| //===-- llvm/Support/Compiler.h - Compiler abstraction support --*- C++ -*-===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This file defines several macros, based on the current compiler. This allows |
| // use of compiler-specific features in a way that remains portable. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef LLVM_SUPPORT_COMPILER_H |
| #define LLVM_SUPPORT_COMPILER_H |
| |
| #include "llvm/Config/llvm-config.h" |
| |
| #if defined(_MSC_VER) |
| #include <sal.h> |
| #endif |
| |
| #ifndef __has_feature |
| # define __has_feature(x) 0 |
| #endif |
| |
| #ifndef __has_extension |
| # define __has_extension(x) 0 |
| #endif |
| |
| #ifndef __has_attribute |
| # define __has_attribute(x) 0 |
| #endif |
| |
| #ifndef __has_cpp_attribute |
| # define __has_cpp_attribute(x) 0 |
| #endif |
| |
| #ifndef __has_builtin |
| # define __has_builtin(x) 0 |
| #endif |
| |
| /// \macro LLVM_GNUC_PREREQ |
| /// \brief Extend the default __GNUC_PREREQ even if glibc's features.h isn't |
| /// available. |
| #ifndef LLVM_GNUC_PREREQ |
| # if defined(__GNUC__) && defined(__GNUC_MINOR__) && defined(__GNUC_PATCHLEVEL__) |
| # define LLVM_GNUC_PREREQ(maj, min, patch) \ |
| ((__GNUC__ << 20) + (__GNUC_MINOR__ << 10) + __GNUC_PATCHLEVEL__ >= \ |
| ((maj) << 20) + ((min) << 10) + (patch)) |
| # elif defined(__GNUC__) && defined(__GNUC_MINOR__) |
| # define LLVM_GNUC_PREREQ(maj, min, patch) \ |
| ((__GNUC__ << 20) + (__GNUC_MINOR__ << 10) >= ((maj) << 20) + ((min) << 10)) |
| # else |
| # define LLVM_GNUC_PREREQ(maj, min, patch) 0 |
| # endif |
| #endif |
| |
| /// \macro LLVM_MSC_PREREQ |
| /// \brief Is the compiler MSVC of at least the specified version? |
| /// The common \param version values to check for are: |
| /// * 1800: Microsoft Visual Studio 2013 / 12.0 |
| /// * 1900: Microsoft Visual Studio 2015 / 14.0 |
| #ifdef _MSC_VER |
| #define LLVM_MSC_PREREQ(version) (_MSC_VER >= (version)) |
| |
| // We require at least MSVC 2013. |
| #if !LLVM_MSC_PREREQ(1800) |
| #error LLVM requires at least MSVC 2013. |
| #endif |
| |
| #else |
| #define LLVM_MSC_PREREQ(version) 0 |
| #endif |
| |
| #if !defined(_MSC_VER) || defined(__clang__) || LLVM_MSC_PREREQ(1900) |
| #define LLVM_NOEXCEPT noexcept |
| #else |
| #define LLVM_NOEXCEPT throw() |
| #endif |
| |
| /// \brief Does the compiler support ref-qualifiers for *this? |
| /// |
| /// Sadly, this is separate from just rvalue reference support because GCC |
| /// and MSVC implemented this later than everything else. |
| #if __has_feature(cxx_rvalue_references) || LLVM_GNUC_PREREQ(4, 8, 1) |
| #define LLVM_HAS_RVALUE_REFERENCE_THIS 1 |
| #else |
| #define LLVM_HAS_RVALUE_REFERENCE_THIS 0 |
| #endif |
| |
| /// Expands to '&' if ref-qualifiers for *this are supported. |
| /// |
| /// This can be used to provide lvalue/rvalue overrides of member functions. |
| /// The rvalue override should be guarded by LLVM_HAS_RVALUE_REFERENCE_THIS |
| #if LLVM_HAS_RVALUE_REFERENCE_THIS |
| #define LLVM_LVALUE_FUNCTION & |
| #else |
| #define LLVM_LVALUE_FUNCTION |
| #endif |
| |
| #if __has_feature(cxx_constexpr) || defined(__GXX_EXPERIMENTAL_CXX0X__) || LLVM_MSC_PREREQ(1900) |
| # define LLVM_CONSTEXPR constexpr |
| #else |
| # define LLVM_CONSTEXPR |
| #endif |
| |
