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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 version of GCC is too old - please use 4.9 or newer.
16#endif
17
18/*
19 * This macro obfuscates arithmetic on a variable address so that gcc
20 * shouldn't recognize the original var, and make assumptions about it.
21 *
22 * This is needed because the C standard makes it undefined to do
23 * pointer arithmetic on "objects" outside their boundaries and the
24 * gcc optimizers assume this is the case. In particular they
25 * assume such arithmetic does not wrap.
26 *
27 * A miscompilation has been observed because of this on PPC.
28 * To work around it we hide the relationship of the pointer and the object
29 * using this macro.
30 *
31 * Versions of the ppc64 compiler before 4.1 had a bug where use of
32 * RELOC_HIDE could trash r30. The bug can be worked around by changing
33 * the inline assembly constraint from =g to =r, in this particular
34 * case either is valid.
35 */
36#define RELOC_HIDE(ptr, off) \
37({ \
38 unsigned long __ptr; \
39 __asm__ ("" : "=r"(__ptr) : "0"(ptr)); \
40 (typeof(ptr)) (__ptr + (off)); \
41})
42
43#ifdef CONFIG_RETPOLINE
44#define __noretpoline __attribute__((__indirect_branch__("keep")))
45#endif
46
47#define __UNIQUE_ID(prefix) __PASTE(__PASTE(__UNIQUE_ID_, prefix), __COUNTER__)
48
49#define __compiletime_object_size(obj) __builtin_object_size(obj, 0)
50
51#define __compiletime_warning(message) __attribute__((__warning__(message)))
52#define __compiletime_error(message) __attribute__((__error__(message)))
53
54#if defined(LATENT_ENTROPY_PLUGIN) && !defined(__CHECKER__)
55#define __latent_entropy __attribute__((latent_entropy))
56#endif
57
58/*
59 * calling noreturn functions, __builtin_unreachable() and __builtin_trap()
60 * confuse the stack allocation in gcc, leading to overly large stack
61 * frames, see https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82365
62 *
63 * Adding an empty inline assembly before it works around the problem
64 */
65#define barrier_before_unreachable() asm volatile("")
66
67/*
68 * Mark a position in code as unreachable. This can be used to
69 * suppress control flow warnings after asm blocks that transfer
70 * control elsewhere.
71 */
72#define unreachable() \
73 do { \
74 annotate_unreachable(); \
75 barrier_before_unreachable(); \
76 __builtin_unreachable(); \
77 } while (0)
78
79#if defined(RANDSTRUCT_PLUGIN) && !defined(__CHECKER__)
80#define __randomize_layout __attribute__((randomize_layout))
81#define __no_randomize_layout __attribute__((no_randomize_layout))
82/* This anon struct can add padding, so only enable it under randstruct. */
83#define randomized_struct_fields_start struct {
84#define randomized_struct_fields_end } __randomize_layout;
85#endif
86
87/*
88 * GCC 'asm goto' miscompiles certain code sequences:
89 *
90 * http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58670
91 *
92 * Work it around via a compiler barrier quirk suggested by Jakub Jelinek.
93 *
94 * (asm goto is automatically volatile - the naming reflects this.)
95 */
96#define asm_volatile_goto(x...) do { asm goto(x); asm (""); } while (0)
97
98/*
99 * sparse (__CHECKER__) pretends to be gcc, but can't do constant
100 * folding in __builtin_bswap*() (yet), so don't set these for it.
101 */
102#if defined(CONFIG_ARCH_USE_BUILTIN_BSWAP) && !defined(__CHECKER__)
103#define __HAVE_BUILTIN_BSWAP32__
104#define __HAVE_BUILTIN_BSWAP64__
105#define __HAVE_BUILTIN_BSWAP16__
106#endif /* CONFIG_ARCH_USE_BUILTIN_BSWAP && !__CHECKER__ */
107
108#if GCC_VERSION >= 70000
109#define KASAN_ABI_VERSION 5
110#elif GCC_VERSION >= 50000
111#define KASAN_ABI_VERSION 4
112#elif GCC_VERSION >= 40902
113#define KASAN_ABI_VERSION 3
114#endif
115
116#if __has_attribute(__no_sanitize_address__)
117#define __no_sanitize_address __attribute__((no_sanitize_address))
118#else
119#define __no_sanitize_address
120#endif
121
122#if defined(__SANITIZE_THREAD__) && __has_attribute(__no_sanitize_thread__)
123#define __no_sanitize_thread __attribute__((no_sanitize_thread))
124#else
125#define __no_sanitize_thread
126#endif
127
128#if __has_attribute(__no_sanitize_undefined__)
129#define __no_sanitize_undefined __attribute__((no_sanitize_undefined))
130#else
131#define __no_sanitize_undefined
132#endif
133
134#if GCC_VERSION >= 50100
135#define COMPILER_HAS_GENERIC_BUILTIN_OVERFLOW 1
136#endif
137
138/*
139 * Turn individual warnings and errors on and off locally, depending
140 * on version.
141 */
142#define __diag_GCC(version, severity, s) \
143 __diag_GCC_ ## version(__diag_GCC_ ## severity s)
144
145/* Severity used in pragma directives */
146#define __diag_GCC_ignore ignored
147#define __diag_GCC_warn warning
148#define __diag_GCC_error error
149
150#define __diag_str1(s) #s
151#define __diag_str(s) __diag_str1(s)
152#define __diag(s) _Pragma(__diag_str(GCC diagnostic s))
153
154#if GCC_VERSION >= 80000
155#define __diag_GCC_8(s) __diag(s)
156#else
157#define __diag_GCC_8(s)
158#endif