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carbon-lang/toolchain/check/handle_observe.cpp
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Özgür T. ÖnsoyandDana Jansens 08385adeb5 Implement checking observe declarations (#6709)
This adds SemIR structs and implements building `observe` lists, as well
as naming, formatting, and importing `observe` declarations.

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Co-authored-by: Dana Jansens <danakj@orodu.net>
2026-07-08 17:07:10 +00:00

123 lines
4.6 KiB
C++

// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
// Exceptions. See /LICENSE for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
#include "common/hashtable_key_context.h"
#include "toolchain/check/context.h"
#include "toolchain/check/convert.h"
#include "toolchain/check/diagnostic_helpers.h"
#include "toolchain/check/generic.h"
#include "toolchain/check/handle.h"
#include "toolchain/check/inst.h"
#include "toolchain/check/type.h"
#include "toolchain/parse/node_ids.h"
#include "toolchain/parse/node_kind.h"
#include "toolchain/sem_ir/ids.h"
#include "toolchain/sem_ir/inst.h"
#include "toolchain/sem_ir/typed_insts.h"
namespace Carbon::Check {
auto HandleParseNode(Context& context, Parse::ObserveIntroducerId node_id)
-> bool {
auto scope_inst_id = context.scope_stack().PeekInstId();
if (!context.insts()
.IsOneOf<SemIR::InterfaceWithSelfDecl, SemIR::FunctionDecl>(
scope_inst_id)) {
CARBON_DIAGNOSTIC(
ObserveInWrongScope, Error,
"`observe` can only be used in an `interface` or `function`");
context.emitter().Emit(node_id, ObserveInWrongScope);
scope_inst_id = SemIR::ErrorInst::InstId;
}
context.args_type_info_stack().Push();
context.node_stack().Push(node_id, scope_inst_id);
return true;
}
auto HandleParseNode(Context& context, Parse::ObserveEqualEqualId node_id)
-> bool {
auto [rhs_node_id, rhs_inst_id] = context.node_stack().PopExprWithNodeId();
auto [lhs_node_id, lhs_inst_id] = context.node_stack().PopExprWithNodeId();
if (context.node_stack().Peek<Parse::NodeKind::ObserveIntroducer>() ==
SemIR::ErrorInst::InstId) {
context.node_stack().Push(rhs_node_id, rhs_inst_id);
return true;
}
auto rhs_as_type = ExprAsType(context, rhs_node_id, rhs_inst_id);
auto lhs_as_type = ExprAsType(context, lhs_node_id, lhs_inst_id);
// TODO: Type check lhs and rhs are same type.
// Push rhs again for chain == expressions.
context.node_stack().Push(rhs_node_id, rhs_inst_id);
context.args_type_info_stack().AddInstId(
AddInstInNoBlock<SemIR::ObserveEquivalent>(
context, node_id,
{.lhs_id = GetCanonicalFacetOrTypeValue(context, lhs_as_type.inst_id),
.rhs_id =
GetCanonicalFacetOrTypeValue(context, rhs_as_type.inst_id)}));
return true;
}
auto HandleParseNode(Context& context, Parse::ObserveImplsId node_id) -> bool {
auto [rhs_node_id, rhs_inst_id] = context.node_stack().PopExprWithNodeId();
auto [lhs_node_id, lhs_inst_id] = context.node_stack().PopExprWithNodeId();
if (context.node_stack().Peek<Parse::NodeKind::ObserveIntroducer>() ==
SemIR::ErrorInst::InstId) {
context.node_stack().Push(rhs_node_id, rhs_inst_id);
return true;
}
auto rhs_as_type = ExprAsType(context, rhs_node_id, rhs_inst_id);
auto lhs_as_type = ExprAsType(context, lhs_node_id, lhs_inst_id);
if (!context.types().IsFacetTypeOrError(rhs_as_type.type_id)) {
DiagnoseImplsOnNonFacetType(context, rhs_node_id);
auto [node_id, scope_inst_id] =
context.node_stack()
.PopWithNodeId<Parse::NodeKind::ObserveIntroducer>();
context.node_stack().Push(node_id, SemIR::ErrorInst::InstId);
}
// Dummy node for ObserveDeclId.
context.node_stack().Push(rhs_node_id, rhs_inst_id);
context.args_type_info_stack().AddInstId(
AddInstInNoBlock<SemIR::ObserveImpls>(
context, node_id,
{.lhs_id = GetCanonicalFacetOrTypeValue(context, lhs_as_type.inst_id),
.rhs_id =
GetCanonicalFacetOrTypeValue(context, rhs_as_type.inst_id)}));
return true;
}
auto HandleParseNode(Context& context, Parse::ObserveDeclId node_id) -> bool {
context.node_stack().PopAndIgnore();
auto scope_inst_id =
context.node_stack().Pop<Parse::NodeKind::ObserveIntroducer>();
auto operations_id = context.args_type_info_stack().Pop();
if (scope_inst_id == SemIR::ErrorInst::InstId) {
// We already diagnosed the errors.
return true;
}
auto observe_decl = SemIR::ObserveDecl{// To be filled in after.
.observe_id = SemIR::ObserveId::None};
auto decl_id = AddPlaceholderInst(context, node_id, observe_decl);
observe_decl.observe_id =
context.observes().Add({.decl_id = decl_id,
.operations_id = operations_id,
.enclosing_scope_inst_id = scope_inst_id});
ReplaceInstBeforeConstantUse(context, decl_id, observe_decl);
context.observe_stack().AppendToTop(observe_decl.observe_id);
return true;
}
} // namespace Carbon::Check