--- old/src/hotspot/cpu/x86/macroAssembler_x86.hpp	2019-10-12 12:11:33.680743457 +0900
+++ new/src/hotspot/cpu/x86/macroAssembler_x86.hpp	2019-10-12 12:11:33.541742825 +0900
@@ -114,7 +114,8 @@
       // short offset operators (jmp and jcc)
       char* disp = (char*) &branch[1];
       int imm8 = target - (address) &disp[1];
-      guarantee(this->is8bit(imm8), "Short forward jump exceeds 8-bit offset at %s:%d", file, line);
+      guarantee(this->is8bit(imm8), "Short forward jump exceeds 8-bit offset at %s:%d",
+                file == NULL ? "<NULL>" : file, line);
       *disp = imm8;
     } else {
       int* disp = (int*) &branch[(op == 0x0F || op == 0xC7)? 2: 1];