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Diffstat (limited to 'src/3rdparty/llvm/include/llvm/Support/PointerLikeTypeTraits.h')
-rw-r--r-- | src/3rdparty/llvm/include/llvm/Support/PointerLikeTypeTraits.h | 116 |
1 files changed, 116 insertions, 0 deletions
diff --git a/src/3rdparty/llvm/include/llvm/Support/PointerLikeTypeTraits.h b/src/3rdparty/llvm/include/llvm/Support/PointerLikeTypeTraits.h new file mode 100644 index 0000000000..794230d606 --- /dev/null +++ b/src/3rdparty/llvm/include/llvm/Support/PointerLikeTypeTraits.h @@ -0,0 +1,116 @@ +//===- llvm/Support/PointerLikeTypeTraits.h - Pointer Traits ----*- 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 the PointerLikeTypeTraits class. This allows data +// structures to reason about pointers and other things that are pointer sized. +// +//===----------------------------------------------------------------------===// + +#ifndef LLVM_SUPPORT_POINTERLIKETYPETRAITS_H +#define LLVM_SUPPORT_POINTERLIKETYPETRAITS_H + +#include "llvm/Support/DataTypes.h" +#include <type_traits> + +namespace llvm { + +/// A traits type that is used to handle pointer types and things that are just +/// wrappers for pointers as a uniform entity. +template <typename T> struct PointerLikeTypeTraits; + +namespace detail { +/// A tiny meta function to compute the log2 of a compile time constant. +template <size_t N> +struct ConstantLog2 + : std::integral_constant<size_t, ConstantLog2<N / 2>::value + 1> {}; +template <> struct ConstantLog2<1> : std::integral_constant<size_t, 0> {}; + +// Provide a trait to check if T is pointer-like. +template <typename T, typename U = void> struct HasPointerLikeTypeTraits { + static const bool value = false; +}; + +// sizeof(T) is valid only for a complete T. +template <typename T> struct HasPointerLikeTypeTraits< + T, decltype((sizeof(PointerLikeTypeTraits<T>) + sizeof(T)), void())> { + static const bool value = true; +}; + +template <typename T> struct IsPointerLike { + static const bool value = HasPointerLikeTypeTraits<T>::value; +}; + +template <typename T> struct IsPointerLike<T *> { + static const bool value = true; +}; +} // namespace detail + +// Provide PointerLikeTypeTraits for non-cvr pointers. +template <typename T> struct PointerLikeTypeTraits<T *> { + static inline void *getAsVoidPointer(T *P) { return P; } + static inline T *getFromVoidPointer(void *P) { return static_cast<T *>(P); } + + enum { NumLowBitsAvailable = detail::ConstantLog2<alignof(T)>::value }; +}; + +template <> struct PointerLikeTypeTraits<void *> { + static inline void *getAsVoidPointer(void *P) { return P; } + static inline void *getFromVoidPointer(void *P) { return P; } + + /// Note, we assume here that void* is related to raw malloc'ed memory and + /// that malloc returns objects at least 4-byte aligned. However, this may be + /// wrong, or pointers may be from something other than malloc. In this case, + /// you should specify a real typed pointer or avoid this template. + /// + /// All clients should use assertions to do a run-time check to ensure that + /// this is actually true. + enum { NumLowBitsAvailable = 2 }; +}; + +// Provide PointerLikeTypeTraits for const things. +template <typename T> struct PointerLikeTypeTraits<const T> { + typedef PointerLikeTypeTraits<T> NonConst; + + static inline const void *getAsVoidPointer(const T P) { + return NonConst::getAsVoidPointer(P); + } + static inline const T getFromVoidPointer(const void *P) { + return NonConst::getFromVoidPointer(const_cast<void *>(P)); + } + enum { NumLowBitsAvailable = NonConst::NumLowBitsAvailable }; +}; + +// Provide PointerLikeTypeTraits for const pointers. +template <typename T> struct PointerLikeTypeTraits<const T *> { + typedef PointerLikeTypeTraits<T *> NonConst; + + static inline const void *getAsVoidPointer(const T *P) { + return NonConst::getAsVoidPointer(const_cast<T *>(P)); + } + static inline const T *getFromVoidPointer(const void *P) { + return NonConst::getFromVoidPointer(const_cast<void *>(P)); + } + enum { NumLowBitsAvailable = NonConst::NumLowBitsAvailable }; +}; + +// Provide PointerLikeTypeTraits for uintptr_t. +template <> struct PointerLikeTypeTraits<uintptr_t> { + static inline void *getAsVoidPointer(uintptr_t P) { + return reinterpret_cast<void *>(P); + } + static inline uintptr_t getFromVoidPointer(void *P) { + return reinterpret_cast<uintptr_t>(P); + } + // No bits are available! + enum { NumLowBitsAvailable = 0 }; +}; + +} // end namespace llvm + +#endif |