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/SmallSet.h" 12 #include "llvm/ADT/StringRef.h" 13 #include "llvm/ADT/StringSet.h" 14 #include "llvm/ADT/StringSwitch.h" 15 #include "llvm/BinaryFormat/Wasm.h" 16 #include "llvm/Object/Binary.h" 17 #include "llvm/Object/Error.h" 18 #include "llvm/Object/ObjectFile.h" 19 #include "llvm/Object/SymbolicFile.h" 20 #include "llvm/Object/Wasm.h" 21 #include "llvm/Support/Endian.h" 22 #include "llvm/Support/Error.h" 23 #include "llvm/Support/ErrorHandling.h" 24 #include "llvm/Support/Format.h" 25 #include "llvm/Support/LEB128.h" 26 #include "llvm/Support/ScopedPrinter.h" 27 #include "llvm/TargetParser/SubtargetFeature.h" 28 #include "llvm/TargetParser/Triple.h" 29 #include <algorithm> 30 #include <cassert> 31 #include <cstdint> 32 #include <cstring> 33 #include <limits> 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)) << ", Flags=0x" 43 << Twine::utohexstr(Info.Flags) << " ["; 44 switch (getBinding()) { 45 case wasm::WASM_SYMBOL_BINDING_GLOBAL: Out << "global"; break; 46 case wasm::WASM_SYMBOL_BINDING_LOCAL: Out << "local"; break; 47 case wasm::WASM_SYMBOL_BINDING_WEAK: Out << "weak"; break; 48 } 49 if (isHidden()) { 50 Out << ", hidden"; 51 } else { 52 Out << ", default"; 53 } 54 Out << "]"; 55 if (!isTypeData()) { 56 Out << ", ElemIndex=" << Info.ElementIndex; 57 } else if (isDefined()) { 58 Out << ", Segment=" << Info.DataRef.Segment; 59 Out << ", Offset=" << Info.DataRef.Offset; 60 Out << ", Size=" << Info.DataRef.Size; 61 } 62 } 63 64 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP) 65 LLVM_DUMP_METHOD void WasmSymbol::dump() const { print(dbgs()); } 66 #endif 67 68 Expected<std::unique_ptr<WasmObjectFile>> 69 ObjectFile::createWasmObjectFile(MemoryBufferRef Buffer) { 70 Error Err = Error::success(); 71 auto ObjectFile = std::make_unique<WasmObjectFile>(Buffer, Err); 72 if (Err) 73 return std::move(Err); 74 75 return std::move(ObjectFile); 76 } 77 78 #define VARINT7_MAX ((1 << 7) - 1) 79 #define VARINT7_MIN (-(1 << 7)) 80 #define VARUINT7_MAX (1 << 7) 81 #define VARUINT1_MAX (1) 82 83 static uint8_t readUint8(WasmObjectFile::ReadContext &Ctx) { 84 if (Ctx.Ptr == Ctx.End) 85 report_fatal_error("EOF while reading uint8"); 86 return *Ctx.Ptr++; 87 } 88 89 static uint32_t readUint32(WasmObjectFile::ReadContext &Ctx) { 90 if (Ctx.Ptr + 4 > Ctx.End) 91 report_fatal_error("EOF while reading uint32"); 92 uint32_t Result = support::endian::read32le(Ctx.Ptr); 93 Ctx.Ptr += 4; 94 return Result; 95 } 96 97 static int32_t readFloat32(WasmObjectFile::ReadContext &Ctx) { 98 if (Ctx.Ptr + 4 > Ctx.End) 99 report_fatal_error("EOF while reading float64"); 100 int32_t Result = 0; 101 memcpy(&Result, Ctx.Ptr, sizeof(Result)); 102 Ctx.Ptr += sizeof(Result); 103 return Result; 104 } 105 106 static int64_t readFloat64(WasmObjectFile::ReadContext &Ctx) { 107 if (Ctx.Ptr + 8 > Ctx.End) 108 report_fatal_error("EOF while reading float64"); 109 int64_t Result = 0; 110 memcpy(&Result, Ctx.Ptr, sizeof(Result)); 111 Ctx.Ptr += sizeof(Result); 112 return Result; 113 } 114 115 static uint64_t readULEB128(WasmObjectFile::ReadContext &Ctx) { 116 unsigned Count; 117 const char *Error = nullptr; 118 uint64_t Result = decodeULEB128(Ctx.Ptr, &Count, Ctx.End, &Error); 119 if (Error) 120 report_fatal_error(Error); 121 Ctx.Ptr += Count; 122 return Result; 123 } 124 125 static StringRef readString(WasmObjectFile::ReadContext &Ctx) { 126 uint32_t StringLen = readULEB128(Ctx); 127 if (Ctx.Ptr + StringLen > Ctx.End) 128 report_fatal_error("EOF while reading string"); 129 StringRef Return = 130 StringRef(reinterpret_cast<const char *>(Ctx.Ptr), StringLen); 131 Ctx.Ptr += StringLen; 132 return Return; 133 } 134 135 static int64_t readLEB128(WasmObjectFile::ReadContext &Ctx) { 136 unsigned Count; 137 const char *Error = nullptr; 138 uint64_t Result = decodeSLEB128(Ctx.Ptr, &Count, Ctx.End, &Error); 139 if (Error) 140 report_fatal_error(Error); 141 Ctx.Ptr += Count; 142 return Result; 143 } 144 145 static uint8_t readVaruint1(WasmObjectFile::ReadContext &Ctx) { 146 int64_t Result = readLEB128(Ctx); 147 if (Result > VARUINT1_MAX || Result < 0) 148 report_fatal_error("LEB is outside Varuint1 range"); 149 return Result; 150 } 151 152 static int32_t readVarint32(WasmObjectFile::ReadContext &Ctx) { 153 int64_t Result = readLEB128(Ctx); 154 if (Result > INT32_MAX || Result < INT32_MIN) 155 report_fatal_error("LEB is outside Varint32 range"); 156 return Result; 157 } 158 159 static uint32_t readVaruint32(WasmObjectFile::ReadContext &Ctx) { 160 uint64_t Result = readULEB128(Ctx); 161 if (Result > UINT32_MAX) 162 report_fatal_error("LEB is outside Varuint32 range"); 163 return Result; 164 } 165 166 static int64_t readVarint64(WasmObjectFile::ReadContext &Ctx) { 167 return readLEB128(Ctx); 168 } 169 170 static uint64_t readVaruint64(WasmObjectFile::ReadContext &Ctx) { 171 return readULEB128(Ctx); 172 } 173 174 static uint8_t readOpcode(WasmObjectFile::ReadContext &Ctx) { 175 return readUint8(Ctx); 176 } 177 178 static wasm::ValType parseValType(WasmObjectFile::ReadContext &Ctx, 179 uint32_t Code) { 180 // only directly encoded FUNCREF/EXTERNREF/EXNREF are supported 181 // (not ref null func, ref null extern, or ref null exn) 182 switch (Code) { 183 case wasm::WASM_TYPE_I32: 184 case wasm::WASM_TYPE_I64: 185 case wasm::WASM_TYPE_F32: 186 case wasm::WASM_TYPE_F64: 187 case wasm::WASM_TYPE_V128: 188 case wasm::WASM_TYPE_FUNCREF: 189 case wasm::WASM_TYPE_EXTERNREF: 190 case wasm::WASM_TYPE_EXNREF: 191 return wasm::ValType(Code); 192 } 193 if (Code == wasm::WASM_TYPE_NULLABLE || Code == wasm::WASM_TYPE_NONNULLABLE) { 194 /* Discard HeapType */ readVarint64(Ctx); 195 } 196 return wasm::ValType(wasm::ValType::OTHERREF); 197 } 198 199 static Error readInitExpr(wasm::WasmInitExpr &Expr, 200 WasmObjectFile::ReadContext &Ctx) { 201 auto Start = Ctx.Ptr; 202 203 Expr.Extended = false; 204 Expr.Inst.Opcode = readOpcode(Ctx); 205 switch (Expr.Inst.Opcode) { 206 case wasm::WASM_OPCODE_I32_CONST: 207 Expr.Inst.Value.Int32 = readVarint32(Ctx); 208 break; 209 case wasm::WASM_OPCODE_I64_CONST: 210 Expr.Inst.Value.Int64 = readVarint64(Ctx); 211 break; 212 case wasm::WASM_OPCODE_F32_CONST: 213 Expr.Inst.Value.Float32 = readFloat32(Ctx); 214 break; 215 case wasm::WASM_OPCODE_F64_CONST: 216 Expr.Inst.Value.Float64 = readFloat64(Ctx); 217 break; 218 case wasm::WASM_OPCODE_GLOBAL_GET: 219 Expr.Inst.Value.Global = readULEB128(Ctx); 220 break; 221 case wasm::WASM_OPCODE_REF_NULL: { 222 /* Discard type */ parseValType(Ctx, readVaruint32(Ctx)); 223 break; 224 } 225 default: 226 Expr.Extended = true; 227 } 228 229 if (!Expr.Extended) { 230 uint8_t EndOpcode = readOpcode(Ctx); 231 if (EndOpcode != wasm::WASM_OPCODE_END) 232 Expr.Extended = true; 233 } 234 235 if (Expr.Extended) { 236 Ctx.Ptr = Start; 237 while (true) { 238 uint8_t Opcode = readOpcode(Ctx); 239 switch (Opcode) { 240 case wasm::WASM_OPCODE_I32_CONST: 241 case wasm::WASM_OPCODE_GLOBAL_GET: 242 case wasm::WASM_OPCODE_REF_NULL: 243 case wasm::WASM_OPCODE_REF_FUNC: 244 case wasm::WASM_OPCODE_I64_CONST: 245 readULEB128(Ctx); 246 break; 247 case wasm::WASM_OPCODE_F32_CONST: 248 readFloat32(Ctx); 249 break; 250 case wasm::WASM_OPCODE_F64_CONST: 251 readFloat64(Ctx); 252 break; 253 case wasm::WASM_OPCODE_I32_ADD: 254 case wasm::WASM_OPCODE_I32_SUB: 255 case wasm::WASM_OPCODE_I32_MUL: 256 case wasm::WASM_OPCODE_I64_ADD: 257 case wasm::WASM_OPCODE_I64_SUB: 258 case wasm::WASM_OPCODE_I64_MUL: 259 break; 260 case wasm::WASM_OPCODE_GC_PREFIX: 261 break; 262 // The GC opcodes are in a separate (prefixed space). This flat switch 263 // structure works as long as there is no overlap between the GC and 264 // general opcodes used in init exprs. 265 case wasm::WASM_OPCODE_STRUCT_NEW: 266 case wasm::WASM_OPCODE_STRUCT_NEW_DEFAULT: 267 case wasm::WASM_OPCODE_ARRAY_NEW: 268 case wasm::WASM_OPCODE_ARRAY_NEW_DEFAULT: 269 readULEB128(Ctx); // heap type index 270 break; 271 case wasm::WASM_OPCODE_ARRAY_NEW_FIXED: 272 readULEB128(Ctx); // heap type index 273 readULEB128(Ctx); // array size 274 break; 275 case wasm::WASM_OPCODE_REF_I31: 276 break; 277 case wasm::WASM_OPCODE_END: 278 Expr.Body = ArrayRef<uint8_t>(Start, Ctx.Ptr - Start); 279 return Error::success(); 280 default: 281 return make_error<GenericBinaryError>( 282 Twine("invalid opcode in init_expr: ") + Twine(unsigned(Opcode)), 283 object_error::parse_failed); 284 } 285 } 286 } 287 288 return Error::success(); 289 } 290 291 static wasm::WasmLimits readLimits(WasmObjectFile::ReadContext &Ctx) { 292 wasm::WasmLimits Result; 293 Result.Flags = readVaruint32(Ctx); 294 Result.Minimum = readVaruint64(Ctx); 295 if (Result.Flags & wasm::WASM_LIMITS_FLAG_HAS_MAX) 296 Result.Maximum = readVaruint64(Ctx); 297 return Result; 298 } 299 300 static wasm::WasmTableType readTableType(WasmObjectFile::ReadContext &Ctx) { 301 wasm::WasmTableType TableType; 302 auto ElemType = parseValType(Ctx, readVaruint32(Ctx)); 303 TableType.ElemType = ElemType; 304 TableType.Limits = readLimits(Ctx); 305 return TableType; 306 } 307 308 static Error readSection(WasmSection &Section, WasmObjectFile::ReadContext &Ctx, 309 WasmSectionOrderChecker &Checker) { 310 Section.Type = readUint8(Ctx); 311 LLVM_DEBUG(dbgs() << "readSection type=" << Section.Type << "\n"); 312 // When reading the section's size, store the size of the LEB used to encode 313 // it. This allows objcopy/strip to reproduce the binary identically. 