| /// LLVM_LIBRARY_VISIBILITY - If a class marked with this attribute is linked |
| /// into a shared library, then the class should be private to the library and |
| /// not accessible from outside it. Can also be used to mark variables and |
| /// functions, making them private to any shared library they are linked into. |
| /// On PE/COFF targets, library visibility is the default, so this isn't needed. |
| #if (__has_attribute(visibility) || LLVM_GNUC_PREREQ(4, 0, 0)) && \ |
| !defined(__MINGW32__) && !defined(__CYGWIN__) && !defined(LLVM_ON_WIN32) |
| #define LLVM_LIBRARY_VISIBILITY __attribute__ ((visibility("hidden"))) |
| #else |
| #define LLVM_LIBRARY_VISIBILITY |
| #endif |
| |
| #if __has_attribute(sentinel) || LLVM_GNUC_PREREQ(3, 0, 0) |
| #define LLVM_END_WITH_NULL __attribute__((sentinel)) |
| #else |
| #define LLVM_END_WITH_NULL |
| #endif |
| |
| #if __has_attribute(used) || LLVM_GNUC_PREREQ(3, 1, 0) |
| #define LLVM_ATTRIBUTE_USED __attribute__((__used__)) |
| #else |
| #define LLVM_ATTRIBUTE_USED |
| #endif |
| |
| #if __has_attribute(warn_unused_result) || LLVM_GNUC_PREREQ(3, 4, 0) |
| #define LLVM_ATTRIBUTE_UNUSED_RESULT __attribute__((__warn_unused_result__)) |
| #elif defined(_MSC_VER) |
| #define LLVM_ATTRIBUTE_UNUSED_RESULT _Check_return_ |
| #else |
| #define LLVM_ATTRIBUTE_UNUSED_RESULT |
| #endif |
| |
| // Some compilers warn about unused functions. When a function is sometimes |
| // used or not depending on build settings (e.g. a function only called from |
| // within "assert"), this attribute can be used to suppress such warnings. |
| // |
| // However, it shouldn't be used for unused *variables*, as those have a much |
| // more portable solution: |
| // (void)unused_var_name; |
| // Prefer cast-to-void wherever it is sufficient. |
| #if __has_attribute(unused) || LLVM_GNUC_PREREQ(3, 1, 0) |
| #define LLVM_ATTRIBUTE_UNUSED __attribute__((__unused__)) |
| #else |
| #define LLVM_ATTRIBUTE_UNUSED |
| #endif |
| |
| // FIXME: Provide this for PE/COFF targets. |
| #if (__has_attribute(weak) || LLVM_GNUC_PREREQ(4, 0, 0)) && \ |
| (!defined(__MINGW32__) && !defined(__CYGWIN__) && !defined(LLVM_ON_WIN32)) |
| #define LLVM_ATTRIBUTE_WEAK __attribute__((__weak__)) |
| #else |
| #define LLVM_ATTRIBUTE_WEAK |
| #endif |
| |
| // Prior to clang 3.2, clang did not accept any spelling of |
| // __has_attribute(const), so assume it is supported. |
| #if defined(__clang__) || defined(__GNUC__) |
| // aka 'CONST' but following LLVM Conventions. |
| #define LLVM_READNONE __attribute__((__const__)) |
| #else |
| #define LLVM_READNONE |
| #endif |
| |
| #if __has_attribute(pure) || defined(__GNUC__) |
| // aka 'PURE' but following LLVM Conventions. |
| #define LLVM_READONLY __attribute__((__pure__)) |
| #else |
| #define LLVM_READONLY |
| #endif |
| |
| #if __has_builtin(__builtin_expect) || LLVM_GNUC_PREREQ(4, 0, 0) |
| #define LLVM_LIKELY(EXPR) __builtin_expect((bool)(EXPR), true) |
| #define LLVM_UNLIKELY(EXPR) __builtin_expect((bool)(EXPR), false) |
| #else |
| #define LLVM_LIKELY(EXPR) (EXPR) |
| #define LLVM_UNLIKELY(EXPR) (EXPR) |
| #endif |
| |
| /// LLVM_ATTRIBUTE_NOINLINE - On compilers where we have a directive to do so, |
| /// mark a method "not for inlining". |
| #if __has_attribute(noinline) || LLVM_GNUC_PREREQ(3, 4, 0) |
