Add array index assertion: BasicStore should not expect any fancy
ElementRegions that have non-zero array indices.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@70867 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/BasicStore.cpp b/lib/Analysis/BasicStore.cpp
index 598191f57..95bb6f1 100644
--- a/lib/Analysis/BasicStore.cpp
+++ b/lib/Analysis/BasicStore.cpp
@@ -212,11 +212,14 @@
     case loc::MemRegionKind: {
       const MemRegion *R = cast<loc::MemRegionVal>(BaseL).getRegion();
       
-      if (isa<ElementRegion>(R)) {
+      if (const ElementRegion *ER = dyn_cast<ElementRegion>(R)) {
         // int x;
         // char* y = (char*) &x;
         // 'y' => ElementRegion(0, VarRegion('x'))
         // y[0] = 'a';
+        assert(ER->getIndex().isUnknown() ||
+               cast<nonloc::ConcreteInt>(ER->getIndex()).getValue() == 0);
+        ER = ER; // silence 'unused' warning in release modes.
         return Base;
       }