314 const uint8_t *PreSizePtr = Ctx.Ptr; 315 uint32_t Size = readVaruint32(Ctx); 316 Section.HeaderSecSizeEncodingLen = Ctx.Ptr - PreSizePtr; 317 Section.Offset = Ctx.Ptr - Ctx.Start; 318 if (Size == 0) 319 return make_error<StringError>("zero length section", 320 object_error::parse_failed); 321 if (Ctx.Ptr + Size > Ctx.End) 322 return make_error<StringError>("section too large", 323 object_error::parse_failed); 324 if (Section.Type == wasm::WASM_SEC_CUSTOM) { 325 WasmObjectFile::ReadContext SectionCtx; 326 SectionCtx.Start = Ctx.Ptr; 327 SectionCtx.Ptr = Ctx.Ptr; 328 SectionCtx.End = Ctx.Ptr + Size; 329 330 Section.Name = readString(SectionCtx); 331 332 uint32_t SectionNameSize = SectionCtx.Ptr - SectionCtx.Start; 333 Ctx.Ptr += SectionNameSize; 334 Size -= SectionNameSize; 335 } 336 337 if (!Checker.isValidSectionOrder(Section.Type, Section.Name)) { 338 return make_error<StringError>("out of order section type: " + 339 llvm::to_string(Section.Type), 340 object_error::parse_failed); 341 } 342 343 Section.Content = ArrayRef<uint8_t>(Ctx.Ptr, Size); 344 Ctx.Ptr += Size; 345 return Error::success(); 346 } 347 348 WasmObjectFile::WasmObjectFile(MemoryBufferRef Buffer, Error &Err) 349 : ObjectFile(Binary::ID_Wasm, Buffer) { 350 ErrorAsOutParameter ErrAsOutParam(&Err); 351 Header.Magic = getData().substr(0, 4); 352 if (Header.Magic != StringRef("\0asm", 4)) { 353 Err = make_error<StringError>("invalid magic number", 354 object_error::parse_failed); 355 return; 356 } 357 358 ReadContext Ctx; 359 Ctx.Start = getData().bytes_begin(); 360 Ctx.Ptr = Ctx.Start + 4; 361 Ctx.End = Ctx.Start + getData().size(); 362 363 if (Ctx.Ptr + 4 > Ctx.End) { 364 Err = make_error<StringError>("missing version number", 365 object_error::parse_failed); 366 return; 367 } 368 369 Header.Version = readUint32(Ctx); 370 if (Header.Version != wasm::WasmVersion) { 371 Err = make_error<StringError>("invalid version number: " + 372 Twine(Header.Version), 373 object_error::parse_failed); 374 return; 375 } 376 377 WasmSectionOrderChecker Checker; 378 while (Ctx.Ptr < Ctx.End) { 379 WasmSection Sec; 380 if ((Err = readSection(Sec, Ctx, Checker))) 381 return; 382 if ((Err = parseSection(Sec))) 383 return; 384 385 Sections.push_back(Sec); 386 } 387 } 388 389 Error WasmObjectFile::parseSection(WasmSection &Sec) { 390 ReadContext Ctx; 391 Ctx.Start = Sec.Content.data(); 392 Ctx.End = Ctx.Start + Sec.Content.size(); 393 Ctx.Ptr = Ctx.Start; 394 switch (Sec.Type) { 395 case wasm::WASM_SEC_CUSTOM: 396 return parseCustomSection(Sec, Ctx); 397 case wasm::WASM_SEC_TYPE: 398 return parseTypeSection(Ctx); 399 case wasm::WASM_SEC_IMPORT: 400 return parseImportSection(Ctx); 401 case wasm::WASM_SEC_FUNCTION: 402 return parseFunctionSection(Ctx); 403 case wasm::WASM_SEC_TABLE: 404 return parseTableSection(Ctx); 405 case wasm::WASM_SEC_MEMORY: 406 return parseMemorySection(Ctx); 407 case wasm::WASM_SEC_TAG: 408 return parseTagSection(Ctx); 409 case wasm::WASM_SEC_GLOBAL: 410 return parseGlobalSection(Ctx); 411 case wasm::WASM_SEC_EXPORT: 412 return parseExportSection(Ctx); 413 case wasm::WASM_SEC_START: 414 return parseStartSection(Ctx); 415 case wasm::WASM_SEC_ELEM: 416 return parseElemSection(Ctx); 417 case wasm::WASM_SEC_CODE: 418 return parseCodeSection(Ctx); 419 case wasm::WASM_SEC_DATA: 420 return parseDataSection(Ctx); 421 case wasm::WASM_SEC_DATACOUNT: 422 return parseDataCountSection(Ctx); 423 default: 424 return make_error<GenericBinaryError>( 425 "invalid section type: " + Twine(Sec.Type), object_error::parse_failed); 426 } 427 } 428 429 Error WasmObjectFile::parseDylinkSection(ReadContext &Ctx) { 430 // Legacy "dylink" section support. 431 // See parseDylink0Section for the current "dylink.0" section parsing. 432 HasDylinkSection = true; 433 DylinkInfo.MemorySize = readVaruint32(Ctx); 434 DylinkInfo.MemoryAlignment = readVaruint32(Ctx); 435 DylinkInfo.TableSize = readVaruint32(Ctx); 436 DylinkInfo.TableAlignment = readVaruint32(Ctx); 437 uint32_t Count = readVaruint32(Ctx); 438 while (Count--) { 439 DylinkInfo.Needed.push_back(readString(Ctx)); 440 } 441 442 if (Ctx.Ptr != Ctx.End) 443 return make_error<GenericBinaryError>("dylink section ended prematurely", 444 object_error::parse_failed); 445 return Error::success(); 446 } 447 448 Error WasmObjectFile::parseDylink0Section(ReadContext &Ctx) { 449 // See 450 // https://github.com/WebAssembly/tool-conventions/blob/main/DynamicLinking.md 451 HasDylinkSection = true; 452 453 const uint8_t *OrigEnd = Ctx.End; 454 while (Ctx.Ptr < OrigEnd) { 455 Ctx.End = OrigEnd; 456 uint8_t Type = readUint8(Ctx); 457 uint32_t Size = readVaruint32(Ctx); 458 LLVM_DEBUG(dbgs() << "readSubsection type=" << int(Type) << " size=" << Size 459 << "\n"); 460 Ctx.End = Ctx.Ptr + Size; 461 uint32_t Count; 462 switch (Type) { 463 case wasm::WASM_DYLINK_MEM_INFO: 464 DylinkInfo.MemorySize = readVaruint32(Ctx); 465 DylinkInfo.MemoryAlignment = readVaruint32(Ctx); 466 DylinkInfo.TableSize = readVaruint32(Ctx); 467 DylinkInfo.TableAlignment = readVaruint32(Ctx); 468 break; 469 case wasm::WASM_DYLINK_NEEDED: 470 Count = readVaruint32(Ctx); 471 while (Count--) { 472 DylinkInfo.Needed.push_back(readString(Ctx)); 473 } 474 break; 475 case wasm::WASM_DYLINK_EXPORT_INFO: { 476 uint32_t Count = readVaruint32(Ctx); 477 while (Count--) { 478 DylinkInfo.ExportInfo.push_back({readString(Ctx), readVaruint32(Ctx)}); 479 } 480 break; 481 } 482 case wasm::WASM_DYLINK_IMPORT_INFO: { 483 uint32_t Count = readVaruint32(Ctx); 484 while (Count--) { 485 DylinkInfo.ImportInfo.push_back( 486 {readString(Ctx), readString(Ctx), readVaruint32(Ctx)}); 487 } 488 break; 489 } 490 default: 491 LLVM_DEBUG(dbgs() << "unknown dylink.0 sub-section: " << Type << "\n"); 492 Ctx.Ptr += Size; 493 break; 494 } 495 if (Ctx.Ptr != Ctx.End) { 496 return make_error<GenericBinaryError>( 497 "dylink.0 sub-section ended prematurely", object_error::parse_failed); 498 } 499 } 500 501 if (Ctx.Ptr != Ctx.End) 502 return make_error<GenericBinaryError>("dylink.0 section ended prematurely", 503 object_error::parse_failed); 504 return Error::success(); 505 } 506 507 Error WasmObjectFile::parseNameSection(ReadContext &Ctx) { 508 llvm::DenseSet<uint64_t> SeenFunctions; 509 llvm::DenseSet<uint64_t> SeenGlobals; 510 llvm::DenseSet<uint64_t> SeenSegments; 511 512 // If we have linking section (symbol table) or if we are parsing a DSO 513 // then we don't use the name section for symbol information. 514 bool PopulateSymbolTable = !HasLinkingSection && !HasDylinkSection; 515 516 // If we are using the name section for symbol information then it will 517 // supersede any symbols created by the export section. 518 if (PopulateSymbolTable) 519 Symbols.clear(); 520 521 while (Ctx.Ptr < Ctx.End) { 522 uint8_t Type = readUint8(Ctx); 523 uint32_t Size = readVaruint32(Ctx); 524 const uint8_t *SubSectionEnd = Ctx.Ptr + Size; 525 526 switch (Type) { 527 case wasm::WASM_NAMES_FUNCTION: 528 case wasm::WASM_NAMES_GLOBAL: 529 case wasm::WASM_NAMES_DATA_SEGMENT: { 530 uint32_t Count = readVaruint32(Ctx); 531 while (Count--) { 532 uint32_t Index = readVaruint32(Ctx); 533 StringRef Name = readString(Ctx); 534 wasm::NameType nameType = wasm::NameType::FUNCTION; 535 wasm::WasmSymbolInfo Info{Name, 536 /*Kind */ wasm::WASM_SYMBOL_TYPE_FUNCTION, 537 /* Flags */ 0, 538 /* ImportModule */ std::nullopt, 539 /* ImportName */ std::nullopt, 540 /* ExportName */ std::nullopt, 541 {/* ElementIndex */ Index}}; 542 const wasm::WasmSignature *Signature = nullptr; 543 const wasm::WasmGlobalType *GlobalType = nullptr; 544 const wasm::WasmTableType *TableType = nullptr; 545 if (Type == wasm::WASM_NAMES_FUNCTION) { 546 if (!SeenFunctions.insert(Index).second) 547 return make_error<GenericBinaryError>( 548 "function named more than once", object_error::parse_failed); 549 if (!isValidFunctionIndex(Index) || Name.empty()) 550 return make_error<GenericBinaryError>("invalid function name entry", 551 object_error::parse_failed); 552 553 if (isDefinedFunctionIndex(Index)) { 554 wasm::WasmFunction &F = getDefinedFunction(Index); 555 F.DebugName = Name; 556 Signature = &Signatures[F.SigIndex]; 557 if (F.ExportName) { 558 Info.ExportName = F.ExportName; 559 Info.Flags |= wasm::WASM_SYMBOL_BINDING_GLOBAL; 560 } else { 561 Info.Flags |= wasm::WASM_SYMBOL_BINDING_LOCAL; 562 } 563 } else { 564 Info.Flags |= wasm::WASM_SYMBOL_UNDEFINED; 565 } 566 } else if (Type == wasm::WASM_NAMES_GLOBAL) { 567 if (!SeenGlobals.insert(Index).second) 568 return make_error<GenericBinaryError>("global named more than once", 569 object_error::parse_failed); 570 if (!isValidGlobalIndex(Index) || Name.empty()) 571 return make_error<GenericBinaryError>("invalid global name entry", 572 object_error::parse_failed); 573 nameType = wasm::NameType::GLOBAL; 574 Info.Kind = wasm::WASM_SYMBOL_TYPE_GLOBAL; 575 if (isDefinedGlobalIndex(Index)) { 576 GlobalType = &getDefinedGlobal(Index).Type; 577 } else { 578 Info.Flags |= wasm::WASM_SYMBOL_UNDEFINED; 579 } 580 } else { 581 if (!SeenSegments.insert(Index).second) 582 return make_error<GenericBinaryError>( 583 "segment named more than once", object_error::parse_failed); 584 if (Index > DataSegments.size()) 585 return make_error<GenericBinaryError>("invalid data segment name entry", 586 object_error::parse_failed); 587 nameType = wasm::NameType::DATA_SEGMENT; 588 Info.Kind = wasm::WASM_SYMBOL_TYPE_DATA; 589 Info.Flags |= wasm::WASM_SYMBOL_BINDING_LOCAL; 590 assert(Index < DataSegments.size()); 591 Info.DataRef = wasm::WasmDataReference{ 592 Index, 0, DataSegments[Index].Data.Content.size()}; 593 } 594 DebugNames.push_back(wasm::WasmDebugName{nameType, Index, Name}); 595 if (PopulateSymbolTable) 596 Symbols.emplace_back(Info, GlobalType, TableType, Signature); 597 } 598 break; 599 } 600 // Ignore local names for now 601 case wasm::WASM_NAMES_LOCAL: 602 default: 603 Ctx.Ptr += Size; 604 break; 605 } 606 if (Ctx.Ptr != SubSectionEnd) 607 return make_error<GenericBinaryError>( 608 "name sub-section ended prematurely", object_error::parse_failed); 609 } 610 611 if (Ctx.Ptr != Ctx.End) 612 return make_error<GenericBinaryError>("name section ended prematurely", 613 object_error::parse_failed); 614 return Error::success(); 615 } 616 617 Error WasmObjectFile::parseLinkingSection(ReadContext &Ctx) { 618 HasLinkingSection = true; 619 