1//===-- ValueObjectConstResultImpl.cpp ------------------------------------===//
2//
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
6//
7//===----------------------------------------------------------------------===//
8
9#include "lldb/Core/ValueObjectConstResultImpl.h"
10
11#include "lldb/Core/Value.h"
12#include "lldb/Core/ValueObject.h"
13#include "lldb/Core/ValueObjectConstResult.h"
14#include "lldb/Core/ValueObjectConstResultCast.h"
15#include "lldb/Core/ValueObjectConstResultChild.h"
16#include "lldb/Symbol/CompilerType.h"
17#include "lldb/Target/ExecutionContext.h"
18#include "lldb/Utility/DataBufferHeap.h"
19#include "lldb/Utility/Endian.h"
20#include "lldb/Utility/Scalar.h"
21
22#include <string>
23
24namespace lldb_private {
25class DataExtractor;
26}
27namespace lldb_private {
28class Status;
29}
30
31using namespace lldb;
32using namespace lldb_private;
33
34ValueObjectConstResultImpl::ValueObjectConstResultImpl(
35 ValueObject *valobj, lldb::addr_t live_address)
36 : m_impl_backend(valobj), m_live_address(live_address),
37 m_live_address_type(eAddressTypeLoad),
38 m_address_of_backend() {}
39
40lldb::ValueObjectSP ValueObjectConstResultImpl::Dereference(Status &error) {
41 if (m_impl_backend == nullptr)
42 return lldb::ValueObjectSP();
43
44 return m_impl_backend->ValueObject::Dereference(error);
45}
46
47ValueObject *ValueObjectConstResultImpl::CreateChildAtIndex(
48 size_t idx, bool synthetic_array_member, int32_t synthetic_index) {
49 if (m_impl_backend == nullptr)
50 return nullptr;
51
52 m_impl_backend->UpdateValueIfNeeded(update_format: false);
53
54 ValueObjectConstResultChild *valobj = nullptr;
55
56 bool omit_empty_base_classes = true;
57 bool ignore_array_bounds = synthetic_array_member;
58 std::string child_name_str;
59 uint32_t child_byte_size = 0;
60 int32_t child_byte_offset = 0;
61 uint32_t child_bitfield_bit_size = 0;
62 uint32_t child_bitfield_bit_offset = 0;
63 bool child_is_base_class = false;
64 bool child_is_deref_of_parent = false;
65 uint64_t language_flags;
66
67 const bool transparent_pointers = !synthetic_array_member;
68 CompilerType compiler_type = m_impl_backend->GetCompilerType();
69 CompilerType child_compiler_type;
70
71 ExecutionContext exe_ctx(m_impl_backend->GetExecutionContextRef());
72
73 child_compiler_type = compiler_type.GetChildCompilerTypeAtIndex(
74 exe_ctx: &exe_ctx, idx, transparent_pointers, omit_empty_base_classes,
75 ignore_array_bounds, child_name&: child_name_str, child_byte_size, child_byte_offset,
76 child_bitfield_bit_size, child_bitfield_bit_offset, child_is_base_class,
77 child_is_deref_of_parent, valobj: m_impl_backend, language_flags);
78
79 // One might think we should check that the size of the children
80 // is always strictly positive, hence we could avoid creating a
81 // ValueObject if that's not the case, but it turns out there
82 // are languages out there which allow zero-size types with
83 // children (e.g. Swift).
84 if (child_compiler_type) {
85 if (synthetic_index)
86 child_byte_offset += child_byte_size * synthetic_index;
87
88 ConstString child_name;
89 if (!child_name_str.empty())
90 child_name.SetCString(child_name_str.c_str());
91
92 lldb::addr_t child_live_addr = LLDB_INVALID_ADDRESS;
93 // Transfer the live address (with offset) to the child. But if
94 // the parent is a pointer, the live address is where that pointer
95 // value lives in memory, so the children live addresses aren't
96 // offsets from that value, they are just other load addresses that
97 // are recorded in the Value of the child ValueObjects.
