1 //===- WasmObjectFile.cpp - Wasm object file implementation ---------------===// 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/ADT/ArrayRef.h" 10 #include "llvm/ADT/DenseSet.h" 11 #include "llvm/ADT/STLExtras.h" 12 #include "llvm/ADT/SmallSet.h" 13 #include "llvm/ADT/StringRef.h" 14 #include "llvm/ADT/StringSet.h" 15 #include "llvm/ADT/StringSwitch.h" 16 #include "llvm/ADT/Triple.h" 17 #include "llvm/BinaryFormat/Wasm.h" 18 #include "llvm/MC/SubtargetFeature.h" 19 #include "llvm/Object/Binary.h" 20 #include "llvm/Object/Error.h" 21 #include "llvm/Object/ObjectFile.h" 22 #include "llvm/Object/SymbolicFile.h" 23 #include "llvm/Object/Wasm.h" 24 #include "llvm/Support/Endian.h" 25 #include "llvm/Support/Error.h" 26 #include "llvm/Support/ErrorHandling.h" 27 #include "llvm/Support/LEB128.h" 28 #include "llvm/Support/ScopedPrinter.h" 29 #include <algorithm> 30 #include <cassert> 31 #include <cstdint> 32 #include <cstring> 33 #include <system_error> 34 35 #define DEBUG_TYPE "wasm-object" 36 37 using namespace llvm; 38 using namespace object; 39 40 void WasmSymbol::print(raw_ostream &Out) const { 41 Out << "Name=" << Info.Name 42 << ", Kind=" << toString(wasm::WasmSymbolType(Info.Kind)) 43 << ", Flags=" << Info.Flags; 44 if (!isTypeData()) { 45 Out << ", ElemIndex=" << Info.ElementIndex; 46 } else if (isDefined()) { 47 Out << ", Segment=" << Info.DataRef.Segment; 48 Out << ", Offset=" << Info.DataRef.Offset; 49 Out << ", Size=" << Info.DataRef.Size; 50 } 51 } 52 53 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP) 54 LLVM_DUMP_METHOD void WasmSymbol::dump() const { print(dbgs()); } 55 #endif 56 57 Expected<std::unique_ptr<WasmObjectFile>> 58 ObjectFile::createWasmObjectFile(MemoryBufferRef Buffer) { 59 Error Err = Error::success(); 60 auto ObjectFile = std::make_unique<WasmObjectFile>(Buffer, Err); 61 if (Err) 62 return std::move(Err); 63 64 return std::move(ObjectFile); 65 } 66 67 #define VARINT7_MAX ((1 << 7) - 1) 68 #define VARINT7_MIN (-(1 << 7)) 69 #define VARUINT7_MAX (1 << 7) 70 #define VARUINT1_MAX (1) 71 72 static uint8_t readUint8(WasmObjectFile::ReadContext &Ctx) { 73 if (Ctx.Ptr == Ctx.End) 74 report_fatal_error("EOF while reading uint8"); 75 return *Ctx.Ptr++; 76 } 77 78 static uint32_t readUint32(WasmObjectFile::ReadContext &Ctx) { 79 if (Ctx.Ptr + 4 > Ctx.End) 80 report_fatal_error("EOF while reading uint32"); 81 uint32_t Result = support::endian::read32le(Ctx.Ptr); 82 Ctx.Ptr += 4; 83 return Result; 84 } 85 86 static int32_t readFloat32(WasmObjectFile::ReadContext &Ctx) { 87 if (Ctx.Ptr + 4 > Ctx.End) 88 report_fatal_error("EOF while reading float64"); 89 int32_t Result = 0; 90 memcpy(&Result, Ctx.Ptr, sizeof(Result)); 91 Ctx.Ptr += sizeof(Result); 92 return Result; 93 } 94 95 static int64_t readFloat64(WasmObjectFile::ReadContext &Ctx) { 96 if (Ctx.Ptr + 8 > Ctx.End) 97 report_fatal_error("EOF while reading float64"); 98 int64_t Result = 0; 99 memcpy(&Result, Ctx.Ptr, sizeof(Result)); 100 Ctx.Ptr += sizeof(Result); 101 return Result; 102 } 103 104 static uint64_t readULEB128(WasmObjectFile::ReadContext &Ctx) { 105 unsigned Count; 106 const char *Error = nullptr; 107 uint64_t Result = decodeULEB128(Ctx.Ptr, &Count, Ctx.End, &Error); 108 if (Error) 109 report_fatal_error(Error); 110 Ctx.Ptr += Count; 111 return Result; 112 } 113 114 static StringRef readString(WasmObjectFile::ReadContext &Ctx) { 115 uint32_t StringLen = readULEB128(Ctx); 116 if (Ctx.Ptr + StringLen > Ctx.End) 117 report_fatal_error("EOF while reading string"); 118 StringRef Return = 119 StringRef(reinterpret_cast<const char *>(Ctx.Ptr), StringLen); 120 Ctx.Ptr += StringLen; 121 return Return; 122 } 123 124 static int64_t readLEB128(WasmObjectFile::ReadContext &Ctx) { 125 unsigned Count; 126 const char *Error = nullptr; 127 uint64_t Result = decodeSLEB128(Ctx.Ptr, &Count, Ctx.End, &Error); 128 if (Error) 129 report_fatal_error(Error); 130 Ctx.Ptr += Count; 131 return Result; 132 } 133 134 static uint8_t readVaruint1(WasmObjectFile::ReadContext &Ctx) { 135 int64_t Result = readLEB128(Ctx); 136 if (Result > VARUINT1_MAX || Result < 0) 137 report_fatal_error("LEB is outside Varuint1 range"); 138 return Result; 139 } 140 141 static int32_t readVarint32(WasmObjectFile::ReadContext &Ctx) { 142 int64_t Result = readLEB128(Ctx); 143 if (Result > INT32_MAX || Result < INT32_MIN) 144 report_fatal_error("LEB is outside Varint32 range"); 145 return Result; 146 } 147 148 static uint32_t readVaruint32(WasmObjectFile::ReadContext &Ctx) { 149 uint64_t Result = readULEB128(Ctx); 150 if (Result > UINT32_MAX) 151 report_fatal_error("LEB is outside Varuint32 range"); 152 return Result; 153 } 154 155 static int64_t readVarint64(WasmObjectFile::ReadContext &Ctx) { 156 return readLEB128(Ctx); 157 } 158 159 static uint64_t readVaruint64(WasmObjectFile::ReadContext &Ctx) { 160 return readULEB128(Ctx); 161 } 162 163 static uint8_t readOpcode(WasmObjectFile::ReadContext &Ctx) { 164 return readUint8(Ctx); 165 } 166 167 static Error readInitExpr(wasm::WasmInitExpr &Expr, 168 WasmObjectFile::ReadContext &Ctx) { 169 Expr.Opcode = readOpcode(Ctx); 170 171 switch (Expr.Opcode) { 172 case wasm::WASM_OPCODE_I32_CONST: 173 Expr.Value.Int32 = readVarint32(Ctx); 174 break; 175 case wasm::WASM_OPCODE_I64_CONST: 176 Expr.Value.Int64 = readVarint64(Ctx); 177 break; 178 case wasm::WASM_OPCODE_F32_CONST: 179 Expr.Value.Float32 = readFloat32(Ctx); 180 break; 181 case wasm::WASM_OPCODE_F64_CONST: 182 Expr.Value.Float64 = readFloat64(Ctx); 183 break; 184 case wasm::WASM_OPCODE_GLOBAL_GET: 185 Expr.Value.Global = readULEB128(Ctx); 186 break; 187 case wasm::WASM_OPCODE_REF_NULL: { 188 wasm::ValType Ty = static_cast<wasm::ValType>(readULEB128(Ctx)); 189 if (Ty != wasm::ValType::EXTERNREF) { 190 return make_error<GenericBinaryError>("Invalid type for ref.null", 191 object_error::parse_failed); 192 } 193 break; 194 } 195 default: 196 return make_error<GenericBinaryError>("Invalid opcode in init_expr", 197 object_error::parse_failed); 198 } 199 200 uint8_t EndOpcode = readOpcode(Ctx); 201 if (EndOpcode != wasm::WASM_OPCODE_END) { 202 return make_error<GenericBinaryError>("Invalid init_expr", 203 object_error::parse_failed); 204 } 205 return Error::success(); 206 } 207 208 static wasm::WasmLimits readLimits(WasmObjectFile::ReadContext &Ctx) { 209 wasm::WasmLimits Result; 210 Result.Flags = readVaruint32(Ctx); 211 Result.Initial = readVaruint64(Ctx); 212 if (Result.Flags & wasm::WASM_LIMITS_FLAG_HAS_MAX) 213 Result.Maximum = readVaruint64(Ctx); 214 return Result; 215 } 216 217 static wasm::WasmTable readTable(WasmObjectFile::ReadContext &Ctx) { 218 wasm::WasmTable Table; 219 Table.ElemType = readUint8(Ctx); 220 Table.Limits = readLimits(Ctx); 221 // The caller needs to set Table.Index field for Table 222 return Table; 223 } 224 225 static Error readSection(WasmSection &Section, WasmObjectFile::ReadContext &Ctx, 226 WasmSectionOrderChecker &Checker) { 227 Section.Offset = Ctx.Ptr - Ctx.Start; 228 Section.Type = readUint8(Ctx); 229 LLVM_DEBUG(dbgs() << "readSection type=" << Section.Type << "\n"); 230 uint32_t Size = readVaruint32(Ctx); 231 if (Size == 0) 232 return make_error<StringError>("Zero length section", 233 object_error::parse_failed); 234 if (Ctx.Ptr + Size > Ctx.End) 235 return make_error<StringError>("Section too large", 236 object_error::parse_failed); 237 if (Section.Type == wasm::WASM_SEC_CUSTOM) { 238 WasmObjectFile::ReadContext SectionCtx; 239 SectionCtx.Start = Ctx.Ptr; 240 SectionCtx.Ptr = Ctx.Ptr; 241 SectionCtx.End = Ctx.Ptr + Size; 242 243 Section.Name = readString(SectionCtx); 244 245 uint32_t SectionNameSize = SectionCtx.Ptr - SectionCtx.Start; 246 Ctx.Ptr += SectionNameSize; 247 Size -= SectionNameSize; 248 } 249 250 if (!Checker.isValidSectionOrder(Section.Type, Section.Name)) { 251 return