[WebAssembly] Rename symbols types in preparation to adding wasm globals. NFC.

[sbc100]

Summary

Purely a rename, no functional change.

We want to use GlobalSymbol to represent real wasm globals and
DataSymbol for pointers to things in linear memory (what ELF would
call STT_OBJECT).

This reduces the size the patch to add the explicit symbol table
which is coming soon!

[ruiu]

LGTM

wasm/Driver.cpp

void LinkerDriver::link(ArrayRef<const char *> ArgsArr) {
 
   Symbol *EntrySym = nullptr;
   if (!Config->Relocatable) {
     static WasmSignature NullSignature = {{}, WASM_TYPE_NORESULT};
 
     // Add synthetic symbols before any others
     WasmSym::CallCtors = Symtab->addSyntheticFunction(
         "__wasm_call_ctors", &NullSignature, WASM_SYMBOL_VISIBILITY_HIDDEN);
-    WasmSym::StackPointer = Symtab->addSyntheticGlobal("__stack_pointer");
-    WasmSym::HeapBase = Symtab->addSyntheticGlobal("__heap_base");
-    WasmSym::DsoHandle = Symtab->addSyntheticGlobal("__dso_handle");
-    WasmSym::DataEnd = Symtab->addSyntheticGlobal("__data_end");
+    WasmSym::StackPointer = Symtab->addSyntheticDataSymbol("__stack_pointer");
+    WasmSym::HeapBase = Symtab->addSyntheticDataSymbol("__heap_base");
+    WasmSym::DsoHandle = Symtab->addSyntheticDataSymbol("__dso_handle");
+    WasmSym::DataEnd = Symtab->addSyntheticDataSymbol("__data_end");
 
     if (!Config->Entry.empty())
       EntrySym = addUndefinedFunction(Config->Entry, &NullSignature);
 
     // Handle the `--undefined <sym>` options.
     for (auto* Arg : Args.filtered(OPT_undefined))
       addUndefinedFunction(Arg->getValue(), nullptr);
   }

wasm/InputFiles.h

public:
   std::vector<InputFunction *> Functions;
 
   ArrayRef<Symbol *> getSymbols() const { return Symbols; }
 
   FunctionSymbol *getFunctionSymbol(uint32_t Index) const {
     return cast<FunctionSymbol>(FunctionSymbols[Index]);
   }
 
-  GlobalSymbol *getGlobalSymbol(uint32_t Index) const {
-    return cast<GlobalSymbol>(GlobalSymbols[Index]);
+  DataSymbol *getDataSymbol(uint32_t Index) const {
+    return cast<DataSymbol>(DataSymbols[Index]);
   }
 
 private:
   uint32_t relocateVirtualAddress(uint32_t Index) const;
   uint32_t relocateTypeIndex(uint32_t Original) const;
   uint32_t relocateGlobalIndex(uint32_t Original) const;
   uint32_t relocateTableIndex(uint32_t Original) const;
 
-  Symbol *createDefinedGlobal(const WasmSymbol &Sym, InputSegment *Segment,
-                              uint32_t Address);
+  Symbol *createDefinedData(const WasmSymbol &Sym, InputSegment *Segment,
   Symbol *createDefinedFunction(const WasmSymbol &Sym, InputFunction *Function);
   Symbol *createUndefined(const WasmSymbol &Sym, Symbol::Kind Kind,
                           const WasmSignature *Signature = nullptr);
   void initializeSymbols();
   InputSegment *getSegment(const WasmSymbol &WasmSym) const;
   const WasmSignature *getFunctionSig(const WasmSymbol &Sym) const;
   uint32_t getGlobalValue(const WasmSymbol &Sym) const;
   InputFunction *getFunction(const WasmSymbol &Sym) const;
   bool isExcludedByComdat(InputChunk *Chunk) const;
 
   // List of all symbols referenced or defined by this file.
   std::vector<Symbol *> Symbols;
 
   // List of all function symbols indexed by the function index space
   std::vector<Symbol *> FunctionSymbols;
 
   // List of all global symbols indexed by the global index space
-  std::vector<Symbol *> GlobalSymbols;
+  std::vector<Symbol *> DataSymbols;
 
   uint32_t NumGlobalImports = 0;
   uint32_t NumFunctionImports = 0;
   std::unique_ptr<WasmObjectFile> WasmObj;
 };
 
 // Opens a given file.
 llvm::Optional<MemoryBufferRef> readFile(StringRef Path);
 
