Rollup merge of rust-lang#69740 - mark-i-m:describe-it-3, r=eddyb

Replace some desc logic in librustc_lint with article_and_desc

r? @eddyb @Centril @matthewjasper

Followup to rust-lang#69674

Blocked on rust-lang#69498

Author: Centril

src/librustc_lint/builtin.rs

@@ -349,6 +349,7 @@ impl MissingDoc {
         id: Option<hir::HirId>,
         attrs: &[ast::Attribute],
         sp: Span,
+        article: &'static str,
         desc: &'static str,
     ) {
         // If we're building a test harness, then warning about
@@ -374,7 +375,7 @@ impl MissingDoc {
         let has_doc = attrs.iter().any(|a| has_doc(a));
         if !has_doc {
             cx.struct_span_lint(MISSING_DOCS, cx.tcx.sess.source_map().def_span(sp), |lint| {
-                lint.build(&format!("missing documentation for {}", desc)).emit()
+                lint.build(&format!("missing documentation for {} {}", article, desc)).emit()
             });
         }
     }
@@ -398,7 +399,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for MissingDoc {
     }
 
     fn check_crate(&mut self, cx: &LateContext<'_, '_>, krate: &hir::Crate<'_>) {
-        self.check_missing_docs_attrs(cx, None, &krate.item.attrs, krate.item.span, "crate");
+        self.check_missing_docs_attrs(cx, None, &krate.item.attrs, krate.item.span, "the", "crate");
 
         for macro_def in krate.exported_macros {
             let has_doc = macro_def.attrs.iter().any(|a| has_doc(a));
@@ -413,12 +414,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for MissingDoc {
     }
 
     fn check_item(&mut self, cx: &LateContext<'_, '_>, it: &hir::Item<'_>) {
-        let desc = match it.kind {
-            hir::ItemKind::Fn(..) => "a function",
-            hir::ItemKind::Mod(..) => "a module",
-            hir::ItemKind::Enum(..) => "an enum",
-            hir::ItemKind::Struct(..) => "a struct",
-            hir::ItemKind::Union(..) => "a union",
+        match it.kind {
             hir::ItemKind::Trait(.., trait_item_refs) => {
                 // Issue #11592: traits are always considered exported, even when private.
                 if let hir::VisibilityKind::Inherited = it.vis.node {
@@ -428,51 +424,55 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for MissingDoc {
                     }
                     return;
                 }
-                "a trait"
             }
-            hir::ItemKind::TyAlias(..) => "a type alias",
             hir::ItemKind::Impl { of_trait: Some(ref trait_ref), items, .. } => {
                 // If the trait is private, add the impl items to `private_traits` so they don't get
                 // reported for missing docs.
                 let real_trait = trait_ref.path.res.def_id();
                 if let Some(hir_id) = cx.tcx.hir().as_local_hir_id(real_trait) {
-                    match cx.tcx.hir().find(hir_id) {
-                        Some(Node::Item(item)) => {
-                            if let hir::VisibilityKind::Inherited = item.vis.node {
-                                for impl_item_ref in items {
-                                    self.private_traits.insert(impl_item_ref.id.hir_id);
-                                }
+                    if let Some(Node::Item(item)) = cx.tcx.hir().find(hir_id) {
+                        if let hir::VisibilityKind::Inherited = item.vis.node {
+                            for impl_item_ref in items {
+                                self.private_traits.insert(impl_item_ref.id.hir_id);
                             }
                         }
-                        _ => {}
                     }
                 }
                 return;
             }
-            hir::ItemKind::Const(..) => "a constant",
-            hir::ItemKind::Static(..) => "a static",
+
+            hir::ItemKind::TyAlias(..)
+            | hir::ItemKind::Fn(..)
+            | hir::ItemKind::Mod(..)
+            | hir::ItemKind::Enum(..)
+            | hir::ItemKind::Struct(..)
+            | hir::ItemKind::Union(..)
+            | hir::ItemKind::Const(..)
+            | hir::ItemKind::Static(..) => {}
+
             _ => return,
         };
 
-        self.check_missing_docs_attrs(cx, Some(it.hir_id), &it.attrs, it.span, desc);
+        let def_id = cx.tcx.hir().local_def_id(it.hir_id);
+        let (article, desc) = cx.tcx.article_and_description(def_id);
+
+        self.check_missing_docs_attrs(cx, Some(it.hir_id), &it.attrs, it.span, article, desc);
     }
 
     fn check_trait_item(&mut self, cx: &LateContext<'_, '_>, trait_item: &hir::TraitItem<'_>) {
         if self.private_traits.contains(&trait_item.hir_id) {
             return;
         }
 
-        let desc = match trait_item.kind {
-            hir::TraitItemKind::Const(..) => "an associated constant",
-            hir::TraitItemKind::Fn(..) => "a trait method",
-            hir::TraitItemKind::Type(..) => "an associated type",
-        };
+        let def_id = cx.tcx.hir().local_def_id(trait_item.hir_id);
+        let (article, desc) = cx.tcx.article_and_description(def_id);
 
         self.check_missing_docs_attrs(
             cx,
             Some(trait_item.hir_id),
             &trait_item.attrs,
             trait_item.span,
+            article,
             desc,
         );
     }
@@ -483,29 +483,33 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for MissingDoc {
             return;
         }
 
