0b411f56e1
This is a pure refactoring split out from #80689. It represents the most invasive part of that PR, requiring changes in every caller of `parse_outer_attributes` In order to eagerly expand `#[cfg]` attributes while preserving the original `TokenStream`, we need to know the range of tokens that corresponds to every attribute target. This is accomplished by making `parse_outer_attributes` return an opaque `AttrWrapper` struct. An `AttrWrapper` must be converted to a plain `AttrVec` by passing it to `collect_tokens_trailing_token`. This makes it difficult to accidentally construct an AST node with attributes without calling `collect_tokens_trailing_token`, since AST nodes store an `AttrVec`, not an `AttrWrapper`. As a result, we now call `collect_tokens_trailing_token` for attribute targets which only support inert attributes, such as generic arguments and struct fields. Currently, the constructed `LazyTokenStream` is simply discarded. Future PRs will record the token range corresponding to the attribute target, allowing those tokens to be removed from an enclosing `collect_tokens_trailing_token` call if necessary. |
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| Cargo.toml | ||
| README.md | ||
The rustc_ast crate contains those things concerned purely with syntax
– that is, the AST ("abstract syntax tree"), parser, pretty-printer,
lexer, macro expander, and utilities for traversing ASTs.
For more information about how these things work in rustc, see the rustc dev guide: