Updating test stderr files

src/test/ui/associated-consts/associated-const-dead-code.stderr

@@ -2,8 +2,11 @@ error: associated constant is never used: `BAR`
   --> $DIR/associated-const-dead-code.rs:6:5
    |
 LL |     const BAR: u32 = 1;
-   |     ^^^^^^^^^^^^^^^^^^^
+   |     ^^^^^^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_BAR`
    |
+   = note: the leading underscore helps signal to the reader that the associated constant may still serve
+           a purpose even if it isn't used in a way that we can detect (e.g. the associated constant
+           is only used through FFI or used only for its effect when dropped)
 note: the lint level is defined here
   --> $DIR/associated-const-dead-code.rs:1:9
    |

src/test/ui/derive-uninhabited-enum-38885.stderr

@@ -2,8 +2,11 @@ warning: variant is never constructed: `Void`
   --> $DIR/derive-uninhabited-enum-38885.rs:13:5
    |
 LL |     Void(Void),
-   |     ^^^^^^^^^^
+   |     ^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_Void`
    |
+   = note: the leading underscore helps signal to the reader that the variant may still serve
+           a purpose even if it isn't used in a way that we can detect (e.g. the variant
+           is only used through FFI or used only for its effect when dropped)
    = note: `-W dead-code` implied by `-W unused`
 
 warning: 1 warning emitted

src/test/ui/issues/issue-37515.stderr

@@ -2,8 +2,11 @@ warning: type alias is never used: `Z`
   --> $DIR/issue-37515.rs:5:1
    |
 LL | type Z = dyn for<'x> Send;
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_Z`
    |
+   = note: the leading underscore helps signal to the reader that the type alias may still serve
+           a purpose even if it isn't used in a way that we can detect (e.g. the type alias
+           is only used through FFI or used only for its effect when dropped)
 note: the lint level is defined here
   --> $DIR/issue-37515.rs:3:9
    |

src/test/ui/lint/dead-code/basic.stderr

@@ -2,8 +2,11 @@ error: function is never used: `foo`
   --> $DIR/basic.rs:4:4
    |
 LL | fn foo() {
-   |    ^^^
+   |    ^^^ help: if this is intentional, prefix it with an underscore: `_foo`
    |
+   = note: the leading underscore helps signal to the reader that the function may still serve
+           a purpose even if it isn't used in a way that we can detect (e.g. the function
+           is only used through FFI or used only for its effect when dropped)
 note: the lint level is defined here
   --> $DIR/basic.rs:1:9
    |

src/test/ui/lint/dead-code/const-and-self.stderr

@@ -2,8 +2,11 @@ warning: variant is never constructed: `B`
   --> $DIR/const-and-self.rs:33:5
    |
 LL |     B,
-   |     ^
+   |     ^ help: if this is intentional, prefix it with an underscore: `_B`
    |
+   = note: the leading underscore helps signal to the reader that the variant may still serve
+           a purpose even if it isn't used in a way that we can detect (e.g. the variant
+           is only used through FFI or used only for its effect when dropped)
 note: the lint level is defined here
   --> $DIR/const-and-self.rs:3:9
    |
@@ -14,7 +17,11 @@ warning: variant is never constructed: `C`
   --> $DIR/const-and-self.rs:34:5
    |
 LL |     C,
-   |     ^
+   |     ^ help: if this is intentional, prefix it with an underscore: `_C`
+   |
+   = note: the leading underscore helps signal to the reader that the variant may still serve
+           a purpose even if it isn't used in a way that we can detect (e.g. the variant
+           is only used through FFI or used only for its effect when dropped)
 
 warning: 2 warnings emitted
 

src/test/ui/lint/dead-code/drop-only-field-issue-81658.stderr

@@ -2,8 +2,11 @@ error: field is never read: `guard`
   --> $DIR/drop-only-field-issue-81658.rs:15:5
    |
 LL |     guard: MutexGuard<'a, T>,
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_guard`
    |
+   = note: the leading underscore helps signal to the reader that the field may still serve
+           a purpose even if it isn't used in a way that we can detect (e.g. the field
+           is only used through FFI or used only for its effect when dropped)
 note: the lint level is defined here
   --> $DIR/drop-only-field-issue-81658.rs:8:9
    |

src/test/ui/lint/dead-code/empty-unused-enum.stderr

@@ -2,8 +2,11 @@ error: enum is never used: `E`
   --> $DIR/empty-unused-enum.rs:3:6
    |
 LL | enum E {}
-   |      ^
+   |      ^ help: if this is intentional, prefix it with an underscore: `_E`
    |
+   = note: the leading underscore helps signal to the reader that the enum may still serve
+           a purpose even if it isn't used in a way that we can detect (e.g. the enum
+           is only used through FFI or used only for its effect when dropped)
 note: the lint level is defined here
   --> $DIR/empty-unused-enum.rs:1:9
    |

