Name resolution

[NalaGinrut]

The resolution rules are not well documented in Rust doc, the rustc relies on librustc_resolve.

I'm going to list all the rules here (or wiki) for the reference.

[NalaGinrut]

• Traverse AST top-down and resolve every encountered name.
• The situation that new scope should be added:
  • A block enclosing with curly braces
  • Let binding
  • Hygiene macro
• The rustc introduced a concept of Ribs to include all these kinds of scopes. Each Ribs maintain its own stack for storing the scopes. I think this can be implemented by a base class Scope. Maybe we don't have to reinvent a new concept.
• These items have their own namespace, so the identifier is NOT unique among them:
  • Types
  • Values
  • Macros.

[bjorn3]

The RFC for the current name resolution is: https://github.com/rust-lang/rfcs/blob/master/text/1560-name-resolution.md

[NalaGinrut]

Oh nice! That's what we need, I googled an obsoleted result. Thanks!

[NalaGinrut]

I think we should also add an option to dump the AST after the resolution, for debugging the resolution.

[philberty]

I agree we can reuse the same command line option and i think dumping to file would be really helpful aswell lets makea new issue to dump to file instead of console

[bjorn3]

Rustc has several versions of this: rustc -Zunpretty=help

[NalaGinrut]

@bjorn3 nice to know it, however, -Z seems only for nightly.

@philberty If you just want to output the current result to a file with an option, I think it's just a few lines code. It's possible to refactor the current dump framework to support multiple dump format, and even for a different stage of the pipeline, but I don't think it's our current work. Anyway it's a good idea to add to TODO.

[NalaGinrut]

The resolution relies on macro expansion, so I'm starting to work on macros parallelly. #17

[philberty]

Sorry for the closed issues i wanted to see if tagging commits linked them to issues but it seems to just close them instead