r212435 - CodeGen: Refactor RTTI emission
David Majnemer
david.majnemer at gmail.com
Sun Jul 6 23:20:48 PDT 2014
Author: majnemer
Date: Mon Jul 7 01:20:47 2014
New Revision: 212435
URL: http://llvm.org/viewvc/llvm-project?rev=212435&view=rev
Log:
CodeGen: Refactor RTTI emission
Let's not expose ABI specific minutia inside of CodeGenModule and Type.
Instead, let's abstract it through CXXABI.
This gets rid of:
CodeGenModule::getCompleteObjectLocator,
CodeGenModule::EmitFundamentalTypeDescriptor{s,},
CodeGenModule::getMSTypeDescriptor,
CodeGenModule::getMSCompleteObjectLocator,
CGCXXABI::shouldRTTIBeUnique,
CGCXXABI::classifyRTTIUniqueness.
CGRTTI was *almost* entirely centered around providing Itanium-style
RTTI information. Instead of providing interfaces that only it
consumes, move it to the ItaniumCXXABI implementation file. This allows
it to have access to Itanium-specific implementation details without
providing useless expansion points for the Microsoft ABI side.
Differential Revision: http://reviews.llvm.org/D4261
Removed:
cfe/trunk/lib/CodeGen/CGRTTI.cpp
cfe/trunk/lib/CodeGen/MicrosoftRTTI.cpp
Modified:
cfe/trunk/lib/CodeGen/CGCXXABI.cpp
cfe/trunk/lib/CodeGen/CGCXXABI.h
cfe/trunk/lib/CodeGen/CMakeLists.txt
cfe/trunk/lib/CodeGen/CodeGenModule.cpp
cfe/trunk/lib/CodeGen/CodeGenModule.h
cfe/trunk/lib/CodeGen/ItaniumCXXABI.cpp
cfe/trunk/lib/CodeGen/MicrosoftCXXABI.cpp
Modified: cfe/trunk/lib/CodeGen/CGCXXABI.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGCXXABI.cpp?rev=212435&r1=212434&r2=212435&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGCXXABI.cpp (original)
+++ cfe/trunk/lib/CodeGen/CGCXXABI.cpp Mon Jul 7 01:20:47 2014
@@ -325,31 +325,3 @@ LValue CGCXXABI::EmitThreadLocalVarDeclL
bool CGCXXABI::NeedsVTTParameter(GlobalDecl GD) {
return false;
}
-
-/// What sort of uniqueness rules should we use for the RTTI for the
-/// given type?
-CGCXXABI::RTTIUniquenessKind
-CGCXXABI::classifyRTTIUniqueness(QualType CanTy,
- llvm::GlobalValue::LinkageTypes Linkage) {
- if (shouldRTTIBeUnique())
- return RUK_Unique;
-
- // It's only necessary for linkonce_odr or weak_odr linkage.
- if (Linkage != llvm::GlobalValue::LinkOnceODRLinkage &&
- Linkage != llvm::GlobalValue::WeakODRLinkage)
- return RUK_Unique;
-
- // It's only necessary with default visibility.
- if (CanTy->getVisibility() != DefaultVisibility)
- return RUK_Unique;
-
- // If we're not required to publish this symbol, hide it.
- if (Linkage == llvm::GlobalValue::LinkOnceODRLinkage)
- return RUK_NonUniqueHidden;
-
- // If we're required to publish this symbol, as we might be under an
- // explicit instantiation, leave it with default visibility but
- // enable string-comparisons.
- assert(Linkage == llvm::GlobalValue::WeakODRLinkage);
- return RUK_NonUniqueVisible;
-}
Modified: cfe/trunk/lib/CodeGen/CGCXXABI.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGCXXABI.h?rev=212435&r1=212434&r2=212435&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGCXXABI.h (original)
+++ cfe/trunk/lib/CodeGen/CGCXXABI.h Mon Jul 7 01:20:47 2014
@@ -207,6 +207,8 @@ public:
llvm::Value *ptr,
QualType type) = 0;
+ virtual llvm::Constant *getAddrOfRTTIDescriptor(QualType Ty) = 0;
+
virtual bool shouldTypeidBeNullChecked(bool IsDeref,
QualType SrcRecordTy) = 0;
virtual void EmitBadTypeidCall(CodeGenFunction &CGF) = 0;
@@ -516,36 +518,6 @@ public:
virtual LValue EmitThreadLocalVarDeclLValue(CodeGenFunction &CGF,
const VarDecl *VD,
QualType LValType);
-
- /**************************** RTTI Uniqueness ******************************/
-
-protected:
- /// Returns true if the ABI requires RTTI type_info objects to be unique
- /// across a program.
- virtual bool shouldRTTIBeUnique() { return true; }
-
-public:
- /// What sort of unique-RTTI behavior should we use?
- enum RTTIUniquenessKind {
- /// We are guaranteeing, or need to guarantee, that the RTTI string
- /// is unique.
- RUK_Unique,
-
- /// We are not guaranteeing uniqueness for the RTTI string, so we
- /// can demote to hidden visibility but must use string comparisons.
- RUK_NonUniqueHidden,
-
- /// We are not guaranteeing uniqueness for the RTTI string, so we
- /// have to use string comparisons, but we also have to emit it with
- /// non-hidden visibility.
- RUK_NonUniqueVisible
- };
-
- /// Return the required visibility status for the given type and linkage in
- /// the current ABI.
- RTTIUniquenessKind
- classifyRTTIUniqueness(QualType CanTy,
- llvm::GlobalValue::LinkageTypes Linkage);
};
// Create an instance of a C++ ABI class:
Removed: cfe/trunk/lib/CodeGen/CGRTTI.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGRTTI.cpp?rev=212434&view=auto
==============================================================================
--- cfe/trunk/lib/CodeGen/CGRTTI.cpp (original)
+++ cfe/trunk/lib/CodeGen/CGRTTI.cpp (removed)
@@ -1,998 +0,0 @@
-//===--- CGCXXRTTI.cpp - Emit LLVM Code for C++ RTTI descriptors ----------===//
-//
-// The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-// This contains code dealing with C++ code generation of RTTI descriptors.
-//
-//===----------------------------------------------------------------------===//
-
-#include "CodeGenModule.h"
-#include "CGCXXABI.h"
-#include "CGObjCRuntime.h"
-#include "clang/AST/RecordLayout.h"
-#include "clang/AST/Type.h"
-#include "clang/Frontend/CodeGenOptions.h"
-
-using namespace clang;
-using namespace CodeGen;
-
-namespace {
-class ItaniumRTTIBuilder {
- CodeGenModule &CGM; // Per-module state.
- llvm::LLVMContext &VMContext;
-
- /// Fields - The fields of the RTTI descriptor currently being built.
- SmallVector<llvm::Constant *, 16> Fields;
-
- /// GetAddrOfTypeName - Returns the mangled type name of the given type.
- llvm::GlobalVariable *
- GetAddrOfTypeName(QualType Ty, llvm::GlobalVariable::LinkageTypes Linkage);
-
- /// GetAddrOfExternalRTTIDescriptor - Returns the constant for the RTTI
- /// descriptor of the given type.
- llvm::Constant *GetAddrOfExternalRTTIDescriptor(QualType Ty);
-
- /// BuildVTablePointer - Build the vtable pointer for the given type.
- void BuildVTablePointer(const Type *Ty);
-
- /// BuildSIClassTypeInfo - Build an abi::__si_class_type_info, used for single
- /// inheritance, according to the Itanium C++ ABI, 2.9.5p6b.
- void BuildSIClassTypeInfo(const CXXRecordDecl *RD);
-
- /// 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 BuildVMIClassTypeInfo(const CXXRecordDecl *RD);
-
- /// BuildPointerTypeInfo - Build an abi::__pointer_type_info struct, used
- /// for pointer types.
- void BuildPointerTypeInfo(QualType PointeeTy);
-
- /// BuildObjCObjectTypeInfo - Build the appropriate kind of
- /// type_info for an object type.
- void BuildObjCObjectTypeInfo(const ObjCObjectType *Ty);
-
- /// BuildPointerToMemberTypeInfo - Build an abi::__pointer_to_member_type_info
- /// struct, used for member pointer types.
- void BuildPointerToMemberTypeInfo(const MemberPointerType *Ty);
-
-public:
- ItaniumRTTIBuilder(CodeGenModule &CGM) : CGM(CGM),
- VMContext(CGM.getModule().getContext()) { }
-
- // Pointer type info flags.
- enum {
- /// PTI_Const - Type has const qualifier.
- PTI_Const = 0x1,
-
- /// PTI_Volatile - Type has volatile qualifier.
- PTI_Volatile = 0x2,
-
- /// PTI_Restrict - Type has restrict qualifier.
- PTI_Restrict = 0x4,
-
- /// PTI_Incomplete - Type is incomplete.
- PTI_Incomplete = 0x8,
-
- /// PTI_ContainingClassIncomplete - Containing class is incomplete.
- /// (in pointer to member).
- PTI_ContainingClassIncomplete = 0x10
- };
-
- // VMI type info flags.
- enum {
- /// VMI_NonDiamondRepeat - Class has non-diamond repeated inheritance.
- VMI_NonDiamondRepeat = 0x1,
-
- /// VMI_DiamondShaped - Class is diamond shaped.
- VMI_DiamondShaped = 0x2
- };
-
- // Base class type info flags.
- enum {
- /// BCTI_Virtual - Base class is virtual.
- BCTI_Virtual = 0x1,
-
- /// BCTI_Public - Base class is public.
- BCTI_Public = 0x2
- };
-
- /// BuildTypeInfo - Build the RTTI type info struct for the given type.
- ///
- /// \param Force - true to force the creation of this RTTI value
- llvm::Constant *BuildTypeInfo(QualType Ty, bool Force = false);
-};
-}
-
-llvm::GlobalVariable *
-ItaniumRTTIBuilder::GetAddrOfTypeName(QualType Ty,
- llvm::GlobalVariable::LinkageTypes Linkage) {
- SmallString<256> OutName;
- llvm::raw_svector_ostream Out(OutName);
- CGM.getCXXABI().getMangleContext().mangleCXXRTTIName(Ty, Out);
- Out.flush();
- StringRef Name = OutName.str();
-
- // We know that the mangled name of the type starts at index 4 of the
- // mangled name of the typename, so we can just index into it in order to
- // get the mangled name of the type.
- llvm::Constant *Init = llvm::ConstantDataArray::getString(VMContext,
- Name.substr(4));
-
- llvm::GlobalVariable *GV =
- CGM.CreateOrReplaceCXXRuntimeVariable(Name, Init->getType(), Linkage);
-
- GV->setInitializer(Init);
-
- return GV;
-}
-
-llvm::Constant *
-ItaniumRTTIBuilder::GetAddrOfExternalRTTIDescriptor(QualType Ty) {
- // Mangle the RTTI name.
- SmallString<256> OutName;
- llvm::raw_svector_ostream Out(OutName);
- CGM.getCXXABI().getMangleContext().mangleCXXRTTI(Ty, Out);
- Out.flush();
- StringRef Name = OutName.str();
-
- // Look for an existing global.
- llvm::GlobalVariable *GV = CGM.getModule().getNamedGlobal(Name);
-
- if (!GV) {
- // Create a new global variable.
- GV = new llvm::GlobalVariable(CGM.getModule(), CGM.Int8PtrTy,
- /*Constant=*/true,
- llvm::GlobalValue::ExternalLinkage, nullptr,
- Name);
- }
-
- return llvm::ConstantExpr::getBitCast(GV, CGM.Int8PtrTy);
-}
-
-/// TypeInfoIsInStandardLibrary - Given a builtin type, returns whether the type
-/// info for that type is defined in the standard library.
-static bool TypeInfoIsInStandardLibrary(const BuiltinType *Ty) {
- // Itanium C++ ABI 2.9.2:
- // Basic type information (e.g. for "int", "bool", etc.) will be kept in
- // the run-time support library. Specifically, the run-time support
- // library should contain type_info objects for the types X, X* and
- // X const*, for every X in: void, std::nullptr_t, bool, wchar_t, char,
- // unsigned char, signed char, short, unsigned short, int, unsigned int,
- // long, unsigned long, long long, unsigned long long, float, double,
- // long double, char16_t, char32_t, and the IEEE 754r decimal and
- // half-precision floating point types.
- switch (Ty->getKind()) {
- case BuiltinType::Void:
- case BuiltinType::NullPtr:
- case BuiltinType::Bool:
- case BuiltinType::WChar_S:
- case BuiltinType::WChar_U:
- case BuiltinType::Char_U:
- case BuiltinType::Char_S:
- case BuiltinType::UChar:
- case BuiltinType::SChar:
- case BuiltinType::Short:
- case BuiltinType::UShort:
- case BuiltinType::Int:
- case BuiltinType::UInt:
- case BuiltinType::Long:
- case BuiltinType::ULong:
- case BuiltinType::LongLong:
- case BuiltinType::ULongLong:
- case BuiltinType::Half:
- case BuiltinType::Float:
- case BuiltinType::Double:
- case BuiltinType::LongDouble:
- case BuiltinType::Char16:
- case BuiltinType::Char32:
- case BuiltinType::Int128:
- case BuiltinType::UInt128:
- case BuiltinType::OCLImage1d:
- case BuiltinType::OCLImage1dArray:
- case BuiltinType::OCLImage1dBuffer:
- case BuiltinType::OCLImage2d:
- case BuiltinType::OCLImage2dArray:
- case BuiltinType::OCLImage3d:
- case BuiltinType::OCLSampler:
- case BuiltinType::OCLEvent:
- return true;
-
- case BuiltinType::Dependent:
-#define BUILTIN_TYPE(Id, SingletonId)
-#define PLACEHOLDER_TYPE(Id, SingletonId) \
- case BuiltinType::Id:
-#include "clang/AST/BuiltinTypes.def"
- llvm_unreachable("asking for RRTI for a placeholder type!");
-
- case BuiltinType::ObjCId:
- case BuiltinType::ObjCClass:
- case BuiltinType::ObjCSel:
- llvm_unreachable("FIXME: Objective-C types are unsupported!");
- }
-
- llvm_unreachable("Invalid BuiltinType Kind!");
-}
-
-static bool TypeInfoIsInStandardLibrary(const PointerType *PointerTy) {
- QualType PointeeTy = PointerTy->getPointeeType();
- const BuiltinType *BuiltinTy = dyn_cast<BuiltinType>(PointeeTy);
- if (!BuiltinTy)
- return false;
-
- // Check the qualifiers.
