From cef736f8a05bab8d9a16f7120b5800670ef768ee Mon Sep 17 00:00:00 2001 From: Hirochika Matsumoto Date: Sun, 26 Sep 2021 00:53:37 +0900 Subject: [PATCH] Suggest similarly named assoc items in trait impls Previously, the compiler didn't suggest similarly named associated items unlike we do in many situations. This patch adds such diagnostics for associated functions, types and constants. --- compiler/rustc_resolve/src/diagnostics.rs | 30 +++++++- compiler/rustc_resolve/src/late.rs | 28 +++++-- .../rustc_resolve/src/late/diagnostics.rs | 38 +++++++++- compiler/rustc_resolve/src/lib.rs | 6 +- src/test/ui/error-codes/E0407.stderr | 5 +- src/test/ui/hygiene/assoc_item_ctxt.stderr | 5 +- .../ui/suggestions/suggest-trait-items.rs | 48 ++++++++++++ .../ui/suggestions/suggest-trait-items.stderr | 74 +++++++++++++++++++ 8 files changed, 216 insertions(+), 18 deletions(-) create mode 100644 src/test/ui/suggestions/suggest-trait-items.rs create mode 100644 src/test/ui/suggestions/suggest-trait-items.stderr diff --git a/compiler/rustc_resolve/src/diagnostics.rs b/compiler/rustc_resolve/src/diagnostics.rs index 435c79d2daf45..b1d02f90be113 100644 --- a/compiler/rustc_resolve/src/diagnostics.rs +++ b/compiler/rustc_resolve/src/diagnostics.rs @@ -198,7 +198,7 @@ impl<'a> Resolver<'a> { err.span_label(first_use_span, format!("first use of `{}`", name)); err } - ResolutionError::MethodNotMemberOfTrait(method, trait_) => { + ResolutionError::MethodNotMemberOfTrait(method, trait_, candidate) => { let mut err = struct_span_err!( self.session, span, @@ -208,9 +208,17 @@ impl<'a> Resolver<'a> { trait_ ); err.span_label(span, format!("not a member of trait `{}`", trait_)); + if let Some(candidate) = candidate { + err.span_suggestion( + method.span, + "there is an associated function with a similar name", + candidate.to_ident_string(), + Applicability::MaybeIncorrect, + ); + } err } - ResolutionError::TypeNotMemberOfTrait(type_, trait_) => { + ResolutionError::TypeNotMemberOfTrait(type_, trait_, candidate) => { let mut err = struct_span_err!( self.session, span, @@ -220,9 +228,17 @@ impl<'a> Resolver<'a> { trait_ ); err.span_label(span, format!("not a member of trait `{}`", trait_)); + if let Some(candidate) = candidate { + err.span_suggestion( + type_.span, + "there is an associated type with a similar name", + candidate.to_ident_string(), + Applicability::MaybeIncorrect, + ); + } err } - ResolutionError::ConstNotMemberOfTrait(const_, trait_) => { + ResolutionError::ConstNotMemberOfTrait(const_, trait_, candidate) => { let mut err = struct_span_err!( self.session, span, @@ -232,6 +248,14 @@ impl<'a> Resolver<'a> { trait_ ); err.span_label(span, format!("not a member of trait `{}`", trait_)); + if let Some(candidate) = candidate { + err.span_suggestion( + const_.span, + "there is an associated constant with a similar name", + candidate.to_ident_string(), + Applicability::MaybeIncorrect, + ); + } err } ResolutionError::VariableNotBoundInPattern(binding_error) => { diff --git a/compiler/rustc_resolve/src/late.rs b/compiler/rustc_resolve/src/late.rs index 3c48a76224fd9..9563325796538 100644 --- a/compiler/rustc_resolve/src/late.rs +++ b/compiler/rustc_resolve/src/late.rs @@ -1309,14 +1309,15 @@ impl<'a: 'ast, 'b, 'ast> LateResolutionVisitor<'a, 'b, 'ast> { use crate::ResolutionError::*; match &item.kind { AssocItemKind::Const(_default, _ty, _expr) => { - debug!