perf/core clang fixes:

Changes to make tools/{perf,lib/{bpf,traceevent,api}} build with
 CC=clang, to, for instance, take advantage of warnings (Arnaldo Carvalho de Melo):
 
 - Conditionally request some warning options not available on clang
 
 - Set the maximum optimization level to -O3 when using CC=clang, leave
   the previous setting of -O6 otherwise.
 
 - Make it an error to pass a signed value to OPTION_UINTEGER, so that
   we can remove abs(unsigned int) calls in 'perf bench futex'.
 
 - Make sure dprintf() is not defined before using that name in 'perf bench numa'
 
 - Avoid using field after variable sized type, its a GNU extension, use
   equivalent code.
 
 - Fix some bugs where some variables could be used unitialized,
   something not caught by gcc.
 
 - Fix some spots where we were testing struct->array[] members against
   NULL, it will always evaluate to 'true'.
 
 - Add missing parse_events_error() prototype in the bison file.
 
 There are still one problem when trying to build the python support, but
 this are the 'size' outputs for 'make -C tools/perf NO_LIBPYTHON' for
 gcc and clang builds:
 
   DW_AT_producer: clang version 4.0.0 (http://llvm.org/git/clang.git f5be8ba13adc4ba1011a7ccd60c844bd60427c1c) (ht
 
   $ size ~/bin/perf
      text    data     bss     dec     hex     filename
   3447514  831320 23901696  28180530  1ae0032 /home/acme/bin/perf
 
   DW_AT_producer: GNU C99 6.3.1 20161221 (Red Hat 6.3.1-1) -mtune=generic -march=x86-64 -ggdb3 -O6 -std=gnu99
 +-fno-omit-frame-pointer -funwind-tables -fstack-protector-all
 
   $ size ~/bin/perf
      text    data     bss     dec     hex     filename
   3671662  836480 23902752  28410894  1b1840e /home/acme/bin/perf
 
 Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v2
 
 iQIcBAABCAAGBQJYpHzlAAoJENZQFvNTUqpAtq8QAKrP64GRQDvoAS9bT6Zjvh/x
 xPcjD+XcMg+r/peFRQ1YOhKxmWCUwJweVIrl54e5yuOgXnClIXjnZcVwjqiJDHL3
 bGBDZss3hFWY5y0mO6Ny8ME0bgb4LKErCp81uobAbDQ6rxzSFId6plnJy7CgeX5L
 eB5FfnYWDPmgLY03nfyGwmR07NT8bDHeQu3yGruB8EDW7aQc8lMtqhRBAJEK6T1x
 oAabuimlU5CGqKxuCHOUqckr+rFbARNt76wvgzRcuVQnZ7h3llDXF0LaW2IEDaiM
 LRx+F//zE1BcklR/WgryWZBcaCFwF9jTvhzQRRhUAXPbLrKLak6+WFnJH1fcFL0l
 zyVpA6yqBVRaCYLt/OcVad40AGOjjEITpbgBfpzkHGEafzZAacddOn9okZyJvvQO
 LNFReECFvDoslJdyXHN5n9CwnkaD7PowkTCqr6SShKpft0oITy+SZYbNeCxi9YST
 HW3i6XisweGgLUjElA29pBfVj28Xe2PTKlOcEPcp/at2drFFLUSikCLZWOYSaJX7
 Or7EqhxI0G6OpPmvGt0FdQKUvoZ+YcAeR54RzEHMBmKNZ/GWTKbcFAQX9LQ9MNMn
 NrXEzwdbMxD9tkw4tfs6iEchEUYqEbOQdK/hWJRfeQE12QGKDtueJe1TI78kZbeL
 oEdmZMfMahOI9Lx4He6M
 =ge2k
 -----END PGP SIGNATURE-----

Merge tag 'perf-core-for-mingo-4.11-20170215' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/core

Pull perf/core clang fixes from Arnaldo Carvalho de Melo:

Changes to make tools/{perf,lib/{bpf,traceevent,api}} build with
CC=clang, to, for instance, take advantage of warnings (Arnaldo Carvalho de Melo):

- Conditionally request some warning options not available on clang

- Set the maximum optimization level to -O3 when using CC=clang, leave
  the previous setting of -O6 otherwise.

