include/llvm/Object/Wasm.h

   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/master/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/StringMap.h"
  21 #include "llvm/ADT/StringRef.h"
  22 #include "llvm/BinaryFormat/Wasm.h"
  23 #include "llvm/Config/llvm-config.h"
  24 #include "llvm/MC/MCSymbolWasm.h"
  25 #include "llvm/Object/Binary.h"
  26 #include "llvm/Object/ObjectFile.h"
  27 #include "llvm/Support/Error.h"
  28 #include "llvm/Support/MemoryBuffer.h"
  29 #include <cstddef>
  30 #include <cstdint>
  31 #include <vector>
  32
  33 namespace llvm {
  34 namespace object {
  35
  36 class WasmSymbol {
  37 public:
  38   WasmSymbol(const wasm::WasmSymbolInfo &Info,
  39              const wasm::WasmGlobalType *GlobalType,
  40              const wasm::WasmEventType *EventType,
  41              const wasm::WasmSignature *Signature)
  42       : Info(Info), GlobalType(GlobalType), EventType(EventType),
  43         Signature(Signature) {}
  44
  45   const wasm::WasmSymbolInfo &Info;
  46   const wasm::WasmGlobalType *GlobalType;
  47   const wasm::WasmEventType *EventType;
  48   const wasm::WasmSignature *Signature;
  49
  50   bool isTypeFunction() const {
  51     return Info.Kind == wasm::WASM_SYMBOL_TYPE_FUNCTION;
  52   }
  53
  54   bool isTypeData() const { return Info.Kind == wasm::WASM_SYMBOL_TYPE_DATA; }
  55
  56   bool isTypeGlobal() const {
  57     return Info.Kind == wasm::WASM_SYMBOL_TYPE_GLOBAL;
  58   }
  59
  60   bool isTypeSection() const {
  61     return Info.Kind == wasm::WASM_SYMBOL_TYPE_SECTION;
  62   }
  63
  64   bool isTypeEvent() const { return Info.Kind == wasm::WASM_SYMBOL_TYPE_EVENT; }
  65
  66   bool isDefined() const { return !isUndefined(); }
  67
  68   bool isUndefined() const {
  69     return (Info.Flags & wasm::WASM_SYMBOL_UNDEFINED) != 0;
  70   }
  71
  72   bool isBindingWeak() const {
  73     return getBinding() == wasm::WASM_SYMBOL_BINDING_WEAK;
  74   }
  75
  76   bool isBindingGlobal() const {
  77     return getBinding() == wasm::WASM_SYMBOL_BINDING_GLOBAL;
  78   }
  79
  80   bool isBindingLocal() const {
  81     return getBinding() == wasm::WASM_SYMBOL_BINDING_LOCAL;
  82   }
  83
  84   unsigned getBinding() const {
  85     return Info.Flags & wasm::WASM_SYMBOL_BINDING_MASK;
  86   }
  87
  88   bool isHidden() const {
  89     return getVisibility() == wasm::WASM_SYMBOL_VISIBILITY_HIDDEN;
  90   }
  91
  92   unsigned getVisibility() const {
  93     return Info.Flags & wasm::WASM_SYMBOL_VISIBILITY_MASK;
  94   }
  95
  96   void print(raw_ostream &Out) const;
  97
  98 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
  99   LLVM_DUMP_METHOD void dump() const;
 100 #endif
 101 };
 102
 103 struct WasmSection {
 104   WasmSection() = default;
 105
 106   uint32_t Type = 0;         // Section type (See below)
 107   uint32_t Offset = 0;       // Offset with in the file
 108   StringRef Name;            // Section name (User-defined sections only)
 109   ArrayRef<uint8_t> Content; // Section content
 110   std::vector<wasm::WasmRelocation> Relocations; // Relocations for this section
 111 };
 112
 113 struct WasmSegment {
 114   uint32_t SectionOffset;
 115   wasm::WasmDataSegment Data;
 116 };
 117
 118 class WasmObjectFile : public ObjectFile {
 119
 120 public:
 121   WasmObjectFile(MemoryBufferRef Object, Error &Err);
 122
 123   const wasm::WasmObjectHeader &getHeader() const;
 124   const WasmSymbol &getWasmSymbol(const DataRefImpl &Symb) const;
 125   const WasmSymbol &getWasmSymbol(const SymbolRef &Symbol) const;
 126   const WasmSection &getWasmSection(const SectionRef &Section) const;
 127   const wasm::WasmRelocation &getWasmRelocation(const RelocationRef &Ref) const;
