forked from OSchip/llvm-project
2793 lines
104 KiB
C++
2793 lines
104 KiB
C++
//===--- CGClass.cpp - Emit LLVM Code for C++ classes -----------*- C++ -*-===//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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//
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// This contains code dealing with C++ code generation of classes
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//
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//===----------------------------------------------------------------------===//
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#include "CGBlocks.h"
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#include "CGCXXABI.h"
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#include "CGDebugInfo.h"
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#include "CGRecordLayout.h"
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#include "CodeGenFunction.h"
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#include "clang/AST/CXXInheritance.h"
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#include "clang/AST/DeclTemplate.h"
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#include "clang/AST/EvaluatedExprVisitor.h"
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#include "clang/AST/RecordLayout.h"
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#include "clang/AST/StmtCXX.h"
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#include "clang/Basic/TargetBuiltins.h"
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#include "clang/CodeGen/CGFunctionInfo.h"
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#include "clang/Frontend/CodeGenOptions.h"
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#include "llvm/IR/Intrinsics.h"
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#include "llvm/IR/Metadata.h"
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using namespace clang;
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using namespace CodeGen;
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/// Return the best known alignment for an unknown pointer to a
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/// particular class.
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CharUnits CodeGenModule::getClassPointerAlignment(const CXXRecordDecl *RD) {
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if (!RD->isCompleteDefinition())
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return CharUnits::One(); // Hopefully won't be used anywhere.
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auto &layout = getContext().getASTRecordLayout(RD);
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// If the class is final, then we know that the pointer points to an
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// object of that type and can use the full alignment.
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if (RD->hasAttr<FinalAttr>()) {
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return layout.getAlignment();
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// Otherwise, we have to assume it could be a subclass.
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} else {
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return layout.getNonVirtualAlignment();
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}
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}
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/// Return the best known alignment for a pointer to a virtual base,
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/// given the alignment of a pointer to the derived class.
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CharUnits CodeGenModule::getVBaseAlignment(CharUnits actualDerivedAlign,
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const CXXRecordDecl *derivedClass,
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const CXXRecordDecl *vbaseClass) {
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// The basic idea here is that an underaligned derived pointer might
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// indicate an underaligned base pointer.
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assert(vbaseClass->isCompleteDefinition());
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auto &baseLayout = getContext().getASTRecordLayout(vbaseClass);
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CharUnits expectedVBaseAlign = baseLayout.getNonVirtualAlignment();
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return getDynamicOffsetAlignment(actualDerivedAlign, derivedClass,
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expectedVBaseAlign);
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}
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CharUnits
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CodeGenModule::getDynamicOffsetAlignment(CharUnits actualBaseAlign,
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const CXXRecordDecl *baseDecl,
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CharUnits expectedTargetAlign) {
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// If the base is an incomplete type (which is, alas, possible with
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// member pointers), be pessimistic.
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if (!baseDecl->isCompleteDefinition())
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return std::min(actualBaseAlign, expectedTargetAlign);
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auto &baseLayout = getContext().getASTRecordLayout(baseDecl);
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CharUnits expectedBaseAlign = baseLayout.getNonVirtualAlignment();
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// If the class is properly aligned, assume the target offset is, too.
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//
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// This actually isn't necessarily the right thing to do --- if the
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// class is a complete object, but it's only properly aligned for a
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// base subobject, then the alignments of things relative to it are
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// probably off as well. (Note that this requires the alignment of
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// the target to be greater than the NV alignment of the derived
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// class.)
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//
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// However, our approach to this kind of under-alignment can only
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// ever be best effort; after all, we're never going to propagate
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// alignments through variables or parameters. Note, in particular,
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// that constructing a polymorphic type in an address that's less
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// than pointer-aligned will generally trap in the constructor,
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// unless we someday add some sort of attribute to change the
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// assumed alignment of 'this'. So our goal here is pretty much
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// just to allow the user to explicitly say that a pointer is
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// under-aligned and then safely access its fields and v-tables.
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if (actualBaseAlign >= expectedBaseAlign) {
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return expectedTargetAlign;
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}
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// Otherwise, we might be offset by an arbitrary multiple of the
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// actual alignment. The correct adjustment is to take the min of
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// the two alignments.
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return std::min(actualBaseAlign, expectedTargetAlign);
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}
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Address CodeGenFunction::LoadCXXThisAddress() {
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assert(CurFuncDecl && "loading 'this' without a func declaration?");
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assert(isa<CXXMethodDecl>(CurFuncDecl));
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// Lazily compute CXXThisAlignment.
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if (CXXThisAlignment.isZero()) {
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// Just use the best known alignment for the parent.
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// TODO: if we're currently emitting a complete-object ctor/dtor,
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// we can always use the complete-object alignment.
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auto RD = cast<CXXMethodDecl>(CurFuncDecl)->getParent();
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CXXThisAlignment = CGM.getClassPointerAlignment(RD);
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}
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return Address(LoadCXXThis(), CXXThisAlignment);
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}
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/// Emit the address of a field using a member data pointer.
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///
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/// \param E Only used for emergency diagnostics
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Address
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CodeGenFunction::EmitCXXMemberDataPointerAddress(const Expr *E, Address base,
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llvm::Value *memberPtr,
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const MemberPointerType *memberPtrType,
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AlignmentSource *alignSource) {
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// Ask the ABI to compute the actual address.
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llvm::Value *ptr =
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CGM.getCXXABI().EmitMemberDataPointerAddress(*this, E, base,
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memberPtr, memberPtrType);
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QualType memberType = memberPtrType->getPointeeType();
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CharUnits memberAlign = getNaturalTypeAlignment(memberType, alignSource);
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memberAlign =
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CGM.getDynamicOffsetAlignment(base.getAlignment(),
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memberPtrType->getClass()->getAsCXXRecordDecl(),
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memberAlign);
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return Address(ptr, memberAlign);
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}
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CharUnits CodeGenModule::computeNonVirtualBaseClassOffset(
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const CXXRecordDecl *DerivedClass, CastExpr::path_const_iterator Start,
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CastExpr::path_const_iterator End) {
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CharUnits Offset = CharUnits::Zero();
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const ASTContext &Context = getContext();
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const CXXRecordDecl *RD = DerivedClass;
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for (CastExpr::path_const_iterator I = Start; I != End; ++I) {
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const CXXBaseSpecifier *Base = *I;
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assert(!Base->isVirtual() && "Should not see virtual bases here!");
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// Get the layout.
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const ASTRecordLayout &Layout = Context.getASTRecordLayout(RD);
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const CXXRecordDecl *BaseDecl =
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cast<CXXRecordDecl>(Base->getType()->getAs<RecordType>()->getDecl());
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// Add the offset.
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Offset += Layout.getBaseClassOffset(BaseDecl);
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RD = BaseDecl;
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}
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return Offset;
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}
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llvm::Constant *
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CodeGenModule::GetNonVirtualBaseClassOffset(const CXXRecordDecl *ClassDecl,
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CastExpr::path_const_iterator PathBegin,
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CastExpr::path_const_iterator PathEnd) {
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assert(PathBegin != PathEnd && "Base path should not be empty!");
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CharUnits Offset =
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computeNonVirtualBaseClassOffset(ClassDecl, PathBegin, PathEnd);
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if (Offset.isZero())
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return nullptr;
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llvm::Type *PtrDiffTy =
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Types.ConvertType(getContext().getPointerDiffType());
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return llvm::ConstantInt::get(PtrDiffTy, Offset.getQuantity());
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}
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/// Gets the address of a direct base class within a complete object.
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/// This should only be used for (1) non-virtual bases or (2) virtual bases
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/// when the type is known to be complete (e.g. in complete destructors).
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///
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/// The object pointed to by 'This' is assumed to be non-null.
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Address
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CodeGenFunction::GetAddressOfDirectBaseInCompleteClass(Address This,
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const CXXRecordDecl *Derived,
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const CXXRecordDecl *Base,
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bool BaseIsVirtual) {
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// 'this' must be a pointer (in some address space) to Derived.
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assert(This.getElementType() == ConvertType(Derived));
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// Compute the offset of the virtual base.
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CharUnits Offset;
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const ASTRecordLayout &Layout = getContext().getASTRecordLayout(Derived);
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if (BaseIsVirtual)
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Offset = Layout.getVBaseClassOffset(Base);
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else
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Offset = Layout.getBaseClassOffset(Base);
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// Shift and cast down to the base type.
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// TODO: for complete types, this should be possible with a GEP.
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Address V = This;
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if (!Offset.isZero()) {
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V = Builder.CreateElementBitCast(V, Int8Ty);
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V = Builder.CreateConstInBoundsByteGEP(V, Offset);
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}
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V = Builder.CreateElementBitCast(V, ConvertType(Base));
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return V;
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}
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static Address
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ApplyNonVirtualAndVirtualOffset(CodeGenFunction &CGF, Address addr,
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CharUnits nonVirtualOffset,
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llvm::Value *virtualOffset,
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const CXXRecordDecl *derivedClass,
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const CXXRecordDecl *nearestVBase) {
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// Assert that we have something to do.
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assert(!nonVirtualOffset.isZero() || virtualOffset != nullptr);
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// Compute the offset from the static and dynamic components.
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llvm::Value *baseOffset;
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if (!nonVirtualOffset.isZero()) {
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baseOffset = llvm::ConstantInt::get(CGF.PtrDiffTy,
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nonVirtualOffset.getQuantity());
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if (virtualOffset) {
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baseOffset = CGF.Builder.CreateAdd(virtualOffset, baseOffset);
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}
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} else {
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baseOffset = virtualOffset;
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}
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// Apply the base offset.
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llvm::Value *ptr = addr.getPointer();
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ptr = CGF.Builder.CreateBitCast(ptr, CGF.Int8PtrTy);
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ptr = CGF.Builder.CreateInBoundsGEP(ptr, baseOffset, "add.ptr");
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// If we have a virtual component, the alignment of the result will
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// be relative only to the known alignment of that vbase.
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CharUnits alignment;
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if (virtualOffset) {
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assert(nearestVBase && "virtual offset without vbase?");
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alignment = CGF.CGM.getVBaseAlignment(addr.getAlignment(),
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derivedClass, nearestVBase);
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} else {
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alignment = addr.getAlignment();
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}
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alignment = alignment.alignmentAtOffset(nonVirtualOffset);
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return Address(ptr, alignment);
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}
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Address CodeGenFunction::GetAddressOfBaseClass(
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Address Value, const CXXRecordDecl *Derived,
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CastExpr::path_const_iterator PathBegin,
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CastExpr::path_const_iterator PathEnd, bool NullCheckValue,
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SourceLocation Loc) {
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assert(PathBegin != PathEnd && "Base path should not be empty!");
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CastExpr::path_const_iterator Start = PathBegin;
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const CXXRecordDecl *VBase = nullptr;
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// Sema has done some convenient canonicalization here: if the
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// access path involved any virtual steps, the conversion path will
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// *start* with a step down to the correct virtual base subobject,
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// and hence will not require any further steps.
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if ((*Start)->isVirtual()) {
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VBase =
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cast<CXXRecordDecl>((*Start)->getType()->getAs<RecordType>()->getDecl());
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++Start;
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}
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// Compute the static offset of the ultimate destination within its
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// allocating subobject (the virtual base, if there is one, or else
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// the "complete" object that we see).
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CharUnits NonVirtualOffset = CGM.computeNonVirtualBaseClassOffset(
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VBase ? VBase : Derived, Start, PathEnd);
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// If there's a virtual step, we can sometimes "devirtualize" it.
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// For now, that's limited to when the derived type is final.
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// TODO: "devirtualize" this for accesses to known-complete objects.
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if (VBase && Derived->hasAttr<FinalAttr>()) {
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const ASTRecordLayout &layout = getContext().getASTRecordLayout(Derived);
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CharUnits vBaseOffset = layout.getVBaseClassOffset(VBase);
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NonVirtualOffset += vBaseOffset;
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VBase = nullptr; // we no longer have a virtual step
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}
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// Get the base pointer type.
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llvm::Type *BasePtrTy =
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ConvertType((PathEnd[-1])->getType())->getPointerTo();
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QualType DerivedTy = getContext().getRecordType(Derived);
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CharUnits DerivedAlign = CGM.getClassPointerAlignment(Derived);
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// If the static offset is zero and we don't have a virtual step,
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// just do a bitcast; null checks are unnecessary.
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if (NonVirtualOffset.isZero() && !VBase) {
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if (sanitizePerformTypeCheck()) {
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EmitTypeCheck(TCK_Upcast, Loc, Value.getPointer(),
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DerivedTy, DerivedAlign, !NullCheckValue);
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}
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return Builder.CreateBitCast(Value, BasePtrTy);
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}
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llvm::BasicBlock *origBB = nullptr;
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llvm::BasicBlock *endBB = nullptr;
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// Skip over the offset (and the vtable load) if we're supposed to
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// null-check the pointer.
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if (NullCheckValue) {
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origBB = Builder.GetInsertBlock();
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llvm::BasicBlock *notNullBB = createBasicBlock("cast.notnull");
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endBB = createBasicBlock("cast.end");
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llvm::Value *isNull = Builder.CreateIsNull(Value.getPointer());
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Builder.CreateCondBr(isNull, endBB, notNullBB);
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EmitBlock(notNullBB);
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}
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if (sanitizePerformTypeCheck()) {
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EmitTypeCheck(VBase ? TCK_UpcastToVirtualBase : TCK_Upcast, Loc,
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Value.getPointer(), DerivedTy, DerivedAlign, true);
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}
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// Compute the virtual offset.
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llvm::Value *VirtualOffset = nullptr;
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if (VBase) {
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VirtualOffset =
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CGM.getCXXABI().GetVirtualBaseClassOffset(*this, Value, Derived, VBase);
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}
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// Apply both offsets.
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Value = ApplyNonVirtualAndVirtualOffset(*this, Value, NonVirtualOffset,
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VirtualOffset, Derived, VBase);
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// Cast to the destination type.
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Value = Builder.CreateBitCast(Value, BasePtrTy);
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// Build a phi if we needed a null check.
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if (NullCheckValue) {
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llvm::BasicBlock *notNullBB = Builder.GetInsertBlock();
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Builder.CreateBr(endBB);
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EmitBlock(endBB);
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llvm::PHINode *PHI = Builder.CreatePHI(BasePtrTy, 2, "cast.result");
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PHI->addIncoming(Value.getPointer(), notNullBB);
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PHI->addIncoming(llvm::Constant::getNullValue(BasePtrTy), origBB);
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Value = Address(PHI, Value.getAlignment());
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}
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return Value;
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}
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Address
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CodeGenFunction::GetAddressOfDerivedClass(Address BaseAddr,
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const CXXRecordDecl *Derived,
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CastExpr::path_const_iterator PathBegin,
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CastExpr::path_const_iterator PathEnd,
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bool NullCheckValue) {
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assert(PathBegin != PathEnd && "Base path should not be empty!");
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QualType DerivedTy =
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getContext().getCanonicalType(getContext().getTagDeclType(Derived));
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llvm::Type *DerivedPtrTy = ConvertType(DerivedTy)->getPointerTo();
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llvm::Value *NonVirtualOffset =
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CGM.GetNonVirtualBaseClassOffset(Derived, PathBegin, PathEnd);
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if (!NonVirtualOffset) {
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// No offset, we can just cast back.
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return Builder.CreateBitCast(BaseAddr, DerivedPtrTy);
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}
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llvm::BasicBlock *CastNull = nullptr;
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llvm::BasicBlock *CastNotNull = nullptr;
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llvm::BasicBlock *CastEnd = nullptr;
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if (NullCheckValue) {
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CastNull = createBasicBlock("cast.null");
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CastNotNull = createBasicBlock("cast.notnull");
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CastEnd = createBasicBlock("cast.end");
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llvm::Value *IsNull = Builder.CreateIsNull(BaseAddr.getPointer());
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Builder.CreateCondBr(IsNull, CastNull, CastNotNull);
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EmitBlock(CastNotNull);
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}
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// Apply the offset.
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llvm::Value *Value = Builder.CreateBitCast(BaseAddr.getPointer(), Int8PtrTy);
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Value = Builder.CreateGEP(Value, Builder.CreateNeg(NonVirtualOffset),
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"sub.ptr");
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// Just cast.
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Value = Builder.CreateBitCast(Value, DerivedPtrTy);
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// Produce a PHI if we had a null-check.