make_error<StringError>("Out of order section type: " + 252 llvm::to_string(Section.Type), 253 object_error::parse_failed); 254 } 255 256 Section.Content = ArrayRef<uint8_t>(Ctx.Ptr, Size); 257 Ctx.Ptr += Size; 258 return Error::success(); 259 } 260 261 WasmObjectFile::WasmObjectFile(MemoryBufferRef Buffer, Error &Err) 262 : ObjectFile(Binary::ID_Wasm, Buffer) { 263 ErrorAsOutParameter ErrAsOutParam(&Err); 264 Header.Magic = getData().substr(0, 4); 265 if (Header.Magic != StringRef("\0asm", 4)) { 266 Err = 267 make_error<StringError>("Bad magic number", object_error::parse_failed); 268 return; 269 } 270 271 ReadContext Ctx; 272 Ctx.Start = getData().bytes_begin(); 273 Ctx.Ptr = Ctx.Start + 4; 274 Ctx.End = Ctx.Start + getData().size(); 275 276 if (Ctx.Ptr + 4 > Ctx.End) { 277 Err = make_error<StringError>("Missing version number", 278 object_error::parse_failed); 279 return; 280 } 281 282 Header.Version = readUint32(Ctx); 283 if (Header.Version != wasm::WasmVersion) { 284 Err = make_error<StringError>("Bad version number", 285 object_error::parse_failed); 286 return; 287 } 288 289 WasmSection Sec; 290 WasmSectionOrderChecker Checker; 291 while (Ctx.Ptr < Ctx.End) { 292 if ((Err = readSection(Sec, Ctx, Checker))) 293 return; 294 if ((Err = parseSection(Sec))) 295 return; 296 297 Sections.push_back(Sec); 298 } 299 } 300 301 Error WasmObjectFile::parseSection(WasmSection &Sec) { 302 ReadContext Ctx; 303 Ctx.Start = Sec.Content.data(); 304 Ctx.End = Ctx.Start + Sec.Content.size(); 305 Ctx.Ptr = Ctx.Start; 306 switch (Sec.Type) { 307 case wasm::WASM_SEC_CUSTOM: 308 return parseCustomSection(Sec, Ctx); 309 case wasm::WASM_SEC_TYPE: 310 return parseTypeSection(Ctx); 311 case wasm::WASM_SEC_IMPORT: 312 return parseImportSection(Ctx); 313 case wasm::WASM_SEC_FUNCTION: 314 return parseFunctionSection(Ctx); 315 case wasm::WASM_SEC_TABLE: 316 return parseTableSection(Ctx); 317 case wasm::WASM_SEC_MEMORY: 318 return parseMemorySection(Ctx); 319 case wasm::WASM_SEC_EVENT: 320 return parseEventSection(Ctx); 321 case wasm::WASM_SEC_GLOBAL: 322 return parseGlobalSection(Ctx); 323 case wasm::WASM_SEC_EXPORT: 324 return parseExportSection(Ctx); 325 case wasm::WASM_SEC_START: 326 return parseStartSection(Ctx); 327 case wasm::WASM_SEC_ELEM: 328 return parseElemSection(Ctx); 329 case wasm::WASM_SEC_CODE: 330 return parseCodeSection(Ctx); 331 case wasm::WASM_SEC_DATA: 332 return parseDataSection(Ctx); 333 case wasm::WASM_SEC_DATACOUNT: 334 return parseDataCountSection(Ctx); 335 default: 336 return make_error<GenericBinaryError>( 337 "Invalid section type: " + Twine(Sec.Type), object_error::parse_failed); 338 } 339 } 340 341 Error WasmObjectFile::parseDylinkSection(ReadContext &Ctx) { 342 // See https://github.com/WebAssembly/tool-conventions/blob/master/DynamicLinking.md 343 HasDylinkSection = true; 344 DylinkInfo.MemorySize = readVaruint32(Ctx); 345 DylinkInfo.MemoryAlignment = readVaruint32(Ctx); 346 DylinkInfo.TableSize = readVaruint32(Ctx); 347 DylinkInfo.TableAlignment = readVaruint32(Ctx); 348 uint32_t Count = readVaruint32(Ctx); 349 while (Count--) { 350 DylinkInfo.Needed.push_back(readString(Ctx)); 351 } 352 if (Ctx.Ptr != Ctx.End) 353 return make_error<GenericBinaryError>("dylink section ended prematurely", 354 object_error::parse_failed); 355 return Error::success(); 356 } 357 358 Error WasmObjectFile::parseNameSection(ReadContext &Ctx) { 359 llvm::DenseSet<uint64_t> Seen; 360 if (FunctionTypes.size() && !SeenCodeSection) { 361 return make_error<GenericBinaryError>("Names must come after code section", 362 object_error::parse_failed); 363 } 364 365 while (Ctx.Ptr < Ctx.End) { 366 uint8_t Type = readUint8(Ctx); 367 uint32_t Size = readVaruint32(Ctx); 368 const uint8_t *SubSectionEnd = Ctx.Ptr + Size; 369 switch (Type) { 370 case wasm::WASM_NAMES_FUNCTION: { 371 uint32_t Count = readVaruint32(Ctx); 372 while (Count--) { 373 uint32_t Index = readVaruint32(Ctx); 374 if (!Seen.insert(Index).second) 375 return make_error<GenericBinaryError>("Function named more than once", 376 object_error::parse_failed); 377 StringRef Name = readString(Ctx); 378 if (!isValidFunctionIndex(Index) || Name.empty()) 379 return make_error<GenericBinaryError>("Invalid name entry", 380 object_error::parse_failed); 381 DebugNames.push_back(wasm::WasmFunctionName{Index, Name}); 382 if (isDefinedFunctionIndex(Index)) 383 getDefinedFunction(Index).DebugName = Name; 384 } 385 break; 386 } 387 // Ignore local names for now 388 case wasm::WASM_NAMES_LOCAL: 389 default: 390 Ctx.Ptr += Size; 391 break; 392 } 393 if (Ctx.Ptr != SubSectionEnd) 394 return make_error<GenericBinaryError>( 395 "Name sub-section ended prematurely", object_error::parse_failed); 396 } 397 398 if (Ctx.Ptr != Ctx.End) 399 return make_error<GenericBinaryError>("Name section ended prematurely", 400 object_error::parse_failed); 401 return Error::success(); 402 } 403 404 Error WasmObjectFile::parseLinkingSection(ReadContext &Ctx) { 405 HasLinkingSection = true; 406 if (FunctionTypes.size() && !SeenCodeSection) { 407 return make_error<GenericBinaryError>( 408 "Linking data must come after code section", 409 object_error::parse_failed); 410 } 411 412 LinkingData.Version = readVaruint32(Ctx); 413 if (LinkingData.Version != wasm::WasmMetadataVersion) { 414 return make_error<GenericBinaryError>( 415 "Unexpected metadata version: " + Twine(LinkingData.Version) + 416 " (Expected: " + Twine(wasm::WasmMetadataVersion) + ")", 417 object_error::parse_failed); 418 } 419 420 const uint8_t *OrigEnd = Ctx.End; 421 while (Ctx.Ptr < OrigEnd) { 422 Ctx.End = OrigEnd; 423 uint8_t Type = readUint8(Ctx); 424 uint32_t Size = readVaruint32(Ctx); 425 LLVM_DEBUG(dbgs() << "readSubsection type=" << int(Type) << " size=" << Size 426 << "\n"); 427 Ctx.End = Ctx.Ptr + Size; 428 switch (Type) { 429 case wasm::WASM_SYMBOL_TABLE: 430 if (Error Err = parseLinkingSectionSymtab(Ctx)) 431 return Err; 432 break; 433 case wasm::WASM_SEGMENT_INFO: { 434 uint32_t Count = readVaruint32(Ctx); 435 if (Count > DataSegments.size()) 436 return make_error<GenericBinaryError>("Too many segment names", 437 object_error::parse_failed); 438 for (uint32_t I = 0; I < Count; I++) { 439 DataSegments[I].Data.Name = readString(Ctx); 440 DataSegments[I].Data.Alignment = readVaruint32(Ctx); 441 DataSegments[I].Data.LinkerFlags = readVaruint32(Ctx); 442 } 443 break; 444 } 445 case wasm::WASM_INIT_FUNCS: { 446 uint32_t Count = readVaruint32(Ctx); 447 LinkingData.InitFunctions.reserve(Count); 448 for (uint32_t I = 0; I < Count; I++) { 449 wasm::WasmInitFunc Init; 450 Init.Priority = readVaruint32(Ctx); 451 Init.Symbol = readVaruint32(Ctx); 452 if (!isValidFunctionSymbol(Init.Symbol)) 453 return make_error<GenericBinaryError>("Invalid function symbol: " + 454 Twine(Init.Symbol), 455 object_error::parse_failed); 456 LinkingData.InitFunctions.emplace_back(Init); 457 } 458 break; 459 } 460 case wasm::WASM_COMDAT_INFO: 461 if (Error Err = parseLinkingSectionComdat(Ctx)) 462 return Err; 463 break; 464 default: 465 Ctx.Ptr += Size; 466 break; 467 } 468 if (Ctx.Ptr != Ctx.End) 469 return make_error<GenericBinaryError>( 470 "Linking sub-section ended prematurely", object_error::parse_failed); 471 } 472 if (Ctx.Ptr != OrigEnd) 473 return make_error<GenericBinaryError>("Linking section ended prematurely", 474 object_error::parse_failed); 475 return Error::success(); 476 } 477 478 Error WasmObjectFile::parseLinkingSectionSymtab(ReadContext &Ctx) { 479 uint32_t Count = readVaruint32(Ctx); 480 LinkingData.SymbolTable.reserve(Count); 481 Symbols.reserve(Count); 482 StringSet<> SymbolNames; 483 484 std::vector<wasm::WasmImport *> ImportedGlobals; 485 std::vector<wasm::WasmImport *> ImportedFunctions; 486 std::vector<wasm::WasmImport *> ImportedEvents; 487 ImportedGlobals.reserve(Imports.size()); 488 