1475 lines
55 KiB
C++
1475 lines
55 KiB
C++
//===--- CGExprAgg.cpp - Emit LLVM Code from Aggregate Expressions --------===//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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//
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// This contains code to emit Aggregate Expr nodes as LLVM code.
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//
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//===----------------------------------------------------------------------===//
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#include "CodeGenFunction.h"
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#include "CGObjCRuntime.h"
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#include "CodeGenModule.h"
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#include "clang/AST/ASTContext.h"
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#include "clang/AST/DeclCXX.h"
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#include "clang/AST/DeclTemplate.h"
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#include "clang/AST/StmtVisitor.h"
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#include "llvm/IR/Constants.h"
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#include "llvm/IR/Function.h"
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#include "llvm/IR/GlobalVariable.h"
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#include "llvm/IR/Intrinsics.h"
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using namespace clang;
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using namespace CodeGen;
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//===----------------------------------------------------------------------===//
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// Aggregate Expression Emitter
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//===----------------------------------------------------------------------===//
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namespace {
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class AggExprEmitter : public StmtVisitor<AggExprEmitter> {
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CodeGenFunction &CGF;
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CGBuilderTy &Builder;
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AggValueSlot Dest;
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/// We want to use 'dest' as the return slot except under two
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/// conditions:
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/// - The destination slot requires garbage collection, so we
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/// need to use the GC API.
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/// - The destination slot is potentially aliased.
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bool shouldUseDestForReturnSlot() const {
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return !(Dest.requiresGCollection() || Dest.isPotentiallyAliased());
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}
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ReturnValueSlot getReturnValueSlot() const {
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if (!shouldUseDestForReturnSlot())
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return ReturnValueSlot();
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return ReturnValueSlot(Dest.getAddr(), Dest.isVolatile());
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}
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AggValueSlot EnsureSlot(QualType T) {
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if (!Dest.isIgnored()) return Dest;
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return CGF.CreateAggTemp(T, "agg.tmp.ensured");
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}
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void EnsureDest(QualType T) {
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if (!Dest.isIgnored()) return;
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Dest = CGF.CreateAggTemp(T, "agg.tmp.ensured");
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}
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public:
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AggExprEmitter(CodeGenFunction &cgf, AggValueSlot Dest)
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: CGF(cgf), Builder(CGF.Builder), Dest(Dest) {
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}
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//===--------------------------------------------------------------------===//
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// Utilities
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//===--------------------------------------------------------------------===//
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/// EmitAggLoadOfLValue - Given an expression with aggregate type that
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/// represents a value lvalue, this method emits the address of the lvalue,
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/// then loads the result into DestPtr.
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void EmitAggLoadOfLValue(const Expr *E);
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/// EmitFinalDestCopy - Perform the final copy to DestPtr, if desired.
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void EmitFinalDestCopy(QualType type, const LValue &src);
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void EmitFinalDestCopy(QualType type, RValue src,
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CharUnits srcAlignment = CharUnits::Zero());
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void EmitCopy(QualType type, const AggValueSlot &dest,
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const AggValueSlot &src);
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void EmitMoveFromReturnSlot(const Expr *E, RValue Src);
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void EmitArrayInit(llvm::Value *DestPtr, llvm::ArrayType *AType,
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QualType elementType, InitListExpr *E);
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AggValueSlot::NeedsGCBarriers_t needsGC(QualType T) {
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if (CGF.getLangOpts().getGC() && TypeRequiresGCollection(T))
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return AggValueSlot::NeedsGCBarriers;
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return AggValueSlot::DoesNotNeedGCBarriers;
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}
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bool TypeRequiresGCollection(QualType T);
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//===--------------------------------------------------------------------===//
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// Visitor Methods
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//===--------------------------------------------------------------------===//
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void VisitStmt(Stmt *S) {
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CGF.ErrorUnsupported(S, "aggregate expression");
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}
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void VisitParenExpr(ParenExpr *PE) { Visit(PE->getSubExpr()); }
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void VisitGenericSelectionExpr(GenericSelectionExpr *GE) {
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Visit(GE->getResultExpr());
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}
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void VisitUnaryExtension(UnaryOperator *E) { Visit(E->getSubExpr()); }
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void VisitSubstNonTypeTemplateParmExpr(SubstNonTypeTemplateParmExpr *E) {
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return Visit(E->getReplacement());
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}
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// l-values.
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void VisitDeclRefExpr(DeclRefExpr *E) {
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// For aggregates, we should always be able to emit the variable
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// as an l-value unless it's a reference. This is due to the fact
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// that we can't actually ever see a normal l2r conversion on an
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// aggregate in C++, and in C there's no language standard
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// actively preventing us from listing variables in the captures
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// list of a block.
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if (E->getDecl()->getType()->isReferenceType()) {
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if (CodeGenFunction::ConstantEmission result
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= CGF.tryEmitAsConstant(E)) {
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EmitFinalDestCopy(E->getType(), result.getReferenceLValue(CGF, E));
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return;
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}
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}
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EmitAggLoadOfLValue(E);
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}
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void VisitMemberExpr(MemberExpr *ME) { EmitAggLoadOfLValue(ME); }
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void VisitUnaryDeref(UnaryOperator *E) { EmitAggLoadOfLValue(E); }
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void VisitStringLiteral(StringLiteral *E) { EmitAggLoadOfLValue(E); }
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void VisitCompoundLiteralExpr(CompoundLiteralExpr *E);
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void VisitArraySubscriptExpr(ArraySubscriptExpr *E) {
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EmitAggLoadOfLValue(E);
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}
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void VisitPredefinedExpr(const PredefinedExpr *E) {
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EmitAggLoadOfLValue(E);
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}
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// Operators.
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void VisitCastExpr(CastExpr *E);
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void VisitCallExpr(const CallExpr *E);
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void VisitStmtExpr(const StmtExpr *E);
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void VisitBinaryOperator(const BinaryOperator *BO);
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void VisitPointerToDataMemberBinaryOperator(const BinaryOperator *BO);
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void VisitBinAssign(const BinaryOperator *E);
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void VisitBinComma(const BinaryOperator *E);
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void VisitObjCMessageExpr(ObjCMessageExpr *E);
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void VisitObjCIvarRefExpr(ObjCIvarRefExpr *E) {
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EmitAggLoadOfLValue(E);
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}
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void VisitAbstractConditionalOperator(const AbstractConditionalOperator *CO);
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void VisitChooseExpr(const ChooseExpr *CE);
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void VisitInitListExpr(InitListExpr *E);
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void VisitImplicitValueInitExpr(ImplicitValueInitExpr *E);
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void VisitCXXDefaultArgExpr(CXXDefaultArgExpr *DAE) {
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Visit(DAE->getExpr());
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}
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void VisitCXXDefaultInitExpr(CXXDefaultInitExpr *DIE) {
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CodeGenFunction::CXXDefaultInitExprScope Scope(CGF);
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Visit(DIE->getExpr());
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}
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void VisitCXXBindTemporaryExpr(CXXBindTemporaryExpr *E);
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void VisitCXXConstructExpr(const CXXConstructExpr *E);
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void VisitLambdaExpr(LambdaExpr *E);
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void VisitCXXStdInitializerListExpr(CXXStdInitializerListExpr *E);
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void VisitExprWithCleanups(ExprWithCleanups *E);
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void VisitCXXScalarValueInitExpr(CXXScalarValueInitExpr *E);
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void VisitCXXTypeidExpr(CXXTypeidExpr *E) { EmitAggLoadOfLValue(E); }
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void VisitMaterializeTemporaryExpr(MaterializeTemporaryExpr *E);
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void VisitOpaqueValueExpr(OpaqueValueExpr *E);
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void VisitPseudoObjectExpr(PseudoObjectExpr *E) {
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if (E->isGLValue()) {
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LValue LV = CGF.EmitPseudoObjectLValue(E);
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return EmitFinalDestCopy(E->getType(), LV);
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}
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CGF.EmitPseudoObjectRValue(E, EnsureSlot(E->getType()));
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}
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void VisitVAArgExpr(VAArgExpr *E);
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void EmitInitializationToLValue(Expr *E, LValue Address);
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void EmitNullInitializationToLValue(LValue Address);
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// case Expr::ChooseExprClass:
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void VisitCXXThrowExpr(const CXXThrowExpr *E) { CGF.EmitCXXThrowExpr(E); }
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void VisitAtomicExpr(AtomicExpr *E) {
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CGF.EmitAtomicExpr(E, EnsureSlot(E->getType()).getAddr());
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}
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};
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} // end anonymous namespace.