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if (NullCheckValue) {
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Builder.CreateBr(CastEnd);
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EmitBlock(CastNull);
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Builder.CreateBr(CastEnd);
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EmitBlock(CastEnd);
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llvm::PHINode *PHI = Builder.CreatePHI(Value->getType(), 2);
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PHI->addIncoming(Value, CastNotNull);
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PHI->addIncoming(llvm::Constant::getNullValue(Value->getType()), CastNull);
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Value = PHI;
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}
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return Address(Value, CGM.getClassPointerAlignment(Derived));
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}
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llvm::Value *CodeGenFunction::GetVTTParameter(GlobalDecl GD,
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bool ForVirtualBase,
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bool Delegating) {
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if (!CGM.getCXXABI().NeedsVTTParameter(GD)) {
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// This constructor/destructor does not need a VTT parameter.
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return nullptr;
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}
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const CXXRecordDecl *RD = cast<CXXMethodDecl>(CurCodeDecl)->getParent();
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const CXXRecordDecl *Base = cast<CXXMethodDecl>(GD.getDecl())->getParent();
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llvm::Value *VTT;
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uint64_t SubVTTIndex;
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if (Delegating) {
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// If this is a delegating constructor call, just load the VTT.
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return LoadCXXVTT();
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} else if (RD == Base) {
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// If the record matches the base, this is the complete ctor/dtor
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// variant calling the base variant in a class with virtual bases.
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assert(!CGM.getCXXABI().NeedsVTTParameter(CurGD) &&
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"doing no-op VTT offset in base dtor/ctor?");
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assert(!ForVirtualBase && "Can't have same class as virtual base!");
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SubVTTIndex = 0;
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} else {
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const ASTRecordLayout &Layout = getContext().getASTRecordLayout(RD);
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CharUnits BaseOffset = ForVirtualBase ?
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Layout.getVBaseClassOffset(Base) :
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Layout.getBaseClassOffset(Base);
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SubVTTIndex =
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CGM.getVTables().getSubVTTIndex(RD, BaseSubobject(Base, BaseOffset));
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assert(SubVTTIndex != 0 && "Sub-VTT index must be greater than zero!");
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}
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if (CGM.getCXXABI().NeedsVTTParameter(CurGD)) {
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// A VTT parameter was passed to the constructor, use it.
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VTT = LoadCXXVTT();
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VTT = Builder.CreateConstInBoundsGEP1_64(VTT, SubVTTIndex);
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} else {
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// We're the complete constructor, so get the VTT by name.
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VTT = CGM.getVTables().GetAddrOfVTT(RD);
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VTT = Builder.CreateConstInBoundsGEP2_64(VTT, 0, SubVTTIndex);
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}
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return VTT;
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}
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namespace {
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/// Call the destructor for a direct base class.
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struct CallBaseDtor final : EHScopeStack::Cleanup {
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const CXXRecordDecl *BaseClass;
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bool BaseIsVirtual;
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CallBaseDtor(const CXXRecordDecl *Base, bool BaseIsVirtual)
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: BaseClass(Base), BaseIsVirtual(BaseIsVirtual) {}
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void Emit(CodeGenFunction &CGF, Flags flags) override {
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const CXXRecordDecl *DerivedClass =
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cast<CXXMethodDecl>(CGF.CurCodeDecl)->getParent();
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const CXXDestructorDecl *D = BaseClass->getDestructor();
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Address Addr =
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CGF.GetAddressOfDirectBaseInCompleteClass(CGF.LoadCXXThisAddress(),
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DerivedClass, BaseClass,
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BaseIsVirtual);
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CGF.EmitCXXDestructorCall(D, Dtor_Base, BaseIsVirtual,
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/*Delegating=*/false, Addr);
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}
|
|
};
|
|
|
|
/// A visitor which checks whether an initializer uses 'this' in a
|
|
/// way which requires the vtable to be properly set.
|
|
struct DynamicThisUseChecker : ConstEvaluatedExprVisitor<DynamicThisUseChecker> {
|
|
typedef ConstEvaluatedExprVisitor<DynamicThisUseChecker> super;
|
|
|
|
bool UsesThis;
|
|
|
|
DynamicThisUseChecker(const ASTContext &C) : super(C), UsesThis(false) {}
|
|
|
|
// Black-list all explicit and implicit references to 'this'.
|
|
//
|
|
// Do we need to worry about external references to 'this' derived
|
|
// from arbitrary code? If so, then anything which runs arbitrary
|
|
// external code might potentially access the vtable.
|
|
void VisitCXXThisExpr(const CXXThisExpr *E) { UsesThis = true; }
|
|
};
|
|
} // end anonymous namespace
|
|
|
|
static bool BaseInitializerUsesThis(ASTContext &C, const Expr *Init) {
|
|
DynamicThisUseChecker Checker(C);
|
|
Checker.Visit(Init);
|
|
return Checker.UsesThis;
|
|
}
|
|
|
|
static void EmitBaseInitializer(CodeGenFunction &CGF,
|
|
const CXXRecordDecl *ClassDecl,
|
|
CXXCtorInitializer *BaseInit,
|
|
CXXCtorType CtorType) {
|
|
assert(BaseInit->isBaseInitializer() &&
|
|
"Must have base initializer!");
|
|
|
|
Address ThisPtr = CGF.LoadCXXThisAddress();
|
|
|
|
const Type *BaseType = BaseInit->getBaseClass();
|
|
CXXRecordDecl *BaseClassDecl =
|
|
cast<CXXRecordDecl>(BaseType->getAs<RecordType>()->getDecl());
|
|
|
|
bool isBaseVirtual = BaseInit->isBaseVirtual();
|
|
|
|
// The base constructor doesn't construct virtual bases.
|
|
if (CtorType == Ctor_Base && isBaseVirtual)
|
|
return;
|
|
|
|
// If the initializer for the base (other than the constructor
|
|
// itself) accesses 'this' in any way, we need to initialize the
|
|
// vtables.
|
|
if (BaseInitializerUsesThis(CGF.getContext(), BaseInit->getInit()))
|
|
CGF.InitializeVTablePointers(ClassDecl);
|
|
|
|
// We can pretend to be a complete class because it only matters for
|
|
// virtual bases, and we only do virtual bases for complete ctors.
|
|
Address V =
|
|
CGF.GetAddressOfDirectBaseInCompleteClass(ThisPtr, ClassDecl,
|
|
BaseClassDecl,
|
|
isBaseVirtual);
|
|
AggValueSlot AggSlot =
|
|
AggValueSlot::forAddr(V, Qualifiers(),
|
|
AggValueSlot::IsDestructed,
|
|
AggValueSlot::DoesNotNeedGCBarriers,
|
|
AggValueSlot::IsNotAliased);
|
|
|
|
CGF.EmitAggExpr(BaseInit->getInit(), AggSlot);
|
|
|
|
if (CGF.CGM.getLangOpts().Exceptions &&
|
|
!BaseClassDecl->hasTrivialDestructor())
|
|
CGF.EHStack.pushCleanup<CallBaseDtor>(EHCleanup, BaseClassDecl,
|
|
isBaseVirtual);
|
|
}
|
|
|
|
static void EmitAggMemberInitializer(CodeGenFunction &CGF,
|
|
LValue LHS,
|
|
Expr *Init,
|
|
Address ArrayIndexVar,
|
|
QualType T,
|
|
ArrayRef<VarDecl *> ArrayIndexes,
|
|
unsigned Index) {
|
|
if (Index == ArrayIndexes.size()) {
|
|
LValue LV = LHS;
|
|
|
|
if (ArrayIndexVar.isValid()) {
|
|
// If we have an array index variable, load it and use it as an offset.
|
|
// Then, increment the value.
|
|
llvm::Value *Dest = LHS.getPointer();
|
|
llvm::Value *ArrayIndex = CGF.Builder.CreateLoad(ArrayIndexVar);
|
|
Dest = CGF.Builder.CreateInBoundsGEP(Dest, ArrayIndex, "destaddress");
|
|
llvm::Value *Next = llvm::ConstantInt::get(ArrayIndex->getType(), 1);
|
|
Next = CGF.Builder.CreateAdd(ArrayIndex, Next, "inc");
|
|
CGF.Builder.CreateStore(Next, ArrayIndexVar);
|
|
|
|
// Update the LValue.
|
|
CharUnits EltSize = CGF.getContext().getTypeSizeInChars(T);
|
|
CharUnits Align = LV.getAlignment().alignmentOfArrayElement(EltSize);
|
|
LV.setAddress(Address(Dest, Align));
|
|
}
|
|
|
|
switch (CGF.getEvaluationKind(T)) {
|
|
case TEK_Scalar:
|
|
CGF.EmitScalarInit(Init, /*decl*/ nullptr, LV, false);
|
|
break;
|
|
case TEK_Complex:
|
|
CGF.EmitComplexExprIntoLValue(Init, LV, /*isInit*/ true);
|
|
break;
|
|
case TEK_Aggregate: {
|
|
AggValueSlot Slot =
|
|
AggValueSlot::forLValue(LV,
|
|
AggValueSlot::IsDestructed,
|
|
AggValueSlot::DoesNotNeedGCBarriers,
|
|
AggValueSlot::IsNotAliased);
|
|
|
|
CGF.EmitAggExpr(Init, Slot);
|
|
break;
|
|
}
|
|
}
|
|
|
|
return;
|
|
}
|
|
|
|
const ConstantArrayType *Array = CGF.getContext().getAsConstantArrayType(T);
|
|
assert(Array && "Array initialization without the array type?");
|
|
Address IndexVar = CGF.GetAddrOfLocalVar(ArrayIndexes[Index]);
|
|
|
|
// Initialize this index variable to zero.
|
|
llvm::Value* Zero
|
|
= llvm::Constant::getNullValue(IndexVar.getElementType());
|
|
CGF.Builder.CreateStore(Zero, IndexVar);
|
|
|
|
// Start the loop with a block that tests the condition.
|
|
llvm::BasicBlock *CondBlock = CGF.createBasicBlock("for.cond");
|
|
llvm::BasicBlock *AfterFor = CGF.createBasicBlock("for.end");
|
|
|
|
CGF.EmitBlock(CondBlock);
|
|
|
|
llvm::BasicBlock *ForBody = CGF.createBasicBlock("for.body");
|
|
// Generate: if (loop-index < number-of-elements) fall to the loop body,
|
|
// otherwise, go to the block after the for-loop.
|
|
uint64_t NumElements = Array->getSize().getZExtValue();
|
|
llvm::Value *Counter = CGF.Builder.CreateLoad(IndexVar);
|
|
llvm::Value *NumElementsPtr =
|
|
llvm::ConstantInt::get(Counter->getType(), NumElements);
|
|
llvm::Value *IsLess = CGF.Builder.CreateICmpULT(Counter, NumElementsPtr,
|
|
"isless");
|
|
|
|
// If the condition is true, execute the body.
|
|
CGF.Builder.CreateCondBr(IsLess, ForBody, AfterFor);
|
|
|
|
CGF.EmitBlock(ForBody);
|
|
llvm::BasicBlock *ContinueBlock = CGF.createBasicBlock("for.inc");
|
|
|
|
// Inside the loop body recurse to emit the inner loop or, eventually, the
|
|
// constructor call.
|
|
EmitAggMemberInitializer(CGF, LHS, Init, ArrayIndexVar,
|
|
Array->getElementType(), ArrayIndexes, Index + 1);
|
|
|
|
CGF.EmitBlock(ContinueBlock);
|
|
|
|
// Emit the increment of the loop counter.
|
|
llvm::Value *NextVal = llvm::ConstantInt::get(Counter->getType(), 1);
|
|
Counter = CGF.Builder.CreateLoad(IndexVar);
|
|
NextVal = CGF.Builder.CreateAdd(Counter, NextVal, "inc");
|
|
CGF.Builder.CreateStore(NextVal, IndexVar);
|
|
|
|
// Finally, branch back up to the condition for the next iteration.
|
|
CGF.EmitBranch(CondBlock);
|
|
|
|
// Emit the fall-through block.
|
|
CGF.EmitBlock(AfterFor, true);
|
|
}
|
|
|
|
static bool isMemcpyEquivalentSpecialMember(const CXXMethodDecl *D) {
|
|
auto *CD = dyn_cast<CXXConstructorDecl>(D);
|
|
if (!(CD && CD->isCopyOrMoveConstructor()) &&
|
|
!D->isCopyAssignmentOperator() && !D->isMoveAssignmentOperator())
|
|
return false;
|
|
|
|
// We can emit a memcpy for a trivial copy or move constructor/assignment.
|
|
if (D->isTrivial() && !D->getParent()->mayInsertExtraPadding())
|
|
return true;
|
|
|
|
// We *must* emit a memcpy for a defaulted union copy or move op.
|
|
if (D->getParent()->isUnion() && D->isDefaulted())
|
|
return true;
|
|
|
|
return false;
|
|
}
|
|
|
|
static void EmitLValueForAnyFieldInitialization(CodeGenFunction &CGF,
|
|
CXXCtorInitializer *MemberInit,
|
|
LValue &LHS) {
|
|
FieldDecl *Field = MemberInit->getAnyMember();
|
|
if (MemberInit->isIndirectMemberInitializer()) {
|
|
// If we are initializing an anonymous union field, drill down to the field.
|
|
IndirectFieldDecl *IndirectField = MemberInit->getIndirectMember();
|
|
for (const auto *I : IndirectField->chain())
|
|
LHS = CGF.EmitLValueForFieldInitialization(LHS, cast<FieldDecl>(I));
|
|
} else {
|
|
LHS = CGF.EmitLValueForFieldInitialization(LHS, Field);
|
|
}
|
|
}
|
|
|
|
static void EmitMemberInitializer(CodeGenFunction &CGF,
|
|
const CXXRecordDecl *ClassDecl,
|
|
CXXCtorInitializer *MemberInit,
|
|
const CXXConstructorDecl *Constructor,
|
|
FunctionArgList &Args) {
|
|
ApplyDebugLocation Loc(CGF, MemberInit->getSourceLocation());
|
|
assert(MemberInit->isAnyMemberInitializer() &&
|
|
"Must have member initializer!");
|
|
assert(MemberInit->getInit() && "Must have initializer!");
|
|
|
|
// non-static data member initializers.
|
|
FieldDecl *Field = MemberInit->getAnyMember();
|
|
QualType FieldType = Field->getType();
|
|
|
|
llvm::Value *ThisPtr = CGF.LoadCXXThis();
|
|
QualType RecordTy = CGF.getContext().getTypeDeclType(ClassDecl);
|
|
LValue LHS = CGF.MakeNaturalAlignAddrLValue(ThisPtr, RecordTy);
|
|
|
|
EmitLValueForAnyFieldInitialization(CGF, MemberInit, LHS);
|
|
|
|
// Special case: if we are in a copy or move constructor, and we are copying
|
|
// an array of PODs or classes with trivial copy constructors, ignore the
|
|
// AST and perform the copy we know is equivalent.
|
|
// FIXME: This is hacky at best... if we had a bit more explicit information
|
|
// in the AST, we could generalize it more easily.
|
|
const ConstantArrayType *Array
|
|
= CGF.getContext().getAsConstantArrayType(FieldType);
|
|
if (Array && Constructor->isDefaulted() &&
|
|
Constructor->isCopyOrMoveConstructor()) {
|
|
QualType BaseElementTy = CGF.getContext().getBaseElementType(Array);
|
|
CXXConstructExpr *CE = dyn_cast<CXXConstructExpr>(MemberInit->getInit());
|
|
if (BaseElementTy.isPODType(CGF.getContext()) ||
|
|
(CE && isMemcpyEquivalentSpecialMember(CE->getConstructor()))) {
|
|
unsigned SrcArgIndex =
|
|
CGF.CGM.getCXXABI().getSrcArgforCopyCtor(Constructor, Args);
|
|
llvm::Value *SrcPtr
|
|
= CGF.Builder.CreateLoad(CGF.GetAddrOfLocalVar(Args[SrcArgIndex]));
|
|
LValue ThisRHSLV = CGF.MakeNaturalAlignAddrLValue(SrcPtr, RecordTy);
|
|
LValue Src = CGF.EmitLValueForFieldInitialization(ThisRHSLV, Field);
|
|
|
|
// Copy the aggregate.
|
|
CGF.EmitAggregateCopy(LHS.getAddress(), Src.getAddress(), FieldType,
|
|
LHS.isVolatileQualified());
|
|
// Ensure that we destroy the objects if an exception is thrown later in
|
|
// the constructor.
