Add ElementRegion to represent memory chunks for array elements.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@57891 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/MemRegion.cpp b/lib/Analysis/MemRegion.cpp
index d8efef2..cae053f 100644
--- a/lib/Analysis/MemRegion.cpp
+++ b/lib/Analysis/MemRegion.cpp
@@ -65,6 +65,16 @@
   SymbolicRegion::ProfileRegion(ID, sym);
 }
 
+void ElementRegion::ProfileRegion(llvm::FoldingSetNodeID& ID, SVal Idx, 
+                                  const MemRegion* superRegion) {
+  ID.AddInteger(MemRegion::ElementRegionKind);
+  ID.AddPointer(superRegion);
+  Idx.Profile(ID);
+}
+
+void ElementRegion::Profile(llvm::FoldingSetNodeID& ID) const {
+  ElementRegion::ProfileRegion(ID, Index, superRegion);
+}
 //===----------------------------------------------------------------------===//
 // Region pretty-printing.
 //===----------------------------------------------------------------------===//
@@ -141,6 +151,24 @@
   return R;
 }
 
+ElementRegion* MemRegionManager::getElementRegion(SVal Idx,
+                                                  const MemRegion* superRegion){
+  llvm::FoldingSetNodeID ID;
+  ElementRegion::ProfileRegion(ID, Idx, superRegion);
+
+  void* InsertPos;
+  MemRegion* data = Regions.FindNodeOrInsertPos(ID, InsertPos);
+  ElementRegion* R = cast_or_null<ElementRegion>(data);
+
+  if (!R) {
+    R = (ElementRegion*) A.Allocate<ElementRegion>();
+    new (R) ElementRegion(Idx, superRegion);
+    Regions.InsertNode(R, InsertPos);
+  }
+
+  return R;
+}
+
 /// getSymbolicRegion - Retrieve or create a "symbolic" memory region.
 SymbolicRegion* MemRegionManager::getSymbolicRegion(const SymbolID sym) {