620 LinkingData.Version = readVaruint32(Ctx); 621 if (LinkingData.Version != wasm::WasmMetadataVersion) { 622 return make_error<GenericBinaryError>( 623 "unexpected metadata version: " + Twine(LinkingData.Version) + 624 " (Expected: " + Twine(wasm::WasmMetadataVersion) + ")", 625 object_error::parse_failed); 626 } 627 628 const uint8_t *OrigEnd = Ctx.End; 629 while (Ctx.Ptr < OrigEnd) { 630 Ctx.End = OrigEnd; 631 uint8_t Type = readUint8(Ctx); 632 uint32_t Size = readVaruint32(Ctx); 633 LLVM_DEBUG(dbgs() << "readSubsection type=" << int(Type) << " size=" << Size 634 << "\n"); 635 Ctx.End = Ctx.Ptr + Size; 636 switch (Type) { 637 case wasm::WASM_SYMBOL_TABLE: 638 if (Error Err = parseLinkingSectionSymtab(Ctx)) 639 return Err; 640 break; 641 case wasm::WASM_SEGMENT_INFO: { 642 uint32_t Count = readVaruint32(Ctx); 643 if (Count > DataSegments.size()) 644 return make_error<GenericBinaryError>("too many segment names", 645 object_error::parse_failed); 646 for (uint32_t I = 0; I < Count; I++) { 647 DataSegments[I].Data.Name = readString(Ctx); 648 DataSegments[I].Data.Alignment = readVaruint32(Ctx); 649 DataSegments[I].Data.LinkingFlags = readVaruint32(Ctx); 650 } 651 break; 652 } 653 case wasm::WASM_INIT_FUNCS: { 654 uint32_t Count = readVaruint32(Ctx); 655 LinkingData.InitFunctions.reserve(Count); 656 for (uint32_t I = 0; I < Count; I++) { 657 wasm::WasmInitFunc Init; 658 Init.Priority = readVaruint32(Ctx); 659 Init.Symbol = readVaruint32(Ctx); 660 if (!isValidFunctionSymbol(Init.Symbol)) 661 return make_error<GenericBinaryError>("invalid function symbol: " + 662 Twine(Init.Symbol), 663 object_error::parse_failed); 664 LinkingData.InitFunctions.emplace_back(Init); 665 } 666 break; 667 } 668 case wasm::WASM_COMDAT_INFO: 669 if (Error Err = parseLinkingSectionComdat(Ctx)) 670 return Err; 671 break; 672 default: 673 Ctx.Ptr += Size; 674 break; 675 } 676 if (Ctx.Ptr != Ctx.End) 677 return make_error<GenericBinaryError>( 678 "linking sub-section ended prematurely", object_error::parse_failed); 679 } 680 if (Ctx.Ptr != OrigEnd) 681 return make_error<GenericBinaryError>("linking section ended prematurely", 682 object_error::parse_failed); 683 return Error::success(); 684 } 685 686 Error WasmObjectFile::parseLinkingSectionSymtab(ReadContext &Ctx) { 687 uint32_t Count = readVaruint32(Ctx); 688 // Clear out any symbol information that was derived from the exports 689 // section. 690 Symbols.clear(); 691 Symbols.reserve(Count); 692 StringSet<> SymbolNames; 693 694 std::vector<wasm::WasmImport *> ImportedGlobals; 695 std::vector<wasm::WasmImport *> ImportedFunctions; 696 std::vector<wasm::WasmImport *> ImportedTags; 697 std::vector<wasm::WasmImport *> ImportedTables; 698 ImportedGlobals.reserve(Imports.size()); 699 ImportedFunctions.reserve(Imports.size()); 700 ImportedTags.reserve(Imports.size()); 701 ImportedTables.reserve(Imports.size()); 702 for (auto &I : Imports) { 703 if (I.Kind == wasm::WASM_EXTERNAL_FUNCTION) 704 ImportedFunctions.emplace_back(&I); 705 else if (I.Kind == wasm::WASM_EXTERNAL_GLOBAL) 706 ImportedGlobals.emplace_back(&I); 707 else if (I.Kind == wasm::WASM_EXTERNAL_TAG) 708 ImportedTags.emplace_back(&I); 709 else if (I.Kind == wasm::WASM_EXTERNAL_TABLE) 710 ImportedTables.emplace_back(&I); 711 } 712 713 while (Count--) { 714 wasm::WasmSymbolInfo Info; 715 const wasm::WasmSignature *Signature = nullptr; 716 const wasm::WasmGlobalType *GlobalType = nullptr; 717 const wasm::WasmTableType *TableType = nullptr; 718 719 Info.Kind = readUint8(Ctx); 720 Info.Flags = readVaruint32(Ctx); 721 bool IsDefined = (Info.Flags & wasm::WASM_SYMBOL_UNDEFINED) == 0; 722 723 switch (Info.Kind) { 724 case wasm::WASM_SYMBOL_TYPE_FUNCTION: 725 Info.ElementIndex = readVaruint32(Ctx); 726 if (!isValidFunctionIndex(Info.ElementIndex) || 727 IsDefined != isDefinedFunctionIndex(Info.ElementIndex)) 728 return make_error<GenericBinaryError>("invalid function symbol index", 729 object_error::parse_failed); 730 if (IsDefined) { 731 Info.Name = readString(Ctx); 732 unsigned FuncIndex = Info.ElementIndex - NumImportedFunctions; 733 wasm::WasmFunction &Function = Functions[FuncIndex]; 734 Signature = &Signatures[Function.SigIndex]; 735 if (Function.SymbolName.empty()) 736 Function.SymbolName = Info.Name; 737 } else { 738 wasm::WasmImport &Import = *ImportedFunctions[Info.ElementIndex]; 739 if ((Info.Flags & wasm::WASM_SYMBOL_EXPLICIT_NAME) != 0) { 740 Info.Name = readString(Ctx); 741 Info.ImportName = Import.Field; 742 } else { 743 Info.Name = Import.Field; 744 } 745 Signature = &Signatures[Import.SigIndex]; 746 Info.ImportModule = Import.Module; 747 } 748 break; 749 750 case wasm::WASM_SYMBOL_TYPE_GLOBAL: 751 Info.ElementIndex = readVaruint32(Ctx); 752 if (!isValidGlobalIndex(Info.ElementIndex) || 753 IsDefined != isDefinedGlobalIndex(Info.ElementIndex)) 754 return make_error<GenericBinaryError>("invalid global symbol index", 755 object_error::parse_failed); 756 if (!IsDefined && (Info.Flags & wasm::WASM_SYMBOL_BINDING_MASK) == 757 wasm::WASM_SYMBOL_BINDING_WEAK) 758 return make_error<GenericBinaryError>("undefined weak global symbol", 759 object_error::parse_failed); 760 if (IsDefined) { 761 Info.Name = readString(Ctx); 762 unsigned GlobalIndex = Info.ElementIndex - NumImportedGlobals; 763 wasm::WasmGlobal &Global = Globals[GlobalIndex]; 764 GlobalType = &Global.Type; 765 if (Global.SymbolName.empty()) 766 Global.SymbolName = Info.Name; 767 } else { 768 wasm::WasmImport &Import = *ImportedGlobals[Info.ElementIndex]; 769 if ((Info.Flags & wasm::WASM_SYMBOL_EXPLICIT_NAME) != 0) { 770 Info.Name = readString(Ctx); 771 Info.ImportName = Import.Field; 772 } else { 773 Info.Name = Import.Field; 774 } 775 GlobalType = &Import.Global; 776 Info.ImportModule = Import.Module; 777 } 778 break; 779 780 case wasm::WASM_SYMBOL_TYPE_TABLE: 781 Info.ElementIndex = readVaruint32(Ctx); 782 if (!isValidTableNumber(Info.ElementIndex) || 783 IsDefined != isDefinedTableNumber(Info.ElementIndex)) 784 return make_error<GenericBinaryError>("invalid table symbol index", 785 object_error::parse_failed); 786 if (!IsDefined && (Info.Flags & wasm::WASM_SYMBOL_BINDING_MASK) == 787 wasm::WASM_SYMBOL_BINDING_WEAK) 788 return make_error<GenericBinaryError>("undefined weak table symbol", 789 object_error::parse_failed); 790 if (IsDefined) { 791 Info.Name = readString(Ctx); 792 unsigned TableNumber = Info.ElementIndex - NumImportedTables; 793 wasm::WasmTable &Table = Tables[TableNumber]; 794 TableType = &Table.Type; 795 if (Table.SymbolName.empty()) 796 Table.SymbolName = Info.Name; 797 } else { 798 wasm::WasmImport &Import = *ImportedTables[Info.ElementIndex]; 799 if ((Info.Flags & wasm::WASM_SYMBOL_EXPLICIT_NAME) != 0) { 800 Info.Name = readString(Ctx); 801 Info.ImportName = Import.Field; 802 } else { 803 Info.Name = Import.Field; 804 } 805 TableType = &Import.Table; 806 Info.ImportModule = Import.Module; 807 } 808 break; 809 810 case wasm::WASM_SYMBOL_TYPE_DATA: 811 Info.Name = readString(Ctx); 812 if (IsDefined) { 813 auto Index = readVaruint32(Ctx); 814 auto Offset = readVaruint64(Ctx); 815 auto Size = readVaruint64(Ctx); 816 if (!(Info.Flags & wasm::WASM_SYMBOL_ABSOLUTE)) { 817 if (static_cast<size_t>(Index) >= DataSegments.size()) 818 return make_error<GenericBinaryError>( 819 "invalid data segment index: " + Twine(Index), 820 object_error::parse_failed); 821 size_t SegmentSize = DataSegments[Index].Data.Content.size(); 822 if (Offset > SegmentSize) 823 return make_error<GenericBinaryError>( 824 "invalid data symbol offset: `" + Info.Name + 825 "` (offset: " + Twine(Offset) + 826 " segment size: " + Twine(SegmentSize) + ")", 827 object_error::parse_failed); 828 } 829 Info.DataRef = wasm::WasmDataReference{Index, Offset, Size}; 830 } 831 break; 832 833 case wasm::WASM_SYMBOL_TYPE_SECTION: { 834 if ((Info.Flags & wasm::WASM_SYMBOL_BINDING_MASK) != 835 wasm::WASM_SYMBOL_BINDING_LOCAL) 836 return make_error<GenericBinaryError>( 837 "section symbols must have local binding", 838 object_error::parse_failed); 839 Info.ElementIndex = readVaruint32(Ctx); 840 // Use somewhat unique section name as symbol name. 841 StringRef SectionName = Sections[Info.ElementIndex].Name; 842 Info.Name = SectionName; 843 break; 844 } 845 846 case wasm::WASM_SYMBOL_TYPE_TAG: { 847 Info.ElementIndex = readVaruint32(Ctx); 848 if (!isValidTagIndex(Info.ElementIndex) || 849 IsDefined != isDefinedTagIndex(Info.ElementIndex)) 850 return make_error<GenericBinaryError>("invalid tag symbol index", 851 object_error::parse_failed); 852 if (!IsDefined && (Info.Flags & wasm::WASM_SYMBOL_BINDING_MASK) == 853 wasm::WASM_SYMBOL_BINDING_WEAK) 854 return make_error<GenericBinaryError>("undefined weak global symbol", 855 object_error::parse_failed); 856 if (IsDefined) { 857 Info.Name = readString(Ctx); 858 unsigned TagIndex = Info.ElementIndex - NumImportedTags; 859 wasm::WasmTag &Tag = Tags[TagIndex]; 860 Signature = &Signatures[Tag.SigIndex]; 861 if (Tag.SymbolName.empty()) 862 Tag.SymbolName = Info.Name; 863 864 } else { 865 wasm::WasmImport &Import = *ImportedTags[Info.ElementIndex]; 866 if ((Info.Flags & wasm::WASM_SYMBOL_EXPLICIT_NAME) != 0) { 867 Info.Name = readString(Ctx); 868 Info.ImportName = Import.Field; 869 } else { 870 Info.Name = Import.Field; 871 } 872 Signature = &Signatures[Import.SigIndex]; 873 Info.ImportModule = Import.Module; 874 } 875 break; 876 } 877 878 default: 879 return make_error<GenericBinaryError>("invalid symbol type: " + 880 Twine(unsigned(Info.Kind)), 881 object_error::parse_failed); 882 } 883 884 if ((Info.Flags & wasm::WASM_SYMBOL_BINDING_MASK) != 885 wasm::WASM_SYMBOL_BINDING_LOCAL && 886 !SymbolNames.insert(Info.Name).second) 887 return make_error<GenericBinaryError>("duplicate symbol name " + 888 Twine(Info.Name), 889 object_error::parse_failed); 890 Symbols.emplace_back(Info, GlobalType, TableType, Signature); 891 LLVM_DEBUG(dbgs() << "Adding