ImportedFunctions.reserve(Imports.size()); 489 ImportedEvents.reserve(Imports.size()); 490 for (auto &I : Imports) { 491 if (I.Kind == wasm::WASM_EXTERNAL_FUNCTION) 492 ImportedFunctions.emplace_back(&I); 493 else if (I.Kind == wasm::WASM_EXTERNAL_GLOBAL) 494 ImportedGlobals.emplace_back(&I); 495 else if (I.Kind == wasm::WASM_EXTERNAL_EVENT) 496 ImportedEvents.emplace_back(&I); 497 } 498 499 while (Count--) { 500 wasm::WasmSymbolInfo Info; 501 const wasm::WasmSignature *Signature = nullptr; 502 const wasm::WasmGlobalType *GlobalType = nullptr; 503 uint8_t TableType = 0; 504 const wasm::WasmEventType *EventType = nullptr; 505 506 Info.Kind = readUint8(Ctx); 507 Info.Flags = readVaruint32(Ctx); 508 bool IsDefined = (Info.Flags & wasm::WASM_SYMBOL_UNDEFINED) == 0; 509 510 switch (Info.Kind) { 511 case wasm::WASM_SYMBOL_TYPE_FUNCTION: 512 Info.ElementIndex = readVaruint32(Ctx); 513 if (!isValidFunctionIndex(Info.ElementIndex) || 514 IsDefined != isDefinedFunctionIndex(Info.ElementIndex)) 515 return make_error<GenericBinaryError>("invalid function symbol index", 516 object_error::parse_failed); 517 if (IsDefined) { 518 Info.Name = readString(Ctx); 519 unsigned FuncIndex = Info.ElementIndex - NumImportedFunctions; 520 Signature = &Signatures[FunctionTypes[FuncIndex]]; 521 wasm::WasmFunction &Function = Functions[FuncIndex]; 522 if (Function.SymbolName.empty()) 523 Function.SymbolName = Info.Name; 524 } else { 525 wasm::WasmImport &Import = *ImportedFunctions[Info.ElementIndex]; 526 if ((Info.Flags & wasm::WASM_SYMBOL_EXPLICIT_NAME) != 0) { 527 Info.Name = readString(Ctx); 528 Info.ImportName = Import.Field; 529 } else { 530 Info.Name = Import.Field; 531 } 532 Signature = &Signatures[Import.SigIndex]; 533 if (!Import.Module.empty()) { 534 Info.ImportModule = Import.Module; 535 } 536 } 537 break; 538 539 case wasm::WASM_SYMBOL_TYPE_GLOBAL: 540 Info.ElementIndex = readVaruint32(Ctx); 541 if (!isValidGlobalIndex(Info.ElementIndex) || 542 IsDefined != isDefinedGlobalIndex(Info.ElementIndex)) 543 return make_error<GenericBinaryError>("invalid global symbol index", 544 object_error::parse_failed); 545 if (!IsDefined && (Info.Flags & wasm::WASM_SYMBOL_BINDING_MASK) == 546 wasm::WASM_SYMBOL_BINDING_WEAK) 547 return make_error<GenericBinaryError>("undefined weak global symbol", 548 object_error::parse_failed); 549 if (IsDefined) { 550 Info.Name = readString(Ctx); 551 unsigned GlobalIndex = Info.ElementIndex - NumImportedGlobals; 552 wasm::WasmGlobal &Global = Globals[GlobalIndex]; 553 GlobalType = &Global.Type; 554 if (Global.SymbolName.empty()) 555 Global.SymbolName = Info.Name; 556 } else { 557 wasm::WasmImport &Import = *ImportedGlobals[Info.ElementIndex]; 558 if ((Info.Flags & wasm::WASM_SYMBOL_EXPLICIT_NAME) != 0) { 559 Info.Name = readString(Ctx); 560 Info.ImportName = Import.Field; 561 } else { 562 Info.Name = Import.Field; 563 } 564 GlobalType = &Import.Global; 565 Info.ImportName = Import.Field; 566 if (!Import.Module.empty()) { 567 Info.ImportModule = Import.Module; 568 } 569 } 570 break; 571 572 case wasm::WASM_SYMBOL_TYPE_TABLE: 573 Info.ElementIndex = readVaruint32(Ctx); 574 if (!isValidTableIndex(Info.ElementIndex) || 575 IsDefined != isDefinedTableIndex(Info.ElementIndex)) 576 return make_error<GenericBinaryError>("invalid table symbol index", 577 object_error::parse_failed); 578 if (!IsDefined && (Info.Flags & wasm::WASM_SYMBOL_BINDING_MASK) == 579 wasm::WASM_SYMBOL_BINDING_WEAK) 580 return make_error<GenericBinaryError>("undefined weak table symbol", 581 object_error::parse_failed); 582 if (IsDefined) { 583 Info.Name = readString(Ctx); 584 unsigned TableIndex = Info.ElementIndex - NumImportedTables; 585 wasm::WasmTable &Table = Tables[TableIndex]; 586 TableType = Table.ElemType; 587 } else { 588 return make_error<GenericBinaryError>("undefined table symbol", 589 object_error::parse_failed); 590 } 591 break; 592 593 case wasm::WASM_SYMBOL_TYPE_DATA: 594 Info.Name = readString(Ctx); 595 if (IsDefined) { 596 auto Index = readVaruint32(Ctx); 597 if (Index >= DataSegments.size()) 598 return make_error<GenericBinaryError>("invalid data symbol index", 599 object_error::parse_failed); 600 auto Offset = readVaruint64(Ctx); 601 auto Size = readVaruint64(Ctx); 602 if (Offset + Size > DataSegments[Index].Data.Content.size()) 603 return make_error<GenericBinaryError>("invalid data symbol offset", 604 object_error::parse_failed); 605 Info.DataRef = wasm::WasmDataReference{Index, Offset, Size}; 606 } 607 break; 608 609 case wasm::WASM_SYMBOL_TYPE_SECTION: { 610 if ((Info.Flags & wasm::WASM_SYMBOL_BINDING_MASK) != 611 wasm::WASM_SYMBOL_BINDING_LOCAL) 612 return make_error<GenericBinaryError>( 613 "Section symbols must have local binding", 614 object_error::parse_failed); 615 Info.ElementIndex = readVaruint32(Ctx); 616 // Use somewhat unique section name as symbol name. 617 StringRef SectionName = Sections[Info.ElementIndex].Name; 618 Info.Name = SectionName; 619 break; 620 } 621 622 case wasm::WASM_SYMBOL_TYPE_EVENT: { 623 Info.ElementIndex = readVaruint32(Ctx); 624 if (!isValidEventIndex(Info.ElementIndex) || 625 IsDefined != isDefinedEventIndex(Info.ElementIndex)) 626 return make_error<GenericBinaryError>("invalid event symbol index", 627 object_error::parse_failed); 628 if (!IsDefined && (Info.Flags & wasm::WASM_SYMBOL_BINDING_MASK) == 629 wasm::WASM_SYMBOL_BINDING_WEAK) 630 return make_error<GenericBinaryError>("undefined weak global symbol", 631 object_error::parse_failed); 632 if (IsDefined) { 633 Info.Name = readString(Ctx); 634 unsigned EventIndex = Info.ElementIndex - NumImportedEvents; 635 wasm::WasmEvent &Event = Events[EventIndex]; 636 Signature = &Signatures[Event.Type.SigIndex]; 637 EventType = &Event.Type; 638 if (Event.SymbolName.empty()) 639 Event.SymbolName = Info.Name; 640 641 } else { 642 wasm::WasmImport &Import = *ImportedEvents[Info.ElementIndex]; 643 if ((Info.Flags & wasm::WASM_SYMBOL_EXPLICIT_NAME) != 0) { 644 Info.Name = readString(Ctx); 645 Info.ImportName = Import.Field; 646 } else { 647 Info.Name = Import.Field; 648 } 649 EventType = &Import.Event; 650 Signature = &Signatures[EventType->SigIndex]; 651 if (!Import.Module.empty()) { 652 Info.ImportModule = Import.Module; 653 } 654 } 655 break; 656 } 657 658 default: 659 return make_error<GenericBinaryError>("Invalid symbol type", 660 object_error::parse_failed); 661 } 662 663 if ((Info.Flags & wasm::WASM_SYMBOL_BINDING_MASK) != 664 wasm::WASM_SYMBOL_BINDING_LOCAL && 665 !SymbolNames.insert(Info.Name).second) 666 return make_error<GenericBinaryError>("Duplicate symbol name " + 667 Twine(Info.Name), 668 object_error::parse_failed); 669 LinkingData.SymbolTable.emplace_back(Info); 670 Symbols.emplace_back(LinkingData.SymbolTable.back(), GlobalType, TableType, 671 EventType, Signature); 672 LLVM_DEBUG(dbgs() << "Adding symbol: " << Symbols.back() << "\n"); 673 } 674 675 return Error::success(); 676 } 677 678 Error WasmObjectFile::parseLinkingSectionComdat(ReadContext &Ctx) { 679 uint32_t ComdatCount = readVaruint32(Ctx); 680 StringSet<> ComdatSet; 681 for (unsigned ComdatIndex = 0; ComdatIndex < ComdatCount; ++ComdatIndex) { 682 StringRef Name = readString(Ctx); 683 if (Name.empty() || !ComdatSet.insert(Name).second) 684 return make_error<GenericBinaryError>("Bad/duplicate COMDAT name " + 685 Twine(Name), 686 object_error::parse_failed); 687 LinkingData.Comdats.emplace_back(Name); 688 uint32_t Flags = readVaruint32(Ctx); 689 if (Flags != 0) 690 return make_error<GenericBinaryError>("Unsupported COMDAT flags", 691 object_error::parse_failed); 692 693 uint32_t EntryCount = readVaruint32(Ctx); 694 while (EntryCount--) { 695 unsigned Kind = readVaruint32(Ctx); 696 unsigned Index = readVaruint32(Ctx); 697 switch (Kind) { 698 default: 699 return make_error<GenericBinaryError>("Invalid COMDAT entry type", 700 