[Sema] Fix missing warning on initializer lists on field initializers with overloaded operators

[zequanwu]

Summary

Bug filed at https://bugs.llvm.org/show_bug.cgi?id=46642

[rtrieu]

clang/lib/Sema/SemaDeclCXX.cpp

3584–3585

Does the warning work if it was changed to be "Visit(Base);" before the return here instead of the change above?

[zequanwu]

Address comment.

clang/lib/Sema/SemaDeclCXX.cpp

3584–3585

Yes, done.

[rtrieu]

LGTM

clang/lib/Sema/SemaDeclCXX.cpp

void HandleMemberExpr(MemberExpr *ME, bool CheckReferenceOnly,
         if (FieldDecl *FD = dyn_cast<FieldDecl>(SubME->getMemberDecl()))
           if (!FD->isAnonymousStructOrUnion())
             FieldME = SubME;
 
         if (!FieldME->getType().isPODType(S.Context))
           AllPODFields = false;
 
         Base = SubME->getBase();
+
+        if (CXXOperatorCallExpr *COCE = dyn_cast<CXXOperatorCallExpr>(Base))
+          if (COCE->getNumArgs() > 0)
+            Base = COCE->getArg(0);
       }
 
       if (!isa<CXXThisExpr>(Base->IgnoreParenImpCasts()))
         return;
 
       if (AddressOf && AllPODFields)
         return;
 
       ValueDecl* FoundVD = FieldME->getMemberDecl();
 
       if (ImplicitCastExpr *BaseCast = dyn_cast<ImplicitCastExpr>(Base)) {
         while (isa<ImplicitCastExpr>(BaseCast->getSubExpr())) {

clang/test/SemaCXX/uninitialized.cpp

struct Dwrapper {
     D d3 = { d3.b, num }; // expected-warning{{uninitialized}}
     Dwrapper() {}  // expected-note{{in this constructor}}
     Dwrapper(int) :
       d1{ num, num },
       d2{ num, d2.a },
       d3{ d3.b, num } // expected-warning{{uninitialized}}
     {}
   };
+  
+  struct E {
+    E();
+    E foo();
+    E* operator->();
+  };
+
+  struct F { F(E); };
+
+  struct EFComposed {
+    F f;
+    E e;
+    EFComposed() : f{ e->foo() }, e() {} // expected-warning{{uninitialized}}
+  };
 }
 
 namespace template_class {
 class Foo {
  public:
     int *Create() { return nullptr; }
 };