1 //===-- LibCxxBitset.cpp ----------------------------------------*- C++ -*-===//
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7 //===----------------------------------------------------------------------===//
10 #include "lldb/DataFormatters/FormattersHelpers.h"
11 #include "lldb/Symbol/ClangASTContext.h"
12 #include "lldb/Target/Target.h"
15 using namespace lldb_private;
19 class BitsetFrontEnd : public SyntheticChildrenFrontEnd {
21 BitsetFrontEnd(ValueObject &valobj);
23 size_t GetIndexOfChildWithName(ConstString name) override {
24 return formatters::ExtractIndexFromString(name.GetCString());
27 bool MightHaveChildren() override { return true; }
28 bool Update() override;
29 size_t CalculateNumChildren() override { return m_elements.size(); }
30 ValueObjectSP GetChildAtIndex(size_t idx) override;
33 std::vector<ValueObjectSP> m_elements;
34 ValueObjectSP m_first;
35 CompilerType m_bool_type;
36 ByteOrder m_byte_order = eByteOrderInvalid;
37 uint8_t m_byte_size = 0;
41 BitsetFrontEnd::BitsetFrontEnd(ValueObject &valobj)
42 : SyntheticChildrenFrontEnd(valobj) {
43 m_bool_type = valobj.GetCompilerType().GetBasicTypeFromAST(eBasicTypeBool);
44 if (auto target_sp = m_backend.GetTargetSP()) {
45 m_byte_order = target_sp->GetArchitecture().GetByteOrder();
46 m_byte_size = target_sp->GetArchitecture().GetAddressByteSize();
51 bool BitsetFrontEnd::Update() {
55 TargetSP target_sp = m_backend.GetTargetSP();
58 size_t capping_size = target_sp->GetMaximumNumberOfChildrenToDisplay();
61 if (auto arg = m_backend.GetCompilerType().GetIntegralTemplateArgument(0))
62 size = arg->value.getLimitedValue(capping_size);
64 m_elements.assign(size, ValueObjectSP());
66 m_first = m_backend.GetChildMemberWithName(ConstString("__first_"), true);
70 ValueObjectSP BitsetFrontEnd::GetChildAtIndex(size_t idx) {
71 if (idx >= m_elements.size() || !m_first)
72 return ValueObjectSP();
75 return m_elements[idx];
77 ExecutionContext ctx = m_backend.GetExecutionContextRef().Lock(false);
80 // For small bitsets __first_ is not an array, but a plain size_t.
81 if (m_first->GetCompilerType().IsArrayType(&type, nullptr, nullptr)) {
82 llvm::Optional<uint64_t> bit_size =
83 type.GetBitSize(ctx.GetBestExecutionContextScope());
84 if (!bit_size || *bit_size == 0)
86 chunk = m_first->GetChildAtIndex(idx / *bit_size, true);
88 type = m_first->GetCompilerType();
94 llvm::Optional<uint64_t> bit_size =
95 type.GetBitSize(ctx.GetBestExecutionContextScope());
96 if (!bit_size || *bit_size == 0)
98 size_t chunk_idx = idx % *bit_size;
99 uint8_t value = !!(chunk->GetValueAsUnsigned(0) & (uint64_t(1) << chunk_idx));
100 DataExtractor data(&value, sizeof(value), m_byte_order, m_byte_size);
102 m_elements[idx] = CreateValueObjectFromData(llvm::formatv("[{0}]", idx).str(),
103 data, ctx, m_bool_type);
105 return m_elements[idx];
108 SyntheticChildrenFrontEnd *formatters::LibcxxBitsetSyntheticFrontEndCreator(
109 CXXSyntheticChildren *, lldb::ValueObjectSP valobj_sp) {
111 return new BitsetFrontEnd(*valobj_sp);