|
|
QualType::DestructionKind dtorKind = FieldType.isDestructedType();
|
|
if (CGF.needsEHCleanup(dtorKind))
|
|
CGF.pushEHDestroy(dtorKind, LHS.getAddress(), FieldType);
|
|
return;
|
|
}
|
|
}
|
|
|
|
ArrayRef<VarDecl *> ArrayIndexes;
|
|
if (MemberInit->getNumArrayIndices())
|
|
ArrayIndexes = MemberInit->getArrayIndexes();
|
|
CGF.EmitInitializerForField(Field, LHS, MemberInit->getInit(), ArrayIndexes);
|
|
}
|
|
|
|
void CodeGenFunction::EmitInitializerForField(FieldDecl *Field, LValue LHS,
|
|
Expr *Init, ArrayRef<VarDecl *> ArrayIndexes) {
|
|
QualType FieldType = Field->getType();
|
|
switch (getEvaluationKind(FieldType)) {
|
|
case TEK_Scalar:
|
|
if (LHS.isSimple()) {
|
|
EmitExprAsInit(Init, Field, LHS, false);
|
|
} else {
|
|
RValue RHS = RValue::get(EmitScalarExpr(Init));
|
|
EmitStoreThroughLValue(RHS, LHS);
|
|
}
|
|
break;
|
|
case TEK_Complex:
|
|
EmitComplexExprIntoLValue(Init, LHS, /*isInit*/ true);
|
|
break;
|
|
case TEK_Aggregate: {
|
|
Address ArrayIndexVar = Address::invalid();
|
|
if (ArrayIndexes.size()) {
|
|
// The LHS is a pointer to the first object we'll be constructing, as
|
|
// a flat array.
|
|
QualType BaseElementTy = getContext().getBaseElementType(FieldType);
|
|
llvm::Type *BasePtr = ConvertType(BaseElementTy);
|
|
BasePtr = llvm::PointerType::getUnqual(BasePtr);
|
|
Address BaseAddrPtr = Builder.CreateBitCast(LHS.getAddress(), BasePtr);
|
|
LHS = MakeAddrLValue(BaseAddrPtr, BaseElementTy);
|
|
|
|
// Create an array index that will be used to walk over all of the
|
|
// objects we're constructing.
|
|
ArrayIndexVar = CreateMemTemp(getContext().getSizeType(), "object.index");
|
|
llvm::Value *Zero =
|
|
llvm::Constant::getNullValue(ArrayIndexVar.getElementType());
|
|
Builder.CreateStore(Zero, ArrayIndexVar);
|
|
|
|
// Emit the block variables for the array indices, if any.
|
|
for (unsigned I = 0, N = ArrayIndexes.size(); I != N; ++I)
|
|
EmitAutoVarDecl(*ArrayIndexes[I]);
|
|
}
|
|
|
|
EmitAggMemberInitializer(*this, LHS, Init, ArrayIndexVar, FieldType,
|
|
ArrayIndexes, 0);
|
|
}
|
|
}
|
|
|
|
// Ensure that we destroy this object if an exception is thrown
|
|
// later in the constructor.
|
|
QualType::DestructionKind dtorKind = FieldType.isDestructedType();
|
|
if (needsEHCleanup(dtorKind))
|
|
pushEHDestroy(dtorKind, LHS.getAddress(), FieldType);
|
|
}
|
|
|
|
/// Checks whether the given constructor is a valid subject for the
|
|
/// complete-to-base constructor delegation optimization, i.e.
|
|
/// emitting the complete constructor as a simple call to the base
|
|
/// constructor.
|
|
static bool IsConstructorDelegationValid(const CXXConstructorDecl *Ctor) {
|
|
|
|
// Currently we disable the optimization for classes with virtual
|
|
// bases because (1) the addresses of parameter variables need to be
|
|
// consistent across all initializers but (2) the delegate function
|
|
// call necessarily creates a second copy of the parameter variable.
|
|
//
|
|
// The limiting example (purely theoretical AFAIK):
|
|
// struct A { A(int &c) { c++; } };
|
|
// struct B : virtual A {
|
|
// B(int count) : A(count) { printf("%d\n", count); }
|
|
// };
|
|
// ...although even this example could in principle be emitted as a
|
|
// delegation since the address of the parameter doesn't escape.
|
|
if (Ctor->getParent()->getNumVBases()) {
|
|
// TODO: white-list trivial vbase initializers. This case wouldn't
|
|
// be subject to the restrictions below.
|
|
|
|
// TODO: white-list cases where:
|
|
// - there are no non-reference parameters to the constructor
|
|
// - the initializers don't access any non-reference parameters
|
|
// - the initializers don't take the address of non-reference
|
|
// parameters
|
|
// - etc.
|
|
// If we ever add any of the above cases, remember that:
|
|
// - function-try-blocks will always blacklist this optimization
|
|
// - we need to perform the constructor prologue and cleanup in
|
|
// EmitConstructorBody.
|
|
|
|
return false;
|
|
}
|
|
|
|
// We also disable the optimization for variadic functions because
|
|
// it's impossible to "re-pass" varargs.
|
|
if (Ctor->getType()->getAs<FunctionProtoType>()->isVariadic())
|
|
return false;
|
|
|
|
// FIXME: Decide if we can do a delegation of a delegating constructor.
|
|
if (Ctor->isDelegatingConstructor())
|
|
return false;
|
|
|
|
return true;
|
|
}
|
|
|
|
// Emit code in ctor (Prologue==true) or dtor (Prologue==false)
|
|
// to poison the extra field paddings inserted under
|
|
// -fsanitize-address-field-padding=1|2.
|
|
void CodeGenFunction::EmitAsanPrologueOrEpilogue(bool Prologue) {
|
|
ASTContext &Context = getContext();
|
|
const CXXRecordDecl *ClassDecl =
|
|
Prologue ? cast<CXXConstructorDecl>(CurGD.getDecl())->getParent()
|
|
: cast<CXXDestructorDecl>(CurGD.getDecl())->getParent();
|
|
if (!ClassDecl->mayInsertExtraPadding()) return;
|
|
|
|
struct SizeAndOffset {
|
|
uint64_t Size;
|
|
uint64_t Offset;
|
|
};
|
|
|
|
unsigned PtrSize = CGM.getDataLayout().getPointerSizeInBits();
|
|
const ASTRecordLayout &Info = Context.getASTRecordLayout(ClassDecl);
|
|
|
|
// Populate sizes and offsets of fields.
|
|
SmallVector<SizeAndOffset, 16> SSV(Info.getFieldCount());
|
|
for (unsigned i = 0, e = Info.getFieldCount(); i != e; ++i)
|
|
SSV[i].Offset =
|
|
Context.toCharUnitsFromBits(Info.getFieldOffset(i)).getQuantity();
|
|
|
|
size_t NumFields = 0;
|
|
for (const auto *Field : ClassDecl->fields()) {
|
|
const FieldDecl *D = Field;
|
|
std::pair<CharUnits, CharUnits> FieldInfo =
|
|
Context.getTypeInfoInChars(D->getType());
|
|
CharUnits FieldSize = FieldInfo.first;
|
|
assert(NumFields < SSV.size());
|
|
SSV[NumFields].Size = D->isBitField() ? 0 : FieldSize.getQuantity();
|
|
NumFields++;
|
|
}
|
|
assert(NumFields == SSV.size());
|
|
if (SSV.size() <= 1) return;
|
|
|
|
// We will insert calls to __asan_* run-time functions.
|
|
// LLVM AddressSanitizer pass may decide to inline them later.
|
|
llvm::Type *Args[2] = {IntPtrTy, IntPtrTy};
|
|
llvm::FunctionType *FTy =
|
|
llvm::FunctionType::get(CGM.VoidTy, Args, false);
|
|
llvm::Constant *F = CGM.CreateRuntimeFunction(
|
|
FTy, Prologue ? "__asan_poison_intra_object_redzone"
|
|
: "__asan_unpoison_intra_object_redzone");
|
|
|
|
llvm::Value *ThisPtr = LoadCXXThis();
|
|
ThisPtr = Builder.CreatePtrToInt(ThisPtr, IntPtrTy);
|
|
uint64_t TypeSize = Info.getNonVirtualSize().getQuantity();
|
|
// For each field check if it has sufficient padding,
|
|
// if so (un)poison it with a call.
|
|
for (size_t i = 0; i < SSV.size(); i++) {
|
|
uint64_t AsanAlignment = 8;
|
|
uint64_t NextField = i == SSV.size() - 1 ? TypeSize : SSV[i + 1].Offset;
|
|
uint64_t PoisonSize = NextField - SSV[i].Offset - SSV[i].Size;
|
|
uint64_t EndOffset = SSV[i].Offset + SSV[i].Size;
|
|
if (PoisonSize < AsanAlignment || !SSV[i].Size ||
|
|
(NextField % AsanAlignment) != 0)
|
|
continue;
|
|
Builder.CreateCall(
|
|
F, {Builder.CreateAdd(ThisPtr, Builder.getIntN(PtrSize, EndOffset)),
|
|
Builder.getIntN(PtrSize, PoisonSize)});
|
|
}
|
|
}
|
|
|
|
/// EmitConstructorBody - Emits the body of the current constructor.
|
|
void CodeGenFunction::EmitConstructorBody(FunctionArgList &Args) {
|
|
EmitAsanPrologueOrEpilogue(true);
|
|
const CXXConstructorDecl *Ctor = cast<CXXConstructorDecl>(CurGD.getDecl());
|
|
CXXCtorType CtorType = CurGD.getCtorType();
|
|
|
|
assert((CGM.getTarget().getCXXABI().hasConstructorVariants() ||
|
|
CtorType == Ctor_Complete) &&
|
|
"can only generate complete ctor for this ABI");
|
|
|
|
// Before we go any further, try the complete->base constructor
|
|
// delegation optimization.
|
|
if (CtorType == Ctor_Complete && IsConstructorDelegationValid(Ctor) &&
|
|
CGM.getTarget().getCXXABI().hasConstructorVariants()) {
|
|
EmitDelegateCXXConstructorCall(Ctor, Ctor_Base, Args, Ctor->getLocEnd());
|
|
return;
|
|
}
|
|
|
|
const FunctionDecl *Definition = nullptr;
|
|
Stmt *Body = Ctor->getBody(Definition);
|
|
assert(Definition == Ctor && "emitting wrong constructor body");
|
|
|
|
// Enter the function-try-block before the constructor prologue if
|
|
// applicable.
|
|
bool IsTryBody = (Body && isa<CXXTryStmt>(Body));
|
|
if (IsTryBody)
|
|
EnterCXXTryStmt(*cast<CXXTryStmt>(Body), true);
|
|
|
|
incrementProfileCounter(Body);
|
|
|
|
RunCleanupsScope RunCleanups(*this);
|
|
|
|
// TODO: in restricted cases, we can emit the vbase initializers of
|
|
// a complete ctor and then delegate to the base ctor.
|
|
|
|
// Emit the constructor prologue, i.e. the base and member
|
|
// initializers.
|
|
EmitCtorPrologue(Ctor, CtorType, Args);
|
|
|
|
// Emit the body of the statement.
|
|
if (IsTryBody)
|
|
EmitStmt(cast<CXXTryStmt>(Body)->getTryBlock());
|
|
else if (Body)
|
|
EmitStmt(Body);
|
|
|
|
// Emit any cleanup blocks associated with the member or base
|
|
// initializers, which includes (along the exceptional path) the
|
|
// destructors for those members and bases that were fully
|
|
// constructed.
|
|
RunCleanups.ForceCleanup();
|
|
|
|
if (IsTryBody)
|
|
ExitCXXTryStmt(*cast<CXXTryStmt>(Body), true);
|
|
}
|
|
|
|
namespace {
|
|
/// RAII object to indicate that codegen is copying the value representation
|
|
/// instead of the object representation. Useful when copying a struct or
|
|
/// class which has uninitialized members and we're only performing
|
|
/// lvalue-to-rvalue conversion on the object but not its members.
|
|
class CopyingValueRepresentation {
|
|
public:
|
|
explicit CopyingValueRepresentation(CodeGenFunction &CGF)
|
|
: CGF(CGF), OldSanOpts(CGF.SanOpts) {
|
|
CGF.SanOpts.set(SanitizerKind::Bool, false);
|
|
CGF.SanOpts.set(SanitizerKind::Enum, false);
|
|
}
|
|
~CopyingValueRepresentation() {
|
|
CGF.SanOpts = OldSanOpts;
|
|
}
|
|
private:
|
|
CodeGenFunction &CGF;
|
|
SanitizerSet OldSanOpts;
|
|
};
|
|
}
|
|
|
|
namespace {
|
|
class FieldMemcpyizer {
|
|
public:
|
|
FieldMemcpyizer(CodeGenFunction &CGF, const CXXRecordDecl *ClassDecl,
|
|
const VarDecl *SrcRec)
|
|
: CGF(CGF), ClassDecl(ClassDecl), SrcRec(SrcRec),
|
|
RecLayout(CGF.getContext().getASTRecordLayout(ClassDecl)),
|
|
FirstField(nullptr), LastField(nullptr), FirstFieldOffset(0),
|
|
LastFieldOffset(0), LastAddedFieldIndex(0) {}
|
|
|
|
bool isMemcpyableField(FieldDecl *F) const {
|
|
// Never memcpy fields when we are adding poisoned paddings.
|
|
if (CGF.getContext().getLangOpts().SanitizeAddressFieldPadding)
|
|
return false;
|
|
Qualifiers Qual = F->getType().getQualifiers();
|
|
if (Qual.hasVolatile() || Qual.hasObjCLifetime())
|
|
return false;
|
|
return true;
|
|
}
|
|
|
|
void addMemcpyableField(FieldDecl *F) {
|
|
if (!FirstField)
|
|
addInitialField(F);
|
|
else
|
|
addNextField(F);
|
|
}
|
|
|
|
CharUnits getMemcpySize(uint64_t FirstByteOffset) const {
|
|
unsigned LastFieldSize =
|
|
LastField->isBitField() ?
|
|
LastField->getBitWidthValue(CGF.getContext()) :
|
|
CGF.getContext().getTypeSize(LastField->getType());
|
|
uint64_t MemcpySizeBits =
|
|
LastFieldOffset + LastFieldSize - FirstByteOffset +
|
|
CGF.getContext().getCharWidth() - 1;
|
|
CharUnits MemcpySize =
|
|
CGF.getContext().toCharUnitsFromBits(MemcpySizeBits);
|
|
return MemcpySize;
|
|
}
|
|
|
|
void emitMemcpy() {
|
|
// Give the subclass a chance to bail out if it feels the memcpy isn't
|
|
// worth it (e.g. Hasn't aggregated enough data).
|
|
if (!FirstField) {
|
|
return;
|
|
}
|
|
|
|
uint64_t FirstByteOffset;
|
|
if (FirstField->isBitField()) {
|
|
const CGRecordLayout &RL =
|
|
CGF.getTypes().getCGRecordLayout(FirstField->getParent());
|
|
const CGBitFieldInfo &BFInfo = RL.getBitFieldInfo(FirstField);
|
|
// FirstFieldOffset is not appropriate for bitfields,
|
|
// we need to use the storage offset instead.
|
|
FirstByteOffset = CGF.getContext().toBits(BFInfo.StorageOffset);
|
|
} else {
|
|
FirstByteOffset = FirstFieldOffset;
|
|
}
|
|
|
|
CharUnits MemcpySize = getMemcpySize(FirstByteOffset);
|
|
QualType RecordTy = CGF.getContext().getTypeDeclType(ClassDecl);
|
|
Address ThisPtr = CGF.LoadCXXThisAddress();
|
|
LValue DestLV = CGF.MakeAddrLValue(ThisPtr, RecordTy);
|
|
LValue Dest = CGF.EmitLValueForFieldInitialization(DestLV, FirstField);
|
|
llvm::Value *SrcPtr = CGF.Builder.CreateLoad(CGF.GetAddrOfLocalVar(SrcRec));
|
|
LValue SrcLV = CGF.MakeNaturalAlignAddrLValue(SrcPtr, RecordTy);
|
|
LValue Src = CGF.EmitLValueForFieldInitialization(SrcLV, FirstField);
|
|
|
|
emitMemcpyIR(Dest.isBitField() ? Dest.getBitFieldAddress() : Dest.getAddress(),
|
|
Src.isBitField() ? Src.getBitFieldAddress() : Src.getAddress(),
|
|
MemcpySize);
|
|
reset();
|
|
}
|
|
|
|
void reset() {
|
|
FirstField = nullptr;
|
|
}
|
|
|
|
protected:
|
|
CodeGenFunction &CGF;
|
|
const CXXRecordDecl *ClassDecl;
|
|
|
|
private:
|
|
|
|
void emitMemcpyIR(Address DestPtr, Address SrcPtr, CharUnits Size) {
|
|
llvm::PointerType *DPT = DestPtr.getType();
|
|
llvm::Type *DBP =
|
|
llvm::Type::getInt8PtrTy(CGF.getLLVMContext(), DPT->getAddressSpace());
|
|
DestPtr = CGF.Builder.CreateBitCast(DestPtr, DBP);
|
|
|
|
llvm::PointerType *SPT = SrcPtr.getType();
|
|
llvm::Type *SBP =
|
|
llvm::Type::getInt8PtrTy(CGF.getLLVMContext(), SPT->getAddressSpace());
|
|
SrcPtr = CGF.Builder.CreateBitCast(SrcPtr, SBP);
|
|
|
|
CGF.Builder.CreateMemCpy(DestPtr, SrcPtr, Size.getQuantity());
|
|
}
|
|
|
|
void addInitialField(FieldDecl *F) {
|
|
FirstField = F;
|
|
LastField = F;
|
|
FirstFieldOffset = RecLayout.getFieldOffset(F->getFieldIndex());
|
|
LastFieldOffset = FirstFieldOffset;
|
|
LastAddedFieldIndex = F->getFieldIndex();
|
|
return;
|
|
}
|
|
|
|
void addNextField(FieldDecl *F) {
|
|
// For the most part, the following invariant will hold:
|
|
// F->getFieldIndex() == LastAddedFieldIndex + 1
|
|
// The one exception is that Sema won't add a copy-initializer for an
|
|
// unnamed bitfield, which will show up here as a gap in the sequence.