| #define LLVM_ATTRIBUTE_NOINLINE __attribute__((noinline)) |
| #elif defined(_MSC_VER) |
| #define LLVM_ATTRIBUTE_NOINLINE __declspec(noinline) |
| #else |
| #define LLVM_ATTRIBUTE_NOINLINE |
| #endif |
| |
| /// LLVM_ATTRIBUTE_ALWAYS_INLINE - On compilers where we have a directive to do |
| /// so, mark a method "always inline" because it is performance sensitive. GCC |
| /// 3.4 supported this but is buggy in various cases and produces unimplemented |
| /// errors, just use it in GCC 4.0 and later. |
| #if __has_attribute(always_inline) || LLVM_GNUC_PREREQ(4, 0, 0) |
| #define LLVM_ATTRIBUTE_ALWAYS_INLINE __attribute__((always_inline)) |
| #elif defined(_MSC_VER) |
| #define LLVM_ATTRIBUTE_ALWAYS_INLINE __forceinline |
| #else |
| #define LLVM_ATTRIBUTE_ALWAYS_INLINE |
| #endif |
| |
| #ifdef __GNUC__ |
| #define LLVM_ATTRIBUTE_NORETURN __attribute__((noreturn)) |
| #elif defined(_MSC_VER) |
| #define LLVM_ATTRIBUTE_NORETURN __declspec(noreturn) |
| #else |
| #define LLVM_ATTRIBUTE_NORETURN |
| #endif |
| |
| #if __has_attribute(returns_nonnull) || LLVM_GNUC_PREREQ(4, 9, 0) |
| #define LLVM_ATTRIBUTE_RETURNS_NONNULL __attribute__((returns_nonnull)) |
| #elif defined(_MSC_VER) |
| #define LLVM_ATTRIBUTE_RETURNS_NONNULL _Ret_notnull_ |
| #else |
| #define LLVM_ATTRIBUTE_RETURNS_NONNULL |
| #endif |
| |
| /// \macro LLVM_ATTRIBUTE_RETURNS_NOALIAS Used to mark a function as returning a |
| /// pointer that does not alias any other valid pointer. |
| #ifdef __GNUC__ |
| #define LLVM_ATTRIBUTE_RETURNS_NOALIAS __attribute__((__malloc__)) |
| #elif defined(_MSC_VER) |
| #define LLVM_ATTRIBUTE_RETURNS_NOALIAS __declspec(restrict) |
| #else |
| #define LLVM_ATTRIBUTE_RETURNS_NOALIAS |
| #endif |
| |
| /// LLVM_FALLTHROUGH - Mark fallthrough cases in switch statements. |
| #if __cplusplus > 201402L && __has_cpp_attribute(fallthrough) |
| #define LLVM_FALLTHROUGH [[fallthrough]] |
| #elif !__cplusplus |
| // Workaround for llvm.org/PR23435, since clang 3.6 and below emit a spurious |
| // error when __has_cpp_attribute is given a scoped attribute in C mode. |
| #define LLVM_FALLTHROUGH |
| #elif __has_cpp_attribute(clang::fallthrough) |
| #define LLVM_FALLTHROUGH [[clang::fallthrough]] |
| #else |
| #define LLVM_FALLTHROUGH |
| #endif |
| |
| /// LLVM_EXTENSION - Support compilers where we have a keyword to suppress |
| /// pedantic diagnostics. |
| #ifdef __GNUC__ |
| #define LLVM_EXTENSION __extension__ |
| #else |
| #define LLVM_EXTENSION |
| #endif |
| |
| // LLVM_ATTRIBUTE_DEPRECATED(decl, "message") |
| #if __has_feature(attribute_deprecated_with_message) |
| # define LLVM_ATTRIBUTE_DEPRECATED(decl, message) \ |
| decl __attribute__((deprecated(message))) |
| #elif defined(__GNUC__) |
| # define LLVM_ATTRIBUTE_DEPRECATED(decl, message) \ |
| decl __attribute__((deprecated)) |
| #elif defined(_MSC_VER) |
| # define LLVM_ATTRIBUTE_DEPRECATED(decl, message) \ |
| __declspec(deprecated(message)) decl |
| #else |
| # define LLVM_ATTRIBUTE_DEPRECATED(decl, message) \ |
| decl |
| #endif |
| |
| /// LLVM_BUILTIN_UNREACHABLE - On compilers which support it, expands |
| /// to an expression which states that it is undefined behavior for the |
| /// compiler to reach this point. Otherwise is not defined. |
