//! Error Reporting for static impl Traits.
+use crate::errors::{
+ ButCallingIntroduces, ButNeedsToSatisfy, DynTraitConstraintSuggestion, MoreTargeted,
+ ReqIntroducedLocations,
+};
use crate::infer::error_reporting::nice_region_error::NiceRegionError;
use crate::infer::lexical_region_resolve::RegionResolutionError;
use crate::infer::{SubregionOrigin, TypeTrace};
use crate::traits::{ObligationCauseCode, UnifyReceiverContext};
use rustc_data_structures::fx::FxIndexSet;
-use rustc_errors::{struct_span_err, Applicability, Diagnostic, ErrorGuaranteed, MultiSpan};
+use rustc_errors::{AddToDiagnostic, Applicability, Diagnostic, ErrorGuaranteed, MultiSpan};
use rustc_hir::def_id::DefId;
use rustc_hir::intravisit::{walk_ty, Visitor};
-use rustc_hir::{self as hir, GenericBound, Item, ItemKind, Lifetime, LifetimeName, Node, TyKind};
+use rustc_hir::{
+ self as hir, GenericBound, GenericParamKind, Item, ItemKind, Lifetime, LifetimeName, Node,
+ TyKind,
+};
use rustc_middle::ty::{
self, AssocItemContainer, StaticLifetimeVisitor, Ty, TyCtxt, TypeSuperVisitable, TypeVisitor,
};
use rustc_span::symbol::Ident;
use rustc_span::Span;
+use rustc_span::def_id::LocalDefId;
use std::ops::ControlFlow;
impl<'a, 'tcx> NiceRegionError<'a, 'tcx> {
}
let param = self.find_param_with_region(*sup_r, *sub_r)?;
- let lifetime = if sup_r.has_name() {
- format!("lifetime `{}`", sup_r)
- } else {
- "an anonymous lifetime `'_`".to_string()
+ let simple_ident = param.param.pat.simple_ident();
+
+ let (has_impl_path, impl_path) = match ctxt.assoc_item.container {
+ AssocItemContainer::TraitContainer => {
+ let id = ctxt.assoc_item.container_id(tcx);
+ (true, tcx.def_path_str(id))
+ }
+ AssocItemContainer::ImplContainer => (false, String::new()),
};
- let mut err = struct_span_err!(
- tcx.sess,
- cause.span,
- E0772,
- "{} has {} but calling `{}` introduces an implicit `'static` lifetime \
- requirement",
- param
- .param
- .pat
- .simple_ident()
- .map(|s| format!("`{}`", s))
- .unwrap_or_else(|| "`fn` parameter".to_string()),
- lifetime,
- ctxt.assoc_item.name,
- );
- err.span_label(param.param_ty_span, &format!("this data with {}...", lifetime));
- err.span_label(
- cause.span,
- &format!(
- "...is used and required to live as long as `'static` here \
- because of an implicit lifetime bound on the {}",
- match ctxt.assoc_item.container {
- AssocItemContainer::TraitContainer => {
- let id = ctxt.assoc_item.container_id(tcx);
- format!("`impl` of `{}`", tcx.def_path_str(id))
- }
- AssocItemContainer::ImplContainer => "inherent `impl`".to_string(),
- },
- ),
- );
+
+ let mut err = self.tcx().sess.create_err(ButCallingIntroduces {
+ param_ty_span: param.param_ty_span,
+ cause_span: cause.span,
+ has_param_name: simple_ident.is_some(),
+ param_name: simple_ident.map(|x| x.to_string()).unwrap_or_default(),
+ has_lifetime: sup_r.has_name(),
+ lifetime: sup_r.to_string(),
+ assoc_item: ctxt.assoc_item.name,
+ has_impl_path,
+ impl_path,
+ });
if self.find_impl_on_dyn_trait(&mut err, param.param_ty, &ctxt) {
let reported = err.emit();
return Some(reported);
} else {
- err.cancel();
+ err.cancel()
}
}
return None;
let sp = var_origin.span();
let return_sp = sub_origin.span();
let param = self.find_param_with_region(*sup_r, *sub_r)?;
- let (lifetime_name, lifetime) = if sup_r.has_name() {
- (sup_r.to_string(), format!("lifetime `{}`", sup_r))
- } else {
- ("'_".to_owned(), "an anonymous lifetime `'_`".to_string())
- };
- let param_name = param
- .param
- .pat
- .simple_ident()
- .map(|s| format!("`{}`", s))
- .unwrap_or_else(|| "`fn` parameter".to_string());
- let mut err = struct_span_err!(
- tcx.sess,
- sp,
- E0759,
- "{} has {} but it needs to satisfy a `'static` lifetime requirement",
- param_name,
- lifetime,
- );
+ let simple_ident = param.param.pat.simple_ident();
+ let lifetime_name = if sup_r.has_name() { sup_r.to_string() } else { "'_".to_owned() };
let (mention_influencer, influencer_point) =
if sup_origin.span().overlaps(param.param_ty_span) {
} else {
(!sup_origin.span().overlaps(return_sp), param.param_ty_span)
};
- err.span_label(influencer_point, &format!("this data with {}...", lifetime));
debug!("try_report_static_impl_trait: param_info={:?}", param);
spans.dedup_by_key(|span| (span.lo(), span.hi()));
// We try to make the output have fewer overlapping spans if possible.