|
|
assert(F->getFieldIndex() >= LastAddedFieldIndex + 1 &&
|
|
"Cannot aggregate fields out of order.");
|
|
LastAddedFieldIndex = F->getFieldIndex();
|
|
|
|
// The 'first' and 'last' fields are chosen by offset, rather than field
|
|
// index. This allows the code to support bitfields, as well as regular
|
|
// fields.
|
|
uint64_t FOffset = RecLayout.getFieldOffset(F->getFieldIndex());
|
|
if (FOffset < FirstFieldOffset) {
|
|
FirstField = F;
|
|
FirstFieldOffset = FOffset;
|
|
} else if (FOffset > LastFieldOffset) {
|
|
LastField = F;
|
|
LastFieldOffset = FOffset;
|
|
}
|
|
}
|
|
|
|
const VarDecl *SrcRec;
|
|
const ASTRecordLayout &RecLayout;
|
|
FieldDecl *FirstField;
|
|
FieldDecl *LastField;
|
|
uint64_t FirstFieldOffset, LastFieldOffset;
|
|
unsigned LastAddedFieldIndex;
|
|
};
|
|
|
|
class ConstructorMemcpyizer : public FieldMemcpyizer {
|
|
private:
|
|
|
|
/// Get source argument for copy constructor. Returns null if not a copy
|
|
/// constructor.
|
|
static const VarDecl *getTrivialCopySource(CodeGenFunction &CGF,
|
|
const CXXConstructorDecl *CD,
|
|
FunctionArgList &Args) {
|
|
if (CD->isCopyOrMoveConstructor() && CD->isDefaulted())
|
|
return Args[CGF.CGM.getCXXABI().getSrcArgforCopyCtor(CD, Args)];
|
|
return nullptr;
|
|
}
|
|
|
|
// Returns true if a CXXCtorInitializer represents a member initialization
|
|
// that can be rolled into a memcpy.
|
|
bool isMemberInitMemcpyable(CXXCtorInitializer *MemberInit) const {
|
|
if (!MemcpyableCtor)
|
|
return false;
|
|
FieldDecl *Field = MemberInit->getMember();
|
|
assert(Field && "No field for member init.");
|
|
QualType FieldType = Field->getType();
|
|
CXXConstructExpr *CE = dyn_cast<CXXConstructExpr>(MemberInit->getInit());
|
|
|
|
// Bail out on non-memcpyable, not-trivially-copyable members.
|
|
if (!(CE && isMemcpyEquivalentSpecialMember(CE->getConstructor())) &&
|
|
!(FieldType.isTriviallyCopyableType(CGF.getContext()) ||
|
|
FieldType->isReferenceType()))
|
|
return false;
|
|
|
|
// Bail out on volatile fields.
|
|
if (!isMemcpyableField(Field))
|
|
return false;
|
|
|
|
// Otherwise we're good.
|
|
return true;
|
|
}
|
|
|
|
public:
|
|
ConstructorMemcpyizer(CodeGenFunction &CGF, const CXXConstructorDecl *CD,
|
|
FunctionArgList &Args)
|
|
: FieldMemcpyizer(CGF, CD->getParent(), getTrivialCopySource(CGF, CD, Args)),
|
|
ConstructorDecl(CD),
|
|
MemcpyableCtor(CD->isDefaulted() &&
|
|
CD->isCopyOrMoveConstructor() &&
|
|
CGF.getLangOpts().getGC() == LangOptions::NonGC),
|
|
Args(Args) { }
|
|
|
|
void addMemberInitializer(CXXCtorInitializer *MemberInit) {
|
|
if (isMemberInitMemcpyable(MemberInit)) {
|
|
AggregatedInits.push_back(MemberInit);
|
|
addMemcpyableField(MemberInit->getMember());
|
|
} else {
|
|
emitAggregatedInits();
|
|
EmitMemberInitializer(CGF, ConstructorDecl->getParent(), MemberInit,
|
|
ConstructorDecl, Args);
|
|
}
|
|
}
|
|
|
|
void emitAggregatedInits() {
|
|
if (AggregatedInits.size() <= 1) {
|
|
// This memcpy is too small to be worthwhile. Fall back on default
|
|
// codegen.
|
|
if (!AggregatedInits.empty()) {
|
|
CopyingValueRepresentation CVR(CGF);
|
|
EmitMemberInitializer(CGF, ConstructorDecl->getParent(),
|
|
AggregatedInits[0], ConstructorDecl, Args);
|
|
AggregatedInits.clear();
|
|
}
|
|
reset();
|
|
return;
|
|
}
|
|
|
|
pushEHDestructors();
|
|
emitMemcpy();
|
|
AggregatedInits.clear();
|
|
}
|
|
|
|
void pushEHDestructors() {
|
|
Address ThisPtr = CGF.LoadCXXThisAddress();
|
|
QualType RecordTy = CGF.getContext().getTypeDeclType(ClassDecl);
|
|
LValue LHS = CGF.MakeAddrLValue(ThisPtr, RecordTy);
|
|
|
|
for (unsigned i = 0; i < AggregatedInits.size(); ++i) {
|
|
CXXCtorInitializer *MemberInit = AggregatedInits[i];
|
|
QualType FieldType = MemberInit->getAnyMember()->getType();
|
|
QualType::DestructionKind dtorKind = FieldType.isDestructedType();
|
|
if (!CGF.needsEHCleanup(dtorKind))
|
|
continue;
|
|
LValue FieldLHS = LHS;
|
|
EmitLValueForAnyFieldInitialization(CGF, MemberInit, FieldLHS);
|
|
CGF.pushEHDestroy(dtorKind, FieldLHS.getAddress(), FieldType);
|
|
}
|
|
}
|
|
|
|
void finish() {
|
|
emitAggregatedInits();
|
|
}
|
|
|
|
private:
|
|
const CXXConstructorDecl *ConstructorDecl;
|
|
bool MemcpyableCtor;
|
|
FunctionArgList &Args;
|
|
SmallVector<CXXCtorInitializer*, 16> AggregatedInits;
|
|
};
|
|
|
|
class AssignmentMemcpyizer : public FieldMemcpyizer {
|
|
private:
|
|
|
|
// Returns the memcpyable field copied by the given statement, if one
|
|
// exists. Otherwise returns null.
|
|
FieldDecl *getMemcpyableField(Stmt *S) {
|
|
if (!AssignmentsMemcpyable)
|
|
return nullptr;
|
|
if (BinaryOperator *BO = dyn_cast<BinaryOperator>(S)) {
|
|
// Recognise trivial assignments.
|
|
if (BO->getOpcode() != BO_Assign)
|
|
return nullptr;
|
|
MemberExpr *ME = dyn_cast<MemberExpr>(BO->getLHS());
|
|
if (!ME)
|
|
return nullptr;
|
|
FieldDecl *Field = dyn_cast<FieldDecl>(ME->getMemberDecl());
|
|
if (!Field || !isMemcpyableField(Field))
|
|
return nullptr;
|
|
Stmt *RHS = BO->getRHS();
|
|
if (ImplicitCastExpr *EC = dyn_cast<ImplicitCastExpr>(RHS))
|
|
RHS = EC->getSubExpr();
|
|
if (!RHS)
|
|
return nullptr;
|
|
MemberExpr *ME2 = dyn_cast<MemberExpr>(RHS);
|
|
if (dyn_cast<FieldDecl>(ME2->getMemberDecl()) != Field)
|
|
return nullptr;
|
|
return Field;
|
|
} else if (CXXMemberCallExpr *MCE = dyn_cast<CXXMemberCallExpr>(S)) {
|
|
CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(MCE->getCalleeDecl());
|
|
if (!(MD && isMemcpyEquivalentSpecialMember(MD)))
|
|
return nullptr;
|
|
MemberExpr *IOA = dyn_cast<MemberExpr>(MCE->getImplicitObjectArgument());
|
|
if (!IOA)
|
|
return nullptr;
|
|
FieldDecl *Field = dyn_cast<FieldDecl>(IOA->getMemberDecl());
|
|
if (!Field || !isMemcpyableField(Field))
|
|
return nullptr;
|
|
MemberExpr *Arg0 = dyn_cast<MemberExpr>(MCE->getArg(0));
|
|
if (!Arg0 || Field != dyn_cast<FieldDecl>(Arg0->getMemberDecl()))
|
|
return nullptr;
|
|
return Field;
|
|
} else if (CallExpr *CE = dyn_cast<CallExpr>(S)) {
|
|
FunctionDecl *FD = dyn_cast<FunctionDecl>(CE->getCalleeDecl());
|
|
if (!FD || FD->getBuiltinID() != Builtin::BI__builtin_memcpy)
|
|
return nullptr;
|
|
Expr *DstPtr = CE->getArg(0);
|
|
if (ImplicitCastExpr *DC = dyn_cast<ImplicitCastExpr>(DstPtr))
|
|
DstPtr = DC->getSubExpr();
|
|
UnaryOperator *DUO = dyn_cast<UnaryOperator>(DstPtr);
|
|
if (!DUO || DUO->getOpcode() != UO_AddrOf)
|
|
return nullptr;
|
|
MemberExpr *ME = dyn_cast<MemberExpr>(DUO->getSubExpr());
|
|
if (!ME)
|
|
return nullptr;
|
|
FieldDecl *Field = dyn_cast<FieldDecl>(ME->getMemberDecl());
|
|
if (!Field || !isMemcpyableField(Field))
|
|
return nullptr;
|
|
Expr *SrcPtr = CE->getArg(1);
|
|
if (ImplicitCastExpr *SC = dyn_cast<ImplicitCastExpr>(SrcPtr))
|
|
SrcPtr = SC->getSubExpr();
|
|
UnaryOperator *SUO = dyn_cast<UnaryOperator>(SrcPtr);
|
|
if (!SUO || SUO->getOpcode() != UO_AddrOf)
|
|
return nullptr;
|
|
MemberExpr *ME2 = dyn_cast<MemberExpr>(SUO->getSubExpr());
|
|
if (!ME2 || Field != dyn_cast<FieldDecl>(ME2->getMemberDecl()))
|
|
return nullptr;
|
|
return Field;
|
|
}
|
|
|
|
return nullptr;
|
|
}
|
|
|
|
bool AssignmentsMemcpyable;
|
|
SmallVector<Stmt*, 16> AggregatedStmts;
|
|
|
|
public:
|
|
|
|
AssignmentMemcpyizer(CodeGenFunction &CGF, const CXXMethodDecl *AD,
|
|
FunctionArgList &Args)
|
|
: FieldMemcpyizer(CGF, AD->getParent(), Args[Args.size() - 1]),
|
|
AssignmentsMemcpyable(CGF.getLangOpts().getGC() == LangOptions::NonGC) {
|
|
assert(Args.size() == 2);
|
|
}
|
|
|
|
void emitAssignment(Stmt *S) {
|
|
FieldDecl *F = getMemcpyableField(S);
|
|
if (F) {
|
|
addMemcpyableField(F);
|
|
AggregatedStmts.push_back(S);
|
|
} else {
|
|
emitAggregatedStmts();
|
|
CGF.EmitStmt(S);
|
|
}
|
|
}
|
|
|
|
void emitAggregatedStmts() {
|
|
if (AggregatedStmts.size() <= 1) {
|
|
if (!AggregatedStmts.empty()) {
|
|
CopyingValueRepresentation CVR(CGF);
|
|
CGF.EmitStmt(AggregatedStmts[0]);
|
|
}
|
|
reset();
|
|
}
|
|
|
|
emitMemcpy();
|
|
AggregatedStmts.clear();
|
|
}
|
|
|
|
void finish() {
|
|
emitAggregatedStmts();
|
|
}
|
|
};
|
|
} // end anonymous namespace
|
|
|
|
static bool isInitializerOfDynamicClass(const CXXCtorInitializer *BaseInit) {
|
|
const Type *BaseType = BaseInit->getBaseClass();
|
|
const auto *BaseClassDecl =
|
|
cast<CXXRecordDecl>(BaseType->getAs<RecordType>()->getDecl());
|
|
return BaseClassDecl->isDynamicClass();
|
|
}
|
|
|
|
/// EmitCtorPrologue - This routine generates necessary code to initialize
|
|
/// base classes and non-static data members belonging to this constructor.
|
|
void CodeGenFunction::EmitCtorPrologue(const CXXConstructorDecl *CD,
|
|
CXXCtorType CtorType,
|
|
FunctionArgList &Args) {
|
|
if (CD->isDelegatingConstructor())
|
|
return EmitDelegatingCXXConstructorCall(CD, Args);
|
|
|
|
const CXXRecordDecl *ClassDecl = CD->getParent();
|
|
|
|
CXXConstructorDecl::init_const_iterator B = CD->init_begin(),
|
|
E = CD->init_end();
|
|
|
|
llvm::BasicBlock *BaseCtorContinueBB = nullptr;
|
|
if (ClassDecl->getNumVBases() &&
|
|
!CGM.getTarget().getCXXABI().hasConstructorVariants()) {
|
|
// The ABIs that don't have constructor variants need to put a branch
|
|
// before the virtual base initialization code.
|
|
BaseCtorContinueBB =
|
|
CGM.getCXXABI().EmitCtorCompleteObjectHandler(*this, ClassDecl);
|
|
assert(BaseCtorContinueBB);
|
|
}
|
|
|
|
llvm::Value *const OldThis = CXXThisValue;
|
|
// Virtual base initializers first.
|
|
for (; B != E && (*B)->isBaseInitializer() && (*B)->isBaseVirtual(); B++) {
|
|
if (CGM.getCodeGenOpts().StrictVTablePointers &&
|
|
CGM.getCodeGenOpts().OptimizationLevel > 0 &&
|
|
isInitializerOfDynamicClass(*B))
|
|
CXXThisValue = Builder.CreateInvariantGroupBarrier(LoadCXXThis());
|
|
EmitBaseInitializer(*this, ClassDecl, *B, CtorType);
|
|
}
|
|
|
|
if (BaseCtorContinueBB) {
|
|
// Complete object handler should continue to the remaining initializers.
|
|
Builder.CreateBr(BaseCtorContinueBB);
|
|
EmitBlock(BaseCtorContinueBB);
|
|
}
|
|
|
|
// Then, non-virtual base initializers.
|
|
for (; B != E && (*B)->isBaseInitializer(); B++) {
|
|
assert(!(*B)->isBaseVirtual());
|
|
|
|
if (CGM.getCodeGenOpts().StrictVTablePointers &&
|
|
CGM.getCodeGenOpts().OptimizationLevel > 0 &&
|
|
isInitializerOfDynamicClass(*B))
|
|
CXXThisValue = Builder.CreateInvariantGroupBarrier(LoadCXXThis());
|
|
EmitBaseInitializer(*this, ClassDecl, *B, CtorType);
|
|
}
|
|
|
|
CXXThisValue = OldThis;
|
|
|
|
InitializeVTablePointers(ClassDecl);
|
|
|
|
// And finally, initialize class members.
|
|
FieldConstructionScope FCS(*this, LoadCXXThisAddress());
|
|
ConstructorMemcpyizer CM(*this, CD, Args);
|
|
for (; B != E; B++) {
|
|
CXXCtorInitializer *Member = (*B);
|
|
assert(!Member->isBaseInitializer());
|
|
assert(Member->isAnyMemberInitializer() &&
|
|
"Delegating initializer on non-delegating constructor");
|
|
CM.addMemberInitializer(Member);
|
|
}
|
|
CM.finish();
|
|
}
|
|
|
|
static bool
|
|
FieldHasTrivialDestructorBody(ASTContext &Context, const FieldDecl *Field);
|
|
|
|
static bool
|
|
HasTrivialDestructorBody(ASTContext &Context,
|
|
const CXXRecordDecl *BaseClassDecl,
|
|
const CXXRecordDecl *MostDerivedClassDecl)
|
|
{
|
|
// If the destructor is trivial we don't have to check anything else.
