Cancel unemitted diagnostics during error recovery
Follow up to https://github.com/rust-lang/rust/pull/62604. Use @eddyb's preferred style and catch other case of the same problem.
r? @eddyb
Fix#62660
If the explicitly given type of a `self` parameter fails to parse correctly, we need to propagate the error rather than dropping it and causing an ICE.
Fixes#62660.
Do not emit type errors after parse error in last statement of block
When recovering from a parse error inside a block, do not emit type
errors generating on that block's recovered return expression.
Fix#57383.
If the explicitly given type of a `self` parameter fails to parse correctly,
we need to propagate the error rather than dropping it and causing an ICE.
Fixes#62660.
Remove io::Result from syntax::print
Since we're now writing directly to the vector, there's no need to
thread results through the whole printing infrastructure
Remove `ast::Guard`
With the introduction of `ast::ExprKind::Let` in https://github.com/rust-lang/rust/pull/60861, the `ast::Guard` structure is now redundant in terms of representing [`if let` guards](https://github.com/rust-lang/rust/issues/51114) in AST since it can be represented by `ExprKind::Let` syntactically. Therefore, we remove `ast::Guard` here.
However, we keep `hir::Guard` because the semantic representation is a different matter and this story is more unclear right now (might involve `goto 'arm` in HIR or something...).
r? @petrochenkov
Special-case literals in `parse_bottom_expr`.
This makes parsing faster, particularly for code with large constants,
for two reasons:
- it skips all the keyword comparisons for literals;
- it skips the allocation done by the `mk_expr` call in
`parse_literal_maybe_minus`.
r? @petrochenkov
Allow attributes in formal function parameters
Implements https://github.com/rust-lang/rust/issues/60406.
This is my first contribution to the compiler and since this is a large and complex project, I am not fully aware of the consequences of the changes I have made.
**TODO**
- [x] Forbid some built-in attributes.
- [x] Expand cfg/cfg_attr
This makes parsing faster, particularly for code with large constants,
for two reasons:
- it skips all the keyword comparisons for literals;
- it replaces the unnecessary `parse_literal_maybe_minus` call with
`parse_lit`, avoiding an unnecessary allocation via `mk_expr`.
