1030: Rewrite our unconstrained type-param error checking r=philberty a=philberty

This is a series of patches that were all required to fix this issue. We
now take advantage of our substitutions abstractions and traits
so that our TypeBoundPredicate's which form the basis of our HRTB code
I think this class is almost akin to rustc existential-trait-references. This now
reuses the same code path to give us the same error checking for generics
as we get with ADT's, functions etc.

With this refactoring in place we can then reuse the abstractions to map the
ID's from the used arguments in the type-bound-predicate, the impl block type
substation mappings and the self type itself.

There are quite a few cases to handle and our testsuite picked up all the regressions
so no behaviour of our existing test-cases have changed now. See each commit for
more detailed information.

Fixes #1019 
Addresses #849

Co-authored-by: Philip Herron <philip.herron@embecosm.com>
This commit is contained in:
bors[bot] 2022-03-17 10:23:04 +00:00 committed by GitHub
commit fe13ad49b1
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GPG Key ID: 4AEE18F83AFDEB23
15 changed files with 482 additions and 239 deletions

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@ -99,6 +99,7 @@ GRS_OBJS = \
rust/rust-hir-type-check-pattern.o \
rust/rust-hir-type-check-expr.o \
rust/rust-hir-dot-operator.o \
rust/rust-hir-type-check-base.o \
rust/rust-autoderef.o \
rust/rust-substitution-mapper.o \
rust/rust-lint-marklive.o \

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@ -133,8 +133,7 @@ public:
GenericArgs (std::vector<Lifetime> lifetime_args,
std::vector<std::unique_ptr<Type> > type_args,
std::vector<GenericArgsBinding> binding_args,
Location locus = Location ())
std::vector<GenericArgsBinding> binding_args, Location locus)
: lifetime_args (std::move (lifetime_args)),
type_args (std::move (type_args)),
binding_args (std::move (binding_args)), locus (locus)
@ -471,7 +470,7 @@ public:
has_separating_scope_resolution, locus),
generic_args (GenericArgs (std::move (lifetime_args),
std::move (type_args),
std::move (binding_args)))
std::move (binding_args), locus))
{}
std::string as_string () const override;

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@ -181,19 +181,37 @@ class TraitReference
public:
TraitReference (const HIR::Trait *hir_trait_ref,
std::vector<TraitItemReference> item_refs,
std::vector<const TraitReference *> super_traits)
std::vector<const TraitReference *> super_traits,
std::vector<TyTy::SubstitutionParamMapping> substs)
: hir_trait_ref (hir_trait_ref), item_refs (item_refs),
super_traits (super_traits)
{}
{
trait_substs.clear ();
trait_substs.reserve (substs.size ());
for (const auto &p : substs)
trait_substs.push_back (p.clone ());
}
TraitReference (TraitReference const &other)
: hir_trait_ref (other.hir_trait_ref), item_refs (other.item_refs)
{}
: hir_trait_ref (other.hir_trait_ref), item_refs (other.item_refs),
super_traits (other.super_traits)
{
trait_substs.clear ();
trait_substs.reserve (other.trait_substs.size ());
for (const auto &p : other.trait_substs)
trait_substs.push_back (p.clone ());
}
TraitReference &operator= (TraitReference const &other)
{
hir_trait_ref = other.hir_trait_ref;
item_refs = other.item_refs;
super_traits = other.super_traits;
trait_substs.clear ();
trait_substs.reserve (other.trait_substs.size ());
for (const auto &p : other.trait_substs)
trait_substs.push_back (p.clone ());
return *this;
}
@ -201,7 +219,10 @@ public:
TraitReference (TraitReference &&other) = default;
TraitReference &operator= (TraitReference &&other) = default;
static TraitReference error () { return TraitReference (nullptr, {}, {}); }
static TraitReference error ()
{
return TraitReference (nullptr, {}, {}, {});
}
bool is_error () const { return hir_trait_ref == nullptr; }
@ -384,10 +405,18 @@ public:
return is_safe;
}
bool trait_has_generics () const { return !trait_substs.empty (); }
std::vector<TyTy::SubstitutionParamMapping> get_trait_substs () const
{
return trait_substs;
}
private:
const HIR::Trait *hir_trait_ref;
std::vector<TraitItemReference> item_refs;
std::vector<const TraitReference *> super_traits;
std::vector<TyTy::SubstitutionParamMapping> trait_substs;
};
class AssociatedImplTrait