 } // namespace wasm
 
 std::string toString(const wasm::InputFile *File);
 
 } // namespace lld
 
 #endif

wasm/InputFiles.cpp

Optional<MemoryBufferRef> lld::wasm::readFile(StringRef Path) {
   make<std::unique_ptr<MemoryBuffer>>(std::move(MB)); // take MB ownership
 
   return MBRef;
 }
 
 void ObjFile::dumpInfo() const {
   log("info for: " + getName() + "\n" +
       "      Total Functions : " + Twine(FunctionSymbols.size()) + "\n" +
-      "        Total Globals : " + Twine(GlobalSymbols.size()) + "\n" +
+      "   Total Data Symbols : " + Twine(DataSymbols.size()) + "\n" +
       "     Function Imports : " + Twine(NumFunctionImports) + "\n" +
       "       Global Imports : " + Twine(NumGlobalImports) + "\n");
 }
 
 uint32_t ObjFile::relocateVirtualAddress(uint32_t GlobalIndex) const {
-  if (auto *DG = dyn_cast<DefinedGlobal>(getGlobalSymbol(GlobalIndex)))
+  if (auto *DG = dyn_cast<DefinedData>(getDataSymbol(GlobalIndex)))
     return DG->getVirtualAddress();
   else
     return 0;
 }
 
 uint32_t ObjFile::relocateFunctionIndex(uint32_t Original) const {
   const FunctionSymbol *Sym = getFunctionSymbol(Original);
   uint32_t Index = Sym->getOutputIndex();
uint32_t ObjFile::relocateTableIndex(uint32_t Original) const {
   const FunctionSymbol *Sym = getFunctionSymbol(Original);
   uint32_t Index = Sym->hasTableIndex() ? Sym->getTableIndex() : 0;
   DEBUG(dbgs() << "relocateTableIndex: " << toString(*Sym) << ": " << Original
                << " -> " << Index << "\n");
   return Index;
 }
 
 uint32_t ObjFile::relocateGlobalIndex(uint32_t Original) const {
-  const Symbol *Sym = getGlobalSymbol(Original);
+  const Symbol *Sym = getDataSymbol(Original);
   uint32_t Index = Sym->getOutputIndex();
   DEBUG(dbgs() << "relocateGlobalIndex: " << toString(*Sym) << ": " << Original
                << " -> " << Index << "\n");
   return Index;
 }
 
 // Relocations contain an index into the function, global or table index
 // space of the input file.  This function takes a relocation and returns the
case WASM_EXTERNAL_FUNCTION:
       break;
     case WASM_EXTERNAL_GLOBAL:
       ++NumGlobalImports;
       break;
     }
   }
 
   FunctionSymbols.resize(NumFunctionImports + WasmObj->functions().size());
-  GlobalSymbols.resize(NumGlobalImports + WasmObj->globals().size());
+  DataSymbols.resize(NumGlobalImports + WasmObj->globals().size());
 
   ArrayRef<WasmFunction> Funcs = WasmObj->functions();
   ArrayRef<uint32_t> FuncTypes = WasmObj->functionTypes();
   ArrayRef<WasmSignature> Types = WasmObj->types();
   ArrayRef<WasmGlobal> Globals = WasmObj->globals();
 
   for (const auto &C : WasmObj->comdats())
     Symtab->addComdat(C, this);
 
   FunctionSymbols.resize(NumFunctionImports + Funcs.size());
-  GlobalSymbols.resize(NumGlobalImports + Globals.size());
+  DataSymbols.resize(NumGlobalImports + Globals.size());
 
   for (const WasmSegment &S : WasmObj->dataSegments()) {
     InputSegment *Seg = make<InputSegment>(S, this);
     Seg->copyRelocations(*DataSection);
     Segments.emplace_back(Seg);
   }
 
   for (size_t I = 0; I < Funcs.size(); ++I) {
     const WasmFunction &Func = Funcs[I];
     const WasmSignature &Sig = Types[FuncTypes[I]];
     InputFunction *F = make<InputFunction>(Sig, &Func, this);
     F->copyRelocations(*CodeSection);
     Functions.emplace_back(F);
   }
 
