[PATCH] perf tools: Fixing uninitialised variable

[PATCH] perf tools: Fixing uninitialised variable

[Mathieu Poirier]

When working natively on arm64 the compiler gets pesky and complains
that variable 'i' is uninitialised, something that breaks the
compilation.  Here no further checks are needed since variable 'found_spe'
can only be true if variable 'i' has been initialised as part of the for
loop.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
---
 tools/perf/arch/arm/util/auxtrace.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/perf/arch/arm/util/auxtrace.c b/tools/perf/arch/arm/util/auxtrace.c
index 2323581b157d..fa639e3e52ac 100644
--- a/tools/perf/arch/arm/util/auxtrace.c
+++ b/tools/perf/arch/arm/util/auxtrace.c
@@ -68,7 +68,7 @@ struct auxtrace_record
 	bool found_spe = false;
 	static struct perf_pmu **arm_spe_pmus = NULL;
 	static int nr_spes = 0;
-	int i;
+	int i = 0;
 
 	if (!evlist)
 		return NULL;
-- 
2.7.4

Re: [PATCH] perf tools: Fixing uninitialised variable

[Kim Phillips]

On Mon, 22 Jan 2018 15:17:40 -0700
Mathieu Poirier <mathieu.poirier@linaro.org> wrote:

> When working natively on arm64 the compiler gets pesky and complains

FWIW, I've only seen this on ARCH=arm64 builds with gcc versions less
than 5, i.e, 4.8.5.

> that variable 'i' is uninitialised, something that breaks the
> compilation.

It'd be nice to include the full compiler error message, to help users
searching for how to fix the error.

>  Here no further checks are needed since variable 'found_spe'
> can only be true if variable 'i' has been initialised as part of the for
> loop.
> 
> Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
> ---

Cc'ing me and adding a:

Fixes: ffd3d18c20b8 ("perf tools: Add ARM Statistical Profiling Extensions (SPE) support")

line would also be nice.

Other than those nits:

Acked-by: Kim Phillips <kim.phillips@arm.com>

Thanks!

Kim