- Qualifiers Quals = PointeeTy.getQualifiers();
- Quals.removeConst();
-
- if (!Quals.empty())
- return false;
-
- return TypeInfoIsInStandardLibrary(BuiltinTy);
-}
-
-/// IsStandardLibraryRTTIDescriptor - Returns whether the type
-/// information for the given type exists in the standard library.
-static bool IsStandardLibraryRTTIDescriptor(QualType Ty) {
- // Type info for builtin types is defined in the standard library.
- if (const BuiltinType *BuiltinTy = dyn_cast<BuiltinType>(Ty))
- return TypeInfoIsInStandardLibrary(BuiltinTy);
-
- // Type info for some pointer types to builtin types is defined in the
- // standard library.
- if (const PointerType *PointerTy = dyn_cast<PointerType>(Ty))
- return TypeInfoIsInStandardLibrary(PointerTy);
-
- return false;
-}
-
-/// ShouldUseExternalRTTIDescriptor - Returns whether the type information for
-/// the given type exists somewhere else, and that we should not emit the type
-/// information in this translation unit. Assumes that it is not a
-/// standard-library type.
-static bool ShouldUseExternalRTTIDescriptor(CodeGenModule &CGM,
- QualType Ty) {
- ASTContext &Context = CGM.getContext();
-
- // If RTTI is disabled, assume it might be disabled in the
- // translation unit that defines any potential key function, too.
- if (!Context.getLangOpts().RTTI) return false;
-
- if (const RecordType *RecordTy = dyn_cast<RecordType>(Ty)) {
- const CXXRecordDecl *RD = cast<CXXRecordDecl>(RecordTy->getDecl());
- if (!RD->hasDefinition())
- return false;
-
- if (!RD->isDynamicClass())
- return false;
-
- // FIXME: this may need to be reconsidered if the key function
- // changes.
- return CGM.getVTables().isVTableExternal(RD);
- }
-
- return false;
-}
-
-/// IsIncompleteClassType - Returns whether the given record type is incomplete.
-static bool IsIncompleteClassType(const RecordType *RecordTy) {
- return !RecordTy->getDecl()->isCompleteDefinition();
-}
-
-/// ContainsIncompleteClassType - Returns whether the given type contains an
-/// incomplete class type. This is true if
-///
-/// * The given type is an incomplete class type.
-/// * The given type is a pointer type whose pointee type contains an
-/// incomplete class type.
-/// * The given type is a member pointer type whose class is an incomplete
-/// class type.
-/// * The given type is a member pointer type whoise pointee type contains an
-/// incomplete class type.
-/// is an indirect or direct pointer to an incomplete class type.
-static bool ContainsIncompleteClassType(QualType Ty) {
- if (const RecordType *RecordTy = dyn_cast<RecordType>(Ty)) {
- if (IsIncompleteClassType(RecordTy))
- return true;
- }
-
- if (const PointerType *PointerTy = dyn_cast<PointerType>(Ty))
- return ContainsIncompleteClassType(PointerTy->getPointeeType());
-
- if (const MemberPointerType *MemberPointerTy =
- dyn_cast<MemberPointerType>(Ty)) {
- // Check if the class type is incomplete.
- const RecordType *ClassType = cast<RecordType>(MemberPointerTy->getClass());
- if (IsIncompleteClassType(ClassType))
- return true;
-
- return ContainsIncompleteClassType(MemberPointerTy->getPointeeType());
- }
-
- return false;
-}
-
-/// getTypeInfoLinkage - Return the linkage that the type info and type info
-/// name constants should have for the given type.
-llvm::GlobalVariable::LinkageTypes
-CodeGenModule::getTypeInfoLinkage(QualType Ty) {
- // Itanium C++ ABI 2.9.5p7:
- // In addition, it and all of the intermediate abi::__pointer_type_info
- // structs in the chain down to the abi::__class_type_info for the
- // incomplete class type must be prevented from resolving to the
- // corresponding type_info structs for the complete class type, possibly
- // by making them local static objects. Finally, a dummy class RTTI is
- // generated for the incomplete type that will not resolve to the final
- // complete class RTTI (because the latter need not exist), possibly by
- // making it a local static object.
- if (ContainsIncompleteClassType(Ty))
- return llvm::GlobalValue::InternalLinkage;
-
- switch (Ty->getLinkage()) {
- case NoLinkage:
- case InternalLinkage:
- case UniqueExternalLinkage:
- return llvm::GlobalValue::InternalLinkage;
-
- case VisibleNoLinkage:
- case ExternalLinkage:
- if (!getLangOpts().RTTI) {
- // RTTI is not enabled, which means that this type info struct is going
- // to be used for exception handling. Give it linkonce_odr linkage.
- return llvm::GlobalValue::LinkOnceODRLinkage;
- }
-
- if (const RecordType *Record = dyn_cast<RecordType>(Ty)) {
- const CXXRecordDecl *RD = cast<CXXRecordDecl>(Record->getDecl());
- if (RD->hasAttr<WeakAttr>())
- return llvm::GlobalValue::WeakODRLinkage;
- if (RD->isDynamicClass())
- return getVTableLinkage(RD);
- }
-
- return llvm::GlobalValue::LinkOnceODRLinkage;
- }
-
- llvm_unreachable("Invalid linkage!");
-}
-
-// CanUseSingleInheritance - Return whether the given record decl has a "single,
-// public, non-virtual base at offset zero (i.e. the derived class is dynamic
-// iff the base is)", according to Itanium C++ ABI, 2.95p6b.
-static bool CanUseSingleInheritance(const CXXRecordDecl *RD) {
- // Check the number of bases.
- if (RD->getNumBases() != 1)
- return false;
-
- // Get the base.
- CXXRecordDecl::base_class_const_iterator Base = RD->bases_begin();
-
- // Check that the base is not virtual.
- if (Base->isVirtual())
- return false;
-
- // Check that the base is public.
- if (Base->getAccessSpecifier() != AS_public)
- return false;
-
- // Check that the class is dynamic iff the base is.
- const CXXRecordDecl *BaseDecl =
- cast<CXXRecordDecl>(Base->getType()->getAs<RecordType>()->getDecl());
- if (!BaseDecl->isEmpty() &&
- BaseDecl->isDynamicClass() != RD->isDynamicClass())
- return false;
-
- return true;
-}
-
-void ItaniumRTTIBuilder::BuildVTablePointer(const Type *Ty) {
- // abi::__class_type_info.
- static const char * const ClassTypeInfo =
- "_ZTVN10__cxxabiv117__class_type_infoE";
- // abi::__si_class_type_info.
- static const char * const SIClassTypeInfo =
- "_ZTVN10__cxxabiv120__si_class_type_infoE";
- // abi::__vmi_class_type_info.
- static const char * const VMIClassTypeInfo =
- "_ZTVN10__cxxabiv121__vmi_class_type_infoE";
-
- const char *VTableName = nullptr;
-
- 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");
-
- case Type::LValueReference:
- case Type::RValueReference:
- llvm_unreachable("References shouldn't get here");
-
- case Type::Auto:
- llvm_unreachable("Undeduced auto type shouldn't get here");
-
- case Type::Builtin:
- // GCC treats vector and complex types as fundamental types.
- case Type::Vector:
- case Type::ExtVector:
- case Type::Complex:
- case Type::Atomic:
- // FIXME: GCC treats block pointers as fundamental types?!
- case Type::BlockPointer:
- // abi::__fundamental_type_info.
- VTableName = "_ZTVN10__cxxabiv123__fundamental_type_infoE";
- break;
-
- case Type::ConstantArray:
- case Type::IncompleteArray:
- case Type::VariableArray:
- // abi::__array_type_info.
- VTableName = "_ZTVN10__cxxabiv117__array_type_infoE";
- break;
-
- case Type::FunctionNoProto:
- case Type::FunctionProto:
- // abi::__function_type_info.
- VTableName = "_ZTVN10__cxxabiv120__function_type_infoE";
- break;
-
- case Type::Enum:
- // abi::__enum_type_info.
- VTableName = "_ZTVN10__cxxabiv116__enum_type_infoE";
- break;
-
- case Type::Record: {
- const CXXRecordDecl *RD =
- cast<CXXRecordDecl>(cast<RecordType>(Ty)->getDecl());
-
- if (!RD->hasDefinition() || !RD->getNumBases()) {
- VTableName = ClassTypeInfo;
- } else if (CanUseSingleInheritance(RD)) {
- VTableName = SIClassTypeInfo;
- } else {
- VTableName = VMIClassTypeInfo;
- }
-
- break;
- }
-
- case Type::ObjCObject:
- // Ignore protocol qualifiers.
- Ty = cast<ObjCObjectType>(Ty)->getBaseType().getTypePtr();
-
- // Handle id and Class.
- if (isa<BuiltinType>(Ty)) {
- VTableName = ClassTypeInfo;
- break;
- }
-
- assert(isa<ObjCInterfaceType>(Ty));
- // Fall through.
-
- case Type::ObjCInterface:
- if (cast<ObjCInterfaceType>(Ty)->getDecl()->getSuperClass()) {
- VTableName = SIClassTypeInfo;
- } else {
- VTableName = ClassTypeInfo;
- }
- break;
-
- case Type::ObjCObjectPointer:
- case Type::Pointer:
- // abi::__pointer_type_info.
- VTableName = "_ZTVN10__cxxabiv119__pointer_type_infoE";
- break;
-
- case Type::MemberPointer:
- // abi::__pointer_to_member_type_info.
- VTableName = "_ZTVN10__cxxabiv129__pointer_to_member_type_infoE";
- break;
- }
-
- llvm::Constant *VTable =
- CGM.getModule().getOrInsertGlobal(VTableName, CGM.Int8PtrTy);
-
- llvm::Type *PtrDiffTy =
- CGM.getTypes().ConvertType(CGM.getContext().getPointerDiffType());
-
- // The vtable address point is 2.
- 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);
-}
-
-llvm::Constant *ItaniumRTTIBuilder::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()) {
- assert(!OldGV->hasAvailableExternallyLinkage() &&
- "available_externally typeinfos not yet implemented");
-
- 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 = CGM.getTypeInfoLinkage(Ty);
-
- // Add the vtable pointer.
- BuildVTablePointer(cast<Type>(Ty));
-
- // And the name.
- llvm::GlobalVariable *TypeName = GetAddrOfTypeName(Ty, Linkage);
- llvm::Constant *TypeNameField;
-
- // If we're supposed to demote the visibility, be sure to set a flag
- // to use a string comparison for type_info comparisons.
- CGCXXABI::RTTIUniquenessKind RTTIUniqueness =
- CGM.getCXXABI().classifyRTTIUniqueness(Ty, Linkage);
- if (RTTIUniqueness != CGCXXABI::RUK_Unique) {
- // The flag is the sign bit, which on ARM64 is defined to be clear
- // for global pointers. This is very ARM64-specific.
- TypeNameField = llvm::ConstantExpr::getPtrToInt(TypeName, CGM.Int64Ty);
- llvm::Constant *flag =
- llvm::ConstantInt::get(CGM.Int64Ty, ((uint64_t)1) << 63);
- TypeNameField = llvm::ConstantExpr::getAdd(TypeNameField, flag);
- TypeNameField =
- llvm::ConstantExpr::getIntToPtr(TypeNameField, CGM.Int8PtrTy);
- } else {
- TypeNameField = llvm::ConstantExpr::getBitCast(TypeName, CGM.Int8PtrTy);
- }
- Fields.push_back(TypeNameField);
-
- 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::Auto:
- llvm_unreachable("Undeduced auto type 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();
- }
-
- // The Itanium ABI specifies that type_info objects must be globally
- // unique, with one exception: if the type is an incomplete class
- // type or a (possibly indirect) pointer to one. That exception
- // affects the general case of comparing type_info objects produced
- // by the typeid operator, which is why the comparison operators on
- // std::type_info generally use the type_info name pointers instead
- // of the object addresses. However, the language's built-in uses
- // of RTTI generally require class types to be complete, even when
- // manipulating pointers to those class types. This allows the
- // implementation of dynamic_cast to rely on address equality tests,
- // which is much faster.
-
- // All of this is to say that it's important that both the type_info
- // object and the type_info name be uniqued when weakly emitted.
-
- // Give the type_info object and name the formal visibility of the
- // type itself.
- llvm::GlobalValue::VisibilityTypes llvmVisibility;
- if (llvm::GlobalValue::isLocalLinkage(Linkage))
- // If the linkage is local, only default visibility makes sense.
- llvmVisibility = llvm::GlobalValue::DefaultVisibility;
- else if (RTTIUniqueness == CGCXXABI::RUK_NonUniqueHidden)
- llvmVisibility = llvm::GlobalValue::HiddenVisibility;
- else
- llvmVisibility = CodeGenModule::GetLLVMVisibility(Ty->getVisibility());
- TypeName->setVisibility(llvmVisibility);
- GV->setVisibility(llvmVisibility);
-
- 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 |= ItaniumRTTIBuilder::PTI_Const;
- if (Quals.hasVolatile())
- Flags |= ItaniumRTTIBuilder::PTI_Volatile;
- if (Quals.hasRestrict())
- Flags |= ItaniumRTTIBuilder::PTI_Restrict;
-
- return Flags;
-}
-
-/// BuildObjCObjectTypeInfo - Build the appropriate kind of type_info
-/// for the given Objective-C object type.
-void ItaniumRTTIBuilder::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 = ItaniumRTTIBuilder(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 ItaniumRTTIBuilder::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 =
- ItaniumRTTIBuilder(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 |= ItaniumRTTIBuilder::VMI_DiamondShaped;
- } else {
- if (Bases.NonVirtualBases.count(BaseDecl))
- Flags |= ItaniumRTTIBuilder::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 |= ItaniumRTTIBuilder::VMI_NonDiamondRepeat;
- } else {
- if (Bases.VirtualBases.count(BaseDecl))
- Flags |= ItaniumRTTIBuilder::VMI_NonDiamondRepeat;
- }
- }
-
- // Walk all bases.
