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

4 files changed, 4 insertions, 4 deletions

diff --git a/lldb/source/Plugins/DynamicLoader/Darwin-Kernel/DynamicLoaderDarwinKernel.cpp b/lldb/source/Plugins/DynamicLoader/Darwin-Kernel/DynamicLoaderDarwinKernel.cpp
index ab1cd93e4e3..760f344e5ab 100644
--- a/lldb/source/Plugins/DynamicLoader/Darwin-Kernel/DynamicLoaderDarwinKernel.cpp
+++ b/lldb/source/Plugins/DynamicLoader/Darwin-Kernel/DynamicLoaderDarwinKernel.cpp
@@ -94,7 +94,7 @@ public:
     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 8f4c65da5d5..aac0a5dc26a 100644
--- a/lldb/source/Plugins/DynamicLoader/MacOSX-DYLD/DynamicLoaderDarwin.h
+++ b/lldb/source/Plugins/DynamicLoader/MacOSX-DYLD/DynamicLoaderDarwin.h
@@ -28,7 +28,7 @@ class DynamicLoaderDarwin : public lldb_private::DynamicLoader {
 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 1e965a52ce6..9ccb3bcbde1 100644
--- a/lldb/source/Plugins/DynamicLoader/MacOSX-DYLD/DynamicLoaderMacOS.h
+++ b/lldb/source/Plugins/DynamicLoader/MacOSX-DYLD/DynamicLoaderMacOS.h
@@ -32,7 +32,7 @@ class DynamicLoaderMacOS : public lldb_private::DynamicLoaderDarwin {
 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 656a2044c02..77c8209b4f5 100644
--- a/lldb/source/Plugins/DynamicLoader/MacOSX-DYLD/DynamicLoaderMacOSXDYLD.h
+++ b/lldb/source/Plugins/DynamicLoader/MacOSX-DYLD/DynamicLoaderMacOSXDYLD.h
@@ -36,7 +36,7 @@ class DynamicLoaderMacOSXDYLD : public lldb_private::DynamicLoaderDarwin {
 public:
   DynamicLoaderMacOSXDYLD(lldb_private::Process *process);
 
-  virtual ~DynamicLoaderMacOSXDYLD() override;
+  ~DynamicLoaderMacOSXDYLD() override;
 
   // Static Functions
   static void Initialize();