Auto merge of #65421 - estebank:variants, r=petrochenkov

Point at local similarly named element and tweak references to variants

Partially address #65386.

Author: bors

src/librustc_resolve/build_reduced_graph.rs

@@ -849,12 +849,14 @@ impl<'a, 'b> BuildReducedGraphVisitor<'a, 'b> {
             Res::Def(kind @ DefKind::Mod, def_id)
             | Res::Def(kind @ DefKind::Enum, def_id)
             | Res::Def(kind @ DefKind::Trait, def_id) => {
-                let module = self.r.new_module(parent,
-                                             ModuleKind::Def(kind, def_id, ident.name),
-                                             def_id,
-                                             expansion,
-                                             span);
-                self.r.define(parent, ident, TypeNS, (module, vis, DUMMY_SP, expansion));
+                let module = self.r.new_module(
+                    parent,
+                    ModuleKind::Def(kind, def_id, ident.name),
+                    def_id,
+                    expansion,
+                    span,
+                );
+                self.r.define(parent, ident, TypeNS, (module, vis, span, expansion));
             }
             Res::Def(DefKind::Struct, _)
             | Res::Def(DefKind::Union, _)
@@ -867,17 +869,17 @@ impl<'a, 'b> BuildReducedGraphVisitor<'a, 'b> {
             | Res::Def(DefKind::AssocOpaqueTy, _)
             | Res::PrimTy(..)
             | Res::ToolMod =>
-                self.r.define(parent, ident, TypeNS, (res, vis, DUMMY_SP, expansion)),
+                self.r.define(parent, ident, TypeNS, (res, vis, span, expansion)),
             Res::Def(DefKind::Fn, _)
             | Res::Def(DefKind::Method, _)
             | Res::Def(DefKind::Static, _)
             | Res::Def(DefKind::Const, _)
             | Res::Def(DefKind::AssocConst, _)
             | Res::Def(DefKind::Ctor(..), _) =>
-                self.r.define(parent, ident, ValueNS, (res, vis, DUMMY_SP, expansion)),
+                self.r.define(parent, ident, ValueNS, (res, vis, span, expansion)),
             Res::Def(DefKind::Macro(..), _)
             | Res::NonMacroAttr(..) =>
-                self.r.define(parent, ident, MacroNS, (res, vis, DUMMY_SP, expansion)),
+                self.r.define(parent, ident, MacroNS, (res, vis, span, expansion)),
             Res::Def(DefKind::TyParam, _) | Res::Def(DefKind::ConstParam, _)
             | Res::Local(..) | Res::SelfTy(..) | Res::SelfCtor(..) | Res::Err =>
                 bug!("unexpected resolution: {:?}", res)

src/librustc_resolve/diagnostics.rs

@@ -58,21 +58,6 @@ fn reduce_impl_span_to_impl_keyword(cm: &SourceMap, impl_span: Span) -> Span {
     impl_span
 }
 
-crate fn add_typo_suggestion(
-    err: &mut DiagnosticBuilder<'_>, suggestion: Option<TypoSuggestion>, span: Span
-) -> bool {
-    if let Some(suggestion) = suggestion {
-        let msg = format!(
-            "{} {} with a similar name exists", suggestion.res.article(), suggestion.res.descr()
-        );
-        err.span_suggestion(
-            span, &msg, suggestion.candidate.to_string(), Applicability::MaybeIncorrect
-        );
-        return true;
-    }
-    false
-}
-
 impl<'a> Resolver<'a> {
     crate fn add_module_candidates(
         &mut self,
@@ -641,7 +626,7 @@ impl<'a> Resolver<'a> {
         let suggestion = self.early_lookup_typo_candidate(
             ScopeSet::Macro(macro_kind), parent_scope, ident, is_expected
         );
-        add_typo_suggestion(err, suggestion, ident.span);
+        self.add_typo_suggestion(err, suggestion, ident.span);
 
