forked from OSchip/llvm-project
1019 lines
35 KiB
C++
1019 lines
35 KiB
C++
//===--- CGCXXRTTI.cpp - Emit LLVM Code for C++ RTTI descriptors ----------===//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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//
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// This contains code dealing with C++ code generation of RTTI descriptors.
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//
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//===----------------------------------------------------------------------===//
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#include "CodeGenModule.h"
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#include "CGCXXABI.h"
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#include "CGObjCRuntime.h"
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#include "clang/AST/RecordLayout.h"
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#include "clang/AST/Type.h"
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#include "clang/Frontend/CodeGenOptions.h"
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using namespace clang;
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using namespace CodeGen;
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namespace {
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class RTTIBuilder {
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CodeGenModule &CGM; // Per-module state.
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llvm::LLVMContext &VMContext;
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/// Fields - The fields of the RTTI descriptor currently being built.
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SmallVector<llvm::Constant *, 16> Fields;
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/// GetAddrOfTypeName - Returns the mangled type name of the given type.
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llvm::GlobalVariable *
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GetAddrOfTypeName(QualType Ty, llvm::GlobalVariable::LinkageTypes Linkage);
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/// GetAddrOfExternalRTTIDescriptor - Returns the constant for the RTTI
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/// descriptor of the given type.
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llvm::Constant *GetAddrOfExternalRTTIDescriptor(QualType Ty);
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/// BuildVTablePointer - Build the vtable pointer for the given type.
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void BuildVTablePointer(const Type *Ty);
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/// BuildSIClassTypeInfo - Build an abi::__si_class_type_info, used for single
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/// inheritance, according to the Itanium C++ ABI, 2.9.5p6b.
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void BuildSIClassTypeInfo(const CXXRecordDecl *RD);
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/// BuildVMIClassTypeInfo - Build an abi::__vmi_class_type_info, used for
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/// classes with bases that do not satisfy the abi::__si_class_type_info
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/// constraints, according ti the Itanium C++ ABI, 2.9.5p5c.
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void BuildVMIClassTypeInfo(const CXXRecordDecl *RD);
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/// BuildPointerTypeInfo - Build an abi::__pointer_type_info struct, used
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/// for pointer types.
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void BuildPointerTypeInfo(QualType PointeeTy);
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/// BuildObjCObjectTypeInfo - Build the appropriate kind of
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/// type_info for an object type.
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void BuildObjCObjectTypeInfo(const ObjCObjectType *Ty);
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/// BuildPointerToMemberTypeInfo - Build an abi::__pointer_to_member_type_info
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/// struct, used for member pointer types.
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void BuildPointerToMemberTypeInfo(const MemberPointerType *Ty);
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public:
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RTTIBuilder(CodeGenModule &CGM) : CGM(CGM),
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VMContext(CGM.getModule().getContext()) { }
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// Pointer type info flags.
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enum {
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/// PTI_Const - Type has const qualifier.
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PTI_Const = 0x1,
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/// PTI_Volatile - Type has volatile qualifier.
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PTI_Volatile = 0x2,
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/// PTI_Restrict - Type has restrict qualifier.
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PTI_Restrict = 0x4,
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/// PTI_Incomplete - Type is incomplete.
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PTI_Incomplete = 0x8,
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/// PTI_ContainingClassIncomplete - Containing class is incomplete.
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/// (in pointer to member).
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PTI_ContainingClassIncomplete = 0x10
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};
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// VMI type info flags.
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enum {
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/// VMI_NonDiamondRepeat - Class has non-diamond repeated inheritance.
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VMI_NonDiamondRepeat = 0x1,
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/// VMI_DiamondShaped - Class is diamond shaped.
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VMI_DiamondShaped = 0x2
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};
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// Base class type info flags.
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enum {
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/// BCTI_Virtual - Base class is virtual.
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BCTI_Virtual = 0x1,
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/// BCTI_Public - Base class is public.
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BCTI_Public = 0x2
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};
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/// BuildTypeInfo - Build the RTTI type info struct for the given type.
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///
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/// \param Force - true to force the creation of this RTTI value
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llvm::Constant *BuildTypeInfo(QualType Ty, bool Force = false);
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};
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}
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llvm::GlobalVariable *
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RTTIBuilder::GetAddrOfTypeName(QualType Ty,
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llvm::GlobalVariable::LinkageTypes Linkage) {
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SmallString<256> OutName;
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llvm::raw_svector_ostream Out(OutName);
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CGM.getCXXABI().getMangleContext().mangleCXXRTTIName(Ty, Out);
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Out.flush();
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StringRef Name = OutName.str();
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// We know that the mangled name of the type starts at index 4 of the
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// mangled name of the typename, so we can just index into it in order to
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// get the mangled name of the type.
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llvm::Constant *Init = llvm::ConstantDataArray::getString(VMContext,
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Name.substr(4));
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llvm::GlobalVariable *GV =
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CGM.CreateOrReplaceCXXRuntimeVariable(Name, Init->getType(), Linkage);
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GV->setInitializer(Init);
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return GV;
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}
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llvm::Constant *RTTIBuilder::GetAddrOfExternalRTTIDescriptor(QualType Ty) {
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// Mangle the RTTI name.
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SmallString<256> OutName;
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llvm::raw_svector_ostream Out(OutName);
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CGM.getCXXABI().getMangleContext().mangleCXXRTTI(Ty, Out);
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Out.flush();
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StringRef Name = OutName.str();
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// Look for an existing global.
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llvm::GlobalVariable *GV = CGM.getModule().getNamedGlobal(Name);
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if (!GV) {
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// Create a new global variable.