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@ -150,8 +150,13 @@ private:
// They also inherit themselves as a bound this enables a trait item to
// reference other Self::trait_items
std::vector<TyTy::SubstitutionParamMapping> self_subst_copy;
for (auto &sub : substitutions)
self_subst_copy.push_back (sub.clone ());
specified_bounds.push_back (
TyTy::TypeBoundPredicate (trait_reference->get_mappings ().get_defid (),
std::move (self_subst_copy),
trait_reference->get_locus ()));
std::vector<const TraitReference *> super_traits;
@ -168,8 +173,8 @@ private:
// FIXME this might be recursive we need a check for that
TraitReference *trait = resolve_trait_path (b->get_path ());
TyTy::TypeBoundPredicate predicate (
trait->get_mappings ().get_defid (), bound->get_locus ());
TyTy::TypeBoundPredicate predicate (*trait,
bound->get_locus ());
specified_bounds.push_back (std::move (predicate));
super_traits.push_back (predicate.get ());
@ -193,7 +198,8 @@ private:
}
TraitReference trait_object (trait_reference, item_refs,
std::move (super_traits));
std::move (super_traits),
std::move (substitutions));
context->insert_trait_reference (
trait_reference->get_mappings ().get_defid (), std::move (trait_object));

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@ -0,0 +1,84 @@
// Copyright (C) 2020-2022 Free Software Foundation, Inc.
// This file is part of GCC.
// GCC is free software; you can redistribute it and/or modify it under
// the terms of the GNU General Public License as published by the Free
// Software Foundation; either version 3, or (at your option) any later
// version.
// GCC is distributed in the hope that it will be useful, but WITHOUT ANY
// WARRANTY; without even the implied warranty of MERCHANTABILITY or
// FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
// for more details.
// You should have received a copy of the GNU General Public License
// along with GCC; see the file COPYING3. If not see
// <http://www.gnu.org/licenses/>.
#include "rust-hir-type-check-base.h"
namespace Rust {
namespace Resolver {
bool
TypeCheckBase::check_for_unconstrained (
const std::vector<TyTy::SubstitutionParamMapping> &params_to_constrain,
const TyTy::SubstitutionArgumentMappings &constraint_a,
const TyTy::SubstitutionArgumentMappings &constraint_b,
const TyTy::BaseType *reference)
{
std::set<HirId> symbols_to_constrain;
std::map<HirId, Location> symbol_to_location;
for (const auto &p : params_to_constrain)
{
HirId ref = p.get_param_ty ()->get_ref ();
symbols_to_constrain.insert (ref);
symbol_to_location.insert ({ref, p.get_param_locus ()});
}
// set up the set of constrained symbols
std::set<HirId> constrained_symbols;
for (const auto &c : constraint_a.get_mappings ())
{
const TyTy::BaseType *arg = c.get_tyty ();
if (arg != nullptr)
{
const TyTy::BaseType *p = arg->get_root ();
constrained_symbols.insert (p->get_ty_ref ());
}
}
for (const auto &c : constraint_b.get_mappings ())
{
const TyTy::BaseType *arg = c.get_tyty ();
if (arg != nullptr)
{
const TyTy::BaseType *p = arg->get_root ();
constrained_symbols.insert (p->get_ty_ref ());
}
}
const auto root = reference->get_root ();
if (root->get_kind () == TyTy::TypeKind::PARAM)
{
const TyTy::ParamType *p = static_cast<const TyTy::ParamType *> (root);
constrained_symbols.insert (p->get_ty_ref ());
}
// check for unconstrained
bool unconstrained = false;
for (auto &sym : symbols_to_constrain)
{
bool used = constrained_symbols.find (sym) != constrained_symbols.end ();
if (!used)
{
Location locus = symbol_to_location.at (sym);
rust_error_at (locus, "unconstrained type parameter");
unconstrained = true;
}
}
return unconstrained;
}
} // namespace Resolver
} // namespace Rust

