mirror of
https://github.com/carbon-language/carbon-lang.git
synced 2026-09-24 20:10:13 +01:00
Dana Jansens
917a6ea971
Currently each interface has a `Self` facet internally that becomes a binding to every entity inside the interface: associated constants, functions, and require decls. Each of these has to be independently generic as a result. This makes is challenging in extended name lookup to move into an extended scope of an interface, as we have a specific for the interface, but the names within require a different specific that includes a `Self` facet value. We generalize this relationship by adding a second generic to Interface, called `generic_with_self`. When we want to work with entities inside the interface, we move from the interface-without-specific to the interface-with-self specific by adding a Self to the specific. This is done independently of any particular entity inside the Interface, as those entities are now all members of the interface-with-self generic. Associated constants no longer need a generic of their own, as they do not have separate generic bindings. Functions retain a generic, but if the function has no generic arguments, it will have no bindings of its own now. Require decls retain a generic so that their specific can be instantiated separately from the interface. Requiring the interface to be complete does not require the types in a require decl to be complete unless it is modified by `extend`. So we allow them to be completed later by keeping them in a separate generic. Named constraints look like interfaces and gain the additional inner generic-with-self, with the same relationship to require decls. This removes the need for name lookup to perform Substitution of a Self facet into the extended scope instruction. Instead, the `SpecificConstant` instruction inserted by a `require` decl is part of the interface-with-self generic. When looking through a FacetType for extended scopes, for each interface, we push the scope with the specific for the interface-with-self. Then the constant value of the `SpecificConstant` is correctly modified by the provided self automatically through applying that specific.
66 lines
2.8 KiB
C++
66 lines
2.8 KiB
C++
// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
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// Exceptions. See /LICENSE for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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#ifndef CARBON_TOOLCHAIN_CHECK_INTERFACE_H_
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#define CARBON_TOOLCHAIN_CHECK_INTERFACE_H_
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#include <optional>
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#include "toolchain/check/context.h"
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#include "toolchain/check/decl_name_stack.h"
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#include "toolchain/check/name_component.h"
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#include "toolchain/parse/node_ids.h"
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#include "toolchain/sem_ir/entity_with_params_base.h"
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#include "toolchain/sem_ir/ids.h"
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#include "toolchain/sem_ir/name_scope.h"
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#include "toolchain/sem_ir/typed_insts.h"
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namespace Carbon::Check {
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// Builds and returns an associated entity for `interface_id` corresponding to
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// the declaration `decl_id`, which can be an associated function or an
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// associated constant. Registers the associated entity in the list for the
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// interface.
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auto BuildAssociatedEntity(Context& context, SemIR::InterfaceId interface_id,
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SemIR::InstId decl_id) -> SemIR::InstId;
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// Gets the self specific of a generic declaration that is an interface member,
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// given a specific for the interface plus a type to use as `Self`.
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auto GetSelfSpecificForInterfaceMemberWithSelfType(
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Context& context, SemIR::LocId loc_id,
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SemIR::SpecificId interface_with_self_specific_id,
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SemIR::GenericId generic_id, SemIR::SpecificId enclosing_specific_id)
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-> SemIR::SpecificId;
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// Gets the type of the specified associated entity, given the specific for the
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// interface and the type of `Self`.
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auto GetTypeForSpecificAssociatedEntity(
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Context& context, SemIR::SpecificId interface_with_self_specific_id,
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SemIR::InstId decl_id) -> SemIR::TypeId;
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// Creates a symbolic binding for `Self` of type `type_id` in the scope of
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// `scope_id`.
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//
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// Returns the symbolic binding instruction.
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auto AddSelfSymbolicBindingToScope(Context& context,
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SemIR::LocId definition_loc_id,
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SemIR::TypeId type_id,
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SemIR::NameScopeId scope_id,
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bool is_template) -> SemIR::InstId;
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// Given a search result `lookup_result` for `name`, returns the previous valid
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// declaration of `name` if there is one. The `entity` is a new decl of the same
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// `name`, and the existing decl need to be of the same entity type. Otherwise,
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// produces diagnostics if needed and returns nullopt.
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template <typename EntityT>
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requires SameAsOneOf<EntityT, SemIR::Interface, SemIR::NamedConstraint>
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auto TryGetExistingDecl(Context& context, const NameComponent& name,
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SemIR::ScopeLookupResult lookup_result,
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const EntityT& entity, bool is_definition)
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-> std::optional<SemIR::Inst>;
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} // namespace Carbon::Check
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#endif // CARBON_TOOLCHAIN_CHECK_INTERFACE_H_
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