2199 lines
		
	
	
		
			81 KiB
		
	
	
	
		
			C++
		
	
	
	
			
		
		
	
	
			2199 lines
		
	
	
		
			81 KiB
		
	
	
	
		
			C++
		
	
	
	
| //===--- CGClass.cpp - Emit LLVM Code for C++ classes ---------------------===//
 | |
| //
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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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| // This contains code dealing with C++ code generation of classes
 | |
| //
 | |
| //===----------------------------------------------------------------------===//
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| 
 | |
| #include "CGBlocks.h"
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| #include "CGCXXABI.h"
 | |
| #include "CGDebugInfo.h"
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| #include "CGRecordLayout.h"
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| #include "CodeGenFunction.h"
 | |
| #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"
 | |
| #include "clang/AST/StmtCXX.h"
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| #include "clang/Basic/TargetBuiltins.h"
 | |
| #include "clang/CodeGen/CGFunctionInfo.h"
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| #include "clang/Frontend/CodeGenOptions.h"
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| 
 | |
| using namespace clang;
 | |
| using namespace CodeGen;
 | |
| 
 | |
| static CharUnits 
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| ComputeNonVirtualBaseClassOffset(ASTContext &Context, 
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|                                  const CXXRecordDecl *DerivedClass,
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|                                  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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|   
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|   const CXXRecordDecl *RD = DerivedClass;
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|   
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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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| 
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|     // Get the layout.
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|     const ASTRecordLayout &Layout = Context.getASTRecordLayout(RD);
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|     
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|     const CXXRecordDecl *BaseDecl = 
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|       cast<CXXRecordDecl>(Base->getType()->getAs<RecordType>()->getDecl());
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|     
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|     // Add the offset.
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|     Offset += Layout.getBaseClassOffset(BaseDecl);
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|     
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|     RD = BaseDecl;
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|   }
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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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| 
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|   CharUnits Offset = 
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|     ComputeNonVirtualBaseClassOffset(getContext(), ClassDecl,
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|                                      PathBegin, PathEnd);
 | |
|   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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|   
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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).
 | |
| ///
 | |
| /// The object pointed to by 'This' is assumed to be non-null.
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| llvm::Value *
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| CodeGenFunction::GetAddressOfDirectBaseInCompleteClass(llvm::Value *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->getType()->isPointerTy() &&
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|          cast<llvm::PointerType>(This->getType())->getElementType()
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|            == ConvertType(Derived));
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| 
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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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|   llvm::Value *V = This;
 | |
|   if (Offset.isPositive()) {
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|     V = Builder.CreateBitCast(V, Int8PtrTy);
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|     V = Builder.CreateConstInBoundsGEP1_64(V, Offset.getQuantity());
 | |
|   }
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|   V = Builder.CreateBitCast(V, ConvertType(Base)->getPointerTo());
 | |
| 
 | |
|   return V;
 | |
| }
 | |
| 
 | |
| static llvm::Value *
 | |
| ApplyNonVirtualAndVirtualOffset(CodeGenFunction &CGF, llvm::Value *ptr,
 | |