- Make it an error to pass a signed value to OPTION_UINTEGER, so that
  we can remove abs(unsigned int) calls in 'perf bench futex'.

- Make sure dprintf() is not defined before using that name in 'perf bench numa'

- Avoid using field after variable sized type, its a GNU extension, use
  equivalent code.

- Fix some bugs where some variables could be used unitialized,
  something not caught by gcc.

- Fix some spots where we were testing struct->array[] members against
  NULL, it will always evaluate to 'true'.

- Add missing parse_events_error() prototype in the bison file.

There are still one problem when trying to build the python support, but
this are the 'size' outputs for 'make -C tools/perf NO_LIBPYTHON' for
gcc and clang builds:

  DW_AT_producer: clang version 4.0.0 (http://llvm.org/git/clang.git f5be8ba13adc4ba1011a7ccd60c844bd60427c1c) (ht

  $ size ~/bin/perf
     text    data     bss     dec     hex     filename
  3447514  831320 23901696  28180530  1ae0032 /home/acme/bin/perf

  DW_AT_producer: GNU C99 6.3.1 20161221 (Red Hat 6.3.1-1) -mtune=generic -march=x86-64 -ggdb3 -O6 -std=gnu99
+-fno-omit-frame-pointer -funwind-tables -fstack-protector-all

  $ size ~/bin/perf
     text    data     bss     dec     hex     filename
  3671662  836480 23902752  28410894  1b1840e /home/acme/bin/perf

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

tools/lib/api/Makefile

@@ -17,7 +17,13 @@ MAKEFLAGS += --no-print-directory
 LIBFILE = $(OUTPUT)libapi.a
 
 CFLAGS := $(EXTRA_WARNINGS) $(EXTRA_CFLAGS)
-CFLAGS += -ggdb3 -Wall -Wextra -std=gnu99 -O6 -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=2 -fPIC
+CFLAGS += -ggdb3 -Wall -Wextra -std=gnu99 -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=2 -fPIC
+
+ifeq ($(CC), clang)
+  CFLAGS += -O3
+else
+  CFLAGS += -O6
+endif
 
 # Treat warnings as errors unless directed not to
 ifneq ($(WERROR),0)

tools/lib/subcmd/Makefile

@@ -19,7 +19,13 @@ MAKEFLAGS += --no-print-directory
 LIBFILE = $(OUTPUT)libsubcmd.a
 
 CFLAGS := $(EXTRA_WARNINGS) $(EXTRA_CFLAGS)
-CFLAGS += -ggdb3 -Wall -Wextra -std=gnu99 -O6 -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=2 -fPIC
+CFLAGS += -ggdb3 -Wall -Wextra -std=gnu99 -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=2 -fPIC
+
+ifeq ($(CC), clang)
+  CFLAGS += -O3
+else
+  CFLAGS += -O6
+endif
 
 # Treat warnings as errors unless directed not to
 ifneq ($(WERROR),0)

tools/lib/subcmd/parse-options.c

@@ -270,6 +270,8 @@ static int get_value(struct parse_opt_ctx_t *p,
 		}
 		if (get_arg(p, opt, flags, &arg))
 			return -1;
+		if (arg[0] == '-')
+			return opterror(opt, "expects an unsigned numerical value", flags);
 		*(unsigned int *)opt->value = strtol(arg, (char **)&s, 10);
 		if (*s)
 			return opterror(opt, "expects a numerical value", flags);
@@ -302,6 +304,8 @@ static int get_value(struct parse_opt_ctx_t *p,
 		}
 		if (get_arg(p, opt, flags, &arg))
 			return -1;
+		if (arg[0] == '-')
+			return opterror(opt, "expects an unsigned numerical value", flags);
 		*(u64 *)opt->value = strtoull(arg, (char **)&s, 10);
 		if (*s)
 			return opterror(opt, "expects a numerical value", flags);

