diff options
8 files changed, 114 insertions, 6 deletions
diff --git a/compiler/rustc_trait_selection/messages.ftl b/compiler/rustc_trait_selection/messages.ftl index 750d2756b4a..7c72318b4d7 100644 --- a/compiler/rustc_trait_selection/messages.ftl +++ b/compiler/rustc_trait_selection/messages.ftl @@ -165,6 +165,8 @@ trait_selection_explicit_lifetime_required_with_param_type = explicit lifetime r trait_selection_fn_consider_casting = consider casting the fn item to a fn pointer: `{$casting}` +trait_selection_fn_consider_casting_both = consider casting both fn items to fn pointers using `as {$sig}` + trait_selection_fn_uniq_types = different fn items have unique types, even if their signatures are the same trait_selection_fps_cast = consider casting to a fn pointer trait_selection_fps_cast_both = consider casting both fn items to fn pointers using `as {$expected_sig}` diff --git a/compiler/rustc_trait_selection/src/error_reporting/infer/mod.rs b/compiler/rustc_trait_selection/src/error_reporting/infer/mod.rs index 5f3f65e4696..9eacd377361 100644 --- a/compiler/rustc_trait_selection/src/error_reporting/infer/mod.rs +++ b/compiler/rustc_trait_selection/src/error_reporting/infer/mod.rs @@ -1844,7 +1844,7 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> { self.suggest_tuple_pattern(cause, &exp_found, diag); self.suggest_accessing_field_where_appropriate(cause, &exp_found, diag); self.suggest_await_on_expect_found(cause, span, &exp_found, diag); - self.suggest_function_pointers(cause, span, &exp_found, diag); + self.suggest_function_pointers(cause, span, &exp_found, terr, diag); self.suggest_turning_stmt_into_expr(cause, &exp_found, diag); } } diff --git a/compiler/rustc_trait_selection/src/error_reporting/infer/suggest.rs b/compiler/rustc_trait_selection/src/error_reporting/infer/suggest.rs index af7e56961b7..231fecf7a4a 100644 --- a/compiler/rustc_trait_selection/src/error_reporting/infer/suggest.rs +++ b/compiler/rustc_trait_selection/src/error_reporting/infer/suggest.rs @@ -12,6 +12,7 @@ use rustc_middle::traits::{ IfExpressionCause, MatchExpressionArmCause, ObligationCause, ObligationCauseCode, StatementAsExpression, }; +use rustc_middle::ty::error::TypeError; use rustc_middle::ty::print::with_no_trimmed_paths; use rustc_middle::ty::{self as ty, GenericArgKind, IsSuggestable, Ty, TypeVisitableExt}; use rustc_span::{Span, sym}; @@ -20,7 +21,7 @@ use tracing::debug; use crate::error_reporting::TypeErrCtxt; use crate::error_reporting::infer::hir::Path; use crate::errors::{ - ConsiderAddingAwait, FnConsiderCasting, FnItemsAreDistinct, FnUniqTypes, + ConsiderAddingAwait, FnConsiderCasting, FnConsiderCastingBoth, FnItemsAreDistinct, FnUniqTypes, FunctionPointerSuggestion, SuggestAccessingField, SuggestRemoveSemiOrReturnBinding, SuggestTuplePatternMany, SuggestTuplePatternOne, TypeErrorAdditionalDiags, }; @@ -381,14 +382,12 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> { } } - pub(super) fn suggest_function_pointers( + pub fn suggest_function_pointers_impl( &self, - cause: &ObligationCause<'tcx>, - span: Span, + span: Option<Span>, exp_found: &ty::error::ExpectedFound<Ty<'tcx>>, diag: &mut Diag<'_>, ) { - debug!("suggest_function_pointers(cause={:?}, exp_found={:?})", cause, exp_found); let ty::error::ExpectedFound { expected, found } = exp_found; let expected_inner = expected.peel_refs(); let found_inner = found.peel_refs(); @@ -411,6 +410,13 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> { return; } + let Some(span) = span else { + let casting = format!