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 #define uninitialized_var(x) x = *(&(x))
   9
  10 /* same as gcc, this was present in clang-2.6 so we can assume it works
  11  * with any version that can compile the kernel
  12  */
  13 #define __UNIQUE_ID(prefix) __PASTE(__PASTE(__UNIQUE_ID_, prefix), __COUNTER__)
  14
  15 /* all clang versions usable with the kernel support KASAN ABI version 5 */
  16 #define KASAN_ABI_VERSION 5
  17
  18 #if __has_feature(address_sanitizer) || __has_feature(hwaddress_sanitizer)
  19 /* Emulate GCC's __SANITIZE_ADDRESS__ flag */
  20 #define __SANITIZE_ADDRESS__
  21 #define __no_sanitize_address \
  22                 __attribute__((no_sanitize("address", "hwaddress")))
  23 #else
  24 #define __no_sanitize_address
  25 #endif
  26
  27 #if __has_feature(thread_sanitizer)
  28 /* emulate gcc's __SANITIZE_THREAD__ flag */
  29 #define __SANITIZE_THREAD__
  30 #define __no_sanitize_thread \
  31                 __attribute__((no_sanitize("thread")))
  32 #else
  33 #define __no_sanitize_thread
  34 #endif
  35
  36 #if __has_feature(undefined_behavior_sanitizer)
  37 /* GCC does not have __SANITIZE_UNDEFINED__ */
  38 #define __no_sanitize_undefined \
  39                 __attribute__((no_sanitize("undefined")))
  40 #else
  41 #define __no_sanitize_undefined
  42 #endif
  43
  44 /*
  45  * Not all versions of clang implement the the type-generic versions
  46  * of the builtin overflow checkers. Fortunately, clang implements
  47  * __has_builtin allowing us to avoid awkward version
  48  * checks. Unfortunately, we don't know which version of gcc clang
  49  * pretends to be, so the macro may or may not be defined.
  50  */
  51 #if __has_builtin(__builtin_mul_overflow) && \
  52     __has_builtin(__builtin_add_overflow) && \
  53     __has_builtin(__builtin_sub_overflow)
  54 #define COMPILER_HAS_GENERIC_BUILTIN_OVERFLOW 1
  55 #endif
  56
  57 /* The following are for compatibility with GCC, from compiler-gcc.h,
  58  * and may be redefined here because they should not be shared with other
  59  * compilers, like ICC.
  60  */
  61 #define barrier() __asm__ __volatile__("" : : : "memory")
  62
  63 #if __has_feature(shadow_call_stack)
  64 # define __noscs        __attribute__((__no_sanitize__("shadow-call-stack")))
  65 #endif