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use super::lifetimes::{Lifetimes, LinkedLifetimes};
use super::{
Borrow, EnumDef, EnumId, Everywhere, OpaqueDef, OpaqueId, OpaqueOwner, OutStructDef,
OutputOnly, ReturnableStructDef, StructDef, TyPosition, TypeContext,
};
/// Path to a struct that may appear as an output.
#[derive(Debug, Clone)]
#[non_exhaustive]
pub enum ReturnableStructPath {
Struct(StructPath),
OutStruct(OutStructPath),
}
/// Path to a struct that can only be used as an output.
pub type OutStructPath = StructPath<OutputOnly>;
/// Path to a struct that can be used in inputs and outputs.
#[derive(Debug, Clone)]
#[non_exhaustive]
pub struct StructPath<P: TyPosition = Everywhere> {
pub lifetimes: Lifetimes,
pub tcx_id: P::StructId,
}
/// Path to an opaque.
///
/// There are three kinds of opaques that Diplomat uses, so this type has two
/// generic arguments to differentiate between the three, while still showing
/// that the three are all paths to opaques. The monomorphized versions that
/// Diplomat uses are:
///
/// 1. `OpaquePath<Optional, MaybeOwn>`: Opaques in return types,
/// which can be optional and either owned or borrowed.
/// 2. `OpaquePath<Optional, Borrow>`: Opaques in method parameters, which can
/// be optional but must be borrowed, since most languages don't have a way to
/// entirely give up ownership of a value.
/// 3. `OpaquePath<NonOptional, Borrow>`: Opaques in the `&self` position, which
/// cannot be optional and must be borrowed for the same reason as above.
#[derive(Debug, Clone)]
#[non_exhaustive]
pub struct OpaquePath<Opt, Owner> {
pub lifetimes: Lifetimes,
pub optional: Opt,
pub owner: Owner,
pub tcx_id: OpaqueId,
}
#[derive(Debug, Copy, Clone)]
pub struct Optional(pub(super) bool);
#[derive(Debug, Copy, Clone)]
#[allow(clippy::exhaustive_structs)] // marker type
pub struct NonOptional;
impl<Owner: OpaqueOwner> OpaquePath<Optional, Owner> {
pub fn is_optional(&self) -> bool {
self.optional.0
}
}
impl<Owner: OpaqueOwner> OpaquePath<NonOptional, Owner> {
pub fn wrap_optional(self) -> OpaquePath<Optional, Owner> {
OpaquePath {
lifetimes: self.lifetimes,
optional: Optional(false),
owner: self.owner,
tcx_id: self.tcx_id,
}
}
}
impl<Opt> OpaquePath<Opt, MaybeOwn> {
pub fn as_borrowed(&self) -> Option<&Borrow> {
self.owner.as_borrowed()
}
}
impl<Opt> OpaquePath<Opt, Borrow> {
pub fn borrowed(&self) -> &Borrow {
&self.owner
}
}
/// Path to an enum.
#[derive(Debug, Clone)]
#[non_exhaustive]
pub struct EnumPath {
pub tcx_id: EnumId,
}
/// Determine whether a pointer to an opaque type is owned or borrowed.
///
/// Since owned opaques cannot be used as inputs, this only appears in output types.
#[derive(Copy, Clone, Debug)]
#[allow(clippy::exhaustive_enums)] // only two answers to this question
pub enum MaybeOwn {
Own,
Borrow(Borrow),
}
impl MaybeOwn {
pub fn as_borrowed(&self) -> Option<&Borrow> {
match self {
MaybeOwn::Own => None,
MaybeOwn::Borrow(borrow) => Some(borrow),
}
}
}
impl ReturnableStructPath {
pub fn resolve<'tcx>(&self, tcx: &'tcx TypeContext) -> ReturnableStructDef<'tcx> {
match self {
ReturnableStructPath::Struct(path) => ReturnableStructDef::Struct(path.resolve(tcx)),
ReturnableStructPath::OutStruct(path) => {
ReturnableStructDef::OutStruct(path.resolve(tcx))
}
}
}
pub(crate) fn lifetimes(&self) -> &Lifetimes {
match self {
Self::Struct(p) => &p.lifetimes,
Self::OutStruct(p) => &p.lifetimes,
}
}
}
impl<P: TyPosition> StructPath<P> {
/// Returns a new [`EnumPath`].
pub(super) fn new(lifetimes: Lifetimes, tcx_id: P::StructId) -> Self {
Self { lifetimes, tcx_id }
}
}
impl StructPath {
/// Returns the [`StructDef`] that this path references.
pub fn resolve<'tcx>(&self, tcx: &'tcx TypeContext) -> &'tcx StructDef {
tcx.resolve_struct(self.tcx_id)
}
}
impl OutStructPath {
/// Returns the [`OutStructDef`] that this path references.
pub fn resolve<'tcx>(&self, tcx: &'tcx TypeContext) -> &'tcx OutStructDef {
tcx.resolve_out_struct(self.tcx_id)
}
/// Get a map of lifetimes used on this path to lifetimes as named in the def site. See [`LinkedLifetimes`]
/// for more information.
pub fn link_lifetimes<'def, 'tcx>(
&'def self,
tcx: &'tcx TypeContext,
) -> LinkedLifetimes<'def, 'tcx> {
let struc = self.resolve(tcx);
let env = &struc.lifetimes;
LinkedLifetimes::new(env, None, &self.lifetimes)
}
}
impl<Opt, Owner> OpaquePath<Opt, Owner> {
/// Returns a new [`EnumPath`].
pub(super) fn new(lifetimes: Lifetimes, optional: Opt, owner: Owner, tcx_id: OpaqueId) -> Self {
Self {
lifetimes,
optional,
owner,
tcx_id,
}
}
/// Returns the [`OpaqueDef`] that this path references.
pub fn resolve<'tcx>(&self, tcx: &'tcx TypeContext) -> &'tcx OpaqueDef {
tcx.resolve_opaque(self.tcx_id)
}
}
impl<Opt, Owner: OpaqueOwner> OpaquePath<Opt, Owner> {
/// Get a map of lifetimes used on this path to lifetimes as named in the def site. See [`LinkedLifetimes`]
/// for more information.
pub fn link_lifetimes<'def, 'tcx>(
&'def self,
tcx: &'tcx TypeContext,
) -> LinkedLifetimes<'def, 'tcx> {
let opaque = self.resolve(tcx);
let env = &opaque.lifetimes;
LinkedLifetimes::new(env, self.owner.lifetime(), &self.lifetimes)
}
}
impl EnumPath {
/// Returns a new [`EnumPath`].
pub(super) fn new(tcx_id: EnumId) -> Self {
Self { tcx_id }
}
/// Returns the [`EnumDef`] that this path references.
pub fn resolve<'tcx>(&self, tcx: &'tcx TypeContext) -> &'tcx EnumDef {
tcx.resolve_enum(self.tcx_id)
}
}