Auto merge of #10300 - koka831:fix/9942, r=xFrednet

Do not lint when imported item contains underscore

fix https://github.com/rust-lang/rust-clippy/issues/9942

changelog: [`wildcard_imports`]: No longer lints when imported items contain an item with the name `_`

9 files changed, 207 insertions, 48 deletions

diff --git a/clippy_lints/src/wildcard_imports.rs b/clippy_lints/src/wildcard_imports.rs
index d09d02a7dfd..70b83149ce1 100644
--- a/clippy_lints/src/wildcard_imports.rs
+++ b/clippy_lints/src/wildcard_imports.rs
@@ -132,6 +132,7 @@ impl LateLintPass<'_> for WildcardImports {
             if self.warn_on_all || !self.check_exceptions(item, use_path.segments);
             let used_imports = cx.tcx.names_imported_by_glob_use(item.owner_id.def_id);
             if !used_imports.is_empty(); // Already handled by `unused_imports`
+            if !used_imports.contains(&kw::Underscore);
             then {
                 let mut applicability = Applicability::MachineApplicable;
                 let import_source_snippet = snippet_with_applicability(cx, use_path.span, "..", &mut applicability);
diff --git a/tests/ui/wildcard_imports.fixed b/tests/ui/wildcard_imports.fixed
index 2828f9d048e..6fdd728b9b7 100644
--- a/tests/ui/wildcard_imports.fixed
+++ b/tests/ui/wildcard_imports.fixed
@@ -69,6 +69,34 @@ mod struct_mod {
     }
 }
 
+// issue 9942
+mod underscore_mod {
+    // allow use of `deref` so that `clippy --fix` includes `Deref`.
+    #![allow(noop_method_call)]
+
+    mod exports_underscore {
+        pub use std::ops::Deref as _;
+        pub fn dummy() {}
+    }
+
+    mod exports_underscore_ish {
+        pub use std::ops::Deref as _Deref;
+        pub fn dummy() {}
+    }
+
+    fn does_not_lint() {
+        use self::exports_underscore::*;
+        let _ = (&0).deref();
+        dummy();
+    }
+
+    fn does_lint() {
+        use self::exports_underscore_ish::{_Deref, dummy};
+        let _ = (&0).deref();
+        dummy();
+    }
+}
+
 fn main() {
     foo();
     multi_foo();
diff --git a/tests/ui/wildcard_imports.rs b/tests/ui/wildcard_imports.rs
index cbe70e505d8..20e06d4b366 100644
--- a/tests/ui/wildcard_imports.rs
+++ b/tests/ui/wildcard_imports.rs
@@ -69,6 +69,34 @@ mod struct_mod {
     }
 }
 
+// issue 9942
+mod underscore_mod {
+    // allow use of `deref` so that `clippy --fix` includes `Deref`.
+    #![allow(noop_method_call)]
+
+    mod exports_underscore {
+        pub use std::ops::Deref as _;
+        pub fn dummy() {}
+    }
+
+    mod exports_underscore_ish {
+        pub use std::ops::Deref as _Deref;
+        pub fn dummy() {}
+    }
+
+    fn does_not_lint() {
+        use self::exports_underscore::*;
+        let _ = (&0).deref();
+        dummy();
+    }
+
+    fn does_lint() {
+        use self::exports_underscore_ish::*;
+        let _ = (&0).deref();
+        dummy();
+    }
+}
+
 fn main() {
     foo();
     multi_foo();
diff --git a/tests/ui/wildcard_imports.stderr b/tests/ui/wildcard_imports.stderr
index 3c750815baf..01a5414778c 100644
--- a/tests/ui/wildcard_imports.stderr
+++ b/tests/ui/wildcard_imports.stderr
@@ -38,55 +38,61 @@ LL | use wildcard_imports_helper::*;
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `wildcard_imports_helper::{ExternA, extern_foo}`
 
 error: usage of wildcard import
-  --> $DIR/wildcard_imports.rs:97:13
+  --> $DIR/wildcard_imports.rs:94:13
+   |
+LL |         use self::exports_underscore_ish::*;
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `self::exports_underscore_ish::{_Deref, dummy}`
+
+error: usage of wildcard import
+  --> $DIR/wildcard_imports.rs:125:13
    |
 LL |         use crate::fn_mod::*;
    |             ^^^^^^^^^^^^^^^^ help: try: `crate::fn_mod::foo`
 
 error: usage of wildcard import
-  --> $DIR/wildcard_imports.rs:103:75
+  --> $DIR/wildcard_imports.rs:131:75
    |
 LL |         use wildcard_imports_helper::inner::inner_for_self_import::{self, *};
    |                                                                           ^ help: try: `inner_extern_foo`
 
