You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.

121 lines
4.1 KiB

//===-- LibCxxBitset.cpp --------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "LibCxx.h"
#include "Plugins/TypeSystem/Clang/TypeSystemClang.h"
#include "lldb/DataFormatters/FormattersHelpers.h"
#include "lldb/Target/Target.h"
using namespace lldb;
using namespace lldb_private;
namespace {
class BitsetFrontEnd : public SyntheticChildrenFrontEnd {
public:
BitsetFrontEnd(ValueObject &valobj);
size_t GetIndexOfChildWithName(ConstString name) override {
return formatters::ExtractIndexFromString(name.GetCString());
}
bool MightHaveChildren() override { return true; }
bool Update() override;
size_t CalculateNumChildren() override { return m_elements.size(); }
ValueObjectSP GetChildAtIndex(size_t idx) override;
private:
// The lifetime of a ValueObject and all its derivative ValueObjects
// (children, clones, etc.) is managed by a ClusterManager. These
// objects are only destroyed when every shared pointer to any of them
// is destroyed, so we must not store a shared pointer to any ValueObject
// derived from our backend ValueObject (since we're in the same cluster).
// Value objects created from raw data (i.e. in a different cluster) must
// be referenced via shared pointer to keep them alive, however.
std::vector<ValueObjectSP> m_elements;
ValueObject* m_first = nullptr;
CompilerType m_bool_type;
ByteOrder m_byte_order = eByteOrderInvalid;
uint8_t m_byte_size = 0;
};
} // namespace
BitsetFrontEnd::BitsetFrontEnd(ValueObject &valobj)
: SyntheticChildrenFrontEnd(valobj) {
m_bool_type = valobj.GetCompilerType().GetBasicTypeFromAST(eBasicTypeBool);
if (auto target_sp = m_backend.GetTargetSP()) {
m_byte_order = target_sp->GetArchitecture().GetByteOrder();
m_byte_size = target_sp->GetArchitecture().GetAddressByteSize();
Update();
}
}
bool BitsetFrontEnd::Update() {
m_elements.clear();
m_first = nullptr;
TargetSP target_sp = m_backend.GetTargetSP();
if (!target_sp)
return false;
size_t capping_size = target_sp->GetMaximumNumberOfChildrenToDisplay();
size_t size = 0;
if (auto arg = m_backend.GetCompilerType().GetIntegralTemplateArgument(0))
size = arg->value.getLimitedValue(capping_size);
m_elements.assign(size, ValueObjectSP());
m_first = m_backend.GetChildMemberWithName(ConstString("__first_"), true).get();
return false;
}
ValueObjectSP BitsetFrontEnd::GetChildAtIndex(size_t idx) {
if (idx >= m_elements.size() || !m_first)
return ValueObjectSP();
if (m_elements[idx])
return m_elements[idx];
ExecutionContext ctx = m_backend.GetExecutionContextRef().Lock(false);
CompilerType type;
ValueObjectSP chunk;
// For small bitsets __first_ is not an array, but a plain size_t.
if (m_first->GetCompilerType().IsArrayType(&type, nullptr, nullptr)) {
llvm::Optional<uint64_t> bit_size =
type.GetBitSize(ctx.GetBestExecutionContextScope());
if (!bit_size || *bit_size == 0)
return {};
chunk = m_first->GetChildAtIndex(idx / *bit_size, true);
} else {
type = m_first->GetCompilerType();
chunk = m_first->GetSP();
}
if (!type || !chunk)
return {};
llvm::Optional<uint64_t> bit_size =
type.GetBitSize(ctx.GetBestExecutionContextScope());
if (!bit_size || *bit_size == 0)
return {};
size_t chunk_idx = idx % *bit_size;
uint8_t value = !!(chunk->GetValueAsUnsigned(0) & (uint64_t(1) << chunk_idx));
DataExtractor data(&value, sizeof(value), m_byte_order, m_byte_size);
m_elements[idx] = CreateValueObjectFromData(llvm::formatv("[{0}]", idx).str(),
data, ctx, m_bool_type);
return m_elements[idx];
}
SyntheticChildrenFrontEnd *formatters::LibcxxBitsetSyntheticFrontEndCreator(
CXXSyntheticChildren *, lldb::ValueObjectSP valobj_sp) {
if (valobj_sp)
return new BitsetFrontEnd(*valobj_sp);
return nullptr;
}