QDoc: Remove empty destructors and add missing override keyword

This change removes reduntant destructors. It also adds the
'override' keyword to overridden destructors to remove warnings
from clang-tidy in Creator.

The patch also replaces two instances of 0 as nullptr constant.

Change-Id: I576c248b7d4637249d167d7bfb8885af4f7811ff
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>

15 files changed, 15 insertions, 40 deletions

diff --git a/src/qdoc/atom.h b/src/qdoc/atom.h
index f13d9012a..70a639158 100644
--- a/src/qdoc/atom.h
+++ b/src/qdoc/atom.h
@@ -211,7 +211,7 @@ class LinkAtom : public Atom
     LinkAtom(const QString &p1, const QString &p2);
     LinkAtom(const LinkAtom &t);
     LinkAtom(Atom *previous, const LinkAtom &t);
-    virtual ~LinkAtom() { }
+    ~LinkAtom() override { }
 
     bool isLinkAtom() const override { return true; }
     Node::Genus genus() override { resolveSquareBracketParams(); return genus_; }
diff --git a/src/qdoc/clangcodeparser.h b/src/qdoc/clangcodeparser.h
index 6946cd238..e0ca2fba1 100644
--- a/src/qdoc/clangcodeparser.h
+++ b/src/qdoc/clangcodeparser.h
@@ -51,7 +51,7 @@ class ClangCodeParser : public CppCodeParser
     Q_DECLARE_TR_FUNCTIONS(QDoc::ClangCodeParser)
 
 public:
-    ~ClangCodeParser();
+    ~ClangCodeParser() override;
 
     void initializeParser(const Config &config) override;
     void terminateParser() override;
diff --git a/src/qdoc/cppcodemarker.h b/src/qdoc/cppcodemarker.h
index 3719e7bf5..2a8456103 100644
--- a/src/qdoc/cppcodemarker.h
+++ b/src/qdoc/cppcodemarker.h
@@ -39,7 +39,7 @@ class CppCodeMarker : public CodeMarker
 
 public:
     CppCodeMarker();
-    ~CppCodeMarker();
+    ~CppCodeMarker() override;
 
     bool recognizeCode(const QString &code) override;
     bool recognizeExtension(const QString &ext) override;
diff --git a/src/qdoc/cppcodeparser.h b/src/qdoc/cppcodeparser.h
index d5f23dde7..c6d6ca788 100644
--- a/src/qdoc/cppcodeparser.h
+++ b/src/qdoc/cppcodeparser.h
@@ -53,7 +53,6 @@ class CppCodeParser : public CodeParser
 
 public:
     CppCodeParser();
-    ~CppCodeParser() = default;
 
     void initializeParser(const Config &config) override;
     void terminateParser() override;
diff --git a/src/qdoc/doc.h b/src/qdoc/doc.h
index 84c198a4b..d67275565 100644
--- a/src/qdoc/doc.h
+++ b/src/qdoc/doc.h
@@ -90,7 +90,7 @@ class TopicRef : public DitaRef
 {
 public:
     TopicRef() { }
-    ~TopicRef();
+    ~TopicRef() override;
 
     bool isMapRef() const override { return false; }
     const DitaRefList *subrefs() const override { return &subrefs_; }
@@ -104,7 +104,6 @@ class MapRef : public DitaRef
 {
 public:
     MapRef() { }
-    ~MapRef() { }
 
     bool isMapRef() const override { return true; }
 };
diff --git a/src/qdoc/htmlgenerator.h b/src/qdoc/htmlgenerator.h
index 26bdb7c43..c1564c5b0 100644
--- a/src/qdoc/htmlgenerator.h
+++ b/src/qdoc/htmlgenerator.h
@@ -53,7 +53,7 @@ public:
 
 public:
     HtmlGenerator();
-    ~HtmlGenerator();
+    ~HtmlGenerator() override;
 
