| //===- WasmObjectFile.cpp - Wasm object file implementation ---------------===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "llvm/ADT/ArrayRef.h" |
| #include "llvm/ADT/DenseSet.h" |
| #include "llvm/ADT/STLExtras.h" |
| #include "llvm/ADT/SmallSet.h" |
| #include "llvm/ADT/StringRef.h" |
| #include "llvm/ADT/StringSet.h" |
| #include "llvm/ADT/Triple.h" |
| #include "llvm/BinaryFormat/Wasm.h" |
| #include "llvm/MC/SubtargetFeature.h" |
| #include "llvm/Object/Binary.h" |
| #include "llvm/Object/Error.h" |
| #include "llvm/Object/ObjectFile.h" |
| #include "llvm/Object/SymbolicFile.h" |
| #include "llvm/Object/Wasm.h" |
| #include "llvm/Support/Endian.h" |
| #include "llvm/Support/Error.h" |
| #include "llvm/Support/ErrorHandling.h" |
| #include "llvm/Support/LEB128.h" |
| #include "llvm/Support/ScopedPrinter.h" |
| #include <algorithm> |
| #include <cassert> |
| #include <cstdint> |
| #include <cstring> |
| #include <system_error> |
| |
| #define DEBUG_TYPE "wasm-object" |
| |
| using namespace llvm; |
| using namespace object; |
| |
| void WasmSymbol::print(raw_ostream &Out) const { |
| Out << "Name=" << Info.Name |
| << ", Kind=" << toString(wasm::WasmSymbolType(Info.Kind)) |
| << ", Flags=" << Info.Flags; |
| if (!isTypeData()) { |
| Out << ", ElemIndex=" << Info.ElementIndex; |
| } else if (isDefined()) { |
| Out << ", Segment=" << Info.DataRef.Segment; |
| Out << ", Offset=" << Info.DataRef.Offset; |
| Out << ", Size=" << Info.DataRef.Size; |
| } |
| } |
| |
| #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP) |
| LLVM_DUMP_METHOD void WasmSymbol::dump() const { print(dbgs()); } |
| #endif |
| |
| Expected<std::unique_ptr<WasmObjectFile>> |
| ObjectFile::createWasmObjectFile(MemoryBufferRef Buffer) { |
| Error Err = Error::success(); |
| auto ObjectFile = std::make_unique<WasmObjectFile>(Buffer, Err); |
| if (Err) |
| return std::move(Err); |
| |
| return std::move(ObjectFile); |
| } |
| |
| #define VARINT7_MAX ((1 << 7) - 1) |
| #define VARINT7_MIN (-(1 << 7)) |
| #define VARUINT7_MAX (1 << 7) |
| #define VARUINT1_MAX (1) |
| |
| static uint8_t readUint8(WasmObjectFile::ReadContext &Ctx) { |
| if (Ctx.Ptr == Ctx.End) |
| report_fatal_error("EOF while reading uint8"); |
| return *Ctx.Ptr++; |
| } |
| |
| static uint32_t readUint32(WasmObjectFile::ReadContext &Ctx) { |
| if (Ctx.Ptr + 4 > Ctx.End) |
| report_fatal_error("EOF while reading uint32"); |
| uint32_t Result = support::endian::read32le(Ctx.Ptr); |
| Ctx.Ptr += 4; |
| return Result; |
| } |
| |
| static int32_t readFloat32(WasmObjectFile::ReadContext &Ctx) { |
| if (Ctx.Ptr + 4 > Ctx.End) |
| report_fatal_error("EOF while reading float64"); |
| int32_t Result = 0; |
| memcpy(&Result, Ctx.Ptr, sizeof(Result)); |
| Ctx.Ptr += sizeof(Result); |
| return Result; |
| } |
| |
| static int64_t readFloat64(WasmObjectFile::ReadContext &Ctx) { |
| if (Ctx.Ptr + 8 > Ctx.End) |
| report_fatal_error("EOF while reading float64"); |
| int64_t Result = 0; |
| memcpy(&Result, Ctx.Ptr, sizeof(Result)); |
| Ctx.Ptr += sizeof(Result); |
| return Result; |
| } |
| |
| static uint64_t readULEB128(WasmObjectFile::ReadContext &Ctx) { |
| unsigned Count; |
| const char *Error = nullptr; |
| uint64_t Result = decodeULEB128(Ctx.Ptr, &Count, Ctx.End, &Error); |
| if (Error) |
| report_fatal_error(Error); |
| Ctx.Ptr += Count; |
| return Result; |
| } |
| |
| static StringRef readString(WasmObjectFile::ReadContext &Ctx) { |
| uint32_t StringLen = readULEB128(Ctx); |
| if (Ctx.Ptr + StringLen > Ctx.End) |
| report_fatal_error("EOF while reading string"); |
| StringRef Return = |
| StringRef(reinterpret_cast<const char *>(Ctx.Ptr), StringLen); |
| Ctx.Ptr += StringLen; |
| return Return; |
| } |
| |
| static int64_t readLEB128(WasmObjectFile::ReadContext &Ctx) { |
| unsigned Count; |
| const char *Error = nullptr; |
| uint64_t Result = decodeSLEB128(Ctx.Ptr, &Count, Ctx.End, &Error); |
| if (Error) |
| report_fatal_error(Error); |
| Ctx.Ptr += Count; |
| return Result; |
| } |
| |
| static uint8_t readVaruint1(WasmObjectFile::ReadContext &Ctx) { |
| int64_t Result = readLEB128(Ctx); |
| if (Result > VARUINT1_MAX || Result < 0) |
| report_fatal_error("LEB is outside Varuint1 range"); |
| return Result; |
| } |
| |
| static int32_t readVarint32(WasmObjectFile::ReadContext &Ctx) { |
| int64_t Result = readLEB128(Ctx); |
| if (Result > INT32_MAX || Result < INT32_MIN) |
| report_fatal_error("LEB is outside Varint32 range"); |
| return Result; |
| } |
| |
| static uint32_t readVaruint32(WasmObjectFile::ReadContext &Ctx) { |
| uint64_t Result = readULEB128(Ctx); |
| if (Result > UINT32_MAX) |
| report_fatal_error("LEB is outside Varuint32 range"); |
| return Result; |
| } |
| |
| static int64_t readVarint64(WasmObjectFile::ReadContext &Ctx) { |
| return readLEB128(Ctx); |
| } |
| |
| static uint8_t readOpcode(WasmObjectFile::ReadContext &Ctx) { |
| return readUint8(Ctx); |
| } |
| |
| static Error readInitExpr(wasm::WasmInitExpr &Expr, |
| WasmObjectFile::ReadContext &Ctx) { |
| Expr.Opcode = readOpcode(Ctx); |
| |
| switch (Expr.Opcode) { |
| case wasm::WASM_OPCODE_I32_CONST: |
| Expr.Value.Int32 = readVarint32(Ctx); |
| break; |
| case wasm::WASM_OPCODE_I64_CONST: |
| Expr.Value.Int64 = readVarint64(Ctx); |
| break; |
| case wasm::WASM_OPCODE_F32_CONST: |
| Expr.Value.Float32 = readFloat32(Ctx); |
| break; |
| case wasm::WASM_OPCODE_F64_CONST: |
| Expr.Value.Float64 = readFloat64(Ctx); |
| break; |
| case wasm::WASM_OPCODE_GLOBAL_GET: |
| Expr.Value.Global = readULEB128(Ctx); |
| break; |
| default: |
| return make_error<GenericBinaryError>("Invalid opcode in init_expr", |
| object_error::parse_failed); |
| } |
| |
| uint8_t EndOpcode = readOpcode(Ctx); |
| if (EndOpcode != wasm::WASM_OPCODE_END) { |
| return make_error<GenericBinaryError>("Invalid init_expr", |
| object_error::parse_failed); |
| } |
| return Error::success(); |
| } |
| |
| static wasm::WasmLimits readLimits(WasmObjectFile::ReadContext &Ctx) { |
| wasm::WasmLimits Result; |
| Result.Flags = readVaruint32(Ctx); |
| Result.Initial = readVaruint32(Ctx); |
| if (Result.Flags & wasm::WASM_LIMITS_FLAG_HAS_MAX) |
| Result.Maximum = readVaruint32(Ctx); |
| return Result; |
| } |
| |
| static wasm::WasmTable readTable(WasmObjectFile::ReadContext &Ctx) { |
| wasm::WasmTable Table; |
| Table.ElemType = readUint8(Ctx); |
| Table.Limits = readLimits(Ctx); |
| return Table; |
| } |
| |
| static Error readSection(WasmSection &Section, WasmObjectFile::ReadContext &Ctx, |
| WasmSectionOrderChecker &Checker) { |
| Section.Offset = Ctx.Ptr - Ctx.Start; |
| Section.Type = readUint8(Ctx); |
| LLVM_DEBUG(dbgs() << "readSection type=" << Section.Type << "\n"); |
| uint32_t Size = readVaruint32(Ctx); |
| if (Size == 0) |
| return make_error<StringError>("Zero length section", |
| object_error::parse_failed); |
| if (Ctx.Ptr + Size > Ctx.End) |
| return make_error<StringError>("Section too large", |
| object_error::parse_failed); |
| if (Section.Type == wasm::WASM_SEC_CUSTOM) { |
| WasmObjectFile::ReadContext SectionCtx; |
| SectionCtx.Start = Ctx.Ptr; |
| SectionCtx.Ptr = Ctx.Ptr; |
| SectionCtx.End = Ctx.Ptr + Size; |
| |
| Section.Name = readString(SectionCtx); |
