991 lines
34 KiB
Rust
991 lines
34 KiB
Rust
//! Generalized type relating mechanism.
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//!
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//! A type relation `R` relates a pair of values `(A, B)`. `A and B` are usually
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//! types or regions but can be other things. Examples of type relations are
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//! subtyping, type equality, etc.
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use crate::mir::interpret::{get_slice_bytes, ConstValue};
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use crate::traits;
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use crate::ty::error::{ExpectedFound, TypeError};
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use crate::ty::subst::{GenericArg, GenericArgKind, SubstsRef};
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use crate::ty::{self, Ty, TyCtxt, TypeFoldable};
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use rustc_hir as ast;
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use rustc_hir::def_id::DefId;
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use rustc_target::spec::abi;
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use std::iter;
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use std::rc::Rc;
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pub type RelateResult<'tcx, T> = Result<T, TypeError<'tcx>>;
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#[derive(Clone, Debug)]
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pub enum Cause {
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ExistentialRegionBound, // relating an existential region bound
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}
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pub trait TypeRelation<'tcx>: Sized {
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fn tcx(&self) -> TyCtxt<'tcx>;
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fn param_env(&self) -> ty::ParamEnv<'tcx>;
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/// Returns a static string we can use for printouts.
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fn tag(&self) -> &'static str;
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/// Returns `true` if the value `a` is the "expected" type in the
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/// relation. Just affects error messages.
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fn a_is_expected(&self) -> bool;
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fn with_cause<F, R>(&mut self, _cause: Cause, f: F) -> R
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where
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F: FnOnce(&mut Self) -> R,
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{
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f(self)
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}
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/// Generic relation routine suitable for most anything.
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fn relate<T: Relate<'tcx>>(&mut self, a: &T, b: &T) -> RelateResult<'tcx, T> {
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Relate::relate(self, a, b)
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}
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/// Relate the two substitutions for the given item. The default
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/// is to look up the variance for the item and proceed
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/// accordingly.
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fn relate_item_substs(
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&mut self,
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item_def_id: DefId,
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a_subst: SubstsRef<'tcx>,
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b_subst: SubstsRef<'tcx>,
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) -> RelateResult<'tcx, SubstsRef<'tcx>> {
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debug!(
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"relate_item_substs(item_def_id={:?}, a_subst={:?}, b_subst={:?})",
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item_def_id, a_subst, b_subst
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);
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let opt_variances = self.tcx().variances_of(item_def_id);
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relate_substs(self, Some(opt_variances), a_subst, b_subst)
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}
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/// Switch variance for the purpose of relating `a` and `b`.
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fn relate_with_variance<T: Relate<'tcx>>(
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&mut self,
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variance: ty::Variance,
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a: &T,
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b: &T,
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) -> RelateResult<'tcx, T>;
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// Overrideable relations. You shouldn't typically call these
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// directly, instead call `relate()`, which in turn calls
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// these. This is both more uniform but also allows us to add
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// additional hooks for other types in the future if needed
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// without making older code, which called `relate`, obsolete.
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fn tys(&mut self, a: Ty<'tcx>, b: Ty<'tcx>) -> RelateResult<'tcx, Ty<'tcx>>;
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fn regions(
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&mut self,
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a: ty::Region<'tcx>,
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b: ty::Region<'tcx>,
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) -> RelateResult<'tcx, ty::Region<'tcx>>;
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fn consts(
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&mut self,
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a: &'tcx ty::Const<'tcx>,
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b: &'tcx ty::Const<'tcx>,
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) -> RelateResult<'tcx, &'tcx ty::Const<'tcx>>;
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fn binders<T>(
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&mut self,
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a: &ty::Binder<T>,
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b: &ty::Binder<T>,
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) -> RelateResult<'tcx, ty::Binder<T>>
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where
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T: Relate<'tcx>;
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}
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pub trait Relate<'tcx>: TypeFoldable<'tcx> {
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fn relate<R: TypeRelation<'tcx>>(
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relation: &mut R,
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a: &Self,
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b: &Self,
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) -> RelateResult<'tcx, Self>;
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}
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///////////////////////////////////////////////////////////////////////////
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// Relate impls
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impl<'tcx> Relate<'tcx> for ty::TypeAndMut<'tcx> {
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fn relate<R: TypeRelation<'tcx>>(
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relation: &mut R,
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a: &ty::TypeAndMut<'tcx>,
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b: &ty::TypeAndMut<'tcx>,
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) -> RelateResult<'tcx, ty::TypeAndMut<'tcx>> {
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debug!("{}.mts({:?}, {:?})", relation.tag(), a, b);
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if a.mutbl != b.mutbl {
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Err(TypeError::Mutability)
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} else {
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let mutbl = a.mutbl;
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let variance = match mutbl {
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ast::Mutability::Not => ty::Covariant,
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ast::Mutability::Mut => ty::Invariant,
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};
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let ty = relation.relate_with_variance(variance, &a.ty, &b.ty)?;
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Ok(ty::TypeAndMut { ty, mutbl })
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}
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}
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}
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pub fn relate_substs<R: TypeRelation<'tcx>>(
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relation: &mut R,
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variances: Option<&[ty::Variance]>,
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a_subst: SubstsRef<'tcx>,
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b_subst: SubstsRef<'tcx>,
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) -> RelateResult<'tcx, SubstsRef<'tcx>> {
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let tcx = relation.tcx();
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let params = a_subst.iter().zip(b_subst).enumerate().map(|(i, (a, b))| {
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let variance = variances.map_or(ty::Invariant, |v| v[i]);
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relation.relate_with_variance(variance, a, b)
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});
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Ok(tcx.mk_substs(params)?)
