1 //===- DWARFFormValue.cpp -------------------------------------------------===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 10 #include "llvm/DebugInfo/DWARF/DWARFFormValue.h" 11 #include "SyntaxHighlighting.h" 12 #include "llvm/ADT/ArrayRef.h" 13 #include "llvm/ADT/None.h" 14 #include "llvm/ADT/Optional.h" 15 #include "llvm/ADT/StringRef.h" 16 #include "llvm/DebugInfo/DWARF/DWARFContext.h" 17 #include "llvm/DebugInfo/DWARF/DWARFRelocMap.h" 18 #include "llvm/DebugInfo/DWARF/DWARFUnit.h" 19 #include "llvm/Support/Dwarf.h" 20 #include "llvm/Support/ErrorHandling.h" 21 #include "llvm/Support/Format.h" 22 #include "llvm/Support/raw_ostream.h" 23 #include <cinttypes> 24 #include <cstdint> 25 #include <limits> 26 27 using namespace llvm; 28 using namespace dwarf; 29 using namespace syntax; 30 31 static const DWARFFormValue::FormClass DWARF4FormClasses[] = { 32 DWARFFormValue::FC_Unknown, // 0x0 33 DWARFFormValue::FC_Address, // 0x01 DW_FORM_addr 34 DWARFFormValue::FC_Unknown, // 0x02 unused 35 DWARFFormValue::FC_Block, // 0x03 DW_FORM_block2 36 DWARFFormValue::FC_Block, // 0x04 DW_FORM_block4 37 DWARFFormValue::FC_Constant, // 0x05 DW_FORM_data2 38 // --- These can be FC_SectionOffset in DWARF3 and below: 39 DWARFFormValue::FC_Constant, // 0x06 DW_FORM_data4 40 DWARFFormValue::FC_Constant, // 0x07 DW_FORM_data8 41 // --- 42 DWARFFormValue::FC_String, // 0x08 DW_FORM_string 43 DWARFFormValue::FC_Block, // 0x09 DW_FORM_block 44 DWARFFormValue::FC_Block, // 0x0a DW_FORM_block1 45 DWARFFormValue::FC_Constant, // 0x0b DW_FORM_data1 46 DWARFFormValue::FC_Flag, // 0x0c DW_FORM_flag 47 DWARFFormValue::FC_Constant, // 0x0d DW_FORM_sdata 48 DWARFFormValue::FC_String, // 0x0e DW_FORM_strp 49 DWARFFormValue::FC_Constant, // 0x0f DW_FORM_udata 50 DWARFFormValue::FC_Reference, // 0x10 DW_FORM_ref_addr 51 DWARFFormValue::FC_Reference, // 0x11 DW_FORM_ref1 52 DWARFFormValue::FC_Reference, // 0x12 DW_FORM_ref2 53 DWARFFormValue::FC_Reference, // 0x13 DW_FORM_ref4 54 DWARFFormValue::FC_Reference, // 0x14 DW_FORM_ref8 55 DWARFFormValue::FC_Reference, // 0x15 DW_FORM_ref_udata 56 DWARFFormValue::FC_Indirect, // 0x16 DW_FORM_indirect 57 DWARFFormValue::FC_SectionOffset, // 0x17 DW_FORM_sec_offset 58 DWARFFormValue::FC_Exprloc, // 0x18 DW_FORM_exprloc 59 DWARFFormValue::FC_Flag, // 0x19 DW_FORM_flag_present 60 }; 61 62 namespace { 63 64 /// A helper class that can be used in DWARFFormValue.cpp functions that need 65 /// to know the byte size of DW_FORM values that vary in size depending on the 66 /// DWARF version, address byte size, or DWARF32 or DWARF64. 