Rollup merge of #70300 - aleksator:66636_reword_unused_variable_warni…

…ng, r=Dylan-DPC

Reword unused variable warning

Fixes #66636

src/doc/rustc/src/json.md

@@ -168,7 +168,7 @@ Diagnostics have the following format:
             "rendered": null
         },
         {
-            "message": "consider prefixing with an underscore",
+            "message": "if this is intentional, prefix it with an underscore",
             "code": null,
             "level": "help",
             "spans": [
@@ -201,7 +201,7 @@ Diagnostics have the following format:
     /* Optional string of the rendered version of the diagnostic as displayed
        by rustc. Note that this may be influenced by the `--json` flag.
     */
-    "rendered": "warning: unused variable: `x`\n --> lib.rs:2:9\n  |\n2 |     let x = 123;\n  |         ^ help: consider prefixing with an underscore: `_x`\n  |\n  = note: `#[warn(unused_variables)]` on by default\n\n"
+    "rendered": "warning: unused variable: `x`\n --> lib.rs:2:9\n  |\n2 |     let x = 123;\n  |         ^ help: if this is intentional, prefix it with an underscore: `_x`\n  |\n  = note: `#[warn(unused_variables)]` on by default\n\n"
 }
 ```
 

src/librustc_passes/liveness.rs

@@ -1565,7 +1565,7 @@ impl<'tcx> Liveness<'_, 'tcx> {
                             }
                         } else {
                             err.multipart_suggestion(
-                                "consider prefixing with an underscore",
+                                "if this is intentional, prefix it with an underscore",
                                 spans.iter().map(|span| (*span, format!("_{}", name))).collect(),
                                 Applicability::MachineApplicable,
                             );

src/test/ui/const-generics/issues/issue-62187-encountered-polymorphic-const.stderr

@@ -10,7 +10,7 @@ warning: unused variable: `foo`
   --> $DIR/issue-62187-encountered-polymorphic-const.rs:15:9
    |
 LL |     let foo = <[u8; 2]>::BIT_LEN;
-   |         ^^^ help: consider prefixing with an underscore: `_foo`
+   |         ^^^ help: if this is intentional, prefix it with an underscore: `_foo`
    |
    = note: `#[warn(unused_variables)]` on by default
 

src/test/ui/issues/issue-17999.stderr

@@ -2,7 +2,7 @@ error: unused variable: `x`
   --> $DIR/issue-17999.rs:5:13
    |
 LL |         let x = ();
-   |             ^ help: consider prefixing with an underscore: `_x`
+   |             ^ help: if this is intentional, prefix it with an underscore: `_x`
    |
 note: the lint level is defined here
   --> $DIR/issue-17999.rs:1:9
@@ -14,7 +14,7 @@ error: unused variable: `a`
   --> $DIR/issue-17999.rs:7:13
    |
 LL |             a => {}
-   |             ^ help: consider prefixing with an underscore: `_a`
+   |             ^ help: if this is intentional, prefix it with an underscore: `_a`
 
 error: aborting due to 2 previous errors
 

src/test/ui/issues/issue-22599.stderr

@@ -2,7 +2,7 @@ error: unused variable: `a`
   --> $DIR/issue-22599.rs:8:19
    |
 LL |     v = match 0 { a => 0 };
-   |                   ^ help: consider prefixing with an underscore: `_a`
+   |                   ^ help: if this is intentional, prefix it with an underscore: `_a`
    |
 note: the lint level is defined here
   --> $DIR/issue-22599.rs:1:9

src/test/ui/issues/issue-56685.stderr

@@ -9,7 +9,7 @@ note: the lint level is defined here
    |
 LL | #![deny(unused_variables)]
    |         ^^^^^^^^^^^^^^^^