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GV = new llvm::GlobalVariable(CGM.getModule(), CGM.Int8PtrTy,
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/*Constant=*/true,
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llvm::GlobalValue::ExternalLinkage, 0, Name);
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}
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return llvm::ConstantExpr::getBitCast(GV, CGM.Int8PtrTy);
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}
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/// TypeInfoIsInStandardLibrary - Given a builtin type, returns whether the type
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/// info for that type is defined in the standard library.
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static bool TypeInfoIsInStandardLibrary(const BuiltinType *Ty) {
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// Itanium C++ ABI 2.9.2:
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// Basic type information (e.g. for "int", "bool", etc.) will be kept in
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// the run-time support library. Specifically, the run-time support
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// library should contain type_info objects for the types X, X* and
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// X const*, for every X in: void, std::nullptr_t, bool, wchar_t, char,
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// unsigned char, signed char, short, unsigned short, int, unsigned int,
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// long, unsigned long, long long, unsigned long long, float, double,
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// long double, char16_t, char32_t, and the IEEE 754r decimal and
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// half-precision floating point types.
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switch (Ty->getKind()) {
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case BuiltinType::Void:
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case BuiltinType::NullPtr:
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case BuiltinType::Bool:
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case BuiltinType::WChar_S:
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case BuiltinType::WChar_U:
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case BuiltinType::Char_U:
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case BuiltinType::Char_S:
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case BuiltinType::UChar:
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case BuiltinType::SChar:
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case BuiltinType::Short:
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case BuiltinType::UShort:
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case BuiltinType::Int:
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case BuiltinType::UInt:
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case BuiltinType::Long:
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case BuiltinType::ULong:
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case BuiltinType::LongLong:
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case BuiltinType::ULongLong:
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case BuiltinType::Half:
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case BuiltinType::Float:
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case BuiltinType::Double:
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case BuiltinType::LongDouble:
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case BuiltinType::Char16:
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case BuiltinType::Char32:
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case BuiltinType::Int128:
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case BuiltinType::UInt128:
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case BuiltinType::OCLImage1d:
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case BuiltinType::OCLImage1dArray:
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case BuiltinType::OCLImage1dBuffer:
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case BuiltinType::OCLImage2d:
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case BuiltinType::OCLImage2dArray:
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case BuiltinType::OCLImage3d:
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case BuiltinType::OCLEvent:
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return true;
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case BuiltinType::Dependent:
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#define BUILTIN_TYPE(Id, SingletonId)
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#define PLACEHOLDER_TYPE(Id, SingletonId) \
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case BuiltinType::Id:
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#include "clang/AST/BuiltinTypes.def"
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llvm_unreachable("asking for RRTI for a placeholder type!");
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case BuiltinType::ObjCId:
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case BuiltinType::ObjCClass:
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case BuiltinType::ObjCSel:
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llvm_unreachable("FIXME: Objective-C types are unsupported!");
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}
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llvm_unreachable("Invalid BuiltinType Kind!");
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}
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static bool TypeInfoIsInStandardLibrary(const PointerType *PointerTy) {
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QualType PointeeTy = PointerTy->getPointeeType();
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const BuiltinType *BuiltinTy = dyn_cast<BuiltinType>(PointeeTy);
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if (!BuiltinTy)
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return false;
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// Check the qualifiers.
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Qualifiers Quals = PointeeTy.getQualifiers();
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Quals.removeConst();
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if (!Quals.empty())
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return false;
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return TypeInfoIsInStandardLibrary(BuiltinTy);
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}
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/// IsStandardLibraryRTTIDescriptor - Returns whether the type
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/// information for the given type exists in the standard library.
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static bool IsStandardLibraryRTTIDescriptor(QualType Ty) {
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// Type info for builtin types is defined in the standard library.
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if (const BuiltinType *BuiltinTy = dyn_cast<BuiltinType>(Ty))
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return TypeInfoIsInStandardLibrary(BuiltinTy);
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// Type info for some pointer types to builtin types is defined in the
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// standard library.
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if (const PointerType *PointerTy = dyn_cast<PointerType>(Ty))
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return TypeInfoIsInStandardLibrary(PointerTy);
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return false;
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}
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/// ShouldUseExternalRTTIDescriptor - Returns whether the type information for
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/// the given type exists somewhere else, and that we should not emit the type
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/// information in this translation unit. Assumes that it is not a
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/// standard-library type.
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static bool ShouldUseExternalRTTIDescriptor(CodeGenModule &CGM, QualType Ty) {
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ASTContext &Context = CGM.getContext();
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// If RTTI is disabled, don't consider key functions.
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if (!Context.getLangOpts().RTTI) return false;
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if (const RecordType *RecordTy = dyn_cast<RecordType>(Ty)) {
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const CXXRecordDecl *RD = cast<CXXRecordDecl>(RecordTy->getDecl());
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if (!RD->hasDefinition())
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return false;
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if (!RD->isDynamicClass())
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return false;
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return !CGM.getVTables().ShouldEmitVTableInThisTU(RD);
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}
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return false;
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}
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/// IsIncompleteClassType - Returns whether the given record type is incomplete.
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static bool IsIncompleteClassType(const RecordType *RecordTy) {
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return !RecordTy->getDecl()->isCompleteDefinition();
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}
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/// ContainsIncompleteClassType - Returns whether the given type contains an
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/// incomplete class type. This is true if
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///
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/// * The given type is an incomplete class type.
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/// * The given type is a pointer type whose pointee type contains an
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/// incomplete class type.
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/// * The given type is a member pointer type whose class is an incomplete
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/// class type.
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/// * The given type is a member pointer type whoise pointee type contains an
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/// incomplete class type.
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/// is an indirect or direct pointer to an incomplete class type.
