Rollup merge of #123744 - compiler-errors:redundant-due-to-glob, r=petrochenkov

Silence `unused_imports` for redundant imports

Quick fix for #121708 (comment)

r? `@petrochenkov` cc `@joshtriplett`

I think this is right, would like confirmation. I also think it's weird that we're using `=` to assign to `is_redundant` but using `per_ns` for the actual spans. Seems like this could be weirdly order dependent, but that's unrelated to this change.

Author: matthiaskrgr

compiler/rustc_resolve/src/imports.rs

@@ -1391,13 +1391,15 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
             let mut redundant_spans: Vec<_> = redundant_span.present_items().collect();
             redundant_spans.sort();
             redundant_spans.dedup();
+            /* FIXME(unused_imports): Add this back as a new lint
             self.lint_buffer.buffer_lint_with_diagnostic(
                 UNUSED_IMPORTS,
                 id,
                 import.span,
                 format!("the item `{source}` is imported redundantly"),
                 BuiltinLintDiag::RedundantImport(redundant_spans, source),
             );
+            */
             return true;
         }
 

compiler/rustc_resolve/src/lib.rs

@@ -177,7 +177,7 @@ enum ImplTraitContext {
 
 /// Used for tracking import use types which will be used for redundant import checking.
 /// ### Used::Scope Example
-///  ```rust,compile_fail
+///  ```rust,ignore (redundant_imports)
 /// #![deny(unused_imports)]
 /// use std::mem::drop;
 /// fn main() {

tests/ui/imports/redundant-import-extern-prelude.rs

@@ -1,17 +1,16 @@
+//@ check-pass
 // Check that we detect imports that are redundant due to the extern prelude
 // and that we emit a reasonable diagnostic.
 // issue: rust-lang/rust#121915
-//~^^^ NOTE the item `aux_issue_121915` is already defined by the extern prelude
 
 // See also the discussion in <https://github.com/rust-lang/rust/pull/122954>.
 
 //@ compile-flags: --extern aux_issue_121915 --edition 2018
 //@ aux-build: aux-issue-121915.rs
 
 #[deny(unused_imports)]
-//~^ NOTE the lint level is defined here
 fn main() {
     use aux_issue_121915;
-    //~^ ERROR the item `aux_issue_121915` is imported redundantly
+    //FIXME(unused_imports): ~^ ERROR the item `aux_issue_121915` is imported redundantly
     aux_issue_121915::item();
 }

tests/ui/imports/redundant-import-extern-prelude.stderr

@@ -1,3 +1,4 @@
+//@ check-pass
 //@ compile-flags: --extern aux_issue_121915 --edition 2015
 //@ aux-build: aux-issue-121915.rs
 
@@ -6,6 +7,6 @@ extern crate aux_issue_121915;
 #[deny(unused_imports)]
 fn main() {
     use aux_issue_121915;
-    //~^ ERROR the item `aux_issue_121915` is imported redundantly
+    //FIXME(unused_imports): ~^ ERROR the item `aux_issue_121915` is imported redundantly
     aux_issue_121915::item();
 }

tests/ui/imports/redundant-import-issue-121915-2015.rs

@@ -1,6 +1,6 @@
+//@ check-pass
 // Check that we detect imports (of built-in attributes) that are redundant due to
 // the language prelude and that we emit a reasonable diagnostic.
-//~^^ NOTE the item `allow` is already defined by the extern prelude
 
 // Note that we use the term "extern prelude" in the label even though "language prelude"
 // would be more correct. However, it's not worth special-casing this.
@@ -10,9 +10,8 @@
 //@ edition: 2018
 
 #![deny(unused_imports)]
-//~^ NOTE the lint level is defined here
 
-use allow; //~ ERROR the item `allow` is imported redundantly
+use allow; //FIXME(unused_imports): ~ ERROR the item `allow` is imported redundantly
 
 #[allow(unused)]
 fn main() {}

tests/ui/imports/redundant-import-issue-121915-2015.stderr

@@ -1,17 +1,16 @@
+//@ check-pass
 // Check that we detect imports that are redundant due to the language prelude
 // and that we emit a reasonable diagnostic.
-//~^^ NOTE the item `u8` is already defined by the extern prelude
 
 // Note that we use the term "extern prelude" in the label even though "language prelude"
 // would be more correct. However, it's not worth special-casing this.
 
 // See also the discussion in <https://github.com/rust-lang/rust/pull/122954>.
 
 #![deny(unused_imports)]
-//~^ NOTE the lint level is defined here
 
 use std::primitive::u8;
-//~^ ERROR the item `u8` is imported redundantly
+//FIXME(unused_imports): ~^ ERROR the item `u8` is imported redundantly
 
 const _: u8 = 0;