Auto merge of #55095 - Manishearth:rollup, r=Manishearth

Rollup of 11 pull requests

Successful merges:

 - #54820 (Closes #54538: `unused_patterns` lint)
 - #54963 (Cleanup rustc/session)
 - #54991 (add test for #23189)
 - #55025 (Add missing lifetime fragment specifier to error message.)
 - #55047 (doc: make core::fmt::Error example more simple)
 - #55048 (Don't collect to vectors where unnecessary)
 - #55060 (clarify pointer add/sub function safety concerns)
 - #55062 (Make EvalContext::step public again)
 - #55066 (Fix incorrect link in println! documentation)
 - #55081 (Deduplicate tests)
 - #55088 (Update rustc documentation link)

Failed merges:

r? @ghost

12 files changed, 98 insertions, 141 deletions

diff --git a/src/test/run-pass/binding/pat-tuple-7.rs b/src/test/run-pass/binding/pat-tuple-7.rs
index c32b52eac33..06bd14d188e 100644
--- a/src/test/run-pass/binding/pat-tuple-7.rs
+++ b/src/test/run-pass/binding/pat-tuple-7.rs
@@ -11,6 +11,7 @@
 // run-pass
 
 fn main() {
+    #[allow(unused_parens)]
     match 0 {
         (pat) => assert_eq!(pat, 0)
     }
diff --git a/src/test/ui/issues/issue-21356.stderr b/src/test/ui/issues/issue-21356.stderr
index 5787476c2f2..924767fb5e1 100644
--- a/src/test/ui/issues/issue-21356.stderr
+++ b/src/test/ui/issues/issue-21356.stderr
@@ -4,7 +4,7 @@ error: invalid fragment specifier `t_ty`
 LL | macro_rules! test { ($wrong:t_ty ..) => () }
    |                      ^^^^^^^^^^^
    |
-   = help: valid fragment specifiers are `ident`, `block`, `stmt`, `expr`, `pat`, `ty`, `literal`, `path`, `meta`, `tt`, `item` and `vis`
+   = help: valid fragment specifiers are `ident`, `block`, `stmt`, `expr`, `pat`, `ty`, `lifetime`, `literal`, `path`, `meta`, `tt`, `item` and `vis`
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/lifetimes/lifetime-errors/ex3-both-anon-regions-both-are-structs-4.rs b/src/test/ui/issues/issue-23189.rs
index 78e6dc2d3e7..7a475d1a6ab 100644
--- a/src/test/ui/lifetimes/lifetime-errors/ex3-both-anon-regions-both-are-structs-4.rs
+++ b/src/test/ui/issues/issue-23189.rs
@@ -1,4 +1,4 @@
-// Copyright 2017 The Rust Project Developers. See the COPYRIGHT
+// Copyright 2018 The Rust Project Developers. See the COPYRIGHT
 // file at the top-level directory of this distribution and at
 // http://rust-lang.org/COPYRIGHT.
 //
@@ -7,13 +7,9 @@
 // <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.
-struct Ref<'a, 'b> {
-    a: &'a u32,
-    b: &'b u32,
-}
 
-fn foo(mut x: Ref) {
-    x.a = x.b; //~ ERROR lifetime mismatch
-}
+mod module {}
 