|                                 CharUnits nonVirtualOffset,
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|                                 llvm::Value *virtualOffset) {
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|   // Assert that we have something to do.
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|   assert(!nonVirtualOffset.isZero() || virtualOffset != nullptr);
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| 
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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,
 | |
|                                         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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|   
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|   // Apply the base offset.
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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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|   return ptr;
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| }
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| 
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| llvm::Value *
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| CodeGenFunction::GetAddressOfBaseClass(llvm::Value *Value, 
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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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| 
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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
 | |
|   // 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
 | |
|   // allocating subobject (the virtual base, if there is one, or else
 | |
|   // the "complete" object that we see).
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|   CharUnits NonVirtualOffset = 
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|     ComputeNonVirtualBaseClassOffset(getContext(), VBase ? VBase : Derived,
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|                                      Start, PathEnd);
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| 
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|   // If there's a virtual step, we can sometimes "devirtualize" it.
 | |
|   // 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>()) {
 | |
|     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
 | |
|   }
 | |
| 
 | |
|   // Get the base pointer type.
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|   llvm::Type *BasePtrTy = 
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|     ConvertType((PathEnd[-1])->getType())->getPointerTo();
 | |
| 
 | |
|   // 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.
 | |
|   if (NonVirtualOffset.isZero() && !VBase) {
 | |
|     return Builder.CreateBitCast(Value, BasePtrTy);
 | |
|   }
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| 
 | |
|   llvm::BasicBlock *origBB = nullptr;
 | |
|   llvm::BasicBlock *endBB = nullptr;
 | |
| 
 | |
|   // Skip over the offset (and the vtable load) if we're supposed to
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|   // null-check the pointer.
 | |
|   if (NullCheckValue) {
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|     origBB = Builder.GetInsertBlock();
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|     llvm::BasicBlock *notNullBB = createBasicBlock("cast.notnull");
 | |
|     endBB = createBasicBlock("cast.end");
 | |
|     
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|     llvm::Value *isNull = Builder.CreateIsNull(Value);
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|     Builder.CreateCondBr(isNull, endBB, notNullBB);
 | |
|     EmitBlock(notNullBB);
 | |
|   }
 | |
| 
 | |
|   // Compute the virtual offset.
 | |
|   llvm::Value *VirtualOffset = nullptr;
 | |
|   if (VBase) {
 | |
|     VirtualOffset =
 | |
|       CGM.getCXXABI().GetVirtualBaseClassOffset(*this, Value, Derived, VBase);
 | |
|   }
 | |
| 
 | |
|   // Apply both offsets.
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|   Value = ApplyNonVirtualAndVirtualOffset(*this, Value, 
 | |
|                                           NonVirtualOffset,
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|                                           VirtualOffset);
 | |
|   
 | |
|   // 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, notNullBB);
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|     PHI->addIncoming(llvm::Constant::getNullValue(BasePtrTy), origBB);
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|     Value = PHI;
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|   }
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|   
 | |
|   return Value;
 | |
| }
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| 
 | |
| llvm::Value *
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| CodeGenFunction::GetAddressOfDerivedClass(llvm::Value *Value,
 | |
|                                           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!");
 | |
| 
 | |
|   QualType DerivedTy =
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|     getContext().getCanonicalType(getContext().getTagDeclType(Derived));