-  // Populate `FunctionSymbols` and `GlobalSymbols` based on the WasmSymbols
+  // Populate `FunctionSymbols` and `DataSymbols` based on the WasmSymbols
   // in the object
   for (const SymbolRef &Sym : WasmObj->symbols()) {
     const WasmSymbol &WasmSym = WasmObj->getWasmSymbol(Sym.getRawDataRefImpl());
     Symbol *S;
     switch (WasmSym.Type) {
     case WasmSymbol::SymbolType::FUNCTION_EXPORT: {
       InputFunction *Function = getFunction(WasmSym);
       if (!isExcludedByComdat(Function)) {
         S = createDefinedFunction(WasmSym, Function);
         break;
       }
       Function->Live = false;
       LLVM_FALLTHROUGH; // Exclude function, and add the symbol as undefined
     }
     case WasmSymbol::SymbolType::FUNCTION_IMPORT:
       S = createUndefined(WasmSym, Symbol::Kind::UndefinedFunctionKind,
                           getFunctionSig(WasmSym));
       break;
     case WasmSymbol::SymbolType::GLOBAL_EXPORT: {
       InputSegment *Segment = getSegment(WasmSym);
       if (!isExcludedByComdat(Segment)) {
-        S = createDefinedGlobal(WasmSym, Segment, getGlobalValue(WasmSym));
+        S = createDefinedData(WasmSym, Segment, getGlobalValue(WasmSym));
         break;
       }
       Segment->Live = false;
       LLVM_FALLTHROUGH; // Exclude global, and add the symbol as undefined
     }
     case WasmSymbol::SymbolType::GLOBAL_IMPORT:
-      S = createUndefined(WasmSym, Symbol::Kind::UndefinedGlobalKind);
+      S = createUndefined(WasmSym, Symbol::Kind::UndefinedDataKind);
       break;
     }
 
     Symbols.push_back(S);
     if (WasmSym.isTypeFunction()) {
       FunctionSymbols[WasmSym.ElementIndex] = S;
       if (WasmSym.HasAltIndex)
         FunctionSymbols[WasmSym.AltIndex] = S;
     } else {
-      GlobalSymbols[WasmSym.ElementIndex] = S;
+      DataSymbols[WasmSym.ElementIndex] = S;
       if (WasmSym.HasAltIndex)
-        GlobalSymbols[WasmSym.AltIndex] = S;
+        DataSymbols[WasmSym.AltIndex] = S;
     }
   }
 
   DEBUG(for (size_t I = 0; I < FunctionSymbols.size(); ++I)
             assert(FunctionSymbols[I] != nullptr);
-        for (size_t I = 0; I < GlobalSymbols.size(); ++I)
-            assert(GlobalSymbols[I] != nullptr););
+        for (size_t I = 0; I < DataSymbols.size(); ++I)
+            assert(DataSymbols[I] != nullptr););
 
   DEBUG(dbgs() << "Functions   : " << FunctionSymbols.size() << "\n");
-  DEBUG(dbgs() << "Globals     : " << GlobalSymbols.size() << "\n");
+  DEBUG(dbgs() << "Globals     : " << DataSymbols.size() << "\n");
 }
 
 Symbol *ObjFile::createUndefined(const WasmSymbol &Sym, Symbol::Kind Kind,
                                  const WasmSignature *Signature) {
   return Symtab->addUndefined(Sym.Name, Kind, Sym.Flags, this, Signature);
 }
 
 Symbol *ObjFile::createDefinedFunction(const WasmSymbol &Sym,
                                        InputFunction *Function) {
   if (Sym.isBindingLocal())
     return make<DefinedFunction>(Sym.Name, Sym.Flags, this, Function);
   return Symtab->addDefined(true, Sym.Name, Sym.Flags, this, Function);
 }
 
-Symbol *ObjFile::createDefinedGlobal(const WasmSymbol &Sym,
-                                     InputSegment *Segment, uint32_t Address) {
+Symbol *ObjFile::createDefinedData(const WasmSymbol &Sym, InputSegment *Segment,
+                                   uint32_t Address) {
   if (Sym.isBindingLocal())
-    return make<DefinedGlobal>(Sym.Name, Sym.Flags, this, Segment, Address);
+    return make<DefinedData>(Sym.Name, Sym.Flags, this, Segment, Address);
   return Symtab->addDefined(false, Sym.Name, Sym.Flags, this, Segment, Address);
 }
 
 void ArchiveFile::parse() {
   // Parse a MemoryBufferRef as an archive file.
   DEBUG(dbgs() << "Parsing library: " << toString(this) << "\n");
   File = CHECK(Archive::create(MB), toString(this));
 