| |
| uint32_t SectionNameSize = SectionCtx.Ptr - SectionCtx.Start; |
| Ctx.Ptr += SectionNameSize; |
| Size -= SectionNameSize; |
| } |
| |
| if (!Checker.isValidSectionOrder(Section.Type, Section.Name)) { |
| return make_error<StringError>("Out of order section type: " + |
| llvm::to_string(Section.Type), |
| object_error::parse_failed); |
| } |
| |
| Section.Content = ArrayRef<uint8_t>(Ctx.Ptr, Size); |
| Ctx.Ptr += Size; |
| return Error::success(); |
| } |
| |
| WasmObjectFile::WasmObjectFile(MemoryBufferRef Buffer, Error &Err) |
| : ObjectFile(Binary::ID_Wasm, Buffer) { |
| ErrorAsOutParameter ErrAsOutParam(&Err); |
| Header.Magic = getData().substr(0, 4); |
| if (Header.Magic != StringRef("\0asm", 4)) { |
| Err = |
| make_error<StringError>("Bad magic number", object_error::parse_failed); |
| return; |
| } |
| |
| ReadContext Ctx; |
| Ctx.Start = getData().bytes_begin(); |
| Ctx.Ptr = Ctx.Start + 4; |
| Ctx.End = Ctx.Start + getData().size(); |
| |
| if (Ctx.Ptr + 4 > Ctx.End) { |
| Err = make_error<StringError>("Missing version number", |
| object_error::parse_failed); |
| return; |
| } |
| |
| Header.Version = readUint32(Ctx); |
| if (Header.Version != wasm::WasmVersion) { |
| Err = make_error<StringError>("Bad version number", |
| object_error::parse_failed); |
| return; |
| } |
| |
| WasmSection Sec; |
| WasmSectionOrderChecker Checker; |
| while (Ctx.Ptr < Ctx.End) { |
| if ((Err = readSection(Sec, Ctx, Checker))) |
| return; |
| if ((Err = parseSection(Sec))) |
| return; |
| |
| Sections.push_back(Sec); |
| } |
| } |
| |
| Error WasmObjectFile::parseSection(WasmSection &Sec) { |
| ReadContext Ctx; |
| Ctx.Start = Sec.Content.data(); |
| Ctx.End = Ctx.Start + Sec.Content.size(); |
| Ctx.Ptr = Ctx.Start; |
| switch (Sec.Type) { |
| case wasm::WASM_SEC_CUSTOM: |
| return parseCustomSection(Sec, Ctx); |
| case wasm::WASM_SEC_TYPE: |
| return parseTypeSection(Ctx); |
| case wasm::WASM_SEC_IMPORT: |
| return parseImportSection(Ctx); |
| case wasm::WASM_SEC_FUNCTION: |
| return parseFunctionSection(Ctx); |
| case wasm::WASM_SEC_TABLE: |
| return parseTableSection(Ctx); |
| case wasm::WASM_SEC_MEMORY: |
| return parseMemorySection(Ctx); |
| case wasm::WASM_SEC_GLOBAL: |
| return parseGlobalSection(Ctx); |
| case wasm::WASM_SEC_EVENT: |
| return parseEventSection(Ctx); |
| case wasm::WASM_SEC_EXPORT: |
| return parseExportSection(Ctx); |
| case wasm::WASM_SEC_START: |
| return parseStartSection(Ctx); |
| case wasm::WASM_SEC_ELEM: |
| return parseElemSection(Ctx); |
| case wasm::WASM_SEC_CODE: |
| return parseCodeSection(Ctx); |
| case wasm::WASM_SEC_DATA: |
| return parseDataSection(Ctx); |
| case wasm::WASM_SEC_DATACOUNT: |
| return parseDataCountSection(Ctx); |
| default: |
| return make_error<GenericBinaryError>( |
| "Invalid section type: " + Twine(Sec.Type), object_error::parse_failed); |
| } |
| } |
| |
| Error WasmObjectFile::parseDylinkSection(ReadContext &Ctx) { |
| // See https://github.com/WebAssembly/tool-conventions/blob/master/DynamicLinking.md |
| HasDylinkSection = true; |
| DylinkInfo.MemorySize = readVaruint32(Ctx); |
| DylinkInfo.MemoryAlignment = readVaruint32(Ctx); |
| DylinkInfo.TableSize = readVaruint32(Ctx); |
| DylinkInfo.TableAlignment = readVaruint32(Ctx); |
| uint32_t Count = readVaruint32(Ctx); |
| while (Count--) { |
| DylinkInfo.Needed.push_back(readString(Ctx)); |
| } |
| if (Ctx.Ptr != Ctx.End) |
| return make_error<GenericBinaryError>("dylink section ended prematurely", |
| object_error::parse_failed); |
| return Error::success(); |
| } |
| |
| Error WasmObjectFile::parseNameSection(ReadContext &Ctx) { |
| llvm::DenseSet<uint64_t> Seen; |
| if (FunctionTypes.size() && !SeenCodeSection) { |
| return make_error<GenericBinaryError>("Names must come after code section", |
| object_error::parse_failed); |
| } |
| |
| while (Ctx.Ptr < Ctx.End) { |
| uint8_t Type = readUint8(Ctx); |
| uint32_t Size = readVaruint32(Ctx); |
| const uint8_t *SubSectionEnd = Ctx.Ptr + Size; |
| switch (Type) { |
| case wasm::WASM_NAMES_FUNCTION: { |
| uint32_t Count = readVaruint32(Ctx); |
| while (Count--) { |
| uint32_t Index = readVaruint32(Ctx); |
| if (!Seen.insert(Index).second) |
| return make_error<GenericBinaryError>("Function named more than once", |
| object_error::parse_failed); |
| StringRef Name = readString(Ctx); |
| if (!isValidFunctionIndex(Index) || Name.empty()) |
| return make_error<GenericBinaryError>("Invalid name entry", |
| object_error::parse_failed); |
| DebugNames.push_back(wasm::WasmFunctionName{Index, Name}); |
| if (isDefinedFunctionIndex(Index)) |
| getDefinedFunction(Index).DebugName = Name; |
| } |
| break; |
| } |
| // Ignore local names for now |
| case wasm::WASM_NAMES_LOCAL: |
| default: |
| Ctx.Ptr += Size; |
| break; |
| } |
| if (Ctx.Ptr != SubSectionEnd) |
| return make_error<GenericBinaryError>( |
| "Name sub-section ended prematurely", object_error::parse_failed); |
| } |
| |
| if (Ctx.Ptr != Ctx.End) |
| return make_error<GenericBinaryError>("Name section ended prematurely", |
| object_error::parse_failed); |
| return Error::success(); |
| } |
| |
| Error WasmObjectFile::parseLinkingSection(ReadContext &Ctx) { |
| HasLinkingSection = true; |
| if (FunctionTypes.size() && !SeenCodeSection) { |
| return make_error<GenericBinaryError>( |
| "Linking data must come after code section", |
| object_error::parse_failed); |
| } |
| |
| LinkingData.Version = readVaruint32(Ctx); |
| if (LinkingData.Version != wasm::WasmMetadataVersion) { |
| return make_error<GenericBinaryError>( |
| "Unexpected metadata version: " + Twine(LinkingData.Version) + |
| " (Expected: " + Twine(wasm::WasmMetadataVersion) + ")", |
| object_error::parse_failed); |
| } |
| |
| const uint8_t *OrigEnd = Ctx.End; |
| while (Ctx.Ptr < OrigEnd) { |
| Ctx.End = OrigEnd; |
| uint8_t Type = readUint8(Ctx); |
| uint32_t Size = readVaruint32(Ctx); |
| LLVM_DEBUG(dbgs() << "readSubsection type=" << int(Type) << " size=" << Size |
| << "\n"); |
| Ctx.End = Ctx.Ptr + Size; |
| switch (Type) { |
| case wasm::WASM_SYMBOL_TABLE: |
| if (Error Err = parseLinkingSectionSymtab(Ctx)) |
| return Err; |
| break; |
| case wasm::WASM_SEGMENT_INFO: { |
| uint32_t Count = readVaruint32(Ctx); |
| if (Count > DataSegments.size()) |
| return make_error<GenericBinaryError>("Too many segment names", |
| object_error::parse_failed); |
| for (uint32_t I = 0; I < Count; I++) { |
| DataSegments[I].Data.Name = readString(Ctx); |
| DataSegments[I].Data.Alignment = readVaruint32(Ctx); |
| DataSegments[I].Data.LinkerFlags = readVaruint32(Ctx); |
| } |
| break; |
| } |
| case wasm::WASM_INIT_FUNCS: { |
| uint32_t Count = readVaruint32(Ctx); |
| LinkingData.InitFunctions.reserve(Count); |
| for (uint32_t I = 0; I < Count; I++) { |
| wasm::WasmInitFunc Init; |
| Init.Priority = readVaruint32(Ctx); |
| Init.Symbol = readVaruint32(Ctx); |
| if (!isValidFunctionSymbol(Init.Symbol)) |
| return make_error<GenericBinaryError>("Invalid function symbol: " + |
| Twine(Init.Symbol), |
| object_error::parse_failed); |
| LinkingData.InitFunctions.emplace_back(Init); |
| } |
| break; |
| } |
| case wasm::WASM_COMDAT_INFO: |
| if (Error Err = parseLinkingSectionComdat(Ctx)) |
| return Err; |