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|   llvm::Type *DerivedPtrTy = ConvertType(DerivedTy)->getPointerTo();
 | |
| 
 | |
|   llvm::Value *NonVirtualOffset =
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|     CGM.GetNonVirtualBaseClassOffset(Derived, PathBegin, PathEnd);
 | |
|   
 | |
|   if (!NonVirtualOffset) {
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|     // No offset, we can just cast back.
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|     return Builder.CreateBitCast(Value, 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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|     
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|     llvm::Value *IsNull = Builder.CreateIsNull(Value);
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|     Builder.CreateCondBr(IsNull, CastNull, CastNotNull);
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|     EmitBlock(CastNotNull);
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|   }
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|   
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|   // Apply the offset.
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|   Value = Builder.CreateBitCast(Value, Int8PtrTy);
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|   Value = Builder.CreateGEP(Value, Builder.CreateNeg(NonVirtualOffset),
 | |
|                             "sub.ptr");
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| 
 | |
|   // Just cast.
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|   Value = Builder.CreateBitCast(Value, DerivedPtrTy);
 | |
| 
 | |
|   if (NullCheckValue) {
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|     Builder.CreateBr(CastEnd);
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|     EmitBlock(CastNull);
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|     Builder.CreateBr(CastEnd);
 | |
|     EmitBlock(CastEnd);
 | |
|     
 | |
|     llvm::PHINode *PHI = Builder.CreatePHI(Value->getType(), 2);
 | |
|     PHI->addIncoming(Value, CastNotNull);
 | |
|     PHI->addIncoming(llvm::Constant::getNullValue(Value->getType()), 
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|                      CastNull);
 | |
|     Value = PHI;
 | |
|   }
 | |
|   
 | |
|   return Value;
 | |
| }
 | |
| 
 | |
| llvm::Value *CodeGenFunction::GetVTTParameter(GlobalDecl GD,
 | |
|                                               bool ForVirtualBase,
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|                                               bool Delegating) {
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|   if (!CGM.getCXXABI().NeedsVTTParameter(GD)) {
 | |
|     // This constructor/destructor does not need a VTT parameter.
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|     return nullptr;
 | |
|   }
 | |
|   
 | |
|   const CXXRecordDecl *RD = cast<CXXMethodDecl>(CurCodeDecl)->getParent();
 | |
|   const CXXRecordDecl *Base = cast<CXXMethodDecl>(GD.getDecl())->getParent();
 | |
| 
 | |
|   llvm::Value *VTT;
 | |
| 
 | |
|   uint64_t SubVTTIndex;
 | |
| 
 | |
|   if (Delegating) {
 | |
|     // If this is a delegating constructor call, just load the VTT.
 | |
|     return LoadCXXVTT();
 | |
|   } else if (RD == Base) {
 | |
|     // If the record matches the base, this is the complete ctor/dtor
 | |
|     // variant calling the base variant in a class with virtual bases.
 | |
|     assert(!CGM.getCXXABI().NeedsVTTParameter(CurGD) &&
 | |
|            "doing no-op VTT offset in base dtor/ctor?");
 | |
|     assert(!ForVirtualBase && "Can't have same class as virtual base!");
 | |
|     SubVTTIndex = 0;
 | |
|   } else {
 | |
|     const ASTRecordLayout &Layout = getContext().getASTRecordLayout(RD);
 | |
|     CharUnits BaseOffset = ForVirtualBase ? 
 | |
|       Layout.getVBaseClassOffset(Base) : 
 | |
|       Layout.getBaseClassOffset(Base);
 | |
| 
 | |
|     SubVTTIndex = 
 | |
|       CGM.getVTables().getSubVTTIndex(RD, BaseSubobject(Base, BaseOffset));
 | |
|     assert(SubVTTIndex != 0 && "Sub-VTT index must be greater than zero!");
 | |
|   }
 | |
|   
 | |
|   if (CGM.getCXXABI().NeedsVTTParameter(CurGD)) {
 | |
|     // A VTT parameter was passed to the constructor, use it.
 | |
|     VTT = LoadCXXVTT();
 | |
|     VTT = Builder.CreateConstInBoundsGEP1_64(VTT, SubVTTIndex);
 | |
|   } else {
 | |
|     // We're the complete constructor, so get the VTT by name.
 | |
|     VTT = CGM.getVTables().GetAddrOfVTT(RD);
 | |
|     VTT = Builder.CreateConstInBoundsGEP2_64(VTT, 0, SubVTTIndex);
 | |
|   }
 | |
| 
 | |
|   return VTT;
 | |
| }
 | |
| 
 | |
| namespace {
 | |
|   /// Call the destructor for a direct base class.
 | |
|   struct CallBaseDtor : EHScopeStack::Cleanup {
 | |
|     const CXXRecordDecl *BaseClass;
 | |
|     bool BaseIsVirtual;
 | |
|     CallBaseDtor(const CXXRecordDecl *Base, bool BaseIsVirtual)
 | |
|       : BaseClass(Base), BaseIsVirtual(BaseIsVirtual) {}
 | |
| 
 | |
|     void Emit(CodeGenFunction &CGF, Flags flags) override {
 | |
|       const CXXRecordDecl *DerivedClass =
 | |
|         cast<CXXMethodDecl>(CGF.CurCodeDecl)->getParent();
