bjoernager/rust
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rustc: Panic by default in DefIdTree::parent

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Only crate root def-ids don't have a parent, and in majority of cases the argument of `DefIdTree::parent` cannot be a crate root.
So we now panic by default in `parent` and introduce a new non-panicing function `opt_parent` for cases where the argument can be a crate root.

Same applies to `local_parent`/`opt_local_parent`.
This commit is contained in:
Vadim Petrochenkov 2022-04-25 22:08:45 +03:00
parent a933de8398
commit 5b5964f569
50 changed files with 162 additions and 176 deletions
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36
compiler/rustc_middle/src/ty/mod.rs
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@ -290,11 +290,28 @@ pub struct ClosureSizeProfileData<'tcx> {
}
pub trait DefIdTree: Copy {
fn parent(self, id: DefId) -> Option<DefId>;
fn opt_parent(self, id: DefId) -> Option<DefId>;
#[inline]
fn local_parent(self, id: LocalDefId) -> Option<LocalDefId> {
Some(self.parent(id.to_def_id())?.expect_local())
#[track_caller]
fn parent(self, id: DefId) -> DefId {
match self.opt_parent(id) {
Some(id) => id,
// not `unwrap_or_else` to avoid breaking caller tracking
None => bug!("{id:?} doesn't have a parent"),
}
}
#[inline]
#[track_caller]
fn opt_local_parent(self, id: LocalDefId) -> Option<LocalDefId> {
self.opt_parent(id.to_def_id()).map(DefId::expect_local)
}
#[inline]
#[track_caller]
fn local_parent(self, id: LocalDefId) -> LocalDefId {
self.parent(id.to_def_id()).expect_local()
}
fn is_descendant_of(self, mut descendant: DefId, ancestor: DefId) -> bool {
@ -303,7 +320,7 @@ pub trait DefIdTree: Copy {
}
while descendant != ancestor {
match self.parent(descendant) {
match self.opt_parent(descendant) {
Some(parent) => descendant = parent,
None => return false,
}
@ -313,7 +330,8 @@ pub trait DefIdTree: Copy {
}
impl<'tcx> DefIdTree for TyCtxt<'tcx> {
fn parent(self, id: DefId) -> Option<DefId> {
#[inline]
fn opt_parent(self, id: DefId) -> Option<DefId> {
self.def_key(id).parent.map(|index| DefId { index, ..id })
}
}
@ -2123,17 +2141,17 @@ impl<'tcx> TyCtxt<'tcx> {
pub fn expect_variant_res(self, res: Res) -> &'tcx VariantDef {
match res {
Res::Def(DefKind::Variant, did) => {
let enum_did = self.parent(did).unwrap();
let enum_did = self.parent(did);
self.adt_def(enum_did).variant_with_id(did)
}
Res::Def(DefKind::Struct | DefKind::Union, did) => self.adt_def(did).non_enum_variant(),
Res::Def(DefKind::Ctor(CtorOf::Variant, ..), variant_ctor_did) => {
let variant_did = self.parent(variant_ctor_did).unwrap();
let enum_did = self.parent(variant_did).unwrap();
let variant_did = self.parent(variant_ctor_did);
let enum_did = self.parent(variant_did);
self.adt_def(enum_did).variant_with_ctor_id(variant_ctor_did)
}
Res::Def(DefKind::Ctor(CtorOf::Struct, ..), ctor_did) => {
let struct_did = self.parent(ctor_did).expect("struct ctor has no parent");
let struct_did = self.parent(ctor_did);
self.adt_def(struct_did).non_enum_variant()
}
_ => bug!("expect_variant_res used with unexpected res {:?}", res),