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}
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impl<'tcx> Relate<'tcx> for ty::FnSig<'tcx> {
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fn relate<R: TypeRelation<'tcx>>(
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relation: &mut R,
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a: &ty::FnSig<'tcx>,
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b: &ty::FnSig<'tcx>,
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) -> RelateResult<'tcx, ty::FnSig<'tcx>> {
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let tcx = relation.tcx();
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if a.c_variadic != b.c_variadic {
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return Err(TypeError::VariadicMismatch(expected_found(
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relation,
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&a.c_variadic,
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&b.c_variadic,
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)));
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}
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let unsafety = relation.relate(&a.unsafety, &b.unsafety)?;
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let abi = relation.relate(&a.abi, &b.abi)?;
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if a.inputs().len() != b.inputs().len() {
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return Err(TypeError::ArgCount);
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}
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let inputs_and_output = a
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.inputs()
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.iter()
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.cloned()
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.zip(b.inputs().iter().cloned())
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.map(|x| (x, false))
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.chain(iter::once(((a.output(), b.output()), true)))
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.map(|((a, b), is_output)| {
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if is_output {
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relation.relate(&a, &b)
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} else {
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relation.relate_with_variance(ty::Contravariant, &a, &b)
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}
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});
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Ok(ty::FnSig {
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inputs_and_output: tcx.mk_type_list(inputs_and_output)?,
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c_variadic: a.c_variadic,
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unsafety,
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abi,
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})
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}
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}
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impl<'tcx> Relate<'tcx> for ast::Unsafety {
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fn relate<R: TypeRelation<'tcx>>(
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relation: &mut R,
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a: &ast::Unsafety,
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b: &ast::Unsafety,
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) -> RelateResult<'tcx, ast::Unsafety> {
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if a != b {
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Err(TypeError::UnsafetyMismatch(expected_found(relation, a, b)))
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} else {
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Ok(*a)
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}
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}
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}
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impl<'tcx> Relate<'tcx> for abi::Abi {
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fn relate<R: TypeRelation<'tcx>>(
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relation: &mut R,
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a: &abi::Abi,
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b: &abi::Abi,
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) -> RelateResult<'tcx, abi::Abi> {
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if a == b { Ok(*a) } else { Err(TypeError::AbiMismatch(expected_found(relation, a, b))) }
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}
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}
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impl<'tcx> Relate<'tcx> for ty::ProjectionTy<'tcx> {
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fn relate<R: TypeRelation<'tcx>>(
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relation: &mut R,
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a: &ty::ProjectionTy<'tcx>,
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b: &ty::ProjectionTy<'tcx>,
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) -> RelateResult<'tcx, ty::ProjectionTy<'tcx>> {
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if a.item_def_id != b.item_def_id {
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Err(TypeError::ProjectionMismatched(expected_found(
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relation,
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&a.item_def_id,
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&b.item_def_id,
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)))
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} else {
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let substs = relation.relate(&a.substs, &b.substs)?;
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Ok(ty::ProjectionTy { item_def_id: a.item_def_id, substs: &substs })
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}
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}
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}
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impl<'tcx> Relate<'tcx> for ty::ExistentialProjection<'tcx> {
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fn relate<R: TypeRelation<'tcx>>(
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relation: &mut R,
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a: &ty::ExistentialProjection<'tcx>,
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b: &ty::ExistentialProjection<'tcx>,
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) -> RelateResult<'tcx, ty::ExistentialProjection<'tcx>> {
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if a.item_def_id != b.item_def_id {
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Err(TypeError::ProjectionMismatched(expected_found(
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relation,
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&a.item_def_id,
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&b.item_def_id,
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)))
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} else {
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let ty = relation.relate(&a.ty, &b.ty)?;
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let substs = relation.relate(&a.substs, &b.substs)?;
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Ok(ty::ExistentialProjection { item_def_id: a.item_def_id, substs, ty })
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}
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}
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}
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impl<'tcx> Relate<'tcx> for Vec<ty::PolyExistentialProjection<'tcx>> {
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fn relate<R: TypeRelation<'tcx>>(
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relation: &mut R,
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a: &Vec<ty::PolyExistentialProjection<'tcx>>,
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b: &Vec<ty::PolyExistentialProjection<'tcx>>,
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) -> RelateResult<'tcx, Vec<ty::PolyExistentialProjection<'tcx>>> {
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// To be compatible, `a` and `b` must be for precisely the
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// same set of traits and item names. We always require that
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// projection bounds lists are sorted by trait-def-id and item-name,
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// so we can just iterate through the lists pairwise, so long as they are the
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// same length.
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if a.len() != b.len() {
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Err(TypeError::ProjectionBoundsLength(expected_found(relation, &a.len(), &b.len())))
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} else {
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a.iter().zip(b).map(|(a, b)| relation.relate(a, b)).collect()
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}
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}
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}
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impl<'tcx> Relate<'tcx> for ty::TraitRef<'tcx> {
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fn relate<R: TypeRelation<'tcx>>(
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relation: &mut R,
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a: &ty::TraitRef<'tcx>,
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b: &ty::TraitRef<'tcx>,
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) -> RelateResult<'tcx, ty::TraitRef<'tcx>> {
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// Different traits cannot be related.
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if a.def_id != b.def_id {
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Err(TypeError::Traits(expected_found(relation, &a.def_id, &b.def_id)))
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} else {
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let substs = relate_substs(relation, None, a.substs, b.substs)?;
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Ok(ty::TraitRef { def_id: a.def_id, substs: substs })
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}
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}
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}
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impl<'tcx> Relate<'tcx> for ty::ExistentialTraitRef<'tcx> {
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fn relate<R: TypeRelation<'tcx>>(
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relation: &mut R,
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a: &ty::ExistentialTraitRef<'tcx>,
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b: &ty::ExistentialTraitRef<'tcx>,
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) -> RelateResult<'tcx, ty::ExistentialTraitRef<'tcx>> {
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// Different traits cannot be related.
