7a626f63f7
slot. The easiest way to do that was to bundle up the information we care about for aggregate slots into a new structure which demands that its creators at least consider the question. I could probably be convinced that the ObjC 'needs GC' bit should be rolled into this structure. Implement generalized copy elision. The main obstacle here is that IR-generation must be much more careful about making sure that exactly llvm-svn: 113962
759 lines
28 KiB
C++
759 lines
28 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 "CodeGenModule.h"
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#include "CGObjCRuntime.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/StmtVisitor.h"
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#include "llvm/Constants.h"
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#include "llvm/Function.h"
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#include "llvm/GlobalVariable.h"
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#include "llvm/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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bool IgnoreResult;
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bool RequiresGCollection;
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ReturnValueSlot getReturnValueSlot() const {
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// If the destination slot requires garbage collection, we can't
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// use the real return value slot, because we have to use the GC
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// API.
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if (RequiresGCollection) 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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public:
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AggExprEmitter(CodeGenFunction &cgf, AggValueSlot Dest,
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bool ignore, bool requiresGCollection)
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: CGF(cgf), Builder(CGF.Builder), Dest(Dest),
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IgnoreResult(ignore), RequiresGCollection(requiresGCollection) {
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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(const Expr *E, LValue Src, bool Ignore = false);
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void EmitFinalDestCopy(const Expr *E, RValue Src, bool Ignore = false);
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void EmitGCMove(const Expr *E, RValue Src);
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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 VisitUnaryExtension(UnaryOperator *E) { Visit(E->getSubExpr()); }
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// l-values.
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void VisitDeclRefExpr(DeclRefExpr *DRE) { EmitAggLoadOfLValue(DRE); }
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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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EmitAggLoadOfLValue(E);
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}
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void VisitArraySubscriptExpr(ArraySubscriptExpr *E) {
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EmitAggLoadOfLValue(E);
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}
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void VisitBlockDeclRefExpr(const BlockDeclRefExpr *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 VisitObjCPropertyRefExpr(ObjCPropertyRefExpr *E);
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void VisitObjCImplicitSetterGetterRefExpr(ObjCImplicitSetterGetterRefExpr *E);
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void VisitConditionalOperator(const ConditionalOperator *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 VisitCXXBindTemporaryExpr(CXXBindTemporaryExpr *E);
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void VisitCXXConstructExpr(const CXXConstructExpr *E);
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void VisitCXXExprWithTemporaries(CXXExprWithTemporaries *E);
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void VisitCXXScalarValueInitExpr(CXXScalarValueInitExpr *E);
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void VisitCXXTypeidExpr(CXXTypeidExpr *E) { EmitAggLoadOfLValue(E); }
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void VisitVAArgExpr(VAArgExpr *E);
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void EmitInitializationToLValue(Expr *E, LValue Address, QualType T);
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void EmitNullInitializationToLValue(LValue Address, QualType T);
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// case Expr::ChooseExprClass:
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void VisitCXXThrowExpr(const CXXThrowExpr *E) { CGF.EmitCXXThrowExpr(E); }
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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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EmitFinalDestCopy(E, 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)->hasTrivialCopyConstructor() ||
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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 RequiresGCollection is set.
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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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/// EmitGCMove(E, Result);
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/// If GC doesn't interfere, this will cause the result to be emitted
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/// directly into the return value slot. If GC does interfere, a final
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/// move will be performed.
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void AggExprEmitter::EmitGCMove(const Expr *E, RValue Src) {
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if (RequiresGCollection) {
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std::pair<uint64_t, unsigned> TypeInfo =
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CGF.getContext().getTypeInfo(E->getType());
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unsigned long size = TypeInfo.first/8;
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const llvm::Type *SizeTy = CGF.ConvertType(CGF.getContext().getSizeType());
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llvm::Value *SizeVal = llvm::ConstantInt::get(SizeTy, size);
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CGF.CGM.getObjCRuntime().EmitGCMemmoveCollectable(CGF, Dest.getAddr(),
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Src.getAggregateAddr(),
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SizeVal);
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}
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}
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/// EmitFinalDestCopy - Perform the final copy to DestPtr, if desired.