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static bool ContainsIncompleteClassType(QualType Ty) {
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if (const RecordType *RecordTy = dyn_cast<RecordType>(Ty)) {
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if (IsIncompleteClassType(RecordTy))
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return true;
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}
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if (const PointerType *PointerTy = dyn_cast<PointerType>(Ty))
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return ContainsIncompleteClassType(PointerTy->getPointeeType());
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if (const MemberPointerType *MemberPointerTy =
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dyn_cast<MemberPointerType>(Ty)) {
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// Check if the class type is incomplete.
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const RecordType *ClassType = cast<RecordType>(MemberPointerTy->getClass());
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if (IsIncompleteClassType(ClassType))
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return true;
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return ContainsIncompleteClassType(MemberPointerTy->getPointeeType());
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}
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return false;
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}
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/// getTypeInfoLinkage - Return the linkage that the type info and type info
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/// name constants should have for the given type.
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static llvm::GlobalVariable::LinkageTypes
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getTypeInfoLinkage(CodeGenModule &CGM, QualType Ty) {
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// Itanium C++ ABI 2.9.5p7:
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// In addition, it and all of the intermediate abi::__pointer_type_info
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// structs in the chain down to the abi::__class_type_info for the
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// incomplete class type must be prevented from resolving to the
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// corresponding type_info structs for the complete class type, possibly
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// by making them local static objects. Finally, a dummy class RTTI is
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// generated for the incomplete type that will not resolve to the final
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// complete class RTTI (because the latter need not exist), possibly by
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// making it a local static object.
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if (ContainsIncompleteClassType(Ty))
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return llvm::GlobalValue::InternalLinkage;
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switch (Ty->getLinkage()) {
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case NoLinkage:
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case InternalLinkage:
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case UniqueExternalLinkage:
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return llvm::GlobalValue::InternalLinkage;
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case ExternalLinkage:
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if (!CGM.getLangOpts().RTTI) {
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// RTTI is not enabled, which means that this type info struct is going
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// to be used for exception handling. Give it linkonce_odr linkage.
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return llvm::GlobalValue::LinkOnceODRLinkage;
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}
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if (const RecordType *Record = dyn_cast<RecordType>(Ty)) {
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const CXXRecordDecl *RD = cast<CXXRecordDecl>(Record->getDecl());
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if (RD->hasAttr<WeakAttr>())
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return llvm::GlobalValue::WeakODRLinkage;
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if (RD->isDynamicClass())
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return CGM.getVTableLinkage(RD);
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}
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return llvm::GlobalValue::LinkOnceODRLinkage;
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}
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llvm_unreachable("Invalid linkage!");
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}
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// CanUseSingleInheritance - Return whether the given record decl has a "single,
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// public, non-virtual base at offset zero (i.e. the derived class is dynamic
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// iff the base is)", according to Itanium C++ ABI, 2.95p6b.
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static bool CanUseSingleInheritance(const CXXRecordDecl *RD) {
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// Check the number of bases.
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if (RD->getNumBases() != 1)
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return false;
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// Get the base.
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CXXRecordDecl::base_class_const_iterator Base = RD->bases_begin();
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// Check that the base is not virtual.
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if (Base->isVirtual())
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return false;
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// Check that the base is public.
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if (Base->getAccessSpecifier() != AS_public)
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return false;
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// Check that the class is dynamic iff the base is.
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const CXXRecordDecl *BaseDecl =
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cast<CXXRecordDecl>(Base->getType()->getAs<RecordType>()->getDecl());
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if (!BaseDecl->isEmpty() &&
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BaseDecl->isDynamicClass() != RD->isDynamicClass())
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return false;
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return true;
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}
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void RTTIBuilder::BuildVTablePointer(const Type *Ty) {
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// abi::__class_type_info.
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static const char * const ClassTypeInfo =
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"_ZTVN10__cxxabiv117__class_type_infoE";
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// abi::__si_class_type_info.
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static const char * const SIClassTypeInfo =
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"_ZTVN10__cxxabiv120__si_class_type_infoE";
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// abi::__vmi_class_type_info.
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static const char * const VMIClassTypeInfo =
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"_ZTVN10__cxxabiv121__vmi_class_type_infoE";
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const char *VTableName = 0;
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switch (Ty->getTypeClass()) {
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#define TYPE(Class, Base)
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#define ABSTRACT_TYPE(Class, Base)
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#define NON_CANONICAL_UNLESS_DEPENDENT_TYPE(Class, Base) case Type::Class:
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#define NON_CANONICAL_TYPE(Class, Base) case Type::Class:
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#define DEPENDENT_TYPE(Class, Base) case Type::Class:
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#include "clang/AST/TypeNodes.def"
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llvm_unreachable("Non-canonical and dependent types shouldn't get here");
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case Type::LValueReference:
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case Type::RValueReference:
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llvm_unreachable("References shouldn't get here");
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case Type::Builtin:
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// GCC treats vector and complex types as fundamental types.
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case Type::Vector:
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case Type::ExtVector:
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case Type::Complex:
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case Type::Atomic:
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// FIXME: GCC treats block pointers as fundamental types?!
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case Type::BlockPointer:
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// abi::__fundamental_type_info.
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VTableName = "_ZTVN10__cxxabiv123__fundamental_type_infoE";
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break;
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case Type::ConstantArray:
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case Type::IncompleteArray:
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case Type::VariableArray:
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// abi::__array_type_info.
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VTableName = "_ZTVN10__cxxabiv117__array_type_infoE";
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break;
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case Type::FunctionNoProto:
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case Type::FunctionProto:
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// abi::__function_type_info.
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VTableName = "_ZTVN10__cxxabiv120__function_type_infoE";
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break;
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case Type::Enum:
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// abi::__enum_type_info.
