[Static Analyzer] General type checker based on dynamic type information.

[xazax.hun]

Summary

This patch adds a checker that utilizes the information that was collected by DynamicTypePropagation and warns when the static type contradicts the dynamic type.

This checker also replaces the AST matching logic in ObjCGenericsChecker's return type checking which was error prone and fragile. As a positive side effect this change also reduced the false negative cases.

[zaks.anna]

test/Analysis/generics.m

239 ↗

(On Diff #35099)

Could you replace these with the full error message. It would much more readable this way.

cfe/trunk/lib/StaticAnalyzer/Checkers/CMakeLists.txt

add_clang_library(clangStaticAnalyzerCheckers
   ChrootChecker.cpp
   ClangCheckers.cpp
   DeadStoresChecker.cpp
   DebugCheckers.cpp
   DereferenceChecker.cpp
   DirectIvarAssignment.cpp
   DivZeroChecker.cpp
   DynamicTypePropagation.cpp
+  DynamicTypeChecker.cpp
   ExprInspectionChecker.cpp
   FixedAddressChecker.cpp
   GenericTaintChecker.cpp
   IdenticalExprChecker.cpp
   IvarInvalidationChecker.cpp
   LLVMConventionsChecker.cpp
   LocalizationChecker.cpp
   MacOSKeychainAPIChecker.cpp

cfe/trunk/lib/StaticAnalyzer/Checkers/Checkers.td

 def CallAndMessageUnInitRefArg : Checker<"CallAndMessageUnInitRefArg">,
   HelpText<"Check for logical errors for function calls and Objective-C message expressions (e.g., uninitialized arguments, null function pointers, and pointer to undefined variables)">,
   DescFile<"CallAndMessageChecker.cpp">;
 
 def TestAfterDivZeroChecker : Checker<"TestAfterDivZero">,
   HelpText<"Check for division by variable that is later compared against 0. Either the comparison is useless or there is division by zero.">,
   DescFile<"TestAfterDivZeroChecker.cpp">;
 
+def DynamicTypeChecker : Checker<"DynamicTypeChecker">,
+  HelpText<"Check for cases where the dynamic and the static type of an object are unrelated.">,
+  DescFile<"DynamicTypeChecker.cpp">;
+
 } // end "alpha.core"
 
 let ParentPackage = Nullability in {
 
 def NullPassedToNonnullChecker : Checker<"NullPassedToNonnull">,
   HelpText<"Warns when a null pointer is passed to a pointer which has a _Nonnull type.">,
   DescFile<"NullabilityChecker.cpp">;
 

