Improved on ir-gen for synthesis of non-trivial default

constructor body whose class has non-static data-members which
required non-trivial construction.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@79125 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 47 insertions, 0 deletions

diff --git a/lib/CodeGen/CGCXX.cpp b/lib/CodeGen/CGCXX.cpp
index a36c887eaa..f2e58af403 100644
--- a/lib/CodeGen/CGCXX.cpp
+++ b/lib/CodeGen/CGCXX.cpp
@@ -1129,6 +1129,29 @@ void CodeGenFunction::EmitCtorPrologue(const CXXConstructorDecl *CD) {
     }
   }
 
+  if (!CD->isTrivial() && CD->getNumBaseOrMemberInitializers() == 0)
+    // Nontrivial default constructor with no initializer list. It may still
+    // contain non-static data members which require construction.
+    for (CXXRecordDecl::field_iterator Field = ClassDecl->field_begin(),
+         FieldEnd = ClassDecl->field_end();
+         Field != FieldEnd; ++Field) {
+      QualType FieldType = getContext().getCanonicalType((*Field)->getType());
+      if (!FieldType->getAs<RecordType>() || Field->isAnonymousStructOrUnion())
+        continue;
+      const RecordType *ClassRec = FieldType->getAs<RecordType>();
+      if (CXXRecordDecl *MemberClassDecl = 
+            dyn_cast<CXXRecordDecl>(ClassRec->getDecl())) {
+        if (MemberClassDecl->hasTrivialConstructor())
+          continue;
+        if (CXXConstructorDecl *MamberCX = 
+              MemberClassDecl->getDefaultConstructor(getContext())) {
+          LoadOfThis = LoadCXXThis();
+          LValue LHS = EmitLValueForField(LoadOfThis, *Field, false, 0);
+          EmitCXXConstructorCall(MamberCX, Ctor_Complete, LHS.getAddress(), 0, 0);
+        }
+      }
+    }
+
   // Initialize the vtable pointer
   if (ClassDecl->isDynamicClass()) {
     if (!LoadOfThis)
diff --git a/test/CodeGenCXX/default-constructor-for-members.cpp b/test/CodeGenCXX/default-constructor-for-members.cpp
new file mode 100644
index 0000000000..28938fcebf
--- /dev/null
+++ b/test/CodeGenCXX/default-constructor-for-members.cpp
@@ -0,0 +1,24 @@
+// RUN: clang-cc -triple x86_64-apple-darwin -S %s -o %t-64.s &&
+// RUN: FileCheck -check-prefix LP64 --input-file=%t-64.s %s &&
+// RUN: clang-cc -triple i386-apple-darwin -S %s -o %t-32.s &&
+// RUN: FileCheck -check-prefix LP32 --input-file=%t-32.s %s &&
+// RUN: true
+
+extern "C" int printf(...);
+
+struct S {
+  S() { printf("S::S()\n"); }
+  int iS;
+};
+
+struct M {
+  S ARR_S; 
+};
+
+int main() {
+  M m1;
+}
+
+// CHECK-LP64: call	__ZN1SC1Ev
+
+// CHECK-LP32: call	L__ZN1SC1Ev