src/test/ui/lint/dead-code/field-used-in-ffi-issue-81658.stderr

@@ -2,8 +2,11 @@ error: field is never read: `items`
   --> $DIR/field-used-in-ffi-issue-81658.rs:13:5
    |
 LL |     items: Option<Vec<T>>,
-   |     ^^^^^^^^^^^^^^^^^^^^^
+   |     ^^^^^^^^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_items`
    |
+   = note: the leading underscore helps signal to the reader that the field may still serve
+           a purpose even if it isn't used in a way that we can detect (e.g. the field
+           is only used through FFI or used only for its effect when dropped)
 note: the lint level is defined here
   --> $DIR/field-used-in-ffi-issue-81658.rs:7:9
    |

src/test/ui/lint/dead-code/impl-trait.stderr

@@ -2,8 +2,11 @@ error: type alias is never used: `Unused`
   --> $DIR/impl-trait.rs:12:1
    |
 LL | type Unused = ();
-   | ^^^^^^^^^^^^^^^^^
+   | ^^^^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_Unused`
    |
+   = note: the leading underscore helps signal to the reader that the type alias may still serve
+           a purpose even if it isn't used in a way that we can detect (e.g. the type alias
+           is only used through FFI or used only for its effect when dropped)
 note: the lint level is defined here
   --> $DIR/impl-trait.rs:1:9
    |

src/test/ui/lint/dead-code/lint-dead-code-1.stderr

@@ -2,8 +2,11 @@ error: struct is never constructed: `Bar`
   --> $DIR/lint-dead-code-1.rs:12:16
    |
 LL |     pub struct Bar;
-   |                ^^^
+   |                ^^^ help: if this is intentional, prefix it with an underscore: `_Bar`
    |
+   = note: the leading underscore helps signal to the reader that the struct may still serve
+           a purpose even if it isn't used in a way that we can detect (e.g. the struct
+           is only used through FFI or used only for its effect when dropped)
 note: the lint level is defined here
   --> $DIR/lint-dead-code-1.rs:5:9
    |
@@ -14,55 +17,91 @@ error: static is never used: `priv_static`
   --> $DIR/lint-dead-code-1.rs:20:1
    |
 LL | static priv_static: isize = 0;
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_priv_static`
+   |
+   = note: the leading underscore helps signal to the reader that the static may still serve
+           a purpose even if it isn't used in a way that we can detect (e.g. the static
+           is only used through FFI or used only for its effect when dropped)
 
 error: constant is never used: `priv_const`
   --> $DIR/lint-dead-code-1.rs:27:1
    |
 LL | const priv_const: isize = 0;
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_priv_const`
+   |
+   = note: the leading underscore helps signal to the reader that the constant may still serve
+           a purpose even if it isn't used in a way that we can detect (e.g. the constant
+           is only used through FFI or used only for its effect when dropped)
 
 error: struct is never constructed: `PrivStruct`
   --> $DIR/lint-dead-code-1.rs:35:8
    |
 LL | struct PrivStruct;
-   |        ^^^^^^^^^^
+   |        ^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_PrivStruct`
+   |
+   = note: the leading underscore helps signal to the reader that the struct may still serve
+           a purpose even if it isn't used in a way that we can detect (e.g. the struct
+           is only used through FFI or used only for its effect when dropped)
 
 error: enum is never used: `priv_enum`
   --> $DIR/lint-dead-code-1.rs:64:6
    |
 LL | enum priv_enum { foo2, bar2 }
-   |      ^^^^^^^^^
+   |      ^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_priv_enum`
+   |
+   = note: the leading underscore helps signal to the reader that the enum may still serve
+           a purpose even if it isn't used in a way that we can detect (e.g. the enum
+           is only used through FFI or used only for its effect when dropped)
 
 error: variant is never constructed: `bar3`
   --> $DIR/lint-dead-code-1.rs:67:5
    |
 LL |     bar3
-   |     ^^^^
+   |     ^^^^ help: if this is intentional, prefix it with an underscore: `_bar3`
+   |
+   = note: the leading underscore helps signal to the reader that the variant may still serve
+           a purpose even if it isn't used in a way that we can detect (e.g. the variant
+           is only used through FFI or used only for its effect when dropped)
 
 error: function is never used: `priv_fn`
   --> $DIR/lint-dead-code-1.rs:88:4
    |
 LL | fn priv_fn() {
-   |    ^^^^^^^
+   |    ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_priv_fn`
+   |
+   = note: the leading underscore helps signal to the reader that the function may still serve
+           a purpose even if it isn't used in a way that we can detect (e.g. the function
+           is only used through FFI or used only for its effect when dropped)
 
 error: function is never used: `foo`
   --> $DIR/lint-dead-code-1.rs:93:4
    |
 LL | fn foo() {
-   |    ^^^
+   |    ^^^ help: if this is intentional, prefix it with an underscore: `_foo`
+   |
+   = note: the leading underscore helps signal to the reader that the function may still serve
+           a purpose even if it isn't used in a way that we can detect (e.g. the function
+           is only used through FFI or used only for its effect when dropped)
 