wasm/MarkLive.cpp

for (const WasmRelocation Reloc : Chunk.getRelocations()) {
       case R_WEBASSEMBLY_TABLE_INDEX_I32:
       case R_WEBASSEMBLY_TABLE_INDEX_SLEB:
         Enqueue(Chunk.File->getFunctionSymbol(Reloc.Index));
         break;
       case R_WEBASSEMBLY_GLOBAL_INDEX_LEB:
       case R_WEBASSEMBLY_MEMORY_ADDR_LEB:
       case R_WEBASSEMBLY_MEMORY_ADDR_SLEB:
       case R_WEBASSEMBLY_MEMORY_ADDR_I32:
-        Enqueue(Chunk.File->getGlobalSymbol(Reloc.Index));
+        Enqueue(Chunk.File->getDataSymbol(Reloc.Index));
         break;
       }
     }
   };
 
   while (!Q.empty())
     EnqueueSuccessors(*Q.pop_back_val());
 

wasm/SymbolTable.h

Symbol *addDefined(bool IsFunction, StringRef Name, uint32_t Flags,
                      InputFile *F, InputChunk *Chunk = nullptr,
                      uint32_t Address = 0);
   Symbol *addUndefined(StringRef Name, Symbol::Kind Kind, uint32_t Flags,
                        InputFile *F, const WasmSignature *Signature = nullptr);
   Symbol *addUndefinedFunction(StringRef Name, const WasmSignature *Type);
   void addLazy(ArchiveFile *F, const Archive::Symbol *Sym);
   bool addComdat(StringRef Name, ObjFile *);
 
-  DefinedGlobal *addSyntheticGlobal(StringRef Name, uint32_t Flags = 0);
+  DefinedData *addSyntheticDataSymbol(StringRef Name, uint32_t Flags = 0);
   DefinedFunction *addSyntheticFunction(StringRef Name,
                                         const WasmSignature *Type,
                                         uint32_t Flags = 0);
 private:
   std::pair<Symbol *, bool> insert(StringRef Name);
 
   llvm::DenseMap<llvm::CachedHashStringRef, ObjFile *> ComdatMap;
   llvm::DenseMap<llvm::CachedHashStringRef, Symbol *> SymMap;

wasm/SymbolTable.cpp

DefinedFunction *SymbolTable::addSyntheticFunction(StringRef Name,
   DEBUG(dbgs() << "addSyntheticFunction: " << Name << "\n");
   Symbol *S;
   bool WasInserted;
   std::tie(S, WasInserted) = insert(Name);
   assert(WasInserted);
   return replaceSymbol<DefinedFunction>(S, Name, Flags, Type);
 }
 
-DefinedGlobal *SymbolTable::addSyntheticGlobal(StringRef Name, uint32_t Flags) {
-  DEBUG(dbgs() << "addSyntheticGlobal: " << Name << "\n");
+DefinedData *SymbolTable::addSyntheticDataSymbol(StringRef Name,
+                                                 uint32_t Flags) {
+  DEBUG(dbgs() << "addSyntheticDataSymbol: " << Name << "\n");
   Symbol *S;
   bool WasInserted;
   std::tie(S, WasInserted) = insert(Name);
   assert(WasInserted);
-  return replaceSymbol<DefinedGlobal>(S, Name, Flags);
+  return replaceSymbol<DefinedData>(S, Name, Flags);
 }
 
 Symbol *SymbolTable::addDefined(bool IsFunction, StringRef Name, uint32_t Flags,
                                 InputFile *F, InputChunk *Chunk,
                                 uint32_t Address) {
   if (IsFunction)
     DEBUG(dbgs() << "addDefined: func:" << Name << "\n");
   else
Symbol *SymbolTable::addDefined(bool IsFunction, StringRef Name, uint32_t Flags,
 
   if (Replace) {
     if (CheckTypes)
       checkSymbolTypes(*S, *F, IsFunction, Chunk);
     if (IsFunction)
       replaceSymbol<DefinedFunction>(S, Name, Flags, F,
                                      cast<InputFunction>(Chunk));
     else
-      replaceSymbol<DefinedGlobal>(S, Name, Flags, F, cast<InputSegment>(Chunk),
+      replaceSymbol<DefinedData>(S, Name, Flags, F, cast<InputSegment>(Chunk),
                                    Address);
   }
   return S;
 }
 
