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."
7 * Common definitions for all gcc versions go here.
9 #define GCC_VERSION (__GNUC__ * 10000 \
10 + __GNUC_MINOR__ * 100 \
11 + __GNUC_PATCHLEVEL__)
13 #if GCC_VERSION < 40600
14 # error Sorry, your compiler is too old - please upgrade it.
15 #elif defined(CONFIG_ARM64) && GCC_VERSION < 50100
17 * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63293
18 * https://lore.kernel.org/r/20210107111841.GN1551@shell.armlinux.org.uk
20 # error Sorry, your version of GCC is too old - please use 5.1 or newer.
24 * This macro obfuscates arithmetic on a variable address so that gcc
25 * shouldn't recognize the original var, and make assumptions about it.
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.
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
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.
41 #define RELOC_HIDE(ptr, off) \
43 unsigned long __ptr; \
44 __asm__ ("" : "=r"(__ptr) : "0"(ptr)); \
45 (typeof(ptr)) (__ptr + (off)); \
49 * A trick to suppress uninitialized variable warning without generating any
52 #define uninitialized_var(x) x = x
54 #ifdef CONFIG_RETPOLINE
55 #define __noretpoline __attribute__((__indirect_branch__("keep")))
58 #define __UNIQUE_ID(prefix) __PASTE(__PASTE(__UNIQUE_ID_, prefix), __COUNTER__)
60 #define __compiletime_object_size(obj) __builtin_object_size(obj, 0)
62 #define __compiletime_warning(message) __attribute__((__warning__(message)))
63 #define __compiletime_error(message) __attribute__((__error__(message)))
65 #if defined(LATENT_ENTROPY_PLUGIN) && !defined(__CHECKER__)
66 #define __latent_entropy __attribute__((latent_entropy))
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
74 * Adding an empty inline assembly before it works around the problem
76 #define barrier_before_unreachable() asm volatile("")
79 * Mark a position in code as unreachable. This can be used to
80 * suppress control flow warnings after asm blocks that transfer
83 #define unreachable() \
85 annotate_unreachable(); \
86 barrier_before_unreachable(); \
87 __builtin_unreachable(); \
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;
99 * GCC 'asm goto' miscompiles certain code sequences:
101 * http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58670
103 * Work it around via a compiler barrier quirk suggested by Jakub Jelinek.
105 * (asm goto is automatically volatile - the naming reflects this.)
107 #define asm_volatile_goto(x...) do { asm goto(x); asm (""); } while (0)
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.
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__
119 #endif /* CONFIG_ARCH_USE_BUILTIN_BSWAP && !__CHECKER__ */
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
129 #if __has_attribute(__no_sanitize_address__)
130 #define __no_sanitize_address __attribute__((no_sanitize_address))
132 #define __no_sanitize_address
135 #if GCC_VERSION >= 50100
136 #define COMPILER_HAS_GENERIC_BUILTIN_OVERFLOW 1
140 * Turn individual warnings and errors on and off locally, depending
143 #define __diag_GCC(version, severity, s) \
144 __diag_GCC_ ## version(__diag_GCC_ ## severity s)
146 /* Severity used in pragma directives */
147 #define __diag_GCC_ignore ignored
148 #define __diag_GCC_warn warning
149 #define __diag_GCC_error error
151 #define __diag_str1(s) #s
152 #define __diag_str(s) __diag_str1(s)
153 #define __diag(s) _Pragma(__diag_str(GCC diagnostic s))
155 #if GCC_VERSION >= 80000
156 #define __diag_GCC_8(s) __diag(s)
158 #define __diag_GCC_8(s)