= LIBBABELTRACE=1
 make_no_sdt	    := NO_SDT=1
+make_with_clangllvm := LIBCLANGLLVM=1
 make_tags           := tags
 make_cscope         := cscope
 make_help           := help
@@ -139,6 +140,7 @@ run += make_no_libbionic
 run += make_no_auxtrace
 run += make_no_libbpf
 run += make_with_babeltrace
+run += make_with_clangllvm
 run += make_help
 run += make_doc
 run += make_perf_o
@@ -278,7 +280,7 @@ endif
 
 MAKEFLAGS := --no-print-directory
 
-clean := @(cd $(PERF); $(MAKE_F) -s $(O_OPT) clean >/dev/null)
+clean := @(cd $(PERF); $(MAKE_F) -s $(O_OPT) clean >/dev/null && $(MAKE) -s $(O_OPT) -C ../build clean >/dev/null)
 
 $(run):
 	$(call clean)
diff --git a/tools/perf/tests/perf-hooks.c b/tools/perf/tests/perf-hooks.c
index 9338cb2c25ab..665ecc19671c 100644
--- a/tools/perf/tests/perf-hooks.c
+++ b/tools/perf/tests/perf-hooks.c
@@ -15,13 +15,13 @@ static void sigsegv_handler(int sig __maybe_unused)
 	exit(-1);
 }
 
-static int hook_flags;
 
-static void the_hook(void)
+static void the_hook(void *_hook_flags)
 {
+	int *hook_flags = _hook_flags;
 	int *p = NULL;
 
-	hook_flags = 1234;
+	*hook_flags = 1234;
 
 	/* Generate a segfault, test perf_hooks__recover */
 	*p = 0;
@@ -29,13 +29,17 @@ static void the_hook(void)
 
 int test__perf_hooks(int subtest __maybe_unused)
 {
+	int hook_flags = 0;
+
 	signal(SIGSEGV, sigsegv_handler);
-	perf_hooks__set_hook("test", the_hook);
+	perf_hooks__set_hook("test", the_hook, &hook_flags);
 	perf_hooks__invoke_test();
 
 	/* hook is triggered? */
-	if (hook_flags != 1234)
+	if (hook_flags != 1234) {
+		pr_debug("Setting failed: %d (%p)\n", hook_flags, &hook_flags);
 		return TEST_FAIL;
+	}
 
 	/* the buggy hook is removed? */
 	if (perf_hooks__get_hook("test"))
diff --git a/tools/perf/tests/tests.h b/tools/perf/tests/tests.h
index 3a1f98f291ba..0d7b251305af 100644
--- a/tools/perf/tests/tests.h
+++ b/tools/perf/tests/tests.h
@@ -92,6 +92,9 @@ int test__sdt_event(int subtest);
 int test__is_printable_array(int subtest);
 int test__bitmap_print(int subtest);
 int test__perf_hooks(int subtest);
+int test__clang(int subtest);
+const char *test__clang_subtest_get_desc(int subtest);
+int test__clang_subtest_get_nr(void);
 
 #if defined(__arm__) || defined(__aarch64__)
 #ifdef HAVE_DWARF_UNWIND_SUPPORT
diff --git a/tools/perf/util/Build b/tools/perf/util/Build
index bdad82a9812d..3840e3a87057 100644
--- a/tools/perf/util/Build
+++ b/tools/perf/util/Build
@@ -126,6 +126,8 @@ endif
 
 libperf-y += perf-hooks.o
 
+libperf-$(CONFIG_CXX) += c++/
+
 CFLAGS_config.o   += -DETC_PERFCONFIG="BUILD_STR($(ETC_PERFCONFIG_SQ))"
 # avoid compiler warnings in 32-bit mode
 CFLAGS_genelf_debug.o  += -Wno-packed
diff --git a/tools/perf/util/annotate.c b/tools/perf/util/annotate.c
index 4012b1de2813..ea7e0de4b9c1 100644
--- a/tools/perf/util/annotate.c
+++ b/tools/perf/util/annotate.c
@@ -237,6 +237,9 @@ static int jump__parse(struct arch *arch __maybe_unused, struct ins_operands *op
 static int jump__scnprintf(struct ins *ins, char *bf, size_t size,
 			   struct ins_operands *ops)
 {
+	if (!ops->target.addr)
+		return ins__raw_scnprintf(ins, bf, size, ops);
+
 	return scnprintf(bf, size, "%-6.6s %" PRIx64, ins->name, ops->target.offset);
 }
 
