compiler-clang.h

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/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __LINUX_COMPILER_TYPES_H
#error "Please do not include <linux/compiler-clang.h> directly, include <linux/compiler.h> instead."
#endif
 
/* Compiler specific definitions for Clang compiler */
 
/* all clang versions usable with the kernel support KASAN ABI version 5 */
#define KASAN_ABI_VERSION 5
 
/*
 * Clang 22 added preprocessor macros to match GCC, in hopes of eventually
 * dropping __has_feature support for sanitizers:
 * https://github.com/llvm/llvm-project/commit/568c23bbd3303518c5056d7f03444dae4fdc8a9c
 * Create these macros for older versions of clang so that it is easy to clean
 * up once the minimum supported version of LLVM for building the kernel always
 * creates these macros.
 *
 * Note: Checking __has_feature(*_sanitizer) is only true if the feature is
 * enabled. Therefore it is not required to additionally check defined(CONFIG_*)
 * to avoid adding redundant attributes in other configurations.
 */
#if __has_feature(address_sanitizer) && !defined(__SANITIZE_ADDRESS__)
#define __SANITIZE_ADDRESS__
#endif
#if __has_feature(hwaddress_sanitizer) && !defined(__SANITIZE_HWADDRESS__)
#define __SANITIZE_HWADDRESS__
#endif
#if __has_feature(thread_sanitizer) && !defined(__SANITIZE_THREAD__)
#define __SANITIZE_THREAD__
#endif
 
/*
 * Treat __SANITIZE_HWADDRESS__ the same as __SANITIZE_ADDRESS__ in the kernel.
 */
#ifdef __SANITIZE_HWADDRESS__
#define __SANITIZE_ADDRESS__
#endif
 
#ifdef __SANITIZE_ADDRESS__
#define __no_sanitize_address \
        __attribute__((no_sanitize("address", "hwaddress")))
#else
#define __no_sanitize_address
#endif
 
#ifdef __SANITIZE_THREAD__
#define __no_sanitize_thread \
        __attribute__((no_sanitize("thread")))
#else
#define __no_sanitize_thread
#endif
 
#if defined(CONFIG_ARCH_USE_BUILTIN_BSWAP)
#define __HAVE_BUILTIN_BSWAP32__
#define __HAVE_BUILTIN_BSWAP64__
#define __HAVE_BUILTIN_BSWAP16__
#endif /* CONFIG_ARCH_USE_BUILTIN_BSWAP */
 
#if __has_feature(undefined_behavior_sanitizer)
/* GCC does not have __SANITIZE_UNDEFINED__ */
#define __no_sanitize_undefined \
        __attribute__((no_sanitize("undefined")))
#else
#define __no_sanitize_undefined
#endif
 
#if __has_feature(memory_sanitizer)
#define __SANITIZE_MEMORY__
/*
 * Unlike other sanitizers, KMSAN still inserts code into functions marked with
 * no_sanitize("kernel-memory"). Using disable_sanitizer_instrumentation
 * provides the behavior consistent with other __no_sanitize_ attributes,
 * guaranteeing that __no_sanitize_memory functions remain uninstrumented.
 */
#define __no_sanitize_memory __disable_sanitizer_instrumentation
 
/*
 * The __no_kmsan_checks attribute ensures that a function does not produce
 * false positive reports by:
 *  - initializing all local variables and memory stores in this function;
 *  - skipping all shadow checks;
 *  - passing initialized arguments to this function's callees.
 */
#define __no_kmsan_checks __attribute__((no_sanitize("kernel-memory")))
#else
#define __no_sanitize_memory
#define __no_kmsan_checks
#endif
 
/*
 * Support for __has_feature(coverage_sanitizer) was added in Clang 13 together
 * with no_sanitize("coverage"). Prior versions of Clang support coverage
 * instrumentation, but cannot be queried for support by the preprocessor.
 */
#if __has_feature(coverage_sanitizer)
#define __no_sanitize_coverage __attribute__((no_sanitize("coverage")))
#else
#define __no_sanitize_coverage
#endif
 
/* Only Clang needs to disable the coverage sanitizer for kstack_erase. */
#define __no_kstack_erase   __no_sanitize_coverage
 
#if __has_feature(shadow_call_stack)
# define __noscs    __attribute__((__no_sanitize__("shadow-call-stack")))
#endif
 
/*
 * Turn individual warnings and errors on and off locally, depending
 * on version.
 */
#define __diag_clang(version, severity, s) \
    __diag_clang_ ## version(__diag_clang_ ## severity s)
 
/* Severity used in pragma directives */
#define __diag_clang_ignore ignored
#define __diag_clang_warn   warning
#define __diag_clang_error  error
 
#define __diag_str1(s)      #s
#define __diag_str(s)       __diag_str1(s)
#define __diag(s)       _Pragma(__diag_str(clang diagnostic s))
 
#if CONFIG_CLANG_VERSION >= 230000
#define __diag_clang_23(s)  __diag(s)
#else
#define __diag_clang_23(s)
#endif
 
#define __diag_clang_all(s) __diag(s)
 
#define __diag_ignore_all(option, comment) \
    __diag_clang(all, ignore, option)
 
/*
 * clang has horrible behavior with "g" or "rm" constraints for asm
 * inputs, turning them into something worse than "m". Avoid using
 * constraints with multiple possible uses (but "ir" seems to be ok):
 *
 *  https://github.com/llvm/llvm-project/issues/20571
 */
#define ASM_INPUT_G "ir"
#define ASM_INPUT_RM "r"
#define ASM_OUTPUT_RM "=r"
 
/*
 * Declare compiler support for __typeof_unqual__() operator.
 *
 * Bindgen uses LLVM even if our C compiler is GCC, so we cannot
 * rely on the auto-detected CONFIG_CC_HAS_TYPEOF_UNQUAL.
 */
#define CC_HAS_TYPEOF_UNQUAL (__clang_major__ > 19 || (__clang_major__ == 19 && __clang_minor__ > 0))