Auto merge of #42894 - petrochenkov:deny, r=nikomatsakis

Make sufficiently old or low-impact compatibility lints deny-by-default

Needs crater run before proceeding.

r? @nikomatsakis

src/librustc/diagnostics.rs

@@ -614,7 +614,7 @@ use std::mem::transmute;
 struct Foo<T>(Vec<T>);
 
 trait MyTransmutableType: Sized {
-    fn transmute(Vec<Self>) -> Foo<Self>;
+    fn transmute(_: Vec<Self>) -> Foo<Self>;
 }
 
 impl MyTransmutableType for u8 {

src/librustc/lint/builtin.rs

@@ -130,6 +130,12 @@ declare_lint! {
     "detect private items in public interfaces not caught by the old implementation"
 }
 
+declare_lint! {
+    pub PUB_USE_OF_PRIVATE_EXTERN_CRATE,
+    Deny,
+    "detect public reexports of private extern crates"
+}
+
 declare_lint! {
     pub INVALID_TYPE_PARAM_DEFAULT,
     Deny,
@@ -144,14 +150,14 @@ declare_lint! {
 
 declare_lint! {
     pub RESOLVE_TRAIT_ON_DEFAULTED_UNIT,
-    Warn,
+    Deny,
     "attempt to resolve a trait on an expression whose type cannot be inferred but which \
      currently defaults to ()"
 }
 
 declare_lint! {
     pub SAFE_EXTERN_STATICS,
-    Warn,
+    Deny,
     "safe access to extern statics was erroneously allowed"
 }
 
@@ -169,14 +175,14 @@ declare_lint! {
 
 declare_lint! {
     pub LEGACY_DIRECTORY_OWNERSHIP,
-    Warn,
+    Deny,
     "non-inline, non-`#[path]` modules (e.g. `mod foo;`) were erroneously allowed in some files \
      not named `mod.rs`"
 }
 
 declare_lint! {
     pub LEGACY_IMPORTS,
-    Warn,
+    Deny,
     "detects names that resolve to ambiguous glob imports with RFC 1560"
 }
 
@@ -188,13 +194,13 @@ declare_lint! {
 
 declare_lint! {
     pub MISSING_FRAGMENT_SPECIFIER,
-    Warn,
+    Deny,
     "detects missing fragment specifiers in unused `macro_rules!` patterns"
 }
 
 declare_lint! {
     pub PARENTHESIZED_PARAMS_IN_TYPES_AND_MODULES,
-    Warn,
+    Deny,
     "detects parenthesized generic parameters in type and module names"
 }
 
@@ -230,6 +236,7 @@ impl LintPass for HardwiredLints {
             TRIVIAL_CASTS,
             TRIVIAL_NUMERIC_CASTS,
             PRIVATE_IN_PUBLIC,
+            PUB_USE_OF_PRIVATE_EXTERN_CRATE,
             INVALID_TYPE_PARAM_DEFAULT,
             CONST_ERR,
             RENAMED_AND_REMOVED_LINTS,

src/librustc_lint/lib.rs

@@ -184,6 +184,10 @@ pub fn register_builtins(store: &mut lint::LintStore, sess: Option<&Session>) {
             id: LintId::of(PRIVATE_IN_PUBLIC),
             reference: "issue #34537 <https://github.com/rust-lang/rust/issues/34537>",
         },
+        FutureIncompatibleInfo {
+            id: LintId::of(PUB_USE_OF_PRIVATE_EXTERN_CRATE),
+            reference: "issue #34537 <https://github.com/rust-lang/rust/issues/34537>",
+        },
         FutureIncompatibleInfo {
             id: LintId::of(PATTERNS_IN_FNS_WITHOUT_BODY),
             reference: "issue #35203 <https://github.com/rust-lang/rust/issues/35203>",

src/librustc_resolve/diagnostics.rs

@@ -837,7 +837,7 @@ impl Something {} // ok!
 trait Foo {
     type N;
 