tools/perf/Makefile.config

@@ -144,8 +144,12 @@ ifndef DEBUG
 endif
 
 ifeq ($(DEBUG),0)
+ifeq ($(CC), clang)
+  CFLAGS += -O3
+else
   CFLAGS += -O6
 endif
+endif
 
 ifdef PARSER_DEBUG
   PARSER_DEBUG_BISON := -t

tools/perf/bench/futex-hash.c

@@ -130,8 +130,6 @@ int bench_futex_hash(int argc, const char **argv,
 	}
 
 	ncpus = sysconf(_SC_NPROCESSORS_ONLN);
-	nsecs = futexbench_sanitize_numeric(nsecs);
-	nfutexes = futexbench_sanitize_numeric(nfutexes);
 
 	sigfillset(&act.sa_mask);
 	act.sa_sigaction = toggle_done;
@@ -139,8 +137,6 @@ int bench_futex_hash(int argc, const char **argv,
 
 	if (!nthreads) /* default to the number of CPUs */
 		nthreads = ncpus;
-	else
-		nthreads = futexbench_sanitize_numeric(nthreads);
 
 	worker = calloc(nthreads, sizeof(*worker));
 	if (!worker)

tools/perf/bench/futex-lock-pi.c

@@ -152,7 +152,6 @@ int bench_futex_lock_pi(int argc, const char **argv,
 		goto err;
 
 	ncpus = sysconf(_SC_NPROCESSORS_ONLN);
-	nsecs = futexbench_sanitize_numeric(nsecs);
 
 	sigfillset(&act.sa_mask);
 	act.sa_sigaction = toggle_done;
@@ -160,8 +159,6 @@ int bench_futex_lock_pi(int argc, const char **argv,
 
 	if (!nthreads)
 		nthreads = ncpus;
-	else
-		nthreads = futexbench_sanitize_numeric(nthreads);
 
 	worker = calloc(nthreads, sizeof(*worker));
 	if (!worker)

tools/perf/bench/futex-requeue.c

@@ -128,8 +128,6 @@ int bench_futex_requeue(int argc, const char **argv,
 
 	if (!nthreads)
 		nthreads = ncpus;
-	else
-		nthreads = futexbench_sanitize_numeric(nthreads);
 
 	worker = calloc(nthreads, sizeof(*worker));
 	if (!worker)

tools/perf/bench/futex-wake-parallel.c

@@ -217,12 +217,8 @@ int bench_futex_wake_parallel(int argc, const char **argv,
 	sigaction(SIGINT, &act, NULL);
 
 	ncpus = sysconf(_SC_NPROCESSORS_ONLN);
-	nwaking_threads = futexbench_sanitize_numeric(nwaking_threads);
-
 	if (!nblocked_threads)
 		nblocked_threads = ncpus;
-	else
-		nblocked_threads = futexbench_sanitize_numeric(nblocked_threads);
 
 	/* some sanity checks */
 	if (nwaking_threads > nblocked_threads || !nwaking_threads)

tools/perf/bench/futex-wake.c

@@ -129,7 +129,6 @@ int bench_futex_wake(int argc, const char **argv,
 	}
 
 	ncpus = sysconf(_SC_NPROCESSORS_ONLN);
-	nwakes = futexbench_sanitize_numeric(nwakes);
 
 	sigfillset(&act.sa_mask);
 	act.sa_sigaction = toggle_done;
@@ -137,8 +136,6 @@ int bench_futex_wake(int argc, const char **argv,
 
