vendor/llvm/llvm-trunk-r366426

1 files changed, 8 insertions, 7 deletions

diff --git a/include/llvm/Support/LEB128.h b/include/llvm/Support/LEB128.h
index 9feb07229225..a02b83ca9597 100644
--- a/include/llvm/Support/LEB128.h
+++ b/include/llvm/Support/LEB128.h
@@ -1,9 +1,8 @@
 //===- llvm/Support/LEB128.h - [SU]LEB128 utility functions -----*- C++ -*-===//
 //
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 //
@@ -166,6 +165,8 @@ inline int64_t decodeSLEB128(const uint8_t *p, unsigned *n = nullptr,
   int64_t Value = 0;
   unsigned Shift = 0;
   uint8_t Byte;
+  if (error)
+    *error = nullptr;
   do {
     if (end && p == end) {
       if (error)
@@ -175,11 +176,11 @@ inline int64_t decodeSLEB128(const uint8_t *p, unsigned *n = nullptr,
       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 (Byte & 0x40)
+  // Sign extend negative numbers if needed.
+  if (Shift < 64 && (Byte & 0x40))
     Value |= (-1ULL) << Shift;
   if (n)
     *n = (unsigned)(p - orig_p);