forked from OSchip/llvm-project
146 lines
4.3 KiB
C++
146 lines
4.3 KiB
C++
//===------ extensible_rtti.h - Extensible RTTI for ORC RT ------*- 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
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// \file
|
|
//
|
|
// Provides an extensible RTTI mechanism, that can be used regardless of whether
|
|
// the runtime is built with -frtti or not. This is predominantly used to
|
|
// support error handling.
|
|
//
|
|
// The RTTIRoot class defines methods for comparing type ids. Implementations
|
|
// of these methods can be injected into new classes using the RTTIExtends
|
|
// class template.
|
|
//
|
|
// E.g.
|
|
//
|
|
// @code{.cpp}
|
|
// class MyBaseClass : public RTTIExtends<MyBaseClass, RTTIRoot> {
|
|
// public:
|
|
// static char ID;
|
|
// virtual void foo() = 0;
|
|
// };
|
|
//
|
|
// class MyDerivedClass1 : public RTTIExtends<MyDerivedClass1, MyBaseClass> {
|
|
// public:
|
|
// static char ID;
|
|
// void foo() override {}
|
|
// };
|
|
//
|
|
// class MyDerivedClass2 : public RTTIExtends<MyDerivedClass2, MyBaseClass> {
|
|
// public:
|
|
// static char ID;
|
|
// void foo() override {}
|
|
// };
|
|
//
|
|
// char MyBaseClass::ID = 0;
|
|
// char MyDerivedClass1::ID = 0;
|
|
// char MyDerivedClass2:: ID = 0;
|
|
//
|
|
// void fn() {
|
|
// std::unique_ptr<MyBaseClass> B = std::make_unique<MyDerivedClass1>();
|
|
// outs() << isa<MyBaseClass>(B) << "\n"; // Outputs "1".
|
|
// outs() << isa<MyDerivedClass1>(B) << "\n"; // Outputs "1".
|
|
// outs() << isa<MyDerivedClass2>(B) << "\n"; // Outputs "0'.
|
|
// }
|
|
//
|
|
// @endcode
|
|
//
|
|
// Note:
|
|
// This header was adapted from llvm/Support/ExtensibleRTTI.h, however the
|
|
// data structures are not shared and the code need not be kept in sync.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#ifndef ORC_RT_EXTENSIBLE_RTTI_H
|
|
#define ORC_RT_EXTENSIBLE_RTTI_H
|
|
|
|
namespace __orc_rt {
|
|
|
|
template <typename ThisT, typename ParentT> class RTTIExtends;
|
|
|
|
/// Base class for the extensible RTTI hierarchy.
|
|
///
|
|
/// This class defines virtual methods, dynamicClassID and isA, that enable
|
|
/// type comparisons.
|
|
class RTTIRoot {
|
|
public:
|
|
virtual ~RTTIRoot() = default;
|
|
|
|
/// Returns the class ID for this type.
|
|
static const void *classID() { return &ID; }
|
|
|
|
/// Returns the class ID for the dynamic type of this RTTIRoot instance.
|
|
virtual const void *dynamicClassID() const = 0;
|
|
|
|
/// Returns true if this class's ID matches the given class ID.
|
|
virtual bool isA(const void *const ClassID) const {
|
|
return ClassID == classID();
|
|
}
|
|
|
|
/// Check whether this instance is a subclass of QueryT.
|
|
template <typename QueryT> bool isA() const { return isA(QueryT::classID()); }
|
|
|
|
static bool classof(const RTTIRoot *R) { return R->isA<RTTIRoot>(); }
|
|
|
|
private:
|
|
virtual void anchor();
|
|
|
|
static char ID;
|
|
};
|
|
|
|
/// Inheritance utility for extensible RTTI.
|
|
///
|
|
/// Supports single inheritance only: A class can only have one
|
|
/// ExtensibleRTTI-parent (i.e. a parent for which the isa<> test will work),
|
|
/// though it can have many non-ExtensibleRTTI parents.
|
|
///
|
|
/// RTTIExtents uses CRTP so the first template argument to RTTIExtends is the
|
|
/// newly introduced type, and the *second* argument is the parent class.
|
|
///
|
|
/// class MyType : public RTTIExtends<MyType, RTTIRoot> {
|
|
/// public:
|
|
/// static char ID;
|
|
/// };
|
|
///
|
|
/// class MyDerivedType : public RTTIExtends<MyDerivedType, MyType> {
|
|
/// public:
|
|
/// static char ID;
|
|
/// };
|
|
///
|
|
template <typename ThisT, typename ParentT> class RTTIExtends : public ParentT {
|
|
public:
|
|
// Inherit constructors and isA methods from ParentT.
|
|
using ParentT::isA;
|
|
using ParentT::ParentT;
|
|
|
|
static char ID;
|
|
|
|
static const void *classID() { return &ThisT::ID; }
|
|
|
|
const void *dynamicClassID() const override { return &ThisT::ID; }
|
|
|
|
bool isA(const void *const ClassID) const override {
|
|
return ClassID == classID() || ParentT::isA(ClassID);
|
|
}
|
|
|
|
static bool classof(const RTTIRoot *R) { return R->isA<ThisT>(); }
|
|
};
|
|
|
|
template <typename ThisT, typename ParentT>
|
|
char RTTIExtends<ThisT, ParentT>::ID = 0;
|
|
|
|
/// Returns true if the given value is an instance of the template type
|
|
/// parameter.
|
|
template <typename To, typename From> bool isa(const From &Value) {
|
|
return To::classof(&Value);
|
|
}
|
|
|
|
} // end namespace __orc_rt
|
|
|
|
#endif // ORC_RT_EXTENSIBLE_RTTI_H
|