bjoernager/rust
bjoernager/rust
1
Fork 0
Code Activity

Lazily resolve type-alias-impl-trait defining uses

Browse source 
by using an opaque type obligation to bubble up comparisons between opaque types and other types

Also uses proper obligation causes so that the body id works, because out of some reason nll uses body ids for logic instead of just diagnostics.
This commit is contained in:
Oli Scherer 2021-08-20 14:47:12 +00:00 • committed by Oli Scherer
parent 8d2b598459
commit 0f6e06b7c0
284 changed files with 2646 additions and 2097 deletions
Download patch file Download diff file Expand all files Collapse all files

20
compiler/rustc_const_eval/src/transform/check_consts/check.rs
View file

@ -11,7 +11,7 @@ use rustc_middle::mir::*;
use rustc_middle::ty::cast::CastTy;
use rustc_middle::ty::subst::{GenericArgKind, InternalSubsts};
use rustc_middle::ty::{self, adjustment::PointerCast, Instance, InstanceDef, Ty, TyCtxt};
use rustc_middle::ty::{Binder, TraitPredicate, TraitRef};
use rustc_middle::ty::{Binder, TraitPredicate, TraitRef, TypeFoldable};
use rustc_mir_dataflow::{self, Analysis};
use rustc_span::{sym, Span, Symbol};
use rustc_trait_selection::traits::SelectionContext;
@ -46,7 +46,10 @@ impl<'mir, 'tcx> Qualifs<'mir, 'tcx> {
location: Location,
) -> bool {
let ty = ccx.body.local_decls[local].ty;
if !NeedsDrop::in_any_value_of_ty(ccx, ty) {
// Peeking into opaque types causes cycles if the current function declares said opaque
// type. Thus we avoid short circuiting on the type and instead run the more expensive
// analysis that looks at the actual usage withhin this function
if !ty.has_opaque_types() && !NeedsDrop::in_any_value_of_ty(ccx, ty) {
return false;
}
@ -100,7 +103,10 @@ impl<'mir, 'tcx> Qualifs<'mir, 'tcx> {
location: Location,
) -> bool {
let ty = ccx.body.local_decls[local].ty;
if !HasMutInterior::in_any_value_of_ty(ccx, ty) {
// Peeking into opaque types causes cycles if the current function declares said opaque
// type. Thus we avoid short circuiting on the type and instead run the more expensive
// analysis that looks at the actual usage withhin this function
if !ty.has_opaque_types() && !HasMutInterior::in_any_value_of_ty(ccx, ty) {
return false;
}
@ -148,7 +154,12 @@ impl<'mir, 'tcx> Qualifs<'mir, 'tcx> {
// If we know that all values of the return type are structurally matchable, there's no
// need to run dataflow.
_ if !CustomEq::in_any_value_of_ty(ccx, ccx.body.return_ty()) => false,
// Opaque types do not participate in const generics or pattern matching, so we can safely count them out.
_ if ccx.body.return_ty().has_opaque_types()
|| !CustomEq::in_any_value_of_ty(ccx, ccx.body.return_ty()) =>
{
false
}
hir::ConstContext::Const | hir::ConstContext::Static(_) => {
let mut cursor = FlowSensitiveAnalysis::new(CustomEq, ccx)
@ -395,6 +406,7 @@ impl<'mir, 'tcx> Checker<'mir, 'tcx> {
| ty::PredicateKind::Projection(_)
| ty::PredicateKind::ConstEvaluatable(..)
| ty::PredicateKind::ConstEquate(..)
| ty::PredicateKind::OpaqueType(..)
| ty::PredicateKind::TypeWellFormedFromEnv(..) => continue,
ty::PredicateKind::ObjectSafe(_) => {
bug!("object safe predicate on function: {:#?}", predicate)

5
compiler/rustc_const_eval/src/transform/validate.rs
View file

@ -78,7 +78,6 @@ pub fn equal_up_to_regions<'tcx>(
}
// Normalize lifetimes away on both sides, then compare.
let param_env = param_env.with_reveal_all_normalized(tcx);
let normalize = |ty: Ty<'tcx>| {
tcx.normalize_erasing_regions(
param_env,
@ -169,9 +168,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
return true;
}
// Normalize projections and things like that.
// FIXME: We need to reveal_all, as some optimizations change types in ways
// that require unfolding opaque types.
let param_env = self.param_env.with_reveal_all_normalized(self.tcx);
let param_env = self.param_env;
let src = self.tcx.normalize_erasing_regions(param_env, src);
let dest = self.tcx.normalize_erasing_regions(param_env, dest);