- for (const auto &I : BaseDecl->bases())
- Flags |= ComputeVMIClassTypeInfoFlags(&I, Bases);
-
- return Flags;
-}
-
-static unsigned ComputeVMIClassTypeInfoFlags(const CXXRecordDecl *RD) {
- unsigned Flags = 0;
- SeenBases Bases;
-
- // Walk all bases.
- for (const auto &I : RD->bases())
- 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 ItaniumRTTIBuilder::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 (const auto &Base : RD->bases()) {
- // The __base_type member points to the RTTI for the base type.
- Fields.push_back(ItaniumRTTIBuilder(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.getItaniumVTableContext().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 ItaniumRTTIBuilder::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 =
- ItaniumRTTIBuilder(CGM).BuildTypeInfo(UnqualifiedPointeeTy);
- Fields.push_back(PointeeTypeInfo);
-}
-
-/// BuildPointerToMemberTypeInfo - Build an abi::__pointer_to_member_type_info
-/// struct, used for member pointer types.
-void
-ItaniumRTTIBuilder::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 =
- ItaniumRTTIBuilder(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(
- ItaniumRTTIBuilder(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);
-
- if (getTarget().getCXXABI().isMicrosoft())
- return getMSTypeDescriptor(Ty);
- return ItaniumRTTIBuilder(*this).BuildTypeInfo(Ty);
-}
-
-void CodeGenModule::EmitFundamentalRTTIDescriptor(QualType Type) {
- QualType PointerType = Context.getPointerType(Type);
- QualType PointerTypeConst = Context.getPointerType(Type.withConst());
- ItaniumRTTIBuilder(*this).BuildTypeInfo(Type, true);
- ItaniumRTTIBuilder(*this).BuildTypeInfo(PointerType, true);
- ItaniumRTTIBuilder(*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.HalfTy, Context.FloatTy,
- Context.DoubleTy, Context.LongDoubleTy,
- Context.Char16Ty, Context.Char32Ty };
- for (unsigned i = 0; i < llvm::array_lengthof(FundamentalTypes); ++i)
- EmitFundamentalRTTIDescriptor(FundamentalTypes[i]);
-}
Modified: cfe/trunk/lib/CodeGen/CMakeLists.txt
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CMakeLists.txt?rev=212435&r1=212434&r2=212435&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CMakeLists.txt (original)
+++ cfe/trunk/lib/CodeGen/CMakeLists.txt Mon Jul 7 01:20:47 2014
@@ -45,7 +45,6 @@ add_clang_library(clangCodeGen
CGObjCRuntime.cpp
CGOpenCLRuntime.cpp
CGOpenMPRuntime.cpp
- CGRTTI.cpp
CGRecordLayoutBuilder.cpp
CGStmt.cpp
CGStmtOpenMP.cpp
@@ -60,7 +59,6 @@ add_clang_library(clangCodeGen
CodeGenTypes.cpp
ItaniumCXXABI.cpp
MicrosoftCXXABI.cpp
- MicrosoftRTTI.cpp
ModuleBuilder.cpp
TargetInfo.cpp
Modified: cfe/trunk/lib/CodeGen/CodeGenModule.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CodeGenModule.cpp?rev=212435&r1=212434&r2=212435&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CodeGenModule.cpp (original)
+++ cfe/trunk/lib/CodeGen/CodeGenModule.cpp Mon Jul 7 01:20:47 2014
@@ -3389,3 +3389,19 @@ llvm::Constant *CodeGenModule::EmitUuido
return llvm::ConstantStruct::getAnon(Fields);
}
+
+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 getCXXABI().getAddrOfRTTIDescriptor(Ty);
+}
+
Modified: cfe/trunk/lib/CodeGen/CodeGenModule.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CodeGenModule.h?rev=212435&r1=212434&r2=212435&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CodeGenModule.h (original)
+++ cfe/trunk/lib/CodeGen/CodeGenModule.h Mon Jul 7 01:20:47 2014
@@ -747,12 +747,6 @@ public:
/// The type of a generic block literal.
llvm::Type *getGenericBlockLiteralType();
- /// \brief Gets or a creats a Microsoft TypeDescriptor.
- llvm::Constant *getMSTypeDescriptor(QualType Ty);
- /// \brief Gets or a creats a Microsoft CompleteObjectLocator.
- llvm::Constant *getMSCompleteObjectLocator(const CXXRecordDecl *RD,
- const VPtrInfo *Info);
-
/// Gets the address of a block which requires no captures.
llvm::Constant *GetAddrOfGlobalBlock(const BlockExpr *BE, const char *);
@@ -973,9 +967,6 @@ public:
F->setLinkage(getFunctionLinkage(GD));
}
- /// \brief Returns the appropriate linkage for the TypeInfo struct for a type.
- llvm::GlobalVariable::LinkageTypes getTypeInfoLinkage(QualType Ty);
-
/// Return the appropriate linkage for the vtable, VTT, and type information
/// of the given class.
llvm::GlobalVariable::LinkageTypes getVTableLinkage(const CXXRecordDecl *RD);
Modified: cfe/trunk/lib/CodeGen/ItaniumCXXABI.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/ItaniumCXXABI.cpp?rev=212435&r1=212434&r2=212435&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/ItaniumCXXABI.cpp (original)
+++ cfe/trunk/lib/CodeGen/ItaniumCXXABI.cpp Mon Jul 7 01:20:47 2014
@@ -109,6 +109,10 @@ public:
llvm::Value *adjustToCompleteObject(CodeGenFunction &CGF, llvm::Value *ptr,
QualType type) override;
+ void EmitFundamentalRTTIDescriptor(QualType Type);
+ void EmitFundamentalRTTIDescriptors();
+ llvm::Constant *getAddrOfRTTIDescriptor(QualType Ty) override;
+
bool shouldTypeidBeNullChecked(bool IsDeref, QualType SrcRecordTy) override;
void EmitBadTypeidCall(CodeGenFunction &CGF) override;
llvm::Value *EmitTypeid(CodeGenFunction &CGF, QualType SrcRecordTy,
@@ -238,6 +242,37 @@ public:
QualType LValType) override;
bool NeedsVTTParameter(GlobalDecl GD) override;
+
+ /**************************** RTTI Uniqueness ******************************/
+
+protected:
+ /// Returns true if the ABI requires RTTI type_info objects to be unique
+ /// across a program.
+ virtual bool shouldRTTIBeUnique() const { return true; }
+
+public:
+ /// What sort of unique-RTTI behavior should we use?
+ enum RTTIUniquenessKind {
+ /// We are guaranteeing, or need to guarantee, that the RTTI string
+ /// is unique.
+ RUK_Unique,
+
+ /// We are not guaranteeing uniqueness for the RTTI string, so we
+ /// can demote to hidden visibility but must use string comparisons.
+ RUK_NonUniqueHidden,
+
+ /// We are not guaranteeing uniqueness for the RTTI string, so we
+ /// have to use string comparisons, but we also have to emit it with
+ /// non-hidden visibility.
+ RUK_NonUniqueVisible
+ };
+
+ /// Return the required visibility status for the given type and linkage in
+ /// the current ABI.
+ RTTIUniquenessKind
+ classifyRTTIUniqueness(QualType CanTy,
+ llvm::GlobalValue::LinkageTypes Linkage) const;
+ friend class ItaniumRTTIBuilder;
};
class ARMCXXABI : public ItaniumCXXABI {
@@ -270,7 +305,7 @@ public:
iOS64CXXABI(CodeGen::CodeGenModule &CGM) : ARMCXXABI(CGM) {}
// ARM64 libraries are prepared for non-unique RTTI.
- bool shouldRTTIBeUnique() override { return false; }
+ bool shouldRTTIBeUnique() const override { return false; }
};
}
@@ -1206,7 +1241,7 @@ void ItaniumCXXABI::emitVTableDefinition
isa<NamespaceDecl>(DC) && cast<NamespaceDecl>(DC)->getIdentifier() &&
cast<NamespaceDecl>(DC)->getIdentifier()->isStr("__cxxabiv1") &&
DC->getParent()->isTranslationUnit())
- CGM.EmitFundamentalRTTIDescriptors();
+ EmitFundamentalRTTIDescriptors();
}
llvm::Value *ItaniumCXXABI::getVTableAddressPointInStructor(
@@ -1944,3 +1979,996 @@ bool ItaniumCXXABI::NeedsVTTParameter(Gl
return false;
}
+
+namespace {
+class ItaniumRTTIBuilder {
+ CodeGenModule &CGM; // Per-module state.
+ llvm::LLVMContext &VMContext;
+ const ItaniumCXXABI &CXXABI; // Per-module state.
+
+ /// Fields - The fields of the RTTI descriptor currently being built.
+ SmallVector<llvm::Constant *, 16> Fields;
+
+ /// GetAddrOfTypeName - Returns the mangled type name of the given type.
+ llvm::GlobalVariable *
+ GetAddrOfTypeName(QualType Ty, llvm::GlobalVariable::LinkageTypes Linkage);
+
+ /// GetAddrOfExternalRTTIDescriptor - Returns the constant for the RTTI
+ /// descriptor of the given type.
+ llvm::Constant *GetAddrOfExternalRTTIDescriptor(QualType Ty);
+
+ /// BuildVTablePointer - Build the vtable pointer for the given type.
+ void BuildVTablePointer(const Type *Ty);
+
+ /// BuildSIClassTypeInfo - Build an abi::__si_class_type_info, used for single
+ /// inheritance, according to the Itanium C++ ABI, 2.9.5p6b.
+ void BuildSIClassTypeInfo(const CXXRecordDecl *RD);
+
+ /// 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 BuildVMIClassTypeInfo(const CXXRecordDecl *RD);
+
+ /// BuildPointerTypeInfo - Build an abi::__pointer_type_info struct, used
+ /// for pointer types.
+ void BuildPointerTypeInfo(QualType PointeeTy);
+
+ /// BuildObjCObjectTypeInfo - Build the appropriate kind of
+ /// type_info for an object type.
+ void BuildObjCObjectTypeInfo(const ObjCObjectType *Ty);
+
+ /// BuildPointerToMemberTypeInfo - Build an abi::__pointer_to_member_type_info
+ /// struct, used for member pointer types.
+ void BuildPointerToMemberTypeInfo(const MemberPointerType *Ty);
+
+public:
+ ItaniumRTTIBuilder(const ItaniumCXXABI &ABI)
+ : CGM(ABI.CGM), VMContext(CGM.getModule().getContext()), CXXABI(ABI) {}
+
+ // Pointer type info flags.
+ enum {
+ /// PTI_Const - Type has const qualifier.
+ PTI_Const = 0x1,
+
+ /// PTI_Volatile - Type has volatile qualifier.
+ PTI_Volatile = 0x2,
+
+ /// PTI_Restrict - Type has restrict qualifier.
+ PTI_Restrict = 0x4,
+
+ /// PTI_Incomplete - Type is incomplete.
+ PTI_Incomplete = 0x8,
+
+ /// PTI_ContainingClassIncomplete - Containing class is incomplete.
+ /// (in pointer to member).
+ PTI_ContainingClassIncomplete = 0x10
+ };
+
+ // VMI type info flags.
+ enum {
+ /// VMI_NonDiamondRepeat - Class has non-diamond repeated inheritance.
+ VMI_NonDiamondRepeat = 0x1,
+
+ /// VMI_DiamondShaped - Class is diamond shaped.
+ VMI_DiamondShaped = 0x2
+ };
+
+ // Base class type info flags.
+ enum {
+ /// BCTI_Virtual - Base class is virtual.
+ BCTI_Virtual = 0x1,
+
+ /// BCTI_Public - Base class is public.
+ BCTI_Public = 0x2
+ };
+
+ /// BuildTypeInfo - Build the RTTI type info struct for the given type.
+ ///
+ /// \param Force - true to force the creation of this RTTI value
+ llvm::Constant *BuildTypeInfo(QualType Ty, bool Force = false);
+};
+}
+
+llvm::GlobalVariable *ItaniumRTTIBuilder::GetAddrOfTypeName(
+ QualType Ty, llvm::GlobalVariable::LinkageTypes Linkage) {
+ SmallString<256> OutName;
+ llvm::raw_svector_ostream Out(OutName);
+ CGM.getCXXABI().getMangleContext().mangleCXXRTTIName(Ty, Out);
+ Out.flush();
+ StringRef Name = OutName.str();
+
+ // We know that the mangled name of the type starts at index 4 of the
+ // mangled name of the typename, so we can just index into it in order to
+ // get the mangled name of the type.
+ llvm::Constant *Init = llvm::ConstantDataArray::getString(VMContext,
+ Name.substr(4));
+
+ llvm::GlobalVariable *GV =
+ CGM.CreateOrReplaceCXXRuntimeVariable(Name, Init->getType(), Linkage);
+
+ GV->setInitializer(Init);
+
+ return GV;
+}
+
+llvm::Constant *
+ItaniumRTTIBuilder::GetAddrOfExternalRTTIDescriptor(QualType Ty) {
+ // Mangle the RTTI name.
+ SmallString<256> OutName;
+ llvm::raw_svector_ostream Out(OutName);
+ CGM.getCXXABI().getMangleContext().mangleCXXRTTI(Ty, Out);
+ Out.flush();
+ StringRef Name = OutName.str();
+
+ // Look for an existing global.
+ llvm::GlobalVariable *GV = CGM.getModule().getNamedGlobal(Name);
+
+ if (!GV) {
+ // Create a new global variable.
+ GV = new llvm::GlobalVariable(CGM.getModule(), CGM.Int8PtrTy,
+ /*Constant=*/true,
+ llvm::GlobalValue::ExternalLinkage, nullptr,
+ Name);
+ }
+
+ return llvm::ConstantExpr::getBitCast(GV, CGM.Int8PtrTy);
+}
+
+/// TypeInfoIsInStandardLibrary - Given a builtin type, returns whether the type
+/// info for that type is defined in the standard library.
+static bool TypeInfoIsInStandardLibrary(const BuiltinType *Ty) {
+ // Itanium C++ ABI 2.9.2:
+ // Basic type information (e.g. for "int", "bool", etc.) will be kept in
+ // the run-time support library. Specifically, the run-time support
+ // library should contain type_info objects for the types X, X* and
+ // X const*, for every X in: void, std::nullptr_t, bool, wchar_t, char,
+ // unsigned char, signed char, short, unsigned short, int, unsigned int,
+ // long, unsigned long, long long, unsigned long long, float, double,
+ // long double, char16_t, char32_t, and the IEEE 754r decimal and
+ // half-precision floating point types.
