Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

Unify tcx.constness query and param env constness checks #102830

Merged
merged 2 commits into from
Oct 12, 2022
Merged

Unify tcx.constness query and param env constness checks #102830

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
c646c4d
Unify tcx.constness and param env constness checks
compiler-errors Oct 9, 2022
bef8681
TyAlias needs encoded constness too, for layout computation in rustdoc
compiler-errors Oct 12, 2022
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
72 changes: 56 additions & 16 deletions compiler/rustc_const_eval/src/const_eval/fn_queries.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -25,12 +25,10 @@ pub fn is_parent_const_impl_raw(tcx: TyCtxt<'_>, def_id: LocalDefId) -> bool {
/// report whether said intrinsic has a `rustc_const_{un,}stable` attribute. Otherwise, return
/// `Constness::NotConst`.
fn constness(tcx: TyCtxt<'_>, def_id: DefId) -> hir::Constness {
let def_id = def_id.expect_local();
let node = tcx.hir().get_by_def_id(def_id);

match node {
let hir_id = tcx.hir().local_def_id_to_hir_id(def_id.expect_local());
match tcx.hir().get(hir_id) {
hir::Node::Ctor(_) => hir::Constness::Const,
hir::Node::Item(hir::Item { kind: hir::ItemKind::Impl(impl_), .. }) => impl_.constness,

hir::Node::ForeignItem(hir::ForeignItem { kind: hir::ForeignItemKind::Fn(..), .. }) => {
// Intrinsics use `rustc_const_{un,}stable` attributes to indicate constness. All other
// foreign items cannot be evaluated at compile-time.
Expand All @@ -41,20 +39,62 @@ fn constness(tcx: TyCtxt<'_>, def_id: DefId) -> hir::Constness {
};
if is_const { hir::Constness::Const } else { hir::Constness::NotConst }
}
_ => {
if let Some(fn_kind) = node.fn_kind() {
if fn_kind.constness() == hir::Constness::Const {
return hir::Constness::Const;
}

// If the function itself is not annotated with `const`, it may still be a `const fn`
// if it resides in a const trait impl.
let is_const = is_parent_const_impl_raw(tcx, def_id);
if is_const { hir::Constness::Const } else { hir::Constness::NotConst }
} else {
hir::Constness::NotConst
hir::Node::TraitItem(hir::TraitItem { kind: hir::TraitItemKind::Fn(..), .. })
if tcx.is_const_default_method(def_id) =>
{
hir::Constness::Const
}

hir::Node::Item(hir::Item { kind: hir::ItemKind::Const(..), .. })
| hir::Node::Item(hir::Item { kind: hir::ItemKind::Static(..), .. })
| hir::Node::TraitItem(hir::TraitItem { kind: hir::TraitItemKind::Const(..), .. })
| hir::Node::AnonConst(_)
| hir::Node::ImplItem(hir::ImplItem { kind: hir::ImplItemKind::Const(..), .. })
| hir::Node::ImplItem(hir::ImplItem {
kind:
hir::ImplItemKind::Fn(
hir::FnSig {
header: hir::FnHeader { constness: hir::Constness::Const, .. },
..
},
..,
),
..
}) => hir::Constness::Const,

hir::Node::ImplItem(hir::ImplItem {
kind: hir::ImplItemKind::Type(..) | hir::ImplItemKind::Fn(..),
..
}) => {
let parent_hir_id = tcx.hir().get_parent_node(hir_id);
match tcx.hir().get(parent_hir_id) {
hir::Node::Item(hir::Item {
kind: hir::ItemKind::Impl(hir::Impl { constness, .. }),
..
}) => *constness,
_ => span_bug!(
tcx.def_span(parent_hir_id.owner),
"impl item's parent node is not an impl",
),
}
}

hir::Node::Item(hir::Item {
kind: hir::ItemKind::Fn(hir::FnSig { header: hir::FnHeader { constness, .. }, .. }, ..),
..
})
| hir::Node::TraitItem(hir::TraitItem {
kind:
hir::TraitItemKind::Fn(hir::FnSig { header: hir::FnHeader { constness, .. }, .. }, ..),
..
})
| hir::Node::Item(hir::Item {
kind: hir::ItemKind::Impl(hir::Impl { constness, .. }),
..
}) => *constness,

