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Jon Ross-Perkins
43065a1257
This adds a distinction between Unused and SoloParseNode, rather than equating the two. This is intended to help identify nodes which are getting pushed but maybe don't need to be. Not totally done because I want to adjust declaration name handling due to a quirk with how it mixes Name with Expression, but almost done. Once that's done the type punning will be completely gone.
65 lines
2.5 KiB
C++
65 lines
2.5 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 SemanticsHandleIfExpressionIf(SemanticsContext& context,
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ParseTree::Node if_node) -> bool {
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auto cond_value_id = context.node_stack().PopExpression();
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context.node_stack().Push(if_node);
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// Convert the condition to `bool`, and branch on it.
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cond_value_id = context.ImplicitAsBool(if_node, cond_value_id);
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auto then_block_id =
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context.AddDominatedBlockAndBranchIf(if_node, cond_value_id);
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auto else_block_id = context.AddDominatedBlockAndBranch(if_node);
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// Push the `else` block and `then` block, and start emitting the `then`.
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context.node_block_stack().Pop();
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context.node_block_stack().Push(else_block_id);
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context.node_block_stack().Push(then_block_id);
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context.AddCurrentCodeBlockToFunction();
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return true;
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}
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auto SemanticsHandleIfExpressionThen(SemanticsContext& context,
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ParseTree::Node then_node) -> bool {
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context.node_stack().Push(then_node, context.node_block_stack().Pop());
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context.AddCurrentCodeBlockToFunction();
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return true;
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}
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auto SemanticsHandleIfExpressionElse(SemanticsContext& context,
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ParseTree::Node else_node) -> bool {
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auto else_value_id = context.node_stack().PopExpression();
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auto [then_node, then_end_block_id] =
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context.node_stack().PopWithParseNode<ParseNodeKind::IfExpressionThen>();
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auto then_value_id = context.node_stack().PopExpression();
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auto if_node =
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context.node_stack().PopForSoloParseNode<ParseNodeKind::IfExpressionIf>();
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// Convert the `else` value to the `then` value's type, and finish the `else`
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// block.
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// TODO: Find a common type, and convert both operands to it instead.
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auto result_type_id = context.semantics_ir().GetNode(then_value_id).type_id();
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else_value_id =
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context.ImplicitAsRequired(else_node, else_value_id, result_type_id);
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auto else_end_block_id = context.node_block_stack().Pop();
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// Create a resumption block and branches to it.
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auto chosen_value_id = context.AddConvergenceBlockWithArgAndPush(
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if_node,
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{{then_end_block_id, then_value_id}, {else_end_block_id, else_value_id}});
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context.AddCurrentCodeBlockToFunction();
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// Push the result value.
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context.node_stack().Push(else_node, chosen_value_id);
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return true;
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}
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} // namespace Carbon
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