 	if (!nthreads)
 		nthreads = ncpus;
-	else
-		nthreads = futexbench_sanitize_numeric(nthreads);
 
 	worker = calloc(nthreads, sizeof(*worker));
 	if (!worker)

tools/perf/bench/futex.h

@@ -7,7 +7,6 @@
 #ifndef _FUTEX_H
 #define _FUTEX_H
 
-#include <stdlib.h>
 #include <unistd.h>
 #include <sys/syscall.h>
 #include <sys/types.h>
@@ -100,7 +99,4 @@ static inline int pthread_attr_setaffinity_np(pthread_attr_t *attr,
 }
 #endif
 
-/* User input sanitation */
-#define futexbench_sanitize_numeric(__n) abs((__n))
-
 #endif /* _FUTEX_H */

tools/perf/bench/numa.c

@@ -43,6 +43,7 @@
 /*
  * Debug printf:
  */
+#undef dprintf
 #define dprintf(x...) do { if (g && g->p.show_details >= 1) printf(x); } while (0)
 
 struct thread_data {

tools/perf/builtin-record.c

@@ -655,22 +655,23 @@ record__finish_output(struct record *rec)
 
 static int record__synthesize_workload(struct record *rec, bool tail)
 {
-	struct {
-		struct thread_map map;
-		struct thread_map_data map_data;
-	} thread_map;
+	int err;
+	struct thread_map *thread_map;
 
 	if (rec->opts.tail_synthesize != tail)
 		return 0;
 
-	thread_map.map.nr = 1;
-	thread_map.map.map[0].pid = rec->evlist->workload.pid;
-	thread_map.map.map[0].comm = NULL;
-	return perf_event__synthesize_thread_map(&rec->tool, &thread_map.map,
+	thread_map = thread_map__new_by_tid(rec->evlist->workload.pid);
+	if (thread_map == NULL)
+		return -1;
+
+	err = perf_event__synthesize_thread_map(&rec->tool, thread_map,
 						 process_synthesized_event,
 						 &rec->session->machines.host,
 						 rec->opts.sample_address,
 						 rec->opts.proc_map_timeout);
+	thread_map__put(thread_map);
+	return err;
 }
 
 static int record__synthesize(struct record *rec, bool tail);

tools/perf/tests/parse-no-sample-id-all.c

@@ -50,7 +50,8 @@ static int process_events(union perf_event **events, size_t count)
 }
 
 struct test_attr_event {
-	struct attr_event attr;
+	struct perf_event_header header;
+	struct perf_event_attr	 attr;
 	u64 id;
 };
 
@@ -71,21 +72,17 @@ int test__parse_no_sample_id_all(int subtest __maybe_unused)
 	int err;
 
 	struct test_attr_event event1 = {
-		.attr = {
 		.header = {
 			.type = PERF_RECORD_HEADER_ATTR,
 			.size = sizeof(struct test_attr_event),
 		},
-		},
 		.id = 1,
 	};
 	struct test_attr_event event2 = {
-		.attr = {
 		.header = {
 			.type = PERF_RECORD_HEADER_ATTR,
 			.size = sizeof(struct test_attr_event),
 		},
-		},
 		.id = 2,
 	};
 	struct mmap_event event3 = {

tools/perf/util/evsel.c

@@ -1448,7 +1448,7 @@ static bool ignore_missing_thread(struct perf_evsel *evsel,
 	return true;
 }
 
-static int __perf_evsel__open(struct perf_evsel *evsel, struct cpu_map *cpus,
+int perf_evsel__open(struct perf_evsel *evsel, struct cpu_map *cpus,
 		     struct thread_map *threads)
 {
 	int cpu, thread, nthreads;
@@ -1459,6 +1459,30 @@ static int __perf_evsel__open(struct perf_evsel *evsel, struct cpu_map *cpus,
 	if (perf_missing_features.write_backward && evsel->attr.write_backward)
 		return -EINVAL;
 
