Switch the primary diagnostic to unknown_lints

This also affects the `non_exhaustive_omitted_patterns` and
`must_not_suspend` lints as they are not stable. This also changes the
diagnostic level to pull from `unknown_lints` instead of always being
allow or deny.

compiler/rustc_lint/src/levels.rs

@@ -17,7 +17,7 @@ use rustc_session::lint::{
     builtin::{self, FORBIDDEN_LINT_GROUPS},
     Level, Lint, LintExpectationId, LintId,
 };
-use rustc_session::parse::feature_err;
+use rustc_session::parse::{add_feature_diagnostics, feature_err};
 use rustc_session::Session;
 use rustc_span::symbol::{sym, Symbol};
 use rustc_span::{source_map::MultiSpan, Span, DUMMY_SP};
@@ -104,10 +104,8 @@ impl<'s> LintLevelsBuilder<'s> {
     fn process_command_line(&mut self, sess: &Session, store: &LintStore) {
         self.sets.lint_cap = sess.opts.lint_cap.unwrap_or(Level::Forbid);
 
-        self.cur = self.sets.list.push(LintSet {
+        self.cur =
-            specs: FxHashMap::default(),
+            self.sets.list.push(LintSet { specs: FxHashMap::default(), parent: COMMAND_LINE });
-            parent: COMMAND_LINE,
-        });
         for &(ref lint_name, level) in &sess.opts.lint_opts {
             store.check_lint_name_cmdline(sess, &lint_name, level, self.registered_tools);
             let orig_level = level;
@@ -134,11 +132,7 @@ impl<'s> LintLevelsBuilder<'s> {
     /// Attempts to insert the `id` to `level_src` map entry. If unsuccessful
     /// (e.g. if a forbid was already inserted on the same scope), then emits a
     /// diagnostic with no change to `specs`.
-    fn insert_spec(
+    fn insert_spec(&mut self, id: LintId, (level, src): LevelAndSource) {
-        &mut self,
-        id: LintId,
-        (level, src): LevelAndSource,
-    ) {
         let (old_level, old_src) =
             self.sets.get_lint_level(id.lint, self.cur, Some(self.current_specs()), &self.sess);
         // Setting to a non-forbid level is an error if the lint previously had
@@ -163,7 +157,10 @@ impl<'s> LintLevelsBuilder<'s> {
                 };
                 debug!(
                     "fcw_warning={:?}, specs.get(&id) = {:?}, old_src={:?}, id_name={:?}",
-                    fcw_warning, self.current_specs(), old_src, id_name
+                    fcw_warning,
+                    self.current_specs(),
+                    old_src,
+                    id_name
                 );
 
                 let decorate_diag = |diag: &mut Diagnostic| {
@@ -249,10 +246,8 @@ impl<'s> LintLevelsBuilder<'s> {
         source_hir_id: Option<HirId>,
     ) -> BuilderPush {
         let prev = self.cur;
-        self.cur = self.sets.list.push(LintSet {
+        self.cur = self.sets.list.push(LintSet { specs: FxHashMap::default(), parent: prev });
-            specs: FxHashMap::default(),
+
-            parent: prev,
-        });
         let sess = self.sess;
         let bad_attr = |span| struct_span_err!(sess, span, E0452, "malformed lint attribute input");
         for (attr_index, attr) in attrs.iter().enumerate() {
@@ -391,8 +386,12 @@ impl<'s> LintLevelsBuilder<'s> {
                             }
                             Err((Some(ids), ref new_lint_name)) => {
                                 let lint = builtin::RENAMED_AND_REMOVED_LINTS;
-                                let (lvl, src) =
+                                let (lvl, src) = self.sets.get_lint_level(
-                                    self.sets.get_lint_level(lint, self.cur, Some(self.current_specs()), &sess);
+                                    lint,
+                                    self.cur,
+                                    Some(self.current_specs()),
+                                    &sess,
+                                );
                                 struct_lint_level(
                                     self.sess,
                                     lint,
@@ -462,8 +461,12 @@ impl<'s> LintLevelsBuilder<'s> {
 
