[analyzer][UninitializedObjectChecker] Refactoring p5.: Handle pedantic mode in the checker class only

[Szelethus]

Summary

A class named FindUninitializedFields shouldn't care about whether the checker will outright ignore all of its results.

lib/StaticAnalyzer/Checkers/UninitializedObject/UninitializedObject.h

 
 using UninitFieldMap = std::map<const FieldRegion *, llvm::SmallString<50>>;
 
 /// Searches for and stores uninitialized fields in a non-union object.
 class FindUninitializedFields {
   ProgramStateRef State;
   const TypedValueRegion *const ObjectR;
 
-  const bool IsPedantic;
   const bool CheckPointeeInitialization;
-
   bool IsAnyFieldInitialized = false;
 
   FieldChainInfo::FieldChain::Factory ChainFactory;
 
   /// A map for assigning uninitialized regions to note messages. For example,
   ///
   ///   struct A {
   ///     int x;
   ///   };
   ///
   ///   A a;
   ///
   /// After analyzing `a`, the map will contain a pair for `a.x`'s region and
   /// the note message "uninitialized field 'this->x'.
   UninitFieldMap UninitFields;
 
 public:
+  /// Constructs the FindUninitializedField object, searches for and stores
+  /// uninitialized fields in R.
   FindUninitializedFields(ProgramStateRef State,
-                          const TypedValueRegion *const R, bool IsPedantic,
+                          const TypedValueRegion *const R,
                           bool CheckPointeeInitialization);
-  const UninitFieldMap &getUninitFields();
+
+  const UninitFieldMap &getUninitFields() { return UninitFields; }
+
+  /// Returns whether the analyzed region contains at least one initialized
+  /// field.
+  bool isAnyFieldInitialized() { return IsAnyFieldInitialized; }
 
 private:
   // For the purposes of this checker, we'll regard the object under checking as
   // a directed tree, where
   //   * the root is the object under checking
   //   * every node is an object that is
   //     - a union
   //     - a non-union record

lib/StaticAnalyzer/Checkers/UninitializedObject/UninitializedObjectChecker.cpp

void UninitializedObjectChecker::checkEndFunction(
   // This avoids essentially the same error being reported multiple times.
   if (willObjectBeAnalyzedLater(CtorDecl, Context))
     return;
 
   Optional<nonloc::LazyCompoundVal> Object = getObjectVal(CtorDecl, Context);
   if (!Object)
     return;
 
-  FindUninitializedFields F(Context.getState(), Object->getRegion(), IsPedantic,
+  FindUninitializedFields F(Context.getState(), Object->getRegion(),
                             CheckPointeeInitialization);
 
   const UninitFieldMap &UninitFields = F.getUninitFields();
 
   if (UninitFields.empty())
     return;
 
+  // In non-pedantic mode, if Object's region doesn't contain a single
+  // initialized field, we'll assume that Object was intentionally left
+  // uninitialized.
+  if (!IsPedantic && !F.isAnyFieldInitialized())
+    return;
+
   // There are uninitialized fields in the record.
 
   ExplodedNode *Node = Context.generateNonFatalErrorNode(Context.getState());
   if (!Node)
     return;
 
   PathDiagnosticLocation LocUsedForUniqueing;
   const Stmt *CallSite = Context.getStackFrame()->getCallSite();
void UninitializedObjectChecker::checkEndFunction(
   Context.emitReport(std::move(Report));
 }
 
 //===----------------------------------------------------------------------===//
 //                   Methods for FindUninitializedFields.
 //===----------------------------------------------------------------------===//
 
 FindUninitializedFields::FindUninitializedFields(
-    ProgramStateRef State, const TypedValueRegion *const R, bool IsPedantic,
+    ProgramStateRef State, const TypedValueRegion *const R,
     bool CheckPointeeInitialization)
-    : State(State), ObjectR(R), IsPedantic(IsPedantic),
-      CheckPointeeInitialization(CheckPointeeInitialization) {}
+    : State(State), ObjectR(R),
+      CheckPointeeInitialization(CheckPointeeInitialization) {
 
-const UninitFieldMap &FindUninitializedFields::getUninitFields() {
   isNonUnionUninit(ObjectR, FieldChainInfo(ChainFactory));
-
-  if (!IsPedantic && !IsAnyFieldInitialized)
-    UninitFields.clear();
-
-  return UninitFields;
 }
 
 bool FindUninitializedFields::addFieldToUninits(FieldChainInfo Chain) {
   if (State->getStateManager().getContext().getSourceManager().isInSystemHeader(
           Chain.getUninitRegion()->getDecl()->getLocation()))
     return false;
 
   UninitFieldMap::mapped_type NoteMsgBuf;