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//===----------------------------------------------------------------------===//
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// Utilities
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//===----------------------------------------------------------------------===//
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/// EmitAggLoadOfLValue - Given an expression with aggregate type that
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/// represents a value lvalue, this method emits the address of the lvalue,
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/// then loads the result into DestPtr.
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void AggExprEmitter::EmitAggLoadOfLValue(const Expr *E) {
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LValue LV = CGF.EmitLValue(E);
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// If the type of the l-value is atomic, then do an atomic load.
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if (LV.getType()->isAtomicType()) {
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CGF.EmitAtomicLoad(LV, E->getExprLoc(), Dest);
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return;
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}
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EmitFinalDestCopy(E->getType(), LV);
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}
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/// \brief True if the given aggregate type requires special GC API calls.
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bool AggExprEmitter::TypeRequiresGCollection(QualType T) {
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// Only record types have members that might require garbage collection.
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const RecordType *RecordTy = T->getAs<RecordType>();
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if (!RecordTy) return false;
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// Don't mess with non-trivial C++ types.
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RecordDecl *Record = RecordTy->getDecl();
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if (isa<CXXRecordDecl>(Record) &&
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(cast<CXXRecordDecl>(Record)->hasNonTrivialCopyConstructor() ||
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!cast<CXXRecordDecl>(Record)->hasTrivialDestructor()))
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return false;
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// Check whether the type has an object member.
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return Record->hasObjectMember();
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}
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/// \brief Perform the final move to DestPtr if for some reason
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/// getReturnValueSlot() didn't use it directly.
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///
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/// The idea is that you do something like this:
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/// RValue Result = EmitSomething(..., getReturnValueSlot());
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/// EmitMoveFromReturnSlot(E, Result);
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///
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/// If nothing interferes, this will cause the result to be emitted
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/// directly into the return value slot. Otherwise, a final move
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/// will be performed.
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void AggExprEmitter::EmitMoveFromReturnSlot(const Expr *E, RValue src) {
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if (shouldUseDestForReturnSlot()) {
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// Logically, Dest.getAddr() should equal Src.getAggregateAddr().
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// The possibility of undef rvalues complicates that a lot,
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// though, so we can't really assert.
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return;
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}
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// Otherwise, copy from there to the destination.
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assert(Dest.getAddr() != src.getAggregateAddr());
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std::pair<CharUnits, CharUnits> typeInfo =
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CGF.getContext().getTypeInfoInChars(E->getType());
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EmitFinalDestCopy(E->getType(), src, typeInfo.second);
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}
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/// EmitFinalDestCopy - Perform the final copy to DestPtr, if desired.
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void AggExprEmitter::EmitFinalDestCopy(QualType type, RValue src,
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CharUnits srcAlign) {
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assert(src.isAggregate() && "value must be aggregate value!");
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LValue srcLV = CGF.MakeAddrLValue(src.getAggregateAddr(), type, srcAlign);
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EmitFinalDestCopy(type, srcLV);
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}
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/// EmitFinalDestCopy - Perform the final copy to DestPtr, if desired.
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void AggExprEmitter::EmitFinalDestCopy(QualType type, const LValue &src) {
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// If Dest is ignored, then we're evaluating an aggregate expression
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// in a context that doesn't care about the result. Note that loads
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// from volatile l-values force the existence of a non-ignored
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// destination.
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if (Dest.isIgnored())
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return;
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AggValueSlot srcAgg =
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AggValueSlot::forLValue(src, AggValueSlot::IsDestructed,
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needsGC(type), AggValueSlot::IsAliased);
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EmitCopy(type, Dest, srcAgg);
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}
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/// Perform a copy from the source into the destination.
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///
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/// \param type - the type of the aggregate being copied; qualifiers are
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/// ignored
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void AggExprEmitter::EmitCopy(QualType type, const AggValueSlot &dest,
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const AggValueSlot &src) {
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if (dest.requiresGCollection()) {
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CharUnits sz = CGF.getContext().getTypeSizeInChars(type);
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llvm::Value *size = llvm::ConstantInt::get(CGF.SizeTy, sz.getQuantity());
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CGF.CGM.getObjCRuntime().EmitGCMemmoveCollectable(CGF,
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dest.getAddr(),
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src.getAddr(),
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size);
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return;
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}
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// If the result of the assignment is used, copy the LHS there also.
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// It's volatile if either side is. Use the minimum alignment of
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// the two sides.
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CGF.EmitAggregateCopy(dest.getAddr(), src.getAddr(), type,
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dest.isVolatile() || src.isVolatile(),
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std::min(dest.getAlignment(), src.getAlignment()));
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}
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/// \brief Emit the initializer for a std::initializer_list initialized with a
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/// real initializer list.
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void
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AggExprEmitter::VisitCXXStdInitializerListExpr(CXXStdInitializerListExpr *E) {
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// Emit an array containing the elements. The array is externally destructed
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// if the std::initializer_list object is.
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ASTContext &Ctx = CGF.getContext();
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LValue Array = CGF.EmitLValue(E->getSubExpr());
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assert(Array.isSimple() && "initializer_list array not a simple lvalue");
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llvm::Value *ArrayPtr = Array.getAddress();
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const ConstantArrayType *ArrayType =
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Ctx.getAsConstantArrayType(E->getSubExpr()->getType());
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assert(ArrayType && "std::initializer_list constructed from non-array");
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// FIXME: Perform the checks on the field types in SemaInit.
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RecordDecl *Record = E->getType()->castAs<RecordType>()->getDecl();
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RecordDecl::field_iterator Field = Record->field_begin();
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if (Field == Record->field_end()) {
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CGF.ErrorUnsupported(E, "weird std::initializer_list");
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return;
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}
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// Start pointer.
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if (!Field->getType()->isPointerType() ||
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!Ctx.hasSameType(Field->getType()->getPointeeType(),
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ArrayType->getElementType())) {
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CGF.ErrorUnsupported(E, "weird std::initializer_list");
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return;
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}
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AggValueSlot Dest = EnsureSlot(E->getType());
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LValue DestLV = CGF.MakeAddrLValue(Dest.getAddr(), E->getType(),
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Dest.getAlignment());
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LValue Start = CGF.EmitLValueForFieldInitialization(DestLV, *Field);
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llvm::Value *Zero = llvm::ConstantInt::get(CGF.PtrDiffTy, 0);
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llvm::Value *IdxStart[] = { Zero, Zero };
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llvm::Value *ArrayStart =
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Builder.CreateInBoundsGEP(ArrayPtr, IdxStart, "arraystart");
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CGF.EmitStoreThroughLValue(RValue::get(ArrayStart), Start);
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++Field;
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if (Field == Record->field_end()) {
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CGF.ErrorUnsupported(E, "weird std::initializer_list");
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return;
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}
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llvm::Value *Size = Builder.getInt(ArrayType->getSize());
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LValue EndOrLength = CGF.EmitLValueForFieldInitialization(DestLV, *Field);
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if (Field->getType()->isPointerType() &&
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Ctx.hasSameType(Field->getType()->getPointeeType(),
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ArrayType->getElementType())) {
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// End pointer.
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llvm::Value *IdxEnd[] = { Zero, Size };
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llvm::Value *ArrayEnd =
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Builder.CreateInBoundsGEP(ArrayPtr, IdxEnd, "arrayend");
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CGF.EmitStoreThroughLValue(RValue::get(ArrayEnd), EndOrLength);
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} else if (Ctx.hasSameType(Field->getType(), Ctx.getSizeType())) {
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// Length.
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CGF.EmitStoreThroughLValue(RValue::get(Size), EndOrLength);
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} else {
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CGF.ErrorUnsupported(E, "weird std::initializer_list");
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return;
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}
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}
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/// \brief Emit initialization of an array from an initializer list.
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void AggExprEmitter::EmitArrayInit(llvm::Value *DestPtr, llvm::ArrayType *AType,
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QualType elementType, InitListExpr *E) {
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uint64_t NumInitElements = E->getNumInits();
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uint64_t NumArrayElements = AType->getNumElements();
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assert(NumInitElements <= NumArrayElements);
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// DestPtr is an array*. Construct an elementType* by drilling
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// down a level.
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llvm::Value *zero = llvm::ConstantInt::get(CGF.SizeTy, 0);
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llvm::Value *indices[] = { zero, zero };
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llvm::Value *begin =
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Builder.CreateInBoundsGEP(DestPtr, indices, "arrayinit.begin");
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// Exception safety requires us to destroy all the
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// already-constructed members if an initializer throws.
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// For that, we'll need an EH cleanup.
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QualType::DestructionKind dtorKind = elementType.isDestructedType();
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llvm::AllocaInst *endOfInit = 0;
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EHScopeStack::stable_iterator cleanup;
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llvm::Instruction *cleanupDominator = 0;
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if (CGF.needsEHCleanup(dtorKind)) {
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// In principle we could tell the cleanup where we are more
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// directly, but the control flow can get so varied here that it
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// would actually be quite complex. Therefore we go through an
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// alloca.