         if macro_kind == MacroKind::Derive &&
            (ident.as_str() == "Send" || ident.as_str() == "Sync") {
@@ -652,6 +637,33 @@ impl<'a> Resolver<'a> {
             err.help("have you added the `#[macro_use]` on the module/import?");
         }
     }
+
+    crate fn add_typo_suggestion(
+        &self,
+        err: &mut DiagnosticBuilder<'_>,
+        suggestion: Option<TypoSuggestion>,
+        span: Span,
+    ) -> bool {
+        if let Some(suggestion) = suggestion {
+            let msg = format!(
+                "{} {} with a similar name exists", suggestion.res.article(), suggestion.res.descr()
+            );
+            err.span_suggestion(
+                span, &msg, suggestion.candidate.to_string(), Applicability::MaybeIncorrect
+            );
+            let def_span = suggestion.res.opt_def_id()
+                .and_then(|def_id| self.definitions.opt_span(def_id));
+            if let Some(span) = def_span {
+                err.span_label(span, &format!(
+                    "similarly named {} `{}` defined here",
+                    suggestion.res.descr(),
+                    suggestion.candidate.as_str(),
+                ));
+            }
+            return true;
+        }
+        false
+    }
 }
 
 impl<'a, 'b> ImportResolver<'a, 'b> {

src/librustc_resolve/error_codes.rs

@@ -974,7 +974,7 @@ function:
 struct Foo { a: bool };
 
 let f = Foo();
-// error: expected function, found `Foo`
+// error: expected function, tuple struct or tuple variant, found `Foo`
 // `Foo` is a struct name, but this expression uses it like a function name
 ```
 
@@ -992,7 +992,8 @@ yield this error:
 