-help: consider prefixing with an underscore
+help: if this is intentional, prefix it with an underscore
    |
 LL |         E::A(_x) | E::B(_x) => {}
    |              ^^         ^^
@@ -20,7 +20,7 @@ error: unused variable: `x`
 LL |         F::A(x, y) | F::B(x, y) => { y },
    |              ^            ^
    |
-help: consider prefixing with an underscore
+help: if this is intentional, prefix it with an underscore
    |
 LL |         F::A(_x, y) | F::B(_x, y) => { y },
    |              ^^            ^^
@@ -29,21 +29,21 @@ error: unused variable: `a`
   --> $DIR/issue-56685.rs:27:14
    |
 LL |         F::C(a, b) => { 3 }
-   |              ^ help: consider prefixing with an underscore: `_a`
+   |              ^ help: if this is intentional, prefix it with an underscore: `_a`
 
 error: unused variable: `b`
   --> $DIR/issue-56685.rs:27:17
    |
 LL |         F::C(a, b) => { 3 }
-   |                 ^ help: consider prefixing with an underscore: `_b`
+   |                 ^ help: if this is intentional, prefix it with an underscore: `_b`
 
 error: unused variable: `x`
   --> $DIR/issue-56685.rs:32:25
    |
 LL |     let _ = if let F::A(x, y) | F::B(x, y) = F::A(1, 2) {
    |                         ^            ^
    |
-help: consider prefixing with an underscore
+help: if this is intentional, prefix it with an underscore
    |
 LL |     let _ = if let F::A(_x, y) | F::B(_x, y) = F::A(1, 2) {
    |                         ^^            ^^
@@ -54,7 +54,7 @@ error: unused variable: `x`
 LL |     while let F::A(x, y) | F::B(x, y) = F::A(1, 2) {
    |                    ^            ^
    |
-help: consider prefixing with an underscore
+help: if this is intentional, prefix it with an underscore
    |
 LL |     while let F::A(_x, y) | F::B(_x, y) = F::A(1, 2) {
    |                    ^^            ^^

src/test/ui/lint/issue-47390-unused-variable-in-struct-pattern.stderr

@@ -2,7 +2,7 @@ warning: unused variable: `i_think_continually`
   --> $DIR/issue-47390-unused-variable-in-struct-pattern.rs:26:9
    |
 LL |     let i_think_continually = 2;
-   |         ^^^^^^^^^^^^^^^^^^^ help: consider prefixing with an underscore: `_i_think_continually`
+   |         ^^^^^^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_i_think_continually`
    |
 note: the lint level is defined here
   --> $DIR/issue-47390-unused-variable-in-struct-pattern.rs:5:9
@@ -15,19 +15,19 @@ warning: unused variable: `mut_unused_var`
   --> $DIR/issue-47390-unused-variable-in-struct-pattern.rs:33:13
    |
 LL |     let mut mut_unused_var = 1;
-   |             ^^^^^^^^^^^^^^ help: consider prefixing with an underscore: `_mut_unused_var`
+   |             ^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_mut_unused_var`
 
 warning: unused variable: `var`
   --> $DIR/issue-47390-unused-variable-in-struct-pattern.rs:37:14
    |
 LL |     let (mut var, unused_var) = (1, 2);
-   |              ^^^ help: consider prefixing with an underscore: `_var`
+   |              ^^^ help: if this is intentional, prefix it with an underscore: `_var`
 
 warning: unused variable: `unused_var`
   --> $DIR/issue-47390-unused-variable-in-struct-pattern.rs:37:19
    |
 LL |     let (mut var, unused_var) = (1, 2);
-   |                   ^^^^^^^^^^ help: consider prefixing with an underscore: `_unused_var`
+   |                   ^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_unused_var`
 
