`struct` pattern parsing and diagnostic tweaks
- Recover from struct parse error on match and point out missing match
body.
- Point at struct when finding non-identifier while parsing its fields.
- Add label to "expected identifier, found {}" error.
Fix#15980.
Treat #[path] files as mod.rs files
Fixes https://github.com/rust-lang/rust/issues/46936, cc @briansmith, @SergioBenitez, @nikomatsakis.
This (insta-stable) change treats files included via `#[path = "bla.rs"] mod foo;` as though they were `mod.rs` files. Namely, it allows them to include `mod` statements and looks for the child modules in sibling directories, rather than in relative `modname/childmodule.rs` files as happens for non-`mod.rs` files.
This change makes the `non_modrs_mods` feature backwards compatible with the existing usage in https://github.com/briansmith/ring, several versions of which are currently broken in beta. If we decide to merge, this change should be backported to beta.
cc https://github.com/rust-lang/rust/issues/37872
r? @jseyfried
fix the doc-comment-decoration-trimming edge-case rustdoc ICE
This `horizontal_trim` function strips the leading whitespace from
doc-comments that have a left-asterisk-margin:
```
/**
* You know what I mean—
*
* comments like this!
*/
```
The index of the column of asterisks is `i`, and if trimming is deemed
possible, we slice each line from `i+1` to the end of the line. But if, in
particular, `i` was 0 _and_ there was an empty line (as in the example
given in the reporting issue), we ended up panicking trying to slice an
empty string from 0+1 (== 1).
Let's tighten our check to say that we can't trim when `i` is even the same
as the length of the line, not just when it's greater. (Any such cases
would panic trying to slice `line` from `line.len()+1`.)
Resolves#47197.
Add help message for incorrect pattern syntax
When I was getting started with rust I often made the mistake of using `||` instead of `|` to match multiple patterns and spent a long time staring at my code wondering what was wrong.
for example:
```
fn main() {
let x = 1;
match x {
1 || 2 => println!("1 or 2"),
_ => println!("Something else"),
}
}
```
If you compile this with current rustc you will see
```
error: expected one of `...`, `..=`, `..`, `=>`, `if`, or `|`, found `||`
--> test.rs:5:11
|
5 | 1 || 2 => println!("1 or 2"),
| -^^ unexpected token
| |
| expected one of `...`, `..=`, `..`, `=>`, `if`, or `|` here
error: aborting due to previous error
```
With my proposed change it will show:
```
error: unexpected token `||` after pattern
--> test.rs:5:11
|
5 | 1 || 2 => println!("1 or 2"),
| ^^
|
= help: did you mean to use `|` to specify multiple patterns instead?
error: aborting due to previous error
```
- Recover from struct parse error on match and point out missing match
body.
- Point at struct when finding non-identifier while parsing its fields.
- Add label to "expected identifier, found {}" error.
This `horizontal_trim` function strips the leading whitespace from
doc-comments that have a left-asterisk-margin:
/**
* You know what I mean—
*
* comments like this!
*/
The index of the column of asterisks is `i`, and if trimming is deemed
possible, we slice each line from `i+1` to the end of the line. But if, in
particular, `i` was 0 _and_ there was an empty line (as in the example
given in the reporting issue), we ended up panicking trying to slice an
empty string from 0+1 (== 1).
Let's tighten our check to say that we can't trim when `i` is even the same
as the length of the line, not just when it's greater. (Any such cases
would panic trying to slice `line` from `line.len()+1`.)
Resolves#47197.
Allow lifetimes in macros
This is a resurrection of PR #41927 which was a resurrection of #33135, which is intended to fix#34303.
In short, this allows macros_rules! to use :lifetime as a matcher to match 'lifetimes.
Still to do:
- [x] Feature gate
Started rebasing @sgrif's PR #33135 off of current master. (Well, actually merging it into a new branch based off current master.)
The following files still need to be fixed or at least reviewed:
- `src/libsyntax/ext/tt/macro_parser.rs`: calls `Parser::parse_lifetime`, which doesn't exist anymore
- `src/libsyntax/parse/parser.rs`: @sgrif added an error message to `Parser::parse_lifetime`. Code has since been refactored, so I just took it out for now.
- `src/libsyntax/ext/tt/transcribe.rs`: This code has been refactored bigtime. Not sure whether @sgrif's changes here are still necessary. Took it out for this commit.