     void initializeGenerator(const Config &config) override;
     void terminateGenerator() override;
diff --git a/src/qdoc/jscodemarker.h b/src/qdoc/jscodemarker.h
index a66f5a54a..3d2ffa1ef 100644
--- a/src/qdoc/jscodemarker.h
+++ b/src/qdoc/jscodemarker.h
@@ -43,7 +43,7 @@ class JsCodeMarker : public QmlCodeMarker
 
 public:
     JsCodeMarker();
-    ~JsCodeMarker();
+    ~JsCodeMarker() override;
 
     bool recognizeCode(const QString &code) override;
     bool recognizeExtension(const QString &ext) override;
diff --git a/src/qdoc/node.cpp b/src/qdoc/node.cpp
index 32a6bc025..5cf323e1c 100644
--- a/src/qdoc/node.cpp
+++ b/src/qdoc/node.cpp
@@ -4587,14 +4587,6 @@ QmlTypeNode::QmlTypeNode(Aggregate *parent, const QString &name, NodeType type)
 }
 
 /*!
-  Needed for printing a debug messages.
- */
-QmlTypeNode::~QmlTypeNode()
-{
-    // nothing.
-}
-
-/*!
   Clear the static maps so that subsequent runs don't try to use
   contents from a previous run.
  */
diff --git a/src/qdoc/node.h b/src/qdoc/node.h
index 13ed755e9..5530e1088 100644
--- a/src/qdoc/node.h
+++ b/src/qdoc/node.h
@@ -401,7 +401,6 @@ public:
         noAutoList_(false) { }
     PageNode(Aggregate *parent, const QString &name, PageType ptype) : Node(Page, parent, name),
         noAutoList_(false) { setPageType(ptype); }
-    virtual ~PageNode() { }
 
     bool isPageNode() const override { return true; }
     bool isTextPageNode() const override { return !isAggregate(); } // PageNode but not Aggregate
@@ -499,7 +498,7 @@ public:
 protected:
     Aggregate(NodeType type, Aggregate *parent, const QString &name)
         : PageNode(type, parent, name), functionCount_(0) { }
-    virtual ~Aggregate();
+    ~Aggregate() override;
     void removeFunctionNode(FunctionNode *fn);
 
 private:
@@ -536,7 +535,7 @@ class NamespaceNode : public Aggregate
 public:
     NamespaceNode(Aggregate *parent, const QString &name) : Aggregate(Namespace, parent, name),
         seen_(false), tree_(nullptr), docNode_(nullptr) { }
-    virtual ~NamespaceNode();
+    ~NamespaceNode() override;
     Tree *tree() const override { return (parent() ? parent()->tree() : tree_); }
 
     bool isFirstClassAggregate() const override { return true; }
@@ -599,7 +598,6 @@ class ClassNode : public Aggregate
 public:
     ClassNode(NodeType type, Aggregate *parent, const QString &name) : Aggregate(type, parent, name),
         abstract_(false),  wrapper_(false), qmlelement(nullptr) { }
-    virtual ~ClassNode() { }
     bool isFirstClassAggregate() const override { return true; }
     bool isClassNode() const override { return true; }
     bool isRelatableType() const override { return true; }
@@ -653,7 +651,6 @@ class HeaderNode : public Aggregate
 {
 public:
     HeaderNode(Aggregate *parent, const QString &name);
-    virtual ~HeaderNode() { }
     bool docMustBeGenerated() const override;
     bool isFirstClassAggregate() const override { return true; }
     bool isRelatableType() const override { return true; }
@@ -675,7 +672,6 @@ class ExampleNode : public PageNode
 public:
     ExampleNode(Aggregate *parent, const QString &name)
         : PageNode(Node::Example, parent, name) { }
-    virtual ~ExampleNode() { }
     QString imageFileName() const override { return imageFileName_; }
     void setImageFileName(const QString &ifn) override { imageFileName_ = ifn; }
     const QStringList &files() const { return files_; }
@@ -715,7 +711,6 @@ class QmlTypeNode : public Aggregate
 {
 public:
     QmlTypeNode(Aggregate *parent, const QString &name, NodeType type = QmlType);
-    virtual ~QmlTypeNode();
     bool isFirstClassAggregate() const override { return true; }
     bool isQtQuickNode() const override {
         return (logicalModuleName() == QLatin1String("QtQuick"));
@@ -770,7 +765,6 @@ class QmlBasicTypeNode : public Aggregate
 {
 public:
     QmlBasicTypeNode(Aggregate *parent, const QString &name, NodeType type = QmlBasicType);
-    virtual ~QmlBasicTypeNode() { }
     bool isFirstClassAggregate() const override { return true; }
 };
 