-    fn bar(Self::N); // ok!
+    fn bar(_: Self::N); // ok!
 }
 
 // or:

src/librustc_resolve/resolve_imports.rs

@@ -18,7 +18,7 @@ use {names_to_string, module_to_string};
 use {resolve_error, ResolutionError};
 
 use rustc::ty;
-use rustc::lint::builtin::PRIVATE_IN_PUBLIC;
+use rustc::lint::builtin::PUB_USE_OF_PRIVATE_EXTERN_CRATE;
 use rustc::hir::def_id::DefId;
 use rustc::hir::def::*;
 use rustc::util::nodemap::FxHashMap;
@@ -296,7 +296,8 @@ impl<'a> Resolver<'a> {
     pub fn import(&self, binding: &'a NameBinding<'a>, directive: &'a ImportDirective<'a>)
                   -> &'a NameBinding<'a> {
         let vis = if binding.pseudo_vis().is_at_least(directive.vis.get(), self) ||
-                     !directive.is_glob() && binding.is_extern_crate() { // c.f. `PRIVATE_IN_PUBLIC`
+                     // c.f. `PUB_USE_OF_PRIVATE_EXTERN_CRATE`
+                     !directive.is_glob() && binding.is_extern_crate() {
             directive.vis.get()
         } else {
             binding.pseudo_vis()
@@ -735,7 +736,8 @@ impl<'a, 'b:'a> ImportResolver<'a, 'b> {
                 let msg = format!("extern crate `{}` is private, and cannot be reexported \
                                    (error E0365), consider declaring with `pub`",
                                    ident);
-                self.session.add_lint(PRIVATE_IN_PUBLIC, directive.id, directive.span, msg);
+                self.session.add_lint(PUB_USE_OF_PRIVATE_EXTERN_CRATE,
+                                      directive.id, directive.span, msg);
             } else if ns == TypeNS {
                 struct_span_err!(self.session, directive.span, E0365,
                                  "`{}` is private, and cannot be reexported", ident)

src/librustc_typeck/diagnostics.rs

@@ -2476,7 +2476,7 @@ trait T2 {
     type Bar;
 
     // error: Baz is used but not declared
-    fn return_bool(&self, &Self::Bar, &Self::Baz) -> bool;
+    fn return_bool(&self, _: &Self::Bar, _: &Self::Baz) -> bool;
 }
 ```
 
@@ -2498,7 +2498,7 @@ trait T2 {
     type Baz; // we declare `Baz` in our trait.
 
     // and now we can use it here:
-    fn return_bool(&self, &Self::Bar, &Self::Baz) -> bool;
+    fn return_bool(&self, _: &Self::Bar, _: &Self::Baz) -> bool;
 }
 ```
 "##,

src/test/compile-fail/associated-types-ICE-when-projecting-out-of-err.rs

@@ -25,7 +25,7 @@ pub trait Sized {
 trait Add<RHS=Self> {
     type Output;
 
-    fn add(self, RHS) -> Self::Output;
+    fn add(self, _: RHS) -> Self::Output;
 }
 
 fn ice<A>(a: A) {

src/test/compile-fail/defaulted-unit-warning.rs

@@ -8,9 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![allow(dead_code)]
-#![allow(unreachable_code)]
-#![deny(resolve_trait_on_defaulted_unit)]
+#![allow(unused)]
 
 trait Deserialize: Sized {
     fn deserialize() -> Result<Self, String>;
@@ -38,4 +36,3 @@ fn smeg() {
 fn main() {
     smeg();
 }
-

src/test/compile-fail/directory_ownership/backcompat-warnings.rs

@@ -10,12 +10,8 @@
 
 // error-pattern: cannot declare a new module at this location
 // error-pattern: will become a hard error
-// error-pattern: compilation successful
-
-#![feature(rustc_attrs)]
 
 #[path="mod_file_not_owning_aux3.rs"]
 mod foo;
 
