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| author | Thomas Weißschuh <thomas@t-8ch.de> | 2023-01-12 00:49:35 +0000 |
|---|---|---|
| committer | Thomas Weißschuh <thomas@t-8ch.de> | 2023-01-12 00:49:35 +0000 |
| commit | a9b89327746b7c5fbe0cedd8aee992de6580ca8a (patch) | |
| tree | df3dfb8a6932bf7faaa34a0ca2d24b9f129d5bac /include | |
| parent | 3870b182b7b0d98f487e023cd0030c8acd2adc1e (diff) | |
| download | util-linux-a9b89327746b7c5fbe0cedd8aee992de6580ca8a.tar.gz | |
c.h: avoid undefined behavior in SINT_MAX macro
The previous implementation relied on signed-integer overflow.
This is undefined behavior.
Instead use an implementation that only requires twos-complement
representation. This is what everybody uses anyways and it will be
required by C23.
Diffstat (limited to 'include')
| -rw-r--r-- | include/c.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/include/c.h b/include/c.h index 0663774d2..eab6ff505 100644 --- a/include/c.h +++ b/include/c.h @@ -526,6 +526,6 @@ static inline void print_features(const char **features, const char *prefix) # define MAP_ANONYMOUS (MAP_ANON) #endif -#define SINT_MAX(t) (((size_t) 1 << (sizeof(t) * 8 - 1)) - 1) +#define SINT_MAX(t) ((t)((~(t) 0) ^ (t) 1 << (sizeof(t) * 8 - 1))) #endif /* UTIL_LINUX_C_H */ |