C.128 override, virtual keyword handling

Summary:
According to [C128] "Virtual functions should specify exactly one
of `virtual`, `override`, or `final`", I've added override where a
virtual function is overriden but the explicit `override` keyword
was missing. Whenever both `virtual` and `override` were specified,
I removed `virtual`. As C.128 puts it:

> [...] writing more than one of these three is both redundant and
> a potential source of errors.

I anticipate a discussion about whether or not to add `override` to
destructors but I went for it because of an example in [ISOCPP1000].
Let me repeat the comment for you here:

Consider this code:

```
    struct Base {
      virtual ~Base(){}
    };

    struct SubClass : Base {
      ~SubClass() {
        std::cout << "It works!\n";
      }
    };

    int main() {
      std::unique_ptr<Base> ptr = std::make_unique<SubClass>();
    }
```

If for some odd reason somebody removes the `virtual` keyword from the
`Base` struct, the code will no longer print `It works!`. So adding
`override` to destructors actively protects us from accidentally
breaking our code at runtime.

[C128]: https://github.com/isocpp/CppCoreGuidelines/blob/master/CppCoreGuidelines.md#c128-virtual-functions-should-specify-exactly-one-of-virtual-override-or-final
[ISOCPP1000]: https://github.com/isocpp/CppCoreGuidelines/issues/1000#issuecomment-476951555

Reviewers: teemperor, JDevlieghere, davide, shafik

Reviewed By: teemperor

Subscribers: kwk, arphaman, kadircet, lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D61440

llvm-svn: 359868
diff --git a/lldb/source/API/SBBreakpointOptionCommon.h b/lldb/source/API/SBBreakpointOptionCommon.h
index b030cc0..52049e4 100644
--- a/lldb/source/API/SBBreakpointOptionCommon.h
+++ b/lldb/source/API/SBBreakpointOptionCommon.h
@@ -24,7 +24,7 @@
   SBBreakpointCallbackBaton(SBBreakpointHitCallback callback,
                             void *baton);
 
-  ~SBBreakpointCallbackBaton();
+  ~SBBreakpointCallbackBaton() override;
 
   static bool PrivateBreakpointHitCallback(void *baton,
                                            lldb_private::StoppointCallbackContext *ctx,
diff --git a/lldb/source/Plugins/DynamicLoader/Darwin-Kernel/DynamicLoaderDarwinKernel.cpp b/lldb/source/Plugins/DynamicLoader/Darwin-Kernel/DynamicLoaderDarwinKernel.cpp
index ab1cd93..760f344 100644
--- a/lldb/source/Plugins/DynamicLoader/Darwin-Kernel/DynamicLoaderDarwinKernel.cpp
+++ b/lldb/source/Plugins/DynamicLoader/Darwin-Kernel/DynamicLoaderDarwinKernel.cpp
@@ -94,7 +94,7 @@
     m_collection_sp->Initialize(g_properties);
   }
 
-  virtual ~DynamicLoaderDarwinKernelProperties() {}
+  ~DynamicLoaderDarwinKernelProperties() override {}
 
   bool GetLoadKexts() const {
     const uint32_t idx = ePropertyLoadKexts;
diff --git a/lldb/source/Plugins/DynamicLoader/MacOSX-DYLD/DynamicLoaderDarwin.h b/lldb/source/Plugins/DynamicLoader/MacOSX-DYLD/DynamicLoaderDarwin.h
index 8f4c65d..aac0a5d 100644
--- a/lldb/source/Plugins/DynamicLoader/MacOSX-DYLD/DynamicLoaderDarwin.h
+++ b/lldb/source/Plugins/DynamicLoader/MacOSX-DYLD/DynamicLoaderDarwin.h
@@ -28,7 +28,7 @@
 public:
   DynamicLoaderDarwin(lldb_private::Process *process);
 
-  virtual ~DynamicLoaderDarwin() override;
+  ~DynamicLoaderDarwin() override;
 
   /// Called after attaching a process.
   ///
diff --git a/lldb/source/Plugins/DynamicLoader/MacOSX-DYLD/DynamicLoaderMacOS.h b/lldb/source/Plugins/DynamicLoader/MacOSX-DYLD/DynamicLoaderMacOS.h
index 1e965a5..9ccb3bc 100644
--- a/lldb/source/Plugins/DynamicLoader/MacOSX-DYLD/DynamicLoaderMacOS.h
+++ b/lldb/source/Plugins/DynamicLoader/MacOSX-DYLD/DynamicLoaderMacOS.h
@@ -32,7 +32,7 @@
 public:
   DynamicLoaderMacOS(lldb_private::Process *process);
 