object_error::parse_failed); 701 case wasm::WASM_COMDAT_DATA: 702 if (Index >= DataSegments.size()) 703 return make_error<GenericBinaryError>( 704 "COMDAT data index out of range", object_error::parse_failed); 705 if (DataSegments[Index].Data.Comdat != UINT32_MAX) 706 return make_error<GenericBinaryError>("Data segment in two COMDATs", 707 object_error::parse_failed); 708 DataSegments[Index].Data.Comdat = ComdatIndex; 709 break; 710 case wasm::WASM_COMDAT_FUNCTION: 711 if (!isDefinedFunctionIndex(Index)) 712 return make_error<GenericBinaryError>( 713 "COMDAT function index out of range", object_error::parse_failed); 714 if (getDefinedFunction(Index).Comdat != UINT32_MAX) 715 return make_error<GenericBinaryError>("Function in two COMDATs", 716 object_error::parse_failed); 717 getDefinedFunction(Index).Comdat = ComdatIndex; 718 break; 719 } 720 } 721 } 722 return Error::success(); 723 } 724 725 Error WasmObjectFile::parseProducersSection(ReadContext &Ctx) { 726 llvm::SmallSet<StringRef, 3> FieldsSeen; 727 uint32_t Fields = readVaruint32(Ctx); 728 for (size_t I = 0; I < Fields; ++I) { 729 StringRef FieldName = readString(Ctx); 730 if (!FieldsSeen.insert(FieldName).second) 731 return make_error<GenericBinaryError>( 732 "Producers section does not have unique fields", 733 object_error::parse_failed); 734 std::vector<std::pair<std::string, std::string>> *ProducerVec = nullptr; 735 if (FieldName == "language") { 736 ProducerVec = &ProducerInfo.Languages; 737 } else if (FieldName == "processed-by") { 738 ProducerVec = &ProducerInfo.Tools; 739 } else if (FieldName == "sdk") { 740 ProducerVec = &ProducerInfo.SDKs; 741 } else { 742 return make_error<GenericBinaryError>( 743 "Producers section field is not named one of language, processed-by, " 744 "or sdk", 745 object_error::parse_failed); 746 } 747 uint32_t ValueCount = readVaruint32(Ctx); 748 llvm::SmallSet<StringRef, 8> ProducersSeen; 749 for (size_t J = 0; J < ValueCount; ++J) { 750 StringRef Name = readString(Ctx); 751 StringRef Version = readString(Ctx); 752 if (!ProducersSeen.insert(Name).second) { 753 return make_error<GenericBinaryError>( 754 "Producers section contains repeated producer", 755 object_error::parse_failed); 756 } 757 ProducerVec->emplace_back(std::string(Name), std::string(Version)); 758 } 759 } 760 if (Ctx.Ptr != Ctx.End) 761 return make_error<GenericBinaryError>("Producers section ended prematurely", 762 object_error::parse_failed); 763 return Error::success(); 764 } 765 766 Error WasmObjectFile::parseTargetFeaturesSection(ReadContext &Ctx) { 767 llvm::SmallSet<std::string, 8> FeaturesSeen; 768 uint32_t FeatureCount = readVaruint32(Ctx); 769 for (size_t I = 0; I < FeatureCount; ++I) { 770 wasm::WasmFeatureEntry Feature; 771 Feature.Prefix = readUint8(Ctx); 772 switch (Feature.Prefix) { 773 case wasm::WASM_FEATURE_PREFIX_USED: 774 case wasm::WASM_FEATURE_PREFIX_REQUIRED: 775 case wasm::WASM_FEATURE_PREFIX_DISALLOWED: 776 break; 777 default: 778 return make_error<GenericBinaryError>("Unknown feature policy prefix", 779 object_error::parse_failed); 780 } 781 Feature.Name = std::string(readString(Ctx)); 782 if (!FeaturesSeen.insert(Feature.Name).second) 783 return make_error<GenericBinaryError>( 784 "Target features section contains repeated feature \"" + 785 Feature.Name + "\"", 786 object_error::parse_failed); 787 TargetFeatures.push_back(Feature); 788 } 789 if (Ctx.Ptr != Ctx.End) 790 return make_error<GenericBinaryError>( 791 "Target features section ended prematurely", 792 object_error::parse_failed); 793 return Error::success(); 794 } 795 796 Error WasmObjectFile::parseRelocSection(StringRef Name, ReadContext &Ctx) { 797 uint32_t SectionIndex = readVaruint32(Ctx); 798 if (SectionIndex >= Sections.size()) 799 return make_error<GenericBinaryError>("Invalid section index", 800 object_error::parse_failed); 801 WasmSection &Section = Sections[SectionIndex]; 802 uint32_t RelocCount = readVaruint32(Ctx); 803 uint32_t EndOffset = Section.Content.size(); 804 uint32_t PreviousOffset = 0; 805 while (RelocCount--) { 806 wasm::WasmRelocation Reloc = {}; 807 Reloc.Type = readVaruint32(Ctx); 808 Reloc.Offset = readVaruint32(Ctx); 809 if (Reloc.Offset < PreviousOffset) 810 return make_error<GenericBinaryError>("Relocations not in offset order", 811 object_error::parse_failed); 812 PreviousOffset = Reloc.Offset; 813 Reloc.Index = readVaruint32(Ctx); 814 switch (Reloc.Type) { 815 case wasm::R_WASM_FUNCTION_INDEX_LEB: 816 case wasm::R_WASM_TABLE_INDEX_SLEB: 817 case wasm::R_WASM_TABLE_INDEX_SLEB64: 818 case wasm::R_WASM_TABLE_INDEX_I32: 819 case wasm::R_WASM_TABLE_INDEX_I64: 820 case wasm::R_WASM_TABLE_INDEX_REL_SLEB: 821 if (!isValidFunctionSymbol(Reloc.Index)) 822 return make_error<GenericBinaryError>("Bad relocation function index", 823 object_error::parse_failed); 824 break; 825 case wasm::R_WASM_TABLE_NUMBER_LEB: 826 if (!isValidTableSymbol(Reloc.Index)) 827 return make_error<GenericBinaryError>("Bad relocation table index", 828 object_error::parse_failed); 829 break; 830 case wasm::R_WASM_TYPE_INDEX_LEB: 831 if (Reloc.Index >= Signatures.size()) 832 return make_error<GenericBinaryError>("Bad relocation type index", 833 object_error::parse_failed); 834 break; 835 case wasm::R_WASM_GLOBAL_INDEX_LEB: 836 // R_WASM_GLOBAL_INDEX_LEB are can be used against function and data 837 // symbols to refer to their GOT entries. 838 if (!isValidGlobalSymbol(Reloc.Index) && 839 !isValidDataSymbol(Reloc.Index) && 840 !isValidFunctionSymbol(Reloc.Index)) 841 return make_error<GenericBinaryError>("Bad relocation global index", 842 object_error::parse_failed); 843 break; 844 case wasm::R_WASM_GLOBAL_INDEX_I32: 845 if (!isValidGlobalSymbol(Reloc.Index)) 846 return make_error<GenericBinaryError>("Bad relocation global index", 847 object_error::parse_failed); 848 break; 849 case wasm::R_WASM_EVENT_INDEX_LEB: 850 if (!isValidEventSymbol(Reloc.Index)) 851 return make_error<GenericBinaryError>("Bad relocation event index", 852 object_error::parse_failed); 853 break; 854 case wasm::R_WASM_MEMORY_ADDR_LEB: 855 case wasm::R_WASM_MEMORY_ADDR_SLEB: 856 case wasm::R_WASM_MEMORY_ADDR_I32: 857 case wasm::R_WASM_MEMORY_ADDR_REL_SLEB: 858 if (!isValidDataSymbol(Reloc.Index)) 859 return make_error<GenericBinaryError>("Bad relocation data index", 860 object_error::parse_failed); 861 Reloc.Addend = readVarint32(Ctx); 862 break; 863 case wasm::R_WASM_MEMORY_ADDR_LEB64: 864 case wasm::R_WASM_MEMORY_ADDR_SLEB64: 865 case wasm::R_WASM_MEMORY_ADDR_I64: 866 case wasm::R_WASM_MEMORY_ADDR_REL_SLEB64: 867 if (!isValidDataSymbol(Reloc.Index)) 868 return make_error<GenericBinaryError>("Bad relocation data index", 869 object_error::parse_failed); 870 Reloc.Addend = readVarint64(Ctx); 871 break; 872 case wasm::R_WASM_FUNCTION_OFFSET_I32: 873 if (!isValidFunctionSymbol(Reloc.Index)) 874 return make_error<GenericBinaryError>("Bad relocation function index", 875 object_error::parse_failed); 876 Reloc.Addend = readVarint32(Ctx); 877 break; 878 case wasm::R_WASM_SECTION_OFFSET_I32: 879 if (!isValidSectionSymbol(Reloc.Index)) 880 return make_error<GenericBinaryError>("Bad relocation section index", 881 object_error::parse_failed); 882 Reloc.Addend = readVarint32(Ctx); 883 break; 884 default: 885 return make_error<GenericBinaryError>("Bad relocation type: " + 886 Twine(Reloc.Type), 887 object_error::parse_failed); 888 } 889 890 // Relocations must fit inside the section, and must appear in order. They 891 // also shouldn't overlap a function/element boundary, but we don't bother 892 // to check that. 893 uint64_t Size = 5; 894 if (Reloc.Type == wasm::R_WASM_MEMORY_ADDR_LEB64 || 895 Reloc.Type == wasm::R_WASM_MEMORY_ADDR_SLEB64 || 896 Reloc.Type == wasm::R_WASM_MEMORY_ADDR_REL_SLEB64) 897 Size = 10; 898 if (Reloc.Type == wasm::R_WASM_TABLE_INDEX_I32 || 899 Reloc.Type == wasm::R_WASM_MEMORY_ADDR_I32 || 900 Reloc.Type == wasm::R_WASM_SECTION_OFFSET_I32 || 901 Reloc.Type == wasm::R_WASM_FUNCTION_OFFSET_I32 || 902 Reloc.Type == wasm::R_WASM_GLOBAL_INDEX_I32) 903 Size = 4; 904 if (Reloc.Type == wasm::R_WASM_TABLE_INDEX_I64 || 905 Reloc.Type == wasm::R_WASM_MEMORY_ADDR_I64) 906 Size = 8; 907 if (Reloc.Offset + Size > EndOffset) 908 return make_error<GenericBinaryError>("Bad relocation offset", 909 object_error::parse_failed); 910 911 Section.Relocations.push_back(Reloc); 912 } 913 if (Ctx.Ptr != Ctx.End) 914 return make_error<GenericBinaryError>("Reloc section ended prematurely", 915 object_error::parse_failed); 916 return Error::success(); 917 } 918 919 Error WasmObjectFile::parseCustomSection(WasmSection &Sec, ReadContext &Ctx) { 920 if (Sec.Name == "dylink") { 921 if (Error Err = parseDylinkSection(Ctx)) 922 return Err; 923 } else if (Sec.Name == "name") { 924 if (Error Err = parseNameSection(Ctx)) 925 return Err; 926 } else if (Sec.Name == "linking") { 927 if (Error Err = parseLinkingSection(Ctx)) 928 return Err; 929 } else if (Sec.Name == "producers") { 930 if (Error Err = parseProducersSection(Ctx)) 931 return Err; 932 } else if (Sec.Name == "target_features") { 933 if (Error Err = parseTargetFeaturesSection(Ctx)) 934 return Err; 935 } else if (Sec.Name.startswith("reloc.")) { 936 if (Error Err = parseRelocSection(Sec.Name, Ctx)) 937 return Err; 938 } 939 return Error::success(); 940 } 941 942 Error WasmObjectFile::parseTypeSection(ReadContext &Ctx) { 943 uint32_t Count = readVaruint32(Ctx); 944 Signatures.reserve(Count); 945 while (Count--) { 946 wasm::WasmSignature Sig; 947 uint8_t Form = readUint8(Ctx); 948 if (Form != wasm::WASM_TYPE_FUNC) { 949 return make_error<GenericBinaryError>("Invalid signature type", 950 object_error::parse_failed); 951 } 952 uint32_t ParamCount = readVaruint32(Ctx); 953 Sig.Params.reserve(ParamCount); 954 while (ParamCount--) { 955 uint32_t ParamType = readUint8(Ctx); 956 Sig.Params.push_back(wasm::ValType(ParamType)); 957 } 958 uint32_t ReturnCount = readVaruint32(Ctx); 959 while (ReturnCount--) { 960 uint32_t ReturnType = readUint8(Ctx); 961 Sig.Returns.push_back(wasm::ValType(ReturnType)); 962 } 963 Signatures.push_back(std::move(Sig)); 964 } 965 if (Ctx.Ptr != Ctx.End) 966 return make_error<GenericBinaryError>("Type section ended prematurely", 967 object_error::parse_failed); 968 return Error::success(); 969 } 970 971 Error WasmObjectFile::parseImportSection(ReadContext &Ctx) { 972 uint32_t Count = readVaruint32(Ctx); 973 Imports.reserve(Count); 974 for (uint32_t I = 0; I < Count; I++) { 975 wasm::WasmImport Im; 976 Im.Module = readString(Ctx); 977 Im.Field = readString(Ctx); 978 Im.Kind = readUint8(Ctx); 979 switch (Im.Kind) { 980 case wasm::WASM_EXTERNAL_FUNCTION: 981 NumImportedFunctions++; 982 Im.SigIndex = readVaruint32(Ctx); 983 break; 984 case wasm::WASM_EXTERNAL_GLOBAL: 985 NumImportedGlobals++; 986 Im.Global.Type = readUint8(Ctx); 987 Im.Global.Mutable = readVaruint1(Ctx); 988 break; 989 case wasm::WASM_EXTERNAL_MEMORY: 990 Im.Memory = readLimits(Ctx); 991 if (Im.Memory.Flags & wasm::WASM_LIMITS_FLAG_IS_64) 992 HasMemory64 = true; 993 break; 994 case wasm::WASM_EXTERNAL_TABLE: { 995 Im.Table = readTable(Ctx); 996 Im.Table.Index = NumImportedTables + Tables.size(); 997 NumImportedTables++; 998 auto ElemType = Im.Table.ElemType; 999 if (ElemType != wasm::WASM_TYPE_FUNCREF && 1000 ElemType != wasm::WASM_TYPE_EXTERNREF) 1001 return make_error<GenericBinaryError>("Invalid table element type", 1002 object_error::parse_failed); 1003 break; 1004 } 1005 case wasm::WASM_EXTERNAL_EVENT: 1006 NumImportedEvents++; 1007 Im.Event.Attribute = readVarint32(Ctx); 1008 Im.Event.SigIndex = readVarint32(Ctx); 1009 break; 1010 default: 1011 return make_error<GenericBinaryError>("Unexpected import kind", 1012 object_error::parse_failed); 1013 } 1014 Imports.push_back(Im); 1015 } 1016 if (Ctx.Ptr != Ctx.End) 1017 return make_error<GenericBinaryError>("Import section ended prematurely", 1018 object_error::parse_failed); 1019 return Error::success(); 1020 } 1021 1022 Error WasmObjectFile::parseFunctionSection(ReadContext &Ctx) { 1023 uint32_t Count = readVaruint32(Ctx); 1024 FunctionTypes.reserve(Count); 1025 Functions.resize(Count); 1026 uint32_t NumTypes = Signatures.size(); 1027 while (Count--) { 1028 uint32_t Type = readVaruint32(Ctx); 1029 if (Type >= NumTypes) 1030 return make_error<GenericBinaryError>("Invalid function type", 1031 object_error::parse_failed); 1032 FunctionTypes.push_back(Type); 1033 } 1034 if (Ctx.Ptr != Ctx.End) 1035 return make_error<GenericBinaryError>("Function section ended prematurely", 1036 object_error::parse_failed); 1037 return Error::success(); 1038 } 1039 1040 Error WasmObjectFile::parseTableSection(ReadContext &Ctx) { 1041 uint32_t Count = readVaruint32(Ctx); 1042 Tables.reserve(Count); 1043 while (Count--) { 1044 wasm::WasmTable T = readTable(Ctx); 1045 T.Index = NumImportedTables + Tables.size(); 1046 Tables.push_back(T); 1047 auto ElemType = Tables.back().ElemType; 1048 if (ElemType != wasm::WASM_TYPE_FUNCREF && 1049 ElemType != wasm::WASM_TYPE_EXTERNREF) { 1050 return make_error<GenericBinaryError>("Invalid table element type", 1051 object_error::parse_failed); 1052 } 1053 } 1054 if (Ctx.Ptr != Ctx.End) 1055 return make_error<GenericBinaryError>("Table section ended prematurely", 1056 object_error::parse_failed); 1057 return Error::success(); 1058 } 1059 1060 Error WasmObjectFile::parseMemorySection(ReadContext &Ctx) { 1061 uint32_t Count = readVaruint32(Ctx); 1062 Memories.reserve(Count); 1063 while (Count--) { 1064 auto Limits = readLimits(Ctx); 1065 if (Limits.Flags & wasm::WASM_LIMITS_FLAG_IS_64) 1066 HasMemory64 = true; 1067 Memories.push_back(Limits); 1068 } 1069 if (Ctx.Ptr != Ctx.End) 1070 return make_error<GenericBinaryError>("Memory section ended prematurely", 1071 object_error::parse_failed); 1072 return Error::success(); 1073 } 1074 1075 Error WasmObjectFile::parseEventSection(ReadContext &Ctx) { 1076 EventSection = Sections.size(); 1077 uint32_t Count = readVarint32(Ctx); 1078 Events.reserve(Count); 1079 while (Count--) { 1080 wasm::WasmEvent Event; 1081 Event.Index = NumImportedEvents + Events.size(); 1082 Event.Type.Attribute = readVaruint32(Ctx); 1083 Event.Type.SigIndex = readVarint32(Ctx); 1084 Events.push_back(Event); 1085 } 1086 1087 if (Ctx.Ptr != Ctx.End) 1088 return make_error<GenericBinaryError>("Event section ended prematurely", 1089 object_error::parse_failed); 1090 return Error::success(); 1091 } 1092 1093 Error WasmObjectFile::parseGlobalSection(ReadContext &Ctx) { 1094 GlobalSection = Sections.size(); 1095 uint32_t Count = readVaruint32(Ctx); 1096 Globals.reserve(Count); 1097 while (Count--) { 1098 wasm::WasmGlobal Global; 1099 Global.Index = NumImportedGlobals + Globals.size(); 1100 Global.Type.Type = readUint8(Ctx); 1101 Global.Type.Mutable = readVaruint1(Ctx); 1102 if (Error Err = readInitExpr(Global.InitExpr, Ctx)) 1103 return Err; 1104 Globals.push_back(Global); 1105 } 1106 if (Ctx.Ptr != Ctx.End) 1107 return make_error<GenericBinaryError>("Global section ended prematurely", 1108 object_error::parse_failed); 1109 return Error::success(); 1110 } 1111 1112 Error WasmObjectFile::parseExportSection(ReadContext &Ctx) { 1113 uint32_t Count = readVaruint32(Ctx); 1114 Exports.reserve(Count); 1115 for (uint32_t I = 0; I < Count; I++) { 1116 wasm::WasmExport Ex; 1117 Ex.Name = readString(Ctx); 1118 Ex.Kind = readUint8(Ctx); 1119 Ex.Index = readVaruint32(Ctx); 1120 switch (Ex.Kind) { 1121 case wasm::WASM_EXTERNAL_FUNCTION: 1122 1123 if (!isDefinedFunctionIndex(Ex.Index)) 1124 return make_error<GenericBinaryError>("Invalid function export", 1125 object_error::parse_failed); 1126 getDefinedFunction(Ex.Index).ExportName = Ex.Name; 1127 break; 