1 //===- Wasm.h - Wasm object file implementation -----------------*- C++ -*-===// 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 // This file declares the WasmObjectFile class, which implements the ObjectFile 10 // interface for Wasm files. 11 // 12 // See: https://github.com/WebAssembly/design/blob/main/BinaryEncoding.md 13 // 14 //===----------------------------------------------------------------------===// 15 16 #ifndef LLVM_OBJECT_WASM_H 17 #define LLVM_OBJECT_WASM_H 18 19 #include "llvm/ADT/ArrayRef.h" 20 #include "llvm/ADT/StringRef.h" 21 #include "llvm/BinaryFormat/Wasm.h" 22 #include "llvm/Config/llvm-config.h" 23 #include "llvm/MC/MCSymbolWasm.h" 24 #include "llvm/Object/Binary.h" 25 #include "llvm/Object/ObjectFile.h" 26 #include "llvm/Support/Error.h" 27 #include "llvm/Support/MemoryBuffer.h" 28 #include <cstddef> 29 #include <cstdint> 30 #include <vector> 31 32 namespace llvm { 33 namespace object { 34 35 class WasmSymbol { 36 public: WasmSymbol(const wasm::WasmSymbolInfo & Info,const wasm::WasmGlobalType * GlobalType,const wasm::WasmTableType * TableType,const wasm::WasmSignature * Signature)37 WasmSymbol(const wasm::WasmSymbolInfo &Info, 38 const wasm::WasmGlobalType *GlobalType, 39 const wasm::WasmTableType *TableType, 40 const wasm::WasmSignature *Signature) 41 : Info(Info), GlobalType(GlobalType), TableType(TableType), 42 Signature(Signature) {} 43 44 const wasm::WasmSymbolInfo &Info; 45 const wasm::WasmGlobalType *GlobalType; 46 const wasm::WasmTableType *TableType; 47 const wasm::WasmSignature *Signature; 48 isTypeFunction()49 bool isTypeFunction() const { 50 return Info.Kind == wasm::WASM_SYMBOL_TYPE_FUNCTION; 51 } 52 isTypeTable()53 bool isTypeTable() const { return Info.Kind == wasm::WASM_SYMBOL_TYPE_TABLE; } 54 isTypeData()55 bool isTypeData() const { return Info.Kind == wasm::WASM_SYMBOL_TYPE_DATA; } 56 isTypeGlobal()57 bool isTypeGlobal() const { 58 return Info.Kind == wasm::WASM_SYMBOL_TYPE_GLOBAL; 59 } 60 isTypeSection()61 bool isTypeSection() const { 62 return Info.Kind == wasm::WASM_SYMBOL_TYPE_SECTION; 63 } 64 isTypeTag()65 bool isTypeTag() const { return Info.Kind == wasm::WASM_SYMBOL_TYPE_TAG; } 66 isDefined()67 bool isDefined() const { return !isUndefined(); } 68 isUndefined()69 bool isUndefined() const { 70 return (Info.Flags & wasm::WASM_SYMBOL_UNDEFINED) != 0; 71 } 72 isBindingWeak()73 bool isBindingWeak() const { 74 return getBinding() == wasm::WASM_SYMBOL_BINDING_WEAK; 75 } 76 isBindingGlobal()77 bool isBindingGlobal() const { 78 return getBinding() == wasm::WASM_SYMBOL_BINDING_GLOBAL; 79 } 80 isBindingLocal()81 bool isBindingLocal() const { 82 return getBinding() == wasm::WASM_SYMBOL_BINDING_LOCAL; 83 } 84 getBinding()85 unsigned getBinding() const { 86 return Info.Flags & wasm::WASM_SYMBOL_BINDING_MASK; 87 } 88 isHidden()89 bool isHidden() const { 90 return getVisibility() == wasm::WASM_SYMBOL_VISIBILITY_HIDDEN; 91 } 92 getVisibility()93 unsigned getVisibility() const { 94 return Info.Flags & wasm::WASM_SYMBOL_VISIBILITY_MASK; 95 } 96 97 void print(raw_ostream &Out) const; 98 99 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP) 100 LLVM_DUMP_METHOD void dump() const; 101 #endif 102 }; 103 104 struct WasmSection { 105 WasmSection() = default; 106 107 uint32_t Type = 0; // Section type (See below) 108 uint32_t Offset = 0; // Offset with in the file 109 StringRef Name; // Section name (User-defined sections only) 110 uint32_t Comdat = UINT32_MAX; // From the "comdat info" section 111 ArrayRef<uint8_t> Content; // Section content 112 std::vector<wasm::WasmRelocation> Relocations; // Relocations for this section 113 }; 114 115 struct WasmSegment { 116 uint32_t