Do not emit type errors on recovered blocks
When a parse error occurs on a block, the parser will recover and create
a block with the statements collected until that point. Now a flag
stating that a recovery has been performed in this block is propagated
so that the type checker knows that the type of the block (which will be
identified as `()`) shouldn't be checked against the expectation to
reduce the amount of irrelevant diagnostic errors shown to the user.
Fix#44579.
When a parse error occurs on a block, the parser will recover and create
a block with the statements collected until that point. Now a flag
stating that a recovery has been performed in this block is propagated
so that the type checker knows that the type of the block (which will be
identified as `()`) shouldn't be checked against the expectation to
reduce the amount of irrelevant diagnostic errors shown to the user.
Generics refactoring (groundwork for const generics)
These changes were suggested by @eddyb.
After this change, the `Generics` contain one `Vec` of an enum for the generic parameters, rather than two separate `Vec`s for lifetime and type parameters. Type params and const params will need to be in a shared `Vec` to preserve their ordering, and moving lifetimes into the same `Vec` should simplify the code that processes `Generics`.
The Generics now contain one Vec of an enum for the generic parameters,
rather than two separate Vec's for lifetime and type parameters.
Additionally, places that previously used Vec<LifetimeDef> now use
Vec<GenericParam> instead.
syntax: Follow-up to the incorrect qpath recovery PR
cc https://github.com/rust-lang/rust/pull/46788
Add tests checking that "priority" of qpath recovery is higher than priority of unary and binary operators
Fix regressed parsing of paths with fn-like generic arguments
r? @estebank
Implement non-mod.rs mod statements
Fixes https://github.com/rust-lang/rust/issues/45385, cc https://github.com/rust-lang/rust/issues/44660
This will fail tidy right now because it doesn't recognize my UI tests as feature-gate tests. However, I'm not sure if compile-fail will work out either because compile-fail usually requires there to be error patterns in the top-level file, which isn't possible with this feature. What's the recommended way to handle this?
Modify message for keyword as identifier name
This is a temporary solution to #46311.
The message is generic enough to cover both cases and is probably a fine enough solution to the specific problem described in the task. However, the underlying reason for this to be wrong is that `next_token_inner` returns `Lifetime` even if the token is a label. That's not simple, as the syntax for both can be quite similar and it may need to take a look to the next token to make a decision. I'm not sure I have enough knowledge about the project to be able to solve that (yet!), so I thought I'll fix the immediate problem first.
Generic Associated Types Parsing & Name Resolution
Hi!
This PR adds parsing for generic associated types! 🎉🎉🎉
Tracking Issue: #44265
## Notes For Reviewers
* [x] I still need to add the stdout and stderr files to my ui tests. It takes me a *long* time to compile the compiler locally, so I'm going to add this as soon as possible in the next day or so.
* [ ] My current ui tests aren't very good or very thorough. I'm reusing the `parse_generics` and `parse_where_clause` methods from elsewhere in the parser, so my changes work without being particularly complex. I'm not sure if I should duplicate all of the generics test cases for generic associated types. It might actually be appropriate to duplicate everything here, since we don't want to rely on an implementation detail in case it changes in the future. If you think so too, I'll adapt all of the generics test cases into the generic associated types test cases.
* [ ] There is still more work required to make the run-pass tests pass here. In particular, we need to make the following errors disappear:
```
error[E0110]: lifetime parameters are not allowed on this type
--> ./src/test/run-pass/rfc1598-generic-associated-types/streaming_iterator.rs:23:41
|
23 | bar: <T as StreamingIterator>::Item<'static>,
| ^^^^^^^ lifetime parameter not allowed on this type
```
```
error[E0261]: use of undeclared lifetime name `'a`
--> ./src/test/run-pass/rfc1598-generic-associated-types/iterable.rs:15:47
|
15 | type Iter<'a>: Iterator<Item = Self::Item<'a>>;
| ^^ undeclared lifetime
```
There is a FIXME comment in streaming_iterator. If you uncomment that line, you get the following:
```
error: expected one of `!`, `+`, `,`, `::`, or `>`, found `=`
--> ./src/test/run-pass/rfc1598-generic-associated-types/streaming_iterator.rs:29:45
|
29 | fn foo<T: for<'a> StreamingIterator<Item<'a>=&'a [i32]>>(iter: T) { /* ... */ }
| ^ expected one of `!`, `+`, `,`, `::`, or `>` here
```
r? @nikomatsakis
