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LibCxxUnorderedMap.cpp
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1//===-- LibCxxUnorderedMap.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 "LibCxx.h"
10
15#include "lldb/Target/Target.h"
18#include "lldb/Utility/Endian.h"
19#include "lldb/Utility/Status.h"
20#include "lldb/Utility/Stream.h"
21#include "llvm/ADT/StringRef.h"
22
23using namespace lldb;
24using namespace lldb_private;
25using namespace lldb_private::formatters;
26
27namespace lldb_private {
28namespace formatters {
31public:
33
35
36 llvm::Expected<uint32_t> CalculateNumChildren() override;
37
38 lldb::ValueObjectSP GetChildAtIndex(uint32_t idx) override;
39
41
42 bool MightHaveChildren() override;
43
44 size_t GetIndexOfChildWithName(ConstString name) override;
45
46private:
49 ValueObject *m_tree = nullptr;
50 size_t m_num_elements = 0;
52 std::vector<std::pair<ValueObject *, uint64_t>> m_elements_cache;
53};
54} // namespace formatters
55} // namespace lldb_private
56
59 : SyntheticChildrenFrontEnd(*valobj_sp), m_element_type(),
60 m_elements_cache() {
61 if (valobj_sp)
62 Update();
63}
64
65llvm::Expected<uint32_t> lldb_private::formatters::
67 return m_num_elements;
68}
69
70static void consumeInlineNamespace(llvm::StringRef &name) {
71 // Delete past an inline namespace, if any: __[a-zA-Z0-9_]+::
72 auto scratch = name;
73 if (scratch.consume_front("__") && std::isalnum(scratch[0])) {
74 scratch = scratch.drop_while([](char c) { return std::isalnum(c); });
75 if (scratch.consume_front("::")) {
76 // Successfully consumed a namespace.
77 name = scratch;
78 }
79 }
80}
81
82static bool isStdTemplate(ConstString type_name, llvm::StringRef type) {
83 llvm::StringRef name = type_name.GetStringRef();
84 // The type name may be prefixed with `std::__<inline-namespace>::`.
85 if (name.consume_front("std::"))
87 return name.consume_front(type) && name.starts_with("<");
88}
89
90static bool isUnorderedMap(ConstString type_name) {
91 return isStdTemplate(type_name, "unordered_map") ||
92 isStdTemplate(type_name, "unordered_multimap");
93}
94
97 if (idx >= CalculateNumChildrenIgnoringErrors())
98 return lldb::ValueObjectSP();
99 if (m_tree == nullptr)
100 return lldb::ValueObjectSP();
101
102 while (idx >= m_elements_cache.size()) {
103 if (m_next_element == nullptr)
104 return lldb::ValueObjectSP();
105
107 ValueObjectSP node_sp = m_next_element->Dereference(error);
108 if (!node_sp || error.Fail())
109 return lldb::ValueObjectSP();
110
111 ValueObjectSP value_sp = node_sp->GetChildMemberWithName("__value_");
112 ValueObjectSP hash_sp = node_sp->GetChildMemberWithName("__hash_");
113 if (!hash_sp || !value_sp) {
114 if (!m_element_type) {
115 auto p1_sp = m_backend.GetChildAtNamePath({"__table_", "__p1_"});
116 if (!p1_sp)
117 return nullptr;
118
120 if (!first_sp)
121 return nullptr;
122
123 m_element_type = first_sp->GetCompilerType();
124 m_element_type = m_element_type.GetTypeTemplateArgument(0);
125 m_element_type = m_element_type.GetPointeeType();
126 m_node_type = m_element_type;
127 m_element_type = m_element_type.GetTypeTemplateArgument(0);
128 // This synthetic provider is used for both unordered_(multi)map and
129 // unordered_(multi)set. For unordered_map, the element type has an
130 // additional type layer, an internal struct (`__hash_value_type`)
131 // that wraps a std::pair. Peel away the internal wrapper type - whose
132 // structure is of no value to users, to expose the std::pair. This
133 // matches the structure returned by the std::map synthetic provider.
134 if (isUnorderedMap(m_backend.GetTypeName())) {
135 std::string name;
136 CompilerType field_type = m_element_type.GetFieldAtIndex(
137 0, name, nullptr, nullptr, nullptr);
138 CompilerType actual_type = field_type.GetTypedefedType();
139 if (isStdTemplate(actual_type.GetTypeName(), "pair"))
140 m_element_type = actual_type;
141 }
142 }
143 if (!m_node_type)
144 return nullptr;
145 node_sp = m_next_element->Cast(m_node_type.GetPointerType())
146 ->Dereference(error);
147 if (!node_sp || error.Fail())
148 return nullptr;
149
150 hash_sp = node_sp->GetChildMemberWithName("__hash_");
151 if (!hash_sp)
152 return nullptr;
153
154 value_sp = node_sp->GetChildMemberWithName("__value_");
155 if (!value_sp) {
156 // clang-format off
157 // Since D101206 (ba79fb2e1f), libc++ wraps the `__value_` in an
158 // anonymous union.