                     CheckLintNameResult::Warning(msg, renamed) => {
                         let lint = builtin::RENAMED_AND_REMOVED_LINTS;
-                        let (renamed_lint_level, src) =
+                        let (renamed_lint_level, src) = self.sets.get_lint_level(
-                            self.sets.get_lint_level(lint, self.cur, Some(self.current_specs()), &sess);
+                            lint,
+                            self.cur,
+                            Some(self.current_specs()),
+                            &sess,
+                        );
                         struct_lint_level(
                             self.sess,
                             lint,
@@ -486,8 +489,12 @@ impl<'s> LintLevelsBuilder<'s> {
                     }
                     CheckLintNameResult::NoLint(suggestion) => {
                         let lint = builtin::UNKNOWN_LINTS;
-                        let (level, src) =
+                        let (level, src) = self.sets.get_lint_level(
-                            self.sets.get_lint_level(lint, self.cur, Some(self.current_specs()), self.sess);
+                            lint,
+                            self.cur,
+                            Some(self.current_specs()),
+                            self.sess,
+                        );
                         struct_lint_level(self.sess, lint, level, src, Some(sp.into()), |lint| {
                             let name = if let Some(tool_ident) = tool_ident {
                                 format!("{}::{}", tool_ident.name, name)
@@ -594,16 +601,14 @@ impl<'s> LintLevelsBuilder<'s> {
     fn check_gated_lint(&self, lint_id: LintId, span: Span) -> bool {
         if let Some(feature) = lint_id.lint.feature_gate {
             if !self.sess.features_untracked().enabled(feature) {
-                let (unknown_lints_level, _) = self.lint_level(builtin::UNKNOWN_LINTS);
+                let (level, src) = self.lint_level(builtin::UNKNOWN_LINTS);
-                if unknown_lints_level != Level::Allow {
+                struct_lint_level(self.sess, lint_id.lint, level, src, Some(span.into()), |lint| {
-                    feature_err(
+                    let mut db =
-                        &self.sess.parse_sess,
+                        lint.build(&format!("unknown lint: `{}`", lint_id.lint.name_lower()));
-                        feature,
+                    db.note(&format!("the `{}` lint is unstable", lint_id.lint.name_lower(),));
-                        span,
+                    add_feature_diagnostics(&mut db, &self.sess.parse_sess, feature);
-                        &format!("the `{}` lint is unstable", lint_id.lint.name_lower()),
+                    db.emit();
-                    )
+                });
-                    .emit();
-                }
                 return false;
             }
         }

compiler/rustc_lint_defs/src/builtin.rs

@@ -3775,6 +3775,7 @@ declare_lint! {
 
 declare_lint! {
     #[doc(hidden)]
+    /// Added for testing unsable lints; perma-unstable.
     pub TEST_UNSTABLE_LINT,
     Deny,
     "this unstable lint is only for testing",

compiler/rustc_session/src/parse.rs

@@ -98,7 +98,26 @@ pub fn feature_err_issue<'a>(
     explain: &str,
 ) -> DiagnosticBuilder<'a, ErrorGuaranteed> {
     let mut err = sess.span_diagnostic.struct_span_err_with_code(span, explain, error_code!(E0658));
+    add_feature_diagnostics_for_issue(&mut err, sess, feature, issue);
+    err
+}
 
+/// Adds the diagnostics for a feature to an existing error.
+pub fn add_feature_diagnostics<'a>(err: &mut Diagnostic, sess: &'a ParseSess, feature: Symbol) {
+    add_feature_diagnostics_for_issue(err, sess, feature, GateIssue::Language);
+}
+
+/// Adds the diagnostics for a feature to an existing error.
+///
+/// This variant allows you to control whether it is a library or language feature.
+/// Almost always, you want to use this for a language feature. If so, prefer
+/// `add_feature_diagnostics`.
+pub fn add_feature_diagnostics_for_issue<'a>(
+    err: &mut Diagnostic,
+    sess: &'a ParseSess,
+    feature: Symbol,
+    issue: GateIssue,
+) {
     if let Some(n) = find_feature_issue(feature, issue) {
         err.note(&format!(
             "see issue #{} <https://github.com/rust-lang/rust/issues/{}> for more information",
@@ -110,8 +129,6 @@ pub fn feature_err_issue<'a>(
     if sess.unstable_features.is_nightly_build() {
         err.help(&format!("add `#![feature({})]` to the crate attributes to enable", feature));
     }
-
-    err
 }
 
