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author | René Scharfe <l.s.r@web.de> | 2018-05-09 23:06:46 +0200 |
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committer | Junio C Hamano <gitster@pobox.com> | 2018-05-10 18:29:57 +0900 |
commit | c112084af965ade0836b7c226c68ecd8b536fc0a (patch) | |
tree | 6d8b6b9c0e758832f8a8ac34b163bbc93433dee8 | |
parent | Git 2.10.5 (diff) | |
download | tgif-c112084af965ade0836b7c226c68ecd8b536fc0a.tar.xz |
fast-export: avoid NULL pointer arithmetic
Clang 6 reports the following warning, which is turned into an error in a
DEVELOPER build:
builtin/fast-export.c:162:28: error: performing pointer arithmetic on a null pointer has undefined behavior [-Werror,-Wnull-pointer-arithmetic]
return ((uint32_t *)NULL) + mark;
~~~~~~~~~~~~~~~~~~ ^
1 error generated.
The compiler is correct, and the error message speaks for itself. There
is no need for any undefined operation -- just cast mark to void * or
uint32_t after an intermediate cast to uintptr_t. That encodes the
integer value into a pointer and later decodes it as intended.
While at it remove an outdated comment -- intptr_t has been used since
ffe659f94d (parse-options: make some arguments optional, add callbacks),
committed in October 2007.
Signed-off-by: Rene Scharfe <l.s.r@web.de>
Acked-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
-rw-r--r-- | builtin/fast-export.c | 7 |
1 files changed, 3 insertions, 4 deletions
diff --git a/builtin/fast-export.c b/builtin/fast-export.c index c0652a7ed0..9aa4f7fce8 100644 --- a/builtin/fast-export.c +++ b/builtin/fast-export.c @@ -154,15 +154,14 @@ static void anonymize_path(struct strbuf *out, const char *path, } } -/* Since intptr_t is C99, we do not use it here */ -static inline uint32_t *mark_to_ptr(uint32_t mark) +static inline void *mark_to_ptr(uint32_t mark) { - return ((uint32_t *)NULL) + mark; + return (void *)(uintptr_t)mark; } static inline uint32_t ptr_to_mark(void * mark) { - return (uint32_t *)mark - (uint32_t *)NULL; + return (uint32_t)(uintptr_t)mark; } static inline void mark_object(struct object *object, uint32_t mark) |