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endOfInit = CGF.CreateTempAlloca(begin->getType(),
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"arrayinit.endOfInit");
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cleanupDominator = Builder.CreateStore(begin, endOfInit);
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CGF.pushIrregularPartialArrayCleanup(begin, endOfInit, elementType,
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CGF.getDestroyer(dtorKind));
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cleanup = CGF.EHStack.stable_begin();
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// Otherwise, remember that we didn't need a cleanup.
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} else {
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dtorKind = QualType::DK_none;
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}
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llvm::Value *one = llvm::ConstantInt::get(CGF.SizeTy, 1);
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// The 'current element to initialize'. The invariants on this
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// variable are complicated. Essentially, after each iteration of
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// the loop, it points to the last initialized element, except
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// that it points to the beginning of the array before any
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// elements have been initialized.
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llvm::Value *element = begin;
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// Emit the explicit initializers.
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for (uint64_t i = 0; i != NumInitElements; ++i) {
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// Advance to the next element.
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if (i > 0) {
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element = Builder.CreateInBoundsGEP(element, one, "arrayinit.element");
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// Tell the cleanup that it needs to destroy up to this
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// element. TODO: some of these stores can be trivially
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// observed to be unnecessary.
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if (endOfInit) Builder.CreateStore(element, endOfInit);
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}
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LValue elementLV = CGF.MakeAddrLValue(element, elementType);
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EmitInitializationToLValue(E->getInit(i), elementLV);
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}
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// Check whether there's a non-trivial array-fill expression.
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// Note that this will be a CXXConstructExpr even if the element
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// type is an array (or array of array, etc.) of class type.
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Expr *filler = E->getArrayFiller();
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bool hasTrivialFiller = true;
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if (CXXConstructExpr *cons = dyn_cast_or_null<CXXConstructExpr>(filler)) {
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assert(cons->getConstructor()->isDefaultConstructor());
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hasTrivialFiller = cons->getConstructor()->isTrivial();
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}
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// Any remaining elements need to be zero-initialized, possibly
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// using the filler expression. We can skip this if the we're
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// emitting to zeroed memory.
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if (NumInitElements != NumArrayElements &&
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!(Dest.isZeroed() && hasTrivialFiller &&
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CGF.getTypes().isZeroInitializable(elementType))) {
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// Use an actual loop. This is basically
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// do { *array++ = filler; } while (array != end);
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// Advance to the start of the rest of the array.
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if (NumInitElements) {
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element = Builder.CreateInBoundsGEP(element, one, "arrayinit.start");
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if (endOfInit) Builder.CreateStore(element, endOfInit);
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}
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// Compute the end of the array.
|
|
llvm::Value *end = Builder.CreateInBoundsGEP(begin,
|
|
llvm::ConstantInt::get(CGF.SizeTy, NumArrayElements),
|
|
"arrayinit.end");
|
|
|
|
llvm::BasicBlock *entryBB = Builder.GetInsertBlock();
|
|
llvm::BasicBlock *bodyBB = CGF.createBasicBlock("arrayinit.body");
|
|
|
|
// Jump into the body.
|
|
CGF.EmitBlock(bodyBB);
|
|
llvm::PHINode *currentElement =
|
|
Builder.CreatePHI(element->getType(), 2, "arrayinit.cur");
|
|
currentElement->addIncoming(element, entryBB);
|
|
|
|
// Emit the actual filler expression.
|
|
LValue elementLV = CGF.MakeAddrLValue(currentElement, elementType);
|
|
if (filler)
|
|
EmitInitializationToLValue(filler, elementLV);
|
|
else
|
|
EmitNullInitializationToLValue(elementLV);
|
|
|
|
// Move on to the next element.
|
|
llvm::Value *nextElement =
|
|
Builder.CreateInBoundsGEP(currentElement, one, "arrayinit.next");
|
|
|
|
// Tell the EH cleanup that we finished with the last element.
|
|
if (endOfInit) Builder.CreateStore(nextElement, endOfInit);
|
|
|
|
// Leave the loop if we're done.
|
|
llvm::Value *done = Builder.CreateICmpEQ(nextElement, end,
|
|
"arrayinit.done");
|
|
llvm::BasicBlock *endBB = CGF.createBasicBlock("arrayinit.end");
|
|
Builder.CreateCondBr(done, endBB, bodyBB);
|
|
currentElement->addIncoming(nextElement, Builder.GetInsertBlock());
|
|
|
|
CGF.EmitBlock(endBB);
|
|
}
|
|
|
|
// Leave the partial-array cleanup if we entered one.
|
|
if (dtorKind) CGF.DeactivateCleanupBlock(cleanup, cleanupDominator);
|
|
}
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
// Visitor Methods
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
void AggExprEmitter::VisitMaterializeTemporaryExpr(MaterializeTemporaryExpr *E){
|
|
Visit(E->GetTemporaryExpr());
|
|
}
|
|
|
|
void AggExprEmitter::VisitOpaqueValueExpr(OpaqueValueExpr *e) {
|
|
EmitFinalDestCopy(e->getType(), CGF.getOpaqueLValueMapping(e));
|
|
}
|
|
|
|
void
|
|
AggExprEmitter::VisitCompoundLiteralExpr(CompoundLiteralExpr *E) {
|
|
if (Dest.isPotentiallyAliased() &&
|
|
E->getType().isPODType(CGF.getContext())) {
|
|
// For a POD type, just emit a load of the lvalue + a copy, because our
|
|
// compound literal might alias the destination.
|
|
EmitAggLoadOfLValue(E);
|
|
return;
|
|
}
|
|
|
|
AggValueSlot Slot = EnsureSlot(E->getType());
|
|
CGF.EmitAggExpr(E->getInitializer(), Slot);
|
|
}
|
|
|
|
/// Attempt to look through various unimportant expressions to find a
|
|
/// cast of the given kind.
|
|
static Expr *findPeephole(Expr *op, CastKind kind) {
|
|
while (true) {
|
|
op = op->IgnoreParens();
|
|
if (CastExpr *castE = dyn_cast<CastExpr>(op)) {
|
|
if (castE->getCastKind() == kind)
|
|
return castE->getSubExpr();
|
|
if (castE->getCastKind() == CK_NoOp)
|
|
continue;
|
|
}
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
void AggExprEmitter::VisitCastExpr(CastExpr *E) {
|
|
switch (E->getCastKind()) {
|
|
case CK_Dynamic: {
|
|
// FIXME: Can this actually happen? We have no test coverage for it.
|
|
assert(isa<CXXDynamicCastExpr>(E) && "CK_Dynamic without a dynamic_cast?");
|
|
LValue LV = CGF.EmitCheckedLValue(E->getSubExpr(),
|
|
CodeGenFunction::TCK_Load);
|
|
// FIXME: Do we also need to handle property references here?
|
|
if (LV.isSimple())
|
|
CGF.EmitDynamicCast(LV.getAddress(), cast<CXXDynamicCastExpr>(E));
|
|
else
|
|
CGF.CGM.ErrorUnsupported(E, "non-simple lvalue dynamic_cast");
|
|
|
|
if (!Dest.isIgnored())
|
|
CGF.CGM.ErrorUnsupported(E, "lvalue dynamic_cast with a destination");
|
|
break;
|
|
}
|
|
|
|
case CK_ToUnion: {
|
|
if (Dest.isIgnored()) break;
|
|
|
|
// GCC union extension
|
|
QualType Ty = E->getSubExpr()->getType();
|
|
QualType PtrTy = CGF.getContext().getPointerType(Ty);
|
|
llvm::Value *CastPtr = Builder.CreateBitCast(Dest.getAddr(),
|
|
CGF.ConvertType(PtrTy));
|
|
EmitInitializationToLValue(E->getSubExpr(),
|
|
CGF.MakeAddrLValue(CastPtr, Ty));
|
|
break;
|
|
}
|
|
|
|
case CK_DerivedToBase:
|
|
case CK_BaseToDerived:
|
|
case CK_UncheckedDerivedToBase: {
|
|
llvm_unreachable("cannot perform hierarchy conversion in EmitAggExpr: "
|
|
"should have been unpacked before we got here");
|
|
}
|
|
|
|
case CK_NonAtomicToAtomic:
|
|
case CK_AtomicToNonAtomic: {
|
|
bool isToAtomic = (E->getCastKind() == CK_NonAtomicToAtomic);
|
|
|
|
// Determine the atomic and value types.