-  virtual ~DynamicLoaderMacOS() override;
+  ~DynamicLoaderMacOS() override;
 
   // Static Functions
   static void Initialize();
diff --git a/lldb/source/Plugins/DynamicLoader/MacOSX-DYLD/DynamicLoaderMacOSXDYLD.h b/lldb/source/Plugins/DynamicLoader/MacOSX-DYLD/DynamicLoaderMacOSXDYLD.h
index 656a204..77c8209 100644
--- a/lldb/source/Plugins/DynamicLoader/MacOSX-DYLD/DynamicLoaderMacOSXDYLD.h
+++ b/lldb/source/Plugins/DynamicLoader/MacOSX-DYLD/DynamicLoaderMacOSXDYLD.h
@@ -36,7 +36,7 @@
 public:
   DynamicLoaderMacOSXDYLD(lldb_private::Process *process);
 
-  virtual ~DynamicLoaderMacOSXDYLD() override;
+  ~DynamicLoaderMacOSXDYLD() override;
 
   // Static Functions
   static void Initialize();
diff --git a/lldb/source/Plugins/ExpressionParser/Clang/ClangDiagnostic.h b/lldb/source/Plugins/ExpressionParser/Clang/ClangDiagnostic.h
index 30a7c93..db50c2a 100644
--- a/lldb/source/Plugins/ExpressionParser/Clang/ClangDiagnostic.h
+++ b/lldb/source/Plugins/ExpressionParser/Clang/ClangDiagnostic.h
@@ -33,7 +33,7 @@
                   uint32_t compiler_id)
       : Diagnostic(message, severity, eDiagnosticOriginClang, compiler_id) {}
 
-  virtual ~ClangDiagnostic() = default;
+  ~ClangDiagnostic() override = default;
 
   bool HasFixIts() const override { return !m_fixit_vec.empty(); }
 
diff --git a/lldb/source/Plugins/ExpressionParser/Clang/ClangExpressionParser.cpp b/lldb/source/Plugins/ExpressionParser/Clang/ClangExpressionParser.cpp
index 925ece5..e3b70fe 100644
--- a/lldb/source/Plugins/ExpressionParser/Clang/ClangExpressionParser.cpp
+++ b/lldb/source/Plugins/ExpressionParser/Clang/ClangExpressionParser.cpp
@@ -153,7 +153,7 @@
   }
 
   void HandleDiagnostic(DiagnosticsEngine::Level DiagLevel,
-                        const clang::Diagnostic &Info) {
+                        const clang::Diagnostic &Info) override {
     if (m_manager) {
       llvm::SmallVector<char, 32> diag_str;
       Info.FormatDiagnostic(diag_str);
@@ -719,7 +719,7 @@
   }
 
   /// Deregisters and destroys this code-completion consumer.
-  virtual ~CodeComplete() {}
+  ~CodeComplete() override {}
 
   /// \name Code-completion filtering
   /// Check if the result should be filtered out.
diff --git a/lldb/source/Plugins/Language/CPlusPlus/CPlusPlusLanguage.cpp b/lldb/source/Plugins/Language/CPlusPlus/CPlusPlusLanguage.cpp
index c2a09cb..44b9e5e 100644
--- a/lldb/source/Plugins/Language/CPlusPlus/CPlusPlusLanguage.cpp
+++ b/lldb/source/Plugins/Language/CPlusPlus/CPlusPlusLanguage.cpp
@@ -914,7 +914,7 @@
 std::unique_ptr<Language::TypeScavenger> CPlusPlusLanguage::GetTypeScavenger() {
   class CPlusPlusTypeScavenger : public Language::ImageListTypeScavenger {
   public:
-    virtual CompilerType AdjustForInclusion(CompilerType &candidate) override {
+    CompilerType AdjustForInclusion(CompilerType &candidate) override {
       LanguageType lang_type(candidate.GetMinimumLanguage());
       if (!Language::LanguageIsC(lang_type) &&
           !Language::LanguageIsCPlusPlus(lang_type))
diff --git a/lldb/source/Plugins/Language/ObjC/NSDictionary.h b/lldb/source/Plugins/Language/ObjC/NSDictionary.h
index e69582d..ecb3fcc 100644
--- a/lldb/source/Plugins/Language/ObjC/NSDictionary.h
+++ b/lldb/source/Plugins/Language/ObjC/NSDictionary.h
@@ -51,8 +51,8 @@
     class Prefix : public Matcher {
     public:
       Prefix(ConstString p);
-      virtual ~Prefix() = default;
-      virtual bool Match(ConstString class_name) override;
+      ~Prefix() override = default;
+      bool Match(ConstString class_name) override;
 