-        let desc = match impl_item.kind {
-            hir::ImplItemKind::Const(..) => "an associated constant",
-            hir::ImplItemKind::Fn(..) => "a method",
-            hir::ImplItemKind::TyAlias(_) => "an associated type",
-            hir::ImplItemKind::OpaqueTy(_) => "an associated `impl Trait` type",
-        };
+        let def_id = cx.tcx.hir().local_def_id(impl_item.hir_id);
+        let (article, desc) = cx.tcx.article_and_description(def_id);
         self.check_missing_docs_attrs(
             cx,
             Some(impl_item.hir_id),
             &impl_item.attrs,
             impl_item.span,
+            article,
             desc,
         );
     }
 
     fn check_struct_field(&mut self, cx: &LateContext<'_, '_>, sf: &hir::StructField<'_>) {
         if !sf.is_positional() {
-            self.check_missing_docs_attrs(cx, Some(sf.hir_id), &sf.attrs, sf.span, "a struct field")
+            self.check_missing_docs_attrs(
+                cx,
+                Some(sf.hir_id),
+                &sf.attrs,
+                sf.span,
+                "a",
+                "struct field",
+            )
         }
     }
 
     fn check_variant(&mut self, cx: &LateContext<'_, '_>, v: &hir::Variant<'_>) {
-        self.check_missing_docs_attrs(cx, Some(v.id), &v.attrs, v.span, "a variant");
+        self.check_missing_docs_attrs(cx, Some(v.id), &v.attrs, v.span, "a", "variant");
     }
 }
 

src/test/rustdoc-ui/deny-missing-docs-crate.stderr

@@ -1,4 +1,4 @@
-error: missing documentation for crate
+error: missing documentation for the crate
   --> $DIR/deny-missing-docs-crate.rs:1:1
    |
 LL | / #![deny(missing_docs)]

src/test/ui/issues/issue-10656.rs

@@ -1,3 +1,3 @@
 #![deny(missing_docs)]
 #![crate_type="lib"]
-//~^^ ERROR missing documentation for crate
+//~^^ ERROR missing documentation for the crate

src/test/ui/issues/issue-10656.stderr

@@ -1,4 +1,4 @@
-error: missing documentation for crate
+error: missing documentation for the crate
   --> $DIR/issue-10656.rs:1:1
    |
 LL | / #![deny(missing_docs)]

src/test/ui/lint/lint-missing-doc.rs

@@ -50,8 +50,8 @@ trait B {
 }
 
 pub trait C { //~ ERROR: missing documentation for a trait
-    fn foo(&self); //~ ERROR: missing documentation for a trait method
-    fn foo_with_impl(&self) {} //~ ERROR: missing documentation for a trait method
+    fn foo(&self); //~ ERROR: missing documentation for an associated function
+    fn foo_with_impl(&self) {} //~ ERROR: missing documentation for an associated function
 }
 
 #[allow(missing_docs)]
@@ -78,7 +78,7 @@ impl Foo {
 }
 
 impl PubFoo {
-    pub fn foo() {} //~ ERROR: missing documentation for a method
+    pub fn foo() {} //~ ERROR: missing documentation for an associated function
     /// dox
     pub fn foo1() {}
     fn foo2() {}

src/test/ui/lint/lint-missing-doc.stderr

@@ -40,13 +40,13 @@ error: missing documentation for a trait
 LL | pub trait C {
    | ^^^^^^^^^^^
 
-error: missing documentation for a trait method
+error: missing documentation for an associated function
   --> $DIR/lint-missing-doc.rs:53:5
    |
 LL |     fn foo(&self);
    |     ^^^^^^^^^^^^^^
 
-error: missing documentation for a trait method
+error: missing documentation for an associated function
   --> $DIR/lint-missing-doc.rs:54:5
    |
 LL |     fn foo_with_impl(&self) {}
@@ -64,7 +64,7 @@ error: missing documentation for an associated type
 LL |     type AssociatedTypeDef = Self;
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-error: missing documentation for a method
+error: missing documentation for an associated function
   --> $DIR/lint-missing-doc.rs:81:5
    |
 LL |     pub fn foo() {}

src/test/ui/lint/lints-in-foreign-macros.rs

@@ -1,7 +1,7 @@
 // aux-build:lints-in-foreign-macros.rs
 // check-pass
 
-#![warn(unused_imports)] //~ missing documentation for crate [missing_docs]
+#![warn(unused_imports)] //~ missing documentation for the crate [missing_docs]
 #![warn(missing_docs)]
 
 #[macro_use]

src/test/ui/lint/lints-in-foreign-macros.stderr

@@ -26,7 +26,7 @@ warning: unused import: `std::string::ToString`
 LL | mod d { baz2!(use std::string::ToString;); }
    |                   ^^^^^^^^^^^^^^^^^^^^^
 
-warning: missing documentation for crate
+warning: missing documentation for the crate
   --> $DIR/lints-in-foreign-macros.rs:4:1
    |
 LL | / #![warn(unused_imports)]

src/test/ui/privacy/private-in-public-non-principal.rs

@@ -10,7 +10,7 @@ pub fn leak_dyn_nonprincipal() -> Box<dyn PubPrincipal + PrivNonPrincipal> { loo
 #[deny(missing_docs)]
 fn container() {
     impl dyn PubPrincipal {
-        pub fn check_doc_lint() {} //~ ERROR missing documentation for a method
+        pub fn check_doc_lint() {} //~ ERROR missing documentation for an associated function
     }
     impl dyn PubPrincipal + PrivNonPrincipal {
         pub fn check_doc_lint() {} // OK, no missing doc lint

src/test/ui/privacy/private-in-public-non-principal.stderr

@@ -8,7 +8,7 @@ LL | pub fn leak_dyn_nonprincipal() -> Box<dyn PubPrincipal + PrivNonPrincipal>
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
    = note: for more information, see issue #34537 <https://github.com/rust-lang/rust/issues/34537>
 
-error: missing documentation for a method
+error: missing documentation for an associated function
   --> $DIR/private-in-public-non-principal.rs:13:9
    |
 LL |         pub fn check_doc_lint() {}