 error: usage of wildcard import
-  --> $DIR/wildcard_imports.rs:104:13
+  --> $DIR/wildcard_imports.rs:132:13
    |
 LL |         use wildcard_imports_helper::*;
    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `wildcard_imports_helper::{ExternA, extern_foo}`
 
 error: usage of wildcard import
-  --> $DIR/wildcard_imports.rs:116:20
+  --> $DIR/wildcard_imports.rs:144:20
    |
 LL |         use self::{inner::*, inner2::*};
    |                    ^^^^^^^^ help: try: `inner::inner_foo`
 
 error: usage of wildcard import
-  --> $DIR/wildcard_imports.rs:116:30
+  --> $DIR/wildcard_imports.rs:144:30
    |
 LL |         use self::{inner::*, inner2::*};
    |                              ^^^^^^^^^ help: try: `inner2::inner_bar`
 
 error: usage of wildcard import
-  --> $DIR/wildcard_imports.rs:123:13
+  --> $DIR/wildcard_imports.rs:151:13
    |
 LL |         use wildcard_imports_helper::*;
    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `wildcard_imports_helper::{ExternExportedEnum, ExternExportedStruct, extern_exported}`
 
 error: usage of wildcard import
-  --> $DIR/wildcard_imports.rs:152:9
+  --> $DIR/wildcard_imports.rs:180:9
    |
 LL |     use crate::in_fn_test::*;
    |         ^^^^^^^^^^^^^^^^^^^^ help: try: `crate::in_fn_test::{ExportedEnum, ExportedStruct, exported}`
 
 error: usage of wildcard import
-  --> $DIR/wildcard_imports.rs:161:9
+  --> $DIR/wildcard_imports.rs:189:9
    |
 LL |     use crate:: in_fn_test::  * ;
    |         ^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `crate:: in_fn_test::exported`
 
 error: usage of wildcard import
-  --> $DIR/wildcard_imports.rs:162:9
+  --> $DIR/wildcard_imports.rs:190:9
    |
 LL |       use crate:: fn_mod::
    |  _________^
@@ -94,40 +100,40 @@ LL | |         *;
    | |_________^ help: try: `crate:: fn_mod::foo`
 
 error: usage of wildcard import
-  --> $DIR/wildcard_imports.rs:173:13
+  --> $DIR/wildcard_imports.rs:201:13
    |
 LL |         use super::*;
    |             ^^^^^^^^ help: try: `super::foofoo`
 
 error: usage of wildcard import
-  --> $DIR/wildcard_imports.rs:208:17
+  --> $DIR/wildcard_imports.rs:236:17
    |
 LL |             use super::*;
    |                 ^^^^^^^^ help: try: `super::insidefoo`
 
 error: usage of wildcard import
-  --> $DIR/wildcard_imports.rs:216:13
+  --> $DIR/wildcard_imports.rs:244:13
    |
 LL |         use crate::super_imports::*;
    |             ^^^^^^^^^^^^^^^^^^^^^^^ help: try: `crate::super_imports::foofoo`
 
 error: usage of wildcard import
-  --> $DIR/wildcard_imports.rs:225:17
+  --> $DIR/wildcard_imports.rs:253:17
    |
 LL |             use super::super::*;
    |                 ^^^^^^^^^^^^^^^ help: try: `super::super::foofoo`
 
 error: usage of wildcard import
-  --> $DIR/wildcard_imports.rs:234:13
+  --> $DIR/wildcard_imports.rs:262:13
    |
 LL |         use super::super::super_imports::*;
    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `super::super::super_imports::foofoo`
 
 error: usage of wildcard import
-  --> $DIR/wildcard_imports.rs:242:13
+  --> $DIR/wildcard_imports.rs:270:13
    |
 LL |         use super::*;
    |             ^^^^^^^^ help: try: `super::foofoo`
 
-error: aborting due to 21 previous errors
+error: aborting due to 22 previous errors
 
diff --git a/tests/ui/wildcard_imports_2021.edition2018.fixed b/tests/ui/wildcard_imports_2021.edition2018.fixed
index b27281fa25c..6a9fe007d65 100644
--- a/tests/ui/wildcard_imports_2021.edition2018.fixed
+++ b/tests/ui/wildcard_imports_2021.edition2018.fixed
@@ -64,6 +64,34 @@ mod struct_mod {
     }
 }
 