| #if __has_builtin(__builtin_unreachable) || LLVM_GNUC_PREREQ(4, 5, 0) |
| # define LLVM_BUILTIN_UNREACHABLE __builtin_unreachable() |
| #elif defined(_MSC_VER) |
| # define LLVM_BUILTIN_UNREACHABLE __assume(false) |
| #endif |
| |
| /// LLVM_BUILTIN_TRAP - On compilers which support it, expands to an expression |
| /// which causes the program to exit abnormally. |
| #if __has_builtin(__builtin_trap) || LLVM_GNUC_PREREQ(4, 3, 0) |
| # define LLVM_BUILTIN_TRAP __builtin_trap() |
| #elif defined(_MSC_VER) |
| // The __debugbreak intrinsic is supported by MSVC, does not require forward |
| // declarations involving platform-specific typedefs (unlike RaiseException), |
| // results in a call to vectored exception handlers, and encodes to a short |
| // instruction that still causes the trapping behavior we want. |
| # define LLVM_BUILTIN_TRAP __debugbreak() |
| #else |
| # define LLVM_BUILTIN_TRAP *(volatile int*)0x11 = 0 |
| #endif |
| |
| /// LLVM_BUILTIN_DEBUGTRAP - On compilers which support it, expands to |
| /// an expression which causes the program to break while running |
| /// under a debugger. |
| #if __has_builtin(__builtin_debugtrap) |
| # define LLVM_BUILTIN_DEBUGTRAP __builtin_debugtrap() |
| #elif defined(_MSC_VER) |
| // The __debugbreak intrinsic is supported by MSVC and breaks while |
| // running under the debugger, and also supports invoking a debugger |
| // when the OS is configured appropriately. |
| # define LLVM_BUILTIN_DEBUGTRAP __debugbreak() |
| #else |
| // Just continue execution when built with compilers that have no |
| // support. This is a debugging aid and not intended to force the |
| // program to abort if encountered. |
| # define LLVM_BUILTIN_DEBUGTRAP |
| #endif |
| |
| /// \macro LLVM_ASSUME_ALIGNED |
| /// \brief Returns a pointer with an assumed alignment. |
| #if __has_builtin(__builtin_assume_aligned) || LLVM_GNUC_PREREQ(4, 7, 0) |
| # define LLVM_ASSUME_ALIGNED(p, a) __builtin_assume_aligned(p, a) |
| #elif defined(LLVM_BUILTIN_UNREACHABLE) |
| // As of today, clang does not support __builtin_assume_aligned. |
| # define LLVM_ASSUME_ALIGNED(p, a) \ |
| (((uintptr_t(p) % (a)) == 0) ? (p) : (LLVM_BUILTIN_UNREACHABLE, (p))) |
| #else |
| # define LLVM_ASSUME_ALIGNED(p, a) (p) |
| #endif |
| |
| /// \macro LLVM_ALIGNAS |
| /// \brief Used to specify a minimum alignment for a structure or variable. The |
| /// alignment must be a constant integer. Use LLVM_PTR_SIZE to compute |
| /// alignments in terms of the size of a pointer. |
| /// |
| /// Note that __declspec(align) has special quirks, it's not legal to pass a |
| /// structure with __declspec(align) as a formal parameter. |
| #ifdef _MSC_VER |
| # define LLVM_ALIGNAS(x) __declspec(align(x)) |
| #elif __GNUC__ && !__has_feature(cxx_alignas) && !LLVM_GNUC_PREREQ(4, 8, 0) |
| # define LLVM_ALIGNAS(x) __attribute__((aligned(x))) |
| #else |
| # define LLVM_ALIGNAS(x) alignas(x) |
| #endif |
| |
| /// \macro LLVM_PACKED |
| /// \brief Used to specify a packed structure. |
| /// LLVM_PACKED( |
| /// struct A { |
| /// int i; |
| /// int j; |
| /// int k; |
| /// long long l; |
| /// }); |
| /// |
| /// LLVM_PACKED_START |
| /// struct B { |
| /// int i; |
| /// int j; |
| /// int k; |
| /// long long l; |
| /// }; |
| /// LLVM_PACKED_END |