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if a.def_id != b.def_id {
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Err(TypeError::Traits(expected_found(relation, &a.def_id, &b.def_id)))
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} else {
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let substs = relate_substs(relation, None, a.substs, b.substs)?;
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Ok(ty::ExistentialTraitRef { def_id: a.def_id, substs: substs })
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}
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}
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}
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#[derive(Debug, Clone, TypeFoldable)]
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struct GeneratorWitness<'tcx>(&'tcx ty::List<Ty<'tcx>>);
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impl<'tcx> Relate<'tcx> for GeneratorWitness<'tcx> {
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fn relate<R: TypeRelation<'tcx>>(
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relation: &mut R,
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a: &GeneratorWitness<'tcx>,
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b: &GeneratorWitness<'tcx>,
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) -> RelateResult<'tcx, GeneratorWitness<'tcx>> {
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assert_eq!(a.0.len(), b.0.len());
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let tcx = relation.tcx();
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let types = tcx.mk_type_list(a.0.iter().zip(b.0).map(|(a, b)| relation.relate(a, b)))?;
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Ok(GeneratorWitness(types))
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}
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}
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impl<'tcx> Relate<'tcx> for Ty<'tcx> {
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fn relate<R: TypeRelation<'tcx>>(
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relation: &mut R,
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a: &Ty<'tcx>,
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b: &Ty<'tcx>,
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) -> RelateResult<'tcx, Ty<'tcx>> {
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relation.tys(a, b)
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}
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}
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/// The main "type relation" routine. Note that this does not handle
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/// inference artifacts, so you should filter those out before calling
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/// it.
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pub fn super_relate_tys<R: TypeRelation<'tcx>>(
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relation: &mut R,
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a: Ty<'tcx>,
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b: Ty<'tcx>,
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) -> RelateResult<'tcx, Ty<'tcx>> {
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let tcx = relation.tcx();
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debug!("super_relate_tys: a={:?} b={:?}", a, b);
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match (&a.kind, &b.kind) {
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(&ty::Infer(_), _) | (_, &ty::Infer(_)) => {
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// The caller should handle these cases!
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bug!("var types encountered in super_relate_tys")
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}
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(ty::Bound(..), _) | (_, ty::Bound(..)) => {
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bug!("bound types encountered in super_relate_tys")
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}
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(&ty::Error, _) | (_, &ty::Error) => Ok(tcx.types.err),
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(&ty::Never, _)
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| (&ty::Char, _)
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| (&ty::Bool, _)
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| (&ty::Int(_), _)
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| (&ty::Uint(_), _)
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| (&ty::Float(_), _)
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| (&ty::Str, _)
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if a == b =>
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{
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Ok(a)
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}
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(&ty::Param(ref a_p), &ty::Param(ref b_p)) if a_p.index == b_p.index => Ok(a),
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(ty::Placeholder(p1), ty::Placeholder(p2)) if p1 == p2 => Ok(a),
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(&ty::Adt(a_def, a_substs), &ty::Adt(b_def, b_substs)) if a_def == b_def => {
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let substs = relation.relate_item_substs(a_def.did, a_substs, b_substs)?;
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Ok(tcx.mk_adt(a_def, substs))
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}
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(&ty::Foreign(a_id), &ty::Foreign(b_id)) if a_id == b_id => Ok(tcx.mk_foreign(a_id)),
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(&ty::Dynamic(ref a_obj, ref a_region), &ty::Dynamic(ref b_obj, ref b_region)) => {
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let region_bound = relation.with_cause(Cause::ExistentialRegionBound, |relation| {
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relation.relate_with_variance(ty::Contravariant, a_region, b_region)
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})?;
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Ok(tcx.mk_dynamic(relation.relate(a_obj, b_obj)?, region_bound))
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}
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(&ty::Generator(a_id, a_substs, movability), &ty::Generator(b_id, b_substs, _))
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if a_id == b_id =>
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{
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// All Generator types with the same id represent
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// the (anonymous) type of the same generator expression. So
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// all of their regions should be equated.
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let substs = relation.relate(&a_substs, &b_substs)?;
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Ok(tcx.mk_generator(a_id, substs, movability))
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}
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(&ty::GeneratorWitness(a_types), &ty::GeneratorWitness(b_types)) => {
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// Wrap our types with a temporary GeneratorWitness struct
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// inside the binder so we can related them
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let a_types = a_types.map_bound(GeneratorWitness);
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let b_types = b_types.map_bound(GeneratorWitness);
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// Then remove the GeneratorWitness for the result
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let types = relation.relate(&a_types, &b_types)?.map_bound(|witness| witness.0);
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Ok(tcx.mk_generator_witness(types))
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}
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(&ty::Closure(a_id, a_substs), &ty::Closure(b_id, b_substs)) if a_id == b_id => {
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// All Closure types with the same id represent
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// the (anonymous) type of the same closure expression. So
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// all of their regions should be equated.
