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https://github.com/carbon-language/carbon-lang.git
synced 2026-09-25 22:02:28 +01:00
Richard Smith
74d52738ff
A `let` declaration is represented by a `bind_name` node in SemIR: ```carbon-semir %b: i32 = bind_name "b", %a ``` Because `Check` encounters the pattern before it sees the value, we first create the `bind_name` node with an unset value and don't add it to the block. Then, once we've seen and converted the initializer, we update the `bind_name` to have the value and add it to the current block, after the initializer code.
72 lines
2.2 KiB
C++
72 lines
2.2 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/parse/context.h"
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namespace Carbon::Parse {
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// Handles an unrecognized declaration, adding an error node.
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static auto HandleUnrecognizedDeclaration(Context& context) -> void {
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CARBON_DIAGNOSTIC(UnrecognizedDeclaration, Error,
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"Unrecognized declaration introducer.");
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context.emitter().Emit(*context.position(), UnrecognizedDeclaration);
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auto cursor = *context.position();
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auto semi = context.SkipPastLikelyEnd(cursor);
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// Locate the EmptyDeclaration at the semi when found, but use the
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// original cursor location for an error when not.
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context.AddLeafNode(NodeKind::EmptyDeclaration, semi ? *semi : cursor,
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/*has_error=*/true);
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}
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auto HandleDeclarationScopeLoop(Context& context) -> void {
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// This maintains the current state unless we're at the end of the scope.
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switch (context.PositionKind()) {
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case Lex::TokenKind::CloseCurlyBrace:
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case Lex::TokenKind::EndOfFile: {
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// This is the end of the scope, so the loop state ends.
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context.PopAndDiscardState();
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break;
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}
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case Lex::TokenKind::Class: {
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context.PushState(State::TypeIntroducerAsClass);
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break;
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}
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case Lex::TokenKind::Constraint: {
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context.PushState(State::TypeIntroducerAsNamedConstraint);
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break;
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}
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case Lex::TokenKind::Fn: {
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context.PushState(State::FunctionIntroducer);
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break;
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}
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case Lex::TokenKind::Interface: {
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context.PushState(State::TypeIntroducerAsInterface);
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break;
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}
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case Lex::TokenKind::Namespace: {
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context.PushState(State::Namespace);
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break;
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}
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case Lex::TokenKind::Semi: {
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context.AddLeafNode(NodeKind::EmptyDeclaration, context.Consume());
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break;
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}
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case Lex::TokenKind::Var: {
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context.PushState(State::VarAsSemicolon);
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break;
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}
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case Lex::TokenKind::Let: {
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context.PushState(State::Let);
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break;
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}
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default: {
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HandleUnrecognizedDeclaration(context);
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break;
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}
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}
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}
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} // namespace Carbon::Parse
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