Files
carbon-lang/toolchain/semantics/semantics_handle_if_statement.cpp
T
Jon Ross-Perkins 67da700dd5 Split Semantics into Check and SemIR namespaces (#3138)
Splits IR files into SemIR, and logic files into Check. These will be
split into separate directories as part of a later move; the namespaces
are being done first in order to vet the switch, and hopefully make
conflicts a little easier to manage due to the substantial renames.

A lot of this is just automated removal of Semantics prefixes from
names, adding namespace references where needed. A few special-cases
are:

- SemanticsIR -> SemIR::File
- A few things were discussed, like Unit, CompileUnit, or CompiledUnit.
Unit was too vague for chandlerc, and I thought CompileUnit might lead
to incorrect inferences (CompilationUnit would be more precise, but
typically written as SemIR::CompilationUnit which is pretty long). File
seemed to be a short name that we could agree on.
- SemanticsIRFormatter -> SemIR::Formatter
- FormatSemanticsIR -> SemIR::FormatFile
- SemanticsFileTest -> CheckFileTest
- It remains in the Testing namespace, where just "FileTest" might be
too broad a name.
- SemanticsDeclarationNameStack::Context ->
Check::DeclarationNameStack::NameContext
  - This avoids a Check::Context name shadowing.

Changes check_internal.h to include ostream.h to improve finding of
Print/operator<< (otherwise it didn't compile).

This is part of #3070
2023-08-23 22:51:23 +00:00

85 lines
3.0 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/semantics/semantics_context.h"
#include "toolchain/semantics/semantics_node.h"
namespace Carbon::Check {
auto HandleIfConditionStart(Context& /*context*/,
ParseTree::Node /*parse_node*/) -> bool {
return true;
}
auto HandleIfCondition(Context& context, ParseTree::Node parse_node) -> bool {
// Convert the condition to `bool`.
auto cond_value_id = context.node_stack().PopExpression();
cond_value_id = context.ImplicitAsBool(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);
// Push the else and then blocks, and start emitting code in the then block.
context.node_block_stack().Pop();
context.node_block_stack().Push(else_block_id);
context.node_block_stack().Push(then_block_id);
context.AddCurrentCodeBlockToFunction();
context.node_stack().Push(parse_node);
return true;
}
auto HandleIfStatementElse(Context& context, ParseTree::Node parse_node)
-> bool {
context.node_stack().PopAndDiscardSoloParseNode<ParseNodeKind::IfCondition>();
// Switch to emitting the else block.
auto then_block_id = context.node_block_stack().PopForAdd();
context.node_stack().Push(parse_node, then_block_id);
context.AddCurrentCodeBlockToFunction();
return true;
}
auto HandleIfStatement(Context& context, ParseTree::Node parse_node) -> bool {
// Either the then or else block, depending on whether there's an `else` node
// on the top of the node stack.
auto sub_block_id = context.node_block_stack().PopForAdd();
switch (auto kind = context.parse_tree().node_kind(
context.node_stack().PeekParseNode())) {
case ParseNodeKind::IfCondition: {
// Branch from then block to else block.
context.node_stack()
.PopAndDiscardSoloParseNode<ParseNodeKind::IfCondition>();
context.AddNodeToBlock(
sub_block_id,
SemIR::Node::Branch::Make(parse_node,
context.node_block_stack().PeekForAdd()));
break;
}
case ParseNodeKind::IfStatementElse: {
// Branch from the then and else blocks to a new resumption block.
SemIR::NodeBlockId then_block_id =
context.node_stack().Pop<ParseNodeKind::IfStatementElse>();
context.AddConvergenceBlockAndPush(parse_node,
{then_block_id, sub_block_id});
break;
}
default: {
CARBON_FATAL() << "Unexpected parse node at start of `if`: " << kind;
}
}
context.AddCurrentCodeBlockToFunction();
return true;
}
} // namespace Carbon::Check