 Symbol *SymbolTable::addUndefined(StringRef Name, Symbol::Kind Kind,
                                   uint32_t Flags, InputFile *F,
                                   const WasmSignature *Type) {
   DEBUG(dbgs() << "addUndefined: " << Name << "\n");
   Symbol *S;
   bool WasInserted;
   std::tie(S, WasInserted) = insert(Name);
   bool IsFunction = Kind == Symbol::UndefinedFunctionKind;
   if (WasInserted) {
     if (IsFunction)
       replaceSymbol<UndefinedFunction>(S, Name, Flags, F, Type);
     else
-      replaceSymbol<UndefinedGlobal>(S, Name, Flags, F);
+      replaceSymbol<UndefinedData>(S, Name, Flags, F);
   } else if (auto *LazySym = dyn_cast<LazySymbol>(S)) {
     DEBUG(dbgs() << "resolved by existing lazy\n");
     auto *AF = cast<ArchiveFile>(LazySym->getFile());
     AF->addMember(&LazySym->getArchiveSymbol());
   } else if (S->isDefined()) {
     DEBUG(dbgs() << "resolved by existing\n");
     checkSymbolTypes(*S, *F, IsFunction, Type);
   }

wasm/Symbols.h

 
 #define INVALID_INDEX UINT32_MAX
 
 // The base class for real symbol classes.
 class Symbol {
 public:
   enum Kind {
     DefinedFunctionKind,
-    DefinedGlobalKind,
+    DefinedDataKind,
 
     LazyKind,
     UndefinedFunctionKind,
-    UndefinedGlobalKind,
+    UndefinedDataKind,
 
-    LastDefinedKind = DefinedGlobalKind,
+    LastDefinedKind = DefinedDataKind,
     InvalidKind,
   };
 
   Kind kind() const { return SymbolKind; }
 
   bool isLazy() const { return SymbolKind == LazyKind; }
   bool isDefined() const { return SymbolKind <= LastDefinedKind; }
   bool isUndefined() const {
-    return SymbolKind == UndefinedGlobalKind ||
+    return SymbolKind == UndefinedDataKind ||
            SymbolKind == UndefinedFunctionKind;
   }
   bool isLocal() const;
   bool isWeak() const;
   bool isHidden() const;
 
   // Returns the symbol name.
   StringRef getName() const { return Name; }
UndefinedFunction(StringRef Name, uint32_t Flags, InputFile *File = nullptr,
                     const WasmSignature *Type = nullptr)
       : FunctionSymbol(Name, UndefinedFunctionKind, Flags, File, Type) {}
 
   static bool classof(const Symbol *S) {
     return S->kind() == UndefinedFunctionKind;
   }
 };
 
-class GlobalSymbol : public Symbol {
+class DataSymbol : public Symbol {
 public:
   static bool classof(const Symbol *S) {
-    return S->kind() == DefinedGlobalKind || S->kind() == UndefinedGlobalKind;
+    return S->kind() == DefinedDataKind || S->kind() == UndefinedDataKind;
   }
 
 protected:
-  GlobalSymbol(StringRef Name, Kind K, uint32_t Flags, InputFile *F,
-               InputChunk *C)
+  DataSymbol(StringRef Name, Kind K, uint32_t Flags, InputFile *F,
       : Symbol(Name, K, Flags, F, C) {}
 };
 
-class DefinedGlobal : public GlobalSymbol {
+class DefinedData : public DataSymbol {
 public:
-  DefinedGlobal(StringRef Name, uint32_t Flags, InputFile *F = nullptr,
+  DefinedData(StringRef Name, uint32_t Flags, InputFile *F = nullptr,
                 InputChunk *C = nullptr, uint32_t Address = 0)
-      : GlobalSymbol(Name, DefinedGlobalKind, Flags, F, C),
+      : DataSymbol(Name, DefinedDataKind, Flags, F, C),
         VirtualAddress(Address) {}
 
   static bool classof(const Symbol *S) {
-    return S->kind() == DefinedGlobalKind;
+    return S->kind() == DefinedDataKind;
   }
 
   uint32_t getVirtualAddress() const;
 
   void setVirtualAddress(uint32_t VA);
 
 protected:
   uint32_t VirtualAddress;
 };
 