SectionOffset; 117 wasm::WasmDataSegment Data; 118 }; 119 120 class WasmObjectFile : public ObjectFile { 121 122 public: 123 WasmObjectFile(MemoryBufferRef Object, Error &Err); 124 125 const wasm::WasmObjectHeader &getHeader() const; 126 const WasmSymbol &getWasmSymbol(const DataRefImpl &Symb) const; 127 const WasmSymbol &getWasmSymbol(const SymbolRef &Symbol) const; 128 const WasmSection &getWasmSection(const SectionRef &Section) const; 129 const wasm::WasmRelocation &getWasmRelocation(const RelocationRef &Ref) const; 130 classof(const Binary * v)131 static bool classof(const Binary *v) { return v->isWasm(); } 132 dylinkInfo()133 const wasm::WasmDylinkInfo &dylinkInfo() const { return DylinkInfo; } getProducerInfo()134 const wasm::WasmProducerInfo &getProducerInfo() const { return ProducerInfo; } getTargetFeatures()135 ArrayRef<wasm::WasmFeatureEntry> getTargetFeatures() const { 136 return TargetFeatures; 137 } types()138 ArrayRef<wasm::WasmSignature> types() const { return Signatures; } imports()139 ArrayRef<wasm::WasmImport> imports() const { return Imports; } tables()140 ArrayRef<wasm::WasmTable> tables() const { return Tables; } memories()141 ArrayRef<wasm::WasmLimits> memories() const { return Memories; } globals()142 ArrayRef<wasm::WasmGlobal> globals() const { return Globals; } tags()143 ArrayRef<wasm::WasmTag> tags() const { return Tags; } exports()144 ArrayRef<wasm::WasmExport> exports() const { return Exports; } syms()145 ArrayRef<WasmSymbol> syms() const { return Symbols; } linkingData()146 const wasm::WasmLinkingData &linkingData() const { return LinkingData; } getNumberOfSymbols()147 uint32_t getNumberOfSymbols() const { return Symbols.size(); } elements()148 ArrayRef<wasm::WasmElemSegment> elements() const { return ElemSegments; } dataSegments()149 ArrayRef<WasmSegment> dataSegments() const { return DataSegments; } functions()150 ArrayRef<wasm::WasmFunction> functions() const { return Functions; } debugNames()151 ArrayRef<wasm::WasmDebugName> debugNames() const { return DebugNames; } startFunction()152 uint32_t startFunction() const { return StartFunction; } getNumImportedGlobals()153 uint32_t getNumImportedGlobals() const { return NumImportedGlobals; } getNumImportedTables()154 uint32_t getNumImportedTables() const { return NumImportedTables; } getNumImportedFunctions()155 uint32_t getNumImportedFunctions() const { return NumImportedFunctions; } getNumImportedTags()156 uint32_t getNumImportedTags() const { return NumImportedTags; } getNumSections()157 uint32_t getNumSections() const { return Sections.size(); } 158 void moveSymbolNext(DataRefImpl &Symb) const override; 159 160 Expected<uint32_t> getSymbolFlags(DataRefImpl Symb) const override; 161 162 basic_symbol_iterator symbol_begin() const override; 163 164 basic_symbol_iterator symbol_end() const override; 165 Expected<StringRef> getSymbolName(DataRefImpl Symb) const override; 166 167 Expected<uint64_t> getSymbolAddress(DataRefImpl Symb) const override; 168 uint64_t getWasmSymbolValue(const WasmSymbol &Sym) const; 169 uint64_t getSymbolValueImpl(DataRefImpl Symb) const override; 170 uint32_t getSymbolAlignment(DataRefImpl Symb) const override; 171 uint64_t getCommonSymbolSizeImpl(DataRefImpl Symb) const override; 172 Expected<SymbolRef::Type> getSymbolType(DataRefImpl Symb) const override; 173 Expected<section_iterator> getSymbolSection(DataRefImpl Symb) const override; 174 uint32_t getSymbolSectionId(SymbolRef Sym) const; 175 176 // Overrides from SectionRef. 