Collect definitions in the modules of a crate accounting for use statements

[nicola-gigante]

Hello there and season's greetings!

I'm using rust-analyzer's crates to analyze some Rust source code.

For each hir::Module of a crate, I use declarations() to get all the ModuleDefs and collecting them.
However, I would also need to get all the ways the same item is publicly visible from outside the crate accounting for pub use statements.

For example consider a library crate MyCrate with the following lib.rs:

mod MyModule {
    pub struct MyStruct { }
}

pub use MyModule::MyStruct;

From declarations() I get MyModule and MyStruct inside of it, but I need to account for the use statement somehow to realize that MyStruct is accessible from outside as MyCrate::MyStruct.

I see there's a scope() function in Module that seems to tell me the visible items but I'm unsure how I should use it for my purpose. It seems to list the items visible inside the module and not those visible from outside of it.

Any help is appreciated!

[ChayimFriedman2]

You can use the symbols database and filter imports:

rust-analyzer/crates/ide-db/src/symbol_index.rs

Line 135 in bbd40f8

pub fn world_symbols(db: &RootDatabase, query: Query) -> Vec<FileSymbol<'_>> {

[ChayimFriedman2]

I would answer your question, but now I re-read your original post and I see that you're doing this for all definitions in a crate. The symbols API is good for few items (as it can filter out most efficiently), but if you're visiting the whole crate you're better of just categorizing every import. It seems we don't currently directly expose an API for getting imports from a module, so you have two options:

• Use Module::scope(). It will include imports, but it will not distinguish between them and declarations. It seems this is fine for your use case, except you only need public imports. You can trick this method into providing only public items however: it takes a visible_from argument. If you will set it to the root module of a dependency of the crate (you can even create such dependency artificially), it will only provide public items.
• Alternatively, depend directly on hir-def. This is less recommended (the API is less stable) but more expressive. You will need to query the def map of the crate, and within the module call .scope.entries() to enumerate all definitions. The import field will tell you whether this is an import, including its visibility.

[nicola-gigante]

Thanks!

The second option seems more promising because I actually need to distinguish between imports and declarations.

Can you point me to an entry point of hir-def? How do I "query the def map of the crate"?

[nicola-gigante]

Oh I see the crate_def_map() function, I think it’s what I need. I’ll experiment a bit more. Thanks!

[ChayimFriedman2]

Yes, that is what you need.