Index: llvm/lib/ObjCopy/MachO/MachOWriter.cpp
===================================================================
--- llvm/lib/ObjCopy/MachO/MachOWriter.cpp
+++ llvm/lib/ObjCopy/MachO/MachOWriter.cpp
@@ -520,8 +520,9 @@
   uint8_t *CurrHashWritePosition = HashWriteStart;
   while (CurrHashReadPosition < HashReadEnd) {
     StringRef Block(reinterpret_cast<char *>(CurrHashReadPosition),
-                    std::min(HashReadEnd - CurrHashReadPosition,
-                             static_cast<ssize_t>(CodeSignature.BlockSize)));
+                    std::min(static_cast<size_t>(HashReadEnd
+                             - CurrHashReadPosition),
+                             static_cast<size_t>(CodeSignature.BlockSize)));
     SHA256 Hasher;
     Hasher.update(Block);
     std::array<uint8_t, 32> Hash = Hasher.final();