-fn main() {}
+fn main() {
+    let _ = module { x: 0 }; //~ERROR expected struct
+}
diff --git a/src/test/ui/issues/issue-23189.stderr b/src/test/ui/issues/issue-23189.stderr
new file mode 100644
index 00000000000..c7bbab4524d
--- /dev/null
+++ b/src/test/ui/issues/issue-23189.stderr
@@ -0,0 +1,9 @@
+error[E0574]: expected struct, variant or union type, found module `module`
+  --> $DIR/issue-23189.rs:14:13
+   |
+LL |     let _ = module { x: 0 }; //~ERROR expected struct
+   |             ^^^^^^ not a struct, variant or union type
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0574`.
diff --git a/src/test/ui/lifetimes/lifetime-errors/ex3-both-anon-regions-both-are-structs-4.nll.stderr b/src/test/ui/lifetimes/lifetime-errors/ex3-both-anon-regions-both-are-structs-4.nll.stderr
deleted file mode 100644
index 4f0efe24cf7..00000000000
--- a/src/test/ui/lifetimes/lifetime-errors/ex3-both-anon-regions-both-are-structs-4.nll.stderr
+++ /dev/null
@@ -1,13 +0,0 @@
-error: unsatisfied lifetime constraints
-  --> $DIR/ex3-both-anon-regions-both-are-structs-4.rs:16:5
-   |
-LL | fn foo(mut x: Ref) {
-   |        -----
-   |        |
-   |        has type `Ref<'_, '1>`
-   |        has type `Ref<'2, '_>`
-LL |     x.a = x.b; //~ ERROR lifetime mismatch
-   |     ^^^^^^^^^ assignment requires that `'1` must outlive `'2`
-
-error: aborting due to previous error
-
diff --git a/src/test/ui/lifetimes/lifetime-errors/ex3-both-anon-regions-both-are-structs-4.stderr b/src/test/ui/lifetimes/lifetime-errors/ex3-both-anon-regions-both-are-structs-4.stderr
deleted file mode 100644
index ccc5e02ab70..00000000000
--- a/src/test/ui/lifetimes/lifetime-errors/ex3-both-anon-regions-both-are-structs-4.stderr
+++ /dev/null
@@ -1,13 +0,0 @@
-error[E0623]: lifetime mismatch
-  --> $DIR/ex3-both-anon-regions-both-are-structs-4.rs:16:11
-   |
-LL | fn foo(mut x: Ref) {
-   |               ---
-   |               |
-   |               this type is declared with multiple lifetimes...
-LL |     x.a = x.b; //~ ERROR lifetime mismatch
-   |           ^^^ ...but data with one lifetime flows into the other here
-
-error: aborting due to previous error
-
-For more information about this error, try `rustc --explain E0623`.
diff --git a/src/test/ui/lint/issue-54538-unused-parens-lint.rs b/src/test/ui/lint/issue-54538-unused-parens-lint.rs
new file mode 100644
index 00000000000..97a2dd59a62
--- /dev/null
+++ b/src/test/ui/lint/issue-54538-unused-parens-lint.rs
@@ -0,0 +1,38 @@
+// Copyright 2018 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.
+
+// compile-pass
+
+#![allow(unreachable_patterns)]
+#![allow(unused_variables)]
+#![warn(unused_parens)]
+
+fn main() {
+    match 1 {
+        (_) => {}         //~ WARNING: unnecessary parentheses around pattern
+        (y) => {}         //~ WARNING: unnecessary parentheses around pattern
+        (ref r) => {}     //~ WARNING: unnecessary parentheses around pattern
+        (e @ 1..=2) => {} //~ WARNING: unnecessary parentheses around outer pattern
+        (1..=2) => {}     // Non ambiguous range pattern should not warn
+        e @ (3..=4) => {} // Non ambiguous range pattern should not warn
+    }
+
+    match &1 {
+        (e @ &(1...2)) => {} //~ WARNING: unnecessary parentheses around outer pattern
+        &(_) => {}           //~ WARNING: unnecessary parentheses around pattern
+        e @ &(1...2) => {}   // Ambiguous range pattern should not warn
+        &(1..=2) => {}       // Ambiguous range pattern should not warn
