Merging upstream version 1.68.2+dfsg1.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

14 files changed, 354 insertions, 0 deletions

diff --git a/tests/ui/underscore-imports/auxiliary/duplicate.rs b/tests/ui/underscore-imports/auxiliary/duplicate.rs
new file mode 100644
index 000000000..92d741b6a
--- /dev/null
+++ b/tests/ui/underscore-imports/auxiliary/duplicate.rs
@@ -0,0 +1,14 @@
+// force-host
+// no-prefer-dynamic
+
+#![crate_type = "proc-macro"]
+
+extern crate proc_macro;
+
+use proc_macro::*;
+
+#[proc_macro_attribute]
+pub fn duplicate(_: TokenStream, input: TokenStream) -> TokenStream {
+    let clone = input.clone();
+    input.into_iter().chain(clone.into_iter()).collect()
+}
diff --git a/tests/ui/underscore-imports/auxiliary/underscore-imports.rs b/tests/ui/underscore-imports/auxiliary/underscore-imports.rs
new file mode 100644
index 000000000..c335336be
--- /dev/null
+++ b/tests/ui/underscore-imports/auxiliary/underscore-imports.rs
@@ -0,0 +1,20 @@
+#[macro_export]
+macro_rules! do_nothing {
+    () => ()
+}
+
+mod m1 {
+    pub trait InScope1 {
+        fn in_scope1(&self) {}
+    }
+    impl InScope1 for () {}
+}
+mod m2 {
+    pub trait InScope2 {
+        fn in_scope2(&self) {}
+    }
+    impl InScope2 for () {}
+}
+
+pub use m1::InScope1 as _;
+pub use m2::InScope2 as _;
diff --git a/tests/ui/underscore-imports/basic.rs b/tests/ui/underscore-imports/basic.rs
new file mode 100644
index 000000000..c021ad5ee
--- /dev/null
+++ b/tests/ui/underscore-imports/basic.rs
@@ -0,0 +1,62 @@
+// check-pass
+// aux-build:underscore-imports.rs
+
+#![warn(unused_imports, unused_extern_crates)]
+
+#[macro_use]
+extern crate underscore_imports as _;
+
+do_nothing!(); // OK
+
+struct S;
+
+mod m {
+    pub trait Tr1 {
+        fn tr1_is_in_scope(&self) {}
+    }
+    pub trait Tr2 {
+        fn tr2_is_in_scope(&self) {}
+    }
+
+    impl Tr1 for ::S {}
+    impl Tr2 for ::S {}
+}
+
+mod unused {
+    use m::Tr1 as _; //~ WARN unused import
+    use S as _; //~ WARN unused import
+    extern crate core as _; // OK
+}
+
+mod outer {
+    mod middle {
+        pub use m::Tr1 as _;
+        pub use m::Tr2 as _; // OK, no name conflict
+        struct Tr1; // OK, no name conflict
+        fn check() {
+            // Both traits are in scope
+            ::S.tr1_is_in_scope();
+            ::S.tr2_is_in_scope();
+        }
+
+        mod inner {
+            // `_` imports are fetched by glob imports
+            use super::*;
+            fn check() {
+                // Both traits are in scope
+                ::S.tr1_is_in_scope();
+                ::S.tr2_is_in_scope();
+            }
+        }
+    }
+
+    // `_` imports are fetched by glob imports
+    use self::middle::*;
+    fn check() {
+        // Both traits are in scope
+        ::S.tr1_is_in_scope();
+        ::S.tr2_is_in_scope();
+    }
+}
+
+fn main() {}
diff --git a/tests/ui/underscore-imports/basic.stderr b/tests/ui/underscore-imports/basic.stderr
new file mode 100644
index 000000000..c51493562
--- /dev/null
+++ b/tests/ui/underscore-imports/basic.stderr
@@ -0,0 +1,20 @@
+warning: unused import: `m::Tr1 as _`
+  --> $DIR/basic.rs:26:9
+   |
+LL |     use m::Tr1 as _;
+   |         ^^^^^^^^^^^
+   |
+note: the lint level is defined here
+  --> $DIR/basic.rs:4:9
+   |
+LL | #![warn(unused_imports, unused_extern_crates)]
+   |         ^^^^^^^^^^^^^^
+