("resolve_implementation AssocItemKind::Const",); + debug!("resolve_implementation AssocItemKind::Const"); // If this is a trait impl, ensure the const // exists in trait this.check_trait_item( item.ident, + &item.kind, ValueNS, item.span, - |n, s| ConstNotMemberOfTrait(n, s), + |i, s, c| ConstNotMemberOfTrait(i, s, c), ); // We allow arbitrary const expressions inside of associated consts, @@ -1338,6 +1339,7 @@ impl<'a: 'ast, 'b, 'ast> LateResolutionVisitor<'a, 'b, 'ast> { ); } AssocItemKind::Fn(box FnKind(.., generics, _)) => { + debug!("resolve_implementation AssocItemKind::Fn"); // We also need a new scope for the impl item type parameters. this.with_generic_param_rib( generics, @@ -1347,9 +1349,10 @@ impl<'a: 'ast, 'b, 'ast> LateResolutionVisitor<'a, 'b, 'ast> { // exists in trait this.check_trait_item( item.ident, + &item.kind, ValueNS, item.span, - |n, s| MethodNotMemberOfTrait(n, s), + |i, s, c| MethodNotMemberOfTrait(i, s, c), ); visit::walk_assoc_item( @@ -1366,6 +1369,7 @@ impl<'a: 'ast, 'b, 'ast> LateResolutionVisitor<'a, 'b, 'ast> { _, _, )) => { + debug!("resolve_implementation AssocItemKind::TyAlias"); // We also need a new scope for the impl item type parameters. this.with_generic_param_rib( generics, @@ -1375,9 +1379,10 @@ impl<'a: 'ast, 'b, 'ast> LateResolutionVisitor<'a, 'b, 'ast> { // exists in trait this.check_trait_item( item.ident, + &item.kind, TypeNS, item.span, - |n, s| TypeNotMemberOfTrait(n, s), + |i, s, c| TypeNotMemberOfTrait(i, s, c), ); visit::walk_assoc_item( @@ -1401,9 +1406,15 @@ impl<'a: 'ast, 'b, 'ast> LateResolutionVisitor<'a, 'b, 'ast> { }); } - fn check_trait_item(&mut self, ident: Ident, ns: Namespace, span: Span, err: F) - where - F: FnOnce(Symbol, &str) -> ResolutionError<'_>, + fn check_trait_item( + &mut self, + ident: Ident, + kind: &AssocItemKind, + ns: Namespace, + span: Span, + err: F, + ) where + F: FnOnce(Ident, &str, Option) -> ResolutionError<'_>, { // If there is a TraitRef in scope for an impl, then the method must be in the // trait. @@ -1420,8 +1431,9 @@ impl<'a: 'ast, 'b, 'ast> LateResolutionVisitor<'a, 'b, 'ast> { ) .is_err() { + let candidate = self.find_similarly_named_assoc_item(ident.name, kind); let path = &self.current_trait_ref.as_ref().unwrap().1.path; - self.report_error(span, err(ident.name, &path_names_to_string(path))); + self.report_error(span, err(ident, &path_names_to_string(path), candidate)); } } } diff --git a/compiler/rustc_resolve/src/late/diagnostics.rs b/compiler/rustc_resolve/src/late/diagnostics.rs index 19136c6ceeb1f..0e6ca1856bb30 100644 --- a/compiler/rustc_resolve/src/late/diagnostics.rs +++ b/compiler/rustc_resolve/src/late/diagnostics.rs @@ -7,8 +7,8 @@ use crate::{PathResult, PathSource, Segment}; use rustc_ast::visit::FnKind; use rustc_ast::{ - self as ast, Expr, ExprKind, GenericParam, GenericParamKind, Item, ItemKind, NodeId, Path, Ty, - TyKind, + self as ast, AssocItemKind, Expr, ExprKind, GenericParam, GenericParamKind, Item, ItemKind, + NodeId, Path, Ty, TyKind, }; use rustc_ast_pretty::pprust::path_segment_to_string; use rustc_data_structures::fx::FxHashSet; @@ -1144,6 +1144,40 @@ impl<'a: 'ast, 'ast> LateResolutionVisitor<'a, '_, 'ast> { true } + /// Given the target `ident` and `kind`, search for the similarly named associated item + /// in `self.current_trait_ref`. + crate fn find_similarly_named_assoc_item( + &mut