1128 case wasm::WASM_EXTERNAL_GLOBAL: 1129 if (!isValidGlobalIndex(Ex.Index)) 1130 return make_error<GenericBinaryError>("Invalid global export", 1131 object_error::parse_failed); 1132 break; 1133 case wasm::WASM_EXTERNAL_EVENT: 1134 if (!isValidEventIndex(Ex.Index)) 1135 return make_error<GenericBinaryError>("Invalid event export", 1136 object_error::parse_failed); 1137 break; 1138 case wasm::WASM_EXTERNAL_MEMORY: 1139 case wasm::WASM_EXTERNAL_TABLE: 1140 break; 1141 default: 1142 return make_error<GenericBinaryError>("Unexpected export kind", 1143 object_error::parse_failed); 1144 } 1145 Exports.push_back(Ex); 1146 } 1147 if (Ctx.Ptr != Ctx.End) 1148 return make_error<GenericBinaryError>("Export section ended prematurely", 1149 object_error::parse_failed); 1150 return Error::success(); 1151 } 1152 1153 bool WasmObjectFile::isValidFunctionIndex(uint32_t Index) const { 1154 return Index < NumImportedFunctions + FunctionTypes.size(); 1155 } 1156 1157 bool WasmObjectFile::isDefinedFunctionIndex(uint32_t Index) const { 1158 return Index >= NumImportedFunctions && isValidFunctionIndex(Index); 1159 } 1160 1161 bool WasmObjectFile::isValidGlobalIndex(uint32_t Index) const { 1162 return Index < NumImportedGlobals + Globals.size(); 1163 } 1164 1165 bool WasmObjectFile::isValidTableIndex(uint32_t Index) const { 1166 return Index < NumImportedTables + Tables.size(); 1167 } 1168 1169 bool WasmObjectFile::isDefinedGlobalIndex(uint32_t Index) const { 1170 return Index >= NumImportedGlobals && isValidGlobalIndex(Index); 1171 } 1172 1173 bool WasmObjectFile::isDefinedTableIndex(uint32_t Index) const { 1174 return Index >= NumImportedTables && isValidTableIndex(Index); 1175 } 1176 1177 bool WasmObjectFile::isValidEventIndex(uint32_t Index) const { 1178 return Index < NumImportedEvents + Events.size(); 1179 } 1180 1181 bool WasmObjectFile::isDefinedEventIndex(uint32_t Index) const { 1182 return Index >= NumImportedEvents && isValidEventIndex(Index); 1183 } 1184 1185 bool WasmObjectFile::isValidFunctionSymbol(uint32_t Index) const { 1186 return Index < Symbols.size() && Symbols[Index].isTypeFunction(); 1187 } 1188 1189 bool WasmObjectFile::isValidTableSymbol(uint32_t Index) const { 1190 return Index < Symbols.size() && Symbols[Index].isTypeTable(); 1191 } 1192 1193 bool WasmObjectFile::isValidGlobalSymbol(uint32_t Index) const { 1194 return Index < Symbols.size() && Symbols[Index].isTypeGlobal(); 1195 } 1196 1197 bool WasmObjectFile::isValidEventSymbol(uint32_t Index) const { 1198 return Index < Symbols.size() && Symbols[Index].isTypeEvent(); 1199 } 1200 1201 bool WasmObjectFile::isValidDataSymbol(uint32_t Index) const { 1202 return Index < Symbols.size() && Symbols[Index].isTypeData(); 1203 } 1204 1205 bool WasmObjectFile::isValidSectionSymbol(uint32_t Index) const { 1206 return Index < Symbols.size() && Symbols[Index].isTypeSection(); 1207 } 1208 1209 wasm::WasmFunction &WasmObjectFile::getDefinedFunction(uint32_t Index) { 1210 assert(isDefinedFunctionIndex(Index)); 1211 return Functions[Index - NumImportedFunctions]; 1212 } 1213 1214 const wasm::WasmFunction & 1215 WasmObjectFile::getDefinedFunction(uint32_t Index) const { 1216 assert(isDefinedFunctionIndex(Index)); 1217 return Functions[Index - NumImportedFunctions]; 1218 } 1219 1220 wasm::WasmGlobal &WasmObjectFile::getDefinedGlobal(uint32_t Index) { 1221 assert(isDefinedGlobalIndex(Index)); 1222 return Globals[Index - NumImportedGlobals]; 1223 } 1224 1225 wasm::WasmEvent &WasmObjectFile::getDefinedEvent(uint32_t Index) { 1226 assert(isDefinedEventIndex(Index)); 1227 return Events[Index - NumImportedEvents]; 1228 } 1229 1230 Error WasmObjectFile::parseStartSection(ReadContext &Ctx) { 1231 StartFunction = readVaruint32(Ctx); 1232 if (!isValidFunctionIndex(StartFunction)) 1233 return make_error<GenericBinaryError>("Invalid start function", 1234 object_error::parse_failed); 1235 return Error::success(); 1236 } 1237 1238 Error WasmObjectFile::parseCodeSection(ReadContext &Ctx) { 1239 SeenCodeSection = true; 1240 CodeSection = Sections.size(); 1241 uint32_t FunctionCount = readVaruint32(Ctx); 1242 if (FunctionCount != FunctionTypes.size()) { 1243 return make_error<GenericBinaryError>("Invalid function count", 1244 object_error::parse_failed); 1245 } 1246 1247 for (uint32_t i = 0; i < FunctionCount; i++) { 1248 wasm::WasmFunction& Function = Functions[i]; 1249 const uint8_t *FunctionStart = Ctx.Ptr; 1250 uint32_t Size = readVaruint32(Ctx); 1251 const uint8_t *FunctionEnd = Ctx.Ptr + Size; 1252 1253 Function.CodeOffset = Ctx.Ptr - FunctionStart; 1254 Function.Index = NumImportedFunctions + i; 1255 Function.CodeSectionOffset = FunctionStart - Ctx.Start; 1256 Function.Size = FunctionEnd - FunctionStart; 1257 1258 uint32_t NumLocalDecls = readVaruint32(Ctx); 1259 Function.Locals.reserve(NumLocalDecls); 1260 while (NumLocalDecls--) { 1261 wasm::WasmLocalDecl Decl; 1262 Decl.Count = readVaruint32(Ctx); 1263 Decl.Type = readUint8(Ctx); 1264 Function.Locals.push_back(Decl); 1265 } 1266 1267 uint32_t BodySize = FunctionEnd - Ctx.Ptr; 1268 Function.Body = ArrayRef<uint8_t>(Ctx.Ptr, BodySize); 1269 // This will be set later when reading in the linking metadata section. 1270 Function.Comdat = UINT32_MAX; 1271 Ctx.Ptr += BodySize; 1272 assert(Ctx.Ptr == FunctionEnd); 1273 } 1274 if (Ctx.Ptr != Ctx.End) 1275 return make_error<GenericBinaryError>("Code section ended prematurely", 1276 object_error::parse_failed); 1277 return Error::success(); 1278 } 1279 1280 Error WasmObjectFile::parseElemSection(ReadContext &Ctx) { 1281 uint32_t Count = readVaruint32(Ctx); 1282 ElemSegments.reserve(Count); 1283 while (Count--) { 1284 wasm::WasmElemSegment Segment; 1285 Segment.TableIndex = readVaruint32(Ctx); 1286 if (Segment.TableIndex != 0) { 1287 return make_error<GenericBinaryError>("Invalid TableIndex", 1288 object_error::parse_failed); 1289 } 1290 if (Error Err = readInitExpr(Segment.Offset, Ctx)) 1291 return Err; 1292 uint32_t NumElems = readVaruint32(Ctx); 1293 while (NumElems--) { 1294 Segment.Functions.push_back(readVaruint32(Ctx)); 1295 } 1296 ElemSegments.push_back(Segment); 1297 } 1298 if (Ctx.Ptr != Ctx.End) 1299 return make_error<GenericBinaryError>("Elem section ended prematurely", 1300 object_error::parse_failed); 1301 return Error::success(); 1302 } 1303 1304 Error WasmObjectFile::parseDataSection(ReadContext &Ctx) { 1305 DataSection = Sections.size(); 1306 uint32_t Count = readVaruint32(Ctx); 1307 if (DataCount && Count != DataCount.getValue()) 1308 return make_error<GenericBinaryError>( 1309 "Number of data segments does not match DataCount section"); 1310 DataSegments.reserve(Count); 1311 while (Count--) { 1312 WasmSegment Segment; 1313 Segment.Data.InitFlags = readVaruint32(Ctx); 1314 Segment.Data.MemoryIndex = (Segment.Data.InitFlags & wasm::WASM_SEGMENT_HAS_MEMINDEX) 1315 ? readVaruint32(Ctx) : 0; 1316 if ((Segment.Data.InitFlags & wasm::WASM_SEGMENT_IS_PASSIVE) == 0) { 1317 if (Error Err = readInitExpr(Segment.Data.Offset, Ctx)) 1318 return Err; 1319 } else { 1320 Segment.Data.Offset.Opcode = wasm::WASM_OPCODE_I32_CONST; 1321 Segment.Data.Offset.Value.Int32 = 0; 1322 } 1323 uint32_t Size = readVaruint32(Ctx); 1324 if (Size > (size_t)(Ctx.End - Ctx.Ptr)) 1325 return make_error<GenericBinaryError>("Invalid segment size", 1326 object_error::parse_failed); 1327 Segment.Data.Content = ArrayRef<uint8_t>(Ctx.Ptr, Size); 1328 // The rest of these Data fields are set later, when reading in the linking 1329 // metadata section. 