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let substs = relation.relate(&a_substs, &b_substs)?;
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Ok(tcx.mk_closure(a_id, &substs))
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}
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(&ty::RawPtr(ref a_mt), &ty::RawPtr(ref b_mt)) => {
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let mt = relation.relate(a_mt, b_mt)?;
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Ok(tcx.mk_ptr(mt))
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}
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(&ty::Ref(a_r, a_ty, a_mutbl), &ty::Ref(b_r, b_ty, b_mutbl)) => {
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let r = relation.relate_with_variance(ty::Contravariant, &a_r, &b_r)?;
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let a_mt = ty::TypeAndMut { ty: a_ty, mutbl: a_mutbl };
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let b_mt = ty::TypeAndMut { ty: b_ty, mutbl: b_mutbl };
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let mt = relation.relate(&a_mt, &b_mt)?;
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Ok(tcx.mk_ref(r, mt))
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}
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(&ty::Array(a_t, sz_a), &ty::Array(b_t, sz_b)) => {
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let t = relation.relate(&a_t, &b_t)?;
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match relation.relate(&sz_a, &sz_b) {
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Ok(sz) => Ok(tcx.mk_ty(ty::Array(t, sz))),
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Err(err) => {
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// Check whether the lengths are both concrete/known values,
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// but are unequal, for better diagnostics.
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let sz_a = sz_a.try_eval_usize(tcx, relation.param_env());
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let sz_b = sz_b.try_eval_usize(tcx, relation.param_env());
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match (sz_a, sz_b) {
|
|
(Some(sz_a_val), Some(sz_b_val)) => Err(TypeError::FixedArraySize(
|
|
expected_found(relation, &sz_a_val, &sz_b_val),
|
|
)),
|
|
_ => return Err(err),
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
(&ty::Slice(a_t), &ty::Slice(b_t)) => {
|
|
let t = relation.relate(&a_t, &b_t)?;
|
|
Ok(tcx.mk_slice(t))
|
|
}
|
|
|
|
(&ty::Tuple(as_), &ty::Tuple(bs)) => {
|
|
if as_.len() == bs.len() {
|
|
Ok(tcx.mk_tup(
|
|
as_.iter()
|
|
.zip(bs)
|
|
.map(|(a, b)| relation.relate(&a.expect_ty(), &b.expect_ty())),
|
|
)?)
|
|
} else if !(as_.is_empty() || bs.is_empty()) {
|
|
Err(TypeError::TupleSize(expected_found(relation, &as_.len(), &bs.len())))
|
|
} else {
|
|
Err(TypeError::Sorts(expected_found(relation, &a, &b)))
|
|
}
|
|
}
|
|
|
|
(&ty::FnDef(a_def_id, a_substs), &ty::FnDef(b_def_id, b_substs))
|
|
if a_def_id == b_def_id =>
|
|
{
|
|
let substs = relation.relate_item_substs(a_def_id, a_substs, b_substs)?;
|
|
Ok(tcx.mk_fn_def(a_def_id, substs))
|
|
}
|
|
|
|
(&ty::FnPtr(a_fty), &ty::FnPtr(b_fty)) => {
|
|
let fty = relation.relate(&a_fty, &b_fty)?;
|
|
Ok(tcx.mk_fn_ptr(fty))
|
|
}
|
|
|
|
(ty::UnnormalizedProjection(a_data), ty::UnnormalizedProjection(b_data)) => {
|
|
let projection_ty = relation.relate(a_data, b_data)?;
|
|
Ok(tcx.mk_ty(ty::UnnormalizedProjection(projection_ty)))
|
|
}
|
|
|
|
// these two are already handled downstream in case of lazy normalization
|
|
(ty::Projection(a_data), ty::Projection(b_data)) => {
|
|
let projection_ty = relation.relate(a_data, b_data)?;
|
|
Ok(tcx.mk_projection(projection_ty.item_def_id, projection_ty.substs))
|
|
}
|
|
|
|
(&ty::Opaque(a_def_id, a_substs), &ty::Opaque(b_def_id, b_substs))
|
|
if a_def_id == b_def_id =>
|
|
{
|
|
let substs = relate_substs(relation, None, a_substs, b_substs)?;
|
|
Ok(tcx.mk_opaque(a_def_id, substs))
|
|
}
|
|
|
|
_ => Err(TypeError::Sorts(expected_found(relation, &a, &b))),
|
|
}
|
|
}
|
|
|
|
/// The main "const relation" routine. Note that this does not handle
|
|
/// inference artifacts, so you should filter those out before calling
|
|
/// it.
|
|
pub fn super_relate_consts<R: TypeRelation<'tcx>>(
|
|
relation: &mut R,
|
|
a: &'tcx ty::Const<'tcx>,
|
|
b: &'tcx ty::Const<'tcx>,
|
|
) -> RelateResult<'tcx, &'tcx ty::Const<'tcx>> {
|
|
let tcx = relation.tcx();
|
|
|
|
let eagerly_eval = |x: &'tcx ty::Const<'tcx>| {
|
|
if !x.val.has_local_value() {
|
|
return x.eval(tcx, relation.param_env()).val;
|
|
}
|
|
x.val
|
|
};
|
|
|
|
// Currently, the values that can be unified are primitive types,
|
|
// and those that derive both `PartialEq` and `Eq`, corresponding
|
|
// to `structural_match` types.
|
|
let new_const_val = match (eagerly_eval(a), eagerly_eval(b)) {
|
|
(ty::ConstKind::Infer(_), _) | (_, ty::ConstKind::Infer(_)) => {
|
|
// The caller should handle these cases!