159 // Child 0: __hash_node_base base class
160 // Child 1: __hash_
161 // Child 2: anonymous union
162 // clang-format on
163 auto anon_union_sp = node_sp->GetChildAtIndex(2);
164 if (!anon_union_sp)
165 return nullptr;
166
167 value_sp = anon_union_sp->GetChildMemberWithName("__value_");
168 if (!value_sp)
169 return nullptr;
170 }
171 }
172 m_elements_cache.push_back(
173 {value_sp.get(), hash_sp->GetValueAsUnsigned(0)});
174 m_next_element = node_sp->GetChildMemberWithName("__next_").get();
175 if (!m_next_element || m_next_element->GetValueAsUnsigned(0) == 0)
176 m_next_element = nullptr;
177 }
178
179 std::pair<ValueObject *, uint64_t> val_hash = m_elements_cache[idx];
180 if (!val_hash.first)
181 return lldb::ValueObjectSP();
182 StreamString stream;
183 stream.Printf("[%" PRIu64 "]", (uint64_t)idx);
184 DataExtractor data;
186 val_hash.first->GetData(data, error);
187 if (error.Fail())
188 return lldb::ValueObjectSP();
189 const bool thread_and_frame_only_if_stopped = true;
190 ExecutionContext exe_ctx = val_hash.first->GetExecutionContextRef().Lock(
191 thread_and_frame_only_if_stopped);
192 return CreateValueObjectFromData(stream.GetString(), data, exe_ctx,
193 m_element_type);
194}
195
198 m_num_elements = 0;
199 m_next_element = nullptr;
200 m_elements_cache.clear();
201 ValueObjectSP table_sp = m_backend.GetChildMemberWithName("__table_");
202 if (!table_sp)
204
205 ValueObjectSP p2_sp = table_sp->GetChildMemberWithName("__p2_");
206 if (!p2_sp)
208
209 ValueObjectSP num_elements_sp = GetFirstValueOfLibCXXCompressedPair(*p2_sp);
210 if (!num_elements_sp)
212
213 ValueObjectSP p1_sp = table_sp->GetChildMemberWithName("__p1_");
214 if (!p1_sp)
216
218 if (!value_sp)
220
221 m_tree = value_sp->GetChildMemberWithName("__next_").get();
222 if (m_tree == nullptr)
224
225 m_num_elements = num_elements_sp->GetValueAsUnsigned(0);
226
227 if (m_num_elements > 0)
228 m_next_element = m_tree;
229
231}
232
235 return true;
236}
237
240 return ExtractIndexFromString(name.GetCString());
241}
242
246 return (valobj_sp ? new LibcxxStdUnorderedMapSyntheticFrontEnd(valobj_sp)
247 : nullptr);
248}
static llvm::raw_ostream & error(Stream &strm)
static bool isStdTemplate(ConstString type_name, llvm::StringRef type)
static bool isUnorderedMap(ConstString type_name)
static void consumeInlineNamespace(llvm::StringRef &name)
Generic representation of a type in a programming language.
Definition: CompilerType.h:36
CompilerType GetFieldAtIndex(size_t idx, std::string &name, uint64_t *bit_offset_ptr, uint32_t *bitfield_bit_size_ptr, bool *is_bitfield_ptr) const
ConstString GetTypeName(bool BaseOnly=false) const
CompilerType GetTypedefedType() const
If the current object represents a typedef type, get the underlying type.
A uniqued constant string class.
Definition: ConstString.h:40
llvm::StringRef GetStringRef() const
Get the string value as a llvm::StringRef.
Definition: ConstString.h:197
const char * GetCString() const
Get the string value as a C string.
Definition: ConstString.h:216
An data extractor class.
Definition: DataExtractor.h:48
"lldb/Target/ExecutionContext.h" A class that contains an execution context.
An error handling class.
Definition: Status.h:44
llvm::StringRef GetString() const
size_t Printf(const char *format,...) __attribute__((format(printf
Output printf formatted output to the stream.
Definition: Stream.cpp:134
std::vector< std::pair< ValueObject *, uint64_t > > m_elements_cache
lldb::ChildCacheState Update() override
This function is assumed to always succeed and if it fails, the front-end should know to deal with it...
size_t ExtractIndexFromString(const char *item_name)
lldb::ValueObjectSP GetFirstValueOfLibCXXCompressedPair(ValueObject &pair)
Definition: LibCxx.cpp:49
SyntheticChildrenFrontEnd * LibcxxStdUnorderedMapSyntheticFrontEndCreator(CXXSyntheticChildren *, lldb::ValueObjectSP)
A class that represents a running process on the host machine.
Definition: SBAddress.h:15
ChildCacheState
Specifies if children need to be re-computed after a call to SyntheticChildrenFrontEnd::Update.
@ eRefetch
Children need to be recomputed dynamically.
std::shared_ptr< lldb_private::ValueObject > ValueObjectSP
Definition: lldb-forward.h:475