1 //===-- DWARFExpressionTest.cpp ----------------------------------*- C++-*-===// 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/Expression/DWARFExpression.h" 10 #include "../../source/Plugins/SymbolFile/DWARF/DWARFUnit.h" 11 #include "../../source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.h" 12 #include "TestingSupport/SubsystemRAII.h" 13 #include "lldb/Core/Module.h" 14 #include "lldb/Core/Section.h" 15 #include "lldb/Core/Value.h" 16 #include "lldb/Core/dwarf.h" 17 #include "lldb/Symbol/ObjectFile.h" 18 #include "lldb/Utility/StreamString.h" 19 #include "llvm/ADT/StringExtras.h" 20 #include "llvm/ObjectYAML/DWARFEmitter.h" 21 #include "llvm/Testing/Support/Error.h" 22 #include "gtest/gtest.h" 23 24 using namespace lldb_private; 25 26 static llvm::Expected<Scalar> Evaluate(llvm::ArrayRef<uint8_t> expr, 27 lldb::ModuleSP module_sp = {}, 28 DWARFUnit *unit = nullptr) { 29 DataExtractor extractor(expr.data(), expr.size(), lldb::eByteOrderLittle, 30 /*addr_size*/ 4); 31 Value result; 32 Status status; 33 if (!DWARFExpression::Evaluate( 34 /*exe_ctx*/ nullptr, /*reg_ctx*/ nullptr, module_sp, extractor, unit, 35 lldb::eRegisterKindLLDB, 36 /*initial_value_ptr*/ nullptr, 37 /*object_address_ptr*/ nullptr, result, &status)) 38 return status.ToError(); 39 40 return result.GetScalar(); 41 } 42 43 /// A mock module holding an object file parsed from YAML. 44 class YAMLModule : public lldb_private::Module { 45 public: 46 YAMLModule(ArchSpec &arch) : Module(FileSpec("test"), arch) {} 47 void SetObjectFile(lldb::ObjectFileSP obj_file) { m_objfile_sp = obj_file; } 48 ObjectFile *GetObjectFile() override { return m_objfile_sp.get(); } 49 }; 50 51 /// A mock object file that can be parsed from YAML. 52 class YAMLObjectFile : public lldb_private::ObjectFile { 53 const lldb::ModuleSP m_module_sp; 54 llvm::StringMap<std::unique_ptr<llvm::MemoryBuffer>> &m_section_map; 55 /// Because there is only one DataExtractor in the ObjectFile 56 /// interface, all sections are copied into a contiguous buffer. 57 std::vector<char> m_buffer; 58 59 public: 60 YAMLObjectFile(const lldb::ModuleSP &module_sp, 61 llvm::StringMap<std::unique_ptr<llvm::MemoryBuffer>> &map) 62 : ObjectFile(module_sp, &module_sp->GetFileSpec(), /*file_offset*/ 0, 63 /*length*/ 0, /*data_sp*/ nullptr, /*data_offset*/ 0), 64 m_module_sp(module_sp), m_section_map(map) {} 65 66 /// Callback for initializing the module's list of sections. 67 void CreateSections(SectionList &unified_section_list) override { 68 lldb::offset_t total_bytes = 0; 69 for (auto &entry : m_section_map) 70 total_bytes += entry.getValue()->getBufferSize(); 71 m_buffer.reserve(total_bytes); 72 m_data = 73 DataExtractor(m_buffer.data(), total_bytes, lldb::eByteOrderLittle, 4); 74 75 lldb::user_id_t sect_id = 1; 76 for (auto &entry : m_section_map) { 77 llvm::StringRef name = entry.getKey(); 78 lldb::SectionType sect_type = 79 llvm::StringSwitch<lldb::SectionType>(name) 80 .Case("debug_info", lldb::eSectionTypeDWARFDebugInfo) 81 .Case("debug_abbrev", lldb::eSectionTypeDWARFDebugAbbrev); 82 auto &membuf = entry.getValue(); 83 lldb::addr_t file_vm_addr = 0; 84 lldb::addr_t vm_size = 0; 85 lldb::offset_t file_offset = m_buffer.size(); 86 lldb::offset_t file_size = membuf->getBufferSize(); 87 m_buffer.resize(file_offset + file_size); 88 memcpy(m_buffer.data() + file_offset, membuf->getBufferStart(), 89 file_size); 90 uint32_t log2align = 0; 91 uint32_t flags = 0; 92 auto section_sp = std::make_shared<lldb_private::Section>( 93 m_module_sp, this, sect_id++, ConstString(name), sect_type, 94 file_vm_addr, vm_size, file_offset, file_size, log2align, flags); 95 unified_section_list.AddSection(section_sp); 96 } 97 } 98 99 /// \{ 100 /// Stub methods that aren't needed here. 101 ConstString GetPluginName() override { return ConstString("YAMLObjectFile"); } 102 uint32_t GetPluginVersion() override { return 0; } 103 void Dump(Stream *s) override {} 104 uint32_t GetAddressByteSize() const override { return 8; } 105 uint32_t GetDependentModules(FileSpecList &file_list) override { return 0; } 106 bool IsExecutable() const override { return 0; } 107 ArchSpec GetArchitecture() override { return {}; } 108 Symtab *GetSymtab() override { return nullptr; } 109 bool IsStripped() override { return false; } 110 UUID GetUUID() override { return {}; } 111 lldb::ByteOrder GetByteOrder() const override { 112 return lldb::eByteOrderLittle; 113 } 114 bool ParseHeader() override { return false; } 115 Type CalculateType() override { return {}; } 116 Strata CalculateStrata() override { return {}; } 117 /// \} 118 }; 119 120 /// Helper class that can construct a module from YAML and evaluate 121 /// DWARF expressions on it. 122 class YAMLModuleTester { 123 SubsystemRAII<FileSystem> subsystems; 124 llvm::StringMap<std::unique_ptr<llvm::MemoryBuffer>> m_sections_map; 125 lldb::ModuleSP m_module_sp; 126 lldb::ObjectFileSP m_objfile_sp; 127 DWARFUnitSP m_dwarf_unit; 128 std::unique_ptr<SymbolFileDWARF> m_symfile_dwarf; 129 130 public: 131 /// Parse the debug info sections from the YAML description. 132 YAMLModuleTester(llvm::StringRef yaml_data, llvm::StringRef triple) { 133 auto sections_map = llvm::DWARFYAML::EmitDebugSections(yaml_data, true); 134 if (!sections_map) 135 return; 136 m_sections_map = std::move(*sections_map); 137 ArchSpec arch(triple); 138 m_module_sp = std::make_shared<YAMLModule>(arch); 139 m_objfile_sp = std::make_shared<YAMLObjectFile>(m_module_sp, m_sections_map); 140 static_cast<YAMLModule *>(m_module_sp.get())->SetObjectFile(m_objfile_sp); 141 142 lldb::user_id_t uid = 0; 143 llvm::StringRef raw_debug_info = m_sections_map["debug_info"]->getBuffer(); 144 lldb_private::DataExtractor debug_info( 145 raw_debug_info.data(), raw_debug_info.size(), 146 m_objfile_sp->GetByteOrder(), m_objfile_sp->GetAddressByteSize()); 147 lldb::offset_t offset_ptr = 0; 148 m_symfile_dwarf = std::make_unique<SymbolFileDWARF>(m_objfile_sp, nullptr); 149 llvm::Expected<DWARFUnitSP> dwarf_unit = DWARFUnit::extract( 150 *m_symfile_dwarf, uid, 151 *static_cast<lldb_private::DWARFDataExtractor *>(&debug_info), 152 DIERef::DebugInfo, &offset_ptr); 153 if (dwarf_unit) 154 m_dwarf_unit = dwarf_unit.get(); 155 } 156 DWARFUnitSP GetDwarfUnit() { return m_dwarf_unit; } 157 158 // Evaluate a raw DWARF expression. 