Auto merge of #44079 - gaurikholkar:named_conf, r=nikomatsakis

Extend E0623 for LateBound and EarlyBound Regions

This is a fix for #43882
```
fn foo<'a,'b>(x: &mut Vec<&'a u8>, y: &'b u8) {
    x.push(y);
}
```
now gives

```
error[E0623]: lifetime mismatch
  --> $DIR/ex3-both-anon-regions-latebound-regions.rs:12:12
   |
11 | fn foo<'a,'b>(x: &mut Vec<&'a u8>, y: &'b u8) {
   |                           ------      ------ these two types are declared with different lifetimes...
12 |     x.push(y);
   |            ^ ...but data from `y` flows into `x` here
```
cc @nikomatsakis @arielb1

Please ignore the second commit. It will be merged in a separate PR.

16 files changed, 73 insertions, 20 deletions

diff --git a/src/test/compile-fail/associated-types-subtyping-1.rs b/src/test/compile-fail/associated-types-subtyping-1.rs
index f9106ba3960..64dcdd39e7c 100644
--- a/src/test/compile-fail/associated-types-subtyping-1.rs
+++ b/src/test/compile-fail/associated-types-subtyping-1.rs
@@ -31,7 +31,7 @@ fn method2<'a,'b,T>(x: &'a T, y: &'b T)
     // Note that &'static T <: &'a T.
     let a: <T as Trait<'a>>::Type = loop { };
     let b: <T as Trait<'b>>::Type = loop { };
-    let _: <T as Trait<'b>>::Type = a; //~ ERROR mismatched types
+    let _: <T as Trait<'b>>::Type = a; //~ ERROR E0623
 }
 
 fn method3<'a,'b,T>(x: &'a T, y: &'b T)
@@ -40,7 +40,7 @@ fn method3<'a,'b,T>(x: &'a T, y: &'b T)
     // Note that &'static T <: &'a T.
     let a: <T as Trait<'a>>::Type = loop { };
     let b: <T as Trait<'b>>::Type = loop { };
-    let _: <T as Trait<'a>>::Type = b; //~ ERROR mismatched types
+    let _: <T as Trait<'a>>::Type = b; //~ ERROR E0623
 }
 
 fn method4<'a,'b,T>(x: &'a T, y: &'b T)
diff --git a/src/test/compile-fail/region-lifetime-bounds-on-fns-where-clause.rs b/src/test/compile-fail/region-lifetime-bounds-on-fns-where-clause.rs
index 6364db1f4b4..f886c0255cc 100644
--- a/src/test/compile-fail/region-lifetime-bounds-on-fns-where-clause.rs
+++ b/src/test/compile-fail/region-lifetime-bounds-on-fns-where-clause.rs
@@ -15,7 +15,7 @@ fn a<'a, 'b>(x: &mut &'a isize, y: &mut &'b isize) where 'b: 'a {
 
 fn b<'a, 'b>(x: &mut &'a isize, y: &mut &'b isize) {
     // Illegal now because there is no `'b:'a` declaration.
-    *x = *y; //~ ERROR E0312
+    *x = *y; //~ ERROR E0623
 }
 
 fn c<'a,'b>(x: &mut &'a isize, y: &mut &'b isize) {
diff --git a/src/test/compile-fail/region-multiple-lifetime-bounds-on-fns-where-clause.rs b/src/test/compile-fail/region-multiple-lifetime-bounds-on-fns-where-clause.rs
index 154135eba38..bae9608c3f0 100644
--- a/src/test/compile-fail/region-multiple-lifetime-bounds-on-fns-where-clause.rs
+++ b/src/test/compile-fail/region-multiple-lifetime-bounds-on-fns-where-clause.rs
@@ -16,8 +16,8 @@ fn a<'a, 'b, 'c>(x: &mut &'a isize, y: &mut &'b isize, z: &mut &'c isize) where
 
 fn b<'a, 'b, 'c>(x: &mut &'a isize, y: &mut &'b isize, z: &mut &'c isize) {
     // Illegal now because there is no `'b:'a` declaration.
-    *x = *y; //~ ERROR E0312
-    *z = *y; //~ ERROR E0312
+    *x = *y; //~ ERROR E0623
+    *z = *y; //~ ERROR E0623
 }
 
 fn c<'a,'b, 'c>(x: &mut &'a isize, y: &mut &'b isize, z: &mut &'c isize) {
diff --git a/src/test/compile-fail/regions-free-region-ordering-caller.rs b/src/test/compile-fail/regions-free-region-ordering-caller.rs
index edca3b7ed41..66b16744cc7 100644
--- a/src/test/compile-fail/regions-free-region-ordering-caller.rs
+++ b/src/test/compile-fail/regions-free-region-ordering-caller.rs
@@ -15,20 +15,16 @@
 struct Paramd<'a> { x: &'a usize }
 
 fn call2<'a, 'b>(a: &'a usize, b: &'b usize) {
-    let z: Option<&'b &'a usize> = None;
-    //~^ ERROR reference has a longer lifetime than the data it references
+    let z: Option<&'b &'a usize> = None;//~ ERROR E0623
 }
 
 fn call3<'a, 'b>(a: &'a usize, b: &'b usize) {
     let y: Paramd<'a> = Paramd { x: a };
-    let z: Option<&'b Paramd<'a>> = None;
-    //~^ ERROR reference has a longer lifetime than the data it references
+    let z: Option<&'b Paramd<'a>> = None;//~ ERROR E0623
 }
 
 fn call4<'a, 'b>(a: &'a usize, b: &'b usize) {
-    let z: Option<&'a &'b usize> = None;
-    //~^ ERROR reference has a longer lifetime than the data it references
+    let z: Option<&'a &'b usize> = None;//~ ERROR E0623
 }
 
