| Attributes |
|---|
| __attribute__((error("message"))) | Declare that calling the marked function is an error. |
| __attribute__((warning("message"))) | Declare that calling the marked function is suspect and should emit a warning. |
| __attribute__((deprecated)) | Declare that using the marked function, type, or variable is deprecated and will emit a warning. |
| __attribute__((const)) | Declare that the marked function is a pure function, only examining its arguments and returning a value without examining or changing anything else. |
| __attribute__((pure)) | Declare that the marked function is a pure function, with no side effects (although it may examine global state). |
| __attribute__((nonnull(n1, ...))) | Declare that the specified arguments (one-based) (or all arguments if no indexes are listed) should only be passed nonnull pointers. |
| __attribute__((noreturn)) | Declare that the marked function will not return (although it may throw). |
| __attribute__((hot)) | Hint that the marked function is "hot" and should be optimized more aggresively and/or placed near other "hot" functions (for cache locality). |
| __attribute__((cold)) | Hint that the marked function is "cold" and should be optimized for size, predicted as unlikely for branch prediction, and/or placed near other "cold" functions (so other functions can have improved cache locality). |
| __attribute__((warn_unused_result)) | Declare that the function's return value is important and should be warned about if ignored. |
| Miscellaneous |
|---|
| case low ... high: | Case branch with a range. |
| 0bbinary-digits | Binary constant. |
