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 11 #include "Plugins/TypeSystem/Clang/TypeSystemClang.h" 12 #include "lldb/Core/ValueObject.h" 13 #include "lldb/Core/ValueObjectConstResult.h" 14 #include "lldb/DataFormatters/FormattersHelpers.h" 15 #include "lldb/Target/Target.h" 16 #include "lldb/Utility/ConstString.h" 17 #include "lldb/Utility/DataBufferHeap.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 23 using namespace lldb; 24 using namespace lldb_private; 25 using namespace lldb_private::formatters; 26 27 namespace lldb_private { 28 namespace formatters { 29 class LibcxxStdUnorderedMapSyntheticFrontEnd 30 : public SyntheticChildrenFrontEnd { 31 public: 32 LibcxxStdUnorderedMapSyntheticFrontEnd(lldb::ValueObjectSP valobj_sp); 33 34 ~LibcxxStdUnorderedMapSyntheticFrontEnd() override = default; 35 36 size_t CalculateNumChildren() override; 37 38 lldb::ValueObjectSP GetChildAtIndex(size_t idx) override; 39 40 bool Update() override; 41 42 bool MightHaveChildren() override; 43 44 size_t GetIndexOfChildWithName(ConstString name) override; 45 46 private: 47 CompilerType m_element_type; 48 CompilerType m_node_type; 49 ValueObject *m_tree = nullptr; 50 size_t m_num_elements = 0; 51 ValueObject *m_next_element = nullptr; 52 std::vector<std::pair<ValueObject *, uint64_t>> m_elements_cache; 53 }; 54 } // namespace formatters 55 } // namespace lldb_private 56 57 lldb_private::formatters::LibcxxStdUnorderedMapSyntheticFrontEnd:: 58 LibcxxStdUnorderedMapSyntheticFrontEnd(lldb::ValueObjectSP valobj_sp) 59 : SyntheticChildrenFrontEnd(*valobj_sp), m_element_type(), 60 m_elements_cache() { 61 if (valobj_sp) 62 Update(); 63 } 64 65 size_t lldb_private::formatters::LibcxxStdUnorderedMapSyntheticFrontEnd:: 66 CalculateNumChildren() { 67 return m_num_elements; 68 } 69 70 static 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 82 static 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::")) 86 consumeInlineNamespace(name); 87 return name.consume_front(type) && name.startswith("<"); 88 } 89 90 static bool isUnorderedMap(ConstString type_name) { 91 return isStdTemplate(type_name, "unordered_map") || 92 isStdTemplate(type_name, "unordered_multimap"); 93 } 94 95 lldb::ValueObjectSP lldb_private::formatters:: 96 LibcxxStdUnorderedMapSyntheticFrontEnd::GetChildAtIndex(size_t idx) { 97 if (idx >= CalculateNumChildren()) 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(); 105 106 Status error; 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; 118 119 ValueObjectSP first_sp = nullptr; 120 switch (p1_sp->GetCompilerType().GetNumDirectBaseClasses()) { 121 case 1: 122 // Assume a pre llvm r300140 __compressed_pair implementation: 123 first_sp = p1_sp->GetChildMemberWithName("__first_"); 124 break; 125 case 2: { 126 // Assume a post llvm r300140 __compressed_pair implementation: 127 ValueObjectSP first_elem_parent_sp = 128 p1_sp->GetChildAtIndex(0, true); 129 first_sp = p1_sp->GetChildMemberWithName("__value_"); 130 break; 131 } 132 default: 133 return nullptr; 134 } 135 136 if (!first_sp) 137 return nullptr; 138 m_element_type = first_sp->GetCompilerType(); 139 m_element_type = m_element_type.GetTypeTemplateArgument(0); 140 m_element_type = m_element_type.GetPointeeType(); 141 m_node_type = m_element_type; 142 m_element_type = m_element_type.GetTypeTemplateArgument(0); 143 // This synthetic provider is used for both unordered_(multi)map and 144 // unordered_(multi)set. For unordered_map, the element type has an 145 // additional type layer, an internal struct (`__hash_value_type`) 146 // that wraps a std::pair. Peel away the internal wrapper type - whose 147 // structure is of no value to users, to expose the std::pair. This 148 // matches the structure returned by the std::map synthetic provider. 