diff options
| author | Rasmus Villemoes <ravi@prevas.dk> | 2025-07-07 22:36:53 +0200 |
|---|---|---|
| committer | Tom Rini <trini@konsulko.com> | 2025-07-14 12:43:28 -0600 |
| commit | dc323f3bee318514af9d7c6fed1e01c712bc71ae (patch) | |
| tree | 2f552b86cd2e9a650ea33ebed0ce32cecbbdd78f /include/limits.h | |
| parent | e37de002fac3895e8d0b60ae2015e17bb33e2b5b (diff) | |
move more limits from kernel.h to limits.h and standardize their definitions
In a customer project that was building a stand-alone application, I
hit a problem related to the fact that our LONG_MAX and friends are
not standards-compliant, in that they are not "suitable for use in #if
preprocessing directives"
... /toolchain_none/arm-cortexa8-eabi/sys-include/machine/_default_types.h:25:31: error: missing binary operator before token "long"
25 | || ( defined(LLONG_MAX) && (LLONG_MAX > 0x7fffffff) )
| ^~~~~~~~~
So following up on commit 13de8483388 ("mbedtls: add mbedtls into the
build system"), move the rest of the macros associated to the standard
C types {signed,unsigned} {char, short, int, long, long long} (and of
course bare 'char') to limits.h.
Make use of the fact that both gcc and clang provide suitable
predefined __FOO_MAX__ macros for the signed types, and use a standard
scheme for defining the FOO_MIN and UFOO_MAX macros in terms of
FOO_MAX.
Note that suffixes like L and ULL are allowed for preprocessor
integers; it is (casts) which are not. And using appropriate suffixes,
we can arrange for the type of e.g. UINT_MAX to be "unsigned int" due
to integer promotion rules.
Signed-off-by: Rasmus Villemoes <ravi@prevas.dk>
Diffstat (limited to 'include/limits.h')
| -rw-r--r-- | include/limits.h | 30 |
1 files changed, 28 insertions, 2 deletions
diff --git a/include/limits.h b/include/limits.h index 1d0bbf69be7..4dcfbe9b156 100644 --- a/include/limits.h +++ b/include/limits.h @@ -3,8 +3,34 @@ #ifndef _LIMITS_H #define _LIMITS_H -#define INT_MAX 0x7fffffff -#define UINT_MAX 0xffffffffU +#define SCHAR_MAX __SCHAR_MAX__ +#define SCHAR_MIN (-SCHAR_MAX - 1) +#define UCHAR_MAX (SCHAR_MAX * 2 + 1) + +#ifdef __CHAR_UNSIGNED__ +#define CHAR_MAX UCHAR_MAX +#define CHAR_MIN 0 +#else +#define CHAR_MAX SCHAR_MAX +#define CHAR_MIN SCHAR_MIN +#endif + +#define SHRT_MAX __SHRT_MAX__ +#define SHRT_MIN (-SHRT_MAX - 1) +#define USHRT_MAX (SHRT_MAX * 2 + 1) + +#define INT_MAX __INT_MAX__ +#define INT_MIN (-INT_MAX - 1) +#define UINT_MAX (INT_MAX * 2U + 1U) + +#define LONG_MAX __LONG_MAX__ +#define LONG_MIN (-LONG_MAX - 1L) +#define ULONG_MAX (LONG_MAX * 2UL + 1UL) + +#define LLONG_MAX __LONG_LONG_MAX__ +#define LLONG_MIN (-LLONG_MAX - 1LL) +#define ULLONG_MAX (LLONG_MAX * 2ULL + 1ULL) + #define CHAR_BIT 8 #define UINT32_MAX 0xffffffffU #define UINT64_MAX 0xffffffffffffffffULL |