[analyzer] Do not believe lazy binding when symbolic region types do not match

This fixes a crash when analyzing LLVM that was exposed by r177220 (modeling of
trivial copy/move assignment operators).

When we look up a lazy binding for “Builder”, we see the direct binding of Loc at offset 0.
Previously, we believed the binding, which led to a crash. Now, we do not believe it as
the types do not match.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@177453 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 16 insertions, 5 deletions

diff --git a/lib/StaticAnalyzer/Core/RegionStore.cpp b/lib/StaticAnalyzer/Core/RegionStore.cpp
index 82db23dd6b..731c3ed8cc 100644
--- a/lib/StaticAnalyzer/Core/RegionStore.cpp
+++ b/lib/StaticAnalyzer/Core/RegionStore.cpp
@@ -1265,6 +1265,17 @@ SVal RegionStoreManager::getBinding(RegionBindingsConstRef B, Loc L, QualType T)
   return svalBuilder.getRegionValueSymbolVal(R);
 }
 
+static QualType getUnderlyingType(const SubRegion *R) {
+  QualType RegionTy;
+  if (const TypedValueRegion *TVR = dyn_cast<TypedValueRegion>(R))
+    RegionTy = TVR->getValueType();
+
+  if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(R))
+    RegionTy = SR->getSymbol()->getType();
+
+  return RegionTy;
+}
+
 /// Checks to see if store \p B has a lazy binding for region \p R.
 ///
 /// If \p AllowSubregionBindings is \c false, a lazy binding will be rejected
@@ -1283,11 +1294,11 @@ getExistingLazyBinding(SValBuilder &SVB, RegionBindingsConstRef B,
   if (!LCV)
     return None;
 
-  // If the LCV is for a subregion, the types won't match, and we shouldn't
-  // reuse the binding. Unfortuately we can only check this if the destination
-  // region is a TypedValueRegion.
-  if (const TypedValueRegion *TVR = dyn_cast<TypedValueRegion>(R)) {
-    QualType RegionTy = TVR->getValueType();
+  // If the LCV is for a subregion, the types might not match, and we shouldn't
+  // reuse the binding.
+  QualType RegionTy = getUnderlyingType(R);
+  if (!RegionTy.isNull() &&
+      !RegionTy->isVoidPointerType()) {
     QualType SourceRegionTy = LCV->getRegion()->getValueType();
     if (!SVB.getContext().hasSameUnqualifiedType(RegionTy, SourceRegionTy))
       return None;