| /* SPDX-License-Identifier: GPL-2.0 */ |
| #ifndef __LINUX_COMPILER_ATTRIBUTES_H |
| #define __LINUX_COMPILER_ATTRIBUTES_H |
| |
| /* |
| * The attributes in this file are unconditionally defined and they directly |
| * map to compiler attribute(s), unless one of the compilers does not support |
| * the attribute. In that case, __has_attribute is used to check for support |
| * and the reason is stated in its comment ("Optional: ..."). |
| * |
| * Any other "attributes" (i.e. those that depend on a configuration option, |
| * on a compiler, on an architecture, on plugins, on other attributes...) |
| * should be defined elsewhere (e.g. compiler_types.h or compiler-*.h). |
| * The intention is to keep this file as simple as possible, as well as |
| * compiler- and version-agnostic (e.g. avoiding GCC_VERSION checks). |
| * |
| * This file is meant to be sorted (by actual attribute name, |
| * not by #define identifier). Use the __attribute__((__name__)) syntax |
| * (i.e. with underscores) to avoid future collisions with other macros. |
| * Provide links to the documentation of each supported compiler, if it exists. |
| */ |
| |
| /* |
| * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-alias-function-attribute |
| */ |
| #define __alias(symbol) __attribute__((__alias__(#symbol))) |
| |
| /* |
| * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-aligned-function-attribute |
| * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Type-Attributes.html#index-aligned-type-attribute |
| * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Variable-Attributes.html#index-aligned-variable-attribute |
| */ |
| #define __aligned(x) __attribute__((__aligned__(x))) |
| #define __aligned_largest __attribute__((__aligned__)) |
| |
| /* |
| * Note: do not use this directly. Instead, use __alloc_size() since it is conditionally |
| * available and includes other attributes. |
| * |
| * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-alloc_005fsize-function-attribute |
| * clang: https://clang.llvm.org/docs/AttributeReference.html#alloc-size |
| */ |
| #define __alloc_size__(x, ...) __attribute__((__alloc_size__(x, ## __VA_ARGS__))) |
| |
| /* |
| * Note: users of __always_inline currently do not write "inline" themselves, |
| * which seems to be required by gcc to apply the attribute according |
| * to its docs (and also "warning: always_inline function might not be |
| * inlinable [-Wattributes]" is emitted). |
| * |
| * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-always_005finline-function-attribute |
| * clang: mentioned |
| */ |
| #define __always_inline inline __attribute__((__always_inline__)) |
| |
| /* |
| * The second argument is optional (default 0), so we use a variadic macro |
| * to make the shorthand. |
| * |
| * Beware: Do not apply this to functions which may return |
| * ERR_PTRs. Also, it is probably unwise to apply it to functions |
| * returning extra information in the low bits (but in that case the |
| * compiler should see some alignment anyway, when the return value is |
| * massaged by 'flags = ptr & 3; ptr &= ~3;'). |
| * |
| * Optional: not supported by icc |
| * |
| * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-assume_005faligned-function-attribute |
| * clang: https://clang.llvm.org/docs/AttributeReference.html#assume-aligned |
| */ |
| #if __has_attribute(__assume_aligned__) |
| # define __assume_aligned(a, ...) __attribute__((__assume_aligned__(a, ## __VA_ARGS__))) |
| #else |
| # define __assume_aligned(a, ...) |
| #endif |
| |
| /* |
| * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-cold-function-attribute |
| * gcc: https://gcc.gnu.org/onlinedocs/gcc/Label-Attributes.html#index-cold-label-attribute |
| */ |
| #define __cold __attribute__((__cold__)) |
| |
| /* |
| * Note the long name. |
| * |
| * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-const-function-attribute |
| */ |
| #define __attribute_const__ __attribute__((__const__)) |
| |
| /* |
| * Optional: only supported since gcc >= 9 |
| * Optional: not supported by clang |
| * Optional: not supported by icc |
| * |
| * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-copy-function-attribute |
| */ |
| #if __has_attribute(__copy__) |