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void AggExprEmitter::EmitFinalDestCopy(const Expr *E, RValue Src, bool Ignore) {
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assert(Src.isAggregate() && "value must be aggregate value!");
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// If Dest is ignored, then we're evaluating an aggregate expression
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// in a context (like an expression statement) that doesn't care
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// about the result. C says that an lvalue-to-rvalue conversion is
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// performed in these cases; C++ says that it is not. In either
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// case, we don't actually need to do anything unless the value is
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// volatile.
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if (Dest.isIgnored()) {
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if (!Src.isVolatileQualified() ||
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CGF.CGM.getLangOptions().CPlusPlus ||
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(IgnoreResult && Ignore))
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return;
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// If the source is volatile, we must read from it; to do that, we need
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// some place to put it.
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Dest = CGF.CreateAggTemp(E->getType(), "agg.tmp");
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}
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if (RequiresGCollection) {
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std::pair<uint64_t, unsigned> TypeInfo =
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CGF.getContext().getTypeInfo(E->getType());
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unsigned long size = TypeInfo.first/8;
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const llvm::Type *SizeTy = CGF.ConvertType(CGF.getContext().getSizeType());
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llvm::Value *SizeVal = llvm::ConstantInt::get(SizeTy, size);
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CGF.CGM.getObjCRuntime().EmitGCMemmoveCollectable(CGF,
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Dest.getAddr(),
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Src.getAggregateAddr(),
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SizeVal);
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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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// FIXME: Pass VolatileDest as well. I think we also need to merge volatile
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// from the source as well, as we can't eliminate it if either operand
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// is volatile, unless copy has volatile for both source and destination..
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CGF.EmitAggregateCopy(Dest.getAddr(), Src.getAggregateAddr(), E->getType(),
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Dest.isVolatile()|Src.isVolatileQualified());
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}
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/// EmitFinalDestCopy - Perform the final copy to DestPtr, if desired.
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void AggExprEmitter::EmitFinalDestCopy(const Expr *E, LValue Src, bool Ignore) {
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assert(Src.isSimple() && "Can't have aggregate bitfield, vector, etc");
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EmitFinalDestCopy(E, RValue::getAggregate(Src.getAddress(),
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Src.isVolatileQualified()),
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Ignore);
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}
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//===----------------------------------------------------------------------===//
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// Visitor Methods
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//===----------------------------------------------------------------------===//
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void AggExprEmitter::VisitCastExpr(CastExpr *E) {
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if (Dest.isIgnored() && E->getCastKind() != CK_Dynamic) {
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Visit(E->getSubExpr());
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return;
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}
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switch (E->getCastKind()) {
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default: assert(0 && "Unhandled cast kind!");
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case CK_Dynamic: {
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assert(isa<CXXDynamicCastExpr>(E) && "CK_Dynamic without a dynamic_cast?");
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LValue LV = CGF.EmitCheckedLValue(E->getSubExpr());
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// FIXME: Do we also need to handle property references here?
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if (LV.isSimple())
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CGF.EmitDynamicCast(LV.getAddress(), cast<CXXDynamicCastExpr>(E));
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else
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CGF.CGM.ErrorUnsupported(E, "non-simple lvalue dynamic_cast");
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if (!Dest.isIgnored())
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CGF.CGM.ErrorUnsupported(E, "lvalue dynamic_cast with a destination");
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break;
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}
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case CK_ToUnion: {
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// GCC union extension
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QualType Ty = E->getSubExpr()->getType();
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QualType PtrTy = CGF.getContext().getPointerType(Ty);
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llvm::Value *CastPtr = Builder.CreateBitCast(Dest.getAddr(),
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CGF.ConvertType(PtrTy));
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EmitInitializationToLValue(E->getSubExpr(), CGF.MakeAddrLValue(CastPtr, Ty),
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Ty);
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break;
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}
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case CK_DerivedToBase:
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case CK_BaseToDerived:
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case CK_UncheckedDerivedToBase: {
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assert(0 && "cannot perform hierarchy conversion in EmitAggExpr: "
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"should have been unpacked before we got here");
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break;
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}
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// FIXME: Remove the CK_Unknown check here.
