mirror of
https://github.com/carbon-language/carbon-lang.git
synced 2026-09-25 10:20:12 +01:00
Richard Smith
4b69264cb1
Add validation that every code block in a function is terminated by a sequence of terminating instructions, and that terminators don't appear anywhere else in code blocks. This required tracking whether we're in a reachable code block. That's done on the fly when we create a new code block; the new `SemanticsNodeBlockId::Unreachable` is used to represent the case where we're not actually creating a code block because we're in unreachable code.
95 lines
3.5 KiB
C++
95 lines
3.5 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/semantics/semantics_context.h"
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namespace Carbon {
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auto SemanticsHandleFunctionDeclaration(SemanticsContext& context,
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ParseTree::Node parse_node) -> bool {
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return context.TODO(parse_node, "HandleFunctionDeclaration");
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}
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auto SemanticsHandleFunctionDefinition(SemanticsContext& context,
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ParseTree::Node parse_node) -> bool {
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auto function_id = context.node_stack().Pop<SemanticsFunctionId>(
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ParseNodeKind::FunctionDefinitionStart);
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// If the `}` of the function is reachable, reject if we need a return value
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// and otherwise add an implicit `return;`.
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if (context.is_current_position_reachable()) {
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if (context.semantics_ir()
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.GetFunction(function_id)
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.return_type_id.is_valid()) {
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CARBON_DIAGNOSTIC(
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MissingReturnStatement, Error,
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"Missing `return` at end of function with declared return type.");
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context.emitter().Emit(parse_node, MissingReturnStatement);
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} else {
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context.AddNode(SemanticsNode::Return::Make(parse_node));
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}
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}
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context.return_scope_stack().pop_back();
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context.PopScope();
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context.node_block_stack().Pop();
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return true;
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}
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auto SemanticsHandleFunctionDefinitionStart(SemanticsContext& context,
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ParseTree::Node parse_node)
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-> bool {
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SemanticsTypeId return_type_id = SemanticsTypeId::Invalid;
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if (context.parse_tree().node_kind(context.node_stack().PeekParseNode()) ==
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ParseNodeKind::ReturnType) {
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return_type_id =
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context.node_stack().Pop<SemanticsTypeId>(ParseNodeKind::ReturnType);
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} else {
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// Canonicalize the empty tuple for the implicit return.
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context.CanonicalizeType(SemanticsNodeId::BuiltinEmptyTupleType);
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}
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auto param_refs_id = context.node_stack().Pop<SemanticsNodeBlockId>(
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ParseNodeKind::ParameterList);
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auto [name_node, name_id] =
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context.node_stack().PopWithParseNode<SemanticsStringId>(
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ParseNodeKind::Identifier);
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auto fn_node = context.node_stack().PopForSoloParseNode(
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ParseNodeKind::FunctionIntroducer);
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// Create the entry block.
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auto outer_block = context.node_block_stack().PeekForAdd();
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context.node_block_stack().Push();
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// Add the callable.
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auto function_id = context.semantics_ir().AddFunction(
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{.name_id = name_id,
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.param_refs_id = param_refs_id,
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.return_type_id = return_type_id,
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.body_block_ids = {context.node_block_stack().PeekForAdd()}});
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auto decl_id = context.AddNodeToBlock(
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outer_block,
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SemanticsNode::FunctionDeclaration::Make(fn_node, function_id));
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context.AddNameToLookup(name_node, name_id, decl_id);
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context.PushScope();
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for (auto ref_id : context.semantics_ir().GetNodeBlock(param_refs_id)) {
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auto ref = context.semantics_ir().GetNode(ref_id);
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auto [name_id, target_id] = ref.GetAsBindName();
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context.AddNameToLookup(ref.parse_node(), name_id, target_id);
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}
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context.return_scope_stack().push_back(decl_id);
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context.node_stack().Push(parse_node, function_id);
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return true;
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}
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auto SemanticsHandleFunctionIntroducer(SemanticsContext& context,
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ParseTree::Node 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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} // namespace Carbon
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