|
|
QualType atomicType = E->getSubExpr()->getType();
|
|
QualType valueType = E->getType();
|
|
if (isToAtomic) std::swap(atomicType, valueType);
|
|
|
|
assert(atomicType->isAtomicType());
|
|
assert(CGF.getContext().hasSameUnqualifiedType(valueType,
|
|
atomicType->castAs<AtomicType>()->getValueType()));
|
|
|
|
// Just recurse normally if we're ignoring the result or the
|
|
// atomic type doesn't change representation.
|
|
if (Dest.isIgnored() || !CGF.CGM.isPaddedAtomicType(atomicType)) {
|
|
return Visit(E->getSubExpr());
|
|
}
|
|
|
|
CastKind peepholeTarget =
|
|
(isToAtomic ? CK_AtomicToNonAtomic : CK_NonAtomicToAtomic);
|
|
|
|
// These two cases are reverses of each other; try to peephole them.
|
|
if (Expr *op = findPeephole(E->getSubExpr(), peepholeTarget)) {
|
|
assert(CGF.getContext().hasSameUnqualifiedType(op->getType(),
|
|
E->getType()) &&
|
|
"peephole significantly changed types?");
|
|
return Visit(op);
|
|
}
|
|
|
|
// If we're converting an r-value of non-atomic type to an r-value
|
|
// of atomic type, just emit directly into the relevant sub-object.
|
|
if (isToAtomic) {
|
|
AggValueSlot valueDest = Dest;
|
|
if (!valueDest.isIgnored() && CGF.CGM.isPaddedAtomicType(atomicType)) {
|
|
// Zero-initialize. (Strictly speaking, we only need to intialize
|
|
// the padding at the end, but this is simpler.)
|
|
if (!Dest.isZeroed())
|
|
CGF.EmitNullInitialization(Dest.getAddr(), atomicType);
|
|
|
|
// Build a GEP to refer to the subobject.
|
|
llvm::Value *valueAddr =
|
|
CGF.Builder.CreateStructGEP(valueDest.getAddr(), 0);
|
|
valueDest = AggValueSlot::forAddr(valueAddr,
|
|
valueDest.getAlignment(),
|
|
valueDest.getQualifiers(),
|
|
valueDest.isExternallyDestructed(),
|
|
valueDest.requiresGCollection(),
|
|
valueDest.isPotentiallyAliased(),
|
|
AggValueSlot::IsZeroed);
|
|
}
|
|
|
|
CGF.EmitAggExpr(E->getSubExpr(), valueDest);
|
|
return;
|
|
}
|
|
|
|
// Otherwise, we're converting an atomic type to a non-atomic type.
|
|
// Make an atomic temporary, emit into that, and then copy the value out.
|
|
AggValueSlot atomicSlot =
|
|
CGF.CreateAggTemp(atomicType, "atomic-to-nonatomic.temp");
|
|
CGF.EmitAggExpr(E->getSubExpr(), atomicSlot);
|
|
|
|
llvm::Value *valueAddr =
|
|
Builder.CreateStructGEP(atomicSlot.getAddr(), 0);
|
|
RValue rvalue = RValue::getAggregate(valueAddr, atomicSlot.isVolatile());
|
|
return EmitFinalDestCopy(valueType, rvalue);
|
|
}
|
|
|
|
case CK_LValueToRValue:
|
|
// If we're loading from a volatile type, force the destination
|
|
// into existence.
|
|
if (E->getSubExpr()->getType().isVolatileQualified()) {
|
|
EnsureDest(E->getType());
|
|
return Visit(E->getSubExpr());
|
|
}
|
|
|
|
// fallthrough
|
|
|
|
case CK_NoOp:
|
|
case CK_UserDefinedConversion:
|
|
case CK_ConstructorConversion:
|
|
assert(CGF.getContext().hasSameUnqualifiedType(E->getSubExpr()->getType(),
|
|
E->getType()) &&
|
|
"Implicit cast types must be compatible");
|
|
Visit(E->getSubExpr());
|
|
break;
|
|
|
|
case CK_LValueBitCast:
|
|
llvm_unreachable("should not be emitting lvalue bitcast as rvalue");
|
|
|
|
case CK_Dependent:
|
|
case CK_BitCast:
|
|
case CK_ArrayToPointerDecay:
|
|
case CK_FunctionToPointerDecay:
|
|
case CK_NullToPointer:
|
|
case CK_NullToMemberPointer:
|
|
case CK_BaseToDerivedMemberPointer:
|
|
case CK_DerivedToBaseMemberPointer:
|
|
case CK_MemberPointerToBoolean:
|
|
case CK_ReinterpretMemberPointer:
|
|
case CK_IntegralToPointer:
|
|
case CK_PointerToIntegral:
|
|
case CK_PointerToBoolean:
|
|
case CK_ToVoid:
|
|
case CK_VectorSplat:
|
|
case CK_IntegralCast:
|
|
case CK_IntegralToBoolean:
|
|
case CK_IntegralToFloating:
|
|
case CK_FloatingToIntegral:
|
|
case CK_FloatingToBoolean:
|
|
case CK_FloatingCast:
|
|
case CK_CPointerToObjCPointerCast:
|
|
case CK_BlockPointerToObjCPointerCast:
|
|
case CK_AnyPointerToBlockPointerCast:
|
|
case CK_ObjCObjectLValueCast:
|
|
case CK_FloatingRealToComplex:
|
|
case CK_FloatingComplexToReal:
|
|
case CK_FloatingComplexToBoolean:
|
|
case CK_FloatingComplexCast:
|
|
case CK_FloatingComplexToIntegralComplex:
|
|
case CK_IntegralRealToComplex:
|
|
case CK_IntegralComplexToReal:
|
|
case CK_IntegralComplexToBoolean:
|
|
case CK_IntegralComplexCast:
|
|
case CK_IntegralComplexToFloatingComplex:
|
|
case CK_ARCProduceObject:
|
|
case CK_ARCConsumeObject:
|
|
case CK_ARCReclaimReturnedObject:
|
|
case CK_ARCExtendBlockObject:
|
|
case CK_CopyAndAutoreleaseBlockObject:
|
|
case CK_BuiltinFnToFnPtr:
|
|
case CK_ZeroToOCLEvent:
|
|
llvm_unreachable("cast kind invalid for aggregate types");
|
|
}
|
|
}
|
|
|
|
void AggExprEmitter::VisitCallExpr(const CallExpr *E) {
|
|
if (E->getCallReturnType()->isReferenceType()) {
|
|
EmitAggLoadOfLValue(E);
|
|
return;
|
|
}
|
|
|
|
RValue RV = CGF.EmitCallExpr(E, getReturnValueSlot());
|
|
EmitMoveFromReturnSlot(E, RV);
|
|
}
|
|
|
|
void AggExprEmitter::VisitObjCMessageExpr(ObjCMessageExpr *E) {
|
|
RValue RV = CGF.EmitObjCMessageExpr(E, getReturnValueSlot());
|
|
EmitMoveFromReturnSlot(E, RV);
|
|
}
|
|
|
|
void AggExprEmitter::VisitBinComma(const BinaryOperator *E) {
|
|
CGF.EmitIgnoredExpr(E->getLHS());
|
|
Visit(E->getRHS());
|
|
}
|
|
|
|
void AggExprEmitter::VisitStmtExpr(const StmtExpr *E) {
|
|
CodeGenFunction::StmtExprEvaluation eval(CGF);
|
|
CGF.EmitCompoundStmt(*E->getSubStmt(), true, Dest);
|
|
}
|
|
|
|
void AggExprEmitter::VisitBinaryOperator(const BinaryOperator *E) {
|
|
if (E->getOpcode() == BO_PtrMemD || E->getOpcode() == BO_PtrMemI)
|
|
VisitPointerToDataMemberBinaryOperator(E);
|
|
else
|
|
CGF.ErrorUnsupported(E, "aggregate binary expression");
|
|
}
|
|
|
|
void AggExprEmitter::VisitPointerToDataMemberBinaryOperator(
|
|
const BinaryOperator *E) {
|
|
LValue LV = CGF.EmitPointerToDataMemberBinaryExpr(E);
|
|
EmitFinalDestCopy(E->getType(), LV);
|
|
}
|
|
|
|
/// Is the value of the given expression possibly a reference to or
|
|
/// into a __block variable?
|
|
static bool isBlockVarRef(const Expr *E) {
|
|
// Make sure we look through parens.
|
|
E = E->IgnoreParens();
|
|
|
|
// Check for a direct reference to a __block variable.
|
|
if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E)) {
|
|
const VarDecl *var = dyn_cast<VarDecl>(DRE->getDecl());
|
|
return (var && var->hasAttr<BlocksAttr>());
|
|
}
|
|
|
|
// More complicated stuff.