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VTableName = "_ZTVN10__cxxabiv116__enum_type_infoE";
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break;
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case Type::Record: {
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const CXXRecordDecl *RD =
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cast<CXXRecordDecl>(cast<RecordType>(Ty)->getDecl());
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if (!RD->hasDefinition() || !RD->getNumBases()) {
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VTableName = ClassTypeInfo;
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} else if (CanUseSingleInheritance(RD)) {
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VTableName = SIClassTypeInfo;
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} else {
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VTableName = VMIClassTypeInfo;
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}
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break;
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}
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case Type::ObjCObject:
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// Ignore protocol qualifiers.
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Ty = cast<ObjCObjectType>(Ty)->getBaseType().getTypePtr();
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// Handle id and Class.
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if (isa<BuiltinType>(Ty)) {
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VTableName = ClassTypeInfo;
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break;
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}
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assert(isa<ObjCInterfaceType>(Ty));
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// Fall through.
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case Type::ObjCInterface:
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if (cast<ObjCInterfaceType>(Ty)->getDecl()->getSuperClass()) {
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VTableName = SIClassTypeInfo;
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} else {
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VTableName = ClassTypeInfo;
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}
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break;
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case Type::ObjCObjectPointer:
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case Type::Pointer:
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// abi::__pointer_type_info.
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VTableName = "_ZTVN10__cxxabiv119__pointer_type_infoE";
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break;
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case Type::MemberPointer:
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// abi::__pointer_to_member_type_info.
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VTableName = "_ZTVN10__cxxabiv129__pointer_to_member_type_infoE";
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break;
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}
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llvm::Constant *VTable =
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CGM.getModule().getOrInsertGlobal(VTableName, CGM.Int8PtrTy);
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llvm::Type *PtrDiffTy =
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CGM.getTypes().ConvertType(CGM.getContext().getPointerDiffType());
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// The vtable address point is 2.
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|
llvm::Constant *Two = llvm::ConstantInt::get(PtrDiffTy, 2);
|
|
VTable = llvm::ConstantExpr::getInBoundsGetElementPtr(VTable, Two);
|
|
VTable = llvm::ConstantExpr::getBitCast(VTable, CGM.Int8PtrTy);
|
|
|
|
Fields.push_back(VTable);
|
|
}
|
|
|
|
// maybeUpdateRTTILinkage - Will update the linkage of the RTTI data structures
|
|
// from available_externally to the correct linkage if necessary. An example of
|
|
// this is:
|
|
//
|
|
// struct A {
|
|
// virtual void f();
|
|
// };
|
|
//
|
|
// const std::type_info &g() {
|
|
// return typeid(A);
|
|
// }
|
|
//
|
|
// void A::f() { }
|
|
//
|
|
// When we're generating the typeid(A) expression, we do not yet know that
|
|
// A's key function is defined in this translation unit, so we will give the
|
|
// typeinfo and typename structures available_externally linkage. When A::f
|
|
// forces the vtable to be generated, we need to change the linkage of the
|
|
// typeinfo and typename structs, otherwise we'll end up with undefined
|
|
// externals when linking.
|
|
static void
|
|
maybeUpdateRTTILinkage(CodeGenModule &CGM, llvm::GlobalVariable *GV,
|
|
QualType Ty) {
|
|
// We're only interested in globals with available_externally linkage.
|
|
if (!GV->hasAvailableExternallyLinkage())
|
|
return;
|
|
|
|
// Get the real linkage for the type.
|
|
llvm::GlobalVariable::LinkageTypes Linkage = getTypeInfoLinkage(CGM, Ty);
|
|
|
|
// If variable is supposed to have available_externally linkage, we don't
|
|
// need to do anything.
|
|
if (Linkage == llvm::GlobalVariable::AvailableExternallyLinkage)
|
|
return;
|
|
|
|
// Update the typeinfo linkage.
|
|
GV->setLinkage(Linkage);
|
|
|
|
// Get the typename global.
|
|
SmallString<256> OutName;
|
|
llvm::raw_svector_ostream Out(OutName);
|
|
CGM.getCXXABI().getMangleContext().mangleCXXRTTIName(Ty, Out);
|
|
Out.flush();
|
|
StringRef Name = OutName.str();
|
|
|
|
llvm::GlobalVariable *TypeNameGV = CGM.getModule().getNamedGlobal(Name);
|
|
|
|
assert(TypeNameGV->hasAvailableExternallyLinkage() &&
|
|
"Type name has different linkage from type info!");
|
|
|
|
// And update its linkage.
|
|
TypeNameGV->setLinkage(Linkage);
|
|
}
|
|
|
|
llvm::Constant *RTTIBuilder::BuildTypeInfo(QualType Ty, bool Force) {
|
|
// We want to operate on the canonical type.
|
|
Ty = CGM.getContext().getCanonicalType(Ty);
|
|
|
|
// Check if we've already emitted an RTTI descriptor for this type.
|
|
SmallString<256> OutName;
|
|
llvm::raw_svector_ostream Out(OutName);
|
|
CGM.getCXXABI().getMangleContext().mangleCXXRTTI(Ty, Out);
|
|
Out.flush();
|
|
StringRef Name = OutName.str();
|
|
|
|
llvm::GlobalVariable *OldGV = CGM.getModule().getNamedGlobal(Name);
|
|
if (OldGV && !OldGV->isDeclaration()) {
|
|
maybeUpdateRTTILinkage(CGM, OldGV, Ty);
|
|
|
|
return llvm::ConstantExpr::getBitCast(OldGV, CGM.Int8PtrTy);
|
|
}
|
|
|
|
// Check if there is already an external RTTI descriptor for this type.
