Don't make statement nonterminals match pattern nonterminals
Right now, the heuristic we use to check if a token may begin a pattern nonterminal falls back to `may_be_ident`:
ef71f1047e/compiler/rustc_parse/src/parser/nonterminal.rs (L21-L37)
This has the unfortunate side effect that a `stmt` nonterminal eagerly matches against a `pat` nonterminal, leading to a parse error:
```rust
macro_rules! m {
($pat:pat) => {};
($stmt:stmt) => {};
}
macro_rules! m2 {
($stmt:stmt) => {
m! { $stmt }
};
}
m2! { let x = 1 }
```
This PR fixes it by more accurately reflecting the set of nonterminals that may begin a pattern nonterminal.
As a side-effect, I modified `Token::can_begin_pattern` to work correctly and used that in `Parser::nonterminal_may_begin_with`.
Add `#[warn(unreachable_pub)]` to a bunch of compiler crates
By default `unreachable_pub` identifies things that need not be `pub` and tells you to make them `pub(crate)`. But sometimes those things don't need any kind of visibility. So they way I did these was to remove the visibility entirely for each thing the lint identifies, and then add `pub(crate)` back in everywhere the compiler said it was necessary. (Or occasionally `pub(super)` when context suggested that was appropriate.) Tedious, but results in more `pub` removal.
There are plenty more crates to do but this seems like enough for a first PR.
r? `@compiler-errors`
improve error message when `global_asm!` uses `asm!` options
specifically, what was
error: expected one of `)`, `att_syntax`, or `raw`, found `preserves_flags`
--> $DIR/bad-options.rs:45:25
|
LL | global_asm!("", options(preserves_flags));
| ^^^^^^^^^^^^^^^ expected one of `)`, `att_syntax`, or `raw`
is now
error: the `preserves_flags` option cannot be used with `global_asm!`
--> $DIR/bad-options.rs:45:25
|
LL | global_asm!("", options(preserves_flags));
| ^^^^^^^^^^^^^^^ the `preserves_flags` option is not meaningful for global-scoped inline assembly
mirroring the phrasing of the [reference](https://doc.rust-lang.org/reference/inline-assembly.html#options).
This is also a bit of a refactor for a future `naked_asm!` macro (for use in `#[naked]` functions). Currently this sort of error can come up when switching from inline to global asm, or when a user just isn't that experienced with assembly. With `naked_asm!` added to the mix hitting this error is more likely.
Rollup of 6 pull requests
Successful merges:
- #126908 (Use Cow<'static, str> for InlineAsmTemplatePiece::String)
- #127999 (Inject arm32 shims into Windows metadata generation)
- #128137 (CStr: derive PartialEq, Eq; add test for Ord)
- #128185 (Fix a span error when parsing a wrong param of function.)
- #128187 (Fix 1.80.0 version in RELEASES.md)
- #128189 (Turn an unreachable code path into an ICE)
r? `@ghost`
`@rustbot` modify labels: rollup
`#[naked]`: use an allowlist for allowed options on `asm!` in naked functions
tracking issue: https://github.com/rust-lang/rust/issues/90957
this is mostly just a refactor, but using an allowlist (rather than a denylist) for which asm options are allowed in naked functions is a little safer.
These options are disallowed because naked functions are effectively global asm, but defined using inline asm.
Some parser improvements
I was looking closely at attribute handling in the parser while debugging some issues relating to #124141, and found a few small improvements.
``@spastorino``
This commit does the following.
- Pulls the code out of `AttrTokenStream::to_token_trees` into a new
function `attrs_and_tokens_to_token_trees`.
- Simplifies `TokenStream::from_ast` by calling the new function. This
is nicer than the old way, which created a temporary
`AttrTokenStream` containing a single `AttrsTarget` (which required
some cloning) just to call `to_token_trees` on it. (It is good to
remove this use of `AttrsTarget` which isn't related to `cfg_attr`
expansion.)
The only place it is meaningfully used is in a panic message in
`TokenStream::from_ast`. But `node.span()` doesn't need to be printed
because `node` is also printed and it must contain the span.
Added dots at the sentence ends of rustc AST doc
Just a tiny improvement for the AST documentation by bringing consistency to sentence ends. I intentionally didn't terminate every sentence, there are still some members not having them, but at least there's no mixing style on the type level.
Match ergonomics 2024: Implement TC's match ergonomics proposal
Under gate `ref_pat_eat_one_layer_2024_structural`. Enabling `ref_pat_eat_one_layer_2024` at the same time allows the union of what the individual gates allow. `@traviscross`
r? `@Nadrieril`
cc https://github.com/rust-lang/rust/issues/123076
`@rustbot` label A-edition-2024 A-patterns
Parenthesize break values containing leading label
The AST pretty printer previously produced invalid syntax in the case of `break` expressions with a value that begins with a loop or block label.
```rust
macro_rules! expr {
($e:expr) => {
$e
};
}
fn main() {
loop {
break expr!('a: loop { break 'a 1; } + 1);
};
}
```
`rustc -Zunpretty=expanded main.rs `:
```console
#![feature(prelude_import)]
#![no_std]
#[prelude_import]
use ::std::prelude::rust_2015::*;
#[macro_use]
extern crate std;
macro_rules! expr { ($e:expr) => { $e }; }
fn main() { loop { break 'a: loop { break 'a 1; } + 1; }; }
```
The expanded code is not valid Rust syntax. Printing invalid syntax is bad because it blocks `cargo expand` from being able to format the output as Rust syntax using rustfmt.
```console
error: parentheses are required around this expression to avoid confusion with a labeled break expression
--> <anon>:9:26
|
9 | fn main() { loop { break 'a: loop { break 'a 1; } + 1; }; }
| ^^^^^^^^^^^^^^^^^^^^^^^^
|
help: wrap the expression in parentheses
|
9 | fn main() { loop { break ('a: loop { break 'a 1; }) + 1; }; }
| + +
```
This PR updates the AST pretty-printer to insert parentheses around the value of a `break` expression as required to avoid this edge case.
Currently it uses a mixture of functional style (`flat_map`) and
imperative style (`push`), which is a bit hard to read. This commit
converts it to fully imperative, which is more concise and avoids the
need for `smallvec`.
I.e. change the return type from `TokenStream` to `Vec<TokenTree>`.
Most of the callsites require a `TokenStream`, but the recursive call
used to create `target_tokens` requires a `Vec<TokenTree>`. It's easy
to convert a `Vec<TokenTree>` to a `TokenStream` (just call
`TokenStream::new`) but it's harder to convert a `TokenStream` to a
`Vec<TokenTree>` (either iterate/clone/collect, or use `Lrc::into_inner`
if appropriate).
So this commit changes the return value to simplify that `target_tokens`
call site.