 | |
| 
 | |
|       const CXXDestructorDecl *D = BaseClass->getDestructor();
 | |
|       llvm::Value *Addr = 
 | |
|         CGF.GetAddressOfDirectBaseInCompleteClass(CGF.LoadCXXThis(),
 | |
|                                                   DerivedClass, BaseClass,
 | |
|                                                   BaseIsVirtual);
 | |
|       CGF.EmitCXXDestructorCall(D, Dtor_Base, BaseIsVirtual,
 | |
|                                 /*Delegating=*/false, Addr);
 | |
|     }
 | |
|   };
 | |
| 
 | |
|   /// A visitor which checks whether an initializer uses 'this' in a
 | |
|   /// way which requires the vtable to be properly set.
 | |
|   struct DynamicThisUseChecker : EvaluatedExprVisitor<DynamicThisUseChecker> {
 | |
|     typedef EvaluatedExprVisitor<DynamicThisUseChecker> super;
 | |
| 
 | |
|     bool UsesThis;
 | |
| 
 | |
|     DynamicThisUseChecker(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(CXXThisExpr *E) { UsesThis = true; }
 | |
|   };
 | |
| }
 | |
| 
 | |
| static bool BaseInitializerUsesThis(ASTContext &C, const Expr *Init) {
 | |
|   DynamicThisUseChecker Checker(C);
 | |
|   Checker.Visit(const_cast<Expr*>(Init));
 | |
|   return Checker.UsesThis;
 | |
| }
 | |
| 
 | |
| static void EmitBaseInitializer(CodeGenFunction &CGF, 
 | |
|                                 const CXXRecordDecl *ClassDecl,
 | |
|                                 CXXCtorInitializer *BaseInit,
 | |
|                                 CXXCtorType CtorType) {
 | |
|   assert(BaseInit->isBaseInitializer() &&
 | |
|          "Must have base initializer!");
 | |
| 
 | |
|   llvm::Value *ThisPtr = CGF.LoadCXXThis();
 | |
|   
 | |
|   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.
 | |
|   llvm::Value *V = 
 | |
|     CGF.GetAddressOfDirectBaseInCompleteClass(ThisPtr, ClassDecl,
 | |
|                                               BaseClassDecl,
 | |
|                                               isBaseVirtual);
 | |
|   CharUnits Alignment = CGF.getContext().getTypeAlignInChars(BaseType);
 | |
|   AggValueSlot AggSlot =
 | |
|     AggValueSlot::forAddr(V, Alignment, 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,
 | |
|                                      llvm::Value *ArrayIndexVar,
 | |
|                                      QualType T,
 | |
|                                      ArrayRef<VarDecl *> ArrayIndexes,
 | |
|                                      unsigned Index) {
 | |
|   if (Index == ArrayIndexes.size()) {
 | |
|     LValue LV = LHS;
 | |
| 
 | |
|     if (ArrayIndexVar) {
 | |
|       // If we have an array index variable, load it and use it as an offset.
 | |
|       // Then, increment the value.
 | |
|       llvm::Value *Dest = LHS.getAddress();
 | |
|       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.
 | |
|       LV.setAddress(Dest);
 | |
|       CharUnits Align = CGF.getContext().getTypeAlignInChars(T);
 | |
|       LV.setAlignment(std::min(Align, LV.getAlignment()));
 | |
|     }
 | |
| 
 | |
|     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?");
 | |
|   llvm::Value *IndexVar
 | |
|     = CGF.GetAddrOfLocalVar(ArrayIndexes[Index]);
 | |
|   assert(IndexVar && "Array index variable not loaded");
 | |
|   
 | |
|   // Initialize this index variable to zero.
 | |
|   llvm::Value* Zero
 | |
|     = llvm::Constant::getNullValue(
 | |
|                               CGF.ConvertType(CGF.getContext().getSizeType()));
 | |
|   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 void EmitMemberInitializer(CodeGenFunction &CGF,
 | |
|                                   const CXXRecordDecl *ClassDecl,
 | |
|                                   CXXCtorInitializer *MemberInit,
 | |
|                                   const CXXConstructorDecl *Constructor,
 | |
|                                   FunctionArgList &Args) {
 | |
|   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);
 | |
| 
 | |
|   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));
 | |
|     FieldType = MemberInit->getIndirectMember()->getAnonField()->getType();
 | |
|   } else {
 | |
|     LHS = CGF.EmitLValueForFieldInitialization(LHS, Field);
 | |
|   }
 | |
| 
 | |
|   // 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 && CE->getConstructor()->isTrivial())) {
 | |
|       // Find the source pointer. We know it's the last argument because
 | |
|       // we know we're in an implicit copy constructor.
 | |
|       unsigned SrcArgIndex = Args.size() - 1;
 | |
|       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());
 | |
|       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: {
 | |
|     llvm::Value *ArrayIndexVar = nullptr;
 | |
|     if (ArrayIndexes.size()) {
 | |
|       llvm::Type *SizeTy = ConvertType(getContext().getSizeType());
 | |
|       
 | |
|       // 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);
 | |
|       llvm::Value *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 = CreateTempAlloca(SizeTy, "object.index");
 | |
|       llvm::Value *Zero = llvm::Constant::getNullValue(SizeTy);
 | |
|       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;
 | |
| }
