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/*
94 * sparse (__CHECKER__) pretends to be gcc, but can't do constant
95 * folding in __builtin_bswap*() (yet), so don't set these for it.
96 */
97#if defined(CONFIG_ARCH_USE_BUILTIN_BSWAP) && !defined(__CHECKER__)
98#define __HAVE_BUILTIN_BSWAP32__
99#define __HAVE_BUILTIN_BSWAP64__
100#define __HAVE_BUILTIN_BSWAP16__
101#endif /* CONFIG_ARCH_USE_BUILTIN_BSWAP && !__CHECKER__ */
102
103#if GCC_VERSION >= 70000
104#define KASAN_ABI_VERSION 5
105#elif GCC_VERSION >= 50000
106#define KASAN_ABI_VERSION 4
107#elif GCC_VERSION >= 40902
108#define KASAN_ABI_VERSION 3
109#endif
110
111#if __has_attribute(__no_sanitize_address__)
112#define __no_sanitize_address __attribute__((no_sanitize_address))
113#else
114#define __no_sanitize_address
115#endif
116
117#if defined(__SANITIZE_THREAD__) && __has_attribute(__no_sanitize_thread__)
118#define __no_sanitize_thread __attribute__((no_sanitize_thread))
119#else
120#define __no_sanitize_thread
121#endif
122
123#if __has_attribute(__no_sanitize_undefined__)
124#define __no_sanitize_undefined __attribute__((no_sanitize_undefined))
125#else
126#define __no_sanitize_undefined
127#endif
128
129#if GCC_VERSION >= 50100
130#define COMPILER_HAS_GENERIC_BUILTIN_OVERFLOW 1
131#endif
132
133/*
134 * Turn individual warnings and errors on and off locally, depending
135 * on version.
136 */
137#define __diag_GCC(version, severity, s) \
138 __diag_GCC_ ## version(__diag_GCC_ ## severity s)
139
140/* Severity used in pragma directives */
141#define __diag_GCC_ignore ignored
142#define __diag_GCC_warn warning
143#define __diag_GCC_error error
144
145#define __diag_str1(s) #s
146#define __diag_str(s) __diag_str1(s)
147#define __diag(s) _Pragma(__diag_str(GCC diagnostic s))
148
149#if GCC_VERSION >= 80000
150#define __diag_GCC_8(s) __diag(s)
151#else
152#define __diag_GCC_8(s)
153#endif