From 7082d656ae9bcd26392caf72e50e0f7a61c8f285 Mon Sep 17 00:00:00 2001 From: Jan Beulich Date: Tue, 21 Mar 2023 13:47:11 +0100 Subject: [PATCH] bunzip: work around gcc13 warning MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit While provable that length[0] is always initialized (because symCount cannot be zero), upcoming gcc13 fails to recognize this and warns about the unconditional use of the value immediately following the loop. See also https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106511. Reported-by: Martin Liška Signed-off-by: Jan Beulich Acked-by: Andrew Cooper master commit: 402195e56de0aacf97e05c80ed367d464ca6938b master date: 2023-03-14 10:45:28 +0100 --- xen/common/bunzip2.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/xen/common/bunzip2.c b/xen/common/bunzip2.c index 61b80aff1b..4466426941 100644 --- a/xen/common/bunzip2.c +++ b/xen/common/bunzip2.c @@ -233,6 +233,11 @@ static int __init get_next_block(struct bunzip_data *bd) becomes negative, so an unsigned inequality catches it.) */ t = get_bits(bd, 5)-1; + /* GCC 13 has apparently improved use-before-set detection, but + it can't figure out that length[0] is always intialized by + virtue of symCount always being positive when making it here. + See https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106511. */ + length[0] = 0; for (i = 0; i < symCount; i++) { for (;;) { if (((unsigned)t) > (MAX_HUFCODE_BITS-1)) -- 2.30.2