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Diffstat (limited to 'third_party/llvm-project/include/llvm/Support/Casting.h')
| -rw-r--r-- | third_party/llvm-project/include/llvm/Support/Casting.h | 408 |
1 files changed, 408 insertions, 0 deletions
diff --git a/third_party/llvm-project/include/llvm/Support/Casting.h b/third_party/llvm-project/include/llvm/Support/Casting.h new file mode 100644 index 000000000..46bdedb04 --- /dev/null +++ b/third_party/llvm-project/include/llvm/Support/Casting.h @@ -0,0 +1,408 @@ +//===- llvm/Support/Casting.h - Allow flexible, checked, casts --*- C++ -*-===// +// +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. +// See https://llvm.org/LICENSE.txt for license information. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception +// +//===----------------------------------------------------------------------===// +// +// This file defines the isa<X>(), cast<X>(), dyn_cast<X>(), cast_or_null<X>(), +// and dyn_cast_or_null<X>() templates. +// +//===----------------------------------------------------------------------===// + +#ifndef LLVM_SUPPORT_CASTING_H +#define LLVM_SUPPORT_CASTING_H + +#include "llvm/Support/Compiler.h" +#include "llvm/Support/type_traits.h" +#include <cassert> +#include <memory> +#include <type_traits> + +namespace llvm { + +//===----------------------------------------------------------------------===// +// isa<x> Support Templates +//===----------------------------------------------------------------------===// + +// Define a template that can be specialized by smart pointers to reflect the +// fact that they are automatically dereferenced, and are not involved with the +// template selection process... the default implementation is a noop. +// +template<typename From> struct simplify_type { + using SimpleType = From; // The real type this represents... + + // An accessor to get the real value... + static SimpleType &getSimplifiedValue(From &Val) { return Val; } +}; + +template<typename From> struct simplify_type<const From> { + using NonConstSimpleType = typename simplify_type<From>::SimpleType; + using SimpleType = + typename add_const_past_pointer<NonConstSimpleType>::type; + using RetType = + typename add_lvalue_reference_if_not_pointer<SimpleType>::type; + + static RetType getSimplifiedValue(const From& Val) { + return simplify_type<From>::getSimplifiedValue(const_cast<From&>(Val)); + } +}; + +// The core of the implementation of isa<X> is here; To and From should be +// the names of classes. This template can be specialized to customize the +// implementation of isa<> without rewriting it from scratch. +template <typename To, typename From, typename Enabler = void> +struct isa_impl { + static inline bool doit(const From &Val) { + return To::classof(&Val); + } +}; + +/// Always allow upcasts, and perform no dynamic check for them. +template <typename To, typename From> +struct isa_impl< + To, From, typename std::enable_if<std::is_base_of<To, From>::value>::type> { + static inline bool doit(const From &) { return true; } +}; + +template <typename To, typename From> struct isa_impl_cl { + static inline bool doit(const From &Val) { + return isa_impl<To, From>::doit(Val); + } +}; + +template <typename To, typename From> struct isa_impl_cl<To, const From> { + static inline bool doit(const From &Val) { + return isa_impl<To, From>::doit(Val); + } +}; + +template <typename To, typename From> +struct isa_impl_cl<To, const std::unique_ptr<From>> { + static inline bool doit(const std::unique_ptr<From> &Val) { + assert(Val && "isa<> used on a null pointer"); + return isa_impl_cl<To, From>::doit(*Val); + } +}; + +template <typename To, typename From> struct isa_impl_cl<To, From*> { + static inline bool doit(const From *Val) { + assert(Val && "isa<> used on a null pointer"); + return isa_impl<To, From>::doit(*Val); + } +}; + +template <typename To, typename From> struct isa_impl_cl<To, From*const> { + static inline bool doit(const From *Val) { + assert(Val && "isa<> used on a null pointer"); + return isa_impl<To, From>::doit(*Val); + } +}; + +template <typename To, typename From> struct isa_impl_cl<To, const From*> { + static inline bool doit(const From *Val) { + assert(Val && "isa<> used on a null pointer"); + return isa_impl<To, From>::doit(*Val); + } +}; + +template <typename To, typename From> struct isa_impl_cl<To, const From*const> { + static inline bool doit(const From *Val) { + assert(Val && "isa<> used on a null pointer"); + return isa_impl<To, From>::doit(*Val); + } +}; + +template<typename To, typename From, typename SimpleFrom> +struct isa_impl_wrap { + // When From != SimplifiedType, we can simplify the type some more by using + // the simplify_type template. + static bool doit(const From &Val) { + return isa_impl_wrap<To, SimpleFrom, + typename simplify_type<SimpleFrom>::SimpleType>::doit( + simplify_type<const