Migrate "invalid variable declaration" errors to SessionDiagnostic
After seeing the great blog post on Inside Rust, I decided to try my hand at this. Just one diagnostic for now to get used to the workflow and to check if this is the way to do it or if there are any problems.
Fix documentation of rustc_parse::parser::Parser::parse_stmt_without_recovery
Something seems to have gotten out of sync during the creation of #81177, where both the argument and comment were introduced.
- Rename `ast::Lit::token` as `ast::Lit::token_lit`, because its type is
`token::Lit`, which is not a token. (This has been confusing me for a
long time.)
reasonable because we have an `ast::token::Lit` inside an `ast::Lit`.
- Rename `LitKind::{from,to}_lit_token` as
`LitKind::{from,to}_token_lit`, to match the above change and
`token::Lit`.
Adjust span of fn argument declaration
Span of a fn argument declaration goes from:
```
fn foo(i : i32 , ...)
^^^^^^^^
```
to:
```
fn foo(i : i32 , ...)
^^^^^^^
```
That is, we don't include the extra spacing up to the trailing comma, which I think is more correct.
cc https://github.com/rust-lang/rust/pull/99646#discussion_r944568074
r? ``@estebank``
---
The two tests that had dramatic changes in their rendering I think actually are improved, though they are kinda poor spans both before and after the changes. 🤷 Thoughts?
`Parser::parse_bottom_expr` currently constructs an empty `attrs` and
then passes it to a large number of other functions. This makes the code
harder to read than it should be, because it's not clear that many
`attrs` arguments are always empty.
This commit removes `attrs` and the passing, simplifying a lot of
functions. The commit also renames `Parser::mk_expr` (which takes an
`attrs` argument) as `mk_expr_with_attrs`, and introduces a new
`mk_expr` which creates an expression with no attributes, which is the
more common case.
Stringify non-shorthand visibility correctly
This makes `stringify!(pub(in crate))` evaluate to `pub(in crate)` rather than `pub(crate)`, matching the behavior before the `crate` shorthand was removed. Further, this changes `stringify!(pub(in super))` to evaluate to `pub(in super)` rather than the current `pub(super)`. If the latter is not desired (it is _technically_ breaking), it can be undone.
Fixes#99981
`@rustbot` label +C-bug +regression-from-stable-to-beta +T-compiler
Use `&mut Diagnostic` instead of `&mut DiagnosticBuilder` unless needed
This seems to be the established convention (02ff9e0) when `DiagnosticBuilder` was first added. I am guilty of introducing some of these.
Improve diagnostics for `const a: = expr;`
Adds a suggestion to write a type when there is a colon, but the type is not present.
I've also shrunk spans a little, so the suggestions are a little nicer.
Resolves#100146
r? `@compiler-errors`
Use Parser's `restrictions` instead of `let_expr_allowed`
This also means that the `ALLOW_LET` flag is reset properly for subexpressions, so we can properly deny things like `a && (b && let c = d)`. Also the parser is a tiny bit smaller now.
It doesn't reject _all_ bad `let` expr usages, just a bit more.
cc `@c410-f3r`
