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#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;
};
};
#if __cpp_attributes && defined(__has_cpp_attribute)
#if __has_cpp_attribute(nodiscard)
#define MY_NODISCARD [[nodiscard]]
#elif __has_cpp_attribute(gnu::warn_unused_result)
#define MY_NODISCARD [[gnu::warn_unused_result]]
#endif /* __has_cpp_attribute(gnu::warn_unused_result) */
#endif /* __cpp_attributes && defined(__has_cpp_attribute) */
#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
#ifndef MY_NODISCARD
#define MY_NODISCARD MY_ATTRIBUTE((warn_unused_result))
#endif /* MY_NODISCARD */
#if __has_attribute(no_sanitize_undefined)
# define SUPPRESS_UBSAN __attribute__((no_sanitize_undefined))
#else
# define SUPPRESS_UBSAN
#endif
#endif /* MY_COMPILER_INCLUDED */