mirror of
https://github.com/carbon-language/carbon-lang.git
synced 2026-09-24 22:02:23 +01:00
Richard Smith
b44ba47cf3
Add `Dependent` value and initializing representations for types whose representations are unknown because they are dependent. When generating SemIR in such cases, use a worst-case initializing representation that both provides a destination address and also propagates a potential result value. Use this to fix incorrect lowering and lowering crashes for specific functions involving generic types that don't use a copy value representation. In lowering, be careful to distinguish between whether the initializing representation for the generic return type uses a return slot (which affects whether the SemIR declaration and call have one) and whether the initializing representation for the specific return type uses a return slot (which affects whether the LLVM IR declaration and call have one).
115 lines
4.4 KiB
C++
115 lines
4.4 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/lower/function_context.h"
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#include "toolchain/sem_ir/expr_info.h"
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#include "toolchain/sem_ir/file.h"
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namespace Carbon::Lower {
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auto HandleInst(FunctionContext& context, SemIR::InstId inst_id,
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SemIR::BindValue inst) -> void {
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auto inst_type = context.GetTypeIdOfInst(inst_id);
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switch (context.GetValueRepr(inst_type).repr.kind) {
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case SemIR::ValueRepr::Unknown:
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CARBON_FATAL(
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"Value binding for type with incomplete value representation");
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case SemIR::ValueRepr::Dependent:
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CARBON_FATAL(
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"Value binding for type with dependent value representation");
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case SemIR::ValueRepr::None:
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// Nothing should use this value, but StubRef needs a value to
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// propagate.
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// TODO: Remove this now the StubRefs are gone.
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context.SetLocal(inst_id,
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llvm::PoisonValue::get(context.GetType(inst_type)));
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break;
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case SemIR::ValueRepr::Copy:
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context.SetLocal(
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inst_id,
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context.LoadObject(inst_type, context.GetValue(inst.value_id)));
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break;
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case SemIR::ValueRepr::Pointer:
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context.SetLocal(inst_id, context.GetValue(inst.value_id));
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break;
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case SemIR::ValueRepr::Custom:
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CARBON_FATAL("TODO: Add support for BindValue with custom value rep");
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}
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}
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auto HandleInst(FunctionContext& context, SemIR::InstId inst_id,
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SemIR::InPlaceInit inst) -> void {
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auto type = context.GetTypeIdOfInst(inst_id);
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auto* value = context.GetValue(inst.dest_id);
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// If the initializing representation is by-value, and the value
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// representation is by-copy, then we need to load from the storage. Otherwise
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// we want a pointer to the result.
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switch (context.GetInitRepr(type).kind) {
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case SemIR::InitRepr::None:
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case SemIR::InitRepr::InPlace:
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break;
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case SemIR::InitRepr::ByCopy:
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switch (context.GetValueRepr(type).repr.kind) {
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case SemIR::ValueRepr::Unknown:
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CARBON_FATAL("Unexpected incomplete type");
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case SemIR::ValueRepr::Dependent:
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CARBON_FATAL("Unexpected dependent type");
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case SemIR::ValueRepr::None:
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case SemIR::ValueRepr::Pointer:
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break;
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case SemIR::ValueRepr::Copy:
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value = context.builder().CreateLoad(context.GetType(type), value);
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break;
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case SemIR::ValueRepr::Custom:
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CARBON_FATAL(
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"TODO: Add support for InPlaceInit with custom value rep");
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}
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break;
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case SemIR::InitRepr::Incomplete:
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CARBON_FATAL("Unexpected incomplete type");
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case SemIR::InitRepr::Dependent:
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CARBON_FATAL("Unexpected dependent type");
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}
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context.SetLocal(inst_id, value);
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}
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auto HandleInst(FunctionContext& context, SemIR::InstId inst_id,
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SemIR::Temporary inst) -> void {
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context.FinishInit(context.GetTypeIdOfInst(inst_id), inst.storage_id,
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inst.init_id);
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context.SetLocal(inst_id, context.GetValue(inst.storage_id));
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}
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auto HandleInst(FunctionContext& context, SemIR::InstId inst_id,
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SemIR::TemporaryStorage /*inst*/) -> void {
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context.SetLocal(
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inst_id, context.CreateAlloca(context.GetTypeOfInst(inst_id), "temp"));
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}
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auto HandleInst(FunctionContext& context, SemIR::InstId inst_id,
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SemIR::ValueAsRef inst) -> void {
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CARBON_CHECK(SemIR::GetExprCategory(context.sem_ir(), inst.value_id) ==
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SemIR::ExprCategory::Value);
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auto inst_type = context.GetTypeIdOfInst(inst_id);
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auto value_repr = context.GetValueRepr(inst_type);
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CARBON_CHECK(value_repr.repr.kind == SemIR::ValueRepr::Pointer);
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context.SetLocal(inst_id, context.GetValue(inst.value_id));
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}
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auto HandleInst(FunctionContext& context, SemIR::InstId inst_id,
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SemIR::ValueOfInitializer inst) -> void {
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CARBON_CHECK(SemIR::GetExprCategory(context.sem_ir(), inst.init_id) ==
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SemIR::ExprCategory::Initializing);
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auto inst_type = context.GetTypeIdOfInst(inst_id);
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auto value_repr = context.GetValueRepr(inst_type);
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auto init_repr = context.GetInitRepr(inst_type);
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CARBON_CHECK(value_repr.repr.kind == SemIR::ValueRepr::Copy);
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CARBON_CHECK(init_repr.kind == SemIR::InitRepr::ByCopy);
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context.SetLocal(inst_id, context.GetValue(inst.init_id));
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}
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} // namespace Carbon::Lower
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