From>::getSimplifiedValue(Val)); + } +}; + +template<typename To, typename FromTy> +struct isa_impl_wrap<To, FromTy, FromTy> { + // When From == SimpleType, we are as simple as we are going to get. + static bool doit(const FromTy &Val) { + return isa_impl_cl<To,FromTy>::doit(Val); + } +}; + +// isa<X> - Return true if the parameter to the template is an instance of the +// template type argument. Used like this: +// +// if (isa<Type>(myVal)) { ... } +// +template <class X, class Y> LLVM_NODISCARD inline bool isa(const Y &Val) { + return isa_impl_wrap<X, const Y, + typename simplify_type<const Y>::SimpleType>::doit(Val); +} + +// isa_and_nonnull<X> - Functionally identical to isa, except that a null value +// is accepted. +// +template <class X, class Y> +LLVM_NODISCARD inline bool isa_and_nonnull(const Y &Val) { + if (!Val) + return false; + return isa<X>(Val); +} + +//===----------------------------------------------------------------------===// +// cast<x> Support Templates +//===----------------------------------------------------------------------===// + +template<class To, class From> struct cast_retty; + +// Calculate what type the 'cast' function should return, based on a requested +// type of To and a source type of From. +template<class To, class From> struct cast_retty_impl { + using ret_type = To &; // Normal case, return Ty& +}; +template<class To, class From> struct cast_retty_impl<To, const From> { + using ret_type = const To &; // Normal case, return Ty& +}; + +template<class To, class From> struct cast_retty_impl<To, From*> { + using ret_type = To *; // Pointer arg case, return Ty* +}; + +template<class To, class From> struct cast_retty_impl<To, const From*> { + using ret_type = const To *; // Constant pointer arg case, return const Ty* +}; + +template<class To, class From> struct cast_retty_impl<To, const From*const> { + using ret_type = const To *; // Constant pointer arg case, return const Ty* +}; + +template <class To, class From> +struct cast_retty_impl<To, std::unique_ptr<From>> { +private: + using PointerType = typename cast_retty_impl<To, From *>::ret_type; + using ResultType = typename std::remove_pointer<PointerType>::type; + +public: + using ret_type = std::unique_ptr<ResultType>; +}; + +template<class To, class From, class SimpleFrom> +struct cast_retty_wrap { + // When the simplified type and the from type are not the same, use the type + // simplifier to reduce the type, then reuse cast_retty_impl to get the + // resultant type. + using ret_type = typename cast_retty<To, SimpleFrom>::ret_type; +}; + +template<class To, class FromTy> +struct cast_retty_wrap<To, FromTy, FromTy> { + // When the simplified type is equal to the from type, use it directly. + using ret_type = typename cast_retty_impl<To,FromTy>::ret_type; +}; + +template<class To, class From> +struct cast_retty { + using ret_type = typename cast_retty_wrap< + To, From, typename simplify_type<From>::SimpleType>::ret_type; +}; + +// Ensure the non-simple values are converted using the simplify_type template +// that may be specialized by smart pointers... +// +template<class To, class From, class SimpleFrom> struct cast_convert_val { + // This is not a simple type, use the template to simplify it... + static typename cast_retty<To, From>::ret_type doit(From &Val) { + return cast_convert_val<To, SimpleFrom, + typename simplify_type<SimpleFrom>::SimpleType>::doit( + simplify_type<From>::getSimplifiedValue(Val)); + } +}; + +template<class To, class FromTy> struct cast_convert_val<To,FromTy,FromTy> { + // This _is_ a simple type, just cast it. + static typename cast_retty<To, FromTy>::ret_type doit(const FromTy &Val) { + typename cast_retty<To, FromTy>::ret_type Res2 + = (typename cast_retty<To, FromTy>::ret_type)const_cast<FromTy&>(Val); + return Res2; + } +}; + +template <class X> struct is_simple_type { + static const bool value = + std::is_same<X, typename simplify_type<X>::SimpleType>::value; +}; + +// cast<X> - Return the argument parameter cast to the specified type. This +// casting operator asserts that the type is correct, so it does not return null +// on failure. It does not allow a null argument (use cast_or_null for that). +// It is typically used like this: +// +// cast<Instruction>(myVal)->getParent() +// +template <class X, class Y> +inline typename std::enable_if<!is_simple_type<Y>::value, + typename cast_retty<X, const Y>::ret_type>::type +cast(const Y &Val) { + assert(isa<X>(Val) && "cast<Ty>() argument of incompatible type!"); + return cast_convert_val< + X, const Y, typename simplify_type<const Y>::SimpleType>::doit(Val); +} + +template <class X, class Y> +inline typename cast_retty<X, Y>::ret_type cast(Y &Val) { + assert(isa<X>(Val) && "cast<Ty>() argument of incompatible type!"); + return cast_convert_val<X, Y, + typename