|
|
bug!("var types encountered in super_relate_consts: {:?} {:?}", a, b)
|
|
}
|
|
(ty::ConstKind::Param(a_p), ty::ConstKind::Param(b_p)) if a_p.index == b_p.index => {
|
|
return Ok(a);
|
|
}
|
|
(ty::ConstKind::Placeholder(p1), ty::ConstKind::Placeholder(p2)) if p1 == p2 => {
|
|
return Ok(a);
|
|
}
|
|
(ty::ConstKind::Value(a_val), ty::ConstKind::Value(b_val)) => {
|
|
let new_val = match (a_val, b_val) {
|
|
(ConstValue::Scalar(a_val), ConstValue::Scalar(b_val)) if a.ty == b.ty => {
|
|
if a_val == b_val {
|
|
Ok(ConstValue::Scalar(a_val))
|
|
} else if let ty::FnPtr(_) = a.ty.kind {
|
|
let alloc_map = tcx.alloc_map.lock();
|
|
let a_instance = alloc_map.unwrap_fn(a_val.assert_ptr().alloc_id);
|
|
let b_instance = alloc_map.unwrap_fn(b_val.assert_ptr().alloc_id);
|
|
if a_instance == b_instance {
|
|
Ok(ConstValue::Scalar(a_val))
|
|
} else {
|
|
Err(TypeError::ConstMismatch(expected_found(relation, &a, &b)))
|
|
}
|
|
} else {
|
|
Err(TypeError::ConstMismatch(expected_found(relation, &a, &b)))
|
|
}
|
|
}
|
|
|
|
(a_val @ ConstValue::Slice { .. }, b_val @ ConstValue::Slice { .. }) => {
|
|
let a_bytes = get_slice_bytes(&tcx, a_val);
|
|
let b_bytes = get_slice_bytes(&tcx, b_val);
|
|
if a_bytes == b_bytes {
|
|
Ok(a_val)
|
|
} else {
|
|
Err(TypeError::ConstMismatch(expected_found(relation, &a, &b)))
|
|
}
|
|
}
|
|
|
|
// FIXME(const_generics): handle `ConstValue::ByRef`.
|
|
_ => Err(TypeError::ConstMismatch(expected_found(relation, &a, &b))),
|
|
};
|
|
|
|
new_val.map(ty::ConstKind::Value)
|
|
}
|
|
|
|
// FIXME(const_generics): this is wrong, as it is a projection
|
|
(
|
|
ty::ConstKind::Unevaluated(a_def_id, a_substs, a_promoted),
|
|
ty::ConstKind::Unevaluated(b_def_id, b_substs, b_promoted),
|
|
) if a_def_id == b_def_id && a_promoted == b_promoted => {
|
|
let substs =
|
|
relation.relate_with_variance(ty::Variance::Invariant, &a_substs, &b_substs)?;
|
|
Ok(ty::ConstKind::Unevaluated(a_def_id, &substs, a_promoted))
|
|
}
|
|
_ => Err(TypeError::ConstMismatch(expected_found(relation, &a, &b))),
|
|
};
|
|
new_const_val.map(|val| tcx.mk_const(ty::Const { val, ty: a.ty }))
|
|
}
|
|
|
|
impl<'tcx> Relate<'tcx> for &'tcx ty::List<ty::ExistentialPredicate<'tcx>> {
|
|
fn relate<R: TypeRelation<'tcx>>(
|
|
relation: &mut R,
|
|
a: &Self,
|
|
b: &Self,
|
|
) -> RelateResult<'tcx, Self> {
|
|
if a.len() != b.len() {
|
|
return Err(TypeError::ExistentialMismatch(expected_found(relation, a, b)));
|
|
}
|
|
|
|
let tcx = relation.tcx();
|
|
let v = a.iter().zip(b.iter()).map(|(ep_a, ep_b)| {
|
|
use crate::ty::ExistentialPredicate::*;
|
|
match (*ep_a, *ep_b) {
|
|
(Trait(ref a), Trait(ref b)) => Ok(Trait(relation.relate(a, b)?)),
|
|
(Projection(ref a), Projection(ref b)) => Ok(Projection(relation.relate(a, b)?)),
|
|
(AutoTrait(ref a), AutoTrait(ref b)) if a == b => Ok(AutoTrait(*a)),
|
|
_ => Err(TypeError::ExistentialMismatch(expected_found(relation, a, b))),
|
|
}
|
|
});
|
|
Ok(tcx.mk_existential_predicates(v)?)
|
|
}
|
|
}
|
|
|
|
impl<'tcx> Relate<'tcx> for ty::ClosureSubsts<'tcx> {
|
|
fn relate<R: TypeRelation<'tcx>>(
|
|
relation: &mut R,
|
|
a: &ty::ClosureSubsts<'tcx>,
|
|
b: &ty::ClosureSubsts<'tcx>,
|
|
) -> RelateResult<'tcx, ty::ClosureSubsts<'tcx>> {
|
|
let substs = relate_substs(relation, None, a.substs, b.substs)?;
|
|
Ok(ty::ClosureSubsts { substs })
|
|
}
|
|
}
|
|
|
|
impl<'tcx> Relate<'tcx> for ty::GeneratorSubsts<'tcx> {
|
|
fn relate<R: TypeRelation<'tcx>>(
|
|
relation: &mut R,
|
|
a: &ty::GeneratorSubsts<'tcx>,
|
|
b: &ty::GeneratorSubsts<'tcx>,
|
|
) -> RelateResult<'tcx, ty::GeneratorSubsts<'tcx>> {
|
|
let substs = relate_substs(relation, None, a.substs, b.substs)?;
|
|
Ok(ty::GeneratorSubsts { substs })
|
|
}
|
|
}
|
|
|
|
impl<'tcx> Relate<'tcx> for SubstsRef<'tcx> {
|
|