|
|
|
|
// Binary operators.
|
|
if (const BinaryOperator *op = dyn_cast<BinaryOperator>(E)) {
|
|
// For an assignment or pointer-to-member operation, just care
|
|
// about the LHS.
|
|
if (op->isAssignmentOp() || op->isPtrMemOp())
|
|
return isBlockVarRef(op->getLHS());
|
|
|
|
// For a comma, just care about the RHS.
|
|
if (op->getOpcode() == BO_Comma)
|
|
return isBlockVarRef(op->getRHS());
|
|
|
|
// FIXME: pointer arithmetic?
|
|
return false;
|
|
|
|
// Check both sides of a conditional operator.
|
|
} else if (const AbstractConditionalOperator *op
|
|
= dyn_cast<AbstractConditionalOperator>(E)) {
|
|
return isBlockVarRef(op->getTrueExpr())
|
|
|| isBlockVarRef(op->getFalseExpr());
|
|
|
|
// OVEs are required to support BinaryConditionalOperators.
|
|
} else if (const OpaqueValueExpr *op
|
|
= dyn_cast<OpaqueValueExpr>(E)) {
|
|
if (const Expr *src = op->getSourceExpr())
|
|
return isBlockVarRef(src);
|
|
|
|
// Casts are necessary to get things like (*(int*)&var) = foo().
|
|
// We don't really care about the kind of cast here, except
|
|
// we don't want to look through l2r casts, because it's okay
|
|
// to get the *value* in a __block variable.
|
|
} else if (const CastExpr *cast = dyn_cast<CastExpr>(E)) {
|
|
if (cast->getCastKind() == CK_LValueToRValue)
|
|
return false;
|
|
return isBlockVarRef(cast->getSubExpr());
|
|
|
|
// Handle unary operators. Again, just aggressively look through
|
|
// it, ignoring the operation.
|
|
} else if (const UnaryOperator *uop = dyn_cast<UnaryOperator>(E)) {
|
|
return isBlockVarRef(uop->getSubExpr());
|
|
|
|
// Look into the base of a field access.
|
|
} else if (const MemberExpr *mem = dyn_cast<MemberExpr>(E)) {
|
|
return isBlockVarRef(mem->getBase());
|
|
|
|
// Look into the base of a subscript.
|
|
} else if (const ArraySubscriptExpr *sub = dyn_cast<ArraySubscriptExpr>(E)) {
|
|
return isBlockVarRef(sub->getBase());
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
void AggExprEmitter::VisitBinAssign(const BinaryOperator *E) {
|
|
// For an assignment to work, the value on the right has
|
|
// to be compatible with the value on the left.
|
|
assert(CGF.getContext().hasSameUnqualifiedType(E->getLHS()->getType(),
|
|
E->getRHS()->getType())
|
|
&& "Invalid assignment");
|
|
|
|
// If the LHS might be a __block variable, and the RHS can
|
|
// potentially cause a block copy, we need to evaluate the RHS first
|
|
// so that the assignment goes the right place.
|
|
// This is pretty semantically fragile.
|
|
if (isBlockVarRef(E->getLHS()) &&
|
|
E->getRHS()->HasSideEffects(CGF.getContext())) {
|
|
// Ensure that we have a destination, and evaluate the RHS into that.
|
|
EnsureDest(E->getRHS()->getType());
|
|
Visit(E->getRHS());
|
|
|
|
// Now emit the LHS and copy into it.
|
|
LValue LHS = CGF.EmitCheckedLValue(E->getLHS(), CodeGenFunction::TCK_Store);
|
|
|
|
// That copy is an atomic copy if the LHS is atomic.
|
|
if (LHS.getType()->isAtomicType()) {
|
|
CGF.EmitAtomicStore(Dest.asRValue(), LHS, /*isInit*/ false);
|
|
return;
|
|
}
|
|
|
|
EmitCopy(E->getLHS()->getType(),
|
|
AggValueSlot::forLValue(LHS, AggValueSlot::IsDestructed,
|
|
needsGC(E->getLHS()->getType()),
|
|
AggValueSlot::IsAliased),
|
|
Dest);
|
|
return;
|
|
}
|
|
|
|
LValue LHS = CGF.EmitLValue(E->getLHS());
|
|
|
|
// If we have an atomic type, evaluate into the destination and then
|
|
// do an atomic copy.
|
|
if (LHS.getType()->isAtomicType()) {
|
|
EnsureDest(E->getRHS()->getType());
|
|
Visit(E->getRHS());
|
|
CGF.EmitAtomicStore(Dest.asRValue(), LHS, /*isInit*/ false);
|
|
return;
|
|
}
|
|
|
|
// Codegen the RHS so that it stores directly into the LHS.
|
|
AggValueSlot LHSSlot =
|
|
AggValueSlot::forLValue(LHS, AggValueSlot::IsDestructed,
|
|
needsGC(E->getLHS()->getType()),
|
|
AggValueSlot::IsAliased);
|
|
// A non-volatile aggregate destination might have volatile member.
|
|
if (!LHSSlot.isVolatile() &&
|
|
CGF.hasVolatileMember(E->getLHS()->getType()))
|
|
LHSSlot.setVolatile(true);
|
|
|
|
CGF.EmitAggExpr(E->getRHS(), LHSSlot);
|
|
|
|
// Copy into the destination if the assignment isn't ignored.
|
|
EmitFinalDestCopy(E->getType(), LHS);
|
|
}
|
|
|
|
void AggExprEmitter::
|
|
VisitAbstractConditionalOperator(const AbstractConditionalOperator *E) {
|
|
llvm::BasicBlock *LHSBlock = CGF.createBasicBlock("cond.true");
|
|
llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("cond.false");
|
|
llvm::BasicBlock *ContBlock = CGF.createBasicBlock("cond.end");
|
|
|
|
// Bind the common expression if necessary.
|
|
CodeGenFunction::OpaqueValueMapping binding(CGF, E);
|
|
|
|
CodeGenFunction::ConditionalEvaluation eval(CGF);
|
|
CGF.EmitBranchOnBoolExpr(E->getCond(), LHSBlock, RHSBlock);
|
|
|
|
// Save whether the destination's lifetime is externally managed.
|
|
bool isExternallyDestructed = Dest.isExternallyDestructed();
|
|
|
|
eval.begin(CGF);
|
|
CGF.EmitBlock(LHSBlock);
|
|
Visit(E->getTrueExpr());
|
|
eval.end(CGF);
|
|
|
|
assert(CGF.HaveInsertPoint() && "expression evaluation ended with no IP!");
|
|
CGF.Builder.CreateBr(ContBlock);
|
|
|
|
// If the result of an agg expression is unused, then the emission
|
|
// of the LHS might need to create a destination slot. That's fine
|
|
// with us, and we can safely emit the RHS into the same slot, but
|
|
// we shouldn't claim that it's already being destructed.
|
|
Dest.setExternallyDestructed(isExternallyDestructed);
|
|
|
|
eval.begin(CGF);
|
|
CGF.EmitBlock(RHSBlock);
|
|
Visit(E->getFalseExpr());
|
|
eval.end(CGF);
|
|
|
|
CGF.EmitBlock(ContBlock);
|
|
}
|
|
|
|
void AggExprEmitter::VisitChooseExpr(const ChooseExpr *CE) {
|
|
Visit(CE->getChosenSubExpr());
|
|
}
|
|
|
|
void AggExprEmitter::VisitVAArgExpr(VAArgExpr *VE) {
|
|
llvm::Value *ArgValue = CGF.EmitVAListRef(VE->getSubExpr());
|
|
llvm::Value *ArgPtr = CGF.EmitVAArg(ArgValue, VE->getType());
|
|
|
|
if (!ArgPtr) {
|
|
CGF.ErrorUnsupported(VE, "aggregate va_arg expression");
|
|
return;
|
|
}
|
|
|
|
EmitFinalDestCopy(VE->getType(), CGF.MakeAddrLValue(ArgPtr, VE->getType()));
|
|
}
|
|
|
|
void AggExprEmitter::VisitCXXBindTemporaryExpr(CXXBindTemporaryExpr *E) {
|
|
// Ensure that we have a slot, but if we already do, remember
|
|
// whether it was externally destructed.
|
|
bool wasExternallyDestructed = Dest.isExternallyDestructed();
|
|
EnsureDest(E->getType());
|
|
|
|
// We're going to push a destructor if there isn't already one.
|
|
Dest.setExternallyDestructed();
|
|
|
|
Visit(E->getSubExpr());
|
|
|
|
// Push that destructor we promised.