     private:
       ConstString m_prefix;
@@ -60,8 +60,8 @@
     class Full : public Matcher {
     public:
       Full(ConstString n);
-      virtual ~Full() = default;
-      virtual bool Match(ConstString class_name) override;
+      ~Full() override = default;
+      bool Match(ConstString class_name) override;
 
     private:
       ConstString m_name;
diff --git a/lldb/source/Plugins/Language/ObjC/ObjCLanguage.cpp b/lldb/source/Plugins/Language/ObjC/ObjCLanguage.cpp
index ad29534..45cb485 100644
--- a/lldb/source/Plugins/Language/ObjC/ObjCLanguage.cpp
+++ b/lldb/source/Plugins/Language/ObjC/ObjCLanguage.cpp
@@ -994,7 +994,7 @@
   
   class ObjCDebugInfoScavenger : public Language::ImageListTypeScavenger {
   public:
-    virtual CompilerType AdjustForInclusion(CompilerType &candidate) override {
+    CompilerType AdjustForInclusion(CompilerType &candidate) override {
       LanguageType lang_type(candidate.GetMinimumLanguage());
       if (!Language::LanguageIsObjC(lang_type))
         return CompilerType();
diff --git a/lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCRuntimeV2.cpp b/lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCRuntimeV2.cpp
index 9362eb2..9f2540f 100644
--- a/lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCRuntimeV2.cpp
+++ b/lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCRuntimeV2.cpp
@@ -2659,7 +2659,8 @@
 };
 
 class ObjCExceptionThrowFrameRecognizer : public StackFrameRecognizer {
-  lldb::RecognizedStackFrameSP RecognizeFrame(lldb::StackFrameSP frame) {
+  lldb::RecognizedStackFrameSP
+  RecognizeFrame(lldb::StackFrameSP frame) override {
     return lldb::RecognizedStackFrameSP(
         new ObjCExceptionRecognizedStackFrame(frame));
   };
diff --git a/lldb/source/Plugins/LanguageRuntime/RenderScript/RenderScriptRuntime/RenderScriptExpressionOpts.h b/lldb/source/Plugins/LanguageRuntime/RenderScript/RenderScriptRuntime/RenderScriptExpressionOpts.h
index 00425b7..3ec4e37 100644
--- a/lldb/source/Plugins/LanguageRuntime/RenderScript/RenderScriptRuntime/RenderScriptExpressionOpts.h
+++ b/lldb/source/Plugins/LanguageRuntime/RenderScript/RenderScriptRuntime/RenderScriptExpressionOpts.h
@@ -34,7 +34,7 @@
   RenderScriptRuntimeModulePass(const lldb_private::Process *process)
       : ModulePass(ID), m_process_ptr(process) {}
 
-  bool runOnModule(llvm::Module &module);
+  bool runOnModule(llvm::Module &module) override;
 
 private:
   const lldb_private::Process *m_process_ptr;
diff --git a/lldb/source/Plugins/ObjectFile/PECOFF/ObjectFilePECOFF.h b/lldb/source/Plugins/ObjectFile/PECOFF/ObjectFilePECOFF.h
index 3c8fba3..9b696de 100644
--- a/lldb/source/Plugins/ObjectFile/PECOFF/ObjectFilePECOFF.h
+++ b/lldb/source/Plugins/ObjectFile/PECOFF/ObjectFilePECOFF.h
@@ -113,7 +113,7 @@
 
   uint32_t GetDependentModules(lldb_private::FileSpecList &files) override;
 
-  virtual lldb_private::Address GetEntryPointAddress() override;
+  lldb_private::Address GetEntryPointAddress() override;
 
   lldb_private::Address GetBaseAddress() override;
 
diff --git a/lldb/source/Plugins/Platform/gdb-server/PlatformRemoteGDBServer.h b/lldb/source/Plugins/Platform/gdb-server/PlatformRemoteGDBServer.h
index 94d61bb..c774daa 100644
--- a/lldb/source/Plugins/Platform/gdb-server/PlatformRemoteGDBServer.h
+++ b/lldb/source/Plugins/Platform/gdb-server/PlatformRemoteGDBServer.h
@@ -33,7 +33,7 @@
 