@@ -783,7 +777,6 @@ public:
                     const QString &name,
                     const QString &type,
                     bool attached);
-    virtual ~QmlPropertyNode() { }
 
     void setDataType(const QString &dataType) override { type_ = dataType; }
     void setStored(bool stored) { stored_ = toFlagValue(stored); }
@@ -847,7 +840,6 @@ class EnumNode : public Node
 {
 public:
     EnumNode(Aggregate *parent, const QString &name) : Node(Enum, parent, name), flagsType_(nullptr) { }
-    virtual ~EnumNode() { }
 
     void addItem(const EnumItem &item);
     void setFlagsType(TypedefNode *typedeff);
@@ -870,7 +862,6 @@ class TypedefNode : public Node
 public:
     TypedefNode(Aggregate *parent, const QString &name) : Node(Typedef, parent, name),
         associatedEnum_(nullptr) { }
-    virtual ~TypedefNode() { }
 
     bool hasAssociatedEnum() const { return associatedEnum_ != nullptr; }
     const EnumNode *associatedEnum() const { return associatedEnum_; }
@@ -889,7 +880,6 @@ class TypeAliasNode : public TypedefNode
 public:
     TypeAliasNode(Aggregate *parent, const QString &name, const QString &aliasedType)
         : TypedefNode(parent, name), aliasedType_(aliasedType) { }
-    virtual ~TypeAliasNode() { }
 
     QString aliasedType() { return aliasedType_; }
     Node *clone(Aggregate *parent) override;
@@ -915,7 +905,7 @@ public:
         : Node(Node::SharedComment, parent, group) {
         collective_.reserve(count);
     }
-    virtual ~SharedCommentNode() { collective_.clear(); }
+    ~SharedCommentNode() override { collective_.clear(); }
 
     bool isPropertyGroup() const override { return !collective_.isEmpty() &&
             (collective_.at(0)->isQmlProperty() || collective_.at(0)->isJsProperty());
@@ -959,7 +949,6 @@ public:
 
     FunctionNode(Aggregate *parent, const QString &name); // C++ function (Plain)
     FunctionNode(Metaness type, Aggregate *parent, const QString &name, bool attached = false);
-    virtual ~FunctionNode() { }
 
     Node *clone(Aggregate *parent) override;
     Metaness metaness() const { return metaness_; }
@@ -1108,7 +1097,6 @@ public:
     enum { NumFunctionRoles = Notifier + 1 };
 
     PropertyNode(Aggregate *parent, const QString &name);
-    virtual ~PropertyNode() { }
 
     void setDataType(const QString &dataType) override { type_ = dataType; }
     void addFunction(FunctionNode *function, FunctionRole role);
@@ -1192,7 +1180,6 @@ class VariableNode : public Node
 {
 public:
     VariableNode(Aggregate *parent, const QString &name);
-    virtual ~VariableNode() { }
 
     void setLeftType(const QString &leftType) { leftType_ = leftType; }
     void setRightType(const QString &rightType) { rightType_ = rightType; }
@@ -1221,7 +1208,6 @@ class CollectionNode : public PageNode
 public:
     CollectionNode(NodeType type, Aggregate *parent, const QString &name)
         : PageNode(type, parent, name), seen_(false) { }
-    virtual ~CollectionNode() { }
 
     bool isCollectionNode() const override { return true; }
     QString qtVariable() const override { return qtVariable_; }
diff --git a/src/qdoc/parameters.cpp b/src/qdoc/parameters.cpp
index 1b37cca89..c723fe9cc 100644
--- a/src/qdoc/parameters.cpp
+++ b/src/qdoc/parameters.cpp
@@ -84,13 +84,13 @@ QString Parameter::signature(bool includeValue) const
  */
 