 warning: unused variable: `corridors_of_light`
   --> $DIR/issue-47390-unused-variable-in-struct-pattern.rs:45:26

src/test/ui/lint/lint-match-arms.stderr

@@ -2,7 +2,7 @@ error: unused variable: `y`
   --> $DIR/lint-match-arms.rs:5:9
    |
 LL |         y => (),
-   |         ^ help: consider prefixing with an underscore: `_y`
+   |         ^ help: if this is intentional, prefix it with an underscore: `_y`
    |
 note: the lint level is defined here
   --> $DIR/lint-match-arms.rs:3:16

src/test/ui/lint/lint-removed-allow.stderr

@@ -2,7 +2,7 @@ error: unused variable: `unused`
   --> $DIR/lint-removed-allow.rs:8:17
    |
 LL | fn main() { let unused = (); }
-   |                 ^^^^^^ help: consider prefixing with an underscore: `_unused`
+   |                 ^^^^^^ help: if this is intentional, prefix it with an underscore: `_unused`
    |
 note: the lint level is defined here
   --> $DIR/lint-removed-allow.rs:7:8

src/test/ui/lint/lint-removed-cmdline.stderr

@@ -18,7 +18,7 @@ error: unused variable: `unused`
   --> $DIR/lint-removed-cmdline.rs:12:17
    |
 LL | fn main() { let unused = (); }
-   |                 ^^^^^^ help: consider prefixing with an underscore: `_unused`
+   |                 ^^^^^^ help: if this is intentional, prefix it with an underscore: `_unused`
    |
 note: the lint level is defined here
   --> $DIR/lint-removed-cmdline.rs:11:8

src/test/ui/lint/lint-removed.stderr

@@ -10,7 +10,7 @@ error: unused variable: `unused`
   --> $DIR/lint-removed.rs:8:17
    |
 LL | fn main() { let unused = (); }
-   |                 ^^^^^^ help: consider prefixing with an underscore: `_unused`
+   |                 ^^^^^^ help: if this is intentional, prefix it with an underscore: `_unused`
    |
 note: the lint level is defined here
   --> $DIR/lint-removed.rs:7:8

src/test/ui/lint/lint-renamed-allow.stderr

@@ -2,7 +2,7 @@ error: unused variable: `unused`
   --> $DIR/lint-renamed-allow.rs:8:17
    |
 LL | fn main() { let unused = (); }
-   |                 ^^^^^^ help: consider prefixing with an underscore: `_unused`
+   |                 ^^^^^^ help: if this is intentional, prefix it with an underscore: `_unused`
    |
 note: the lint level is defined here
   --> $DIR/lint-renamed-allow.rs:7:8

src/test/ui/lint/lint-renamed-cmdline.stderr

@@ -18,7 +18,7 @@ error: unused variable: `unused`
   --> $DIR/lint-renamed-cmdline.rs:8:17
    |
 LL | fn main() { let unused = (); }
-   |                 ^^^^^^ help: consider prefixing with an underscore: `_unused`
+   |                 ^^^^^^ help: if this is intentional, prefix it with an underscore: `_unused`
    |
 note: the lint level is defined here
   --> $DIR/lint-renamed-cmdline.rs:7:8

src/test/ui/lint/lint-renamed.stderr

@@ -10,7 +10,7 @@ error: unused variable: `unused`
   --> $DIR/lint-renamed.rs:4:17
    |
 LL | fn main() { let unused = (); }
-   |                 ^^^^^^ help: consider prefixing with an underscore: `_unused`
+   |                 ^^^^^^ help: if this is intentional, prefix it with an underscore: `_unused`
    |
 note: the lint level is defined here
   --> $DIR/lint-renamed.rs:3:8

src/test/ui/lint/lint-unused-variables.stderr

@@ -2,7 +2,7 @@ error: unused variable: `a`
   --> $DIR/lint-unused-variables.rs:8:5
    |
 LL |     a: i32,
-   |     ^ help: consider prefixing with an underscore: `_a`
+   |     ^ help: if this is intentional, prefix it with an underscore: `_a`
    |
 note: the lint level is defined here