-#[rustc_error]
 fn main() {}

src/test/compile-fail/imports/rfc-1560-warning-cycle.rs

@@ -8,7 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(rustc_attrs)]
 #![allow(unused)]
 
 pub struct Foo;
@@ -20,12 +19,11 @@ mod bar {
         use *; //~ NOTE `Foo` could refer to the name imported here
         use bar::*; //~ NOTE `Foo` could also refer to the name imported here
         fn f(_: Foo) {}
-        //~^ WARN `Foo` is ambiguous
+        //~^ ERROR `Foo` is ambiguous
         //~| WARN hard error in a future release
         //~| NOTE see issue #38260
-        //~| NOTE #[warn(legacy_imports)] on by default
+        //~| NOTE #[deny(legacy_imports)] on by default
     }
 }
 
-#[rustc_error]
-fn main() {} //~ ERROR compilation successful
+fn main() {}

src/test/compile-fail/issue-13853-5.rs

@@ -11,7 +11,7 @@
 trait Deserializer<'a> { }
 
 trait Deserializable {
-    fn deserialize_token<'a, D: Deserializer<'a>>(D, &'a str) -> Self;
+    fn deserialize_token<'a, D: Deserializer<'a>>(_: D, _: &'a str) -> Self;
 }
 
 impl<'a, T: Deserializable> Deserializable for &'a str {

src/test/compile-fail/issue-18400.rs

@@ -9,8 +9,8 @@
 // except according to those terms.
 
 trait Set<T> {
-    fn contains(&self, T) -> bool;
-    fn set(&mut self, T);
+    fn contains(&self, _: T) -> bool;
+    fn set(&mut self, _: T);
 }
 
 impl<'a, T, S> Set<&'a [T]> for S where

src/test/compile-fail/issue-20831-debruijn.rs

@@ -22,7 +22,7 @@ pub trait Subscriber {
 
 pub trait Publisher<'a> {
     type Output;
-    fn subscribe(&mut self, Box<Subscriber<Input=Self::Output> + 'a>);
+    fn subscribe(&mut self, _: Box<Subscriber<Input=Self::Output> + 'a>);
 }
 
 pub trait Processor<'a> : Subscriber + Publisher<'a> { }

src/test/compile-fail/issue-32995-2.rs

@@ -8,23 +8,17 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![deny(parenthesized_params_in_types_and_modules)]
-//~^ NOTE lint level defined here
-//~| NOTE lint level defined here
-//~| NOTE lint level defined here
-#![allow(dead_code, unused_variables)]
 #![feature(conservative_impl_trait)]
+#![allow(unused)]
 
 fn main() {
     { fn f<X: ::std::marker()::Send>() {} }
     //~^ ERROR parenthesized parameters may only be used with a trait
     //~| WARN previously accepted
-    //~| NOTE issue #42238
 
     { fn f() -> impl ::std::marker()::Send { } }
     //~^ ERROR parenthesized parameters may only be used with a trait
     //~| WARN previously accepted
-    //~| NOTE issue #42238
 }
 
 #[derive(Clone)]
@@ -33,4 +27,3 @@ struct X;
 impl ::std::marker()::Copy for X {}
 //~^ ERROR parenthesized parameters may only be used with a trait
 //~| WARN previously accepted
-//~| NOTE issue #42238

src/test/compile-fail/issue-32995.rs

@@ -8,26 +8,16 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![deny(parenthesized_params_in_types_and_modules)]
-//~^ NOTE lint level defined here
-//~| NOTE lint level defined here
-//~| NOTE lint level defined here
-//~| NOTE lint level defined here
-//~| NOTE lint level defined here
-//~| NOTE lint level defined here
-//~| NOTE lint level defined here
-#![allow(dead_code, unused_variables)]
+#![allow(unused)]
 
 fn main() {
     let x: usize() = 1;
     //~^ ERROR parenthesized parameters may only be used with a trait
     //~| WARN previously accepted
-    //~| NOTE issue #42238
 