1330 Segment.Data.Alignment = 0; 1331 Segment.Data.LinkerFlags = 0; 1332 Segment.Data.Comdat = UINT32_MAX; 1333 Segment.SectionOffset = Ctx.Ptr - Ctx.Start; 1334 Ctx.Ptr += Size; 1335 DataSegments.push_back(Segment); 1336 } 1337 if (Ctx.Ptr != Ctx.End) 1338 return make_error<GenericBinaryError>("Data section ended prematurely", 1339 object_error::parse_failed); 1340 return Error::success(); 1341 } 1342 1343 Error WasmObjectFile::parseDataCountSection(ReadContext &Ctx) { 1344 DataCount = readVaruint32(Ctx); 1345 return Error::success(); 1346 } 1347 1348 const wasm::WasmObjectHeader &WasmObjectFile::getHeader() const { 1349 return Header; 1350 } 1351 1352 void WasmObjectFile::moveSymbolNext(DataRefImpl &Symb) const { Symb.d.b++; } 1353 1354 Expected<uint32_t> WasmObjectFile::getSymbolFlags(DataRefImpl Symb) const { 1355 uint32_t Result = SymbolRef::SF_None; 1356 const WasmSymbol &Sym = getWasmSymbol(Symb); 1357 1358 LLVM_DEBUG(dbgs() << "getSymbolFlags: ptr=" << &Sym << " " << Sym << "\n"); 1359 if (Sym.isBindingWeak()) 1360 Result |= SymbolRef::SF_Weak; 1361 if (!Sym.isBindingLocal()) 1362 Result |= SymbolRef::SF_Global; 1363 if (Sym.isHidden()) 1364 Result |= SymbolRef::SF_Hidden; 1365 if (!Sym.isDefined()) 1366 Result |= SymbolRef::SF_Undefined; 1367 if (Sym.isTypeFunction()) 1368 Result |= SymbolRef::SF_Executable; 1369 return Result; 1370 } 1371 1372 basic_symbol_iterator WasmObjectFile::symbol_begin() const { 1373 DataRefImpl Ref; 1374 Ref.d.a = 1; // Arbitrary non-zero value so that Ref.p is non-null 1375 Ref.d.b = 0; // Symbol index 1376 return BasicSymbolRef(Ref, this); 1377 } 1378 1379 basic_symbol_iterator WasmObjectFile::symbol_end() const { 1380 DataRefImpl Ref; 1381 Ref.d.a = 1; // Arbitrary non-zero value so that Ref.p is non-null 1382 Ref.d.b = Symbols.size(); // Symbol index 1383 return BasicSymbolRef(Ref, this); 1384 } 1385 1386 const WasmSymbol &WasmObjectFile::getWasmSymbol(const DataRefImpl &Symb) const { 1387 return Symbols[Symb.d.b]; 1388 } 1389 1390 const WasmSymbol &WasmObjectFile::getWasmSymbol(const SymbolRef &Symb) const { 1391 return getWasmSymbol(Symb.getRawDataRefImpl()); 1392 } 1393 1394 Expected<StringRef> WasmObjectFile::getSymbolName(DataRefImpl Symb) const { 1395 return getWasmSymbol(Symb).Info.Name; 1396 } 1397 1398 Expected<uint64_t> WasmObjectFile::getSymbolAddress(DataRefImpl Symb) const { 1399 auto &Sym = getWasmSymbol(Symb); 1400 if (Sym.Info.Kind == wasm::WASM_SYMBOL_TYPE_FUNCTION && 1401 isDefinedFunctionIndex(Sym.Info.ElementIndex)) 1402 return getDefinedFunction(Sym.Info.ElementIndex).CodeSectionOffset; 1403 else 1404 return getSymbolValue(Symb); 1405 } 1406 1407 uint64_t WasmObjectFile::getWasmSymbolValue(const WasmSymbol &Sym) const { 1408 switch (Sym.Info.Kind) { 1409 case wasm::WASM_SYMBOL_TYPE_FUNCTION: 1410 case wasm::WASM_SYMBOL_TYPE_GLOBAL: 1411 case wasm::WASM_SYMBOL_TYPE_EVENT: 1412 return Sym.Info.ElementIndex; 1413 case wasm::WASM_SYMBOL_TYPE_DATA: { 1414 // The value of a data symbol is the segment offset, plus the symbol 1415 // offset within the segment. 1416 uint32_t SegmentIndex = Sym.Info.DataRef.Segment; 1417 const wasm::WasmDataSegment &Segment = DataSegments[SegmentIndex].Data; 1418 if (Segment.Offset.Opcode == wasm::WASM_OPCODE_I32_CONST) { 1419 return Segment.Offset.Value.Int32 + Sym.Info.DataRef.Offset; 1420 } else if (Segment.Offset.Opcode == wasm::WASM_OPCODE_I64_CONST) { 1421 return Segment.Offset.Value.Int64 + Sym.Info.DataRef.Offset; 1422 } else { 1423 llvm_unreachable("unknown init expr opcode"); 1424 } 1425 } 1426 case wasm::WASM_SYMBOL_TYPE_SECTION: 1427 return 0; 1428 } 1429 llvm_unreachable("invalid symbol type"); 1430 } 1431 1432 uint64_t WasmObjectFile::getSymbolValueImpl(DataRefImpl Symb) const { 1433 return getWasmSymbolValue(getWasmSymbol(Symb)); 1434 } 1435 1436 uint32_t WasmObjectFile::getSymbolAlignment(DataRefImpl Symb) const { 1437 llvm_unreachable("not yet implemented"); 1438 return 0; 1439 } 1440 1441 uint64_t WasmObjectFile::getCommonSymbolSizeImpl(DataRefImpl Symb) const { 1442 llvm_unreachable("not yet implemented"); 1443 return 0; 1444 } 1445 1446 Expected<SymbolRef::Type> 1447 WasmObjectFile::getSymbolType(DataRefImpl Symb) const { 1448 const WasmSymbol &Sym = getWasmSymbol(Symb); 1449 1450 switch (Sym.Info.Kind) { 1451 case wasm::WASM_SYMBOL_TYPE_FUNCTION: 1452 return SymbolRef::ST_Function; 1453 case wasm::WASM_SYMBOL_TYPE_GLOBAL: 1454 return SymbolRef::ST_Other; 1455 case wasm::WASM_SYMBOL_TYPE_DATA: 1456 return SymbolRef::ST_Data; 1457 case wasm::WASM_SYMBOL_TYPE_SECTION: 1458 return SymbolRef::ST_Debug; 1459 case wasm::WASM_SYMBOL_TYPE_EVENT: 1460 return SymbolRef::ST_Other; 1461 } 1462 1463 llvm_unreachable("Unknown WasmSymbol::SymbolType"); 1464 return SymbolRef::ST_Other; 1465 } 1466 1467 Expected<section_iterator> 1468 WasmObjectFile::getSymbolSection(DataRefImpl Symb) const { 1469 const WasmSymbol &Sym = getWasmSymbol(Symb); 1470 if (Sym.isUndefined()) 1471 return section_end(); 1472 1473 DataRefImpl Ref; 1474 Ref.d.a = getSymbolSectionIdImpl(Sym); 1475 return section_iterator(SectionRef(Ref, this)); 1476 } 1477 1478 uint32_t WasmObjectFile::getSymbolSectionId(SymbolRef Symb) const { 1479 const WasmSymbol &Sym = getWasmSymbol(Symb); 1480 return getSymbolSectionIdImpl(Sym); 1481 } 1482 1483 uint32_t WasmObjectFile::getSymbolSectionIdImpl(const WasmSymbol &Sym) const { 1484 switch (Sym.Info.Kind) { 1485 case wasm::WASM_SYMBOL_TYPE_FUNCTION: 1486 return CodeSection; 1487 case wasm::WASM_SYMBOL_TYPE_GLOBAL: 1488 return GlobalSection; 1489 case wasm::WASM_SYMBOL_TYPE_DATA: 1490 return DataSection; 1491 case wasm::WASM_SYMBOL_TYPE_SECTION: 1492 return Sym.Info.ElementIndex; 1493 case wasm::WASM_SYMBOL_TYPE_EVENT: 1494 return EventSection; 1495 default: 1496 llvm_unreachable("Unknown WasmSymbol::SymbolType"); 1497 } 1498 } 1499 1500 void WasmObjectFile::moveSectionNext(DataRefImpl &Sec) const { Sec.d.a++; } 1501 1502 Expected<StringRef> WasmObjectFile::getSectionName(DataRefImpl Sec) const { 1503 const WasmSection &S = Sections[Sec.d.a]; 1504 #define ECase(X) \ 1505 case wasm::WASM_SEC_##X: \ 1506 return #X; 1507 switch (S.Type) { 1508 ECase(TYPE); 1509 ECase(IMPORT); 1510 ECase(FUNCTION); 1511 ECase(TABLE); 1512 ECase(MEMORY); 1513 ECase(GLOBAL); 1514 ECase(EVENT); 1515 ECase(EXPORT); 1516 ECase(START); 1517 ECase(ELEM); 1518 ECase(CODE); 1519 ECase(DATA); 1520 ECase(DATACOUNT); 1521 case wasm::WASM_SEC_CUSTOM: 1522 return S.Name; 1523 default: 1524 return createStringError(object_error::invalid_section_index, ""); 1525 } 1526 #undef ECase 1527 } 1528 1529 uint64_t WasmObjectFile::getSectionAddress(DataRefImpl Sec) const { return 0; } 1530 1531 uint64_t WasmObjectFile::getSectionIndex(DataRefImpl Sec) const { 1532 return Sec.d.a; 1533 } 1534 1535 uint64_t WasmObjectFile::getSectionSize(DataRefImpl Sec) const { 1536 const WasmSection &S = Sections[Sec.d.a]; 1537 return S.Content.size(); 1538 } 1539 1540 Expected<ArrayRef<uint8_t>> 1541 WasmObjectFile::getSectionContents(DataRefImpl Sec) const { 1542 const WasmSection &S = Sections[Sec.d.a]; 1543 // This will never fail since wasm sections can never be empty (user-sections 1544 // must have a name and non-user sections each have a defined structure). 