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@ -47,6 +47,14 @@ protected:
TraitReference *resolve_trait_path (HIR::TypePath &);
TyTy::TypeBoundPredicate get_predicate_from_bound (HIR::TypePath &path);
bool check_for_unconstrained (
const std::vector<TyTy::SubstitutionParamMapping> &params_to_constrain,
const TyTy::SubstitutionArgumentMappings &constraint_a,
const TyTy::SubstitutionArgumentMappings &constraint_b,
const TyTy::BaseType *reference);
Analysis::Mappings *mappings;
Resolver *resolver;
TypeCheckContext *context;

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@ -70,7 +70,7 @@ public:
}
}
std::vector<TyTy::TypeBoundPredicate> specified_bounds;
auto specified_bound = TyTy::TypeBoundPredicate::error ();
TraitReference *trait_reference = &TraitReference::error_node ();
if (impl_block.has_trait_ref ())
{
@ -78,26 +78,7 @@ public:
trait_reference = TraitResolver::Resolve (*ref.get ());
rust_assert (!trait_reference->is_error ());
// setup the bound
TyTy::TypeBoundPredicate predicate (
trait_reference->get_mappings ().get_defid (), ref->get_locus ());
auto &final_seg = ref->get_final_segment ();
if (final_seg->is_generic_segment ())
{
auto final_generic_seg
= static_cast<HIR::TypePathSegmentGeneric *> (final_seg.get ());
if (final_generic_seg->has_generic_args ())
{
HIR::GenericArgs &generic_args
= final_generic_seg->get_generic_args ();
// this is applying generic arguments to a trait
// reference
predicate.apply_generic_arguments (&generic_args);
}
}
specified_bounds.push_back (std::move (predicate));
specified_bound = get_predicate_from_bound (*ref.get ());
}
TyTy::BaseType *self = nullptr;
@ -108,11 +89,25 @@ public:
"failed to resolve Self for ImplBlock");
return;
}
// inherit the bounds
self->inherit_bounds (specified_bounds);
if (!specified_bound.is_error ())
self->inherit_bounds ({specified_bound});
// check for any unconstrained type-params
const TyTy::SubstitutionArgumentMappings trait_constraints
= specified_bound.get_substitution_arguments ();
const TyTy::SubstitutionArgumentMappings impl_constraints
= GetUsedSubstArgs::From (self);
bool impl_block_has_unconstrained_typarams
= check_for_unconstrained (substitutions, trait_constraints,
impl_constraints, self);
if (impl_block_has_unconstrained_typarams)
return;
// validate the impl items
bool is_trait_impl_block = !trait_reference->is_error ();
std::vector<const TraitItemReference *> trait_item_refs;
for (auto &impl_item : impl_block.get_impl_items ())
{

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@ -468,9 +468,8 @@ public:
ResolveWhereClauseItem::Resolve (*where_clause_item.get ());
}
auto self
= TypeCheckType::Resolve (impl_block.get_type ().get (), &substitutions);
if (self == nullptr || self->get_kind () == TyTy::TypeKind::ERROR)
auto self = TypeCheckType::Resolve (impl_block.get_type ().get ());
if (self->get_kind () == TyTy::TypeKind::ERROR)
return;
for (auto &impl_item : impl_block.get_impl_items ())