| break; |
| default: |
| Ctx.Ptr += Size; |
| break; |
| } |
| if (Ctx.Ptr != Ctx.End) |
| return make_error<GenericBinaryError>( |
| "Linking sub-section ended prematurely", object_error::parse_failed); |
| } |
| if (Ctx.Ptr != OrigEnd) |
| return make_error<GenericBinaryError>("Linking section ended prematurely", |
| object_error::parse_failed); |
| return Error::success(); |
| } |
| |
| Error WasmObjectFile::parseLinkingSectionSymtab(ReadContext &Ctx) { |
| uint32_t Count = readVaruint32(Ctx); |
| LinkingData.SymbolTable.reserve(Count); |
| Symbols.reserve(Count); |
| StringSet<> SymbolNames; |
| |
| std::vector<wasm::WasmImport *> ImportedGlobals; |
| std::vector<wasm::WasmImport *> ImportedFunctions; |
| std::vector<wasm::WasmImport *> ImportedEvents; |
| ImportedGlobals.reserve(Imports.size()); |
| ImportedFunctions.reserve(Imports.size()); |
| ImportedEvents.reserve(Imports.size()); |
| for (auto &I : Imports) { |
| if (I.Kind == wasm::WASM_EXTERNAL_FUNCTION) |
| ImportedFunctions.emplace_back(&I); |
| else if (I.Kind == wasm::WASM_EXTERNAL_GLOBAL) |
| ImportedGlobals.emplace_back(&I); |
| else if (I.Kind == wasm::WASM_EXTERNAL_EVENT) |
| ImportedEvents.emplace_back(&I); |
| } |
| |
| while (Count--) { |
| wasm::WasmSymbolInfo Info; |
| const wasm::WasmSignature *Signature = nullptr; |
| const wasm::WasmGlobalType *GlobalType = nullptr; |
| const wasm::WasmEventType *EventType = nullptr; |
| |
| Info.Kind = readUint8(Ctx); |
| Info.Flags = readVaruint32(Ctx); |
| bool IsDefined = (Info.Flags & wasm::WASM_SYMBOL_UNDEFINED) == 0; |
| |
| switch (Info.Kind) { |
| case wasm::WASM_SYMBOL_TYPE_FUNCTION: |
| Info.ElementIndex = readVaruint32(Ctx); |
| if (!isValidFunctionIndex(Info.ElementIndex) || |
| IsDefined != isDefinedFunctionIndex(Info.ElementIndex)) |
| return make_error<GenericBinaryError>("invalid function symbol index", |
| object_error::parse_failed); |
| if (IsDefined) { |
| Info.Name = readString(Ctx); |
| unsigned FuncIndex = Info.ElementIndex - NumImportedFunctions; |
| Signature = &Signatures[FunctionTypes[FuncIndex]]; |
| wasm::WasmFunction &Function = Functions[FuncIndex]; |
| if (Function.SymbolName.empty()) |
| Function.SymbolName = Info.Name; |
| } else { |
| wasm::WasmImport &Import = *ImportedFunctions[Info.ElementIndex]; |
| if ((Info.Flags & wasm::WASM_SYMBOL_EXPLICIT_NAME) != 0) |
| Info.Name = readString(Ctx); |
| else |
| Info.Name = Import.Field; |
| Signature = &Signatures[Import.SigIndex]; |
| Info.ImportName = Import.Field; |
| Info.ImportModule = Import.Module; |
| } |
| break; |
| |
| case wasm::WASM_SYMBOL_TYPE_GLOBAL: |
| Info.ElementIndex = readVaruint32(Ctx); |
| if (!isValidGlobalIndex(Info.ElementIndex) || |
| IsDefined != isDefinedGlobalIndex(Info.ElementIndex)) |
| return make_error<GenericBinaryError>("invalid global symbol index", |
| object_error::parse_failed); |
| if (!IsDefined && (Info.Flags & wasm::WASM_SYMBOL_BINDING_MASK) == |
| wasm::WASM_SYMBOL_BINDING_WEAK) |
| return make_error<GenericBinaryError>("undefined weak global symbol", |
| object_error::parse_failed); |
| if (IsDefined) { |
| Info.Name = readString(Ctx); |
| unsigned GlobalIndex = Info.ElementIndex - NumImportedGlobals; |
| wasm::WasmGlobal &Global = Globals[GlobalIndex]; |
| GlobalType = &Global.Type; |
| if (Global.SymbolName.empty()) |
| Global.SymbolName = Info.Name; |
| } else { |
| wasm::WasmImport &Import = *ImportedGlobals[Info.ElementIndex]; |
| if ((Info.Flags & wasm::WASM_SYMBOL_EXPLICIT_NAME) != 0) |
| Info.Name = readString(Ctx); |
| else |
| Info.Name = Import.Field; |
| GlobalType = &Import.Global; |
| Info.ImportName = Import.Field; |
| Info.ImportModule = Import.Module; |
| } |
| break; |
| |
| case wasm::WASM_SYMBOL_TYPE_DATA: |
| Info.Name = readString(Ctx); |
| if (IsDefined) { |
| uint32_t Index = readVaruint32(Ctx); |
| if (Index >= DataSegments.size()) |
| return make_error<GenericBinaryError>("invalid data symbol index", |
| object_error::parse_failed); |
| uint32_t Offset = readVaruint32(Ctx); |
| uint32_t Size = readVaruint32(Ctx); |
| if (Offset + Size > DataSegments[Index].Data.Content.size()) |
| return make_error<GenericBinaryError>("invalid data symbol offset", |
| object_error::parse_failed); |
| Info.DataRef = wasm::WasmDataReference{Index, Offset, Size}; |
| } |
| break; |
| |
| case wasm::WASM_SYMBOL_TYPE_SECTION: { |
| if ((Info.Flags & wasm::WASM_SYMBOL_BINDING_MASK) != |
| wasm::WASM_SYMBOL_BINDING_LOCAL) |
| return make_error<GenericBinaryError>( |
| "Section symbols must have local binding", |
| object_error::parse_failed); |
| Info.ElementIndex = readVaruint32(Ctx); |
| // Use somewhat unique section name as symbol name. |
| StringRef SectionName = Sections[Info.ElementIndex].Name; |
| Info.Name = SectionName; |
| break; |
| } |
| |
| case wasm::WASM_SYMBOL_TYPE_EVENT: { |
| Info.ElementIndex = readVaruint32(Ctx); |
| if (!isValidEventIndex(Info.ElementIndex) || |
| IsDefined != isDefinedEventIndex(Info.ElementIndex)) |
| return make_error<GenericBinaryError>("invalid event symbol index", |
| object_error::parse_failed); |
| if (!IsDefined && (Info.Flags & wasm::WASM_SYMBOL_BINDING_MASK) == |
| wasm::WASM_SYMBOL_BINDING_WEAK) |
| return make_error<GenericBinaryError>("undefined weak global symbol", |
| object_error::parse_failed); |
| if (IsDefined) { |
| Info.Name = readString(Ctx); |
| unsigned EventIndex = Info.ElementIndex - NumImportedEvents; |
| wasm::WasmEvent &Event = Events[EventIndex]; |
| Signature = &Signatures[Event.Type.SigIndex]; |
| EventType = &Event.Type; |
| if (Event.SymbolName.empty()) |
| Event.SymbolName = Info.Name; |
| |
| } else { |
| wasm::WasmImport &Import = *ImportedEvents[Info.ElementIndex]; |
| if ((Info.Flags & wasm::WASM_SYMBOL_EXPLICIT_NAME) != 0) |
| Info.Name = readString(Ctx); |
| else |
| Info.Name = Import.Field; |
| EventType = &Import.Event; |
| Signature = &Signatures[EventType->SigIndex]; |
| Info.ImportName = Import.Field; |
| Info.ImportModule = Import.Module; |
| } |
| break; |
| } |
| |
| default: |
| return make_error<GenericBinaryError>("Invalid symbol type", |
| object_error::parse_failed); |
| } |
| |
| if ((Info.Flags & wasm::WASM_SYMBOL_BINDING_MASK) != |
| wasm::WASM_SYMBOL_BINDING_LOCAL && |
| !SymbolNames.insert(Info.Name).second) |
| return make_error<GenericBinaryError>("Duplicate symbol name " + |
| Twine(Info.Name), |
| object_error::parse_failed); |
| LinkingData.SymbolTable.emplace_back(Info); |
| Symbols.emplace_back(LinkingData.SymbolTable.back(), GlobalType, EventType, |
| Signature); |
| LLVM_DEBUG(dbgs() << "Adding symbol: " << Symbols.back() << "\n"); |
| } |
| |
| return Error::success(); |
| } |
| |
| Error WasmObjectFile::parseLinkingSectionComdat(ReadContext &Ctx) { |
| uint32_t ComdatCount = readVaruint32(Ctx); |
| StringSet<> ComdatSet; |
| for (unsigned ComdatIndex = 0; ComdatIndex < ComdatCount; ++ComdatIndex) { |
| StringRef Name = readString(Ctx); |
| if (Name.empty() || !ComdatSet.insert(Name).second) |
| return make_error<GenericBinaryError>("Bad/duplicate COMDAT name " + |
| Twine(Name), |
| object_error::parse_failed); |
| LinkingData.Comdats.emplace_back(Name); |
| uint32_t Flags = readVaruint32(Ctx); |
| if (Flags != 0) |
