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https://github.com/carbon-language/carbon-lang.git
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Richard Smith
44fca1669a
Previously, we created scopes for implicit parameter lists and tuple
patterns, but that meant that bindings went out of scope too soon. We
now keep them in scope until the end of the enclosing declaration. This
is accomplished by pushing a scope for parameters when we handle a name
that might have them, and then popping the scope again if it turns out
that there were no parameters.
For a case such as:
```carbon
fn A(T:! type).B(U:! type).F(x: T, y: U) {
var z: T;
}
```
... we now have the following scopes in the stack:
- A parameter scope containing `T`.
- A class scope for `A(T:! type)`.
- A parameter scope containing `U`.
- A class scope for `A(T:! type).B(U:! type)`.
- A parameter scope containing `x: T` and `y: U`.
- A function body scope containing `z: T`.
The innermost scope when check processes a declaration of a function,
class, or similar is now often a parameter scope rather than the
enclosing scope in which the class or function is declared, so the
target scope is now passed explicitly into the modifier checking code
that wants to inspect that enclosing scope.
103 lines
3.9 KiB
C++
103 lines
3.9 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/check/context.h"
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#include "toolchain/check/convert.h"
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#include "toolchain/check/modifiers.h"
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namespace Carbon::Check {
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auto HandleVariableIntroducer(Context& context,
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Parse::VariableIntroducerId parse_node) -> bool {
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// No action, just a bracketing node.
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context.node_stack().Push(parse_node);
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context.decl_state_stack().Push(DeclState::Var);
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return true;
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}
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auto HandleReturnedModifier(Context& context,
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Parse::ReturnedModifierId parse_node) -> bool {
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// No action, just a bracketing node.
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context.node_stack().Push(parse_node);
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return true;
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}
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auto HandleVariableInitializer(Context& context,
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Parse::VariableInitializerId parse_node)
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-> bool {
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SemIR::InstId init_id = context.node_stack().PopExpr();
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context.node_stack().Push(parse_node, init_id);
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return true;
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}
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auto HandleVariableDecl(Context& context, Parse::VariableDeclId parse_node)
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-> bool {
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// Handle the optional initializer.
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std::optional<SemIR::InstId> init_id =
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context.node_stack().PopIf<Parse::NodeKind::VariableInitializer>();
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if (context.node_stack().PeekIs<Parse::NodeKind::TuplePattern>()) {
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return context.TODO(parse_node, "tuple pattern in var");
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}
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// Extract the name binding.
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auto value_id = context.node_stack().PopPattern();
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if (auto bind_name = context.insts().TryGetAs<SemIR::AnyBindName>(value_id)) {
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// Form a corresponding name in the current context, and bind the name to
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// the variable.
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auto name_context = context.decl_name_stack().MakeUnqualifiedName(
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context.insts().GetParseNode(value_id),
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context.bind_names().Get(bind_name->bind_name_id).name_id);
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context.decl_name_stack().AddNameToLookup(name_context, value_id);
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value_id = bind_name->value_id;
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} else if (auto field_decl =
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context.insts().TryGetAs<SemIR::FieldDecl>(value_id)) {
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// Introduce the field name into the class.
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auto name_context = context.decl_name_stack().MakeUnqualifiedName(
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context.insts().GetParseNode(value_id), field_decl->name_id);
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context.decl_name_stack().AddNameToLookup(name_context, value_id);
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}
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// TODO: Handle other kinds of pattern.
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// Pop the `returned` specifier if present.
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context.node_stack()
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.PopAndDiscardSoloParseNodeIf<Parse::NodeKind::ReturnedModifier>();
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// If there was an initializer, assign it to the storage.
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if (init_id.has_value()) {
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if (context.GetCurrentScopeAs<SemIR::ClassDecl>()) {
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// TODO: In a class scope, we should instead save the initializer
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// somewhere so that we can use it as a default.
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context.TODO(parse_node, "Field initializer");
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} else {
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init_id = Initialize(context, parse_node, value_id, *init_id);
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// TODO: Consider using different instruction kinds for assignment versus
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// initialization.
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context.AddInst({parse_node, SemIR::Assign{value_id, *init_id}});
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}
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}
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context.node_stack()
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.PopAndDiscardSoloParseNode<Parse::NodeKind::VariableIntroducer>();
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// Process declaration modifiers.
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// TODO: For a qualified `var` declaration, this should use the target scope
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// of the name introduced in the declaration. See #2590.
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CheckAccessModifiersOnDecl(context, Lex::TokenKind::Var,
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context.current_scope_id());
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LimitModifiersOnDecl(context, KeywordModifierSet::Access,
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Lex::TokenKind::Var);
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auto modifiers = context.decl_state_stack().innermost().modifier_set;
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if (!!(modifiers & KeywordModifierSet::Access)) {
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context.TODO(context.decl_state_stack().innermost().saw_access_modifier,
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"access modifier");
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}
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context.decl_state_stack().Pop(DeclState::Var);
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return true;
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}
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} // namespace Carbon::Check
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