symbol: " << Symbols.back() << "\n"); 892 } 893 894 return Error::success(); 895 } 896 897 Error WasmObjectFile::parseLinkingSectionComdat(ReadContext &Ctx) { 898 uint32_t ComdatCount = readVaruint32(Ctx); 899 StringSet<> ComdatSet; 900 for (unsigned ComdatIndex = 0; ComdatIndex < ComdatCount; ++ComdatIndex) { 901 StringRef Name = readString(Ctx); 902 if (Name.empty() || !ComdatSet.insert(Name).second) 903 return make_error<GenericBinaryError>("bad/duplicate COMDAT name " + 904 Twine(Name), 905 object_error::parse_failed); 906 LinkingData.Comdats.emplace_back(Name); 907 uint32_t Flags = readVaruint32(Ctx); 908 if (Flags != 0) 909 return make_error<GenericBinaryError>("unsupported COMDAT flags", 910 object_error::parse_failed); 911 912 uint32_t EntryCount = readVaruint32(Ctx); 913 while (EntryCount--) { 914 unsigned Kind = readVaruint32(Ctx); 915 unsigned Index = readVaruint32(Ctx); 916 switch (Kind) { 917 default: 918 return make_error<GenericBinaryError>("invalid COMDAT entry type", 919 object_error::parse_failed); 920 case wasm::WASM_COMDAT_DATA: 921 if (Index >= DataSegments.size()) 922 return make_error<GenericBinaryError>( 923 "COMDAT data index out of range", object_error::parse_failed); 924 if (DataSegments[Index].Data.Comdat != UINT32_MAX) 925 return make_error<GenericBinaryError>("data segment in two COMDATs", 926 object_error::parse_failed); 927 DataSegments[Index].Data.Comdat = ComdatIndex; 928 break; 929 case wasm::WASM_COMDAT_FUNCTION: 930 if (!isDefinedFunctionIndex(Index)) 931 return make_error<GenericBinaryError>( 932 "COMDAT function index out of range", object_error::parse_failed); 933 if (getDefinedFunction(Index).Comdat != UINT32_MAX) 934 return make_error<GenericBinaryError>("function in two COMDATs", 935 object_error::parse_failed); 936 getDefinedFunction(Index).Comdat = ComdatIndex; 937 break; 938 case wasm::WASM_COMDAT_SECTION: 939 if (Index >= Sections.size()) 940 return make_error<GenericBinaryError>( 941 "COMDAT section index out of range", object_error::parse_failed); 942 if (Sections[Index].Type != wasm::WASM_SEC_CUSTOM) 943 return make_error<GenericBinaryError>( 944 "non-custom section in a COMDAT", object_error::parse_failed); 945 Sections[Index].Comdat = ComdatIndex; 946 break; 947 } 948 } 949 } 950 return Error::success(); 951 } 952 953 Error WasmObjectFile::parseProducersSection(ReadContext &Ctx) { 954 llvm::SmallSet<StringRef, 3> FieldsSeen; 955 uint32_t Fields = readVaruint32(Ctx); 956 for (size_t I = 0; I < Fields; ++I) { 957 StringRef FieldName = readString(Ctx); 958 if (!FieldsSeen.insert(FieldName).second) 959 return make_error<GenericBinaryError>( 960 "producers section does not have unique fields", 961 object_error::parse_failed); 962 std::vector<std::pair<std::string, std::string>> *ProducerVec = nullptr; 963 if (FieldName == "language") { 964 ProducerVec = &ProducerInfo.Languages; 965 } else if (FieldName == "processed-by") { 966 ProducerVec = &ProducerInfo.Tools; 967 } else if (FieldName == "sdk") { 968 ProducerVec = &ProducerInfo.SDKs; 969 } else { 970 return make_error<GenericBinaryError>( 971 "producers section field is not named one of language, processed-by, " 972 "or sdk", 973 object_error::parse_failed); 974 } 975 uint32_t ValueCount = readVaruint32(Ctx); 976 llvm::SmallSet<StringRef, 8> ProducersSeen; 977 for (size_t J = 0; J < ValueCount; ++J) { 978 StringRef Name = readString(Ctx); 979 StringRef Version = readString(Ctx); 980 if (!ProducersSeen.insert(Name).second) { 981 return make_error<GenericBinaryError>( 982 "producers section contains repeated producer", 983 object_error::parse_failed); 984 } 985 ProducerVec->emplace_back(std::string(Name), std::string(Version)); 986 } 987 } 988 if (Ctx.Ptr != Ctx.End) 989 return make_error<GenericBinaryError>("producers section ended prematurely", 990 object_error::parse_failed); 991 return Error::success(); 992 } 993 994 Error WasmObjectFile::parseTargetFeaturesSection(ReadContext &Ctx) { 995 llvm::SmallSet<std::string, 8> FeaturesSeen; 996 uint32_t FeatureCount = readVaruint32(Ctx); 997 for (size_t I = 0; I < FeatureCount; ++I) { 998 wasm::WasmFeatureEntry Feature; 999 Feature.Prefix = readUint8(Ctx); 1000 switch (Feature.Prefix) { 1001 case wasm::WASM_FEATURE_PREFIX_USED: 1002 case wasm::WASM_FEATURE_PREFIX_DISALLOWED: 1003 break; 1004 default: 1005 return make_error<GenericBinaryError>("unknown feature policy prefix", 1006 object_error::parse_failed); 1007 } 1008 Feature.Name = std::string(readString(Ctx)); 1009 if (!FeaturesSeen.insert(Feature.Name).second) 1010 return make_error<GenericBinaryError>( 1011 "target features section contains repeated feature \"" + 1012 Feature.Name + "\"", 1013 object_error::parse_failed); 1014 TargetFeatures.push_back(Feature); 1015 } 1016 if (Ctx.Ptr != Ctx.End) 1017 return make_error<GenericBinaryError>( 1018 "target features section ended prematurely", 1019 object_error::parse_failed); 1020 return Error::success(); 1021 } 1022 1023 Error WasmObjectFile::parseRelocSection(StringRef Name, ReadContext &Ctx) { 1024 uint32_t SectionIndex = readVaruint32(Ctx); 1025 if (SectionIndex >= Sections.size()) 1026 return make_error<GenericBinaryError>("invalid section index", 1027 object_error::parse_failed); 1028 WasmSection &Section = Sections[SectionIndex]; 1029 uint32_t RelocCount = readVaruint32(Ctx); 1030 uint32_t EndOffset = Section.Content.size(); 1031 uint32_t PreviousOffset = 0; 1032 while (RelocCount--) { 1033 wasm::WasmRelocation Reloc = {}; 1034 uint32_t type = readVaruint32(Ctx); 1035 Reloc.Type = type; 1036 Reloc.Offset = readVaruint32(Ctx); 1037 if (Reloc.Offset < PreviousOffset) 1038 return make_error<GenericBinaryError>("relocations not in offset order", 1039 object_error::parse_failed); 1040 1041 auto badReloc = [&](StringRef msg) { 1042 return make_error<GenericBinaryError>( 1043 msg + ": " + Twine(Symbols[Reloc.Index].Info.Name), 1044 object_error::parse_failed); 1045 }; 1046 1047 PreviousOffset = Reloc.Offset; 1048 Reloc.Index = readVaruint32(Ctx); 1049 switch (type) { 1050 case wasm::R_WASM_FUNCTION_INDEX_LEB: 1051 case wasm::R_WASM_FUNCTION_INDEX_I32: 1052 case wasm::R_WASM_TABLE_INDEX_SLEB: 1053 case wasm::R_WASM_TABLE_INDEX_SLEB64: 1054 case wasm::R_WASM_TABLE_INDEX_I32: 1055 case wasm::R_WASM_TABLE_INDEX_I64: 1056 case wasm::R_WASM_TABLE_INDEX_REL_SLEB: 1057 case wasm::R_WASM_TABLE_INDEX_REL_SLEB64: 1058 if (!isValidFunctionSymbol(Reloc.Index)) 1059 return badReloc("invalid function relocation"); 1060 break; 1061 case wasm::R_WASM_TABLE_NUMBER_LEB: 1062 if (!isValidTableSymbol(Reloc.Index)) 1063 return badReloc("invalid table relocation"); 1064 break; 1065 case wasm::R_WASM_TYPE_INDEX_LEB: 1066 if (Reloc.Index >= Signatures.size()) 1067 return badReloc("invalid relocation type index"); 1068 break; 1069 case wasm::R_WASM_GLOBAL_INDEX_LEB: 1070 // R_WASM_GLOBAL_INDEX_LEB are can be used against function and data 1071 // symbols to refer to their GOT entries. 1072 if (!isValidGlobalSymbol(Reloc.Index) && 1073 !isValidDataSymbol(Reloc.Index) && 1074 !isValidFunctionSymbol(Reloc.Index)) 1075 return badReloc("invalid global relocation"); 1076 break; 1077 case wasm::R_WASM_GLOBAL_INDEX_I32: 1078 if (!isValidGlobalSymbol(Reloc.Index)) 1079 return badReloc("invalid global relocation"); 1080 break; 1081 case wasm::R_WASM_TAG_INDEX_LEB: 1082 if (!isValidTagSymbol(Reloc.Index)) 1083 return badReloc("invalid tag relocation"); 1084 break; 1085 case wasm::R_WASM_MEMORY_ADDR_LEB: 1086 case wasm::R_WASM_MEMORY_ADDR_SLEB: 1087 case wasm::R_WASM_MEMORY_ADDR_I32: 1088 case wasm::R_WASM_MEMORY_ADDR_REL_SLEB: 1089 case wasm::R_WASM_MEMORY_ADDR_TLS_SLEB: 1090 case wasm::R_WASM_MEMORY_ADDR_LOCREL_I32: 1091 if (!isValidDataSymbol(Reloc.Index)) 1092 return badReloc("invalid data relocation"); 1093 Reloc.Addend = readVarint32(Ctx); 1094 break; 1095 case wasm::R_WASM_MEMORY_ADDR_LEB64: 1096 case wasm::R_WASM_MEMORY_ADDR_SLEB64: 1097 case wasm::R_WASM_MEMORY_ADDR_I64: 1098 case wasm::R_WASM_MEMORY_ADDR_REL_SLEB64: 1099 case wasm::R_WASM_MEMORY_ADDR_TLS_SLEB64: 1100 if (!isValidDataSymbol(Reloc.Index)) 1101 return badReloc("invalid data relocation"); 1102 Reloc.Addend = readVarint64(Ctx); 1103 break; 1104 case wasm::R_WASM_FUNCTION_OFFSET_I32: 1105 if (!isValidFunctionSymbol(Reloc.Index)) 1106 return badReloc("invalid function relocation"); 1107 Reloc.Addend = readVarint32(Ctx); 1108 break; 1109 case wasm::R_WASM_FUNCTION_OFFSET_I64: 1110 if (!isValidFunctionSymbol(Reloc.Index)) 1111 return badReloc("invalid function relocation"); 1112 Reloc.Addend = readVarint64(Ctx); 1113 break; 1114 case wasm::R_WASM_SECTION_OFFSET_I32: 1115 if (!isValidSectionSymbol(Reloc.Index)) 1116 return badReloc("invalid section relocation"); 1117 Reloc.Addend = readVarint32(Ctx); 1118 break; 1119 default: 1120 return make_error<GenericBinaryError>("invalid relocation type: " + 1121 Twine(type), 1122 object_error::parse_failed); 1123 } 1124 1125 // Relocations must fit inside the section, and must appear in order. They 1126 // also shouldn't overlap a function/element boundary, but we don't bother 1127 // to check that. 1128 uint64_t Size = 5; 1129 if (Reloc.Type == wasm::R_WASM_MEMORY_ADDR_LEB64 || 1130 Reloc.Type == wasm::R_WASM_MEMORY_ADDR_SLEB64 || 1131 Reloc.Type == wasm::R_WASM_MEMORY_ADDR_REL_SLEB64) 1132 Size = 10; 1133 if (Reloc.Type == wasm::R_WASM_TABLE_INDEX_I32 || 1134 Reloc.Type == wasm::R_WASM_MEMORY_ADDR_I32 || 1135 Reloc.Type == wasm::R_WASM_MEMORY_ADDR_LOCREL_I32 || 1136 Reloc.Type == wasm::R_WASM_SECTION_OFFSET_I32 || 1137 Reloc.Type == wasm::R_WASM_FUNCTION_OFFSET_I32 || 1138 Reloc.Type == wasm::R_WASM_FUNCTION_INDEX_I32 || 1139 Reloc.Type == wasm::R_WASM_GLOBAL_INDEX_I32) 1140 Size = 4; 1141 if (Reloc.Type == wasm::R_WASM_TABLE_INDEX_I64 || 1142 Reloc.Type == wasm::R_WASM_MEMORY_ADDR_I64 || 1143 Reloc.Type == wasm::R_WASM_FUNCTION_OFFSET_I64) 1144 Size = 8; 1145 