 | |
| 
 | |
| /// EmitConstructorBody - Emits the body of the current constructor.
 | |
| void CodeGenFunction::EmitConstructorBody(FunctionArgList &Args) {
 | |
|   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()) {
 | |
|     if (CGDebugInfo *DI = getDebugInfo()) 
 | |
|       DI->EmitLocation(Builder, Ctor->getLocEnd());
 | |
|     EmitDelegateCXXConstructorCall(Ctor, Ctor_Base, Args, Ctor->getLocEnd());
 | |
|     return;
 | |
|   }
 | |
| 
 | |
|   Stmt *Body = Ctor->getBody();
 | |
| 
 | |
|   // Enter the function-try-block before the constructor prologue if
 | |
|   // applicable.
 | |
|   bool IsTryBody = (Body && isa<CXXTryStmt>(Body));
 | |
|   if (IsTryBody)
 | |
|     EnterCXXTryStmt(*cast<CXXTryStmt>(Body), true);
 | |
| 
 | |
|   RegionCounter Cnt = getPGORegionCounter(Body);
 | |
|   Cnt.beginRegion(Builder);
 | |
| 
 | |
|   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), SO(*CGF.SanOpts), OldSanOpts(CGF.SanOpts) {
 | |
|       SO.Bool = false;
 | |
|       SO.Enum = false;
 | |
|       CGF.SanOpts = &SO;
 | |
|     }
 | |
|     ~CopyingValueRepresentation() {
 | |
|       CGF.SanOpts = OldSanOpts;
 | |
|     }
 | |
|   private:
 | |
|     CodeGenFunction &CGF;
 | |
|     SanitizerOptions SO;
 | |
|     const SanitizerOptions *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) {}
 | |
| 
 | |
|     static bool isMemcpyableField(FieldDecl *F) {
 | |
|       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() const {
 | |
|       unsigned LastFieldSize =
 | |
|         LastField->isBitField() ?
 | |
|           LastField->getBitWidthValue(CGF.getContext()) :
 | |
|           CGF.getContext().getTypeSize(LastField->getType()); 
 | |
|       uint64_t MemcpySizeBits =
 | |
|         LastFieldOffset + LastFieldSize - FirstFieldOffset +
 | |
|         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;
 | |
|       }
 | |
| 
 | |
|       CharUnits Alignment;
 | |
| 
 | |
|       if (FirstField->isBitField()) {
 | |
|         const CGRecordLayout &RL =
 | |
|           CGF.getTypes().getCGRecordLayout(FirstField->getParent());
 | |
|         const CGBitFieldInfo &BFInfo = RL.getBitFieldInfo(FirstField);
 | |
|         Alignment = CharUnits::fromQuantity(BFInfo.StorageAlignment);
 | |
|       } else {
 | |
|         Alignment = CGF.getContext().getDeclAlign(FirstField);
 | |
|       }
 | |
| 
 | |
|       assert((CGF.getContext().toCharUnitsFromBits(FirstFieldOffset) %
 | |
|               Alignment) == 0 && "Bad field alignment.");
 | |
| 
 | |
|       CharUnits MemcpySize = getMemcpySize();
 | |
|       QualType RecordTy = CGF.getContext().getTypeDeclType(ClassDecl);
 | |
|       llvm::Value *ThisPtr = CGF.LoadCXXThis();
 | |
|       LValue DestLV = CGF.MakeNaturalAlignAddrLValue(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.getBitFieldAddr() : Dest.getAddress(),
 | |
|                    Src.isBitField() ? Src.getBitFieldAddr() : Src.getAddress(),
 | |
|                    MemcpySize, Alignment);
 | |
|       reset();
 | |
|     }
 | |
| 
 | |
|     void reset() {
 | |
|       FirstField = nullptr;
 | |
|     }
 | |
| 
 | |
|   protected:
 | |
|     CodeGenFunction &CGF;
 | |
|     const CXXRecordDecl *ClassDecl;
 | |
| 
 | |
|   private:
 | |
| 
 | |
|     void emitMemcpyIR(llvm::Value *DestPtr, llvm::Value *SrcPtr,
 | |
|                       CharUnits Size, CharUnits Alignment) {
 | |
|       llvm::PointerType *DPT = cast<llvm::PointerType>(DestPtr->getType());
 | |
|       llvm::Type *DBP =
 | |
|         llvm::Type::getInt8PtrTy(CGF.getLLVMContext(), DPT->getAddressSpace());
 | |
|       DestPtr = CGF.Builder.CreateBitCast(DestPtr, DBP);
 | |
| 
 | |
|       llvm::PointerType *SPT = cast<llvm::PointerType>(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(),
 | |
|                                Alignment.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(const CXXConstructorDecl *CD,
 | |
|                                                FunctionArgList &Args) {
 | |
|       if (CD->isCopyOrMoveConstructor() && CD->isDefaulted())
 | |
|         return Args[Args.size() - 1];
 | |
|       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-POD, not-trivially-constructable members.
 | |
|       if (!(CE && CE->getConstructor()->isTrivial()) &&
 | |
|           !(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(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);
 | |
|         }
 | |
|         reset();
 | |
|         return;
 | |
|       }
 | |
| 
 | |
|       pushEHDestructors();
 | |
|       emitMemcpy();
 | |
|       AggregatedInits.clear();
 | |
|     }
 | |
| 
 | |
|     void pushEHDestructors() {
 | |
|       llvm::Value *ThisPtr = CGF.LoadCXXThis();
 | |
|       QualType RecordTy = CGF.getContext().getTypeDeclType(ClassDecl);
 | |
|       LValue LHS = CGF.MakeNaturalAlignAddrLValue(ThisPtr, RecordTy);
 | |
| 
 | |
|       for (unsigned i = 0; i < AggregatedInits.size(); ++i) {
 | |
|         QualType FieldType = AggregatedInits[i]->getMember()->getType();
 | |
|         QualType::DestructionKind dtorKind = FieldType.isDestructedType();
 | |
|         if (CGF.needsEHCleanup(dtorKind))
