[support] Add a macro wrapper for alignas and simplify some code.

[oota-llvm.git] / include / llvm / Support / Compiler.h

diff --git a/include/llvm/Support/Compiler.h b/include/llvm/Support/Compiler.h
index e0a4e1fc18ead092aec12d747c49180a30fe7cb2..1a49956e22526bbd57fa2cadb3c4bf58da0d1a81 100644 (file)
--- a/include/llvm/Support/Compiler.h
+++ b/include/llvm/Support/Compiler.h
@@ -52,14 +52,14 @@
 /// \macro LLVM_MSC_PREREQ
 /// \brief Is the compiler MSVC of at least the specified version?
 /// The common \param version values to check for are:
-///  * 1700: Microsoft Visual Studio 2012 / 11.0
 ///  * 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 2012.
-#if !LLVM_MSC_PREREQ(1700)
-#error LLVM requires at least MSVC 2012.
+// We require at least MSVC 2013.
+#if !LLVM_MSC_PREREQ(1800)
+#error LLVM requires at least MSVC 2013.
 #endif
 
 #else
@@ -82,16 +82,6 @@
 #define LLVM_HAS_RVALUE_REFERENCE_THIS 0
 #endif
 
-/// \macro LLVM_HAS_VARIADIC_TEMPLATES
-/// \brief Does this compiler support variadic templates.
-///
-/// Implies LLVM_HAS_RVALUE_REFERENCES and the existence of std::forward.
-#if __has_feature(cxx_variadic_templates) || LLVM_MSC_PREREQ(1800)
-# define LLVM_HAS_VARIADIC_TEMPLATES 1
-#else
-# define LLVM_HAS_VARIADIC_TEMPLATES 0
-#endif
-
 /// Expands to '&' if r-value references are supported.
 ///
 /// This can be used to provide l-value/r-value overrides of member functions.
@@ -102,24 +92,6 @@
 #define LLVM_LVALUE_FUNCTION
 #endif
 
-/// LLVM_DELETED_FUNCTION - Expands to = delete if the compiler supports it.
-/// Use to mark functions as uncallable. Member functions with this should
-/// be declared private so that some behavior is kept in C++03 mode.
-///
-/// class DontCopy {
-/// private:
-///   DontCopy(const DontCopy&) LLVM_DELETED_FUNCTION;
-///   DontCopy &operator =(const DontCopy&) LLVM_DELETED_FUNCTION;
-/// public:
-///   ...
-/// };
-#if __has_feature(cxx_deleted_functions) || \
-    defined(__GXX_EXPERIMENTAL_CXX0X__) || LLVM_MSC_PREREQ(1800)
-#define LLVM_DELETED_FUNCTION = delete
-#else
-#define LLVM_DELETED_FUNCTION
-#endif
-
 #if __has_feature(cxx_constexpr) || defined(__GXX_EXPERIMENTAL_CXX0X__)
 # define LLVM_CONSTEXPR constexpr
 #else
@@ -287,19 +259,12 @@
 /// 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(LLVM_ON_WIN32)
-#if defined(_WIN64)
-extern "C" __declspec(dllimport) void __stdcall RaiseException(
-    unsigned long, unsigned long, unsigned long, const unsigned long long *);
-#else
-extern "C" __declspec(dllimport) void __stdcall RaiseException(
-    unsigned long, unsigned long, unsigned long, const unsigned long *);
-#endif
-# define LLVM_BUILTIN_TRAP                                                     \
-  do {                                                                         \
-    ::RaiseException(0x8000DEAD, 0x1 /*EXCEPTION_NONCONTINUABLE*/, 0, nullptr);\
-    __assume(false);                                                           \
-  } while (0)
+#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
@@ -316,6 +281,20 @@ extern "C" __declspec(dllimport) void __stdcall RaiseException(
 # 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.
+///
+/// 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_FUNCTION_NAME
 /// \brief Expands to __func__ on compilers which support it.  Otherwise,
 /// expands to a compiler-dependent replacement.
@@ -357,26 +336,6 @@ extern "C" __declspec(dllimport) void __stdcall RaiseException(
 # define LLVM_IS_UNALIGNED_ACCESS_FAST 0
 #endif
 
-/// \macro LLVM_EXPLICIT
-/// \brief Expands to explicit on compilers which support explicit conversion
-/// operators. Otherwise expands to nothing.
-#if __has_feature(cxx_explicit_conversions) || \
-    defined(__GXX_EXPERIMENTAL_CXX0X__) || LLVM_MSC_PREREQ(1800)
-#define LLVM_EXPLICIT explicit
-#else
-#define LLVM_EXPLICIT
-#endif
-
-/// \brief Does the compiler support generalized initializers (using braced
-/// lists and std::initializer_list).  While clang may claim it supports general
-/// initializers, if we're using MSVC's headers, we might not have a usable
-/// std::initializer list type from the STL.  Disable this for now.
-#if __has_feature(cxx_generalized_initializers) && !defined(_MSC_VER)
-#define LLVM_HAS_INITIALIZER_LISTS 1
-#else
-#define LLVM_HAS_INITIALIZER_LISTS 0
-#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.