[EH] Fix for clang bug 24005 - no cleanup for array of memcpy-able objects in struct

[• d.zobnin.bugzilla]

Summary

The fix is to emit cleanup for arrays of memcpy-able objects in struct if an exception is thrown later during copy-construction.

[rjmccall]

LGTM.

cfe/trunk/lib/CodeGen/CGClass.cpp

if (BaseElementTy.isPODType(CGF.getContext()) ||
       llvm::Value *SrcPtr
         = CGF.Builder.CreateLoad(CGF.GetAddrOfLocalVar(Args[SrcArgIndex]));
       LValue ThisRHSLV = CGF.MakeNaturalAlignAddrLValue(SrcPtr, RecordTy);
       LValue Src = CGF.EmitLValueForFieldInitialization(ThisRHSLV, Field);
 
       // Copy the aggregate.
       CGF.EmitAggregateCopy(LHS.getAddress(), Src.getAddress(), FieldType,
                             LHS.isVolatileQualified());
+      // Ensure that we destroy the objects if an exception is thrown later in
+      // the constructor.
+      QualType::DestructionKind dtorKind = FieldType.isDestructedType();
+      if (CGF.needsEHCleanup(dtorKind))
+        CGF.pushEHDestroy(dtorKind, LHS.getAddress(), FieldType); 
       return;
     }
   }
 
   ArrayRef<VarDecl *> ArrayIndexes;
   if (MemberInit->getNumArrayIndices())
     ArrayIndexes = MemberInit->getArrayIndexes();
   CGF.EmitInitializerForField(Field, LHS, MemberInit->getInit(), ArrayIndexes);

cfe/trunk/test/CodeGenCXX/eh-aggregate-copy-destroy.cpp

+// Check that in case of copying an array of memcpy-able objects, their
+// destructors will be called if an exception is thrown.
+//
+// RUN: %clang_cc1 -triple x86_64-apple-darwin10 -fexceptions -fcxx-exceptions -O0 -fno-elide-constructors -emit-llvm %s -o - | FileCheck %s
+
+struct ImplicitCopy {
+  int x;
+  ImplicitCopy() { x = 10; }
+  ~ImplicitCopy() { x = 20; }
+};
+
+struct ThrowCopy {
+  ThrowCopy() {}
+  ThrowCopy(const ThrowCopy &) { throw 1; }
+};
+
+struct Container {
+  ImplicitCopy b[2];
+  ThrowCopy c;
+};
+
+int main () {
+  try {
+    Container c1;
+    // CHECK_LABEL: main
+    // CHECK-NOT: call void @_ZN9ThrowCopyC1ERKS_
+    // CHECK: invoke void @_ZN9ThrowCopyC1ERKS_
+    // CHECK: invoke void @_ZN12ImplicitCopyD1Ev
+    Container c2(c1);
+  }
+  catch (...) {
+    return 1;
+  }
+
+  return 0;
+}
+