+    }
+
+    match &1 {
+        e @ &(1...2) | e @ &(3..=4) => {} // Complex ambiguous pattern should not warn
+        &_ => {}
+    }
+}
diff --git a/src/test/ui/lint/issue-54538-unused-parens-lint.stderr b/src/test/ui/lint/issue-54538-unused-parens-lint.stderr
new file mode 100644
index 00000000000..b76b969fd2b
--- /dev/null
+++ b/src/test/ui/lint/issue-54538-unused-parens-lint.stderr
@@ -0,0 +1,42 @@
+warning: unnecessary parentheses around pattern
+  --> $DIR/issue-54538-unused-parens-lint.rs:19:9
+   |
+LL |         (_) => {}         //~ WARNING: unnecessary parentheses around pattern
+   |         ^^^ help: remove these parentheses
+   |
+note: lint level defined here
+  --> $DIR/issue-54538-unused-parens-lint.rs:15:9
+   |
+LL | #![warn(unused_parens)]
+   |         ^^^^^^^^^^^^^
+
+warning: unnecessary parentheses around pattern
+  --> $DIR/issue-54538-unused-parens-lint.rs:20:9
+   |
+LL |         (y) => {}         //~ WARNING: unnecessary parentheses around pattern
+   |         ^^^ help: remove these parentheses
+
+warning: unnecessary parentheses around pattern
+  --> $DIR/issue-54538-unused-parens-lint.rs:21:9
+   |
+LL |         (ref r) => {}     //~ WARNING: unnecessary parentheses around pattern
+   |         ^^^^^^^ help: remove these parentheses
+
+warning: unnecessary parentheses around pattern
+  --> $DIR/issue-54538-unused-parens-lint.rs:22:9
+   |
+LL |         (e @ 1..=2) => {} //~ WARNING: unnecessary parentheses around outer pattern
+   |         ^^^^^^^^^^^ help: remove these parentheses
+
+warning: unnecessary parentheses around pattern
+  --> $DIR/issue-54538-unused-parens-lint.rs:28:9
+   |
+LL |         (e @ &(1...2)) => {} //~ WARNING: unnecessary parentheses around outer pattern
+   |         ^^^^^^^^^^^^^^ help: remove these parentheses
+
+warning: unnecessary parentheses around pattern
+  --> $DIR/issue-54538-unused-parens-lint.rs:29:10
+   |
+LL |         &(_) => {}           //~ WARNING: unnecessary parentheses around pattern
+   |          ^^^ help: remove these parentheses
+
diff --git a/src/test/ui/lint/lint-group-style.rs b/src/test/ui/lint/lint-group-style.rs
deleted file mode 100644
index 55d6168e6e0..00000000000
--- a/src/test/ui/lint/lint-group-style.rs
+++ /dev/null
@@ -1,36 +0,0 @@
-// Copyright 2014–2017 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.
-
-#![deny(nonstandard_style)]
-#![allow(dead_code)]
-
-fn CamelCase() {} //~ ERROR should have a snake
-
-#[allow(nonstandard_style)]
-mod test {
-    fn CamelCase() {}
-
-    #[forbid(nonstandard_style)]
-    mod bad {
-        fn CamelCase() {} //~ ERROR should have a snake
-
-        static bad: isize = 1; //~ ERROR should have an upper
-    }
-
-    mod warn {
-        #![warn(nonstandard_style)]
-
-        fn CamelCase() {} //~ WARN should have a snake
-
-        struct snake_case; //~ WARN should have a camel
-    }
-}
-
-fn main() {}
diff --git a/src/test/ui/lint/lint-group-style.stderr b/src/test/ui/lint/lint-group-style.stderr
deleted file mode 100644
index 6b91ce5b93c..00000000000
--- a/src/test/ui/lint/lint-group-style.stderr
+++ /dev/null
@@ -1,67 +0,0 @@
-error: function `CamelCase` should have a snake case name such as `camel_case`
-  --> $DIR/lint-group-style.rs:14:1
-   |
-LL | fn CamelCase() {} //~ ERROR should have a snake
-   | ^^^^^^^^^^^^^^^^^
-   |
-note: lint level defined here
-  --> $DIR/lint-group-style.rs:11:9
-   |
-LL | #![deny(nonstandard_style)]
