avoid shifting signed integers 31 bits

We sometimes use 32-bit unsigned integers as bit-fields.
It's fine to access the MSB, because it's unsigned. However,
doing so as "1 << 31" is wrong, because the constant "1" is
a signed int, and we shift into the sign bit, causing
undefined behavior.

We can fix this by using "1U" as the constant.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
Jeff King
2015-12-29 01:35:46 -05:00
committed by Junio C Hamano
parent 1ff88560c8
commit 9a93c6686f
3 changed files with 3 additions and 3 deletions

2
diff.h
View File

@ -91,7 +91,7 @@ typedef struct strbuf *(*diff_prefix_fn_t)(struct diff_options *opt, void *data)
#define DIFF_OPT_DIRSTAT_BY_LINE (1 << 28)
#define DIFF_OPT_FUNCCONTEXT (1 << 29)
#define DIFF_OPT_PICKAXE_IGNORE_CASE (1 << 30)
#define DIFF_OPT_DEFAULT_FOLLOW_RENAMES (1 << 31)
#define DIFF_OPT_DEFAULT_FOLLOW_RENAMES (1U << 31)
#define DIFF_OPT_TST(opts, flag) ((opts)->flags & DIFF_OPT_##flag)
#define DIFF_OPT_TOUCHED(opts, flag) ((opts)->touched_flags & DIFF_OPT_##flag)