diff options
Diffstat (limited to 'mysql/my_compiler.h')
| -rw-r--r-- | mysql/my_compiler.h | 178 |
1 files changed, 178 insertions, 0 deletions
diff --git a/mysql/my_compiler.h b/mysql/my_compiler.h new file mode 100644 index 0000000..2092537 --- /dev/null +++ b/mysql/my_compiler.h @@ -0,0 +1,178 @@ +#ifndef MY_COMPILER_INCLUDED +#define MY_COMPILER_INCLUDED + +/* Copyright (c) 2010, 2016, Oracle and/or its affiliates. All rights reserved. + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; version 2 of the License. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */ + +/** + Header for compiler-dependent features. + + Intended to contain a set of reusable wrappers for preprocessor + macros, attributes, pragmas, and any other features that are + specific to a target compiler. +*/ + +#include <stddef.h> /* size_t */ + +#if defined __GNUC__ +/* + Convenience macro to test the minimum required GCC version. + These should be used with care as Clang also sets __GNUC__ and + __GNUC_MINOR__ (currently to 4.2). Prefer using feature specific + CMake checks in configure.cmake instead. +*/ +# define MY_GNUC_PREREQ(maj, min) \ + ((__GNUC__ << 16) + __GNUC_MINOR__ >= ((maj) << 16) + (min)) +# define GCC_VERSION (__GNUC__ * 1000 + __GNUC_MINOR__) +#else +# define MY_GNUC_PREREQ(maj, min) (0) +#endif + +/* + The macros below are borrowed from include/linux/compiler.h in the + Linux kernel. Use them to indicate the likelyhood of the truthfulness + of a condition. This serves two purposes - newer versions of gcc will be + able to optimize for branch predication, which could yield siginficant + performance gains in frequently executed sections of the code, and the + other reason to use them is for documentation +*/ +#ifdef HAVE_BUILTIN_EXPECT + +// likely/unlikely are likely to clash with other symbols, do not #define +#if defined(__cplusplus) +inline bool likely(bool expr) +{ + return __builtin_expect(expr, true); +} +inline bool unlikely(bool expr) +{ + return __builtin_expect(expr, false); +} +#else +# define likely(x) __builtin_expect((x),1) +# define unlikely(x) __builtin_expect((x),0) +#endif + +#else /* HAVE_BUILTIN_EXPECT */ + +#if defined(__cplusplus) +inline bool likely(bool expr) +{ + return expr; +} +inline bool unlikely(bool expr) +{ + return expr; +} +#else +# define likely(x) (x) +# define unlikely(x) (x) +#endif + +#endif /* HAVE_BUILTIN_EXPECT */ + +/* Comunicate to the compiler the unreachability of the code. */ +#ifdef HAVE_BUILTIN_UNREACHABLE +# define MY_ASSERT_UNREACHABLE() __builtin_unreachable() +#else +# define MY_ASSERT_UNREACHABLE() do { assert(0); } while (0) +#endif + +#if defined __GNUC__ || defined __SUNPRO_C || defined __SUNPRO_CC +/* Specifies the minimum alignment of a type. */ +# define MY_ALIGNOF(type) __alignof__(type) +/* Determine the alignment requirement of a type. */ +# define MY_ALIGNED(n) __attribute__((__aligned__((n)))) +/* Microsoft Visual C++ */ +#elif defined _MSC_VER +# define MY_ALIGNOF(type) __alignof(type) +# define MY_ALIGNED(n) __declspec(align(n)) +#else /* Make sure they are defined for other compilers. */ +# define MY_ALIGNOF(type) +# define MY_ALIGNED(size) +#endif + +/* Visual Studio requires '__inline' for C code */ +#if !defined(__cplusplus) && defined(_MSC_VER) +# define inline __inline +#endif + +/* Provide __func__ macro definition for Visual Studio. */ +#if defined(_MSC_VER) +# define __func__ __FUNCTION__ +#endif + +/** + C++ Type Traits +*/ +#ifdef __cplusplus + +/** + Opaque storage with a particular alignment. + Partial specialization used due to MSVC++. +*/ +template<size_t alignment> struct my_alignment_imp; +template<> struct MY_ALIGNED(1) my_alignment_imp<1> {}; +template<> struct MY_ALIGNED(2) my_alignment_imp<2> {}; +template<> struct MY_ALIGNED(4) my_alignment_imp<4> {}; +template<> struct MY_ALIGNED(8) my_alignment_imp<8> {}; +template<> struct MY_ALIGNED(16) my_alignment_imp<16> {}; + +/** + A POD type with a given size and alignment. + + @remark If the compiler does not support a alignment attribute + (MY_ALIGN macro), the default alignment of a double is + used instead. + + @tparam size The minimum size. + @tparam alignment The desired alignment: 1, 2, 4, 8 or 16. +*/ +template <size_t size, size_t alignment> +struct my_aligned_storage +{ + union + { + char data[size]; + my_alignment_imp<alignment> align; + }; +}; + +#endif /* __cplusplus */ + +/* + Disable MY_ATTRIBUTE for Sun Studio and Visual Studio. + Note that Sun Studio supports some __attribute__ variants, + but not format or unused which we use quite a lot. +*/ +#ifndef MY_ATTRIBUTE +#if defined(__GNUC__) +# define MY_ATTRIBUTE(A) __attribute__(A) +#else +# define MY_ATTRIBUTE(A) +#endif +#endif + +#ifndef __has_attribute +# define __has_attribute(x) 0 +#endif + +#if __has_attribute(no_sanitize_undefined) +# define SUPPRESS_UBSAN __attribute__((no_sanitize_undefined)) +#else +# define SUPPRESS_UBSAN +#endif + +#endif /* MY_COMPILER_INCLUDED */ |