 /// Info about a parsing session.

src/test/ui/feature-gates/feature-gate-non_exhaustive_omitted_patterns_lint.rs

@@ -1,9 +1,11 @@
+// check-fail
+
 #![deny(non_exhaustive_omitted_patterns)]
-//~^ ERROR the `non_exhaustive_omitted_patterns` lint is unstable
+//~^ WARNING unknown lint: `non_exhaustive_omitted_patterns`
-//~| ERROR the `non_exhaustive_omitted_patterns` lint is unstable
+//~| WARNING unknown lint: `non_exhaustive_omitted_patterns`
 #![allow(non_exhaustive_omitted_patterns)]
-//~^ ERROR the `non_exhaustive_omitted_patterns` lint is unstable
+//~^ WARNING unknown lint: `non_exhaustive_omitted_patterns`
-//~| ERROR the `non_exhaustive_omitted_patterns` lint is unstable
+//~| WARNING unknown lint: `non_exhaustive_omitted_patterns`
 
 fn main() {
     enum Foo {
@@ -11,14 +13,15 @@ fn main() {
     }
 
     #[allow(non_exhaustive_omitted_patterns)]
+    //~^ WARNING unknown lint: `non_exhaustive_omitted_patterns`
+    //~| WARNING unknown lint: `non_exhaustive_omitted_patterns`
+    //~| WARNING unknown lint: `non_exhaustive_omitted_patterns`
+    //~| WARNING unknown lint: `non_exhaustive_omitted_patterns`
     match Foo::A {
         Foo::A => {}
         Foo::B => {}
     }
-    //~^^^^^ ERROR the `non_exhaustive_omitted_patterns` lint is unstable
+    //~^^^^ ERROR non-exhaustive patterns: `C` not covered
-    //~| ERROR the `non_exhaustive_omitted_patterns` lint is unstable
-    //~| ERROR the `non_exhaustive_omitted_patterns` lint is unstable
-    //~| ERROR the `non_exhaustive_omitted_patterns` lint is unstable
 
     match Foo::A {
         Foo::A => {}
@@ -26,6 +29,6 @@ fn main() {
         #[warn(non_exhaustive_omitted_patterns)]
         _ => {}
     }
-    //~^^^ ERROR the `non_exhaustive_omitted_patterns` lint is unstable
+    //~^^^ WARNING unknown lint: `non_exhaustive_omitted_patterns`
-    //~| ERROR the `non_exhaustive_omitted_patterns` lint is unstable
+    //~| WARNING unknown lint: `non_exhaustive_omitted_patterns`
 }

src/test/ui/feature-gates/feature-gate-non_exhaustive_omitted_patterns_lint.stderr

@@ -1,93 +1,119 @@
-error[E0658]: the `non_exhaustive_omitted_patterns` lint is unstable
+warning: unknown lint: `non_exhaustive_omitted_patterns`
-  --> $DIR/feature-gate-non_exhaustive_omitted_patterns_lint.rs:1:1
+  --> $DIR/feature-gate-non_exhaustive_omitted_patterns_lint.rs:3:1
    |
 LL | #![deny(non_exhaustive_omitted_patterns)]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
+   = note: `#[warn(non_exhaustive_omitted_patterns)]` on by default
+   = note: the `non_exhaustive_omitted_patterns` lint is unstable
    = note: see issue #89554 <https://github.com/rust-lang/rust/issues/89554> for more information
    = help: add `#![feature(non_exhaustive_omitted_patterns_lint)]` to the crate attributes to enable
 
