Rewrite representability
This commit is contained in:
Cameron Steffen
parent
e42c4d7218
commit
ff940db666
61 changed files with 537 additions and 744 deletions
|
|
@ -1,8 +1,18 @@
|
|||
use rustc_middle::ty::{self, AdtSizedConstraint, Ty, TyCtxt};
|
||||
use rustc_data_structures::fx::FxHashSet;
|
||||
use rustc_errors::{pluralize, struct_span_err, Applicability, MultiSpan};
|
||||
use rustc_hir as hir;
|
||||
use rustc_hir::def::DefKind;
|
||||
use rustc_middle::ty::Representability;
|
||||
use rustc_middle::ty::{self, AdtSizedConstraint, DefIdTree, Ty, TyCtxt};
|
||||
use rustc_query_system::query::QueryInfo;
|
||||
use rustc_query_system::Value;
|
||||
use rustc_span::def_id::LocalDefId;
|
||||
use rustc_span::Span;
|
||||
|
||||
use std::fmt::Write;
|
||||
|
||||
impl<'tcx> Value<TyCtxt<'tcx>> for Ty<'_> {
|
||||
fn from_cycle_error(tcx: TyCtxt<'tcx>) -> Self {
|
||||
fn from_cycle_error(tcx: TyCtxt<'tcx>, _: &[QueryInfo]) -> Self {
|
||||
// SAFETY: This is never called when `Self` is not `Ty<'tcx>`.
|
||||
// FIXME: Represent the above fact in the trait system somehow.
|
||||
unsafe { std::mem::transmute::<Ty<'tcx>, Ty<'_>>(tcx.ty_error()) }
|
||||
|
|
@ -10,7 +20,7 @@ impl<'tcx> Value<TyCtxt<'tcx>> for Ty<'_> {
|
|||
}
|
||||
|
||||
impl<'tcx> Value<TyCtxt<'tcx>> for ty::SymbolName<'_> {
|
||||
fn from_cycle_error(tcx: TyCtxt<'tcx>) -> Self {
|
||||
fn from_cycle_error(tcx: TyCtxt<'tcx>, _: &[QueryInfo]) -> Self {
|
||||
// SAFETY: This is never called when `Self` is not `SymbolName<'tcx>`.
|
||||
// FIXME: Represent the above fact in the trait system somehow.
|
||||
unsafe {
|
||||
|
|
@ -22,7 +32,7 @@ impl<'tcx> Value<TyCtxt<'tcx>> for ty::SymbolName<'_> {
|
|||
}
|
||||
|
||||
impl<'tcx> Value<TyCtxt<'tcx>> for AdtSizedConstraint<'_> {
|
||||
fn from_cycle_error(tcx: TyCtxt<'tcx>) -> Self {
|
||||
fn from_cycle_error(tcx: TyCtxt<'tcx>, _: &[QueryInfo]) -> Self {
|
||||
// SAFETY: This is never called when `Self` is not `AdtSizedConstraint<'tcx>`.
|
||||
// FIXME: Represent the above fact in the trait system somehow.
|
||||
unsafe {
|
||||
|
|
@ -34,7 +44,7 @@ impl<'tcx> Value<TyCtxt<'tcx>> for AdtSizedConstraint<'_> {
|
|||
}
|
||||
|
||||
impl<'tcx> Value<TyCtxt<'tcx>> for ty::Binder<'_, ty::FnSig<'_>> {
|
||||
fn from_cycle_error(tcx: TyCtxt<'tcx>) -> Self {
|
||||
fn from_cycle_error(tcx: TyCtxt<'tcx>, _: &[QueryInfo]) -> Self {
|
||||
let err = tcx.ty_error();
|
||||
// FIXME(compiler-errors): It would be nice if we could get the
|
||||
// query key, so we could at least generate a fn signature that
|
||||
|
|
@ -52,3 +62,153 @@ impl<'tcx> Value<TyCtxt<'tcx>> for ty::Binder<'_, ty::FnSig<'_>> {
|
|||
unsafe { std::mem::transmute::<ty::PolyFnSig<'tcx>, ty::Binder<'_, ty::FnSig<'_>>>(fn_sig) }
|
||||
}
|
||||
}
|
||||
|
||||
impl<'tcx> Value<TyCtxt<'tcx>> for Representability {
|
||||
fn from_cycle_error(tcx: TyCtxt<'tcx>, cycle: &[QueryInfo]) -> Self {
|
||||
let mut item_and_field_ids = Vec::new();
|
||||
let mut representable_ids = FxHashSet::default();
|
||||
for info in cycle {
|
||||
if info.query.name == "representability"
|
||||
&& let Some(field_id) = info.query.def_id
|
||||
&& let Some(field_id) = field_id.as_local()
|
||||
&& let Some(DefKind::Field) = info.query.def_kind
|
||||
{
|
||||
let parent_id = tcx.parent(field_id.to_def_id());
|
||||
let item_id = match tcx.def_kind(parent_id) {
|
||||
DefKind::Variant => tcx.parent(parent_id),
|
||||
_ => parent_id,
|
||||
};
|
||||
item_and_field_ids.push((item_id.expect_local(), field_id));
|
||||
}
|
||||
}
|
||||
for info in cycle {
|
||||
if info.query.name == "representability_adt_ty"
|
||||
&& let Some(def_id) = info.query.ty_adt_id
|
||||
&& let Some(def_id) = def_id.as_local()
|
||||
&& !item_and_field_ids.iter().any(|&(id, _)| id == def_id)
|
||||
{
|
||||
representable_ids.insert(def_id);
|
||||
}
|
||||
}
|
||||
recursive_type_error(tcx, item_and_field_ids, &representable_ids);
|
||||
Representability::Infinite
|
||||
}
|
||||
}
|
||||
|
||||
// item_and_field_ids should form a cycle where each field contains the
|
||||
// type in the next element in the list
|
||||
pub fn recursive_type_error(
|
||||
tcx: TyCtxt<'_>,