149 if (isUnorderedMap(m_backend.GetTypeName())) { 150 std::string name; 151 CompilerType field_type = m_element_type.GetFieldAtIndex( 152 0, name, nullptr, nullptr, nullptr); 153 CompilerType actual_type = field_type.GetTypedefedType(); 154 if (isStdTemplate(actual_type.GetTypeName(), "pair")) 155 m_element_type = actual_type; 156 } 157 } 158 if (!m_node_type) 159 return nullptr; 160 node_sp = node_sp->Cast(m_node_type); 161 value_sp = node_sp->GetChildMemberWithName("__value_"); 162 hash_sp = node_sp->GetChildMemberWithName("__hash_"); 163 if (!value_sp || !hash_sp) 164 return nullptr; 165 } 166 m_elements_cache.push_back( 167 {value_sp.get(), hash_sp->GetValueAsUnsigned(0)}); 168 m_next_element = node_sp->GetChildMemberWithName("__next_").get(); 169 if (!m_next_element || m_next_element->GetValueAsUnsigned(0) == 0) 170 m_next_element = nullptr; 171 } 172 173 std::pair<ValueObject *, uint64_t> val_hash = m_elements_cache[idx]; 174 if (!val_hash.first) 175 return lldb::ValueObjectSP(); 176 StreamString stream; 177 stream.Printf("[%" PRIu64 "]", (uint64_t)idx); 178 DataExtractor data; 179 Status error; 180 val_hash.first->GetData(data, error); 181 if (error.Fail()) 182 return lldb::ValueObjectSP(); 183 const bool thread_and_frame_only_if_stopped = true; 184 ExecutionContext exe_ctx = val_hash.first->GetExecutionContextRef().Lock( 185 thread_and_frame_only_if_stopped); 186 return CreateValueObjectFromData(stream.GetString(), data, exe_ctx, 187 m_element_type); 188 } 189 190 bool lldb_private::formatters::LibcxxStdUnorderedMapSyntheticFrontEnd:: 191 Update() { 192 m_num_elements = 0; 193 m_next_element = nullptr; 194 m_elements_cache.clear(); 195 ValueObjectSP table_sp = m_backend.GetChildMemberWithName("__table_"); 196 if (!table_sp) 197 return false; 198 199 ValueObjectSP p2_sp = table_sp->GetChildMemberWithName("__p2_"); 200 ValueObjectSP num_elements_sp = nullptr; 201 llvm::SmallVector<llvm::StringRef, 3> next_path; 202 switch (p2_sp->GetCompilerType().GetNumDirectBaseClasses()) { 203 case 1: 204 // Assume a pre llvm r300140 __compressed_pair implementation: 205 num_elements_sp = p2_sp->GetChildMemberWithName("__first_"); 206 next_path.append({"__p1_", "__first_", "__next_"}); 207 break; 208 case 2: { 209 // Assume a post llvm r300140 __compressed_pair implementation: 210 ValueObjectSP first_elem_parent = p2_sp->GetChildAtIndex(0, true); 211 num_elements_sp = first_elem_parent->GetChildMemberWithName("__value_"); 212 next_path.append({"__p1_", "__value_", "__next_"}); 213 break; 214 } 215 default: 216 return false; 217 } 218 219 if (!num_elements_sp) 220 return false; 221 222 m_tree = table_sp->GetChildAtNamePath(next_path).get(); 223 if (m_tree == nullptr) 224 return false; 225 226 m_num_elements = num_elements_sp->GetValueAsUnsigned(0); 227 228 if (m_num_elements > 0) 229 m_next_element = 230 table_sp->GetChildAtNamePath(next_path).get(); 231 return false; 232 } 233 234 bool lldb_private::formatters::LibcxxStdUnorderedMapSyntheticFrontEnd:: 235 MightHaveChildren() { 236 return true; 237 } 238 239 size_t lldb_private::formatters::LibcxxStdUnorderedMapSyntheticFrontEnd:: 240 GetIndexOfChildWithName(ConstString name) { 241 return ExtractIndexFromString(name.GetCString()); 242 } 243 244 SyntheticChildrenFrontEnd * 245 lldb_private::formatters::LibcxxStdUnorderedMapSyntheticFrontEndCreator( 246 CXXSyntheticChildren *, lldb::ValueObjectSP valobj_sp) { 247 return (valobj_sp ? new LibcxxStdUnorderedMapSyntheticFrontEnd(valobj_sp) 248 : nullptr); 249 } 250