| return make_error<GenericBinaryError>("Unsupported COMDAT flags", |
| object_error::parse_failed); |
| |
| uint32_t EntryCount = readVaruint32(Ctx); |
| while (EntryCount--) { |
| unsigned Kind = readVaruint32(Ctx); |
| unsigned Index = readVaruint32(Ctx); |
| switch (Kind) { |
| default: |
| return make_error<GenericBinaryError>("Invalid COMDAT entry type", |
| object_error::parse_failed); |
| case wasm::WASM_COMDAT_DATA: |
| if (Index >= DataSegments.size()) |
| return make_error<GenericBinaryError>( |
| "COMDAT data index out of range", object_error::parse_failed); |
| if (DataSegments[Index].Data.Comdat != UINT32_MAX) |
| return make_error<GenericBinaryError>("Data segment in two COMDATs", |
| object_error::parse_failed); |
| DataSegments[Index].Data.Comdat = ComdatIndex; |
| break; |
| case wasm::WASM_COMDAT_FUNCTION: |
| if (!isDefinedFunctionIndex(Index)) |
| return make_error<GenericBinaryError>( |
| "COMDAT function index out of range", object_error::parse_failed); |
| if (getDefinedFunction(Index).Comdat != UINT32_MAX) |
| return make_error<GenericBinaryError>("Function in two COMDATs", |
| object_error::parse_failed); |
| getDefinedFunction(Index).Comdat = ComdatIndex; |
| break; |
| } |
| } |
| } |
| return Error::success(); |
| } |
| |
| Error WasmObjectFile::parseProducersSection(ReadContext &Ctx) { |
| llvm::SmallSet<StringRef, 3> FieldsSeen; |
| uint32_t Fields = readVaruint32(Ctx); |
| for (size_t I = 0; I < Fields; ++I) { |
| StringRef FieldName = readString(Ctx); |
| if (!FieldsSeen.insert(FieldName).second) |
| return make_error<GenericBinaryError>( |
| "Producers section does not have unique fields", |
| object_error::parse_failed); |
| std::vector<std::pair<std::string, std::string>> *ProducerVec = nullptr; |
| if (FieldName == "language") { |
| ProducerVec = &ProducerInfo.Languages; |
| } else if (FieldName == "processed-by") { |
| ProducerVec = &ProducerInfo.Tools; |
| } else if (FieldName == "sdk") { |
| ProducerVec = &ProducerInfo.SDKs; |
| } else { |
| return make_error<GenericBinaryError>( |
| "Producers section field is not named one of language, processed-by, " |
| "or sdk", |
| object_error::parse_failed); |
| } |
| uint32_t ValueCount = readVaruint32(Ctx); |
| llvm::SmallSet<StringRef, 8> ProducersSeen; |
| for (size_t J = 0; J < ValueCount; ++J) { |
| StringRef Name = readString(Ctx); |
| StringRef Version = readString(Ctx); |
| if (!ProducersSeen.insert(Name).second) { |
| return make_error<GenericBinaryError>( |
| "Producers section contains repeated producer", |
| object_error::parse_failed); |
| } |
| ProducerVec->emplace_back(Name, Version); |
| } |
| } |
| if (Ctx.Ptr != Ctx.End) |
| return make_error<GenericBinaryError>("Producers section ended prematurely", |
| object_error::parse_failed); |
| return Error::success(); |
| } |
| |
| Error WasmObjectFile::parseTargetFeaturesSection(ReadContext &Ctx) { |
| llvm::SmallSet<std::string, 8> FeaturesSeen; |
| uint32_t FeatureCount = readVaruint32(Ctx); |
| for (size_t I = 0; I < FeatureCount; ++I) { |
| wasm::WasmFeatureEntry Feature; |
| Feature.Prefix = readUint8(Ctx); |
| switch (Feature.Prefix) { |
| case wasm::WASM_FEATURE_PREFIX_USED: |
| case wasm::WASM_FEATURE_PREFIX_REQUIRED: |
| case wasm::WASM_FEATURE_PREFIX_DISALLOWED: |
| break; |
| default: |
| return make_error<GenericBinaryError>("Unknown feature policy prefix", |
| object_error::parse_failed); |
| } |
| Feature.Name = readString(Ctx); |
| if (!FeaturesSeen.insert(Feature.Name).second) |
| return make_error<GenericBinaryError>( |
| "Target features section contains repeated feature \"" + |
| Feature.Name + "\"", |
| object_error::parse_failed); |
| TargetFeatures.push_back(Feature); |
| } |
| if (Ctx.Ptr != Ctx.End) |
| return make_error<GenericBinaryError>( |
| "Target features section ended prematurely", |
| object_error::parse_failed); |
| return Error::success(); |
| } |
| |
| Error WasmObjectFile::parseRelocSection(StringRef Name, ReadContext &Ctx) { |
| uint32_t SectionIndex = readVaruint32(Ctx); |
| if (SectionIndex >= Sections.size()) |
| return make_error<GenericBinaryError>("Invalid section index", |
| object_error::parse_failed); |
| WasmSection &Section = Sections[SectionIndex]; |
| uint32_t RelocCount = readVaruint32(Ctx); |
| uint32_t EndOffset = Section.Content.size(); |
| uint32_t PreviousOffset = 0; |
| while (RelocCount--) { |
| wasm::WasmRelocation Reloc = {}; |
| Reloc.Type = readVaruint32(Ctx); |
| Reloc.Offset = readVaruint32(Ctx); |
| if (Reloc.Offset < PreviousOffset) |
| return make_error<GenericBinaryError>("Relocations not in offset order", |
| object_error::parse_failed); |
| PreviousOffset = Reloc.Offset; |
| Reloc.Index = readVaruint32(Ctx); |
| switch (Reloc.Type) { |
| case wasm::R_WASM_FUNCTION_INDEX_LEB: |
| case wasm::R_WASM_TABLE_INDEX_SLEB: |
| case wasm::R_WASM_TABLE_INDEX_I32: |
| case wasm::R_WASM_TABLE_INDEX_REL_SLEB: |
| if (!isValidFunctionSymbol(Reloc.Index)) |
| return make_error<GenericBinaryError>("Bad relocation function index", |
| object_error::parse_failed); |
| break; |
| case wasm::R_WASM_TYPE_INDEX_LEB: |
| if (Reloc.Index >= Signatures.size()) |
| return make_error<GenericBinaryError>("Bad relocation type index", |
| object_error::parse_failed); |
| break; |
| case wasm::R_WASM_GLOBAL_INDEX_LEB: |
| // R_WASM_GLOBAL_INDEX_LEB are can be used against function and data |
| // symbols to refer to their GOT entries. |
| if (!isValidGlobalSymbol(Reloc.Index) && |
| !isValidDataSymbol(Reloc.Index) && |
| !isValidFunctionSymbol(Reloc.Index)) |
| return make_error<GenericBinaryError>("Bad relocation global index", |
| object_error::parse_failed); |
| break; |
| case wasm::R_WASM_EVENT_INDEX_LEB: |
| if (!isValidEventSymbol(Reloc.Index)) |
| return make_error<GenericBinaryError>("Bad relocation event index", |
| object_error::parse_failed); |
| break; |
| case wasm::R_WASM_MEMORY_ADDR_LEB: |
| case wasm::R_WASM_MEMORY_ADDR_SLEB: |
| case wasm::R_WASM_MEMORY_ADDR_I32: |
| case wasm::R_WASM_MEMORY_ADDR_REL_SLEB: |
| if (!isValidDataSymbol(Reloc.Index)) |
| return make_error<GenericBinaryError>("Bad relocation data index", |
| object_error::parse_failed); |
| Reloc.Addend = readVarint32(Ctx); |
| break; |
| case wasm::R_WASM_FUNCTION_OFFSET_I32: |
| if (!isValidFunctionSymbol(Reloc.Index)) |
| return make_error<GenericBinaryError>("Bad relocation function index", |
| object_error::parse_failed); |
| Reloc.Addend = readVarint32(Ctx); |
| break; |
| case wasm::R_WASM_SECTION_OFFSET_I32: |
| if (!isValidSectionSymbol(Reloc.Index)) |
| return make_error<GenericBinaryError>("Bad relocation section index", |
| object_error::parse_failed); |
| Reloc.Addend = readVarint32(Ctx); |
| break; |
| default: |
| return make_error<GenericBinaryError>("Bad relocation type: " + |
| Twine(Reloc.Type), |
| object_error::parse_failed); |
| } |
| |
| // Relocations must fit inside the section, and must appear in order. They |
| // also shouldn't overlap a function/element boundary, but we don't bother |
| // to check that. |
| uint64_t Size = 5; |
| if (Reloc.Type == wasm::R_WASM_TABLE_INDEX_I32 || |
| Reloc.Type == wasm::R_WASM_MEMORY_ADDR_I32 || |
| Reloc.Type == wasm::R_WASM_SECTION_OFFSET_I32 || |