|
|
if (!wasExternallyDestructed)
|
|
CGF.EmitCXXTemporary(E->getTemporary(), E->getType(), Dest.getAddr());
|
|
}
|
|
|
|
void
|
|
AggExprEmitter::VisitCXXConstructExpr(const CXXConstructExpr *E) {
|
|
AggValueSlot Slot = EnsureSlot(E->getType());
|
|
CGF.EmitCXXConstructExpr(E, Slot);
|
|
}
|
|
|
|
void
|
|
AggExprEmitter::VisitLambdaExpr(LambdaExpr *E) {
|
|
AggValueSlot Slot = EnsureSlot(E->getType());
|
|
CGF.EmitLambdaExpr(E, Slot);
|
|
}
|
|
|
|
void AggExprEmitter::VisitExprWithCleanups(ExprWithCleanups *E) {
|
|
CGF.enterFullExpression(E);
|
|
CodeGenFunction::RunCleanupsScope cleanups(CGF);
|
|
Visit(E->getSubExpr());
|
|
}
|
|
|
|
void AggExprEmitter::VisitCXXScalarValueInitExpr(CXXScalarValueInitExpr *E) {
|
|
QualType T = E->getType();
|
|
AggValueSlot Slot = EnsureSlot(T);
|
|
EmitNullInitializationToLValue(CGF.MakeAddrLValue(Slot.getAddr(), T));
|
|
}
|
|
|
|
void AggExprEmitter::VisitImplicitValueInitExpr(ImplicitValueInitExpr *E) {
|
|
QualType T = E->getType();
|
|
AggValueSlot Slot = EnsureSlot(T);
|
|
EmitNullInitializationToLValue(CGF.MakeAddrLValue(Slot.getAddr(), T));
|
|
}
|
|
|
|
/// isSimpleZero - If emitting this value will obviously just cause a store of
|
|
/// zero to memory, return true. This can return false if uncertain, so it just
|
|
/// handles simple cases.
|
|
static bool isSimpleZero(const Expr *E, CodeGenFunction &CGF) {
|
|
E = E->IgnoreParens();
|
|
|
|
// 0
|
|
if (const IntegerLiteral *IL = dyn_cast<IntegerLiteral>(E))
|
|
return IL->getValue() == 0;
|
|
// +0.0
|
|
if (const FloatingLiteral *FL = dyn_cast<FloatingLiteral>(E))
|
|
return FL->getValue().isPosZero();
|
|
// int()
|
|
if ((isa<ImplicitValueInitExpr>(E) || isa<CXXScalarValueInitExpr>(E)) &&
|
|
CGF.getTypes().isZeroInitializable(E->getType()))
|
|
return true;
|
|
// (int*)0 - Null pointer expressions.
|
|
if (const CastExpr *ICE = dyn_cast<CastExpr>(E))
|
|
return ICE->getCastKind() == CK_NullToPointer;
|
|
// '\0'
|
|
if (const CharacterLiteral *CL = dyn_cast<CharacterLiteral>(E))
|
|
return CL->getValue() == 0;
|
|
|
|
// Otherwise, hard case: conservatively return false.
|
|
return false;
|
|
}
|
|
|
|
|
|
void
|
|
AggExprEmitter::EmitInitializationToLValue(Expr *E, LValue LV) {
|
|
QualType type = LV.getType();
|
|
// FIXME: Ignore result?
|
|
// FIXME: Are initializers affected by volatile?
|
|
if (Dest.isZeroed() && isSimpleZero(E, CGF)) {
|
|
// Storing "i32 0" to a zero'd memory location is a noop.
|
|
return;
|
|
} else if (isa<ImplicitValueInitExpr>(E) || isa<CXXScalarValueInitExpr>(E)) {
|
|
return EmitNullInitializationToLValue(LV);
|
|
} else if (type->isReferenceType()) {
|
|
RValue RV = CGF.EmitReferenceBindingToExpr(E);
|
|
return CGF.EmitStoreThroughLValue(RV, LV);
|
|
}
|
|
|
|
switch (CGF.getEvaluationKind(type)) {
|
|
case TEK_Complex:
|
|
CGF.EmitComplexExprIntoLValue(E, LV, /*isInit*/ true);
|
|
return;
|
|
case TEK_Aggregate:
|
|
CGF.EmitAggExpr(E, AggValueSlot::forLValue(LV,
|
|
AggValueSlot::IsDestructed,
|
|
AggValueSlot::DoesNotNeedGCBarriers,
|
|
AggValueSlot::IsNotAliased,
|
|
Dest.isZeroed()));
|
|
return;
|
|
case TEK_Scalar:
|
|
if (LV.isSimple()) {
|
|
CGF.EmitScalarInit(E, /*D=*/0, LV, /*Captured=*/false);
|
|
} else {
|
|
CGF.EmitStoreThroughLValue(RValue::get(CGF.EmitScalarExpr(E)), LV);
|
|
}
|
|
return;
|
|
}
|
|
llvm_unreachable("bad evaluation kind");
|
|
}
|
|
|
|
void AggExprEmitter::EmitNullInitializationToLValue(LValue lv) {
|
|
QualType type = lv.getType();
|
|
|
|
// If the destination slot is already zeroed out before the aggregate is
|
|
// copied into it, we don't have to emit any zeros here.
|
|
if (Dest.isZeroed() && CGF.getTypes().isZeroInitializable(type))
|
|
return;
|
|
|
|
if (CGF.hasScalarEvaluationKind(type)) {
|
|
// For non-aggregates, we can store the appropriate null constant.
|
|
llvm::Value *null = CGF.CGM.EmitNullConstant(type);
|
|
// Note that the following is not equivalent to
|
|
// EmitStoreThroughBitfieldLValue for ARC types.
|
|
if (lv.isBitField()) {
|
|
CGF.EmitStoreThroughBitfieldLValue(RValue::get(null), lv);
|
|
} else {
|
|
assert(lv.isSimple());
|
|
CGF.EmitStoreOfScalar(null, lv, /* isInitialization */ true);
|
|
}
|
|
} else {
|
|
// There's a potential optimization opportunity in combining
|
|
// memsets; that would be easy for arrays, but relatively
|
|
// difficult for structures with the current code.
|
|
CGF.EmitNullInitialization(lv.getAddress(), lv.getType());
|
|
}
|
|
}
|
|
|
|
void AggExprEmitter::VisitInitListExpr(InitListExpr *E) {
|
|
#if 0
|
|
// FIXME: Assess perf here? Figure out what cases are worth optimizing here
|
|
// (Length of globals? Chunks of zeroed-out space?).
|
|
//
|
|
// If we can, prefer a copy from a global; this is a lot less code for long
|
|
// globals, and it's easier for the current optimizers to analyze.
|
|
if (llvm::Constant* C = CGF.CGM.EmitConstantExpr(E, E->getType(), &CGF)) {
|
|
llvm::GlobalVariable* GV =
|
|
new llvm::GlobalVariable(CGF.CGM.getModule(), C->getType(), true,
|
|
llvm::GlobalValue::InternalLinkage, C, "");
|
|
EmitFinalDestCopy(E->getType(), CGF.MakeAddrLValue(GV, E->getType()));
|
|
return;
|
|
}
|
|
#endif
|
|
if (E->hadArrayRangeDesignator())
|
|
CGF.ErrorUnsupported(E, "GNU array range designator extension");
|
|
|
|
AggValueSlot Dest = EnsureSlot(E->getType());
|
|
|
|
LValue DestLV = CGF.MakeAddrLValue(Dest.getAddr(), E->getType(),
|
|
Dest.getAlignment());
|
|
|
|
// Handle initialization of an array.
|
|
if (E->getType()->isArrayType()) {
|
|
if (E->isStringLiteralInit())
|
|
return Visit(E->getInit(0));
|
|
|
|
QualType elementType =
|
|
CGF.getContext().getAsArrayType(E->getType())->getElementType();
|
|
|
|
llvm::PointerType *APType =
|
|
cast<llvm::PointerType>(Dest.getAddr()->getType());
|
|
llvm::ArrayType *AType =
|
|
cast<llvm::ArrayType>(APType->getElementType());
|
|
|
|
EmitArrayInit(Dest.getAddr(), AType, elementType, E);
|
|
return;
|
|
}
|
|
|
|
assert(E->getType()->isRecordType() && "Only support structs/unions here!");
|
|
|
|
// Do struct initialization; this code just sets each individual member
|
|
// to the approprate value. This makes bitfield support automatic;
|
|
// the disadvantage is that the generated code is more difficult for
|
|
// the optimizer, especially with bitfields.
|
|
unsigned NumInitElements = E->getNumInits();
|
|
RecordDecl *record = E->getType()->castAs<RecordType>()->getDecl();
|
|
|
|
// Prepare a 'this' for CXXDefaultInitExprs.