diff --git a/tools/perf/util/bpf-loader.c b/tools/perf/util/bpf-loader.c
index a5fd275238f7..36c861103291 100644
--- a/tools/perf/util/bpf-loader.c
+++ b/tools/perf/util/bpf-loader.c
@@ -14,11 +14,11 @@
 #include "debug.h"
 #include "bpf-loader.h"
 #include "bpf-prologue.h"
-#include "llvm-utils.h"
 #include "probe-event.h"
 #include "probe-finder.h" // for MAX_PROBES
 #include "parse-events.h"
 #include "llvm-utils.h"
+#include "c++/clang-c.h"
 
 #define DEFINE_PRINT_FN(name, level) \
 static int libbpf_##name(const char *fmt, ...)	\
@@ -86,10 +86,21 @@ struct bpf_object *bpf__prepare_load(const char *filename, bool source)
 		void *obj_buf;
 		size_t obj_buf_sz;
 
-		err = llvm__compile_bpf(filename, &obj_buf, &obj_buf_sz);
-		if (err)
-			return ERR_PTR(-BPF_LOADER_ERRNO__COMPILE);
+		perf_clang__init();
+		err = perf_clang__compile_bpf(filename, &obj_buf, &obj_buf_sz);
+		perf_clang__cleanup();
+		if (err) {
+			pr_warning("bpf: builtin compilation failed: %d, try external compiler\n", err);
+			err = llvm__compile_bpf(filename, &obj_buf, &obj_buf_sz);
+			if (err)
+				return ERR_PTR(-BPF_LOADER_ERRNO__COMPILE);
+		} else
+			pr_debug("bpf: successfull builtin compilation\n");
 		obj = bpf_object__open_buffer(obj_buf, obj_buf_sz, filename);
+
+		if (!IS_ERR(obj) && llvm_param.dump_obj)
+			llvm__dump_obj(filename, obj_buf, obj_buf_sz);
+
 		free(obj_buf);
 	} else
 		obj = bpf_object__open(filename);
diff --git a/tools/perf/util/c++/Build b/tools/perf/util/c++/Build
new file mode 100644
index 000000000000..988fef1b11d7
--- /dev/null
+++ b/tools/perf/util/c++/Build
@@ -0,0 +1,2 @@
+libperf-$(CONFIG_CLANGLLVM) += clang.o
+libperf-$(CONFIG_CLANGLLVM) += clang-test.o
diff --git a/tools/perf/util/c++/clang-c.h b/tools/perf/util/c++/clang-c.h
new file mode 100644
index 000000000000..0eadd792ab1f
--- /dev/null
+++ b/tools/perf/util/c++/clang-c.h
@@ -0,0 +1,43 @@
+#ifndef PERF_UTIL_CLANG_C_H
+#define PERF_UTIL_CLANG_C_H
+
+#include <stddef.h>	/* for size_t */
+#include <util-cxx.h>	/* for __maybe_unused */
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#ifdef HAVE_LIBCLANGLLVM_SUPPORT
+extern void perf_clang__init(void);
+extern void perf_clang__cleanup(void);
+
+extern int test__clang_to_IR(void);
+extern int test__clang_to_obj(void);
+
+extern int perf_clang__compile_bpf(const char *filename,
+				   void **p_obj_buf,
+				   size_t *p_obj_buf_sz);
+#else
+
+
+static inline void perf_clang__init(void) { }
+static inline void perf_clang__cleanup(void) { }
+
+static inline int test__clang_to_IR(void) { return -1; }
+static inline int test__clang_to_obj(void) { return -1;}
+
+static inline int
+perf_clang__compile_bpf(const char *filename __maybe_unused,
+			void **p_obj_buf __maybe_unused,
+			size_t *p_obj_buf_sz __maybe_unused)
+{
+	return -ENOTSUP;
+}
+
+#endif
+
+#ifdef __cplusplus
+}
+#endif
+#endif
diff --git a/tools/perf/util/c++/clang-test.cpp b/tools/perf/util/c++/clang-test.cpp
new file mode 100644
index 000000000000..9b11e8c82798
--- /dev/null
+++ b/tools/perf/util/c++/clang-test.cpp
@@ -0,0 +1,62 @@
+#include "clang.h"
+#include "clang-c.h"
+#include "llvm/IR/Function.h"
+#include "llvm/IR/LLVMContext.h"
+
+#include <util-cxx.h>
+#include <tests/llvm.h>
+#include <string>
+
+class perf_clang_scope {
+public:
+	explicit perf_clang_scope() {perf_clang__init();}
+	~perf_clang_scope() {perf_clang__cleanup();}
+};
+
+static std::unique_ptr<llvm::Module>
+__test__clang_to_IR(void)
+{
+	unsigned int kernel_version;
+
+	if (fetch_kernel_version(&kernel_version, NULL, 0))
+		return std::unique_ptr<llvm::Module>(nullptr);
+
+	std::string cflag_kver("-DLINUX_VERSION_CODE=" +