-
 fn main() {}
diff --git a/src/test/compile-fail/regions-infer-contravariance-due-to-decl.rs b/src/test/compile-fail/regions-infer-contravariance-due-to-decl.rs
index b7ef19d1e3b..6e1c765724b 100644
--- a/src/test/compile-fail/regions-infer-contravariance-due-to-decl.rs
+++ b/src/test/compile-fail/regions-infer-contravariance-due-to-decl.rs
@@ -32,7 +32,7 @@ fn use_<'short,'long>(c: Contravariant<'short>,
     // 'short <= 'long, this would be true if the Contravariant type were
     // covariant with respect to its parameter 'a.
 
-    let _: Contravariant<'long> = c; //~ ERROR mismatched types
+    let _: Contravariant<'long> = c; //~ ERROR E0623
 }
 
 fn main() {}
diff --git a/src/test/compile-fail/regions-infer-covariance-due-to-decl.rs b/src/test/compile-fail/regions-infer-covariance-due-to-decl.rs
index 0d3d9dacbd6..1ab8ba4439b 100644
--- a/src/test/compile-fail/regions-infer-covariance-due-to-decl.rs
+++ b/src/test/compile-fail/regions-infer-covariance-due-to-decl.rs
@@ -29,7 +29,7 @@ fn use_<'short,'long>(c: Covariant<'long>,
     // 'short <= 'long, this would be true if the Covariant type were
     // contravariant with respect to its parameter 'a.
 
-    let _: Covariant<'short> = c; //~ ERROR mismatched types
+    let _: Covariant<'short> = c; //~ ERROR E0623
 }
 
 fn main() {}
diff --git a/src/test/compile-fail/regions-lifetime-bounds-on-fns.rs b/src/test/compile-fail/regions-lifetime-bounds-on-fns.rs
index 89254516ac6..ef1c58bf972 100644
--- a/src/test/compile-fail/regions-lifetime-bounds-on-fns.rs
+++ b/src/test/compile-fail/regions-lifetime-bounds-on-fns.rs
@@ -15,7 +15,7 @@ fn a<'a, 'b:'a>(x: &mut &'a isize, y: &mut &'b isize) {
 
 fn b<'a, 'b>(x: &mut &'a isize, y: &mut &'b isize) {
     // Illegal now because there is no `'b:'a` declaration.
-    *x = *y; //~ ERROR E0312
+    *x = *y; //~ ERROR E0623
 }
 
 fn c<'a,'b>(x: &mut &'a isize, y: &mut &'b isize) {
diff --git a/src/test/compile-fail/regions-variance-contravariant-use-covariant-in-second-position.rs b/src/test/compile-fail/regions-variance-contravariant-use-covariant-in-second-position.rs
index a7ef3ec9ac1..1dfebd54ec3 100644
--- a/src/test/compile-fail/regions-variance-contravariant-use-covariant-in-second-position.rs
+++ b/src/test/compile-fail/regions-variance-contravariant-use-covariant-in-second-position.rs
@@ -32,7 +32,7 @@ fn use_<'short,'long>(c: S<'long, 'short>,
     // 'short <= 'long, this would be true if the Contravariant type were
     // covariant with respect to its parameter 'a.
 
-    let _: S<'long, 'long> = c; //~ ERROR mismatched types
+    let _: S<'long, 'long> = c; //~ ERROR E0623
 }
 
 fn main() {}
diff --git a/src/test/compile-fail/regions-variance-contravariant-use-covariant.rs b/src/test/compile-fail/regions-variance-contravariant-use-covariant.rs
index a79249ade4f..caf6a86fc0b 100644
--- a/src/test/compile-fail/regions-variance-contravariant-use-covariant.rs
+++ b/src/test/compile-fail/regions-variance-contravariant-use-covariant.rs
@@ -30,7 +30,7 @@ fn use_<'short,'long>(c: Contravariant<'short>,
     // 'short <= 'long, this would be true if the Contravariant type were
     // covariant with respect to its parameter 'a.
 
-    let _: Contravariant<'long> = c; //~ ERROR mismatched types
+    let _: Contravariant<'long> = c; //~ ERROR E0623
 }
 
 fn main() {}
diff --git a/src/test/compile-fail/regions-variance-covariant-use-contravariant.rs b/src/test/compile-fail/regions-variance-covariant-use-contravariant.rs
index f42b7027d9e..60dc3d94a2e 100644
--- a/src/test/compile-fail/regions-variance-covariant-use-contravariant.rs
+++ b/src/test/compile-fail/regions-variance-covariant-use-contravariant.rs
@@ -30,7 +30,7 @@ fn use_<'short,'long>(c: Covariant<'long>,
     // 'short <= 'long, this would be true if the Covariant type were
     // contravariant with respect to its parameter 'a.
 