-class UndefinedGlobal : public GlobalSymbol {
+class UndefinedData : public DataSymbol {
 public:
-  UndefinedGlobal(StringRef Name, uint32_t Flags, InputFile *File = nullptr)
-      : GlobalSymbol(Name, UndefinedGlobalKind, Flags, File, nullptr) {}
+  UndefinedData(StringRef Name, uint32_t Flags, InputFile *File = nullptr)
+      : DataSymbol(Name, UndefinedDataKind, Flags, File, nullptr) {}
   static bool classof(const Symbol *S) {
-    return S->kind() == UndefinedGlobalKind;
+    return S->kind() == UndefinedDataKind;
   }
 };
 
 class LazySymbol : public Symbol {
 public:
   LazySymbol(StringRef Name, InputFile *File, const Archive::Symbol &Sym)
       : Symbol(Name, LazyKind, 0, File, nullptr), ArchiveSymbol(Sym) {}
 
   static bool classof(const Symbol *S) { return S->kind() == LazyKind; }
 
   const Archive::Symbol &getArchiveSymbol() { return ArchiveSymbol; }
 
 protected:
   Archive::Symbol ArchiveSymbol;
 };
 
 // linker-generated symbols
 struct WasmSym {
   // __stack_pointer
   // Global that holds the address of the top of the explicit value stack in
   // linear memory.
-  static DefinedGlobal *StackPointer;
+  static DefinedData *StackPointer;
 
   // __data_end
   // Symbol marking the end of the data and bss.
-  static DefinedGlobal *DataEnd;
+  static DefinedData *DataEnd;
 
   // __heap_base
   // Symbol marking the end of the data, bss and explicit stack.  Any linear
   // memory following this address is not used by the linked code and can
   // therefore be used as a backing store for brk()/malloc() implementations.
-  static DefinedGlobal *HeapBase;
+  static DefinedData *HeapBase;
 
   // __wasm_call_ctors
   // Function that directly calls all ctors in priority order.
   static DefinedFunction *CallCtors;
 
   // __dso_handle
-  // Global used in calls to __cxa_atexit to determine current DLL
-  static DefinedGlobal *DsoHandle;
+  // Symbol used in calls to __cxa_atexit to determine current DLL
+  static DefinedData *DsoHandle;
 };
 
 // A buffer class that is large enough to hold any Symbol-derived
 // object. We allocate memory using this class and instantiate a symbol
 // using the placement new.
 union SymbolUnion {
   alignas(DefinedFunction) char A[sizeof(DefinedFunction)];
-  alignas(DefinedGlobal) char B[sizeof(DefinedGlobal)];
+  alignas(DefinedData) char B[sizeof(DefinedData)];
   alignas(LazySymbol) char C[sizeof(LazySymbol)];
   alignas(UndefinedFunction) char D[sizeof(UndefinedFunction)];
-  alignas(UndefinedGlobal) char E[sizeof(UndefinedFunction)];
+  alignas(UndefinedData) char E[sizeof(UndefinedFunction)];
 };
 
 template <typename T, typename... ArgT>
 T *replaceSymbol(Symbol *S, ArgT &&... Arg) {
   static_assert(std::is_trivially_destructible<T>(),
                 "Symbol types must be trivially destructible");
   static_assert(sizeof(T) <= sizeof(SymbolUnion), "Symbol too small");
   static_assert(alignof(T) <= alignof(SymbolUnion),

wasm/Symbols.cpp

 #define DEBUG_TYPE "lld"
 
 using namespace llvm;
 using namespace llvm::wasm;
 using namespace lld;
 using namespace lld::wasm;
 
 DefinedFunction *WasmSym::CallCtors;
-DefinedGlobal *WasmSym::DsoHandle;
-DefinedGlobal *WasmSym::DataEnd;
-DefinedGlobal *WasmSym::HeapBase;
-DefinedGlobal *WasmSym::StackPointer;
+DefinedData *WasmSym::DsoHandle;
+DefinedData *WasmSym::DataEnd;
+DefinedData *WasmSym::HeapBase;
+DefinedData *WasmSym::StackPointer;
 
 bool Symbol::hasOutputIndex() const {
   if (auto *F = dyn_cast_or_null<InputFunction>(Chunk))
     return F->hasOutputIndex();
   return OutputIndex != INVALID_INDEX;
 }
 
 uint32_t Symbol::getOutputIndex() const {
if (auto *F = dyn_cast_or_null<InputFunction>(Chunk)) {
     F->setTableIndex(Index);
     return;
   }
   DEBUG(dbgs() << "setTableIndex " << Name << " -> " << Index << "\n");
   assert(TableIndex == INVALID_INDEX);
   TableIndex = Index;
 }
 
-uint32_t DefinedGlobal::getVirtualAddress() const {
+uint32_t DefinedData::getVirtualAddress() const {
   DEBUG(dbgs() << "getVirtualAddress: " << getName() << "\n");
   return Chunk ? dyn_cast<InputSegment>(Chunk)->translateVA(VirtualAddress)
                : VirtualAddress;
 }
 
