bjoernager/rust
bjoernager/rust
1
Fork 0
Code Activity

Keep track of patterns that could have introduced a binding, but didn't

Browse source 
When we recover from a pattern parse error, or a pattern uses `..`, we keep track of that and affect resolution error for missing bindings that could have been provided by that pattern. We differentiate between `..` and parse recovery. We silence resolution errors likely caused by the pattern parse error.

```
error[E0425]: cannot find value `title` in this scope
  --> $DIR/struct-pattern-with-missing-fields-resolve-error.rs:19:30
   |
LL |         println!("[{}]({})", title, url);
   |                              ^^^^^ not found in this scope
   |
note: `Website` has a field `title` which could have been included in this pattern, but it wasn't
  --> $DIR/struct-pattern-with-missing-fields-resolve-error.rs:17:12
   |
LL | / struct Website {
LL | |     url: String,
LL | |     title: Option<String> ,
   | |     ----- defined here
LL | | }
   | |_-
...
LL |       if let Website { url, .. } = website {
   |              ^^^^^^^^^^^^^^^^^^^ this pattern doesn't include `title`, which is available in `Website`
```

Fix #74863.
This commit is contained in:
Esteban Küber 2024-12-13 21:51:33 +00:00
parent 21fe748be1
commit 0f82cfffda
8 changed files with 158 additions and 7 deletions
Download patch file Download diff file Expand all files Collapse all files

22
tests/ui/pattern/struct-pattern-with-missing-fields-resolve-error.rs Normal file
View file

@ -0,0 +1,22 @@
struct Website {
url: String,
title: Option<String> ,//~ NOTE defined here
}
fn main() {
let website = Website {
url: "http://www.example.com".into(),
title: Some("Example Domain".into()),
};
if let Website { url, Some(title) } = website { //~ ERROR expected `,`
//~^ NOTE while parsing the fields for this pattern
println!("[{}]({})", title, url); // we hide the errors for `title` and `url`
}
if let Website { url, .. } = website { //~ NOTE `Website` has a field `title`
//~^ NOTE this pattern
println!("[{}]({})", title, url); //~ ERROR cannot find value `title` in this scope
//~^ NOTE not found in this scope
}
}

30
tests/ui/pattern/struct-pattern-with-missing-fields-resolve-error.stderr Normal file
View file

@ -0,0 +1,30 @@
error: expected `,`
--> $DIR/struct-pattern-with-missing-fields-resolve-error.rs:12:31
|
LL | if let Website { url, Some(title) } = website {
| ------- ^
| |
| while parsing the fields for this pattern
error[E0425]: cannot find value `title` in this scope
--> $DIR/struct-pattern-with-missing-fields-resolve-error.rs:19:30
|
LL | println!("[{}]({})", title, url);
| ^^^^^ not found in this scope
|
note: `Website` has a field `title` which could have been included in this pattern, but it wasn't
--> $DIR/struct-pattern-with-missing-fields-resolve-error.rs:17:12
|
LL | / struct Website {
LL | | url: String,
LL | | title: Option<String> ,
| | ----- defined here
LL | | }
| |_-
...
LL | if let Website { url, .. } = website {
| ^^^^^^^^^^^^^^^^^^^ this pattern doesn't include `title`, which is available in `Website`
error: aborting due to 2 previous errors
For more information about this error, try `rustc --explain E0425`.