     let b: ::std::boxed()::Box<_> = Box::new(1);
     //~^ ERROR parenthesized parameters may only be used with a trait
     //~| WARN previously accepted
-    //~| NOTE issue #42238
 
     macro_rules! pathexpr {
         ($p:path) => { $p }
@@ -36,27 +26,22 @@ fn main() {
     let p = pathexpr!(::std::str()::from_utf8)(b"foo").unwrap();
     //~^ ERROR parenthesized parameters may only be used with a trait
     //~| WARN previously accepted
-    //~| NOTE issue #42238
 
     let p = pathexpr!(::std::str::from_utf8())(b"foo").unwrap();
     //~^ ERROR parenthesized parameters may only be used with a trait
     //~| WARN previously accepted
-    //~| NOTE issue #42238
 
     let o : Box<::std::marker()::Send> = Box::new(1);
     //~^ ERROR parenthesized parameters may only be used with a trait
     //~| WARN previously accepted
-    //~| NOTE issue #42238
 
     let o : Box<Send + ::std::marker()::Sync> = Box::new(1);
     //~^ ERROR parenthesized parameters may only be used with a trait
     //~| WARN previously accepted
-    //~| NOTE issue #42238
 }
 
 fn foo<X:Default>() {
     let d : X() = Default::default();
     //~^ ERROR parenthesized parameters may only be used with a trait
     //~| WARN previously accepted
-    //~| NOTE issue #42238
 }

src/test/compile-fail/issue-35869.rs

@@ -11,9 +11,9 @@
 #![feature(conservative_impl_trait)]
 
 trait Foo {
-    fn foo(fn(u8) -> ()); //~ NOTE type in trait
-    fn bar(Option<u8>); //~ NOTE type in trait
-    fn baz((u8, u16)); //~ NOTE type in trait
+    fn foo(_: fn(u8) -> ()); //~ NOTE type in trait
+    fn bar(_: Option<u8>); //~ NOTE type in trait
+    fn baz(_: (u8, u16)); //~ NOTE type in trait
     fn qux() -> u8; //~ NOTE type in trait
 }
 

src/test/compile-fail/issue-38293.rs

@@ -11,7 +11,6 @@
 // Test that `fn foo::bar::{self}` only imports `bar` in the type namespace.
 
 #![allow(unused)]
-#![deny(legacy_imports)]
 
 mod foo {
     pub fn f() { }

src/test/compile-fail/issue-39404.rs

@@ -8,12 +8,10 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![deny(missing_fragment_specifier)] //~ NOTE lint level defined here
-#![allow(unused_macros)]
+#![allow(unused)]
 
 macro_rules! m { ($i) => {} }
 //~^ ERROR missing fragment specifier
 //~| WARN previously accepted
-//~| NOTE issue #40107
 
 fn main() {}

src/test/compile-fail/no-patterns-in-args-2.rs

@@ -17,6 +17,7 @@ trait Tr {
                      //~^ WARN was previously accepted
     fn g1(arg: u8); // OK
     fn g2(_: u8); // OK
+    #[allow(anonymous_parameters)]
     fn g3(u8); // OK
 }
 

src/test/compile-fail/pub-reexport-priv-extern-crate.rs

@@ -9,7 +9,6 @@
 // except according to those terms.
 
 #![allow(unused)]
-#![deny(private_in_public)]
 
 extern crate core;
 pub use core as reexported_core; //~ ERROR `core` is private, and cannot be reexported

src/test/compile-fail/safe-extern-statics-mut.rs

@@ -10,9 +10,6 @@
 
 // aux-build:extern-statics.rs
 
-#![allow(unused)]
-#![deny(safe_extern_statics)]
-
 extern crate extern_statics;
 use extern_statics::*;
 

src/test/compile-fail/safe-extern-statics.rs

@@ -11,7 +11,6 @@
 // aux-build:extern-statics.rs
 
 #![allow(unused)]
-#![deny(safe_extern_statics)]
 
 extern crate extern_statics;
 use extern_statics::*;

src/test/compile-fail/type-parameter-invalid-lint.rs

@@ -10,7 +10,6 @@
 
 // gate-test-default_type_parameter_fallback
 
-#![deny(invalid_type_param_default)]
 #![allow(unused)]
 
 fn avg<T=i32>(_: T) {}

src/test/compile-fail/type-params-in-different-spaces-2.rs

@@ -12,7 +12,7 @@
 // type parameters on a trait correctly.
 