| #ifdef _MSC_VER |
| # define LLVM_PACKED(d) __pragma(pack(push, 1)) d __pragma(pack(pop)) |
| # define LLVM_PACKED_START __pragma(pack(push, 1)) |
| # define LLVM_PACKED_END __pragma(pack(pop)) |
| #else |
| # define LLVM_PACKED(d) d __attribute__((packed)) |
| # define LLVM_PACKED_START _Pragma("pack(push, 1)") |
| # define LLVM_PACKED_END _Pragma("pack(pop)") |
| #endif |
| |
| /// \macro LLVM_PTR_SIZE |
| /// \brief A constant integer equivalent to the value of sizeof(void*). |
| /// Generally used in combination with LLVM_ALIGNAS or when doing computation in |
| /// the preprocessor. |
| #ifdef __SIZEOF_POINTER__ |
| # define LLVM_PTR_SIZE __SIZEOF_POINTER__ |
| #elif defined(_WIN64) |
| # define LLVM_PTR_SIZE 8 |
| #elif defined(_WIN32) |
| # define LLVM_PTR_SIZE 4 |
| #elif defined(_MSC_VER) |
| # error "could not determine LLVM_PTR_SIZE as a constant int for MSVC" |
| #else |
| # define LLVM_PTR_SIZE sizeof(void *) |
| #endif |
| |
| /// \macro LLVM_FUNCTION_NAME |
| /// \brief Expands to __func__ on compilers which support it. Otherwise, |
| /// expands to a compiler-dependent replacement. |
| #if defined(_MSC_VER) |
| # define LLVM_FUNCTION_NAME __FUNCTION__ |
| #else |
| # define LLVM_FUNCTION_NAME __func__ |
| #endif |
| |
| /// \macro LLVM_MEMORY_SANITIZER_BUILD |
| /// \brief Whether LLVM itself is built with MemorySanitizer instrumentation. |
| #if __has_feature(memory_sanitizer) |
| # define LLVM_MEMORY_SANITIZER_BUILD 1 |
| # include <sanitizer/msan_interface.h> |
| #else |
| # define LLVM_MEMORY_SANITIZER_BUILD 0 |
| # define __msan_allocated_memory(p, size) |
| # define __msan_unpoison(p, size) |
| #endif |
| |
| /// \macro LLVM_ADDRESS_SANITIZER_BUILD |
| /// \brief Whether LLVM itself is built with AddressSanitizer instrumentation. |
| #if __has_feature(address_sanitizer) || defined(__SANITIZE_ADDRESS__) |
| # define LLVM_ADDRESS_SANITIZER_BUILD 1 |
| # include <sanitizer/asan_interface.h> |
| #else |
| # define LLVM_ADDRESS_SANITIZER_BUILD 0 |
| # define __asan_poison_memory_region(p, size) |
| # define __asan_unpoison_memory_region(p, size) |
| #endif |
| |
| /// \macro LLVM_THREAD_SANITIZER_BUILD |
| /// \brief Whether LLVM itself is built with ThreadSanitizer instrumentation. |
| #if __has_feature(thread_sanitizer) || defined(__SANITIZE_THREAD__) |
| # define LLVM_THREAD_SANITIZER_BUILD 1 |
| #else |
| # define LLVM_THREAD_SANITIZER_BUILD 0 |
| #endif |
| |
| #if LLVM_THREAD_SANITIZER_BUILD |
| // Thread Sanitizer is a tool that finds races in code. |
| // See http://code.google.com/p/data-race-test/wiki/DynamicAnnotations . |
| // tsan detects these exact functions by name. |
| #ifdef __cplusplus |
| extern "C" { |
| #endif |
| void AnnotateHappensAfter(const char *file, int line, const volatile void *cv); |
| void AnnotateHappensBefore(const char *file, int line, const volatile void *cv); |
| void AnnotateIgnoreWritesBegin(const char *file, int line); |
| void AnnotateIgnoreWritesEnd(const char *file, int line); |
| #ifdef __cplusplus |
| } |
| #endif |
| |
| // This marker is used to define a happens-before arc. The race detector will |
| // infer an arc from the begin to the end when they share the same pointer |
| // argument. |
| # define TsanHappensBefore(cv) AnnotateHappensBefore(__FILE__, __LINE__, cv) |
