Generates problem markers for a C++ project using clang-tidy

[lmcbout]

Fixes #5532

Description

Run the C/C++ linting tool clang-tidy as a task to generate problem markers which can be later consumed by the problems-view.

Setup

1. Open a C/C++ project
2. Enable the preference cpp.clangTidy
3. • Test using the preference only: "cpp.clangTidyChecks": "*"
   • Test using the .clang-tidy file: create a clang-tidy file at the root of the workspace, and add the following:

Checks: "read*"
WarningsAsErrors: "hicpp-*"

This will verify the linter with the selected files for the "readability" flaws.
If you happen to test for "hicpp* warnings, they will be reported as errors
because of WarningsAsErrors: "hicpp-*"

How to Test

1. Create a tasks.json file under the directory .theia of the workspace.
2. Add the following task:

{
    "tasks": [
        {
            "label": "[Task] clang-tidy",
            "type": "shell",
            "cwd": "${workspaceFolder}",
            "command": "clang-tidy",
            "args": [
                "*"
            ],
            "options": {},
            "problemMatcher": [
                "$clangTidyMatcher"
            ]
        }
    ]
}

3. Run the task: F1 then Tasks: Run Tasks then shell: [Task] clang-tidy.

Additional Information

• Requires clang-tidy executable
• Requires clangd version 9 or later
• Note: If you add the file and the preference, the linter will merge the preference option with the file options. If you want to apply only the preference option even if the .clang-tidy is present, just put :
  "cpp.clangTidyChecks": "-*" will disable all default checks (-*) and add you choice of linter after, reference http://clang.llvm.org/extra/clang-tidy/

[vince-fugnitto]

You are missing a serviceIdentifier in your spec file:
https://travis-ci.org/theia-ide/theia/jobs/548224808#L5606

[vince-fugnitto]

Please rebase the original PR from @elaihau, the commit sha are different e16cfb5 vs e3ba87e

[vince-fugnitto]

@lmcbout can you provide a meaningful commit message?
I see that @elaihau's commit message is very detailed and it'd be nice if you commented on what your PR addresses, and provides as features.

[vince-fugnitto]

@lmcbout you are missing the updates to the cpp-task-provider.spec.ts test file to include the new service identifier symbol ProblemMatcherRegistry.

[elaihau]

I moved interfaces around in #5024. Some of the imports in this PR need update.

[vince-fugnitto]

I think the commit message needs updating, it isn't informative enough about the new functionality and is quite hard to follow:

clang-tidy uses the .clang-tidy file checks
When you define in "task.json" a problem matcher with "$clangTidyMatcher",
it creates an entry in the "problems" view with a tag: "clang-tidy-task"
The result in the "Problems" view is persistent until you
re-generates the task.

Something more appropriate may be:

Enable running the `clang-tidy` C/C++ linting present from clang-tidy as a task.
With the new updates, linting can be performed across an entire workspace using user
specified checks and linting rules. The problem markers collected when executing the
task will be recorded and displayed in the `problems-widget`...

and then you can finish up with the specifics you previously mentioned.

[vince-fugnitto]

@lmcbout can you re-push, it looks like the eca check didn't work?

[lmcbout]

@vince-fugnitto I just revalidate the ECA and all checks are green
Thanks for your input

[vince-fugnitto]

@lmcbout am I doing something wrong, I followed the task you provided in the description and it's not running at the moment.

[lmcbout]

@vince-fugnitto are you using clang version 9 ?

[vince-fugnitto]

@vince-fugnitto are you using clang version 9 ?

Yes, clangd version 9.0.0-svn362989-1~exp1+0~20190610220635.500~1.gbp18c431 (trunk)

[lmcbout]

@vince-fugnitto to run the task, you need to install "clang-tidy"
sudo apt-get install clang-tidy

Note: the task is using the program clang-tidy" and Theia is using "clang" version 9 with the preference setting

[vince-fugnitto]

@vince-fugnitto to run the task, you need to install "clang-tidy"
sudo apt-get install clang-tidy

Note: the task is using the program clang-tidy" and Theia is using "clang" version 9 with the preference setting

Clang-tidy is already there no?
You can see from the problems-widget.

[lmcbout]

No , you see two things in the problem marker:
1- [clang-tidy] which comes from clangd version 9 and the info is build from with the Theia preferences
2-[clang-tidy-task] is using clang-tidy executable, not using clangd -clang-tidy option

[vince-fugnitto]

to run the task, you need to install "clang-tidy"

If it is required to have clang-tidy as an executable then I believe it should be
reflected/documented somewhere.

[lmcbout]

Added a comment in the Readme.md file to install clang-tidy tool

[vince-fugnitto]

Added a comment in the Readme.md file to install clang-tidy tool

It's fine for linux but not other operating systems unfortunately.

[vince-fugnitto]

The PR works well, I had to update the task that was provided in the documentation to only lint the *.cpp files, I found it odd that the task would lint all files (even those that are not .cpp, .h) if not specified.

Maybe it'd be good another person tests as well, maybe @elaihau could you take a look too?

[lmcbout]

@vince-fugnitto I added some comments in the README file

[vince-fugnitto]

I won't comment anymore on the documentation :)
I'll take the time once the PR is complete to update the documentation for the cpp package more thoroughly.

[elaihau]

Tested in my local env with the help from Vincent.