 trait Tr<T> : Sized {
-    fn op(T) -> Self;
+    fn op(_: T) -> Self;
 }
 
 trait A:    Tr<Self> {

src/test/compile-fail/variance-trait-bounds.rs

@@ -19,7 +19,7 @@ trait Getter<T> {
 }
 
 trait Setter<T> {
-    fn get(&self, T);
+    fn get(&self, _: T);
 }
 
 #[rustc_variance]

src/test/run-pass/associated-types-projection-in-object-type.rs

@@ -26,7 +26,7 @@ pub trait Subscriber {
 
 pub trait Publisher<'a> {
     type Output;
-    fn subscribe(&mut self, Box<Subscriber<Input=Self::Output> + 'a>);
+    fn subscribe(&mut self, _: Box<Subscriber<Input=Self::Output> + 'a>);
 }
 
 pub trait Processor<'a> : Subscriber + Publisher<'a> { }

src/test/run-pass/auxiliary/issue_3979_traits.rs

@@ -13,7 +13,7 @@
 #![crate_type = "lib"]
 
 pub trait Positioned {
-  fn SetX(&mut self, isize);
+  fn SetX(&mut self, _: isize);
   fn X(&self) -> isize;
 }
 

src/test/run-pass/auxiliary/xcrate-trait-lifetime-param.rs

@@ -9,5 +9,5 @@
 // except according to those terms.
 
 pub trait FromBuf<'a> {
-    fn from_buf(&'a [u8]) -> Self;
+    fn from_buf(_: &'a [u8]) -> Self;
 }

src/test/run-pass/dropck_legal_cycles.rs

@@ -442,7 +442,7 @@ pub fn main() {
 }
 
 trait Named {
-    fn new(&'static str) -> Self;
+    fn new(_: &'static str) -> Self;
     fn name(&self) -> &str;
 }
 
@@ -932,9 +932,9 @@ trait Context {
 }
 
 trait PrePost<T> {
-    fn pre(&mut self, &T);
-    fn post(&mut self, &T);
-    fn hit_limit(&mut self, &T);
+    fn pre(&mut self, _: &T);
+    fn post(&mut self, _: &T);
+    fn hit_limit(&mut self, _: &T);
 }
 
 trait Children<'a> {

src/test/run-pass/issue-13105.rs

@@ -11,6 +11,7 @@
 // pretty-expanded FIXME #23616
 
 trait Foo {
+    #[allow(anonymous_parameters)]
     fn quux(u8) {}
 }
 

src/test/run-pass/issue-13775.rs

@@ -11,6 +11,7 @@
 // pretty-expanded FIXME #23616
 
 trait Foo {
+    #[allow(anonymous_parameters)]
     fn bar(&self, isize) {}
 }
 

src/test/run-pass/issue-14919.rs

@@ -26,7 +26,7 @@ impl<'a, 'b> Matcher for CharPredMatcher<'a, 'b> {
 }
 
 trait IntoMatcher<'a, T> {
-    fn into_matcher(self, &'a str) -> T;
+    fn into_matcher(self, _: &'a str) -> T;
 }
 
 impl<'a, 'b, F> IntoMatcher<'a, CharPredMatcher<'a, 'b>> for F where F: FnMut(char) -> bool + 'b {

src/test/run-pass/issue-19098.rs

@@ -9,7 +9,7 @@
 // except according to those terms.
 