("{fn_name} as {sig}"); + diag.subdiagnostic(FnItemsAreDistinct); + diag.subdiagnostic(FnConsiderCasting { casting }); + return; + }; + let sugg = match (expected.is_ref(), found.is_ref()) { (true, false) => FunctionPointerSuggestion::UseRef { span, fn_name }, (false, true) => FunctionPointerSuggestion::RemoveRef { span, fn_name }, @@ -445,6 +451,12 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> { } let fn_name = self.tcx.def_path_str_with_args(*did2, args2); + + let Some(span) = span else { + diag.subdiagnostic(FnConsiderCastingBoth { sig: *expected_sig }); + return; + }; + let sug = if found.is_ref() { FunctionPointerSuggestion::CastBothRef { span, @@ -488,6 +500,23 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> { }; } + pub(super) fn suggest_function_pointers( + &self, + cause: &ObligationCause<'tcx>, + span: Span, + exp_found: &ty::error::ExpectedFound<Ty<'tcx>>, + terr: TypeError<'tcx>, + diag: &mut Diag<'_>, + ) { + debug!("suggest_function_pointers(cause={:?}, exp_found={:?})", cause, exp_found); + + if exp_found.expected.peel_refs().is_fn() && exp_found.found.peel_refs().is_fn() { + self.suggest_function_pointers_impl(Some(span), exp_found, diag); + } else if let TypeError::Sorts(exp_found) = terr { + self.suggest_function_pointers_impl(None, &exp_found, diag); + } + } + pub fn should_suggest_as_ref_kind( &self, expected: Ty<'tcx>, diff --git a/compiler/rustc_trait_selection/src/error_reporting/traits/fulfillment_errors.rs b/compiler/rustc_trait_selection/src/error_reporting/traits/fulfillment_errors.rs index 5021fd8bf83..6d39cbce3b7 100644 --- a/compiler/rustc_trait_selection/src/error_reporting/traits/fulfillment_errors.rs +++ b/compiler/rustc_trait_selection/src/error_reporting/traits/fulfillment_errors.rs @@ -1969,6 +1969,7 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> { StringPart::highlighted(exp_found.found.to_string()), StringPart::normal("`"), ]); + self.suggest_function_pointers_impl(None, &exp_found, err); } true diff --git a/compiler/rustc_trait_selection/src/errors.rs b/compiler/rustc_trait_selection/src/errors.rs index 2dfa72972ba..c8672b9dbd2 100644 --- a/compiler/rustc_trait_selection/src/errors.rs +++ b/compiler/rustc_trait_selection/src/errors.rs @@ -1497,6 +1497,12 @@ pub struct FnConsiderCasting { } #[derive(Subdiagnostic)] +#[help(trait_selection_fn_consider_casting_both)] +pub struct FnConsiderCastingBoth<'a> { + pub sig: Binder<'a, FnSig<'a>>, +} + +#[derive(Subdiagnostic)] pub enum SuggestAccessingField<'a> { #[suggestion( trait_selection_suggest_accessing_field, diff --git a/tests/ui/did_you_mean/casting-fn-item-to-fn-pointer.rs b/tests/ui/did_you_mean/casting-fn-item-to-fn-pointer.rs new file mode 100644 index 00000000000..fa1663d49eb --- /dev/null +++ b/tests/ui/did_you_mean/casting-fn-item-to-fn-pointer.rs @@ -0,0 +1,9 @@ +//@ edition: 2021 + +fn foo() {} + +fn main() { + let _: Vec<(&str, fn())> = [("foo", foo)].into_iter().collect(); //~ ERROR + let _: Vec<fn()> = [foo].into_iter().collect(); //~ ERROR + let _: Vec<fn()> = Vec::from([foo]); //~ ERROR +} diff --git a/tests/ui/did_you_mean/casting-fn-item-to-fn-pointer.stderr b/tests/ui/did_you_mean/casting-fn-item-to-fn-pointer.stderr new file mode 100644 index 00000000000..d069d39514d --- /dev/null +++ b/tests/ui/did_you_mean/casting-fn-item-to-fn-pointer.stderr @@ -0,0 +1,59 @@ +error[E0277]: a value of type `Vec<(&str, fn())>` cannot