   --> $DIR/lint-unused-variables.rs:5:9
@@ -14,61 +14,61 @@ error: unused variable: `b`
   --> $DIR/lint-unused-variables.rs:14:5
    |
 LL |     b: i32,
-   |     ^ help: consider prefixing with an underscore: `_b`
+   |     ^ help: if this is intentional, prefix it with an underscore: `_b`
 
 error: unused variable: `a`
   --> $DIR/lint-unused-variables.rs:68:9
    |
 LL |         a: i32,
-   |         ^ help: consider prefixing with an underscore: `_a`
+   |         ^ help: if this is intentional, prefix it with an underscore: `_a`
 
 error: unused variable: `b`
   --> $DIR/lint-unused-variables.rs:74:9
    |
 LL |         b: i32,
-   |         ^ help: consider prefixing with an underscore: `_b`
+   |         ^ help: if this is intentional, prefix it with an underscore: `_b`
 
 error: unused variable: `b`
   --> $DIR/lint-unused-variables.rs:42:9
    |
 LL |         b: i32,
-   |         ^ help: consider prefixing with an underscore: `_b`
+   |         ^ help: if this is intentional, prefix it with an underscore: `_b`
 
 error: unused variable: `b`
   --> $DIR/lint-unused-variables.rs:47:9
    |
 LL |         b: i32,
-   |         ^ help: consider prefixing with an underscore: `_b`
+   |         ^ help: if this is intentional, prefix it with an underscore: `_b`
 
 error: unused variable: `a`
   --> $DIR/lint-unused-variables.rs:22:9
    |
 LL |         a: i32,
-   |         ^ help: consider prefixing with an underscore: `_a`
+   |         ^ help: if this is intentional, prefix it with an underscore: `_a`
 
 error: unused variable: `b`
   --> $DIR/lint-unused-variables.rs:29:9
    |
 LL |         b: i32,
-   |         ^ help: consider prefixing with an underscore: `_b`
+   |         ^ help: if this is intentional, prefix it with an underscore: `_b`
 
 error: unused variable: `b`
   --> $DIR/lint-unused-variables.rs:34:9
    |
 LL |         b: i32,
-   |         ^ help: consider prefixing with an underscore: `_b`
+   |         ^ help: if this is intentional, prefix it with an underscore: `_b`
 
 error: unused variable: `b`
   --> $DIR/lint-unused-variables.rs:55:9
    |
 LL |         b: i32,
-   |         ^ help: consider prefixing with an underscore: `_b`
+   |         ^ help: if this is intentional, prefix it with an underscore: `_b`
 
 error: unused variable: `b`
   --> $DIR/lint-unused-variables.rs:60:9
    |
 LL |         b: i32,
-   |         ^ help: consider prefixing with an underscore: `_b`
+   |         ^ help: if this is intentional, prefix it with an underscore: `_b`
 
 error: aborting due to 11 previous errors
 

src/test/ui/lint/lint-uppercase-variables.stderr

@@ -22,7 +22,7 @@ warning: unused variable: `Foo`
   --> $DIR/lint-uppercase-variables.rs:22:9
    |
 LL |         Foo => {}
-   |         ^^^ help: consider prefixing with an underscore: `_Foo`
+   |         ^^^ help: if this is intentional, prefix it with an underscore: `_Foo`
    |
 note: the lint level is defined here
   --> $DIR/lint-uppercase-variables.rs:1:9
@@ -35,13 +35,13 @@ warning: unused variable: `Foo`
   --> $DIR/lint-uppercase-variables.rs:28:9
    |
 LL |     let Foo = foo::Foo::Foo;
-   |         ^^^ help: consider prefixing with an underscore: `_Foo`
+   |         ^^^ help: if this is intentional, prefix it with an underscore: `_Foo`
 
 warning: unused variable: `Foo`
   --> $DIR/lint-uppercase-variables.rs:33:17
    |
 LL |     fn in_param(Foo: foo::Foo) {}
-   |                 ^^^ help: consider prefixing with an underscore: `_Foo`