-error[E0658]: the `non_exhaustive_omitted_patterns` lint is unstable
+warning: unknown lint: `non_exhaustive_omitted_patterns`
-  --> $DIR/feature-gate-non_exhaustive_omitted_patterns_lint.rs:4:1
+  --> $DIR/feature-gate-non_exhaustive_omitted_patterns_lint.rs:6:1
    |
 LL | #![allow(non_exhaustive_omitted_patterns)]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
+   = note: the `non_exhaustive_omitted_patterns` lint is unstable
    = note: see issue #89554 <https://github.com/rust-lang/rust/issues/89554> for more information
    = help: add `#![feature(non_exhaustive_omitted_patterns_lint)]` to the crate attributes to enable
 
-error[E0658]: the `non_exhaustive_omitted_patterns` lint is unstable
+warning: unknown lint: `non_exhaustive_omitted_patterns`
-  --> $DIR/feature-gate-non_exhaustive_omitted_patterns_lint.rs:13:5
+  --> $DIR/feature-gate-non_exhaustive_omitted_patterns_lint.rs:15:5
    |
 LL |     #[allow(non_exhaustive_omitted_patterns)]
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
+   = note: the `non_exhaustive_omitted_patterns` lint is unstable
    = note: see issue #89554 <https://github.com/rust-lang/rust/issues/89554> for more information
    = help: add `#![feature(non_exhaustive_omitted_patterns_lint)]` to the crate attributes to enable
 
-error[E0658]: the `non_exhaustive_omitted_patterns` lint is unstable
+warning: unknown lint: `non_exhaustive_omitted_patterns`
-  --> $DIR/feature-gate-non_exhaustive_omitted_patterns_lint.rs:13:5
+  --> $DIR/feature-gate-non_exhaustive_omitted_patterns_lint.rs:15:5
    |
 LL |     #[allow(non_exhaustive_omitted_patterns)]
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
+   = note: the `non_exhaustive_omitted_patterns` lint is unstable
    = note: see issue #89554 <https://github.com/rust-lang/rust/issues/89554> for more information
    = help: add `#![feature(non_exhaustive_omitted_patterns_lint)]` to the crate attributes to enable
 
-error[E0658]: the `non_exhaustive_omitted_patterns` lint is unstable
+warning: unknown lint: `non_exhaustive_omitted_patterns`
-  --> $DIR/feature-gate-non_exhaustive_omitted_patterns_lint.rs:26:9
+  --> $DIR/feature-gate-non_exhaustive_omitted_patterns_lint.rs:29:9
    |
 LL |         #[warn(non_exhaustive_omitted_patterns)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
+   = note: the `non_exhaustive_omitted_patterns` lint is unstable
    = note: see issue #89554 <https://github.com/rust-lang/rust/issues/89554> for more information
    = help: add `#![feature(non_exhaustive_omitted_patterns_lint)]` to the crate attributes to enable
 
-error[E0658]: the `non_exhaustive_omitted_patterns` lint is unstable
+warning: unknown lint: `non_exhaustive_omitted_patterns`
-  --> $DIR/feature-gate-non_exhaustive_omitted_patterns_lint.rs:1:1
+  --> $DIR/feature-gate-non_exhaustive_omitted_patterns_lint.rs:3:1
    |
 LL | #![deny(non_exhaustive_omitted_patterns)]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
+   = note: the `non_exhaustive_omitted_patterns` lint is unstable
    = note: see issue #89554 <https://github.com/rust-lang/rust/issues/89554> for more information
    = help: add `#![feature(non_exhaustive_omitted_patterns_lint)]` to the crate attributes to enable
 
-error[E0658]: the `non_exhaustive_omitted_patterns` lint is unstable
+warning: unknown lint: `non_exhaustive_omitted_patterns`
-  --> $DIR/feature-gate-non_exhaustive_omitted_patterns_lint.rs:4:1
+  --> $DIR/feature-gate-non_exhaustive_omitted_patterns_lint.rs:6:1
    |
 LL | #![allow(non_exhaustive_omitted_patterns)]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
+   = note: the `non_exhaustive_omitted_patterns` lint is unstable
    = note: see issue #89554 <https://github.com/rust-lang/rust/issues/89554> for more information
    = help: add `#![feature(non_exhaustive_omitted_patterns_lint)]` to the crate attributes to enable
 