be built from an iterator over elements of type `(&str, fn() {foo})` + --> $DIR/casting-fn-item-to-fn-pointer.rs:6:59 + | +LL | let _: Vec<(&str, fn())> = [("foo", foo)].into_iter().collect(); + | ^^^^^^^ value of type `Vec<(&str, fn())>` cannot be built from `std::iter::Iterator<Item=(&str, fn() {foo})>` + | + = help: the trait `FromIterator<(&_, fn() {foo})>` is not implemented for `Vec<(&str, fn())>` + but trait `FromIterator<(&_, fn())>` is implemented for it + = help: for that trait implementation, expected `fn()`, found `fn() {foo}` + = note: fn items are distinct from fn pointers + = help: consider casting the fn item to a fn pointer: `foo as fn()` +note: the method call chain might not have had the expected associated types + --> $DIR/casting-fn-item-to-fn-pointer.rs:6:47 + | +LL | let _: Vec<(&str, fn())> = [("foo", foo)].into_iter().collect(); + | -------------- ^^^^^^^^^^^ `Iterator::Item` is `(&str, fn() {foo})` here + | | + | this expression has type `[(&str, fn() {foo}); 1]` +note: required by a bound in `collect` + --> $SRC_DIR/core/src/iter/traits/iterator.rs:LL:COL + +error[E0277]: a value of type `Vec<fn()>` cannot be built from an iterator over elements of type `fn() {foo}` + --> $DIR/casting-fn-item-to-fn-pointer.rs:7:42 + | +LL | let _: Vec<fn()> = [foo].into_iter().collect(); + | ^^^^^^^ value of type `Vec<fn()>` cannot be built from `std::iter::Iterator<Item=fn() {foo}>` + | + = help: the trait `FromIterator<fn() {foo}>` is not implemented for `Vec<fn()>` + but trait `FromIterator<fn()>` is implemented for it + = help: for that trait implementation, expected `fn()`, found `fn() {foo}` + = note: fn items are distinct from fn pointers + = help: consider casting the fn item to a fn pointer: `foo as fn()` +note: the method call chain might not have had the expected associated types + --> $DIR/casting-fn-item-to-fn-pointer.rs:7:30 + | +LL | let _: Vec<fn()> = [foo].into_iter().collect(); + | ----- ^^^^^^^^^^^ `Iterator::Item` is `fn() {foo}` here + | | + | this expression has type `[fn() {foo}; 1]` +note: required by a bound in `collect` + --> $SRC_DIR/core/src/iter/traits/iterator.rs:LL:COL + +error[E0308]: mismatched types + --> $DIR/casting-fn-item-to-fn-pointer.rs:8:24 + | +LL | let _: Vec<fn()> = Vec::from([foo]); + | --------- ^^^^^^^^^^^^^^^^ expected `Vec<fn()>`, found `Vec<fn() {foo}>` + | | + | expected due to this + | + = note: expected struct `Vec<fn()>` + found struct `Vec<fn() {foo}>` + = note: fn items are distinct from fn pointers + = help: consider casting the fn item to a fn pointer: `foo as fn()` + +error: aborting due to 3 previous errors + +Some errors have detailed explanations: E0277, E0308. +For more information about an error, try `rustc --explain E0277`. diff --git a/tests/ui/typeck/issue-107775.stderr b/tests/ui/typeck/issue-107775.stderr index 180b0183a3f..dad7e1581e7 100644 --- a/tests/ui/typeck/issue-107775.stderr +++ b/tests/ui/typeck/issue-107775.stderr @@ -10,6 +10,8 @@ LL | Self { map } | = note: expected struct `HashMap<u16, fn(_) -> Pin<Box<(dyn Future<Output = ()> + Send + 'static)>>>` found struct `HashMap<{integer}, fn(_) -> Pin<Box<dyn Future<Output = ()> + Send>> {<Struct as Trait>::do_something::<'_>}>` + = note: fn items are distinct from fn pointers + = help: consider casting the fn item to a fn pointer: `<Struct as Trait>::do_something::<'_> as fn(u8) -> Pin<Box<(dyn Future<Output = ()> + Send + 'static)>>` error: aborting due to 1 previous error |