fn relate<R: TypeRelation<'tcx>>(
|
|
relation: &mut R,
|
|
a: &SubstsRef<'tcx>,
|
|
b: &SubstsRef<'tcx>,
|
|
) -> RelateResult<'tcx, SubstsRef<'tcx>> {
|
|
relate_substs(relation, None, a, b)
|
|
}
|
|
}
|
|
|
|
impl<'tcx> Relate<'tcx> for ty::Region<'tcx> {
|
|
fn relate<R: TypeRelation<'tcx>>(
|
|
relation: &mut R,
|
|
a: &ty::Region<'tcx>,
|
|
b: &ty::Region<'tcx>,
|
|
) -> RelateResult<'tcx, ty::Region<'tcx>> {
|
|
relation.regions(*a, *b)
|
|
}
|
|
}
|
|
|
|
impl<'tcx> Relate<'tcx> for &'tcx ty::Const<'tcx> {
|
|
fn relate<R: TypeRelation<'tcx>>(
|
|
relation: &mut R,
|
|
a: &&'tcx ty::Const<'tcx>,
|
|
b: &&'tcx ty::Const<'tcx>,
|
|
) -> RelateResult<'tcx, &'tcx ty::Const<'tcx>> {
|
|
relation.consts(*a, *b)
|
|
}
|
|
}
|
|
|
|
impl<'tcx, T: Relate<'tcx>> Relate<'tcx> for ty::Binder<T> {
|
|
fn relate<R: TypeRelation<'tcx>>(
|
|
relation: &mut R,
|
|
a: &ty::Binder<T>,
|
|
b: &ty::Binder<T>,
|
|
) -> RelateResult<'tcx, ty::Binder<T>> {
|
|
relation.binders(a, b)
|
|
}
|
|
}
|
|
|
|
impl<'tcx, T: Relate<'tcx>> Relate<'tcx> for Rc<T> {
|
|
fn relate<R: TypeRelation<'tcx>>(
|
|
relation: &mut R,
|
|
a: &Rc<T>,
|
|
b: &Rc<T>,
|
|
) -> RelateResult<'tcx, Rc<T>> {
|
|
let a: &T = a;
|
|
let b: &T = b;
|
|
Ok(Rc::new(relation.relate(a, b)?))
|
|
}
|
|
}
|
|
|
|
impl<'tcx, T: Relate<'tcx>> Relate<'tcx> for Box<T> {
|
|
fn relate<R: TypeRelation<'tcx>>(
|
|
relation: &mut R,
|
|
a: &Box<T>,
|
|
b: &Box<T>,
|
|
) -> RelateResult<'tcx, Box<T>> {
|
|
let a: &T = a;
|
|
let b: &T = b;
|
|
Ok(Box::new(relation.relate(a, b)?))
|
|
}
|
|
}
|
|
|
|
impl<'tcx> Relate<'tcx> for GenericArg<'tcx> {
|
|
fn relate<R: TypeRelation<'tcx>>(
|
|
relation: &mut R,
|
|
a: &GenericArg<'tcx>,
|
|
b: &GenericArg<'tcx>,
|
|
) -> RelateResult<'tcx, GenericArg<'tcx>> {
|
|
match (a.unpack(), b.unpack()) {
|
|
(GenericArgKind::Lifetime(a_lt), GenericArgKind::Lifetime(b_lt)) => {
|
|
Ok(relation.relate(&a_lt, &b_lt)?.into())
|
|
}
|
|
(GenericArgKind::Type(a_ty), GenericArgKind::Type(b_ty)) => {
|
|
Ok(relation.relate(&a_ty, &b_ty)?.into())
|
|
}
|
|
(GenericArgKind::Const(a_ct), GenericArgKind::Const(b_ct)) => {
|
|
Ok(relation.relate(&a_ct, &b_ct)?.into())
|
|
}
|
|
(GenericArgKind::Lifetime(unpacked), x) => {
|
|
bug!("impossible case reached: can't relate: {:?} with {:?}", unpacked, x)
|
|
}
|
|
(GenericArgKind::Type(unpacked), x) => {
|
|
bug!("impossible case reached: can't relate: {:?} with {:?}", unpacked, x)
|
|
}
|
|
(GenericArgKind::Const(unpacked), x) => {
|
|
bug!("impossible case reached: can't relate: {:?} with {:?}", unpacked, x)
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
impl<'tcx> Relate<'tcx> for ty::TraitPredicate<'tcx> {
|
|
fn relate<R: TypeRelation<'tcx>>(
|
|
relation: &mut R,
|
|
a: &ty::TraitPredicate<'tcx>,
|
|
b: &ty::TraitPredicate<'tcx>,
|
|
) -> RelateResult<'tcx, ty::TraitPredicate<'tcx>> {
|
|
Ok(ty::TraitPredicate { trait_ref: relation.relate(&a.trait_ref, &b.trait_ref)? })
|
|
}
|
|
}
|
|
|
|
impl<'tcx> Relate<'tcx> for ty::ProjectionPredicate<'tcx> {
|
|
fn relate<R: TypeRelation<'tcx>>(
|
|
relation: &mut R,
|
|
a: &ty::ProjectionPredicate<'tcx>,
|
|
b: &ty::ProjectionPredicate<'tcx>,
|
|
) -> RelateResult<'tcx, ty::ProjectionPredicate<'tcx>> {
|
|
Ok(ty::ProjectionPredicate {
|
|
projection_ty: relation.relate(&a.projection_ty, &b.projection_ty)?,
|
|
ty: relation.relate(&a.ty, &b.ty)?,
|
|
})
|
|
}
|
|
}
|
|
|
|
impl<'tcx> Relate<'tcx> for traits::WhereClause<'tcx> {
|
|
fn relate<R: TypeRelation<'tcx>>(
|
|
relation: &mut R,
|
|
a: &traits::WhereClause<'tcx>,
|
|
b: &traits::WhereClause<'tcx>,
|
|
) -> RelateResult<'tcx, traits::WhereClause<'tcx>> {
|
|
use crate::traits::WhereClause::*;
|
|
match (a, b) {
|
|
(Implemented(a_pred), Implemented(b_pred)) => {
|
|
Ok(Implemented(relation.relate(a_pred, b_pred)?))
