diff --git a/llvm/include/llvm/Support/ELF.h b/llvm/include/llvm/Support/ELF.h
index 3552c872eeb2..01c72a3afa24 100644
--- a/llvm/include/llvm/Support/ELF.h
+++ b/llvm/include/llvm/Support/ELF.h
@@ -280,6 +280,7 @@ struct Elf32_Phdr {
   Elf32_Word p_align;  // Segment alignment constraint
 };
 
+// Segment types.
 enum {
   PT_NULL    = 0, // Unused segment.
   PT_LOAD    = 1, // Loadable segment.
@@ -292,6 +293,14 @@ enum {
   PT_HIPROC  = 0x7fffffff  // Highest processor-specific program hdr entry type.
 };
 
+// Segment flag bits.
+enum {
+  PF_X        = 1,         // Execute
+  PF_W        = 2,         // Write
+  PF_R        = 4,         // Read
+  PF_MASKPROC = 0xf0000000 // Unspecified
+};
+
 } // end namespace ELF
 
 } // end namespace llvm