1 files changed, 115 insertions, 0 deletions
diff --git a/lld/MachO/Relocations.h b/lld/MachO/Relocations.h
new file mode 100644
index 000000000000..91b2d00f26a1
--- /dev/null
+++ b/lld/MachO/Relocations.h
@@ -0,0 +1,115 @@
+//===- Relocations.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_RELOCATIONS_H
+#define LLD_MACHO_RELOCATIONS_H
+
+#include "llvm/ADT/BitmaskEnum.h"
+#include "llvm/ADT/PointerUnion.h"
+#include "llvm/BinaryFormat/MachO.h"
+#include "llvm/Support/Endian.h"
+
+#include <cstddef>
+#include <cstdint>
+
+namespace lld {
+namespace macho {
+LLVM_ENABLE_BITMASK_ENUMS_IN_NAMESPACE();
+
+class Symbol;
+class InputSection;
+
+enum class RelocAttrBits {
+  _0 = 0,              // invalid
+  PCREL = 1 << 0,      // Value is PC-relative offset
+  ABSOLUTE = 1 << 1,   // Value is an absolute address or fixed offset
+  BYTE4 = 1 << 2,      // 4 byte datum
+  BYTE8 = 1 << 3,      // 8 byte datum
+  EXTERN = 1 << 4,     // Can have an external symbol
+  LOCAL = 1 << 5,      // Can have a local symbol
+  ADDEND = 1 << 6,     // *_ADDEND paired prefix reloc
+  SUBTRAHEND = 1 << 7, // *_SUBTRACTOR paired prefix reloc
+  BRANCH = 1 << 8,     // Value is branch target
+  GOT = 1 << 9,        // References a symbol in the Global Offset Table
+  TLV = 1 << 10,       // References a thread-local symbol
+  LOAD = 1 << 11,      // Relaxable indirect load
+  POINTER = 1 << 12,   // Non-relaxable indirect load (pointer is taken)
+  UNSIGNED = 1 << 13,  // *_UNSIGNED relocs
+  LLVM_MARK_AS_BITMASK_ENUM(/*LargestValue*/ (1 << 14) - 1),
+};
+// Note: SUBTRACTOR always pairs with UNSIGNED (a delta between two symbols).
+
+struct RelocAttrs {
+  llvm::StringRef name;
+  RelocAttrBits bits;
+  bool hasAttr(RelocAttrBits b) const { return (bits & b) == b; }
+};
+
+struct Reloc {
+  uint8_t type = llvm::MachO::GENERIC_RELOC_INVALID;
+  bool pcrel = false;
+  uint8_t length = 0;
+  // The offset from the start of the subsection that this relocation belongs
+  // to.
+  uint64_t offset = 0;
+  // Adding this offset to the address of the referent symbol or subsection
+  // gives the destination that this relocation refers to.
+  int64_t addend = 0;
+  llvm::PointerUnion<Symbol *, InputSection *> referent = nullptr;
+};
+
+bool validateSymbolRelocation(const Symbol *, const InputSection *,
+                              const Reloc &);
+
+/*
+ * v: The value the relocation is attempting to encode
+ * bits: The number of bits actually available to encode this relocation
+ */
+void reportRangeError(const Reloc &, const llvm::Twine &v, uint8_t bits,
+                      int64_t min, uint64_t max);
+
+struct SymbolDiagnostic {
+  const Symbol *symbol;
+  llvm::StringRef reason;
+};
+
+void reportRangeError(SymbolDiagnostic, const llvm::Twine &v, uint8_t bits,
+                      int64_t min, uint64_t max);
+
+template <typename Diagnostic>
+inline void checkInt(Diagnostic d, int64_t v, int bits) {
+  if (v != llvm::SignExtend64(v, bits))
+    reportRangeError(d, llvm::Twine(v), bits, llvm::minIntN(bits),
+                     llvm::maxIntN(bits));
+}
+
+template <typename Diagnostic>
+inline void checkUInt(Diagnostic d, uint64_t v, int bits) {
+  if ((v >> bits) != 0)
+    reportRangeError(d, llvm::Twine(v), bits, 0, llvm::maxUIntN(bits));
+}
+
+inline void writeAddress(uint8_t *loc, uint64_t addr, uint8_t length) {
+  switch (length) {
+  case 2:
+    llvm::support::endian::write32le(loc, addr);
+    break;
+  case 3:
+    llvm::support::endian::write64le(loc, addr);
+    break;
+  default:
+    llvm_unreachable("invalid r_length");
+  }
+}
+
+extern const RelocAttrs invalidRelocAttrs;
+
+} // namespace macho
+} // namespace lld
+
+#endif