Rollup merge of rust-lang#54870 - flip1995:stabilize_tool_lints, r=Manishearth

Stabilize tool lints

cc rust-lang#44690

This stabilizes the `tool_lints` feature.

This is my first stabilization PR, let me know if I missed something. I followed the guide on https://forge.rust-lang.org. Should the documentation of the `tool_lints` be moved to `rust-lang-nursery/reference`?

r? @Manishearth @nrc

Author: pietroalbini

src/doc/unstable-book/src/language-features/tool-lints.md

@@ -18,11 +18,10 @@ use lint::context::CheckLintNameResult;
 use lint::{self, Lint, LintId, Level, LintSource};
 use rustc_data_structures::stable_hasher::{HashStable, ToStableHashKey,
                                            StableHasher, StableHasherResult};
-use session::{config::nightly_options, Session};
+use session::Session;
 use syntax::ast;
 use syntax::attr;
 use syntax::source_map::MultiSpan;
-use syntax::feature_gate;
 use syntax::symbol::Symbol;
 use util::nodemap::FxHashMap;
 
@@ -228,28 +227,14 @@ impl<'a> LintLevelsBuilder<'a> {
                     }
                 };
                 let tool_name = if let Some(lint_tool) = word.is_scoped() {
-                    let gate_feature = !self.sess.features_untracked().tool_lints;
-                    let known_tool = attr::is_known_lint_tool(lint_tool);
-                    if gate_feature {
-                        feature_gate::emit_feature_err(
-                            &sess.parse_sess,
-                            "tool_lints",
-                            word.span,
-                            feature_gate::GateIssue::Language,
-                            &format!("scoped lint `{}` is experimental", word.ident),
-                        );
-                    }
-                    if !known_tool {
+                    if !attr::is_known_lint_tool(lint_tool) {
                         span_err!(
                             sess,
                             lint_tool.span,
                             E0710,
                             "an unknown tool name found in scoped lint: `{}`",
                             word.ident
                         );
-                    }
-
-                    if gate_feature || !known_tool {
                         continue;
                     }
 
@@ -299,13 +284,7 @@ impl<'a> LintLevelsBuilder<'a> {
                                     "change it to",
                                     new_lint_name.to_string(),
                                     Applicability::MachineApplicable,
-                                );
-
-                                if nightly_options::is_nightly_build() {
-                                    err.emit();
-                                } else {
-                                    err.cancel();
-                                }
+                                ).emit();
 
                                 let src = LintSource::Node(Symbol::intern(&new_lint_name), li.span);
                                 for id in ids {

src/librustc/lint/levels.rs

@@ -433,9 +433,6 @@ declare_features! (
     // #[doc(alias = "...")]
     (active, doc_alias, "1.27.0", Some(50146), None),
 
-    // Scoped lints
-    (active, tool_lints, "1.28.0", Some(44690), None),
-
     // Allows irrefutable patterns in if-let and while-let statements (RFC 2086)
     (active, irrefutable_let_patterns, "1.27.0", Some(44495), None),
 
@@ -679,6 +676,8 @@ declare_features! (
     (accepted, pattern_parentheses, "1.31.0", Some(51087), None),
     // Allows the definition of `const fn` functions.
     (accepted, min_const_fn, "1.31.0", Some(53555), None),
+    // Scoped lints
+    (accepted, tool_lints, "1.31.0", Some(44690), None),
 );
 
 // If you change this, please modify src/doc/unstable-book as well. You must

src/libsyntax/feature_gate.rs

@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(tool_lints)]
+
 #![deny(unknown_lints)]
 
 #[allow(clippy::almost_swapped)]

src/test/run-pass/tool_lints.rs

@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(tool_lints)]
+
 #![feature(rust_2018_preview)]
 #![deny(unknown_lints)]
 

src/test/run-pass/tool_lints_2018_preview.rs

@@ -11,8 +11,8 @@
 // aux-build:lint_tool_test.rs
 // ignore-stage1
 // compile-flags: --cfg foo
+
 #![feature(plugin)]
-#![feature(tool_lints)]
 #![plugin(lint_tool_test)]
 #![allow(dead_code)]
 #![cfg_attr(foo, warn(test_lint))]

src/test/ui-fulldeps/lint_tool_test.rs

@@ -10,7 +10,7 @@
 
 // Don't allow tool_lints, which aren't scoped
 
-#![feature(tool_lints)]
+
 #![deny(unknown_lints)]
 
 #![deny(clippy)] //~ ERROR: unknown lint: `clippy`

src/test/ui/feature-gates/feature-gate-tool_lints-fail.rs

@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(tool_lints)]
+
 
 #[warn(foo::bar)]
 //~^ ERROR an unknown tool name found in scoped lint: `foo::bar`

src/test/ui/feature-gates/feature-gate-tool_lints-fail.stderr

@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(tool_lints)]
+
 
 #![deny(foo::bar)] //~ ERROR an unknown tool name found in scoped lint: `foo::bar`