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case CK_Unknown:
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case CK_NoOp:
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case CK_UserDefinedConversion:
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case CK_ConstructorConversion:
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assert(CGF.getContext().hasSameUnqualifiedType(E->getSubExpr()->getType(),
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E->getType()) &&
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"Implicit cast types must be compatible");
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Visit(E->getSubExpr());
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break;
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case CK_LValueBitCast:
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llvm_unreachable("there are no lvalue bit-casts on aggregates");
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break;
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}
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}
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void AggExprEmitter::VisitCallExpr(const CallExpr *E) {
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if (E->getCallReturnType()->isReferenceType()) {
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EmitAggLoadOfLValue(E);
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return;
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}
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RValue RV = CGF.EmitCallExpr(E, getReturnValueSlot());
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EmitGCMove(E, RV);
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}
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void AggExprEmitter::VisitObjCMessageExpr(ObjCMessageExpr *E) {
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RValue RV = CGF.EmitObjCMessageExpr(E, getReturnValueSlot());
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EmitGCMove(E, RV);
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}
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void AggExprEmitter::VisitObjCPropertyRefExpr(ObjCPropertyRefExpr *E) {
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RValue RV = CGF.EmitObjCPropertyGet(E, getReturnValueSlot());
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EmitGCMove(E, RV);
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}
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void AggExprEmitter::VisitObjCImplicitSetterGetterRefExpr(
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ObjCImplicitSetterGetterRefExpr *E) {
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RValue RV = CGF.EmitObjCPropertyGet(E, getReturnValueSlot());
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EmitGCMove(E, RV);
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}
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void AggExprEmitter::VisitBinComma(const BinaryOperator *E) {
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CGF.EmitAnyExpr(E->getLHS(), AggValueSlot::ignored(), true);
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Visit(E->getRHS());
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}
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void AggExprEmitter::VisitStmtExpr(const StmtExpr *E) {
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CGF.EmitCompoundStmt(*E->getSubStmt(), true, Dest);
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}
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void AggExprEmitter::VisitBinaryOperator(const BinaryOperator *E) {
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if (E->getOpcode() == BO_PtrMemD || E->getOpcode() == BO_PtrMemI)
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VisitPointerToDataMemberBinaryOperator(E);
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else
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CGF.ErrorUnsupported(E, "aggregate binary expression");
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}
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void AggExprEmitter::VisitPointerToDataMemberBinaryOperator(
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const BinaryOperator *E) {
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LValue LV = CGF.EmitPointerToDataMemberBinaryExpr(E);
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EmitFinalDestCopy(E, LV);
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}
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void AggExprEmitter::VisitBinAssign(const BinaryOperator *E) {
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// For an assignment to work, the value on the right has
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// to be compatible with the value on the left.
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assert(CGF.getContext().hasSameUnqualifiedType(E->getLHS()->getType(),
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E->getRHS()->getType())
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&& "Invalid assignment");
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LValue LHS = CGF.EmitLValue(E->getLHS());
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// We have to special case property setters, otherwise we must have
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// a simple lvalue (no aggregates inside vectors, bitfields).