self, + ident: Symbol, + kind: &AssocItemKind, + ) -> Option { + let module = if let Some((module, _)) = self.current_trait_ref { + module + } else { + return None; + }; + if ident == kw::Underscore { + // We do nothing for `_`. + return None; + } + + let resolutions = self.r.resolutions(module); + let targets = resolutions + .borrow() + .iter() + .filter_map(|(key, res)| res.borrow().binding.map(|binding| (key, binding.res()))) + .filter(|(_, res)| match (kind, res) { + (AssocItemKind::Const(..), Res::Def(DefKind::AssocConst, _)) => true, + (AssocItemKind::Fn(_), Res::Def(DefKind::AssocFn, _)) => true, + (AssocItemKind::TyAlias(..), Res::Def(DefKind::AssocTy, _)) => true, + _ => false, + }) + .map(|(key, _)| key.ident.name) + .collect::>(); + + find_best_match_for_name(&targets, ident, None) + } + fn lookup_assoc_candidate( &mut self, ident: Ident, diff --git a/compiler/rustc_resolve/src/lib.rs b/compiler/rustc_resolve/src/lib.rs index 68db06370ffea..22d77d4432159 100644 --- a/compiler/rustc_resolve/src/lib.rs +++ b/compiler/rustc_resolve/src/lib.rs @@ -202,11 +202,11 @@ enum ResolutionError<'a> { /// parameter list. NameAlreadyUsedInParameterList(Symbol, Span), /// Error E0407: method is not a member of trait. - MethodNotMemberOfTrait(Symbol, &'a str), + MethodNotMemberOfTrait(Ident, &'a str, Option), /// Error E0437: type is not a member of trait. - TypeNotMemberOfTrait(Symbol, &'a str), + TypeNotMemberOfTrait(Ident, &'a str, Option), /// Error E0438: const is not a member of trait. - ConstNotMemberOfTrait(Symbol, &'a str), + ConstNotMemberOfTrait(Ident, &'a str, Option), /// Error E0408: variable `{}` is not bound in all patterns. VariableNotBoundInPattern(&'a BindingError), /// Error E0409: variable `{}` is bound in inconsistent ways within the same match arm. diff --git a/src/test/ui/error-codes/E0407.stderr b/src/test/ui/error-codes/E0407.stderr index 567fc879040d3..6f6d1ff6a8f41 100644 --- a/src/test/ui/error-codes/E0407.stderr +++ b/src/test/ui/error-codes/E0407.stderr @@ -2,7 +2,10 @@ error[E0407]: method `b` is not a member of trait `Foo` --> $DIR/E0407.rs:9:5 | LL | fn b() {} - | ^^^^^^^^^ not a member of trait `Foo` + | ^^^-^^^^^ + | | | + | | help: there is an associated function with a similar name: `a` + | not a member of trait `Foo` error: aborting due to previous error diff --git a/src/test/ui/hygiene/assoc_item_ctxt.stderr b/src/test/ui/hygiene/assoc_item_ctxt.stderr index 6e4fecf0ce4b2..517b1ff598888 100644 --- a/src/test/ui/hygiene/assoc_item_ctxt.stderr +++ b/src/test/ui/hygiene/assoc_item_ctxt.stderr @@ -2,7 +2,10 @@ error[E0407]: method `method` is not a member of trait `Tr` --> $DIR/assoc_item_ctxt.rs:35:13 | LL | fn method() {} - | ^^^^^^^^^^^^^^ not a member of trait `Tr` + | ^^^------^^^^^ + | | | + | | help: there is an associated function with a similar name: `method` + | not a member of trait `Tr` ... LL | mac_trait_impl!