Implement a lint to warn about unused macro rules
This implements a new lint to warn about unused macro rules (arms/matchers), similar to the `unused_macros` lint added by #41907 that warns about entire macros.
```rust
macro_rules! unused_empty {
(hello) => { println!("Hello, world!") };
() => { println!("empty") }; //~ ERROR: 1st rule of macro `unused_empty` is never used
}
fn main() {
unused_empty!(hello);
}
```
Builds upon #96149 and #96156.
Fixes#73576
Begin fixing all the broken doctests in `compiler/`
Begins to fix#95994.
All of them pass now but 24 of them I've marked with `ignore HELP (<explanation>)` (asking for help) as I'm unsure how to get them to work / if we should leave them as they are.
There are also a few that I marked `ignore` that could maybe be made to work but seem less important.
Each `ignore` has a rough "reason" for ignoring after it parentheses, with
- `(pseudo-rust)` meaning "mostly rust-like but contains foreign syntax"
- `(illustrative)` a somewhat catchall for either a fragment of rust that doesn't stand on its own (like a lone type), or abbreviated rust with ellipses and undeclared types that would get too cluttered if made compile-worthy.
- `(not-rust)` stuff that isn't rust but benefits from the syntax highlighting, like MIR.
- `(internal)` uses `rustc_*` code which would be difficult to make work with the testing setup.
Those reason notes are a bit inconsistently applied and messy though. If that's important I can go through them again and try a more principled approach. When I run `rg '```ignore \(' .` on the repo, there look to be lots of different conventions other people have used for this sort of thing. I could try unifying them all if that would be helpful.
I'm not sure if there was a better existing way to do this but I wrote my own script to help me run all the doctests and wade through the output. If that would be useful to anyone else, I put it here: https://github.com/Elliot-Roberts/rust_doctest_fixing_tool
Add a new Rust attribute to support embedding debugger visualizers
Implemented [this RFC](https://github.com/rust-lang/rfcs/pull/3191) to add support for embedding debugger visualizers into a PDB.
Added a new attribute `#[debugger_visualizer]` and updated the `CrateMetadata` to store debugger visualizers for crate dependencies.
RFC: https://github.com/rust-lang/rfcs/pull/3191
Cleanup `DebuggerVisualizerFile` type and other minor cleanup of queries.
Merge the queries for debugger visualizers into a single query.
Revert move of `resolve_path` to `rustc_builtin_macros`. Update dependencies in Cargo.toml for `rustc_passes`.
Respond to PR comments. Load visualizer files into opaque bytes `Vec<u8>`. Debugger visualizers for dynamically linked crates should not be embedded in the current crate.
Update the unstable book with the new feature. Add the tracking issue for the debugger_visualizer feature.
Respond to PR comments and minor cleanups.
Change `span_suggestion` (and variants) to take `impl ToString` rather
than `String` for the suggested code, as this simplifies the
requirements on the diagnostic derive.
Signed-off-by: David Wood <david.wood@huawei.com>
The code currently ignores the actual delimiter on the RHS and fakes up
a `NoDelim`/`DelimSpan::dummy()` one. This commit changes it to use the
actual delimiter.
The commit also reorders the fields for the `Delimited` variant to match
the `Sequence` variant.
Create (unstable) 2024 edition
[On Zulip](https://rust-lang.zulipchat.com/#narrow/stream/213817-t-lang/topic/Deprecating.20macro.20scoping.20shenanigans/near/272860652), there was a small aside regarding creating the 2024 edition now as opposed to later. There was a reasonable amount of support and no stated opposition.
This change creates the 2024 edition in the compiler and creates a prelude for the 2024 edition. There is no current difference between the 2021 and 2024 editions. Cargo and other tools will need to be updated separately, as it's not in the same repository. This change permits the vast majority of work towards the next edition to proceed _now_ instead of waiting until 2024.
For sanity purposes, I've merged the "hello" UI tests into a single file with multiple revisions. Otherwise we'd end up with a file per edition, despite them being essentially identical.
````@rustbot```` label +T-lang +S-waiting-on-review
Not sure on the relevant team, to be honest.
Remove `<mbe::TokenTree as Clone>`
`mbe::TokenTree` doesn't really need to implement `Clone`, and getting rid of that impl leads to some speed-ups.
r? `@petrochenkov`
Loading the fallback bundle in compilation sessions that won't go on to
emit any errors unnecessarily degrades compile time performance, so
lazily create the Fluent bundle when it is first required.
Signed-off-by: David Wood <david.wood@huawei.com>
When a `macro_rules! foo { ... }` invocation is compiled the name used
is `foo`, not `macro_rules!`. This is different to all other macro
invocations, and confused me when I was inserted debugging println
statements for macro evaluation.
This commit changes it to `macro_rules` (or just `macro`), which is what
I expected. There are no externally visible changes.
expand: Remove `ParseSess::missing_fragment_specifiers`
It was used for deduplicating some errors for legacy code which are mostly deduplicated even without that, but at cost of global mutable state, which is not a good tradeoff.
cc https://github.com/rust-lang/rust/pull/95747#issuecomment-1091619403
r? ``@nnethercote``
Left overs of #95761
These are just nits. Feel free to close this PR if all modifications are not worth merging.
* `#![feature(decl_macro)]` is not needed anymore in `rustc_expand`
* `tuple_impls` does not require `$Tuple:ident`. I guess it is there to enhance readability?
r? ```@petrochenkov```
refactor: simplify few string related interactions
Few small optimizations:
check_doc_keyword: don't alloc string for emptiness check
check_doc_alias_value: get argument as Symbol to prevent needless string convertions
check_doc_attrs: don't alloc vec, iterate over slice.
replace as_str() check with symbol check
get_single_str_from_tts: don't prealloc string
trivial string to str replace
LifetimeScopeForPath::NonElided use Vec<Symbol> instead of Vec<String>
AssertModuleSource use FxHashSet<Symbol> instead of BTreeSet<String>
CrateInfo.crate_name replace FxHashMap<CrateNum, String> with FxHashMap<CrateNum, Symbol>
It was used for deduplicating some errors for legacy code which are mostly deduplicated even without that, but at cost of global mutable state, which is not a good tradeoff.
Remove explicit delimiter token trees from `Delimited`.
They were introduced by the final commit in #95159 and gave a
performance win. But since the introduction of `MatcherLoc` they are no
longer needed. This commit reverts that change, making the code a bit
simpler.
r? `@petrochenkov`
They were introduced by the final commit in #95159 and gave a
performance win. But since the introduction of `MatcherLoc` they are no
longer needed. This commit reverts that change, making the code a bit
simpler.
check_doc_alias_value: get argument as Symbol to prevent needless string convertions
check_doc_attrs: don't alloc vec, iterate over slice. Vec introduced in #83149, but no perf run posted on merge
replace as_str() check with symbol check
get_single_str_from_tts: don't prealloc string
trivial string to str replace
LifetimeScopeForPath::NonElided use Vec<Symbol> instead of Vec<String>
AssertModuleSource use BTreeSet<Symbol> instead of BTreeSet<String>
CrateInfo.crate_name replace FxHashMap<CrateNum, String> with FxHashMap<CrateNum, Symbol>
By heap allocating the argument within `NtPath`, `NtVis`, and `NtStmt`.
This slightly reduces cumulative and peak allocation amounts, most
notably on `deep-vector`.
Currently it's called in `parse_tt` every time a match rule is invoked.
This commit moves it so it's called instead once per match rule, in
`compile_declarative_macro. This is a performance win.
The commit also moves `compute_locs` out of `TtParser`, because there's
no longer any reason for it to be in there.
