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Avoid misleading message/label in match-cfg-fake-edges.rs test

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This commit is contained in:
Esteban Küber 2022-06-22 12:59:48 -07:00
parent 8ab1cd9fdc
commit a86fa4fa38
2 changed files with 46 additions and 25 deletions
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64
compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
View File

@ -339,23 +339,48 @@ fn report_use_of_uninitialized(
Some(name) => (format!("`{name}`"), format!("`{name}`"), format!("`{name}` ")),
None => ("value".to_string(), "the variable".to_string(), String::new()),
};
// We use the statements were the binding was initialized, and inspect the HIR to look
// for the branching codepaths that aren't covered, to point at them.
let hir_id = self.mir_hir_id();
let map = self.infcx.tcx.hir();
let body_id = map.body_owned_by(hir_id);
let body = map.body(body_id);
let mut visitor = ConditionVisitor { spans: &spans, name: &name, errors: vec![] };
visitor.visit_body(&body);
let isnt_initialized =
if let InitializationRequiringAction::PartialAssignment = desired_action {
// The same error is emitted for bindings that are *sometimes* initialized and the ones
// that are *partially* initialized by assigning to a field of an uninitialized
// binding. We differentiate between them for more accurate wording here.
"isn't fully initialized"
} else if spans.iter().filter(|i| !i.contains(span)).count() == 0 {
// We filter above to avoid misleading wording in cases like the following, where `x`
// has an `init`, but it is in the same place we're looking at:
// ```
// let x;
// x += 1;
// ```
} else if spans
.iter()
.filter(|i| {
// We filter these to avoid misleading wording in cases like the following,
// where `x` has an `init`, but it is in the same place we're looking at:
// ```
// let x;
// x += 1;
// ```
!i.contains(span)
// We filter these to avoid incorrect main message on `match-cfg-fake-edges.rs`
&& !visitor
.errors
.iter()
.map(|(sp, _)| *sp)
.any(|sp| span < sp && !sp.contains(span))
})
.count()
== 0
{
"isn't initialized"
} else {
"is possibly-uninitialized"
};
let used = desired_action.as_general_verb_in_past_tense();
let mut err =
struct_span_err!(self, span, E0381, "{used} binding {desc}{isnt_initialized}");
@ -372,22 +397,7 @@ fn report_use_of_uninitialized(
}
err.span_label(span, format!("{binding} {used} here but it {isnt_initialized}"));
// We use the statements were the binding was initialized, and inspect the HIR to look
// for the branching codepaths that aren't covered, to point at them.
let hir_id = self.mir_hir_id();
let map = self.infcx.tcx.hir();
let body_id = map.body_owned_by(hir_id);
let body = map.body(body_id);
let mut visitor = ConditionVisitor { spans: &spans, name: &name, errors: vec![] };
visitor.visit_body(&body);
if visitor.errors.is_empty() {
for sp in &spans {
if *sp < span && !sp.overlaps(span) {
err.span_label(*sp, "binding initialized here in some conditions");
}
}
}
let mut shown = false;
for (sp, label) in visitor.errors {
if sp < span && !sp.overlaps(span) {
// When we have a case like `match-cfg-fake-edges.rs`, we don't want to mention
@ -404,6 +414,14 @@ fn report_use_of_uninitialized(
// };
// ```
err.span_label(sp, &label);
shown = true;
}
}
if !shown {
for sp in &spans {
if *sp < span && !sp.overlaps(span) {
err.span_label(*sp, "binding initialized here in some conditions");
}
}
}
err.span_label(decl_span, "binding declared here but left uninitialized");

7
src/test/ui/nll/match-cfg-fake-edges.stderr
View File

@ -1,11 +1,14 @@
error[E0381]: used binding `x` is possibly-uninitialized
error[E0381]: used binding `x` isn't initialized
--> $DIR/match-cfg-fake-edges.rs:21:13
|
LL | let x;
| - binding declared here but left uninitialized
...
LL | _ if { x = 2; true } => 1,
| ----- binding initialized here in some conditions
LL | _ if {
LL | x;
| ^ `x` used here but it is possibly-uninitialized
| ^ `x` used here but it isn't initialized
error[E0382]: use of moved value: `x`
--> $DIR/match-cfg-fake-edges.rs:35:13