-void DefinedGlobal::setVirtualAddress(uint32_t Value) {
+void DefinedData::setVirtualAddress(uint32_t Value) {
   DEBUG(dbgs() << "setVirtualAddress " << Name << " -> " << Value << "\n");
   VirtualAddress = Value;
 }
 
 std::string lld::toString(const wasm::Symbol &Sym) {
   if (Config->Demangle)
     if (Optional<std::string> S = demangleItanium(Sym.getName()))
       return "`" + *S + "'";
   return Sym.getName();
 }
 
 std::string lld::toString(wasm::Symbol::Kind Kind) {
   switch (Kind) {
   case wasm::Symbol::DefinedFunctionKind:
     return "DefinedFunction";
-  case wasm::Symbol::DefinedGlobalKind:
-    return "DefinedGlobal";
+  case wasm::Symbol::DefinedDataKind:
+    return "DefinedData";
   case wasm::Symbol::UndefinedFunctionKind:
     return "UndefinedFunction";
-  case wasm::Symbol::UndefinedGlobalKind:
-    return "UndefinedGlobal";
+  case wasm::Symbol::UndefinedDataKind:
+    return "UndefinedData";
   case wasm::Symbol::LazyKind:
     return "LazyKind";
   }
   llvm_unreachable("Invalid symbol kind!");
 }

wasm/Writer.cpp

private:
 
   uint64_t FileSize = 0;
   uint32_t DataSize = 0;
   uint32_t NumMemoryPages = 0;
 
   std::vector<const WasmSignature *> Types;
   DenseMap<WasmSignature, int32_t, WasmSignatureDenseMapInfo> TypeIndices;
   std::vector<const FunctionSymbol *> ImportedFunctions;
-  std::vector<const GlobalSymbol *> ImportedGlobals;
+  std::vector<const DataSymbol *> ImportedGlobals;
   std::vector<WasmExportEntry> ExportedSymbols;
-  std::vector<const DefinedGlobal *> DefinedGlobals;
+  std::vector<const DefinedData *> DefinedDataSymbols;
   std::vector<InputFunction *> DefinedFunctions;
   std::vector<const FunctionSymbol *> IndirectFunctions;
   std::vector<WasmInitFunc> InitFunctions;
 
   // Elements that are used to construct the final output
   std::string Header;
   std::vector<OutputSection *> OutputSections;
 
void Writer::createMemorySection() {
   raw_ostream &OS = Section->getStream();
 
   writeUleb128(OS, 1, "memory count");
   writeUleb128(OS, 0, "memory limits flags");
   writeUleb128(OS, NumMemoryPages, "initial pages");
 }
 
 void Writer::createGlobalSection() {
-  if (DefinedGlobals.empty())
+  if (DefinedDataSymbols.empty())
     return;
 
   SyntheticSection *Section = createSyntheticSection(WASM_SEC_GLOBAL);
   raw_ostream &OS = Section->getStream();
 
-  writeUleb128(OS, DefinedGlobals.size(), "global count");
-  for (const DefinedGlobal *Sym : DefinedGlobals) {
+  writeUleb128(OS, DefinedDataSymbols.size(), "global count");
+  for (const DefinedData *Sym : DefinedDataSymbols) {
     WasmGlobal Global;
     Global.Type.Type = WASM_TYPE_I32;
     Global.Type.Mutable = Sym == WasmSym::StackPointer;
     Global.InitExpr.Opcode = WASM_OPCODE_I32_CONST;
     Global.InitExpr.Value.Int32 = Sym->getVirtualAddress();
     writeGlobal(OS, Global);
   }
 }

 void Writer::calculateImports() {
   for (Symbol *Sym : Symtab->getSymbols()) {
     if (!Sym->isUndefined() || (Sym->isWeak() && !Config->Relocatable))
       continue;
 
     if (auto *F = dyn_cast<FunctionSymbol>(Sym)) {
       F->setOutputIndex(ImportedFunctions.size());
       ImportedFunctions.push_back(F);
-    } else if (auto *G = dyn_cast<GlobalSymbol>(Sym)) {
+    } else if (auto *G = dyn_cast<DataSymbol>(Sym)) {
       G->setOutputIndex(ImportedGlobals.size());
       ImportedGlobals.push_back(G);
     }
   }
 }
 
 void Writer::calculateExports() {
   bool ExportHidden = Config->Relocatable;
void Writer::calculateExports() {
   if (WasmSym::CallCtors && (!WasmSym::CallCtors->isHidden() || ExportHidden))
     ExportedSymbols.emplace_back(
         WasmExportEntry{WasmSym::CallCtors, WasmSym::CallCtors->getName()});
 
