nordic-dev.net/rust
nordic-dev.net/rust
2
0
Fork 0
mirror of https://github.com/rust-lang/rust.git synced 2024-11-01 23:12:02 +00:00
Code Issues Packages Projects Releases Wiki Activity

Rollup merge of #82655 - SkiFire13:fix-issue-81314, r=estebank

Browse Source 
Highlight identifier span instead of whole pattern span in `unused` lint

Fixes #81314

This pretty much just changes the span highlighted in the lint from `pat_sp` to `ident.span`. There's however an exception, which is in patterns with shorthands like `Point { y, ref mut x }`, where a suggestion to change just `x` would be invalid; in those cases I had to keep the pattern span. Another option would be suggesting something like `Point { y, x: ref mut _x }`.

I also added a new test since there weren't any test that checked the `unused` lint with optional patterns.
This commit is contained in:
Guillaume Gomez 2021-03-02 00:50:09 +01:00 committed by GitHub
commit d259d1d98a
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
8 changed files with 126 additions and 58 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

107
compiler/rustc_passes/src/liveness.rs
View File

@ -1494,12 +1494,13 @@ impl<'tcx> Liveness<'_, 'tcx> {
// bindings, and we also consider the first pattern to be the "authoritative" set of ids.
// However, we should take the ids and spans of variables with the same name from the later
// patterns so the suggestions to prefix with underscores will apply to those too.
let mut vars: FxIndexMap<Symbol, (LiveNode, Variable, Vec<(HirId, Span)>)> = <_>::default();
let mut vars: FxIndexMap<Symbol, (LiveNode, Variable, Vec<(HirId, Span, Span)>)> =
<_>::default();
pat.each_binding(|_, hir_id, pat_sp, ident| {
let ln = entry_ln.unwrap_or_else(|| self.live_node(hir_id, pat_sp));
let var = self.variable(hir_id, ident.span);
let id_and_sp = (hir_id, pat_sp);
let id_and_sp = (hir_id, pat_sp, ident.span);
vars.entry(self.ir.variable_name(var))
.and_modify(|(.., hir_ids_and_spans)| hir_ids_and_spans.push(id_and_sp))
.or_insert_with(|| (ln, var, vec![id_and_sp]));
@ -1508,7 +1509,8 @@ impl<'tcx> Liveness<'_, 'tcx> {
for (_, (ln, var, hir_ids_and_spans)) in vars {
if self.used_on_entry(ln, var) {
let id = hir_ids_and_spans[0].0;
let spans = hir_ids_and_spans.into_iter().map(|(_, sp)| sp).collect();
let spans =
hir_ids_and_spans.into_iter().map(|(_, _, ident_span)| ident_span).collect();
on_used_on_entry(spans, id, ln, var);
} else {
self.report_unused(hir_ids_and_spans, ln, var);
@ -1516,7 +1518,12 @@ impl<'tcx> Liveness<'_, 'tcx> {
}
}
fn report_unused(&self, hir_ids_and_spans: Vec<(HirId, Span)>, ln: LiveNode, var: Variable) {
fn report_unused(
&self,
hir_ids_and_spans: Vec<(HirId, Span, Span)>,
ln: LiveNode,
var: Variable,
) {
let first_hir_id = hir_ids_and_spans[0].0;
if let Some(name) = self.should_warn(var).filter(|name| name != "self") {
@ -1530,7 +1537,10 @@ impl<'tcx> Liveness<'_, 'tcx> {
self.ir.tcx.struct_span_lint_hir(
lint::builtin::UNUSED_VARIABLES,
first_hir_id,
hir_ids_and_spans.into_iter().map(|(_, sp)| sp).collect::<Vec<_>>(),
hir_ids_and_spans
.into_iter()
.map(|(_, _, ident_span)| ident_span)
.collect::<Vec<_>>(),
|lint| {
lint.build(&format!("variable `{}` is assigned to, but never used", name))
.note(&format!("consider using `_{}` instead", name))
@ -1538,54 +1548,67 @@ impl<'tcx> Liveness<'_, 'tcx> {
},
)
} else {
self.ir.tcx.struct_span_lint_hir(
lint::builtin::UNUSED_VARIABLES,
first_hir_id,
hir_ids_and_spans.iter().map(|(_, sp)| *sp).collect::<Vec<_>>(),
|lint| {
let mut err = lint.build(&format!("unused variable: `{}`", name));
let (shorthands, non_shorthands): (Vec<_>, Vec<_>) =
hir_ids_and_spans.iter().copied().partition(|(hir_id, _, ident_span)| {
let var = self.variable(*hir_id, *ident_span);
self.ir.variable_is_shorthand(var)
});
let (shorthands, non_shorthands): (Vec<_>, Vec<_>) =
hir_ids_and_spans.into_iter().partition(|(hir_id, span)| {
let var = self.variable(*hir_id, *span);
self.ir.variable_is_shorthand(var)
});
let mut shorthands = shorthands
.into_iter()
.map(|(_, span)| (span, format!("{}: _", name)))
.collect::<Vec<_>>();
// If we have both shorthand and non-shorthand, prefer the "try ignoring
// the field" message, and suggest `_` for the non-shorthands. If we only
// have non-shorthand, then prefix with an underscore instead.
if !shorthands.is_empty() {
shorthands.extend(
non_shorthands
.into_iter()
.map(|(_, span)| (span, "_".to_string()))
.collect::<Vec<_>>(),
);
// If we have both shorthand and non-shorthand, prefer the "try ignoring
// the field" message, and suggest `_` for the non-shorthands. If we only
// have non-shorthand, then prefix with an underscore instead.
if !shorthands.is_empty() {
let shorthands = shorthands
.into_iter()
.map(|(_, pat_span, _)| (pat_span, format!("{}: _", name)))
.chain(
non_shorthands
.into_iter()
.map(|(_, pat_span, _)| (pat_span, "_".to_string())),
)
.collect::<Vec<_>>();
self.ir.tcx.struct_span_lint_hir(
lint::builtin::UNUSED_VARIABLES,
first_hir_id,
hir_ids_and_spans
.iter()
.map(|(_, pat_span, _)| *pat_span)
.collect::<Vec<_>>(),
|lint| {
let mut err = lint.build(&format!("unused variable: `{}`", name));
err.multipart_suggestion(
"try ignoring the field",
shorthands,
Applicability::MachineApplicable,
);
} else {
err.emit()
},
);
} else {
let non_shorthands = non_shorthands
.into_iter()
.map(|(_, _, ident_span)| (ident_span, format!("_{}", name)))
.collect::<Vec<_>>();
self.ir.tcx.struct_span_lint_hir(
lint::builtin::UNUSED_VARIABLES,
first_hir_id,
hir_ids_and_spans
.iter()
.map(|(_, _, ident_span)| *ident_span)
.collect::<Vec<_>>(),
|lint| {
let mut err = lint.build(&format!("unused variable: `{}`", name));
err.multipart_suggestion(
"if this is intentional, prefix it with an underscore",
non_shorthands
.into_iter()
.map(|(_, span)| (span, format!("_{}", name)))
.collect::<Vec<_>>(),
non_shorthands,
Applicability::MachineApplicable,
);
}
err.emit()
},
);
err.emit()
},
);
}
}
}
}

