bjoernager/rust
bjoernager/rust
1
Fork 0
Code Issues Pull requests Activity

AmbiguityCause should not eagerly format strings

Browse source
This commit is contained in:
Michael Goulet 2023-11-24 18:10:30 +00:00
parent b06258cde4
commit 0750a5df4d
3 changed files with 56 additions and 69 deletions
Download patch file Download diff file Expand all files Collapse all files

84
compiler/rustc_trait_selection/src/traits/select/mod.rs
View file

@ -46,6 +46,7 @@ use rustc_middle::ty::GenericArgsRef;
use rustc_middle::ty::{self, EarlyBinder, PolyProjectionPredicate, ToPolyTraitRef, ToPredicate};
use rustc_middle::ty::{Ty, TyCtxt, TypeFoldable, TypeVisitableExt};
use rustc_span::symbol::sym;
use rustc_span::Symbol;
use std::cell::{Cell, RefCell};
use std::cmp;
@ -59,13 +60,13 @@ mod candidate_assembly;
mod confirmation;
#[derive(Clone, Debug, Eq, PartialEq, Hash)]
pub enum IntercrateAmbiguityCause {
DownstreamCrate { trait_desc: String, self_desc: Option<String> },
UpstreamCrateUpdate { trait_desc: String, self_desc: Option<String> },
ReservationImpl { message: String },
pub enum IntercrateAmbiguityCause<'tcx> {
DownstreamCrate { trait_ref: ty::TraitRef<'tcx>, self_ty: Option<Ty<'tcx>> },
UpstreamCrateUpdate { trait_ref: ty::TraitRef<'tcx>, self_ty: Option<Ty<'tcx>> },
ReservationImpl { message: Symbol },
}
impl IntercrateAmbiguityCause {
impl<'tcx> IntercrateAmbiguityCause<'tcx> {
/// Emits notes when the overlap is caused by complex intercrate ambiguities.
/// See #23980 for details.
pub fn add_intercrate_ambiguity_hint(&self, err: &mut Diagnostic) {
@ -73,28 +74,32 @@ impl IntercrateAmbiguityCause {
}
pub fn intercrate_ambiguity_hint(&self) -> String {
match self {
IntercrateAmbiguityCause::DownstreamCrate { trait_desc, self_desc } => {
let self_desc = if let Some(ty) = self_desc {
format!(" for type `{ty}`")
} else {
String::new()
};
format!("downstream crates may implement trait `{trait_desc}`{self_desc}")
}
IntercrateAmbiguityCause::UpstreamCrateUpdate { trait_desc, self_desc } => {
let self_desc = if let Some(ty) = self_desc {
format!(" for type `{ty}`")
} else {
String::new()
};
with_no_trimmed_paths!(match self {
IntercrateAmbiguityCause::DownstreamCrate { trait_ref, self_ty } => {
format!(
"upstream crates may add a new impl of trait `{trait_desc}`{self_desc} \
in future versions"
"downstream crates may implement trait `{trait_desc}`{self_desc}",
trait_desc = trait_ref.print_only_trait_path(),
self_desc = if let Some(self_ty) = self_ty {
format!(" for type `{self_ty}`")
} else {
String::new()
}
)
}
IntercrateAmbiguityCause::ReservationImpl { message } => message.clone(),
}
IntercrateAmbiguityCause::UpstreamCrateUpdate { trait_ref, self_ty } => {
format!(
"upstream crates may add a new impl of trait `{trait_desc}`{self_desc} \
in future versions",
trait_desc = trait_ref.print_only_trait_path(),
self_desc = if let Some(self_ty) = self_ty {
format!(" for type `{self_ty}`")
} else {
String::new()
}
)
}
IntercrateAmbiguityCause::ReservationImpl { message } => message.to_string(),
})
}
}
@ -114,7 +119,7 @@ pub struct SelectionContext<'cx, 'tcx> {
/// We don't do his until we detect a coherence error because it can
/// lead to false overflow results (#47139) and because always
/// computing it may negatively impact performance.
intercrate_ambiguity_causes: Option<FxIndexSet<IntercrateAmbiguityCause>>,
intercrate_ambiguity_causes: Option<FxIndexSet<IntercrateAmbiguityCause<'tcx>>>,
/// The mode that trait queries run in, which informs our error handling
/// policy. In essence, canonicalized queries need their errors propagated
@ -270,7 +275,9 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
/// Gets the intercrate ambiguity causes collected since tracking
/// was enabled and disables tracking at the same time. If
/// tracking is not enabled, just returns an empty vector.
pub fn take_intercrate_ambiguity_causes(&mut self) -> FxIndexSet<IntercrateAmbiguityCause> {
pub fn take_intercrate_ambiguity_causes(
&mut self,
) -> FxIndexSet<IntercrateAmbiguityCause<'tcx>> {
assert!(self.is_intercrate());
self.intercrate_ambiguity_causes.take().unwrap_or_default()
}
@ -428,19 +435,11 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
);
if !trait_ref.references_error() {
let self_ty = trait_ref.self_ty();
let (trait_desc, self_desc) = with_no_trimmed_paths!({
let trait_desc = trait_ref.print_only_trait_path().to_string();
let self_desc =
self_ty.has_concrete_skeleton().then(|| self_ty.to_string());
(trait_desc, self_desc)
});
let self_ty = self_ty.has_concrete_skeleton().then(|| self_ty);
let cause = if let Conflict::Upstream = conflict {
IntercrateAmbiguityCause::UpstreamCrateUpdate {
trait_desc,
self_desc,
}
IntercrateAmbiguityCause::UpstreamCrateUpdate { trait_ref, self_ty }
} else {
IntercrateAmbiguityCause::DownstreamCrate { trait_desc, self_desc }
IntercrateAmbiguityCause::DownstreamCrate { trait_ref, self_ty }
};
debug!(?cause, "evaluate_stack: pushing cause");
self.intercrate_ambiguity_causes.as_mut().unwrap().insert(cause);
@ -1451,20 +1450,17 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
if let ImplCandidate(def_id) = candidate {
if let ty::ImplPolarity::Reservation = tcx.impl_polarity(def_id) {
if let Some(intercrate_ambiguity_clauses) = &mut self.intercrate_ambiguity_causes {
let value = tcx
let message = tcx
.get_attr(def_id, sym::rustc_reservation_impl)
.and_then(|a| a.value_str());
if let Some(value) = value {
if let Some(message) = message {
debug!(
"filter_reservation_impls: \
reservation impl ambiguity on {:?}",
def_id
);
intercrate_ambiguity_clauses.insert(
IntercrateAmbiguityCause::ReservationImpl {
message: value.to_string(),
},
);
intercrate_ambiguity_clauses
.insert(IntercrateAmbiguityCause::ReservationImpl { message });
}
}
return Ok(None);