| Reloc.Type == wasm::R_WASM_FUNCTION_OFFSET_I32) |
| Size = 4; |
| if (Reloc.Offset + Size > EndOffset) |
| return make_error<GenericBinaryError>("Bad relocation offset", |
| object_error::parse_failed); |
| |
| Section.Relocations.push_back(Reloc); |
| } |
| if (Ctx.Ptr != Ctx.End) |
| return make_error<GenericBinaryError>("Reloc section ended prematurely", |
| object_error::parse_failed); |
| return Error::success(); |
| } |
| |
| Error WasmObjectFile::parseCustomSection(WasmSection &Sec, ReadContext &Ctx) { |
| if (Sec.Name == "dylink") { |
| if (Error Err = parseDylinkSection(Ctx)) |
| return Err; |
| } else if (Sec.Name == "name") { |
| if (Error Err = parseNameSection(Ctx)) |
| return Err; |
| } else if (Sec.Name == "linking") { |
| if (Error Err = parseLinkingSection(Ctx)) |
| return Err; |
| } else if (Sec.Name == "producers") { |
| if (Error Err = parseProducersSection(Ctx)) |
| return Err; |
| } else if (Sec.Name == "target_features") { |
| if (Error Err = parseTargetFeaturesSection(Ctx)) |
| return Err; |
| } else if (Sec.Name.startswith("reloc.")) { |
| if (Error Err = parseRelocSection(Sec.Name, Ctx)) |
| return Err; |
| } |
| return Error::success(); |
| } |
| |
| Error WasmObjectFile::parseTypeSection(ReadContext &Ctx) { |
| uint32_t Count = readVaruint32(Ctx); |
| Signatures.reserve(Count); |
| while (Count--) { |
| wasm::WasmSignature Sig; |
| uint8_t Form = readUint8(Ctx); |
| if (Form != wasm::WASM_TYPE_FUNC) { |
| return make_error<GenericBinaryError>("Invalid signature type", |
| object_error::parse_failed); |
| } |
| uint32_t ParamCount = readVaruint32(Ctx); |
| Sig.Params.reserve(ParamCount); |
| while (ParamCount--) { |
| uint32_t ParamType = readUint8(Ctx); |
| Sig.Params.push_back(wasm::ValType(ParamType)); |
| } |
| uint32_t ReturnCount = readVaruint32(Ctx); |
| while (ReturnCount--) { |
| uint32_t ReturnType = readUint8(Ctx); |
| Sig.Returns.push_back(wasm::ValType(ReturnType)); |
| } |
| Signatures.push_back(std::move(Sig)); |
| } |
| if (Ctx.Ptr != Ctx.End) |
| return make_error<GenericBinaryError>("Type section ended prematurely", |
| object_error::parse_failed); |
| return Error::success(); |
| } |
| |
| Error WasmObjectFile::parseImportSection(ReadContext &Ctx) { |
| uint32_t Count = readVaruint32(Ctx); |
| Imports.reserve(Count); |
| for (uint32_t I = 0; I < Count; I++) { |
| wasm::WasmImport Im; |
| Im.Module = readString(Ctx); |
| Im.Field = readString(Ctx); |
| Im.Kind = readUint8(Ctx); |
| switch (Im.Kind) { |
| case wasm::WASM_EXTERNAL_FUNCTION: |
| NumImportedFunctions++; |
| Im.SigIndex = readVaruint32(Ctx); |
| break; |
| case wasm::WASM_EXTERNAL_GLOBAL: |
| NumImportedGlobals++; |
| Im.Global.Type = readUint8(Ctx); |
| Im.Global.Mutable = readVaruint1(Ctx); |
| break; |
| case wasm::WASM_EXTERNAL_MEMORY: |
| Im.Memory = readLimits(Ctx); |
| break; |
| case wasm::WASM_EXTERNAL_TABLE: |
| Im.Table = readTable(Ctx); |
| if (Im.Table.ElemType != wasm::WASM_TYPE_FUNCREF) |
| return make_error<GenericBinaryError>("Invalid table element type", |
| object_error::parse_failed); |
| break; |
| case wasm::WASM_EXTERNAL_EVENT: |
| NumImportedEvents++; |
| Im.Event.Attribute = readVarint32(Ctx); |
| Im.Event.SigIndex = readVarint32(Ctx); |
| break; |
| default: |
| return make_error<GenericBinaryError>("Unexpected import kind", |
| object_error::parse_failed); |
| } |
| Imports.push_back(Im); |
| } |
| if (Ctx.Ptr != Ctx.End) |
| return make_error<GenericBinaryError>("Import section ended prematurely", |
| object_error::parse_failed); |
| return Error::success(); |
| } |
| |
| Error WasmObjectFile::parseFunctionSection(ReadContext &Ctx) { |
| uint32_t Count = readVaruint32(Ctx); |
| FunctionTypes.reserve(Count); |
| Functions.resize(Count); |
| uint32_t NumTypes = Signatures.size(); |
| while (Count--) { |
| uint32_t Type = readVaruint32(Ctx); |
| if (Type >= NumTypes) |
| return make_error<GenericBinaryError>("Invalid function type", |
| object_error::parse_failed); |
| FunctionTypes.push_back(Type); |
| } |
| if (Ctx.Ptr != Ctx.End) |
| return make_error<GenericBinaryError>("Function section ended prematurely", |
| object_error::parse_failed); |
| return Error::success(); |
| } |
| |
| Error WasmObjectFile::parseTableSection(ReadContext &Ctx) { |
| uint32_t Count = readVaruint32(Ctx); |
| Tables.reserve(Count); |
| while (Count--) { |
| Tables.push_back(readTable(Ctx)); |
| if (Tables.back().ElemType != wasm::WASM_TYPE_FUNCREF) { |
| return make_error<GenericBinaryError>("Invalid table element type", |
| object_error::parse_failed); |
| } |
| } |
| if (Ctx.Ptr != Ctx.End) |
| return make_error<GenericBinaryError>("Table section ended prematurely", |
| object_error::parse_failed); |
| return Error::success(); |
| } |
| |
| Error WasmObjectFile::parseMemorySection(ReadContext &Ctx) { |
| uint32_t Count = readVaruint32(Ctx); |
| Memories.reserve(Count); |
| while (Count--) { |
| Memories.push_back(readLimits(Ctx)); |
| } |
| if (Ctx.Ptr != Ctx.End) |
| return make_error<GenericBinaryError>("Memory section ended prematurely", |
| object_error::parse_failed); |
| return Error::success(); |
| } |
| |
| Error WasmObjectFile::parseGlobalSection(ReadContext &Ctx) { |
| GlobalSection = Sections.size(); |
| uint32_t Count = readVaruint32(Ctx); |
| Globals.reserve(Count); |
| while (Count--) { |
| wasm::WasmGlobal Global; |
| Global.Index = NumImportedGlobals + Globals.size(); |
| Global.Type.Type = readUint8(Ctx); |
| Global.Type.Mutable = readVaruint1(Ctx); |
| if (Error Err = readInitExpr(Global.InitExpr, Ctx)) |
| return Err; |
| Globals.push_back(Global); |
| } |
| if (Ctx.Ptr != Ctx.End) |
| return make_error<GenericBinaryError>("Global section ended prematurely", |
| object_error::parse_failed); |
| return Error::success(); |
| } |
| |
| Error WasmObjectFile::parseEventSection(ReadContext &Ctx) { |
| EventSection = Sections.size(); |
| uint32_t Count = readVarint32(Ctx); |
| Events.reserve(Count); |
| while (Count--) { |
| wasm::WasmEvent Event; |
| Event.Index = NumImportedEvents + Events.size(); |
| Event.Type.Attribute = readVaruint32(Ctx); |
| Event.Type.SigIndex = readVarint32(Ctx); |
| Events.push_back(Event); |
| } |
| |
| if (Ctx.Ptr != Ctx.End) |
| return make_error<GenericBinaryError>("Event section ended prematurely", |
| object_error::parse_failed); |
| return Error::success(); |
| } |
| |
| Error WasmObjectFile::parseExportSection(ReadContext &Ctx) { |
| uint32_t Count = readVaruint32(Ctx); |
| Exports.reserve(Count); |
| for (uint32_t I = 0; I < Count; I++) { |
| wasm::WasmExport Ex; |
| Ex.Name = readString(Ctx); |
| Ex.Kind = readUint8(Ctx); |
| Ex.Index = readVaruint32(Ctx); |
| switch (Ex.Kind) { |
| case wasm::WASM_EXTERNAL_FUNCTION: |
| |
| if (!isDefinedFunctionIndex(Ex.Index)) |
| return make_error<GenericBinaryError>("Invalid function export", |
| object_error::parse_failed); |
| getDefinedFunction(Ex.Index).ExportName = Ex.Name; |
| break; |
| case wasm::WASM_EXTERNAL_GLOBAL: |
| if (!isValidGlobalIndex(Ex.Index)) |
| return make_error<GenericBinaryError>("Invalid global export", |
| object_error::parse_failed); |
| break; |
| case wasm::WASM_EXTERNAL_EVENT: |
| if (!isValidEventIndex(Ex.Index)) |