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@ -84,11 +84,6 @@ TypeCheckType::visit (HIR::TypePath &path)
}
translated = SubstMapper::Resolve (path_type, path.get_locus (), &args);
if (translated->get_kind () != TyTy::TypeKind::ERROR
&& mappings != nullptr)
{
check_for_unconstrained (args.get_type_args ());
}
}
else if (!args.is_empty ())
{
@ -548,27 +543,11 @@ TypeCheckType::visit (HIR::TraitObjectType &type)
HIR::TypeParamBound &b = *bound.get ();
HIR::TraitBound &trait_bound = static_cast<HIR::TraitBound &> (b);
auto &type_path = trait_bound.get_path ();
TraitReference *trait = resolve_trait_path (type_path);
TyTy::TypeBoundPredicate predicate (trait->get_mappings ().get_defid (),
trait_bound.get_locus ());
auto &final_seg = type_path.get_final_segment ();
if (final_seg->is_generic_segment ())
{
auto final_generic_seg
= static_cast<HIR::TypePathSegmentGeneric *> (final_seg.get ());
if (final_generic_seg->has_generic_args ())
{
HIR::GenericArgs &generic_args
= final_generic_seg->get_generic_args ();
TyTy::TypeBoundPredicate predicate
= get_predicate_from_bound (trait_bound.get_path ());
// this is applying generic arguments to a trait
// reference
predicate.apply_generic_arguments (&generic_args);
}
}
if (predicate.is_object_safe (true, type.get_locus ()))
if (!predicate.is_error ()
&& predicate.is_object_safe (true, type.get_locus ()))
specified_bounds.push_back (std::move (predicate));
}

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@ -57,12 +57,9 @@ class TypeCheckType : public TypeCheckBase
using Rust::Resolver::TypeCheckBase::visit;
public:
static TyTy::BaseType *
Resolve (HIR::Type *type,
std::vector<TyTy::SubstitutionParamMapping> *subst_mappings
= nullptr)
static TyTy::BaseType *Resolve (HIR::Type *type)
{
TypeCheckType resolver (type->get_mappings ().get_hirid (), subst_mappings);
TypeCheckType resolver (type->get_mappings ().get_hirid ());
type->accept_vis (resolver);
rust_assert (resolver.translated != nullptr);
resolver.context->insert_type (type->get_mappings (), resolver.translated);
@ -159,43 +156,10 @@ public:
void visit (HIR::TraitObjectType &type) override;
private:
TypeCheckType (HirId id,
std::vector<TyTy::SubstitutionParamMapping> *subst_mappings)
: TypeCheckBase (), subst_mappings (subst_mappings),
translated (new TyTy::ErrorType (id))
TypeCheckType (HirId id)
: TypeCheckBase (), translated (new TyTy::ErrorType (id))
{}
void
check_for_unconstrained (std::vector<std::unique_ptr<HIR::Type>> &type_args)
{
std::map<std::string, Location> param_location_map;
std::set<std::string> param_tys;
if (subst_mappings != nullptr)
{
for (auto &mapping : *subst_mappings)
{
std::string sym = mapping.get_param_ty ()->get_symbol ();
param_tys.insert (sym);
param_location_map[sym] = mapping.get_generic_param ().get_locus ();
}
}
std::set<std::string> args;
for (auto &arg : type_args)
args.insert (arg->as_string ());
for (auto &exp : param_tys)
{
bool used = args.find (exp) != args.end ();
if (!used)
{
Location locus = param_location_map.at (exp);
rust_error_at (locus, "unconstrained type parameter");
}
}
}
TyTy::BaseType *resolve_root_path (HIR::TypePath &path, size_t *offset,
NodeId *root_resolved_node_id);
@ -205,7 +169,6 @@ private:
TyTy::BaseType *tyseg, const Analysis::NodeMapping &expr_mappings,
Location expr_locus);
std::vector<TyTy::SubstitutionParamMapping> *subst_mappings;
TyTy::BaseType *translated;
};
@ -245,29 +208,10 @@ public:
HIR::TraitBound *b
= static_cast<HIR::TraitBound *> (bound.get ());
auto &type_path = b->get_path ();
TraitReference *trait = resolve_trait_path (type_path);
TyTy::TypeBoundPredicate predicate (
trait->get_mappings ().get_defid (), b->get_locus ());
auto &final_seg = type_path.get_final_segment ();
if (final_seg->is_generic_segment ())
{
auto final_generic_seg
= static_cast<HIR::TypePathSegmentGeneric *> (
final_seg.get ());
if (final_generic_seg->has_generic_args ())
{
HIR::GenericArgs &generic_args
= final_generic_seg->get_generic_args ();
// this is applying generic arguments to a trait
// reference
predicate.apply_generic_arguments (&generic_args);
}
}
specified_bounds.push_back (std::move (predicate));
TyTy::TypeBoundPredicate predicate
= get_predicate_from_bound (b->get_path ());
if (!predicate.is_error ())
specified_bounds.push_back (std::move (predicate));
}
break;
@ -316,29 +260,10 @@ public:
HIR::TraitBound *b
= static_cast<HIR::TraitBound *> (bound.get ());
auto &type_path = b->get_path ();
TraitReference *trait = resolve_trait_path (type_path);
TyTy::TypeBoundPredicate predicate (
trait->get_mappings ().get_defid (), b->get_locus ());
auto &final_seg = type_path.get_final_segment ();
if (final_seg->is_generic_segment ())
{
auto final_generic_seg
= static_cast<HIR::TypePathSegmentGeneric *> (
final_seg.get ());
if (final_generic_seg->has_generic_args ())
{
HIR::GenericArgs &generic_args
= final_generic_seg->get_generic_args ();
// this is applying generic arguments to a trait
// reference
predicate.apply_generic_arguments (&generic_args);
}
}
specified_bounds.push_back (std::move (predicate));
TyTy::TypeBoundPredicate predicate
= get_predicate_from_bound (b->get_path ());
if (!predicate.is_error ())
specified_bounds.push_back (std::move (predicate));
}
break;