177 void moveSectionNext(DataRefImpl &Sec) const override; 178 Expected<StringRef> getSectionName(DataRefImpl Sec) const override; 179 uint64_t getSectionAddress(DataRefImpl Sec) const override; 180 uint64_t getSectionIndex(DataRefImpl Sec) const override; 181 uint64_t getSectionSize(DataRefImpl Sec) const override; 182 Expected<ArrayRef<uint8_t>> 183 getSectionContents(DataRefImpl Sec) const override; 184 uint64_t getSectionAlignment(DataRefImpl Sec) const override; 185 bool isSectionCompressed(DataRefImpl Sec) const override; 186 bool isSectionText(DataRefImpl Sec) const override; 187 bool isSectionData(DataRefImpl Sec) const override; 188 bool isSectionBSS(DataRefImpl Sec) const override; 189 bool isSectionVirtual(DataRefImpl Sec) const override; 190 relocation_iterator section_rel_begin(DataRefImpl Sec) const override; 191 relocation_iterator section_rel_end(DataRefImpl Sec) const override; 192 193 // Overrides from RelocationRef. 194 void moveRelocationNext(DataRefImpl &Rel) const override; 195 uint64_t getRelocationOffset(DataRefImpl Rel) const override; 196 symbol_iterator getRelocationSymbol(DataRefImpl Rel) const override; 197 uint64_t getRelocationType(DataRefImpl Rel) const override; 198 void getRelocationTypeName(DataRefImpl Rel, 199 SmallVectorImpl<char> &Result) const override; 200 201 section_iterator section_begin() const override; 202 section_iterator section_end() const override; 203 uint8_t getBytesInAddress() const override; 204 StringRef getFileFormatName() const override; 205 Triple::ArchType getArch() const override; 206 Expected<SubtargetFeatures> getFeatures() const override; 207 bool isRelocatableObject() const override; 208 bool isSharedObject() const; 209 210 struct ReadContext { 211 const uint8_t *Start; 212 const uint8_t *Ptr; 213 const uint8_t *End; 214 }; 215 216 private: 217 bool isValidFunctionIndex(uint32_t Index) const; 218 bool isDefinedFunctionIndex(uint32_t Index) const; 219 bool isValidGlobalIndex(uint32_t Index) const; 220 bool isValidTableNumber(uint32_t Index) const; 221 bool isDefinedGlobalIndex(uint32_t Index) const; 222 bool isDefinedTableNumber(uint32_t Index) const; 223 bool isValidTagIndex(uint32_t Index) const; 224 bool isDefinedTagIndex(uint32_t Index) const; 225 bool isValidFunctionSymbol(uint32_t Index) const; 226 bool isValidTableSymbol(uint32_t Index) const; 227 bool isValidGlobalSymbol(uint32_t Index) const; 228 bool isValidTagSymbol(uint32_t Index) const; 229 bool isValidDataSymbol(uint32_t Index) const; 230 bool isValidSectionSymbol(uint32_t Index) const; 231 wasm::WasmFunction &getDefinedFunction(uint32_t Index); 232 const wasm::WasmFunction &getDefinedFunction(uint32_t Index) const; 233 wasm::WasmGlobal &getDefinedGlobal(uint32_t Index); 234 wasm::WasmTag &getDefinedTag(uint32_t Index); 235 236 const WasmSection &getWasmSection(DataRefImpl Ref) const; 237 const wasm::WasmRelocation &getWasmRelocation(DataRefImpl Ref) const; 238 uint32_t getSymbolSectionIdImpl(const WasmSymbol &Symb) const; 239 240 Error parseSection(WasmSection &Sec); 241 Error parseCustomSection(WasmSection &Sec, ReadContext &Ctx); 242 243 // Standard section types 244 Error parseTypeSection(ReadContext &Ctx); 245 Error parseImportSection(ReadContext &Ctx); 246 Error parseFunctionSection(ReadContext &Ctx); 247 Error parseTableSection(ReadContext &Ctx); 248 Error parseMemorySection(ReadContext &Ctx); 249 Error parseTagSection(ReadContext &Ctx); 250 Error parseGlobalSection(ReadContext &Ctx); 251 Error parseExportSection(ReadContext &Ctx); 252 Error parseStartSection(ReadContext &Ctx); 253 Error parseElemSection(ReadContext &Ctx); 254 Error parseCodeSection(ReadContext &Ctx); 255 Error parseDataSection(ReadContext &Ctx); 256 Error parseDataCountSection(ReadContext &Ctx); 257 258 // Custom section types 259 Error parseDylinkSection(ReadContext &Ctx); 260 Error