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if (LHS.isPropertyRef()) {
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AggValueSlot Slot = EnsureSlot(E->getRHS()->getType());
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CGF.EmitAggExpr(E->getRHS(), Slot);
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CGF.EmitObjCPropertySet(LHS.getPropertyRefExpr(), Slot.asRValue());
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} else if (LHS.isKVCRef()) {
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AggValueSlot Slot = EnsureSlot(E->getRHS()->getType());
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CGF.EmitAggExpr(E->getRHS(), Slot);
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CGF.EmitObjCPropertySet(LHS.getKVCRefExpr(), Slot.asRValue());
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} else {
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bool RequiresGCollection = false;
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if (CGF.getContext().getLangOptions().getGCMode())
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RequiresGCollection = TypeRequiresGCollection(E->getLHS()->getType());
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// Codegen the RHS so that it stores directly into the LHS.
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AggValueSlot LHSSlot = AggValueSlot::forLValue(LHS, true);
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CGF.EmitAggExpr(E->getRHS(), LHSSlot, false, RequiresGCollection);
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EmitFinalDestCopy(E, LHS, true);
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}
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}
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void AggExprEmitter::VisitConditionalOperator(const ConditionalOperator *E) {
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if (!E->getLHS()) {
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CGF.ErrorUnsupported(E, "conditional operator with missing LHS");
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return;
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}
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llvm::BasicBlock *LHSBlock = CGF.createBasicBlock("cond.true");
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llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("cond.false");
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llvm::BasicBlock *ContBlock = CGF.createBasicBlock("cond.end");
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CGF.EmitBranchOnBoolExpr(E->getCond(), LHSBlock, RHSBlock);
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CGF.BeginConditionalBranch();
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CGF.EmitBlock(LHSBlock);
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// Handle the GNU extension for missing LHS.
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assert(E->getLHS() && "Must have LHS for aggregate value");
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Visit(E->getLHS());
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CGF.EndConditionalBranch();
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CGF.EmitBranch(ContBlock);
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CGF.BeginConditionalBranch();
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CGF.EmitBlock(RHSBlock);
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Visit(E->getRHS());
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CGF.EndConditionalBranch();
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CGF.EmitBranch(ContBlock);
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CGF.EmitBlock(ContBlock);
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}
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void AggExprEmitter::VisitChooseExpr(const ChooseExpr *CE) {
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Visit(CE->getChosenSubExpr(CGF.getContext()));
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}
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void AggExprEmitter::VisitVAArgExpr(VAArgExpr *VE) {
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llvm::Value *ArgValue = CGF.EmitVAListRef(VE->getSubExpr());
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llvm::Value *ArgPtr = CGF.EmitVAArg(ArgValue, VE->getType());
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if (!ArgPtr) {
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CGF.ErrorUnsupported(VE, "aggregate va_arg expression");
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return;
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}
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EmitFinalDestCopy(VE, CGF.MakeAddrLValue(ArgPtr, VE->getType()));
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}
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void AggExprEmitter::VisitCXXBindTemporaryExpr(CXXBindTemporaryExpr *E) {
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// Ensure that we have a slot, but if we already do, remember
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// whether its lifetime was externally managed.
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bool WasManaged = Dest.isLifetimeExternallyManaged();
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Dest = EnsureSlot(E->getType());
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Dest.setLifetimeExternallyManaged();
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Visit(E->getSubExpr());
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// Set up the temporary's destructor if its lifetime wasn't already
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// being managed.