159 llvm::Expected<Scalar> Eval(llvm::ArrayRef<uint8_t> expr) { 160 return ::Evaluate(expr, m_module_sp, m_dwarf_unit.get()); 161 } 162 }; 163 164 /// Unfortunately Scalar's operator==() is really picky. 165 static Scalar GetScalar(unsigned bits, uint64_t value, bool sign) { 166 Scalar scalar; 167 auto type = Scalar::GetBestTypeForBitSize(bits, sign); 168 switch (type) { 169 case Scalar::e_sint: 170 scalar = Scalar((int)value); 171 break; 172 case Scalar::e_slong: 173 scalar = Scalar((long)value); 174 break; 175 case Scalar::e_slonglong: 176 scalar = Scalar((long long)value); 177 break; 178 case Scalar::e_uint: 179 scalar = Scalar((unsigned int)value); 180 break; 181 case Scalar::e_ulong: 182 scalar = Scalar((unsigned long)value); 183 break; 184 case Scalar::e_ulonglong: 185 scalar = Scalar((unsigned long long)value); 186 break; 187 default: 188 llvm_unreachable("not implemented"); 189 } 190 scalar.TruncOrExtendTo(type, bits); 191 if (sign) 192 scalar.MakeSigned(); 193 else 194 scalar.MakeUnsigned(); 195 return scalar; 196 } 197 198 TEST(DWARFExpression, DW_OP_pick) { 199 EXPECT_THAT_EXPECTED(Evaluate({DW_OP_lit1, DW_OP_lit0, DW_OP_pick, 0}), 200 llvm::HasValue(0)); 201 EXPECT_THAT_EXPECTED(Evaluate({DW_OP_lit1, DW_OP_lit0, DW_OP_pick, 1}), 202 llvm::HasValue(1)); 203 EXPECT_THAT_EXPECTED(Evaluate({DW_OP_lit1, DW_OP_lit0, DW_OP_pick, 2}), 204 llvm::Failed()); 205 } 206 207 TEST(DWARFExpression, DW_OP_convert) { 208 /// Auxiliary debug info. 209 const char *yamldata = 210 "debug_abbrev:\n" 211 " - Code: 0x00000001\n" 212 " Tag: DW_TAG_compile_unit\n" 213 " Children: DW_CHILDREN_yes\n" 214 " Attributes:\n" 215 " - Attribute: DW_AT_language\n" 216 " Form: DW_FORM_data2\n" 217 " - Code: 0x00000002\n" 218 " Tag: DW_TAG_base_type\n" 219 " Children: DW_CHILDREN_no\n" 220 " Attributes:\n" 221 " - Attribute: DW_AT_encoding\n" 222 " Form: DW_FORM_data1\n" 223 " - Attribute: DW_AT_byte_size\n" 224 " Form: DW_FORM_data1\n" 225 "debug_info:\n" 226 " - Length:\n" 227 " TotalLength: 0\n" 228 " Version: 4\n" 229 " AbbrOffset: 0\n" 230 " AddrSize: 8\n" 231 " Entries:\n" 232 " - AbbrCode: 0x00000001\n" 233 " Values:\n" 234 " - Value: 0x000000000000000C\n" 235 // 0x0000000e: 236 " - AbbrCode: 0x00000002\n" 237 " Values:\n" 238 " - Value: 0x0000000000000007\n" // DW_ATE_unsigned 239 " - Value: 0x0000000000000004\n" 240 // 0x00000011: 241 " - AbbrCode: 0x00000002\n" 242 " Values:\n" 243 " - Value: 0x0000000000000007\n" // DW_ATE_unsigned 244 " - Value: 0x0000000000000008\n" 245 // 0x00000014: 246 " - AbbrCode: 0x00000002\n" 247 " Values:\n" 248 " - Value: 0x0000000000000005\n" // DW_ATE_signed 249 " - Value: 0x0000000000000008\n" 250 // 0x00000017: 251 " - AbbrCode: 0x00000002\n" 252 " Values:\n" 253 " - Value: 0x0000000000000008\n" // DW_ATE_unsigned_char 254 " - Value: 0x0000000000000001\n" 255 // 0x0000001a: 256 " - AbbrCode: 0x00000002\n" 257 " Values:\n" 258 " - Value: 0x0000000000000006\n" // DW_ATE_signed_char 259 " - Value: 0x0000000000000001\n" 260 // 0x0000001d: 261 " - AbbrCode: 0x00000002\n" 262 " Values:\n" 263 " - Value: 0x000000000000000b\n" // DW_ATE_numeric_string 264 " - Value: 0x0000000000000001\n" 265 "" 266 " - AbbrCode: 0x00000000\n" 267 " Values: []\n"; 268 uint8_t offs_uint32_t = 0x0000000e; 269 uint8_t offs_uint64_t = 0x00000011; 270 uint8_t offs_sint64_t = 0x00000014; 271 uint8_t offs_uchar = 0x00000017; 272 uint8_t offs_schar = 0x0000001a; 273 274 YAMLModuleTester t(yamldata, "i386-unknown-linux"); 275 ASSERT_TRUE((bool)t.GetDwarfUnit()); 276 277 // Constant is given as little-endian. 278 bool is_signed = true; 279 bool not_signed = false; 280 281 // 282 // Positive tests. 283 // 284 285 // Truncate to default unspecified (pointer-sized) type. 286 EXPECT_THAT_EXPECTED( 287 t.Eval({DW_OP_const8u, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77, 0x88, // 288 DW_OP_convert, 0x00}), 289 llvm::HasValue(GetScalar(32, 0x44332211, not_signed))); 290 // Truncate to 32 bits. 291 EXPECT_THAT_EXPECTED(t.Eval({DW_OP_const8u, // 292 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77, 0x88,// 293 DW_OP_convert, offs_uint32_t}), 294 llvm::HasValue(GetScalar(32, 0x44332211, not_signed))); 295 296 // Leave as is. 297 EXPECT_THAT_EXPECTED( 298 t.Eval({DW_OP_const8u, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77, 0x88, // 299 DW_OP_convert, offs_uint64_t}), 300 llvm::HasValue(GetScalar(64, 0x8877665544332211, not_signed))); 301 302 // Sign-extend to 64 bits. 303 EXPECT_THAT_EXPECTED( 304 t.Eval({DW_OP_const4s, 0xcc, 0xdd, 0xee, 0xff, // 305 DW_OP_convert, offs_sint64_t}), 306 llvm::HasValue(GetScalar(64, 0xffffffffffeeddcc, is_signed))); 307 308 // Truncate to 8 bits. 309 EXPECT_THAT_EXPECTED(t.Eval({DW_OP_const4s, 'A', 'B', 'C', 'D', 0xee, 0xff, // 310 DW_OP_convert, offs_uchar}), 311 llvm::HasValue(GetScalar(8, 'A', not_signed))); 312 313 // Also truncate to 8 bits. 314 EXPECT_THAT_EXPECTED(t.Eval({DW_OP_const4s, 'A', 'B', 'C', 'D', 0xee, 0xff, // 315 DW_OP_convert, offs_schar}), 316 llvm::HasValue(GetScalar(8, 'A', is_signed))); 317 318 // 319 // Errors. 320 // 321 322 // No Module. 323 EXPECT_THAT_ERROR(Evaluate({DW_OP_const1s, 'X', DW_OP_convert, 0x00}, nullptr, 324 t.GetDwarfUnit().get()) 325 .takeError(), 326 llvm::Failed()); 327 328 // No DIE. 329 EXPECT_THAT_ERROR( 330 t.Eval({DW_OP_const1s, 'X', DW_OP_convert, 0x01}).takeError(), 331 llvm::Failed()); 332 333 // Unsupported. 334 EXPECT_THAT_ERROR( 335 t.Eval({DW_OP_const1s, 'X', DW_OP_convert, 0x1d}).takeError(), 336 llvm::Failed()); 337 } 338