[llvm] r197647 - Fix a buffer overrun detected by AddressSanitizer.

[Anna Zaks]

Author: zaks
Date: Wed Dec 18 20:35:26 2013
New Revision: 197647

URL: http://llvm.org/viewvc/llvm-project?rev=197647&view=rev
Log:
Fix a buffer overrun detected by AddressSanitizer.

Modified:
    llvm/trunk/include/llvm/ADT/BitVector.h
    llvm/trunk/unittests/ADT/BitVectorTest.cpp

Modified: llvm/trunk/include/llvm/ADT/BitVector.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/ADT/BitVector.h?rev=197647&r1=197646&r2=197647&view=diff
==============================================================================
--- llvm/trunk/include/llvm/ADT/BitVector.h (original)
+++ llvm/trunk/include/llvm/ADT/BitVector.h Wed Dec 18 20:35:26 2013
@@ -267,7 +267,8 @@ public:
       Bits[I / BITWORD_SIZE] = ~0UL;
 
     BitWord PostfixMask = (1UL << (E % BITWORD_SIZE)) - 1;
-    Bits[I / BITWORD_SIZE] |= PostfixMask;
+    if (I < E)
+      Bits[I / BITWORD_SIZE] |= PostfixMask;
 
     return *this;
   }
@@ -305,7 +306,8 @@ public:
       Bits[I / BITWORD_SIZE] = 0UL;
 
     BitWord PostfixMask = (1UL << (E % BITWORD_SIZE)) - 1;
-    Bits[I / BITWORD_SIZE] &= ~PostfixMask;
+    if (I < E)
+      Bits[I / BITWORD_SIZE] &= ~PostfixMask;
 
     return *this;
   }

Modified: llvm/trunk/unittests/ADT/BitVectorTest.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/unittests/ADT/BitVectorTest.cpp?rev=197647&r1=197646&r2=197647&view=diff
==============================================================================
--- llvm/trunk/unittests/ADT/BitVectorTest.cpp (original)
+++ llvm/trunk/unittests/ADT/BitVectorTest.cpp Wed Dec 18 20:35:26 2013
@@ -356,6 +356,12 @@ TYPED_TEST(BitVectorTest, RangeOps) {
   EXPECT_TRUE( E.test(1));
   EXPECT_TRUE( E.test(32));
   EXPECT_FALSE(E.test(33));
+
+  TypeParam BufferOverrun;
+  unsigned size = sizeof(unsigned long) * 8;
+  BufferOverrun.resize(size);
+  BufferOverrun.reset(0, size);
+  BufferOverrun.set(0, size);
 }
 
 TYPED_TEST(BitVectorTest, CompoundTestReset) {