 pub trait Handler {
-    fn handle(&self, &mut String);
+    fn handle(&self, _: &mut String);
 }
 
 impl<F> Handler for F where F: for<'a, 'b> Fn(&'a mut String) {

src/test/run-pass/issue-21726.rs

@@ -23,7 +23,7 @@ fn foo<'a>(s: &'a str) {
 
 trait IntoRef<'a> {
     type T: Clone;
-    fn into_ref(self, &'a str) -> Self::T;
+    fn into_ref(self, _: &'a str) -> Self::T;
 }
 
 impl<'a> IntoRef<'a> for () {

src/test/run-pass/issue-34074.rs

@@ -8,9 +8,10 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-// Make sure several unnamed function arguments don't conflict with each other
+// Make sure several unnamed function parameters don't conflict with each other
 
 trait Tr {
+    #[allow(anonymous_parameters)]
     fn f(u8, u8) {}
 }
 

src/test/run-pass/issue-3979-generics.rs

@@ -12,7 +12,7 @@
 use std::ops::Add;
 
 trait Positioned<S> {
-  fn SetX(&mut self, S);
+  fn SetX(&mut self, _: S);
   fn X(&self) -> S;
 }
 

src/test/run-pass/issue-3979.rs

@@ -10,7 +10,7 @@
 
 
 trait Positioned {
-  fn SetX(&mut self, isize);
+  fn SetX(&mut self, _: isize);
   fn X(&self) -> isize;
 }
 

src/test/run-pass/issue-4107.rs

@@ -13,7 +13,7 @@ pub fn main() {
     let _id: &Mat2<f64> = &Matrix::identity(1.0);
 }
 
-pub trait Index<Index,Result> { fn get(&self, Index) -> Result { panic!() } }
+pub trait Index<Index,Result> { fn get(&self, _: Index) -> Result { panic!() } }
 pub trait Dimensional<T>: Index<usize, T> { }
 
 pub struct Mat2<T> { x: T }

src/test/run-pass/issue-6128.rs

@@ -14,9 +14,8 @@
 use std::collections::HashMap;
 
 trait Graph<Node, Edge> {
-    fn f(&self, Edge);
-    fn g(&self, Node);
-
+    fn f(&self, _: Edge);
+    fn g(&self, _: Node);
 }
 
 impl<E> Graph<isize, E> for HashMap<isize, isize> {

src/test/run-pass/issue-6157.rs

@@ -10,7 +10,7 @@
 
 // pretty-expanded FIXME #23616
 
-pub trait OpInt { fn call(&mut self, isize, isize) -> isize; }
+pub trait OpInt { fn call(&mut self, _: isize, _: isize) -> isize; }
 
 impl<F> OpInt for F where F: FnMut(isize, isize) -> isize {
     fn call(&mut self, a:isize, b:isize) -> isize {

src/test/run-pass/issue-9129.rs

@@ -13,7 +13,7 @@
 #![allow(unknown_features)]
 #![feature(box_syntax)]
 
-pub trait bomb { fn boom(&self, Ident); }
+pub trait bomb { fn boom(&self, _: Ident); }
 pub struct S;
 impl bomb for S { fn boom(&self, _: Ident) { } }
 

src/test/run-pass/linkage1.rs

@@ -32,7 +32,9 @@ fn main() {
     // discarded. By adding and calling `other::bar`, we get around this problem.
     other::bar();
 