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if (!WasManaged)
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CGF.EmitCXXTemporary(E->getTemporary(), Dest.getAddr());
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}
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void
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AggExprEmitter::VisitCXXConstructExpr(const CXXConstructExpr *E) {
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AggValueSlot Slot = EnsureSlot(E->getType());
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CGF.EmitCXXConstructExpr(E, Slot);
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}
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void AggExprEmitter::VisitCXXExprWithTemporaries(CXXExprWithTemporaries *E) {
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CGF.EmitCXXExprWithTemporaries(E, Dest);
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}
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void AggExprEmitter::VisitCXXScalarValueInitExpr(CXXScalarValueInitExpr *E) {
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QualType T = E->getType();
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AggValueSlot Slot = EnsureSlot(T);
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EmitNullInitializationToLValue(CGF.MakeAddrLValue(Slot.getAddr(), T), T);
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}
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void AggExprEmitter::VisitImplicitValueInitExpr(ImplicitValueInitExpr *E) {
|
|
QualType T = E->getType();
|
|
AggValueSlot Slot = EnsureSlot(T);
|
|
EmitNullInitializationToLValue(CGF.MakeAddrLValue(Slot.getAddr(), T), T);
|
|
}
|
|
|
|
void
|
|
AggExprEmitter::EmitInitializationToLValue(Expr* E, LValue LV, QualType T) {
|
|
// FIXME: Ignore result?
|
|
// FIXME: Are initializers affected by volatile?
|
|
if (isa<ImplicitValueInitExpr>(E)) {
|
|
EmitNullInitializationToLValue(LV, T);
|
|
} else if (T->isReferenceType()) {
|
|
RValue RV = CGF.EmitReferenceBindingToExpr(E, /*InitializedDecl=*/0);
|
|
CGF.EmitStoreThroughLValue(RV, LV, T);
|
|
} else if (T->isAnyComplexType()) {
|
|
CGF.EmitComplexExprIntoAddr(E, LV.getAddress(), false);
|
|
} else if (CGF.hasAggregateLLVMType(T)) {
|
|
CGF.EmitAggExpr(E, AggValueSlot::forAddr(LV.getAddress(), false, true));
|
|
} else {
|
|
CGF.EmitStoreThroughLValue(CGF.EmitAnyExpr(E), LV, T);
|
|
}
|
|
}
|
|
|
|
void AggExprEmitter::EmitNullInitializationToLValue(LValue LV, QualType T) {
|
|
if (!CGF.hasAggregateLLVMType(T)) {
|
|
// For non-aggregates, we can store zero
|
|
llvm::Value *Null = llvm::Constant::getNullValue(CGF.ConvertType(T));
|
|
CGF.EmitStoreThroughLValue(RValue::get(Null), LV, T);
|
|
} 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(), T);
|
|
}
|
|
}
|
|
|
|
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, CGF.MakeAddrLValue(GV, E->getType()));
|
|
return;
|
|
}
|
|
#endif
|
|
if (E->hadArrayRangeDesignator())
|
|
CGF.ErrorUnsupported(E, "GNU array range designator extension");
|
|
|
|
llvm::Value *DestPtr = Dest.getAddr();
|
|
|
|
// Handle initialization of an array.
|
|
if (E->getType()->isArrayType()) {
|
|
const llvm::PointerType *APType =
|
|
cast<llvm::PointerType>(DestPtr->getType());
|
|
const llvm::ArrayType *AType =
|
|
cast<llvm::ArrayType>(APType->getElementType());
|
|
|
|
uint64_t NumInitElements = E->getNumInits();
|
|
|
|
if (E->getNumInits() > 0) {
|
|
QualType T1 = E->getType();
|
|
QualType T2 = E->getInit(0)->getType();
|
|
if (CGF.getContext().hasSameUnqualifiedType(T1, T2)) {
|
|
EmitAggLoadOfLValue(E->getInit(0));
|
|
return;
|
|
}
|
|
}
|
|
|
|
uint64_t NumArrayElements = AType->getNumElements();
|
|
QualType ElementType = CGF.getContext().getCanonicalType(E->getType());
|
|
ElementType = CGF.getContext().getAsArrayType(ElementType)->getElementType();
|
|
|
|
// FIXME: were we intentionally ignoring address spaces and GC attributes?