if (Reloc.Offset + Size > EndOffset) 1146 return make_error<GenericBinaryError>("invalid relocation offset", 1147 object_error::parse_failed); 1148 1149 Section.Relocations.push_back(Reloc); 1150 } 1151 if (Ctx.Ptr != Ctx.End) 1152 return make_error<GenericBinaryError>("reloc section ended prematurely", 1153 object_error::parse_failed); 1154 return Error::success(); 1155 } 1156 1157 Error WasmObjectFile::parseCustomSection(WasmSection &Sec, ReadContext &Ctx) { 1158 if (Sec.Name == "dylink") { 1159 if (Error Err = parseDylinkSection(Ctx)) 1160 return Err; 1161 } else if (Sec.Name == "dylink.0") { 1162 if (Error Err = parseDylink0Section(Ctx)) 1163 return Err; 1164 } else if (Sec.Name == "name") { 1165 if (Error Err = parseNameSection(Ctx)) 1166 return Err; 1167 } else if (Sec.Name == "linking") { 1168 if (Error Err = parseLinkingSection(Ctx)) 1169 return Err; 1170 } else if (Sec.Name == "producers") { 1171 if (Error Err = parseProducersSection(Ctx)) 1172 return Err; 1173 } else if (Sec.Name == "target_features") { 1174 if (Error Err = parseTargetFeaturesSection(Ctx)) 1175 return Err; 1176 } else if (Sec.Name.starts_with("reloc.")) { 1177 if (Error Err = parseRelocSection(Sec.Name, Ctx)) 1178 return Err; 1179 } 1180 return Error::success(); 1181 } 1182 1183 Error WasmObjectFile::parseTypeSection(ReadContext &Ctx) { 1184 auto parseFieldDef = [&]() { 1185 uint32_t TypeCode = readVaruint32((Ctx)); 1186 /* Discard StorageType */ parseValType(Ctx, TypeCode); 1187 /* Discard Mutability */ readVaruint32(Ctx); 1188 }; 1189 1190 uint32_t Count = readVaruint32(Ctx); 1191 Signatures.reserve(Count); 1192 while (Count--) { 1193 wasm::WasmSignature Sig; 1194 uint8_t Form = readUint8(Ctx); 1195 if (Form == wasm::WASM_TYPE_REC) { 1196 // Rec groups expand the type index space (beyond what was declared at 1197 // the top of the section, and also consume one element in that space. 1198 uint32_t RecSize = readVaruint32(Ctx); 1199 if (RecSize == 0) 1200 return make_error<GenericBinaryError>("Rec group size cannot be 0", 1201 object_error::parse_failed); 1202 Signatures.reserve(Signatures.size() + RecSize); 1203 Count += RecSize; 1204 Sig.Kind = wasm::WasmSignature::Placeholder; 1205 Signatures.push_back(std::move(Sig)); 1206 HasUnmodeledTypes = true; 1207 continue; 1208 } 1209 if (Form != wasm::WASM_TYPE_FUNC) { 1210 // Currently LLVM only models function types, and not other composite 1211 // types. Here we parse the type declarations just enough to skip past 1212 // them in the binary. 1213 if (Form == wasm::WASM_TYPE_SUB || Form == wasm::WASM_TYPE_SUB_FINAL) { 1214 uint32_t Supers = readVaruint32(Ctx); 1215 if (Supers > 0) { 1216 if (Supers != 1) 1217 return make_error<GenericBinaryError>( 1218 "Invalid number of supertypes", object_error::parse_failed); 1219 /* Discard SuperIndex */ readVaruint32(Ctx); 1220 } 1221 Form = readVaruint32(Ctx); 1222 } 1223 if (Form == wasm::WASM_TYPE_STRUCT) { 1224 uint32_t FieldCount = readVaruint32(Ctx); 1225 while (FieldCount--) { 1226 parseFieldDef(); 1227 } 1228 } else if (Form == wasm::WASM_TYPE_ARRAY) { 1229 parseFieldDef(); 1230 } else { 1231 return make_error<GenericBinaryError>("bad form", 1232 object_error::parse_failed); 1233 } 1234 Sig.Kind = wasm::WasmSignature::Placeholder; 1235 Signatures.push_back(std::move(Sig)); 1236 HasUnmodeledTypes = true; 1237 continue; 1238 } 1239 1240 uint32_t ParamCount = readVaruint32(Ctx); 1241 Sig.Params.reserve(ParamCount); 1242 while (ParamCount--) { 1243 uint32_t ParamType = readUint8(Ctx); 1244 Sig.Params.push_back(parseValType(Ctx, ParamType)); 1245 continue; 1246 } 1247 uint32_t ReturnCount = readVaruint32(Ctx); 1248 while (ReturnCount--) { 1249 uint32_t ReturnType = readUint8(Ctx); 1250 Sig.Returns.push_back(parseValType(Ctx, ReturnType)); 1251 } 1252 1253 Signatures.push_back(std::move(Sig)); 1254 } 1255 if (Ctx.Ptr != Ctx.End) 1256 return make_error<GenericBinaryError>("type section ended prematurely", 1257 object_error::parse_failed); 1258 return Error::success(); 1259 } 1260 1261 Error WasmObjectFile::parseImportSection(ReadContext &Ctx) { 1262 uint32_t Count = readVaruint32(Ctx); 1263 uint32_t NumTypes = Signatures.size(); 1264 Imports.reserve(Count); 1265 for (uint32_t I = 0; I < Count; I++) { 1266 wasm::WasmImport Im; 1267 Im.Module = readString(Ctx); 1268 Im.Field = readString(Ctx); 1269 Im.Kind = readUint8(Ctx); 1270 switch (Im.Kind) { 1271 case wasm::WASM_EXTERNAL_FUNCTION: 1272 NumImportedFunctions++; 1273 Im.SigIndex = readVaruint32(Ctx); 1274 if (Im.SigIndex >= NumTypes) 1275 return make_error<GenericBinaryError>("invalid function type", 1276 object_error::parse_failed); 1277 break; 1278 case wasm::WASM_EXTERNAL_GLOBAL: 1279 NumImportedGlobals++; 1280 Im.Global.Type = readUint8(Ctx); 1281 Im.Global.Mutable = readVaruint1(Ctx); 1282 break; 1283 case wasm::WASM_EXTERNAL_MEMORY: 1284 Im.Memory = readLimits(Ctx); 1285 if (Im.Memory.Flags & wasm::WASM_LIMITS_FLAG_IS_64) 1286 HasMemory64 = true; 1287 break; 1288 case wasm::WASM_EXTERNAL_TABLE: { 1289 Im.Table = readTableType(Ctx); 1290 NumImportedTables++; 1291 auto ElemType = Im.Table.ElemType; 1292 if (ElemType != wasm::ValType::FUNCREF && 1293 ElemType != wasm::ValType::EXTERNREF && 1294 ElemType != wasm::ValType::EXNREF && 1295 ElemType != wasm::ValType::OTHERREF) 1296 return make_error<GenericBinaryError>("invalid table element type", 1297 object_error::parse_failed); 1298 break; 1299 } 1300 case wasm::WASM_EXTERNAL_TAG: 1301 NumImportedTags++; 1302 if (readUint8(Ctx) != 0) // Reserved 'attribute' field 1303 return make_error<GenericBinaryError>("invalid attribute", 1304 object_error::parse_failed); 1305 Im.SigIndex = readVaruint32(Ctx); 1306 if (Im.SigIndex >= NumTypes) 1307 return make_error<GenericBinaryError>("invalid tag type", 1308 object_error::parse_failed); 1309 break; 1310 default: 1311 return make_error<GenericBinaryError>("unexpected import kind", 1312 object_error::parse_failed); 1313 } 1314 Imports.push_back(Im); 1315 } 1316 if (Ctx.Ptr != Ctx.End) 1317 return make_error<GenericBinaryError>("import section ended prematurely", 1318 object_error::parse_failed); 1319 return Error::success(); 1320 } 1321 1322 Error WasmObjectFile::parseFunctionSection(ReadContext &Ctx) { 1323 uint32_t Count = readVaruint32(Ctx); 1324 Functions.reserve(Count); 1325 uint32_t NumTypes = Signatures.size(); 1326 while (Count--) { 1327 uint32_t Type = readVaruint32(Ctx); 1328 if (Type >= NumTypes) 1329 return make_error<GenericBinaryError>("invalid function type", 1330 object_error::parse_failed); 1331 wasm::WasmFunction F; 1332 F.SigIndex = Type; 1333 Functions.push_back(F); 1334 } 1335 if (Ctx.Ptr != Ctx.End) 1336 return make_error<GenericBinaryError>("function section ended prematurely", 1337 object_error::parse_failed); 1338 return Error::success(); 1339 } 1340 1341 Error WasmObjectFile::parseTableSection(ReadContext &Ctx) { 1342 TableSection = Sections.size(); 1343 uint32_t Count = readVaruint32(Ctx); 1344 Tables.reserve(Count); 1345 while (Count--) { 1346 wasm::WasmTable T; 1347 T.Type = readTableType(Ctx); 1348 T.Index = NumImportedTables + Tables.size(); 1349 Tables.push_back(T); 1350 auto ElemType = Tables.back().Type.ElemType; 1351 if (ElemType != wasm::ValType::FUNCREF && 1352 ElemType != wasm::ValType::EXTERNREF && 1353 ElemType != wasm::ValType::EXNREF && 1354 ElemType != wasm::ValType::OTHERREF) { 1355 return make_error<GenericBinaryError>("invalid table element type", 1356 object_error::parse_failed); 1357 } 1358 } 1359 if (Ctx.Ptr != Ctx.End) 1360 return make_error<GenericBinaryError>("table section ended prematurely", 1361 object_error::parse_failed); 1362 return Error::success(); 1363 } 1364 1365 Error WasmObjectFile::parseMemorySection(ReadContext &Ctx) { 1366 uint32_t Count = readVaruint32(Ctx); 1367 Memories.reserve(Count); 1368 while (Count--) { 1369 auto Limits = readLimits(Ctx); 1370 if (Limits.Flags & wasm::WASM_LIMITS_FLAG_IS_64) 1371 HasMemory64 = true; 1372 Memories.push_back(Limits); 1373 } 1374 if (Ctx.Ptr != Ctx.End) 1375 return make_error<GenericBinaryError>("memory section ended prematurely", 1376 object_error::parse_failed); 1377 return Error::success(); 1378 } 1379 1380 Error WasmObjectFile::parseTagSection(ReadContext &Ctx) { 1381 TagSection = Sections.size(); 1382 uint32_t Count = readVaruint32(Ctx); 1383 Tags.reserve(Count); 1384 uint32_t NumTypes = Signatures.size(); 1385 while (Count--) { 1386 if (readUint8(Ctx) != 0) // Reserved 'attribute' field 1387 return make_error<GenericBinaryError>("invalid attribute", 1388 object_error::parse_failed); 1389 uint32_t Type = readVaruint32(Ctx); 1390 if (Type >= NumTypes) 1391 return make_error<GenericBinaryError>("invalid tag type", 1392 object_error::parse_failed); 1393 wasm::WasmTag Tag; 1394 Tag.Index = NumImportedTags + Tags.size(); 1395 Tag.SigIndex = Type; 1396 Signatures[Type].Kind = wasm::WasmSignature::Tag; 1397 Tags.push_back(Tag); 1398 } 1399 1400 if (Ctx.Ptr != Ctx.End) 1401 return make_error<GenericBinaryError>("tag section ended prematurely", 1402 object_error::parse_failed); 1403 return Error::success(); 1404 } 1405 1406 Error WasmObjectFile::parseGlobalSection(ReadContext &Ctx) { 1407 GlobalSection = Sections.size(); 1408 const uint8_t *SectionStart = Ctx.Ptr; 1409 uint32_t Count = readVaruint32(Ctx); 1410 Globals.reserve(Count); 1411 while (Count--) { 1412 wasm::WasmGlobal Global; 1413 Global.Index = NumImportedGlobals + Globals.size(); 1414 const uint8_t *GlobalStart = Ctx.Ptr; 1415 Global.Offset = static_cast<uint32_t>(GlobalStart - SectionStart); 1416 auto GlobalOpcode = readVaruint32(Ctx); 1417 Global.Type.Type = (uint8_t)parseValType(Ctx, GlobalOpcode); 1418 Global.Type.Mutable = readVaruint1(Ctx); 1419 if (Error Err = readInitExpr(Global.InitExpr, Ctx)) 1420 return Err; 1421 Global.Size = static_cast<uint32_t>(Ctx.Ptr - GlobalStart); 1422 Globals.push_back(Global); 