Get the use statements of a module in a way that paths can be resolved

[nicola-gigante]

Hi all,

I'm analyzing some Rust source code in a way that is mixed between semantic understanding and syntactic details.

I've come quite far since the last questions I posted here, everything is going great, congrats for awesome work! :D

Now, for ADTs, traits, impls etc. I've come to a use pattern where I find the hir object I need (e.g. a hir::Struct), extract the semantic info I need from there, then call sema.source(hir) to get the corresponding ast object and get the syntax from there.

Crucially, when I encounter a ast::Path, I can call sema.resolve_path to get back to the semantic elements, and it works because the ast objects come from sema.source() so Semantics "knows" about them. This is what I have understood so far about the usage of these things.

However, now I have to extract the use statements from the modules (as they are written in the source code, so syntactically).
hir::Module does not implement HasSource so the usual pattern does not work.

What comes closest is definition_source(), which gives me alternatives from where I can extract ast::Use items somehow.
But then, when I try to call resolve_path() on the paths coming from the UseTrees, I get the usual error:

Failed to lookup PATH@400..413 in this Semantics.
Make sure to only query nodes derived from this instance of Semantics.
root node:   SOURCE_FILE@0..3880
known nodes: 

So definition_source is not what I need.

But then how do I get to the use statements of a module in a way that allows me to use resolve_path()?

Any help is appreciated!

[ChayimFriedman2]

You can call semantics.module_definition_node().

[nicola-gigante]

Thanks!

That method returns a SyntaxNode, so should I be able to cast it to ast::Module?

[nicola-gigante]

I see it can be casted either to ast::Module or ast::SourceFile and it worked!