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Remove lldb support for Swift "MPE descriptors" #8967

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Remove lldb support for Swift "MPE descriptors" #8967

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7 changes: 0 additions & 7 deletions lldb/source/Plugins/LanguageRuntime/Swift/ReflectionContext.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -44,13 +44,6 @@ struct DescriptorFinderForwarder : public swift::reflection::DescriptorFinder {
return nullptr;
}

std::unique_ptr<swift::reflection::MultiPayloadEnumDescriptorBase>
getMultiPayloadEnumDescriptor(const swift::reflection::TypeRef *TR) override {
if (!m_descriptor_finders.empty() && shouldConsultDescriptorFinder())
return m_descriptor_finders.back()->getMultiPayloadEnumDescriptor(TR);
return nullptr;
}

void PushExternalDescriptorFinder(
swift::reflection::DescriptorFinder *descriptor_finder) {
m_descriptor_finders.push_back(descriptor_finder);
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4 changes: 0 additions & 4 deletions lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParserSwift.h
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Expand Up @@ -89,10 +89,6 @@ class DWARFASTParserSwift : public lldb_private::plugin::dwarf::DWARFASTParser,
std::unique_ptr<swift::reflection::BuiltinTypeDescriptorBase>
getBuiltinTypeDescriptor(const swift::reflection::TypeRef *TR) override;

/// Returns a builtin descriptor constructed from DWARF info.
std::unique_ptr<swift::reflection::MultiPayloadEnumDescriptorBase>
getMultiPayloadEnumDescriptor(const swift::reflection::TypeRef *TR) override;

private:
/// Returns the canonical demangle tree of a die's type.
NodePointer GetCanonicalDemangleTree(DWARFDIE &die);
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125 changes: 0 additions & 125 deletions lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParserSwiftDescriptorFinder.cpp
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Expand Up @@ -281,52 +281,6 @@ class DWARFFieldDescriptorImpl : public swift::reflection::FieldDescriptorBase {
}
};

class DWARFMultiPayloadEnumDescriptorImpl
: public swift::reflection::MultiPayloadEnumDescriptorBase {
ConstString m_mangled_name;
DIERef m_die_ref;
std::vector<uint8_t> m_spare_bits_mask;
uint64_t m_byte_offset;

public:
~DWARFMultiPayloadEnumDescriptorImpl() override = default;

DWARFMultiPayloadEnumDescriptorImpl(ConstString mangled_name, DIERef die_ref,
std::vector<uint8_t> &&spare_bits_mask,
uint64_t byte_offset)
: swift::reflection::MultiPayloadEnumDescriptorBase(),
m_mangled_name(mangled_name), m_die_ref(die_ref),
m_spare_bits_mask(std::move(spare_bits_mask)),
m_byte_offset(byte_offset) {}

llvm::StringRef getMangledTypeName() override {
return m_mangled_name.GetStringRef();
}

uint32_t getContentsSizeInWords() const override {
return m_spare_bits_mask.size() / 4;
}

size_t getSizeInBytes() const override { return m_spare_bits_mask.size(); }

uint32_t getFlags() const override { return usesPayloadSpareBits(); }

bool usesPayloadSpareBits() const override {
return !m_spare_bits_mask.empty();
}

uint32_t getPayloadSpareBitMaskByteOffset() const override {
return m_byte_offset;
}

uint32_t getPayloadSpareBitMaskByteCount() const override {
return getSizeInBytes();
}

const uint8_t *getPayloadSpareBits() const override {
return m_spare_bits_mask.data();
}
};
} // namespace

/// Constructs a builtin type descriptor from DWARF information.
Expand Down Expand Up @@ -374,85 +328,6 @@ DWARFASTParserSwift::getBuiltinTypeDescriptor(
type.GetMangledTypeName());
}

std::unique_ptr<swift::reflection::MultiPayloadEnumDescriptorBase>
DWARFASTParserSwift::getMultiPayloadEnumDescriptor(
const swift::reflection::TypeRef *TR) {
assert(ModuleList::GetGlobalModuleListProperties()
.GetSwiftEnableFullDwarfDebugging() !=
lldb_private::AutoBool::False &&
"Full DWARF debugging for Swift is disabled!");

auto pair = getTypeAndDie(m_swift_typesystem, TR);
if (!pair)
return nullptr;

auto [type, die] = *pair;
if (!die)
return nullptr;

auto kind = getFieldDescriptorKindForDie(type);
if (!kind)
return nullptr;

auto child_die = die.GetFirstChild();
auto bit_offset =
child_die.GetAttributeValueAsUnsigned(llvm::dwarf::DW_AT_bit_offset, 0);

auto byte_offset = (bit_offset + 7) / 8;

const auto &attributes = child_die.GetAttributes();
auto spare_bits_mask_idx =
attributes.FindAttributeIndex(llvm::dwarf::DW_AT_APPLE_spare_bits_mask);
if (spare_bits_mask_idx == UINT32_MAX)
return nullptr;

DWARFFormValue form_value;
attributes.ExtractFormValueAtIndex(spare_bits_mask_idx, form_value);

if (!form_value.IsValid()) {
if (auto *log = GetLog(LLDBLog::Types)) {
std::stringstream ss;
TR->dump(ss);
LLDB_LOG(log,
"Could not produce MultiPayloadEnumTypeInfo for typeref: {0}",
ss.str());
}
return nullptr;
}
// If there's a block data, this is a number bigger than 64 bits already
// encoded as an array.
if (form_value.BlockData()) {
uint64_t block_length = form_value.Unsigned();
std::vector<uint8_t> bytes(form_value.BlockData(),
form_value.BlockData() + block_length);
return std::make_unique<DWARFMultiPayloadEnumDescriptorImpl>(
type.GetMangledTypeName(), *die.GetDIERef(),
std::move(bytes), byte_offset);
}

// If there is no block data, the spare bits mask is encoded as a single 64
// bit number. Convert this to a byte array with only the amount of bytes
// necessary to cover the whole number (see
// MultiPayloadEnumDescriptorBuilder::layout on GenReflection.cpp for a
// similar calculation when emitting this into metadata).
llvm::APInt bits(64, form_value.Unsigned());
auto bitsInMask = bits.getActiveBits();
uint32_t bytesInMask = (bitsInMask + 7) / 8;
auto wordsInMask = (bytesInMask + 3) / 4;
bits = bits.zextOrTrunc(wordsInMask * 32);

std::vector<uint8_t> bytes;
for (size_t i = 0; i < bytesInMask; ++i) {
uint8_t byte = bits.extractBitsAsZExtValue(8, 0);
bytes.push_back(byte);
bits.lshrInPlace(8);
}

return std::make_unique<DWARFMultiPayloadEnumDescriptorImpl>(
type.GetMangledTypeName(), *die.GetDIERef(), std::move(bytes),
byte_offset);
}

namespace {
DWARFDIE FindSuperClassDIE(DWARFDIE &die) {
const auto inheritance_die_it =
Expand Down