include/linux/compiler-clang.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef __LINUX_COMPILER_TYPES_H
   3 #error "Please don't include <linux/compiler-clang.h> directly, include <linux/compiler.h> instead."
   4 #endif
   5
   6 /* Compiler specific definitions for Clang compiler */
   7
   8 /*
   9  * Clang prior to 17 is being silly and considers many __cleanup() variables
  10  * as unused (because they are, their sole purpose is to go out of scope).
  11  *
  12  * https://reviews.llvm.org/D152180
  13  */
  14 #undef __cleanup
  15 #define __cleanup(func) __maybe_unused __attribute__((__cleanup__(func)))
  16
  17 /* same as gcc, this was present in clang-2.6 so we can assume it works
  18  * with any version that can compile the kernel
  19  */
  20 #define __UNIQUE_ID(prefix) __PASTE(__PASTE(__UNIQUE_ID_, prefix), __COUNTER__)
  21
  22 /* all clang versions usable with the kernel support KASAN ABI version 5 */
  23 #define KASAN_ABI_VERSION 5
  24
  25 /*
  26  * Note: Checking __has_feature(*_sanitizer) is only true if the feature is
  27  * enabled. Therefore it is not required to additionally check defined(CONFIG_*)
  28  * to avoid adding redundant attributes in other configurations.
  29  */
  30
  31 #if __has_feature(address_sanitizer) || __has_feature(hwaddress_sanitizer)
  32 /* Emulate GCC's __SANITIZE_ADDRESS__ flag */
  33 #define __SANITIZE_ADDRESS__
  34 #define __no_sanitize_address \
  35                 __attribute__((no_sanitize("address", "hwaddress")))
  36 #else
  37 #define __no_sanitize_address
  38 #endif
  39
  40 #if __has_feature(thread_sanitizer)
  41 /* emulate gcc's __SANITIZE_THREAD__ flag */
  42 #define __SANITIZE_THREAD__
  43 #define __no_sanitize_thread \
  44                 __attribute__((no_sanitize("thread")))
  45 #else
  46 #define __no_sanitize_thread
  47 #endif
  48
  49 #if defined(CONFIG_ARCH_USE_BUILTIN_BSWAP)
  50 #define __HAVE_BUILTIN_BSWAP32__
  51 #define __HAVE_BUILTIN_BSWAP64__
  52 #define __HAVE_BUILTIN_BSWAP16__
  53 #endif /* CONFIG_ARCH_USE_BUILTIN_BSWAP */
  54
  55 #if __has_feature(undefined_behavior_sanitizer)
  56 /* GCC does not have __SANITIZE_UNDEFINED__ */
  57 #define __no_sanitize_undefined \
  58                 __attribute__((no_sanitize("undefined")))
  59 #else
  60 #define __no_sanitize_undefined
  61 #endif
  62
  63 #if __has_feature(memory_sanitizer)
  64 #define __SANITIZE_MEMORY__
  65 /*
  66  * Unlike other sanitizers, KMSAN still inserts code into functions marked with
  67  * no_sanitize("kernel-memory"). Using disable_sanitizer_instrumentation
  68  * provides the behavior consistent with other __no_sanitize_ attributes,
  69  * guaranteeing that __no_sanitize_memory functions remain uninstrumented.
  70  */
  71 #define __no_sanitize_memory __disable_sanitizer_instrumentation
  72
  73 /*
  74  * The __no_kmsan_checks attribute ensures that a function does not produce
  75  * false positive reports by:
  76  *  - initializing all local variables and memory stores in this function;
  77  *  - skipping all shadow checks;
  78  *  - passing initialized arguments to this function's callees.
  79  */
  80 #define __no_kmsan_checks __attribute__((no_sanitize("kernel-memory")))
  81 #else
  82 #define __no_sanitize_memory
  83 #define __no_kmsan_checks
  84 #endif
  85
  86 /*
  87  * Support for __has_feature(coverage_sanitizer) was added in Clang 13 together
  88  * with no_sanitize("coverage"). Prior versions of Clang support coverage
  89  * instrumentation, but cannot be queried for support by the preprocessor.
  90  */
  91 #if __has_feature(coverage_sanitizer)
  92 #define __no_sanitize_coverage __attribute__((no_sanitize("coverage")))
  93 #else
  94 #define __no_sanitize_coverage
  95 #endif
  96
  97 #if __has_feature(shadow_call_stack)
  98 # define __noscs        __attribute__((__no_sanitize__("shadow-call-stack")))
  99 #endif
 100
 101 #if __has_feature(kcfi)
 102 /* Disable CFI checking inside a function. */
 103 #define __nocfi         __attribute__((__no_sanitize__("kcfi")))
 104 #endif
 105
 106 /*
 107  * Turn individual warnings and errors on and off locally, depending
 108  * on version.
 109  */
 110 #define __diag_clang(version, severity, s) \
 111         __diag_clang_ ## version(__diag_clang_ ## severity s)
 112
 113 /* Severity used in pragma directives */
 114 #define __diag_clang_ignore     ignored
 115 #define __diag_clang_warn       warning
 116 #define __diag_clang_error      error
 117
 118 #define __diag_str1(s)          #s
 119 #define __diag_str(s)           __diag_str1(s)
 120 #define __diag(s)               _Pragma(__diag_str(clang diagnostic s))
 121
 122 #if CONFIG_CLANG_VERSION >= 110000
 123 #define __diag_clang_11(s)      __diag(s)
 124 #else
 125 #define __diag_clang_11(s)
 126 #endif
 127
 128 #define __diag_ignore_all(option, comment) \
 129         __diag_clang(11, ignore, option)