+				std::to_string(kernel_version));
+
+	std::unique_ptr<llvm::Module> M =
+		perf::getModuleFromSource({cflag_kver.c_str()},
+					  "perf-test.c",
+					  test_llvm__bpf_base_prog);
+	return M;
+}
+
+extern "C" {
+int test__clang_to_IR(void)
+{
+	perf_clang_scope _scope;
+
+	auto M = __test__clang_to_IR();
+	if (!M)
+		return -1;
+	for (llvm::Function& F : *M)
+		if (F.getName() == "bpf_func__SyS_epoll_wait")
+			return 0;
+	return -1;
+}
+
+int test__clang_to_obj(void)
+{
+	perf_clang_scope _scope;
+
+	auto M = __test__clang_to_IR();
+	if (!M)
+		return -1;
+
+	auto Buffer = perf::getBPFObjectFromModule(&*M);
+	if (!Buffer)
+		return -1;
+	return 0;
+}
+
+}
diff --git a/tools/perf/util/c++/clang.cpp b/tools/perf/util/c++/clang.cpp
new file mode 100644
index 000000000000..1e974152cac2
--- /dev/null
+++ b/tools/perf/util/c++/clang.cpp
@@ -0,0 +1,195 @@
+/*
+ * llvm C frontend for perf. Support dynamically compile C file
+ *
+ * Inspired by clang example code:
+ * http://llvm.org/svn/llvm-project/cfe/trunk/examples/clang-interpreter/main.cpp
+ *
+ * Copyright (C) 2016 Wang Nan <wangnan0@huawei.com>
+ * Copyright (C) 2016 Huawei Inc.
+ */
+
+#include "clang/CodeGen/CodeGenAction.h"
+#include "clang/Frontend/CompilerInvocation.h"
+#include "clang/Frontend/CompilerInstance.h"
+#include "clang/Frontend/TextDiagnosticPrinter.h"
+#include "clang/Tooling/Tooling.h"
+#include "llvm/IR/LegacyPassManager.h"
+#include "llvm/IR/Module.h"
+#include "llvm/Option/Option.h"
+#include "llvm/Support/FileSystem.h"
+#include "llvm/Support/ManagedStatic.h"
+#include "llvm/Support/TargetRegistry.h"
+#include "llvm/Support/TargetSelect.h"
+#include "llvm/Target/TargetMachine.h"
+#include "llvm/Target/TargetOptions.h"
+#include <memory>
+
+#include "clang.h"
+#include "clang-c.h"
+
+namespace perf {
+
+static std::unique_ptr<llvm::LLVMContext> LLVMCtx;
+
+using namespace clang;
+
+static CompilerInvocation *
+createCompilerInvocation(llvm::opt::ArgStringList CFlags, StringRef& Path,
+			 DiagnosticsEngine& Diags)
+{
+	llvm::opt::ArgStringList CCArgs {
+		"-cc1",
+		"-triple", "bpf-pc-linux",
+		"-fsyntax-only",
+		"-ferror-limit", "19",
+		"-fmessage-length", "127",
+		"-O2",
+		"-nostdsysteminc",
+		"-nobuiltininc",
+		"-vectorize-loops",
+		"-vectorize-slp",
+		"-Wno-unused-value",
+		"-Wno-pointer-sign",
+		"-x", "c"};
+
+	CCArgs.append(CFlags.begin(), CFlags.end());
+	CompilerInvocation *CI = tooling::newInvocation(&Diags, CCArgs);
+
+	FrontendOptions& Opts = CI->getFrontendOpts();
+	Opts.Inputs.clear();
+	Opts.Inputs.emplace_back(Path, IK_C);
+	return CI;
+}
+
+static std::unique_ptr<llvm::Module>
+getModuleFromSource(llvm::opt::ArgStringList CFlags,
+		    StringRef Path, IntrusiveRefCntPtr<vfs::FileSystem> VFS)
+{
+	CompilerInstance Clang;
+	Clang.createDiagnostics();
+
+	Clang.setVirtualFileSystem(&*VFS);
+
+	IntrusiveRefCntPtr<CompilerInvocation> CI =
+		createCompilerInvocation(std::move(CFlags), Path,
+					 Clang.getDiagnostics());
+	Clang.setInvocation(&*CI);
+
+	std::unique_ptr<CodeGenAction> Act(new EmitLLVMOnlyAction(&*LLVMCtx));
+	if (!Clang.ExecuteAction(*Act))
+		return std::unique_ptr<llvm::Module>(nullptr);
+
+	return Act->takeModule();
+}
+
+std::unique_ptr<llvm::Module>
+getModuleFromSource(llvm::opt::ArgStringList CFlags,
+		    StringRef Name, StringRef Content)
+{
+	using namespace vfs;
+
+	llvm::IntrusiveRefCntPtr<OverlayFileSystem> OverlayFS(
+			new OverlayFileSystem(getRealFileSystem()));
+	llvm::IntrusiveRefCntPtr<InMemoryFileSystem> MemFS(
+			new InMemoryFileSystem(true));
+
+	/*
+	 * pushOverlay helps setting working dir for MemFS. Must call
+	 * before addFile.
+	 */
