---

yaml
---
r: 221106
b: refs/heads/tmp
c: 0ca8e49
h: refs/heads/master
v: v3

Author: nagisa

[refs]

@@ -25,7 +25,7 @@ refs/tags/0.11.0: e1247cb1d0d681be034adb4b558b5a0c0d5720f9
 refs/tags/0.12.0: f0c419429ef30723ceaf6b42f9b5a2aeb5d2e2d1
 refs/heads/beta: c8bab9d06a179028a0d5129aa62f09d694d9cc49
 refs/tags/1.0.0-alpha: e42bd6d93a1d3433c486200587f8f9e12590a4d7
-refs/heads/tmp: 22502154e6c1aee835554216d4b5054fd8f570f8
+refs/heads/tmp: 0ca8e4994ee43ba9dfbded6e129b30ff5fe7a994
 refs/tags/1.0.0-alpha.2: 4c705f6bc559886632d3871b04f58aab093bfa2f
 refs/tags/homu-tmp: e58601ab085591c71a27ae82137fc313222c2270
 refs/tags/1.0.0-beta: 8cbb92b53468ee2b0c2d3eeb8567005953d40828

branches/tmp/src/librustc_lint/builtin.rs

@@ -53,7 +53,7 @@ use syntax::{abi, ast};
 use syntax::ast_util::{self, is_shift_binop, local_def};
 use syntax::attr::{self, AttrMetaMethods};
 use syntax::codemap::{self, Span};
-use syntax::feature_gate::{KNOWN_ATTRIBUTES, AttributeType, emit_feature_err};
+use syntax::feature_gate::{KNOWN_ATTRIBUTES, AttributeType};
 use syntax::parse::token;
 use syntax::ast::{TyIs, TyUs, TyI8, TyU8, TyI16, TyU16, TyI32, TyU32, TyI64, TyU64};
 use syntax::ptr::P;
@@ -382,11 +382,13 @@ impl LintPass for TypeLimits {
 
         fn check_unsigned_negation_feature(cx: &Context, span: Span) {
             if !cx.sess().features.borrow().negate_unsigned {
-                emit_feature_err(
-                    &cx.sess().parse_sess.span_diagnostic,
-                    "negate_unsigned",
-                    span,
-                    "unary negation of unsigned integers may be removed in the future");
+                // FIXME(#27141): change this to syntax::feature_gate::emit_feature_err…
+                cx.sess().span_warn(span,
+                    "unary negation of unsigned integers will be feature gated in the future");
+                // …and remove following two expressions.
+                if option_env!("CFG_DISABLE_UNSTABLE_FEATURES").is_some() { return; }
+                cx.sess().fileline_help(span, "add #![feature(negate_unsigned)] to the \
+                                               crate attributes to enable the gate in advance");
             }
         }
     }

branches/tmp/src/test/compile-fail/feature-gate-negate-unsigned.rs renamed to branches/tmp/src/test/run-pass/feature-gate-negate-unsigned.rs

@@ -18,21 +18,21 @@ impl std::ops::Neg for S {
 }
 
 const _MAX: usize = -1;
-//~^ ERROR unary negation of unsigned integers may be removed in the future
+//~^ WARN unary negation of unsigned integers will be feature gated in the future
 
 fn main() {
     let a = -1;
-    //~^ ERROR unary negation of unsigned integers may be removed in the future
+    //~^ WARN unary negation of unsigned integers will be feature gated in the future
     let _b : u8 = a; // for infering variable a to u8.
 
     -a;
-    //~^ ERROR unary negation of unsigned integers may be removed in the future
+    //~^ WARN unary negation of unsigned integers will be feature gated in the future
 
     let _d = -1u8;
-    //~^ ERROR unary negation of unsigned integers may be removed in the future
+    //~^ WARN unary negation of unsigned integers will be feature gated in the future
 
     for _ in -10..10u8 {}
-    //~^ ERROR unary negation of unsigned integers may be removed in the future
+    //~^ WARN unary negation of unsigned integers will be feature gated in the future
 
     -S; // should not trigger the gate; issue 26840
 }