+// issue 9942
+mod underscore_mod {
+    // allow use of `deref` so that `clippy --fix` includes `Deref`.
+    #![allow(noop_method_call)]
+
+    mod exports_underscore {
+        pub use std::ops::Deref as _;
+        pub fn dummy() {}
+    }
+
+    mod exports_underscore_ish {
+        pub use std::ops::Deref as _Deref;
+        pub fn dummy() {}
+    }
+
+    fn does_not_lint() {
+        use exports_underscore::*;
+        let _ = (&0).deref();
+        dummy();
+    }
+
+    fn does_lint() {
+        use exports_underscore_ish::{_Deref, dummy};
+        let _ = (&0).deref();
+        dummy();
+    }
+}
+
 fn main() {
     foo();
     multi_foo();
diff --git a/tests/ui/wildcard_imports_2021.edition2018.stderr b/tests/ui/wildcard_imports_2021.edition2018.stderr
index 709a665d65c..e39f240a4aa 100644
--- a/tests/ui/wildcard_imports_2021.edition2018.stderr
+++ b/tests/ui/wildcard_imports_2021.edition2018.stderr
@@ -38,55 +38,61 @@ LL | use wildcard_imports_helper::*;
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `wildcard_imports_helper::{ExternA, extern_foo}`
 
 error: usage of wildcard import
-  --> $DIR/wildcard_imports_2021.rs:91:13
+  --> $DIR/wildcard_imports_2021.rs:89:13
+   |
+LL |         use exports_underscore_ish::*;
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `exports_underscore_ish::{_Deref, dummy}`
+
+error: usage of wildcard import
+  --> $DIR/wildcard_imports_2021.rs:119:13
    |
 LL |         use crate::fn_mod::*;
    |             ^^^^^^^^^^^^^^^^ help: try: `crate::fn_mod::foo`
 
 error: usage of wildcard import
-  --> $DIR/wildcard_imports_2021.rs:97:75
+  --> $DIR/wildcard_imports_2021.rs:125:75
    |
 LL |         use wildcard_imports_helper::inner::inner_for_self_import::{self, *};
    |                                                                           ^ help: try: `inner_extern_foo`
 
 error: usage of wildcard import
-  --> $DIR/wildcard_imports_2021.rs:98:13
+  --> $DIR/wildcard_imports_2021.rs:126:13
    |
 LL |         use wildcard_imports_helper::*;
    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `wildcard_imports_helper::{ExternA, extern_foo}`
 
 error: usage of wildcard import
-  --> $DIR/wildcard_imports_2021.rs:110:20
+  --> $DIR/wildcard_imports_2021.rs:138:20
    |
 LL |         use self::{inner::*, inner2::*};
    |                    ^^^^^^^^ help: try: `inner::inner_foo`
 
 error: usage of wildcard import
-  --> $DIR/wildcard_imports_2021.rs:110:30
+  --> $DIR/wildcard_imports_2021.rs:138:30
    |
 LL |         use self::{inner::*, inner2::*};
    |                              ^^^^^^^^^ help: try: `inner2::inner_bar`
 
 error: usage of wildcard import
-  --> $DIR/wildcard_imports_2021.rs:117:13
+  --> $DIR/wildcard_imports_2021.rs:145:13
    |
 LL |         use wildcard_imports_helper::*;
    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `wildcard_imports_helper::{ExternExportedEnum, ExternExportedStruct, extern_exported}`
 
 error: usage of wildcard import
-  --> $DIR/wildcard_imports_2021.rs:146:9
+  --> $DIR/wildcard_imports_2021.rs:174:9
    |
 LL |     use crate::in_fn_test::*;
    |         ^^^^^^^^^^^^^^^^^^^^ help: try: `crate::in_fn_test::{ExportedEnum, ExportedStruct, exported}`
 
 error: usage of wildcard import
-  --> $DIR/wildcard_imports_2021.rs:155:9
+  --> $DIR/wildcard_imports_2021.rs:183:9
    |
 LL |     use crate:: in_fn_test::  * ;
    |         ^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `crate:: in_fn_test::exported`
 
 error: usage of wildcard import
-  --> $DIR/wildcard_imports_2021.rs:156:9
+  --> $DIR/wildcard_imports_2021.rs:184:9
    |
 LL |       use crate:: fn_mod::
    |  _________^
@@ -94,40 +100,40 @@ LL | |         *;
    | |_________^ help: try: `crate:: fn_mod::foo`
 
 error: usage of wildcard import
-  --> $DIR/wildcard_imports_2021.rs:167:13
+  --> $DIR/wildcard_imports_2021.rs:195:13
    |
 LL |         use super::*;
    |             ^^^^^^^^ help: try: `super::foofoo`
 
