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1#ifndef __LINUX_COMPILER_H
2#error "Please don't include <linux/compiler-gcc.h> directly, include <linux/compiler.h> instead."
3#endif
4
5/*
6 * Common definitions for all gcc versions go here.
7 */
8#define GCC_VERSION (__GNUC__ * 10000 \
9 + __GNUC_MINOR__ * 100 \
10 + __GNUC_PATCHLEVEL__)
11
12
13/* Optimization barrier */
14/* The "volatile" is due to gcc bugs */
15#define barrier() __asm__ __volatile__("": : :"memory")
16
17/*
18 * This macro obfuscates arithmetic on a variable address so that gcc
19 * shouldn't recognize the original var, and make assumptions about it.
20 *
21 * This is needed because the C standard makes it undefined to do
22 * pointer arithmetic on "objects" outside their boundaries and the
23 * gcc optimizers assume this is the case. In particular they
24 * assume such arithmetic does not wrap.
25 *
26 * A miscompilation has been observed because of this on PPC.
27 * To work around it we hide the relationship of the pointer and the object
28 * using this macro.
29 *
30 * Versions of the ppc64 compiler before 4.1 had a bug where use of
31 * RELOC_HIDE could trash r30. The bug can be worked around by changing
32 * the inline assembly constraint from =g to =r, in this particular
33 * case either is valid.
34 */
35#define RELOC_HIDE(ptr, off) \
36 ({ unsigned long __ptr; \
37 __asm__ ("" : "=r"(__ptr) : "0"(ptr)); \
38 (typeof(ptr)) (__ptr + (off)); })
39
40/* Make the optimizer believe the variable can be manipulated arbitrarily. */
41#define OPTIMIZER_HIDE_VAR(var) __asm__ ("" : "=r" (var) : "0" (var))
42
43#ifdef __CHECKER__
44#define __must_be_array(arr) 0
45#else
46/* &a[0] degrades to a pointer: a different type from an array */
47#define __must_be_array(a) BUILD_BUG_ON_ZERO(__same_type((a), &(a)[0]))
48#endif
49
50/*
51 * Force always-inline if the user requests it so via the .config,
52 * or if gcc is too old:
53 */
54#if !defined(CONFIG_ARCH_SUPPORTS_OPTIMIZED_INLINING) || \
55 !defined(CONFIG_OPTIMIZE_INLINING) || (__GNUC__ < 4)
56# define inline inline __attribute__((always_inline)) notrace
57# define __inline__ __inline__ __attribute__((always_inline)) notrace
58# define __inline __inline __attribute__((always_inline)) notrace
59#else
60/* A lot of inline functions can cause havoc with function tracing */
61# define inline inline notrace
62# define __inline__ __inline__ notrace
63# define __inline __inline notrace
64#endif
65
66#define __deprecated __attribute__((deprecated))
67#define __packed __attribute__((packed))
68#define __weak __attribute__((weak))
69
70/*
71 * it doesn't make sense on ARM (currently the only user of __naked) to trace
72 * naked functions because then mcount is called without stack and frame pointer
73 * being set up and there is no chance to restore the lr register to the value
74 * before mcount was called.
75 *
76 * The asm() bodies of naked functions often depend on standard calling conventions,
77 * therefore they must be noinline and noclone. GCC 4.[56] currently fail to enforce
78 * this, so we must do so ourselves. See GCC PR44290.
79 */
80#define __naked __attribute__((naked)) noinline __noclone notrace
81
82#define __noreturn __attribute__((noreturn))
83
84/*
85 * From the GCC manual:
86 *
87 * Many functions have no effects except the return value and their
88 * return value depends only on the parameters and/or global
89 * variables. Such a function can be subject to common subexpression
90 * elimination and loop optimization just as an arithmetic operator
91 * would be.
92 * [...]
93 */
94#define __pure __attribute__((pure))
95#define __aligned(x) __attribute__((aligned(x)))
96#define __printf(a, b) __attribute__((format(printf, a, b)))
97#define __scanf(a, b) __attribute__((format(scanf, a, b)))
98#define noinline __attribute__((noinline))
99#define __attribute_const__ __attribute__((__const__))
100#define __maybe_unused __attribute__((unused))
101#define __always_unused __attribute__((unused))
102
103#define __gcc_header(x) #x
104#define _gcc_header(x) __gcc_header(linux/compiler-gcc##x.h)
105#define gcc_header(x) _gcc_header(x)
106#include gcc_header(__GNUC__)
107
108#if !defined(__noclone)
109#define __noclone /* not needed */
110#endif
111
112/*
113 * A trick to suppress uninitialized variable warning without generating any
114 * code
115 */
116#define uninitialized_var(x) x = x
117
118#define __always_inline inline __attribute__((always_inline))
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#if GCC_VERSION < 40600
14# error Sorry, your compiler is too old - please upgrade it.
15#endif
16
17/* Optimization barrier */
18
19/* The "volatile" is due to gcc bugs */
20#define barrier() __asm__ __volatile__("": : :"memory")
21/*
22 * This version is i.e. to prevent dead stores elimination on @ptr
23 * where gcc and llvm may behave differently when otherwise using
24 * normal barrier(): while gcc behavior gets along with a normal
25 * barrier(), llvm needs an explicit input variable to be assumed
26 * clobbered. The issue is as follows: while the inline asm might
27 * access any memory it wants, the compiler could have fit all of
28 * @ptr into memory registers instead, and since @ptr never escaped
29 * from that, it proved that the inline asm wasn't touching any of
30 * it. This version works well with both compilers, i.e. we're telling
31 * the compiler that the inline asm absolutely may see the contents
32 * of @ptr. See also: https://llvm.org/bugs/show_bug.cgi?id=15495
33 */
34#define barrier_data(ptr) __asm__ __volatile__("": :"r"(ptr) :"memory")
35
36/*
37 * This macro obfuscates arithmetic on a variable address so that gcc
38 * shouldn't recognize the original var, and make assumptions about it.