 | |
|           CGF.pushEHDestroy(dtorKind, LHS.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 && (MD->isCopyAssignmentOperator() ||
 | |
|                        MD->isMoveAssignmentOperator()) &&
 | |
|               MD->isTrivial()))
 | |
|           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();
 | |
|     }
 | |
|   };
 | |
| 
 | |
| }
 | |
| 
 | |
| /// 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);
 | |
|   }
 | |
| 
 | |
|   // Virtual base initializers first.
 | |
|   for (; B != E && (*B)->isBaseInitializer() && (*B)->isBaseVirtual(); B++) {
 | |
|     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());
 | |
|     EmitBaseInitializer(*this, ClassDecl, *B, CtorType);
 | |
|   }
 | |
| 
 | |
|   InitializeVTablePointers(ClassDecl);
 | |
| 
 | |
|   // And finally, initialize class members.
 | |
|   FieldConstructionScope FCS(*this, CXXThisValue);
 | |
|   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());
 | |
|   return HasTrivialDestructorBody(Context, FieldClassDecl, FieldClassDecl);
 | |
| }
 | |
| 
 | |
| /// CanSkipVTablePointerInitialization - Check whether we need to initialize
 | |
| /// any vtable pointers before calling this destructor.
 | |
| static bool CanSkipVTablePointerInitialization(ASTContext &Context,
 | |
|                                                const CXXDestructorDecl *Dtor) {
 | |
|   if (!Dtor->hasTrivialBody())
 | |
|     return false;
 | |
| 
 | |
|   // Check the fields.
 | |
|   const CXXRecordDecl *ClassDecl = Dtor->getParent();
 | |
|   for (const auto *Field : ClassDecl->fields())
 | |
|     if (!FieldHasTrivialDestructorBody(Context, 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();
 | |
| 
 | |
|   // 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, LoadCXXThis());
 | |
|     PopCleanupBlock();
 | |
|     return;
 | |
|   }
 | |
| 
 | |
|   Stmt *Body = Dtor->getBody();
 | |
| 
 | |
|   // 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);
 | |
| 
 | |
|   // 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_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, LoadCXXThis());
 | |
|       break;
 | |
|     }
 | |
|     // Fallthrough: act like we're in the base variant.
 | |
|       
 | |
|   case Dtor_Base:
 | |
|     assert(Body);
 | |
| 
 | |
|     RegionCounter Cnt = getPGORegionCounter(Body);
 | |
|     Cnt.beginRegion(Builder);
 | |
| 
 | |
|     // Enter the cleanup scopes for fields and non-virtual bases.
 | |
|     EnterDtorCleanups(Dtor, Dtor_Base);
 | |
| 
 | |
|     // Initialize the vtable pointers before entering the body.
 | |
|     if (!CanSkipVTablePointerInitialization(getContext(), Dtor))
 | |
|         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 : 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 : 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  : 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.
 | |
|       llvm::Value *thisValue = CGF.LoadCXXThis();
 | |
|       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);
 | |
|     }
 | |
|   };
 | |
| }
 | |
| 
 | |
| /// \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) {
 | |
| 
 | |
|     // 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);
 | |
|   
 | |
|   // 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);
 | |
|   }
 | |
| 
 | |
|   // 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,
 | |
|                                             llvm::Value *arrayBegin,
 | |
|                                           CallExpr::const_arg_iterator argBegin,
 | |
|                                             CallExpr::const_arg_iterator argEnd,
 | |
|                                             bool zeroInitialize) {
 | |
|   QualType elementType;
 | |
|   llvm::Value *numElements =
 | |
|     emitArrayLength(arrayType, elementType, arrayBegin);
 | |
| 
 | |
|   EmitCXXAggrConstructorCall(ctor, numElements, arrayBegin,
 | |
|                              argBegin, argEnd, 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 arrayBegin 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,
 | |
|                                             llvm::Value *arrayBegin,
 | |
|                                          CallExpr::const_arg_iterator argBegin,
 | |
|                                            CallExpr::const_arg_iterator argEnd,
 | |
|                                             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 *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.
 | |
| 
 | |
|   QualType type = getContext().getTypeDeclType(ctor->getParent());
 | |
| 
 | |
|   // Zero initialize the storage, if requested.
 | |
|   if (zeroInitialize)
 | |
|     EmitNullInitialization(cur, 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, *destroyer);
 | |
|     }
 | |
| 
 | |
|     EmitCXXConstructorCall(ctor, Ctor_Complete, /*ForVirtualBase=*/ false,
 | |
|                            /*Delegating=*/false, cur, argBegin, argEnd);
 | |
|   }
 | |
| 
 | |
|   // 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,
 | |
|                                        llvm::Value *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,
