Linux kernel mirror (for testing)
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linux
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/*
14 * This macro obfuscates arithmetic on a variable address so that gcc
15 * shouldn't recognize the original var, and make assumptions about it.
16 *
17 * This is needed because the C standard makes it undefined to do
18 * pointer arithmetic on "objects" outside their boundaries and the
19 * gcc optimizers assume this is the case. In particular they
20 * assume such arithmetic does not wrap.
21 *
22 * A miscompilation has been observed because of this on PPC.
23 * To work around it we hide the relationship of the pointer and the object
24 * using this macro.
25 *
26 * Versions of the ppc64 compiler before 4.1 had a bug where use of
27 * RELOC_HIDE could trash r30. The bug can be worked around by changing
28 * the inline assembly constraint from =g to =r, in this particular
29 * case either is valid.
30 */
31#define RELOC_HIDE(ptr, off) \
32({ \
33 unsigned long __ptr; \
34 __asm__ ("" : "=r"(__ptr) : "0"(ptr)); \
35 (typeof(ptr)) (__ptr + (off)); \
36})
37
38#ifdef CONFIG_RETPOLINE
39#define __noretpoline __attribute__((__indirect_branch__("keep")))
40#endif
41
42#define __UNIQUE_ID(prefix) __PASTE(__PASTE(__UNIQUE_ID_, prefix), __COUNTER__)
43
44#define __compiletime_object_size(obj) __builtin_object_size(obj, 0)
45
46#define __compiletime_warning(message) __attribute__((__warning__(message)))
47#define __compiletime_error(message) __attribute__((__error__(message)))
48
49#if defined(LATENT_ENTROPY_PLUGIN) && !defined(__CHECKER__)
50#define __latent_entropy __attribute__((latent_entropy))
51#endif
52
53/*
54 * calling noreturn functions, __builtin_unreachable() and __builtin_trap()
55 * confuse the stack allocation in gcc, leading to overly large stack
56 * frames, see https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82365
57 *
58 * Adding an empty inline assembly before it works around the problem
59 */
60#define barrier_before_unreachable() asm volatile("")
61
62/*
63 * Mark a position in code as unreachable. This can be used to
64 * suppress control flow warnings after asm blocks that transfer
65 * control elsewhere.
66 */
67#define unreachable() \
68 do { \
69 annotate_unreachable(); \
70 barrier_before_unreachable(); \
71 __builtin_unreachable(); \
72 } while (0)
73
74#if defined(RANDSTRUCT_PLUGIN) && !defined(__CHECKER__)
75#define __randomize_layout __attribute__((randomize_layout))
76#define __no_randomize_layout __attribute__((no_randomize_layout))
77/* This anon struct can add padding, so only enable it under randstruct. */
78#define randomized_struct_fields_start struct {
79#define randomized_struct_fields_end } __randomize_layout;
80#endif
81
82/*
83 * GCC 'asm goto' miscompiles certain code sequences:
84 *
85 * http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58670
86 *
87 * Work it around via a compiler barrier quirk suggested by Jakub Jelinek.
88 *
89 * (asm goto is automatically volatile - the naming reflects this.)
90 */
91#define asm_volatile_goto(x...) do { asm goto(x); asm (""); } while (0)
92
93#if defined(CONFIG_ARCH_USE_BUILTIN_BSWAP)
94#define __HAVE_BUILTIN_BSWAP32__
95#define __HAVE_BUILTIN_BSWAP64__
96#define __HAVE_BUILTIN_BSWAP16__
97#endif /* CONFIG_ARCH_USE_BUILTIN_BSWAP */
98
99#if GCC_VERSION >= 70000
100#define KASAN_ABI_VERSION 5
101#elif GCC_VERSION >= 50000
102#define KASAN_ABI_VERSION 4
103#elif GCC_VERSION >= 40902
104#define KASAN_ABI_VERSION 3
105#endif
106
107#if __has_attribute(__no_sanitize_address__)
108#define __no_sanitize_address __attribute__((no_sanitize_address))
109#else
110#define __no_sanitize_address
111#endif
112
113#if defined(__SANITIZE_THREAD__) && __has_attribute(__no_sanitize_thread__)
114#define __no_sanitize_thread __attribute__((no_sanitize_thread))
115#else
116#define __no_sanitize_thread
117#endif
118
119#if __has_attribute(__no_sanitize_undefined__)
120#define __no_sanitize_undefined __attribute__((no_sanitize_undefined))
121#else
122#define __no_sanitize_undefined
123#endif
124
125#if GCC_VERSION >= 50100
126#define COMPILER_HAS_GENERIC_BUILTIN_OVERFLOW 1
127#endif
128
129/*
130 * Turn individual warnings and errors on and off locally, depending
131 * on version.
132 */
133#define __diag_GCC(version, severity, s) \
134 __diag_GCC_ ## version(__diag_GCC_ ## severity s)
135
136/* Severity used in pragma directives */
137#define __diag_GCC_ignore ignored
138#define __diag_GCC_warn warning
139#define __diag_GCC_error error
140
141#define __diag_str1(s) #s
142#define __diag_str(s) __diag_str1(s)
143#define __diag(s) _Pragma(__diag_str(GCC diagnostic s))
144
145#if GCC_VERSION >= 80000
146#define __diag_GCC_8(s) __diag(s)
147#else
148#define __diag_GCC_8(s)
149#endif