diff options
Diffstat (limited to 'lib/attribute.h')
| -rw-r--r-- | lib/attribute.h | 23 |
1 files changed, 13 insertions, 10 deletions
diff --git a/lib/attribute.h b/lib/attribute.h index 2836b99dad0..5afcb8e81f2 100644 --- a/lib/attribute.h +++ b/lib/attribute.h @@ -80,7 +80,7 @@ /* Attributes for variadic functions. */ /* The variadic function expects a trailing NULL argument. - ATTRIBUTE_SENTINEL () - The last argument is NULL. + ATTRIBUTE_SENTINEL () - The last argument is NULL (requires C99). ATTRIBUTE_SENTINEL ((N)) - The (N+1)st argument from the end is NULL. */ /* Applies to: functions. */ #define ATTRIBUTE_SENTINEL(pos) _GL_ATTRIBUTE_SENTINEL (pos) @@ -170,18 +170,21 @@ /* Applies to: function. */ #define ATTRIBUTE_ALWAYS_INLINE _GL_ATTRIBUTE_ALWAYS_INLINE -/* The function does not affect observable state, and always returns a value. - Compilers can omit duplicate calls with the same arguments if - observable state is not changed between calls. (This attribute is - looser than ATTRIBUTE_CONST.) */ +/* It is OK for a compiler to omit duplicate calls with the same arguments. + This attribute is safe for a function that neither depends on + nor affects observable state, and always returns exactly once - + e.g., does not loop forever, and does not call longjmp. + (This attribute is stricter than ATTRIBUTE_PURE.) */ /* Applies to: functions. */ -#define ATTRIBUTE_PURE _GL_ATTRIBUTE_PURE +#define ATTRIBUTE_CONST _GL_ATTRIBUTE_CONST -/* The function neither depends on nor affects observable state, - and always returns a value. Compilers can omit duplicate calls with - the same arguments. (This attribute is stricter than ATTRIBUTE_PURE.) */ +/* It is OK for a compiler to omit duplicate calls with the same + arguments if observable state is not changed between calls. + This attribute is safe for a function that does not affect + observable state, and always returns exactly once. + (This attribute is looser than ATTRIBUTE_CONST.) */ /* Applies to: functions. */ -#define ATTRIBUTE_CONST _GL_ATTRIBUTE_CONST +#define ATTRIBUTE_PURE _GL_ATTRIBUTE_PURE /* The function is rarely executed. */ /* Applies to: functions. */ |