(); | ------------------ in this macro invocation diff --git a/src/test/ui/suggestions/suggest-trait-items.rs b/src/test/ui/suggestions/suggest-trait-items.rs new file mode 100644 index 0000000000000..9d42a73426096 --- /dev/null +++ b/src/test/ui/suggestions/suggest-trait-items.rs @@ -0,0 +1,48 @@ +trait Foo { + type Type; + + fn foo(); + fn bar(); + fn qux(); +} + +struct A; + +impl Foo for A { +//~^ ERROR not all trait items implemented + type Typ = (); + //~^ ERROR type `Typ` is not a member of trait + //~| HELP there is an associated type with a similar name + + fn fooo() {} + //~^ ERROR method `fooo` is not a member of trait + //~| HELP there is an associated function with a similar name + + fn barr() {} + //~^ ERROR method `barr` is not a member of trait + //~| HELP there is an associated function with a similar name + + fn quux() {} + //~^ ERROR method `quux` is not a member of trait + //~| HELP there is an associated function with a similar name +} +//~^ HELP implement the missing item +//~| HELP implement the missing item +//~| HELP implement the missing item +//~| HELP implement the missing item + +trait Bar { + const Const: i32; +} + +struct B; + +impl Bar for B { +//~^ ERROR not all trait items implemented + const Cnst: i32 = 0; + //~^ ERROR const `Cnst` is not a member of trait + //~| HELP there is an associated constant with a similar name +} +//~^ HELP implement the missing item + +fn main() {} diff --git a/src/test/ui/suggestions/suggest-trait-items.stderr b/src/test/ui/suggestions/suggest-trait-items.stderr new file mode 100644 index 0000000000000..151bae7d1b9cb --- /dev/null +++ b/src/test/ui/suggestions/suggest-trait-items.stderr @@ -0,0 +1,74 @@ +error[E0437]: type `Typ` is not a member of trait `Foo` + --> $DIR/suggest-trait-items.rs:13:5 + | +LL | type Typ = (); + | ^^^^^---^^^^^^ + | | | + | | help: there is an associated type with a similar name: `Type` + | not a member of trait `Foo` + +error[E0407]: method `fooo` is not a member of trait `Foo` + --> $DIR/suggest-trait-items.rs:17:5 + | +LL | fn fooo() {} + | ^^^----^^^^^ + | | | + | | help: there is an associated function with a similar name: `foo` + | not a member of trait `Foo` + +error[E0407]: method `barr` is not a member of trait `Foo` + --> $DIR/suggest-trait-items.rs:21:5 + | +LL | fn barr() {} + | ^^^----^^^^^ + | | | + | | help: there is an associated function with a similar name: `bar` + | not a member of trait `Foo` + +error[E0407]: method `quux` is not a member of trait `Foo` + --> $DIR/suggest-trait-items.rs:25:5 + | +LL | fn quux() {} + | ^^^----^^^^^ + | | | + | | help: there is an associated function with a similar name: `qux` + | not a member of trait `Foo` + +error[E0438]: const `Cnst` is not a member of trait `Bar` + --> $DIR/suggest-trait-items.rs:42:5 + | +LL | const Cnst: i32 = 0; + | ^^^^^^----^^^^^^^^^^ + | | | + | | help: there is an associated constant with a similar name: `Const` + | not a member of trait `Bar` + +error[E0046]: not all trait items implemented, missing: `Type`, `foo`, `bar`, `qux` + --> $DIR/suggest-trait-items.rs:11:1 + | +LL | type Type; + | ---------- `Type` from trait +LL | +LL | fn foo(); + | --------- `foo` from trait +LL | fn bar(); + | --------- `bar` from trait +LL | fn qux(); + | --------- `qux` from trait +... +LL | impl Foo for A { + | ^^^^^^^^^^^^^^ missing `Type`, `foo`, `bar`, `qux` in implementation + +error[E0046]: not all trait items implemented, missing: `Const` + --> $DIR/suggest-trait-items.rs:40:1 + | +LL | const Const: i32; + | ----------------- `Const` from trait +... +LL | impl Bar for B { + | ^^^^^^^^^^^^^^ missing `Const` in implementation + +error: aborting due to 7 previous errors + +Some errors have detailed explanations: E0046, E0407, E0437, E0438. +For more information about an error, try `rustc --explain E0046`.