`#[diagnostic::on_unimplemented]` without filters

This commit adds support for a `#[diagnostic::on_unimplemented]`
attribute with the following options:

* `message` to customize the primary error message
* `note` to add a customized note message to an error message
* `label` to customize the label part of the error message

Co-authored-by: León Orell Valerian Liehr <me@fmease.dev>
Co-authored-by: Michael Goulet <michael@errs.io>

9 files changed, 207 insertions, 6 deletions

diff --git a/tests/ui/diagnostic_namespace/feature-gate-diagnostic_namespace.rs b/tests/ui/diagnostic_namespace/feature-gate-diagnostic_namespace.rs
index a686ed9c84e..b08e291621f 100644
--- a/tests/ui/diagnostic_namespace/feature-gate-diagnostic_namespace.rs
+++ b/tests/ui/diagnostic_namespace/feature-gate-diagnostic_namespace.rs
@@ -1,12 +1,12 @@
 #[diagnostic::non_existing_attribute]
 //~^ERROR `#[diagnostic]` attribute name space is experimental [E0658]
-//~|WARNING unknown diagnostic attribute [unknown_diagnostic_attributes]
+//~|WARNING unknown diagnostic attribute [unknown_or_malformed_diagnostic_attributes]
 pub trait Bar {
 }
 
 #[diagnostic::non_existing_attribute(with_option = "foo")]
 //~^ERROR `#[diagnostic]` attribute name space is experimental [E0658]
-//~|WARNING unknown diagnostic attribute [unknown_diagnostic_attributes]
+//~|WARNING unknown diagnostic attribute [unknown_or_malformed_diagnostic_attributes]
 struct Foo;
 
 fn main() {
diff --git a/tests/ui/diagnostic_namespace/feature-gate-diagnostic_namespace.stderr b/tests/ui/diagnostic_namespace/feature-gate-diagnostic_namespace.stderr
index 45c95cbb3c7..017d00e2c8e 100644
--- a/tests/ui/diagnostic_namespace/feature-gate-diagnostic_namespace.stderr
+++ b/tests/ui/diagnostic_namespace/feature-gate-diagnostic_namespace.stderr
@@ -4,7 +4,7 @@ error[E0658]: `#[diagnostic]` attribute name space is experimental
 LL | #[diagnostic::non_existing_attribute]
    |   ^^^^^^^^^^
    |
-   = note: see issue #94785 <https://github.com/rust-lang/rust/issues/94785> for more information
+   = note: see issue #111996 <https://github.com/rust-lang/rust/issues/111996> for more information
    = help: add `#![feature(diagnostic_namespace)]` to the crate attributes to enable
 
 error[E0658]: `#[diagnostic]` attribute name space is experimental
@@ -13,7 +13,7 @@ error[E0658]: `#[diagnostic]` attribute name space is experimental
 LL | #[diagnostic::non_existing_attribute(with_option = "foo")]
    |   ^^^^^^^^^^
    |
-   = note: see issue #94785 <https://github.com/rust-lang/rust/issues/94785> for more information
+   = note: see issue #111996 <https://github.com/rust-lang/rust/issues/111996> for more information
    = help: add `#![feature(diagnostic_namespace)]` to the crate attributes to enable
 
 warning: unknown diagnostic attribute
@@ -22,7 +22,7 @@ warning: unknown diagnostic attribute
 LL | #[diagnostic::non_existing_attribute]
    |               ^^^^^^^^^^^^^^^^^^^^^^
    |
-   = note: `#[warn(unknown_diagnostic_attributes)]` on by default
+   = note: `#[warn(unknown_or_malformed_diagnostic_attributes)]` on by default
 