-error[E0658]: the `non_exhaustive_omitted_patterns` lint is unstable
+warning: unknown lint: `non_exhaustive_omitted_patterns`
-  --> $DIR/feature-gate-non_exhaustive_omitted_patterns_lint.rs:13:5
+  --> $DIR/feature-gate-non_exhaustive_omitted_patterns_lint.rs:15:5
    |
 LL |     #[allow(non_exhaustive_omitted_patterns)]
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
+   = note: the `non_exhaustive_omitted_patterns` lint is unstable
    = note: see issue #89554 <https://github.com/rust-lang/rust/issues/89554> for more information
    = help: add `#![feature(non_exhaustive_omitted_patterns_lint)]` to the crate attributes to enable
 
-error[E0658]: the `non_exhaustive_omitted_patterns` lint is unstable
+warning: unknown lint: `non_exhaustive_omitted_patterns`
-  --> $DIR/feature-gate-non_exhaustive_omitted_patterns_lint.rs:13:5
+  --> $DIR/feature-gate-non_exhaustive_omitted_patterns_lint.rs:15:5
    |
 LL |     #[allow(non_exhaustive_omitted_patterns)]
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
+   = note: the `non_exhaustive_omitted_patterns` lint is unstable
    = note: see issue #89554 <https://github.com/rust-lang/rust/issues/89554> for more information
    = help: add `#![feature(non_exhaustive_omitted_patterns_lint)]` to the crate attributes to enable
 
-error[E0658]: the `non_exhaustive_omitted_patterns` lint is unstable
+warning: unknown lint: `non_exhaustive_omitted_patterns`
-  --> $DIR/feature-gate-non_exhaustive_omitted_patterns_lint.rs:26:9
+  --> $DIR/feature-gate-non_exhaustive_omitted_patterns_lint.rs:29:9
    |
 LL |         #[warn(non_exhaustive_omitted_patterns)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
+   = note: the `non_exhaustive_omitted_patterns` lint is unstable
    = note: see issue #89554 <https://github.com/rust-lang/rust/issues/89554> for more information
    = help: add `#![feature(non_exhaustive_omitted_patterns_lint)]` to the crate attributes to enable
 
-error: aborting due to 10 previous errors
+error[E0004]: non-exhaustive patterns: `C` not covered
+  --> $DIR/feature-gate-non_exhaustive_omitted_patterns_lint.rs:20:11
+   |
+LL | /     enum Foo {
+LL | |         A, B, C,
+   | |               - not covered
+LL | |     }
+   | |_____- `Foo` defined here
+...
+LL |       match Foo::A {
+   |             ^^^^^^ pattern `C` not covered
+   |
+   = help: ensure that all possible cases are being handled, possibly by adding wildcards or more match arms
+   = note: the matched value is of type `Foo`
 
-For more information about this error, try `rustc --explain E0658`.
+error: aborting due to previous error; 10 warnings emitted
+
+For more information about this error, try `rustc --explain E0004`.

src/test/ui/feature-gates/feature-gate-test_unstable_lint.rs

@@ -0,0 +1,9 @@
+// check-pass
+
+// `test_unstable_lint` is for testing and should never be stabilized.
+#![allow(test_unstable_lint)]
+//~^ WARNING unknown lint: `test_unstable_lint`
+//~| WARNING unknown lint: `test_unstable_lint`
+//~| WARNING unknown lint: `test_unstable_lint`
+
+fn main() {}

src/test/ui/feature-gates/feature-gate-test_unstable_lint.stderr

@@ -0,0 +1,30 @@
+warning: unknown lint: `test_unstable_lint`
+  --> $DIR/feature-gate-test_unstable_lint.rs:4:1
+   |
+LL | #![allow(test_unstable_lint)]
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: `#[warn(test_unstable_lint)]` on by default
+   = note: the `test_unstable_lint` lint is unstable
+   = help: add `#![feature(test_unstable_lint)]` to the crate attributes to enable
+
+warning: unknown lint: `test_unstable_lint`
+  --> $DIR/feature-gate-test_unstable_lint.rs:4:1
+   |
+LL | #![allow(test_unstable_lint)]
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: the `test_unstable_lint` lint is unstable
+   = help: add `#![feature(test_unstable_lint)]` to the crate attributes to enable
+
+warning: unknown lint: `test_unstable_lint`
+  --> $DIR/feature-gate-test_unstable_lint.rs:4:1
+   |
+LL | #![allow(test_unstable_lint)]
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: the `test_unstable_lint` lint is unstable
+   = help: add `#![feature(test_unstable_lint)]` to the crate attributes to enable
+
+warning: 3 warnings emitted
+