|
|
if (BaseClassDecl->hasTrivialDestructor())
|
|
return true;
|
|
|
|
if (!BaseClassDecl->getDestructor()->hasTrivialBody())
|
|
return false;
|
|
|
|
// Check fields.
|
|
for (const auto *Field : BaseClassDecl->fields())
|
|
if (!FieldHasTrivialDestructorBody(Context, Field))
|
|
return false;
|
|
|
|
// Check non-virtual bases.
|
|
for (const auto &I : BaseClassDecl->bases()) {
|
|
if (I.isVirtual())
|
|
continue;
|
|
|
|
const CXXRecordDecl *NonVirtualBase =
|
|
cast<CXXRecordDecl>(I.getType()->castAs<RecordType>()->getDecl());
|
|
if (!HasTrivialDestructorBody(Context, NonVirtualBase,
|
|
MostDerivedClassDecl))
|
|
return false;
|
|
}
|
|
|
|
if (BaseClassDecl == MostDerivedClassDecl) {
|
|
// Check virtual bases.
|
|
for (const auto &I : BaseClassDecl->vbases()) {
|
|
const CXXRecordDecl *VirtualBase =
|
|
cast<CXXRecordDecl>(I.getType()->castAs<RecordType>()->getDecl());
|
|
if (!HasTrivialDestructorBody(Context, VirtualBase,
|
|
MostDerivedClassDecl))
|
|
return false;
|
|
}
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
static bool
|
|
FieldHasTrivialDestructorBody(ASTContext &Context,
|
|
const FieldDecl *Field)
|
|
{
|
|
QualType FieldBaseElementType = Context.getBaseElementType(Field->getType());
|
|
|
|
const RecordType *RT = FieldBaseElementType->getAs<RecordType>();
|
|
if (!RT)
|
|
return true;
|
|
|
|
CXXRecordDecl *FieldClassDecl = cast<CXXRecordDecl>(RT->getDecl());
|
|
|
|
// The destructor for an implicit anonymous union member is never invoked.
|
|
if (FieldClassDecl->isUnion() && FieldClassDecl->isAnonymousStructOrUnion())
|
|
return false;
|
|
|
|
return HasTrivialDestructorBody(Context, FieldClassDecl, FieldClassDecl);
|
|
}
|
|
|
|
/// CanSkipVTablePointerInitialization - Check whether we need to initialize
|
|
/// any vtable pointers before calling this destructor.
|
|
static bool CanSkipVTablePointerInitialization(CodeGenFunction &CGF,
|
|
const CXXDestructorDecl *Dtor) {
|
|
const CXXRecordDecl *ClassDecl = Dtor->getParent();
|
|
if (!ClassDecl->isDynamicClass())
|
|
return true;
|
|
|
|
if (!Dtor->hasTrivialBody())
|
|
return false;
|
|
|
|
// Check the fields.
|
|
for (const auto *Field : ClassDecl->fields())
|
|
if (!FieldHasTrivialDestructorBody(CGF.getContext(), Field))
|
|
return false;
|
|
|
|
return true;
|
|
}
|
|
|
|
/// EmitDestructorBody - Emits the body of the current destructor.
|
|
void CodeGenFunction::EmitDestructorBody(FunctionArgList &Args) {
|
|
const CXXDestructorDecl *Dtor = cast<CXXDestructorDecl>(CurGD.getDecl());
|
|
CXXDtorType DtorType = CurGD.getDtorType();
|
|
|
|
Stmt *Body = Dtor->getBody();
|
|
if (Body)
|
|
incrementProfileCounter(Body);
|
|
|
|
// The call to operator delete in a deleting destructor happens
|
|
// outside of the function-try-block, which means it's always
|
|
// possible to delegate the destructor body to the complete
|
|
// destructor. Do so.
|
|
if (DtorType == Dtor_Deleting) {
|
|
EnterDtorCleanups(Dtor, Dtor_Deleting);
|
|
EmitCXXDestructorCall(Dtor, Dtor_Complete, /*ForVirtualBase=*/false,
|
|
/*Delegating=*/false, LoadCXXThisAddress());
|
|
PopCleanupBlock();
|
|
return;
|
|
}
|
|
|
|
// If the body is a function-try-block, enter the try before
|
|
// anything else.
|
|
bool isTryBody = (Body && isa<CXXTryStmt>(Body));
|
|
if (isTryBody)
|
|
EnterCXXTryStmt(*cast<CXXTryStmt>(Body), true);
|
|
EmitAsanPrologueOrEpilogue(false);
|
|
|
|
// Enter the epilogue cleanups.
|
|
RunCleanupsScope DtorEpilogue(*this);
|
|
|
|
// If this is the complete variant, just invoke the base variant;
|
|
// the epilogue will destruct the virtual bases. But we can't do
|
|
// this optimization if the body is a function-try-block, because
|
|
// we'd introduce *two* handler blocks. In the Microsoft ABI, we
|
|
// always delegate because we might not have a definition in this TU.
|
|
switch (DtorType) {
|
|
case Dtor_Comdat:
|
|
llvm_unreachable("not expecting a COMDAT");
|
|
|
|
case Dtor_Deleting: llvm_unreachable("already handled deleting case");
|
|
|
|
case Dtor_Complete:
|
|
assert((Body || getTarget().getCXXABI().isMicrosoft()) &&
|
|
"can't emit a dtor without a body for non-Microsoft ABIs");
|
|
|
|
// Enter the cleanup scopes for virtual bases.
|
|
EnterDtorCleanups(Dtor, Dtor_Complete);
|
|
|
|
if (!isTryBody) {
|
|
EmitCXXDestructorCall(Dtor, Dtor_Base, /*ForVirtualBase=*/false,
|
|
/*Delegating=*/false, LoadCXXThisAddress());
|
|
break;
|
|
}
|
|
// Fallthrough: act like we're in the base variant.
|
|
|
|
case Dtor_Base:
|
|
assert(Body);
|
|
|
|
// Enter the cleanup scopes for fields and non-virtual bases.
|
|
EnterDtorCleanups(Dtor, Dtor_Base);
|
|
|
|
// Initialize the vtable pointers before entering the body.
|
|
if (!CanSkipVTablePointerInitialization(*this, Dtor)) {
|
|
// Insert the llvm.invariant.group.barrier intrinsic before initializing
|
|
// the vptrs to cancel any previous assumptions we might have made.
|
|
if (CGM.getCodeGenOpts().StrictVTablePointers &&
|
|
CGM.getCodeGenOpts().OptimizationLevel > 0)
|
|
CXXThisValue = Builder.CreateInvariantGroupBarrier(LoadCXXThis());
|
|
InitializeVTablePointers(Dtor->getParent());
|
|
}
|
|
|
|
if (isTryBody)
|
|
EmitStmt(cast<CXXTryStmt>(Body)->getTryBlock());
|
|
else if (Body)
|
|
EmitStmt(Body);
|
|
else {
|
|
assert(Dtor->isImplicit() && "bodyless dtor not implicit");
|
|
// nothing to do besides what's in the epilogue
|
|
}
|
|
// -fapple-kext must inline any call to this dtor into
|
|
// the caller's body.
|
|
if (getLangOpts().AppleKext)
|
|
CurFn->addFnAttr(llvm::Attribute::AlwaysInline);
|
|
|
|
break;
|
|
}
|
|
|
|
// Jump out through the epilogue cleanups.
|
|
DtorEpilogue.ForceCleanup();
|
|
|
|
// Exit the try if applicable.
|
|
if (isTryBody)
|
|
ExitCXXTryStmt(*cast<CXXTryStmt>(Body), true);
|
|
}
|
|
|
|
void CodeGenFunction::emitImplicitAssignmentOperatorBody(FunctionArgList &Args) {
|
|
const CXXMethodDecl *AssignOp = cast<CXXMethodDecl>(CurGD.getDecl());
|
|
const Stmt *RootS = AssignOp->getBody();
|
|
assert(isa<CompoundStmt>(RootS) &&
|
|
"Body of an implicit assignment operator should be compound stmt.");
|
|
const CompoundStmt *RootCS = cast<CompoundStmt>(RootS);
|
|
|
|
LexicalScope Scope(*this, RootCS->getSourceRange());
|
|
|
|
AssignmentMemcpyizer AM(*this, AssignOp, Args);
|
|
for (auto *I : RootCS->body())
|
|
AM.emitAssignment(I);
|
|
AM.finish();
|
|
}
|
|
|
|
namespace {
|
|
/// Call the operator delete associated with the current destructor.
|
|
struct CallDtorDelete final : EHScopeStack::Cleanup {
|
|
CallDtorDelete() {}
|
|
|
|
void Emit(CodeGenFunction &CGF, Flags flags) override {
|
|
const CXXDestructorDecl *Dtor = cast<CXXDestructorDecl>(CGF.CurCodeDecl);
|
|
const CXXRecordDecl *ClassDecl = Dtor->getParent();
|
|
CGF.EmitDeleteCall(Dtor->getOperatorDelete(), CGF.LoadCXXThis(),
|
|
CGF.getContext().getTagDeclType(ClassDecl));
|
|
}
|
|
};
|
|
|
|
struct CallDtorDeleteConditional final : EHScopeStack::Cleanup {
|
|
llvm::Value *ShouldDeleteCondition;
|
|
public:
|
|
CallDtorDeleteConditional(llvm::Value *ShouldDeleteCondition)
|
|
: ShouldDeleteCondition(ShouldDeleteCondition) {
|
|
assert(ShouldDeleteCondition != nullptr);
|
|
}
|
|
|
|
void Emit(CodeGenFunction &CGF, Flags flags) override {
|
|
llvm::BasicBlock *callDeleteBB = CGF.createBasicBlock("dtor.call_delete");
|
|
llvm::BasicBlock *continueBB = CGF.createBasicBlock("dtor.continue");
|
|
llvm::Value *ShouldCallDelete
|
|
= CGF.Builder.CreateIsNull(ShouldDeleteCondition);
|
|
CGF.Builder.CreateCondBr(ShouldCallDelete, continueBB, callDeleteBB);
|
|
|
|
CGF.EmitBlock(callDeleteBB);
|
|
const CXXDestructorDecl *Dtor = cast<CXXDestructorDecl>(CGF.CurCodeDecl);
|
|
const CXXRecordDecl *ClassDecl = Dtor->getParent();
|
|
CGF.EmitDeleteCall(Dtor->getOperatorDelete(), CGF.LoadCXXThis(),
|
|
CGF.getContext().getTagDeclType(ClassDecl));
|
|
CGF.Builder.CreateBr(continueBB);
|
|
|
|
CGF.EmitBlock(continueBB);
|
|
}
|
|
};
|
|
|
|
class DestroyField final : public EHScopeStack::Cleanup {
|
|
const FieldDecl *field;
|
|
CodeGenFunction::Destroyer *destroyer;
|
|
bool useEHCleanupForArray;
|
|
|
|
public:
|
|
DestroyField(const FieldDecl *field, CodeGenFunction::Destroyer *destroyer,
|
|
bool useEHCleanupForArray)
|
|
: field(field), destroyer(destroyer),
|
|
useEHCleanupForArray(useEHCleanupForArray) {}
|
|
|
|
void Emit(CodeGenFunction &CGF, Flags flags) override {
|
|
// Find the address of the field.
|
|
Address thisValue = CGF.LoadCXXThisAddress();
|
|
QualType RecordTy = CGF.getContext().getTagDeclType(field->getParent());
|
|
LValue ThisLV = CGF.MakeAddrLValue(thisValue, RecordTy);
|
|
LValue LV = CGF.EmitLValueForField(ThisLV, field);
|
|
assert(LV.isSimple());
|
|
|
|
CGF.emitDestroy(LV.getAddress(), field->getType(), destroyer,
|
|
flags.isForNormalCleanup() && useEHCleanupForArray);
|
|
}
|
|
};
|
|
|
|
static void EmitSanitizerDtorCallback(CodeGenFunction &CGF, llvm::Value *Ptr,
|
|
CharUnits::QuantityType PoisonSize) {
|
|
// Pass in void pointer and size of region as arguments to runtime
|
|
// function
|
|
llvm::Value *Args[] = {CGF.Builder.CreateBitCast(Ptr, CGF.VoidPtrTy),
|
|
llvm::ConstantInt::get(CGF.SizeTy, PoisonSize)};
|
|
|
|
llvm::Type *ArgTypes[] = {CGF.VoidPtrTy, CGF.SizeTy};
|
|
|
|
llvm::FunctionType *FnType =
|
|
llvm::FunctionType::get(CGF.VoidTy, ArgTypes, false);
|
|
llvm::Value *Fn =
|
|
CGF.CGM.CreateRuntimeFunction(FnType, "__sanitizer_dtor_callback");
|
|
CGF.EmitNounwindRuntimeCall(Fn, Args);
|
|
}
|
|
|
|
class SanitizeDtorMembers final : public EHScopeStack::Cleanup {
|
|
const CXXDestructorDecl *Dtor;
|
|
|
|
public:
|
|
SanitizeDtorMembers(const CXXDestructorDecl *Dtor) : Dtor(Dtor) {}
|
|
|
|
// Generate function call for handling object poisoning.
|
|
// Disables tail call elimination, to prevent the current stack frame
|
|
// from disappearing from the stack trace.
|
|
void Emit(CodeGenFunction &CGF, Flags flags) override {
|
|
const ASTRecordLayout &Layout =
|
|
CGF.getContext().getASTRecordLayout(Dtor->getParent());
|
|
|
|
// Nothing to poison.
|
|
if (Layout.getFieldCount() == 0)
|
|
return;
|
|
|
|
// Prevent the current stack frame from disappearing from the stack trace.
|
|
CGF.CurFn->addFnAttr("disable-tail-calls", "true");
|
|
|
|
// Construct pointer to region to begin poisoning, and calculate poison
|
|
// size, so that only members declared in this class are poisoned.
|
|
ASTContext &Context = CGF.getContext();
|
|
unsigned fieldIndex = 0;
|
|
int startIndex = -1;
|
|
// RecordDecl::field_iterator Field;
|
|
for (const FieldDecl *Field : Dtor->getParent()->fields()) {
|
|
// Poison field if it is trivial
|
|
if (FieldHasTrivialDestructorBody(Context, Field)) {
|
|
// Start sanitizing at this field
|
|
if (startIndex < 0)
|
|
startIndex = fieldIndex;
|
|
|
|
// Currently on the last field, and it must be poisoned with the
|
|
// current block.
|
|
if (fieldIndex == Layout.getFieldCount() - 1) {
|
|
PoisonMembers(CGF, startIndex, Layout.getFieldCount());
|
|
}
|
|
} else if (startIndex >= 0) {
|
|
// No longer within a block of memory to poison, so poison the block
|
|
PoisonMembers(CGF, startIndex, fieldIndex);
|
|
// Re-set the start index
|
|
startIndex = -1;
|
|
}
|
|
fieldIndex += 1;
|
|
}
|
|
}
|
|
|
|
private:
|
|
/// \param layoutStartOffset index of the ASTRecordLayout field to
|
|
/// start poisoning (inclusive)
|
|
/// \param layoutEndOffset index of the ASTRecordLayout field to
|
|
/// end poisoning (exclusive)
|
|
void PoisonMembers(CodeGenFunction &CGF, unsigned layoutStartOffset,
|
|
unsigned layoutEndOffset) {
|
|
ASTContext &Context = CGF.getContext();
|
|
const ASTRecordLayout &Layout =
|
|
Context.getASTRecordLayout(Dtor->getParent());
|
|
|
|
llvm::ConstantInt *OffsetSizePtr = llvm::ConstantInt::get(
|
|
CGF.SizeTy,
|
|
Context.toCharUnitsFromBits(Layout.getFieldOffset(layoutStartOffset))
|
|
.getQuantity());
|
|
|
|
llvm::Value *OffsetPtr = CGF.Builder.CreateGEP(
|
|
CGF.Builder.CreateBitCast(CGF.LoadCXXThis(), CGF.Int8PtrTy),
|
|
OffsetSizePtr);
|
|
|
|
CharUnits::QuantityType PoisonSize;
|
|
if (layoutEndOffset >= Layout.getFieldCount()) {
|
|
PoisonSize = Layout.getNonVirtualSize().getQuantity() -
|
|
Context.toCharUnitsFromBits(
|
|
Layout.getFieldOffset(layoutStartOffset))
|
|
.getQuantity();
|
|
} else {
|
|
PoisonSize = Context.toCharUnitsFromBits(
|
|
Layout.getFieldOffset(layoutEndOffset) -
|
|
Layout.getFieldOffset(layoutStartOffset))
|
|
.getQuantity();
|
|
}
|
|
|
|
if (PoisonSize == 0)
|
|
return;
|
|
|
|
EmitSanitizerDtorCallback(CGF, OffsetPtr, PoisonSize);
|
|
}
|
|
};
|
|
|
|
class SanitizeDtorVTable final : public EHScopeStack::Cleanup {
|
|
const CXXDestructorDecl *Dtor;
|
|
|
|
public:
|
|
SanitizeDtorVTable(const CXXDestructorDecl *Dtor) : Dtor(Dtor) {}
|
|
|
|
// Generate function call for handling vtable pointer poisoning.