 warning: unknown diagnostic attribute
   --> $DIR/feature-gate-diagnostic_namespace.rs:7:15
diff --git a/tests/ui/diagnostic_namespace/non_existing_attributes_accepted.stderr b/tests/ui/diagnostic_namespace/non_existing_attributes_accepted.stderr
index 4f9b7ba2bcf..753077b365e 100644
--- a/tests/ui/diagnostic_namespace/non_existing_attributes_accepted.stderr
+++ b/tests/ui/diagnostic_namespace/non_existing_attributes_accepted.stderr
@@ -4,7 +4,7 @@ warning: unknown diagnostic attribute
 LL | #[diagnostic::non_existing_attribute]
    |               ^^^^^^^^^^^^^^^^^^^^^^
    |
-   = note: `#[warn(unknown_diagnostic_attributes)]` on by default
+   = note: `#[warn(unknown_or_malformed_diagnostic_attributes)]` on by default
 
 warning: unknown diagnostic attribute
   --> $DIR/non_existing_attributes_accepted.rs:8:15
diff --git a/tests/ui/diagnostic_namespace/on_unimplemented/do_not_fail_parsing_on_invalid_options_1.rs b/tests/ui/diagnostic_namespace/on_unimplemented/do_not_fail_parsing_on_invalid_options_1.rs
new file mode 100644
index 00000000000..00fb59d14d7
--- /dev/null
+++ b/tests/ui/diagnostic_namespace/on_unimplemented/do_not_fail_parsing_on_invalid_options_1.rs
@@ -0,0 +1,37 @@
+#![feature(diagnostic_namespace)]
+
+#[diagnostic::on_unimplemented(unsupported = "foo")]
+//~^WARN malformed `on_unimplemented` attribute
+//~|WARN malformed `on_unimplemented` attribute
+trait Foo {}
+
+#[diagnostic::on_unimplemented(message = "Baz")]
+//~^WARN `#[diagnostic::on_unimplemented]` can only be applied to trait definitions
+struct Bar {}
+
+#[diagnostic::on_unimplemented(message = "Boom", unsupported = "Bar")]
+//~^WARN malformed `on_unimplemented` attribute
+//~|WARN malformed `on_unimplemented` attribute
+trait Baz {}
+
+#[diagnostic::on_unimplemented(message = "Boom", on(_Self = "i32", message = "whatever"))]
+//~^WARN malformed `on_unimplemented` attribute
+//~|WARN malformed `on_unimplemented` attribute
+trait Boom {}
+
+#[diagnostic::on_unimplemented = "boom"]
+//~^WARN malformed `on_unimplemented` attribute
+trait Doom {}
+
+fn take_foo(_: impl Foo) {}
+fn take_baz(_: impl Baz) {}
+fn take_boom(_: impl Boom) {}
+
+fn main() {
+    take_foo(1_i32);
+    //~^ERROR the trait bound `i32: Foo` is not satisfied
+    take_baz(1_i32);
+    //~^ERROR Boom
+    take_boom(1_i32);
+    //~^ERROR Boom
+}
diff --git a/tests/ui/diagnostic_namespace/on_unimplemented/do_not_fail_parsing_on_invalid_options_1.stderr b/tests/ui/diagnostic_namespace/on_unimplemented/do_not_fail_parsing_on_invalid_options_1.stderr
new file mode 100644
index 00000000000..bb1b29ef248
--- /dev/null
+++ b/tests/ui/diagnostic_namespace/on_unimplemented/do_not_fail_parsing_on_invalid_options_1.stderr
@@ -0,0 +1,110 @@
+warning: `#[diagnostic::on_unimplemented]` can only be applied to trait definitions
+  --> $DIR/do_not_fail_parsing_on_invalid_options_1.rs:8:1
+   |
+LL | #[diagnostic::on_unimplemented(message = "Baz")]
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: `#[warn(unknown_or_malformed_diagnostic_attributes)]` on by default
+
+warning: malformed `on_unimplemented` attribute
+  --> $DIR/do_not_fail_parsing_on_invalid_options_1.rs:3:32
+   |
+LL | #[diagnostic::on_unimplemented(unsupported = "foo")]
+   |                                ^^^^^^^^^^^^^^^^^^^
+
