Allow tool-lints to specify a feature-gate too

Author: Nemo157

compiler/rustc_lint/src/levels.rs

@@ -440,8 +440,10 @@ impl<'s> LintLevelsBuilder<'s> {
                                     sp,
                                     reason,
                                 );
-                                for id in ids {
-                                    self.insert_spec(*id, (level, src));
+                                for &id in ids {
+                                    if self.check_gated_lint(id, attr.span) {
+                                        self.insert_spec(id, (level, src));
+                                    }
                                 }
                                 if let Level::Expect(expect_id) = level {
                                     self.lint_expectations.push((

compiler/rustc_lint_defs/src/lib.rs

@@ -658,18 +658,21 @@ macro_rules! declare_lint {
 macro_rules! declare_tool_lint {
     (
         $(#[$attr:meta])* $vis:vis $tool:ident ::$NAME:ident, $Level: ident, $desc: expr
+        $(, @feature_gate = $gate:expr;)?
     ) => (
-        $crate::declare_tool_lint!{$(#[$attr])* $vis $tool::$NAME, $Level, $desc, false}
+        $crate::declare_tool_lint!{$(#[$attr])* $vis $tool::$NAME, $Level, $desc, false $(, @feature_gate = $gate;)?}
     );
     (
         $(#[$attr:meta])* $vis:vis $tool:ident ::$NAME:ident, $Level:ident, $desc:expr,
         report_in_external_macro: $rep:expr
+        $(, @feature_gate = $gate:expr;)?
     ) => (
-         $crate::declare_tool_lint!{$(#[$attr])* $vis $tool::$NAME, $Level, $desc, $rep}
+         $crate::declare_tool_lint!{$(#[$attr])* $vis $tool::$NAME, $Level, $desc, $rep $(, @feature_gate = $gate;)?}
     );
     (
         $(#[$attr:meta])* $vis:vis $tool:ident ::$NAME:ident, $Level:ident, $desc:expr,
         $external:expr
+        $(, @feature_gate = $gate:expr;)?
     ) => (
         $(#[$attr])*
         $vis static $NAME: &$crate::Lint = &$crate::Lint {
@@ -680,8 +683,9 @@ macro_rules! declare_tool_lint {
             report_in_external_macro: $external,
             future_incompatible: None,
             is_plugin: true,
-            feature_gate: None,
+            $(feature_gate: Some($gate),)?
             crate_level_only: false,
+            ..$crate::Lint::default_fields_for_macro()
         };
     );
 }