+   |                 ^^^ help: if this is intentional, prefix it with an underscore: `_Foo`
 
 error: structure field `X` should have a snake case name
   --> $DIR/lint-uppercase-variables.rs:10:5

src/test/ui/liveness/liveness-unused.stderr

@@ -17,7 +17,7 @@ error: unused variable: `x`
   --> $DIR/liveness-unused.rs:8:7
    |
 LL | fn f1(x: isize) {
-   |       ^ help: consider prefixing with an underscore: `_x`
+   |       ^ help: if this is intentional, prefix it with an underscore: `_x`
    |
 note: the lint level is defined here
   --> $DIR/liveness-unused.rs:2:9
@@ -29,19 +29,19 @@ error: unused variable: `x`
   --> $DIR/liveness-unused.rs:12:8
    |
 LL | fn f1b(x: &mut isize) {
-   |        ^ help: consider prefixing with an underscore: `_x`
+   |        ^ help: if this is intentional, prefix it with an underscore: `_x`
 
 error: unused variable: `x`
   --> $DIR/liveness-unused.rs:20:9
    |
 LL |     let x: isize;
-   |         ^ help: consider prefixing with an underscore: `_x`
+   |         ^ help: if this is intentional, prefix it with an underscore: `_x`
 
 error: unused variable: `x`
   --> $DIR/liveness-unused.rs:25:9
    |
 LL |     let x = 3;
-   |         ^ help: consider prefixing with an underscore: `_x`
+   |         ^ help: if this is intentional, prefix it with an underscore: `_x`
 
 error: variable `x` is assigned to, but never used
   --> $DIR/liveness-unused.rs:30:13
@@ -76,25 +76,25 @@ error: unused variable: `i`
   --> $DIR/liveness-unused.rs:59:12
    |
 LL |       Some(i) => {
-   |            ^ help: consider prefixing with an underscore: `_i`
+   |            ^ help: if this is intentional, prefix it with an underscore: `_i`
 
 error: unused variable: `x`
   --> $DIR/liveness-unused.rs:79:9
    |
 LL |     for x in 1..10 { }
-   |         ^ help: consider prefixing with an underscore: `_x`
+   |         ^ help: if this is intentional, prefix it with an underscore: `_x`
 
 error: unused variable: `x`
   --> $DIR/liveness-unused.rs:84:10
    |
 LL |     for (x, _) in [1, 2, 3].iter().enumerate() { }
-   |          ^ help: consider prefixing with an underscore: `_x`
+   |          ^ help: if this is intentional, prefix it with an underscore: `_x`
 
 error: unused variable: `x`
   --> $DIR/liveness-unused.rs:89:13
    |
 LL |     for (_, x) in [1, 2, 3].iter().enumerate() {
-   |             ^ help: consider prefixing with an underscore: `_x`
+   |             ^ help: if this is intentional, prefix it with an underscore: `_x`
 
 error: variable `x` is assigned to, but never used
   --> $DIR/liveness-unused.rs:112:9

src/test/ui/never_type/never-assign-dead-code.stderr

@@ -25,7 +25,7 @@ warning: unused variable: `x`
   --> $DIR/never-assign-dead-code.rs:9:9
    |
 LL |     let x: ! = panic!("aah");
-   |         ^ help: consider prefixing with an underscore: `_x`
+   |         ^ help: if this is intentional, prefix it with an underscore: `_x`
    |
 note: the lint level is defined here
   --> $DIR/never-assign-dead-code.rs:6:9

src/test/ui/proc-macro/attributes-included.stderr

@@ -2,7 +2,7 @@ warning: unused variable: `a`
   --> $DIR/attributes-included.rs:17:9
    |
 LL |     let a: i32 = "foo";
-   |         ^ help: consider prefixing with an underscore: `_a`
+   |         ^ help: if this is intentional, prefix it with an underscore: `_a`
    |
 note: the lint level is defined here
   --> $DIR/attributes-included.rs:4:9