1423 } 1424 if (Ctx.Ptr != Ctx.End) 1425 return make_error<GenericBinaryError>("global section ended prematurely", 1426 object_error::parse_failed); 1427 return Error::success(); 1428 } 1429 1430 Error WasmObjectFile::parseExportSection(ReadContext &Ctx) { 1431 uint32_t Count = readVaruint32(Ctx); 1432 Exports.reserve(Count); 1433 Symbols.reserve(Count); 1434 for (uint32_t I = 0; I < Count; I++) { 1435 wasm::WasmExport Ex; 1436 Ex.Name = readString(Ctx); 1437 Ex.Kind = readUint8(Ctx); 1438 Ex.Index = readVaruint32(Ctx); 1439 const wasm::WasmSignature *Signature = nullptr; 1440 const wasm::WasmGlobalType *GlobalType = nullptr; 1441 const wasm::WasmTableType *TableType = nullptr; 1442 wasm::WasmSymbolInfo Info; 1443 Info.Name = Ex.Name; 1444 Info.Flags = 0; 1445 switch (Ex.Kind) { 1446 case wasm::WASM_EXTERNAL_FUNCTION: { 1447 if (!isDefinedFunctionIndex(Ex.Index)) 1448 return make_error<GenericBinaryError>("invalid function export", 1449 object_error::parse_failed); 1450 getDefinedFunction(Ex.Index).ExportName = Ex.Name; 1451 Info.Kind = wasm::WASM_SYMBOL_TYPE_FUNCTION; 1452 Info.ElementIndex = Ex.Index; 1453 unsigned FuncIndex = Info.ElementIndex - NumImportedFunctions; 1454 wasm::WasmFunction &Function = Functions[FuncIndex]; 1455 Signature = &Signatures[Function.SigIndex]; 1456 break; 1457 } 1458 case wasm::WASM_EXTERNAL_GLOBAL: { 1459 if (!isValidGlobalIndex(Ex.Index)) 1460 return make_error<GenericBinaryError>("invalid global export", 1461 object_error::parse_failed); 1462 Info.Kind = wasm::WASM_SYMBOL_TYPE_DATA; 1463 uint64_t Offset = 0; 1464 if (isDefinedGlobalIndex(Ex.Index)) { 1465 auto Global = getDefinedGlobal(Ex.Index); 1466 if (!Global.InitExpr.Extended) { 1467 auto Inst = Global.InitExpr.Inst; 1468 if (Inst.Opcode == wasm::WASM_OPCODE_I32_CONST) { 1469 Offset = Inst.Value.Int32; 1470 } else if (Inst.Opcode == wasm::WASM_OPCODE_I64_CONST) { 1471 Offset = Inst.Value.Int64; 1472 } 1473 } 1474 } 1475 Info.DataRef = wasm::WasmDataReference{0, Offset, 0}; 1476 break; 1477 } 1478 case wasm::WASM_EXTERNAL_TAG: 1479 if (!isValidTagIndex(Ex.Index)) 1480 return make_error<GenericBinaryError>("invalid tag export", 1481 object_error::parse_failed); 1482 Info.Kind = wasm::WASM_SYMBOL_TYPE_TAG; 1483 Info.ElementIndex = Ex.Index; 1484 break; 1485 case wasm::WASM_EXTERNAL_MEMORY: 1486 break; 1487 case wasm::WASM_EXTERNAL_TABLE: 1488 Info.Kind = wasm::WASM_SYMBOL_TYPE_TABLE; 1489 Info.ElementIndex = Ex.Index; 1490 break; 1491 default: 1492 return make_error<GenericBinaryError>("unexpected export kind", 1493 object_error::parse_failed); 1494 } 1495 Exports.push_back(Ex); 1496 if (Ex.Kind != wasm::WASM_EXTERNAL_MEMORY) { 1497 Symbols.emplace_back(Info, GlobalType, TableType, Signature); 1498 LLVM_DEBUG(dbgs() << "Adding symbol: " << Symbols.back() << "\n"); 1499 } 1500 } 1501 if (Ctx.Ptr != Ctx.End) 1502 return make_error<GenericBinaryError>("export section ended prematurely", 1503 object_error::parse_failed); 1504 return Error::success(); 1505 } 1506 1507 bool WasmObjectFile::isValidFunctionIndex(uint32_t Index) const { 1508 return Index < NumImportedFunctions + Functions.size(); 1509 } 1510 1511 bool WasmObjectFile::isDefinedFunctionIndex(uint32_t Index) const { 1512 return Index >= NumImportedFunctions && isValidFunctionIndex(Index); 1513 } 1514 1515 bool WasmObjectFile::isValidGlobalIndex(uint32_t Index) const { 1516 return Index < NumImportedGlobals + Globals.size(); 1517 } 1518 1519 bool WasmObjectFile::isValidTableNumber(uint32_t Index) const { 1520 return Index < NumImportedTables + Tables.size(); 1521 } 1522 1523 bool WasmObjectFile::isDefinedGlobalIndex(uint32_t Index) const { 1524 return Index >= NumImportedGlobals && isValidGlobalIndex(Index); 1525 } 1526 1527 bool WasmObjectFile::isDefinedTableNumber(uint32_t Index) const { 1528 return Index >= NumImportedTables && isValidTableNumber(Index); 1529 } 1530 1531 bool WasmObjectFile::isValidTagIndex(uint32_t Index) const { 1532 return Index < NumImportedTags + Tags.size(); 1533 } 1534 1535 bool WasmObjectFile::isDefinedTagIndex(uint32_t Index) const { 1536 return Index >= NumImportedTags && isValidTagIndex(Index); 1537 } 1538 1539 bool WasmObjectFile::isValidFunctionSymbol(uint32_t Index) const { 1540 return Index < Symbols.size() && Symbols[Index].isTypeFunction(); 1541 } 1542 1543 bool WasmObjectFile::isValidTableSymbol(uint32_t Index) const { 1544 return Index < Symbols.size() && Symbols[Index].isTypeTable(); 1545 } 1546 1547 bool WasmObjectFile::isValidGlobalSymbol(uint32_t Index) const { 1548 return Index < Symbols.size() && Symbols[Index].isTypeGlobal(); 1549 } 1550 1551 bool WasmObjectFile::isValidTagSymbol(uint32_t Index) const { 1552 return Index < Symbols.size() && Symbols[Index].isTypeTag(); 1553 } 1554 1555 bool WasmObjectFile::isValidDataSymbol(uint32_t Index) const { 1556 return Index < Symbols.size() && Symbols[Index].isTypeData(); 1557 } 1558 1559 bool WasmObjectFile::isValidSectionSymbol(uint32_t Index) const { 1560 return Index < Symbols.size() && Symbols[Index].isTypeSection(); 1561 } 1562 1563 wasm::WasmFunction &WasmObjectFile::getDefinedFunction(uint32_t Index) { 1564 assert(isDefinedFunctionIndex(Index)); 1565 return Functions[Index - NumImportedFunctions]; 1566 } 1567 1568 const wasm::WasmFunction & 1569 WasmObjectFile::getDefinedFunction(uint32_t Index) const { 1570 assert(isDefinedFunctionIndex(Index)); 1571 return Functions[Index - NumImportedFunctions]; 1572 } 1573 1574 const wasm::WasmGlobal &WasmObjectFile::getDefinedGlobal(uint32_t Index) const { 1575 assert(isDefinedGlobalIndex(Index)); 1576 return Globals[Index - NumImportedGlobals]; 1577 } 1578 1579 wasm::WasmTag &WasmObjectFile::getDefinedTag(uint32_t Index) { 1580 assert(isDefinedTagIndex(Index)); 1581 return Tags[Index - NumImportedTags]; 1582 } 1583 1584 Error WasmObjectFile::parseStartSection(ReadContext &Ctx) { 1585 StartFunction = readVaruint32(Ctx); 1586 if (!isValidFunctionIndex(StartFunction)) 1587 return make_error<GenericBinaryError>("invalid start function", 1588 object_error::parse_failed); 1589 return Error::success(); 1590 } 1591 1592 Error WasmObjectFile::parseCodeSection(ReadContext &Ctx) { 1593 CodeSection = Sections.size(); 1594 uint32_t FunctionCount = readVaruint32(Ctx); 1595 if (FunctionCount != Functions.size()) { 1596 return make_error<GenericBinaryError>("invalid function count", 1597 object_error::parse_failed); 1598 } 1599 1600 for (uint32_t i = 0; i < FunctionCount; i++) { 1601 wasm::WasmFunction& Function = Functions[i]; 1602 const uint8_t *FunctionStart = Ctx.Ptr; 1603 uint32_t Size = readVaruint32(Ctx); 1604 const uint8_t *FunctionEnd = Ctx.Ptr + Size; 1605 1606 Function.CodeOffset = Ctx.Ptr - FunctionStart; 1607 Function.Index = NumImportedFunctions + i; 1608 Function.CodeSectionOffset = FunctionStart - Ctx.Start; 1609 Function.Size = FunctionEnd - FunctionStart; 1610 1611 uint32_t NumLocalDecls = readVaruint32(Ctx); 1612 Function.Locals.reserve(NumLocalDecls); 1613 while (NumLocalDecls--) { 1614 wasm::WasmLocalDecl Decl; 1615 Decl.Count = readVaruint32(Ctx); 1616 Decl.Type = readUint8(Ctx); 1617 Function.Locals.push_back(Decl); 1618 } 1619 1620 uint32_t BodySize = FunctionEnd - Ctx.Ptr; 1621 // Ensure that Function is within Ctx's buffer. 1622 if (Ctx.Ptr + BodySize > Ctx.End) { 1623 return make_error<GenericBinaryError>("Function extends beyond buffer", 1624 object_error::parse_failed); 1625 } 1626 Function.Body = ArrayRef<uint8_t>(Ctx.Ptr, BodySize); 1627 // This will be set later when reading in the linking metadata section. 1628 Function.Comdat = UINT32_MAX; 1629 Ctx.Ptr += BodySize; 1630 assert(Ctx.Ptr == FunctionEnd); 1631 } 1632 if (Ctx.Ptr != Ctx.End) 1633 return make_error<GenericBinaryError>("code section ended prematurely", 1634 object_error::parse_failed); 1635 return Error::success(); 1636 } 1637 1638 Error WasmObjectFile::parseElemSection(ReadContext &Ctx) { 1639 uint32_t Count = readVaruint32(Ctx); 1640 ElemSegments.reserve(Count); 1641 while (Count--) { 1642 wasm::WasmElemSegment Segment; 1643 Segment.Flags = readVaruint32(Ctx); 1644 1645 uint32_t SupportedFlags = wasm::WASM_ELEM_SEGMENT_HAS_TABLE_NUMBER | 1646 wasm::WASM_ELEM_SEGMENT_IS_PASSIVE | 1647 wasm::WASM_ELEM_SEGMENT_HAS_INIT_EXPRS; 1648 if (Segment.Flags & ~SupportedFlags) 1649 return make_error<GenericBinaryError>( 1650 "Unsupported flags for element segment", object_error::parse_failed); 1651 1652 bool IsPassive = (Segment.Flags & wasm::WASM_ELEM_SEGMENT_IS_PASSIVE) != 0; 1653 bool IsDeclarative = 1654 IsPassive && (Segment.Flags & wasm::WASM_ELEM_SEGMENT_IS_DECLARATIVE); 1655 bool HasTableNumber = 1656 !IsPassive && 1657 (Segment.Flags & wasm::WASM_ELEM_SEGMENT_HAS_TABLE_NUMBER); 1658 bool HasInitExprs = 1659 (Segment.Flags & wasm::WASM_ELEM_SEGMENT_HAS_INIT_EXPRS); 1660 bool HasElemKind = 1661 (Segment.Flags & wasm::WASM_ELEM_SEGMENT_MASK_HAS_ELEM_KIND) && 1662 !HasInitExprs; 1663 1664 if (HasTableNumber) 1665 Segment.TableNumber = readVaruint32(Ctx); 1666 else 1667 Segment.TableNumber = 0; 1668 1669 if (!isValidTableNumber(Segment.TableNumber)) 1670 return make_error<GenericBinaryError>("invalid TableNumber", 1671 object_error::parse_failed); 1672 1673 if (IsPassive || IsDeclarative) { 1674 Segment.Offset.Extended = false; 1675 Segment.Offset.Inst.Opcode = wasm::WASM_OPCODE_I32_CONST; 1676 Segment.Offset.Inst.Value.Int32 = 0; 1677 } else { 1678 if (Error Err = readInitExpr(Segment.Offset, Ctx)) 1679 return Err; 1680 } 1681 1682 if (HasElemKind) { 1683 auto ElemKind = readVaruint32(Ctx); 1684 if (Segment.Flags & wasm::WASM_ELEM_SEGMENT_HAS_INIT_EXPRS) { 1685 Segment.ElemKind = parseValType(Ctx, ElemKind); 1686 if (Segment.ElemKind != wasm::ValType::FUNCREF && 1687 Segment.ElemKind != wasm::ValType::EXTERNREF && 1688 Segment.ElemKind != wasm::ValType::EXNREF && 1689 Segment.ElemKind != wasm::ValType::OTHERREF) { 1690 return