[analyzer] Add a check for IvarRegion in getExtraInvalidatedValues

This diff adds a defensive check in getExtraInvalidatedValues
for the case when there are no regions for the ivar associated with
a property. Corresponding test case added.

Test plan:
make check-clang
make check-clang-analysis

llvm-svn: 300114

2 files changed, 23 insertions, 5 deletions

diff --git a/clang/lib/StaticAnalyzer/Core/CallEvent.cpp b/clang/lib/StaticAnalyzer/Core/CallEvent.cpp
index ef824b8a3b1..ee761689f47 100644
--- a/clang/lib/StaticAnalyzer/Core/CallEvent.cpp
+++ b/clang/lib/StaticAnalyzer/Core/CallEvent.cpp
@@ -695,13 +695,15 @@ void ObjCMethodCall::getExtraInvalidatedValues(
   if (const ObjCPropertyDecl *PropDecl = getAccessedProperty()) {
     if (const ObjCIvarDecl *PropIvar = PropDecl->getPropertyIvarDecl()) {
       SVal IvarLVal = getState()->getLValue(PropIvar, getReceiverSVal());
-      const MemRegion *IvarRegion = IvarLVal.getAsRegion();
-      ETraits->setTrait(
+      if (const MemRegion *IvarRegion = IvarLVal.getAsRegion()) {
+        ETraits->setTrait(
           IvarRegion,
           RegionAndSymbolInvalidationTraits::TK_DoNotInvalidateSuperRegion);
-      ETraits->setTrait(IvarRegion,
-                        RegionAndSymbolInvalidationTraits::TK_SuppressEscape);
-      Values.push_back(IvarLVal);
+        ETraits->setTrait(
+          IvarRegion,
+          RegionAndSymbolInvalidationTraits::TK_SuppressEscape);
+        Values.push_back(IvarLVal);
+      }
       return;
     }
   }
diff --git a/clang/test/Analysis/properties.m b/clang/test/Analysis/properties.m
index 542a339cd6b..e792bb2e6ba 100644
--- a/clang/test/Analysis/properties.m
+++ b/clang/test/Analysis/properties.m
@@ -987,5 +987,21 @@ void testOpaqueConsistency(OpaqueIntWrapper *w) {
 }
 
 @end
+
+@interface Wrapper
+@property(nonatomic, readonly) int value;
+@end
+
+@implementation Wrapper
+@synthesize value;
+@end
+
+void testNoCrashWhenAccessPropertyAndThereAreNoDirectBindingsAtAll() {
+   union {
+    Wrapper *wrapper;
+   } u = { 0 };
+   [u.wrapper value];
+}
+
 #endif // non-ARC