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1 | /* |
2 | * Copyright (c) Meta Platforms, Inc. and affiliates. |
3 | * All rights reserved. |
4 | * |
5 | * This source code is licensed under both the BSD-style license (found in the |
6 | * LICENSE file in the root directory of this source tree) and the GPLv2 (found |
7 | * in the COPYING file in the root directory of this source tree). |
8 | * You may select, at your option, one of the above-listed licenses. |
9 | */ |
10 | |
11 | #ifndef ZSTD_PORTABILITY_MACROS_H |
12 | #define ZSTD_PORTABILITY_MACROS_H |
13 | |
14 | /** |
15 | * This header file contains macro definitions to support portability. |
16 | * This header is shared between C and ASM code, so it MUST only |
17 | * contain macro definitions. It MUST not contain any C code. |
18 | * |
19 | * This header ONLY defines macros to detect platforms/feature support. |
20 | * |
21 | */ |
22 | |
23 | |
24 | /* compat. with non-clang compilers */ |
25 | #ifndef __has_attribute |
26 | #define __has_attribute(x) 0 |
27 | #endif |
28 | |
29 | /* compat. with non-clang compilers */ |
30 | #ifndef __has_builtin |
31 | # define __has_builtin(x) 0 |
32 | #endif |
33 | |
34 | /* compat. with non-clang compilers */ |
35 | #ifndef __has_feature |
36 | # define __has_feature(x) 0 |
37 | #endif |
38 | |
39 | /* detects whether we are being compiled under msan */ |
40 | #ifndef ZSTD_MEMORY_SANITIZER |
41 | # if __has_feature(memory_sanitizer) |
42 | # define ZSTD_MEMORY_SANITIZER 1 |
43 | # else |
44 | # define ZSTD_MEMORY_SANITIZER 0 |
45 | # endif |
46 | #endif |
47 | |
48 | /* detects whether we are being compiled under asan */ |
49 | #ifndef ZSTD_ADDRESS_SANITIZER |
50 | # if __has_feature(address_sanitizer) |
51 | # define ZSTD_ADDRESS_SANITIZER 1 |
52 | # elif defined(__SANITIZE_ADDRESS__) |
53 | # define ZSTD_ADDRESS_SANITIZER 1 |
54 | # else |
55 | # define ZSTD_ADDRESS_SANITIZER 0 |
56 | # endif |
57 | #endif |
58 | |
59 | /* detects whether we are being compiled under dfsan */ |
60 | #ifndef ZSTD_DATAFLOW_SANITIZER |
61 | # if __has_feature(dataflow_sanitizer) |
62 | # define ZSTD_DATAFLOW_SANITIZER 1 |
63 | # else |
64 | # define ZSTD_DATAFLOW_SANITIZER 0 |
65 | # endif |
66 | #endif |
67 | |
68 | /* Mark the internal assembly functions as hidden */ |
69 | #ifdef __ELF__ |
70 | # define ZSTD_HIDE_ASM_FUNCTION(func) .hidden func |
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71 | #elif defined(__APPLE__) |
72 | # define ZSTD_HIDE_ASM_FUNCTION(func) .private_extern func |
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73 | #else |
74 | # define ZSTD_HIDE_ASM_FUNCTION(func) |
75 | #endif |
76 | |
77 | /* Enable runtime BMI2 dispatch based on the CPU. |
78 | * Enabled for clang & gcc >=4.8 on x86 when BMI2 isn't enabled by default. |
79 | */ |
80 | #ifndef DYNAMIC_BMI2 |
81 | #if ((defined(__clang__) && __has_attribute(__target__)) \ |
82 | || (defined(__GNUC__) \ |
83 | && (__GNUC__ >= 5 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 8)))) \ |
84 | && (defined(__x86_64__) || defined(_M_X64)) \ |
85 | && !defined(__BMI2__) |
86 | # define DYNAMIC_BMI2 1 |
87 | #else |
88 | # define DYNAMIC_BMI2 0 |
89 | #endif |
90 | #endif |
91 | |
92 | /** |
93 | * Only enable assembly for GNUC compatible compilers, |
94 | * because other platforms may not support GAS assembly syntax. |
95 | * |
96 | * Only enable assembly for Linux / MacOS, other platforms may |
97 | * work, but they haven't been tested. This could likely be |
98 | * extended to BSD systems. |
99 | * |
100 | * Disable assembly when MSAN is enabled, because MSAN requires |
101 | * 100% of code to be instrumented to work. |
102 | */ |
103 | #if defined(__GNUC__) |
104 | # if defined(__linux__) || defined(__linux) || defined(__APPLE__) |
105 | # if ZSTD_MEMORY_SANITIZER |
106 | # define ZSTD_ASM_SUPPORTED 0 |
107 | # elif ZSTD_DATAFLOW_SANITIZER |
108 | # define ZSTD_ASM_SUPPORTED 0 |
109 | # else |
110 | # define ZSTD_ASM_SUPPORTED 1 |
111 | # endif |
112 | # else |
113 | # define ZSTD_ASM_SUPPORTED 0 |
114 | # endif |
115 | #else |
116 | # define ZSTD_ASM_SUPPORTED 0 |
117 | #endif |
118 | |
119 | /** |
120 | * Determines whether we should enable assembly for x86-64 |
121 | * with BMI2. |
122 | * |
123 | * Enable if all of the following conditions hold: |
124 | * - ASM hasn't been explicitly disabled by defining ZSTD_DISABLE_ASM |
125 | * - Assembly is supported |
126 | * - We are compiling for x86-64 and either: |
127 | * - DYNAMIC_BMI2 is enabled |
128 | * - BMI2 is supported at compile time |
129 | */ |
130 | #if !defined(ZSTD_DISABLE_ASM) && \ |
131 | ZSTD_ASM_SUPPORTED && \ |
132 | defined(__x86_64__) && \ |
133 | (DYNAMIC_BMI2 || defined(__BMI2__)) |
134 | # define ZSTD_ENABLE_ASM_X86_64_BMI2 1 |
135 | #else |
136 | # define ZSTD_ENABLE_ASM_X86_64_BMI2 0 |
137 | #endif |
138 | |
139 | /* |
140 | * For x86 ELF targets, add .note.gnu.property section for Intel CET in |
141 | * assembly sources when CET is enabled. |
142 | * |
143 | * Additionally, any function that may be called indirectly must begin |
144 | * with ZSTD_CET_ENDBRANCH. |
145 | */ |
146 | #if defined(__ELF__) && (defined(__x86_64__) || defined(__i386__)) \ |
147 | && defined(__has_include) |
148 | # if __has_include(<cet.h>) |
149 | # include <cet.h> |
150 | # define ZSTD_CET_ENDBRANCH _CET_ENDBR |
151 | # endif |
152 | #endif |
153 | |
154 | #ifndef ZSTD_CET_ENDBRANCH |
155 | # define ZSTD_CET_ENDBRANCH |
156 | #endif |
157 | |
158 | #endif /* ZSTD_PORTABILITY_MACROS_H */ |