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@ -63,17 +63,101 @@ TypeCheckBase::resolve_trait_path (HIR::TypePath &path)
return TraitResolver::Resolve (path);
}
TyTy::TypeBoundPredicate
TypeCheckBase::get_predicate_from_bound (HIR::TypePath &type_path)
{
TraitReference *trait = resolve_trait_path (type_path);
if (trait->is_error ())
return TyTy::TypeBoundPredicate::error ();
TyTy::TypeBoundPredicate predicate (*trait, type_path.get_locus ());
HIR::GenericArgs args
= HIR::GenericArgs::create_empty (type_path.get_locus ());
auto &final_seg = type_path.get_final_segment ();
if (final_seg->is_generic_segment ())
{
auto final_generic_seg
= static_cast<HIR::TypePathSegmentGeneric *> (final_seg.get ());
if (final_generic_seg->has_generic_args ())
{
args = final_generic_seg->get_generic_args ();
}
}
if (predicate.requires_generic_args ())
{
// this is applying generic arguments to a trait reference
predicate.apply_generic_arguments (&args);
}
return predicate;
}
} // namespace Resolver
namespace TyTy {
TypeBoundPredicate::TypeBoundPredicate (
const Resolver::TraitReference &trait_reference, Location locus)
: SubstitutionRef (trait_reference.get_trait_substs (),
SubstitutionArgumentMappings::error ()),
reference (trait_reference.get_mappings ().get_defid ()), locus (locus),
args (HIR::GenericArgs::create_empty ()), error_flag (false)
{}
TypeBoundPredicate::TypeBoundPredicate (
DefId reference, std::vector<SubstitutionParamMapping> substitutions,
Location locus)
: SubstitutionRef (std::move (substitutions),
SubstitutionArgumentMappings::error ()),
reference (reference), locus (locus),
args (HIR::GenericArgs::create_empty ()), error_flag (false)
{}
TypeBoundPredicate::TypeBoundPredicate (const TypeBoundPredicate &other)
: SubstitutionRef ({}, other.used_arguments), reference (other.reference),
locus (other.locus), args (other.args), error_flag (other.error_flag)
{
substitutions.clear ();
if (!other.is_error ())
{
for (const auto &p : other.get_substs ())
substitutions.push_back (p.clone ());
}
}
TypeBoundPredicate &
TypeBoundPredicate::operator= (const TypeBoundPredicate &other)
{
reference = other.reference;
locus = other.locus;
args = other.args;
error_flag = other.error_flag;
used_arguments = other.used_arguments;
substitutions.clear ();
if (!other.is_error ())
{
for (const auto &p : other.get_substs ())
substitutions.push_back (p.clone ());
}
return *this;
}
TypeBoundPredicate
TypeBoundPredicate::error ()
{
auto p = TypeBoundPredicate (UNKNOWN_DEFID, {}, Location ());
p.error_flag = true;
return p;
}
std::string
TypeBoundPredicate::as_string () const
{
return get ()->as_string ()
+ (has_generic_args ()
? std::string ("<") + args->as_string () + std::string (">")
: "");
return get ()->as_string () + subst_as_string ();
}
const Resolver::TraitReference *
@ -114,8 +198,19 @@ TypeBoundPredicate::is_object_safe (bool emit_error, Location locus) const
void
TypeBoundPredicate::apply_generic_arguments (HIR::GenericArgs *generic_args)
{
args = generic_args;
// TODO verify these arguments are valid and not too many were added
// we need to get the substitutions argument mappings but also remember that
// we have an implicit Self argument which we must be careful to respect
rust_assert (used_arguments.is_empty ());
rust_assert (!substitutions.empty ());
// we setup a dummy implict self argument
SubstitutionArg placeholder_self (&substitutions.front (), nullptr);
used_arguments.get_mappings ().push_back (std::move (placeholder_self));
// now actually perform a substitution
used_arguments = get_mappings_from_generic_args (*generic_args);
error_flag |= used_arguments.is_error ();
args = *generic_args;
}
bool
@ -179,6 +274,34 @@ TypeBoundPredicateItem::get_tyty_for_receiver (
return resolved;
}
bool
TypeBoundPredicate::is_error () const
{
auto context = Resolver::TypeCheckContext::get ();
Resolver::TraitReference *ref = nullptr;
bool ok = context->lookup_trait_reference (reference, &ref);
return !ok || error_flag;
}
BaseType *
TypeBoundPredicate::handle_substitions (SubstitutionArgumentMappings mappings)
{
gcc_unreachable ();
return nullptr;
}
bool
TypeBoundPredicate::requires_generic_args () const
{
if (is_error ())
return false;
return substitutions.size () > 1 && args.is_empty ();
}
// trait item reference
const Resolver::TraitItemReference *
TypeBoundPredicateItem::get_raw_item () const
@ -192,5 +315,55 @@ TypeBoundPredicateItem::needs_implementation () const
return !get_raw_item ()->is_optional ();
}
// TypeBoundsMappings
TypeBoundsMappings::TypeBoundsMappings (
std::vector<TypeBoundPredicate> specified_bounds)
: specified_bounds (specified_bounds)
{}
std::vector<TypeBoundPredicate> &
TypeBoundsMappings::get_specified_bounds ()
{
return specified_bounds;
}
const std::vector<TypeBoundPredicate> &
TypeBoundsMappings::get_specified_bounds () const
{
return specified_bounds;
}
size_t
TypeBoundsMappings::num_specified_bounds () const
{
return specified_bounds.size ();
}
std::string
TypeBoundsMappings::raw_bounds_as_string () const
{
std::string buf;
for (size_t i = 0; i < specified_bounds.size (); i++)
{
const TypeBoundPredicate &b = specified_bounds.at (i);
bool has_next = (i + 1) < specified_bounds.size ();
buf += b.get_name () + (has_next ? " + " : "");
}
return buf;
}
std::string
TypeBoundsMappings::bounds_as_string () const
{
return "bounds:[" + raw_bounds_as_string () + "]";
}
void
TypeBoundsMappings::add_bound (TypeBoundPredicate predicate)
{
specified_bounds.push_back (predicate);
}
} // namespace TyTy
} // namespace Rust

