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authorGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-08-31 09:09:54 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-09-02 07:07:54 +0200
commit529ada21ff9e37a14fd02ab1fb9d58d71d7a0d9e (patch)
parentc47c52cde806f32c4da1e455874f6aa154c06aca (diff)
lz4: fix bogus gcc warning
When building lz4 under gcc-7 we get the following bogus warning: CC [M] lib/lz4/lz4hc_compress.o lib/lz4/lz4hc_compress.c: In function ‘lz4hc_compress’: lib/lz4/lz4hc_compress.c:179:42: warning: ‘delta’ may be used uninitialized in this function [-Wmaybe-uninitialized] chaintable[(size_t)(ptr) & MAXD_MASK] = delta; ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~ lib/lz4/lz4hc_compress.c:134:6: note: ‘delta’ was declared here u16 delta; ^~~~~ This doesn't show up in the 4.4-stable tree due to us turning off warnings like this. It also doesn't show up in newer kernel versions as this code was totally rewritten. So for now, to get the 4.9-stable tree to build with 0 warnings on x86 allmodconfig, let's just shut the compiler up by initializing the variable to 0, despite it not really doing anything. To be far, this code is crazy complex, so the fact that gcc can't determine if the variable is really used or not isn't that bad, I'd blame the code here instead of the compiler. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
1 files changed, 1 insertions, 1 deletions
diff --git a/lib/lz4/lz4hc_compress.c b/lib/lz4/lz4hc_compress.c
index f344f76b6559..6b2e046a9c61 100644
--- a/lib/lz4/lz4hc_compress.c
+++ b/lib/lz4/lz4hc_compress.c
@@ -131,7 +131,7 @@ static inline int lz4hc_insertandfindbestmatch(struct lz4hc_data *hc4,
int nbattempts = MAX_NB_ATTEMPTS;
size_t repl = 0, ml = 0;
- u16 delta;
+ u16 delta = 0;
/* HC4 match finder */
lz4hc_insert(hc4, ip);