bjoernager/rust
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Account for owning item lifetimes in suggestion and annotate tests as run-rustfix

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```
error: lifetime may not live long enough
  --> $DIR/lt-ref-self.rs:12:9
   |
LL |     fn ref_self(&self, f: &u32) -> &u32 {
   |                 -         - let's call the lifetime of this reference `'1`
   |                 |
   |                 let's call the lifetime of this reference `'2`
LL |         f
   |         ^ method was supposed to return data with lifetime `'2` but it is returning data with lifetime `'1`
   |
help: consider introducing a named lifetime parameter and update trait if needed
   |
LL |     fn ref_self<'b>(&'b self, f: &'b u32) -> &'b u32 {
   |                ++++  ++           ++          ++
```
This commit is contained in:
Esteban Küber 2024-05-07 19:35:25 +00:00
parent 120049fab4
commit d1d585d039
27 changed files with 404 additions and 59 deletions
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42
compiler/rustc_infer/src/errors/mod.rs
View file

@ -1,4 +1,5 @@
use hir::GenericParamKind;
use rustc_data_structures::fx::FxHashSet;
use rustc_errors::{
codes::*, Applicability, Diag, DiagMessage, DiagStyledString, EmissionGuarantee, IntoDiagArg,
MultiSpan, SubdiagMessageOp, Subdiagnostic,
@ -362,13 +363,27 @@ impl Subdiagnostic for AddLifetimeParamsSuggestion<'_> {
let node = self.tcx.hir_node_by_def_id(anon_reg.def_id);
let is_impl = matches!(&node, hir::Node::ImplItem(_));
let generics = match node {
let (generics, parent_generics) = match node {
hir::Node::Item(&hir::Item {
kind: hir::ItemKind::Fn(_, ref generics, ..),
..
})
| hir::Node::TraitItem(&hir::TraitItem { ref generics, .. })
| hir::Node::ImplItem(&hir::ImplItem { ref generics, .. }) => generics,
| hir::Node::ImplItem(&hir::ImplItem { ref generics, .. }) => (
generics,
match self.tcx.parent_hir_node(self.tcx.local_def_id_to_hir_id(anon_reg.def_id))
{
hir::Node::Item(hir::Item {
kind: hir::ItemKind::Trait(_, _, ref generics, ..),
..
})
| hir::Node::Item(hir::Item {
kind: hir::ItemKind::Impl(hir::Impl { ref generics, .. }),
..
}) => Some(generics),
_ => None,
},
),
_ => return false,
};
@ -379,8 +394,29 @@ impl Subdiagnostic for AddLifetimeParamsSuggestion<'_> {
.map(|p| p.name.ident().name)
.find(|i| *i != kw::UnderscoreLifetime);
let introduce_new = suggestion_param_name.is_none();
let mut default = "'a".to_string();
if let Some(parent_generics) = parent_generics {
let used: FxHashSet<_> = parent_generics
.params
.iter()
.filter(|p| matches!(p.kind, GenericParamKind::Lifetime { .. }))
.map(|p| p.name.ident().name)
.filter(|i| *i != kw::UnderscoreLifetime)
.map(|l| l.to_string())
.collect();
if let Some(lt) =
('a'..='z').map(|it| format!("'{it}")).find(|it| !used.contains(it))
{
// We want a lifetime that *isn't* present in the `trait` or `impl` that assoc
// `fn` belongs to. We could suggest reusing one of their lifetimes, but it is
// likely to be an over-constraining lifetime requirement, so we always add a
// lifetime to the `fn`.
default = lt;
}
}
let suggestion_param_name =
suggestion_param_name.map(|n| n.to_string()).unwrap_or_else(|| "'a".to_owned());
suggestion_param_name.map(|n| n.to_string()).unwrap_or_else(|| default);
struct ImplicitLifetimeFinder {
suggestions: Vec<(Span, String)>,