+warning: unused import: `S as _`
+  --> $DIR/basic.rs:27:9
+   |
+LL |     use S as _;
+   |         ^^^^^^
+
+warning: 2 warnings emitted
+
diff --git a/tests/ui/underscore-imports/cycle.rs b/tests/ui/underscore-imports/cycle.rs
new file mode 100644
index 000000000..bacf9b2d5
--- /dev/null
+++ b/tests/ui/underscore-imports/cycle.rs
@@ -0,0 +1,18 @@
+// Check that cyclic glob imports are allowed with underscore imports
+
+// check-pass
+
+mod x {
+    pub use crate::y::*;
+    pub use std::ops::Deref as _;
+}
+
+mod y {
+    pub use crate::x::*;
+    pub use std::ops::Deref as _;
+}
+
+pub fn main() {
+    use x::*;
+    (&0).deref();
+}
diff --git a/tests/ui/underscore-imports/duplicate.rs b/tests/ui/underscore-imports/duplicate.rs
new file mode 100644
index 000000000..20bc7848a
--- /dev/null
+++ b/tests/ui/underscore-imports/duplicate.rs
@@ -0,0 +1,15 @@
+// check-pass
+// aux-build:duplicate.rs
+
+extern crate duplicate;
+
+#[duplicate::duplicate]
+use main as _; // OK
+
+macro_rules! duplicate {
+    ($item: item) => { $item $item }
+}
+
+duplicate!(use std as _;); // OK
+
+fn main() {}
diff --git a/tests/ui/underscore-imports/hygiene-2.rs b/tests/ui/underscore-imports/hygiene-2.rs
new file mode 100644
index 000000000..510d91d0d
--- /dev/null
+++ b/tests/ui/underscore-imports/hygiene-2.rs
@@ -0,0 +1,34 @@
+// Make sure that underscore imports with different contexts can exist in the
+// same scope.
+
+// check-pass
+
+#![feature(decl_macro)]
+
+mod x {
+    pub use std::ops::Deref as _;
+}
+
+macro n() {
+    pub use crate::x::*;
+}
+
+#[macro_export]
+macro_rules! p {
+    () => { pub use crate::x::*; }
+}
+
+macro m($y:ident) {
+    mod $y {
+        crate::n!(); // Reexport of `Deref` should not be imported in `main`
+        crate::p!(); // Reexport of `Deref` should be imported into `main`
+    }
+}
+
+m!(y);
+
+fn main() {
+    use crate::y::*;
+    #[allow(noop_method_call)]
+    (&()).deref();
+}
diff --git a/tests/ui/underscore-imports/hygiene.rs b/tests/ui/underscore-imports/hygiene.rs
new file mode 100644
index 000000000..c4db65245
--- /dev/null
+++ b/tests/ui/underscore-imports/hygiene.rs
@@ -0,0 +1,40 @@
+// Make sure that underscore imports have the same hygiene considerations as other imports.
+
+// check-pass
+
+#![feature(decl_macro)]
+
+mod x {
+    pub use std::ops::Deref as _;
+}
+
+macro glob_import() {
+    pub use crate::x::*;
+}
+
+macro underscore_import() {
+    use std::ops::DerefMut as _;
+}
+
+mod y {
+    crate::glob_import!();
+    crate::underscore_import!();
+}
+
+macro create_module($y:ident) {
+    mod $y {
+        crate::glob_import!();
+        crate::underscore_import!();
+    }
+}
+
+create_module!(z);
+
+fn main() {
+    use crate::y::*;
+    use crate::z::*;
+    glob_import!();
+    underscore_import!();
+    (&()).deref();
+    (&mut ()).deref_mut();
+}
diff --git a/tests/ui/underscore-imports/intercrate.rs b/tests/ui/underscore-imports/intercrate.rs
new file mode 100644
index 000000000..144f95bac
--- /dev/null
+++ b/tests/ui/underscore-imports/intercrate.rs
@@ -0,0 +1,11 @@
+// check-pass
+// aux-build:underscore-imports.rs
+
+extern crate underscore_imports;
+
+use underscore_imports::*;
+
+fn main() {
+    ().in_scope1();
+    ().in_scope2();
+}
diff --git a/tests/ui/underscore-imports/macro-expanded.rs b/tests/ui/underscore-imports/macro-expanded.rs
new file mode 100644
index 000000000..43f527bc9
--- /dev/null
