1 //===-- DWARFExpression.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 "llvm/DebugInfo/DWARF/DWARFExpression.h" 10 #include "llvm/DebugInfo/DWARF/DWARFUnit.h" 11 #include "llvm/BinaryFormat/Dwarf.h" 12 #include "llvm/MC/MCRegisterInfo.h" 13 #include "llvm/Support/Format.h" 14 #include <cassert> 15 #include <cstdint> 16 #include <vector> 17 18 using namespace llvm; 19 using namespace dwarf; 20 21 namespace llvm { 22 23 typedef std::vector<DWARFExpression::Operation::Description> DescVector; 24 25 static DescVector getDescriptions() { 26 DescVector Descriptions; 27 typedef DWARFExpression::Operation Op; 28 typedef Op::Description Desc; 29 30 Descriptions.resize(0xff); 31 Descriptions[DW_OP_addr] = Desc(Op::Dwarf2, Op::SizeAddr); 32 Descriptions[DW_OP_deref] = Desc(Op::Dwarf2); 33 Descriptions[DW_OP_const1u] = Desc(Op::Dwarf2, Op::Size1); 34 Descriptions[DW_OP_const1s] = Desc(Op::Dwarf2, Op::SignedSize1); 35 Descriptions[DW_OP_const2u] = Desc(Op::Dwarf2, Op::Size2); 36 Descriptions[DW_OP_const2s] = Desc(Op::Dwarf2, Op::SignedSize2); 37 Descriptions[DW_OP_const4u] = Desc(Op::Dwarf2, Op::Size4); 38 Descriptions[DW_OP_const4s] = Desc(Op::Dwarf2, Op::SignedSize4); 39 Descriptions[DW_OP_const8u] = Desc(Op::Dwarf2, Op::Size8); 40 Descriptions[DW_OP_const8s] = Desc(Op::Dwarf2, Op::SignedSize8); 41 Descriptions[DW_OP_constu] = Desc(Op::Dwarf2, Op::SizeLEB); 42 Descriptions[DW_OP_consts] = Desc(Op::Dwarf2, Op::SignedSizeLEB); 43 Descriptions[DW_OP_dup] = Desc(Op::Dwarf2); 44 Descriptions[DW_OP_drop] = Desc(Op::Dwarf2); 45 Descriptions[DW_OP_over] = Desc(Op::Dwarf2); 46 Descriptions[DW_OP_pick] = Desc(Op::Dwarf2, Op::Size1); 47 Descriptions[DW_OP_swap] = Desc(Op::Dwarf2); 48 Descriptions[DW_OP_rot] = Desc(Op::Dwarf2); 49 Descriptions[DW_OP_xderef] = Desc(Op::Dwarf2); 50 Descriptions[DW_OP_abs] = Desc(Op::Dwarf2); 51 Descriptions[DW_OP_and] = Desc(Op::Dwarf2); 52 Descriptions[DW_OP_div] = Desc(Op::Dwarf2); 53 Descriptions[DW_OP_minus] = Desc(Op::Dwarf2); 54 Descriptions[DW_OP_mod] = Desc(Op::Dwarf2); 55 Descriptions[DW_OP_mul] = Desc(Op::Dwarf2); 56 Descriptions[DW_OP_neg] = Desc(Op::Dwarf2); 57 Descriptions[DW_OP_not] = Desc(Op::Dwarf2); 58 Descriptions[DW_OP_or] = Desc(Op::Dwarf2); 59 Descriptions[DW_OP_plus] = Desc(Op::Dwarf2); 60 Descriptions[DW_OP_plus_uconst] = Desc(Op::Dwarf2, Op::SizeLEB); 61 Descriptions[DW_OP_shl] = Desc(Op::Dwarf2); 62 Descriptions[DW_OP_shr] = Desc(Op::Dwarf2); 63 Descriptions[DW_OP_shra] = Desc(Op::Dwarf2); 64 Descriptions[DW_OP_xor] = Desc(Op::Dwarf2); 65 Descriptions[DW_OP_skip] = Desc(Op::Dwarf2, Op::SignedSize2); 66 Descriptions[DW_OP_bra] = Desc(Op::Dwarf2, Op::SignedSize2); 67 Descriptions[DW_OP_eq] = Desc(Op::Dwarf2); 68 Descriptions[DW_OP_ge] = Desc(Op::Dwarf2); 69 Descriptions[DW_OP_gt] = Desc(Op::Dwarf2); 70 Descriptions[DW_OP_le] = Desc(Op::Dwarf2); 71 Descriptions[DW_OP_lt] = Desc(Op::Dwarf2); 72 Descriptions[DW_OP_ne] = Desc(Op::Dwarf2); 73 for (uint16_t LA = DW_OP_lit0; LA <= DW_OP_lit31; ++LA) 74 Descriptions[LA] = Desc(Op::Dwarf2); 75 for (uint16_t LA = DW_OP_reg0; LA <= DW_OP_reg31; ++LA) 76 Descriptions[LA] = Desc(Op::Dwarf2); 77 for (uint16_t LA = DW_OP_breg0; LA <= DW_OP_breg31; ++LA) 78 Descriptions[LA] = Desc(Op::Dwarf2, Op::SignedSizeLEB); 79 Descriptions[DW_OP_regx] = Desc(Op::Dwarf2, Op::SizeLEB); 80 Descriptions[DW_OP_fbreg] = Desc(Op::Dwarf2, Op::SignedSizeLEB); 81 Descriptions[DW_OP_bregx] = Desc(Op::Dwarf2, Op::SizeLEB, Op::SignedSizeLEB); 82 Descriptions[DW_OP_piece] = Desc(Op::Dwarf2, Op::SizeLEB); 83 Descriptions[DW_OP_deref_size] = Desc(Op::Dwarf2, Op::Size1); 84 Descriptions[DW_OP_xderef_size] = Desc(Op::Dwarf2, Op::Size1); 85 Descriptions[DW_OP_nop] = Desc(Op::Dwarf2); 86 Descriptions[DW_OP_push_object_address] = Desc(Op::Dwarf3); 87 Descriptions[DW_OP_call2] = Desc(Op::Dwarf3, Op::Size2); 88 Descriptions[DW_OP_call4] = Desc(Op::Dwarf3, Op::Size4); 89 Descriptions[DW_OP_call_ref] = Desc(Op::Dwarf3, Op::SizeRefAddr); 90 Descriptions[DW_OP_form_tls_address] = Desc(Op::Dwarf3); 91 Descriptions[DW_OP_call_frame_cfa] = Desc(Op::Dwarf3); 92 Descriptions[DW_OP_bit_piece] = Desc(Op::Dwarf3, Op::SizeLEB, Op::SizeLEB); 93 Descriptions[DW_OP_implicit_value] = 94 Desc(Op::Dwarf3, Op::SizeLEB, Op::SizeBlock); 95 Descriptions[DW_OP_stack_value] = Desc(Op::Dwarf3); 96 Descriptions[DW_OP_WASM_location] = 97 Desc(Op::Dwarf4, Op::SizeLEB, Op::SignedSizeLEB); 98 Descriptions[DW_OP_GNU_push_tls_address] = Desc(Op::Dwarf3); 99 Descriptions[DW_OP_addrx] = Desc(Op::Dwarf4, Op::SizeLEB); 100 Descriptions[DW_OP_GNU_addr_index] = Desc(Op::Dwarf4, Op::SizeLEB); 101 Descriptions[DW_OP_GNU_const_index] = Desc(Op::Dwarf4, Op::SizeLEB); 102 Descriptions[DW_OP_GNU_entry_value] = Desc(Op::Dwarf4, Op::SizeLEB); 103 104 Descriptions[DW_OP_convert] = Desc(Op::Dwarf5, Op::BaseTypeRef); 105 Descriptions[DW_OP_entry_value] = Desc(Op::Dwarf5, Op::SizeLEB); 106 107 return Descriptions; 108 } 109 110 static DWARFExpression::Operation::Description getOpDesc(unsigned OpCode) { 111 // FIXME: Make this constexpr once all compilers are smart enough to do it. 112 static DescVector Descriptions = getDescriptions(); 113 // Handle possible corrupted or unsupported operation. 114 if (OpCode >= Descriptions.size()) 115 return {}; 116 return Descriptions[OpCode]; 117 } 118 119 static uint8_t getRefAddrSize(uint8_t AddrSize, uint16_t Version) { 120 return (Version == 2) ? AddrSize : 4; 121 } 122 123 bool DWARFExpression::Operation::extract(DataExtractor Data, uint16_t Version, 124 uint8_t AddressSize, uint64_t Offset) { 125 Opcode = Data.getU8(&Offset); 126 127 Desc = getOpDesc(Opcode); 128 if (Desc.Version == Operation::DwarfNA) { 129 EndOffset = Offset; 130 return false; 131 } 132 133 for (unsigned Operand = 0; Operand < 2; ++Operand) { 134 unsigned Size = Desc.Op[Operand]; 135 unsigned Signed = Size & Operation::SignBit; 136 137 if (Size == Operation::SizeNA) 138 break; 139 140 switch (Size & ~Operation::SignBit) { 141 case Operation::Size1: 142 Operands[Operand] = Data.getU8(&Offset); 143 if (Signed) 144 Operands[Operand] = (int8_t)Operands[Operand]; 145 break; 146 case Operation::Size2: 147 Operands[Operand] = Data.getU16(&Offset); 148 if (Signed) 149 Operands[Operand] = (int16_t)Operands[Operand]; 150 break; 151 case Operation::Size4: 152 Operands[Operand] = Data.getU32(&Offset); 153 if (Signed) 154 Operands[Operand] = (int32_t)Operands[Operand]; 155 break; 156 case Operation::Size8: 157 Operands[Operand] = Data.getU64(&Offset); 158 break; 159 case Operation::SizeAddr: 160 if (AddressSize == 8) { 161 Operands[Operand] = Data.getU64(&Offset); 162 } else if (AddressSize == 4) { 163 Operands[Operand] = Data.getU32(&Offset); 164 } else { 165 assert(AddressSize == 2); 166 Operands[Operand] = Data.getU16(&Offset); 167 } 168 break; 169 case Operation::SizeRefAddr: 170 if (getRefAddrSize(AddressSize, Version) == 8) { 171 Operands[Operand] = Data.getU64(&Offset); 172 } else if (getRefAddrSize(AddressSize, Version) == 4) { 173 Operands[Operand] = Data.getU32(&Offset); 174 } else { 175 assert(getRefAddrSize(AddressSize, Version) == 2); 176 Operands[Operand] = Data.getU16(&Offset); 177 } 178 break; 179 case Operation::SizeLEB: 180 if (Signed) 181 Operands[Operand] = Data.getSLEB128(&Offset); 182 else 183 Operands[Operand] = Data.getULEB128(&Offset); 184 break; 185 case Operation::BaseTypeRef: 186 Operands[Operand] = Data.getULEB128(&Offset); 187 break; 188 case Operation::SizeBlock: 189 // We need a size, so this cannot be the first operand 190 if (Operand == 0) 191 return false; 192 // Store the offset of the block as the value. 193 Operands[Operand] = Offset; 194 Offset += Operands[Operand - 1]; 195 break; 196 default: 197 llvm_unreachable("Unknown DWARFExpression Op size"); 198 } 199 200 OperandEndOffsets[Operand] = Offset; 201 } 202 203 EndOffset = Offset; 204 return true; 205 } 206 207 static bool prettyPrintRegisterOp(raw_ostream &OS, uint8_t Opcode, 208 uint64_t Operands[2], 209 const MCRegisterInfo *MRI, bool isEH) { 210 if (!MRI) 211 return false; 212 213 uint64_t DwarfRegNum; 214 unsigned OpNum = 0; 215 216 if (Opcode == DW_OP_bregx || Opcode == DW_OP_regx) 217 DwarfRegNum = Operands[OpNum++]; 218 else if (Opcode >= DW_OP_breg0 && Opcode < DW_OP_bregx) 219 DwarfRegNum = Opcode - DW_OP_breg0; 220 else 221 DwarfRegNum = Opcode - DW_OP_reg0; 222 223 if (Optional<unsigned> LLVMRegNum = MRI->getLLVMRegNum(DwarfRegNum, isEH)) { 224 if (const char *RegName = MRI->getName(*LLVMRegNum)) { 225 if ((Opcode >= DW_OP_breg0 && Opcode <= DW_OP_breg31) || 226 Opcode == DW_OP_bregx) 227 OS << format(" %s%+" PRId64, RegName, Operands[OpNum]); 228 else 229 OS << ' ' << RegName; 230 return true; 231 } 232 } 233 234 return false; 235 } 236 237 bool DWARFExpression::Operation::print(raw_ostream &OS, 238 const DWARFExpression *Expr, 239 const MCRegisterInfo *RegInfo, 240 DWARFUnit *U, 241 bool isEH) { 242 if (Error) { 