_ => hir::Constness::NotConst,
}
}

Expand Down
56 changes: 41 additions & 15 deletions compiler/rustc_metadata/src/rmeta/encoder.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1059,6 +1059,43 @@ fn should_encode_const(def_kind: DefKind) -> bool {
}
}

fn should_encode_constness(def_kind: DefKind) -> bool {
match def_kind {
DefKind::Struct
| DefKind::Union
| DefKind::Enum
| DefKind::Trait
| DefKind::AssocTy
| DefKind::Fn
| DefKind::Const
| DefKind::Static(..)
| DefKind::Ctor(..)
| DefKind::AssocFn
| DefKind::AssocConst
| DefKind::AnonConst
| DefKind::InlineConst
| DefKind::OpaqueTy
| DefKind::ImplTraitPlaceholder
| DefKind::Impl
| DefKind::Closure
| DefKind::Generator
| DefKind::TyAlias => true,
DefKind::Variant
| DefKind::TraitAlias
| DefKind::ForeignTy
| DefKind::Field
| DefKind::TyParam
| DefKind::Mod
| DefKind::ForeignMod
| DefKind::ConstParam
| DefKind::Macro(..)
| DefKind::Use
| DefKind::LifetimeParam
| DefKind::GlobalAsm
| DefKind::ExternCrate => false,
}
}

fn should_encode_trait_impl_trait_tys<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId) -> bool {
if tcx.def_kind(def_id) != DefKind::AssocFn {
return false;
Expand Down Expand Up @@ -1165,6 +1202,9 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
{
record!(self.tables.trait_impl_trait_tys[def_id] <- table);
}
if should_encode_constness(def_kind) {
self.tables.constness.set(def_id.index, tcx.constness(def_id));
}
}
let inherent_impls = tcx.crate_inherent_impls(());
for (def_id, implementations) in inherent_impls.inherent_impls.iter() {
Expand Down Expand Up @@ -1192,7 +1232,6 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
};

record!(self.tables.variant_data[def_id] <- data);
self.tables.constness.set(def_id.index, hir::Constness::Const);
record_array!(self.tables.children[def_id] <- variant.fields.iter().map(|f| {
assert!(f.did.is_local());
f.did.index
Expand Down Expand Up @@ -1220,7 +1259,6 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
};

record!(self.tables.variant_data[def_id] <- data);
self.tables.constness.set(def_id.index, hir::Constness::Const);
if variant.ctor_kind == CtorKind::Fn {
record!(self.tables.fn_sig[def_id] <- tcx.fn_sig(def_id));
}
Expand Down Expand Up @@ -1284,7 +1322,6 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {

record!(self.tables.repr_options[def_id] <- adt_def.repr());
record!(self.tables.variant_data[def_id] <- data);
self.tables.constness.set(def_id.index, hir::Constness::Const);
if variant.ctor_kind == CtorKind::Fn {
record!(self.tables.fn_sig[def_id] <- tcx.fn_sig(def_id));
}
Expand Down Expand Up @@ -1320,7 +1357,6 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
}
};
self.tables.asyncness.set(def_id.index, m_sig.header.asyncness);
self.tables.constness.set(def_id.index, hir::Constness::NotConst);
}
ty::AssocKind::Type => {
self.encode_explicit_item_bounds(def_id);
Expand All @@ -1345,13 +1381,6 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
let hir::ImplItemKind::Fn(ref sig, body) = ast_item.kind else { bug!() };
self.tables.asyncness.set(def_id.index, sig.header.asyncness);
record_array!(self.tables.fn_arg_names[def_id] <- self.tcx.hir().body_param_names(body));
// Can be inside `impl const Trait`, so using sig.header.constness is not reliable
let constness = if self.tcx.is_const_fn_raw(def_id) {
hir::Constness::Const
} else {
hir::Constness::NotConst
};
self.tables.constness.set(def_id.index, constness);
}
ty::AssocKind::Const | ty::AssocKind::Type => {}
}
Expand Down Expand Up @@ -1474,7 +1503,6 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
hir::ItemKind::Fn(ref sig, .., body) => {
self.tables.asyncness.set(def_id.index, sig.header.asyncness);
record_array!(self.tables.fn_arg_names[def_id] <- self.tcx.hir().body_param_names(body));
self.tables.constness.set(def_id.index, sig.header.constness);
}
hir::ItemKind::Macro(ref macro_def, _) => {
if macro_def.macro_rules {
Expand All @@ -1495,7 +1523,6 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
hir::ItemKind::Struct(ref struct_def, _) => {
let adt_def = self.tcx.adt_def(def_id);
record!(self.tables.repr_options[def_id] <- adt_def.repr());
self.tables.constness.set(def_id.index, hir::Constness::Const);

