mirror of
https://github.com/carbon-language/carbon-lang.git
synced 2026-09-24 22:02:23 +01:00
Jon Ross-Perkins
4923445e3a
We frequently want to operate on singletons. Per discussion, drop `Singleton` to make the code shorter. This started off as wanting to write `inst_id.is_error()`, but the dependency relationship between ids.h and singleton_insts.h would require some kind of delayed evaluation to allow the implementation to remain in headers (which I suspect is helpful to have for inlining). I could have added something like `IsErrorInst`, forward declared in ids.h and defined in singleton_insts.h (which would always be included by typed_insts.h), but the template approach felt like a decent balance between (a) removing the boilerplate `::SingletonInstId`, (b) understandability, (c) still visually mirroring if we immediately return a singleton, and (d) flexibility for more than just `ErrorInst`. But TBH I'd probably still have written `is_error()` if it didn't require addressing the cross-header cycle. Then I tried `SemIR::InstId::Is<SemIR::ErrorInst>`, which generally worked with types but generated the complaint that it didn't shorten *all* singleton uses. So pulling back on `::Is`, and instead just dropping `Singleton`.
100 lines
3.8 KiB
C++
100 lines
3.8 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/control_flow.h"
|
|
#include "toolchain/check/convert.h"
|
|
#include "toolchain/check/handle.h"
|
|
#include "toolchain/check/literal.h"
|
|
|
|
namespace Carbon::Check {
|
|
|
|
auto HandleParseNode(Context& context, Parse::IfExprIfId node_id) -> bool {
|
|
// Alias node_id for if/then/else consistency.
|
|
auto& if_node = node_id;
|
|
|
|
auto [cond_node, cond_value_id] = context.node_stack().PopExprWithNodeId();
|
|
|
|
// Convert the condition to `bool`, and branch on it.
|
|
cond_value_id = ConvertToBoolValue(context, if_node, cond_value_id);
|
|
context.node_stack().Push(cond_node, cond_value_id);
|
|
auto then_block_id =
|
|
AddDominatedBlockAndBranchIf(context, if_node, cond_value_id);
|
|
auto else_block_id = AddDominatedBlockAndBranch(context, if_node);
|
|
|
|
// Start emitting the `then` block.
|
|
context.inst_block_stack().Pop();
|
|
context.inst_block_stack().Push(then_block_id);
|
|
context.region_stack().AddToRegion(then_block_id, node_id);
|
|
|
|
context.node_stack().Push(if_node, else_block_id);
|
|
return true;
|
|
}
|
|
|
|
// If the operand is an `IntLiteral`, convert it to a suitably-sized `Int` type.
|
|
// TODO: For now we always pick `i32`.
|
|
static auto DecayIntLiteralToSizedInt(Context& context, Parse::NodeId node_id,
|
|
SemIR::InstId operand_id)
|
|
-> SemIR::InstId {
|
|
if (context.types().GetInstId(context.insts().Get(operand_id).type_id()) ==
|
|
SemIR::IntLiteralType::InstId) {
|
|
operand_id = ConvertToValueOfType(
|
|
context, node_id, operand_id,
|
|
MakeIntType(context, node_id, SemIR::IntKind::Signed,
|
|
context.ints().Add(32)));
|
|
}
|
|
return operand_id;
|
|
}
|
|
|
|
auto HandleParseNode(Context& context, Parse::IfExprThenId node_id) -> bool {
|
|
auto then_value_id = context.node_stack().PopExpr();
|
|
auto else_block_id = context.node_stack().Peek<Parse::NodeKind::IfExprIf>();
|
|
|
|
// Convert the first operand to a value.
|
|
then_value_id = ConvertToValueExpr(context, then_value_id);
|
|
then_value_id = DecayIntLiteralToSizedInt(context, node_id, then_value_id);
|
|
|
|
// Start emitting the `else` block.
|
|
context.inst_block_stack().Push(else_block_id);
|
|
context.region_stack().AddToRegion(else_block_id, node_id);
|
|
|
|
context.node_stack().Push(node_id, then_value_id);
|
|
return true;
|
|
}
|
|
|
|
auto HandleParseNode(Context& context, Parse::IfExprElseId node_id) -> bool {
|
|
if (context.return_scope_stack().empty()) {
|
|
context.TODO(node_id,
|
|
"Control flow expressions are currently only supported inside "
|
|
"functions.");
|
|
}
|
|
// Alias node_id for if/then/else consistency.
|
|
auto& else_node = node_id;
|
|
|
|
auto else_value_id = context.node_stack().PopExpr();
|
|
auto then_value_id = context.node_stack().Pop<Parse::NodeKind::IfExprThen>();
|
|
auto [if_node, _] =
|
|
context.node_stack().PopWithNodeId<Parse::NodeKind::IfExprIf>();
|
|
auto cond_value_id = context.node_stack().PopExpr();
|
|
|
|
// Convert the `else` value to the `then` value's type, and finish the `else`
|
|
// block.
|
|
// TODO: Find a common type, and convert both operands to it instead.
|
|
auto result_type_id = context.insts().Get(then_value_id).type_id();
|
|
else_value_id =
|
|
ConvertToValueOfType(context, else_node, else_value_id, result_type_id);
|
|
|
|
// Create a resumption block and branches to it.
|
|
auto chosen_value_id = AddConvergenceBlockWithArgAndPush(
|
|
context, if_node, {else_value_id, then_value_id});
|
|
SetBlockArgResultBeforeConstantUse(context, chosen_value_id, cond_value_id,
|
|
then_value_id, else_value_id);
|
|
|
|
// Push the result value.
|
|
context.node_stack().Push(else_node, chosen_value_id);
|
|
return true;
|
|
}
|
|
|
|
} // namespace Carbon::Check
|