12
src/test/ui/lint/issue-47390-unused-variable-in-struct-pattern.stderr
View File

@ -12,16 +12,16 @@ LL | #![warn(unused)] // UI tests pass `-A unused` (#43896)
= note: `#[warn(unused_variables)]` implied by `#[warn(unused)]`
warning: unused variable: `mut_unused_var`
--> $DIR/issue-47390-unused-variable-in-struct-pattern.rs:33:9
--> $DIR/issue-47390-unused-variable-in-struct-pattern.rs:33:13
|
LL | let mut mut_unused_var = 1;
| ^^^^^^^^^^^^^^^^^^ help: if this is intentional, prefix it 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:37:10
--> $DIR/issue-47390-unused-variable-in-struct-pattern.rs:37:14
|
LL | let (mut var, unused_var) = (1, 2);
| ^^^^^^^ help: if this is intentional, prefix it 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
@ -36,10 +36,10 @@ LL | if let SoulHistory { corridors_of_light,
| ^^^^^^^^^^^^^^^^^^ help: try ignoring the field: `corridors_of_light: _`
warning: variable `hours_are_suns` is assigned to, but never used
--> $DIR/issue-47390-unused-variable-in-struct-pattern.rs:46:26
--> $DIR/issue-47390-unused-variable-in-struct-pattern.rs:46:30
|
LL | mut hours_are_suns,
| ^^^^^^^^^^^^^^^^^^
| ^^^^^^^^^^^^^^
|
= note: consider using `_hours_are_suns` instead

12
src/test/ui/lint/issue-81314-unused-span-ident.fixed Normal file
View File

@ -0,0 +1,12 @@
// run-rustfix
// Regression test for #81314: Unused variable lint should
// span only the identifier and not the rest of the pattern
#![deny(unused)]
fn main() {
let [_rest @ ..] = [1, 2, 3]; //~ ERROR unused variable
}
pub fn foo([_rest @ ..]: &[i32]) { //~ ERROR unused variable
}

12
src/test/ui/lint/issue-81314-unused-span-ident.rs Normal file
View File

@ -0,0 +1,12 @@
// run-rustfix
// Regression test for #81314: Unused variable lint should
// span only the identifier and not the rest of the pattern
#![deny(unused)]
fn main() {
let [rest @ ..] = [1, 2, 3]; //~ ERROR unused variable
}
pub fn foo([rest @ ..]: &[i32]) { //~ ERROR unused variable
}

21
src/test/ui/lint/issue-81314-unused-span-ident.stderr Normal file
View File

@ -0,0 +1,21 @@
error: unused variable: `rest`
--> $DIR/issue-81314-unused-span-ident.rs:8:10
|
LL | let [rest @ ..] = [1, 2, 3];
| ^^^^ help: if this is intentional, prefix it with an underscore: `_rest`
|
note: the lint level is defined here
--> $DIR/issue-81314-unused-span-ident.rs:5:9
|
LL | #![deny(unused)]
| ^^^^^^
= note: `#[deny(unused_variables)]` implied by `#[deny(unused)]`
error: unused variable: `rest`
--> $DIR/issue-81314-unused-span-ident.rs:11:13
|
LL | pub fn foo([rest @ ..]: &[i32]) {
| ^^^^ help: if this is intentional, prefix it with an underscore: `_rest`
error: aborting due to 2 previous errors

4
src/test/ui/liveness/liveness-consts.stderr
View File

@ -1,8 +1,8 @@
warning: variable `a` is assigned to, but never used
--> $DIR/liveness-consts.rs:7:9
--> $DIR/liveness-consts.rs:7:13
|
LL | let mut a = 0;
| ^^^^^
| ^
|
note: the lint level is defined here
--> $DIR/liveness-consts.rs:2:9

8
src/test/ui/liveness/liveness-dead.stderr
View File

@ -1,8 +1,8 @@
error: value assigned to `x` is never read
--> $DIR/liveness-dead.rs:9:9
--> $DIR/liveness-dead.rs:9:13
|
LL | let mut x: isize = 3;
| ^^^^^
| ^
|
note: the lint level is defined here
--> $DIR/liveness-dead.rs:2:9
@ -20,10 +20,10 @@ LL | x = 4;
= help: maybe it is overwritten before being read?
error: value passed to `x` is never read
--> $DIR/liveness-dead.rs:20:7
--> $DIR/liveness-dead.rs:20:11
|
LL | fn f4(mut x: i32) {
| ^^^^^
| ^
|
= help: maybe it is overwritten before being read?

8
src/test/ui/liveness/liveness-unused.stderr
View File

@ -44,10 +44,10 @@ LL | let x = 3;
| ^ help: if this is intentional, prefix it with an underscore: `_x`
error: variable `x` is assigned to, but never used
--> $DIR/liveness-unused.rs:30:9
--> $DIR/liveness-unused.rs:30:13
|
LL | let mut x = 3;
| ^^^^^
| ^
|
= note: consider using `_x` instead
@ -65,10 +65,10 @@ LL | #![deny(unused_assignments)]
= help: maybe it is overwritten before being read?
error: variable `z` is assigned to, but never used
--> $DIR/liveness-unused.rs:37:9
--> $DIR/liveness-unused.rs:37:13
|
LL | let mut z = 3;
| ^^^^^
| ^
|
= note: consider using `_z` instead