+ switch (Ty->getKind()) {
+ case BuiltinType::Void:
+ case BuiltinType::NullPtr:
+ case BuiltinType::Bool:
+ case BuiltinType::WChar_S:
+ case BuiltinType::WChar_U:
+ case BuiltinType::Char_U:
+ case BuiltinType::Char_S:
+ case BuiltinType::UChar:
+ case BuiltinType::SChar:
+ case BuiltinType::Short:
+ case BuiltinType::UShort:
+ case BuiltinType::Int:
+ case BuiltinType::UInt:
+ case BuiltinType::Long:
+ case BuiltinType::ULong:
+ case BuiltinType::LongLong:
+ case BuiltinType::ULongLong:
+ case BuiltinType::Half:
+ case BuiltinType::Float:
+ case BuiltinType::Double:
+ case BuiltinType::LongDouble:
+ case BuiltinType::Char16:
+ case BuiltinType::Char32:
+ case BuiltinType::Int128:
+ case BuiltinType::UInt128:
+ case BuiltinType::OCLImage1d:
+ case BuiltinType::OCLImage1dArray:
+ case BuiltinType::OCLImage1dBuffer:
+ case BuiltinType::OCLImage2d:
+ case BuiltinType::OCLImage2dArray:
+ case BuiltinType::OCLImage3d:
+ case BuiltinType::OCLSampler:
+ case BuiltinType::OCLEvent:
+ return true;
+
+ case BuiltinType::Dependent:
+#define BUILTIN_TYPE(Id, SingletonId)
+#define PLACEHOLDER_TYPE(Id, SingletonId) \
+ case BuiltinType::Id:
+#include "clang/AST/BuiltinTypes.def"
+ llvm_unreachable("asking for RRTI for a placeholder type!");
+
+ case BuiltinType::ObjCId:
+ case BuiltinType::ObjCClass:
+ case BuiltinType::ObjCSel:
+ llvm_unreachable("FIXME: Objective-C types are unsupported!");
+ }
+
+ llvm_unreachable("Invalid BuiltinType Kind!");
+}
+
+static bool TypeInfoIsInStandardLibrary(const PointerType *PointerTy) {
+ QualType PointeeTy = PointerTy->getPointeeType();
+ const BuiltinType *BuiltinTy = dyn_cast<BuiltinType>(PointeeTy);
+ if (!BuiltinTy)
+ return false;
+
+ // Check the qualifiers.
+ Qualifiers Quals = PointeeTy.getQualifiers();
+ Quals.removeConst();
+
+ if (!Quals.empty())
+ return false;
+
+ return TypeInfoIsInStandardLibrary(BuiltinTy);
+}
+
+/// IsStandardLibraryRTTIDescriptor - Returns whether the type
+/// information for the given type exists in the standard library.
+static bool IsStandardLibraryRTTIDescriptor(QualType Ty) {
+ // Type info for builtin types is defined in the standard library.
+ if (const BuiltinType *BuiltinTy = dyn_cast<BuiltinType>(Ty))
+ return TypeInfoIsInStandardLibrary(BuiltinTy);
+
+ // Type info for some pointer types to builtin types is defined in the
+ // standard library.
+ if (const PointerType *PointerTy = dyn_cast<PointerType>(Ty))
+ return TypeInfoIsInStandardLibrary(PointerTy);
+
+ return false;
+}
+
+/// ShouldUseExternalRTTIDescriptor - Returns whether the type information for
+/// the given type exists somewhere else, and that we should not emit the type
+/// information in this translation unit. Assumes that it is not a
+/// standard-library type.
+static bool ShouldUseExternalRTTIDescriptor(CodeGenModule &CGM,
+ QualType Ty) {
+ ASTContext &Context = CGM.getContext();
+
+ // If RTTI is disabled, assume it might be disabled in the
+ // translation unit that defines any potential key function, too.
+ if (!Context.getLangOpts().RTTI) return false;
+
+ if (const RecordType *RecordTy = dyn_cast<RecordType>(Ty)) {
+ const CXXRecordDecl *RD = cast<CXXRecordDecl>(RecordTy->getDecl());
+ if (!RD->hasDefinition())
+ return false;
+
+ if (!RD->isDynamicClass())
+ return false;
+
+ // FIXME: this may need to be reconsidered if the key function
+ // changes.
+ return CGM.getVTables().isVTableExternal(RD);
+ }
+
+ return false;
+}
+
+/// IsIncompleteClassType - Returns whether the given record type is incomplete.
+static bool IsIncompleteClassType(const RecordType *RecordTy) {
+ return !RecordTy->getDecl()->isCompleteDefinition();
+}
+
+/// ContainsIncompleteClassType - Returns whether the given type contains an
+/// incomplete class type. This is true if
+///
+/// * The given type is an incomplete class type.
+/// * The given type is a pointer type whose pointee type contains an
+/// incomplete class type.
+/// * The given type is a member pointer type whose class is an incomplete
+/// class type.
+/// * The given type is a member pointer type whoise pointee type contains an
+/// incomplete class type.
+/// is an indirect or direct pointer to an incomplete class type.
+static bool ContainsIncompleteClassType(QualType Ty) {
+ if (const RecordType *RecordTy = dyn_cast<RecordType>(Ty)) {
+ if (IsIncompleteClassType(RecordTy))
+ return true;
+ }
+
+ if (const PointerType *PointerTy = dyn_cast<PointerType>(Ty))
+ return ContainsIncompleteClassType(PointerTy->getPointeeType());
+
+ if (const MemberPointerType *MemberPointerTy =
+ dyn_cast<MemberPointerType>(Ty)) {
+ // Check if the class type is incomplete.
+ const RecordType *ClassType = cast<RecordType>(MemberPointerTy->getClass());
+ if (IsIncompleteClassType(ClassType))
+ return true;
+
+ return ContainsIncompleteClassType(MemberPointerTy->getPointeeType());
+ }
+
+ return false;
+}
+
+// CanUseSingleInheritance - Return whether the given record decl has a "single,
+// public, non-virtual base at offset zero (i.e. the derived class is dynamic
+// iff the base is)", according to Itanium C++ ABI, 2.95p6b.
+static bool CanUseSingleInheritance(const CXXRecordDecl *RD) {
+ // Check the number of bases.
+ if (RD->getNumBases() != 1)
+ return false;
+
+ // Get the base.
+ CXXRecordDecl::base_class_const_iterator Base = RD->bases_begin();
+
+ // Check that the base is not virtual.
+ if (Base->isVirtual())
+ return false;
+
+ // Check that the base is public.
+ if (Base->getAccessSpecifier() != AS_public)
+ return false;
+
+ // Check that the class is dynamic iff the base is.
+ const CXXRecordDecl *BaseDecl =
+ cast<CXXRecordDecl>(Base->getType()->getAs<RecordType>()->getDecl());
+ if (!BaseDecl->isEmpty() &&
+ BaseDecl->isDynamicClass() != RD->isDynamicClass())
+ return false;
+
+ return true;
+}
+
+void ItaniumRTTIBuilder::BuildVTablePointer(const Type *Ty) {
+ // abi::__class_type_info.
+ static const char * const ClassTypeInfo =
+ "_ZTVN10__cxxabiv117__class_type_infoE";
+ // abi::__si_class_type_info.
+ static const char * const SIClassTypeInfo =
+ "_ZTVN10__cxxabiv120__si_class_type_infoE";
+ // abi::__vmi_class_type_info.
+ static const char * const VMIClassTypeInfo =
+ "_ZTVN10__cxxabiv121__vmi_class_type_infoE";
+
+ const char *VTableName = nullptr;
+
+ 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");
+
+ case Type::LValueReference:
+ case Type::RValueReference:
+ llvm_unreachable("References shouldn't get here");
+
+ case Type::Auto:
+ llvm_unreachable("Undeduced auto type shouldn't get here");
+
+ case Type::Builtin:
+ // GCC treats vector and complex types as fundamental types.
+ case Type::Vector:
+ case Type::ExtVector:
+ case Type::Complex:
+ case Type::Atomic:
+ // FIXME: GCC treats block pointers as fundamental types?!
+ case Type::BlockPointer:
+ // abi::__fundamental_type_info.
+ VTableName = "_ZTVN10__cxxabiv123__fundamental_type_infoE";
+ break;
+
+ case Type::ConstantArray:
+ case Type::IncompleteArray:
+ case Type::VariableArray:
+ // abi::__array_type_info.
+ VTableName = "_ZTVN10__cxxabiv117__array_type_infoE";
+ break;
+
+ case Type::FunctionNoProto:
+ case Type::FunctionProto:
+ // abi::__function_type_info.
+ VTableName = "_ZTVN10__cxxabiv120__function_type_infoE";
+ break;
+
+ case Type::Enum:
+ // abi::__enum_type_info.
+ VTableName = "_ZTVN10__cxxabiv116__enum_type_infoE";
+ break;
+
+ case Type::Record: {
+ const CXXRecordDecl *RD =
+ cast<CXXRecordDecl>(cast<RecordType>(Ty)->getDecl());
+
+ if (!RD->hasDefinition() || !RD->getNumBases()) {
+ VTableName = ClassTypeInfo;
+ } else if (CanUseSingleInheritance(RD)) {
+ VTableName = SIClassTypeInfo;
+ } else {
+ VTableName = VMIClassTypeInfo;
+ }
+
+ break;
+ }
+
+ case Type::ObjCObject:
+ // Ignore protocol qualifiers.
+ Ty = cast<ObjCObjectType>(Ty)->getBaseType().getTypePtr();
+
+ // Handle id and Class.
+ if (isa<BuiltinType>(Ty)) {
+ VTableName = ClassTypeInfo;
+ break;
+ }
+
+ assert(isa<ObjCInterfaceType>(Ty));
+ // Fall through.
+
+ case Type::ObjCInterface:
+ if (cast<ObjCInterfaceType>(Ty)->getDecl()->getSuperClass()) {
+ VTableName = SIClassTypeInfo;
+ } else {
+ VTableName = ClassTypeInfo;
+ }
+ break;
+
+ case Type::ObjCObjectPointer:
+ case Type::Pointer:
+ // abi::__pointer_type_info.
+ VTableName = "_ZTVN10__cxxabiv119__pointer_type_infoE";
+ break;
+
+ case Type::MemberPointer:
+ // abi::__pointer_to_member_type_info.
+ VTableName = "_ZTVN10__cxxabiv129__pointer_to_member_type_infoE";
+ break;
+ }
+
+ llvm::Constant *VTable =
+ CGM.getModule().getOrInsertGlobal(VTableName, CGM.Int8PtrTy);
+
+ llvm::Type *PtrDiffTy =
+ CGM.getTypes().ConvertType(CGM.getContext().getPointerDiffType());
+
+ // The vtable address point is 2.
+ 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);
+}
+
+/// \brief Return the linkage that the type info and type info name constants
+/// should have for the given type.
+static llvm::GlobalVariable::LinkageTypes getTypeInfoLinkage(CodeGenModule &CGM,
+ QualType Ty) {
+ // Itanium C++ ABI 2.9.5p7:
+ // In addition, it and all of the intermediate abi::__pointer_type_info
+ // structs in the chain down to the abi::__class_type_info for the
+ // incomplete class type must be prevented from resolving to the
+ // corresponding type_info structs for the complete class type, possibly
+ // by making them local static objects. Finally, a dummy class RTTI is
+ // generated for the incomplete type that will not resolve to the final
+ // complete class RTTI (because the latter need not exist), possibly by
+ // making it a local static object.
+ if (ContainsIncompleteClassType(Ty))
+ return llvm::GlobalValue::InternalLinkage;
+
+ switch (Ty->getLinkage()) {
+ case NoLinkage:
+ case InternalLinkage:
+ case UniqueExternalLinkage:
+ return llvm::GlobalValue::InternalLinkage;
+
+ case VisibleNoLinkage:
+ case ExternalLinkage:
+ if (!CGM.getLangOpts().RTTI) {
+ // RTTI is not enabled, which means that this type info struct is going
+ // to be used for exception handling. Give it linkonce_odr linkage.
+ return llvm::GlobalValue::LinkOnceODRLinkage;
+ }
+
+ if (const RecordType *Record = dyn_cast<RecordType>(Ty)) {
+ const CXXRecordDecl *RD = cast<CXXRecordDecl>(Record->getDecl());
+ if (RD->hasAttr<WeakAttr>())
+ return llvm::GlobalValue::WeakODRLinkage;
+ if (RD->isDynamicClass())
+ return CGM.getVTableLinkage(RD);
+ }
+
+ return llvm::GlobalValue::LinkOnceODRLinkage;
+ }
+
+ llvm_unreachable("Invalid linkage!");
+}
+
+llvm::Constant *ItaniumRTTIBuilder::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()) {
+ assert(!OldGV->hasAvailableExternallyLinkage() &&
+ "available_externally typeinfos not yet implemented");
+
+ 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);
+ llvm::Constant *TypeNameField;
+
+ // If we're supposed to demote the visibility, be sure to set a flag
+ // to use a string comparison for type_info comparisons.
+ ItaniumCXXABI::RTTIUniquenessKind RTTIUniqueness =
+ CXXABI.classifyRTTIUniqueness(Ty, Linkage);
+ if (RTTIUniqueness != ItaniumCXXABI::RUK_Unique) {
+ // The flag is the sign bit, which on ARM64 is defined to be clear
+ // for global pointers. This is very ARM64-specific.
+ TypeNameField = llvm::ConstantExpr::getPtrToInt(TypeName, CGM.Int64Ty);
+ llvm::Constant *flag =
+ llvm::ConstantInt::get(CGM.Int64Ty, ((uint64_t)1) << 63);
+ TypeNameField = llvm::ConstantExpr::getAdd(TypeNameField, flag);
+ TypeNameField =
+ llvm::ConstantExpr::getIntToPtr(TypeNameField, CGM.Int8PtrTy);
+ } else {
+ TypeNameField = llvm::ConstantExpr::getBitCast(TypeName, CGM.Int8PtrTy);
+ }
+ Fields.push_back(TypeNameField);
+
+ 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::Auto:
+ llvm_unreachable("Undeduced auto type 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();
+ }
+
+ // The Itanium ABI specifies that type_info objects must be globally
+ // unique, with one exception: if the type is an incomplete class
+ // type or a (possibly indirect) pointer to one. That exception
+ // affects the general case of comparing type_info objects produced
+ // by the typeid operator, which is why the comparison operators on
+ // std::type_info generally use the type_info name pointers instead
+ // of the object addresses. However, the language's built-in uses
+ // of RTTI generally require class types to be complete, even when
+ // manipulating pointers to those class types. This allows the
+ // implementation of dynamic_cast to rely on address equality tests,
+ // which is much faster.