 Parameters::Parameters()
-  : valid_(true), privateSignal_(false), tok_(0), tokenizer_(0)
+  : valid_(true), privateSignal_(false), tok_(0), tokenizer_(nullptr)
 {
     // nothing.
 }
 
 Parameters::Parameters(const QString &signature)
-    : valid_(true), privateSignal_(false), tok_(0), tokenizer_(0)
+    : valid_(true), privateSignal_(false), tok_(0), tokenizer_(nullptr)
 {
     if (!signature.isEmpty()) {
         if (!parse(signature)) {
diff --git a/src/qdoc/puredocparser.h b/src/qdoc/puredocparser.h
index ef6e5d13f..7d814e982 100644
--- a/src/qdoc/puredocparser.h
+++ b/src/qdoc/puredocparser.h
@@ -41,7 +41,7 @@ class PureDocParser : public CppCodeParser
 
 public:
     PureDocParser() : tokenizer_(nullptr), tok_(0) { pureParser_ = this; }
-    virtual ~PureDocParser() { pureParser_ = nullptr; }
+    ~PureDocParser() override { pureParser_ = nullptr; }
 
     QStringList sourceFileNameFilter() override;
     void parseSourceFile(const Location &location, const QString &filePath) override;
diff --git a/src/qdoc/qmlcodemarker.h b/src/qdoc/qmlcodemarker.h
index 76df699b3..e28d46309 100644
--- a/src/qdoc/qmlcodemarker.h
+++ b/src/qdoc/qmlcodemarker.h
@@ -47,7 +47,7 @@ class QmlCodeMarker : public CppCodeMarker
 
 public:
     QmlCodeMarker();
-    ~QmlCodeMarker();
+    ~QmlCodeMarker() override;
 
     bool recognizeCode(const QString &code) override;
     bool recognizeExtension(const QString &ext) override;
diff --git a/src/qdoc/qmlcodeparser.h b/src/qdoc/qmlcodeparser.h
index 8ccc06160..85923137b 100644
--- a/src/qdoc/qmlcodeparser.h
+++ b/src/qdoc/qmlcodeparser.h
@@ -55,7 +55,7 @@ class QmlCodeParser : public CodeParser
 
 public:
     QmlCodeParser();
-    virtual ~QmlCodeParser();
+    ~QmlCodeParser() override;
 
     void initializeParser(const Config &config) override;
     void terminateParser() override;
diff --git a/src/qdoc/qmlvisitor.h b/src/qdoc/qmlvisitor.h
index c30b08350..fae02c1e2 100644
--- a/src/qdoc/qmlvisitor.h
+++ b/src/qdoc/qmlvisitor.h
@@ -66,7 +66,7 @@ public:
                   QQmlJS::Engine *engine,
                   const QSet<QString> &commands,
                   const QSet<QString> &topics);
-    virtual ~QmlDocVisitor();
+    ~QmlDocVisitor() override;
 
     bool visit(QQmlJS::AST::UiImport *import) override;
     void endVisit(QQmlJS::AST::UiImport *definition) override;
diff --git a/src/qdoc/webxmlgenerator.h b/src/qdoc/webxmlgenerator.h
index 2cfd81b8e..b52ffb398 100644
--- a/src/qdoc/webxmlgenerator.h
+++ b/src/qdoc/webxmlgenerator.h
@@ -42,7 +42,6 @@ class WebXMLGenerator : public HtmlGenerator, public IndexSectionWriter
 {
 public:
     explicit WebXMLGenerator() {}
-    ~WebXMLGenerator() {}
 
     void initializeGenerator(const Config &config) override;
     void terminateGenerator() override;