|
|
CodeGenFunction::FieldConstructionScope FCS(CGF, Dest.getAddr());
|
|
|
|
if (record->isUnion()) {
|
|
// Only initialize one field of a union. The field itself is
|
|
// specified by the initializer list.
|
|
if (!E->getInitializedFieldInUnion()) {
|
|
// Empty union; we have nothing to do.
|
|
|
|
#ifndef NDEBUG
|
|
// Make sure that it's really an empty and not a failure of
|
|
// semantic analysis.
|
|
for (RecordDecl::field_iterator Field = record->field_begin(),
|
|
FieldEnd = record->field_end();
|
|
Field != FieldEnd; ++Field)
|
|
assert(Field->isUnnamedBitfield() && "Only unnamed bitfields allowed");
|
|
#endif
|
|
return;
|
|
}
|
|
|
|
// FIXME: volatility
|
|
FieldDecl *Field = E->getInitializedFieldInUnion();
|
|
|
|
LValue FieldLoc = CGF.EmitLValueForFieldInitialization(DestLV, Field);
|
|
if (NumInitElements) {
|
|
// Store the initializer into the field
|
|
EmitInitializationToLValue(E->getInit(0), FieldLoc);
|
|
} else {
|
|
// Default-initialize to null.
|
|
EmitNullInitializationToLValue(FieldLoc);
|
|
}
|
|
|
|
return;
|
|
}
|
|
|
|
// We'll need to enter cleanup scopes in case any of the member
|
|
// initializers throw an exception.
|
|
SmallVector<EHScopeStack::stable_iterator, 16> cleanups;
|
|
llvm::Instruction *cleanupDominator = 0;
|
|
|
|
// Here we iterate over the fields; this makes it simpler to both
|
|
// default-initialize fields and skip over unnamed fields.
|
|
unsigned curInitIndex = 0;
|
|
for (RecordDecl::field_iterator field = record->field_begin(),
|
|
fieldEnd = record->field_end();
|
|
field != fieldEnd; ++field) {
|
|
// We're done once we hit the flexible array member.
|
|
if (field->getType()->isIncompleteArrayType())
|
|
break;
|
|
|
|
// Always skip anonymous bitfields.
|
|
if (field->isUnnamedBitfield())
|
|
continue;
|
|
|
|
// We're done if we reach the end of the explicit initializers, we
|
|
// have a zeroed object, and the rest of the fields are
|
|
// zero-initializable.
|
|
if (curInitIndex == NumInitElements && Dest.isZeroed() &&
|
|
CGF.getTypes().isZeroInitializable(E->getType()))
|
|
break;
|
|
|
|
|
|
LValue LV = CGF.EmitLValueForFieldInitialization(DestLV, *field);
|
|
// We never generate write-barries for initialized fields.
|
|
LV.setNonGC(true);
|
|
|
|
if (curInitIndex < NumInitElements) {
|
|
// Store the initializer into the field.
|
|
EmitInitializationToLValue(E->getInit(curInitIndex++), LV);
|
|
} else {
|
|
// We're out of initalizers; default-initialize to null
|
|
EmitNullInitializationToLValue(LV);
|
|
}
|
|
|
|
// Push a destructor if necessary.
|
|
// FIXME: if we have an array of structures, all explicitly
|
|
// initialized, we can end up pushing a linear number of cleanups.
|
|
bool pushedCleanup = false;
|
|
if (QualType::DestructionKind dtorKind
|
|
= field->getType().isDestructedType()) {
|
|
assert(LV.isSimple());
|
|
if (CGF.needsEHCleanup(dtorKind)) {
|
|
if (!cleanupDominator)
|
|
cleanupDominator = CGF.Builder.CreateUnreachable(); // placeholder
|
|
|
|
CGF.pushDestroy(EHCleanup, LV.getAddress(), field->getType(),
|
|
CGF.getDestroyer(dtorKind), false);
|
|
cleanups.push_back(CGF.EHStack.stable_begin());
|
|
pushedCleanup = true;
|
|
}
|
|
}
|
|
|
|
// If the GEP didn't get used because of a dead zero init or something
|
|
// else, clean it up for -O0 builds and general tidiness.
|
|
if (!pushedCleanup && LV.isSimple())
|
|
if (llvm::GetElementPtrInst *GEP =
|
|
dyn_cast<llvm::GetElementPtrInst>(LV.getAddress()))
|
|
if (GEP->use_empty())
|
|
GEP->eraseFromParent();
|
|
}
|
|
|
|
// Deactivate all the partial cleanups in reverse order, which
|
|
// generally means popping them.
|
|
for (unsigned i = cleanups.size(); i != 0; --i)
|
|
CGF.DeactivateCleanupBlock(cleanups[i-1], cleanupDominator);
|
|
|
|
// Destroy the placeholder if we made one.
|
|
if (cleanupDominator)
|
|
cleanupDominator->eraseFromParent();
|
|
}
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
// Entry Points into this File
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
/// GetNumNonZeroBytesInInit - Get an approximate count of the number of
|
|
/// non-zero bytes that will be stored when outputting the initializer for the
|
|
/// specified initializer expression.
|
|
static CharUnits GetNumNonZeroBytesInInit(const Expr *E, CodeGenFunction &CGF) {
|
|
E = E->IgnoreParens();
|
|
|
|
// 0 and 0.0 won't require any non-zero stores!
|
|
if (isSimpleZero(E, CGF)) return CharUnits::Zero();
|
|
|
|
// If this is an initlist expr, sum up the size of sizes of the (present)
|
|
// elements. If this is something weird, assume the whole thing is non-zero.
|
|
const InitListExpr *ILE = dyn_cast<InitListExpr>(E);
|
|
if (ILE == 0 || !CGF.getTypes().isZeroInitializable(ILE->getType()))
|
|
return CGF.getContext().getTypeSizeInChars(E->getType());
|
|
|
|
// InitListExprs for structs have to be handled carefully. If there are
|
|
// reference members, we need to consider the size of the reference, not the
|
|
// referencee. InitListExprs for unions and arrays can't have references.
|
|
if (const RecordType *RT = E->getType()->getAs<RecordType>()) {
|
|
if (!RT->isUnionType()) {
|
|
RecordDecl *SD = E->getType()->getAs<RecordType>()->getDecl();
|
|
CharUnits NumNonZeroBytes = CharUnits::Zero();
|
|
|
|
unsigned ILEElement = 0;
|
|
for (RecordDecl::field_iterator Field = SD->field_begin(),
|
|
FieldEnd = SD->field_end(); Field != FieldEnd; ++Field) {
|
|
// We're done once we hit the flexible array member or run out of
|
|
// InitListExpr elements.
|
|
if (Field->getType()->isIncompleteArrayType() ||
|
|
ILEElement == ILE->getNumInits())
|
|
break;
|
|
if (Field->isUnnamedBitfield())
|
|
continue;
|
|
|
|
const Expr *E = ILE->getInit(ILEElement++);
|
|
|
|
// Reference values are always non-null and have the width of a pointer.
|
|
if (Field->getType()->isReferenceType())
|
|
NumNonZeroBytes += CGF.getContext().toCharUnitsFromBits(
|
|
CGF.getTarget().getPointerWidth(0));
|
|
else
|
|
NumNonZeroBytes += GetNumNonZeroBytesInInit(E, CGF);
|
|
}
|
|
|
|
return NumNonZeroBytes;
|
|
}
|
|
}
|
|
|
|
|
|
CharUnits NumNonZeroBytes = CharUnits::Zero();
|
|
for (unsigned i = 0, e = ILE->getNumInits(); i != e; ++i)
|
|
NumNonZeroBytes += GetNumNonZeroBytesInInit(ILE->getInit(i), CGF);
|
|
return NumNonZeroBytes;
|
|
}
|
|
|
|
/// CheckAggExprForMemSetUse - If the initializer is large and has a lot of
|
|
/// zeros in it, emit a memset and avoid storing the individual zeros.
|
|
///
|
|
static void CheckAggExprForMemSetUse(AggValueSlot &Slot, const Expr *E,
|
|
CodeGenFunction &CGF) {
|
|
// If the slot is already known to be zeroed, nothing to do. Don't mess with
|
|
// volatile stores.
|
|
if (Slot.isZeroed() || Slot.isVolatile() || Slot.getAddr() == 0) return;
|
|
|
|
// C++ objects with a user-declared constructor don't need zero'ing.
|
|
if (CGF.getLangOpts().CPlusPlus)
|
|
if (const RecordType *RT = CGF.getContext()
|
|
.getBaseElementType(E->getType())->getAs<RecordType>()) {
|
|
const CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl());
|
|
if (RD->hasUserDeclaredConstructor())
|
|
return;
|
|
}
|
|
|
|
// If the type is 16-bytes or smaller, prefer individual stores over memset.
