1 files changed, 72 insertions, 0 deletions
diff --git a/wasm/SymbolTable.h b/wasm/SymbolTable.h
new file mode 100644
index 000000000000..e1e7da120b93
--- /dev/null
+++ b/wasm/SymbolTable.h
@@ -0,0 +1,72 @@
+//===- SymbolTable.h --------------------------------------------*- C++ -*-===//
+//
+//                             The LLVM Linker
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLD_WASM_SYMBOL_TABLE_H
+#define LLD_WASM_SYMBOL_TABLE_H
+
+#include "InputFiles.h"
+#include "Symbols.h"
+
+#include "llvm/ADT/CachedHashString.h"
+#include "llvm/ADT/DenseMap.h"
+#include "llvm/Support/raw_ostream.h"
+
+using llvm::object::WasmSymbol;
+using llvm::wasm::WasmSignature;
+
+namespace lld {
+namespace wasm {
+
+class InputSegment;
+
+// SymbolTable is a bucket of all known symbols, including defined,
+// undefined, or lazy symbols (the last one is symbols in archive
+// files whose archive members are not yet loaded).
+//
+// We put all symbols of all files to a SymbolTable, and the
+// SymbolTable selects the "best" symbols if there are name
+// conflicts. For example, obviously, a defined symbol is better than
+// an undefined symbol. Or, if there's a conflict between a lazy and a
+// undefined, it'll read an archive member to read a real definition
+// to replace the lazy symbol. The logic is implemented in the
+// add*() functions, which are called by input files as they are parsed.
+// There is one add* function per symbol type.
+class SymbolTable {
+public:
+  void addFile(InputFile *File);
+
+  std::vector<ObjFile *> ObjectFiles;
+  std::vector<Symbol *> SyntheticSymbols;
+
+  void reportDuplicate(Symbol *Existing, InputFile *NewFile);
+  void reportRemainingUndefines();
+
+  ArrayRef<Symbol *> getSymbols() const { return SymVector; }
+  Symbol *find(StringRef Name);
+
+  Symbol *addDefined(InputFile *F, const WasmSymbol *Sym,
+                     const InputSegment *Segment = nullptr);
+  Symbol *addUndefined(InputFile *F, const WasmSymbol *Sym);
+  Symbol *addUndefinedFunction(StringRef Name, const WasmSignature *Type);
+  Symbol *addDefinedGlobal(StringRef Name);
+  void addLazy(ArchiveFile *F, const Archive::Symbol *Sym);
+
+private:
+  std::pair<Symbol *, bool> insert(StringRef Name);
+
+  llvm::DenseMap<llvm::CachedHashStringRef, Symbol *> SymMap;
+  std::vector<Symbol *> SymVector;
+};
+
+extern SymbolTable *Symtab;
+
+} // namespace wasm
+} // namespace lld
+
+#endif