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Auto merge of #98588 - b-naber:valtrees-cleanup, r=lcnr

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Use only ty::Unevaluated<'tcx, ()> in type system

r? `@lcnr`
This commit is contained in:
bors
2022-09-17 03:04:22 +00:00
parent 95a992a686 d77248e6d2
commit c524c7dd25
59 changed files with 383 additions and 323 deletions
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52
compiler/rustc_const_eval/src/transform/check_consts/qualifs.rs
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@@ -346,31 +346,43 @@ where
};
// Check the qualifs of the value of `const` items.
if let Some(ct) = constant.literal.const_for_ty() {
if let ty::ConstKind::Unevaluated(ty::Unevaluated { def, substs: _, promoted }) = ct.kind()
{
// Use qualifs of the type for the promoted. Promoteds in MIR body should be possible
// only for `NeedsNonConstDrop` with precise drop checking. This is the only const
// check performed after the promotion. Verify that with an assertion.
assert!(promoted.is_none() || Q::ALLOW_PROMOTED);
// Don't peek inside trait associated constants.
if promoted.is_none() && cx.tcx.trait_of_item(def.did).is_none() {
let qualifs = if let Some((did, param_did)) = def.as_const_arg() {
cx.tcx.at(constant.span).mir_const_qualif_const_arg((did, param_did))
} else {
cx.tcx.at(constant.span).mir_const_qualif(def.did)
};
// FIXME(valtrees): check whether const qualifs should behave the same
// way for type and mir constants.
let uneval = match constant.literal {
ConstantKind::Ty(ct) if matches!(ct.kind(), ty::ConstKind::Unevaluated(_)) => {
let ty::ConstKind::Unevaluated(uv) = ct.kind() else { unreachable!() };
if !Q::in_qualifs(&qualifs) {
return false;
}
Some(uv.expand())
}
ConstantKind::Ty(_) => None,
ConstantKind::Unevaluated(uv, _) => Some(uv),
ConstantKind::Val(..) => None,
};
// Just in case the type is more specific than
// the definition, e.g., impl associated const
// with type parameters, take it into account.
if let Some(ty::Unevaluated { def, substs: _, promoted }) = uneval {
// Use qualifs of the type for the promoted. Promoteds in MIR body should be possible
// only for `NeedsNonConstDrop` with precise drop checking. This is the only const
// check performed after the promotion. Verify that with an assertion.
assert!(promoted.is_none() || Q::ALLOW_PROMOTED);
// Don't peek inside trait associated constants.
if promoted.is_none() && cx.tcx.trait_of_item(def.did).is_none() {
let qualifs = if let Some((did, param_did)) = def.as_const_arg() {
cx.tcx.at(constant.span).mir_const_qualif_const_arg((did, param_did))
} else {
cx.tcx.at(constant.span).mir_const_qualif(def.did)
};
if !Q::in_qualifs(&qualifs) {
return false;
}
// Just in case the type is more specific than
// the definition, e.g., impl associated const
// with type parameters, take it into account.
}
}
// Otherwise use the qualifs of the type.
Q::in_any_value_of_ty(cx, constant.literal.ty())
}