+
+ // All of this is to say that it's important that both the type_info
+ // object and the type_info name be uniqued when weakly emitted.
+
+ // Give the type_info object and name the formal visibility of the
+ // type itself.
+ llvm::GlobalValue::VisibilityTypes llvmVisibility;
+ if (llvm::GlobalValue::isLocalLinkage(Linkage))
+ // If the linkage is local, only default visibility makes sense.
+ llvmVisibility = llvm::GlobalValue::DefaultVisibility;
+ else if (RTTIUniqueness == ItaniumCXXABI::RUK_NonUniqueHidden)
+ llvmVisibility = llvm::GlobalValue::HiddenVisibility;
+ else
+ llvmVisibility = CodeGenModule::GetLLVMVisibility(Ty->getVisibility());
+ TypeName->setVisibility(llvmVisibility);
+ GV->setVisibility(llvmVisibility);
+
+ 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 |= ItaniumRTTIBuilder::PTI_Const;
+ if (Quals.hasVolatile())
+ Flags |= ItaniumRTTIBuilder::PTI_Volatile;
+ if (Quals.hasRestrict())
+ Flags |= ItaniumRTTIBuilder::PTI_Restrict;
+
+ return Flags;
+}
+
+/// BuildObjCObjectTypeInfo - Build the appropriate kind of type_info
+/// for the given Objective-C object type.
+void ItaniumRTTIBuilder::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 =
+ ItaniumRTTIBuilder(CXXABI).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 ItaniumRTTIBuilder::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 =
+ ItaniumRTTIBuilder(CXXABI).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 |= ItaniumRTTIBuilder::VMI_DiamondShaped;
+ } else {
+ if (Bases.NonVirtualBases.count(BaseDecl))
+ Flags |= ItaniumRTTIBuilder::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 |= ItaniumRTTIBuilder::VMI_NonDiamondRepeat;
+ } else {
+ if (Bases.VirtualBases.count(BaseDecl))
+ Flags |= ItaniumRTTIBuilder::VMI_NonDiamondRepeat;
+ }
+ }
+
+ // Walk all bases.
+ for (const auto &I : BaseDecl->bases())
+ Flags |= ComputeVMIClassTypeInfoFlags(&I, Bases);
+
+ return Flags;
+}
+
+static unsigned ComputeVMIClassTypeInfoFlags(const CXXRecordDecl *RD) {
+ unsigned Flags = 0;
+ SeenBases Bases;
+
+ // Walk all bases.
+ for (const auto &I : RD->bases())
+ 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 ItaniumRTTIBuilder::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 (const auto &Base : RD->bases()) {
+ // The __base_type member points to the RTTI for the base type.
+ Fields.push_back(ItaniumRTTIBuilder(CXXABI).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.getItaniumVTableContext().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 ItaniumRTTIBuilder::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 =
+ ItaniumRTTIBuilder(CXXABI).BuildTypeInfo(UnqualifiedPointeeTy);
+ Fields.push_back(PointeeTypeInfo);
+}
+
+/// BuildPointerToMemberTypeInfo - Build an abi::__pointer_to_member_type_info
+/// struct, used for member pointer types.
+void
+ItaniumRTTIBuilder::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 =
+ ItaniumRTTIBuilder(CXXABI).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(
+ ItaniumRTTIBuilder(CXXABI).BuildTypeInfo(QualType(ClassType, 0)));
+}
+
+llvm::Constant *ItaniumCXXABI::getAddrOfRTTIDescriptor(QualType Ty) {
+ return ItaniumRTTIBuilder(*this).BuildTypeInfo(Ty);
+}
+
+void ItaniumCXXABI::EmitFundamentalRTTIDescriptor(QualType Type) {
+ QualType PointerType = getContext().getPointerType(Type);
+ QualType PointerTypeConst = getContext().getPointerType(Type.withConst());
+ ItaniumRTTIBuilder(*this).BuildTypeInfo(Type, true);
+ ItaniumRTTIBuilder(*this).BuildTypeInfo(PointerType, true);
+ ItaniumRTTIBuilder(*this).BuildTypeInfo(PointerTypeConst, true);
+}
+
+void ItaniumCXXABI::EmitFundamentalRTTIDescriptors() {
+ QualType FundamentalTypes[] = {
+ getContext().VoidTy, getContext().NullPtrTy,
+ getContext().BoolTy, getContext().WCharTy,
+ getContext().CharTy, getContext().UnsignedCharTy,
+ getContext().SignedCharTy, getContext().ShortTy,
+ getContext().UnsignedShortTy, getContext().IntTy,
+ getContext().UnsignedIntTy, getContext().LongTy,
+ getContext().UnsignedLongTy, getContext().LongLongTy,
+ getContext().UnsignedLongLongTy, getContext().HalfTy,
+ getContext().FloatTy, getContext().DoubleTy,
+ getContext().LongDoubleTy, getContext().Char16Ty,
+ getContext().Char32Ty,
+ };
+ for (const QualType &FundamentalType : FundamentalTypes)
+ EmitFundamentalRTTIDescriptor(FundamentalType);
+}
+
+/// What sort of uniqueness rules should we use for the RTTI for the
+/// given type?
+ItaniumCXXABI::RTTIUniquenessKind ItaniumCXXABI::classifyRTTIUniqueness(
+ QualType CanTy, llvm::GlobalValue::LinkageTypes Linkage) const {
+ if (shouldRTTIBeUnique())
+ return RUK_Unique;
+
+ // It's only necessary for linkonce_odr or weak_odr linkage.
+ if (Linkage != llvm::GlobalValue::LinkOnceODRLinkage &&
+ Linkage != llvm::GlobalValue::WeakODRLinkage)
+ return RUK_Unique;
+
+ // It's only necessary with default visibility.
+ if (CanTy->getVisibility() != DefaultVisibility)
+ return RUK_Unique;
+
+ // If we're not required to publish this symbol, hide it.
+ if (Linkage == llvm::GlobalValue::LinkOnceODRLinkage)
+ return RUK_NonUniqueHidden;
+
+ // If we're required to publish this symbol, as we might be under an
+ // explicit instantiation, leave it with default visibility but
+ // enable string-comparisons.
+ assert(Linkage == llvm::GlobalValue::WeakODRLinkage);
+ return RUK_NonUniqueVisible;
+}
Modified: cfe/trunk/lib/CodeGen/MicrosoftCXXABI.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/MicrosoftCXXABI.cpp?rev=212435&r1=212434&r2=212435&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/MicrosoftCXXABI.cpp (original)
+++ cfe/trunk/lib/CodeGen/MicrosoftCXXABI.cpp Mon Jul 7 01:20:47 2014
@@ -57,6 +57,11 @@ public:
llvm::Value *ptr,
QualType type) override;
+ llvm::GlobalVariable *getMSCompleteObjectLocator(const CXXRecordDecl *RD,
+ const VPtrInfo *Info);
+
+ llvm::Constant *getAddrOfRTTIDescriptor(QualType Ty) override;
+
bool shouldTypeidBeNullChecked(bool IsDeref, QualType SrcRecordTy) override;
void EmitBadTypeidCall(CodeGenFunction &CGF) override;
llvm::Value *EmitTypeid(CodeGenFunction &CGF, QualType SrcRecordTy,
@@ -1059,7 +1064,7 @@ void MicrosoftCXXABI::emitVTableDefiniti
if (VTable->hasInitializer())
continue;
- llvm::Constant *RTTI = CGM.getMSCompleteObjectLocator(RD, Info);
+ llvm::Constant *RTTI = getMSCompleteObjectLocator(RD, Info);
const VTableLayout &VTLayout =
VFTContext.getVFTableLayout(RD, Info->FullOffsetInMDC);
@@ -2364,3 +2369,509 @@ llvm::Value *MicrosoftCXXABI::EmitLoadOf
CGCXXABI *clang::CodeGen::CreateMicrosoftCXXABI(CodeGenModule &CGM) {
return new MicrosoftCXXABI(CGM);
}
+
+// MS RTTI Overview:
+// The run time type information emitted by cl.exe contains 5 distinct types of
+// structures. Many of them reference each other.
+//
+// TypeInfo: Static classes that are returned by typeid.
+//
+// CompleteObjectLocator: Referenced by vftables. They contain information
+// required for dynamic casting, including OffsetFromTop. They also contain
+// a reference to the TypeInfo for the type and a reference to the
+// CompleteHierarchyDescriptor for the type.
+//
+// ClassHieararchyDescriptor: Contains information about a class hierarchy.
+// Used during dynamic_cast to walk a class hierarchy. References a base
+// class array and the size of said array.
+//
+// BaseClassArray: Contains a list of classes in a hierarchy. BaseClassArray is
+// somewhat of a misnomer because the most derived class is also in the list
+// as well as multiple copies of virtual bases (if they occur multiple times
+// in the hiearchy.) The BaseClassArray contains one BaseClassDescriptor for
+// every path in the hierarchy, in pre-order depth first order. Note, we do
+// not declare a specific llvm type for BaseClassArray, it's merely an array
+// of BaseClassDescriptor pointers.
+//
+// BaseClassDescriptor: Contains information about a class in a class hierarchy.
+// BaseClassDescriptor is also somewhat of a misnomer for the same reason that
+// BaseClassArray is. It contains information about a class within a
+// hierarchy such as: is this base is ambiguous and what is its offset in the
+// vbtable. The names of the BaseClassDescriptors have all of their fields
+// mangled into them so they can be aggressively deduplicated by the linker.
+
+static bool isImageRelative(CodeGenModule &CGM) {
+ return CGM.getTarget().getPointerWidth(/*AddressSpace=*/0) == 64;
+}
+
+static llvm::Type *getImageRelativeType(CodeGenModule &CGM,
+ llvm::Type *PtrType) {
+ if (!isImageRelative(CGM))
+ return PtrType;
+ return CGM.IntTy;
+}
+
+static llvm::GlobalVariable *getImageBase(CodeGenModule &CGM) {
+ StringRef Name = "__ImageBase";
+ if (llvm::GlobalVariable *GV = CGM.getModule().getNamedGlobal(Name))
+ return GV;
+
+ return new llvm::GlobalVariable(CGM.getModule(), CGM.Int8Ty,
+ /*isConstant=*/true,
+ llvm::GlobalValue::ExternalLinkage,
+ /*Initializer=*/nullptr, Name);
+}
+
+static llvm::Constant *getImageRelativeConstant(CodeGenModule &CGM,
+ llvm::Constant *PtrVal) {
+ if (!isImageRelative(CGM))
+ return PtrVal;
+
+ llvm::Constant *ImageBaseAsInt =
+ llvm::ConstantExpr::getPtrToInt(getImageBase(CGM), CGM.IntPtrTy);
+ llvm::Constant *PtrValAsInt =
+ llvm::ConstantExpr::getPtrToInt(PtrVal, CGM.IntPtrTy);
+ llvm::Constant *Diff =
+ llvm::ConstantExpr::getSub(PtrValAsInt, ImageBaseAsInt,
+ /*HasNUW=*/true, /*HasNSW=*/true);
+ return llvm::ConstantExpr::getTrunc(Diff, CGM.IntTy);
+}
+
+// 5 routines for constructing the llvm types for MS RTTI structs.
+static llvm::StructType *getClassHierarchyDescriptorType(CodeGenModule &CGM);
+
+static llvm::StructType *getTypeDescriptorType(CodeGenModule &CGM,
+ StringRef TypeInfoString) {
+ llvm::SmallString<32> TDTypeName("MSRTTITypeDescriptor");
+ TDTypeName += TypeInfoString.size();
+ if (auto Type = CGM.getModule().getTypeByName(TDTypeName))
+ return Type;
+ llvm::Type *FieldTypes[] = {
+ CGM.Int8PtrPtrTy,
+ CGM.Int8PtrTy,
+ llvm::ArrayType::get(CGM.Int8Ty, TypeInfoString.size() + 1)};
+ return llvm::StructType::create(CGM.getLLVMContext(), FieldTypes, TDTypeName);
+}
+
+static llvm::StructType *getBaseClassDescriptorType(CodeGenModule &CGM) {
+ static const char Name[] = "MSRTTIBaseClassDescriptor";
+ if (auto Type = CGM.getModule().getTypeByName(Name))
+ return Type;
+ llvm::Type *FieldTypes[] = {
+ getImageRelativeType(CGM, CGM.Int8PtrTy),
+ CGM.IntTy,
+ CGM.IntTy,
+ CGM.IntTy,
+ CGM.IntTy,
+ CGM.IntTy,
+ getImageRelativeType(
+ CGM, getClassHierarchyDescriptorType(CGM)->getPointerTo()),
+ };
+ return llvm::StructType::create(CGM.getLLVMContext(), FieldTypes, Name);
+}
+
+static llvm::StructType *getClassHierarchyDescriptorType(CodeGenModule &CGM) {
+ static const char Name[] = "MSRTTIClassHierarchyDescriptor";
+ if (auto Type = CGM.getModule().getTypeByName(Name))
+ return Type;
+ // Forward-declare RTTIClassHierarchyDescriptor to break a cycle.