|
|
void Emit(CodeGenFunction &CGF, Flags flags) override {
|
|
assert(Dtor->getParent()->isDynamicClass());
|
|
(void)Dtor;
|
|
ASTContext &Context = CGF.getContext();
|
|
// Poison vtable and vtable ptr if they exist for this class.
|
|
llvm::Value *VTablePtr = CGF.LoadCXXThis();
|
|
|
|
CharUnits::QuantityType PoisonSize =
|
|
Context.toCharUnitsFromBits(CGF.PointerWidthInBits).getQuantity();
|
|
// Pass in void pointer and size of region as arguments to runtime
|
|
// function
|
|
EmitSanitizerDtorCallback(CGF, VTablePtr, PoisonSize);
|
|
}
|
|
};
|
|
} // end anonymous namespace
|
|
|
|
/// \brief Emit all code that comes at the end of class's
|
|
/// destructor. This is to call destructors on members and base classes
|
|
/// in reverse order of their construction.
|
|
void CodeGenFunction::EnterDtorCleanups(const CXXDestructorDecl *DD,
|
|
CXXDtorType DtorType) {
|
|
assert((!DD->isTrivial() || DD->hasAttr<DLLExportAttr>()) &&
|
|
"Should not emit dtor epilogue for non-exported trivial dtor!");
|
|
|
|
// The deleting-destructor phase just needs to call the appropriate
|
|
// operator delete that Sema picked up.
|
|
if (DtorType == Dtor_Deleting) {
|
|
assert(DD->getOperatorDelete() &&
|
|
"operator delete missing - EnterDtorCleanups");
|
|
if (CXXStructorImplicitParamValue) {
|
|
// If there is an implicit param to the deleting dtor, it's a boolean
|
|
// telling whether we should call delete at the end of the dtor.
|
|
EHStack.pushCleanup<CallDtorDeleteConditional>(
|
|
NormalAndEHCleanup, CXXStructorImplicitParamValue);
|
|
} else {
|
|
EHStack.pushCleanup<CallDtorDelete>(NormalAndEHCleanup);
|
|
}
|
|
return;
|
|
}
|
|
|
|
const CXXRecordDecl *ClassDecl = DD->getParent();
|
|
|
|
// Unions have no bases and do not call field destructors.
|
|
if (ClassDecl->isUnion())
|
|
return;
|
|
|
|
// The complete-destructor phase just destructs all the virtual bases.
|
|
if (DtorType == Dtor_Complete) {
|
|
// Poison the vtable pointer such that access after the base
|
|
// and member destructors are invoked is invalid.
|
|
if (CGM.getCodeGenOpts().SanitizeMemoryUseAfterDtor &&
|
|
SanOpts.has(SanitizerKind::Memory) && ClassDecl->getNumVBases() &&
|
|
ClassDecl->isPolymorphic())
|
|
EHStack.pushCleanup<SanitizeDtorVTable>(NormalAndEHCleanup, DD);
|
|
|
|
// We push them in the forward order so that they'll be popped in
|
|
// the reverse order.
|
|
for (const auto &Base : ClassDecl->vbases()) {
|
|
CXXRecordDecl *BaseClassDecl
|
|
= cast<CXXRecordDecl>(Base.getType()->getAs<RecordType>()->getDecl());
|
|
|
|
// Ignore trivial destructors.
|
|
if (BaseClassDecl->hasTrivialDestructor())
|
|
continue;
|
|
|
|
EHStack.pushCleanup<CallBaseDtor>(NormalAndEHCleanup,
|
|
BaseClassDecl,
|
|
/*BaseIsVirtual*/ true);
|
|
}
|
|
|
|
return;
|
|
}
|
|
|
|
assert(DtorType == Dtor_Base);
|
|
// Poison the vtable pointer if it has no virtual bases, but inherits
|
|
// virtual functions.
|
|
if (CGM.getCodeGenOpts().SanitizeMemoryUseAfterDtor &&
|
|
SanOpts.has(SanitizerKind::Memory) && !ClassDecl->getNumVBases() &&
|
|
ClassDecl->isPolymorphic())
|
|
EHStack.pushCleanup<SanitizeDtorVTable>(NormalAndEHCleanup, DD);
|
|
|
|
// Destroy non-virtual bases.
|
|
for (const auto &Base : ClassDecl->bases()) {
|
|
// Ignore virtual bases.
|
|
if (Base.isVirtual())
|
|
continue;
|
|
|
|
CXXRecordDecl *BaseClassDecl = Base.getType()->getAsCXXRecordDecl();
|
|
|
|
// Ignore trivial destructors.
|
|
if (BaseClassDecl->hasTrivialDestructor())
|
|
continue;
|
|
|
|
EHStack.pushCleanup<CallBaseDtor>(NormalAndEHCleanup,
|
|
BaseClassDecl,
|
|
/*BaseIsVirtual*/ false);
|
|
}
|
|
|
|
// Poison fields such that access after their destructors are
|
|
// invoked, and before the base class destructor runs, is invalid.
|
|
if (CGM.getCodeGenOpts().SanitizeMemoryUseAfterDtor &&
|
|
SanOpts.has(SanitizerKind::Memory))
|
|
EHStack.pushCleanup<SanitizeDtorMembers>(NormalAndEHCleanup, DD);
|
|
|
|
// Destroy direct fields.
|
|
for (const auto *Field : ClassDecl->fields()) {
|
|
QualType type = Field->getType();
|
|
QualType::DestructionKind dtorKind = type.isDestructedType();
|
|
if (!dtorKind) continue;
|
|
|
|
// Anonymous union members do not have their destructors called.
|
|
const RecordType *RT = type->getAsUnionType();
|
|
if (RT && RT->getDecl()->isAnonymousStructOrUnion()) continue;
|
|
|
|
CleanupKind cleanupKind = getCleanupKind(dtorKind);
|
|
EHStack.pushCleanup<DestroyField>(cleanupKind, Field,
|
|
getDestroyer(dtorKind),
|
|
cleanupKind & EHCleanup);
|
|
}
|
|
}
|
|
|
|
/// EmitCXXAggrConstructorCall - Emit a loop to call a particular
|
|
/// constructor for each of several members of an array.
|
|
///
|
|
/// \param ctor the constructor to call for each element
|
|
/// \param arrayType the type of the array to initialize
|
|
/// \param arrayBegin an arrayType*
|
|
/// \param zeroInitialize true if each element should be
|
|
/// zero-initialized before it is constructed
|
|
void CodeGenFunction::EmitCXXAggrConstructorCall(
|
|
const CXXConstructorDecl *ctor, const ConstantArrayType *arrayType,
|
|
Address arrayBegin, const CXXConstructExpr *E, bool zeroInitialize) {
|
|
QualType elementType;
|
|
llvm::Value *numElements =
|
|
emitArrayLength(arrayType, elementType, arrayBegin);
|
|
|
|
EmitCXXAggrConstructorCall(ctor, numElements, arrayBegin, E, zeroInitialize);
|
|
}
|
|
|
|
/// EmitCXXAggrConstructorCall - Emit a loop to call a particular
|
|
/// constructor for each of several members of an array.
|
|
///
|
|
/// \param ctor the constructor to call for each element
|
|
/// \param numElements the number of elements in the array;
|
|
/// may be zero
|
|
/// \param arrayBase a T*, where T is the type constructed by ctor
|
|
/// \param zeroInitialize true if each element should be
|
|
/// zero-initialized before it is constructed
|
|
void CodeGenFunction::EmitCXXAggrConstructorCall(const CXXConstructorDecl *ctor,
|
|
llvm::Value *numElements,
|
|
Address arrayBase,
|
|
const CXXConstructExpr *E,
|
|
bool zeroInitialize) {
|
|
// It's legal for numElements to be zero. This can happen both
|
|
// dynamically, because x can be zero in 'new A[x]', and statically,
|
|
// because of GCC extensions that permit zero-length arrays. There
|
|
// are probably legitimate places where we could assume that this
|
|
// doesn't happen, but it's not clear that it's worth it.
|
|
llvm::BranchInst *zeroCheckBranch = nullptr;
|
|
|
|
// Optimize for a constant count.
|
|
llvm::ConstantInt *constantCount
|
|
= dyn_cast<llvm::ConstantInt>(numElements);
|
|
if (constantCount) {
|
|
// Just skip out if the constant count is zero.
|
|
if (constantCount->isZero()) return;
|
|
|
|
// Otherwise, emit the check.
|
|
} else {
|
|
llvm::BasicBlock *loopBB = createBasicBlock("new.ctorloop");
|
|
llvm::Value *iszero = Builder.CreateIsNull(numElements, "isempty");
|
|
zeroCheckBranch = Builder.CreateCondBr(iszero, loopBB, loopBB);
|
|
EmitBlock(loopBB);
|
|
}
|
|
|
|
// Find the end of the array.
|
|
llvm::Value *arrayBegin = arrayBase.getPointer();
|
|
llvm::Value *arrayEnd = Builder.CreateInBoundsGEP(arrayBegin, numElements,
|
|
"arrayctor.end");
|
|
|
|
// Enter the loop, setting up a phi for the current location to initialize.
|
|
llvm::BasicBlock *entryBB = Builder.GetInsertBlock();
|
|
llvm::BasicBlock *loopBB = createBasicBlock("arrayctor.loop");
|
|
EmitBlock(loopBB);
|
|
llvm::PHINode *cur = Builder.CreatePHI(arrayBegin->getType(), 2,
|
|
"arrayctor.cur");
|
|
cur->addIncoming(arrayBegin, entryBB);
|
|
|
|
// Inside the loop body, emit the constructor call on the array element.
|
|
|
|
// The alignment of the base, adjusted by the size of a single element,
|
|
// provides a conservative estimate of the alignment of every element.
|
|
// (This assumes we never start tracking offsetted alignments.)
|
|
//
|
|
// Note that these are complete objects and so we don't need to
|
|
// use the non-virtual size or alignment.
|
|
QualType type = getContext().getTypeDeclType(ctor->getParent());
|
|
CharUnits eltAlignment =
|
|
arrayBase.getAlignment()
|
|
.alignmentOfArrayElement(getContext().getTypeSizeInChars(type));
|
|
Address curAddr = Address(cur, eltAlignment);
|
|
|
|
// Zero initialize the storage, if requested.
|
|
if (zeroInitialize)
|
|
EmitNullInitialization(curAddr, type);
|
|
|
|
// C++ [class.temporary]p4:
|
|
// There are two contexts in which temporaries are destroyed at a different
|
|
// point than the end of the full-expression. The first context is when a
|
|
// default constructor is called to initialize an element of an array.
|
|
// If the constructor has one or more default arguments, the destruction of
|
|
// every temporary created in a default argument expression is sequenced
|
|
// before the construction of the next array element, if any.
|
|
|
|
{
|
|
RunCleanupsScope Scope(*this);
|
|
|
|
// Evaluate the constructor and its arguments in a regular
|
|
// partial-destroy cleanup.
|
|
if (getLangOpts().Exceptions &&
|
|
!ctor->getParent()->hasTrivialDestructor()) {
|
|
Destroyer *destroyer = destroyCXXObject;
|
|
pushRegularPartialArrayCleanup(arrayBegin, cur, type, eltAlignment,
|
|
*destroyer);
|
|
}
|
|
|
|
EmitCXXConstructorCall(ctor, Ctor_Complete, /*ForVirtualBase=*/false,
|
|
/*Delegating=*/false, curAddr, E);
|
|
}
|
|
|
|
// Go to the next element.
|
|
llvm::Value *next =
|
|
Builder.CreateInBoundsGEP(cur, llvm::ConstantInt::get(SizeTy, 1),
|
|
"arrayctor.next");
|
|
cur->addIncoming(next, Builder.GetInsertBlock());
|
|
|
|
// Check whether that's the end of the loop.
|
|
llvm::Value *done = Builder.CreateICmpEQ(next, arrayEnd, "arrayctor.done");
|
|
llvm::BasicBlock *contBB = createBasicBlock("arrayctor.cont");
|
|
Builder.CreateCondBr(done, contBB, loopBB);
|
|
|
|
// Patch the earlier check to skip over the loop.
|
|
if (zeroCheckBranch) zeroCheckBranch->setSuccessor(0, contBB);
|
|
|
|
EmitBlock(contBB);
|
|
}
|
|
|
|
void CodeGenFunction::destroyCXXObject(CodeGenFunction &CGF,
|
|
Address addr,
|
|
QualType type) {
|
|
const RecordType *rtype = type->castAs<RecordType>();
|
|
const CXXRecordDecl *record = cast<CXXRecordDecl>(rtype->getDecl());
|
|
const CXXDestructorDecl *dtor = record->getDestructor();
|
|
assert(!dtor->isTrivial());
|
|
CGF.EmitCXXDestructorCall(dtor, Dtor_Complete, /*for vbase*/ false,
|
|
/*Delegating=*/false, addr);
|
|
}
|
|
|
|
void CodeGenFunction::EmitCXXConstructorCall(const CXXConstructorDecl *D,
|
|
CXXCtorType Type,
|
|
bool ForVirtualBase,
|
|
bool Delegating, Address This,
|
|
const CXXConstructExpr *E) {
|
|
const CXXRecordDecl *ClassDecl = D->getParent();
|
|
|
|
// C++11 [class.mfct.non-static]p2:
|
|
// If a non-static member function of a class X is called for an object that
|
|
// is not of type X, or of a type derived from X, the behavior is undefined.
|
|
// FIXME: Provide a source location here.
|
|
EmitTypeCheck(CodeGenFunction::TCK_ConstructorCall, SourceLocation(),
|
|
This.getPointer(), getContext().getRecordType(ClassDecl));
|
|
|
|
if (D->isTrivial() && D->isDefaultConstructor()) {
|
|
assert(E->getNumArgs() == 0 && "trivial default ctor with args");
|
|
return;
|
|
}
|
|
|
|
// If this is a trivial constructor, just emit what's needed. If this is a
|
|
// union copy constructor, we must emit a memcpy, because the AST does not
|
|
// model that copy.
|
|
if (isMemcpyEquivalentSpecialMember(D)) {
|
|
assert(E->getNumArgs() == 1 && "unexpected argcount for trivial ctor");
|
|
|
|
const Expr *Arg = E->getArg(0);
|
|
QualType SrcTy = Arg->getType();
|
|
Address Src = EmitLValue(Arg).getAddress();
|
|
QualType DestTy = getContext().getTypeDeclType(ClassDecl);
|
|
EmitAggregateCopyCtor(This, Src, DestTy, SrcTy);
|
|
return;
|
|
}
|
|
|
|
CallArgList Args;
|
|
|
|
// Push the this ptr.
|
|
Args.add(RValue::get(This.getPointer()), D->getThisType(getContext()));
|
|
|
|
// Add the rest of the user-supplied arguments.
|
|
const FunctionProtoType *FPT = D->getType()->castAs<FunctionProtoType>();
|
|
EmitCallArgs(Args, FPT, E->arguments(), E->getConstructor());
|
|
|
|
// Insert any ABI-specific implicit constructor arguments.
|
|
unsigned ExtraArgs = CGM.getCXXABI().addImplicitConstructorArgs(
|
|
*this, D, Type, ForVirtualBase, Delegating, Args);
|
|
|
|
// Emit the call.
|
|
llvm::Value *Callee = CGM.getAddrOfCXXStructor(D, getFromCtorType(Type));
|
|
const CGFunctionInfo &Info =
|
|
CGM.getTypes().arrangeCXXConstructorCall(Args, D, Type, ExtraArgs);
|
|
EmitCall(Info, Callee, ReturnValueSlot(), Args, D);
|
|
|
|
// Generate vtable assumptions if we're constructing a complete object
|
|
// with a vtable. We don't do this for base subobjects for two reasons:
|
|
// first, it's incorrect for classes with virtual bases, and second, we're
|
|
// about to overwrite the vptrs anyway.
|
|
// We also have to make sure if we can refer to vtable:
|
|
// - Otherwise we can refer to vtable if it's safe to speculatively emit.
