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

1 files changed, 8 insertions, 8 deletions

diff --git a/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp b/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp
index 890b5366020..db95d91449e 100644
--- a/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp
+++ b/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp
@@ -135,7 +135,7 @@ public:
     m_collection_sp->Initialize(g_properties);
   }
 
-  virtual ~PluginProperties() {}
+  ~PluginProperties() override {}
 
   uint64_t GetPacketTimeout() {
     const uint32_t idx = ePropertyPacketTimeout;
@@ -5158,7 +5158,7 @@ public:
     m_option_group.Finalize();
   }
 
-  ~CommandObjectProcessGDBRemoteSpeedTest() {}
+  ~CommandObjectProcessGDBRemoteSpeedTest() override {}
 
   Options *GetOptions() override { return &m_option_group; }
 
@@ -5209,7 +5209,7 @@ public:
       : 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 @@ public:
             "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 @@ public:
                             "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 @@ public:
                          "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 @@ public:
                        interpreter)));
   }
 
-  ~CommandObjectProcessGDBRemotePacket() {}
+  ~CommandObjectProcessGDBRemotePacket() override {}
 };
 
 class CommandObjectMultiwordProcessGDBRemote : public CommandObjectMultiword {
@@ -5412,7 +5412,7 @@ public:
         CommandObjectSP(new CommandObjectProcessGDBRemotePacket(interpreter)));
   }
 
-  ~CommandObjectMultiwordProcessGDBRemote() {}
+  ~CommandObjectMultiwordProcessGDBRemote() override {}
 };
 
 CommandObject *ProcessGDBRemote::GetPluginCommandObject() {