[ExecutionEngine] Correct the size of a write in a COFF i386 relocation

[xiaobai]

Summary

We want to be writing a 32bit value, so we should be writing 4 bytes
instead of 2.

[smeenai]

Looks like a pretty small and obvious fix to me. However, you should reupload this patch and add llvm-commits as a subscriber, so that an email gets sent out to the mailing list.

[smeenai]

(as in, create a new differential. Adding llvm-commits to this one won't trigger an email with the patch contents, I believe.)

[xiaobai]

I'll do just that. Thanks!

lib/ExecutionEngine/RuntimeDyld/Targets/RuntimeDyldCOFFI386.h

case COFF::IMAGE_REL_I386_SECREL:
       // 32-bit offset of the target from the beginning of its section.
       assert(static_cast<int32_t>(RE.Addend) <= INT32_MAX &&
              "relocation overflow");
       assert(static_cast<int32_t>(RE.Addend) >= INT32_MIN &&
              "relocation underflow");
       DEBUG(dbgs() << "\t\tOffset: " << RE.Offset
                    << " RelType: IMAGE_REL_I386_SECREL Value: " << RE.Addend
                    << '\n');
-      writeBytesUnaligned(RE.Addend, Target, 2);
+      writeBytesUnaligned(RE.Addend, Target, 4);
       break;
     default:
       llvm_unreachable("unsupported relocation type");
     }
   }
 
   void registerEHFrames() override {}
 };
 
 }
 
 #endif