+ llvm::StructType *Type = llvm::StructType::create(CGM.getLLVMContext(), Name);
+ llvm::Type *FieldTypes[] = {
+ CGM.IntTy,
+ CGM.IntTy,
+ CGM.IntTy,
+ getImageRelativeType(
+ CGM,
+ getBaseClassDescriptorType(CGM)->getPointerTo()->getPointerTo()),
+ };
+ Type->setBody(FieldTypes);
+ return Type;
+}
+
+static llvm::StructType *getCompleteObjectLocatorType(CodeGenModule &CGM) {
+ static const char Name[] = "MSRTTICompleteObjectLocator";
+ if (auto Type = CGM.getModule().getTypeByName(Name))
+ return Type;
+ llvm::StructType *Type = llvm::StructType::create(CGM.getLLVMContext(), Name);
+ llvm::Type *FieldTypes[] = {
+ CGM.IntTy,
+ CGM.IntTy,
+ CGM.IntTy,
+ getImageRelativeType(CGM, CGM.Int8PtrTy),
+ getImageRelativeType(
+ CGM, getClassHierarchyDescriptorType(CGM)->getPointerTo()),
+ getImageRelativeType(CGM, Type),
+ };
+ llvm::ArrayRef<llvm::Type *> FieldTypesRef(
+ std::begin(FieldTypes),
+ isImageRelative(CGM) ? std::end(FieldTypes) : std::end(FieldTypes) - 1);
+ Type->setBody(FieldTypesRef);
+ return Type;
+}
+
+static llvm::GlobalVariable *getTypeInfoVTable(CodeGenModule &CGM) {
+ StringRef MangledName("\01??_7type_info@@6B@");
+ if (auto VTable = CGM.getModule().getNamedGlobal(MangledName))
+ return VTable;
+ return new llvm::GlobalVariable(CGM.getModule(), CGM.Int8PtrTy,
+ /*Constant=*/true,
+ llvm::GlobalVariable::ExternalLinkage,
+ /*Initializer=*/nullptr, MangledName);
+}
+
+namespace {
+
+/// \brief A Helper struct that stores information about a class in a class
+/// hierarchy. The information stored in these structs struct is used during
+/// the generation of ClassHierarchyDescriptors and BaseClassDescriptors.
+// During RTTI creation, MSRTTIClasses are stored in a contiguous array with
+// implicit depth first pre-order tree connectivity. getFirstChild and
+// getNextSibling allow us to walk the tree efficiently.
+struct MSRTTIClass {
+ enum {
+ IsPrivateOnPath = 1 | 8,
+ IsAmbiguous = 2,
+ IsPrivate = 4,
+ IsVirtual = 16,
+ HasHierarchyDescriptor = 64
+ };
+ MSRTTIClass(const CXXRecordDecl *RD) : RD(RD) {}
+ uint32_t initialize(const MSRTTIClass *Parent,
+ const CXXBaseSpecifier *Specifier);
+
+ MSRTTIClass *getFirstChild() { return this + 1; }
+ static MSRTTIClass *getNextChild(MSRTTIClass *Child) {
+ return Child + 1 + Child->NumBases;
+ }
+
+ const CXXRecordDecl *RD, *VirtualRoot;
+ uint32_t Flags, NumBases, OffsetInVBase;
+};
+
+/// \brief Recursively initialize the base class array.
+uint32_t MSRTTIClass::initialize(const MSRTTIClass *Parent,
+ const CXXBaseSpecifier *Specifier) {
+ Flags = HasHierarchyDescriptor;
+ if (!Parent) {
+ VirtualRoot = nullptr;
+ OffsetInVBase = 0;
+ } else {
+ if (Specifier->getAccessSpecifier() != AS_public)
+ Flags |= IsPrivate | IsPrivateOnPath;
+ if (Specifier->isVirtual()) {
+ Flags |= IsVirtual;
+ VirtualRoot = RD;
+ OffsetInVBase = 0;
+ } else {
+ if (Parent->Flags & IsPrivateOnPath)
+ Flags |= IsPrivateOnPath;
+ VirtualRoot = Parent->VirtualRoot;
+ OffsetInVBase = Parent->OffsetInVBase + RD->getASTContext()
+ .getASTRecordLayout(Parent->RD).getBaseClassOffset(RD).getQuantity();
+ }
+ }
+ NumBases = 0;
+ MSRTTIClass *Child = getFirstChild();
+ for (const CXXBaseSpecifier &Base : RD->bases()) {
+ NumBases += Child->initialize(this, &Base) + 1;
+ Child = getNextChild(Child);
+ }
+ return NumBases;
+}
+
+static llvm::GlobalValue::LinkageTypes getLinkageForRTTI(QualType Ty) {
+ switch (Ty->getLinkage()) {
+ case NoLinkage:
+ case InternalLinkage:
+ case UniqueExternalLinkage:
+ return llvm::GlobalValue::InternalLinkage;
+
+ case VisibleNoLinkage:
+ case ExternalLinkage:
+ return llvm::GlobalValue::LinkOnceODRLinkage;
+ }
+ llvm_unreachable("Invalid linkage!");
+}
+
+/// \brief An ephemeral helper class for building MS RTTI types. It caches some
+/// calls to the module and information about the most derived class in a
+/// hierarchy.
+struct MSRTTIBuilder {
+ enum {
+ HasBranchingHierarchy = 1,
+ HasVirtualBranchingHierarchy = 2,
+ HasAmbiguousBases = 4
+ };
+
+ MSRTTIBuilder(CodeGenModule &CGM, const CXXRecordDecl *RD)
+ : CGM(CGM), Context(CGM.getContext()), VMContext(CGM.getLLVMContext()),
+ Module(CGM.getModule()), RD(RD),
+ Linkage(getLinkageForRTTI(CGM.getContext().getTagDeclType(RD))),
+ Mangler(
+ cast<MicrosoftMangleContext>(CGM.getCXXABI().getMangleContext())) {}
+
+ llvm::GlobalVariable *getBaseClassDescriptor(const MSRTTIClass &Classes);
+ llvm::GlobalVariable *
+ getBaseClassArray(SmallVectorImpl<MSRTTIClass> &Classes);
+ llvm::GlobalVariable *getClassHierarchyDescriptor();
+ llvm::GlobalVariable *getCompleteObjectLocator(const VPtrInfo *Info);
+
+ CodeGenModule &CGM;
+ ASTContext &Context;
+ llvm::LLVMContext &VMContext;
+ llvm::Module &Module;
+ const CXXRecordDecl *RD;
+ llvm::GlobalVariable::LinkageTypes Linkage;
+ MicrosoftMangleContext &Mangler;
+};
+
+} // namespace
+
+/// \brief Recursively serializes a class hierarchy in pre-order depth first
+/// order.
+static void serializeClassHierarchy(SmallVectorImpl<MSRTTIClass> &Classes,
+ const CXXRecordDecl *RD) {
+ Classes.push_back(MSRTTIClass(RD));
+ for (const CXXBaseSpecifier &Base : RD->bases())
+ serializeClassHierarchy(Classes, Base.getType()->getAsCXXRecordDecl());
+}
+
+/// \brief Find ambiguity among base classes.
+static void
+detectAmbiguousBases(SmallVectorImpl<MSRTTIClass> &Classes) {
+ llvm::SmallPtrSet<const CXXRecordDecl *, 8> VirtualBases;
+ llvm::SmallPtrSet<const CXXRecordDecl *, 8> UniqueBases;
+ llvm::SmallPtrSet<const CXXRecordDecl *, 8> AmbiguousBases;
+ for (MSRTTIClass *Class = &Classes.front(); Class <= &Classes.back();) {
+ if ((Class->Flags & MSRTTIClass::IsVirtual) &&
+ !VirtualBases.insert(Class->RD)) {
+ Class = MSRTTIClass::getNextChild(Class);
+ continue;
+ }
+ if (!UniqueBases.insert(Class->RD))
+ AmbiguousBases.insert(Class->RD);
+ Class++;
+ }
+ if (AmbiguousBases.empty())
+ return;
+ for (MSRTTIClass &Class : Classes)
+ if (AmbiguousBases.count(Class.RD))
+ Class.Flags |= MSRTTIClass::IsAmbiguous;
+}
+
+llvm::GlobalVariable *MSRTTIBuilder::getClassHierarchyDescriptor() {
+ SmallString<256> MangledName;
+ {
+ llvm::raw_svector_ostream Out(MangledName);
+ Mangler.mangleCXXRTTIClassHierarchyDescriptor(RD, Out);
+ }
+
+ // Check to see if we've already declared this ClassHierarchyDescriptor.
+ if (auto CHD = Module.getNamedGlobal(MangledName))
+ return CHD;
+
+ // Serialize the class hierarchy and initialize the CHD Fields.
+ SmallVector<MSRTTIClass, 8> Classes;
+ serializeClassHierarchy(Classes, RD);
+ Classes.front().initialize(/*Parent=*/nullptr, /*Specifier=*/nullptr);
+ detectAmbiguousBases(Classes);
+ int Flags = 0;
+ for (auto Class : Classes) {
+ if (Class.RD->getNumBases() > 1)
+ Flags |= HasBranchingHierarchy;
+ // Note: cl.exe does not calculate "HasAmbiguousBases" correctly. We
+ // believe the field isn't actually used.
+ if (Class.Flags & MSRTTIClass::IsAmbiguous)
+ Flags |= HasAmbiguousBases;
+ }
+ if ((Flags & HasBranchingHierarchy) && RD->getNumVBases() != 0)
+ Flags |= HasVirtualBranchingHierarchy;
+ // These gep indices are used to get the address of the first element of the
+ // base class array.
+ llvm::Value *GEPIndices[] = {llvm::ConstantInt::get(CGM.IntTy, 0),
+ llvm::ConstantInt::get(CGM.IntTy, 0)};
+
+ // Forward-declare the class hierarchy descriptor
+ auto Type = getClassHierarchyDescriptorType(CGM);
+ auto CHD = new llvm::GlobalVariable(Module, Type, /*Constant=*/true, Linkage,
+ /*Initializer=*/nullptr,
+ MangledName.c_str());
+
+ // Initialize the base class ClassHierarchyDescriptor.
+ llvm::Constant *Fields[] = {
+ llvm::ConstantInt::get(CGM.IntTy, 0), // Unknown
+ llvm::ConstantInt::get(CGM.IntTy, Flags),
+ llvm::ConstantInt::get(CGM.IntTy, Classes.size()),
+ getImageRelativeConstant(CGM,
+ llvm::ConstantExpr::getInBoundsGetElementPtr(
+ getBaseClassArray(Classes),
+ llvm::ArrayRef<llvm::Value *>(GEPIndices))),
+ };
+ CHD->setInitializer(llvm::ConstantStruct::get(Type, Fields));
+ return CHD;
+}
+
+llvm::GlobalVariable *
+MSRTTIBuilder::getBaseClassArray(SmallVectorImpl<MSRTTIClass> &Classes) {
+ SmallString<256> MangledName;
+ {
+ llvm::raw_svector_ostream Out(MangledName);
+ Mangler.mangleCXXRTTIBaseClassArray(RD, Out);
+ }
+
+ // Forward-declare the base class array.
+ // cl.exe pads the base class array with 1 (in 32 bit mode) or 4 (in 64 bit
+ // mode) bytes of padding. We provide a pointer sized amount of padding by
+ // adding +1 to Classes.size(). The sections have pointer alignment and are
+ // marked pick-any so it shouldn't matter.
+ auto PtrType = getImageRelativeType(
+ CGM, getBaseClassDescriptorType(CGM)->getPointerTo());
+ auto ArrayType = llvm::ArrayType::get(PtrType, Classes.size() + 1);
+ auto BCA = new llvm::GlobalVariable(Module, ArrayType,
+ /*Constant=*/true, Linkage, /*Initializer=*/nullptr, MangledName.c_str());
+
+ // Initialize the BaseClassArray.
+ SmallVector<llvm::Constant *, 8> BaseClassArrayData;
+ for (MSRTTIClass &Class : Classes)
+ BaseClassArrayData.push_back(
+ getImageRelativeConstant(CGM, getBaseClassDescriptor(Class)));
+ BaseClassArrayData.push_back(llvm::Constant::getNullValue(PtrType));
+ BCA->setInitializer(llvm::ConstantArray::get(ArrayType, BaseClassArrayData));
+ return BCA;
+}
+
+llvm::GlobalVariable *
+MSRTTIBuilder::getBaseClassDescriptor(const MSRTTIClass &Class) {
+ // Compute the fields for the BaseClassDescriptor. They are computed up front
+ // because they are mangled into the name of the object.
+ uint32_t OffsetInVBTable = 0;
+ int32_t VBPtrOffset = -1;
+ if (Class.VirtualRoot) {
+ auto &VTableContext = CGM.getMicrosoftVTableContext();
+ OffsetInVBTable = VTableContext.getVBTableIndex(RD, Class.VirtualRoot) * 4;
+ VBPtrOffset = Context.getASTRecordLayout(RD).getVBPtrOffset().getQuantity();
+ }
+
+ SmallString<256> MangledName;
+ {
+ llvm::raw_svector_ostream Out(MangledName);
+ Mangler.mangleCXXRTTIBaseClassDescriptor(Class.RD, Class.OffsetInVBase,
+ VBPtrOffset, OffsetInVBTable,
+ Class.Flags, Out);
+ }
+
+ // Check to see if we've already declared declared this object.
+ if (auto BCD = Module.getNamedGlobal(MangledName))
+ return BCD;
+
+ // Forward-declare the base class descriptor.
+ auto Type = getBaseClassDescriptorType(CGM);
+ auto BCD = new llvm::GlobalVariable(Module, Type, /*Constant=*/true, Linkage,
+ /*Initializer=*/nullptr,
+ MangledName.c_str());
+
+ // Initialize the BaseClassDescriptor.
+ llvm::Constant *Fields[] = {
+ getImageRelativeConstant(
+ CGM, CGM.GetAddrOfRTTIDescriptor(Context.getTypeDeclType(Class.RD))),
+ llvm::ConstantInt::get(CGM.IntTy, Class.NumBases),
+ llvm::ConstantInt::get(CGM.IntTy, Class.OffsetInVBase),
+ llvm::ConstantInt::get(CGM.IntTy, VBPtrOffset),
+ llvm::ConstantInt::get(CGM.IntTy, OffsetInVBTable),
+ llvm::ConstantInt::get(CGM.IntTy, Class.Flags),
+ getImageRelativeConstant(
+ CGM, MSRTTIBuilder(CGM, Class.RD).getClassHierarchyDescriptor()),
+ };
+ BCD->setInitializer(llvm::ConstantStruct::get(Type, Fields));
+ return BCD;
+}
+
+llvm::GlobalVariable *
+MSRTTIBuilder::getCompleteObjectLocator(const VPtrInfo *Info) {
+ SmallString<256> MangledName;
+ {
+ llvm::raw_svector_ostream Out(MangledName);
+ Mangler.mangleCXXRTTICompleteObjectLocator(RD, Info->MangledPath, Out);
+ }
+
+ // Check to see if we've already computed this complete object locator.