make_error<GenericBinaryError>("invalid elem type", 1691 object_error::parse_failed); 1692 } 1693 } else { 1694 if (ElemKind != 0) 1695 return make_error<GenericBinaryError>("invalid elem type", 1696 object_error::parse_failed); 1697 Segment.ElemKind = wasm::ValType::FUNCREF; 1698 } 1699 } else if (HasInitExprs) { 1700 auto ElemType = parseValType(Ctx, readVaruint32(Ctx)); 1701 Segment.ElemKind = ElemType; 1702 } else { 1703 Segment.ElemKind = wasm::ValType::FUNCREF; 1704 } 1705 1706 uint32_t NumElems = readVaruint32(Ctx); 1707 1708 if (HasInitExprs) { 1709 while (NumElems--) { 1710 wasm::WasmInitExpr Expr; 1711 if (Error Err = readInitExpr(Expr, Ctx)) 1712 return Err; 1713 } 1714 } else { 1715 while (NumElems--) { 1716 Segment.Functions.push_back(readVaruint32(Ctx)); 1717 } 1718 } 1719 ElemSegments.push_back(Segment); 1720 } 1721 if (Ctx.Ptr != Ctx.End) 1722 return make_error<GenericBinaryError>("elem section ended prematurely", 1723 object_error::parse_failed); 1724 return Error::success(); 1725 } 1726 1727 Error WasmObjectFile::parseDataSection(ReadContext &Ctx) { 1728 DataSection = Sections.size(); 1729 uint32_t Count = readVaruint32(Ctx); 1730 if (DataCount && Count != *DataCount) 1731 return make_error<GenericBinaryError>( 1732 "number of data segments does not match DataCount section"); 1733 DataSegments.reserve(Count); 1734 while (Count--) { 1735 WasmSegment Segment; 1736 Segment.Data.InitFlags = readVaruint32(Ctx); 1737 Segment.Data.MemoryIndex = 1738 (Segment.Data.InitFlags & wasm::WASM_DATA_SEGMENT_HAS_MEMINDEX) 1739 ? readVaruint32(Ctx) 1740 : 0; 1741 if ((Segment.Data.InitFlags & wasm::WASM_DATA_SEGMENT_IS_PASSIVE) == 0) { 1742 if (Error Err = readInitExpr(Segment.Data.Offset, Ctx)) 1743 return Err; 1744 } else { 1745 Segment.Data.Offset.Extended = false; 1746 Segment.Data.Offset.Inst.Opcode = wasm::WASM_OPCODE_I32_CONST; 1747 Segment.Data.Offset.Inst.Value.Int32 = 0; 1748 } 1749 uint32_t Size = readVaruint32(Ctx); 1750 if (Size > (size_t)(Ctx.End - Ctx.Ptr)) 1751 return make_error<GenericBinaryError>("invalid segment size", 1752 object_error::parse_failed); 1753 Segment.Data.Content = ArrayRef<uint8_t>(Ctx.Ptr, Size); 1754 // The rest of these Data fields are set later, when reading in the linking 1755 // metadata section. 1756 Segment.Data.Alignment = 0; 1757 Segment.Data.LinkingFlags = 0; 1758 Segment.Data.Comdat = UINT32_MAX; 1759 Segment.SectionOffset = Ctx.Ptr - Ctx.Start; 1760 Ctx.Ptr += Size; 1761 DataSegments.push_back(Segment); 1762 } 1763 if (Ctx.Ptr != Ctx.End) 1764 return make_error<GenericBinaryError>("data section ended prematurely", 1765 object_error::parse_failed); 1766 return Error::success(); 1767 } 1768 1769 Error WasmObjectFile::parseDataCountSection(ReadContext &Ctx) { 1770 DataCount = readVaruint32(Ctx); 1771 return Error::success(); 1772 } 1773 1774 const wasm::WasmObjectHeader &WasmObjectFile::getHeader() const { 1775 return Header; 1776 } 1777 1778 void WasmObjectFile::moveSymbolNext(DataRefImpl &Symb) const { Symb.d.b++; } 1779 1780 Expected<uint32_t> WasmObjectFile::getSymbolFlags(DataRefImpl Symb) const { 1781 uint32_t Result = SymbolRef::SF_None; 1782 const WasmSymbol &Sym = getWasmSymbol(Symb); 1783 1784 LLVM_DEBUG(dbgs() << "getSymbolFlags: ptr=" << &Sym << " " << Sym << "\n"); 1785 if (Sym.isBindingWeak()) 1786 Result |= SymbolRef::SF_Weak; 1787 if (!Sym.isBindingLocal()) 1788 Result |= SymbolRef::SF_Global; 1789 if (Sym.isHidden()) 1790 Result |= SymbolRef::SF_Hidden; 1791 if (!Sym.isDefined()) 1792 Result |= SymbolRef::SF_Undefined; 1793 if (Sym.isTypeFunction()) 1794 Result |= SymbolRef::SF_Executable; 1795 return Result; 1796 } 1797 1798 basic_symbol_iterator WasmObjectFile::symbol_begin() const { 1799 DataRefImpl Ref; 1800 Ref.d.a = 1; // Arbitrary non-zero value so that Ref.p is non-null 1801 Ref.d.b = 0; // Symbol index 1802 return BasicSymbolRef(Ref, this); 1803 } 1804 1805 basic_symbol_iterator WasmObjectFile::symbol_end() const { 1806 DataRefImpl Ref; 1807 Ref.d.a = 1; // Arbitrary non-zero value so that Ref.p is non-null 1808 Ref.d.b = Symbols.size(); // Symbol index 1809 return BasicSymbolRef(Ref, this); 1810 } 1811 1812 const WasmSymbol &WasmObjectFile::getWasmSymbol(const DataRefImpl &Symb) const { 1813 return Symbols[Symb.d.b]; 1814 } 1815 1816 const WasmSymbol &WasmObjectFile::getWasmSymbol(const SymbolRef &Symb) const { 1817 return getWasmSymbol(Symb.getRawDataRefImpl()); 1818 } 1819 1820 Expected<StringRef> WasmObjectFile::getSymbolName(DataRefImpl Symb) const { 1821 return getWasmSymbol(Symb).Info.Name; 1822 } 1823 1824 Expected<uint64_t> WasmObjectFile::getSymbolAddress(DataRefImpl Symb) const { 1825 auto &Sym = getWasmSymbol(Symb); 1826 if (!Sym.isDefined()) 1827 return 0; 1828 Expected<section_iterator> Sec = getSymbolSection(Symb); 1829 if (!Sec) 1830 return Sec.takeError(); 1831 uint32_t SectionAddress = getSectionAddress(Sec.get()->getRawDataRefImpl()); 1832 if (Sym.Info.Kind == wasm::WASM_SYMBOL_TYPE_FUNCTION && 1833 isDefinedFunctionIndex(Sym.Info.ElementIndex)) { 1834 return getDefinedFunction(Sym.Info.ElementIndex).CodeSectionOffset + 1835 SectionAddress; 1836 } 1837 if (Sym.Info.Kind == wasm::WASM_SYMBOL_TYPE_GLOBAL && 1838 isDefinedGlobalIndex(Sym.Info.ElementIndex)) { 1839 return getDefinedGlobal(Sym.Info.ElementIndex).Offset + SectionAddress; 1840 } 1841 1842 return getSymbolValue(Symb); 1843 } 1844 1845 uint64_t WasmObjectFile::getWasmSymbolValue(const WasmSymbol &Sym) const { 1846 switch (Sym.Info.Kind) { 1847 case wasm::WASM_SYMBOL_TYPE_FUNCTION: 1848 case wasm::WASM_SYMBOL_TYPE_GLOBAL: 1849 case wasm::WASM_SYMBOL_TYPE_TAG: 1850 case wasm::WASM_SYMBOL_TYPE_TABLE: 1851 return Sym.Info.ElementIndex; 1852 case wasm::WASM_SYMBOL_TYPE_DATA: { 1853 // The value of a data symbol is the segment offset, plus the symbol 1854 // offset within the segment. 1855 uint32_t SegmentIndex = Sym.Info.DataRef.Segment; 1856 const wasm::WasmDataSegment &Segment = DataSegments[SegmentIndex].Data; 1857 if (Segment.Offset.Extended) { 1858 llvm_unreachable("extended init exprs not supported"); 1859 } else if (Segment.Offset.Inst.Opcode == wasm::WASM_OPCODE_I32_CONST) { 1860 return Segment.Offset.Inst.Value.Int32 + Sym.Info.DataRef.Offset; 1861 } else if (Segment.Offset.Inst.Opcode == wasm::WASM_OPCODE_I64_CONST) { 1862 return Segment.Offset.Inst.Value.Int64 + Sym.Info.DataRef.Offset; 1863 } else if (Segment.Offset.Inst.Opcode == wasm::WASM_OPCODE_GLOBAL_GET) { 1864 return Sym.Info.DataRef.Offset; 1865 } else { 1866 llvm_unreachable("unknown init expr opcode"); 1867 } 1868 } 1869 case wasm::WASM_SYMBOL_TYPE_SECTION: 1870 return 0; 1871 } 1872 llvm_unreachable("invalid symbol type"); 1873 } 1874 1875 uint64_t WasmObjectFile::getSymbolValueImpl(DataRefImpl Symb) const { 1876 return getWasmSymbolValue(getWasmSymbol(Symb)); 1877 } 1878 1879 uint32_t WasmObjectFile::getSymbolAlignment(DataRefImpl Symb) const { 1880 llvm_unreachable("not yet implemented"); 1881 return 0; 1882 } 1883 1884 uint64_t WasmObjectFile::getCommonSymbolSizeImpl(DataRefImpl Symb) const { 1885 llvm_unreachable("not yet implemented"); 1886 return 0; 1887 } 1888 1889 Expected<SymbolRef::Type> 1890 WasmObjectFile::getSymbolType(DataRefImpl Symb) const { 1891 const WasmSymbol &Sym = getWasmSymbol(Symb); 1892 1893 switch (Sym.Info.Kind) { 1894 case wasm::WASM_SYMBOL_TYPE_FUNCTION: 1895 return SymbolRef::ST_Function; 1896 case wasm::WASM_SYMBOL_TYPE_GLOBAL: 1897 return SymbolRef::ST_Other; 1898 case wasm::WASM_SYMBOL_TYPE_DATA: 1899 return SymbolRef::ST_Data; 1900 case wasm::WASM_SYMBOL_TYPE_SECTION: 1901 return SymbolRef::ST_Debug; 1902 case wasm::WASM_SYMBOL_TYPE_TAG: 1903 return SymbolRef::ST_Other; 1904 case wasm::WASM_SYMBOL_TYPE_TABLE: 1905 return SymbolRef::ST_Other; 1906 } 1907 1908 llvm_unreachable("unknown WasmSymbol::SymbolType"); 1909 return SymbolRef::ST_Other; 1910 } 1911 1912 Expected<section_iterator> 1913 WasmObjectFile::getSymbolSection(DataRefImpl Symb) const { 1914 const WasmSymbol &Sym = getWasmSymbol(Symb); 1915 if (Sym.isUndefined()) 1916 return section_end(); 1917 1918 DataRefImpl Ref; 1919 Ref.d.a = getSymbolSectionIdImpl(Sym); 1920 return section_iterator(SectionRef(Ref, this)); 1921 } 1922 1923 uint32_t WasmObjectFile::getSymbolSectionId(SymbolRef Symb) const { 1924 const WasmSymbol &Sym = getWasmSymbol(Symb); 1925 return getSymbolSectionIdImpl(Sym); 1926 } 1927 1928 uint32_t WasmObjectFile::getSymbolSectionIdImpl(const WasmSymbol &Sym) const { 1929 switch (Sym.Info.Kind) { 1930 case wasm::WASM_SYMBOL_TYPE_FUNCTION: 1931 return CodeSection; 1932 case wasm::WASM_SYMBOL_TYPE_GLOBAL: 1933 return GlobalSection; 1934 case wasm::WASM_SYMBOL_TYPE_DATA: 1935 return DataSection; 1936 case wasm::WASM_SYMBOL_TYPE_SECTION: 1937 return Sym.Info.ElementIndex; 1938 case wasm::WASM_SYMBOL_TYPE_TAG: 1939 return TagSection; 1940 case wasm::WASM_SYMBOL_TYPE_TABLE: 1941 return TableSection; 1942 default: 1943 llvm_unreachable("unknown WasmSymbol::SymbolType"); 1944 } 1945 } 1946 1947 uint32_t WasmObjectFile::getSymbolSize(SymbolRef Symb) const { 1948 const WasmSymbol &Sym = getWasmSymbol(Symb); 1949 if (!Sym.isDefined()) 1950 return 0; 1951 if (Sym.isTypeGlobal()) 1952 return getDefinedGlobal(Sym.Info.ElementIndex).Size; 1953 if (Sym.isTypeData()) 1954 return Sym.Info.DataRef.Size; 1955 if (Sym.isTypeFunction()) 1956 return functions()[Sym.Info.ElementIndex - getNumImportedFunctions()].Size; 1957 // Currently symbol size is only tracked for data segments and functions. In 1958 // principle we could also track size (e.g. binary size) for tables, globals 1959 // and element segments etc too. 1960 return 0; 1961 } 1962 1963 void WasmObjectFile::moveSectionNext(DataRefImpl &Sec) const { Sec.d.a++; } 1964 1965 Expected<StringRef> WasmObjectFile::getSectionName(DataRefImpl Sec) const { 1966 const WasmSection &S = Sections[Sec.d.a]; 1967 if (S.Type == wasm::WASM_SEC_CUSTOM) 1968 return S.Name; 1969 if (S.Type > wasm::WASM_SEC_LAST_KNOWN) 1970 return createStringError(object_error::invalid_section_index, ""); 1971 return wasm::sectionTypeToString(S.Type); 1972 } 1973 1974 uint64_t WasmObjectFile::getSectionAddress(DataRefImpl Sec) const { 1975 // For object files, use 0 for section addresses, and section offsets for 1976 // symbol addresses. For linked files, use file offsets. 