-    assert!(!foo.is_null());
-    assert_eq!(unsafe { *foo }, 3);
-    assert!(something_that_should_never_exist.is_null());
+    unsafe {
+        assert!(!foo.is_null());
+        assert_eq!(*foo, 3);
+        assert!(something_that_should_never_exist.is_null());
+    }
 }

src/test/run-pass/regions-early-bound-trait-param.rs

@@ -63,7 +63,7 @@ fn make_val<T:MakerTrait>() -> T {
 }
 
 trait RefMakerTrait<'q> {
-    fn mk(Self) -> &'q Self;
+    fn mk(_: Self) -> &'q Self;
 }
 
 fn make_ref<'r, T:RefMakerTrait<'r>>(t:T) -> &'r T {

src/test/run-pass/supertrait-default-generics.rs

@@ -14,7 +14,7 @@
 use std::ops::Add;
 
 trait Positioned<S> {
-  fn SetX(&mut self, S);
+  fn SetX(&mut self, _: S);
   fn X(&self) -> S;
 }
 

src/test/run-pass/thread-local-extern-static.rs

@@ -22,5 +22,7 @@ extern {
 }
 
 fn main() {
-    assert_eq!(FOO, 3);
+    unsafe {
+        assert_eq!(FOO, 3);
+    }
 }

src/test/run-pass/trait-inheritance-static.rs

@@ -10,7 +10,7 @@
 
 
 pub trait MyNum {
-    fn from_int(isize) -> Self;
+    fn from_int(_: isize) -> Self;
 }
 
 pub trait NumExt: MyNum { }

src/test/run-pass/trait-inheritance-static2.rs

@@ -11,7 +11,7 @@
 pub trait MyEq {}
 
 pub trait MyNum {
-    fn from_int(isize) -> Self;
+    fn from_int(_: isize) -> Self;
 }
 
 pub trait NumExt: MyEq + MyNum { }

src/test/run-pass/trait-object-generics.rs

@@ -41,7 +41,7 @@ impl<A1, A2, A3> Impl<A1, A2, A3> {
 enum Type<T> { Constant(T) }
 
 trait Trait<K,V> {
-    fn method(&self,Type<(K,V)>) -> isize;
+    fn method(&self, _: Type<(K,V)>) -> isize;
 }
 
 impl<V> Trait<u8,V> for () {

src/test/run-pass/where-clause-bounds-inconsistency.rs

@@ -15,10 +15,10 @@ trait Bound {
 }
 
 trait Trait {
-    fn a<T>(&self, T) where T: Bound;
-    fn b<T>(&self, T) where T: Bound;
-    fn c<T: Bound>(&self, T);
-    fn d<T: Bound>(&self, T);
+    fn a<T>(&self, _: T) where T: Bound;
+    fn b<T>(&self, _: T) where T: Bound;
+    fn c<T: Bound>(&self, _: T);
+    fn d<T: Bound>(&self, _: T);
 }
 
 impl Trait for bool {

src/test/ui/compare-method/proj-outlives-region.rs

@@ -8,9 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![allow(dead_code)]
-#![deny(extra_requirement_in_impl)]
-
 // Test that we elaborate `Type: 'region` constraints and infer various important things.
 
 trait Master<'a, T: ?Sized, U> {

src/test/ui/compare-method/proj-outlives-region.stderr

@@ -1,10 +1,10 @@
 error[E0276]: impl has stricter requirements than trait
-  --> $DIR/proj-outlives-region.rs:22:5
+  --> $DIR/proj-outlives-region.rs:19:5
    |
-17 |     fn foo() where T: 'a;
+14 |     fn foo() where T: 'a;
    |     --------------------- definition of `foo` from trait
 ...
-22 |     fn foo() where U: 'a { } //~ ERROR E0276
+19 |     fn foo() where U: 'a { } //~ ERROR E0276
    |     ^^^^^^^^^^^^^^^^^^^^^^^^ impl has extra requirement `U: 'a`
    |
    = note: #[deny(extra_requirement_in_impl)] on by default

src/test/ui/compare-method/region-extra.rs

@@ -8,9 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![allow(dead_code)]
-#![deny(extra_requirement_in_impl)]
-
 // Test that you cannot add an extra where clause in the impl relating
 // two regions.
 

