[MachO] Add comments to explain the semantics of chained fixups structures.

diff --git a/llvm/include/llvm/BinaryFormat/MachO.h b/llvm/include/llvm/BinaryFormat/MachO.h
index 474480f..8f47fab 100644 (file)
--- a/llvm/include/llvm/BinaryFormat/MachO.h
+++ b/llvm/include/llvm/BinaryFormat/MachO.h
@@ -1039,8 +1039,8 @@ enum {
 // Values for dyld_chained_starts_in_segment::page_start.
 enum {
   DYLD_CHAINED_PTR_START_NONE = 0xFFFF,
-  DYLD_CHAINED_PTR_START_MULTI = 0x8000,
-  DYLD_CHAINED_PTR_START_LAST = 0x8000,
+  DYLD_CHAINED_PTR_START_MULTI = 0x8000, // page which has multiple starts
+  DYLD_CHAINED_PTR_START_LAST = 0x8000,  // last chain_start for a given page
 };
 
 // Values for dyld_chained_starts_in_segment::pointer_format.