[PATCH] D67025: Add .inl as valid C++ header type

[Sam McCall via Phabricator via cfe-commits]

sammccall added a comment.

(sorry i thought i sent these comments earlier)

This is a change to clang rather than clangd, so it affects the behavior of the compiler and other clang-based tools.
While it might do something useful in clangd, I'm skeptical of its general applicability because with this extension we do not expect that such files will be parseable.

I think the evidence you've found is that editors (e.g. clangd!) should handle these files, but not necessarily compilers.

> one has to add #include "header.hpp" at the top of .inl files to make it work but thats not a big deal.

It may not be a big burden to add it to code that you own, but making the compiler misinterpret other people's code where this #include isn't present can be a problem.

I think ideally we'd express this behavior at the clangd level instead. Something like "we suspect this file contains $LANGUAGE, so if the compile flags/extension don't imply anything particular, treat it that way".
As well as being less intrusive, this is a more general, useful feature:

- LSP allows the editor to specify the language, typically based in editor UI, so this would give the user control over whether such files were treated as C/C++/ObjC/ObjC++ etc rather than hard-coding C++. (We can still have a default).
- this needn't be specific to suffix ".inl". LLVM uses ".inc", I'm sure other codebases use other extensions.

(And the reason i never sent the comment is i couldn't come to a conclusion on the best way to do this inside clangd. Needs some more thought...)


Repository:
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  https://reviews.llvm.org/D67025/new/

https://reviews.llvm.org/D67025