From: Philip Herron <herron.philip@googlemail.com>
During CallExpr argument type checking we may be calling a default
implementation of a trait function this will require any possible
associated types to be resolved and setup. This monomoprhization call does
this but it will premtivly do extra unification of types which will throw
off type checking later on. This fix is required for my work into type
bounds checking.
Fixes #1773
Signed-off-by: Philip Herron <herron.philip@googlemail.com>
gcc/rust/ChangeLog:
* typecheck/rust-hir-trait-reference.h: change interface to return self
* typecheck/rust-hir-trait-resolve.cc: likewise
* typecheck/rust-hir-type-check-path.cc (TypeCheckExpr::resolve_segments): likewise
* typecheck/rust-tyty-call.cc (TypeCheckCallExpr::visit): remove monomorphization hack
gcc/testsuite/ChangeLog:
* rust/compile/issue-1773.rs: New test.
---
gcc/rust/typecheck/rust-hir-trait-reference.h | 5 +--
gcc/rust/typecheck/rust-hir-trait-resolve.cc | 10 +++---
.../typecheck/rust-hir-type-check-path.cc | 36 ++++++++++++++-----
gcc/rust/typecheck/rust-tyty-call.cc | 1 -
gcc/testsuite/rust/compile/issue-1773.rs | 20 +++++++++++
5 files changed, 56 insertions(+), 16 deletions(-)
create mode 100644 gcc/testsuite/rust/compile/issue-1773.rs
@@ -497,8 +497,9 @@ public:
TyTy::BaseType *get_self () { return self; }
- void setup_associated_types (const TyTy::BaseType *self,
- const TyTy::TypeBoundPredicate &bound);
+ TyTy::BaseType *
+ setup_associated_types (const TyTy::BaseType *self,
+ const TyTy::TypeBoundPredicate &bound);
void reset_associated_types ();
@@ -377,13 +377,10 @@ TraitItemReference::associated_type_reset () const
placeholder->clear_associated_type ();
}
-void
+TyTy::BaseType *
AssociatedImplTrait::setup_associated_types (
const TyTy::BaseType *self, const TyTy::TypeBoundPredicate &bound)
{
- if (!bound.contains_associated_types ())
- return;
-
// compute the constrained impl block generic arguments based on self and the
// higher ranked trait bound
TyTy::BaseType *receiver = self->clone ();
@@ -486,6 +483,7 @@ AssociatedImplTrait::setup_associated_types (
TyTy::TyWithLocation (receiver), TyTy::TyWithLocation (impl_self_infer),
impl_predicate.get_locus ());
rust_assert (result->get_kind () != TyTy::TypeKind::ERROR);
+ TyTy::BaseType *self_result = result;
// unify the bounds arguments
std::vector<TyTy::BaseType *> hrtb_bound_arguments;
@@ -500,7 +498,7 @@ AssociatedImplTrait::setup_associated_types (
}
if (impl_trait_predicate_args.size () != hrtb_bound_arguments.size ())
- return;
+ return self_result;
for (size_t i = 0; i < impl_trait_predicate_args.size (); i++)
{
@@ -554,6 +552,8 @@ AssociatedImplTrait::setup_associated_types (
resolved_trait_item->associated_type_set (substituted);
});
iter.go ();
+
+ return self_result;
}
void
@@ -379,16 +379,36 @@ TypeCheckExpr::resolve_segments (NodeId root_resolved_node_id,
if (associated_impl_block != nullptr)
{
- // get the type of the parent Self
- HirId impl_ty_id
- = associated_impl_block->get_type ()->get_mappings ().get_hirid ();
+ // associated types
+ HirId impl_block_id
+ = associated_impl_block->get_mappings ().get_hirid ();
+
+ AssociatedImplTrait *associated = nullptr;
+ bool found_impl_trait
+ = context->lookup_associated_trait_impl (impl_block_id,
+ &associated);
TyTy::BaseType *impl_block_ty = nullptr;
- bool ok = query_type (impl_ty_id, &impl_block_ty);
- rust_assert (ok);
+ if (found_impl_trait)
+ {
+ TyTy::TypeBoundPredicate predicate (*associated->get_trait (),
+ seg.get_locus ());
+ impl_block_ty
+ = associated->setup_associated_types (prev_segment, predicate);
+ }
+ else
+ {
+ // get the type of the parent Self
+ HirId impl_ty_id = associated_impl_block->get_type ()
+ ->get_mappings ()
+ .get_hirid ();
- if (impl_block_ty->needs_generic_substitutions ())
- impl_block_ty
- = SubstMapper::InferSubst (impl_block_ty, seg.get_locus ());
+ bool ok = query_type (impl_ty_id, &impl_block_ty);
+ rust_assert (ok);
+
+ if (impl_block_ty->needs_generic_substitutions ())
+ impl_block_ty
+ = SubstMapper::InferSubst (impl_block_ty, seg.get_locus ());
+ }
prev_segment = unify_site (seg.get_mappings ().get_hirid (),
TyTy::TyWithLocation (prev_segment),
@@ -85,7 +85,6 @@ TypeCheckCallExpr::visit (ADTType &type)
void
TypeCheckCallExpr::visit (FnType &type)
{
- type.monomorphize ();
if (call.num_params () != type.num_params ())
{
if (type.is_varadic ())
new file mode 100644
@@ -0,0 +1,20 @@
+trait Foo<T> {
+ type A;
+
+ fn test(a: Self::A) -> Self::A {
+ a
+ }
+}
+
+struct Bar<T>(T);
+impl<T> Foo<T> for Bar<i32> {
+ type A = T;
+}
+
+fn main() {
+ let a;
+ a = Bar(123);
+
+ let b;
+ b = Bar::test(a.0);
+}