+	if (cpus == NULL) {
+		static struct cpu_map *empty_cpu_map;
+
+		if (empty_cpu_map == NULL) {
+			empty_cpu_map = cpu_map__dummy_new();
+			if (empty_cpu_map == NULL)
+				return -ENOMEM;
+		}
+
+		cpus = empty_cpu_map;
+	}
+
+	if (threads == NULL) {
+		static struct thread_map *empty_thread_map;
+
+		if (empty_thread_map == NULL) {
+			empty_thread_map = thread_map__new_by_tid(-1);
+			if (empty_thread_map == NULL)
+				return -ENOMEM;
+		}
+
+		threads = empty_thread_map;
+	}
+
 	if (evsel->system_wide)
 		nthreads = 1;
 	else
@@ -1655,46 +1679,16 @@ void perf_evsel__close(struct perf_evsel *evsel, int ncpus, int nthreads)
 	perf_evsel__free_fd(evsel);
 }
 
-static struct {
-	struct cpu_map map;
-	int cpus[1];
-} empty_cpu_map = {
-	.map.nr	= 1,
-	.cpus	= { -1, },
-};
-
-static struct {
-	struct thread_map map;
-	int threads[1];
-} empty_thread_map = {
-	.map.nr	 = 1,
-	.threads = { -1, },
-};
-
-int perf_evsel__open(struct perf_evsel *evsel, struct cpu_map *cpus,
-		     struct thread_map *threads)
-{
-	if (cpus == NULL) {
-		/* Work around old compiler warnings about strict aliasing */
-		cpus = &empty_cpu_map.map;
-	}
-
-	if (threads == NULL)
-		threads = &empty_thread_map.map;
-
-	return __perf_evsel__open(evsel, cpus, threads);
-}
-
 int perf_evsel__open_per_cpu(struct perf_evsel *evsel,
 			     struct cpu_map *cpus)
 {
-	return __perf_evsel__open(evsel, cpus, &empty_thread_map.map);
+	return perf_evsel__open(evsel, cpus, NULL);
 }
 
 int perf_evsel__open_per_thread(struct perf_evsel *evsel,
 				struct thread_map *threads)
 {
-	return __perf_evsel__open(evsel, &empty_cpu_map.map, threads);
+	return perf_evsel__open(evsel, NULL, threads);
 }
 
 static int perf_evsel__parse_id_sample(const struct perf_evsel *evsel,

tools/perf/util/intel-pt-decoder/Build

@@ -23,4 +23,8 @@ $(OUTPUT)util/intel-pt-decoder/intel-pt-insn-decoder.o: util/intel-pt-decoder/in
 	$(call rule_mkdir)
 	$(call if_changed_dep,cc_o_c)
 
-CFLAGS_intel-pt-insn-decoder.o += -I$(OUTPUT)util/intel-pt-decoder -Wno-override-init
+CFLAGS_intel-pt-insn-decoder.o += -I$(OUTPUT)util/intel-pt-decoder
+
+ifneq ($(CC), clang)
+  CFLAGS_intel-pt-insn-decoder.o += -Wno-override-init
+endif

tools/perf/util/machine.c

@@ -782,7 +782,7 @@ static u64 machine__get_running_kernel_start(struct machine *machine,
 
 int __machine__create_kernel_maps(struct machine *machine, struct dso *kernel)
 {
-	enum map_type type;
+	int type;
 	u64 start = machine__get_running_kernel_start(machine, NULL);
 
