[PATCH 1/9] perf bench: fix assert when NDEBUG is defined

From: Arnaldo Carvalho de Melo
Date: Sat Sep 08 2012 - 16:38:13 EST

From: Irina Tirdea <irina.tirdea@xxxxxxxxx>

When NDEBUG is defined, the assert macro will be expanded to nothing.
Some assert calls used in perf are also including some functionality
(e.g. system calls), not only validity checks. Therefore, if NDEBUG is
defined, this functionality will be removed along with the assert. Perf
also defines BUG_ON based on assert, so it has the same problem.

Define BUG_ON so that the condition will be executed when NDEBUG is
defined. Replace the assert statements that have these side effects
with BUG_ON.

For defining BUG_ON, use "if (cond) {}" insted of "if (cond) ;" because
in the latter case build fails with "error: suggest braces around empty
body in an âifâ statement [-Werror=empty-body]"

Suggested-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Signed-off-by: Irina Tirdea <irina.tirdea@xxxxxxxxx>
Reviewed-by: Namhyung Kim <namhyung@xxxxxxxxxx>
Reviewed-by: Pekka Enberg <penberg@xxxxxxxxxx>
Cc: David Ahern <dsahern@xxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Namhyung Kim <namhyung.kim@xxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
Link: http://lkml.kernel.org/r/1347082551-2394-1-git-send-email-irina.tirdea@xxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
tools/perf/bench/sched-pipe.c | 6 +++---
tools/perf/util/include/linux/kernel.h | 4 ++++
2 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/tools/perf/bench/sched-pipe.c b/tools/perf/bench/sched-pipe.c
index 0c7454f..15911e9 100644
--- a/tools/perf/bench/sched-pipe.c
+++ b/tools/perf/bench/sched-pipe.c
@@ -56,13 +56,13 @@ int bench_sched_pipe(int argc, const char **argv,
* causes error in building environment for perf
int __used ret, wait_stat;
- pid_t pid, retpid;
+ pid_t pid, retpid __used;

argc = parse_options(argc, argv, options,
bench_sched_pipe_usage, 0);

- assert(!pipe(pipe_1));
- assert(!pipe(pipe_2));
+ BUG_ON(pipe(pipe_1));
+ BUG_ON(pipe(pipe_2));

pid = fork();
assert(pid >= 0);
diff --git a/tools/perf/util/include/linux/kernel.h b/tools/perf/util/include/linux/kernel.h
index b6842c1..4af9a10 100644
--- a/tools/perf/util/include/linux/kernel.h
+++ b/tools/perf/util/include/linux/kernel.h
@@ -47,8 +47,12 @@

#ifndef BUG_ON
+#ifdef NDEBUG
+#define BUG_ON(cond) do { if (cond) {} } while (0)
#define BUG_ON(cond) assert(!(cond))

* Both need more care to handle endianness

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