|
|
|
|
for (uint64_t i = 0; i != NumArrayElements; ++i) {
|
|
llvm::Value *NextVal = Builder.CreateStructGEP(DestPtr, i, ".array");
|
|
LValue LV = CGF.MakeAddrLValue(NextVal, ElementType);
|
|
if (i < NumInitElements)
|
|
EmitInitializationToLValue(E->getInit(i), LV, ElementType);
|
|
|
|
else
|
|
EmitNullInitializationToLValue(LV, ElementType);
|
|
}
|
|
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 *SD = E->getType()->getAs<RecordType>()->getDecl();
|
|
|
|
// If we're initializing the whole aggregate, just do it in place.
|
|
// FIXME: This is a hack around an AST bug (PR6537).
|
|
if (NumInitElements == 1 && E->getType() == E->getInit(0)->getType()) {
|
|
EmitInitializationToLValue(E->getInit(0),
|
|
CGF.MakeAddrLValue(DestPtr, E->getType()),
|
|
E->getType());
|
|
return;
|
|
}
|
|
|
|
|
|
if (E->getType()->isUnionType()) {
|
|
// 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 = SD->field_begin(),
|
|
FieldEnd = SD->field_end();
|
|
Field != FieldEnd; ++Field)
|
|
assert(Field->isUnnamedBitfield() && "Only unnamed bitfields allowed");
|
|
#endif
|
|
return;
|
|
}
|
|
|
|
// FIXME: volatility
|
|
FieldDecl *Field = E->getInitializedFieldInUnion();
|
|
LValue FieldLoc = CGF.EmitLValueForFieldInitialization(DestPtr, Field, 0);
|
|
|
|
if (NumInitElements) {
|
|
// Store the initializer into the field
|
|
EmitInitializationToLValue(E->getInit(0), FieldLoc, Field->getType());
|
|
} else {
|
|
// Default-initialize to null
|
|
EmitNullInitializationToLValue(FieldLoc, Field->getType());
|
|
}
|
|
|
|
return;
|
|
}
|
|
|
|
// Here we iterate over the fields; this makes it simpler to both
|
|
// default-initialize fields and skip over unnamed fields.
|
|
unsigned CurInitVal = 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
|
|
if (Field->getType()->isIncompleteArrayType())
|
|
break;
|
|
|
|
if (Field->isUnnamedBitfield())
|
|
continue;
|
|
|
|
// FIXME: volatility
|
|
LValue FieldLoc = CGF.EmitLValueForFieldInitialization(DestPtr, *Field, 0);
|
|
// We never generate write-barries for initialized fields.
|
|
FieldLoc.setNonGC(true);
|
|
if (CurInitVal < NumInitElements) {
|
|
// Store the initializer into the field.
|
|
EmitInitializationToLValue(E->getInit(CurInitVal++), FieldLoc,
|
|
Field->getType());
|
|
} else {
|
|
// We're out of initalizers; default-initialize to null
|
|
EmitNullInitializationToLValue(FieldLoc, Field->getType());
|
|
}
|
|
}
|
|
}
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
// Entry Points into this File
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
/// 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.
|
|
///
|
|
/// \param IsInitializer - true if this evaluation is initializing an
|
|
/// object whose lifetime is already being managed.
|
|
//
|
|
// FIXME: Take Qualifiers object.