|
|
bool IsStdLib = IsStandardLibraryRTTIDescriptor(Ty);
|
|
if (!Force && (IsStdLib || ShouldUseExternalRTTIDescriptor(CGM, Ty)))
|
|
return GetAddrOfExternalRTTIDescriptor(Ty);
|
|
|
|
// Emit the standard library with external linkage.
|
|
llvm::GlobalVariable::LinkageTypes Linkage;
|
|
if (IsStdLib)
|
|
Linkage = llvm::GlobalValue::ExternalLinkage;
|
|
else
|
|
Linkage = getTypeInfoLinkage(CGM, Ty);
|
|
|
|
// Add the vtable pointer.
|
|
BuildVTablePointer(cast<Type>(Ty));
|
|
|
|
// And the name.
|
|
llvm::GlobalVariable *TypeName = GetAddrOfTypeName(Ty, Linkage);
|
|
|
|
Fields.push_back(llvm::ConstantExpr::getBitCast(TypeName, CGM.Int8PtrTy));
|
|
|
|
switch (Ty->getTypeClass()) {
|
|
#define TYPE(Class, Base)
|
|
#define ABSTRACT_TYPE(Class, Base)
|
|
#define NON_CANONICAL_UNLESS_DEPENDENT_TYPE(Class, Base) case Type::Class:
|
|
#define NON_CANONICAL_TYPE(Class, Base) case Type::Class:
|
|
#define DEPENDENT_TYPE(Class, Base) case Type::Class:
|
|
#include "clang/AST/TypeNodes.def"
|
|
llvm_unreachable("Non-canonical and dependent types shouldn't get here");
|
|
|
|
// GCC treats vector types as fundamental types.
|
|
case Type::Builtin:
|
|
case Type::Vector:
|
|
case Type::ExtVector:
|
|
case Type::Complex:
|
|
case Type::BlockPointer:
|
|
// Itanium C++ ABI 2.9.5p4:
|
|
// abi::__fundamental_type_info adds no data members to std::type_info.
|
|
break;
|
|
|
|
case Type::LValueReference:
|
|
case Type::RValueReference:
|
|
llvm_unreachable("References shouldn't get here");
|
|
|
|
case Type::ConstantArray:
|
|
case Type::IncompleteArray:
|
|
case Type::VariableArray:
|
|
// Itanium C++ ABI 2.9.5p5:
|
|
// abi::__array_type_info adds no data members to std::type_info.
|
|
break;
|
|
|
|
case Type::FunctionNoProto:
|
|
case Type::FunctionProto:
|
|
// Itanium C++ ABI 2.9.5p5:
|
|
// abi::__function_type_info adds no data members to std::type_info.
|
|
break;
|
|
|
|
case Type::Enum:
|
|
// Itanium C++ ABI 2.9.5p5:
|
|
// abi::__enum_type_info adds no data members to std::type_info.
|
|
break;
|
|
|
|
case Type::Record: {
|
|
const CXXRecordDecl *RD =
|
|
cast<CXXRecordDecl>(cast<RecordType>(Ty)->getDecl());
|
|
if (!RD->hasDefinition() || !RD->getNumBases()) {
|
|
// We don't need to emit any fields.
|
|
break;
|
|
}
|
|
|
|
if (CanUseSingleInheritance(RD))
|
|
BuildSIClassTypeInfo(RD);
|
|
else
|
|
BuildVMIClassTypeInfo(RD);
|
|
|
|
break;
|
|
}
|
|
|
|
case Type::ObjCObject:
|
|
case Type::ObjCInterface:
|
|
BuildObjCObjectTypeInfo(cast<ObjCObjectType>(Ty));
|
|
break;
|
|
|
|
case Type::ObjCObjectPointer:
|
|
BuildPointerTypeInfo(cast<ObjCObjectPointerType>(Ty)->getPointeeType());
|
|
break;
|
|
|
|
case Type::Pointer:
|
|
BuildPointerTypeInfo(cast<PointerType>(Ty)->getPointeeType());
|
|
break;
|
|
|
|
case Type::MemberPointer:
|
|
BuildPointerToMemberTypeInfo(cast<MemberPointerType>(Ty));
|
|
break;
|
|
|
|
case Type::Atomic:
|
|
// No fields, at least for the moment.
|
|
break;
|
|
}
|
|
|
|
llvm::Constant *Init = llvm::ConstantStruct::getAnon(Fields);
|
|
|
|
llvm::GlobalVariable *GV =
|
|
new llvm::GlobalVariable(CGM.getModule(), Init->getType(),
|
|
/*Constant=*/true, Linkage, Init, Name);
|
|
|
|
// If there's already an old global variable, replace it with the new one.
|
|
if (OldGV) {
|
|
GV->takeName(OldGV);
|
|
llvm::Constant *NewPtr =
|
|
llvm::ConstantExpr::getBitCast(GV, OldGV->getType());
|
|
OldGV->replaceAllUsesWith(NewPtr);
|
|
OldGV->eraseFromParent();
|
|
}
|
|
|
|
// GCC only relies on the uniqueness of the type names, not the
|
|
// type_infos themselves, so we can emit these as hidden symbols.
|
|
// But don't do this if we're worried about strict visibility
|
|
// compatibility.
|
|
if (const RecordType *RT = dyn_cast<RecordType>(Ty)) {
|
|
const CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl());
|
|
|
|
CGM.setTypeVisibility(GV, RD, CodeGenModule::TVK_ForRTTI);
|
|
CGM.setTypeVisibility(TypeName, RD, CodeGenModule::TVK_ForRTTIName);
|
|
} else {
|
|
Visibility TypeInfoVisibility = DefaultVisibility;
|
|
if (CGM.getCodeGenOpts().HiddenWeakVTables &&
|
|
Linkage == llvm::GlobalValue::LinkOnceODRLinkage)
|
|
TypeInfoVisibility = HiddenVisibility;
|
|
|
|
// The type name should have the same visibility as the type itself.
