Add asserts to SmallVector so that calls to front() and back() only succeed

if the vector is not empty.  This will ensure that calls to these functions
will reference elements in the vector.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@173321 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/include/llvm/ADT/SmallVector.h b/include/llvm/ADT/SmallVector.h
index 951e5741ffba7150dca14858f478d61528ed9a6c..9167f872185d94bc4dd54bee7c84616f2a2d98ba 100644 (file)
--- a/include/llvm/ADT/SmallVector.h
+++ b/include/llvm/ADT/SmallVector.h
@@ -145,16 +145,20 @@ public:
   }
 
   reference front() {
+    assert(!empty());
     return begin()[0];
   }
   const_reference front() const {
+    assert(!empty());
     return begin()[0];
   }
 
   reference back() {
+    assert(!empty());
     return end()[-1];
   }
   const_reference back() const {
+    assert(!empty());
     return end()[-1];
   }
 };