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@ -201,11 +201,16 @@ BaseType::inherit_bounds (
const BaseType *
BaseType::get_root () const
{
const BaseType *root = this;
while (root->get_kind () == TyTy::REF)
const TyTy::BaseType *root = this;
if (get_kind () == TyTy::REF)
{
const ReferenceType *r = static_cast<const ReferenceType *> (root);
root = r->get_base ();
root = r->get_base ()->get_root ();
}
else if (get_kind () == TyTy::POINTER)
{
const PointerType *r = static_cast<const PointerType *> (root);
root = r->get_base ()->get_root ();
}
return root;
}
@ -543,11 +548,11 @@ SubstitutionRef::get_mappings_from_generic_args (HIR::GenericArgs &args)
rust_error_at (
r,
"generic item takes at least %lu type arguments but %lu were supplied",
substitutions.size (), args.get_type_args ().size ());
(min_required_substitutions () - offs), args.get_type_args ().size ());
return SubstitutionArgumentMappings::error ();
}
std::vector<SubstitutionArg> mappings;
std::vector<SubstitutionArg> mappings = used_arguments.get_mappings ();
for (auto &arg : args.get_type_args ())
{
BaseType *resolved = Resolver::TypeCheckType::Resolve (arg.get ());
@ -2351,7 +2356,7 @@ ParamType::handle_substitions (SubstitutionArgumentMappings mappings)
SubstitutionArg arg = SubstitutionArg::error ();
bool ok = mappings.get_argument_for_symbol (this, &arg);
if (ok)
if (ok && !arg.is_error ())
p->set_ty_ref (arg.get_tyty ()->get_ref ());
return p;

