How to get LSP to work with *-inl.h files?

[nguyenvukhang]

In the areas of the codebase I've explored, I observe a pattern of having some *.h file, and then an accompanying *-inl.h file. Take for example cachelib/cachebench/cache/Cache.h and cachelib/cachebench/cache/Cache-inl.h.

Among the *.h and *-inl.h pairs I've seen so far, I notice that the *.h file is the one and only file in the codebase that includes (#include) the corresponding *-inl.h file. However, LSP servers don't understand this. When I open a *-inl.h file, the LSP server is at a loss of where to find declarations when I, as a human, know to look in the corresponding *.h file.

My current fix, with the clangd lsp, is to include a flag that no one would use such as __LSP_BE_HAPPY__ in a .clangd file at root:

CompileFlags:
  Add:
    - '-D__LSP_BE_HAPPY__'

and then manually make the following changes:

1. In Cache.h, make this edit:

   +#ifndef __LSP_BE_HAPPY__
    #include "cachelib/cachebench/cache/Cache-inl.h"
   +#endif

   To remove the recursion at LSP-analysis time.
2. In Cache-inl.h, prepend it with a

   #include "cachelib/cachebench/cache/Cache.h"

   So that the LSP server knows where to look for declarations or other #includes.

However, one issue remains. When I go to reference or go to definition in Cache.h, LSP doesn't know to search in Cache-inl.h (because it's no longer included).

So my question is this: is there an existing practice on getting LSP servers to understand the specific relationship between these two files?