 ```compile_fail,E0423
 println("");
-// error: expected function, found macro `println`
+// error: expected function, tuple struct or tuple variant,
+// found macro `println`
 // did you mean `println!(...)`? (notice the trailing `!`)
 ```
 
@@ -1592,7 +1593,7 @@ enum State {
 
 fn print_on_failure(state: &State) {
     match *state {
-        // error: expected unit struct/variant or constant, found tuple
+        // error: expected unit struct, unit variant or constant, found tuple
         //        variant `State::Failed`
         State::Failed => println!("Failed"),
         _ => ()

src/librustc_resolve/late.rs

@@ -199,21 +199,36 @@ impl<'a> PathSource<'a> {
     }
 
     fn descr_expected(self) -> &'static str {
-        match self {
+        match &self {
             PathSource::Type => "type",
             PathSource::Trait(_) => "trait",
-            PathSource::Pat => "unit struct/variant or constant",
+            PathSource::Pat => "unit struct, unit variant or constant",
             PathSource::Struct => "struct, variant or union type",
-            PathSource::TupleStruct => "tuple struct/variant",
+            PathSource::TupleStruct => "tuple struct or tuple variant",
             PathSource::TraitItem(ns) => match ns {
                 TypeNS => "associated type",
                 ValueNS => "method or associated constant",
                 MacroNS => bug!("associated macro"),
             },
-            PathSource::Expr(parent) => match parent.map(|p| &p.kind) {
+            PathSource::Expr(parent) => match &parent.as_ref().map(|p| &p.kind) {
                 // "function" here means "anything callable" rather than `DefKind::Fn`,
                 // this is not precise but usually more helpful than just "value".
-                Some(&ExprKind::Call(..)) => "function",
+                Some(ExprKind::Call(call_expr, _)) => {
+                    match &call_expr.kind {
+                        ExprKind::Path(_, path) => {
+                            let mut msg = "function";
+                            if let Some(segment) = path.segments.iter().last() {
+                                if let Some(c) = segment.ident.to_string().chars().next() {
+                                    if c.is_uppercase() {
+                                        msg = "function, tuple struct or tuple variant";
+                                    }
+                                }
+                            }
+                            msg
+                        }
+                        _ => "function"
+                    }
+                }
                 _ => "value",
             },
         }

src/librustc_resolve/late/diagnostics.rs

@@ -1,7 +1,7 @@
 use crate::{CrateLint, Module, ModuleKind, ModuleOrUniformRoot};
 use crate::{PathResult, PathSource, Segment};
 use crate::path_names_to_string;
-use crate::diagnostics::{add_typo_suggestion, ImportSuggestion, TypoSuggestion};
+use crate::diagnostics::{ImportSuggestion, TypoSuggestion};
 use crate::late::{LateResolutionVisitor, RibKind};
 
 use errors::{Applicability, DiagnosticBuilder, DiagnosticId};
@@ -254,18 +254,19 @@ impl<'a> LateResolutionVisitor<'a, '_> {
         }
 
         // Try Levenshtein algorithm.
-        let levenshtein_worked = add_typo_suggestion(
-            &mut err, self.lookup_typo_candidate(path, ns, is_expected, span), ident_span
-        );
+        let typo_sugg = self.lookup_typo_candidate(path, ns, is_expected, span);
+        let levenshtein_worked = self.r.add_typo_suggestion(&mut err, typo_sugg, ident_span);
 
         // Try context-dependent help if relaxed lookup didn't work.
         if let Some(res) = res {
-            if self.smart_resolve_context_dependent_help(&mut err,
-                                                         span,
-                                                         source,
-                                                         res,
-                                                         &path_str,
-                                                         &fallback_label) {
+            if self.smart_resolve_context_dependent_help(
+                &mut err,
+                span,
+                source,
+                res,
+                &path_str,
+                &fallback_label,
+            ) {
                 return (err, candidates);
             }
         }

src/librustc_typeck/check/mod.rs

@@ -2269,7 +2269,7 @@ pub fn check_enum<'tcx>(tcx: TyCtxt<'tcx>, sp: Span, vs: &'tcx [hir::Variant], i
 
 fn report_unexpected_variant_res(tcx: TyCtxt<'_>, res: Res, span: Span, qpath: &QPath) {
     span_err!(tcx.sess, span, E0533,
-              "expected unit struct/variant or constant, found {} `{}`",
+              "expected unit struct, unit variant or constant, found {} `{}`",
               res.descr(),
               hir::print::to_string(tcx.hir(), |s| s.print_qpath(qpath, false)));
 }

src/librustc_typeck/check/pat.rs

@@ -613,9 +613,11 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             }
         };
         let report_unexpected_res = |res: Res| {
-            let msg = format!("expected tuple struct/variant, found {} `{}`",
-                              res.descr(),
-                              hir::print::to_string(tcx.hir(), |s| s.print_qpath(qpath, false)));
+            let msg = format!(
+                "expected tuple struct or tuple variant, found {} `{}`",
+                res.descr(),
+                hir::print::to_string(tcx.hir(), |s| s.print_qpath(qpath, false)),
+            );
             let mut err = struct_span_err!(tcx.sess, pat.span, E0164, "{}", msg);
             match (res, &pat.kind) {
                 (Res::Def(DefKind::Fn, _), _) | (Res::Def(DefKind::Method, _), _) => {

src/librustc_typeck/error_codes.rs

@@ -4346,11 +4346,12 @@ enum X {
     Entry,
 }
 
-X::Entry(); // error: expected function, found `X::Entry`
+X::Entry(); // error: expected function, tuple struct or tuple variant,
+            // found `X::Entry`
 
 // Or even simpler:
 let x = 0i32;
-x(); // error: expected function, found `i32`
+x(); // error: expected function, tuple struct or tuple variant, found `i32`
 ```
 
 Only functions and methods can be called using `()`. Example:

src/test/ui/associated-types/associated-types-eq-1.stderr

@@ -1,6 +1,8 @@
 error[E0412]: cannot find type `A` in this scope
   --> $DIR/associated-types-eq-1.rs:10:12
    |
+LL | fn foo2<I: Foo>(x: I) {
+   |         - similarly named type parameter `I` defined here
 LL |     let _: A = x.boo();
    |            ^ help: a type parameter with a similar name exists: `I`
 

src/test/ui/class-missing-self.rs

@@ -7,7 +7,7 @@ impl Cat {
     fn meow(&self) {
       println!("Meow");
       meows += 1; //~ ERROR cannot find value `meows` in this scope
-      sleep();     //~ ERROR cannot find function `sleep` in this scope
+      sleep();     //~ ERROR cannot find function `sleep` in this
     }
 
 }