Include graph lookup should occur for source files as well as header files, when determining primary TU source file about vscode-cpptools

[sean-mcmanus]

It's creating a new TU for the #included .cpp files instead of using main.cpp's TU. @Colengms Do you know anything about this?

It works in VS (with a project).

[Colengms]

This is because the C/C++ Extension will currently assume that a file with a source extension such as .cpp can be interpreted independently, not as a header of another source file. We could improve this for your scenario by always performing a (costly) lookup to detect this scenario, when opening any file instead of just those with header extensions. We can use this issue to track implementing that.

[Sochsenfeld]

That makes sense, but i am still confused as to why it worked before. I have used this style for projects for a few years now and it always worked. I only noticed that when i opened the files independently the lookup does not work. But when i opened my projects as a whole workspace or as the whole folder the lookup worked. That made sense to me and I always assumed it was an IntelliSense feature to notice things within the workspace and that the other source files are included in the main.cpp. Could there be an explanation why it worked before?

[sean-mcmanus]

@Colengms This is a 1.19.4 regression, i.e. it works correctly with 1.18.5. @Sochsenfeld You should be able to downgrade to 1.18.5 and it should work.

[Sochsenfeld]

Amazing, thank you! That works for now!

[FrankHB]

@Colengms This is a 1.19.4 regression, i.e. it works correctly with 1.18.5. @Sochsenfeld You should be able to downgrade to 1.18.5 and it should work.

This also affects #include MACRO_NAME forms when the a file is included in the source (or the header file) designated by MACRO_NAME indirectly after macro expansion. However in this case the downgrade also does not work. The behavior is a slightly different: 1.18.5 would still generate further diagnostics about the failure on subsequent multiple #include MACRO_NAME lines, while 1.19.4 would only complain at the first line. Perhaps better a separate issue?

(NOTE: The value of includePath contains something like ${workspaceFolder}/**. Without ** there is no problem.)

[sean-mcmanus]

@Sochsenfeld @FrankHB Fixed with https://github.com/microsoft/vscode-cpptools/releases/tag/v1.19.5