// Encode def_ids for each field and method
// for methods, write all the stuff get_trait_method
Expand Down Expand Up @@ -1524,9 +1551,8 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
is_non_exhaustive: variant.is_field_list_non_exhaustive(),
});
}
hir::ItemKind::Impl(hir::Impl { defaultness, constness, .. }) => {
hir::ItemKind::Impl(hir::Impl { defaultness, .. }) => {
self.tables.impl_defaultness.set(def_id.index, *defaultness);
self.tables.constness.set(def_id.index, *constness);

let trait_ref = self.tcx.impl_trait_ref(def_id);
if let Some(trait_ref) = trait_ref {
Expand Down
69 changes: 1 addition & 68 deletions compiler/rustc_ty_utils/src/ty.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -133,77 +133,10 @@ fn param_env(tcx: TyCtxt<'_>, def_id: DefId) -> ty::ParamEnv<'_> {
let local_did = def_id.as_local();
let hir_id = local_did.map(|def_id| tcx.hir().local_def_id_to_hir_id(def_id));

let constness = match hir_id {
Some(hir_id) => match tcx.hir().get(hir_id) {
hir::Node::TraitItem(hir::TraitItem { kind: hir::TraitItemKind::Fn(..), .. })
if tcx.is_const_default_method(def_id) =>
{
hir::Constness::Const
}

hir::Node::Item(hir::Item { kind: hir::ItemKind::Const(..), .. })
| hir::Node::Item(hir::Item { kind: hir::ItemKind::Static(..), .. })
| hir::Node::TraitItem(hir::TraitItem {
kind: hir::TraitItemKind::Const(..), ..
})
| hir::Node::AnonConst(_)
| hir::Node::ImplItem(hir::ImplItem { kind: hir::ImplItemKind::Const(..), .. })
| hir::Node::ImplItem(hir::ImplItem {
kind:
hir::ImplItemKind::Fn(
hir::FnSig {
header: hir::FnHeader { constness: hir::Constness::Const, .. },
..
},
..,
),
..
}) => hir::Constness::Const,

hir::Node::ImplItem(hir::ImplItem {
kind: hir::ImplItemKind::Type(..) | hir::ImplItemKind::Fn(..),
..
}) => {
let parent_hir_id = tcx.hir().get_parent_node(hir_id);
match tcx.hir().get(parent_hir_id) {
hir::Node::Item(hir::Item {
kind: hir::ItemKind::Impl(hir::Impl { constness, .. }),
..
}) => *constness,
_ => span_bug!(
tcx.def_span(parent_hir_id.owner),
"impl item's parent node is not an impl",
),
}
}

hir::Node::Item(hir::Item {
kind:
hir::ItemKind::Fn(hir::FnSig { header: hir::FnHeader { constness, .. }, .. }, ..),
..
})
| hir::Node::TraitItem(hir::TraitItem {
kind:
hir::TraitItemKind::Fn(
hir::FnSig { header: hir::FnHeader { constness, .. }, .. },
..,
),
..
})
| hir::Node::Item(hir::Item {
kind: hir::ItemKind::Impl(hir::Impl { constness, .. }),
..
}) => *constness,

_ => hir::Constness::NotConst,
},
None => hir::Constness::NotConst,
};

let unnormalized_env = ty::ParamEnv::new(
tcx.intern_predicates(&predicates),
traits::Reveal::UserFacing,
constness,
tcx.constness(def_id),
);

let body_id =
Expand Down