- let require_msg = if spans.is_empty() {
- "...is used and required to live as long as `'static` here"
- } else {
- "...and is required to live as long as `'static` here"
- };
let require_span =
if sup_origin.span().overlaps(return_sp) { sup_origin.span() } else { return_sp };
- for span in &spans {
- err.span_label(*span, "...is used here...");
- }
-
- if spans.iter().any(|sp| sp.overlaps(return_sp) || *sp > return_sp) {
- // If any of the "captured here" labels appears on the same line or after
- // `require_span`, we put it on a note to ensure the text flows by appearing
- // always at the end.
- err.span_note(require_span, require_msg);
+ let spans_empty = spans.is_empty();
+ let require_as_note = spans.iter().any(|sp| sp.overlaps(return_sp) || *sp > return_sp);
+ let bound = if let SubregionOrigin::RelateParamBound(_, _, Some(bound)) = sub_origin {
+ Some(*bound)
} else {
- // We don't need a note, it's already at the end, it can be shown as a `span_label`.
- err.span_label(require_span, require_msg);
- }
+ None
+ };
+
+ let mut subdiag = None;
- if let SubregionOrigin::RelateParamBound(_, _, Some(bound)) = sub_origin {
- err.span_note(*bound, "`'static` lifetime requirement introduced by this bound");
- }
if let SubregionOrigin::Subtype(box TypeTrace { cause, .. }) = sub_origin {
if let ObligationCauseCode::ReturnValue(hir_id)
| ObligationCauseCode::BlockTailExpression(hir_id) = cause.code()
let parent_id = tcx.hir().get_parent_item(*hir_id);
if let Some(fn_decl) = tcx.hir().fn_decl_by_hir_id(parent_id.into()) {
let mut span: MultiSpan = fn_decl.output.span().into();
+ let mut spans = Vec::new();
let mut add_label = true;
if let hir::FnRetTy::Return(ty) = fn_decl.output {
let mut v = StaticLifetimeVisitor(vec![], tcx.hir());
v.visit_ty(ty);
if !v.0.is_empty() {
span = v.0.clone().into();
- for sp in v.0 {
- span.push_span_label(sp, "`'static` requirement introduced here");
- }
+ spans = v.0;
add_label = false;
}
}
- if add_label {
- span.push_span_label(
- fn_decl.output.span(),
- "requirement introduced by this return type",
- );
- }
- span.push_span_label(cause.span, "because of this returned expression");
- err.span_note(
+ let fn_decl_span = fn_decl.output.span();
+
+ subdiag = Some(ReqIntroducedLocations {
span,
- "`'static` lifetime requirement introduced by the return type",
- );
+ spans,
+ fn_decl_span,
+ cause_span: cause.span,
+ add_label,
+ });
}
}
}
+ let diag = ButNeedsToSatisfy {
+ sp,
+ influencer_point,
+ spans: spans.clone(),
+ // If any of the "captured here" labels appears on the same line or after
+ // `require_span`, we put it on a note to ensure the text flows by appearing
+ // always at the end.
+ require_span_as_note: require_as_note.then_some(require_span),
+ // We don't need a note, it's already at the end, it can be shown as a `span_label`.
+ require_span_as_label: (!require_as_note).then_some(require_span),
+ req_introduces_loc: subdiag,
+
+ has_lifetime: sup_r.has_name(),
+ lifetime: lifetime_name.clone(),
+ has_param_name: simple_ident.is_some(),
+ param_name: simple_ident.map(|x| x.to_string()).unwrap_or_default(),
+ spans_empty,
+ bound,
+ };
+
+ let mut err = self.tcx().sess.create_err(diag);
+
let fn_returns = tcx.return_type_impl_or_dyn_traits(anon_reg_sup.def_id);
let mut override_error_code = None;
}
if let (Some(ident), true) = (override_error_code, fn_returns.is_empty()) {
// Provide a more targeted error code and description.