+	OverlayFS->pushOverlay(MemFS);
+	MemFS->addFile(Twine(Name), 0, llvm::MemoryBuffer::getMemBuffer(Content));
+
+	return getModuleFromSource(std::move(CFlags), Name, OverlayFS);
+}
+
+std::unique_ptr<llvm::Module>
+getModuleFromSource(llvm::opt::ArgStringList CFlags, StringRef Path)
+{
+	IntrusiveRefCntPtr<vfs::FileSystem> VFS(vfs::getRealFileSystem());
+	return getModuleFromSource(std::move(CFlags), Path, VFS);
+}
+
+std::unique_ptr<llvm::SmallVectorImpl<char>>
+getBPFObjectFromModule(llvm::Module *Module)
+{
+	using namespace llvm;
+
+	std::string TargetTriple("bpf-pc-linux");
+	std::string Error;
+	const Target* Target = TargetRegistry::lookupTarget(TargetTriple, Error);
+	if (!Target) {
+		llvm::errs() << Error;
+		return std::unique_ptr<llvm::SmallVectorImpl<char>>(nullptr);
+	}
+
+	llvm::TargetOptions Opt;
+	TargetMachine *TargetMachine =
+		Target->createTargetMachine(TargetTriple,
+					    "generic", "",
+					    Opt, Reloc::Static);
+
+	Module->setDataLayout(TargetMachine->createDataLayout());
+	Module->setTargetTriple(TargetTriple);
+
+	std::unique_ptr<SmallVectorImpl<char>> Buffer(new SmallVector<char, 0>());
+	raw_svector_ostream ostream(*Buffer);
+
+	legacy::PassManager PM;
+	if (TargetMachine->addPassesToEmitFile(PM, ostream,
+					       TargetMachine::CGFT_ObjectFile)) {
+		llvm::errs() << "TargetMachine can't emit a file of this type\n";
+		return std::unique_ptr<llvm::SmallVectorImpl<char>>(nullptr);;
+	}
+	PM.run(*Module);
+
+	return std::move(Buffer);
+}
+
+}
+
+extern "C" {
+void perf_clang__init(void)
+{
+	perf::LLVMCtx.reset(new llvm::LLVMContext());
+	LLVMInitializeBPFTargetInfo();
+	LLVMInitializeBPFTarget();
+	LLVMInitializeBPFTargetMC();
+	LLVMInitializeBPFAsmPrinter();
+}
+
+void perf_clang__cleanup(void)
+{
+	perf::LLVMCtx.reset(nullptr);
+	llvm::llvm_shutdown();
+}
+
+int perf_clang__compile_bpf(const char *filename,
+			    void **p_obj_buf,
+			    size_t *p_obj_buf_sz)
+{
+	using namespace perf;
+
+	if (!p_obj_buf || !p_obj_buf_sz)
+		return -EINVAL;
+
+	llvm::opt::ArgStringList CFlags;
+	auto M = getModuleFromSource(std::move(CFlags), filename);
+	if (!M)
+		return  -EINVAL;
+	auto O = getBPFObjectFromModule(&*M);
+	if (!O)
+		return -EINVAL;
+
+	size_t size = O->size_in_bytes();
+	void *buffer;
+
+	buffer = malloc(size);
+	if (!buffer)
+		return -ENOMEM;
+	memcpy(buffer, O->data(), size);
+	*p_obj_buf = buffer;
+	*p_obj_buf_sz = size;
+	return 0;
+}
+}
diff --git a/tools/perf/util/c++/clang.h b/tools/perf/util/c++/clang.h
new file mode 100644
index 000000000000..dd8b0427550d
--- /dev/null
+++ b/tools/perf/util/c++/clang.h
@@ -0,0 +1,26 @@
+#ifndef PERF_UTIL_CLANG_H
+#define PERF_UTIL_CLANG_H
+
+#include "llvm/ADT/StringRef.h"
+#include "llvm/IR/LLVMContext.h"
+#include "llvm/IR/Module.h"
+#include "llvm/Option/Option.h"
+#include <memory>
+
+namespace perf {
+
+using namespace llvm;
+
+std::unique_ptr<Module>
+getModuleFromSource(opt::ArgStringList CFlags,
+		    StringRef Name, StringRef Content);
+
+std::unique_ptr<Module>
+getModuleFromSource(opt::ArgStringList CFlags,
+		    StringRef Path);
+
+std::unique_ptr<llvm::SmallVectorImpl<char>>
+getBPFObjectFromModule(llvm::Module *Module);
+
+}
+#endif
diff --git a/tools/perf/util/llvm-utils.c b/tools/perf/util/llvm-utils.c
index 27b6f303720a..b23ff44cf214 100644
--- a/tools/perf/util/llvm-utils.c
+++ b/tools/perf/util/llvm-utils.c
@@ -7,6 +7,7 @@
 #include <limits.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <linux/err.h>
 #include "debug.h"
 #include "llvm-utils.h"
 #include "config.h"
@@ -282,9 +283,10 @@ static const char *kinc_fetch_script =
 "rm -rf $TMPDIR\n"
 "exit $RET\n";
 