 error: usage of wildcard import
-  --> $DIR/wildcard_imports_2021.rs:202:17
+  --> $DIR/wildcard_imports_2021.rs:230:17
    |
 LL |             use super::*;
    |                 ^^^^^^^^ help: try: `super::insidefoo`
 
 error: usage of wildcard import
-  --> $DIR/wildcard_imports_2021.rs:210:13
+  --> $DIR/wildcard_imports_2021.rs:238:13
    |
 LL |         use crate::super_imports::*;
    |             ^^^^^^^^^^^^^^^^^^^^^^^ help: try: `crate::super_imports::foofoo`
 
 error: usage of wildcard import
-  --> $DIR/wildcard_imports_2021.rs:219:17
+  --> $DIR/wildcard_imports_2021.rs:247:17
    |
 LL |             use super::super::*;
    |                 ^^^^^^^^^^^^^^^ help: try: `super::super::foofoo`
 
 error: usage of wildcard import
-  --> $DIR/wildcard_imports_2021.rs:228:13
+  --> $DIR/wildcard_imports_2021.rs:256:13
    |
 LL |         use super::super::super_imports::*;
    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `super::super::super_imports::foofoo`
 
 error: usage of wildcard import
-  --> $DIR/wildcard_imports_2021.rs:236:13
+  --> $DIR/wildcard_imports_2021.rs:264:13
    |
 LL |         use super::*;
    |             ^^^^^^^^ help: try: `super::foofoo`
 
-error: aborting due to 21 previous errors
+error: aborting due to 22 previous errors
 
diff --git a/tests/ui/wildcard_imports_2021.edition2021.fixed b/tests/ui/wildcard_imports_2021.edition2021.fixed
index b27281fa25c..6a9fe007d65 100644
--- a/tests/ui/wildcard_imports_2021.edition2021.fixed
+++ b/tests/ui/wildcard_imports_2021.edition2021.fixed
@@ -64,6 +64,34 @@ mod struct_mod {
     }
 }
 
+// issue 9942
+mod underscore_mod {
+    // allow use of `deref` so that `clippy --fix` includes `Deref`.
+    #![allow(noop_method_call)]
+
+    mod exports_underscore {
+        pub use std::ops::Deref as _;
+        pub fn dummy() {}
+    }
+
+    mod exports_underscore_ish {
+        pub use std::ops::Deref as _Deref;
+        pub fn dummy() {}
+    }
+
+    fn does_not_lint() {
+        use exports_underscore::*;
+        let _ = (&0).deref();
+        dummy();
+    }
+
+    fn does_lint() {
+        use exports_underscore_ish::{_Deref, dummy};
+        let _ = (&0).deref();
+        dummy();
+    }
+}
+
 fn main() {
     foo();
     multi_foo();
diff --git a/tests/ui/wildcard_imports_2021.edition2021.stderr b/tests/ui/wildcard_imports_2021.edition2021.stderr
index 709a665d65c..e39f240a4aa 100644
--- a/tests/ui/wildcard_imports_2021.edition2021.stderr
+++ b/tests/ui/wildcard_imports_2021.edition2021.stderr
@@ -38,55 +38,61 @@ LL | use wildcard_imports_helper::*;
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `wildcard_imports_helper::{ExternA, extern_foo}`
 
 error: usage of wildcard import
-  --> $DIR/wildcard_imports_2021.rs:91:13
+  --> $DIR/wildcard_imports_2021.rs:89:13
+   |
+LL |         use exports_underscore_ish::*;
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `exports_underscore_ish::{_Deref, dummy}`
+
+error: usage of wildcard import
+  --> $DIR/wildcard_imports_2021.rs:119:13
    |
 LL |         use crate::fn_mod::*;
    |             ^^^^^^^^^^^^^^^^ help: try: `crate::fn_mod::foo`
 
 error: usage of wildcard import
-  --> $DIR/wildcard_imports_2021.rs:97:75
+  --> $DIR/wildcard_imports_2021.rs:125:75
    |
 LL |         use wildcard_imports_helper::inner::inner_for_self_import::{self, *};
    |                                                                           ^ help: try: `inner_extern_foo`
 
 error: usage of wildcard import
-  --> $DIR/wildcard_imports_2021.rs:98:13
+  --> $DIR/wildcard_imports_2021.rs:126:13
    |
 LL |         use wildcard_imports_helper::*;
    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `wildcard_imports_helper::{ExternA, extern_foo}`
 
 error: usage of wildcard import
-  --> $DIR/wildcard_imports_2021.rs:110:20
+  --> $DIR/wildcard_imports_2021.rs:138:20
    |
 LL |         use self::{inner::*, inner2::*};
    |                    ^^^^^^^^ help: try: `inner::inner_foo`
 