|
|
}
|
|
|
|
(ProjectionEq(a_pred), ProjectionEq(b_pred)) => {
|
|
Ok(ProjectionEq(relation.relate(a_pred, b_pred)?))
|
|
}
|
|
|
|
(RegionOutlives(a_pred), RegionOutlives(b_pred)) => {
|
|
Ok(RegionOutlives(ty::OutlivesPredicate(
|
|
relation.relate(&a_pred.0, &b_pred.0)?,
|
|
relation.relate(&a_pred.1, &b_pred.1)?,
|
|
)))
|
|
}
|
|
|
|
(TypeOutlives(a_pred), TypeOutlives(b_pred)) => {
|
|
Ok(TypeOutlives(ty::OutlivesPredicate(
|
|
relation.relate(&a_pred.0, &b_pred.0)?,
|
|
relation.relate(&a_pred.1, &b_pred.1)?,
|
|
)))
|
|
}
|
|
|
|
_ => Err(TypeError::Mismatch),
|
|
}
|
|
}
|
|
}
|
|
|
|
impl<'tcx> Relate<'tcx> for traits::WellFormed<'tcx> {
|
|
fn relate<R: TypeRelation<'tcx>>(
|
|
relation: &mut R,
|
|
a: &traits::WellFormed<'tcx>,
|
|
b: &traits::WellFormed<'tcx>,
|
|
) -> RelateResult<'tcx, traits::WellFormed<'tcx>> {
|
|
use crate::traits::WellFormed::*;
|
|
match (a, b) {
|
|
(Trait(a_pred), Trait(b_pred)) => Ok(Trait(relation.relate(a_pred, b_pred)?)),
|
|
(Ty(a_ty), Ty(b_ty)) => Ok(Ty(relation.relate(a_ty, b_ty)?)),
|
|
_ => Err(TypeError::Mismatch),
|
|
}
|
|
}
|
|
}
|
|
|
|
impl<'tcx> Relate<'tcx> for traits::FromEnv<'tcx> {
|
|
fn relate<R: TypeRelation<'tcx>>(
|
|
relation: &mut R,
|
|
a: &traits::FromEnv<'tcx>,
|
|
b: &traits::FromEnv<'tcx>,
|
|
) -> RelateResult<'tcx, traits::FromEnv<'tcx>> {
|
|
use crate::traits::FromEnv::*;
|
|
match (a, b) {
|
|
(Trait(a_pred), Trait(b_pred)) => Ok(Trait(relation.relate(a_pred, b_pred)?)),
|
|
(Ty(a_ty), Ty(b_ty)) => Ok(Ty(relation.relate(a_ty, b_ty)?)),
|
|
_ => Err(TypeError::Mismatch),
|
|
}
|
|
}
|
|
}
|
|
|
|
impl<'tcx> Relate<'tcx> for traits::DomainGoal<'tcx> {
|
|
fn relate<R: TypeRelation<'tcx>>(
|
|
relation: &mut R,
|
|
a: &traits::DomainGoal<'tcx>,
|
|
b: &traits::DomainGoal<'tcx>,
|
|
) -> RelateResult<'tcx, traits::DomainGoal<'tcx>> {
|
|
use crate::traits::DomainGoal::*;
|
|
match (a, b) {
|
|
(Holds(a_wc), Holds(b_wc)) => Ok(Holds(relation.relate(a_wc, b_wc)?)),
|
|
(WellFormed(a_wf), WellFormed(b_wf)) => Ok(WellFormed(relation.relate(a_wf, b_wf)?)),
|
|
(FromEnv(a_fe), FromEnv(b_fe)) => Ok(FromEnv(relation.relate(a_fe, b_fe)?)),
|
|
|
|
(Normalize(a_pred), Normalize(b_pred)) => {
|
|
Ok(Normalize(relation.relate(a_pred, b_pred)?))
|
|
}
|
|
|
|
_ => Err(TypeError::Mismatch),
|
|
}
|
|
}
|
|
}
|
|
|
|
impl<'tcx> Relate<'tcx> for traits::Goal<'tcx> {
|
|
fn relate<R: TypeRelation<'tcx>>(
|
|
relation: &mut R,
|
|
a: &traits::Goal<'tcx>,
|
|
b: &traits::Goal<'tcx>,
|
|
) -> RelateResult<'tcx, traits::Goal<'tcx>> {
|
|
use crate::traits::GoalKind::*;
|
|
match (a, b) {
|
|
(Implies(a_clauses, a_goal), Implies(b_clauses, b_goal)) => {
|
|
let clauses = relation.relate(a_clauses, b_clauses)?;
|
|
let goal = relation.relate(a_goal, b_goal)?;
|
|
Ok(relation.tcx().mk_goal(Implies(clauses, goal)))
|
|
}
|
|
|
|
(And(a_left, a_right), And(b_left, b_right)) => {
|
|
let left = relation.relate(a_left, b_left)?;
|
|
let right = relation.relate(a_right, b_right)?;
|
|
Ok(relation.tcx().mk_goal(And(left, right)))
|
|
}
|
|
|
|
(Not(a_goal), Not(b_goal)) => {
|
|
let goal = relation.relate(a_goal, b_goal)?;
|
|
Ok(relation.tcx().mk_goal(Not(goal)))
|
|
}
|
|
|
|
(DomainGoal(a_goal), DomainGoal(b_goal)) => {
|
|
let goal = relation.relate(a_goal, b_goal)?;
|
|
Ok(relation.tcx().mk_goal(DomainGoal(goal)))
|
|
}
|
|
|
|
(Quantified(a_qkind, a_goal), Quantified(b_qkind, b_goal)) if a_qkind == b_qkind => {
|
|
let goal = relation.relate(a_goal, b_goal)?;
|
|
Ok(relation.tcx().mk_goal(Quantified(*a_qkind, goal)))
|
|
}
|
|
|
|
(CannotProve, CannotProve) => Ok(*a),
|
|
|
|
_ => Err(TypeError::Mismatch),
|
|
}
|
|
}
|
|
}
|
|
|
|
impl<'tcx> Relate<'tcx> for traits::Goals<'tcx> {
|
|
fn relate<R: TypeRelation<'tcx>>(
|
|
relation: &mut R,
|
|
a: &traits::Goals<'tcx>,
|
|
b: &traits::Goals<'tcx>,
|
|
) -> RelateResult<'tcx, traits::Goals<'tcx>> {
|
|
if a.len() != b.len() {
|
|
return Err(TypeError::Mismatch);
|
|
}
|
|
|
|
let tcx = relation.tcx();
|
|
let goals = a.iter().zip(b.iter()).map(|(a, b)| relation.relate(a, b));
|
|
Ok(tcx.mk_goals(goals)?)