   PlatformRemoteGDBServer();
 
-  virtual ~PlatformRemoteGDBServer();
+  ~PlatformRemoteGDBServer() override;
 
   // lldb_private::PluginInterface functions
   ConstString GetPluginName() override { return GetPluginNameStatic(); }
diff --git a/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp b/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp
index 890b536..db95d91 100644
--- a/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp
+++ b/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp
@@ -135,7 +135,7 @@
     m_collection_sp->Initialize(g_properties);
   }
 
-  virtual ~PluginProperties() {}
+  ~PluginProperties() override {}
 
   uint64_t GetPacketTimeout() {
     const uint32_t idx = ePropertyPacketTimeout;
@@ -5158,7 +5158,7 @@
     m_option_group.Finalize();
   }
 
-  ~CommandObjectProcessGDBRemoteSpeedTest() {}
+  ~CommandObjectProcessGDBRemoteSpeedTest() override {}
 
   Options *GetOptions() override { return &m_option_group; }
 
@@ -5209,7 +5209,7 @@
       : CommandObjectParsed(interpreter, "process plugin packet history",
                             "Dumps the packet history buffer. ", NULL) {}
 
-  ~CommandObjectProcessGDBRemotePacketHistory() {}
+  ~CommandObjectProcessGDBRemotePacketHistory() override {}
 
   bool DoExecute(Args &command, CommandReturnObject &result) override {
     const size_t argc = command.GetArgumentCount();
@@ -5240,7 +5240,7 @@
             "Maximum size that lldb will try to read/write one one chunk.",
             NULL) {}
 
-  ~CommandObjectProcessGDBRemotePacketXferSize() {}
+  ~CommandObjectProcessGDBRemotePacketXferSize() override {}
 
   bool DoExecute(Args &command, CommandReturnObject &result) override {
     const size_t argc = command.GetArgumentCount();
@@ -5282,7 +5282,7 @@
                             "stripped from the result.",
                             NULL) {}
 
-  ~CommandObjectProcessGDBRemotePacketSend() {}
+  ~CommandObjectProcessGDBRemotePacketSend() override {}
 
   bool DoExecute(Args &command, CommandReturnObject &result) override {
     const size_t argc = command.GetArgumentCount();
@@ -5333,7 +5333,7 @@
                          "encoded into a valid 'qRcmd' packet, sent and the "
                          "response will be printed.") {}
 
-  ~CommandObjectProcessGDBRemotePacketMonitor() {}
+  ~CommandObjectProcessGDBRemotePacketMonitor() override {}
 
   bool DoExecute(llvm::StringRef command,
                  CommandReturnObject &result) override {
@@ -5397,7 +5397,7 @@
                        interpreter)));
   }
 
-  ~CommandObjectProcessGDBRemotePacket() {}
+  ~CommandObjectProcessGDBRemotePacket() override {}
 };
 
 class CommandObjectMultiwordProcessGDBRemote : public CommandObjectMultiword {
@@ -5412,7 +5412,7 @@
         CommandObjectSP(new CommandObjectProcessGDBRemotePacket(interpreter)));
   }
 
-  ~CommandObjectMultiwordProcessGDBRemote() {}
+  ~CommandObjectMultiwordProcessGDBRemote() override {}
 };
 
 CommandObject *ProcessGDBRemote::GetPluginCommandObject() {
diff --git a/lldb/source/Plugins/Process/minidump/ProcessMinidump.cpp b/lldb/source/Plugins/Process/minidump/ProcessMinidump.cpp
index 5d32ba6..f59bd83 100644
--- a/lldb/source/Plugins/Process/minidump/ProcessMinidump.cpp
+++ b/lldb/source/Plugins/Process/minidump/ProcessMinidump.cpp
@@ -683,7 +683,7 @@
     m_option_group.Finalize();
   }
 
-  ~CommandObjectProcessMinidumpDump() {}
+  ~CommandObjectProcessMinidumpDump() override {}
 
   Options *GetOptions() override { return &m_option_group; }
 
@@ -813,7 +813,7 @@
         CommandObjectSP(new CommandObjectProcessMinidumpDump(interpreter)));
   }
 