 error: usage of wildcard import
-  --> $DIR/wildcard_imports_2021.rs:110:30
+  --> $DIR/wildcard_imports_2021.rs:138:30
    |
 LL |         use self::{inner::*, inner2::*};
    |                              ^^^^^^^^^ help: try: `inner2::inner_bar`
 
 error: usage of wildcard import
-  --> $DIR/wildcard_imports_2021.rs:117:13
+  --> $DIR/wildcard_imports_2021.rs:145:13
    |
 LL |         use wildcard_imports_helper::*;
    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `wildcard_imports_helper::{ExternExportedEnum, ExternExportedStruct, extern_exported}`
 
 error: usage of wildcard import
-  --> $DIR/wildcard_imports_2021.rs:146:9
+  --> $DIR/wildcard_imports_2021.rs:174:9
    |
 LL |     use crate::in_fn_test::*;
    |         ^^^^^^^^^^^^^^^^^^^^ help: try: `crate::in_fn_test::{ExportedEnum, ExportedStruct, exported}`
 
 error: usage of wildcard import
-  --> $DIR/wildcard_imports_2021.rs:155:9
+  --> $DIR/wildcard_imports_2021.rs:183:9
    |
 LL |     use crate:: in_fn_test::  * ;
    |         ^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `crate:: in_fn_test::exported`
 
 error: usage of wildcard import
-  --> $DIR/wildcard_imports_2021.rs:156:9
+  --> $DIR/wildcard_imports_2021.rs:184:9
    |
 LL |       use crate:: fn_mod::
    |  _________^
@@ -94,40 +100,40 @@ LL | |         *;
    | |_________^ help: try: `crate:: fn_mod::foo`
 
 error: usage of wildcard import
-  --> $DIR/wildcard_imports_2021.rs:167:13
+  --> $DIR/wildcard_imports_2021.rs:195:13
    |
 LL |         use super::*;
    |             ^^^^^^^^ help: try: `super::foofoo`
 
 error: usage of wildcard import
-  --> $DIR/wildcard_imports_2021.rs:202:17
+  --> $DIR/wildcard_imports_2021.rs:230:17
    |
 LL |             use super::*;
    |                 ^^^^^^^^ help: try: `super::insidefoo`
 
 error: usage of wildcard import
-  --> $DIR/wildcard_imports_2021.rs:210:13
+  --> $DIR/wildcard_imports_2021.rs:238:13
    |
 LL |         use crate::super_imports::*;
    |             ^^^^^^^^^^^^^^^^^^^^^^^ help: try: `crate::super_imports::foofoo`
 
 error: usage of wildcard import
-  --> $DIR/wildcard_imports_2021.rs:219:17
+  --> $DIR/wildcard_imports_2021.rs:247:17
    |
 LL |             use super::super::*;
    |                 ^^^^^^^^^^^^^^^ help: try: `super::super::foofoo`
 
 error: usage of wildcard import
-  --> $DIR/wildcard_imports_2021.rs:228:13
+  --> $DIR/wildcard_imports_2021.rs:256:13
    |
 LL |         use super::super::super_imports::*;
    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `super::super::super_imports::foofoo`
 
 error: usage of wildcard import
-  --> $DIR/wildcard_imports_2021.rs:236:13
+  --> $DIR/wildcard_imports_2021.rs:264:13
    |
 LL |         use super::*;
    |             ^^^^^^^^ help: try: `super::foofoo`
 
-error: aborting due to 21 previous errors
+error: aborting due to 22 previous errors
 
diff --git a/tests/ui/wildcard_imports_2021.rs b/tests/ui/wildcard_imports_2021.rs
index 7dd2103eca7..18ebc0f5127 100644
--- a/tests/ui/wildcard_imports_2021.rs
+++ b/tests/ui/wildcard_imports_2021.rs
@@ -64,6 +64,34 @@ mod struct_mod {
     }
 }
 
+// issue 9942
+mod underscore_mod {
+    // allow use of `deref` so that `clippy --fix` includes `Deref`.
+    #![allow(noop_method_call)]
+
+    mod exports_underscore {
+        pub use std::ops::Deref as _;
+        pub fn dummy() {}
+    }
+
+    mod exports_underscore_ish {
+        pub use std::ops::Deref as _Deref;
+        pub fn dummy() {}
+    }
+
+    fn does_not_lint() {
+        use exports_underscore::*;
+        let _ = (&0).deref();
+        dummy();
+    }
+
+    fn does_lint() {
+        use exports_underscore_ish::*;
+        let _ = (&0).deref();
+        dummy();
+    }
+}
+
 fn main() {
     foo();
     multi_foo();