- err.code(rustc_errors::error_code!(E0772));
- err.set_primary_message(&format!(
- "{} has {} but calling `{}` introduces an implicit `'static` lifetime \
- requirement",
- param_name, lifetime, ident,
- ));
+ let retarget_subdiag = MoreTargeted { ident };
+ retarget_subdiag.add_to_diagnostic(&mut err);
}
let arg = match param.param.pat.simple_ident() {
Some(arg),
captures,
Some((param.param_ty_span, param.param_ty.to_string())),
+ Some(anon_reg_sup.def_id),
);
let reported = err.emit();
arg: Option<String>,
captures: String,
param: Option<(Span, String)>,
+ scope_def_id: Option<LocalDefId>,
) {
debug!("try_report_static_impl_trait: fn_return={:?}", fn_returns);
// FIXME: account for the need of parens in `&(dyn Trait + '_)`
_ => false,
}) {
} else {
- err.span_suggestion_verbose(
- fn_return.span.shrink_to_hi(),
- &format!("{declare} `{ty}` {captures}, {explicit}",),
- &plus_lt,
- Applicability::MaybeIncorrect,
- );
+ // get a lifetime name of existing named lifetimes if any
+ let existing_lt_name = if let Some(id) = scope_def_id
+ && let Some(generics) = tcx.hir().get_generics(id)
+ && let named_lifetimes = generics
+ .params
+ .iter()
+ .filter(|p| matches!(p.kind, GenericParamKind::Lifetime { kind: hir::LifetimeParamKind::Explicit }))
+ .map(|p| { if let hir::ParamName::Plain(name) = p.name {Some(name.to_string())} else {None}})
+ .filter(|n| ! matches!(n, None))
+ .collect::<Vec<_>>()
+ && named_lifetimes.len() > 0 {
+ named_lifetimes[0].clone()
+ } else {
+ None
+ };
+ let name = if let Some(name) = &existing_lt_name {
+ format!("{}", name)
+ } else {
+ format!("'a")
+ };
+ // if there are more than one elided lifetimes in inputs, the explicit `'_` lifetime cannot be used.
+ // introducing a new lifetime `'a` or making use of one from existing named lifetimes if any
+ if let Some(id) = scope_def_id
+ && let Some(generics) = tcx.hir().get_generics(id)
+ && let mut spans_suggs = generics
+ .params
+ .iter()
+ .filter(|p| p.is_elided_lifetime())
+ .map(|p|
+ if p.span.hi() - p.span.lo() == rustc_span::BytePos(1) { // Ampersand (elided without '_)
+ (p.span.shrink_to_hi(),format!("{name} "))
+ } else { // Underscore (elided with '_)
+ (p.span, format!("{name}"))
+ }
+ )
+ .collect::<Vec<_>>()
+ && spans_suggs.len() > 1
+ {
+ let use_lt =
+ if existing_lt_name == None {
+ spans_suggs.push((generics.span.shrink_to_hi(), format!("<{name}>")));
+ format!("you can introduce a named lifetime parameter `{name}`")
+ } else {
+ // make use the existing named lifetime
+ format!("you can use the named lifetime parameter `{name}`")
+ };
+ spans_suggs
+ .push((fn_return.span.shrink_to_hi(), format!(" + {name} ")));
+ err.multipart_suggestion_verbose(
+ &format!(
+ "{declare} `{ty}` {captures}, {use_lt}",
+ ),
+ spans_suggs,
+ Applicability::MaybeIncorrect,
+ );
+ } else {
+ err.span_suggestion_verbose(
+ fn_return.span.shrink_to_hi(),
+ &format!("{declare} `{ty}` {captures}, {explicit}",),
+ &plus_lt,
+ Applicability::MaybeIncorrect,
+ );
+ }
}
}
TyKind::TraitObject(_, lt, _) => {
let mut traits = vec![];
let mut hir_v = HirTraitObjectVisitor(&mut traits, *found_did);
hir_v.visit_ty(&self_ty);
- for span in &traits {
- let mut multi_span: MultiSpan = vec![*span].into();
- multi_span
- .push_span_label(*span, "this has an implicit `'static` lifetime requirement");
- multi_span.push_span_label(
- ident.span,
- "calling this method introduces the `impl`'s 'static` requirement",
- );
- err.span_note(multi_span, "the used `impl` has a `'static` requirement");
- err.span_suggestion_verbose(
- span.shrink_to_hi(),
- "consider relaxing the implicit `'static` requirement",
- " + '_",
- Applicability::MaybeIncorrect,
- );
+ for &span in &traits {
+ let subdiag = DynTraitConstraintSuggestion { span, ident };
+ subdiag.add_to_diagnostic(err);
suggested = true;
}
}
if let Some(def_id) = preds.principal_def_id() {
self.0.insert(def_id);
}
- ControlFlow::CONTINUE
+ ControlFlow::Continue(())
}
_ => t.super_visit_with(self),
}
projects / rust.git / blobdiff