98 if (m_live_address != LLDB_INVALID_ADDRESS) {
99 if (!compiler_type.IsPointerType())
100 child_live_addr = m_live_address + child_byte_offset;
101 }
102 valobj = new ValueObjectConstResultChild(
103 *m_impl_backend, child_compiler_type, child_name, child_byte_size,
104 child_byte_offset, child_bitfield_bit_size, child_bitfield_bit_offset,
105 child_is_base_class, child_is_deref_of_parent, child_live_addr,
106 language_flags);
107 }
108
109 return valobj;
110}
111
112lldb::ValueObjectSP ValueObjectConstResultImpl::GetSyntheticChildAtOffset(
113 uint32_t offset, const CompilerType &type, bool can_create,
114 ConstString name_const_str) {
115 if (m_impl_backend == nullptr)
116 return lldb::ValueObjectSP();
117
118 return m_impl_backend->ValueObject::GetSyntheticChildAtOffset(
119 offset, type, can_create, name_const_str);
120}
121
122lldb::ValueObjectSP ValueObjectConstResultImpl::AddressOf(Status &error) {
123 if (m_address_of_backend.get() != nullptr)
124 return m_address_of_backend;
125
126 if (m_impl_backend == nullptr)
127 return lldb::ValueObjectSP();
128 if (m_live_address != LLDB_INVALID_ADDRESS) {
129 CompilerType compiler_type(m_impl_backend->GetCompilerType());
130
131 lldb::DataBufferSP buffer(new lldb_private::DataBufferHeap(
132 &m_live_address, sizeof(lldb::addr_t)));
133
134 std::string new_name("&");
135 new_name.append(s: m_impl_backend->GetName().AsCString(value_if_empty: ""));
136 ExecutionContext exe_ctx(m_impl_backend->GetExecutionContextRef());
137 m_address_of_backend = ValueObjectConstResult::Create(
138 exe_scope: exe_ctx.GetBestExecutionContextScope(), compiler_type: compiler_type.GetPointerType(),
139 name: ConstString(new_name.c_str()), result_data_sp: buffer, byte_order: endian::InlHostByteOrder(),
140 addr_size: exe_ctx.GetAddressByteSize());
141
142 m_address_of_backend->GetValue().SetValueType(Value::ValueType::Scalar);
143 m_address_of_backend->GetValue().GetScalar() = m_live_address;
144
145 return m_address_of_backend;
146 } else
147 return m_impl_backend->ValueObject::AddressOf(error);
148}
149
150lldb::ValueObjectSP
151ValueObjectConstResultImpl::Cast(const CompilerType &compiler_type) {
152 if (m_impl_backend == nullptr)
153 return lldb::ValueObjectSP();
154
155 ValueObjectConstResultCast *result_cast =
156 new ValueObjectConstResultCast(*m_impl_backend, m_impl_backend->GetName(),
157 compiler_type, m_live_address);
158 return result_cast->GetSP();
159}
160
161lldb::addr_t
162ValueObjectConstResultImpl::GetAddressOf(bool scalar_is_load_address,
163 AddressType *address_type) {
164
165 if (m_impl_backend == nullptr)
166 return 0;
167
168 if (m_live_address == LLDB_INVALID_ADDRESS) {
169 return m_impl_backend->ValueObject::GetAddressOf(scalar_is_load_address,
170 address_type);
171 }
172
173 if (address_type)
174 *address_type = m_live_address_type;
175
176 return m_live_address;
177}
178
179size_t ValueObjectConstResultImpl::GetPointeeData(DataExtractor &data,
180 uint32_t item_idx,
181 uint32_t item_count) {
182 if (m_impl_backend == nullptr)
183 return 0;
184 return m_impl_backend->ValueObject::GetPointeeData(data, item_idx,
185 item_count);
186}
187

source code of lldb/source/Core/ValueObjectConstResultImpl.cpp