File 64104238-bunzip-gcc13.patch of Package xen
# Commit 402195e56de0aacf97e05c80ed367d464ca6938b
# Date 2023-03-14 10:45:28 +0100
# Author Jan Beulich <jbeulich@suse.com>
# Committer Jan Beulich <jbeulich@suse.com>
bunzip: work around gcc13 warning
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 <martin.liska@suse.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
--- a/xen/common/bunzip2.c
+++ b/xen/common/bunzip2.c
@@ -233,6 +233,11 @@ static int __init get_next_block(struct
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))