67 class FormSizeHelper { 68 uint16_t Version; 69 uint8_t AddrSize; 70 llvm::dwarf::DwarfFormat Format; 71 72 public: 73 FormSizeHelper(uint16_t V, uint8_t A, llvm::dwarf::DwarfFormat F) 74 : Version(V), AddrSize(A), Format(F) {} 75 76 uint8_t getAddressByteSize() const { return AddrSize; } 77 78 uint8_t getRefAddrByteSize() const { 79 if (Version == 2) 80 return AddrSize; 81 return getDwarfOffsetByteSize(); 82 } 83 84 uint8_t getDwarfOffsetByteSize() const { 85 switch (Format) { 86 case dwarf::DwarfFormat::DWARF32: 87 return 4; 88 case dwarf::DwarfFormat::DWARF64: 89 return 8; 90 } 91 llvm_unreachable("Invalid Format value"); 92 } 93 }; 94 95 } // end anonymous namespace 96 97 template <class T> 98 static Optional<uint8_t> getFixedByteSize(dwarf::Form Form, const T *U) { 99 switch (Form) { 100 case DW_FORM_addr: 101 if (U) 102 return U->getAddressByteSize(); 103 return None; 104 105 case DW_FORM_block: // ULEB128 length L followed by L bytes. 106 case DW_FORM_block1: // 1 byte length L followed by L bytes. 107 case DW_FORM_block2: // 2 byte length L followed by L bytes. 108 case DW_FORM_block4: // 4 byte length L followed by L bytes. 109 case DW_FORM_string: // C-string with null terminator. 110 case DW_FORM_sdata: // SLEB128. 111 case DW_FORM_udata: // ULEB128. 112 case DW_FORM_ref_udata: // ULEB128. 113 case DW_FORM_indirect: // ULEB128. 114 case DW_FORM_exprloc: // ULEB128 length L followed by L bytes. 115 case DW_FORM_strx: // ULEB128. 116 case DW_FORM_addrx: // ULEB128. 117 case DW_FORM_loclistx: // ULEB128. 118 case DW_FORM_rnglistx: // ULEB128. 119 case DW_FORM_GNU_addr_index: // ULEB128. 120 case DW_FORM_GNU_str_index: // ULEB128. 121 return None; 122 123 case DW_FORM_ref_addr: 124 if (U) 125 return U->getRefAddrByteSize(); 126 return None; 127 128 case DW_FORM_flag: 129 case DW_FORM_data1: 130 case DW_FORM_ref1: 131 case DW_FORM_strx1: 132 case DW_FORM_addrx1: 133 return 1; 134 135 case DW_FORM_data2: 136 case DW_FORM_ref2: 137 case DW_FORM_strx2: 138 case DW_FORM_addrx2: 139 return 2; 140 141 case DW_FORM_data4: 142 case DW_FORM_ref4: 143 case DW_FORM_ref_sup4: 144 case DW_FORM_strx4: 145 case DW_FORM_addrx4: 146 return 4; 147 148 case DW_FORM_strp: 149 case DW_FORM_GNU_ref_alt: 150 case DW_FORM_GNU_strp_alt: 151 case DW_FORM_line_strp: 152 case DW_FORM_sec_offset: 153 case DW_FORM_strp_sup: 154 if (U) 155 return U->getDwarfOffsetByteSize(); 156 return None; 157 158 case DW_FORM_data8: 159 case DW_FORM_ref8: 160 case DW_FORM_ref_sig8: 161 case DW_FORM_ref_sup8: 162 return 8; 163 164 case DW_FORM_flag_present: 165 return 0; 166 167 case DW_FORM_data16: 168 return 16; 169 170 case DW_FORM_implicit_const: 171 // The implicit value is stored in the abbreviation as a SLEB128, and 172 // there no data in debug info. 173 return 0; 174 175 default: 176 llvm_unreachable("Handle this form in this switch statement"); 177 } 178 return None; 179 } 180 181 template <class T> 182 static bool skipFormValue(dwarf::Form Form, const DataExtractor &DebugInfoData, 183 uint32_t *OffsetPtr, const T *U) { 184 bool Indirect = false; 185 do { 186 switch (Form) { 187 // Blocks of inlined data that have a length field and the data bytes 188 // inlined in the .debug_info. 189 case DW_FORM_exprloc: 190 case DW_FORM_block: { 191 uint64_t size = DebugInfoData.getULEB128(OffsetPtr); 192 *OffsetPtr += size; 193 return true; 194 } 195 case DW_FORM_block1: { 196 uint8_t size = DebugInfoData.getU8(OffsetPtr); 197 *OffsetPtr += size; 198 return true; 199 } 200 case DW_FORM_block2: { 201 uint16_t size = DebugInfoData.getU16(OffsetPtr); 202 *OffsetPtr += size; 203 return true; 204 } 205 case DW_FORM_block4: { 206 uint32_t size = DebugInfoData.getU32(OffsetPtr); 207 *OffsetPtr += size; 208 return true; 209 } 210 211 // Inlined NULL terminated C-strings. 212 case DW_FORM_string: 213 DebugInfoData.getCStr(OffsetPtr); 214 return true; 215 216 case DW_FORM_addr: 217 case DW_FORM_ref_addr: 218 case DW_FORM_flag_present: 219 case DW_FORM_data1: 220 case DW_FORM_data2: 221 case DW_FORM_data4: 222 case DW_FORM_data8: 223 case DW_FORM_flag: 224 case DW_FORM_ref1: 225 case DW_FORM_ref2: 226 case DW_FORM_ref4: 227 case DW_FORM_ref8: 228 case DW_FORM_ref_sig8: 229 case DW_FORM_ref_sup4: 230 case DW_FORM_ref_sup8: 231 case DW_FORM_strx1: 232 case DW_FORM_strx2: 233 case DW_FORM_strx4: 234 case DW_FORM_addrx1: 235 case DW_FORM_addrx2: 236 case DW_FORM_addrx4: 237 case DW_FORM_sec_offset: 238 case DW_FORM_strp: 239 case DW_FORM_strp_sup: 240 case DW_FORM_line_strp: 241 case DW_FORM_GNU_ref_alt: 242 case DW_FORM_GNU_strp_alt: 243 if (Optional<uint8_t> FixedSize = ::getFixedByteSize(Form, U)) { 244 *OffsetPtr += *FixedSize; 245 return true; 246 } 247 return false; 248 249 // signed or unsigned LEB 128 values. 250 case DW_FORM_sdata: 251 DebugInfoData.getSLEB128(OffsetPtr); 252 return true; 253 254 case DW_FORM_udata: 255 case DW_FORM_ref_udata: 256 case DW_FORM_strx: 257 case DW_FORM_addrx: 258 case DW_FORM_loclistx: 259 case DW_FORM_rnglistx: 260 case DW_FORM_GNU_addr_index: 261 case DW_FORM_GNU_str_index: 262 DebugInfoData.getULEB128(OffsetPtr); 263 return true; 264 265 case DW_FORM_indirect: 266 Indirect = true; 267 Form = static_cast<dwarf::Form>(DebugInfoData.getULEB128(OffsetPtr)); 268 break; 269 270 default: 271 return false; 272 } 273 } while (Indirect); 274 return true; 275 } 276 277 Optional<uint8_t> DWARFFormValue::getFixedByteSize(dwarf::Form Form, 278 const DWARFUnit *U) { 279 return ::getFixedByteSize(Form, U); 280 } 281 282 Optional<uint8_t> 283 DWARFFormValue::getFixedByteSize(dwarf::Form Form, uint16_t Version, 284 uint8_t AddrSize, 285 llvm::dwarf::DwarfFormat Format) { 286 FormSizeHelper FSH(Version, AddrSize, Format); 287 return ::getFixedByteSize(Form, &FSH); 288 } 289 290 bool DWARFFormValue::isFormClass(DWARFFormValue::FormClass FC) const { 291 // First, check DWARF4 form classes. 292 if (Form < makeArrayRef(DWARF4FormClasses).size() && 293 DWARF4FormClasses[Form] == FC) 294 return true; 295 // Check more forms from DWARF4 and DWARF5 proposals. 