   for (ObjFile *File : Symtab->ObjectFiles) {
     for (Symbol *Sym : File->getSymbols()) {
       if (!Sym->isDefined() || File != Sym->getFile())
         continue;
-      if (isa<GlobalSymbol>(Sym))
+      if (!isa<FunctionSymbol>(Sym))
         continue;
       if (!Sym->getChunk()->Live)
         continue;
 
       if ((Sym->isHidden() || Sym->isLocal()) && !ExportHidden)
         continue;
       ExportedSymbols.emplace_back(WasmExportEntry{Sym, BudgeLocalName(Sym)});
     }
   }
 
-  for (const Symbol *Sym : DefinedGlobals) {
+  for (const Symbol *Sym : DefinedDataSymbols) {
     // Can't export the SP right now because its mutable, and mutuable globals
     // are yet supported in the official binary format.
     // TODO(sbc): Remove this if/when the "mutable global" proposal is accepted.
     if (Sym == WasmSym::StackPointer)
       continue;
     ExportedSymbols.emplace_back(WasmExportEntry{Sym, BudgeLocalName(Sym)});
   }
 }
void Writer::calculateTypes() {
   for (const FunctionSymbol *Sym : ImportedFunctions)
     registerType(*Sym->getFunctionType());
 
   for (const InputFunction *F : DefinedFunctions)
     registerType(F->Signature);
 }
 
 void Writer::assignIndexes() {
-  uint32_t GlobalIndex = ImportedGlobals.size() + DefinedGlobals.size();
+  uint32_t GlobalIndex = ImportedGlobals.size() + DefinedDataSymbols.size();
   uint32_t FunctionIndex = ImportedFunctions.size() + DefinedFunctions.size();
 
-  auto AddDefinedGlobal = [&](DefinedGlobal *Sym) {
+  auto AddDefinedData = [&](DefinedData *Sym) {
     if (Sym) {
-      DefinedGlobals.emplace_back(Sym);
+      DefinedDataSymbols.emplace_back(Sym);
       Sym->setOutputIndex(GlobalIndex++);
     }
   };
-  AddDefinedGlobal(WasmSym::StackPointer);
-  AddDefinedGlobal(WasmSym::HeapBase);
-  AddDefinedGlobal(WasmSym::DataEnd);
+  AddDefinedData(WasmSym::StackPointer);
+  AddDefinedData(WasmSym::HeapBase);
+  AddDefinedData(WasmSym::DataEnd);
 
   if (Config->Relocatable)
-    DefinedGlobals.reserve(Symtab->getSymbols().size());
+    DefinedDataSymbols.reserve(Symtab->getSymbols().size());
 
   uint32_t TableIndex = kInitialTableOffset;
 
   if (Config->Relocatable) {
     for (ObjFile *File : Symtab->ObjectFiles) {
       DEBUG(dbgs() << "Globals: " << File->getName() << "\n");
       for (Symbol *Sym : File->getSymbols()) {
         // Create wasm globals for data symbols defined in this file
         if (File != Sym->getFile())
           continue;
-        if (auto *G = dyn_cast<DefinedGlobal>(Sym))
-          AddDefinedGlobal(G);
+        if (auto *G = dyn_cast<DefinedData>(Sym))
+          AddDefinedData(G);
       }
     }
   }
 
   for (ObjFile *File : Symtab->ObjectFiles) {
     DEBUG(dbgs() << "Functions: " << File->getName() << "\n");
     for (InputFunction *Func : File->Functions) {
       if (!Func->Live)
void Writer::run() {
   calculateInitFunctions();
   if (!Config->Relocatable)
     createCtorFunction();
   log("-- calculateTypes");
   calculateTypes();
 
   if (errorHandler().Verbose) {
     log("Defined Functions: " + Twine(DefinedFunctions.size()));
-    log("Defined Globals  : " + Twine(DefinedGlobals.size()));
+    log("Defined Data Syms: " + Twine(DefinedDataSymbols.size()));
     log("Function Imports : " + Twine(ImportedFunctions.size()));
     log("Global Imports   : " + Twine(ImportedGlobals.size()));
     log("Total Imports    : " +
         Twine(ImportedFunctions.size() + ImportedGlobals.size()));
     for (ObjFile *File : Symtab->ObjectFiles)
       File->dumpInfo();
   }