-   |         ^^^^^^^^^^^^^^^^^
-   = note: #[deny(non_snake_case)] implied by #[deny(nonstandard_style)]
-
-error: function `CamelCase` should have a snake case name such as `camel_case`
-  --> $DIR/lint-group-style.rs:22:9
-   |
-LL |         fn CamelCase() {} //~ ERROR should have a snake
-   |         ^^^^^^^^^^^^^^^^^
-   |
-note: lint level defined here
-  --> $DIR/lint-group-style.rs:20:14
-   |
-LL |     #[forbid(nonstandard_style)]
-   |              ^^^^^^^^^^^^^^^^^
-   = note: #[forbid(non_snake_case)] implied by #[forbid(nonstandard_style)]
-
-error: static variable `bad` should have an upper case name such as `BAD`
-  --> $DIR/lint-group-style.rs:24:9
-   |
-LL |         static bad: isize = 1; //~ ERROR should have an upper
-   |         ^^^^^^^^^^^^^^^^^^^^^^
-   |
-note: lint level defined here
-  --> $DIR/lint-group-style.rs:20:14
-   |
-LL |     #[forbid(nonstandard_style)]
-   |              ^^^^^^^^^^^^^^^^^
-   = note: #[forbid(non_upper_case_globals)] implied by #[forbid(nonstandard_style)]
-
-warning: function `CamelCase` should have a snake case name such as `camel_case`
-  --> $DIR/lint-group-style.rs:30:9
-   |
-LL |         fn CamelCase() {} //~ WARN should have a snake
-   |         ^^^^^^^^^^^^^^^^^
-   |
-note: lint level defined here
-  --> $DIR/lint-group-style.rs:28:17
-   |
-LL |         #![warn(nonstandard_style)]
-   |                 ^^^^^^^^^^^^^^^^^
-   = note: #[warn(non_snake_case)] implied by #[warn(nonstandard_style)]
-
-warning: type `snake_case` should have a camel case name such as `SnakeCase`
-  --> $DIR/lint-group-style.rs:32:9
-   |
-LL |         struct snake_case; //~ WARN should have a camel
-   |         ^^^^^^^^^^^^^^^^^^
-   |
-note: lint level defined here
-  --> $DIR/lint-group-style.rs:28:17
-   |
-LL |         #![warn(nonstandard_style)]
-   |                 ^^^^^^^^^^^^^^^^^
-   = note: #[warn(non_camel_case_types)] implied by #[warn(nonstandard_style)]
-
-error: aborting due to 3 previous errors
-
diff --git a/src/test/ui/macros/macro-invalid-fragment-spec.stderr b/src/test/ui/macros/macro-invalid-fragment-spec.stderr
index 765621f51d4..e683d47cf54 100644
--- a/src/test/ui/macros/macro-invalid-fragment-spec.stderr
+++ b/src/test/ui/macros/macro-invalid-fragment-spec.stderr
@@ -4,7 +4,7 @@ error: invalid fragment specifier `foo`
 LL |     ($x:foo) => ()
    |      ^^^^^^
    |
-   = help: valid fragment specifiers are `ident`, `block`, `stmt`, `expr`, `pat`, `ty`, `literal`, `path`, `meta`, `tt`, `item` and `vis`
+   = help: valid fragment specifiers are `ident`, `block`, `stmt`, `expr`, `pat`, `ty`, `lifetime`, `literal`, `path`, `meta`, `tt`, `item` and `vis`
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/unused/unused-macro-with-bad-frag-spec.stderr b/src/test/ui/unused/unused-macro-with-bad-frag-spec.stderr
index 88435878905..20b1ae690ec 100644
--- a/src/test/ui/unused/unused-macro-with-bad-frag-spec.stderr
+++ b/src/test/ui/unused/unused-macro-with-bad-frag-spec.stderr
@@ -4,7 +4,7 @@ error: invalid fragment specifier `t_ty`
 LL |     ($wrong:t_ty) => () //~ ERROR invalid fragment specifier `t_ty`
    |      ^^^^^^^^^^^
    |
-   = help: valid fragment specifiers are `ident`, `block`, `stmt`, `expr`, `pat`, `ty`, `literal`, `path`, `meta`, `tt`, `item` and `vis`
+   = help: valid fragment specifiers are `ident`, `block`, `stmt`, `expr`, `pat`, `ty`, `lifetime`, `literal`, `path`, `meta`, `tt`, `item` and `vis`
 
 error: aborting due to previous error