bjoernager/rust
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Merge impl_constness and is_const_fn_raw.

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This commit is contained in:
Camille GILLOT 2022-03-13 11:12:50 +01:00
parent e62f483842
commit 15b2d1a97c
8 changed files with 52 additions and 63 deletions
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66
compiler/rustc_const_eval/src/const_eval/fn_queries.rs
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@ -1,7 +1,8 @@
use rustc_hir as hir;
use rustc_hir::def::DefKind;
use rustc_hir::def_id::{DefId, LocalDefId};
use rustc_middle::ty::query::Providers;
use rustc_middle::ty::TyCtxt;
use rustc_middle::ty::{DefIdTree, TyCtxt};
use rustc_span::symbol::Symbol;
use rustc_target::spec::abi::Abi;
@ -16,44 +17,47 @@ pub fn is_unstable_const_fn(tcx: TyCtxt<'_>, def_id: DefId) -> Option<Symbol> {
}
pub fn is_parent_const_impl_raw(tcx: TyCtxt<'_>, def_id: LocalDefId) -> bool {
let hir_id = tcx.hir().local_def_id_to_hir_id(def_id);
let parent_id = tcx.hir().get_parent_node(hir_id);
matches!(
tcx.hir().get(parent_id),
hir::Node::Item(hir::Item {
kind: hir::ItemKind::Impl(hir::Impl { constness: hir::Constness::Const, .. }),
..
})
)
let parent_id = tcx.local_parent(def_id).unwrap();
tcx.def_kind(parent_id) == DefKind::Impl
&& tcx.impl_constness(parent_id) == hir::Constness::Const
}
/// Checks whether the function has a `const` modifier or, in case it is an intrinsic, whether
/// said intrinsic has a `rustc_const_{un,}stable` attribute.
fn is_const_fn_raw(tcx: TyCtxt<'_>, def_id: DefId) -> bool {
fn impl_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);
if let hir::Node::ForeignItem(hir::ForeignItem { kind: hir::ForeignItemKind::Fn(..), .. }) =
node
{
// Intrinsics use `rustc_const_{un,}stable` attributes to indicate constness. All other
// foreign items cannot be evaluated at compile-time.
let hir_id = tcx.hir().local_def_id_to_hir_id(def_id);
if let Abi::RustIntrinsic | Abi::PlatformIntrinsic = tcx.hir().get_foreign_abi(hir_id) {
tcx.lookup_const_stability(def_id).is_some()
} else {
false
}
} else if let Some(fn_kind) = node.fn_kind() {
if fn_kind.constness() == hir::Constness::Const {
return true;
match node {
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.
let hir_id = tcx.hir().local_def_id_to_hir_id(def_id);
let is_const = if let Abi::RustIntrinsic | Abi::PlatformIntrinsic =
tcx.hir().get_foreign_abi(hir_id)
{
tcx.lookup_const_stability(def_id).is_some()
} else {
false
};
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.
is_parent_const_impl_raw(tcx, def_id)
} else {
matches!(node, hir::Node::Ctor(_))
// 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
}
}
}
}
@ -77,5 +81,5 @@ fn is_promotable_const_fn(tcx: TyCtxt<'_>, def_id: DefId) -> bool {
}
pub fn provide(providers: &mut Providers) {
*providers = Providers { is_const_fn_raw, is_promotable_const_fn, ..*providers };
*providers = Providers { impl_constness, is_promotable_const_fn, ..*providers };
}