[llvm] r364461 - Fix some undefined behavior (excessive shift of signed value) in r364253 detected by ubsan

[David Blaikie via llvm-commits]

Author: dblaikie
Date: Wed Jun 26 12:18:50 2019
New Revision: 364461

URL: http://llvm.org/viewvc/llvm-project?rev=364461&view=rev
Log:
Fix some undefined behavior (excessive shift of signed value) in r364253 detected by ubsan

Modified:
    llvm/trunk/include/llvm/Support/LEB128.h

Modified: llvm/trunk/include/llvm/Support/LEB128.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Support/LEB128.h?rev=364461&r1=364460&r2=364461&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Support/LEB128.h (original)
+++ llvm/trunk/include/llvm/Support/LEB128.h Wed Jun 26 12:18:50 2019
@@ -176,7 +176,7 @@ inline int64_t decodeSLEB128(const uint8
       return 0;
     }
     Byte = *p++;
-    Value |= (int64_t(Byte & 0x7f) << Shift);
+    Value |= (uint64_t(Byte & 0x7f) << Shift);
     Shift += 7;
   } while (Byte >= 128);
   // Sign extend negative numbers if needed.