 128
 129   static bool classof(const Binary *v) { return v->isWasm(); }
 130
 131   const wasm::WasmDylinkInfo &dylinkInfo() const { return DylinkInfo; }
 132   const wasm::WasmProducerInfo &getProducerInfo() const { return ProducerInfo; }
 133   ArrayRef<wasm::WasmSignature> types() const { return Signatures; }
 134   ArrayRef<uint32_t> functionTypes() const { return FunctionTypes; }
 135   ArrayRef<wasm::WasmImport> imports() const { return Imports; }
 136   ArrayRef<wasm::WasmTable> tables() const { return Tables; }
 137   ArrayRef<wasm::WasmLimits> memories() const { return Memories; }
 138   ArrayRef<wasm::WasmGlobal> globals() const { return Globals; }
 139   ArrayRef<wasm::WasmEvent> events() const { return Events; }
 140   ArrayRef<wasm::WasmExport> exports() const { return Exports; }
 141   ArrayRef<WasmSymbol> syms() const { return Symbols; }
 142   const wasm::WasmLinkingData &linkingData() const { return LinkingData; }
 143   uint32_t getNumberOfSymbols() const { return Symbols.size(); }
 144   ArrayRef<wasm::WasmElemSegment> elements() const { return ElemSegments; }
 145   ArrayRef<WasmSegment> dataSegments() const { return DataSegments; }
 146   ArrayRef<wasm::WasmFunction> functions() const { return Functions; }
 147   ArrayRef<wasm::WasmFunctionName> debugNames() const { return DebugNames; }
 148   uint32_t startFunction() const { return StartFunction; }
 149   uint32_t getNumImportedGlobals() const { return NumImportedGlobals; }
 150   uint32_t getNumImportedFunctions() const { return NumImportedFunctions; }
 151   uint32_t getNumImportedEvents() const { return NumImportedEvents; }
 152   void moveSymbolNext(DataRefImpl &Symb) const override;
 153
 154   uint32_t getSymbolFlags(DataRefImpl Symb) const override;
 155
 156   basic_symbol_iterator symbol_begin() const override;
 157
 158   basic_symbol_iterator symbol_end() const override;
 159   Expected<StringRef> getSymbolName(DataRefImpl Symb) const override;
 160
 161   Expected<uint64_t> getSymbolAddress(DataRefImpl Symb) const override;
 162   uint64_t getWasmSymbolValue(const WasmSymbol &Sym) const;
 163   uint64_t getSymbolValueImpl(DataRefImpl Symb) const override;
 164   uint32_t getSymbolAlignment(DataRefImpl Symb) const override;
 165   uint64_t getCommonSymbolSizeImpl(DataRefImpl Symb) const override;
 166   Expected<SymbolRef::Type> getSymbolType(DataRefImpl Symb) const override;
 167   Expected<section_iterator> getSymbolSection(DataRefImpl Symb) const override;
 168
 169   // Overrides from SectionRef.
 170   void moveSectionNext(DataRefImpl &Sec) const override;
 171   std::error_code getSectionName(DataRefImpl Sec,
 172                                  StringRef &Res) const override;
 173   uint64_t getSectionAddress(DataRefImpl Sec) const override;
 174   uint64_t getSectionIndex(DataRefImpl Sec) const override;
 175   uint64_t getSectionSize(DataRefImpl Sec) const override;
 176   std::error_code getSectionContents(DataRefImpl Sec,
 177                                      StringRef &Res) const override;
 178   uint64_t getSectionAlignment(DataRefImpl Sec) const override;
 179   bool isSectionCompressed(DataRefImpl Sec) const override;
 180   bool isSectionText(DataRefImpl Sec) const override;
 181   bool isSectionData(DataRefImpl Sec) const override;
 182   bool isSectionBSS(DataRefImpl Sec) const override;
 183   bool isSectionVirtual(DataRefImpl Sec) const override;
 184   bool isSectionBitcode(DataRefImpl Sec) const override;
 185   relocation_iterator section_rel_begin(DataRefImpl Sec) const override;
 186   relocation_iterator section_rel_end(DataRefImpl Sec) const override;
 187
 188   // Overrides from RelocationRef.