src/test/ui/lint/must_not_suspend/gated.rs

@@ -1,12 +1,15 @@
+// check-pass
+
 // edition:2018
-#![deny(must_not_suspend)]  //~ ERROR the `must_not_suspend`
+#![deny(must_not_suspend)]
-//~| ERROR the `must_not_suspend`
+//~^ WARNING unknown lint: `must_not_suspend`
-//~| ERROR the `must_not_suspend`
+//~| WARNING unknown lint: `must_not_suspend`
+//~| WARNING unknown lint: `must_not_suspend`
 
 async fn other() {}
 
 pub async fn uhoh(m: std::sync::Mutex<()>) {
-    let _guard = m.lock().unwrap(); //~ ERROR `MutexGuard` held across
+    let _guard = m.lock().unwrap();
     other().await;
 }
 

src/test/ui/lint/must_not_suspend/gated.stderr

@@ -1,54 +1,33 @@
-error[E0658]: the `must_not_suspend` lint is unstable
+warning: unknown lint: `must_not_suspend`
-  --> $DIR/gated.rs:2:1
+  --> $DIR/gated.rs:4:1
    |
 LL | #![deny(must_not_suspend)]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
+   = note: `#[warn(must_not_suspend)]` on by default
+   = note: the `must_not_suspend` lint is unstable
    = note: see issue #83310 <https://github.com/rust-lang/rust/issues/83310> for more information
    = help: add `#![feature(must_not_suspend)]` to the crate attributes to enable
 
-error[E0658]: the `must_not_suspend` lint is unstable
+warning: unknown lint: `must_not_suspend`
-  --> $DIR/gated.rs:2:1
+  --> $DIR/gated.rs:4:1
    |
 LL | #![deny(must_not_suspend)]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
+   = note: the `must_not_suspend` lint is unstable
    = note: see issue #83310 <https://github.com/rust-lang/rust/issues/83310> for more information
    = help: add `#![feature(must_not_suspend)]` to the crate attributes to enable
 
-error[E0658]: the `must_not_suspend` lint is unstable
+warning: unknown lint: `must_not_suspend`
-  --> $DIR/gated.rs:2:1
+  --> $DIR/gated.rs:4:1
    |
 LL | #![deny(must_not_suspend)]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
+   = note: the `must_not_suspend` lint is unstable
    = note: see issue #83310 <https://github.com/rust-lang/rust/issues/83310> for more information
    = help: add `#![feature(must_not_suspend)]` to the crate attributes to enable
 
-error: `MutexGuard` held across a suspend point, but should not be
+warning: 3 warnings emitted
-  --> $DIR/gated.rs:9:9
-   |
-LL |     let _guard = m.lock().unwrap();
-   |         ^^^^^^
-LL |     other().await;
-   |            ------ the value is held across this suspend point
-   |
-note: the lint level is defined here
-  --> $DIR/gated.rs:2:9
-   |
-LL | #![deny(must_not_suspend)]
-   |         ^^^^^^^^^^^^^^^^
-note: holding a MutexGuard across suspend points can cause deadlocks, delays, and cause Futures to not implement `Send`
-  --> $DIR/gated.rs:9:9
-   |
-LL |     let _guard = m.lock().unwrap();
-   |         ^^^^^^
-help: consider using a block (`{ ... }`) to shrink the value's scope, ending before the suspend point
-  --> $DIR/gated.rs:9:9
-   |
-LL |     let _guard = m.lock().unwrap();
-   |         ^^^^^^
 
-error: aborting due to 4 previous errors
-
-For more information about this error, try `rustc --explain E0658`.