-static inline void
-get_kbuild_opts(char **kbuild_dir, char **kbuild_include_opts)
+void llvm__get_kbuild_opts(char **kbuild_dir, char **kbuild_include_opts)
 {
+	static char *saved_kbuild_dir;
+	static char *saved_kbuild_include_opts;
 	int err;
 
 	if (!kbuild_dir || !kbuild_include_opts)
@@ -293,10 +295,28 @@ get_kbuild_opts(char **kbuild_dir, char **kbuild_include_opts)
 	*kbuild_dir = NULL;
 	*kbuild_include_opts = NULL;
 
+	if (saved_kbuild_dir && saved_kbuild_include_opts &&
+	    !IS_ERR(saved_kbuild_dir) && !IS_ERR(saved_kbuild_include_opts)) {
+		*kbuild_dir = strdup(saved_kbuild_dir);
+		*kbuild_include_opts = strdup(saved_kbuild_include_opts);
+
+		if (*kbuild_dir && *kbuild_include_opts)
+			return;
+
+		zfree(kbuild_dir);
+		zfree(kbuild_include_opts);
+		/*
+		 * Don't fall through: it may breaks saved_kbuild_dir and
+		 * saved_kbuild_include_opts if detect them again when
+		 * memory is low.
+		 */
+		return;
+	}
+
 	if (llvm_param.kbuild_dir && !llvm_param.kbuild_dir[0]) {
 		pr_debug("[llvm.kbuild-dir] is set to \"\" deliberately.\n");
 		pr_debug("Skip kbuild options detection.\n");
-		return;
+		goto errout;
 	}
 