+ if (auto COL = Module.getNamedGlobal(MangledName))
+ return COL;
+
+ // Compute the fields of the complete object locator.
+ int OffsetToTop = Info->FullOffsetInMDC.getQuantity();
+ int VFPtrOffset = 0;
+ // The offset includes the vtordisp if one exists.
+ if (const CXXRecordDecl *VBase = Info->getVBaseWithVPtr())
+ if (Context.getASTRecordLayout(RD)
+ .getVBaseOffsetsMap()
+ .find(VBase)
+ ->second.hasVtorDisp())
+ VFPtrOffset = Info->NonVirtualOffset.getQuantity() + 4;
+
+ // Forward-declare the complete object locator.
+ llvm::StructType *Type = getCompleteObjectLocatorType(CGM);
+ auto COL = new llvm::GlobalVariable(Module, Type, /*Constant=*/true, Linkage,
+ /*Initializer=*/nullptr, MangledName.c_str());
+
+ // Initialize the CompleteObjectLocator.
+ llvm::Constant *Fields[] = {
+ llvm::ConstantInt::get(CGM.IntTy, isImageRelative(CGM)),
+ llvm::ConstantInt::get(CGM.IntTy, OffsetToTop),
+ llvm::ConstantInt::get(CGM.IntTy, VFPtrOffset),
+ getImageRelativeConstant(
+ CGM, CGM.GetAddrOfRTTIDescriptor(Context.getTypeDeclType(RD))),
+ getImageRelativeConstant(CGM, getClassHierarchyDescriptor()),
+ getImageRelativeConstant(CGM, COL),
+ };
+ llvm::ArrayRef<llvm::Constant *> FieldsRef(Fields);
+ if (!isImageRelative(CGM))
+ FieldsRef = FieldsRef.slice(0, FieldsRef.size() - 1);
+ COL->setInitializer(llvm::ConstantStruct::get(Type, FieldsRef));
+ return COL;
+}
+
+/// \brief Gets a TypeDescriptor. Returns a llvm::Constant * rather than a
+/// llvm::GlobalVariable * because different type descriptors have different
+/// types, and need to be abstracted. They are abstracting by casting the
+/// address to an Int8PtrTy.
+llvm::Constant *MicrosoftCXXABI::getAddrOfRTTIDescriptor(QualType Type) {
+ auto &Mangler(getMangleContext());
+ SmallString<256> MangledName, TypeInfoString;
+ {
+ llvm::raw_svector_ostream Out(MangledName);
+ Mangler.mangleCXXRTTI(Type, Out);
+ }
+
+ // Check to see if we've already declared this TypeDescriptor.
+ if (llvm::GlobalVariable *GV = CGM.getModule().getNamedGlobal(MangledName))
+ return llvm::ConstantExpr::getBitCast(GV, CGM.Int8PtrTy);
+
+ // Compute the fields for the TypeDescriptor.
+ {
+ llvm::raw_svector_ostream Out(TypeInfoString);
+ Mangler.mangleCXXRTTIName(Type, Out);
+ }
+
+ // Declare and initialize the TypeDescriptor.
+ llvm::Constant *Fields[] = {
+ getTypeInfoVTable(CGM), // VFPtr
+ llvm::ConstantPointerNull::get(CGM.Int8PtrTy), // Runtime data
+ llvm::ConstantDataArray::getString(CGM.getLLVMContext(), TypeInfoString)};
+ llvm::StructType *TypeDescriptorType =
+ getTypeDescriptorType(CGM, TypeInfoString);
+ return llvm::ConstantExpr::getBitCast(
+ new llvm::GlobalVariable(
+ CGM.getModule(), TypeDescriptorType, /*Constant=*/false,
+ getLinkageForRTTI(Type),
+ llvm::ConstantStruct::get(TypeDescriptorType, Fields),
+ MangledName.c_str()),
+ CGM.Int8PtrTy);
+}
+
+/// \brief Gets or a creates a Microsoft CompleteObjectLocator.
+llvm::GlobalVariable *
+MicrosoftCXXABI::getMSCompleteObjectLocator(const CXXRecordDecl *RD,
+ const VPtrInfo *Info) {
+ return MSRTTIBuilder(CGM, RD).getCompleteObjectLocator(Info);
+}
Removed: cfe/trunk/lib/CodeGen/MicrosoftRTTI.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/MicrosoftRTTI.cpp?rev=212434&view=auto
==============================================================================
--- cfe/trunk/lib/CodeGen/MicrosoftRTTI.cpp (original)
+++ cfe/trunk/lib/CodeGen/MicrosoftRTTI.cpp (removed)
@@ -1,529 +0,0 @@
-//===--- CGCXXRTTI.cpp - Emit LLVM Code for C++ RTTI descriptors ----------===//
-//
-// The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-// This contains code dealing with C++ code generation of RTTI descriptors.
-//
-//===----------------------------------------------------------------------===//
-
-#include "CodeGenModule.h"
-#include "CGCXXABI.h"
-#include "CGObjCRuntime.h"
-#include "clang/AST/RecordLayout.h"
-#include "clang/AST/Type.h"
-#include "clang/Frontend/CodeGenOptions.h"
-
-using namespace clang;
-using namespace CodeGen;
-
-// MS RTTI Overview:
-// The run time type information emitted by cl.exe contains 5 distinct types of
-// structures. Many of them reference each other.
-//
-// TypeInfo: Static classes that are returned by typeid.
-//
-// CompleteObjectLocator: Referenced by vftables. They contain information
-// required for dynamic casting, including OffsetFromTop. They also contain
-// a reference to the TypeInfo for the type and a reference to the
-// CompleteHierarchyDescriptor for the type.
-//
-// ClassHieararchyDescriptor: Contains information about a class hierarchy.
-// Used during dynamic_cast to walk a class hierarchy. References a base
-// class array and the size of said array.
-//
-// BaseClassArray: Contains a list of classes in a hierarchy. BaseClassArray is
-// somewhat of a misnomer because the most derived class is also in the list
-// as well as multiple copies of virtual bases (if they occur multiple times
-// in the hiearchy.) The BaseClassArray contains one BaseClassDescriptor for
-// every path in the hierarchy, in pre-order depth first order. Note, we do
-// not declare a specific llvm type for BaseClassArray, it's merely an array
-// of BaseClassDescriptor pointers.
-//
-// BaseClassDescriptor: Contains information about a class in a class hierarchy.
-// BaseClassDescriptor is also somewhat of a misnomer for the same reason that
-// BaseClassArray is. It contains information about a class within a
-// hierarchy such as: is this base is ambiguous and what is its offset in the
-// vbtable. The names of the BaseClassDescriptors have all of their fields
-// mangled into them so they can be aggressively deduplicated by the linker.
-
-static bool isImageRelative(CodeGenModule &CGM) {
- return CGM.getTarget().getPointerWidth(/*AddressSpace=*/0) == 64;
-}
-
-static llvm::Type *getImageRelativeType(CodeGenModule &CGM,
- llvm::Type *PtrType) {
- if (!isImageRelative(CGM))
- return PtrType;
- return CGM.IntTy;
-}
-
-static llvm::GlobalVariable *getImageBase(CodeGenModule &CGM) {
- StringRef Name = "__ImageBase";
- if (llvm::GlobalVariable *GV = CGM.getModule().getNamedGlobal(Name))
- return GV;
-
- return new llvm::GlobalVariable(CGM.getModule(), CGM.Int8Ty,
- /*isConstant=*/true,
- llvm::GlobalValue::ExternalLinkage,
- /*Initializer=*/nullptr, Name);
-}
-
-static llvm::Constant *getImageRelativeConstant(CodeGenModule &CGM,
- llvm::Constant *PtrVal) {
- if (!isImageRelative(CGM))
- return PtrVal;
-
- llvm::Constant *ImageBaseAsInt =
- llvm::ConstantExpr::getPtrToInt(getImageBase(CGM), CGM.IntPtrTy);
- llvm::Constant *PtrValAsInt =
- llvm::ConstantExpr::getPtrToInt(PtrVal, CGM.IntPtrTy);
- llvm::Constant *Diff =
- llvm::ConstantExpr::getSub(PtrValAsInt, ImageBaseAsInt,
- /*HasNUW=*/true, /*HasNSW=*/true);
- return llvm::ConstantExpr::getTrunc(Diff, CGM.IntTy);
-}
-
-// 5 routines for constructing the llvm types for MS RTTI structs.
-static llvm::StructType *getClassHierarchyDescriptorType(CodeGenModule &CGM);
-
-static llvm::StructType *getTypeDescriptorType(CodeGenModule &CGM,
- StringRef TypeInfoString) {
- llvm::SmallString<32> TDTypeName("MSRTTITypeDescriptor");
- TDTypeName += TypeInfoString.size();
- if (auto Type = CGM.getModule().getTypeByName(TDTypeName))
- return Type;
- llvm::Type *FieldTypes[] = {
- CGM.Int8PtrPtrTy,
- CGM.Int8PtrTy,
- llvm::ArrayType::get(CGM.Int8Ty, TypeInfoString.size() + 1)};
- return llvm::StructType::create(CGM.getLLVMContext(), FieldTypes, TDTypeName);
-}
-
-static llvm::StructType *getBaseClassDescriptorType(CodeGenModule &CGM) {
- static const char Name[] = "MSRTTIBaseClassDescriptor";
- if (auto Type = CGM.getModule().getTypeByName(Name))
- return Type;
- llvm::Type *FieldTypes[] = {
- getImageRelativeType(CGM, CGM.Int8PtrTy),
- CGM.IntTy,
- CGM.IntTy,
- CGM.IntTy,
- CGM.IntTy,
- CGM.IntTy,
- getImageRelativeType(
- CGM, getClassHierarchyDescriptorType(CGM)->getPointerTo()),
- };
- return llvm::StructType::create(CGM.getLLVMContext(), FieldTypes, Name);
-}
-
-static llvm::StructType *getClassHierarchyDescriptorType(CodeGenModule &CGM) {
- static const char Name[] = "MSRTTIClassHierarchyDescriptor";
- if (auto Type = CGM.getModule().getTypeByName(Name))
- return Type;
- // Forward-declare RTTIClassHierarchyDescriptor to break a cycle.
- llvm::StructType *Type = llvm::StructType::create(CGM.getLLVMContext(), Name);
- llvm::Type *FieldTypes[] = {
- CGM.IntTy,
- CGM.IntTy,
- CGM.IntTy,
- getImageRelativeType(
- CGM,
- getBaseClassDescriptorType(CGM)->getPointerTo()->getPointerTo()),
- };
- Type->setBody(FieldTypes);
- return Type;
-}
-
-static llvm::StructType *getCompleteObjectLocatorType(CodeGenModule &CGM) {
- static const char Name[] = "MSRTTICompleteObjectLocator";
- if (auto Type = CGM.getModule().getTypeByName(Name))
- return Type;
- llvm::StructType *Type = llvm::StructType::create(CGM.getLLVMContext(), Name);
- llvm::Type *FieldTypes[] = {
- CGM.IntTy,
- CGM.IntTy,
- CGM.IntTy,
- getImageRelativeType(CGM, CGM.Int8PtrTy),
- getImageRelativeType(
- CGM, getClassHierarchyDescriptorType(CGM)->getPointerTo()),
- getImageRelativeType(CGM, Type),
- };
- ArrayRef<llvm::Type *> FieldTypesRef(
- std::begin(FieldTypes),
- isImageRelative(CGM) ? std::end(FieldTypes) : std::end(FieldTypes) - 1);
- Type->setBody(FieldTypesRef);
- return Type;
-}
-
-static llvm::GlobalVariable *getTypeInfoVTable(CodeGenModule &CGM) {
- StringRef MangledName("\01??_7type_info@@6B@");
- if (auto VTable = CGM.getModule().getNamedGlobal(MangledName))
- return VTable;
- return new llvm::GlobalVariable(CGM.getModule(), CGM.Int8PtrTy,
- /*Constant=*/true,
- llvm::GlobalVariable::ExternalLinkage,
- /*Initializer=*/nullptr, MangledName);
-}
-
-namespace {
-
-/// \brief A Helper struct that stores information about a class in a class
-/// hierarchy. The information stored in these structs struct is used during
-/// the generation of ClassHierarchyDescriptors and BaseClassDescriptors.
-// During RTTI creation, MSRTTIClasses are stored in a contiguous array with
-// implicit depth first pre-order tree connectivity. getFirstChild and
-// getNextSibling allow us to walk the tree efficiently.
-struct MSRTTIClass {
- enum {
- IsPrivateOnPath = 1 | 8,
- IsAmbiguous = 2,
- IsPrivate = 4,
- IsVirtual = 16,
- HasHierarchyDescriptor = 64
- };
- MSRTTIClass(const CXXRecordDecl *RD) : RD(RD) {}
- uint32_t initialize(const MSRTTIClass *Parent,
- const CXXBaseSpecifier *Specifier);
-
- MSRTTIClass *getFirstChild() { return this + 1; }
- static MSRTTIClass *getNextChild(MSRTTIClass *Child) {
- return Child + 1 + Child->NumBases;
- }
-
- const CXXRecordDecl *RD, *VirtualRoot;
- uint32_t Flags, NumBases, OffsetInVBase;
-};
-
-/// \brief Recursively initialize the base class array.
-uint32_t MSRTTIClass::initialize(const MSRTTIClass *Parent,
- const CXXBaseSpecifier *Specifier) {
- Flags = HasHierarchyDescriptor;
- if (!Parent) {
- VirtualRoot = nullptr;
- OffsetInVBase = 0;
- } else {
- if (Specifier->getAccessSpecifier() != AS_public)
- Flags |= IsPrivate | IsPrivateOnPath;
- if (Specifier->isVirtual()) {
- Flags |= IsVirtual;
- VirtualRoot = RD;
- OffsetInVBase = 0;
- } else {
- if (Parent->Flags & IsPrivateOnPath)
- Flags |= IsPrivateOnPath;
- VirtualRoot = Parent->VirtualRoot;
- OffsetInVBase = Parent->OffsetInVBase + RD->getASTContext()
- .getASTRecordLayout(Parent->RD).getBaseClassOffset(RD).getQuantity();
- }
- }
- NumBases = 0;
- MSRTTIClass *Child = getFirstChild();
- for (const CXXBaseSpecifier &Base : RD->bases()) {
- NumBases += Child->initialize(this, &Base) + 1;
- Child = getNextChild(Child);
- }
- return NumBases;
-}
-
-static llvm::GlobalValue::LinkageTypes getLinkageForRTTI(QualType Ty) {
- switch (Ty->getLinkage()) {
- case NoLinkage:
- case InternalLinkage:
- case UniqueExternalLinkage:
- return llvm::GlobalValue::InternalLinkage;
-
- case VisibleNoLinkage:
- case ExternalLinkage:
- return llvm::GlobalValue::LinkOnceODRLinkage;
- }
- llvm_unreachable("Invalid linkage!");
-}
-
-/// \brief An ephemeral helper class for building MS RTTI types. It caches some
-/// calls to the module and information about the most derived class in a
-/// hierarchy.
