Auto merge of #101479 - Dylan-DPC:rollup-v8ite0y, r=Dylan-DPC

Rollup of 5 pull requests

Successful merges:

 - #100658 (TyCtxt::get_attr should check that no duplicates are allowed)
 - #101021 (Migrate ``rustc_middle`` diagnostic)
 - #101287 (Document eager evaluation of `bool::then_some` argument)
 - #101412 (Some more cleanup in `core`)
 - #101427 (Fix ICE, generalize 'move generics to trait' suggestion for >0 non-rcvr arguments)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup

6 files changed, 91 insertions, 0 deletions

diff --git a/src/test/ui/attributes/issue-100631.rs b/src/test/ui/attributes/issue-100631.rs
new file mode 100644
index 00000000000..0fefcf83fd5
--- /dev/null
+++ b/src/test/ui/attributes/issue-100631.rs
@@ -0,0 +1,8 @@
+// issue #100631, make sure `TyCtxt::get_attr` only called by case that compiler
+// can reasonably deal with multiple attributes.
+// `repr` will use `TyCtxt::get_attrs` since it's `DuplicatesOk`.
+#[repr(C)] //~ ERROR: unsupported representation for zero-variant enum [E0084]
+#[repr(C)]
+enum Foo {}
+
+fn main() {}
diff --git a/src/test/ui/attributes/issue-100631.stderr b/src/test/ui/attributes/issue-100631.stderr
new file mode 100644
index 00000000000..caa5351ddc7
--- /dev/null
+++ b/src/test/ui/attributes/issue-100631.stderr
@@ -0,0 +1,12 @@
+error[E0084]: unsupported representation for zero-variant enum
+  --> $DIR/issue-100631.rs:4:1
+   |
+LL | #[repr(C)]
+   | ^^^^^^^^^^
+LL | #[repr(C)]
+LL | enum Foo {}
+   | -------- zero-variant enum
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0084`.
diff --git a/src/test/ui/suggestions/issue-101421.rs b/src/test/ui/suggestions/issue-101421.rs
new file mode 100644
index 00000000000..b615997d1a9
--- /dev/null
+++ b/src/test/ui/suggestions/issue-101421.rs
@@ -0,0 +1,12 @@
+pub trait Ice {
+    fn f(&self, _: ());
+}
+
+impl Ice for () {
+    fn f(&self, _: ()) {}
+}
+
+fn main() {
+    ().f::<()>(());
+    //~^ ERROR this associated function takes 0 generic arguments but 1 generic argument was supplied
+}
diff --git a/src/test/ui/suggestions/issue-101421.stderr b/src/test/ui/suggestions/issue-101421.stderr
new file mode 100644
index 00000000000..f8e1efb8820
--- /dev/null
+++ b/src/test/ui/suggestions/issue-101421.stderr
@@ -0,0 +1,17 @@
+error[E0107]: this associated function takes 0 generic arguments but 1 generic argument was supplied
+  --> $DIR/issue-101421.rs:10:8
+   |
+LL |     ().f::<()>(());
+   |        ^------ help: remove these generics
+   |        |
+   |        expected 0 generic arguments
+   |
+note: associated function defined here, with 0 generic parameters
+  --> $DIR/issue-101421.rs:2:8
+   |
+LL |     fn f(&self, _: ());
+   |        ^
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0107`.
diff --git a/src/test/ui/suggestions/move-generic-to-trait-in-method-with-params.rs b/src/test/ui/suggestions/move-generic-to-trait-in-method-with-params.rs
new file mode 100644
index 00000000000..2f540060a34
--- /dev/null
+++ b/src/test/ui/suggestions/move-generic-to-trait-in-method-with-params.rs
@@ -0,0 +1,18 @@
+// Generalizes the suggestion introduced in #100838
+
+trait Foo<T> {
+    fn bar(&self, _: T);
+}
+
+impl Foo<i32> for i32 {
+    fn bar(&self, x: i32) {
+        println!("{}", self + x);
+    }
+}
+
+fn main() {
+    1.bar::<i32>(0);
+    //~^ ERROR this associated function takes 0 generic arguments but 1 generic argument was supplied
+    //~| HELP consider moving this generic argument to the `Foo` trait, which takes up to 1 argument
+    //~| HELP remove these generics
+}
diff --git a/src/test/ui/suggestions/move-generic-to-trait-in-method-with-params.stderr b/src/test/ui/suggestions/move-generic-to-trait-in-method-with-params.stderr
new file mode 100644
index 00000000000..9557220f6bb
--- /dev/null
+++ b/src/test/ui/suggestions/move-generic-to-trait-in-method-with-params.stderr
@@ -0,0 +1,24 @@
+error[E0107]: this associated function takes 0 generic arguments but 1 generic argument was supplied
+  --> $DIR/move-generic-to-trait-in-method-with-params.rs:14:7
+   |
+LL |     1.bar::<i32>(0);
+   |       ^^^ expected 0 generic arguments
+   |
+note: associated function defined here, with 0 generic parameters
+  --> $DIR/move-generic-to-trait-in-method-with-params.rs:4:8
+   |
+LL |     fn bar(&self, _: T);
+   |        ^^^
+help: consider moving this generic argument to the `Foo` trait, which takes up to 1 argument
+   |
+LL |     Foo::<i32>::bar(1, 0);
+   |     ~~~~~~~~~~~~~~~~~~~~~
+help: remove these generics
+   |
+LL -     1.bar::<i32>(0);
+LL +     1.bar(0);
+   |
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0107`.