simplify_type<Y>::SimpleType>::doit(Val); +} + +template <class X, class Y> +inline typename cast_retty<X, Y *>::ret_type cast(Y *Val) { + assert(isa<X>(Val) && "cast<Ty>() argument of incompatible type!"); + return cast_convert_val<X, Y*, + typename simplify_type<Y*>::SimpleType>::doit(Val); +} + +template <class X, class Y> +inline typename cast_retty<X, std::unique_ptr<Y>>::ret_type +cast(std::unique_ptr<Y> &&Val) { + assert(isa<X>(Val.get()) && "cast<Ty>() argument of incompatible type!"); + using ret_type = typename cast_retty<X, std::unique_ptr<Y>>::ret_type; + return ret_type( + cast_convert_val<X, Y *, typename simplify_type<Y *>::SimpleType>::doit( + Val.release())); +} + +// cast_or_null<X> - Functionally identical to cast, except that a null value is +// accepted. +// +template <class X, class Y> +LLVM_NODISCARD inline + typename std::enable_if<!is_simple_type<Y>::value, + typename cast_retty<X, const Y>::ret_type>::type + cast_or_null(const Y &Val) { + if (!Val) + return nullptr; + assert(isa<X>(Val) && "cast_or_null<Ty>() argument of incompatible type!"); + return cast<X>(Val); +} + +template <class X, class Y> +LLVM_NODISCARD inline + typename std::enable_if<!is_simple_type<Y>::value, + typename cast_retty<X, Y>::ret_type>::type + cast_or_null(Y &Val) { + if (!Val) + return nullptr; + assert(isa<X>(Val) && "cast_or_null<Ty>() argument of incompatible type!"); + return cast<X>(Val); +} + +template <class X, class Y> +LLVM_NODISCARD inline typename cast_retty<X, Y *>::ret_type +cast_or_null(Y *Val) { + if (!Val) return nullptr; + assert(isa<X>(Val) && "cast_or_null<Ty>() argument of incompatible type!"); + return cast<X>(Val); +} + +template <class X, class Y> +inline typename cast_retty<X, std::unique_ptr<Y>>::ret_type +cast_or_null(std::unique_ptr<Y> &&Val) { + if (!Val) + return nullptr; + return cast<X>(std::move(Val)); +} + +// dyn_cast<X> - Return the argument parameter cast to the specified type. This +// casting operator returns null if the argument is of the wrong type, so it can +// be used to test for a type as well as cast if successful. This should be +// used in the context of an if statement like this: +// +// if (const Instruction *I = dyn_cast<Instruction>(myVal)) { ... } +// + +template <class X, class Y> +LLVM_NODISCARD inline + typename std::enable_if<!is_simple_type<Y>::value, + typename cast_retty<X, const Y>::ret_type>::type + dyn_cast(const Y &Val) { + return isa<X>(Val) ? cast<X>(Val) : nullptr; +} + +template <class X, class Y> +LLVM_NODISCARD inline typename cast_retty<X, Y>::ret_type dyn_cast(Y &Val) { + return isa<X>(Val) ? cast<X>(Val) : nullptr; +} + +template <class X, class Y> +LLVM_NODISCARD inline typename cast_retty<X, Y *>::ret_type dyn_cast(Y *Val) { + return isa<X>(Val) ? cast<X>(Val) : nullptr; +} + +// dyn_cast_or_null<X> - Functionally identical to dyn_cast, except that a null +// value is accepted. +// +template <class X, class Y> +LLVM_NODISCARD inline + typename std::enable_if<!is_simple_type<Y>::value, + typename cast_retty<X, const Y>::ret_type>::type + dyn_cast_or_null(const Y &Val) { + return (Val && isa<X>(Val)) ? cast<X>(Val) : nullptr; +} + +template <class X, class Y> +LLVM_NODISCARD inline + typename std::enable_if<!is_simple_type<Y>::value, + typename cast_retty<X, Y>::ret_type>::type + dyn_cast_or_null(Y &Val) { + return (Val && isa<X>(Val)) ? cast<X>(Val) : nullptr; +} + +template <class X, class Y> +LLVM_NODISCARD inline typename cast_retty<X, Y *>::ret_type +dyn_cast_or_null(Y *Val) { + return (Val && isa<X>(Val)) ? cast<X>(Val) : nullptr; +} + +// unique_dyn_cast<X> - Given a unique_ptr<Y>, try to return a unique_ptr<X>, +// taking ownership of the input pointer iff isa<X>(Val) is true. If the +// cast is successful, From refers to nullptr on exit and the casted value +// is returned. If the cast is unsuccessful, the function returns nullptr +// and From is unchanged. +template <class X, class Y> +LLVM_NODISCARD inline auto unique_dyn_cast(std::unique_ptr<Y> &Val) + -> decltype(cast<X>(Val)) { + if (!isa<X>(Val)) + return nullptr; + return cast<X>(std::move(Val)); +} + +template <class X, class Y> +LLVM_NODISCARD inline auto unique_dyn_cast(std::unique_ptr<Y> &&Val) + -> decltype(cast<X>(Val)) { + return unique_dyn_cast<X, Y>(Val); +} + +// dyn_cast_or_null<X> - Functionally identical to unique_dyn_cast, except that +// a null value is accepted. +template <class X, class Y> +LLVM_NODISCARD inline auto unique_dyn_cast_or_null(std::unique_ptr<Y> &Val) + -> decltype(cast<X>(Val)) { + if (!Val) + return nullptr; + return unique_dyn_cast<X, Y>(Val); +} + +template <class X, class Y> +LLVM_NODISCARD inline auto unique_dyn_cast_or_null(std::unique_ptr<Y> &&Val) + -> decltype(cast<X>(Val)) { + return unique_dyn_cast_or_null<X, Y>(Val); +} + +} // end namespace llvm + +#endif // LLVM_SUPPORT_CASTING_H |