From a4165851e769ebc32da48904d58f144f2d93e69a Mon Sep 17 00:00:00 2001
From: Jeff King <peff@peff.net>
Date: Thu, 24 Oct 2013 04:45:13 -0400
Subject: [PATCH] silence gcc array-bounds warning
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In shorten_unambiguous_ref, we build and cache a reverse-map of the
rev-parse rules like this:
static char **scanf_fmts;
static int nr_rules;
if (!nr_rules) {
for (; ref_rev_parse_rules[nr_rules]; nr_rules++)
... generate scanf_fmts ...
}
where ref_rev_parse_rules is terminated with a NULL pointer.
Compiling with "gcc -O2 -Wall" does not cause any problems, but
compiling with "-O3 -Wall" generates:
$ make CFLAGS='-O3 -Wall' refs.o
refs.c: In function ‘shorten_unambiguous_ref’:
refs.c:3379:29: warning: array subscript is above array bounds [-Warray-bounds]
for (; ref_rev_parse_rules[nr_rules]; nr_rules++)
Curiously, we can silence this by explicitly nr_rules to 0
in the beginning of the loop, even though the compiler
should be able to tell that we follow this code path only
when nr_rules is already 0.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
refs.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/refs.c b/refs.c
index 1e5e7b4ad9..e264f7a9f4 100644
--- a/refs.c
+++ b/refs.c
@@ -1688,7 +1688,7 @@ char *shorten_unambiguous_ref(const char *ref)
size_t total_len = 0;
/* the rule list is NULL terminated, count them first */
- for (; ref_rev_parse_rules[nr_rules]; nr_rules++)
+ for (nr_rules = 0; ref_rev_parse_rules[nr_rules]; nr_rules++)
/* no +1 because strlen("%s") < strlen("%.*s") */
total_len += strlen(ref_rev_parse_rules[nr_rules]);