2 * Copyright (c) Meta Platforms, Inc. and affiliates.
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.
11 #ifndef ZSTD_PORTABILITY_MACROS_H
12 #define ZSTD_PORTABILITY_MACROS_H
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.
19 * This header ONLY defines macros to detect platforms/feature support.
24 /* compat. with non-clang compilers */
25 #ifndef __has_attribute
26 #define __has_attribute(x) 0
29 /* compat. with non-clang compilers */
31 # define __has_builtin(x) 0
34 /* compat. with non-clang compilers */
36 # define __has_feature(x) 0
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
44 # define ZSTD_MEMORY_SANITIZER 0
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
55 # define ZSTD_ADDRESS_SANITIZER 0
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
64 # define ZSTD_DATAFLOW_SANITIZER 0
68 /* Mark the internal assembly functions as hidden */
70 # define ZSTD_HIDE_ASM_FUNCTION(func) .hidden func
71 #elif defined(__APPLE__)
72 # define ZSTD_HIDE_ASM_FUNCTION(func) .private_extern func
74 # define ZSTD_HIDE_ASM_FUNCTION(func)
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.
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)) \
86 # define DYNAMIC_BMI2 1
88 # define DYNAMIC_BMI2 0
93 * Only enable assembly for GNUC compatible compilers,
94 * because other platforms may not support GAS assembly syntax.
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.
100 * Disable assembly when MSAN is enabled, because MSAN requires
101 * 100% of code to be instrumented to work.
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
110 # define ZSTD_ASM_SUPPORTED 1
113 # define ZSTD_ASM_SUPPORTED 0
116 # define ZSTD_ASM_SUPPORTED 0
120 * Determines whether we should enable assembly for x86-64
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
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
136 # define ZSTD_ENABLE_ASM_X86_64_BMI2 0
140 * For x86 ELF targets, add .note.gnu.property section for Intel CET in
141 * assembly sources when CET is enabled.
143 * Additionally, any function that may be called indirectly must begin
144 * with ZSTD_CET_ENDBRANCH.
146 #if defined(__ELF__) && (defined(__x86_64__) || defined(__i386__)) \
147 && defined(__has_include)
148 # if __has_include(<cet.h>)
150 # define ZSTD_CET_ENDBRANCH _CET_ENDBR
154 #ifndef ZSTD_CET_ENDBRANCH
155 # define ZSTD_CET_ENDBRANCH
158 #endif /* ZSTD_PORTABILITY_MACROS_H */