C++1y: Allow aggregates to have default initializers.
Add a CXXDefaultInitExpr, analogous to CXXDefaultArgExpr, and use it both in
CXXCtorInitializers and in InitListExprs to represent a default initializer.
There's an additional complication here: because the default initializer can
refer to the initialized object via its 'this' pointer, we need to make sure
that 'this' points to the right thing within the evaluation.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@179958 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/CGClass.cpp b/lib/CodeGen/CGClass.cpp
index 0592556..2b9a55b 100644
--- a/lib/CodeGen/CGClass.cpp
+++ b/lib/CodeGen/CGClass.cpp
@@ -1139,6 +1139,7 @@
InitializeVTablePointers(ClassDecl);
// And finally, initialize class members.
+ FieldConstructionScope FCS(*this, CXXThisValue);
ConstructorMemcpyizer CM(*this, CD, Args);
for (; B != E; B++) {
CXXCtorInitializer *Member = (*B);
diff --git a/lib/CodeGen/CGExpr.cpp b/lib/CodeGen/CGExpr.cpp
index a0725b5..ea13de1 100644
--- a/lib/CodeGen/CGExpr.cpp
+++ b/lib/CodeGen/CGExpr.cpp
@@ -903,6 +903,10 @@
return EmitNullInitializationLValue(cast<CXXScalarValueInitExpr>(E));
case Expr::CXXDefaultArgExprClass:
return EmitLValue(cast<CXXDefaultArgExpr>(E)->getExpr());
+ case Expr::CXXDefaultInitExprClass: {
+ CXXDefaultInitExprScope Scope(*this);
+ return EmitLValue(cast<CXXDefaultInitExpr>(E)->getExpr());
+ }
case Expr::CXXTypeidExprClass:
return EmitCXXTypeidLValue(cast<CXXTypeidExpr>(E));
diff --git a/lib/CodeGen/CGExprAgg.cpp b/lib/CodeGen/CGExprAgg.cpp
index 6b29b31..b974e1d 100644
--- a/lib/CodeGen/CGExprAgg.cpp
+++ b/lib/CodeGen/CGExprAgg.cpp
@@ -170,6 +170,10 @@
void VisitCXXDefaultArgExpr(CXXDefaultArgExpr *DAE) {
Visit(DAE->getExpr());
}
+ void VisitCXXDefaultInitExpr(CXXDefaultInitExpr *DIE) {
+ CodeGenFunction::CXXDefaultInitExprScope Scope(CGF);
+ Visit(DIE->getExpr());
+ }
void VisitCXXBindTemporaryExpr(CXXBindTemporaryExpr *E);
void VisitCXXConstructExpr(const CXXConstructExpr *E);
void VisitLambdaExpr(LambdaExpr *E);
@@ -1189,7 +1193,10 @@
// 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.
diff --git a/lib/CodeGen/CGExprComplex.cpp b/lib/CodeGen/CGExprComplex.cpp
index 5fc73aa..36f974a 100644
--- a/lib/CodeGen/CGExprComplex.cpp
+++ b/lib/CodeGen/CGExprComplex.cpp
@@ -182,6 +182,10 @@
ComplexPairTy VisitCXXDefaultArgExpr(CXXDefaultArgExpr *DAE) {
return Visit(DAE->getExpr());
}
+ ComplexPairTy VisitCXXDefaultInitExpr(CXXDefaultInitExpr *DIE) {
+ CodeGenFunction::CXXDefaultInitExprScope Scope(CGF);
+ return Visit(DIE->getExpr());
+ }
ComplexPairTy VisitExprWithCleanups(ExprWithCleanups *E) {
CGF.enterFullExpression(E);
CodeGenFunction::RunCleanupsScope Scope(CGF);
diff --git a/lib/CodeGen/CGExprConstant.cpp b/lib/CodeGen/CGExprConstant.cpp
index faaf646..f5c8187 100644
--- a/lib/CodeGen/CGExprConstant.cpp
+++ b/lib/CodeGen/CGExprConstant.cpp
@@ -757,6 +757,12 @@
return Visit(DAE->getExpr());
}
+ llvm::Constant *VisitCXXDefaultInitExpr(CXXDefaultInitExpr *DIE) {
+ // No need for a DefaultInitExprScope: we don't handle 'this' in a
+ // constant expression.