| |
| // This marker defines the destination of a happens-before arc. |
| # define TsanHappensAfter(cv) AnnotateHappensAfter(__FILE__, __LINE__, cv) |
| |
| // Ignore any races on writes between here and the next TsanIgnoreWritesEnd. |
| # define TsanIgnoreWritesBegin() AnnotateIgnoreWritesBegin(__FILE__, __LINE__) |
| |
| // Resume checking for racy writes. |
| # define TsanIgnoreWritesEnd() AnnotateIgnoreWritesEnd(__FILE__, __LINE__) |
| #else |
| # define TsanHappensBefore(cv) |
| # define TsanHappensAfter(cv) |
| # define TsanIgnoreWritesBegin() |
| # define TsanIgnoreWritesEnd() |
| #endif |
| |
| /// \macro LLVM_NO_SANITIZE |
| /// \brief Disable a particular sanitizer for a function. |
| #if __has_attribute(no_sanitize) |
| #define LLVM_NO_SANITIZE(KIND) __attribute__((no_sanitize(KIND))) |
| #else |
| #define LLVM_NO_SANITIZE(KIND) |
| #endif |
| |
| /// \brief Mark debug helper function definitions like dump() that should not be |
| /// stripped from debug builds. |
| // FIXME: Move this to a private config.h as it's not usable in public headers. |
| #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP) |
| #define LLVM_DUMP_METHOD LLVM_ATTRIBUTE_NOINLINE LLVM_ATTRIBUTE_USED |
| #else |
| #define LLVM_DUMP_METHOD LLVM_ATTRIBUTE_NOINLINE |
| #endif |
| |
| /// \macro LLVM_PRETTY_FUNCTION |
| /// \brief Gets a user-friendly looking function signature for the current scope |
| /// using the best available method on each platform. The exact format of the |
| /// resulting string is implementation specific and non-portable, so this should |
| /// only be used, for example, for logging or diagnostics. |
| #if defined(_MSC_VER) |
| #define LLVM_PRETTY_FUNCTION __FUNCSIG__ |
| #elif defined(__GNUC__) || defined(__clang__) |
| #define LLVM_PRETTY_FUNCTION __PRETTY_FUNCTION__ |
| #else |
| #define LLVM_PRETTY_FUNCTION __func__ |
| #endif |
| |
| /// \macro LLVM_THREAD_LOCAL |
| /// \brief A thread-local storage specifier which can be used with globals, |
| /// extern globals, and static globals. |
| /// |
| /// This is essentially an extremely restricted analog to C++11's thread_local |
| /// support, and uses that when available. However, it falls back on |
| /// platform-specific or vendor-provided extensions when necessary. These |
| /// extensions don't support many of the C++11 thread_local's features. You |
| /// should only use this for PODs that you can statically initialize to |
| /// some constant value. In almost all circumstances this is most appropriate |
| /// for use with a pointer, integer, or small aggregation of pointers and |
| /// integers. |
| #if LLVM_ENABLE_THREADS |
| #if __has_feature(cxx_thread_local) |
| #define LLVM_THREAD_LOCAL thread_local |
| #elif defined(_MSC_VER) |
| // MSVC supports this with a __declspec. |
| #define LLVM_THREAD_LOCAL __declspec(thread) |
| #else |
| // Clang, GCC, and other compatible compilers used __thread prior to C++11 and |
| // we only need the restricted functionality that provides. |
| #define LLVM_THREAD_LOCAL __thread |
| #endif |
| #else // !LLVM_ENABLE_THREADS |
| // If threading is disabled entirely, this compiles to nothing and you get |
| // a normal global variable. |
| #define LLVM_THREAD_LOCAL |
| #endif |
| |
| #endif |