|
||||
mut item_and_field_ids: Vec<(LocalDefId, LocalDefId)>,
|
||||
representable_ids: &FxHashSet<LocalDefId>,
|
||||
) {
|
||||
const ITEM_LIMIT: usize = 5;
|
||||
|
||||
// Rotate the cycle so that the item with the lowest span is first
|
||||
let start_index = item_and_field_ids
|
||||
.iter()
|
||||
.enumerate()
|
||||
.min_by_key(|&(_, &(id, _))| tcx.def_span(id))
|
||||
.unwrap()
|
||||
.0;
|
||||
item_and_field_ids.rotate_left(start_index);
|
||||
|
||||
let cycle_len = item_and_field_ids.len();
|
||||
let show_cycle_len = cycle_len.min(ITEM_LIMIT);
|
||||
|
||||
let mut err_span = MultiSpan::from_spans(
|
||||
item_and_field_ids[..show_cycle_len]
|
||||
.iter()
|
||||
.map(|(id, _)| tcx.def_span(id.to_def_id()))
|
||||
.collect(),
|
||||
);
|
||||
let mut suggestion = Vec::with_capacity(show_cycle_len * 2);
|
||||
for i in 0..show_cycle_len {
|
||||
let (_, field_id) = item_and_field_ids[i];
|
||||
let (next_item_id, _) = item_and_field_ids[(i + 1) % cycle_len];
|
||||
// Find the span(s) that contain the next item in the cycle
|
||||
let hir_id = tcx.hir().local_def_id_to_hir_id(field_id);
|
||||
let hir::Node::Field(field) = tcx.hir().get(hir_id) else { bug!("expected field") };
|
||||
let mut found = Vec::new();
|
||||
find_item_ty_spans(tcx, field.ty, next_item_id, &mut found, representable_ids);
|
||||
|
||||
// Couldn't find the type. Maybe it's behind a type alias?
|
||||
// In any case, we'll just suggest boxing the whole field.
|
||||
if found.is_empty() {
|
||||
found.push(field.ty.span);
|
||||
}
|
||||
|
||||
for span in found {
|
||||
err_span.push_span_label(span, "recursive without indirection");
|
||||
// FIXME(compiler-errors): This suggestion might be erroneous if Box is shadowed
|
||||
suggestion.push((span.shrink_to_lo(), "Box<".to_string()));
|
||||
suggestion.push((span.shrink_to_hi(), ">".to_string()));
|
||||
}
|
||||
}
|
||||
let items_list = {
|
||||
let mut s = String::new();
|
||||
for (i, (item_id, _)) in item_and_field_ids.iter().enumerate() {
|
||||
let path = tcx.def_path_str(item_id.to_def_id());
|
||||
write!(&mut s, "`{path}`").unwrap();
|
||||
if i == (ITEM_LIMIT - 1) && cycle_len > ITEM_LIMIT {
|
||||
write!(&mut s, " and {} more", cycle_len - 5).unwrap();
|
||||
break;
|
||||
}
|
||||
if cycle_len > 1 && i < cycle_len - 2 {
|
||||
s.push_str(", ");
|
||||
} else if cycle_len > 1 && i == cycle_len - 2 {
|
||||
s.push_str(" and ")
|
||||
}
|
||||
}
|
||||
s
|
||||
};
|
||||
let mut err = struct_span_err!(
|
||||
tcx.sess,
|
||||
err_span,
|
||||
E0072,
|
||||
"recursive type{} {} {} infinite size",
|
||||
pluralize!(cycle_len),
|
||||
items_list,
|
||||
pluralize!("has", cycle_len),
|
||||
);
|
||||
err.multipart_suggestion(
|
||||
"insert some indirection (e.g., a `Box`, `Rc`, or `&`) to break the cycle",
|
||||
suggestion,
|
||||
Applicability::HasPlaceholders,
|
||||
);
|
||||
err.emit();
|
||||
}
|
||||
|
||||
fn find_item_ty_spans(
|
||||
tcx: TyCtxt<'_>,
|
||||
ty: &hir::Ty<'_>,
|
||||
needle: LocalDefId,
|
||||
spans: &mut Vec<Span>,
|
||||
seen_representable: &FxHashSet<LocalDefId>,
|
||||
) {
|
||||
match ty.kind {
|
||||
hir::TyKind::Path(hir::QPath::Resolved(_, path)) => {
|
||||
if let Some(def_id) = path.res.opt_def_id() {
|
||||
let check_params = def_id.as_local().map_or(true, |def_id| {
|
||||
if def_id == needle {
|
||||
spans.push(ty.span);
|
||||
}
|
||||
seen_representable.contains(&def_id)
|
||||
});
|
||||
if check_params && let Some(args) = path.segments.last().unwrap().args {
|
||||
let params_in_repr = tcx.params_in_repr(def_id);
|
||||
for (i, arg) in args.args.iter().enumerate() {
|
||||
if let hir::GenericArg::Type(ty) = arg && params_in_repr.contains(i as u32) {
|
||||
find_item_ty_spans(tcx, ty, needle, spans, seen_representable);
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
hir::TyKind::Array(ty, _) => find_item_ty_spans(tcx, ty, needle, spans, seen_representable),
|
||||
hir::TyKind::Tup(tys) => {
|
||||
tys.iter().for_each(|ty| find_item_ty_spans(tcx, ty, needle, spans, seen_representable))
|
||||
}
|
||||
_ => {}
|
||||
}
|
||||
}
|
||||
|
|
|
|||
Loading…
Add table
Add a link
Reference in a new issue