| return make_error<GenericBinaryError>("Invalid event export", |
| object_error::parse_failed); |
| break; |
| case wasm::WASM_EXTERNAL_MEMORY: |
| case wasm::WASM_EXTERNAL_TABLE: |
| break; |
| default: |
| return make_error<GenericBinaryError>("Unexpected export kind", |
| object_error::parse_failed); |
| } |
| Exports.push_back(Ex); |
| } |
| if (Ctx.Ptr != Ctx.End) |
| return make_error<GenericBinaryError>("Export section ended prematurely", |
| object_error::parse_failed); |
| return Error::success(); |
| } |
| |
| bool WasmObjectFile::isValidFunctionIndex(uint32_t Index) const { |
| return Index < NumImportedFunctions + FunctionTypes.size(); |
| } |
| |
| bool WasmObjectFile::isDefinedFunctionIndex(uint32_t Index) const { |
| return Index >= NumImportedFunctions && isValidFunctionIndex(Index); |
| } |
| |
| bool WasmObjectFile::isValidGlobalIndex(uint32_t Index) const { |
| return Index < NumImportedGlobals + Globals.size(); |
| } |
| |
| bool WasmObjectFile::isDefinedGlobalIndex(uint32_t Index) const { |
| return Index >= NumImportedGlobals && isValidGlobalIndex(Index); |
| } |
| |
| bool WasmObjectFile::isValidEventIndex(uint32_t Index) const { |
| return Index < NumImportedEvents + Events.size(); |
| } |
| |
| bool WasmObjectFile::isDefinedEventIndex(uint32_t Index) const { |
| return Index >= NumImportedEvents && isValidEventIndex(Index); |
| } |
| |
| bool WasmObjectFile::isValidFunctionSymbol(uint32_t Index) const { |
| return Index < Symbols.size() && Symbols[Index].isTypeFunction(); |
| } |
| |
| bool WasmObjectFile::isValidGlobalSymbol(uint32_t Index) const { |
| return Index < Symbols.size() && Symbols[Index].isTypeGlobal(); |
| } |
| |
| bool WasmObjectFile::isValidEventSymbol(uint32_t Index) const { |
| return Index < Symbols.size() && Symbols[Index].isTypeEvent(); |
| } |
| |
| bool WasmObjectFile::isValidDataSymbol(uint32_t Index) const { |
| return Index < Symbols.size() && Symbols[Index].isTypeData(); |
| } |
| |
| bool WasmObjectFile::isValidSectionSymbol(uint32_t Index) const { |
| return Index < Symbols.size() && Symbols[Index].isTypeSection(); |
| } |
| |
| wasm::WasmFunction &WasmObjectFile::getDefinedFunction(uint32_t Index) { |
| assert(isDefinedFunctionIndex(Index)); |
| return Functions[Index - NumImportedFunctions]; |
| } |
| |
| const wasm::WasmFunction & |
| WasmObjectFile::getDefinedFunction(uint32_t Index) const { |
| assert(isDefinedFunctionIndex(Index)); |
| return Functions[Index - NumImportedFunctions]; |
| } |
| |
| wasm::WasmGlobal &WasmObjectFile::getDefinedGlobal(uint32_t Index) { |
| assert(isDefinedGlobalIndex(Index)); |
| return Globals[Index - NumImportedGlobals]; |
| } |
| |
| wasm::WasmEvent &WasmObjectFile::getDefinedEvent(uint32_t Index) { |
| assert(isDefinedEventIndex(Index)); |
| return Events[Index - NumImportedEvents]; |
| } |
| |
| Error WasmObjectFile::parseStartSection(ReadContext &Ctx) { |
| StartFunction = readVaruint32(Ctx); |
| if (!isValidFunctionIndex(StartFunction)) |
| return make_error<GenericBinaryError>("Invalid start function", |
| object_error::parse_failed); |
| return Error::success(); |
| } |
| |
| Error WasmObjectFile::parseCodeSection(ReadContext &Ctx) { |
| SeenCodeSection = true; |
| CodeSection = Sections.size(); |
| uint32_t FunctionCount = readVaruint32(Ctx); |
| if (FunctionCount != FunctionTypes.size()) { |
| return make_error<GenericBinaryError>("Invalid function count", |
| object_error::parse_failed); |
| } |
| |
| for (uint32_t i = 0; i < FunctionCount; i++) { |
| wasm::WasmFunction& Function = Functions[i]; |
| const uint8_t *FunctionStart = Ctx.Ptr; |
| uint32_t Size = readVaruint32(Ctx); |
| const uint8_t *FunctionEnd = Ctx.Ptr + Size; |
| |
| Function.CodeOffset = Ctx.Ptr - FunctionStart; |
| Function.Index = NumImportedFunctions + i; |
| Function.CodeSectionOffset = FunctionStart - Ctx.Start; |
| Function.Size = FunctionEnd - FunctionStart; |
| |
| uint32_t NumLocalDecls = readVaruint32(Ctx); |
| Function.Locals.reserve(NumLocalDecls); |
| while (NumLocalDecls--) { |
| wasm::WasmLocalDecl Decl; |
| Decl.Count = readVaruint32(Ctx); |
| Decl.Type = readUint8(Ctx); |
| Function.Locals.push_back(Decl); |
| } |
| |
| uint32_t BodySize = FunctionEnd - Ctx.Ptr; |
| Function.Body = ArrayRef<uint8_t>(Ctx.Ptr, BodySize); |
| // This will be set later when reading in the linking metadata section. |
| Function.Comdat = UINT32_MAX; |
| Ctx.Ptr += BodySize; |
| assert(Ctx.Ptr == FunctionEnd); |
| } |
| if (Ctx.Ptr != Ctx.End) |
| return make_error<GenericBinaryError>("Code section ended prematurely", |
| object_error::parse_failed); |
| return Error::success(); |
| } |
| |
| Error WasmObjectFile::parseElemSection(ReadContext &Ctx) { |
| uint32_t Count = readVaruint32(Ctx); |
| ElemSegments.reserve(Count); |
| while (Count--) { |
| wasm::WasmElemSegment Segment; |
| Segment.TableIndex = readVaruint32(Ctx); |
| if (Segment.TableIndex != 0) { |
| return make_error<GenericBinaryError>("Invalid TableIndex", |
| object_error::parse_failed); |
| } |
| if (Error Err = readInitExpr(Segment.Offset, Ctx)) |
| return Err; |
| uint32_t NumElems = readVaruint32(Ctx); |
| while (NumElems--) { |
| Segment.Functions.push_back(readVaruint32(Ctx)); |
| } |
| ElemSegments.push_back(Segment); |
| } |
| if (Ctx.Ptr != Ctx.End) |
| return make_error<GenericBinaryError>("Elem section ended prematurely", |
| object_error::parse_failed); |
| return Error::success(); |
| } |
| |
| Error WasmObjectFile::parseDataSection(ReadContext &Ctx) { |
| DataSection = Sections.size(); |
| uint32_t Count = readVaruint32(Ctx); |
| if (DataCount && Count != DataCount.getValue()) |
| return make_error<GenericBinaryError>( |
| "Number of data segments does not match DataCount section"); |
| DataSegments.reserve(Count); |
| while (Count--) { |
| WasmSegment Segment; |
| Segment.Data.InitFlags = readVaruint32(Ctx); |
| Segment.Data.MemoryIndex = (Segment.Data.InitFlags & wasm::WASM_SEGMENT_HAS_MEMINDEX) |
| ? readVaruint32(Ctx) : 0; |
| if ((Segment.Data.InitFlags & wasm::WASM_SEGMENT_IS_PASSIVE) == 0) { |
| if (Error Err = readInitExpr(Segment.Data.Offset, Ctx)) |
| return Err; |
| } else { |
| Segment.Data.Offset.Opcode = wasm::WASM_OPCODE_I32_CONST; |
| Segment.Data.Offset.Value.Int32 = 0; |
| } |
| uint32_t Size = readVaruint32(Ctx); |
| if (Size > (size_t)(Ctx.End - Ctx.Ptr)) |
| return make_error<GenericBinaryError>("Invalid segment size", |
| object_error::parse_failed); |
| Segment.Data.Content = ArrayRef<uint8_t>(Ctx.Ptr, Size); |
| // The rest of these Data fields are set later, when reading in the linking |
| // metadata section. |
| Segment.Data.Alignment = 0; |
| Segment.Data.LinkerFlags = 0; |
| Segment.Data.Comdat = UINT32_MAX; |
| Segment.SectionOffset = Ctx.Ptr - Ctx.Start; |
| Ctx.Ptr += Size; |
| DataSegments.push_back(Segment); |
| } |
| if (Ctx.Ptr != Ctx.End) |
| return make_error<GenericBinaryError>("Data section ended prematurely", |
| object_error::parse_failed); |
| return Error::success(); |
| } |
| |
| Error WasmObjectFile::parseDataCountSection(ReadContext &Ctx) { |
| DataCount = readVaruint32(Ctx); |
| return Error::success(); |
| } |
| |
| const wasm::WasmObjectHeader &WasmObjectFile::getHeader() const { |