39 *
40 * This is needed because the C standard makes it undefined to do
41 * pointer arithmetic on "objects" outside their boundaries and the
42 * gcc optimizers assume this is the case. In particular they
43 * assume such arithmetic does not wrap.
44 *
45 * A miscompilation has been observed because of this on PPC.
46 * To work around it we hide the relationship of the pointer and the object
47 * using this macro.
48 *
49 * Versions of the ppc64 compiler before 4.1 had a bug where use of
50 * RELOC_HIDE could trash r30. The bug can be worked around by changing
51 * the inline assembly constraint from =g to =r, in this particular
52 * case either is valid.
53 */
54#define RELOC_HIDE(ptr, off) \
55({ \
56 unsigned long __ptr; \
57 __asm__ ("" : "=r"(__ptr) : "0"(ptr)); \
58 (typeof(ptr)) (__ptr + (off)); \
59})
60
61/*
62 * A trick to suppress uninitialized variable warning without generating any
63 * code
64 */
65#define uninitialized_var(x) x = x
66
67#ifdef CONFIG_RETPOLINE
68#define __noretpoline __attribute__((__indirect_branch__("keep")))
69#endif
70
71#define __UNIQUE_ID(prefix) __PASTE(__PASTE(__UNIQUE_ID_, prefix), __COUNTER__)
72
73#define __compiletime_object_size(obj) __builtin_object_size(obj, 0)
74
75#define __compiletime_warning(message) __attribute__((__warning__(message)))
76#define __compiletime_error(message) __attribute__((__error__(message)))
77
78#if defined(LATENT_ENTROPY_PLUGIN) && !defined(__CHECKER__)
79#define __latent_entropy __attribute__((latent_entropy))
80#endif
81
82/*
83 * calling noreturn functions, __builtin_unreachable() and __builtin_trap()
84 * confuse the stack allocation in gcc, leading to overly large stack
85 * frames, see https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82365
86 *
87 * Adding an empty inline assembly before it works around the problem
88 */
89#define barrier_before_unreachable() asm volatile("")
90
91/*
92 * Mark a position in code as unreachable. This can be used to
93 * suppress control flow warnings after asm blocks that transfer
94 * control elsewhere.
95 */
96#define unreachable() \
97 do { \
98 annotate_unreachable(); \
99 barrier_before_unreachable(); \
100 __builtin_unreachable(); \
101 } while (0)
102
103#if defined(RANDSTRUCT_PLUGIN) && !defined(__CHECKER__)
104#define __randomize_layout __attribute__((randomize_layout))
105#define __no_randomize_layout __attribute__((no_randomize_layout))
106/* This anon struct can add padding, so only enable it under randstruct. */
107#define randomized_struct_fields_start struct {
108#define randomized_struct_fields_end } __randomize_layout;
109#endif
110
111/*
112 * GCC 'asm goto' miscompiles certain code sequences:
113 *
114 * http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58670
115 *
116 * Work it around via a compiler barrier quirk suggested by Jakub Jelinek.
117 *
118 * (asm goto is automatically volatile - the naming reflects this.)
119 */
120#define asm_volatile_goto(x...) do { asm goto(x); asm (""); } while (0)
121
122/*
123 * sparse (__CHECKER__) pretends to be gcc, but can't do constant
124 * folding in __builtin_bswap*() (yet), so don't set these for it.
125 */
126#if defined(CONFIG_ARCH_USE_BUILTIN_BSWAP) && !defined(__CHECKER__)
127#define __HAVE_BUILTIN_BSWAP32__
128#define __HAVE_BUILTIN_BSWAP64__
129#if GCC_VERSION >= 40800
130#define __HAVE_BUILTIN_BSWAP16__
131#endif
132#endif /* CONFIG_ARCH_USE_BUILTIN_BSWAP && !__CHECKER__ */
133
134#if GCC_VERSION >= 70000
135#define KASAN_ABI_VERSION 5
136#elif GCC_VERSION >= 50000
137#define KASAN_ABI_VERSION 4
138#elif GCC_VERSION >= 40902
139#define KASAN_ABI_VERSION 3
140#endif
141
142#if __has_attribute(__no_sanitize_address__)
143#define __no_sanitize_address __attribute__((no_sanitize_address))
144#else
145#define __no_sanitize_address
146#endif
147
148#if GCC_VERSION >= 50100
149#define COMPILER_HAS_GENERIC_BUILTIN_OVERFLOW 1
150#endif
151
152/*
153 * Turn individual warnings and errors on and off locally, depending
154 * on version.
155 */
156#define __diag_GCC(version, severity, s) \
157 __diag_GCC_ ## version(__diag_GCC_ ## severity s)
158
159/* Severity used in pragma directives */
160#define __diag_GCC_ignore ignored
161#define __diag_GCC_warn warning
162#define __diag_GCC_error error
163
164#define __diag_str1(s) #s
165#define __diag_str(s) __diag_str1(s)
166#define __diag(s) _Pragma(__diag_str(GCC diagnostic s))
167
168#if GCC_VERSION >= 80000
169#define __diag_GCC_8(s) __diag(s)
170#else
171#define __diag_GCC_8(s)
172#endif
173
174#define __no_fgcse __attribute__((optimize("-fno-gcse")))