1977 // See also getSymbolAddress. 1978 return isRelocatableObject() || isSharedObject() ? 0 1979 : Sections[Sec.d.a].Offset; 1980 } 1981 1982 uint64_t WasmObjectFile::getSectionIndex(DataRefImpl Sec) const { 1983 return Sec.d.a; 1984 } 1985 1986 uint64_t WasmObjectFile::getSectionSize(DataRefImpl Sec) const { 1987 const WasmSection &S = Sections[Sec.d.a]; 1988 return S.Content.size(); 1989 } 1990 1991 Expected<ArrayRef<uint8_t>> 1992 WasmObjectFile::getSectionContents(DataRefImpl Sec) const { 1993 const WasmSection &S = Sections[Sec.d.a]; 1994 // This will never fail since wasm sections can never be empty (user-sections 1995 // must have a name and non-user sections each have a defined structure). 1996 return S.Content; 1997 } 1998 1999 uint64_t WasmObjectFile::getSectionAlignment(DataRefImpl Sec) const { 2000 return 1; 2001 } 2002 2003 bool WasmObjectFile::isSectionCompressed(DataRefImpl Sec) const { 2004 return false; 2005 } 2006 2007 bool WasmObjectFile::isSectionText(DataRefImpl Sec) const { 2008 return getWasmSection(Sec).Type == wasm::WASM_SEC_CODE; 2009 } 2010 2011 bool WasmObjectFile::isSectionData(DataRefImpl Sec) const { 2012 return getWasmSection(Sec).Type == wasm::WASM_SEC_DATA; 2013 } 2014 2015 bool WasmObjectFile::isSectionBSS(DataRefImpl Sec) const { return false; } 2016 2017 bool WasmObjectFile::isSectionVirtual(DataRefImpl Sec) const { return false; } 2018 2019 relocation_iterator WasmObjectFile::section_rel_begin(DataRefImpl Ref) const { 2020 DataRefImpl RelocRef; 2021 RelocRef.d.a = Ref.d.a; 2022 RelocRef.d.b = 0; 2023 return relocation_iterator(RelocationRef(RelocRef, this)); 2024 } 2025 2026 relocation_iterator WasmObjectFile::section_rel_end(DataRefImpl Ref) const { 2027 const WasmSection &Sec = getWasmSection(Ref); 2028 DataRefImpl RelocRef; 2029 RelocRef.d.a = Ref.d.a; 2030 RelocRef.d.b = Sec.Relocations.size(); 2031 return relocation_iterator(RelocationRef(RelocRef, this)); 2032 } 2033 2034 void WasmObjectFile::moveRelocationNext(DataRefImpl &Rel) const { Rel.d.b++; } 2035 2036 uint64_t WasmObjectFile::getRelocationOffset(DataRefImpl Ref) const { 2037 const wasm::WasmRelocation &Rel = getWasmRelocation(Ref); 2038 return Rel.Offset; 2039 } 2040 2041 symbol_iterator WasmObjectFile::getRelocationSymbol(DataRefImpl Ref) const { 2042 const wasm::WasmRelocation &Rel = getWasmRelocation(Ref); 2043 if (Rel.Type == wasm::R_WASM_TYPE_INDEX_LEB) 2044 return symbol_end(); 2045 DataRefImpl Sym; 2046 Sym.d.a = 1; 2047 Sym.d.b = Rel.Index; 2048 return symbol_iterator(SymbolRef(Sym, this)); 2049 } 2050 2051 uint64_t WasmObjectFile::getRelocationType(DataRefImpl Ref) const { 2052 const wasm::WasmRelocation &Rel = getWasmRelocation(Ref); 2053 return Rel.Type; 2054 } 2055 2056 void WasmObjectFile::getRelocationTypeName( 2057 DataRefImpl Ref, SmallVectorImpl<char> &Result) const { 2058 const wasm::WasmRelocation &Rel = getWasmRelocation(Ref); 2059 StringRef Res = "Unknown"; 2060 2061 #define WASM_RELOC(name, value) \ 2062 case wasm::name: \ 2063 Res = #name; \ 2064 break; 2065 2066 switch (Rel.Type) { 2067 #include "llvm/BinaryFormat/WasmRelocs.def" 2068 } 2069 2070 #undef WASM_RELOC 2071 2072 Result.append(Res.begin(), Res.end()); 2073 } 2074 2075 section_iterator WasmObjectFile::section_begin() const { 2076 DataRefImpl Ref; 2077 Ref.d.a = 0; 2078 return section_iterator(SectionRef(Ref, this)); 2079 } 2080 2081 section_iterator WasmObjectFile::section_end() const { 2082 DataRefImpl Ref; 2083 Ref.d.a = Sections.size(); 2084 return section_iterator(SectionRef(Ref, this)); 2085 } 2086 2087 uint8_t WasmObjectFile::getBytesInAddress() const { 2088 return HasMemory64 ? 8 : 4; 2089 } 2090 2091 StringRef WasmObjectFile::getFileFormatName() const { return "WASM"; } 2092 2093 Triple::ArchType WasmObjectFile::getArch() const { 2094 return HasMemory64 ? Triple::wasm64 : Triple::wasm32; 2095 } 2096 2097 Expected<SubtargetFeatures> WasmObjectFile::getFeatures() const { 2098 return SubtargetFeatures(); 2099 } 2100 2101 bool WasmObjectFile::isRelocatableObject() const { return HasLinkingSection; } 2102 2103 bool WasmObjectFile::isSharedObject() const { return HasDylinkSection; } 2104 2105 const WasmSection &WasmObjectFile::getWasmSection(DataRefImpl Ref) const { 2106 assert(Ref.d.a < Sections.size()); 2107 return Sections[Ref.d.a]; 2108 } 2109 2110 const WasmSection & 2111 WasmObjectFile::getWasmSection(const SectionRef &Section) const { 2112 return getWasmSection(Section.getRawDataRefImpl()); 2113 } 2114 2115 const wasm::WasmRelocation & 2116 WasmObjectFile::getWasmRelocation(const RelocationRef &Ref) const { 2117 return getWasmRelocation(Ref.getRawDataRefImpl()); 2118 } 2119 2120 const wasm::WasmRelocation & 2121 WasmObjectFile::getWasmRelocation(DataRefImpl Ref) const { 2122 assert(Ref.d.a < Sections.size()); 2123 const WasmSection &Sec = Sections[Ref.d.a]; 2124 assert(Ref.d.b < Sec.Relocations.size()); 2125 return Sec.Relocations[Ref.d.b]; 2126 } 2127 2128 int WasmSectionOrderChecker::getSectionOrder(unsigned ID, 2129 StringRef CustomSectionName) { 2130 switch (ID) { 2131 case wasm::WASM_SEC_CUSTOM: 2132 return StringSwitch<unsigned>(CustomSectionName) 2133 .Case("dylink", WASM_SEC_ORDER_DYLINK) 2134 .Case("dylink.0", WASM_SEC_ORDER_DYLINK) 2135 .Case("linking", WASM_SEC_ORDER_LINKING) 2136 .StartsWith("reloc.", WASM_SEC_ORDER_RELOC) 2137 .Case("name", WASM_SEC_ORDER_NAME) 2138 .Case("producers", WASM_SEC_ORDER_PRODUCERS) 2139 .Case("target_features", WASM_SEC_ORDER_TARGET_FEATURES) 2140 .Default(WASM_SEC_ORDER_NONE); 2141 case wasm::WASM_SEC_TYPE: 2142 return WASM_SEC_ORDER_TYPE; 2143 case wasm::WASM_SEC_IMPORT: 2144 return WASM_SEC_ORDER_IMPORT; 2145 case wasm::WASM_SEC_FUNCTION: 2146 return WASM_SEC_ORDER_FUNCTION; 2147 case wasm::WASM_SEC_TABLE: 2148 return WASM_SEC_ORDER_TABLE; 2149 case wasm::WASM_SEC_MEMORY: 2150 return WASM_SEC_ORDER_MEMORY; 2151 case wasm::WASM_SEC_GLOBAL: 2152 return WASM_SEC_ORDER_GLOBAL; 2153 case wasm::WASM_SEC_EXPORT: 2154 return WASM_SEC_ORDER_EXPORT; 2155 case wasm::WASM_SEC_START: 2156 return WASM_SEC_ORDER_START; 2157 case wasm::WASM_SEC_ELEM: 2158 return WASM_SEC_ORDER_ELEM; 2159 case wasm::WASM_SEC_CODE: 2160 return WASM_SEC_ORDER_CODE; 2161 case wasm::WASM_SEC_DATA: 2162 return WASM_SEC_ORDER_DATA; 2163 case wasm::WASM_SEC_DATACOUNT: 2164 return WASM_SEC_ORDER_DATACOUNT; 2165 case wasm::WASM_SEC_TAG: 2166 return WASM_SEC_ORDER_TAG; 2167 default: 2168 return WASM_SEC_ORDER_NONE; 2169 } 2170 } 2171 2172 // Represents the edges in a directed graph where any node B reachable from node 2173 // A is not allowed to appear before A in the section ordering, but may appear 2174 // afterward. 2175 int WasmSectionOrderChecker::DisallowedPredecessors 2176 [WASM_NUM_SEC_ORDERS][WASM_NUM_SEC_ORDERS] = { 2177 // WASM_SEC_ORDER_NONE 2178 {}, 2179 // WASM_SEC_ORDER_TYPE 2180 {WASM_SEC_ORDER_TYPE, WASM_SEC_ORDER_IMPORT}, 2181 // WASM_SEC_ORDER_IMPORT 2182 {WASM_SEC_ORDER_IMPORT, WASM_SEC_ORDER_FUNCTION}, 2183 // WASM_SEC_ORDER_FUNCTION 2184 {WASM_SEC_ORDER_FUNCTION, WASM_SEC_ORDER_TABLE}, 2185 // WASM_SEC_ORDER_TABLE 2186 {WASM_SEC_ORDER_TABLE, WASM_SEC_ORDER_MEMORY}, 2187 // WASM_SEC_ORDER_MEMORY 2188 {WASM_SEC_ORDER_MEMORY, WASM_SEC_ORDER_TAG}, 2189 // WASM_SEC_ORDER_TAG 2190 {WASM_SEC_ORDER_TAG, WASM_SEC_ORDER_GLOBAL}, 2191 // WASM_SEC_ORDER_GLOBAL 2192 {WASM_SEC_ORDER_GLOBAL, WASM_SEC_ORDER_EXPORT}, 2193 // WASM_SEC_ORDER_EXPORT 2194 {WASM_SEC_ORDER_EXPORT, WASM_SEC_ORDER_START}, 2195 // WASM_SEC_ORDER_START 2196 {WASM_SEC_ORDER_START, WASM_SEC_ORDER_ELEM}, 2197 // WASM_SEC_ORDER_ELEM 2198 {WASM_SEC_ORDER_ELEM, WASM_SEC_ORDER_DATACOUNT}, 2199 // WASM_SEC_ORDER_DATACOUNT 2200 {WASM_SEC_ORDER_DATACOUNT, WASM_SEC_ORDER_CODE}, 2201 // WASM_SEC_ORDER_CODE 2202 {WASM_SEC_ORDER_CODE, WASM_SEC_ORDER_DATA}, 2203 // WASM_SEC_ORDER_DATA 2204 {WASM_SEC_ORDER_DATA, WASM_SEC_ORDER_LINKING}, 2205 2206 // Custom Sections 2207 // WASM_SEC_ORDER_DYLINK 2208 {WASM_SEC_ORDER_DYLINK, WASM_SEC_ORDER_TYPE}, 2209 // WASM_SEC_ORDER_LINKING 2210 {WASM_SEC_ORDER_LINKING, WASM_SEC_ORDER_RELOC, WASM_SEC_ORDER_NAME}, 2211 // WASM_SEC_ORDER_RELOC (can be repeated) 2212 {}, 2213 // WASM_SEC_ORDER_NAME 2214 {WASM_SEC_ORDER_NAME, WASM_SEC_ORDER_PRODUCERS}, 2215 // WASM_SEC_ORDER_PRODUCERS 2216 {WASM_SEC_ORDER_PRODUCERS, WASM_SEC_ORDER_TARGET_FEATURES}, 2217 // WASM_SEC_ORDER_TARGET_FEATURES 2218 {WASM_SEC_ORDER_TARGET_FEATURES}}; 2219 2220 bool WasmSectionOrderChecker::isValidSectionOrder(unsigned ID, 2221 StringRef CustomSectionName) { 2222 int Order = getSectionOrder(ID, CustomSectionName); 2223 if (Order == WASM_SEC_ORDER_NONE) 2224 return true; 2225 2226 // Disallowed predecessors we need to check for 2227 SmallVector<int, WASM_NUM_SEC_ORDERS> WorkList; 2228 2229 // Keep track of completed checks to avoid repeating work 2230 bool Checked[WASM_NUM_SEC_ORDERS] = {}; 2231 2232 int Curr = Order; 2233 while (true) { 2234 // Add new disallowed predecessors to work list 2235 for (size_t I = 0;; ++I) { 2236 int Next = DisallowedPredecessors[Curr][I]; 2237 if (Next == WASM_SEC_ORDER_NONE) 2238 break; 2239 if (Checked[Next]) 2240 continue; 2241 WorkList.push_back(Next); 2242 Checked[Next] = true; 2243 } 2244 2245 if (WorkList.empty()) 2246 break; 2247 2248 // Consider next disallowed predecessor 2249 Curr = WorkList.pop_back_val(); 2250 if (Seen[Curr]) 2251 return false; 2252 } 2253 2254 // Have not seen any disallowed predecessors 2255 Seen[Order] = true; 2256 return true; 2257 } 2258