|
|
}
|
|
}
|
|
|
|
impl<'tcx> Relate<'tcx> for traits::Clause<'tcx> {
|
|
fn relate<R: TypeRelation<'tcx>>(
|
|
relation: &mut R,
|
|
a: &traits::Clause<'tcx>,
|
|
b: &traits::Clause<'tcx>,
|
|
) -> RelateResult<'tcx, traits::Clause<'tcx>> {
|
|
use crate::traits::Clause::*;
|
|
match (a, b) {
|
|
(Implies(a_clause), Implies(b_clause)) => {
|
|
let clause = relation.relate(a_clause, b_clause)?;
|
|
Ok(Implies(clause))
|
|
}
|
|
|
|
(ForAll(a_clause), ForAll(b_clause)) => {
|
|
let clause = relation.relate(a_clause, b_clause)?;
|
|
Ok(ForAll(clause))
|
|
}
|
|
|
|
_ => Err(TypeError::Mismatch),
|
|
}
|
|
}
|
|
}
|
|
|
|
impl<'tcx> Relate<'tcx> for traits::Clauses<'tcx> {
|
|
fn relate<R: TypeRelation<'tcx>>(
|
|
relation: &mut R,
|
|
a: &traits::Clauses<'tcx>,
|
|
b: &traits::Clauses<'tcx>,
|
|
) -> RelateResult<'tcx, traits::Clauses<'tcx>> {
|
|
if a.len() != b.len() {
|
|
return Err(TypeError::Mismatch);
|
|
}
|
|
|
|
let tcx = relation.tcx();
|
|
let clauses = a.iter().zip(b.iter()).map(|(a, b)| relation.relate(a, b));
|
|
Ok(tcx.mk_clauses(clauses)?)
|
|
}
|
|
}
|
|
|
|
impl<'tcx> Relate<'tcx> for traits::ProgramClause<'tcx> {
|
|
fn relate<R: TypeRelation<'tcx>>(
|
|
relation: &mut R,
|
|
a: &traits::ProgramClause<'tcx>,
|
|
b: &traits::ProgramClause<'tcx>,
|
|
) -> RelateResult<'tcx, traits::ProgramClause<'tcx>> {
|
|
Ok(traits::ProgramClause {
|
|
goal: relation.relate(&a.goal, &b.goal)?,
|
|
hypotheses: relation.relate(&a.hypotheses, &b.hypotheses)?,
|
|
category: traits::ProgramClauseCategory::Other,
|
|
})
|
|
}
|
|
}
|
|
|
|
impl<'tcx> Relate<'tcx> for traits::Environment<'tcx> {
|
|
fn relate<R: TypeRelation<'tcx>>(
|
|
relation: &mut R,
|
|
a: &traits::Environment<'tcx>,
|
|
b: &traits::Environment<'tcx>,
|
|
) -> RelateResult<'tcx, traits::Environment<'tcx>> {
|
|
Ok(traits::Environment { clauses: relation.relate(&a.clauses, &b.clauses)? })
|
|
}
|
|
}
|
|
|
|
impl<'tcx, G> Relate<'tcx> for traits::InEnvironment<'tcx, G>
|
|
where
|
|
G: Relate<'tcx>,
|
|
{
|
|
fn relate<R: TypeRelation<'tcx>>(
|
|
relation: &mut R,
|
|
a: &traits::InEnvironment<'tcx, G>,
|
|
b: &traits::InEnvironment<'tcx, G>,
|
|
) -> RelateResult<'tcx, traits::InEnvironment<'tcx, G>> {
|
|
Ok(traits::InEnvironment {
|
|
environment: relation.relate(&a.environment, &b.environment)?,
|
|
goal: relation.relate(&a.goal, &b.goal)?,
|
|
})
|
|
}
|
|
}
|
|
|
|
///////////////////////////////////////////////////////////////////////////
|
|
// Error handling
|
|
|
|
pub fn expected_found<R, T>(relation: &mut R, a: &T, b: &T) -> ExpectedFound<T>
|
|
where
|
|
R: TypeRelation<'tcx>,
|
|
T: Clone,
|
|
{
|
|
expected_found_bool(relation.a_is_expected(), a, b)
|
|
}
|
|
|
|
pub fn expected_found_bool<T>(a_is_expected: bool, a: &T, b: &T) -> ExpectedFound<T>
|
|
where
|
|
T: Clone,
|
|
{
|
|
let a = a.clone();
|
|
let b = b.clone();
|
|
if a_is_expected {
|
|
ExpectedFound { expected: a, found: b }
|
|
} else {
|
|
ExpectedFound { expected: b, found: a }
|
|
}
|
|
}
|