};
use rustc_hir as hir;
use rustc_middle::hir::map::fn_sig;
-use rustc_middle::middle::resolve_lifetime::LifetimeScopeForPath;
use rustc_middle::ty::{self as ty, AssocItems, AssocKind, TyCtxt};
use rustc_session::Session;
use rustc_span::def_id::DefId;
/// Handles the `wrong number of type / lifetime / ... arguments` family of error messages.
pub struct WrongNumberOfGenericArgs<'a, 'tcx> {
- crate tcx: TyCtxt<'tcx>,
+ pub(crate) tcx: TyCtxt<'tcx>,
- crate angle_brackets: AngleBrackets,
+ pub(crate) angle_brackets: AngleBrackets,
- crate gen_args_info: GenericArgsInfo,
+ pub(crate) gen_args_info: GenericArgsInfo,
/// Offending path segment
- crate path_segment: &'a hir::PathSegment<'a>,
+ pub(crate) path_segment: &'a hir::PathSegment<'a>,
/// Generic parameters as expected by type or trait
- crate gen_params: &'a ty::Generics,
+ pub(crate) gen_params: &'a ty::Generics,
/// Index offset into parameters. Depends on whether `Self` is included and on
/// number of lifetime parameters in case we're processing missing or redundant
/// type or constant arguments.
- crate params_offset: usize,
+ pub(crate) params_offset: usize,
/// Generic arguments as provided by user
- crate gen_args: &'a hir::GenericArgs<'a>,
+ pub(crate) gen_args: &'a hir::GenericArgs<'a>,
/// DefId of the generic type
- crate def_id: DefId,
+ pub(crate) def_id: DefId,
}
// Provides information about the kind of arguments that were provided for
}
// Creates lifetime name suggestions from the lifetime parameter names
- fn get_lifetime_args_suggestions_from_param_names(&self, num_params_to_take: usize) -> String {
+ fn get_lifetime_args_suggestions_from_param_names(
+ &self,
+ path_hir_id: Option<hir::HirId>,
+ num_params_to_take: usize,
+ ) -> String {
+ debug!(?path_hir_id);
+
+ if let Some(path_hir_id) = path_hir_id {
+ let mut ret = Vec::new();
+ 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())
+ }));
+ // Suggest `'static` when in const/static item-like.
+ if let hir::Node::Item(hir::Item {
+ kind: hir::ItemKind::Static { .. } | hir::ItemKind::Const { .. },
+ ..
+ })
+ | hir::Node::TraitItem(hir::TraitItem {
+ kind: hir::TraitItemKind::Const { .. },
+ ..
+ })
+ | hir::Node::ImplItem(hir::ImplItem {
+ kind: hir::ImplItemKind::Const { .. },
+ ..
+ })
+ | hir::Node::ForeignItem(hir::ForeignItem {
+ kind: hir::ForeignItemKind::Static { .. },
+ ..
+ })
+ | hir::Node::AnonConst(..) = node
+ {
+ ret.extend(
+ std::iter::repeat("'static".to_owned())
+ .take(num_params_to_take.saturating_sub(ret.len())),
+ );
+ }
+ if ret.len() >= num_params_to_take {
+ return ret[..num_params_to_take].join(", ");
+ }
+ // We cannot refer to lifetimes defined in an outer function.
+ if let hir::Node::Item(_) = node {
+ break;
+ }
+ }
+ }
+
+ // We could not gather enough lifetime parameters in the scope.
+ // We use the parameter names from the target type's definition instead.
self.gen_params
.params
.iter()
let num_params_to_take = num_missing_args;
let msg = format!("add missing {} argument{}", self.kind(), pluralize!(num_missing_args));
- // we first try to get lifetime name suggestions from scope or elision information. If none is
- // available we use the parameter definitions
- let suggested_args = if let Some(hir_id) = self.path_segment.hir_id {
- if let Some(lifetimes_in_scope) = self.tcx.lifetime_scope(hir_id) {
- match lifetimes_in_scope {
- LifetimeScopeForPath::NonElided(param_names) => {
- debug!("NonElided(param_names: {:?})", param_names);
-
- if param_names.len() >= num_params_to_take {
- // use lifetime parameters in scope for suggestions
- param_names
- .iter()
- .take(num_params_to_take)
- .map(|p| p.as_str())
- .collect::<Vec<_>>()
- .join(", ")
- } else {
- // Not enough lifetime arguments in scope -> create suggestions from
- // lifetime parameter names in definition. An error for the incorrect
- // lifetime scope will be output later.
- self.get_lifetime_args_suggestions_from_param_names(num_params_to_take)
- }
- }
- LifetimeScopeForPath::Elided => {
- debug!("Elided");
- // use suggestions of the form `<'_, '_>` in case lifetime can be elided
- ["'_"].repeat(num_params_to_take).join(",")
- }
- }
- } else {
- self.get_lifetime_args_suggestions_from_param_names(num_params_to_take)
- }
- } else {
- self.get_lifetime_args_suggestions_from_param_names(num_params_to_take)
- };
-
+ let suggested_args = self.get_lifetime_args_suggestions_from_param_names(
+ self.path_segment.hir_id,
+ num_params_to_take,
+ );
debug!("suggested_args: {:?}", &suggested_args);
match self.angle_brackets {
err.span_suggestion(
span_redundant_lt_args,
&msg_lifetimes,
- String::new(),
+ "",
Applicability::MaybeIncorrect,
);
};
err.span_suggestion(
span_redundant_type_or_const_args,
&msg_types_or_consts,
- String::new(),
+ "",
Applicability::MaybeIncorrect,
);
};
if self.gen_args.parenthesized { "parenthetical " } else { "" },
);
- err.span_suggestion(span, &msg, String::new(), Applicability::MaybeIncorrect);
+ err.span_suggestion(span, &msg, "", Applicability::MaybeIncorrect);
} else if redundant_lifetime_args && redundant_type_or_const_args {
remove_lifetime_args(err);
remove_type_or_const_args(err);
projects / rustc.git / blobdiff