| # define __copy(symbol) __attribute__((__copy__(symbol))) |
| #else |
| # define __copy(symbol) |
| #endif |
| |
| /* |
| * Don't. Just don't. See commit 771c035372a0 ("deprecate the '__deprecated' |
| * attribute warnings entirely and for good") for more information. |
| * |
| * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-deprecated-function-attribute |
| * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Type-Attributes.html#index-deprecated-type-attribute |
| * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Variable-Attributes.html#index-deprecated-variable-attribute |
| * gcc: https://gcc.gnu.org/onlinedocs/gcc/Enumerator-Attributes.html#index-deprecated-enumerator-attribute |
| * clang: https://clang.llvm.org/docs/AttributeReference.html#deprecated |
| */ |
| #define __deprecated |
| |
| /* |
| * Optional: not supported by clang |
| * Optional: not supported by icc |
| * |
| * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Type-Attributes.html#index-designated_005finit-type-attribute |
| */ |
| #if __has_attribute(__designated_init__) |
| # define __designated_init __attribute__((__designated_init__)) |
| #else |
| # define __designated_init |
| #endif |
| |
| /* |
| * Optional: only supported since clang >= 14.0 |
| * |
| * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-error-function-attribute |
| */ |
| #if __has_attribute(__error__) |
| # define __compiletime_error(msg) __attribute__((__error__(msg))) |
| #else |
| # define __compiletime_error(msg) |
| #endif |
| |
| /* |
| * Optional: not supported by clang |
| * |
| * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-externally_005fvisible-function-attribute |
| */ |
| #if __has_attribute(__externally_visible__) |
| # define __visible __attribute__((__externally_visible__)) |
| #else |
| # define __visible |
| #endif |
| |
| /* |
| * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-format-function-attribute |
| * clang: https://clang.llvm.org/docs/AttributeReference.html#format |
| */ |
| #define __printf(a, b) __attribute__((__format__(printf, a, b))) |
| #define __scanf(a, b) __attribute__((__format__(scanf, a, b))) |
| |
| /* |
| * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-gnu_005finline-function-attribute |
| * clang: https://clang.llvm.org/docs/AttributeReference.html#gnu-inline |
| */ |
| #define __gnu_inline __attribute__((__gnu_inline__)) |
| |
| /* |
| * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-malloc-function-attribute |
| * clang: https://clang.llvm.org/docs/AttributeReference.html#malloc |
| */ |
| #define __malloc __attribute__((__malloc__)) |
| |
| /* |
| * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Type-Attributes.html#index-mode-type-attribute |
| * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Variable-Attributes.html#index-mode-variable-attribute |
| */ |
| #define __mode(x) __attribute__((__mode__(x))) |
| |
| /* |
| * Optional: only supported since gcc >= 7 |
| * |
| * gcc: https://gcc.gnu.org/onlinedocs/gcc/x86-Function-Attributes.html#index-no_005fcaller_005fsaved_005fregisters-function-attribute_002c-x86 |
| * clang: https://clang.llvm.org/docs/AttributeReference.html#no-caller-saved-registers |
| */ |
| #if __has_attribute(__no_caller_saved_registers__) |
| # define __no_caller_saved_registers __attribute__((__no_caller_saved_registers__)) |
| #else |
| # define __no_caller_saved_registers |
| #endif |
| |
| /* |
| * Optional: not supported by clang |
| * |
| * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-noclone-function-attribute |
| */ |
| #if __has_attribute(__noclone__) |
| # define __noclone __attribute__((__noclone__)) |
| #else |
| # define __noclone |
| #endif |
| |
| /* |
| * Add the pseudo keyword 'fallthrough' so case statement blocks |
| * must end with any of these keywords: |
| * break; |
| * fallthrough; |
| * continue; |
| * goto <label>; |
| * return [expression]; |
| * |
| * gcc: https://gcc.gnu.org/onlinedocs/gcc/Statement-Attributes.html#Statement-Attributes |
| */ |
| #if __has_attribute(__fallthrough__) |
| # define fallthrough __attribute__((__fallthrough__)) |
| #else |
| # define fallthrough do {} while (0) /* fallthrough */ |
| #endif |
| |
| /* |
| * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#Common-Function-Attributes |
| * clang: https://clang.llvm.org/docs/AttributeReference.html#flatten |
| */ |
| # define __flatten __attribute__((flatten)) |
| |
| /* |
| * Note the missing underscores. |
| * |
| * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-noinline-function-attribute |
| * clang: mentioned |
| */ |
| #define noinline __attribute__((__noinline__)) |
| |
| /* |
| * Optional: only supported since gcc >= 8 |
| * Optional: not supported by clang |
| * Optional: not supported by icc |
| * |
| * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Variable-Attributes.html#index-nonstring-variable-attribute |
| */ |
| #if __has_attribute(__nonstring__) |
| # define __nonstring __attribute__((__nonstring__)) |
| #else |
| # define __nonstring |
| #endif |
| |
| /* |
| * Optional: only supported since GCC >= 7.1, clang >= 13.0. |
| * |
| * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-no_005fprofile_005finstrument_005ffunction-function-attribute |
| * clang: https://clang.llvm.org/docs/AttributeReference.html#no-profile-instrument-function |
| */ |
| #if __has_attribute(__no_profile_instrument_function__) |
| # define __no_profile __attribute__((__no_profile_instrument_function__)) |
| #else |
| # define __no_profile |
| #endif |
| |
| /* |
| * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-noreturn-function-attribute |
| * clang: https://clang.llvm.org/docs/AttributeReference.html#noreturn |
| * clang: https://clang.llvm.org/docs/AttributeReference.html#id1 |
| */ |
| #define __noreturn __attribute__((__noreturn__)) |
| |
| /* |
| * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Type-Attributes.html#index-packed-type-attribute |
| * clang: https://gcc.gnu.org/onlinedocs/gcc/Common-Variable-Attributes.html#index-packed-variable-attribute |
| */ |
| #define __packed __attribute__((__packed__)) |
| |
| /* |
| * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-pure-function-attribute |
| */ |
| #define __pure __attribute__((__pure__)) |
| |
| /* |
| * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-section-function-attribute |
| * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Variable-Attributes.html#index-section-variable-attribute |
| * clang: https://clang.llvm.org/docs/AttributeReference.html#section-declspec-allocate |
| */ |
| #define __section(section) __attribute__((__section__(section))) |
| |
| /* |
| * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-unused-function-attribute |
| * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Type-Attributes.html#index-unused-type-attribute |
| * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Variable-Attributes.html#index-unused-variable-attribute |
| * gcc: https://gcc.gnu.org/onlinedocs/gcc/Label-Attributes.html#index-unused-label-attribute |
| * clang: https://clang.llvm.org/docs/AttributeReference.html#maybe-unused-unused |
| */ |
| #define __always_unused __attribute__((__unused__)) |
| #define __maybe_unused __attribute__((__unused__)) |
| |
| /* |
| * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-used-function-attribute |
| * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Variable-Attributes.html#index-used-variable-attribute |
| */ |
| #define __used __attribute__((__used__)) |
| |
| /* |
| * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-warn_005funused_005fresult-function-attribute |
| * clang: https://clang.llvm.org/docs/AttributeReference.html#nodiscard-warn-unused-result |
| */ |
| #define __must_check __attribute__((__warn_unused_result__)) |
| |
| /* |
| * Optional: only supported since clang >= 14.0 |
| * |
| * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-warning-function-attribute |
| */ |
| #if __has_attribute(__warning__) |
| # define __compiletime_warning(msg) __attribute__((__warning__(msg))) |
| #else |
| # define __compiletime_warning(msg) |
| #endif |
| |
| /* |
| * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-weak-function-attribute |
| * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Variable-Attributes.html#index-weak-variable-attribute |
| */ |
| #define __weak __attribute__((__weak__)) |
| |
| #endif /* __LINUX_COMPILER_ATTRIBUTES_H */ |