1545 return S.Content; 1546 } 1547 1548 uint64_t WasmObjectFile::getSectionAlignment(DataRefImpl Sec) const { 1549 return 1; 1550 } 1551 1552 bool WasmObjectFile::isSectionCompressed(DataRefImpl Sec) const { 1553 return false; 1554 } 1555 1556 bool WasmObjectFile::isSectionText(DataRefImpl Sec) const { 1557 return getWasmSection(Sec).Type == wasm::WASM_SEC_CODE; 1558 } 1559 1560 bool WasmObjectFile::isSectionData(DataRefImpl Sec) const { 1561 return getWasmSection(Sec).Type == wasm::WASM_SEC_DATA; 1562 } 1563 1564 bool WasmObjectFile::isSectionBSS(DataRefImpl Sec) const { return false; } 1565 1566 bool WasmObjectFile::isSectionVirtual(DataRefImpl Sec) const { return false; } 1567 1568 relocation_iterator WasmObjectFile::section_rel_begin(DataRefImpl Ref) const { 1569 DataRefImpl RelocRef; 1570 RelocRef.d.a = Ref.d.a; 1571 RelocRef.d.b = 0; 1572 return relocation_iterator(RelocationRef(RelocRef, this)); 1573 } 1574 1575 relocation_iterator WasmObjectFile::section_rel_end(DataRefImpl Ref) const { 1576 const WasmSection &Sec = getWasmSection(Ref); 1577 DataRefImpl RelocRef; 1578 RelocRef.d.a = Ref.d.a; 1579 RelocRef.d.b = Sec.Relocations.size(); 1580 return relocation_iterator(RelocationRef(RelocRef, this)); 1581 } 1582 1583 void WasmObjectFile::moveRelocationNext(DataRefImpl &Rel) const { Rel.d.b++; } 1584 1585 uint64_t WasmObjectFile::getRelocationOffset(DataRefImpl Ref) const { 1586 const wasm::WasmRelocation &Rel = getWasmRelocation(Ref); 1587 return Rel.Offset; 1588 } 1589 1590 symbol_iterator WasmObjectFile::getRelocationSymbol(DataRefImpl Ref) const { 1591 const wasm::WasmRelocation &Rel = getWasmRelocation(Ref); 1592 if (Rel.Type == wasm::R_WASM_TYPE_INDEX_LEB) 1593 return symbol_end(); 1594 DataRefImpl Sym; 1595 Sym.d.a = 1; 1596 Sym.d.b = Rel.Index; 1597 return symbol_iterator(SymbolRef(Sym, this)); 1598 } 1599 1600 uint64_t WasmObjectFile::getRelocationType(DataRefImpl Ref) const { 1601 const wasm::WasmRelocation &Rel = getWasmRelocation(Ref); 1602 return Rel.Type; 1603 } 1604 1605 void WasmObjectFile::getRelocationTypeName( 1606 DataRefImpl Ref, SmallVectorImpl<char> &Result) const { 1607 const wasm::WasmRelocation &Rel = getWasmRelocation(Ref); 1608 StringRef Res = "Unknown"; 1609 1610 #define WASM_RELOC(name, value) \ 1611 case wasm::name: \ 1612 Res = #name; \ 1613 break; 1614 1615 switch (Rel.Type) { 1616 #include "llvm/BinaryFormat/WasmRelocs.def" 1617 } 1618 1619 #undef WASM_RELOC 1620 1621 Result.append(Res.begin(), Res.end()); 1622 } 1623 1624 section_iterator WasmObjectFile::section_begin() const { 1625 DataRefImpl Ref; 1626 Ref.d.a = 0; 1627 return section_iterator(SectionRef(Ref, this)); 1628 } 1629 1630 section_iterator WasmObjectFile::section_end() const { 1631 DataRefImpl Ref; 1632 Ref.d.a = Sections.size(); 1633 return section_iterator(SectionRef(Ref, this)); 1634 } 1635 1636 uint8_t WasmObjectFile::getBytesInAddress() const { 1637 return HasMemory64 ? 8 : 4; 1638 } 1639 1640 StringRef WasmObjectFile::getFileFormatName() const { return "WASM"; } 1641 1642 Triple::ArchType WasmObjectFile::getArch() const { 1643 return HasMemory64 ? Triple::wasm64 : Triple::wasm32; 1644 } 1645 1646 SubtargetFeatures WasmObjectFile::getFeatures() const { 1647 return SubtargetFeatures(); 1648 } 1649 1650 bool WasmObjectFile::isRelocatableObject() const { return HasLinkingSection; } 1651 1652 bool WasmObjectFile::isSharedObject() const { return HasDylinkSection; } 1653 1654 const WasmSection &WasmObjectFile::getWasmSection(DataRefImpl Ref) const { 1655 assert(Ref.d.a < Sections.size()); 1656 return Sections[Ref.d.a]; 1657 } 1658 1659 const WasmSection & 1660 WasmObjectFile::getWasmSection(const SectionRef &Section) const { 1661 return getWasmSection(Section.getRawDataRefImpl()); 1662 } 1663 1664 const wasm::WasmRelocation & 1665 WasmObjectFile::getWasmRelocation(const RelocationRef &Ref) const { 1666 return getWasmRelocation(Ref.getRawDataRefImpl()); 1667 } 1668 1669 const wasm::WasmRelocation & 1670 WasmObjectFile::getWasmRelocation(DataRefImpl Ref) const { 1671 assert(Ref.d.a < Sections.size()); 1672 const WasmSection &Sec = Sections[Ref.d.a]; 1673 assert(Ref.d.b < Sec.Relocations.size()); 1674 return Sec.Relocations[Ref.d.b]; 1675 } 1676 1677 int WasmSectionOrderChecker::getSectionOrder(unsigned ID, 1678 StringRef CustomSectionName) { 1679 switch (ID) { 1680 case wasm::WASM_SEC_CUSTOM: 1681 return StringSwitch<unsigned>(CustomSectionName) 1682 .Case("dylink", WASM_SEC_ORDER_DYLINK) 1683 .Case("linking", WASM_SEC_ORDER_LINKING) 1684 .StartsWith("reloc.", WASM_SEC_ORDER_RELOC) 1685 .Case("name", WASM_SEC_ORDER_NAME) 1686 .Case("producers", WASM_SEC_ORDER_PRODUCERS) 1687 .Case("target_features", WASM_SEC_ORDER_TARGET_FEATURES) 1688 .Default(WASM_SEC_ORDER_NONE); 1689 case wasm::WASM_SEC_TYPE: 1690 return WASM_SEC_ORDER_TYPE; 1691 case wasm::WASM_SEC_IMPORT: 1692 return WASM_SEC_ORDER_IMPORT; 1693 case wasm::WASM_SEC_FUNCTION: 1694 return WASM_SEC_ORDER_FUNCTION; 1695 case wasm::WASM_SEC_TABLE: 1696 return WASM_SEC_ORDER_TABLE; 1697 case wasm::WASM_SEC_MEMORY: 1698 return WASM_SEC_ORDER_MEMORY; 1699 case wasm::WASM_SEC_GLOBAL: 1700 return WASM_SEC_ORDER_GLOBAL; 1701 case wasm::WASM_SEC_EXPORT: 1702 return WASM_SEC_ORDER_EXPORT; 1703 case wasm::WASM_SEC_START: 1704 return WASM_SEC_ORDER_START; 1705 case wasm::WASM_SEC_ELEM: 1706 return WASM_SEC_ORDER_ELEM; 1707 case wasm::WASM_SEC_CODE: 1708 return WASM_SEC_ORDER_CODE; 1709 case wasm::WASM_SEC_DATA: 1710 return WASM_SEC_ORDER_DATA; 1711 case wasm::WASM_SEC_DATACOUNT: 1712 return WASM_SEC_ORDER_DATACOUNT; 1713 case wasm::WASM_SEC_EVENT: 1714 return WASM_SEC_ORDER_EVENT; 1715 default: 1716 return WASM_SEC_ORDER_NONE; 1717 } 1718 } 1719 1720 // Represents the edges in a directed graph where any node B reachable from node 1721 // A is not allowed to appear before A in the section ordering, but may appear 1722 // afterward. 1723 int WasmSectionOrderChecker::DisallowedPredecessors 1724 [WASM_NUM_SEC_ORDERS][WASM_NUM_SEC_ORDERS] = { 1725 // WASM_SEC_ORDER_NONE 1726 {}, 1727 // WASM_SEC_ORDER_TYPE 1728 {WASM_SEC_ORDER_TYPE, WASM_SEC_ORDER_IMPORT}, 1729 // WASM_SEC_ORDER_IMPORT 1730 {WASM_SEC_ORDER_IMPORT, WASM_SEC_ORDER_FUNCTION}, 1731 // WASM_SEC_ORDER_FUNCTION 1732 {WASM_SEC_ORDER_FUNCTION, WASM_SEC_ORDER_TABLE}, 1733 // WASM_SEC_ORDER_TABLE 1734 {WASM_SEC_ORDER_TABLE, WASM_SEC_ORDER_MEMORY}, 1735 // WASM_SEC_ORDER_MEMORY 1736 {WASM_SEC_ORDER_MEMORY, WASM_SEC_ORDER_EVENT}, 1737 // WASM_SEC_ORDER_EVENT 1738 {WASM_SEC_ORDER_EVENT, WASM_SEC_ORDER_GLOBAL}, 1739 // WASM_SEC_ORDER_GLOBAL 1740 {WASM_SEC_ORDER_GLOBAL, WASM_SEC_ORDER_EXPORT}, 1741 // WASM_SEC_ORDER_EXPORT 1742 {WASM_SEC_ORDER_EXPORT, WASM_SEC_ORDER_START}, 1743 // WASM_SEC_ORDER_START 1744 {WASM_SEC_ORDER_START, WASM_SEC_ORDER_ELEM}, 1745 // WASM_SEC_ORDER_ELEM 1746 {WASM_SEC_ORDER_ELEM, WASM_SEC_ORDER_DATACOUNT}, 1747 // WASM_SEC_ORDER_DATACOUNT 1748 {WASM_SEC_ORDER_DATACOUNT, WASM_SEC_ORDER_CODE}, 1749 // WASM_SEC_ORDER_CODE 1750 {WASM_SEC_ORDER_CODE, WASM_SEC_ORDER_DATA}, 1751 // WASM_SEC_ORDER_DATA 1752 {WASM_SEC_ORDER_DATA, WASM_SEC_ORDER_LINKING}, 1753 1754 // Custom Sections 1755 // WASM_SEC_ORDER_DYLINK 1756 {WASM_SEC_ORDER_DYLINK, WASM_SEC_ORDER_TYPE}, 1757 // WASM_SEC_ORDER_LINKING 1758 {WASM_SEC_ORDER_LINKING, WASM_SEC_ORDER_RELOC, WASM_SEC_ORDER_NAME}, 1759 // WASM_SEC_ORDER_RELOC (can be repeated) 1760 {}, 1761 // WASM_SEC_ORDER_NAME 1762 {WASM_SEC_ORDER_NAME, WASM_SEC_ORDER_PRODUCERS}, 1763 // WASM_SEC_ORDER_PRODUCERS 1764 {WASM_SEC_ORDER_PRODUCERS, WASM_SEC_ORDER_TARGET_FEATURES}, 1765 // WASM_SEC_ORDER_TARGET_FEATURES 1766 {WASM_SEC_ORDER_TARGET_FEATURES}}; 1767 1768 bool WasmSectionOrderChecker::isValidSectionOrder(unsigned ID, 1769 StringRef CustomSectionName) { 1770 int Order = getSectionOrder(ID, CustomSectionName); 1771 if (Order == WASM_SEC_ORDER_NONE) 1772 return true; 1773 1774 // Disallowed predecessors we need to check for 1775 SmallVector<int, WASM_NUM_SEC_ORDERS> WorkList; 1776 1777 // Keep track of completed checks to avoid repeating work 1778 bool Checked[WASM_NUM_SEC_ORDERS] = {}; 1779 1780 int Curr = Order; 1781 while (true) { 1782 // Add new disallowed predecessors to work list 1783 for (size_t I = 0;; ++I) { 1784 int Next = DisallowedPredecessors[Curr][I]; 1785 if (Next == WASM_SEC_ORDER_NONE) 1786 break; 1787 if (Checked[Next]) 1788 continue; 1789 WorkList.push_back(Next); 1790 Checked[Next] = true; 1791 } 1792 1793 if (WorkList.empty()) 1794 break; 1795 1796 // Consider next disallowed predecessor 1797 Curr = WorkList.pop_back_val(); 1798 if (Seen[Curr]) 1799 return false; 1800 } 1801 1802 // Have not seen any disallowed predecessors 1803 Seen[Order] = true; 1804 return true; 1805 } 1806