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| author | Johannes Schindelin <johannes.schindelin@gmx.de> | 2021-11-02 16:46:09 +0100 |
|---|---|---|
| committer | Junio C Hamano <gitster@pobox.com> | 2021-11-03 19:22:27 +0100 |
| commit | e2ffeae3f6795939e1af9f8e2b5fa151343eec66 (patch) | |
| tree | 3af0e19e645178ec68b0cf191c11fa77de291241 | |
| parent | odb: teach read_blob_entry to use size_t (diff) | |
| download | git-e2ffeae3f6795939e1af9f8e2b5fa151343eec66.tar.xz git-e2ffeae3f6795939e1af9f8e2b5fa151343eec66.zip | |
git-compat-util: introduce more size_t helpers
We will use them in the next commit.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
| -rw-r--r-- | git-compat-util.h | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/git-compat-util.h b/git-compat-util.h index a508dbe5a3..1f41e5611a 100644 --- a/git-compat-util.h +++ b/git-compat-util.h @@ -113,6 +113,14 @@ #define unsigned_mult_overflows(a, b) \ ((a) && (b) > maximum_unsigned_value_of_type(a) / (a)) +/* + * Returns true if the left shift of "a" by "shift" bits will + * overflow. The type of "a" must be unsigned. + */ +#define unsigned_left_shift_overflows(a, shift) \ + ((shift) < bitsizeof(a) && \ + (a) > maximum_unsigned_value_of_type(a) >> (shift)) + #ifdef __GNUC__ #define TYPEOF(x) (__typeof__(x)) #else @@ -859,6 +867,23 @@ static inline size_t st_sub(size_t a, size_t b) return a - b; } +static inline size_t st_left_shift(size_t a, unsigned shift) +{ + if (unsigned_left_shift_overflows(a, shift)) + die("size_t overflow: %"PRIuMAX" << %u", + (uintmax_t)a, shift); + return a << shift; +} + +static inline unsigned long cast_size_t_to_ulong(size_t a) +{ + if (a != (unsigned long)a) + die("object too large to read on this platform: %" + PRIuMAX" is cut off to %lu", + (uintmax_t)a, (unsigned long)a); + return (unsigned long)a; +} + #ifdef HAVE_ALLOCA_H # include <alloca.h> # define xalloca(size) (alloca(size)) |