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, 4 insertions, 4 deletions

diff --git a/lldb/unittests/Process/gdb-remote/GDBRemoteClientBaseTest.cpp b/lldb/unittests/Process/gdb-remote/GDBRemoteClientBaseTest.cpp
index 477f65a59da..afba5c64266 100644
--- a/lldb/unittests/Process/gdb-remote/GDBRemoteClientBaseTest.cpp
+++ b/lldb/unittests/Process/gdb-remote/GDBRemoteClientBaseTest.cpp
@@ -29,11 +29,11 @@ struct MockDelegate : public GDBRemoteClientBase::ContinueDelegate {
   unsigned stop_reply_called = 0;
   std::vector<std::string> structured_data_packets;
 
-  void HandleAsyncStdout(llvm::StringRef out) { output += out; }
-  void HandleAsyncMisc(llvm::StringRef data) { misc_data += data; }
-  void HandleStopReply() { ++stop_reply_called; }
+  void HandleAsyncStdout(llvm::StringRef out) override { output += out; }
+  void HandleAsyncMisc(llvm::StringRef data) override { misc_data += data; }
+  void HandleStopReply() override { ++stop_reply_called; }
 
-  void HandleAsyncStructuredDataPacket(llvm::StringRef data) {
+  void HandleAsyncStructuredDataPacket(llvm::StringRef data) override {
     structured_data_packets.push_back(data);
   }
 };