src/test/ui/unknown-unstable-lints/deny-unstable-lint-command-line.rs

@@ -0,0 +1,6 @@
+// check-fail
+// compile-flags: -Dunknown_lints -Atest_unstable_lint
+// error-pattern: unknown lint: `test_unstable_lint`
+// error-pattern: the `test_unstable_lint` lint is unstable
+
+fn main() {}

src/test/ui/unknown-unstable-lints/deny-unstable-lint-command-line.stderr

@@ -0,0 +1,18 @@
+error: unknown lint: `test_unstable_lint`
+   |
+   = note: `-D test-unstable-lint` implied by `-D unknown-lints`
+   = note: the `test_unstable_lint` lint is unstable
+   = help: add `#![feature(test_unstable_lint)]` to the crate attributes to enable
+
+error: unknown lint: `test_unstable_lint`
+   |
+   = note: the `test_unstable_lint` lint is unstable
+   = help: add `#![feature(test_unstable_lint)]` to the crate attributes to enable
+
+error: unknown lint: `test_unstable_lint`
+   |
+   = note: the `test_unstable_lint` lint is unstable
+   = help: add `#![feature(test_unstable_lint)]` to the crate attributes to enable
+
+error: aborting due to 3 previous errors
+

src/test/ui/unknown-unstable-lints/deny-unstable-lint-inline.rs

@@ -0,0 +1,9 @@
+// check-fail
+
+#![deny(unknown_lints)]
+#![allow(test_unstable_lint)]
+//~^ ERROR unknown lint: `test_unstable_lint`
+//~| ERROR unknown lint: `test_unstable_lint`
+//~| ERROR unknown lint: `test_unstable_lint`
+
+fn main() {}

src/test/ui/unknown-unstable-lints/deny-unstable-lint-inline.stderr

@@ -0,0 +1,35 @@
+error: unknown lint: `test_unstable_lint`
+  --> $DIR/deny-unstable-lint-inline.rs:4:1
+   |
+LL | #![allow(test_unstable_lint)]
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+note: the lint level is defined here
+  --> $DIR/deny-unstable-lint-inline.rs:3:9
+   |
+LL | #![deny(unknown_lints)]
+   |         ^^^^^^^^^^^^^
+   = note: `#[deny(test_unstable_lint)]` implied by `#[deny(unknown_lints)]`
+   = note: the `test_unstable_lint` lint is unstable
+   = help: add `#![feature(test_unstable_lint)]` to the crate attributes to enable
+
+error: unknown lint: `test_unstable_lint`
+  --> $DIR/deny-unstable-lint-inline.rs:4:1
+   |
+LL | #![allow(test_unstable_lint)]
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: the `test_unstable_lint` lint is unstable
+   = help: add `#![feature(test_unstable_lint)]` to the crate attributes to enable
+
+error: unknown lint: `test_unstable_lint`
+  --> $DIR/deny-unstable-lint-inline.rs:4:1
+   |
+LL | #![allow(test_unstable_lint)]
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: the `test_unstable_lint` lint is unstable
+   = help: add `#![feature(test_unstable_lint)]` to the crate attributes to enable
+
+error: aborting due to 3 previous errors
+

src/test/ui/unknown-unstable-lints/unstable-lint-command-line.rs

@@ -1,5 +0,0 @@
-// check-fail
-// compile-flags: -Atest_unstable_lint
-// error-pattern: the `test_unstable_lint` lint is unstable
-
-fn main() {}

src/test/ui/unknown-unstable-lints/unstable-lint-command-line.stderr

@@ -1,11 +0,0 @@
-error[E0658]: the `test_unstable_lint` lint is unstable
-   |
-   = help: add `#![feature(test_unstable_lint)]` to the crate attributes to enable
-
-error[E0658]: the `test_unstable_lint` lint is unstable
-   |
-   = help: add `#![feature(test_unstable_lint)]` to the crate attributes to enable
-
-error: aborting due to 2 previous errors
-
-For more information about this error, try `rustc --explain E0658`.

