Fix cleanup registration for lambda captures.
Lambda captures should be destroyed if an exception is thrown only if
the construction of the complete lambda-expression has not completed.
(If the lambda-expression has been fully constructed, any exception will
invoke its destructor, which will destroy the captures.)
This is directly modeled after how we handle the equivalent situation in
InitListExprs.
Note that EmitLambdaLValue was unreachable because in C++11 onwards the
frontend never creates the awkward situation where a prvalue expression
(such as a lambda) is used in an lvalue context (such as the left-hand
side of a class member access).
llvm-svn: 351487
diff --git a/clang/lib/CodeGen/CGExprAgg.cpp b/clang/lib/CodeGen/CGExprAgg.cpp
index db49b3f..be6e938 100644
--- a/clang/lib/CodeGen/CGExprAgg.cpp
+++ b/clang/lib/CodeGen/CGExprAgg.cpp
@@ -1264,7 +1264,52 @@
void
AggExprEmitter::VisitLambdaExpr(LambdaExpr *E) {
AggValueSlot Slot = EnsureSlot(E->getType());
- CGF.EmitLambdaExpr(E, Slot);
+ LValue SlotLV = CGF.MakeAddrLValue(Slot.getAddress(), E->getType());
+
+ // We'll need to enter cleanup scopes in case any of the element
+ // initializers throws an exception.
+ SmallVector<EHScopeStack::stable_iterator, 16> Cleanups;
+ llvm::Instruction *CleanupDominator = nullptr;
+
+ CXXRecordDecl::field_iterator CurField = E->getLambdaClass()->field_begin();
+ for (LambdaExpr::const_capture_init_iterator i = E->capture_init_begin(),
+ e = E->capture_init_end();
+ i != e; ++i, ++CurField) {
+ // Emit initialization
+ LValue LV = CGF.EmitLValueForFieldInitialization(SlotLV, *CurField);
+ if (CurField->hasCapturedVLAType()) {
+ CGF.EmitLambdaVLACapture(CurField->getCapturedVLAType(), LV);
+ continue;
+ }
+
+ EmitInitializationToLValue(*i, LV);
+
+ // Push a destructor if necessary.
+ if (QualType::DestructionKind DtorKind =
+ CurField->getType().isDestructedType()) {
+ assert(LV.isSimple());
+ if (CGF.needsEHCleanup(DtorKind)) {
+ if (!CleanupDominator)
+ CleanupDominator = CGF.Builder.CreateAlignedLoad(
+ CGF.Int8Ty,
+ llvm::Constant::getNullValue(CGF.Int8PtrTy),
+ CharUnits::One()); // placeholder
+
+ CGF.pushDestroy(EHCleanup, LV.getAddress(), CurField->getType(),
+ CGF.getDestroyer(DtorKind), false);
+ Cleanups.push_back(CGF.EHStack.stable_begin());
+ }
+ }
+ }
+
+ // 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();
}
void AggExprEmitter::VisitExprWithCleanups(ExprWithCleanups *E) {