tools: Adopt noinline from kernel sources

To have a more compact way to ask the compiler not to inline a function
and to make tools/ source code look like kernel code.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-bis4pqxegt6gbm5dlqs937tn@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/include/linux/compiler-gcc.h

@@ -20,6 +20,8 @@
 /* &a[0] degrades to a pointer: a different type from an array */
 #define __must_be_array(a)	BUILD_BUG_ON_ZERO(__same_type((a), &(a)[0]))
 
+#define  noinline	__attribute__((noinline))
+
 #define __noreturn	__attribute__((noreturn))
 
 #define __printf(a, b)	__attribute__((format(printf, a, b)))

tools/include/linux/compiler.h

@@ -17,6 +17,10 @@
 # define __always_inline	inline __attribute__((always_inline))
 #endif
 
+#ifndef noinline
+#define noinline
+#endif
+
 /* Are two types/vars the same type (ignoring qualifiers)? */
 #ifndef __same_type
 # define __same_type(a, b) __builtin_types_compatible_p(typeof(a), typeof(b))

tools/perf/tests/bp_signal.c

@@ -62,8 +62,7 @@ static void __test_function(volatile long *ptr)
 }
 #endif
 
-__attribute__ ((noinline))
-static int test_function(void)
+static noinline int test_function(void)
 {
 	__test_function(&the_var);
 	the_var++;

tools/perf/tests/bp_signal_overflow.c

@@ -28,8 +28,7 @@
 
 static int overflows;
 
-__attribute__ ((noinline))
-static int test_function(void)
+static noinline int test_function(void)
 {
 	return time(NULL);
 }

tools/perf/tests/dwarf-unwind.c

@@ -76,8 +76,7 @@ static int unwind_entry(struct unwind_entry *entry, void *arg)
 	return strcmp((const char *) symbol, funcs[idx]);
 }
 
-__attribute__ ((noinline))
-static int unwind_thread(struct thread *thread)
+static noinline int unwind_thread(struct thread *thread)
 {
 	struct perf_sample sample;
 	unsigned long cnt = 0;
@@ -108,8 +107,7 @@ static int unwind_thread(struct thread *thread)
 
 static int global_unwind_retval = -INT_MAX;
 
-__attribute__ ((noinline))
-static int compare(void *p1, void *p2)
+static noinline int compare(void *p1, void *p2)
 {
 	/* Any possible value should be 'thread' */
 	struct thread *thread = *(struct thread **)p1;
@@ -128,8 +126,7 @@ static int compare(void *p1, void *p2)
 	return p1 - p2;
 }
 
-__attribute__ ((noinline))
-static int krava_3(struct thread *thread)
+static noinline int krava_3(struct thread *thread)
 {
 	struct thread *array[2] = {thread, thread};
 	void *fp = &bsearch;
@@ -147,14 +144,12 @@ static int krava_3(struct thread *thread)
 	return global_unwind_retval;
 }
 
-__attribute__ ((noinline))
-static int krava_2(struct thread *thread)
+static noinline int krava_2(struct thread *thread)
 {
 	return krava_3(thread);
 }
 
-__attribute__ ((noinline))
-static int krava_1(struct thread *thread)
+static noinline int krava_1(struct thread *thread)
 {
 	return krava_2(thread);
 }