-    let _: Covariant<'short> = c; //~ ERROR mismatched types
+    let _: Covariant<'short> = c; //~ ERROR E0623
 }
 
 fn main() {}
diff --git a/src/test/compile-fail/regions-variance-invariant-use-contravariant.rs b/src/test/compile-fail/regions-variance-invariant-use-contravariant.rs
index 71023b26c27..96478fa5909 100644
--- a/src/test/compile-fail/regions-variance-invariant-use-contravariant.rs
+++ b/src/test/compile-fail/regions-variance-invariant-use-contravariant.rs
@@ -27,7 +27,7 @@ fn use_<'short,'long>(c: Invariant<'long>,
     // 'short <= 'long, this would be true if the Invariant type were
     // contravariant with respect to its parameter 'a.
 
-    let _: Invariant<'short> = c; //~ ERROR mismatched types
+    let _: Invariant<'short> = c; //~ ERROR E0623
 }
 
 fn main() { }
diff --git a/src/test/compile-fail/variance-cell-is-invariant.rs b/src/test/compile-fail/variance-cell-is-invariant.rs
index b8a8f9ad91c..1ddbcf4ab84 100644
--- a/src/test/compile-fail/variance-cell-is-invariant.rs
+++ b/src/test/compile-fail/variance-cell-is-invariant.rs
@@ -21,7 +21,7 @@ fn use_<'short,'long>(c: Foo<'short>,
                       s: &'short isize,
                       l: &'long isize,
                       _where:Option<&'short &'long ()>) {
-    let _: Foo<'long> = c; //~ ERROR mismatched types
+    let _: Foo<'long> = c; //~ ERROR E0623
 }
 
 fn main() {
diff --git a/src/test/ui/lifetime-errors/ex3-both-anon-regions-earlybound-regions.rs b/src/test/ui/lifetime-errors/ex3-both-anon-regions-earlybound-regions.rs
new file mode 100644
index 00000000000..5d182008209
--- /dev/null
+++ b/src/test/ui/lifetime-errors/ex3-both-anon-regions-earlybound-regions.rs
@@ -0,0 +1,21 @@
+// Copyright 2017 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+trait Foo<'a> {}
+impl<'a, T> Foo<'a> for T {}
+
+fn baz<'a, 'b, T>(x: &mut Vec<&'a T>, y: &T)
+    where i32: Foo<'a>,
+          u32: Foo<'b>
+{
+    x.push(y);
+}
+fn main() {
+let x = baz;
+}
diff --git a/src/test/ui/lifetime-errors/ex3-both-anon-regions-earlybound-regions.stderr b/src/test/ui/lifetime-errors/ex3-both-anon-regions-earlybound-regions.stderr
new file mode 100644
index 00000000000..58f2cb94cec
--- /dev/null
+++ b/src/test/ui/lifetime-errors/ex3-both-anon-regions-earlybound-regions.stderr
@@ -0,0 +1,11 @@
+error[E0623]: lifetime mismatch
+  --> $DIR/ex3-both-anon-regions-earlybound-regions.rs:17:12
+   |
+13 | fn baz<'a, 'b, T>(x: &mut Vec<&'a T>, y: &T)
+   |                               -----      -- these two types are declared with different lifetimes...
+...
+17 |     x.push(y);
+   |            ^ ...but data from `y` flows into `x` here
+
+error: aborting due to previous error
+
diff --git a/src/test/ui/lifetime-errors/ex3-both-anon-regions-latebound-regions.rs b/src/test/ui/lifetime-errors/ex3-both-anon-regions-latebound-regions.rs
new file mode 100644
index 00000000000..5abfc983f88
--- /dev/null
+++ b/src/test/ui/lifetime-errors/ex3-both-anon-regions-latebound-regions.rs
@@ -0,0 +1,15 @@
+// Copyright 2017 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+fn foo<'a,'b>(x: &mut Vec<&'a u8>, y: &'b u8) {
+    x.push(y);
+}
+
+fn main() { }
\ No newline at end of file
diff --git a/src/test/ui/lifetime-errors/ex3-both-anon-regions-latebound-regions.stderr b/src/test/ui/lifetime-errors/ex3-both-anon-regions-latebound-regions.stderr
new file mode 100644
index 00000000000..be628f226d3
--- /dev/null
+++ b/src/test/ui/lifetime-errors/ex3-both-anon-regions-latebound-regions.stderr
@@ -0,0 +1,10 @@
+error[E0623]: lifetime mismatch
+  --> $DIR/ex3-both-anon-regions-latebound-regions.rs:12:12
+   |
+11 | fn foo<'a,'b>(x: &mut Vec<&'a u8>, y: &'b u8) {
+   |                           ------      ------ these two types are declared with different lifetimes...
+12 |     x.push(y);
+   |            ^ ...but data from `y` flows into `x` here
+
+error: aborting due to previous error
+