src/test/ui/unknown-unstable-lints/unstable-lint-inline.rs

@@ -1,6 +0,0 @@
-// check-fail
-// error-pattern: the `test_unstable_lint` lint is unstable
-
-#![allow(test_unstable_lint)]
-
-fn main() {}

src/test/ui/unknown-unstable-lints/unstable-lint-inline.stderr

@@ -1,19 +0,0 @@
-error[E0658]: the `test_unstable_lint` lint is unstable
-  --> $DIR/unstable-lint-inline.rs:4:1
-   |
-LL | #![allow(test_unstable_lint)]
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-   |
-   = help: add `#![feature(test_unstable_lint)]` to the crate attributes to enable
-
-error[E0658]: the `test_unstable_lint` lint is unstable
-  --> $DIR/unstable-lint-inline.rs:4:1
-   |
-LL | #![allow(test_unstable_lint)]
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-   |
-   = help: add `#![feature(test_unstable_lint)]` to the crate attributes to enable
-
-error: aborting due to 2 previous errors
-
-For more information about this error, try `rustc --explain E0658`.

src/test/ui/unknown-unstable-lints/warn-unknown-unstable-lint-command-line.rs

@@ -0,0 +1,6 @@
+// check-pass
+// compile-flags: -Wunknown_lints -Atest_unstable_lint
+// error-pattern: unknown lint: `test_unstable_lint`
+// error-pattern: the `test_unstable_lint` lint is unstable
+
+fn main() {}

src/test/ui/unknown-unstable-lints/warn-unknown-unstable-lint-command-line.stderr

@@ -0,0 +1,18 @@
+warning: unknown lint: `test_unstable_lint`
+   |
+   = note: `-W test-unstable-lint` implied by `-W unknown-lints`
+   = note: the `test_unstable_lint` lint is unstable
+   = help: add `#![feature(test_unstable_lint)]` to the crate attributes to enable
+
+warning: unknown lint: `test_unstable_lint`
+   |
+   = note: the `test_unstable_lint` lint is unstable
+   = help: add `#![feature(test_unstable_lint)]` to the crate attributes to enable
+
+warning: unknown lint: `test_unstable_lint`
+   |
+   = note: the `test_unstable_lint` lint is unstable
+   = help: add `#![feature(test_unstable_lint)]` to the crate attributes to enable
+
+warning: 3 warnings emitted
+

src/test/ui/unknown-unstable-lints/warn-unknown-unstable-lint-inline.rs

@@ -0,0 +1,9 @@
+// check-pass
+
+#![warn(unknown_lints)]
+#![allow(test_unstable_lint)]
+//~^ WARNING unknown lint: `test_unstable_lint`
+//~| WARNING unknown lint: `test_unstable_lint`
+//~| WARNING unknown lint: `test_unstable_lint`
+
+fn main() {}

src/test/ui/unknown-unstable-lints/warn-unknown-unstable-lint-inline.stderr

@@ -0,0 +1,35 @@
+warning: unknown lint: `test_unstable_lint`
+  --> $DIR/warn-unknown-unstable-lint-inline.rs:4:1
+   |
+LL | #![allow(test_unstable_lint)]
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+note: the lint level is defined here
+  --> $DIR/warn-unknown-unstable-lint-inline.rs:3:9
+   |
+LL | #![warn(unknown_lints)]
+   |         ^^^^^^^^^^^^^
+   = note: `#[warn(test_unstable_lint)]` implied by `#[warn(unknown_lints)]`
+   = note: the `test_unstable_lint` lint is unstable
+   = help: add `#![feature(test_unstable_lint)]` to the crate attributes to enable
+
+warning: unknown lint: `test_unstable_lint`
+  --> $DIR/warn-unknown-unstable-lint-inline.rs:4:1
+   |
+LL | #![allow(test_unstable_lint)]
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: the `test_unstable_lint` lint is unstable
+   = help: add `#![feature(test_unstable_lint)]` to the crate attributes to enable
+
+warning: unknown lint: `test_unstable_lint`
+  --> $DIR/warn-unknown-unstable-lint-inline.rs:4:1
+   |
+LL | #![allow(test_unstable_lint)]
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: the `test_unstable_lint` lint is unstable
+   = help: add `#![feature(test_unstable_lint)]` to the crate attributes to enable
+
+warning: 3 warnings emitted
+