296 switch (Form) { 297 case DW_FORM_ref_sig8: 298 case DW_FORM_GNU_ref_alt: 299 return (FC == FC_Reference); 300 case DW_FORM_GNU_addr_index: 301 return (FC == FC_Address); 302 case DW_FORM_GNU_str_index: 303 case DW_FORM_GNU_strp_alt: 304 return (FC == FC_String); 305 case DW_FORM_implicit_const: 306 return (FC == FC_Constant); 307 default: 308 break; 309 } 310 // In DWARF3 DW_FORM_data4 and DW_FORM_data8 served also as a section offset. 311 // Don't check for DWARF version here, as some producers may still do this 312 // by mistake. Also accept DW_FORM_strp since this is .debug_str section 313 // offset. 314 return (Form == DW_FORM_data4 || Form == DW_FORM_data8 || 315 Form == DW_FORM_strp) && 316 FC == FC_SectionOffset; 317 } 318 319 bool DWARFFormValue::extractValue(const DataExtractor &Data, 320 uint32_t *OffsetPtr, const DWARFUnit *CU) { 321 U = CU; 322 bool Indirect = false; 323 bool IsBlock = false; 324 Value.data = nullptr; 325 // Read the value for the form into value and follow and DW_FORM_indirect 326 // instances we run into 327 do { 328 Indirect = false; 329 switch (Form) { 330 case DW_FORM_addr: 331 case DW_FORM_ref_addr: { 332 if (!U) 333 return false; 334 uint16_t AddrSize = (Form == DW_FORM_addr) ? U->getAddressByteSize() 335 : U->getRefAddrByteSize(); 336 Value.uval = 337 getRelocatedValue(Data, AddrSize, OffsetPtr, U->getRelocMap()); 338 break; 339 } 340 case DW_FORM_exprloc: 341 case DW_FORM_block: 342 Value.uval = Data.getULEB128(OffsetPtr); 343 IsBlock = true; 344 break; 345 case DW_FORM_block1: 346 Value.uval = Data.getU8(OffsetPtr); 347 IsBlock = true; 348 break; 349 case DW_FORM_block2: 350 Value.uval = Data.getU16(OffsetPtr); 351 IsBlock = true; 352 break; 353 case DW_FORM_block4: 354 Value.uval = Data.getU32(OffsetPtr); 355 IsBlock = true; 356 break; 357 case DW_FORM_data1: 358 case DW_FORM_ref1: 359 case DW_FORM_flag: 360 case DW_FORM_strx1: 361 case DW_FORM_addrx1: 362 Value.uval = Data.getU8(OffsetPtr); 363 break; 364 case DW_FORM_data2: 365 case DW_FORM_ref2: 366 case DW_FORM_strx2: 367 case DW_FORM_addrx2: 368 Value.uval = Data.getU16(OffsetPtr); 369 break; 370 case DW_FORM_data4: 371 case DW_FORM_ref4: 372 case DW_FORM_ref_sup4: 373 case DW_FORM_strx4: 374 case DW_FORM_addrx4: { 375 const RelocAddrMap *RelocMap = U ? U->getRelocMap() : nullptr; 376 Value.uval = getRelocatedValue(Data, 4, OffsetPtr, RelocMap); 377 break; 378 } 379 case DW_FORM_data8: 380 case DW_FORM_ref8: 381 case DW_FORM_ref_sup8: 382 Value.uval = Data.getU64(OffsetPtr); 383 break; 384 case DW_FORM_sdata: 385 Value.sval = Data.getSLEB128(OffsetPtr); 386 break; 387 case DW_FORM_udata: 388 case DW_FORM_ref_udata: 389 Value.uval = Data.getULEB128(OffsetPtr); 390 break; 391 case DW_FORM_string: 392 Value.cstr = Data.getCStr(OffsetPtr); 393 break; 394 case DW_FORM_indirect: 395 Form = static_cast<dwarf::Form>(Data.getULEB128(OffsetPtr)); 396 Indirect = true; 397 break; 398 case DW_FORM_strp: 399 case DW_FORM_sec_offset: 