 error: function is never used: `bar`
   --> $DIR/lint-dead-code-1.rs:98:4
    |
 LL | fn bar() {
-   |    ^^^
+   |    ^^^ help: if this is intentional, prefix it with an underscore: `_bar`
+   |
+   = note: the leading underscore helps signal to the reader that the function may still serve
+           a purpose even if it isn't used in a way that we can detect (e.g. the function
+           is only used through FFI or used only for its effect when dropped)
 
 error: function is never used: `baz`
   --> $DIR/lint-dead-code-1.rs:102:4
    |
 LL | fn baz() -> impl Copy {
-   |    ^^^
+   |    ^^^ help: if this is intentional, prefix it with an underscore: `_baz`
+   |
+   = note: the leading underscore helps signal to the reader that the function may still serve
+           a purpose even if it isn't used in a way that we can detect (e.g. the function
+           is only used through FFI or used only for its effect when dropped)
 
 error: aborting due to 10 previous errors
 

src/test/ui/lint/dead-code/lint-dead-code-2.stderr

@@ -2,8 +2,11 @@ error: function is never used: `dead_fn`
   --> $DIR/lint-dead-code-2.rs:22:4
    |
 LL | fn dead_fn() {}
-   |    ^^^^^^^
+   |    ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_dead_fn`
    |
+   = note: the leading underscore helps signal to the reader that the function may still serve
+           a purpose even if it isn't used in a way that we can detect (e.g. the function
+           is only used through FFI or used only for its effect when dropped)
 note: the lint level is defined here
   --> $DIR/lint-dead-code-2.rs:2:9
    |
@@ -14,13 +17,21 @@ error: function is never used: `dead_fn2`
   --> $DIR/lint-dead-code-2.rs:25:4
    |
 LL | fn dead_fn2() {}
-   |    ^^^^^^^^
+   |    ^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_dead_fn2`
+   |
+   = note: the leading underscore helps signal to the reader that the function may still serve
+           a purpose even if it isn't used in a way that we can detect (e.g. the function
+           is only used through FFI or used only for its effect when dropped)
 
 error: function is never used: `main`
   --> $DIR/lint-dead-code-2.rs:38:4
    |
 LL | fn main() {
-   |    ^^^^
+   |    ^^^^ help: if this is intentional, prefix it with an underscore: `_main`
+   |
+   = note: the leading underscore helps signal to the reader that the function may still serve
+           a purpose even if it isn't used in a way that we can detect (e.g. the function
+           is only used through FFI or used only for its effect when dropped)
 
 error: aborting due to 3 previous errors
 

src/test/ui/lint/dead-code/lint-dead-code-3.stderr

@@ -2,8 +2,11 @@ error: struct is never constructed: `Foo`
   --> $DIR/lint-dead-code-3.rs:14:8
    |
 LL | struct Foo;
-   |        ^^^
+   |        ^^^ help: if this is intentional, prefix it with an underscore: `_Foo`
    |
+   = note: the leading underscore helps signal to the reader that the struct may still serve
+           a purpose even if it isn't used in a way that we can detect (e.g. the struct
+           is only used through FFI or used only for its effect when dropped)
 note: the lint level is defined here
   --> $DIR/lint-dead-code-3.rs:4:9
    |
@@ -14,25 +17,41 @@ error: associated function is never used: `foo`
   --> $DIR/lint-dead-code-3.rs:16:8
    |
 LL |     fn foo(&self) {
-   |        ^^^
+   |        ^^^ help: if this is intentional, prefix it with an underscore: `_foo`
+   |
+   = note: the leading underscore helps signal to the reader that the associated function may still serve
+           a purpose even if it isn't used in a way that we can detect (e.g. the associated function
+           is only used through FFI or used only for its effect when dropped)
 
 error: function is never used: `bar`
   --> $DIR/lint-dead-code-3.rs:21:4
    |
 LL | fn bar() {
-   |    ^^^
+   |    ^^^ help: if this is intentional, prefix it with an underscore: `_bar`
+   |
+   = note: the leading underscore helps signal to the reader that the function may still serve
+           a purpose even if it isn't used in a way that we can detect (e.g. the function
+           is only used through FFI or used only for its effect when dropped)
 
 error: enum is never used: `c_void`
   --> $DIR/lint-dead-code-3.rs:60:6
    |
 LL | enum c_void {}
-   |      ^^^^^^
+   |      ^^^^^^ help: if this is intentional, prefix it with an underscore: `_c_void`
+   |
+   = note: the leading underscore helps signal to the reader that the enum may still serve
+           a purpose even if it isn't used in a way that we can detect (e.g. the enum
+           is only used through FFI or used only for its effect when dropped)
 
 error: function is never used: `free`
   --> $DIR/lint-dead-code-3.rs:62:5
    |
 LL |     fn free(p: *const c_void);
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_free`
+   |
+   = note: the leading underscore helps signal to the reader that the function may still serve
+           a purpose even if it isn't used in a way that we can detect (e.g. the function
+           is only used through FFI or used only for its effect when dropped)
 
 error: aborting due to 5 previous errors