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@ -108,92 +108,24 @@ private:
const Resolver::TraitItemReference *trait_item_ref;
};
class TypeBoundPredicate
{
public:
TypeBoundPredicate (DefId reference, Location locus)
: reference (reference), locus (locus), args (nullptr)
{}
std::string as_string () const;
const Resolver::TraitReference *get () const;
Location get_locus () const { return locus; }
std::string get_name () const;
// check that this predicate is object-safe see:
// https://doc.rust-lang.org/reference/items/traits.html#object-safety
bool is_object_safe (bool emit_error, Location locus) const;
void apply_generic_arguments (HIR::GenericArgs *generic_args);
bool contains_item (const std::string &search) const;
TypeBoundPredicateItem
lookup_associated_item (const std::string &search) const;
HIR::GenericArgs *get_generic_args () { return args; }
const HIR::GenericArgs *get_generic_args () const { return args; }
bool has_generic_args () const
{
if (args == nullptr)
return false;
return args->has_generic_args ();
}
private:
DefId reference;
Location locus;
HIR::GenericArgs *args;
};
class TypeBoundsMappings
{
protected:
TypeBoundsMappings (std::vector<TypeBoundPredicate> specified_bounds)
: specified_bounds (specified_bounds)
{}
TypeBoundsMappings (std::vector<TypeBoundPredicate> specified_bounds);
public:
std::vector<TypeBoundPredicate> &get_specified_bounds ()
{
return specified_bounds;
}
std::vector<TypeBoundPredicate> &get_specified_bounds ();
const std::vector<TypeBoundPredicate> &get_specified_bounds () const
{
return specified_bounds;
}
const std::vector<TypeBoundPredicate> &get_specified_bounds () const;
size_t num_specified_bounds () const { return specified_bounds.size (); }
size_t num_specified_bounds () const;
std::string raw_bounds_as_string () const
{
std::string buf;
for (size_t i = 0; i < specified_bounds.size (); i++)
{
const TypeBoundPredicate &b = specified_bounds.at (i);
bool has_next = (i + 1) < specified_bounds.size ();
buf += b.get_name () + (has_next ? " + " : "");
}
return buf;
}
std::string raw_bounds_as_string () const;
std::string bounds_as_string () const
{
return "bounds:[" + raw_bounds_as_string () + "]";
}
std::string bounds_as_string () const;
protected:
void add_bound (TypeBoundPredicate predicate)
{
specified_bounds.push_back (predicate);
}
void add_bound (TypeBoundPredicate predicate);
std::vector<TypeBoundPredicate> specified_bounds;
};
@ -619,7 +551,13 @@ public:
: generic (other.generic), param (other.param)
{}
std::string as_string () const { return param->get_name (); }
std::string as_string () const
{
if (param == nullptr)
return "nullptr";
return param->get_name ();
}
bool fill_param_ty (BaseType &type, Location locus);
@ -683,7 +621,9 @@ public:
BaseType *get_tyty () { return argument; }
const SubstitutionParamMapping *get_param_mapping () { return param; }
const BaseType *get_tyty () const { return argument; }