400 case DW_FORM_GNU_ref_alt: 401 case DW_FORM_GNU_strp_alt: 402 case DW_FORM_line_strp: 403 case DW_FORM_strp_sup: { 404 if (!U) 405 return false; 406 Value.uval = getRelocatedValue(Data, U->getDwarfOffsetByteSize(), 407 OffsetPtr, U->getRelocMap()); 408 break; 409 } 410 case DW_FORM_flag_present: 411 Value.uval = 1; 412 break; 413 case DW_FORM_ref_sig8: 414 Value.uval = Data.getU64(OffsetPtr); 415 break; 416 case DW_FORM_GNU_addr_index: 417 case DW_FORM_GNU_str_index: 418 Value.uval = Data.getULEB128(OffsetPtr); 419 break; 420 default: 421 // DWARFFormValue::skipValue() will have caught this and caused all 422 // DWARF DIEs to fail to be parsed, so this code is not be reachable. 423 llvm_unreachable("unsupported form"); 424 } 425 } while (Indirect); 426 427 if (IsBlock) { 428 StringRef Str = Data.getData().substr(*OffsetPtr, Value.uval); 429 Value.data = nullptr; 430 if (!Str.empty()) { 431 Value.data = reinterpret_cast<const uint8_t *>(Str.data()); 432 *OffsetPtr += Value.uval; 433 } 434 } 435 436 return true; 437 } 438 439 bool DWARFFormValue::skipValue(DataExtractor DebugInfoData, uint32_t *OffsetPtr, 440 const DWARFUnit *U) const { 441 return DWARFFormValue::skipValue(Form, DebugInfoData, OffsetPtr, U); 442 } 443 444 bool DWARFFormValue::skipValue(dwarf::Form Form, DataExtractor DebugInfoData, 445 uint32_t *OffsetPtr, const DWARFUnit *U) { 446 return skipFormValue(Form, DebugInfoData, OffsetPtr, U); 447 } 448 449 bool DWARFFormValue::skipValue(dwarf::Form Form, DataExtractor DebugInfoData, 450 uint32_t *OffsetPtr, uint16_t Version, 451 uint8_t AddrSize, 452 llvm::dwarf::DwarfFormat Format) { 453 FormSizeHelper FSH(Version, AddrSize, Format); 454 return skipFormValue(Form, DebugInfoData, OffsetPtr, &FSH); 455 } 456 457 void DWARFFormValue::dump(raw_ostream &OS) const { 458 uint64_t UValue = Value.uval; 459 bool CURelativeOffset = false; 460 461 switch (Form) { 462 case DW_FORM_addr: 463 OS << format("0x%016" PRIx64, UValue); 464 break; 465 case DW_FORM_GNU_addr_index: { 466 OS << format(" indexed (%8.8x) address = ", (uint32_t)UValue); 467 uint64_t Address; 468 if (U == nullptr) 469 OS << "<invalid dwarf unit>"; 470 else if (U->getAddrOffsetSectionItem(UValue, Address)) 471 OS << format("0x%016" PRIx64, Address); 472 else 473 OS << "<no .debug_addr section>"; 474 break; 475 } 476 case DW_FORM_flag_present: 477 OS << "true"; 478 break; 479 case DW_FORM_flag: 480 case DW_FORM_data1: 481 OS << format("0x%02x", (uint8_t)UValue); 482 break; 483 case DW_FORM_data2: 484 OS << format("0x%04x", (uint16_t)UValue); 485 break; 486 case DW_FORM_data4: 487 OS << format("0x%08x", (uint32_t)UValue); 488 break; 489 case DW_FORM_ref_sig8: 490 case DW_FORM_data8: 491 OS << format("0x%016" PRIx64, UValue); 492 break; 493 case DW_FORM_string: 494 OS << '"'; 495 OS.write_escaped(Value.cstr); 496 OS << '"'; 497 break; 498 case DW_FORM_exprloc: 499 case