Any info on C++ class methods seems to be absent in a clangd index, while C functions are indexed properly

[Arech]

Hello dear maintainers of clangd.
This might be very well known to you, though I wasn't able to find mentions of it in docs and discussions/issues, - it seems that clangd-indexer create a database (binary/dex as well as yaml) where C-functions are properly described (signature, return types, possibly template arguments, etc), while C++ methods have only a name. Is it a bug or a feature? If it's the former, any change of fixing it soon?
Thanks!

Discussed in #1229

^{Originally posted by Arech July 27, 2022}
Hi!
Thank you for this fantastically interesting project!
I'm trying to find if it's possible to use clangd as kind of a database about a code in my sample C++ project. I've stumbled upon an issue I brought to the title - it looks like my clangd doesn't have any information about C++ methods (besides their name) in the database, while it has all the info (arguments, return type) for C-style (global?) functions. Is it expected for clangd toolset v14.0.3 (the latest compiled with tools I've found), or I'm doing something wrong?

My approach is:

1. generate compile_commands.json with

cmake -B %BUILD_DIR% -G Ninja -DCMAKE_EXPORT_COMPILE_COMMANDS=1

2. index with clangd-indexer.exe with

%LLVM_HOME%\clangd-indexer.exe --executor=all-TUs --enable-fs-discriminator --execute-concurrency=0
 --generate-merged-base-profiles --import-constants-with-refs --import-full-type-definitions
 --print-summary-global-ids --propagate-attrs --static-func-full-module-prefix
%BUILD_DIR%/compile_commands.json > %BUILD_DIR%/%INDEX_FILE%

(well, it seems that most of options doesn't affect the issue, since the output is the same if only --executor=all-TUs is specified - and without it I get a weird error, I don't know how to fix)

3. run clangd-index-server.exe with

%LLVM_HOME%\clangd-index-server.exe --server-address=%SERVER_ADDR% --log=verbose --trace-file=%TRACE_FILE% --pretty
 --enable-fs-discriminator --generate-merged-base-profiles --import-constants-with-refs --import-full-type-definitions
 --print-summary-global-ids --propagate-attrs --static-func-full-module-prefix
%INDEX_FILE% %PROJ_ROOT%

(well, almost the same here, only options up to --pretty seems to affect anything and the rest, though are printed with --help-hidden doesn't seem to do anything helpful to the issue, - I'm leaving it here just to show what I've already tried)

4. Explore FuzzyFindReply of the server using https://github.com/frabert/ClangQL (symbols -based table)

And what I get it is more-or-less complete information for C-style functions, like double std::log10(double), but I get only a symbol name and scope for C++ method, like std::vector::erase. Thought, each such symbol might have multiple entries, which I presume corresponds to a different function instantiation...

Also I verify the output by looking at the clangd-index-server log output, - there's indeed info for C-functions, but nothing for C++ methods, so it's likely not an issue of ClangQL...

Does such info exist in the clangd database at all? If yes, is it possible to fetch it and how exactly?

ADDED: reindexed into --format=yaml and unfortunately,no such info exist in the index file. C functions are fully specified, while C++ methods only have a name... Is it a bug, I presume?

Thank you!

[HighCommander4]

Linking to https://discourse.llvm.org/t/c-class-methods-info-in-clang-indexer-database/70764 where this has been discussed. I'm going to close this issue, any follow-up discussion can take place on Discourse or in #1229.