bjoernager/rust
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Change how suggested lifetime args are computed.

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This commit is contained in:
Camille GILLOT 2022-11-06 09:45:34 +00:00
parent 5f5e7a8eec
commit 41090346d8
11 changed files with 83 additions and 55 deletions
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68
compiler/rustc_hir_analysis/src/structured_errors/wrong_number_of_generic_args.rs
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@ -296,25 +296,35 @@ impl<'a, 'tcx> WrongNumberOfGenericArgs<'a, 'tcx> {
) -> String {
debug!(?path_hir_id);
// If there was already a lifetime among the arguments, just replicate that one.
if let Some(lt) = self.gen_args.args.iter().find_map(|arg| match arg {
hir::GenericArg::Lifetime(lt) => Some(lt),
_ => None,
}) {
return std::iter::repeat(lt.to_string())
.take(num_params_to_take)
.collect::<Vec<_>>()
.join(", ");
}
let mut ret = Vec::new();
let mut ty_id = None;
for (id, node) in self.tcx.hir().parent_iter(path_hir_id) {
debug!(?id);
let params = if let Some(generics) = node.generics() {
generics.params
} else if let hir::Node::Ty(ty) = node
&& let hir::TyKind::BareFn(bare_fn) = ty.kind
{
bare_fn.generic_params
} else {
&[]
};
ret.extend(params.iter().filter_map(|p| {
let hir::GenericParamKind::Lifetime { kind: hir::LifetimeParamKind::Explicit }
= p.kind
else { return None };
let hir::ParamName::Plain(name) = p.name else { return None };
Some(name.to_string())
}));
if let hir::Node::Ty(_) = node {
ty_id = Some(id);
}
// Suggest `'_` when in function parameter or elided function return.
if let Some(fn_decl) = node.fn_decl() && let Some(ty_id) = ty_id {
let in_arg = fn_decl.inputs.iter().any(|t| t.hir_id == ty_id);
let in_ret = matches!(fn_decl.output, hir::FnRetTy::Return(ty) if ty.hir_id == ty_id);
if in_arg || (in_ret && fn_decl.lifetime_elision_allowed) {
return std::iter::repeat("'_".to_owned()).take(num_params_to_take).collect::<Vec<_>>().join(", ");
}
}
// Suggest `'static` when in const/static item-like.
if let hir::Node::Item(hir::Item {
kind: hir::ItemKind::Static { .. } | hir::ItemKind::Const { .. },
@ -334,11 +344,29 @@ impl<'a, 'tcx> WrongNumberOfGenericArgs<'a, 'tcx> {
})
| hir::Node::AnonConst(..) = node
{
ret.extend(
std::iter::repeat("'static".to_owned())
.take(num_params_to_take.saturating_sub(ret.len())),
);
return std::iter::repeat("'static".to_owned())
.take(num_params_to_take.saturating_sub(ret.len()))
.collect::<Vec<_>>()
.join(", ");
}
let params = if let Some(generics) = node.generics() {
generics.params
} else if let hir::Node::Ty(ty) = node
&& let hir::TyKind::BareFn(bare_fn) = ty.kind
{
bare_fn.generic_params
} else {
&[]
};
ret.extend(params.iter().filter_map(|p| {
let hir::GenericParamKind::Lifetime { kind: hir::LifetimeParamKind::Explicit }
= p.kind
else { return None };
let hir::ParamName::Plain(name) = p.name else { return None };
Some(name.to_string())
}));
if ret.len() >= num_params_to_take {
return ret[..num_params_to_take].join(", ");
}