Files
carbon-lang/toolchain/check/handle_alias.cpp
T
Jon Ross-Perkins e62973a8ef Address the LocIdAndInst::ReusingLoc TODO (#4211)
The TODO for switching to ReusingLoc (previously Untyped) had been there
for a while, so I'm trying to address it here. The intent had been to be
clearer about when the construction is validated, particularly so that
we aren't accidentally accepting an incorrect NodeId. Note, this does
fix an incorrect use of InvalidNodeId where NoLoc should've been called.

Since this changes the semantics of when `Parse::NodeId` is helpful in
`typed_nodes.h`, I'm doing a pass to either refine or switch to
`Parse::InvalidNodeId` where it compiles. I think most remaining
`Parse::NodeId` examples are things we _should_ be able to refine with a
little more work (versus before where `Parse::NodeId` also indicated
`LocId` construction might be used).

I'm also changing context.h to use `requires` that match what
`LocIdAndInst` has, I think it makes the diagnostics a little better.
And note I do add an overload for `ImportIRInstId`, also matching
`LocIdAndInst`, and widely used for import refs.
2024-08-13 18:52:24 +00:00

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3.0 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 "toolchain/check/context.h"
#include "toolchain/check/handle.h"
#include "toolchain/check/modifiers.h"
#include "toolchain/check/name_component.h"
#include "toolchain/parse/node_ids.h"
#include "toolchain/sem_ir/ids.h"
#include "toolchain/sem_ir/typed_insts.h"
namespace Carbon::Check {
auto HandleParseNode(Context& context, Parse::AliasIntroducerId /*node_id*/)
-> bool {
context.decl_introducer_state_stack().Push<Lex::TokenKind::Alias>();
context.decl_name_stack().PushScopeAndStartName();
return true;
}
auto HandleParseNode(Context& /*context*/,
Parse::AliasInitializerId /*node_id*/) -> bool {
return true;
}
auto HandleParseNode(Context& context, Parse::AliasId /*node_id*/) -> bool {
auto [expr_node, expr_id] = context.node_stack().PopExprWithNodeId();
auto name_context = context.decl_name_stack().FinishName(
PopNameComponentWithoutParams(context, Lex::TokenKind::Alias));
auto introducer =
context.decl_introducer_state_stack().Pop<Lex::TokenKind::Alias>();
LimitModifiersOnDecl(context, introducer, KeywordModifierSet::Access);
auto entity_name_id = context.entity_names().Add(
{.name_id = name_context.name_id_for_new_inst(),
.parent_scope_id = name_context.parent_scope_id_for_new_inst(),
.bind_index = SemIR::CompileTimeBindIndex::Invalid});
auto alias_type_id = SemIR::TypeId::Invalid;
auto alias_value_id = SemIR::InstId::Invalid;
if (expr_id.is_builtin()) {
// Type (`bool`) and value (`false`) literals provided by the builtin
// structure should be turned into name references.
// TODO: Look into handling `false`, this doesn't do it right now because it
// sees a value instruction instead of a builtin.
alias_type_id = context.insts().Get(expr_id).type_id();
alias_value_id = expr_id;
} else if (auto inst = context.insts().TryGetAs<SemIR::NameRef>(expr_id)) {
// Pass through name references, albeit changing the name in use.
alias_type_id = inst->type_id;
alias_value_id = inst->value_id;
} else {
CARBON_DIAGNOSTIC(AliasRequiresNameRef, Error,
"Alias initializer must be a name reference.");
context.emitter().Emit(expr_node, AliasRequiresNameRef);
alias_type_id = SemIR::TypeId::Error;
alias_value_id = SemIR::InstId::BuiltinError;
}
auto alias_id = context.AddInstReusingLoc<SemIR::BindAlias>(
name_context.loc_id, {.type_id = alias_type_id,
.entity_name_id = entity_name_id,
.value_id = alias_value_id});
// Add the name of the binding to the current scope.
context.decl_name_stack().PopScope();
context.decl_name_stack().AddNameOrDiagnoseDuplicate(
name_context, alias_id, introducer.modifier_set.GetAccessKind());
return true;
}
} // namespace Carbon::Check