src/test/ui/compare-method/region-extra.stderr

@@ -1,10 +1,10 @@
 error[E0276]: impl has stricter requirements than trait
-  --> $DIR/region-extra.rs:22:5
+  --> $DIR/region-extra.rs:19:5
    |
-18 |     fn foo();
+15 |     fn foo();
    |     --------- definition of `foo` from trait
 ...
-22 |     fn foo() where 'a: 'b { }
+19 |     fn foo() where 'a: 'b { }
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^ impl has extra requirement `'a: 'b`
 
 error: aborting due to previous error

src/test/ui/compare-method/region-unrelated.rs

@@ -8,9 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![allow(dead_code)]
-#![deny(extra_requirement_in_impl)]
-
 // Test that we elaborate `Type: 'region` constraints and infer various important things.
 
 trait Master<'a, T: ?Sized, U> {

src/test/ui/compare-method/region-unrelated.stderr

@@ -1,10 +1,10 @@
 error[E0276]: impl has stricter requirements than trait
-  --> $DIR/region-unrelated.rs:22:5
+  --> $DIR/region-unrelated.rs:19:5
    |
-17 |     fn foo() where T: 'a;
+14 |     fn foo() where T: 'a;
    |     --------------------- definition of `foo` from trait
 ...
-22 |     fn foo() where V: 'a { }
+19 |     fn foo() where V: 'a { }
    |     ^^^^^^^^^^^^^^^^^^^^^^^^ impl has extra requirement `V: 'a`
    |
    = note: #[deny(extra_requirement_in_impl)] on by default

src/test/ui/span/issue-7575.rs

@@ -12,12 +12,12 @@
 // ignore-tidy-linelength
 
 trait CtxtFn {
-    fn f8(self, usize) -> usize;
-    fn f9(usize) -> usize; //~ NOTE candidate
+    fn f8(self, _: usize) -> usize;
+    fn f9(_: usize) -> usize; //~ NOTE candidate
 }
 
 trait OtherTrait {
-    fn f9(usize) -> usize; //~ NOTE candidate
+    fn f9(_: usize) -> usize; //~ NOTE candidate
 }
 
 // Note: this trait is not implemented, but we can't really tell
@@ -26,7 +26,7 @@ trait OtherTrait {
 // candidate. This seems not unreasonable -- perhaps the user meant to
 // implement it, after all.
 trait UnusedTrait {
-    fn f9(usize) -> usize; //~ NOTE candidate
+    fn f9(_: usize) -> usize; //~ NOTE candidate
 }
 
 impl CtxtFn for usize {

src/test/ui/span/issue-7575.stderr

@@ -8,20 +8,20 @@ error[E0599]: no method named `f9` found for type `usize` in the current scope
 note: candidate #1 is defined in the trait `CtxtFn`
   --> $DIR/issue-7575.rs:16:5
    |
-16 |     fn f9(usize) -> usize; //~ NOTE candidate
-   |     ^^^^^^^^^^^^^^^^^^^^^^
+16 |     fn f9(_: usize) -> usize; //~ NOTE candidate
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^
    = help: to disambiguate the method call, write `CtxtFn::f9(u, 342)` instead
 note: candidate #2 is defined in the trait `OtherTrait`
   --> $DIR/issue-7575.rs:20:5
    |
-20 |     fn f9(usize) -> usize; //~ NOTE candidate
-   |     ^^^^^^^^^^^^^^^^^^^^^^
+20 |     fn f9(_: usize) -> usize; //~ NOTE candidate
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^
    = help: to disambiguate the method call, write `OtherTrait::f9(u, 342)` instead
 note: candidate #3 is defined in the trait `UnusedTrait`
   --> $DIR/issue-7575.rs:29:5
    |
-29 |     fn f9(usize) -> usize; //~ NOTE candidate
-   |     ^^^^^^^^^^^^^^^^^^^^^^
+29 |     fn f9(_: usize) -> usize; //~ NOTE candidate
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^
    = help: to disambiguate the method call, write `UnusedTrait::f9(u, 342)` instead
    = help: items from traits can only be used if the trait is implemented and in scope
    = note: the following traits define an item `f9`, perhaps you need to implement one of them: