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Allow for a missing adt_def in NamePrivacyVisitor. #121482

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Merged
merged 1 commit into from
Feb 23, 2024
Merged

Allow for a missing adt_def in NamePrivacyVisitor. #121482

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5 changes: 4 additions & 1 deletion compiler/rustc_privacy/src/lib.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -988,7 +988,10 @@ impl<'tcx> Visitor<'tcx> for NamePrivacyVisitor<'tcx> {
fn visit_expr(&mut self, expr: &'tcx hir::Expr<'tcx>) {
if let hir::ExprKind::Struct(qpath, fields, ref base) = expr.kind {
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how do we ge an exprkind struct in the example you gave?

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The range somehow becomes a struct. Here's partial output with -Zunpretty=hir-tree:

Expr {
    hir_id: HirId(DefId(0:3 ~ unreachable_issue_121455[470e]::test).8),
    kind: Struct(
        LangItem(
            Range,
            tests/ui/privacy/unreachable-issue-121455.rs:3:14: 3:18 (#0),
        ),  
        [   
            ExprField {
                ... 
            },  
            ExprField {
                ... 
            },  
        ],  
        None,
    ),  
    span: tests/ui/privacy/unreachable-issue-121455.rs:3:14: 3:18 (#0),
},

let res = self.typeck_results().qpath_res(qpath, expr.hir_id);
let adt = self.typeck_results().expr_ty(expr).ty_adt_def().unwrap();
let Some(adt) = self.typeck_results().expr_ty(expr).ty_adt_def() else {
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is this error case only reachable for ty::Error? If so, I'm wondering if we should return Resut<Option<AdtDef>, ErrorGuaranteed>. The churn may be useless, or it exposes more such cases

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@nnethercote nnethercote Feb 23, 2024 •
edited
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I checked, and yes, the result of self.typeck_results().expr_ty(expr) is ty::Error. I don't know if that's the only thing that can reach here; it's the only thing we've seen reach here because this is the first time the the adt_def has ever failed.

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As for ty_adt_def's return type... it has ~100 call sites. I looked through some of them, I don't see any patterns where having an ErrorGuaranteed would be useful. There were a couple of places where a normal error (not a span_delayed_bug) was emitted in the case where it returned None.

self.tcx.dcx().span_delayed_bug(expr.span, "no adt_def for expression");
return;
};
let variant = adt.variant_of_res(res);
if let Some(base) = *base {
// If the expression uses FRU we need to make sure all the unmentioned fields
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6 changes: 6 additions & 0 deletions tests/ui/privacy/unreachable-issue-121455.rs
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@@ -0,0 +1,6 @@
fn test(s: &Self::Id) {
//~^ ERROR failed to resolve: `Self` is only available in impls, traits, and type definitions
match &s[0..3] {}
}

fn main() {}
9 changes: 9 additions & 0 deletions tests/ui/privacy/unreachable-issue-121455.stderr
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@@ -0,0 +1,9 @@
error[E0433]: failed to resolve: `Self` is only available in impls, traits, and type definitions
--> $DIR/unreachable-issue-121455.rs:1:13
|
LL | fn test(s: &Self::Id) {
| ^^^^ `Self` is only available in impls, traits, and type definitions

error: aborting due to 1 previous error

For more information about this error, try `rustc --explain E0433`.