+warning: malformed `on_unimplemented` attribute
+  --> $DIR/do_not_fail_parsing_on_invalid_options_1.rs:12:50
+   |
+LL | #[diagnostic::on_unimplemented(message = "Boom", unsupported = "Bar")]
+   |                                                  ^^^^^^^^^^^^^^^^^^^
+
+warning: malformed `on_unimplemented` attribute
+  --> $DIR/do_not_fail_parsing_on_invalid_options_1.rs:17:50
+   |
+LL | #[diagnostic::on_unimplemented(message = "Boom", on(_Self = "i32", message = "whatever"))]
+   |                                                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+warning: malformed `on_unimplemented` attribute
+  --> $DIR/do_not_fail_parsing_on_invalid_options_1.rs:22:1
+   |
+LL | #[diagnostic::on_unimplemented = "boom"]
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+warning: malformed `on_unimplemented` attribute
+  --> $DIR/do_not_fail_parsing_on_invalid_options_1.rs:3:32
+   |
+LL | #[diagnostic::on_unimplemented(unsupported = "foo")]
+   |                                ^^^^^^^^^^^^^^^^^^^
+
+error[E0277]: the trait bound `i32: Foo` is not satisfied
+  --> $DIR/do_not_fail_parsing_on_invalid_options_1.rs:31:14
+   |
+LL |     take_foo(1_i32);
+   |     -------- ^^^^^ the trait `Foo` is not implemented for `i32`
+   |     |
+   |     required by a bound introduced by this call
+   |
+help: this trait has no implementations, consider adding one
+  --> $DIR/do_not_fail_parsing_on_invalid_options_1.rs:6:1
+   |
+LL | trait Foo {}
+   | ^^^^^^^^^
+note: required by a bound in `take_foo`
+  --> $DIR/do_not_fail_parsing_on_invalid_options_1.rs:26:21
+   |
+LL | fn take_foo(_: impl Foo) {}
+   |                     ^^^ required by this bound in `take_foo`
+
+warning: malformed `on_unimplemented` attribute
+  --> $DIR/do_not_fail_parsing_on_invalid_options_1.rs:12:50
+   |
+LL | #[diagnostic::on_unimplemented(message = "Boom", unsupported = "Bar")]
+   |                                                  ^^^^^^^^^^^^^^^^^^^
+
+error[E0277]: Boom
+  --> $DIR/do_not_fail_parsing_on_invalid_options_1.rs:33:14
+   |
+LL |     take_baz(1_i32);
+   |     -------- ^^^^^ the trait `Baz` is not implemented for `i32`
+   |     |
+   |     required by a bound introduced by this call
+   |
+help: this trait has no implementations, consider adding one
+  --> $DIR/do_not_fail_parsing_on_invalid_options_1.rs:15:1
+   |
+LL | trait Baz {}
+   | ^^^^^^^^^
+note: required by a bound in `take_baz`
+  --> $DIR/do_not_fail_parsing_on_invalid_options_1.rs:27:21
+   |
+LL | fn take_baz(_: impl Baz) {}
+   |                     ^^^ required by this bound in `take_baz`
+
+warning: malformed `on_unimplemented` attribute
+  --> $DIR/do_not_fail_parsing_on_invalid_options_1.rs:17:50
+   |
+LL | #[diagnostic::on_unimplemented(message = "Boom", on(_Self = "i32", message = "whatever"))]
+   |                                                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error[E0277]: Boom
+  --> $DIR/do_not_fail_parsing_on_invalid_options_1.rs:35:15
+   |
+LL |     take_boom(1_i32);
+   |     --------- ^^^^^ the trait `Boom` is not implemented for `i32`
+   |     |
+   |     required by a bound introduced by this call
+   |
+help: this trait has no implementations, consider adding one
+  --> $DIR/do_not_fail_parsing_on_invalid_options_1.rs:20:1
+   |
+LL | trait Boom {}
