user settings C_Cpp > Default: Compiler Path behavior from setting empty string vs undefined

[snehara99]

Hi, so I noticed a possible bug or unexpected behavior regarding the compiler path settings while trying to repro a user issue on vscode-cmake-tools (3096):

If I remove the default compilerPath from my user settings.json completely (set undefined), compilerPathIsExplicit depends only on the compilerPath setting in c_cpp_properties.json. However, if the default compilerPath in user settings is set to an empty string rather than being undefined, compilerPathIsExplicit is always true.

I think this difference in behavior between the default compiler path in user settings being an empty string vs being undefined can be confusing, but I also understand this may be expected behavior. I just wanted to point it out.

However, I think a larger issue is when changing the default user settings via the UI rather than the settings.json file, an empty string versus undefined is indistinguishable. Erasing the default compiler path results in the default compiler path to be set to an empty string in the user settings.json file rather than undefined. I think this could cause unanticipated problems for users using the UI rather than the settings.json file.

I'm not sure if this is a bug, but I think it would help if some warning was given in the UI at least. Let me know if you'd like any clarification, thanks!

[browntarik]

This is by design but displaying a notification in the language status UI may be helpful.

[browntarik]

Since we need the VS Code UI to distinguish between an undefined or empty string for the optimal fix, we decided to keep this as known issue. This is a regression from an older fix we had for this issue so we may take a look at this as well.

[Colengms]

#10797 somewhat addresses the issue in VS Code's settings UI, but does not address the same issue in C/C++: Edit Configuration (UI).

[sean-mcmanus]

@Colengms So we should keep this issue open or create another issue for that or what?

[sean-mcmanus]

The settings UI issue is fixed with https://github.com/microsoft/vscode-cpptools/releases/tag/v1.15.2 . I'm not sure if we need another issue to track the Edit Configuration (UI) case or not (feel free to open a new issue if you want).