|
|
std::pair<CharUnits, CharUnits> TypeInfo =
|
|
CGF.getContext().getTypeInfoInChars(E->getType());
|
|
if (TypeInfo.first <= CharUnits::fromQuantity(16))
|
|
return;
|
|
|
|
// Check to see if over 3/4 of the initializer are known to be zero. If so,
|
|
// we prefer to emit memset + individual stores for the rest.
|
|
CharUnits NumNonZeroBytes = GetNumNonZeroBytesInInit(E, CGF);
|
|
if (NumNonZeroBytes*4 > TypeInfo.first)
|
|
return;
|
|
|
|
// Okay, it seems like a good idea to use an initial memset, emit the call.
|
|
llvm::Constant *SizeVal = CGF.Builder.getInt64(TypeInfo.first.getQuantity());
|
|
CharUnits Align = TypeInfo.second;
|
|
|
|
llvm::Value *Loc = Slot.getAddr();
|
|
|
|
Loc = CGF.Builder.CreateBitCast(Loc, CGF.Int8PtrTy);
|
|
CGF.Builder.CreateMemSet(Loc, CGF.Builder.getInt8(0), SizeVal,
|
|
Align.getQuantity(), false);
|
|
|
|
// Tell the AggExprEmitter that the slot is known zero.
|
|
Slot.setZeroed();
|
|
}
|
|
|
|
|
|
|
|
|
|
/// EmitAggExpr - Emit the computation of the specified expression of aggregate
|
|
/// type. The result is computed into DestPtr. Note that if DestPtr is null,
|
|
/// the value of the aggregate expression is not needed. If VolatileDest is
|
|
/// true, DestPtr cannot be 0.
|
|
void CodeGenFunction::EmitAggExpr(const Expr *E, AggValueSlot Slot) {
|
|
assert(E && hasAggregateEvaluationKind(E->getType()) &&
|
|
"Invalid aggregate expression to emit");
|
|
assert((Slot.getAddr() != 0 || Slot.isIgnored()) &&
|
|
"slot has bits but no address");
|
|
|
|
// Optimize the slot if possible.
|
|
CheckAggExprForMemSetUse(Slot, E, *this);
|
|
|
|
AggExprEmitter(*this, Slot).Visit(const_cast<Expr*>(E));
|
|
}
|
|
|
|
LValue CodeGenFunction::EmitAggExprToLValue(const Expr *E) {
|
|
assert(hasAggregateEvaluationKind(E->getType()) && "Invalid argument!");
|
|
llvm::Value *Temp = CreateMemTemp(E->getType());
|
|
LValue LV = MakeAddrLValue(Temp, E->getType());
|
|
EmitAggExpr(E, AggValueSlot::forLValue(LV, AggValueSlot::IsNotDestructed,
|
|
AggValueSlot::DoesNotNeedGCBarriers,
|
|
AggValueSlot::IsNotAliased));
|
|
return LV;
|
|
}
|
|
|
|
void CodeGenFunction::EmitAggregateCopy(llvm::Value *DestPtr,
|
|
llvm::Value *SrcPtr, QualType Ty,
|
|
bool isVolatile,
|
|
CharUnits alignment,
|
|
bool isAssignment) {
|
|
assert(!Ty->isAnyComplexType() && "Shouldn't happen for complex");
|
|
|
|
if (getLangOpts().CPlusPlus) {
|
|
if (const RecordType *RT = Ty->getAs<RecordType>()) {
|
|
CXXRecordDecl *Record = cast<CXXRecordDecl>(RT->getDecl());
|
|
assert((Record->hasTrivialCopyConstructor() ||
|
|
Record->hasTrivialCopyAssignment() ||
|
|
Record->hasTrivialMoveConstructor() ||
|
|
Record->hasTrivialMoveAssignment()) &&
|
|
"Trying to aggregate-copy a type without a trivial copy/move "
|
|
"constructor or assignment operator");
|
|
// Ignore empty classes in C++.
|
|
if (Record->isEmpty())
|
|
return;
|
|
}
|
|
}
|
|
|
|
// Aggregate assignment turns into llvm.memcpy. This is almost valid per
|
|
// C99 6.5.16.1p3, which states "If the value being stored in an object is
|
|
// read from another object that overlaps in anyway the storage of the first
|
|
// object, then the overlap shall be exact and the two objects shall have
|
|
// qualified or unqualified versions of a compatible type."
|
|
//
|
|
// memcpy is not defined if the source and destination pointers are exactly
|
|
// equal, but other compilers do this optimization, and almost every memcpy
|
|
// implementation handles this case safely. If there is a libc that does not
|
|
// safely handle this, we can add a target hook.
|
|
|
|
// Get data size and alignment info for this aggregate. If this is an
|
|
// assignment don't copy the tail padding. Otherwise copying it is fine.
|
|
std::pair<CharUnits, CharUnits> TypeInfo;
|
|
if (isAssignment)
|
|
TypeInfo = getContext().getTypeInfoDataSizeInChars(Ty);
|
|
else
|
|
TypeInfo = getContext().getTypeInfoInChars(Ty);
|
|
|
|
if (alignment.isZero())
|
|
alignment = TypeInfo.second;
|
|
|
|
// FIXME: Handle variable sized types.
|
|
|
|
// FIXME: If we have a volatile struct, the optimizer can remove what might
|
|
// appear to be `extra' memory ops:
|
|
//
|
|
// volatile struct { int i; } a, b;
|
|
//
|
|
// int main() {
|
|
// a = b;
|
|
// a = b;
|
|
// }
|
|
//
|
|
// we need to use a different call here. We use isVolatile to indicate when
|
|
// either the source or the destination is volatile.
|
|
|
|
llvm::PointerType *DPT = cast<llvm::PointerType>(DestPtr->getType());
|
|
llvm::Type *DBP =
|
|
llvm::Type::getInt8PtrTy(getLLVMContext(), DPT->getAddressSpace());
|
|
DestPtr = Builder.CreateBitCast(DestPtr, DBP);
|
|
|
|
llvm::PointerType *SPT = cast<llvm::PointerType>(SrcPtr->getType());
|
|
llvm::Type *SBP =
|
|
llvm::Type::getInt8PtrTy(getLLVMContext(), SPT->getAddressSpace());
|
|
SrcPtr = Builder.CreateBitCast(SrcPtr, SBP);
|
|
|
|
// Don't do any of the memmove_collectable tests if GC isn't set.
|
|
if (CGM.getLangOpts().getGC() == LangOptions::NonGC) {
|
|
// fall through
|
|
} else if (const RecordType *RecordTy = Ty->getAs<RecordType>()) {
|
|
RecordDecl *Record = RecordTy->getDecl();
|
|
if (Record->hasObjectMember()) {
|
|
CharUnits size = TypeInfo.first;
|
|
llvm::Type *SizeTy = ConvertType(getContext().getSizeType());
|
|
llvm::Value *SizeVal = llvm::ConstantInt::get(SizeTy, size.getQuantity());
|
|
CGM.getObjCRuntime().EmitGCMemmoveCollectable(*this, DestPtr, SrcPtr,
|
|
SizeVal);
|
|
return;
|
|
}
|
|
} else if (Ty->isArrayType()) {
|
|
QualType BaseType = getContext().getBaseElementType(Ty);
|
|
if (const RecordType *RecordTy = BaseType->getAs<RecordType>()) {
|
|
if (RecordTy->getDecl()->hasObjectMember()) {
|
|
CharUnits size = TypeInfo.first;
|
|
llvm::Type *SizeTy = ConvertType(getContext().getSizeType());
|
|
llvm::Value *SizeVal =
|
|
llvm::ConstantInt::get(SizeTy, size.getQuantity());
|
|
CGM.getObjCRuntime().EmitGCMemmoveCollectable(*this, DestPtr, SrcPtr,
|
|
SizeVal);
|
|
return;
|
|
}
|
|
}
|
|
}
|
|
|
|
// Determine the metadata to describe the position of any padding in this
|
|
// memcpy, as well as the TBAA tags for the members of the struct, in case
|
|
// the optimizer wishes to expand it in to scalar memory operations.
|
|
llvm::MDNode *TBAAStructTag = CGM.getTBAAStructInfo(Ty);
|
|
|
|
Builder.CreateMemCpy(DestPtr, SrcPtr,
|
|
llvm::ConstantInt::get(IntPtrTy,
|
|
TypeInfo.first.getQuantity()),
|
|
alignment.getQuantity(), isVolatile,
|
|
/*TBAATag=*/0, TBAAStructTag);
|
|
}
|