+ return Visit(DIE->getExpr());
+ }
+
llvm::Constant *VisitMaterializeTemporaryExpr(MaterializeTemporaryExpr *E) {
return Visit(E->GetTemporaryExpr());
}
diff --git a/lib/CodeGen/CGExprScalar.cpp b/lib/CodeGen/CGExprScalar.cpp
index ea1eae8..c1c252d 100644
--- a/lib/CodeGen/CGExprScalar.cpp
+++ b/lib/CodeGen/CGExprScalar.cpp
@@ -344,6 +344,10 @@
Value *VisitCXXDefaultArgExpr(CXXDefaultArgExpr *DAE) {
return Visit(DAE->getExpr());
}
+ Value *VisitCXXDefaultInitExpr(CXXDefaultInitExpr *DIE) {
+ CodeGenFunction::CXXDefaultInitExprScope Scope(CGF);
+ return Visit(DIE->getExpr());
+ }
Value *VisitCXXThisExpr(CXXThisExpr *TE) {
return CGF.LoadCXXThis();
}
diff --git a/lib/CodeGen/CodeGenFunction.cpp b/lib/CodeGen/CodeGenFunction.cpp
index cda3ce0..a12e7dc 100644
--- a/lib/CodeGen/CodeGenFunction.cpp
+++ b/lib/CodeGen/CodeGenFunction.cpp
@@ -45,6 +45,7 @@
DidCallStackSave(false),
IndirectBranch(0), SwitchInsn(0), CaseRangeBlock(0), UnreachableBlock(0),
CXXABIThisDecl(0), CXXABIThisValue(0), CXXThisValue(0),
+ CXXDefaultInitExprThis(0),
CXXStructorImplicitParamDecl(0), CXXStructorImplicitParamValue(0),
OutermostConditional(0), CurLexicalScope(0), TerminateLandingPad(0),
TerminateHandler(0), TrapBB(0) {
diff --git a/lib/CodeGen/CodeGenFunction.h b/lib/CodeGen/CodeGenFunction.h
index 6e2d627..f0c2c1e 100644
--- a/lib/CodeGen/CodeGenFunction.h
+++ b/lib/CodeGen/CodeGenFunction.h
@@ -1206,12 +1206,53 @@
/// lazily by getUnreachableBlock().
llvm::BasicBlock *UnreachableBlock;
+public:
+ /// A scope within which we are constructing the fields of an object which
+ /// might use a CXXDefaultInitExpr. This stashes away a 'this' value to use
+ /// if we need to evaluate a CXXDefaultInitExpr within the evaluation.
+ class FieldConstructionScope {
+ public:
+ FieldConstructionScope(CodeGenFunction &CGF, llvm::Value *This)
+ : CGF(CGF), OldCXXDefaultInitExprThis(CGF.CXXDefaultInitExprThis) {
+ CGF.CXXDefaultInitExprThis = This;
+ }
+ ~FieldConstructionScope() {
+ CGF.CXXDefaultInitExprThis = OldCXXDefaultInitExprThis;
+ }
+
+ private:
+ CodeGenFunction &CGF;
+ llvm::Value *OldCXXDefaultInitExprThis;
+ };
+
+ /// The scope of a CXXDefaultInitExpr. Within this scope, the value of 'this'
+ /// is overridden to be the object under construction.
+ class CXXDefaultInitExprScope {
+ public:
+ CXXDefaultInitExprScope(CodeGenFunction &CGF)
+ : CGF(CGF), OldCXXThisValue(CGF.CXXThisValue) {
+ CGF.CXXThisValue = CGF.CXXDefaultInitExprThis;
+ }
+ ~CXXDefaultInitExprScope() {
+ CGF.CXXThisValue = OldCXXThisValue;
+ }
+
+ public:
+ CodeGenFunction &CGF;
+ llvm::Value *OldCXXThisValue;
+ };
+
+private:
/// CXXThisDecl - When generating code for a C++ member function,
/// this will hold the implicit 'this' declaration.
ImplicitParamDecl *CXXABIThisDecl;
llvm::Value *CXXABIThisValue;
llvm::Value *CXXThisValue;
+ /// The value of 'this' to use when evaluating CXXDefaultInitExprs within
+ /// this expression.
+ llvm::Value *CXXDefaultInitExprThis;
+
/// CXXStructorImplicitParamDecl - When generating code for a constructor or
/// destructor, this will hold the implicit argument (e.g. VTT).
ImplicitParamDecl *CXXStructorImplicitParamDecl;