243 OS << "<decoding error>"; 244 return false; 245 } 246 247 StringRef Name = OperationEncodingString(Opcode); 248 assert(!Name.empty() && "DW_OP has no name!"); 249 OS << Name; 250 251 if ((Opcode >= DW_OP_breg0 && Opcode <= DW_OP_breg31) || 252 (Opcode >= DW_OP_reg0 && Opcode <= DW_OP_reg31) || 253 Opcode == DW_OP_bregx || Opcode == DW_OP_regx) 254 if (prettyPrintRegisterOp(OS, Opcode, Operands, RegInfo, isEH)) 255 return true; 256 257 for (unsigned Operand = 0; Operand < 2; ++Operand) { 258 unsigned Size = Desc.Op[Operand]; 259 unsigned Signed = Size & Operation::SignBit; 260 261 if (Size == Operation::SizeNA) 262 break; 263 264 if (Size == Operation::BaseTypeRef && U) { 265 auto Die = U->getDIEForOffset(U->getOffset() + Operands[Operand]); 266 if (Die && Die.getTag() == dwarf::DW_TAG_base_type) { 267 OS << format(" (0x%08" PRIx64 ")", U->getOffset() + Operands[Operand]); 268 if (auto Name = Die.find(dwarf::DW_AT_name)) 269 OS << " \"" << Name->getAsCString() << "\""; 270 } else { 271 OS << format(" <invalid base_type ref: 0x%" PRIx64 ">", 272 Operands[Operand]); 273 } 274 } else if (Size == Operation::SizeBlock) { 275 uint64_t Offset = Operands[Operand]; 276 for (unsigned i = 0; i < Operands[Operand - 1]; ++i) 277 OS << format(" 0x%02x", Expr->Data.getU8(&Offset)); 278 } else { 279 if (Signed) 280 OS << format(" %+" PRId64, (int64_t)Operands[Operand]); 281 else if (Opcode != DW_OP_entry_value && 282 Opcode != DW_OP_GNU_entry_value) 283 OS << format(" 0x%" PRIx64, Operands[Operand]); 284 } 285 } 286 return true; 287 } 288 289 void DWARFExpression::print(raw_ostream &OS, const MCRegisterInfo *RegInfo, 290 DWARFUnit *U, bool IsEH) const { 291 uint32_t EntryValExprSize = 0; 292 for (auto &Op : *this) { 293 if (!Op.print(OS, this, RegInfo, U, IsEH)) { 294 uint64_t FailOffset = Op.getEndOffset(); 295 while (FailOffset < Data.getData().size()) 296 OS << format(" %02x", Data.getU8(&FailOffset)); 297 return; 298 } 299 300 if (Op.getCode() == DW_OP_entry_value || 301 Op.getCode() == DW_OP_GNU_entry_value) { 302 OS << "("; 303 EntryValExprSize = Op.getRawOperand(0); 304 continue; 305 } 306 307 if (EntryValExprSize) { 308 EntryValExprSize--; 309 if (EntryValExprSize == 0) 310 OS << ")"; 311 } 312 313 if (Op.getEndOffset() < Data.getData().size()) 314 OS << ", "; 315 } 316 } 317 318 bool DWARFExpression::Operation::verify(DWARFUnit *U) { 319 320 for (unsigned Operand = 0; Operand < 2; ++Operand) { 321 unsigned Size = Desc.Op[Operand]; 322 323 if (Size == Operation::SizeNA) 324 break; 325 326 if (Size == Operation::BaseTypeRef) { 327 auto Die = U->getDIEForOffset(U->getOffset() + Operands[Operand]); 328 if (!Die || Die.getTag() != dwarf::DW_TAG_base_type) { 329 Error = true; 330 return false; 331 } 332 } 333 } 334 335 return true; 336 } 337 338 bool DWARFExpression::verify(DWARFUnit *U) { 339 for (auto &Op : *this) 340 if (!Op.verify(U)) 341 return false; 342 343 return true; 344 } 345 346 } // namespace llvm 347