+++ b/tests/ui/underscore-imports/macro-expanded.rs
@@ -0,0 +1,45 @@
+// Check that macro expanded underscore imports behave as expected
+
+// check-pass
+
+#![feature(decl_macro, rustc_attrs)]
+
+mod x {
+    pub use std::ops::Not as _;
+}
+
+macro m() {
+    mod w {
+        mod y {
+            pub use std::ops::Deref as _;
+        }
+        use crate::x::*;
+        use self::y::*;
+        use std::ops::DerefMut as _;
+        fn f() {
+            false.not();
+            (&()).deref();
+            (&mut ()).deref_mut();
+        }
+    }
+}
+
+#[rustc_macro_transparency = "transparent"]
+macro n() {
+    mod z {
+        pub use std::ops::Deref as _;
+    }
+    use crate::x::*;
+    use crate::z::*;
+    use std::ops::DerefMut as _;
+    fn f() {
+        false.not();
+        (&()).deref();
+        (&mut ()).deref_mut();
+    }
+}
+
+m!();
+n!();
+
+fn main() {}
diff --git a/tests/ui/underscore-imports/shadow.rs b/tests/ui/underscore-imports/shadow.rs
new file mode 100644
index 000000000..325f2001b
--- /dev/null
+++ b/tests/ui/underscore-imports/shadow.rs
@@ -0,0 +1,23 @@
+// Check that underscore imports don't cause glob imports to be unshadowed
+
+mod a {
+    pub use std::ops::Deref as Shadow;
+}
+
+mod b {
+    pub use crate::a::*;
+    macro_rules! m {
+        ($i:ident) => { pub struct $i; }
+    }
+    m!(Shadow);
+}
+
+mod c {
+    use crate::b::Shadow as _; // Only imports the struct
+
+    fn f(x: &()) {
+        x.deref(); //~ ERROR no method named `deref` found
+    }
+}
+
+fn main() {}
diff --git a/tests/ui/underscore-imports/shadow.stderr b/tests/ui/underscore-imports/shadow.stderr
new file mode 100644
index 000000000..7faede4e6
--- /dev/null
+++ b/tests/ui/underscore-imports/shadow.stderr
@@ -0,0 +1,15 @@
+error[E0599]: no method named `deref` found for reference `&()` in the current scope
+  --> $DIR/shadow.rs:19:11
+   |
+LL |         x.deref();
+   |           ^^^^^ method not found in `&()`
+   |
+   = help: items from traits can only be used if the trait is in scope
+help: the following trait is implemented but not in scope; perhaps add a `use` for it:
+   |
+LL |     use std::ops::Deref;
+   |
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0599`.
diff --git a/tests/ui/underscore-imports/unused-2018.rs b/tests/ui/underscore-imports/unused-2018.rs
new file mode 100644
index 000000000..d06a26a5f
--- /dev/null
+++ b/tests/ui/underscore-imports/unused-2018.rs
@@ -0,0 +1,17 @@
+// edition:2018
+
+#![deny(unused_imports)]
+
+mod multi_segment {
+    use core::any; //~ ERROR unused import: `core::any`
+}
+
+mod single_segment {
+    use core; //~ ERROR unused import: `core`
+}
+
+mod single_segment_underscore {
+    use core as _; // OK
+}
+
+fn main() {}
diff --git a/tests/ui/underscore-imports/unused-2018.stderr b/tests/ui/underscore-imports/unused-2018.stderr
new file mode 100644
index 000000000..2afb9a10e
--- /dev/null
+++ b/tests/ui/underscore-imports/unused-2018.stderr
@@ -0,0 +1,20 @@
+error: unused import: `core::any`
+  --> $DIR/unused-2018.rs:6:9
+   |
+LL |     use core::any;
+   |         ^^^^^^^^^
+   |
+note: the lint level is defined here
+  --> $DIR/unused-2018.rs:3:9
+   |
+LL | #![deny(unused_imports)]
+   |         ^^^^^^^^^^^^^^
+
+error: unused import: `core`
+  --> $DIR/unused-2018.rs:10:9
+   |
+LL |     use core;
+   |         ^^^^
+
+error: aborting due to 2 previous errors
+