 | |
|                                         llvm::Value *This,
 | |
|                                         CallExpr::const_arg_iterator ArgBeg,
 | |
|                                         CallExpr::const_arg_iterator ArgEnd) {
 | |
|   // If this is a trivial constructor, just emit what's needed.
 | |
|   if (D->isTrivial()) {
 | |
|     if (ArgBeg == ArgEnd) {
 | |
|       // Trivial default constructor, no codegen required.
 | |
|       assert(D->isDefaultConstructor() &&
 | |
|              "trivial 0-arg ctor not a default ctor");
 | |
|       return;
 | |
|     }
 | |
| 
 | |
|     assert(ArgBeg + 1 == ArgEnd && "unexpected argcount for trivial ctor");
 | |
|     assert(D->isCopyOrMoveConstructor() &&
 | |
|            "trivial 1-arg ctor not a copy/move ctor");
 | |
| 
 | |
|     const Expr *E = (*ArgBeg);
 | |
|     QualType Ty = E->getType();
 | |
|     llvm::Value *Src = EmitLValue(E).getAddress();
 | |
|     EmitAggregateCopy(This, Src, Ty);
 | |
|     return;
 | |
|   }
 | |
| 
 | |
|   // 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,
 | |
|                 getContext().getRecordType(D->getParent()));
 | |
| 
 | |
|   CallArgList Args;
 | |
| 
 | |
|   // Push the this ptr.
 | |
|   Args.add(RValue::get(This), D->getThisType(getContext()));
 | |
| 
 | |
|   // Add the rest of the user-supplied arguments.
 | |
|   const FunctionProtoType *FPT = D->getType()->castAs<FunctionProtoType>();
 | |
|   EmitCallArgs(Args, FPT, ArgBeg, ArgEnd);
 | |
| 
 | |
|   // 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.GetAddrOfCXXConstructor(D, Type);
 | |
|   const CGFunctionInfo &Info =
 | |
|       CGM.getTypes().arrangeCXXConstructorCall(Args, D, Type, ExtraArgs);
 | |
|   EmitCall(Info, Callee, ReturnValueSlot(), Args, D);
 | |
| }
 | |
| 
 | |
| void
 | |
| CodeGenFunction::EmitSynthesizedCXXCopyCtorCall(const CXXConstructorDecl *D,
 | |
|                                         llvm::Value *This, llvm::Value *Src,
 | |
|                                         CallExpr::const_arg_iterator ArgBeg,
 | |
|                                         CallExpr::const_arg_iterator ArgEnd) {
 | |
|   if (D->isTrivial()) {
 | |
|     assert(ArgBeg + 1 == ArgEnd && "unexpected argcount for trivial ctor");
 | |
|     assert(D->isCopyOrMoveConstructor() &&
 | |
|            "trivial 1-arg ctor not a copy/move ctor");
 | |
|     EmitAggregateCopy(This, Src, (*ArgBeg)->getType());
 | |
|     return;
 | |
|   }
 | |
|   llvm::Value *Callee = CGM.GetAddrOfCXXConstructor(D, clang::Ctor_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), 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), QT);
 | |
| 
 | |
|   // Skip over first argument (Src).
 | |
|   EmitCallArgs(Args, FPT->isVariadic(), FPT->param_type_begin() + 1,
 | |
|                FPT->param_type_end(), ArgBeg + 1, ArgEnd);
 | |
| 
 | |
|   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.GetAddrOfCXXConstructor(Ctor, CtorType);
 | |
|   EmitCall(CGM.getTypes().arrangeCXXConstructorDeclaration(Ctor, CtorType),
 | |
|            Callee, ReturnValueSlot(), DelegateArgs, Ctor);
 | |
| }
 | |
| 
 | |
| namespace {
 | |
|   struct CallDelegatingCtorDtor : EHScopeStack::Cleanup {
 | |
|     const CXXDestructorDecl *Dtor;
 | |
|     llvm::Value *Addr;
 | |
|     CXXDtorType Type;
 | |
| 
 | |
|     CallDelegatingCtorDtor(const CXXDestructorDecl *D, llvm::Value *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);
 | |
|     }
 | |
|   };
 | |
| }
 | |
| 
 | |
| void
 | |
| CodeGenFunction::EmitDelegatingCXXConstructorCall(const CXXConstructorDecl *Ctor,
 | |
|                                                   const FunctionArgList &Args) {
 | |
|   assert(Ctor->isDelegatingConstructor());
 | |
| 
 | |
|   llvm::Value *ThisPtr = LoadCXXThis();
 | |
| 
 | |
|   QualType Ty = getContext().getTagDeclType(Ctor->getParent());
 | |
|   CharUnits Alignment = getContext().getTypeAlignInChars(Ty);
 | |
|   AggValueSlot AggSlot =
 | |
|     AggValueSlot::forAddr(ThisPtr, Alignment, 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,
 | |
|                                             llvm::Value *This) {
 | |
|   CGM.getCXXABI().EmitDestructorCall(*this, DD, Type, ForVirtualBase,
 | |
|                                      Delegating, This);
 | |
| }
 | |
| 
 | |
| namespace {
 | |
|   struct CallLocalDtor : EHScopeStack::Cleanup {
 | |
|     const CXXDestructorDecl *Dtor;
 | |
|     llvm::Value *Addr;
 | |
| 
 | |
|     CallLocalDtor(const CXXDestructorDecl *D, llvm::Value *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,
 | |
|                                             llvm::Value *Addr) {
 | |
|   EHStack.pushCleanup<CallLocalDtor>(NormalAndEHCleanup, D, Addr);
 | |
| }
 | |
| 
 | |
| void CodeGenFunction::PushDestructorCleanup(QualType T, llvm::Value *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(BaseSubobject Base, 
 | |
|                                          const CXXRecordDecl *NearestVBase,
 | |
|                                          CharUnits OffsetFromNearestVBase,
 | |
|                                          const CXXRecordDecl *VTableClass) {
