Files
carbon-lang/toolchain/check/handle_if_statement.cpp
T
josh11bandChandler Carruth 7edfd8e02a Rename SemIR::Node to SemIR::Inst (#3355)
And generally replace "node" by "inst" in the code and "instruction" in
comments.

---------

Co-authored-by: Chandler Carruth <chandlerc@gmail.com>
2023-11-02 17:58:30 +00:00

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2.7 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/convert.h"
#include "toolchain/sem_ir/inst.h"
namespace Carbon::Check {
auto HandleIfConditionStart(Context& /*context*/, Parse::Node /*parse_node*/)
-> bool {
return true;
}
auto HandleIfCondition(Context& context, Parse::Node parse_node) -> bool {
// Convert the condition to `bool`.
auto cond_value_id = context.node_stack().PopExpression();
cond_value_id = ConvertToBoolValue(context, parse_node, cond_value_id);
// Create the then block and the else block, and branch to the right one. If
// there is no `else`, the then block will terminate with a branch to the
// else block, which will be reused as the resumption block.
auto then_block_id =
context.AddDominatedBlockAndBranchIf(parse_node, cond_value_id);
auto else_block_id = context.AddDominatedBlockAndBranch(parse_node);
// Start emitting the `then` block.
context.inst_block_stack().Pop();
context.inst_block_stack().Push(then_block_id);
context.AddCurrentCodeBlockToFunction();
context.node_stack().Push(parse_node, else_block_id);
return true;
}
auto HandleIfStatementElse(Context& context, Parse::Node parse_node) -> bool {
auto else_block_id = context.node_stack().Pop<Parse::NodeKind::IfCondition>();
// Switch to emitting the `else` block.
context.inst_block_stack().Push(else_block_id);
context.AddCurrentCodeBlockToFunction();
context.node_stack().Push(parse_node);
return true;
}
auto HandleIfStatement(Context& context, Parse::Node parse_node) -> bool {
switch (auto kind = context.parse_tree().node_kind(
context.node_stack().PeekParseNode())) {
case Parse::NodeKind::IfCondition: {
// Branch from then block to else block, and start emitting the else
// block.
auto else_block_id =
context.node_stack().Pop<Parse::NodeKind::IfCondition>();
context.AddInst(SemIR::Branch{parse_node, else_block_id});
context.inst_block_stack().Pop();
context.inst_block_stack().Push(else_block_id);
break;
}
case Parse::NodeKind::IfStatementElse: {
// Branch from the then and else blocks to a new resumption block.
context.node_stack()
.PopAndDiscardSoloParseNode<Parse::NodeKind::IfStatementElse>();
context.AddConvergenceBlockAndPush(parse_node, /*num_blocks=*/2);
break;
}
default: {
CARBON_FATAL() << "Unexpected parse node at start of `if`: " << kind;
}
}
context.AddCurrentCodeBlockToFunction();
return true;
}
} // namespace Carbon::Check