Refine PointerSubChecker: compare the base region instead of the original

region, so that arithmetic within a memory chunk is allowed.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@86652 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 18 insertions, 0 deletions

diff --git a/lib/Analysis/MemRegion.cpp b/lib/Analysis/MemRegion.cpp
index ad3d36e79d..8c0b85c0c7 100644
--- a/lib/Analysis/MemRegion.cpp
+++ b/lib/Analysis/MemRegion.cpp
@@ -378,6 +378,24 @@ bool MemRegion::hasGlobalsOrParametersStorage() const {
   return false;
 }
 
+// getBaseRegion strips away all elements and fields, and get the base region
+// of them.
+const MemRegion *MemRegion::getBaseRegion() const {
+  const MemRegion *R = this;
+  while (true) {
+    if (const ElementRegion *ER = dyn_cast<ElementRegion>(R)) {
+      R = ER->getSuperRegion();
+      continue;
+    }
+    if (const FieldRegion *FR = dyn_cast<FieldRegion>(R)) {
+      R = FR->getSuperRegion();
+      continue;
+    }
+    break;
+  }
+  return R;
+}
+
 //===----------------------------------------------------------------------===//
 // View handling.
 //===----------------------------------------------------------------------===//