 	err = detect_kbuild_dir(kbuild_dir);
@@ -306,7 +326,7 @@ get_kbuild_opts(char **kbuild_dir, char **kbuild_include_opts)
 "Hint:\tSet correct kbuild directory using 'kbuild-dir' option in [llvm]\n"
 "     \tsection of ~/.perfconfig or set it to \"\" to suppress kbuild\n"
 "     \tdetection.\n\n");
-		return;
+		goto errout;
 	}
 
 	pr_debug("Kernel build dir is set to %s\n", *kbuild_dir);
@@ -325,14 +345,43 @@ get_kbuild_opts(char **kbuild_dir, char **kbuild_include_opts)
 
 		free(*kbuild_dir);
 		*kbuild_dir = NULL;
-		return;
+		goto errout;
 	}
 
 	pr_debug("include option is set to %s\n", *kbuild_include_opts);
+
+	saved_kbuild_dir = strdup(*kbuild_dir);
+	saved_kbuild_include_opts = strdup(*kbuild_include_opts);
+
+	if (!saved_kbuild_dir || !saved_kbuild_include_opts) {
+		zfree(&saved_kbuild_dir);
+		zfree(&saved_kbuild_include_opts);
+	}
+	return;
+errout:
+	saved_kbuild_dir = ERR_PTR(-EINVAL);
+	saved_kbuild_include_opts = ERR_PTR(-EINVAL);
 }
 
-static void
-dump_obj(const char *path, void *obj_buf, size_t size)
+int llvm__get_nr_cpus(void)
+{
+	static int nr_cpus_avail = 0;
+	char serr[STRERR_BUFSIZE];
+
+	if (nr_cpus_avail > 0)
+		return nr_cpus_avail;
+
+	nr_cpus_avail = sysconf(_SC_NPROCESSORS_CONF);
+	if (nr_cpus_avail <= 0) {
+		pr_err(
+"WARNING:\tunable to get available CPUs in this system: %s\n"
+"        \tUse 128 instead.\n", str_error_r(errno, serr, sizeof(serr)));
+		nr_cpus_avail = 128;
+	}
+	return nr_cpus_avail;
+}
+
+void llvm__dump_obj(const char *path, void *obj_buf, size_t size)
 {
 	char *obj_path = strdup(path);
 	FILE *fp;
@@ -406,15 +455,9 @@ int llvm__compile_bpf(const char *path, void **p_obj_buf,
 	 * This is an optional work. Even it fail we can continue our
 	 * work. Needn't to check error return.
 	 */
-	get_kbuild_opts(&kbuild_dir, &kbuild_include_opts);
+	llvm__get_kbuild_opts(&kbuild_dir, &kbuild_include_opts);
 
-	nr_cpus_avail = sysconf(_SC_NPROCESSORS_CONF);
-	if (nr_cpus_avail <= 0) {
-		pr_err(
-"WARNING:\tunable to get available CPUs in this system: %s\n"
-"        \tUse 128 instead.\n", str_error_r(errno, serr, sizeof(serr)));
-		nr_cpus_avail = 128;
-	}
+	nr_cpus_avail = llvm__get_nr_cpus();
 	snprintf(nr_cpus_avail_str, sizeof(nr_cpus_avail_str), "%d",
 		 nr_cpus_avail);
 
@@ -453,9 +496,6 @@ int llvm__compile_bpf(const char *path, void **p_obj_buf,
 	free(kbuild_dir);
 	free(kbuild_include_opts);
 
-	if (llvm_param.dump_obj)
-		dump_obj(path, obj_buf, obj_buf_sz);
-
 	if (!p_obj_buf)
 		free(obj_buf);
 	else
diff --git a/tools/perf/util/llvm-utils.h b/tools/perf/util/llvm-utils.h
index 9f501cef06a1..c87a2a92a88f 100644
--- a/tools/perf/util/llvm-utils.h
+++ b/tools/perf/util/llvm-utils.h
@@ -50,4 +50,10 @@ int llvm__compile_bpf(const char *path, void **p_obj_buf, size_t *p_obj_buf_sz);
 