+   | ^^^^^^^^^^
+note: required by a bound in `take_boom`
+  --> $DIR/do_not_fail_parsing_on_invalid_options_1.rs:28:22
+   |
+LL | fn take_boom(_: impl Boom) {}
+   |                      ^^^^ required by this bound in `take_boom`
+
+error: aborting due to 3 previous errors; 8 warnings emitted
+
+For more information about this error, try `rustc --explain E0277`.
diff --git a/tests/ui/diagnostic_namespace/on_unimplemented/feature-gate-diagnostic_on_unimplemented.rs b/tests/ui/diagnostic_namespace/on_unimplemented/feature-gate-diagnostic_on_unimplemented.rs
new file mode 100644
index 00000000000..609a840c118
--- /dev/null
+++ b/tests/ui/diagnostic_namespace/on_unimplemented/feature-gate-diagnostic_on_unimplemented.rs
@@ -0,0 +1,7 @@
+#[diagnostic::on_unimplemented(message = "Foo")]
+//~^ERROR `#[diagnostic]` attribute name space is experimental [E0658]
+pub trait Bar {
+}
+
+fn main() {
+}
diff --git a/tests/ui/diagnostic_namespace/on_unimplemented/feature-gate-diagnostic_on_unimplemented.stderr b/tests/ui/diagnostic_namespace/on_unimplemented/feature-gate-diagnostic_on_unimplemented.stderr
new file mode 100644
index 00000000000..21f02e3a73b
--- /dev/null
+++ b/tests/ui/diagnostic_namespace/on_unimplemented/feature-gate-diagnostic_on_unimplemented.stderr
@@ -0,0 +1,12 @@
+error[E0658]: `#[diagnostic]` attribute name space is experimental
+  --> $DIR/feature-gate-diagnostic_on_unimplemented.rs:1:3
+   |
+LL | #[diagnostic::on_unimplemented(message = "Foo")]
+   |   ^^^^^^^^^^
+   |
+   = note: see issue #111996 <https://github.com/rust-lang/rust/issues/111996> for more information
+   = help: add `#![feature(diagnostic_namespace)]` to the crate attributes to enable
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0658`.
diff --git a/tests/ui/diagnostic_namespace/on_unimplemented/on_unimplemented_simple.rs b/tests/ui/diagnostic_namespace/on_unimplemented/on_unimplemented_simple.rs
new file mode 100644
index 00000000000..797edbc9ec5
--- /dev/null
+++ b/tests/ui/diagnostic_namespace/on_unimplemented/on_unimplemented_simple.rs
@@ -0,0 +1,11 @@
+#![feature(diagnostic_namespace)]
+
+#[diagnostic::on_unimplemented(message = "Foo", label = "Bar", note = "Baz")]
+trait Foo {}
+
+fn takes_foo(_: impl Foo) {}
+
+fn main() {
+    takes_foo(());
+    //~^ERROR Foo
+}
diff --git a/tests/ui/diagnostic_namespace/on_unimplemented/on_unimplemented_simple.stderr b/tests/ui/diagnostic_namespace/on_unimplemented/on_unimplemented_simple.stderr
new file mode 100644
index 00000000000..549c7caa720
--- /dev/null
+++ b/tests/ui/diagnostic_namespace/on_unimplemented/on_unimplemented_simple.stderr
@@ -0,0 +1,24 @@
+error[E0277]: Foo
+  --> $DIR/on_unimplemented_simple.rs:9:15
+   |
+LL |     takes_foo(());
+   |     --------- ^^ Bar
+   |     |
+   |     required by a bound introduced by this call
+   |
+   = help: the trait `Foo` is not implemented for `()`
+   = note: Baz
+help: this trait has no implementations, consider adding one
+  --> $DIR/on_unimplemented_simple.rs:4:1
+   |
+LL | trait Foo {}
+   | ^^^^^^^^^
+note: required by a bound in `takes_foo`
+  --> $DIR/on_unimplemented_simple.rs:6:22
+   |
+LL | fn takes_foo(_: impl Foo) {}
+   |                      ^^^ required by this bound in `takes_foo`
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0277`.