 | |
|   // Compute the address point.
 | |
|   bool NeedsVirtualOffset;
 | |
|   llvm::Value *VTableAddressPoint =
 | |
|       CGM.getCXXABI().getVTableAddressPointInStructor(
 | |
|           *this, VTableClass, Base, NearestVBase, NeedsVirtualOffset);
 | |
|   if (!VTableAddressPoint)
 | |
|     return;
 | |
| 
 | |
|   // Compute where to store the address point.
 | |
|   llvm::Value *VirtualOffset = nullptr;
 | |
|   CharUnits NonVirtualOffset = CharUnits::Zero();
 | |
|   
 | |
|   if (NeedsVirtualOffset) {
 | |
|     // 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,
 | |
|                                                               LoadCXXThis(),
 | |
|                                                               VTableClass,
 | |
|                                                               NearestVBase);
 | |
|     NonVirtualOffset = OffsetFromNearestVBase;
 | |
|   } else {
 | |
|     // We can just use the base offset in the complete class.
 | |
|     NonVirtualOffset = Base.getBaseOffset();
 | |
|   }
 | |
|   
 | |
|   // Apply the offsets.
 | |
|   llvm::Value *VTableField = LoadCXXThis();
 | |
|   
 | |
|   if (!NonVirtualOffset.isZero() || VirtualOffset)
 | |
|     VTableField = ApplyNonVirtualAndVirtualOffset(*this, VTableField, 
 | |
|                                                   NonVirtualOffset,
 | |
|                                                   VirtualOffset);
 | |
| 
 | |
|   // Finally, store the address point.
 | |
|   llvm::Type *AddressPointPtrTy =
 | |
|     VTableAddressPoint->getType()->getPointerTo();
 | |
|   VTableField = Builder.CreateBitCast(VTableField, AddressPointPtrTy);
 | |
|   llvm::StoreInst *Store = Builder.CreateStore(VTableAddressPoint, VTableField);
 | |
|   CGM.DecorateInstruction(Store, CGM.getTBAAInfoForVTablePtr());
 | |
| }
 | |
| 
 | |
| void
 | |
| CodeGenFunction::InitializeVTablePointers(BaseSubobject Base, 
 | |
|                                           const CXXRecordDecl *NearestVBase,
 | |
|                                           CharUnits OffsetFromNearestVBase,
 | |
|                                           bool BaseIsNonVirtualPrimaryBase,
 | |
|                                           const CXXRecordDecl *VTableClass,
 | |
|                                           VisitedVirtualBasesSetTy& VBases) {
 | |
|   // 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.
 | |
|     InitializeVTablePointer(Base, NearestVBase, OffsetFromNearestVBase,
 | |
|                             VTableClass);
 | |
|   }
 | |
|   
 | |
|   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))
 | |
|         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;
 | |
|     }
 | |
|     
 | |
|     InitializeVTablePointers(BaseSubobject(BaseDecl, BaseOffset), 
 | |
|                              I.isVirtual() ? BaseDecl : NearestVBase,
 | |
|                              BaseOffsetFromNearestVBase,
 | |
|                              BaseDeclIsNonVirtualPrimaryBase, 
 | |
|                              VTableClass, VBases);
 | |
|   }
 | |
| }
 | |
| 
 | |
| 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.
 | |
|   VisitedVirtualBasesSetTy VBases;
 | |
|   InitializeVTablePointers(BaseSubobject(RD, CharUnits::Zero()), 
 | |
|                            /*NearestVBase=*/nullptr,
 | |
|                            /*OffsetFromNearestVBase=*/CharUnits::Zero(),
 | |
|                            /*BaseIsNonVirtualPrimaryBase=*/false, RD, VBases);
 | |
| 
 | |
|   if (RD->getNumVBases())
 | |
|     CGM.getCXXABI().initializeHiddenVirtualInheritanceMembers(*this, RD);
 | |
| }
 | |
| 
 | |
| llvm::Value *CodeGenFunction::GetVTablePtr(llvm::Value *This,
 | |
|                                            llvm::Type *Ty) {
 | |
|   llvm::Value *VTablePtrSrc = Builder.CreateBitCast(This, Ty->getPointerTo());
 | |
|   llvm::Instruction *VTable = Builder.CreateLoad(VTablePtrSrc, "vtable");
 | |
|   CGM.DecorateInstruction(VTable, CGM.getTBAAInfoForVTablePtr());
 | |
|   return VTable;
 | |
| }
 | |
| 
 | |
| 
 | |
| // 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()->isRecordType();
 | |
| 
 | |
|   // We can't devirtualize the call.
 | |
|   return false;
 | |
| }
 | |
| 
 | |
| llvm::Value *
 | |
| CodeGenFunction::EmitCXXOperatorMemberCallee(const CXXOperatorCallExpr *E,
 | |
|                                              const CXXMethodDecl *MD,
 | |
|                                              llvm::Value *This) {
 | |
|   llvm::FunctionType *fnType =
 | |
|     CGM.getTypes().GetFunctionType(
 | |
|                              CGM.getTypes().arrangeCXXMethodDeclaration(MD));
 | |
| 
 | |
|   if (MD->isVirtual() && !CanDevirtualizeMemberFunctionCall(E->getArg(0), MD))
 | |
|     return CGM.getCXXABI().getVirtualFunctionPointer(*this, MD, This, fnType);
 | |
| 
 | |
|   return CGM.GetAddrOfFunction(MD, fnType);
 | |
| }
 | |
| 
 | |
| 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));
 | |
|   llvm::Value *ThisPtr = GetAddrOfBlockDecl(variable, false);
 | |
|   CallArgs.add(RValue::get(ThisPtr), 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);
 | |
| }
 |