1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef __LINUX_COMPILER_TYPES_H 3 #error "Please don't include <linux/compiler-gcc.h> directly, include <linux/compiler.h> instead." 4 #endif 5 6 /* 7 * Common definitions for all gcc versions go here. 8 */ 9 #define GCC_VERSION (__GNUC__ * 10000 \ 10 + __GNUC_MINOR__ * 100 \ 11 + __GNUC_PATCHLEVEL__) 12 13 #if GCC_VERSION < 40600 14 # error Sorry, your compiler is too old - please upgrade it. 15 #elif defined(CONFIG_ARM64) && GCC_VERSION < 50100 16 /* 17 * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63293 18 * https://lore.kernel.org/r/20210107111841.GN1551@shell.armlinux.org.uk 19 */ 20 # error Sorry, your version of GCC is too old - please use 5.1 or newer. 21 #endif 22 23 /* 24 * This macro obfuscates arithmetic on a variable address so that gcc 25 * shouldn't recognize the original var, and make assumptions about it. 26 * 27 * This is needed because the C standard makes it undefined to do 28 * pointer arithmetic on "objects" outside their boundaries and the 29 * gcc optimizers assume this is the case. In particular they 30 * assume such arithmetic does not wrap. 31 * 32 * A miscompilation has been observed because of this on PPC. 33 * To work around it we hide the relationship of the pointer and the object 34 * using this macro. 35 * 36 * Versions of the ppc64 compiler before 4.1 had a bug where use of 37 * RELOC_HIDE could trash r30. The bug can be worked around by changing 38 * the inline assembly constraint from =g to =r, in this particular 39 * case either is valid. 40 */ 41 #define RELOC_HIDE(ptr, off) \ 42 ({ \ 43 unsigned long __ptr; \ 44 __asm__ ("" : "=r"(__ptr) : "0"(ptr)); \ 45 (typeof(ptr)) (__ptr + (off)); \ 46 }) 47 48 /* 49 * A trick to suppress uninitialized variable warning without generating any 50 * code 51 */ 52 #define uninitialized_var(x) x = x 53 54 #ifdef CONFIG_RETPOLINE 55 #define __noretpoline __attribute__((__indirect_branch__("keep"))) 56 #endif 57 58 #define __UNIQUE_ID(prefix) __PASTE(__PASTE(__UNIQUE_ID_, prefix), __COUNTER__) 59 60 #define __compiletime_object_size(obj) __builtin_object_size(obj, 0) 61 62 #define __compiletime_warning(message) __attribute__((__warning__(message))) 63 #define __compiletime_error(message) __attribute__((__error__(message))) 64 65 #if defined(LATENT_ENTROPY_PLUGIN) && !defined(__CHECKER__) 66 #define __latent_entropy __attribute__((latent_entropy)) 67 #endif 68 69 /* 70 * calling noreturn functions, __builtin_unreachable() and __builtin_trap() 71 * confuse the stack allocation in gcc, leading to overly large stack 72 * frames, see https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82365 73 * 74 * Adding an empty inline assembly before it works around the problem 75 */ 76 #define barrier_before_unreachable() asm volatile("") 77 78 /* 79 * Mark a position in code as unreachable. This can be used to 80 * suppress control flow warnings after asm blocks that transfer 81 * control elsewhere. 82 */ 83 #define unreachable() \ 84 do { \ 85 annotate_unreachable(); \ 86 barrier_before_unreachable(); \ 87 __builtin_unreachable(); \ 88 } while (0) 89 90 #if defined(RANDSTRUCT_PLUGIN) && !defined(__CHECKER__) 91 #define __randomize_layout __attribute__((randomize_layout)) 92 #define __no_randomize_layout __attribute__((no_randomize_layout)) 93 /* This anon struct can add padding, so only enable it under randstruct. */ 94 #define randomized_struct_fields_start struct { 95 #define randomized_struct_fields_end } __randomize_layout; 96 #endif 97 98 /* 99 * GCC 'asm goto' miscompiles certain code sequences: 100 * 101 * http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58670 102 * 103 * Work it around via a compiler barrier quirk suggested by Jakub Jelinek. 104 * 105 * (asm goto is automatically volatile - the naming reflects this.) 106 */ 107 #define asm_volatile_goto(x...) do { asm goto(x); asm (""); } while (0) 108 109 /* 110 * sparse (__CHECKER__) pretends to be gcc, but can't do constant 111 * folding in __builtin_bswap*() (yet), so don't set these for it. 112 */ 113 #if defined(CONFIG_ARCH_USE_BUILTIN_BSWAP) && !defined(__CHECKER__) 114 #define __HAVE_BUILTIN_BSWAP32__ 115 #define __HAVE_BUILTIN_BSWAP64__ 116 #if GCC_VERSION >= 40800 117 #define __HAVE_BUILTIN_BSWAP16__ 118 #endif 119 #endif /* CONFIG_ARCH_USE_BUILTIN_BSWAP && !__CHECKER__ */ 120 121 #if GCC_VERSION >= 70000 122 #define KASAN_ABI_VERSION 5 123 #elif GCC_VERSION >= 50000 124 #define KASAN_ABI_VERSION 4 125 #elif GCC_VERSION >= 40902 126 #define KASAN_ABI_VERSION 3 127 #endif 128 129 #if __has_attribute(__no_sanitize_address__) 130 #define __no_sanitize_address __attribute__((no_sanitize_address)) 131 #else 132 #define __no_sanitize_address 133 #endif 134 135 #if GCC_VERSION >= 50100 136 #define COMPILER_HAS_GENERIC_BUILTIN_OVERFLOW 1 137 #endif 138 139 /* 140 * Turn individual warnings and errors on and off locally, depending 141 * on version. 142 */ 143 #define __diag_GCC(version, severity, s) \ 144 __diag_GCC_ ## version(__diag_GCC_ ## severity s) 145 146 /* Severity used in pragma directives */ 147 #define __diag_GCC_ignore ignored 148 #define __diag_GCC_warn warning 149 #define __diag_GCC_error error 150 151 #define __diag_str1(s) #s 152 #define __diag_str(s) __diag_str1(s) 153 #define __diag(s) _Pragma(__diag_str(GCC diagnostic s)) 154 155 #if GCC_VERSION >= 80000 156 #define __diag_GCC_8(s) __diag(s) 157 #else 158 #define __diag_GCC_8(s) 159 #endif 160