const SubstitutionParamMapping *get_param_mapping () const { return param; }
static SubstitutionArg error () { return SubstitutionArg (nullptr, nullptr); }
@ -702,7 +642,8 @@ public:
std::string as_string () const
{
return param->as_string () + ":" + argument->as_string ();
return param->as_string ()
+ (argument != nullptr ? ":" + argument->as_string () : "");
}
private:
@ -780,8 +721,12 @@ public:
size_t size () const { return mappings.size (); }
bool is_empty () const { return size () == 0; }
std::vector<SubstitutionArg> &get_mappings () { return mappings; }
const std::vector<SubstitutionArg> &get_mappings () const { return mappings; }
std::string as_string () const
{
std::string buffer;
@ -1007,6 +952,62 @@ protected:
SubstitutionArgumentMappings used_arguments;
};
class TypeBoundPredicate : public SubstitutionRef
{
public:
TypeBoundPredicate (const Resolver::TraitReference &trait_reference,
Location locus);
TypeBoundPredicate (DefId reference,
std::vector<SubstitutionParamMapping> substitutions,
Location locus);
TypeBoundPredicate (const TypeBoundPredicate &other);
TypeBoundPredicate &operator= (const TypeBoundPredicate &other);
static TypeBoundPredicate error ();
std::string as_string () const;
const Resolver::TraitReference *get () const;
Location get_locus () const { return locus; }
std::string get_name () const;
// check that this predicate is object-safe see:
// https://doc.rust-lang.org/reference/items/traits.html#object-safety
bool is_object_safe (bool emit_error, Location locus) const;
void apply_generic_arguments (HIR::GenericArgs *generic_args);
bool contains_item (const std::string &search) const;
TypeBoundPredicateItem
lookup_associated_item (const std::string &search) const;
HIR::GenericArgs *get_generic_args () { return &args; }
const HIR::GenericArgs *get_generic_args () const { return &args; }
bool has_generic_args () const { return args.has_generic_args (); }
// WARNING THIS WILL ALWAYS RETURN NULLPTR
BaseType *
handle_substitions (SubstitutionArgumentMappings mappings) override final;
bool is_error () const;
bool requires_generic_args () const;
private:
DefId reference;
Location locus;
HIR::GenericArgs args;
bool error_flag;
};
// https://doc.rust-lang.org/nightly/nightly-rustc/rustc_middle/ty/struct.VariantDef.html
class VariantDef
{

View File

@ -0,0 +1,19 @@
trait A<T> {
type Output;
fn test(self, a: &T) -> &Self::Output;
}
struct Foo<T> {
// { dg-warning "struct is never constructed" "" { target *-*-* } .-1 }
start: T,
end: T,
}
impl<X> A<X> for Foo<usize> {
type Output = X;
fn test(self, a: &X) -> &Self::Output {
a
}
}

View File

@ -0,0 +1,20 @@
trait A<T> {
type Output;
fn test(self, a: &T) -> &Self::Output;
}
struct Foo<T> {
start: T,
end: T,
}
impl<T> A for Foo<usize> {
// { dg-error "generic item takes at least 1 type arguments but 0 were supplied" "" { target *-*-* } .-1 }
// { dg-error "unconstrained type parameter" "" { target *-*-* } .-2 }
type Output = T;
fn test(self, a: &T) -> &Self::Output {
a
}
}