[analyzer] Enforce super-region classes for various memory regions.

We now check the type of the super-region pointer for most SubRegion classes
in compile time; some checks are run-time though.

This is an API-breaking change (we now require explicit casts to specific region
sub-classes), but in practice very few checkers are affected.

Differential Revision: https://reviews.llvm.org/D26838

llvm-svn: 300189

1 files changed, 3 insertions, 2 deletions

diff --git a/clang/lib/StaticAnalyzer/Core/RegionStore.cpp b/clang/lib/StaticAnalyzer/Core/RegionStore.cpp
index f0c2df4627b..dd7e9dd1178 100644
--- a/clang/lib/StaticAnalyzer/Core/RegionStore.cpp
+++ b/clang/lib/StaticAnalyzer/Core/RegionStore.cpp
@@ -1341,7 +1341,8 @@ SVal RegionStoreManager::ArrayToPointer(Loc Array, QualType T) {
   if (!Array.getAs<loc::MemRegionVal>())
     return UnknownVal();
 
-  const MemRegion* R = Array.castAs<loc::MemRegionVal>().getRegion();
+  const SubRegion *R =
+      cast<SubRegion>(Array.castAs<loc::MemRegionVal>().getRegion());
   NonLoc ZeroIdx = svalBuilder.makeZeroArrayIndex();
   return loc::MemRegionVal(MRMgr.getElementRegion(T, ZeroIdx, R, Ctx));
 }
@@ -1384,7 +1385,7 @@ SVal RegionStoreManager::getBinding(RegionBindingsConstRef B, Loc L, QualType T)
         T = SR->getSymbol()->getType();
       }
     }
-    MR = GetElementZeroRegion(MR, T);
+    MR = GetElementZeroRegion(cast<SubRegion>(MR), T);
   }
 
   // FIXME: Perhaps this method should just take a 'const MemRegion*' argument