Merge tag 'perf-core-for-mingo-20161205' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/core

Pull perf/core improvements and fixes from Arnaldo Carvalho de Melo:

Fixes:

 - Do not show a bogus target address in 'perf annotate' for targetless powerpc
   jump instructions such as 'bctr' (Ravi Bangoria)

 - Fix tools/build race conditions with the fixdep utility (Jiri Olsa)

 - Fix building objtool with clang (Peter Foley)

Infrastructure changes:

- Support linking perf with clang and LLVM libraries, initially statically, but
  this limitation will be lifted and shared libraries, when available, will
  be preferred to the static build, that should, as with other features, be
  enabled explicitly (Wang Nan)

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

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