 	/* In case of renewal the kernel map, destroy previous one */
@@ -813,7 +813,7 @@ int __machine__create_kernel_maps(struct machine *machine, struct dso *kernel)
 
 void machine__destroy_kernel_maps(struct machine *machine)
 {
-	enum map_type type;
+	int type;
 
 	for (type = 0; type < MAP__NR_TYPES; ++type) {
 		struct kmap *kmap;

tools/perf/util/parse-events.c

@@ -2020,17 +2020,14 @@ static bool is_event_supported(u8 type, unsigned config)
 		.config = config,
 		.disabled = 1,
 	};
-	struct {
-		struct thread_map map;
-		int threads[1];
-	} tmap = {
-		.map.nr	 = 1,
-		.threads = { 0 },
-	};
+	struct thread_map *tmap = thread_map__new_by_tid(0);
+
+	if (tmap == NULL)
+		return false;
 
 	evsel = perf_evsel__new(&attr);
 	if (evsel) {
-		open_return = perf_evsel__open(evsel, NULL, &tmap.map);
+		open_return = perf_evsel__open(evsel, NULL, tmap);
 		ret = open_return >= 0;
 
 		if (open_return == -EACCES) {
@@ -2042,7 +2039,7 @@ static bool is_event_supported(u8 type, unsigned config)
 			 *
 			 */
 			evsel->attr.exclude_kernel = 1;
-			ret = perf_evsel__open(evsel, NULL, &tmap.map) >= 0;
+			ret = perf_evsel__open(evsel, NULL, tmap) >= 0;
 		}
 		perf_evsel__delete(evsel);
 	}

tools/perf/util/parse-events.y

@@ -17,6 +17,8 @@
 #include "parse-events.h"
 #include "parse-events-bison.h"
 
+void parse_events_error(YYLTYPE *loc, void *data, void *scanner, char const *msg);
+
 #define ABORT_ON(val) \
 do { \
 	if (val) \

tools/perf/util/pmu.c

@@ -945,12 +945,12 @@ static int check_info_data(struct perf_pmu_alias *alias,
 	 * define unit, scale and snapshot, fail
 	 * if there's more than one.
 	 */
-	if ((info->unit && alias->unit) ||
+	if ((info->unit && alias->unit[0]) ||
 	    (info->scale && alias->scale) ||
 	    (info->snapshot && alias->snapshot))
 		return -EINVAL;
 
-	if (alias->unit)
+	if (alias->unit[0])
 		info->unit = alias->unit;
 
 	if (alias->scale)

tools/perf/util/probe-event.c

@@ -2061,7 +2061,7 @@ static int find_perf_probe_point_from_map(struct probe_trace_point *tp,
 					  bool is_kprobe)
 {
 	struct symbol *sym = NULL;
-	struct map *map;
+	struct map *map = NULL;
 	u64 addr = tp->address;
 	int ret = -ENOENT;
 

tools/perf/util/session.c

@@ -1901,7 +1901,7 @@ int maps__set_kallsyms_ref_reloc_sym(struct map **maps,
 				     const char *symbol_name, u64 addr)
 {
 	char *bracket;
-	enum map_type i;
+	int i;
 	struct ref_reloc_sym *ref;
 
 	ref = zalloc(sizeof(struct ref_reloc_sym));

tools/scripts/Makefile.include

@@ -32,7 +32,6 @@ EXTRA_WARNINGS += -Wold-style-definition
 EXTRA_WARNINGS += -Wpacked
 EXTRA_WARNINGS += -Wredundant-decls
 EXTRA_WARNINGS += -Wshadow
-EXTRA_WARNINGS += -Wstrict-aliasing=3
 EXTRA_WARNINGS += -Wstrict-prototypes
 EXTRA_WARNINGS += -Wswitch-default
 EXTRA_WARNINGS += -Wswitch-enum
@@ -40,6 +39,10 @@ EXTRA_WARNINGS += -Wundef
 EXTRA_WARNINGS += -Wwrite-strings
 EXTRA_WARNINGS += -Wformat
 
+ifneq ($(CC), clang)
+EXTRA_WARNINGS += -Wstrict-aliasing=3
+endif
+
 ifneq ($(findstring $(MAKEFLAGS), w),w)
 PRINT_DIR = --no-print-directory
 else