|
|
Visibility ExplicitVisibility = Ty->getVisibility();
|
|
TypeName->setVisibility(CodeGenModule::
|
|
GetLLVMVisibility(ExplicitVisibility));
|
|
|
|
TypeInfoVisibility = minVisibility(TypeInfoVisibility, Ty->getVisibility());
|
|
GV->setVisibility(CodeGenModule::GetLLVMVisibility(TypeInfoVisibility));
|
|
}
|
|
|
|
GV->setUnnamedAddr(true);
|
|
|
|
return llvm::ConstantExpr::getBitCast(GV, CGM.Int8PtrTy);
|
|
}
|
|
|
|
/// ComputeQualifierFlags - Compute the pointer type info flags from the
|
|
/// given qualifier.
|
|
static unsigned ComputeQualifierFlags(Qualifiers Quals) {
|
|
unsigned Flags = 0;
|
|
|
|
if (Quals.hasConst())
|
|
Flags |= RTTIBuilder::PTI_Const;
|
|
if (Quals.hasVolatile())
|
|
Flags |= RTTIBuilder::PTI_Volatile;
|
|
if (Quals.hasRestrict())
|
|
Flags |= RTTIBuilder::PTI_Restrict;
|
|
|
|
return Flags;
|
|
}
|
|
|
|
/// BuildObjCObjectTypeInfo - Build the appropriate kind of type_info
|
|
/// for the given Objective-C object type.
|
|
void RTTIBuilder::BuildObjCObjectTypeInfo(const ObjCObjectType *OT) {
|
|
// Drop qualifiers.
|
|
const Type *T = OT->getBaseType().getTypePtr();
|
|
assert(isa<BuiltinType>(T) || isa<ObjCInterfaceType>(T));
|
|
|
|
// The builtin types are abi::__class_type_infos and don't require
|
|
// extra fields.
|
|
if (isa<BuiltinType>(T)) return;
|
|
|
|
ObjCInterfaceDecl *Class = cast<ObjCInterfaceType>(T)->getDecl();
|
|
ObjCInterfaceDecl *Super = Class->getSuperClass();
|
|
|
|
// Root classes are also __class_type_info.
|
|
if (!Super) return;
|
|
|
|
QualType SuperTy = CGM.getContext().getObjCInterfaceType(Super);
|
|
|
|
// Everything else is single inheritance.
|
|
llvm::Constant *BaseTypeInfo = RTTIBuilder(CGM).BuildTypeInfo(SuperTy);
|
|
Fields.push_back(BaseTypeInfo);
|
|
}
|
|
|
|
/// BuildSIClassTypeInfo - Build an abi::__si_class_type_info, used for single
|
|
/// inheritance, according to the Itanium C++ ABI, 2.95p6b.
|
|
void RTTIBuilder::BuildSIClassTypeInfo(const CXXRecordDecl *RD) {
|
|
// Itanium C++ ABI 2.9.5p6b:
|
|
// It adds to abi::__class_type_info a single member pointing to the
|
|
// type_info structure for the base type,
|
|
llvm::Constant *BaseTypeInfo =
|
|
RTTIBuilder(CGM).BuildTypeInfo(RD->bases_begin()->getType());
|
|
Fields.push_back(BaseTypeInfo);
|
|
}
|
|
|
|
namespace {
|
|
/// SeenBases - Contains virtual and non-virtual bases seen when traversing
|
|
/// a class hierarchy.
|
|
struct SeenBases {
|
|
llvm::SmallPtrSet<const CXXRecordDecl *, 16> NonVirtualBases;
|
|
llvm::SmallPtrSet<const CXXRecordDecl *, 16> VirtualBases;
|
|
};
|
|
}
|
|
|
|
/// ComputeVMIClassTypeInfoFlags - Compute the value of the flags member in
|
|
/// abi::__vmi_class_type_info.
|
|
///
|
|
static unsigned ComputeVMIClassTypeInfoFlags(const CXXBaseSpecifier *Base,
|
|
SeenBases &Bases) {
|
|
|
|
unsigned Flags = 0;
|
|
|
|
const CXXRecordDecl *BaseDecl =
|
|
cast<CXXRecordDecl>(Base->getType()->getAs<RecordType>()->getDecl());
|
|
|
|
if (Base->isVirtual()) {
|
|
// Mark the virtual base as seen.
|
|
if (!Bases.VirtualBases.insert(BaseDecl)) {
|
|
// If this virtual base has been seen before, then the class is diamond
|
|
// shaped.
|
|
Flags |= RTTIBuilder::VMI_DiamondShaped;
|
|
} else {
|
|
if (Bases.NonVirtualBases.count(BaseDecl))
|
|
Flags |= RTTIBuilder::VMI_NonDiamondRepeat;
|
|
}
|
|
} else {
|
|
// Mark the non-virtual base as seen.
|
|
if (!Bases.NonVirtualBases.insert(BaseDecl)) {
|
|
// If this non-virtual base has been seen before, then the class has non-
|
|
// diamond shaped repeated inheritance.
|
|
Flags |= RTTIBuilder::VMI_NonDiamondRepeat;
|
|
} else {
|
|
if (Bases.VirtualBases.count(BaseDecl))
|
|
Flags |= RTTIBuilder::VMI_NonDiamondRepeat;
|
|
}
|
|
}
|
|
|
|
// Walk all bases.