parseDylink0Section(ReadContext &Ctx); 261 Error parseNameSection(ReadContext &Ctx); 262 Error parseLinkingSection(ReadContext &Ctx); 263 Error parseLinkingSectionSymtab(ReadContext &Ctx); 264 Error parseLinkingSectionComdat(ReadContext &Ctx); 265 Error parseProducersSection(ReadContext &Ctx); 266 Error parseTargetFeaturesSection(ReadContext &Ctx); 267 Error parseRelocSection(StringRef Name, ReadContext &Ctx); 268 269 wasm::WasmObjectHeader Header; 270 std::vector<WasmSection> Sections; 271 wasm::WasmDylinkInfo DylinkInfo; 272 wasm::WasmProducerInfo ProducerInfo; 273 std::vector<wasm::WasmFeatureEntry> TargetFeatures; 274 std::vector<wasm::WasmSignature> Signatures; 275 std::vector<wasm::WasmTable> Tables; 276 std::vector<wasm::WasmLimits> Memories; 277 std::vector<wasm::WasmGlobal> Globals; 278 std::vector<wasm::WasmTag> Tags; 279 std::vector<wasm::WasmImport> Imports; 280 std::vector<wasm::WasmExport> Exports; 281 std::vector<wasm::WasmElemSegment> ElemSegments; 282 std::vector<WasmSegment> DataSegments; 283 std::optional<size_t> DataCount; 284 std::vector<wasm::WasmFunction> Functions; 285 std::vector<WasmSymbol> Symbols; 286 std::vector<wasm::WasmDebugName> DebugNames; 287 uint32_t StartFunction = -1; 288 bool HasLinkingSection = false; 289 bool HasDylinkSection = false; 290 bool HasMemory64 = false; 291 wasm::WasmLinkingData LinkingData; 292 uint32_t NumImportedGlobals = 0; 293 uint32_t NumImportedTables = 0; 294 uint32_t NumImportedFunctions = 0; 295 uint32_t NumImportedTags = 0; 296 uint32_t CodeSection = 0; 297 uint32_t DataSection = 0; 298 uint32_t TagSection = 0; 299 uint32_t GlobalSection = 0; 300 uint32_t TableSection = 0; 301 }; 302 303 class WasmSectionOrderChecker { 304 public: 305 // We define orders for all core wasm sections and known custom sections. 306 enum : int { 307 // Sentinel, must be zero 308 WASM_SEC_ORDER_NONE = 0, 309 310 // Core sections 311 WASM_SEC_ORDER_TYPE, 312 WASM_SEC_ORDER_IMPORT, 313 WASM_SEC_ORDER_FUNCTION, 314 WASM_SEC_ORDER_TABLE, 315 WASM_SEC_ORDER_MEMORY, 316 WASM_SEC_ORDER_TAG, 317 WASM_SEC_ORDER_GLOBAL, 318 WASM_SEC_ORDER_EXPORT, 319 WASM_SEC_ORDER_START, 320 WASM_SEC_ORDER_ELEM, 321 WASM_SEC_ORDER_DATACOUNT, 322 WASM_SEC_ORDER_CODE, 323 WASM_SEC_ORDER_DATA, 324 325 // Custom sections 326 // "dylink" should be the very first section in the module 327 WASM_SEC_ORDER_DYLINK, 328 // "linking" section requires DATA section in order to validate data symbols 329 WASM_SEC_ORDER_LINKING, 330 // Must come after "linking" section in order to validate reloc indexes. 331 WASM_SEC_ORDER_RELOC, 332 // "name" section must appear after DATA. Comes after "linking" to allow 333 // symbol table to set default function name. 334 WASM_SEC_ORDER_NAME, 335 // "producers" section must appear after "name" section. 336 WASM_SEC_ORDER_PRODUCERS, 337 // "target_features" section must appear after producers section 338 WASM_SEC_ORDER_TARGET_FEATURES, 339 340 // Must be last 341 WASM_NUM_SEC_ORDERS 342 343 }; 344 345 // Sections that may or may not be present, but cannot be predecessors 346 static int DisallowedPredecessors[WASM_NUM_SEC_ORDERS][WASM_NUM_SEC_ORDERS]; 347 348 bool isValidSectionOrder(unsigned ID, StringRef CustomSectionName = ""); 349 350 private: 351 bool Seen[WASM_NUM_SEC_ORDERS] = {}; // Sections that have been seen already 352 353 // Returns -1 for unknown sections. 354 int getSectionOrder(unsigned ID, StringRef CustomSectionName = ""); 355 }; 356 357 } // end namespace object 358 359 inline raw_ostream &operator<<(raw_ostream &OS, const object::WasmSymbol &Sym) { 360 Sym.print(OS); 361 return OS; 362 } 363 364 } // end namespace llvm 365 366 #endif // LLVM_OBJECT_WASM_H 367