| return Header; |
| } |
| |
| void WasmObjectFile::moveSymbolNext(DataRefImpl &Symb) const { Symb.d.b++; } |
| |
| uint32_t WasmObjectFile::getSymbolFlags(DataRefImpl Symb) const { |
| uint32_t Result = SymbolRef::SF_None; |
| const WasmSymbol &Sym = getWasmSymbol(Symb); |
| |
| LLVM_DEBUG(dbgs() << "getSymbolFlags: ptr=" << &Sym << " " << Sym << "\n"); |
| if (Sym.isBindingWeak()) |
| Result |= SymbolRef::SF_Weak; |
| if (!Sym.isBindingLocal()) |
| Result |= SymbolRef::SF_Global; |
| if (Sym.isHidden()) |
| Result |= SymbolRef::SF_Hidden; |
| if (!Sym.isDefined()) |
| Result |= SymbolRef::SF_Undefined; |
| if (Sym.isTypeFunction()) |
| Result |= SymbolRef::SF_Executable; |
| return Result; |
| } |
| |
| basic_symbol_iterator WasmObjectFile::symbol_begin() const { |
| DataRefImpl Ref; |
| Ref.d.a = 1; // Arbitrary non-zero value so that Ref.p is non-null |
| Ref.d.b = 0; // Symbol index |
| return BasicSymbolRef(Ref, this); |
| } |
| |
| basic_symbol_iterator WasmObjectFile::symbol_end() const { |
| DataRefImpl Ref; |
| Ref.d.a = 1; // Arbitrary non-zero value so that Ref.p is non-null |
| Ref.d.b = Symbols.size(); // Symbol index |
| return BasicSymbolRef(Ref, this); |
| } |
| |
| const WasmSymbol &WasmObjectFile::getWasmSymbol(const DataRefImpl &Symb) const { |
| return Symbols[Symb.d.b]; |
| } |
| |
| const WasmSymbol &WasmObjectFile::getWasmSymbol(const SymbolRef &Symb) const { |
| return getWasmSymbol(Symb.getRawDataRefImpl()); |
| } |
| |
| Expected<StringRef> WasmObjectFile::getSymbolName(DataRefImpl Symb) const { |
| return getWasmSymbol(Symb).Info.Name; |
| } |
| |
| Expected<uint64_t> WasmObjectFile::getSymbolAddress(DataRefImpl Symb) const { |
| auto &Sym = getWasmSymbol(Symb); |
| if (Sym.Info.Kind == wasm::WASM_SYMBOL_TYPE_FUNCTION && |
| isDefinedFunctionIndex(Sym.Info.ElementIndex)) |
| return getDefinedFunction(Sym.Info.ElementIndex).CodeSectionOffset; |
| else |
| return getSymbolValue(Symb); |
| } |
| |
| uint64_t WasmObjectFile::getWasmSymbolValue(const WasmSymbol &Sym) const { |
| switch (Sym.Info.Kind) { |
| case wasm::WASM_SYMBOL_TYPE_FUNCTION: |
| case wasm::WASM_SYMBOL_TYPE_GLOBAL: |
| case wasm::WASM_SYMBOL_TYPE_EVENT: |
| return Sym.Info.ElementIndex; |
| case wasm::WASM_SYMBOL_TYPE_DATA: { |
| // The value of a data symbol is the segment offset, plus the symbol |
| // offset within the segment. |
| uint32_t SegmentIndex = Sym.Info.DataRef.Segment; |
| const wasm::WasmDataSegment &Segment = DataSegments[SegmentIndex].Data; |
| assert(Segment.Offset.Opcode == wasm::WASM_OPCODE_I32_CONST); |
| return Segment.Offset.Value.Int32 + Sym.Info.DataRef.Offset; |
| } |
| case wasm::WASM_SYMBOL_TYPE_SECTION: |
| return 0; |
| } |
| llvm_unreachable("invalid symbol type"); |
| } |
| |
| uint64_t WasmObjectFile::getSymbolValueImpl(DataRefImpl Symb) const { |
| return getWasmSymbolValue(getWasmSymbol(Symb)); |
| } |
| |
| uint32_t WasmObjectFile::getSymbolAlignment(DataRefImpl Symb) const { |
| llvm_unreachable("not yet implemented"); |
| return 0; |
| } |
| |
| uint64_t WasmObjectFile::getCommonSymbolSizeImpl(DataRefImpl Symb) const { |
| llvm_unreachable("not yet implemented"); |
| return 0; |
| } |
| |
| Expected<SymbolRef::Type> |
| WasmObjectFile::getSymbolType(DataRefImpl Symb) const { |
| const WasmSymbol &Sym = getWasmSymbol(Symb); |
| |
| switch (Sym.Info.Kind) { |
| case wasm::WASM_SYMBOL_TYPE_FUNCTION: |
| return SymbolRef::ST_Function; |
| case wasm::WASM_SYMBOL_TYPE_GLOBAL: |
| return SymbolRef::ST_Other; |
| case wasm::WASM_SYMBOL_TYPE_DATA: |
| return SymbolRef::ST_Data; |
| case wasm::WASM_SYMBOL_TYPE_SECTION: |
| return SymbolRef::ST_Debug; |
| case wasm::WASM_SYMBOL_TYPE_EVENT: |
| return SymbolRef::ST_Other; |
| } |
| |
| llvm_unreachable("Unknown WasmSymbol::SymbolType"); |
| return SymbolRef::ST_Other; |
| } |
| |
| Expected<section_iterator> |
| WasmObjectFile::getSymbolSection(DataRefImpl Symb) const { |
| const WasmSymbol &Sym = getWasmSymbol(Symb); |
| if (Sym.isUndefined()) |
| return section_end(); |
| |
| DataRefImpl Ref; |
| switch (Sym.Info.Kind) { |
| case wasm::WASM_SYMBOL_TYPE_FUNCTION: |
| Ref.d.a = CodeSection; |
| break; |
| case wasm::WASM_SYMBOL_TYPE_GLOBAL: |
| Ref.d.a = GlobalSection; |
| break; |
| case wasm::WASM_SYMBOL_TYPE_DATA: |
| Ref.d.a = DataSection; |
| break; |
| case wasm::WASM_SYMBOL_TYPE_SECTION: |
| Ref.d.a = Sym.Info.ElementIndex; |
| break; |
| case wasm::WASM_SYMBOL_TYPE_EVENT: |
| Ref.d.a = EventSection; |
| break; |
| default: |
| llvm_unreachable("Unknown WasmSymbol::SymbolType"); |
| } |
| return section_iterator(SectionRef(Ref, this)); |
| } |
| |
| void WasmObjectFile::moveSectionNext(DataRefImpl &Sec) const { Sec.d.a++; } |
| |
| Expected<StringRef> WasmObjectFile::getSectionName(DataRefImpl Sec) const { |
| const WasmSection &S = Sections[Sec.d.a]; |
| #define ECase(X) \ |
| case wasm::WASM_SEC_##X: \ |
| return #X; |
| switch (S.Type) { |
| ECase(TYPE); |
| ECase(IMPORT); |
| ECase(FUNCTION); |
| ECase(TABLE); |
| ECase(MEMORY); |
| ECase(GLOBAL); |
| ECase(EVENT); |
| ECase(EXPORT); |
| ECase(START); |
| ECase(ELEM); |
| ECase(CODE); |
| ECase(DATA); |
| ECase(DATACOUNT); |
| case wasm::WASM_SEC_CUSTOM: |
| return S.Name; |
| default: |
| return createStringError(object_error::invalid_section_index, ""); |
| } |
| #undef ECase |
| } |
| |
| uint64_t WasmObjectFile::getSectionAddress(DataRefImpl Sec) const { return 0; } |
| |
| uint64_t WasmObjectFile::getSectionIndex(DataRefImpl Sec) const { |
| return Sec.d.a; |
| } |
| |
| uint64_t WasmObjectFile::getSectionSize(DataRefImpl Sec) const { |
| const WasmSection &S = Sections[Sec.d.a]; |
| return S.Content.size(); |
| } |
| |
| Expected<ArrayRef<uint8_t>> |
| WasmObjectFile::getSectionContents(DataRefImpl Sec) const { |
| const WasmSection &S = Sections[Sec.d.a]; |
| // This will never fail since wasm sections can never be empty (user-sections |
| // must have a name and non-user sections each have a defined structure). |
| return S.Content; |
| } |
| |
| uint64_t WasmObjectFile::getSectionAlignment(DataRefImpl Sec) const { |
| return 1; |
| } |
| |
| bool WasmObjectFile::isSectionCompressed(DataRefImpl Sec) const { |
| return false; |
| } |
| |
| bool WasmObjectFile::isSectionText(DataRefImpl Sec) const { |
| return getWasmSection(Sec).Type == wasm::WASM_SEC_CODE; |
| } |
| |
| bool WasmObjectFile::isSectionData(DataRefImpl Sec) const { |
| return getWasmSection(Sec).Type == wasm::WASM_SEC_DATA; |
| } |
| |
| bool WasmObjectFile::isSectionBSS(DataRefImpl Sec) const { return false; } |
| |
| bool WasmObjectFile::isSectionVirtual(DataRefImpl Sec) const { return false; } |
| |
| bool WasmObjectFile::isSectionBitcode(DataRefImpl Sec) const { return false; } |
| |
| relocation_iterator WasmObjectFile::section_rel_begin(DataRefImpl Ref) const { |
| DataRefImpl RelocRef; |
| RelocRef.d.a = Ref.d.a; |
| RelocRef.d.b = 0; |
| return relocation_iterator(RelocationRef(RelocRef, this)); |
| } |
| |
| relocation_iterator WasmObjectFile::section_rel_end(DataRefImpl Ref) const { |
| const WasmSection &Sec = getWasmSection(Ref); |
| DataRefImpl RelocRef; |
| RelocRef.d.a = Ref.d.a; |
| RelocRef.d.b = Sec.Relocations.size(); |
