On 12/18/2017 4:49 PM, Stefan Beller wrote:
I was compiling origin/master today with stricter compiler flags today
and was greeted by

t/helper/test-lazy-init-name-hash.c: In function ‘cmd_main’:
t/helper/test-lazy-init-name-hash.c:172:5: error: ‘nr_threads_used’ may be used 
uninitialized in this function [-Werror=maybe-uninitialized]
      printf("avg [size %8d] [single %f] %c [multi %f %d]\n",
      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
          nr,
          ~~~
          (double)avg_single/1000000000,
          ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
          (avg_single < avg_multi ? '<' : '>'),
          ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
          (double)avg_multi/1000000000,
          ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
          nr_threads_used);
          ~~~~~~~~~~~~~~~~
t/helper/test-lazy-init-name-hash.c:115:6: note: ‘nr_threads_used’ was declared 
here
   int nr_threads_used;
       ^~~~~~~~~~~~~~~

I do not see how we can arrive at that line without having `nr_threads_used`
initialized, as we'd have `count > 1`  (which asserts that we ran the
loop above at least once, such that it *should* be initialized).

I do not have time to dive into further analysis.

Signed-off-by: Stefan Beller <sbel...@google.com>
---
  t/helper/test-lazy-init-name-hash.c | 2 +-
  1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/t/helper/test-lazy-init-name-hash.c 
b/t/helper/test-lazy-init-name-hash.c
index 6368a89345..297fb01d61 100644
--- a/t/helper/test-lazy-init-name-hash.c
+++ b/t/helper/test-lazy-init-name-hash.c
@@ -112,7 +112,7 @@ static void analyze_run(void)
  {
        uint64_t t1s, t1m, t2s, t2m;
        int cache_nr_limit;
-       int nr_threads_used;
+       int nr_threads_used = 0;
        int i;
        int nr;

Agreed. It should not be a problem.  Explicitly initializing it is fine.


Signed-off-by: Jeff Hostetler <jeffh...@microsoft.com>


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