f0adebc39d
Add explanatory note to async block type mismatch error
The async block type mismatch error might leave the user wondering as to why it occurred. The new note should give them the needed context.
Changes this diagnostic:
```
error[E0308]: mismatched types
--> src/main.rs:5:23
|
2 | let a = async { 1 };
| ----------- the expected `async` block
3 | let b = async { 2 };
| ----------- the found `async` block
4 |
5 | let bad = vec![a, b];
| ^ expected `async` block, found a different `async` block
|
= note: expected `async` block `{async block@src/main.rs:2:13: 2:24}`
found `async` block `{async block@src/main.rs:3:13: 3:24}`
```
to this:
```
error[E0308]: mismatched types
--> src/main.rs:5:23
|
2 | let a = async { 1 };
| ----------- the expected `async` block
3 | let b = async { 2 };
| ----------- the found `async` block
4 |
5 | let bad = vec![a, b];
| ^ expected `async` block, found a different `async` block
|
= note: expected `async` block `{async block@src/main.rs:2:13: 2:24}`
found `async` block `{async block@src/main.rs:3:13: 3:24}`
= note: no two async blocks, even if identical, have the same type
= help: consider pinning your async block and and casting it to a trait object
```
Fixes #125737
UI Tests
This folder contains rustc's
UI tests.
Test Directives (Headers)
Typically, a UI test will have some test directives / headers which are special comments that tell compiletest how to build and intepret a test.
As part of an on-going effort to rewrite compiletest
(see https://github.com/rust-lang/compiler-team/issues/536), a major
change proposal to change legacy compiletest-style headers // <directive>
to ui_test-style headers
//@ <directive> was accepted (see
https://github.com/rust-lang/compiler-team/issues/512.
An example directive is ignore-test. In legacy compiletest style, the header
would be written as
// ignore-test
but in ui_test style, the header would be written as
//@ ignore-test
compiletest is changed to accept only //@ directives for UI tests
(currently), and will reject and report an error if it encounters any
comments // <content> that may be parsed as an legacy compiletest-style
test header. To fix this, you should migrate to the ui_test-style header
//@ <content>.