[clangd][misc-include-cleaner] quote includes are inserted instead of angle includes

[sengir]

My codebase uses angle includes for non-system includes. I have clangd configured with Style: QuotedHeaders and Style: AngledHeaders filters set up to ensure that inserted headers are using angle brackets. When headers are inserted due to a completion (Completion: HeaderInsertion: IWYU), they are correctly inserted as angle includes. However, when headers are added due to Diagnostics: MissingIncludes: Strict, they are inserted with quote includes. From a quick glance, it seems like this is due to IncludeCleaner not being aware of these {Quoted,Angled}Headers settings from clangd.

[llvmbot]

@llvm/issue-subscribers-clangd

Author: William Sengir (sengir)

My codebase uses angle includes for non-system includes. I have clangd configured with `Style: QuotedHeaders` and `Style: AngledHeaders` filters set up to ensure that inserted headers are using angle brackets. When headers are inserted due to a completion (`Completion: HeaderInsertion: IWYU`), they are correctly inserted as angle includes. However, when headers are added due to `Diagnostics: MissingIncludes: Strict`, they are inserted with quote includes. From a quick glance, it seems like this is due to IncludeCleaner not being aware of these `{Quoted,Angled}Headers` settings from clangd.

[HighCommander4]

Yeah, this is a known deficiency on the QuotedHeaders/AngledHeaders setting implementation.

When these settings were added in #67749, I pointed out during review that include-cleaner does not respect them, and requested that the patch be updated to address this. However, that never happened, and we ended up merging the PR without this.

A follow-up PR to implement include-cleaner support for these settings would be welcome.

(cc @kleinesfilmroellchen as the author of the original PR)

[llvmbot]

@llvm/issue-subscribers-clang-include-cleaner

Author: William Sengir (sengir)

My codebase uses angle includes for non-system includes. I have clangd configured with `Style: QuotedHeaders` and `Style: AngledHeaders` filters set up to ensure that inserted headers are using angle brackets. When headers are inserted due to a completion (`Completion: HeaderInsertion: IWYU`), they are correctly inserted as angle includes. However, when headers are added due to `Diagnostics: MissingIncludes: Strict`, they are inserted with quote includes. From a quick glance, it seems like this is due to IncludeCleaner not being aware of these `{Quoted,Angled}Headers` settings from clangd.

[kleinesfilmroellchen]

Always great how everyone cares about this issue but noone wants to fix it themselves.

[kadircet]

sorry for lack of attention here, some clues if anyone is interested to lower the barrier;

https://github.com/llvm/llvm-project/blob/main/clang-tools-extra/clangd/IncludeCleaner.cpp#L139-L153 is the place that receives the spelling from include-cleaner and turns it into a replacement. it also has access to paths of physical files.

it should be trivial to perform checks against configs and use quoted/angled includes if config says so, overwriting whatever include-cleaner chose underneath.

[Harald-R]

Created #140594 with a proposed fix for this issue. Tested locally with the example provided here. Reviews are welcome :)

The original PR also mentions a refactoring of the code to reduce duplication and have common code for all header insertion mechanisms. I am not yet familiar enough with the codebase to make this refactoring, so if people are okay with the fix, it could be included now and the refactoring could be done separately.