|
|
for (CXXRecordDecl::base_class_const_iterator I = BaseDecl->bases_begin(),
|
|
E = BaseDecl->bases_end(); I != E; ++I)
|
|
Flags |= ComputeVMIClassTypeInfoFlags(I, Bases);
|
|
|
|
return Flags;
|
|
}
|
|
|
|
static unsigned ComputeVMIClassTypeInfoFlags(const CXXRecordDecl *RD) {
|
|
unsigned Flags = 0;
|
|
SeenBases Bases;
|
|
|
|
// Walk all bases.
|
|
for (CXXRecordDecl::base_class_const_iterator I = RD->bases_begin(),
|
|
E = RD->bases_end(); I != E; ++I)
|
|
Flags |= ComputeVMIClassTypeInfoFlags(I, Bases);
|
|
|
|
return Flags;
|
|
}
|
|
|
|
/// BuildVMIClassTypeInfo - Build an abi::__vmi_class_type_info, used for
|
|
/// classes with bases that do not satisfy the abi::__si_class_type_info
|
|
/// constraints, according ti the Itanium C++ ABI, 2.9.5p5c.
|
|
void RTTIBuilder::BuildVMIClassTypeInfo(const CXXRecordDecl *RD) {
|
|
llvm::Type *UnsignedIntLTy =
|
|
CGM.getTypes().ConvertType(CGM.getContext().UnsignedIntTy);
|
|
|
|
// Itanium C++ ABI 2.9.5p6c:
|
|
// __flags is a word with flags describing details about the class
|
|
// structure, which may be referenced by using the __flags_masks
|
|
// enumeration. These flags refer to both direct and indirect bases.
|
|
unsigned Flags = ComputeVMIClassTypeInfoFlags(RD);
|
|
Fields.push_back(llvm::ConstantInt::get(UnsignedIntLTy, Flags));
|
|
|
|
// Itanium C++ ABI 2.9.5p6c:
|
|
// __base_count is a word with the number of direct proper base class
|
|
// descriptions that follow.
|
|
Fields.push_back(llvm::ConstantInt::get(UnsignedIntLTy, RD->getNumBases()));
|
|
|
|
if (!RD->getNumBases())
|
|
return;
|
|
|
|
llvm::Type *LongLTy =
|
|
CGM.getTypes().ConvertType(CGM.getContext().LongTy);
|
|
|
|
// Now add the base class descriptions.
|
|
|
|
// Itanium C++ ABI 2.9.5p6c:
|
|
// __base_info[] is an array of base class descriptions -- one for every
|
|
// direct proper base. Each description is of the type:
|
|
//
|
|
// struct abi::__base_class_type_info {
|
|
// public:
|
|
// const __class_type_info *__base_type;
|
|
// long __offset_flags;
|
|
//
|
|
// enum __offset_flags_masks {
|
|
// __virtual_mask = 0x1,
|
|
// __public_mask = 0x2,
|
|
// __offset_shift = 8
|
|
// };
|
|
// };
|
|
for (CXXRecordDecl::base_class_const_iterator I = RD->bases_begin(),
|
|
E = RD->bases_end(); I != E; ++I) {
|
|
const CXXBaseSpecifier *Base = I;
|
|
|
|
// The __base_type member points to the RTTI for the base type.
|
|
Fields.push_back(RTTIBuilder(CGM).BuildTypeInfo(Base->getType()));
|
|
|
|
const CXXRecordDecl *BaseDecl =
|
|
cast<CXXRecordDecl>(Base->getType()->getAs<RecordType>()->getDecl());
|
|
|
|
int64_t OffsetFlags = 0;
|
|
|
|
// All but the lower 8 bits of __offset_flags are a signed offset.
|
|
// For a non-virtual base, this is the offset in the object of the base
|
|
// subobject. For a virtual base, this is the offset in the virtual table of
|
|
// the virtual base offset for the virtual base referenced (negative).
|
|
CharUnits Offset;
|
|
if (Base->isVirtual())
|
|
Offset =
|
|
CGM.getVTableContext().getVirtualBaseOffsetOffset(RD, BaseDecl);
|
|
else {
|
|
const ASTRecordLayout &Layout = CGM.getContext().getASTRecordLayout(RD);
|
|
Offset = Layout.getBaseClassOffset(BaseDecl);
|
|
};
|
|
|
|
OffsetFlags = uint64_t(Offset.getQuantity()) << 8;
|
|
|
|
// The low-order byte of __offset_flags contains flags, as given by the
|
|
// masks from the enumeration __offset_flags_masks.
|
|
if (Base->isVirtual())
|
|
OffsetFlags |= BCTI_Virtual;
|
|
if (Base->getAccessSpecifier() == AS_public)
|
|
OffsetFlags |= BCTI_Public;
|
|
|
|
Fields.push_back(llvm::ConstantInt::get(LongLTy, OffsetFlags));
|
|
}
|
|
}
|
|
|
|
/// BuildPointerTypeInfo - Build an abi::__pointer_type_info struct,
|
|
/// used for pointer types.
|
|
void RTTIBuilder::BuildPointerTypeInfo(QualType PointeeTy) {
|
|
Qualifiers Quals;
|
|
QualType UnqualifiedPointeeTy =
|
|
CGM.getContext().getUnqualifiedArrayType(PointeeTy, Quals);
|
|
|
|
// Itanium C++ ABI 2.9.5p7:
|
|
// __flags is a flag word describing the cv-qualification and other
|
|
// attributes of the type pointed to
|
|
unsigned Flags = ComputeQualifierFlags(Quals);
|
|
|
|
// Itanium C++ ABI 2.9.5p7:
|
|
// When the abi::__pbase_type_info is for a direct or indirect pointer to an
|
|
// incomplete class type, the incomplete target type flag is set.
