rustc_lint: Move unused_doc_comments from pre-expansion to early lints

Author: petrochenkov

src/librustc_lint/lib.rs

@@ -94,7 +94,7 @@ fn lint_mod(tcx: TyCtxt<'_>, module_def_id: DefId) {
 
 macro_rules! pre_expansion_lint_passes {
     ($macro:path, $args:tt) => {
-        $macro!($args, [KeywordIdents: KeywordIdents, UnusedDocComment: UnusedDocComment,]);
+        $macro!($args, [KeywordIdents: KeywordIdents,]);
     };
 }
 
@@ -114,6 +114,7 @@ macro_rules! early_lint_passes {
                 NonAsciiIdents: NonAsciiIdents,
                 IncompleteFeatures: IncompleteFeatures,
                 RedundantSemicolon: RedundantSemicolon,
+                UnusedDocComment: UnusedDocComment,
             ]
         );
     };

src/test/ui/useless-comment.rs

@@ -6,7 +6,7 @@ macro_rules! mac {
     () => {}
 }
 
-/// foo //~ ERROR unused doc comment
+/// foo //FIXME ERROR unused doc comment
 mac!();
 
 fn foo() {
@@ -29,7 +29,7 @@ fn foo() {
     #[doc = "bar"] //~ ERROR unused doc comment
     3;
 
-    /// bar //~ ERROR unused doc comment
+    /// bar //FIXME ERROR unused doc comment
     mac!();
 
     let x = /** comment */ 47; //~ ERROR unused doc comment

src/test/ui/useless-comment.stderr

@@ -1,25 +1,16 @@
 error: unused doc comment
-  --> $DIR/useless-comment.rs:9:1
+  --> $DIR/useless-comment.rs:13:5
    |
-LL | /// foo
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-LL | mac!();
-   | ------- rustdoc does not generate documentation for macro expansions
+LL |     /// a
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+LL |     let x = 12;
+   |     ----------- rustdoc does not generate documentation for statements
    |
 note: the lint level is defined here
   --> $DIR/useless-comment.rs:3:9
    |
 LL | #![deny(unused_doc_comments)]
    |         ^^^^^^^^^^^^^^^^^^^
-   = help: to document an item produced by a macro, the macro must produce the documentation as part of its expansion
-
-error: unused doc comment
-  --> $DIR/useless-comment.rs:13:5
-   |
-LL |     /// a
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-LL |     let x = 12;
-   |     ----------- rustdoc does not generate documentation for statements
 
 error: unused doc comment
   --> $DIR/useless-comment.rs:16:5
@@ -68,16 +59,6 @@ LL |     #[doc = "bar"]
 LL |     3;
    |     - rustdoc does not generate documentation for expressions
 
-error: unused doc comment
-  --> $DIR/useless-comment.rs:32:5
-   |
-LL |     /// bar
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-LL |     mac!();
-   |     ------- rustdoc does not generate documentation for macro expansions
-   |
-   = help: to document an item produced by a macro, the macro must produce the documentation as part of its expansion
-
 error: unused doc comment
   --> $DIR/useless-comment.rs:35:13
    |
@@ -94,5 +75,5 @@ LL | |
 LL | |     }
    | |_____- rustdoc does not generate documentation for expressions
 
-error: aborting due to 10 previous errors
+error: aborting due to 8 previous errors