DW_FORM_block: 500 case DW_FORM_block1: 501 case DW_FORM_block2: 502 case DW_FORM_block4: 503 if (UValue > 0) { 504 switch (Form) { 505 case DW_FORM_exprloc: 506 case DW_FORM_block: 507 OS << format("<0x%" PRIx64 "> ", UValue); 508 break; 509 case DW_FORM_block1: 510 OS << format("<0x%2.2x> ", (uint8_t)UValue); 511 break; 512 case DW_FORM_block2: 513 OS << format("<0x%4.4x> ", (uint16_t)UValue); 514 break; 515 case DW_FORM_block4: 516 OS << format("<0x%8.8x> ", (uint32_t)UValue); 517 break; 518 default: 519 break; 520 } 521 522 const uint8_t *DataPtr = Value.data; 523 if (DataPtr) { 524 // UValue contains size of block 525 const uint8_t *EndDataPtr = DataPtr + UValue; 526 while (DataPtr < EndDataPtr) { 527 OS << format("%2.2x ", *DataPtr); 528 ++DataPtr; 529 } 530 } else 531 OS << "NULL"; 532 } 533 break; 534 535 case DW_FORM_sdata: 536 OS << Value.sval; 537 break; 538 case DW_FORM_udata: 539 OS << Value.uval; 540 break; 541 case DW_FORM_strp: 542 OS << format(" .debug_str[0x%8.8x] = ", (uint32_t)UValue); 543 dumpString(OS); 544 break; 545 case DW_FORM_GNU_str_index: 546 OS << format(" indexed (%8.8x) string = ", (uint32_t)UValue); 547 dumpString(OS); 548 break; 549 case DW_FORM_GNU_strp_alt: 550 OS << format("alt indirect string, offset: 0x%" PRIx64 "", UValue); 551 dumpString(OS); 552 break; 553 case DW_FORM_ref_addr: 554 OS << format("0x%016" PRIx64, UValue); 555 break; 556 case DW_FORM_ref1: 557 CURelativeOffset = true; 558 OS << format("cu + 0x%2.2x", (uint8_t)UValue); 559 break; 560 case DW_FORM_ref2: 561 CURelativeOffset = true; 562 OS << format("cu + 0x%4.4x", (uint16_t)UValue); 563 break; 564 case DW_FORM_ref4: 565 CURelativeOffset = true; 566 OS << format("cu + 0x%4.4x", (uint32_t)UValue); 567 break; 568 case DW_FORM_ref8: 569 CURelativeOffset = true; 570 OS << format("cu + 0x%8.8" PRIx64, UValue); 571 break; 572 case DW_FORM_ref_udata: 573 CURelativeOffset = true; 574 OS << format("cu + 0x%" PRIx64, UValue); 575 break; 576 case DW_FORM_GNU_ref_alt: 577 OS << format("<alt 0x%" PRIx64 ">", UValue); 578 break; 579 580 // All DW_FORM_indirect attributes should be resolved prior to calling 581 // this function 582 case DW_FORM_indirect: 583 OS << "DW_FORM_indirect"; 584 break; 585 586 // Should be formatted to 64-bit for DWARF64. 587 case DW_FORM_sec_offset: 588 OS << format("0x%08x", (uint32_t)UValue); 589 break; 590 591 default: 592 OS << format("DW_FORM(0x%4.4x)", Form); 593 break; 594 } 595 596 if (CURelativeOffset) { 597 OS << " => {"; 598 WithColor(OS, syntax::Address).get() 599 << format("0x%8.8" PRIx64, UValue + (U ? U->getOffset() : 0)); 600 OS << "}"; 601 } 602 } 603 604 void DWARFFormValue::dumpString(raw_ostream &OS) const { 605 Optional<const char *> DbgStr = getAsCString(); 606 if (DbgStr.hasValue()) { 607 raw_ostream &COS = WithColor(OS, syntax::String); 608 COS << '"'; 609 COS.write_escaped(DbgStr.getValue()); 610 COS << '"'; 611 } 612 } 613 614 Optional<const char *> DWARFFormValue::getAsCString() const { 615 if (!isFormClass(FC_String)) 616 return None; 617 if (Form == DW_FORM_string) 618 return Value.cstr; 619 // FIXME: Add support for DW_FORM_GNU_strp_alt 620 if (Form == DW_FORM_GNU_strp_alt || U == nullptr) 621 return None; 622 uint32_t Offset = Value.uval; 623 if (Form == DW_FORM_GNU_str_index) { 624 uint32_t StrOffset; 625 if (!U->getStringOffsetSectionItem(Offset, StrOffset)) 626 return None; 627 Offset = StrOffset; 628 } 629 if (const char *Str = U->getStringExtractor().getCStr(&Offset)) { 630 return Str; 631 } 632 return None; 633 } 634 635 Optional<uint64_t> DWARFFormValue::getAsAddress() const { 636 if (!isFormClass(FC_Address)) 637 return None; 638 if (Form == DW_FORM_GNU_addr_index) { 639 uint32_t Index = Value.uval; 640 uint64_t Result; 641 if (!U || !U->getAddrOffsetSectionItem(Index, Result)) 642 return None; 643 return Result; 644 } 645 return Value.uval; 646 } 647 648 Optional<uint64_t> DWARFFormValue::getAsReference() const { 649 if (!isFormClass(FC_Reference)) 650 return None; 651 switch (Form) { 652 case DW_FORM_ref1: 653 case DW_FORM_ref2: 654 case DW_FORM_ref4: 655 case DW_FORM_ref8: 656 case DW_FORM_ref_udata: 657 if (!U) 658 return None; 659 return Value.uval + U->getOffset(); 660 case DW_FORM_ref_addr: 661 case DW_FORM_ref_sig8: 662 case DW_FORM_GNU_ref_alt: 663 return Value.uval; 664 default: 665 return None; 666 } 667 } 668 669 Optional<uint64_t> DWARFFormValue::getAsSectionOffset() const { 670 if (!isFormClass(FC_SectionOffset)) 671 return None; 672 return Value.uval; 673 } 674 675 Optional<uint64_t> DWARFFormValue::getAsUnsignedConstant() const { 676 if ((!isFormClass(FC_Constant) && !isFormClass(FC_Flag)) || 677 Form == DW_FORM_sdata) 678 return None; 679 return Value.uval; 680 } 681 682 Optional<int64_t> DWARFFormValue::getAsSignedConstant() const { 683 if ((!isFormClass(FC_Constant) && !isFormClass(FC_Flag)) || 684 (Form == DW_FORM_udata && 685 uint64_t(std::numeric_limits<int64_t>::max()) < Value.uval)) 686 return None; 687 switch (Form) { 688 case DW_FORM_data4: 689 return int32_t(Value.uval); 690 case DW_FORM_data2: 691 return int16_t(Value.uval); 692 case DW_FORM_data1: 693 return int8_t(Value.uval); 694 case DW_FORM_sdata: 695 case DW_FORM_data8: 696 default: 697 return Value.sval; 698 } 699 } 700 701 Optional<ArrayRef<uint8_t>> DWARFFormValue::getAsBlock() const { 702 if (!isFormClass(FC_Block) && !isFormClass(FC_Exprloc)) 703 return None; 704 return makeArrayRef(Value.data, Value.uval); 705 } 706 707 Optional<uint64_t> DWARFFormValue::getAsCStringOffset() const { 708 if (!isFormClass(FC_String) && Form == DW_FORM_string) 709 return None; 710 return Value.uval; 711 } 712 713 Optional<uint64_t> DWARFFormValue::getAsReferenceUVal() const { 714 if (!isFormClass(FC_Reference)) 715 return None; 716 return Value.uval; 717 } 718