Change to give a help message

This commit is contained in:
John Ginger 2018-12-07 14:15:36 +00:00
parent 70536d4b4c
commit c0e3f4b8bb
4 changed files with 19 additions and 13 deletions

View file

@ -1657,13 +1657,15 @@ impl<'a, 'tcx> Liveness<'a, 'tcx> {
fn report_dead_assign(&self, hir_id: HirId, sp: Span, var: Variable, is_argument: bool) { fn report_dead_assign(&self, hir_id: HirId, sp: Span, var: Variable, is_argument: bool) {
if let Some(name) = self.should_warn(var) { if let Some(name) = self.should_warn(var) {
if is_argument { if is_argument {
self.ir.tcx.lint_hir(lint::builtin::UNUSED_ASSIGNMENTS, hir_id, sp, self.ir.tcx.struct_span_lint_hir(lint::builtin::UNUSED_ASSIGNMENTS, hir_id, sp,
&format!("value passed to `{}` is never read &format!("value passed to `{}` is never read", name))
(maybe it is overwritten before being read)", name)); .help("maybe it is overwritten before being read?")
.emit();
} else { } else {
self.ir.tcx.lint_hir(lint::builtin::UNUSED_ASSIGNMENTS, hir_id, sp, self.ir.tcx.struct_span_lint_hir(lint::builtin::UNUSED_ASSIGNMENTS, hir_id, sp,
&format!("value assigned to `{}` is never read &format!("value assigned to `{}` is never read", name))
(maybe it is overwritten before being read)", name)); .help("maybe it is overwritten before being read?")
.emit();
} }
} }
} }

View file

@ -44,7 +44,6 @@ LL | mut hours_are_suns,
= note: consider using `_hours_are_suns` instead = note: consider using `_hours_are_suns` instead
warning: value assigned to `hours_are_suns` is never read warning: value assigned to `hours_are_suns` is never read
(maybe it is overwritten before being read)
--> $DIR/issue-47390-unused-variable-in-struct-pattern.rs:50:9 --> $DIR/issue-47390-unused-variable-in-struct-pattern.rs:50:9
| |
LL | hours_are_suns = false; LL | hours_are_suns = false;
@ -56,6 +55,7 @@ note: lint level defined here
LL | #![warn(unused)] // UI tests pass `-A unused` (#43896) LL | #![warn(unused)] // UI tests pass `-A unused` (#43896)
| ^^^^^^ | ^^^^^^
= note: #[warn(unused_assignments)] implied by #[warn(unused)] = note: #[warn(unused_assignments)] implied by #[warn(unused)]
= help: maybe it is overwritten before being read?
warning: unused variable: `fire` warning: unused variable: `fire`
--> $DIR/issue-47390-unused-variable-in-struct-pattern.rs:54:32 --> $DIR/issue-47390-unused-variable-in-struct-pattern.rs:54:32

View file

@ -1,5 +1,4 @@
error: value assigned to `x` is never read error: value assigned to `x` is never read
(maybe it is overwritten before being read)
--> $DIR/liveness-dead.rs:19:13 --> $DIR/liveness-dead.rs:19:13
| |
LL | let mut x: isize = 3; //~ ERROR: value assigned to `x` is never read LL | let mut x: isize = 3; //~ ERROR: value assigned to `x` is never read
@ -10,27 +9,31 @@ note: lint level defined here
| |
LL | #![deny(unused_assignments)] LL | #![deny(unused_assignments)]
| ^^^^^^^^^^^^^^^^^^ | ^^^^^^^^^^^^^^^^^^
= help: maybe it is overwritten before being read?
error: value assigned to `x` is never read error: value assigned to `x` is never read
(maybe it is overwritten before being read)
--> $DIR/liveness-dead.rs:27:5 --> $DIR/liveness-dead.rs:27:5
| |
LL | x = 4; //~ ERROR: value assigned to `x` is never read LL | x = 4; //~ ERROR: value assigned to `x` is never read
| ^ | ^
|
= help: maybe it is overwritten before being read?
error: value passed to `x` is never read error: value passed to `x` is never read
(maybe it is overwritten before being read)
--> $DIR/liveness-dead.rs:30:11 --> $DIR/liveness-dead.rs:30:11
| |
LL | fn f4(mut x: i32) { //~ ERROR: value passed to `x` is never read LL | fn f4(mut x: i32) { //~ ERROR: value passed to `x` is never read
| ^ | ^
|
= help: maybe it is overwritten before being read?
error: value assigned to `x` is never read error: value assigned to `x` is never read
(maybe it is overwritten before being read)
--> $DIR/liveness-dead.rs:37:5 --> $DIR/liveness-dead.rs:37:5
| |
LL | x = 4; //~ ERROR: value assigned to `x` is never read LL | x = 4; //~ ERROR: value assigned to `x` is never read
| ^ | ^
|
= help: maybe it is overwritten before being read?
error: aborting due to 4 previous errors error: aborting due to 4 previous errors

View file

@ -50,7 +50,6 @@ LL | let mut x = 3;
= note: consider using `_x` instead = note: consider using `_x` instead
error: value assigned to `x` is never read error: value assigned to `x` is never read
(maybe it is overwritten before being read)
--> $DIR/liveness-unused.rs:42:5 --> $DIR/liveness-unused.rs:42:5
| |
LL | x += 4; LL | x += 4;
@ -61,6 +60,7 @@ note: lint level defined here
| |
LL | #![deny(unused_assignments)] LL | #![deny(unused_assignments)]
| ^^^^^^^^^^^^^^^^^^ | ^^^^^^^^^^^^^^^^^^
= help: maybe it is overwritten before being read?
error: variable `z` is assigned to, but never used error: variable `z` is assigned to, but never used
--> $DIR/liveness-unused.rs:47:13 --> $DIR/liveness-unused.rs:47:13
@ -103,11 +103,12 @@ LL | let x;
= note: consider using `_x` instead = note: consider using `_x` instead
error: value assigned to `x` is never read error: value assigned to `x` is never read
(maybe it is overwritten before being read)
--> $DIR/liveness-unused.rs:126:9 --> $DIR/liveness-unused.rs:126:9
| |
LL | x = 0; //~ ERROR value assigned to `x` is never read LL | x = 0; //~ ERROR value assigned to `x` is never read
| ^ | ^
|
= help: maybe it is overwritten before being read?
error: aborting due to 13 previous errors error: aborting due to 13 previous errors