mirror of
https://github.com/carbon-language/carbon-lang.git
synced 2026-09-24 22:02:23 +01:00
Geoff RomerandRichard Smith
e023f75254
The bulk of this change is changing most pattern insts to be `Always` rather than `AlwaysUnique` constants, so that they can be wrapped in `SpecificConstant`s to perform substitution. That then lets thunking rely much more on `SpecificConstant` wrappers instead of deep-copying the inst tree with modified types. This approach to thunking should scale better, particularly as things like form generics make function signatures more complex, because we can leverage the existing support for constant evaluation and substitution. Unfortunately, applying this approach to binding patterns will require more work; see the TODO near the top of `thunk.cpp` for details. --------- Co-authored-by: Richard Smith <richard@metafoo.co.uk>
103 lines
3.3 KiB
C++
103 lines
3.3 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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#include "toolchain/sem_ir/pattern.h"
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#include "toolchain/base/kind_switch.h"
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#include "toolchain/sem_ir/ids.h"
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#include "toolchain/sem_ir/typed_insts.h"
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namespace Carbon::SemIR {
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// Returns the pattern instruction corresponding to the given ID, after
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// unwrapping any simple pattern operators such as `var`.
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static auto GetUnwrapped(const File& sem_ir, InstId pattern_id)
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-> std::pair<InstId, Inst> {
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auto inst_id = pattern_id;
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while (true) {
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auto inst = sem_ir.insts().Get(inst_id);
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CARBON_KIND_SWITCH(inst) {
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case CARBON_KIND_ANY(SemIR::AnyVarPattern, var_pattern): {
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inst_id = var_pattern.subpattern_id;
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break;
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}
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case CARBON_KIND(SemIR::SpecificConstant specific_constant): {
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inst_id = specific_constant.inst_id;
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break;
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}
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case CARBON_KIND(SemIR::ImportRefLoaded _): {
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inst_id = sem_ir.constant_values().GetConstantInstId(inst_id);
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break;
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}
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default:
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return {inst_id, inst};
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}
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}
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}
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// Returns the name and entity name introduced by the given instruction if it is
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// a binding pattern, or otherwise `{None, None}`.
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static auto GetBoundEntityName(const File& sem_ir, Inst inst)
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-> std::pair<NameId, EntityNameId> {
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if (auto binding_pattern = inst.TryAs<AnyBindingPattern>()) {
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return {sem_ir.entity_names().Get(binding_pattern->entity_name_id).name_id,
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binding_pattern->entity_name_id};
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}
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return {NameId::None, EntityNameId::None};
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}
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auto IsSelfPattern(const File& sem_ir, InstId pattern_id) -> bool {
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auto [_, inst] = GetUnwrapped(sem_ir, pattern_id);
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auto [name_id, entity_name_id] = GetBoundEntityName(sem_ir, inst);
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return name_id == NameId::SelfValue;
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}
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auto GetFirstBindingNameFromPatternId(const File& sem_ir, InstId pattern_id)
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-> EntityNameId {
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llvm::SmallVector<InstId> work_list = {pattern_id};
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while (!work_list.empty()) {
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auto [_, inst] = GetUnwrapped(sem_ir, work_list.pop_back_val());
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if (auto tuple_patt = inst.TryAs<TuplePattern>()) {
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auto block = sem_ir.inst_blocks().Get(tuple_patt->elements_id);
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work_list.append(block.rbegin(), block.rend());
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continue;
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}
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// TODO: Look through struct patterns.
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if (auto ref_pattern = inst.TryAs<RefParamPattern>()) {
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// TODO: This introduces a name, but we don't model it as a binding.
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return EntityNameId::None;
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}
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auto [name_id, entity_name_id] = GetBoundEntityName(sem_ir, inst);
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CARBON_CHECK(entity_name_id.has_value(), "Unhandled pattern inst kind {0}",
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inst);
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// Skip unnamed bindings.
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if (name_id != NameId::Underscore) {
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return entity_name_id;
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}
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}
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return EntityNameId::None;
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}
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auto GetPrettyNameFromPatternId(const File& sem_ir, InstId pattern_id)
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-> NameId {
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auto [inst_id, inst] = GetUnwrapped(sem_ir, pattern_id);
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CARBON_KIND_SWITCH(inst) {
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case CARBON_KIND_ANY(SemIR::AnyLeafParamPattern, param_pattern): {
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return param_pattern.pretty_name_id;
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}
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case CARBON_KIND_ANY(SemIR::AnyBindingPattern, _): {
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return GetBoundEntityName(sem_ir, inst).first;
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}
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default:
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return NameId::None;
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}
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}
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} // namespace Carbon::SemIR
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