#ifndef LLVM_SUPPORT_CASTING_H
#define LLVM_SUPPORT_CASTING_H
+#include "llvm/Support/Compiler.h"
+#include "llvm/Support/type_traits.h"
#include <cassert>
namespace llvm {
// isa<x> Support Templates
//===----------------------------------------------------------------------===//
-template<typename FromCl> struct isa_impl_cl;
-
// 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<const From> {
- typedef const From SimpleType;
- static SimpleType &getSimplifiedValue(const From &Val) {
- return simplify_type<From>::getSimplifiedValue(static_cast<From&>(Val));
+ typedef typename simplify_type<From>::SimpleType NonConstSimpleType;
+ typedef typename add_const_past_pointer<NonConstSimpleType>::type
+ SimpleType;
+ typedef typename add_lvalue_reference_if_not_pointer<SimpleType>::type
+ RetType;
+ static RetType getSimplifiedValue(const From& Val) {
+ return simplify_type<From>::getSimplifiedValue(const_cast<From&>(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 <typename To, typename From>
+// 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);
}
};
-template<typename To, typename From, typename SimpleType>
-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_cl<const SimpleType>::template
- isa<To>(simplify_type<const From>::getSimplifiedValue(Val));
+/// \brief 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 FromTy>
-struct isa_impl_wrap<To, const FromTy, const FromTy> {
- // When From == SimpleType, we are as simple as we are going to get.
- static bool doit(const FromTy &Val) {
- return isa_impl<To,FromTy>::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);
}
};
-// isa_impl_cl - Use class partial specialization to transform types to a single
-// canonical form for isa_impl.
-//
-template<typename FromCl>
-struct isa_impl_cl {
- template<class ToCl>
- static bool isa(const FromCl &Val) {
- return isa_impl_wrap<ToCl,const FromCl,
- typename simplify_type<const FromCl>::SimpleType>::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);
}
};
-// Specialization used to strip const qualifiers off of the FromCl type...
-template<typename FromCl>
-struct isa_impl_cl<const FromCl> {
- template<class ToCl>
- static bool isa(const FromCl &Val) {
- return isa_impl_cl<FromCl>::template isa<ToCl>(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);
}
};
-// Define pointer traits in terms of base traits...
-template<class FromCl>
-struct isa_impl_cl<FromCl*> {
- template<class ToCl>
- static bool isa(FromCl *Val) {
- return isa_impl_cl<FromCl>::template isa<ToCl>(*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));
}
};
-// Define reference traits in terms of base traits...
-template<class FromCl>
-struct isa_impl_cl<FromCl&> {
- template<class ToCl>
- static bool isa(FromCl &Val) {
- return isa_impl_cl<FromCl>::template isa<ToCl>(&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>
-inline bool isa(const Y &Val) {
- return isa_impl_cl<Y>::template isa<X>(Val);
+LLVM_ATTRIBUTE_UNUSED_RESULT inline bool isa(const Y &Val) {
+ return isa_impl_wrap<X, const Y,
+ typename simplify_type<const Y>::SimpleType>::doit(Val);
}
//===----------------------------------------------------------------------===//
//
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(const From &Val) {
+ 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 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. But it will correctly return NULL when the input is NULL.
-// Used Like this:
+// 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 cast_retty<X, Y>::ret_type cast(const Y &Val) {
+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);
+}
+
// cast_or_null<X> - Functionally identical to cast, except that a null value is
// accepted.
//
template <class X, class Y>
-inline typename cast_retty<X, Y*>::ret_type cast_or_null(Y *Val) {
- if (Val == 0) return 0;
+LLVM_ATTRIBUTE_UNUSED_RESULT 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, Y>::ret_type dyn_cast(const Y &Val) {
- return isa<X>(Val) ? cast<X, Y>(Val) : 0;
+LLVM_ATTRIBUTE_UNUSED_RESULT 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_ATTRIBUTE_UNUSED_RESULT 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_ATTRIBUTE_UNUSED_RESULT 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>
-inline typename cast_retty<X, Y*>::ret_type dyn_cast_or_null(Y *Val) {
- return (Val && isa<X>(Val)) ? cast<X>(Val) : 0;
+LLVM_ATTRIBUTE_UNUSED_RESULT inline typename cast_retty<X, Y *>::ret_type
+dyn_cast_or_null(Y *Val) {
+ return (Val && isa<X>(Val)) ? cast<X>(Val) : nullptr;
}
} // End llvm namespace
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