|
|
// FIXME: If vtable is used by ctor/dtor, or if vtable is external and we are
|
|
// sure that definition of vtable is not hidden,
|
|
// then we are always safe to refer to it.
|
|
// FIXME: It looks like InstCombine is very inefficient on dealing with
|
|
// assumes. Make assumption loads require -fstrict-vtable-pointers temporarily.
|
|
if (CGM.getCodeGenOpts().OptimizationLevel > 0 &&
|
|
ClassDecl->isDynamicClass() && Type != Ctor_Base &&
|
|
CGM.getCXXABI().canSpeculativelyEmitVTable(ClassDecl) &&
|
|
CGM.getCodeGenOpts().StrictVTablePointers)
|
|
EmitVTableAssumptionLoads(ClassDecl, This);
|
|
}
|
|
|
|
void CodeGenFunction::EmitVTableAssumptionLoad(const VPtr &Vptr, Address This) {
|
|
llvm::Value *VTableGlobal =
|
|
CGM.getCXXABI().getVTableAddressPoint(Vptr.Base, Vptr.VTableClass);
|
|
if (!VTableGlobal)
|
|
return;
|
|
|
|
// We can just use the base offset in the complete class.
|
|
CharUnits NonVirtualOffset = Vptr.Base.getBaseOffset();
|
|
|
|
if (!NonVirtualOffset.isZero())
|
|
This =
|
|
ApplyNonVirtualAndVirtualOffset(*this, This, NonVirtualOffset, nullptr,
|
|
Vptr.VTableClass, Vptr.NearestVBase);
|
|
|
|
llvm::Value *VPtrValue =
|
|
GetVTablePtr(This, VTableGlobal->getType(), Vptr.VTableClass);
|
|
llvm::Value *Cmp =
|
|
Builder.CreateICmpEQ(VPtrValue, VTableGlobal, "cmp.vtables");
|
|
Builder.CreateAssumption(Cmp);
|
|
}
|
|
|
|
void CodeGenFunction::EmitVTableAssumptionLoads(const CXXRecordDecl *ClassDecl,
|
|
Address This) {
|
|
if (CGM.getCXXABI().doStructorsInitializeVPtrs(ClassDecl))
|
|
for (const VPtr &Vptr : getVTablePointers(ClassDecl))
|
|
EmitVTableAssumptionLoad(Vptr, This);
|
|
}
|
|
|
|
void
|
|
CodeGenFunction::EmitSynthesizedCXXCopyCtorCall(const CXXConstructorDecl *D,
|
|
Address This, Address Src,
|
|
const CXXConstructExpr *E) {
|
|
if (isMemcpyEquivalentSpecialMember(D)) {
|
|
assert(E->getNumArgs() == 1 && "unexpected argcount for trivial ctor");
|
|
assert(D->isCopyOrMoveConstructor() &&
|
|
"trivial 1-arg ctor not a copy/move ctor");
|
|
EmitAggregateCopyCtor(This, Src,
|
|
getContext().getTypeDeclType(D->getParent()),
|
|
(*E->arg_begin())->getType());
|
|
return;
|
|
}
|
|
llvm::Value *Callee = CGM.getAddrOfCXXStructor(D, StructorType::Complete);
|
|
assert(D->isInstance() &&
|
|
"Trying to emit a member call expr on a static method!");
|
|
|
|
const FunctionProtoType *FPT = D->getType()->castAs<FunctionProtoType>();
|
|
|
|
CallArgList Args;
|
|
|
|
// Push the this ptr.
|
|
Args.add(RValue::get(This.getPointer()), D->getThisType(getContext()));
|
|
|
|
// Push the src ptr.
|
|
QualType QT = *(FPT->param_type_begin());
|
|
llvm::Type *t = CGM.getTypes().ConvertType(QT);
|
|
Src = Builder.CreateBitCast(Src, t);
|
|
Args.add(RValue::get(Src.getPointer()), QT);
|
|
|
|
// Skip over first argument (Src).
|
|
EmitCallArgs(Args, FPT, drop_begin(E->arguments(), 1), E->getConstructor(),
|
|
/*ParamsToSkip*/ 1);
|
|
|
|
EmitCall(CGM.getTypes().arrangeCXXMethodCall(Args, FPT, RequiredArgs::All),
|
|
Callee, ReturnValueSlot(), Args, D);
|
|
}
|
|
|
|
void
|
|
CodeGenFunction::EmitDelegateCXXConstructorCall(const CXXConstructorDecl *Ctor,
|
|
CXXCtorType CtorType,
|
|
const FunctionArgList &Args,
|
|
SourceLocation Loc) {
|
|
CallArgList DelegateArgs;
|
|
|
|
FunctionArgList::const_iterator I = Args.begin(), E = Args.end();
|
|
assert(I != E && "no parameters to constructor");
|
|
|
|
// this
|
|
DelegateArgs.add(RValue::get(LoadCXXThis()), (*I)->getType());
|
|
++I;
|
|
|
|
// vtt
|
|
if (llvm::Value *VTT = GetVTTParameter(GlobalDecl(Ctor, CtorType),
|
|
/*ForVirtualBase=*/false,
|
|
/*Delegating=*/true)) {
|
|
QualType VoidPP = getContext().getPointerType(getContext().VoidPtrTy);
|
|
DelegateArgs.add(RValue::get(VTT), VoidPP);
|
|
|
|
if (CGM.getCXXABI().NeedsVTTParameter(CurGD)) {
|
|
assert(I != E && "cannot skip vtt parameter, already done with args");
|
|
assert((*I)->getType() == VoidPP && "skipping parameter not of vtt type");
|
|
++I;
|
|
}
|
|
}
|
|
|
|
// Explicit arguments.
|
|
for (; I != E; ++I) {
|
|
const VarDecl *param = *I;
|
|
// FIXME: per-argument source location
|
|
EmitDelegateCallArg(DelegateArgs, param, Loc);
|
|
}
|
|
|
|
llvm::Value *Callee =
|
|
CGM.getAddrOfCXXStructor(Ctor, getFromCtorType(CtorType));
|
|
EmitCall(CGM.getTypes()
|
|
.arrangeCXXStructorDeclaration(Ctor, getFromCtorType(CtorType)),
|
|
Callee, ReturnValueSlot(), DelegateArgs, Ctor);
|
|
}
|
|
|
|
namespace {
|
|
struct CallDelegatingCtorDtor final : EHScopeStack::Cleanup {
|
|
const CXXDestructorDecl *Dtor;
|
|
Address Addr;
|
|
CXXDtorType Type;
|
|
|
|
CallDelegatingCtorDtor(const CXXDestructorDecl *D, Address Addr,
|
|
CXXDtorType Type)
|
|
: Dtor(D), Addr(Addr), Type(Type) {}
|
|
|
|
void Emit(CodeGenFunction &CGF, Flags flags) override {
|
|
CGF.EmitCXXDestructorCall(Dtor, Type, /*ForVirtualBase=*/false,
|
|
/*Delegating=*/true, Addr);
|
|
}
|
|
};
|
|
} // end anonymous namespace
|
|
|
|
void
|
|
CodeGenFunction::EmitDelegatingCXXConstructorCall(const CXXConstructorDecl *Ctor,
|
|
const FunctionArgList &Args) {
|
|
assert(Ctor->isDelegatingConstructor());
|
|
|
|
Address ThisPtr = LoadCXXThisAddress();
|
|
|
|
AggValueSlot AggSlot =
|
|
AggValueSlot::forAddr(ThisPtr, Qualifiers(),
|
|
AggValueSlot::IsDestructed,
|
|
AggValueSlot::DoesNotNeedGCBarriers,
|
|
AggValueSlot::IsNotAliased);
|
|
|
|
EmitAggExpr(Ctor->init_begin()[0]->getInit(), AggSlot);
|
|
|
|
const CXXRecordDecl *ClassDecl = Ctor->getParent();
|
|
if (CGM.getLangOpts().Exceptions && !ClassDecl->hasTrivialDestructor()) {
|
|
CXXDtorType Type =
|
|
CurGD.getCtorType() == Ctor_Complete ? Dtor_Complete : Dtor_Base;
|
|
|
|
EHStack.pushCleanup<CallDelegatingCtorDtor>(EHCleanup,
|
|
ClassDecl->getDestructor(),
|
|
ThisPtr, Type);
|
|
}
|
|
}
|
|
|
|
void CodeGenFunction::EmitCXXDestructorCall(const CXXDestructorDecl *DD,
|
|
CXXDtorType Type,
|
|
bool ForVirtualBase,
|
|
bool Delegating,
|
|
Address This) {
|
|
CGM.getCXXABI().EmitDestructorCall(*this, DD, Type, ForVirtualBase,
|
|
Delegating, This);
|
|
}
|
|
|
|
namespace {
|
|
struct CallLocalDtor final : EHScopeStack::Cleanup {
|
|
const CXXDestructorDecl *Dtor;
|
|
Address Addr;
|
|
|
|
CallLocalDtor(const CXXDestructorDecl *D, Address Addr)
|
|
: Dtor(D), Addr(Addr) {}
|
|
|
|
void Emit(CodeGenFunction &CGF, Flags flags) override {
|
|
CGF.EmitCXXDestructorCall(Dtor, Dtor_Complete,
|
|
/*ForVirtualBase=*/false,
|
|
/*Delegating=*/false, Addr);
|
|
}
|
|
};
|
|
}
|
|
|
|
void CodeGenFunction::PushDestructorCleanup(const CXXDestructorDecl *D,
|
|
Address Addr) {
|
|
EHStack.pushCleanup<CallLocalDtor>(NormalAndEHCleanup, D, Addr);
|
|
}
|
|
|
|
void CodeGenFunction::PushDestructorCleanup(QualType T, Address Addr) {
|
|
CXXRecordDecl *ClassDecl = T->getAsCXXRecordDecl();
|
|
if (!ClassDecl) return;
|
|
if (ClassDecl->hasTrivialDestructor()) return;
|
|
|
|
const CXXDestructorDecl *D = ClassDecl->getDestructor();
|
|
assert(D && D->isUsed() && "destructor not marked as used!");
|
|
PushDestructorCleanup(D, Addr);
|
|
}
|
|
|
|
void CodeGenFunction::InitializeVTablePointer(const VPtr &Vptr) {
|
|
// Compute the address point.
|
|
llvm::Value *VTableAddressPoint =
|
|
CGM.getCXXABI().getVTableAddressPointInStructor(
|
|
*this, Vptr.VTableClass, Vptr.Base, Vptr.NearestVBase);
|
|
|
|
if (!VTableAddressPoint)
|
|
return;
|
|
|
|
// Compute where to store the address point.
|
|
llvm::Value *VirtualOffset = nullptr;
|
|
CharUnits NonVirtualOffset = CharUnits::Zero();
|
|
|
|
if (CGM.getCXXABI().isVirtualOffsetNeededForVTableField(*this, Vptr)) {
|
|
// We need to use the virtual base offset offset because the virtual base
|
|
// might have a different offset in the most derived class.
|
|
|
|
VirtualOffset = CGM.getCXXABI().GetVirtualBaseClassOffset(
|
|
*this, LoadCXXThisAddress(), Vptr.VTableClass, Vptr.NearestVBase);
|
|
NonVirtualOffset = Vptr.OffsetFromNearestVBase;
|
|
} else {
|
|
// We can just use the base offset in the complete class.
|
|
NonVirtualOffset = Vptr.Base.getBaseOffset();
|
|
}
|
|
|
|
// Apply the offsets.
|
|
Address VTableField = LoadCXXThisAddress();
|
|
|
|
if (!NonVirtualOffset.isZero() || VirtualOffset)
|
|
VTableField = ApplyNonVirtualAndVirtualOffset(
|
|
*this, VTableField, NonVirtualOffset, VirtualOffset, Vptr.VTableClass,
|
|
Vptr.NearestVBase);
|
|
|
|
// Finally, store the address point. Use the same LLVM types as the field to
|
|
// support optimization.
|
|
llvm::Type *VTablePtrTy =
|
|
llvm::FunctionType::get(CGM.Int32Ty, /*isVarArg=*/true)
|
|
->getPointerTo()
|
|
->getPointerTo();
|
|
VTableField = Builder.CreateBitCast(VTableField, VTablePtrTy->getPointerTo());
|
|
VTableAddressPoint = Builder.CreateBitCast(VTableAddressPoint, VTablePtrTy);
|
|
|
|
llvm::StoreInst *Store = Builder.CreateStore(VTableAddressPoint, VTableField);
|
|
CGM.DecorateInstructionWithTBAA(Store, CGM.getTBAAInfoForVTablePtr());
|
|
if (CGM.getCodeGenOpts().OptimizationLevel > 0 &&
|
|
CGM.getCodeGenOpts().StrictVTablePointers)
|
|
CGM.DecorateInstructionWithInvariantGroup(Store, Vptr.VTableClass);
|
|
}
|
|
|
|
CodeGenFunction::VPtrsVector
|
|
CodeGenFunction::getVTablePointers(const CXXRecordDecl *VTableClass) {
|
|
CodeGenFunction::VPtrsVector VPtrsResult;
|
|
VisitedVirtualBasesSetTy VBases;
|
|
getVTablePointers(BaseSubobject(VTableClass, CharUnits::Zero()),
|
|
/*NearestVBase=*/nullptr,
|
|
/*OffsetFromNearestVBase=*/CharUnits::Zero(),
|
|
/*BaseIsNonVirtualPrimaryBase=*/false, VTableClass, VBases,
|
|
VPtrsResult);
|
|
return VPtrsResult;
|
|
}
|
|
|
|
void CodeGenFunction::getVTablePointers(BaseSubobject Base,
|
|
const CXXRecordDecl *NearestVBase,
|
|
CharUnits OffsetFromNearestVBase,
|
|
bool BaseIsNonVirtualPrimaryBase,
|
|
const CXXRecordDecl *VTableClass,
|
|
VisitedVirtualBasesSetTy &VBases,
|
|
VPtrsVector &Vptrs) {
|
|
// If this base is a non-virtual primary base the address point has already
|
|
// been set.
|
|
if (!BaseIsNonVirtualPrimaryBase) {
|
|
// Initialize the vtable pointer for this base.
|
|
VPtr Vptr = {Base, NearestVBase, OffsetFromNearestVBase, VTableClass};
|
|
Vptrs.push_back(Vptr);
|
|
}
|
|
|
|
const CXXRecordDecl *RD = Base.getBase();
|
|
|
|
// Traverse bases.
|
|
for (const auto &I : RD->bases()) {
|
|
CXXRecordDecl *BaseDecl
|
|
= cast<CXXRecordDecl>(I.getType()->getAs<RecordType>()->getDecl());
|
|
|
|
// Ignore classes without a vtable.
|
|
if (!BaseDecl->isDynamicClass())
|
|
continue;
|
|
|
|
CharUnits BaseOffset;
|
|
CharUnits BaseOffsetFromNearestVBase;
|
|
bool BaseDeclIsNonVirtualPrimaryBase;
|
|
|
|
if (I.isVirtual()) {
|
|
// Check if we've visited this virtual base before.
|
|
if (!VBases.insert(BaseDecl).second)
|
|
continue;
|
|
|
|
const ASTRecordLayout &Layout =
|
|
getContext().getASTRecordLayout(VTableClass);
|
|
|
|
BaseOffset = Layout.getVBaseClassOffset(BaseDecl);
|
|
BaseOffsetFromNearestVBase = CharUnits::Zero();
|
|
BaseDeclIsNonVirtualPrimaryBase = false;
|
|
} else {
|
|
const ASTRecordLayout &Layout = getContext().getASTRecordLayout(RD);
|
|
|
|
BaseOffset = Base.getBaseOffset() + Layout.getBaseClassOffset(BaseDecl);
|
|
BaseOffsetFromNearestVBase =
|
|
OffsetFromNearestVBase + Layout.getBaseClassOffset(BaseDecl);
|
|
BaseDeclIsNonVirtualPrimaryBase = Layout.getPrimaryBase() == BaseDecl;
|
|
}
|
|
|
|
getVTablePointers(
|
|
BaseSubobject(BaseDecl, BaseOffset),
|
|
I.isVirtual() ? BaseDecl : NearestVBase, BaseOffsetFromNearestVBase,
|
|
BaseDeclIsNonVirtualPrimaryBase, VTableClass, VBases, Vptrs);
|
|
}
|
|
}
|
|
|
|
void CodeGenFunction::InitializeVTablePointers(const CXXRecordDecl *RD) {
|
|
// Ignore classes without a vtable.
|
|
if (!RD->isDynamicClass())
|
|
return;
|
|
|
|
// Initialize the vtable pointers for this class and all of its bases.