 189   void moveRelocationNext(DataRefImpl &Rel) const override;
 190   uint64_t getRelocationOffset(DataRefImpl Rel) const override;
 191   symbol_iterator getRelocationSymbol(DataRefImpl Rel) const override;
 192   uint64_t getRelocationType(DataRefImpl Rel) const override;
 193   void getRelocationTypeName(DataRefImpl Rel,
 194                              SmallVectorImpl<char> &Result) const override;
 195
 196   section_iterator section_begin() const override;
 197   section_iterator section_end() const override;
 198   uint8_t getBytesInAddress() const override;
 199   StringRef getFileFormatName() const override;
 200   Triple::ArchType getArch() const override;
 201   SubtargetFeatures getFeatures() const override;
 202   bool isRelocatableObject() const override;
 203   bool isSharedObject() const;
 204
 205   struct ReadContext {
 206     const uint8_t *Start;
 207     const uint8_t *Ptr;
 208     const uint8_t *End;
 209   };
 210
 211 private:
 212   bool isValidFunctionIndex(uint32_t Index) const;
 213   bool isDefinedFunctionIndex(uint32_t Index) const;
 214   bool isValidGlobalIndex(uint32_t Index) const;
 215   bool isDefinedGlobalIndex(uint32_t Index) const;
 216   bool isValidEventIndex(uint32_t Index) const;
 217   bool isDefinedEventIndex(uint32_t Index) const;
 218   bool isValidFunctionSymbol(uint32_t Index) const;
 219   bool isValidGlobalSymbol(uint32_t Index) const;
 220   bool isValidEventSymbol(uint32_t Index) const;
 221   bool isValidDataSymbol(uint32_t Index) const;
 222   bool isValidSectionSymbol(uint32_t Index) const;
 223   wasm::WasmFunction &getDefinedFunction(uint32_t Index);
 224   const wasm::WasmFunction &getDefinedFunction(uint32_t Index) const;
 225   wasm::WasmGlobal &getDefinedGlobal(uint32_t Index);
 226   wasm::WasmEvent &getDefinedEvent(uint32_t Index);
 227
 228   const WasmSection &getWasmSection(DataRefImpl Ref) const;
 229   const wasm::WasmRelocation &getWasmRelocation(DataRefImpl Ref) const;
 230
 231   Error parseSection(WasmSection &Sec);
 232   Error parseCustomSection(WasmSection &Sec, ReadContext &Ctx);
 233
 234   // Standard section types
 235   Error parseTypeSection(ReadContext &Ctx);
 236   Error parseImportSection(ReadContext &Ctx);
 237   Error parseFunctionSection(ReadContext &Ctx);
 238   Error parseTableSection(ReadContext &Ctx);
 239   Error parseMemorySection(ReadContext &Ctx);
 240   Error parseGlobalSection(ReadContext &Ctx);
 241   Error parseEventSection(ReadContext &Ctx);
 242   Error parseExportSection(ReadContext &Ctx);
 243   Error parseStartSection(ReadContext &Ctx);
 244   Error parseElemSection(ReadContext &Ctx);
 245   Error parseCodeSection(ReadContext &Ctx);
 246   Error parseDataSection(ReadContext &Ctx);
 247
 248   // Custom section types
 249   Error parseDylinkSection(ReadContext &Ctx);
 250   Error parseNameSection(ReadContext &Ctx);
 251   Error parseLinkingSection(ReadContext &Ctx);
 252   Error parseLinkingSectionSymtab(ReadContext &Ctx);
 253   Error parseLinkingSectionComdat(ReadContext &Ctx);
 254   Error parseProducersSection(ReadContext &Ctx);
 255   Error parseRelocSection(StringRef Name, ReadContext &Ctx);
