diff options
Diffstat (limited to 'include/linux/compiler_attributes.h')
| -rw-r--r-- | include/linux/compiler_attributes.h | 207 |
1 files changed, 166 insertions, 41 deletions
diff --git a/include/linux/compiler_attributes.h b/include/linux/compiler_attributes.h index 6122efdad6ad..c16d4199bf92 100644 --- a/include/linux/compiler_attributes.h +++ b/include/linux/compiler_attributes.h @@ -21,31 +21,6 @@ */ /* - * __has_attribute is supported on gcc >= 5, clang >= 2.9 and icc >= 17. - * In the meantime, to support 4.6 <= gcc < 5, we implement __has_attribute - * by hand. - * - * sparse does not support __has_attribute (yet) and defines __GNUC_MINOR__ - * depending on the compiler used to build it; however, these attributes have - * no semantic effects for sparse, so it does not matter. Also note that, - * in order to avoid sparse's warnings, even the unsupported ones must be - * defined to 0. - */ -#ifndef __has_attribute -# define __has_attribute(x) __GCC4_has_attribute_##x -# define __GCC4_has_attribute___assume_aligned__ (__GNUC_MINOR__ >= 9) -# define __GCC4_has_attribute___copy__ 0 -# define __GCC4_has_attribute___designated_init__ 0 -# define __GCC4_has_attribute___externally_visible__ 1 -# define __GCC4_has_attribute___no_caller_saved_registers__ 0 -# define __GCC4_has_attribute___noclone__ 1 -# define __GCC4_has_attribute___nonstring__ 0 -# define __GCC4_has_attribute___no_sanitize_address__ (__GNUC_MINOR__ >= 8) -# define __GCC4_has_attribute___no_sanitize_undefined__ (__GNUC_MINOR__ >= 9) -# define __GCC4_has_attribute___fallthrough__ 0 -#endif - -/* * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-alias-function-attribute */ #define __alias(symbol) __attribute__((__alias__(#symbol))) @@ -59,6 +34,16 @@ #define __aligned_largest __attribute__((__aligned__)) /* + * Note: do not use this directly. Instead, use __alloc_size() since it is conditionally + * available and includes other attributes. For GCC < 9.1, __alloc_size__ gets undefined + * in compiler-gcc.h, due to misbehaviors. + * + * 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 @@ -79,23 +64,16 @@ * compiler should see some alignment anyway, when the return value is * massaged by 'flags = ptr & 3; ptr &= ~3;'). * - * Optional: only supported since gcc >= 4.9 - * 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 +#define __assume_aligned(a, ...) __attribute__((__assume_aligned__(a, ## __VA_ARGS__))) /* - * 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 + * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Variable-Attributes.html#index-cleanup-variable-attribute + * clang: https://clang.llvm.org/docs/AttributeReference.html#cleanup */ -#define __cold __attribute__((__cold__)) +#define __cleanup(func) __attribute__((__cleanup__(func))) /* * Note the long name. @@ -107,7 +85,6 @@ /* * 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 */ @@ -118,6 +95,18 @@ #endif /* + * Optional: not supported by gcc + * Optional: only supported since clang >= 14.0 + * + * clang: https://clang.llvm.org/docs/AttributeReference.html#diagnose_as_builtin + */ +#if __has_attribute(__diagnose_as_builtin__) +# define __diagnose_as(builtin...) __attribute__((__diagnose_as_builtin__(builtin))) +#else +# define __diagnose_as(builtin...) +#endif + +/* * Don't. Just don't. See commit 771c035372a0 ("deprecate the '__deprecated' * attribute warnings entirely and for good") for more information. * @@ -130,9 +119,7 @@ #define __deprecated /* - * Optional: only supported since gcc >= 5.1 * 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 */ @@ -143,6 +130,17 @@ #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 @@ -168,6 +166,7 @@ /* * 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__)) @@ -205,6 +204,7 @@ * must end with any of these keywords: * break; * fallthrough; + * continue; * goto <label>; * return [expression]; * @@ -217,6 +217,12 @@ #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 @@ -227,7 +233,6 @@ /* * 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 */ @@ -238,6 +243,18 @@ #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 @@ -245,12 +262,53 @@ #define __noreturn __attribute__((__noreturn__)) /* + * Optional: only supported since GCC >= 11.1, clang >= 7.0. + * + * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-no_005fstack_005fprotector-function-attribute + * clang: https://clang.llvm.org/docs/AttributeReference.html#no-stack-protector-safebuffers + */ +#if __has_attribute(__no_stack_protector__) +# define __no_stack_protector __attribute__((__no_stack_protector__)) +#else +# define __no_stack_protector +#endif + +/* + * Optional: not supported by gcc. + * + * clang: https://clang.llvm.org/docs/AttributeReference.html#overloadable + */ +#if __has_attribute(__overloadable__) +# define __overloadable __attribute__((__overloadable__)) +#else +# define __overloadable +#endif + +/* * 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__)) /* + * Note: the "type" argument should match any __builtin_object_size(p, type) usage. + * + * Optional: not supported by gcc. + * + * clang: https://clang.llvm.org/docs/AttributeReference.html#pass-object-size-pass-dynamic-object-size + */ +#if __has_attribute(__pass_dynamic_object_size__) +# define __pass_dynamic_object_size(type) __attribute__((__pass_dynamic_object_size__(type))) +#else +# define __pass_dynamic_object_size(type) +#endif +#if __has_attribute(__pass_object_size__) +# define __pass_object_size(type) __attribute__((__pass_object_size__(type))) +#else +# define __pass_object_size(type) +#endif + +/* * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-pure-function-attribute */ #define __pure __attribute__((__pure__)) @@ -260,7 +318,19 @@ * 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(S) __attribute__((__section__(#S))) +#define __section(section) __attribute__((__section__(section))) + +/* + * Optional: only supported since gcc >= 12 + * + * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Variable-Attributes.html#index-uninitialized-variable-attribute + * clang: https://clang.llvm.org/docs/AttributeReference.html#uninitialized + */ +#if __has_attribute(__uninitialized__) +# define __uninitialized __attribute__((__uninitialized__)) +#else +# define __uninitialized +#endif /* * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-unused-function-attribute @@ -279,9 +349,64 @@ #define __used __attribute__((__used__)) /* + * The __used attribute guarantees that the attributed variable will be + * always emitted by a compiler. It doesn't prevent the compiler from + * throwing 'unused' warnings when it can't detect how the variable is + * actually used. It's a compiler implementation details either emit + * the warning in that case or not. + * + * The combination of both 'used' and 'unused' attributes ensures that + * the variable would be emitted, and will not trigger 'unused' warnings. + * The attribute is applicable for functions, static and global variables. + */ +#define __always_used __used __maybe_unused + +/* + * 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 + +/* + * Optional: only supported since clang >= 14.0 + * + * clang: https://clang.llvm.org/docs/AttributeReference.html#disable-sanitizer-instrumentation + * + * disable_sanitizer_instrumentation is not always similar to + * no_sanitize((<sanitizer-name>)): the latter may still let specific sanitizers + * insert code into functions to prevent false positives. Unlike that, + * disable_sanitizer_instrumentation prevents all kinds of instrumentation to + * functions with the attribute. + */ +#if __has_attribute(disable_sanitizer_instrumentation) +# define __disable_sanitizer_instrumentation \ + __attribute__((disable_sanitizer_instrumentation)) +#else +# define __disable_sanitizer_instrumentation +#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__)) +/* + * Used by functions that use '__builtin_return_address'. These function + * don't want to be splited or made inline, which can make + * the '__builtin_return_address' get unexpected address. + */ +#define __fix_address noinline __noclone + #endif /* __LINUX_COMPILER_ATTRIBUTES_H */ |