Implement c_cpp_properties.json file generator fixes #1201

[nx10]

What problem did you solve?

This PR implements a command "Generate c_cpp_properties.json" that generates the file by collecting information from invoking the compiler and from the DESCRIPTION file.
This enables code completion, IntelliSense, etc. for C/C++ files in R packages.

The issue is described in more detail here: #1201

Demo

Code_rcwvV3zBYQ.mp4

TODO

• This seems to work under Windows and Ubuntu for the projects I tried it with, it should however be tested on more packages and platforms before it's merged.
• At some point it might make sense to suggest to the user to run this when the Makevars or DESCRIPTION files change.
• The command could be renamed to something like 'Configure R-extension for C/C++' to be more descriptive.

[nx10]

I just realized: With some packages you need to run ./configure before running the command (and might want to run ./cleanup after) in order to capture all includes and defines. I will add an automation of this later.

Should be working as expected now.

[renkun-ken]

I came across this tweet which points to /~https://github.com/r-lib/usethis/blob/main/R/vscode.R, but it does not look like general enough. Not sure if it is helpful here.

[nx10]

I came across this tweet which points to /~https://github.com/r-lib/usethis/blob/main/R/vscode.R, but it does not look like general enough. Not sure if it is helpful here.

Thanks, this captures LinkingTo detectives from the DESCRIPTION and general R paths, but this PR also compiles dummy files to capture everything in configure and Makevars (defines, local includes, system dependencies, ...). I imagine the usethis script is meant to be edited manually later.

(I'm not sure why the CI fails, it might be an unrelated issue)

[renkun-ken]

I tried it with latest httpgd on macOS, and the following file is produced (an empty includePath is present):

{
  "configurations": [
    {
      "name": "Mac",
      "defines": [
        "NDEBUG",
        "BOOST_NO_AUTO_PTR",
        "FMT_HEADER_ONLY"
      ],
      "includePath": [
        "${workspaceFolder}/src",
        "/Library/Frameworks/R.framework/Versions/4.2/Resources/include",
        "${workspaceFolder}/src/lib",
        "/usr/local/include",
        ""
      ],
      "compilerPath": "/usr/bin/clang++",
      "cStandard": "${default}",
      "cppStandard": "gnu++14",
      "intelliSenseMode": "macos-clang-x64"
    }
  ],
  "version": 4
}

with the following error:

[nx10]

I tried it with latest httpgd on macOS, and the following file is produced (an empty includePath is present):

{
  "configurations": [
    {
      "name": "Mac",
      "defines": [
        "NDEBUG",
        "BOOST_NO_AUTO_PTR",
        "FMT_HEADER_ONLY"
      ],
      "includePath": [
        "${workspaceFolder}/src",
        "/Library/Frameworks/R.framework/Versions/4.2/Resources/include",
        "${workspaceFolder}/src/lib",
        "/usr/local/include",
        ""
      ],
      "compilerPath": "/usr/bin/clang++",
      "cStandard": "${default}",
      "cppStandard": "gnu++14",
      "intelliSenseMode": "macos-clang-x64"
    }
  ],
  "version": 4
}

with the following error:

That has probably to do with the the escaping of the small R code that collects the library paths, I will put it in an R file shortly.

R code is executed at many parts of the extension in different ways, maybe there should be a unified interface for that. If I have time I will prepare a separate PR.

Edit: Should work now. Can you test again?

[renkun-ken]

If the command is executed in a package that does not require c/c++ compilation (e.g. lintr), the following error shows up:

It would be nice to have more understandable error messages regarding such case.

[nx10]

If the command is executed in a package that does not require c/c++ compilation (e.g. lintr), the following error shows up:

It would be nice to have more understandable error messages regarding such case.

This is a bug, even when no C/C++ is used, the action should generate a config as you should be able to run it prior to adding C/C++ files.

Can you try again? I don't get this error but have added stricter null checks everywhere (7d4ade3).

A bit off-topic but what's the consensus on tsconfig.json "compilerOptions": { "strict": true }?

[renkun-ken]

I tried it with httpgd, languageserver, and RMariaDB and all work nicely!

LGTM
Thanks for the nice work!

[nx10]

Thank you for your comments and the review!