1 files changed, 138 insertions, 0 deletions
diff --git a/lld/MachO/Symbols.h b/lld/MachO/Symbols.h
new file mode 100644
index 000000000000..63748ee48324
--- /dev/null
+++ b/lld/MachO/Symbols.h
@@ -0,0 +1,138 @@
+//===- Symbols.h ------------------------------------------------*- C++ -*-===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLD_MACHO_SYMBOLS_H
+#define LLD_MACHO_SYMBOLS_H
+
+#include "InputSection.h"
+#include "Target.h"
+#include "lld/Common/ErrorHandler.h"
+#include "lld/Common/Strings.h"
+#include "llvm/Object/Archive.h"
+
+namespace lld {
+namespace macho {
+
+class InputSection;
+class DylibFile;
+class ArchiveFile;
+
+struct StringRefZ {
+  StringRefZ(const char *s) : data(s), size(-1) {}
+  StringRefZ(StringRef s) : data(s.data()), size(s.size()) {}
+
+  const char *data;
+  const uint32_t size;
+};
+
+class Symbol {
+public:
+  enum Kind {
+    DefinedKind,
+    UndefinedKind,
+    DylibKind,
+    LazyKind,
+  };
+
+  Kind kind() const { return static_cast<Kind>(symbolKind); }
+
+  StringRef getName() const { return {name.data, name.size}; }
+
+  uint64_t getVA() const;
+
+  uint64_t getFileOffset() const;
+
+  uint32_t gotIndex = UINT32_MAX;
+
+protected:
+  Symbol(Kind k, StringRefZ name) : symbolKind(k), name(name) {}
+
+  Kind symbolKind;
+  StringRefZ name;
+};
+
+class Defined : public Symbol {
+public:
+  Defined(StringRefZ name, InputSection *isec, uint32_t value)
+      : Symbol(DefinedKind, name), isec(isec), value(value) {}
+
+  InputSection *isec;
+  uint32_t value;
+
+  static bool classof(const Symbol *s) { return s->kind() == DefinedKind; }
+};
+
+class Undefined : public Symbol {
+public:
+  Undefined(StringRefZ name) : Symbol(UndefinedKind, name) {}
+
+  static bool classof(const Symbol *s) { return s->kind() == UndefinedKind; }
+};
+
+class DylibSymbol : public Symbol {
+public:
+  DylibSymbol(DylibFile *file, StringRefZ name)
+      : Symbol(DylibKind, name), file(file) {}
+
+  static bool classof(const Symbol *s) { return s->kind() == DylibKind; }
+
+  DylibFile *file;
+  uint32_t stubsIndex = UINT32_MAX;
+  uint32_t lazyBindOffset = UINT32_MAX;
+};
+
+class LazySymbol : public Symbol {
+public:
+  LazySymbol(ArchiveFile *file, const llvm::object::Archive::Symbol &sym)
+      : Symbol(LazyKind, sym.getName()), file(file), sym(sym) {}
+
+  static bool classof(const Symbol *s) { return s->kind() == LazyKind; }
+
+  void fetchArchiveMember();
+
+private:
+  ArchiveFile *file;
+  const llvm::object::Archive::Symbol sym;
+};
+
+inline uint64_t Symbol::getVA() const {
+  if (auto *d = dyn_cast<Defined>(this))
+    return d->isec->getVA() + d->value;
+  return 0;
+}
+
+inline uint64_t Symbol::getFileOffset() const {
+  if (auto *d = dyn_cast<Defined>(this))
+    return d->isec->getFileOffset() + d->value;
+  llvm_unreachable("attempt to get an offset from an undefined symbol");
+}
+
+union SymbolUnion {
+  alignas(Defined) char a[sizeof(Defined)];
+  alignas(Undefined) char b[sizeof(Undefined)];
+  alignas(DylibSymbol) char c[sizeof(DylibSymbol)];
+  alignas(LazySymbol) char d[sizeof(LazySymbol)];
+};
+
+template <typename T, typename... ArgT>
+void replaceSymbol(Symbol *s, ArgT &&... arg) {
+  static_assert(sizeof(T) <= sizeof(SymbolUnion), "SymbolUnion too small");
+  static_assert(alignof(T) <= alignof(SymbolUnion),
+                "SymbolUnion not aligned enough");
+  assert(static_cast<Symbol *>(static_cast<T *>(nullptr)) == nullptr &&
+         "Not a Symbol");
+
+  new (s) T(std::forward<ArgT>(arg)...);
+}
+
+} // namespace macho
+
+std::string toString(const macho::Symbol &);
+} // namespace lld
+
+#endif