-  ~CommandObjectMultiwordProcessMinidump() {}
+  ~CommandObjectMultiwordProcessMinidump() override {}
 };
 
 CommandObject *ProcessMinidump::GetPluginCommandObject() {
diff --git a/lldb/source/Plugins/StructuredData/DarwinLog/StructuredDataDarwinLog.cpp b/lldb/source/Plugins/StructuredData/DarwinLog/StructuredDataDarwinLog.cpp
index 3994dd0..81a2712 100644
--- a/lldb/source/Plugins/StructuredData/DarwinLog/StructuredDataDarwinLog.cpp
+++ b/lldb/source/Plugins/StructuredData/DarwinLog/StructuredDataDarwinLog.cpp
@@ -141,7 +141,7 @@
     m_collection_sp->Initialize(g_properties);
   }
 
-  virtual ~StructuredDataDarwinLogProperties() {}
+  ~StructuredDataDarwinLogProperties() override {}
 
   bool GetEnableOnStartup() const {
     const uint32_t idx = ePropertyEnableOnStartup;
diff --git a/lldb/source/Plugins/StructuredData/DarwinLog/StructuredDataDarwinLog.h b/lldb/source/Plugins/StructuredData/DarwinLog/StructuredDataDarwinLog.h
index 7ff3721..8fa1eed 100644
--- a/lldb/source/Plugins/StructuredData/DarwinLog/StructuredDataDarwinLog.h
+++ b/lldb/source/Plugins/StructuredData/DarwinLog/StructuredDataDarwinLog.h
@@ -65,7 +65,7 @@
 
   void ModulesDidLoad(Process &process, ModuleList &module_list) override;
 
-  ~StructuredDataDarwinLog();
+  ~StructuredDataDarwinLog() override;
 
 private:
   // Private constructors
diff --git a/lldb/source/Symbol/ClangASTContext.cpp b/lldb/source/Symbol/ClangASTContext.cpp
index 726963f..22c9a70 100644
--- a/lldb/source/Symbol/ClangASTContext.cpp
+++ b/lldb/source/Symbol/ClangASTContext.cpp
@@ -951,7 +951,7 @@
   }
 
   void HandleDiagnostic(DiagnosticsEngine::Level DiagLevel,
-                        const clang::Diagnostic &info) {
+                        const clang::Diagnostic &info) override {
     if (m_log) {
       llvm::SmallVector<char, 32> diag_str(10);
       info.FormatDiagnostic(diag_str);
diff --git a/lldb/source/Symbol/PostfixExpression.cpp b/lldb/source/Symbol/PostfixExpression.cpp
index df51288..9b6108c 100644
--- a/lldb/source/Symbol/PostfixExpression.cpp
+++ b/lldb/source/Symbol/PostfixExpression.cpp
@@ -124,23 +124,23 @@
   using Visitor<>::Dispatch;
 
 private:
-  void Visit(BinaryOpNode &binary, Node *&);
+  void Visit(BinaryOpNode &binary, Node *&) override;
 
-  void Visit(InitialValueNode &val, Node *&);
+  void Visit(InitialValueNode &val, Node *&) override;
 
-  void Visit(IntegerNode &integer, Node *&) {
+  void Visit(IntegerNode &integer, Node *&) override {
     m_out_stream.PutHex8(DW_OP_constu);
     m_out_stream.PutULEB128(integer.GetValue());
     ++m_stack_depth;
   }
 
-  void Visit(RegisterNode &reg, Node *&);
+  void Visit(RegisterNode &reg, Node *&) override;
 
-  void Visit(SymbolNode &symbol, Node *&) {
+  void Visit(SymbolNode &symbol, Node *&) override {
     llvm_unreachable("Symbols should have been resolved by now!");
   }
 
-  void Visit(UnaryOpNode &unary, Node *&);
+  void Visit(UnaryOpNode &unary, Node *&) override;
 
   Stream &m_out_stream;
 
diff --git a/lldb/source/Target/StructuredDataPlugin.cpp b/lldb/source/Target/StructuredDataPlugin.cpp
index 842708b..a22902d 100644
--- a/lldb/source/Target/StructuredDataPlugin.cpp
+++ b/lldb/source/Target/StructuredDataPlugin.cpp
@@ -23,7 +23,7 @@
                                "Parent for per-plugin structured data commands",
                                "plugin structured-data <plugin>") {}
 
-  ~CommandStructuredData() {}
+  ~CommandStructuredData() override {}
 };
 }