mirror of
https://github.com/rust-lang/rust.git
synced 2024-11-22 23:04:33 +00:00
8acbfe27d6
parser: provide better suggestions and errors on closures with braces missing
We currently provide wrong suggestions and unhelpful errors on closure bodies with braces missing.
For example, given the following code:
```rust
fn main() {
let _x = Box::new(|x|x+1;);
}
```
the current output is:
```
error: expected expression, found `)`
--> ./main.rs:2:30
|
2 | let _x = Box::new(|x|x+1;);
| ^ expected expression
error: closure bodies that contain statements must be surrounded by braces
--> ./main.rs:2:25
|
2 | let _x = Box::new(|x|x+1;);
| ^
3 | }
| ^
|
note: statement found outside of a block
--> ./main.rs:2:29
|
2 | let _x = Box::new(|x|x+1;);
| ---^ this `;` turns the preceding closure into a statement
| |
| this expression is a statement because of the trailing semicolon
note: the closure body may be incorrectly delimited
--> ./main.rs:2:23
|
2 | let _x = Box::new(|x|x+1;);
| ^^^^^^ this is the parsed closure...
3 | }
| - ...but likely you meant the closure to end here
help: try adding braces
|
2 ~ let _x = Box::new(|x| {x+1;);
3 ~ }}
|
error: expected `;`, found `}`
--> ./main.rs:2:32
|
2 | let _x = Box::new(|x|x+1;);
| ^ help: add `;` here
3 | }
| - unexpected token
error: aborting due to 3 previous errors
```
We got 3 errors, but all but the second are unnecessary or just wrong.
This commit allows outputting correct suggestions and errors. The above code would output like this:
```
error: closure bodies that contain statements must be surrounded by braces
--> ./main.rs:2:25
|
2 | let _x = Box::new(|x|x+1;);
| ^ ^
|
note: statement found outside of a block
--> ./main.rs:2:29
|
2 | let _x = Box::new(|x|x+1;);
| ---^ this `;` turns the preceding closure into a statement
| |
| this expression is a statement because of the trailing semicolon
note: the closure body may be incorrectly delimited
--> ./main.rs:2:23
|
2 | let _x = Box::new(|x|x+1;);
| ^^^^^^ - ...but likely you meant the closure to end here
| |
| this is the parsed closure...
help: try adding braces
|
2 | let _x = Box::new(|x| {x+1;});
| + +
error: aborting due to previous error
```
Fixes https://github.com/rust-lang/rust/issues/107959.
r? diagnostics
|
||
|---|---|---|
| .. | ||
| rustc | ||
| rustc_abi | ||
| rustc_apfloat | ||
| rustc_arena | ||
| rustc_ast | ||
| rustc_ast_lowering | ||
| rustc_ast_passes | ||
| rustc_ast_pretty | ||
| rustc_attr | ||
| rustc_baked_icu_data | ||
| rustc_borrowck | ||
| rustc_builtin_macros | ||
| rustc_codegen_cranelift | ||
| rustc_codegen_gcc | ||
| rustc_codegen_llvm | ||
| rustc_codegen_ssa | ||
| rustc_const_eval | ||
| rustc_data_structures | ||
| rustc_driver | ||
| rustc_driver_impl | ||
| rustc_error_codes | ||
| rustc_error_messages | ||
| rustc_errors | ||
| rustc_expand | ||
| rustc_feature | ||
| rustc_fs_util | ||
| rustc_graphviz | ||
| rustc_hir | ||
| rustc_hir_analysis | ||
| rustc_hir_pretty | ||
| rustc_hir_typeck | ||
| rustc_incremental | ||
| rustc_index | ||
| rustc_infer | ||
| rustc_interface | ||
| rustc_lexer | ||
| rustc_lint | ||
| rustc_lint_defs | ||
| rustc_llvm | ||
| rustc_log | ||
| rustc_macros | ||
| rustc_metadata | ||
| rustc_middle | ||
| rustc_mir_build | ||
| rustc_mir_dataflow | ||
| rustc_mir_transform | ||
| rustc_monomorphize | ||
| rustc_parse | ||
| rustc_parse_format | ||
| rustc_passes | ||
| rustc_plugin_impl | ||
| rustc_privacy | ||
| rustc_query_impl | ||
| rustc_query_system | ||
| rustc_resolve | ||
| rustc_serialize | ||
| rustc_session | ||
| rustc_smir | ||
| rustc_span | ||
| rustc_symbol_mangling | ||
| rustc_target | ||
| rustc_trait_selection | ||
| rustc_traits | ||
| rustc_transmute | ||
| rustc_ty_utils | ||
| rustc_type_ir | ||