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