|
|
void CodeGenFunction::EmitAggExpr(const Expr *E, AggValueSlot Slot,
|
|
bool IgnoreResult,
|
|
bool RequiresGCollection) {
|
|
assert(E && hasAggregateLLVMType(E->getType()) &&
|
|
"Invalid aggregate expression to emit");
|
|
assert((Slot.getAddr() != 0 || Slot.isIgnored())
|
|
&& "slot has bits but no address");
|
|
|
|
AggExprEmitter(*this, Slot, IgnoreResult, RequiresGCollection)
|
|
.Visit(const_cast<Expr*>(E));
|
|
}
|
|
|
|
LValue CodeGenFunction::EmitAggExprToLValue(const Expr *E) {
|
|
assert(hasAggregateLLVMType(E->getType()) && "Invalid argument!");
|
|
llvm::Value *Temp = CreateMemTemp(E->getType());
|
|
LValue LV = MakeAddrLValue(Temp, E->getType());
|
|
AggValueSlot Slot
|
|
= AggValueSlot::forAddr(Temp, LV.isVolatileQualified(), false);
|
|
EmitAggExpr(E, Slot);
|
|
return LV;
|
|
}
|
|
|
|
void CodeGenFunction::EmitAggregateCopy(llvm::Value *DestPtr,
|
|
llvm::Value *SrcPtr, QualType Ty,
|
|
bool isVolatile) {
|
|
assert(!Ty->isAnyComplexType() && "Shouldn't happen for complex");
|
|
|
|
if (getContext().getLangOptions().CPlusPlus) {
|
|
if (const RecordType *RT = Ty->getAs<RecordType>()) {
|
|
CXXRecordDecl *Record = cast<CXXRecordDecl>(RT->getDecl());
|
|
assert((Record->hasTrivialCopyConstructor() ||
|
|
Record->hasTrivialCopyAssignment()) &&
|
|
"Trying to aggregate-copy a type without a trivial copy "
|
|
"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 size and alignment info for this aggregate.
|
|
std::pair<uint64_t, unsigned> TypeInfo = getContext().getTypeInfo(Ty);
|
|
|
|
// 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.
|
|
|
|
const llvm::PointerType *DPT = cast<llvm::PointerType>(DestPtr->getType());
|
|
const llvm::Type *DBP =
|
|
llvm::Type::getInt8PtrTy(VMContext, DPT->getAddressSpace());
|
|
DestPtr = Builder.CreateBitCast(DestPtr, DBP, "tmp");
|
|
|
|
const llvm::PointerType *SPT = cast<llvm::PointerType>(SrcPtr->getType());
|
|
const llvm::Type *SBP =
|
|
llvm::Type::getInt8PtrTy(VMContext, SPT->getAddressSpace());
|
|
SrcPtr = Builder.CreateBitCast(SrcPtr, SBP, "tmp");
|
|
|
|
if (const RecordType *RecordTy = Ty->getAs<RecordType>()) {
|
|
RecordDecl *Record = RecordTy->getDecl();
|
|
if (Record->hasObjectMember()) {
|
|
unsigned long size = TypeInfo.first/8;
|
|
const llvm::Type *SizeTy = ConvertType(getContext().getSizeType());
|
|
llvm::Value *SizeVal = llvm::ConstantInt::get(SizeTy, size);
|
|
CGM.getObjCRuntime().EmitGCMemmoveCollectable(*this, DestPtr, SrcPtr,
|
|
SizeVal);
|
|
return;
|
|
}
|
|
} else if (getContext().getAsArrayType(Ty)) {
|
|
QualType BaseType = getContext().getBaseElementType(Ty);
|
|
if (const RecordType *RecordTy = BaseType->getAs<RecordType>()) {
|
|
if (RecordTy->getDecl()->hasObjectMember()) {
|
|
unsigned long size = TypeInfo.first/8;
|
|
const llvm::Type *SizeTy = ConvertType(getContext().getSizeType());
|
|
llvm::Value *SizeVal = llvm::ConstantInt::get(SizeTy, size);
|
|
CGM.getObjCRuntime().EmitGCMemmoveCollectable(*this, DestPtr, SrcPtr,
|
|
SizeVal);
|
|
return;
|
|
}
|
|
}
|
|
}
|
|
|
|
Builder.CreateCall5(CGM.getMemCpyFn(DestPtr->getType(), SrcPtr->getType(),
|
|
IntPtrTy),
|
|
DestPtr, SrcPtr,
|
|
// TypeInfo.first describes size in bits.
|
|
llvm::ConstantInt::get(IntPtrTy, TypeInfo.first/8),
|
|
Builder.getInt32(TypeInfo.second/8),
|
|
Builder.getInt1(isVolatile));
|
|
}
|