mikros/rust
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Use structured suggestion for bad Fn traits

Browse Source
This commit is contained in:
Esteban Küber 2019-12-13 08:22:58 -08:00
parent 66ea471f9d
commit 8d316a5a67
5 changed files with 40 additions and 20 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

39
src/librustc_typeck/astconv.rs
View File

@ -4,9 +4,9 @@
use crate::hir::def::{CtorOf, DefKind, Res};
use crate::hir::def_id::DefId;
use crate::hir::print;
use crate::hir::ptr::P;
use crate::hir::HirVec;
use crate::hir::{self, ExprKind, GenericArg, GenericArgs};
use crate::hir::{self, ExprKind, GenericArg, GenericArgs, HirVec};
use crate::lint;
use crate::middle::lang_items::SizedTraitLangItem;
use crate::middle::resolve_lifetime as rl;
@ -1025,19 +1025,46 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
&& trait_segment.generic_args().parenthesized != trait_def.paren_sugar
{
// For now, require that parenthetical notation be used only with `Fn()` etc.
let (msg, help) = if trait_def.paren_sugar {
let (msg, sugg) = if trait_def.paren_sugar {
(
"the precise format of `Fn`-family traits' type parameters is subject to \
change",
Some("use parenthetical notation instead: `Fn(Foo, Bar) -> Baz`"),
Some(format!(
"{}{} -> {}",
trait_segment.ident,
trait_segment
.args
.as_ref()
.and_then(|args| args.args.get(0))
.and_then(|arg| match arg {
hir::GenericArg::Type(ty) => {
Some(print::to_string(print::NO_ANN, |s| s.print_type(ty)))
}
_ => None,
})
.unwrap_or_else(|| "()".to_string()),
trait_segment
.generic_args()
.bindings
.iter()
.filter_map(|b| match (b.ident.as_str() == "Output", &b.kind) {
(true, hir::TypeBindingKind::Equality { ty }) => {
Some(print::to_string(print::NO_ANN, |s| s.print_type(ty)))
}
_ => None,
})
.next()
.unwrap_or_else(|| "()".to_string()),
)),
)
} else {
("parenthetical notation is only stable when used with `Fn`-family traits", None)
};
let sess = &self.tcx().sess.parse_sess;
let mut err = feature_err(sess, sym::unboxed_closures, span, msg);
if let Some(help) = help {
err.help(help);
if let Some(sugg) = sugg {
let msg = "use parenthetical notation instead";
err.span_suggestion(span, msg, sugg, Applicability::MaybeIncorrect);
}
err.emit();
}

9
src/test/ui/feature-gates/feature-gate-unboxed-closures-manual-impls.stderr
View File

@ -38,11 +38,10 @@ error[E0658]: the precise format of `Fn`-family traits' type parameters is subje
--> $DIR/feature-gate-unboxed-closures-manual-impls.rs:9:6
|
LL | impl Fn<()> for Foo {
| ^^^^^^
| ^^^^^^ help: use parenthetical notation instead: `Fn() -> ()`
|
= note: for more information, see https://github.com/rust-lang/rust/issues/29625
= help: add `#![feature(unboxed_closures)]` to the crate attributes to enable
= help: use parenthetical notation instead: `Fn(Foo, Bar) -> Baz`
error[E0229]: associated type bindings are not allowed here
--> $DIR/feature-gate-unboxed-closures-manual-impls.rs:15:6
@ -54,21 +53,19 @@ error[E0658]: the precise format of `Fn`-family traits' type parameters is subje
--> $DIR/feature-gate-unboxed-closures-manual-impls.rs:21:6
|
LL | impl FnMut<()> for Bar {
| ^^^^^^^^^
| ^^^^^^^^^ help: use parenthetical notation instead: `FnMut() -> ()`
|
= note: for more information, see https://github.com/rust-lang/rust/issues/29625
= help: add `#![feature(unboxed_closures)]` to the crate attributes to enable
= help: use parenthetical notation instead: `Fn(Foo, Bar) -> Baz`
error[E0658]: the precise format of `Fn`-family traits' type parameters is subject to change
--> $DIR/feature-gate-unboxed-closures-manual-impls.rs:27:6
|
LL | impl FnOnce<()> for Baz {
| ^^^^^^^^^^
| ^^^^^^^^^^ help: use parenthetical notation instead: `FnOnce() -> ()`
|
= note: for more information, see https://github.com/rust-lang/rust/issues/29625
= help: add `#![feature(unboxed_closures)]` to the crate attributes to enable
= help: use parenthetical notation instead: `Fn(Foo, Bar) -> Baz`
error: aborting due to 8 previous errors

3
src/test/ui/feature-gates/feature-gate-unboxed-closures.stderr
View File

@ -11,11 +11,10 @@ error[E0658]: the precise format of `Fn`-family traits' type parameters is subje
--> $DIR/feature-gate-unboxed-closures.rs:5:6
|
LL | impl FnOnce<(u32, u32)> for Test {
| ^^^^^^^^^^^^^^^^^^
| ^^^^^^^^^^^^^^^^^^ help: use parenthetical notation instead: `FnOnce(u32, u32) -> ()`
|
= note: for more information, see https://github.com/rust-lang/rust/issues/29625
= help: add `#![feature(unboxed_closures)]` to the crate attributes to enable
= help: use parenthetical notation instead: `Fn(Foo, Bar) -> Baz`
error: aborting due to 2 previous errors

3
src/test/ui/issues/issue-23024.stderr
View File

@ -2,11 +2,10 @@ error[E0658]: the precise format of `Fn`-family traits' type parameters is subje
--> $DIR/issue-23024.rs:9:39
|
LL | println!("{:?}",(vfnfer[0] as dyn Fn)(3));
| ^^
| ^^ help: use parenthetical notation instead: `Fn() -> ()`
|
= note: for more information, see https://github.com/rust-lang/rust/issues/29625
= help: add `#![feature(unboxed_closures)]` to the crate attributes to enable
= help: use parenthetical notation instead: `Fn(Foo, Bar) -> Baz`
error[E0107]: wrong number of type arguments: expected 1, found 0
--> $DIR/issue-23024.rs:9:39

6
src/test/ui/unboxed-closures/unboxed-closure-sugar-not-used-on-fn.stderr
View File

@ -2,21 +2,19 @@ error[E0658]: the precise format of `Fn`-family traits' type parameters is subje
--> $DIR/unboxed-closure-sugar-not-used-on-fn.rs:3:17
|
LL | fn bar1(x: &dyn Fn<(), Output=()>) {
| ^^
| ^^ help: use parenthetical notation instead: `Fn() -> ()`
|
= note: for more information, see https://github.com/rust-lang/rust/issues/29625
= help: add `#![feature(unboxed_closures)]` to the crate attributes to enable
= help: use parenthetical notation instead: `Fn(Foo, Bar) -> Baz`
error[E0658]: the precise format of `Fn`-family traits' type parameters is subject to change
--> $DIR/unboxed-closure-sugar-not-used-on-fn.rs:7:28
|
LL | fn bar2<T>(x: &T) where T: Fn<()> {
| ^^
| ^^ help: use parenthetical notation instead: `Fn() -> ()`
|
= note: for more information, see https://github.com/rust-lang/rust/issues/29625
= help: add `#![feature(unboxed_closures)]` to the crate attributes to enable
= help: use parenthetical notation instead: `Fn(Foo, Bar) -> Baz`
error: aborting due to 2 previous errors