Files
llvm/lldb/source/Target/StructuredDataPlugin.cpp
Raphael Isemann 1756630dfa 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
2019-05-03 10:03:28 +00:00

68 lines
2.3 KiB
C++

//===-- StructuredDataPlugin.cpp --------------------------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "lldb/Target/StructuredDataPlugin.h"
#include "lldb/Core/Debugger.h"
#include "lldb/Interpreter/CommandInterpreter.h"
#include "lldb/Interpreter/CommandObjectMultiword.h"
using namespace lldb;
using namespace lldb_private;
namespace {
class CommandStructuredData : public CommandObjectMultiword {
public:
CommandStructuredData(CommandInterpreter &interpreter)
: CommandObjectMultiword(interpreter, "structured-data",
"Parent for per-plugin structured data commands",
"plugin structured-data <plugin>") {}
~CommandStructuredData() override {}
};
}
StructuredDataPlugin::StructuredDataPlugin(const ProcessWP &process_wp)
: PluginInterface(), m_process_wp(process_wp) {}
StructuredDataPlugin::~StructuredDataPlugin() {}
bool StructuredDataPlugin::GetEnabled(ConstString type_name) const {
// By default, plugins are always enabled. Plugin authors should override
// this if there is an enabled/disabled state for their plugin.
return true;
}
ProcessSP StructuredDataPlugin::GetProcess() const {
return m_process_wp.lock();
}
void StructuredDataPlugin::InitializeBasePluginForDebugger(Debugger &debugger) {
// Create our mutliword command anchor if it doesn't already exist.
auto &interpreter = debugger.GetCommandInterpreter();
if (!interpreter.GetCommandObject("plugin structured-data")) {
// Find the parent command.
auto parent_command =
debugger.GetCommandInterpreter().GetCommandObject("plugin");
if (!parent_command)
return;
// Create the structured-data ommand object.
auto command_name = "structured-data";
auto command_sp = CommandObjectSP(new CommandStructuredData(interpreter));
// Hook it up under the top-level plugin command.
parent_command->LoadSubCommand(command_name, command_sp);
}
}
void StructuredDataPlugin::ModulesDidLoad(Process &process,
ModuleList &module_list) {
// Default implementation does nothing.
}