 /* This function is for test__llvm() use only */
 int llvm__search_clang(void);
+
+/* Following functions are reused by builtin clang support */
+void llvm__get_kbuild_opts(char **kbuild_dir, char **kbuild_include_opts);
+int llvm__get_nr_cpus(void);
+
+void llvm__dump_obj(const char *path, void *obj_buf, size_t size);
 #endif
diff --git a/tools/perf/util/perf-hooks.c b/tools/perf/util/perf-hooks.c
index 4ce88e37dd63..cb368306b12b 100644
--- a/tools/perf/util/perf-hooks.c
+++ b/tools/perf/util/perf-hooks.c
@@ -27,7 +27,7 @@ void perf_hooks__invoke(const struct perf_hook_desc *desc)
 		*(current_perf_hook->p_hook_func) = NULL;
 	} else {
 		current_perf_hook = desc;
-		(**desc->p_hook_func)();
+		(**desc->p_hook_func)(desc->hook_ctx);
 	}
 	current_perf_hook = NULL;
 }
@@ -41,7 +41,9 @@ void perf_hooks__recover(void)
 #define PERF_HOOK(name)					\
 perf_hook_func_t __perf_hook_func_##name = NULL;	\
 struct perf_hook_desc __perf_hook_desc_##name =		\
-	{.hook_name = #name, .p_hook_func = &__perf_hook_func_##name};
+	{.hook_name = #name,				\
+	 .p_hook_func = &__perf_hook_func_##name,	\
+	 .hook_ctx = NULL};
 #include "perf-hooks-list.h"
 #undef PERF_HOOK
 
@@ -54,7 +56,8 @@ static struct perf_hook_desc *perf_hooks[] = {
 #undef PERF_HOOK
 
 int perf_hooks__set_hook(const char *hook_name,
-			 perf_hook_func_t hook_func)
+			 perf_hook_func_t hook_func,
+			 void *hook_ctx)
 {
 	unsigned int i;
 
@@ -65,6 +68,7 @@ int perf_hooks__set_hook(const char *hook_name,
 		if (*(perf_hooks[i]->p_hook_func))
 			pr_warning("Overwrite existing hook: %s\n", hook_name);
 		*(perf_hooks[i]->p_hook_func) = hook_func;
+		perf_hooks[i]->hook_ctx = hook_ctx;
 		return 0;
 	}
 	return -ENOENT;
diff --git a/tools/perf/util/perf-hooks.h b/tools/perf/util/perf-hooks.h
index 1d482b26b4b9..838d5797bc1e 100644
--- a/tools/perf/util/perf-hooks.h
+++ b/tools/perf/util/perf-hooks.h
@@ -5,10 +5,11 @@
 extern "C" {
 #endif
 
-typedef void (*perf_hook_func_t)(void);
+typedef void (*perf_hook_func_t)(void *ctx);
 struct perf_hook_desc {
 	const char * const hook_name;
 	perf_hook_func_t * const p_hook_func;
+	void *hook_ctx;
 };
 
 extern void perf_hooks__invoke(const struct perf_hook_desc *);
@@ -26,7 +27,8 @@ static inline void perf_hooks__invoke_##name(void)	\
 
 extern int
 perf_hooks__set_hook(const char *hook_name,
-		     perf_hook_func_t hook_func);
+		     perf_hook_func_t hook_func,
+		     void *hook_ctx);
 
 extern perf_hook_func_t
 perf_hooks__get_hook(const char *hook_name);
diff --git a/tools/perf/util/util-cxx.h b/tools/perf/util/util-cxx.h
new file mode 100644
index 000000000000..0e0e019c9f34
--- /dev/null
+++ b/tools/perf/util/util-cxx.h
@@ -0,0 +1,26 @@
+/*
+ * Support C++ source use utilities defined in util.h
+ */
+
+#ifndef PERF_UTIL_UTIL_CXX_H
+#define PERF_UTIL_UTIL_CXX_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/*
+ * Now 'new' is the only C++ keyword found in util.h:
+ * in tools/include/linux/rbtree.h
+ *
+ * Other keywords, like class and delete, should be
+ * redefined if necessary.
+ */
+#define new _new
+#include "util.h"
+#undef new
+
+#ifdef __cplusplus
+}
+#endif
+#endif