File 64104238-bunzip-gcc13.patch of Package xen

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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))

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File 64104238-bunzip-gcc13.patch of Package xen

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