| return relocation_iterator(RelocationRef(RelocRef, this)); |
| } |
| |
| void WasmObjectFile::moveRelocationNext(DataRefImpl &Rel) const { Rel.d.b++; } |
| |
| uint64_t WasmObjectFile::getRelocationOffset(DataRefImpl Ref) const { |
| const wasm::WasmRelocation &Rel = getWasmRelocation(Ref); |
| return Rel.Offset; |
| } |
| |
| symbol_iterator WasmObjectFile::getRelocationSymbol(DataRefImpl Ref) const { |
| const wasm::WasmRelocation &Rel = getWasmRelocation(Ref); |
| if (Rel.Type == wasm::R_WASM_TYPE_INDEX_LEB) |
| return symbol_end(); |
| DataRefImpl Sym; |
| Sym.d.a = 1; |
| Sym.d.b = Rel.Index; |
| return symbol_iterator(SymbolRef(Sym, this)); |
| } |
| |
| uint64_t WasmObjectFile::getRelocationType(DataRefImpl Ref) const { |
| const wasm::WasmRelocation &Rel = getWasmRelocation(Ref); |
| return Rel.Type; |
| } |
| |
| void WasmObjectFile::getRelocationTypeName( |
| DataRefImpl Ref, SmallVectorImpl<char> &Result) const { |
| const wasm::WasmRelocation &Rel = getWasmRelocation(Ref); |
| StringRef Res = "Unknown"; |
| |
| #define WASM_RELOC(name, value) \ |
| case wasm::name: \ |
| Res = #name; \ |
| break; |
| |
| switch (Rel.Type) { |
| #include "llvm/BinaryFormat/WasmRelocs.def" |
| } |
| |
| #undef WASM_RELOC |
| |
| Result.append(Res.begin(), Res.end()); |
| } |
| |
| section_iterator WasmObjectFile::section_begin() const { |
| DataRefImpl Ref; |
| Ref.d.a = 0; |
| return section_iterator(SectionRef(Ref, this)); |
| } |
| |
| section_iterator WasmObjectFile::section_end() const { |
| DataRefImpl Ref; |
| Ref.d.a = Sections.size(); |
| return section_iterator(SectionRef(Ref, this)); |
| } |
| |
| uint8_t WasmObjectFile::getBytesInAddress() const { return 4; } |
| |
| StringRef WasmObjectFile::getFileFormatName() const { return "WASM"; } |
| |
| Triple::ArchType WasmObjectFile::getArch() const { return Triple::wasm32; } |
| |
| SubtargetFeatures WasmObjectFile::getFeatures() const { |
| return SubtargetFeatures(); |
| } |
| |
| bool WasmObjectFile::isRelocatableObject() const { return HasLinkingSection; } |
| |
| bool WasmObjectFile::isSharedObject() const { return HasDylinkSection; } |
| |
| const WasmSection &WasmObjectFile::getWasmSection(DataRefImpl Ref) const { |
| assert(Ref.d.a < Sections.size()); |
| return Sections[Ref.d.a]; |
| } |
| |
| const WasmSection & |
| WasmObjectFile::getWasmSection(const SectionRef &Section) const { |
| return getWasmSection(Section.getRawDataRefImpl()); |
| } |
| |
| const wasm::WasmRelocation & |
| WasmObjectFile::getWasmRelocation(const RelocationRef &Ref) const { |
| return getWasmRelocation(Ref.getRawDataRefImpl()); |
| } |
| |
| const wasm::WasmRelocation & |
| WasmObjectFile::getWasmRelocation(DataRefImpl Ref) const { |
| assert(Ref.d.a < Sections.size()); |
| const WasmSection &Sec = Sections[Ref.d.a]; |
| assert(Ref.d.b < Sec.Relocations.size()); |
| return Sec.Relocations[Ref.d.b]; |
| } |
| |
| int WasmSectionOrderChecker::getSectionOrder(unsigned ID, |
| StringRef CustomSectionName) { |
| switch (ID) { |
| case wasm::WASM_SEC_CUSTOM: |
| return StringSwitch<unsigned>(CustomSectionName) |
| .Case("dylink", WASM_SEC_ORDER_DYLINK) |
| .Case("linking", WASM_SEC_ORDER_LINKING) |
| .StartsWith("reloc.", WASM_SEC_ORDER_RELOC) |
| .Case("name", WASM_SEC_ORDER_NAME) |
| .Case("producers", WASM_SEC_ORDER_PRODUCERS) |
| .Case("target_features", WASM_SEC_ORDER_TARGET_FEATURES) |
| .Default(WASM_SEC_ORDER_NONE); |
| case wasm::WASM_SEC_TYPE: |
| return WASM_SEC_ORDER_TYPE; |
| case wasm::WASM_SEC_IMPORT: |
| return WASM_SEC_ORDER_IMPORT; |
| case wasm::WASM_SEC_FUNCTION: |
| return WASM_SEC_ORDER_FUNCTION; |
| case wasm::WASM_SEC_TABLE: |
| return WASM_SEC_ORDER_TABLE; |
| case wasm::WASM_SEC_MEMORY: |
| return WASM_SEC_ORDER_MEMORY; |
| case wasm::WASM_SEC_GLOBAL: |
| return WASM_SEC_ORDER_GLOBAL; |
| case wasm::WASM_SEC_EXPORT: |
| return WASM_SEC_ORDER_EXPORT; |
| case wasm::WASM_SEC_START: |
| return WASM_SEC_ORDER_START; |
| case wasm::WASM_SEC_ELEM: |
| return WASM_SEC_ORDER_ELEM; |
| case wasm::WASM_SEC_CODE: |
| return WASM_SEC_ORDER_CODE; |
| case wasm::WASM_SEC_DATA: |
| return WASM_SEC_ORDER_DATA; |
| case wasm::WASM_SEC_DATACOUNT: |
| return WASM_SEC_ORDER_DATACOUNT; |
| case wasm::WASM_SEC_EVENT: |
| return WASM_SEC_ORDER_EVENT; |
| default: |
| return WASM_SEC_ORDER_NONE; |
| } |
| } |
| |
| // Represents the edges in a directed graph where any node B reachable from node |
| // A is not allowed to appear before A in the section ordering, but may appear |
| // afterward. |
| int WasmSectionOrderChecker::DisallowedPredecessors[WASM_NUM_SEC_ORDERS][WASM_NUM_SEC_ORDERS] = { |
| {}, // WASM_SEC_ORDER_NONE |
| {WASM_SEC_ORDER_TYPE, WASM_SEC_ORDER_IMPORT}, // WASM_SEC_ORDER_TYPE, |
| {WASM_SEC_ORDER_IMPORT, WASM_SEC_ORDER_FUNCTION}, // WASM_SEC_ORDER_IMPORT, |
| {WASM_SEC_ORDER_FUNCTION, WASM_SEC_ORDER_TABLE}, // WASM_SEC_ORDER_FUNCTION, |
| {WASM_SEC_ORDER_TABLE, WASM_SEC_ORDER_MEMORY}, // WASM_SEC_ORDER_TABLE, |
| {WASM_SEC_ORDER_MEMORY, WASM_SEC_ORDER_GLOBAL}, // WASM_SEC_ORDER_MEMORY, |
| {WASM_SEC_ORDER_GLOBAL, WASM_SEC_ORDER_EVENT}, // WASM_SEC_ORDER_GLOBAL, |
| {WASM_SEC_ORDER_EVENT, WASM_SEC_ORDER_EXPORT}, // WASM_SEC_ORDER_EVENT, |
| {WASM_SEC_ORDER_EXPORT, WASM_SEC_ORDER_START}, // WASM_SEC_ORDER_EXPORT, |
| {WASM_SEC_ORDER_START, WASM_SEC_ORDER_ELEM}, // WASM_SEC_ORDER_START, |
| {WASM_SEC_ORDER_ELEM, WASM_SEC_ORDER_DATACOUNT}, // WASM_SEC_ORDER_ELEM, |
| {WASM_SEC_ORDER_DATACOUNT, WASM_SEC_ORDER_CODE}, // WASM_SEC_ORDER_DATACOUNT, |
| {WASM_SEC_ORDER_CODE, WASM_SEC_ORDER_DATA}, // WASM_SEC_ORDER_CODE, |
| {WASM_SEC_ORDER_DATA, WASM_SEC_ORDER_LINKING}, // WASM_SEC_ORDER_DATA, |
| |
| // Custom Sections |
| {WASM_SEC_ORDER_DYLINK, WASM_SEC_ORDER_TYPE}, // WASM_SEC_ORDER_DYLINK, |
| {WASM_SEC_ORDER_LINKING, WASM_SEC_ORDER_RELOC, WASM_SEC_ORDER_NAME}, // WASM_SEC_ORDER_LINKING, |
| {}, // WASM_SEC_ORDER_RELOC (can be repeated), |
| {WASM_SEC_ORDER_NAME, WASM_SEC_ORDER_PRODUCERS}, // WASM_SEC_ORDER_NAME, |
| {WASM_SEC_ORDER_PRODUCERS, WASM_SEC_ORDER_TARGET_FEATURES}, // WASM_SEC_ORDER_PRODUCERS, |
| {WASM_SEC_ORDER_TARGET_FEATURES} // WASM_SEC_ORDER_TARGET_FEATURES |
| }; |
| |
| bool WasmSectionOrderChecker::isValidSectionOrder(unsigned ID, |
| StringRef CustomSectionName) { |
| int Order = getSectionOrder(ID, CustomSectionName); |
| if (Order == WASM_SEC_ORDER_NONE) |
| return true; |
| |
| // Disallowed predecessors we need to check for |
| SmallVector<int, WASM_NUM_SEC_ORDERS> WorkList; |
| |
| // Keep track of completed checks to avoid repeating work |
| bool Checked[WASM_NUM_SEC_ORDERS] = {}; |
| |
| int Curr = Order; |
| while (true) { |
| // Add new disallowed predecessors to work list |
| for (size_t I = 0;; ++I) { |
| int Next = DisallowedPredecessors[Curr][I]; |
| if (Next == WASM_SEC_ORDER_NONE) |
| break; |
| if (Checked[Next]) |
| continue; |
| WorkList.push_back(Next); |
| Checked[Next] = true; |
| } |
| |
| if (WorkList.empty()) |
| break; |
| |
| // Consider next disallowed predecessor |
| Curr = WorkList.pop_back_val(); |
| if (Seen[Curr]) |
| return false; |
| } |
| |
| // Have not seen any disallowed predecessors |
| Seen[Order] = true; |
| return true; |
| } |