 256
 257   wasm::WasmObjectHeader Header;
 258   std::vector<WasmSection> Sections;
 259   wasm::WasmDylinkInfo DylinkInfo;
 260   wasm::WasmProducerInfo ProducerInfo;
 261   std::vector<wasm::WasmSignature> Signatures;
 262   std::vector<uint32_t> FunctionTypes;
 263   std::vector<wasm::WasmTable> Tables;
 264   std::vector<wasm::WasmLimits> Memories;
 265   std::vector<wasm::WasmGlobal> Globals;
 266   std::vector<wasm::WasmEvent> Events;
 267   std::vector<wasm::WasmImport> Imports;
 268   std::vector<wasm::WasmExport> Exports;
 269   std::vector<wasm::WasmElemSegment> ElemSegments;
 270   std::vector<WasmSegment> DataSegments;
 271   std::vector<wasm::WasmFunction> Functions;
 272   std::vector<WasmSymbol> Symbols;
 273   std::vector<wasm::WasmFunctionName> DebugNames;
 274   uint32_t StartFunction = -1;
 275   bool HasLinkingSection = false;
 276   bool HasDylinkSection = false;
 277   wasm::WasmLinkingData LinkingData;
 278   uint32_t NumImportedGlobals = 0;
 279   uint32_t NumImportedFunctions = 0;
 280   uint32_t NumImportedEvents = 0;
 281   uint32_t CodeSection = 0;
 282   uint32_t DataSection = 0;
 283   uint32_t GlobalSection = 0;
 284   uint32_t EventSection = 0;
 285 };
 286
 287 class WasmSectionOrderChecker {
 288 public:
 289   // We define orders for all core wasm sections and known custom sections.
 290   enum : int {
 291     // Core sections
 292     // The order of standard sections is precisely given by the spec.
 293     WASM_SEC_ORDER_TYPE = 1,
 294     WASM_SEC_ORDER_IMPORT = 2,
 295     WASM_SEC_ORDER_FUNCTION = 3,
 296     WASM_SEC_ORDER_TABLE = 4,
 297     WASM_SEC_ORDER_MEMORY = 5,
 298     WASM_SEC_ORDER_GLOBAL = 6,
 299     WASM_SEC_ORDER_EVENT = 7,
 300     WASM_SEC_ORDER_EXPORT = 8,
 301     WASM_SEC_ORDER_START = 9,
 302     WASM_SEC_ORDER_ELEM = 10,
 303     WASM_SEC_ORDER_DATACOUNT = 11,
 304     WASM_SEC_ORDER_CODE = 12,
 305     WASM_SEC_ORDER_DATA = 13,
 306
 307     // Custom sections
 308     // "dylink" should be the very first section in the module
 309     WASM_SEC_ORDER_DYLINK = 0,
 310     // "linking" section requires DATA section in order to validate data symbols
 311     WASM_SEC_ORDER_LINKING = 100,
 312     // Must come after "linking" section in order to validate reloc indexes.
 313     WASM_SEC_ORDER_RELOC = 101,
 314     // "name" section must appear after DATA. Comes after "linking" to allow
 315     // symbol table to set default function name.
 316     WASM_SEC_ORDER_NAME = 102,
 317     // "producers" section must appear after "name" section.
 318     WASM_SEC_ORDER_PRODUCERS = 103
 319   };
 320
 321   bool isValidSectionOrder(unsigned ID, StringRef CustomSectionName = "");
 322
 323 private:
 324   int LastOrder = -1; // Lastly seen known section's order
 325
 326   // Returns -1 for unknown sections.
 327   int getSectionOrder(unsigned ID, StringRef CustomSectionName = "");
 328 };
 329
 330 } // end namespace object
 331
 332 inline raw_ostream &operator<<(raw_ostream &OS, const object::WasmSymbol &Sym) {
 333   Sym.print(OS);
 334   return OS;
 335 }
 336
 337 } // end namespace llvm
 338
 339 #endif // LLVM_OBJECT_WASM_H