Spruce up the diagnostics of some early lints
Implement the various "*(note to myself) in a follow-up PR we should turn parts of this message into a subdiagnostic (help msg or even struct sugg)*" drive-by comments I left in #124417 during my review.
For context, before #124417, only a few early lints touched/decorated/customized their diagnostic because the former API made it a bit awkward. Likely because of that, things that should've been subdiagnostics were just crammed into the primary message. This PR rectifies this.
Add tests for `-Zunpretty=expanded` ported from stringify's tests
This PR adds a new set of tests for the AST pretty-printer.
Previously, pretty-printer edge cases were tested by way of `stringify!` in [tests/ui/macros/stringify.rs](https://github.com/rust-lang/rust/blob/1.78.0/tests/ui/macros/stringify.rs), such as the tests added by 419b26931b and 527e2eac17.
Those tests will no longer provide effective coverage of the AST pretty-printer after #124141. `Nonterminal` and `TokenKind::Interpolated` are being removed, and a consequence is that `stringify!` will perform token stream pretty printing, instead of AST pretty printing, in all of the `stringify!` cases including $:expr and all other interpolations.
This PR adds 2 new ui tests with `compile-flags: -Zunpretty=expanded`:
- **tests/ui/unpretty/expanded-exhaustive.rs** — this test aims for exhaustive coverage of all the variants of `ExprKind`, `ItemKind`, `PatKind`, `StmtKind`, `TyKind`, and `VisibilityKind`. Some parts could use being fleshed out further, but the current state is roughly on par with what exists in the old stringify-based tests.
- **tests/ui/unpretty/expanded-interpolation.rs** — this test covers tricky macro metavariable edge cases that require the AST pretty printer to synthesize parentheses in order for the printed code to be valid Rust syntax.
r? `@nnethercote`
Fix println! ICE when parsing percent prefix number
This PR fixes#125002 ICE occurring, for example, with `println!("%100000", 1)` or `println!("% 100000", 1)`.
## Test Case/Change Explanation
The return type of `Num::from_str` has been changed to `Option<Self>` to handle errors when parsing large integers fails.
1. The first `println!` in the test case covers the change of the first `Num::from_str` usage in `format_foreign.rs:426`.
2. The second `println!` in the test case covers the change of the second `Num::from_str` usage in line 460.
3. The 3rd to 5th `Num::from_str` usages behave the same as before.
The 3rd usage would cause an ICE when `num > u16::MAX` in the previous version, but this commit does not include a fix for the ICE in `println!("{:100000$}")`. I think we need to emit an error in the compiler and have more discussion in another issue/PR.
Update `expr` matcher for Edition 2024 and add `expr_2021` nonterminal
This commit adds a new nonterminal `expr_2021` in macro patterns, and `expr_fragment_specifier_2024` feature flag.
This change also updates `expr` so that on Edition 2024 it will also match `const { ... }` blocks, while `expr_2021` preserves the current behavior of `expr`, matching expressions without `const` blocks.
Joint work with `@vincenzopalazzo.`
Issue #123742
Rename `${length()}` to `${len()}`
Implements the rename suggested in https://github.com/rust-lang/rust/pull/122808#issuecomment-2047722187
> I brought this up in the doc PR but it belongs here – `length` should probably be renamed `len` before stabilization. The latter is de facto standard in the standard library, whereas the former is only used in a single unstable API. These metafunctions aren’t library items of course, but should presumably still be consistent with established names.
r? `@c410-f3r`
Remove `NtIdent` and `NtLifetime`
This is one part of the bigger "remove `Nonterminal` and `TokenKind::Interpolated`" change drafted in #114647. More details in the individual commit messages.
r? `@petrochenkov`
This commit adds a new nonterminal `expr_2021` in macro patterns, and
`expr_fragment_specifier_2024` feature flag. For now, `expr` and
`expr_2021` are treated the same, but in future PRs we will update
`expr` to match to new grammar.
Co-authored-by: Vincezo Palazzo <vincenzopalazzodev@gmail.com>
This span records the declaration of the metavariable in the LHS of the macro.
It's used in a couple of error messages. Unfortunately, it gets in the way of
the long-term goal of removing `TokenKind::Interpolated`. So this commit
removes it, which degrades a couple of (obscure) error messages but makes
things simpler and enables the next commit.
* The WASI targets deal with the `main` symbol a bit differently than
native so some `codegen` and `assembly` tests have been ignored.
* All `ignore-emscripten` directives have been updated to
`ignore-wasm32` to be more clear that all wasm targets are ignored and
it's not just Emscripten.
* Most `ignore-wasm32-bare` directives are now gone.
* Some ignore directives for wasm were switched to `needs-unwind`
instead.
* Many `ignore-wasm32*` directives are removed as the tests work with
WASI as opposed to `wasm32-unknown-unknown`.
This commit is extracted from #122036 and adds a new directive to the
`compiletest` test runner, `//@ needs-threads`. This is intended to
capture the need that a target must implement threading to execute a
specific test, typically one that uses `std::thread`. This is primarily
done for WebAssembly targets which currently do not have threads by
default. This enables transitioning a lot of `//@ ignore-wasm*`-style
ignores into a more self-documenting `//@ needs-threads` directive.
Additionally the `wasm32-wasi-preview1-threads` target, for example,
does actually have threads, but isn't tested in CI at this time. This
change enables running these tests for that target, but not other wasm
targets.
macro_rules: Preserve all metavariable spans in a global side table
This PR preserves spans of `tt` metavariables used to pass tokens to declarative macros.
Such metavariable spans can then be used in span combination operations like `Span::to` to improve all kinds of diagnostics.
Spans of non-`tt` metavariables are currently kept in nonterminal tokens, but the long term plan is remove all nonterminal tokens from rustc parser and rely on the proc macro model with invisible delimiters (#114647, #67062).
In particular, `NtIdent` nonterminal (corresponding to `ident` metavariables) becomes easy to remove when this PR lands (#119412 does it).
The metavariable spans are kept in a global side table keyed by `Span`s of original tokens.
The alternative to the side table is keeping them in `SpanData` instead, but the performance regressions would be large because any spans from tokens passed to declarative macros would stop being inline and would work through span interner instead, and the penalty would be paid even if we never use the metavar span for the given original span.
(But also see the comment on `fn maybe_use_metavar_location` describing the map collision issues with the side table approach.)
There are also other alternatives - keeping the metavar span in `Token` or `TokenTree`, but associating it with `Span` itsel is the most natural choice because metavar spans are used in span combining operations, and those operations are not necessarily tied to tokens.