|
|
if (CGM.getCXXABI().doStructorsInitializeVPtrs(RD))
|
|
for (const VPtr &Vptr : getVTablePointers(RD))
|
|
InitializeVTablePointer(Vptr);
|
|
|
|
if (RD->getNumVBases())
|
|
CGM.getCXXABI().initializeHiddenVirtualInheritanceMembers(*this, RD);
|
|
}
|
|
|
|
llvm::Value *CodeGenFunction::GetVTablePtr(Address This,
|
|
llvm::Type *VTableTy,
|
|
const CXXRecordDecl *RD) {
|
|
Address VTablePtrSrc = Builder.CreateElementBitCast(This, VTableTy);
|
|
llvm::Instruction *VTable = Builder.CreateLoad(VTablePtrSrc, "vtable");
|
|
CGM.DecorateInstructionWithTBAA(VTable, CGM.getTBAAInfoForVTablePtr());
|
|
|
|
if (CGM.getCodeGenOpts().OptimizationLevel > 0 &&
|
|
CGM.getCodeGenOpts().StrictVTablePointers)
|
|
CGM.DecorateInstructionWithInvariantGroup(VTable, RD);
|
|
|
|
return VTable;
|
|
}
|
|
|
|
// If a class has a single non-virtual base and does not introduce or override
|
|
// virtual member functions or fields, it will have the same layout as its base.
|
|
// This function returns the least derived such class.
|
|
//
|
|
// Casting an instance of a base class to such a derived class is technically
|
|
// undefined behavior, but it is a relatively common hack for introducing member
|
|
// functions on class instances with specific properties (e.g. llvm::Operator)
|
|
// that works under most compilers and should not have security implications, so
|
|
// we allow it by default. It can be disabled with -fsanitize=cfi-cast-strict.
|
|
static const CXXRecordDecl *
|
|
LeastDerivedClassWithSameLayout(const CXXRecordDecl *RD) {
|
|
if (!RD->field_empty())
|
|
return RD;
|
|
|
|
if (RD->getNumVBases() != 0)
|
|
return RD;
|
|
|
|
if (RD->getNumBases() != 1)
|
|
return RD;
|
|
|
|
for (const CXXMethodDecl *MD : RD->methods()) {
|
|
if (MD->isVirtual()) {
|
|
// Virtual member functions are only ok if they are implicit destructors
|
|
// because the implicit destructor will have the same semantics as the
|
|
// base class's destructor if no fields are added.
|
|
if (isa<CXXDestructorDecl>(MD) && MD->isImplicit())
|
|
continue;
|
|
return RD;
|
|
}
|
|
}
|
|
|
|
return LeastDerivedClassWithSameLayout(
|
|
RD->bases_begin()->getType()->getAsCXXRecordDecl());
|
|
}
|
|
|
|
void CodeGenFunction::EmitVTablePtrCheckForCall(const CXXMethodDecl *MD,
|
|
llvm::Value *VTable,
|
|
CFITypeCheckKind TCK,
|
|
SourceLocation Loc) {
|
|
const CXXRecordDecl *ClassDecl = MD->getParent();
|
|
if (!SanOpts.has(SanitizerKind::CFICastStrict))
|
|
ClassDecl = LeastDerivedClassWithSameLayout(ClassDecl);
|
|
|
|
EmitVTablePtrCheck(ClassDecl, VTable, TCK, Loc);
|
|
}
|
|
|
|
void CodeGenFunction::EmitVTablePtrCheckForCast(QualType T,
|
|
llvm::Value *Derived,
|
|
bool MayBeNull,
|
|
CFITypeCheckKind TCK,
|
|
SourceLocation Loc) {
|
|
if (!getLangOpts().CPlusPlus)
|
|
return;
|
|
|
|
auto *ClassTy = T->getAs<RecordType>();
|
|
if (!ClassTy)
|
|
return;
|
|
|
|
const CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(ClassTy->getDecl());
|
|
|
|
if (!ClassDecl->isCompleteDefinition() || !ClassDecl->isDynamicClass())
|
|
return;
|
|
|
|
if (!SanOpts.has(SanitizerKind::CFICastStrict))
|
|
ClassDecl = LeastDerivedClassWithSameLayout(ClassDecl);
|
|
|
|
llvm::BasicBlock *ContBlock = nullptr;
|
|
|
|
if (MayBeNull) {
|
|
llvm::Value *DerivedNotNull =
|
|
Builder.CreateIsNotNull(Derived, "cast.nonnull");
|
|
|
|
llvm::BasicBlock *CheckBlock = createBasicBlock("cast.check");
|
|
ContBlock = createBasicBlock("cast.cont");
|
|
|
|
Builder.CreateCondBr(DerivedNotNull, CheckBlock, ContBlock);
|
|
|
|
EmitBlock(CheckBlock);
|
|
}
|
|
|
|
llvm::Value *VTable =
|
|
GetVTablePtr(Address(Derived, getPointerAlign()), Int8PtrTy, ClassDecl);
|
|
|
|
EmitVTablePtrCheck(ClassDecl, VTable, TCK, Loc);
|
|
|
|
if (MayBeNull) {
|
|
Builder.CreateBr(ContBlock);
|
|
EmitBlock(ContBlock);
|
|
}
|
|
}
|
|
|
|
void CodeGenFunction::EmitVTablePtrCheck(const CXXRecordDecl *RD,
|
|
llvm::Value *VTable,
|
|
CFITypeCheckKind TCK,
|
|
SourceLocation Loc) {
|
|
if (CGM.IsCFIBlacklistedRecord(RD))
|
|
return;
|
|
|
|
SanitizerScope SanScope(this);
|
|
|
|
llvm::Metadata *MD =
|
|
CGM.CreateMetadataIdentifierForType(QualType(RD->getTypeForDecl(), 0));
|
|
llvm::Value *BitSetName = llvm::MetadataAsValue::get(getLLVMContext(), MD);
|
|
|
|
llvm::Value *CastedVTable = Builder.CreateBitCast(VTable, Int8PtrTy);
|
|
llvm::Value *BitSetTest =
|
|
Builder.CreateCall(CGM.getIntrinsic(llvm::Intrinsic::bitset_test),
|
|
{CastedVTable, BitSetName});
|
|
|
|
if (CGM.getCodeGenOpts().SanitizeCfiCrossDso) {
|
|
if (auto TypeId = CGM.CreateCfiIdForTypeMetadata(MD)) {
|
|
EmitCfiSlowPathCheck(BitSetTest, TypeId, CastedVTable);
|
|
return;
|
|
}
|
|
}
|
|
|
|
SanitizerMask M;
|
|
switch (TCK) {
|
|
case CFITCK_VCall:
|
|
M = SanitizerKind::CFIVCall;
|
|
break;
|
|
case CFITCK_NVCall:
|
|
M = SanitizerKind::CFINVCall;
|
|
break;
|
|
case CFITCK_DerivedCast:
|
|
M = SanitizerKind::CFIDerivedCast;
|
|
break;
|
|
case CFITCK_UnrelatedCast:
|
|
M = SanitizerKind::CFIUnrelatedCast;
|
|
break;
|
|
}
|
|
|
|
llvm::Constant *StaticData[] = {
|
|
EmitCheckSourceLocation(Loc),
|
|
EmitCheckTypeDescriptor(QualType(RD->getTypeForDecl(), 0)),
|
|
llvm::ConstantInt::get(Int8Ty, TCK),
|
|
};
|
|
EmitCheck(std::make_pair(BitSetTest, M), "cfi_bad_type", StaticData,
|
|
CastedVTable);
|
|
}
|
|
|
|
// FIXME: Ideally Expr::IgnoreParenNoopCasts should do this, but it doesn't do
|
|
// quite what we want.
|
|
static const Expr *skipNoOpCastsAndParens(const Expr *E) {
|
|
while (true) {
|
|
if (const ParenExpr *PE = dyn_cast<ParenExpr>(E)) {
|
|
E = PE->getSubExpr();
|
|
continue;
|
|
}
|
|
|
|
if (const CastExpr *CE = dyn_cast<CastExpr>(E)) {
|
|
if (CE->getCastKind() == CK_NoOp) {
|
|
E = CE->getSubExpr();
|
|
continue;
|
|
}
|
|
}
|
|
if (const UnaryOperator *UO = dyn_cast<UnaryOperator>(E)) {
|
|
if (UO->getOpcode() == UO_Extension) {
|
|
E = UO->getSubExpr();
|
|
continue;
|
|
}
|
|
}
|
|
return E;
|
|
}
|
|
}
|
|
|
|
bool
|
|
CodeGenFunction::CanDevirtualizeMemberFunctionCall(const Expr *Base,
|
|
const CXXMethodDecl *MD) {
|
|
// When building with -fapple-kext, all calls must go through the vtable since
|
|
// the kernel linker can do runtime patching of vtables.
|
|
if (getLangOpts().AppleKext)
|
|
return false;
|
|
|
|
// If the most derived class is marked final, we know that no subclass can
|
|
// override this member function and so we can devirtualize it. For example:
|
|
//
|
|
// struct A { virtual void f(); }
|
|
// struct B final : A { };
|
|
//
|
|
// void f(B *b) {
|
|
// b->f();
|
|
// }
|
|
//
|
|
const CXXRecordDecl *MostDerivedClassDecl = Base->getBestDynamicClassType();
|
|
if (MostDerivedClassDecl->hasAttr<FinalAttr>())
|
|
return true;
|
|
|
|
// If the member function is marked 'final', we know that it can't be
|
|
// overridden and can therefore devirtualize it.
|
|
if (MD->hasAttr<FinalAttr>())
|
|
return true;
|
|
|
|
// Similarly, if the class itself is marked 'final' it can't be overridden
|
|
// and we can therefore devirtualize the member function call.
|
|
if (MD->getParent()->hasAttr<FinalAttr>())
|
|
return true;
|
|
|
|
Base = skipNoOpCastsAndParens(Base);
|
|
if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Base)) {
|
|
if (const VarDecl *VD = dyn_cast<VarDecl>(DRE->getDecl())) {
|
|
// This is a record decl. We know the type and can devirtualize it.
|
|
return VD->getType()->isRecordType();
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
// We can devirtualize calls on an object accessed by a class member access
|
|
// expression, since by C++11 [basic.life]p6 we know that it can't refer to
|
|
// a derived class object constructed in the same location.
|
|
if (const MemberExpr *ME = dyn_cast<MemberExpr>(Base))
|
|
if (const ValueDecl *VD = dyn_cast<ValueDecl>(ME->getMemberDecl()))
|
|
return VD->getType()->isRecordType();
|
|
|
|
// We can always devirtualize calls on temporary object expressions.
|
|
if (isa<CXXConstructExpr>(Base))
|
|
return true;
|
|
|
|
// And calls on bound temporaries.
|
|
if (isa<CXXBindTemporaryExpr>(Base))
|
|
return true;
|
|
|
|
// Check if this is a call expr that returns a record type.
|
|
if (const CallExpr *CE = dyn_cast<CallExpr>(Base))
|
|
return CE->getCallReturnType(getContext())->isRecordType();
|
|
|
|
// We can't devirtualize the call.
|
|
return false;
|
|
}
|
|
|
|
void CodeGenFunction::EmitForwardingCallToLambda(
|
|
const CXXMethodDecl *callOperator,
|
|
CallArgList &callArgs) {
|
|
// Get the address of the call operator.
|
|
const CGFunctionInfo &calleeFnInfo =
|
|
CGM.getTypes().arrangeCXXMethodDeclaration(callOperator);
|
|
llvm::Value *callee =
|
|
CGM.GetAddrOfFunction(GlobalDecl(callOperator),
|
|
CGM.getTypes().GetFunctionType(calleeFnInfo));
|
|
|
|
// Prepare the return slot.
|
|
const FunctionProtoType *FPT =
|
|
callOperator->getType()->castAs<FunctionProtoType>();
|
|
QualType resultType = FPT->getReturnType();
|
|
ReturnValueSlot returnSlot;
|
|
if (!resultType->isVoidType() &&
|
|
calleeFnInfo.getReturnInfo().getKind() == ABIArgInfo::Indirect &&
|
|
!hasScalarEvaluationKind(calleeFnInfo.getReturnType()))
|
|
returnSlot = ReturnValueSlot(ReturnValue, resultType.isVolatileQualified());
|
|
|
|
// We don't need to separately arrange the call arguments because
|
|
// the call can't be variadic anyway --- it's impossible to forward
|
|
// variadic arguments.
|
|
|
|
// Now emit our call.
|
|
RValue RV = EmitCall(calleeFnInfo, callee, returnSlot,
|
|
callArgs, callOperator);
|
|
|
|
// If necessary, copy the returned value into the slot.
|
|
if (!resultType->isVoidType() && returnSlot.isNull())
|
|
EmitReturnOfRValue(RV, resultType);
|
|
else
|
|
EmitBranchThroughCleanup(ReturnBlock);
|
|
}
|
|
|
|
void CodeGenFunction::EmitLambdaBlockInvokeBody() {
|
|
const BlockDecl *BD = BlockInfo->getBlockDecl();
|
|
const VarDecl *variable = BD->capture_begin()->getVariable();
|
|
const CXXRecordDecl *Lambda = variable->getType()->getAsCXXRecordDecl();
|
|
|
|
// Start building arguments for forwarding call
|
|
CallArgList CallArgs;
|
|
|
|
QualType ThisType = getContext().getPointerType(getContext().getRecordType(Lambda));
|
|
Address ThisPtr = GetAddrOfBlockDecl(variable, false);
|
|
CallArgs.add(RValue::get(ThisPtr.getPointer()), ThisType);
|
|
|
|
// Add the rest of the parameters.
|
|
for (auto param : BD->params())
|
|
EmitDelegateCallArg(CallArgs, param, param->getLocStart());
|
|
|
|
assert(!Lambda->isGenericLambda() &&
|
|
"generic lambda interconversion to block not implemented");
|
|
EmitForwardingCallToLambda(Lambda->getLambdaCallOperator(), CallArgs);
|
|
}
|
|
|
|
void CodeGenFunction::EmitLambdaToBlockPointerBody(FunctionArgList &Args) {
|
|
if (cast<CXXMethodDecl>(CurCodeDecl)->isVariadic()) {
|
|
// FIXME: Making this work correctly is nasty because it requires either
|
|
// cloning the body of the call operator or making the call operator forward.
|
|
CGM.ErrorUnsupported(CurCodeDecl, "lambda conversion to variadic function");
|
|
return;
|
|
}
|
|
|
|
EmitFunctionBody(Args, cast<FunctionDecl>(CurGD.getDecl())->getBody());
|
|
}
|
|
|
|
void CodeGenFunction::EmitLambdaDelegatingInvokeBody(const CXXMethodDecl *MD) {
|
|
const CXXRecordDecl *Lambda = MD->getParent();
|
|
|
|
// Start building arguments for forwarding call
|
|
CallArgList CallArgs;
|
|
|
|
QualType ThisType = getContext().getPointerType(getContext().getRecordType(Lambda));
|
|
llvm::Value *ThisPtr = llvm::UndefValue::get(getTypes().ConvertType(ThisType));
|
|
CallArgs.add(RValue::get(ThisPtr), ThisType);
|
|
|
|
// Add the rest of the parameters.
|
|
for (auto Param : MD->params())
|
|
EmitDelegateCallArg(CallArgs, Param, Param->getLocStart());
|
|
|
|
const CXXMethodDecl *CallOp = Lambda->getLambdaCallOperator();
|
|
// For a generic lambda, find the corresponding call operator specialization
|
|
// to which the call to the static-invoker shall be forwarded.
|
|
if (Lambda->isGenericLambda()) {
|
|
assert(MD->isFunctionTemplateSpecialization());
|
|
const TemplateArgumentList *TAL = MD->getTemplateSpecializationArgs();
|
|
FunctionTemplateDecl *CallOpTemplate = CallOp->getDescribedFunctionTemplate();
|
|
void *InsertPos = nullptr;
|
|
FunctionDecl *CorrespondingCallOpSpecialization =
|
|
CallOpTemplate->findSpecialization(TAL->asArray(), InsertPos);
|
|
assert(CorrespondingCallOpSpecialization);
|
|
CallOp = cast<CXXMethodDecl>(CorrespondingCallOpSpecialization);
|
|
}
|
|
EmitForwardingCallToLambda(CallOp, CallArgs);
|
|
}
|
|
|
|
void CodeGenFunction::EmitLambdaStaticInvokeFunction(const CXXMethodDecl *MD) {
|
|
if (MD->isVariadic()) {
|
|
// FIXME: Making this work correctly is nasty because it requires either
|
|
// cloning the body of the call operator or making the call operator forward.
|
|
CGM.ErrorUnsupported(MD, "lambda conversion to variadic function");
|
|
return;
|
|
}
|
|
|
|
EmitLambdaDelegatingInvokeBody(MD);
|
|
}
|