-struct MSRTTIBuilder {
- enum {
- HasBranchingHierarchy = 1,
- HasVirtualBranchingHierarchy = 2,
- HasAmbiguousBases = 4
- };
-
- MSRTTIBuilder(CodeGenModule &CGM, const CXXRecordDecl *RD)
- : CGM(CGM), Context(CGM.getContext()), VMContext(CGM.getLLVMContext()),
- Module(CGM.getModule()), RD(RD),
- Linkage(getLinkageForRTTI(CGM.getContext().getTagDeclType(RD))),
- Mangler(
- cast<MicrosoftMangleContext>(CGM.getCXXABI().getMangleContext())) {}
-
- llvm::GlobalVariable *getBaseClassDescriptor(const MSRTTIClass &Classes);
- llvm::GlobalVariable *
- getBaseClassArray(SmallVectorImpl<MSRTTIClass> &Classes);
- llvm::GlobalVariable *getClassHierarchyDescriptor();
- llvm::GlobalVariable *getCompleteObjectLocator(const VPtrInfo *Info);
-
- CodeGenModule &CGM;
- ASTContext &Context;
- llvm::LLVMContext &VMContext;
- llvm::Module &Module;
- const CXXRecordDecl *RD;
- llvm::GlobalVariable::LinkageTypes Linkage;
- MicrosoftMangleContext &Mangler;
-};
-
-} // namespace
-
-/// \brief Recursively serializes a class hierarchy in pre-order depth first
-/// order.
-static void serializeClassHierarchy(SmallVectorImpl<MSRTTIClass> &Classes,
- const CXXRecordDecl *RD) {
- Classes.push_back(MSRTTIClass(RD));
- for (const CXXBaseSpecifier &Base : RD->bases())
- serializeClassHierarchy(Classes, Base.getType()->getAsCXXRecordDecl());
-}
-
-/// \brief Find ambiguity among base classes.
-static void
-detectAmbiguousBases(SmallVectorImpl<MSRTTIClass> &Classes) {
- llvm::SmallPtrSet<const CXXRecordDecl *, 8> VirtualBases;
- llvm::SmallPtrSet<const CXXRecordDecl *, 8> UniqueBases;
- llvm::SmallPtrSet<const CXXRecordDecl *, 8> AmbiguousBases;
- for (MSRTTIClass *Class = &Classes.front(); Class <= &Classes.back();) {
- if ((Class->Flags & MSRTTIClass::IsVirtual) &&
- !VirtualBases.insert(Class->RD)) {
- Class = MSRTTIClass::getNextChild(Class);
- continue;
- }
- if (!UniqueBases.insert(Class->RD))
- AmbiguousBases.insert(Class->RD);
- Class++;
- }
- if (AmbiguousBases.empty())
- return;
- for (MSRTTIClass &Class : Classes)
- if (AmbiguousBases.count(Class.RD))
- Class.Flags |= MSRTTIClass::IsAmbiguous;
-}
-
-llvm::GlobalVariable *MSRTTIBuilder::getClassHierarchyDescriptor() {
- SmallString<256> MangledName;
- {
- llvm::raw_svector_ostream Out(MangledName);
- Mangler.mangleCXXRTTIClassHierarchyDescriptor(RD, Out);
- }
-
- // Check to see if we've already declared this ClassHierarchyDescriptor.
- if (auto CHD = Module.getNamedGlobal(MangledName))
- return CHD;
-
- // Serialize the class hierarchy and initialize the CHD Fields.
- SmallVector<MSRTTIClass, 8> Classes;
- serializeClassHierarchy(Classes, RD);
- Classes.front().initialize(/*Parent=*/nullptr, /*Specifier=*/nullptr);
- detectAmbiguousBases(Classes);
- int Flags = 0;
- for (auto Class : Classes) {
- if (Class.RD->getNumBases() > 1)
- Flags |= HasBranchingHierarchy;
- // Note: cl.exe does not calculate "HasAmbiguousBases" correctly. We
- // believe the field isn't actually used.
- if (Class.Flags & MSRTTIClass::IsAmbiguous)
- Flags |= HasAmbiguousBases;
- }
- if ((Flags & HasBranchingHierarchy) && RD->getNumVBases() != 0)
- Flags |= HasVirtualBranchingHierarchy;
- // These gep indices are used to get the address of the first element of the
- // base class array.
- llvm::Value *GEPIndices[] = {llvm::ConstantInt::get(CGM.IntTy, 0),
- llvm::ConstantInt::get(CGM.IntTy, 0)};
-
- // Forward-declare the class hierarchy descriptor
- auto Type = getClassHierarchyDescriptorType(CGM);
- auto CHD = new llvm::GlobalVariable(Module, Type, /*Constant=*/true, Linkage,
- /*Initializer=*/nullptr,
- MangledName.c_str());
-
- // Initialize the base class ClassHierarchyDescriptor.
- llvm::Constant *Fields[] = {
- llvm::ConstantInt::get(CGM.IntTy, 0), // Unknown
- llvm::ConstantInt::get(CGM.IntTy, Flags),
- llvm::ConstantInt::get(CGM.IntTy, Classes.size()),
- getImageRelativeConstant(CGM,
- llvm::ConstantExpr::getInBoundsGetElementPtr(
- getBaseClassArray(Classes),
- ArrayRef<llvm::Value *>(GEPIndices))),
- };
- CHD->setInitializer(llvm::ConstantStruct::get(Type, Fields));
- return CHD;
-}
-
-llvm::GlobalVariable *
-MSRTTIBuilder::getBaseClassArray(SmallVectorImpl<MSRTTIClass> &Classes) {
- SmallString<256> MangledName;
- {
- llvm::raw_svector_ostream Out(MangledName);
- Mangler.mangleCXXRTTIBaseClassArray(RD, Out);
- }
-
- // Forward-declare the base class array.
- // cl.exe pads the base class array with 1 (in 32 bit mode) or 4 (in 64 bit
- // mode) bytes of padding. We provide a pointer sized amount of padding by
- // adding +1 to Classes.size(). The sections have pointer alignment and are
- // marked pick-any so it shouldn't matter.
- auto PtrType = getImageRelativeType(
- CGM, getBaseClassDescriptorType(CGM)->getPointerTo());
- auto ArrayType = llvm::ArrayType::get(PtrType, Classes.size() + 1);
- auto BCA = new llvm::GlobalVariable(Module, ArrayType,
- /*Constant=*/true, Linkage, /*Initializer=*/nullptr, MangledName.c_str());
-
- // Initialize the BaseClassArray.
- SmallVector<llvm::Constant *, 8> BaseClassArrayData;
- for (MSRTTIClass &Class : Classes)
- BaseClassArrayData.push_back(
- getImageRelativeConstant(CGM, getBaseClassDescriptor(Class)));
- BaseClassArrayData.push_back(llvm::Constant::getNullValue(PtrType));
- BCA->setInitializer(llvm::ConstantArray::get(ArrayType, BaseClassArrayData));
- return BCA;
-}
-
-llvm::GlobalVariable *
-MSRTTIBuilder::getBaseClassDescriptor(const MSRTTIClass &Class) {
- // Compute the fields for the BaseClassDescriptor. They are computed up front
- // because they are mangled into the name of the object.
- uint32_t OffsetInVBTable = 0;
- int32_t VBPtrOffset = -1;
- if (Class.VirtualRoot) {
- auto &VTableContext = CGM.getMicrosoftVTableContext();
- OffsetInVBTable = VTableContext.getVBTableIndex(RD, Class.VirtualRoot) * 4;
- VBPtrOffset = Context.getASTRecordLayout(RD).getVBPtrOffset().getQuantity();
- }
-
- SmallString<256> MangledName;
- {
- llvm::raw_svector_ostream Out(MangledName);
- Mangler.mangleCXXRTTIBaseClassDescriptor(Class.RD, Class.OffsetInVBase,
- VBPtrOffset, OffsetInVBTable,
- Class.Flags, Out);
- }
-
- // Check to see if we've already declared declared this object.
- if (auto BCD = Module.getNamedGlobal(MangledName))
- return BCD;
-
- // Forward-declare the base class descriptor.
- auto Type = getBaseClassDescriptorType(CGM);
- auto BCD = new llvm::GlobalVariable(Module, Type, /*Constant=*/true, Linkage,
- /*Initializer=*/nullptr,
- MangledName.c_str());
-
- // Initialize the BaseClassDescriptor.
- llvm::Constant *Fields[] = {
- getImageRelativeConstant(
- CGM, CGM.getMSTypeDescriptor(Context.getTypeDeclType(Class.RD))),
- llvm::ConstantInt::get(CGM.IntTy, Class.NumBases),
- llvm::ConstantInt::get(CGM.IntTy, Class.OffsetInVBase),
- llvm::ConstantInt::get(CGM.IntTy, VBPtrOffset),
- llvm::ConstantInt::get(CGM.IntTy, OffsetInVBTable),
- llvm::ConstantInt::get(CGM.IntTy, Class.Flags),
- getImageRelativeConstant(
- CGM, MSRTTIBuilder(CGM, Class.RD).getClassHierarchyDescriptor()),
- };
- BCD->setInitializer(llvm::ConstantStruct::get(Type, Fields));
- return BCD;
-}
-
-llvm::GlobalVariable *
-MSRTTIBuilder::getCompleteObjectLocator(const VPtrInfo *Info) {
- SmallString<256> MangledName;
- {
- llvm::raw_svector_ostream Out(MangledName);
- Mangler.mangleCXXRTTICompleteObjectLocator(RD, Info->MangledPath, Out);
- }
-
- // Check to see if we've already computed this complete object locator.
- if (auto COL = Module.getNamedGlobal(MangledName))
- return COL;
-
- // Compute the fields of the complete object locator.
- int OffsetToTop = Info->FullOffsetInMDC.getQuantity();
- int VFPtrOffset = 0;
- // The offset includes the vtordisp if one exists.
- if (const CXXRecordDecl *VBase = Info->getVBaseWithVPtr())
- if (Context.getASTRecordLayout(RD)
- .getVBaseOffsetsMap()
- .find(VBase)
- ->second.hasVtorDisp())
- VFPtrOffset = Info->NonVirtualOffset.getQuantity() + 4;
-
- // Forward-declare the complete object locator.
- llvm::StructType *Type = getCompleteObjectLocatorType(CGM);
- auto COL = new llvm::GlobalVariable(Module, Type, /*Constant=*/true, Linkage,
- /*Initializer=*/nullptr, MangledName.c_str());
-
- // Initialize the CompleteObjectLocator.
- llvm::Constant *Fields[] = {
- llvm::ConstantInt::get(CGM.IntTy, isImageRelative(CGM)),
- llvm::ConstantInt::get(CGM.IntTy, OffsetToTop),
- llvm::ConstantInt::get(CGM.IntTy, VFPtrOffset),
- getImageRelativeConstant(
- CGM, CGM.getMSTypeDescriptor(Context.getTypeDeclType(RD))),
- getImageRelativeConstant(CGM, getClassHierarchyDescriptor()),
- getImageRelativeConstant(CGM, COL),
- };
- ArrayRef<llvm::Constant *> FieldsRef(Fields);
- if (!isImageRelative(CGM))
- FieldsRef = FieldsRef.slice(0, FieldsRef.size() - 1);
- COL->setInitializer(llvm::ConstantStruct::get(Type, FieldsRef));
- return COL;
-}
-
-
-/// \brief Gets a TypeDescriptor. Returns a llvm::Constant * rather than a
-/// llvm::GlobalVariable * because different type descriptors have different
-/// types, and need to be abstracted. They are abstracting by casting the
-/// address to an Int8PtrTy.
-llvm::Constant *CodeGenModule::getMSTypeDescriptor(QualType Type) {
- auto &Mangler(cast<MicrosoftMangleContext>(getCXXABI().getMangleContext()));
- SmallString<256> MangledName, TypeInfoString;
- {
- llvm::raw_svector_ostream Out(MangledName);
- Mangler.mangleCXXRTTI(Type, Out);
- }
-
- // Check to see if we've already declared this TypeDescriptor.
- if (auto TypeDescriptor = getModule().getNamedGlobal(MangledName))
- return llvm::ConstantExpr::getBitCast(TypeDescriptor, Int8PtrTy);
-
- // Compute the fields for the TypeDescriptor.
- {
- llvm::raw_svector_ostream Out(TypeInfoString);
- Mangler.mangleCXXRTTIName(Type, Out);
- }
-
- // Declare and initialize the TypeDescriptor.
- llvm::Constant *Fields[] = {
- getTypeInfoVTable(*this), // VFPtr
- llvm::ConstantPointerNull::get(Int8PtrTy), // Runtime data
- llvm::ConstantDataArray::getString(VMContext, TypeInfoString)};
- auto TypeDescriptorType = getTypeDescriptorType(*this, TypeInfoString);
- return llvm::ConstantExpr::getBitCast(
- new llvm::GlobalVariable(
- getModule(), TypeDescriptorType, /*Constant=*/false,
- getLinkageForRTTI(Type),
- llvm::ConstantStruct::get(TypeDescriptorType, Fields),
- MangledName.c_str()),
- Int8PtrTy);
-}
-
-llvm::Constant *
-CodeGenModule::getMSCompleteObjectLocator(const CXXRecordDecl *RD,
- const VPtrInfo *Info) {
- if (!getLangOpts().RTTIData)
- return llvm::Constant::getNullValue(Int8PtrTy);
- return MSRTTIBuilder(*this, RD).getCompleteObjectLocator(Info);
-}
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