From 48e863ed69cb29a0b4ff5e20519d30227a1f8df5 Mon Sep 17 00:00:00 2001
From: Mazdak Farrokhzad <twingoow@gmail.com>
Date: Thu, 30 May 2019 15:37:10 +0200
Subject: [PATCH] Harden non-const items to not accept underscore names.

---
 .../ui/parser/underscore_item_not_const.rs    | 30 ++++++
 .../parser/underscore_item_not_const.stderr   | 92 +++++++++++++++++++
 src/test/ui/parser/underscore_static.rs       |  3 -
 src/test/ui/parser/underscore_static.stderr   |  8 --
 4 files changed, 122 insertions(+), 11 deletions(-)
 create mode 100644 src/test/ui/parser/underscore_item_not_const.rs
 create mode 100644 src/test/ui/parser/underscore_item_not_const.stderr
 delete mode 100644 src/test/ui/parser/underscore_static.rs
 delete mode 100644 src/test/ui/parser/underscore_static.stderr

diff --git a/src/test/ui/parser/underscore_item_not_const.rs b/src/test/ui/parser/underscore_item_not_const.rs
new file mode 100644
index 0000000000000..375bdc3a46369
--- /dev/null
+++ b/src/test/ui/parser/underscore_item_not_const.rs
@@ -0,0 +1,30 @@
+// Test that various non-const items and associated consts do not permit `_` as a name.
+
+// Associated `const`s:
+
+pub trait A {
+    const _: () = (); //~ ERROR expected identifier, found reserved identifier `_`
+}
+impl A for () {
+    const _: () = (); //~ ERROR expected identifier, found reserved identifier `_`
+}
+impl dyn A {
+    const _: () = (); //~ ERROR expected identifier, found reserved identifier `_`
+}
+
+// Other kinds of items:
+
+static _: () = (); //~ ERROR expected identifier, found reserved identifier `_`
+struct _(); //~ ERROR expected identifier, found reserved identifier `_`
+enum _ {} //~ ERROR expected identifier, found reserved identifier `_`
+fn _() {} //~ ERROR expected identifier, found reserved identifier `_`
+mod _ {} //~ ERROR expected identifier, found reserved identifier `_`
+type _ = (); //~ ERROR expected identifier, found reserved identifier `_`
+use _; //~ ERROR expected identifier, found reserved identifier `_`
+use _ as g; //~ ERROR expected identifier, found reserved identifier `_`
+trait _ {} //~ ERROR expected identifier, found reserved identifier `_`
+trait _ = Copy; //~ ERROR expected identifier, found reserved identifier `_`
+macro_rules! _ { () => {} } //~ ERROR expected identifier, found reserved identifier `_`
+union _ { f: u8 } //~ ERROR expected one of `!` or `::`, found `_`
+
+fn main() {}
diff --git a/src/test/ui/parser/underscore_item_not_const.stderr b/src/test/ui/parser/underscore_item_not_const.stderr
new file mode 100644
index 0000000000000..deb4a012e32ab
--- /dev/null
+++ b/src/test/ui/parser/underscore_item_not_const.stderr
@@ -0,0 +1,92 @@
+error: expected identifier, found reserved identifier `_`
+  --> $DIR/underscore_item_not_const.rs:6:11
+   |
+LL |     const _: () = ();
+   |           ^ expected identifier, found reserved identifier
+
+error: expected identifier, found reserved identifier `_`
+  --> $DIR/underscore_item_not_const.rs:9:11
+   |
+LL |     const _: () = ();
+   |           ^ expected identifier, found reserved identifier
+
+error: expected identifier, found reserved identifier `_`
+  --> $DIR/underscore_item_not_const.rs:12:11
+   |
+LL |     const _: () = ();
+   |           ^ expected identifier, found reserved identifier
+
+error: expected identifier, found reserved identifier `_`
+  --> $DIR/underscore_item_not_const.rs:17:8
+   |
+LL | static _: () = ();
+   |        ^ expected identifier, found reserved identifier
+
+error: expected identifier, found reserved identifier `_`
+  --> $DIR/underscore_item_not_const.rs:18:8
+   |
+LL | struct _();
+   |        ^ expected identifier, found reserved identifier
+
+error: expected identifier, found reserved identifier `_`
+  --> $DIR/underscore_item_not_const.rs:19:6
+   |
+LL | enum _ {}
+   |      ^ expected identifier, found reserved identifier
+
+error: expected identifier, found reserved identifier `_`
+  --> $DIR/underscore_item_not_const.rs:20:4
+   |
+LL | fn _() {}
+   |    ^ expected identifier, found reserved identifier
+
+error: expected identifier, found reserved identifier `_`
+  --> $DIR/underscore_item_not_const.rs:21:5
+   |
+LL | mod _ {}
+   |     ^ expected identifier, found reserved identifier
+
+error: expected identifier, found reserved identifier `_`
+  --> $DIR/underscore_item_not_const.rs:22:6
+   |
+LL | type _ = ();
+   |      ^ expected identifier, found reserved identifier
+
+error: expected identifier, found reserved identifier `_`
+  --> $DIR/underscore_item_not_const.rs:23:5
+   |
+LL | use _;
+   |     ^ expected identifier, found reserved identifier
+
+error: expected identifier, found reserved identifier `_`
+  --> $DIR/underscore_item_not_const.rs:24:5
+   |
+LL | use _ as g;
+   |     ^ expected identifier, found reserved identifier
+
+error: expected identifier, found reserved identifier `_`
+  --> $DIR/underscore_item_not_const.rs:25:7
+   |
+LL | trait _ {}
+   |       ^ expected identifier, found reserved identifier
+
+error: expected identifier, found reserved identifier `_`
+  --> $DIR/underscore_item_not_const.rs:26:7
+   |
+LL | trait _ = Copy;
+   |       ^ expected identifier, found reserved identifier
+
+error: expected identifier, found reserved identifier `_`
+  --> $DIR/underscore_item_not_const.rs:27:14
+   |
+LL | macro_rules! _ { () => {} }
+   |              ^ expected identifier, found reserved identifier
+
+error: expected one of `!` or `::`, found `_`
+  --> $DIR/underscore_item_not_const.rs:28:7
+   |
+LL | union _ { f: u8 }
+   |       ^ expected one of `!` or `::` here
+
+error: aborting due to 15 previous errors
+
diff --git a/src/test/ui/parser/underscore_static.rs b/src/test/ui/parser/underscore_static.rs
deleted file mode 100644
index 21d6a1bc1b360..0000000000000
--- a/src/test/ui/parser/underscore_static.rs
+++ /dev/null
@@ -1,3 +0,0 @@
-static _: () = (); //~ ERROR expected identifier, found reserved identifier `_`
-
-fn main() {}
diff --git a/src/test/ui/parser/underscore_static.stderr b/src/test/ui/parser/underscore_static.stderr
deleted file mode 100644
index 4c41afdc3f09e..0000000000000
--- a/src/test/ui/parser/underscore_static.stderr
+++ /dev/null
@@ -1,8 +0,0 @@
-error: expected identifier, found reserved identifier `_`
-  --> $DIR/underscore_static.rs:1:8
-   |
-LL | static _: () = ();
-   |        ^ expected identifier, found reserved identifier
-
-error: aborting due to previous error
-