Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
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/* https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58145 */
14#if GCC_VERSION < 40900
15# error Sorry, your compiler is too old - please upgrade it.
16#endif
17
18/* Optimization barrier */
19
20/* The "volatile" is due to gcc bugs */
21#define barrier() __asm__ __volatile__("": : :"memory")
22/*
23 * This version is i.e. to prevent dead stores elimination on @ptr
24 * where gcc and llvm may behave differently when otherwise using
25 * normal barrier(): while gcc behavior gets along with a normal
26 * barrier(), llvm needs an explicit input variable to be assumed
27 * clobbered. The issue is as follows: while the inline asm might
28 * access any memory it wants, the compiler could have fit all of
29 * @ptr into memory registers instead, and since @ptr never escaped
30 * from that, it proved that the inline asm wasn't touching any of
31 * it. This version works well with both compilers, i.e. we're telling
32 * the compiler that the inline asm absolutely may see the contents
33 * of @ptr. See also: https://llvm.org/bugs/show_bug.cgi?id=15495
34 */
35#define barrier_data(ptr) __asm__ __volatile__("": :"r"(ptr) :"memory")
36
37/*
38 * This macro obfuscates arithmetic on a variable address so that gcc
39 * shouldn't recognize the original var, and make assumptions about it.
40 *
41 * This is needed because the C standard makes it undefined to do
42 * pointer arithmetic on "objects" outside their boundaries and the
43 * gcc optimizers assume this is the case. In particular they
44 * assume such arithmetic does not wrap.
45 *
46 * A miscompilation has been observed because of this on PPC.
47 * To work around it we hide the relationship of the pointer and the object
48 * using this macro.
49 *
50 * Versions of the ppc64 compiler before 4.1 had a bug where use of
51 * RELOC_HIDE could trash r30. The bug can be worked around by changing
52 * the inline assembly constraint from =g to =r, in this particular
53 * case either is valid.
54 */
55#define RELOC_HIDE(ptr, off) \
56({ \
57 unsigned long __ptr; \
58 __asm__ ("" : "=r"(__ptr) : "0"(ptr)); \
59 (typeof(ptr)) (__ptr + (off)); \
60})
61
62#ifdef CONFIG_RETPOLINE
63#define __noretpoline __attribute__((__indirect_branch__("keep")))
64#endif
65
66#define __UNIQUE_ID(prefix) __PASTE(__PASTE(__UNIQUE_ID_, prefix), __COUNTER__)
67
68#define __compiletime_object_size(obj) __builtin_object_size(obj, 0)
69
70#define __compiletime_warning(message) __attribute__((__warning__(message)))
71#define __compiletime_error(message) __attribute__((__error__(message)))
72
73#if defined(LATENT_ENTROPY_PLUGIN) && !defined(__CHECKER__)
74#define __latent_entropy __attribute__((latent_entropy))
75#endif
76
77/*
78 * calling noreturn functions, __builtin_unreachable() and __builtin_trap()
79 * confuse the stack allocation in gcc, leading to overly large stack
80 * frames, see https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82365
81 *
82 * Adding an empty inline assembly before it works around the problem
83 */
84#define barrier_before_unreachable() asm volatile("")
85
86/*
87 * Mark a position in code as unreachable. This can be used to
88 * suppress control flow warnings after asm blocks that transfer
89 * control elsewhere.
90 */
91#define unreachable() \
92 do { \
93 annotate_unreachable(); \
94 barrier_before_unreachable(); \
95 __builtin_unreachable(); \
96 } while (0)
97
98#if defined(RANDSTRUCT_PLUGIN) && !defined(__CHECKER__)
99#define __randomize_layout __attribute__((randomize_layout))
100#define __no_randomize_layout __attribute__((no_randomize_layout))
101/* This anon struct can add padding, so only enable it under randstruct. */
102#define randomized_struct_fields_start struct {
103#define randomized_struct_fields_end } __randomize_layout;
104#endif
105
106/*
107 * GCC 'asm goto' miscompiles certain code sequences:
108 *
109 * http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58670
110 *
111 * Work it around via a compiler barrier quirk suggested by Jakub Jelinek.
112 *
113 * (asm goto is automatically volatile - the naming reflects this.)
114 */
115#define asm_volatile_goto(x...) do { asm goto(x); asm (""); } while (0)
116
117/*
118 * sparse (__CHECKER__) pretends to be gcc, but can't do constant
119 * folding in __builtin_bswap*() (yet), so don't set these for it.
120 */
121#if defined(CONFIG_ARCH_USE_BUILTIN_BSWAP) && !defined(__CHECKER__)
122#define __HAVE_BUILTIN_BSWAP32__
123#define __HAVE_BUILTIN_BSWAP64__
124#define __HAVE_BUILTIN_BSWAP16__
125#endif /* CONFIG_ARCH_USE_BUILTIN_BSWAP && !__CHECKER__ */
126
127#if GCC_VERSION >= 70000
128#define KASAN_ABI_VERSION 5
129#elif GCC_VERSION >= 50000
130#define KASAN_ABI_VERSION 4
131#elif GCC_VERSION >= 40902
132#define KASAN_ABI_VERSION 3
133#endif
134
135#if __has_attribute(__no_sanitize_address__)
136#define __no_sanitize_address __attribute__((no_sanitize_address))
137#else
138#define __no_sanitize_address
139#endif
140
141#if defined(__SANITIZE_THREAD__) && __has_attribute(__no_sanitize_thread__)
142#define __no_sanitize_thread __attribute__((no_sanitize_thread))
143#else
144#define __no_sanitize_thread
145#endif
146
147#if __has_attribute(__no_sanitize_undefined__)
148#define __no_sanitize_undefined __attribute__((no_sanitize_undefined))
149#else
150#define __no_sanitize_undefined
151#endif
152
153#if GCC_VERSION >= 50100
154#define COMPILER_HAS_GENERIC_BUILTIN_OVERFLOW 1
155#endif
156
157/*
158 * Turn individual warnings and errors on and off locally, depending
159 * on version.
160 */
161#define __diag_GCC(version, severity, s) \
162 __diag_GCC_ ## version(__diag_GCC_ ## severity s)
163
164/* Severity used in pragma directives */
165#define __diag_GCC_ignore ignored
166#define __diag_GCC_warn warning
167#define __diag_GCC_error error
168
169#define __diag_str1(s) #s
170#define __diag_str(s) __diag_str1(s)
171#define __diag(s) _Pragma(__diag_str(GCC diagnostic s))
172
173#if GCC_VERSION >= 80000
174#define __diag_GCC_8(s) __diag(s)
175#else
176#define __diag_GCC_8(s)
177#endif
178
179#define __no_fgcse __attribute__((optimize("-fno-gcse")))