|
|
if (ContainsIncompleteClassType(UnqualifiedPointeeTy))
|
|
Flags |= PTI_Incomplete;
|
|
|
|
llvm::Type *UnsignedIntLTy =
|
|
CGM.getTypes().ConvertType(CGM.getContext().UnsignedIntTy);
|
|
Fields.push_back(llvm::ConstantInt::get(UnsignedIntLTy, Flags));
|
|
|
|
// Itanium C++ ABI 2.9.5p7:
|
|
// __pointee is a pointer to the std::type_info derivation for the
|
|
// unqualified type being pointed to.
|
|
llvm::Constant *PointeeTypeInfo =
|
|
RTTIBuilder(CGM).BuildTypeInfo(UnqualifiedPointeeTy);
|
|
Fields.push_back(PointeeTypeInfo);
|
|
}
|
|
|
|
/// BuildPointerToMemberTypeInfo - Build an abi::__pointer_to_member_type_info
|
|
/// struct, used for member pointer types.
|
|
void RTTIBuilder::BuildPointerToMemberTypeInfo(const MemberPointerType *Ty) {
|
|
QualType PointeeTy = Ty->getPointeeType();
|
|
|
|
Qualifiers Quals;
|
|
QualType UnqualifiedPointeeTy =
|
|
CGM.getContext().getUnqualifiedArrayType(PointeeTy, Quals);
|
|
|
|
// Itanium C++ ABI 2.9.5p7:
|
|
// __flags is a flag word describing the cv-qualification and other
|
|
// attributes of the type pointed to.
|
|
unsigned Flags = ComputeQualifierFlags(Quals);
|
|
|
|
const RecordType *ClassType = cast<RecordType>(Ty->getClass());
|
|
|
|
// Itanium C++ ABI 2.9.5p7:
|
|
// When the abi::__pbase_type_info is for a direct or indirect pointer to an
|
|
// incomplete class type, the incomplete target type flag is set.
|
|
if (ContainsIncompleteClassType(UnqualifiedPointeeTy))
|
|
Flags |= PTI_Incomplete;
|
|
|
|
if (IsIncompleteClassType(ClassType))
|
|
Flags |= PTI_ContainingClassIncomplete;
|
|
|
|
llvm::Type *UnsignedIntLTy =
|
|
CGM.getTypes().ConvertType(CGM.getContext().UnsignedIntTy);
|
|
Fields.push_back(llvm::ConstantInt::get(UnsignedIntLTy, Flags));
|
|
|
|
// Itanium C++ ABI 2.9.5p7:
|
|
// __pointee is a pointer to the std::type_info derivation for the
|
|
// unqualified type being pointed to.
|
|
llvm::Constant *PointeeTypeInfo =
|
|
RTTIBuilder(CGM).BuildTypeInfo(UnqualifiedPointeeTy);
|
|
Fields.push_back(PointeeTypeInfo);
|
|
|
|
// Itanium C++ ABI 2.9.5p9:
|
|
// __context is a pointer to an abi::__class_type_info corresponding to the
|
|
// class type containing the member pointed to
|
|
// (e.g., the "A" in "int A::*").
|
|
Fields.push_back(RTTIBuilder(CGM).BuildTypeInfo(QualType(ClassType, 0)));
|
|
}
|
|
|
|
llvm::Constant *CodeGenModule::GetAddrOfRTTIDescriptor(QualType Ty,
|
|
bool ForEH) {
|
|
// Return a bogus pointer if RTTI is disabled, unless it's for EH.
|
|
// FIXME: should we even be calling this method if RTTI is disabled
|
|
// and it's not for EH?
|
|
if (!ForEH && !getLangOpts().RTTI)
|
|
return llvm::Constant::getNullValue(Int8PtrTy);
|
|
|
|
if (ForEH && Ty->isObjCObjectPointerType() &&
|
|
LangOpts.ObjCRuntime.isGNUFamily())
|
|
return ObjCRuntime->GetEHType(Ty);
|
|
|
|
return RTTIBuilder(*this).BuildTypeInfo(Ty);
|
|
}
|
|
|
|
void CodeGenModule::EmitFundamentalRTTIDescriptor(QualType Type) {
|
|
QualType PointerType = Context.getPointerType(Type);
|
|
QualType PointerTypeConst = Context.getPointerType(Type.withConst());
|
|
RTTIBuilder(*this).BuildTypeInfo(Type, true);
|
|
RTTIBuilder(*this).BuildTypeInfo(PointerType, true);
|
|
RTTIBuilder(*this).BuildTypeInfo(PointerTypeConst, true);
|
|
}
|
|
|
|
void CodeGenModule::EmitFundamentalRTTIDescriptors() {
|
|
QualType FundamentalTypes[] = { Context.VoidTy, Context.NullPtrTy,
|
|
Context.BoolTy, Context.WCharTy,
|
|
Context.CharTy, Context.UnsignedCharTy,
|
|
Context.SignedCharTy, Context.ShortTy,
|
|
Context.UnsignedShortTy, Context.IntTy,
|
|
Context.UnsignedIntTy, Context.LongTy,
|
|
Context.UnsignedLongTy, Context.LongLongTy,
|
|
Context.UnsignedLongLongTy, Context.FloatTy,
|
|
Context.DoubleTy, Context.LongDoubleTy,
|
|
Context.Char16Ty, Context.Char32Ty };
|
|
for (unsigned i = 0; i < sizeof(FundamentalTypes)/sizeof(QualType); ++i)
|
|
EmitFundamentalRTTIDescriptor(FundamentalTypes[i]);
|
|
}
|