cfe/trunk/lib/StaticAnalyzer/Checkers/DynamicTypeChecker.cpp

+//== DynamicTypeChecker.cpp ------------------------------------ -*- C++ -*--=//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This checker looks for cases where the dynamic type of an object is unrelated
+// to its static type. The type information utilized by this check is collected
+// by the DynamicTypePropagation checker. This check does not report any type
+// error for ObjC Generic types, in order to avoid duplicate erros from the
+// ObjC Generics checker. This checker is not supposed to modify the program
+// state, it is just the observer of the type information provided by other
+// checkers.
+//
+//===----------------------------------------------------------------------===//
+
+#include "ClangSACheckers.h"
+#include "clang/StaticAnalyzer/Core/BugReporter/BugType.h"
+#include "clang/StaticAnalyzer/Core/Checker.h"
+#include "clang/StaticAnalyzer/Core/CheckerManager.h"
+#include "clang/StaticAnalyzer/Core/PathSensitive/CallEvent.h"
+#include "clang/StaticAnalyzer/Core/PathSensitive/DynamicTypeMap.h"
+#include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h"
+#include "clang/StaticAnalyzer/Core/PathSensitive/ProgramStateTrait.h"
+
+using namespace clang;
+using namespace ento;
+
+namespace {
+class DynamicTypeChecker : public Checker<check::PostStmt<ImplicitCastExpr>> {
+  mutable std::unique_ptr<BugType> BT;
+  void initBugType() const {
+    if (!BT)
+      BT.reset(
+          new BugType(this, "Dynamic and static type mismatch", "Type Error"));
+  }
+
+  class DynamicTypeBugVisitor
+      : public BugReporterVisitorImpl<DynamicTypeBugVisitor> {
+  public:
+    DynamicTypeBugVisitor(const MemRegion *Reg) : Reg(Reg) {}
+
+    void Profile(llvm::FoldingSetNodeID &ID) const override {
+      static int X = 0;
+      ID.AddPointer(&X);
+      ID.AddPointer(Reg);
+    }
+
+    PathDiagnosticPiece *VisitNode(const ExplodedNode *N,
+                                   const ExplodedNode *PrevN,
+                                   BugReporterContext &BRC,
+                                   BugReport &BR) override;
+
+  private:
+    // The tracked region.
+    const MemRegion *Reg;
+  };
+
+  void reportTypeError(QualType DynamicType, QualType StaticType,
+                       const MemRegion *Reg, const Stmt *ReportedNode,
+                       CheckerContext &C) const;
+
+public:
+  void checkPostStmt(const ImplicitCastExpr *CE, CheckerContext &C) const;
+};
+}
+
+void DynamicTypeChecker::reportTypeError(QualType DynamicType,
+                                         QualType StaticType,
+                                         const MemRegion *Reg,
+                                         const Stmt *ReportedNode,
+                                         CheckerContext &C) const {
+  initBugType();
+  SmallString<192> Buf;
+  llvm::raw_svector_ostream OS(Buf);
+  OS << "Object has a dynamic type '";
+  QualType::print(DynamicType.getTypePtr(), Qualifiers(), OS, C.getLangOpts(),
+                  llvm::Twine());
+  OS << "' which is incompatible with static type '";
+  QualType::print(StaticType.getTypePtr(), Qualifiers(), OS, C.getLangOpts(),
+                  llvm::Twine());
+  OS << "'";
+  std::unique_ptr<BugReport> R(
+      new BugReport(*BT, OS.str(), C.generateNonFatalErrorNode()));
+  R->markInteresting(Reg);
+  R->addVisitor(llvm::make_unique<DynamicTypeBugVisitor>(Reg));
+  R->addRange(ReportedNode->getSourceRange());
+  C.emitReport(std::move(R));
+}
+
+PathDiagnosticPiece *DynamicTypeChecker::DynamicTypeBugVisitor::VisitNode(
+    const ExplodedNode *N, const ExplodedNode *PrevN, BugReporterContext &BRC,
+    BugReport &BR) {
+  ProgramStateRef State = N->getState();
+  ProgramStateRef StatePrev = PrevN->getState();
+
+  DynamicTypeInfo TrackedType = getDynamicTypeInfo(State, Reg);
+  DynamicTypeInfo TrackedTypePrev = getDynamicTypeInfo(StatePrev, Reg);
+  if (!TrackedType.isValid())
+    return nullptr;
+
+  if (TrackedTypePrev.isValid() &&
+      TrackedTypePrev.getType() == TrackedType.getType())
+    return nullptr;
+
+  // Retrieve the associated statement.
+  const Stmt *S = nullptr;
+  ProgramPoint ProgLoc = N->getLocation();
+  if (Optional<StmtPoint> SP = ProgLoc.getAs<StmtPoint>()) {
+    S = SP->getStmt();
+  }
+
+  if (!S)
+    return nullptr;
+
+  const LangOptions &LangOpts = BRC.getASTContext().getLangOpts();
+
+  SmallString<256> Buf;
+  llvm::raw_svector_ostream OS(Buf);
+  OS << "Type '";
+  QualType::print(TrackedType.getType().getTypePtr(), Qualifiers(), OS,
+                  LangOpts, llvm::Twine());
+  OS << "' is inferred from ";
+
+  if (const auto *ExplicitCast = dyn_cast<ExplicitCastExpr>(S)) {
+    OS << "explicit cast (from '";
+    QualType::print(ExplicitCast->getSubExpr()->getType().getTypePtr(),
+                    Qualifiers(), OS, LangOpts, llvm::Twine());
+    OS << "' to '";
+    QualType::print(ExplicitCast->getType().getTypePtr(), Qualifiers(), OS,
+                    LangOpts, llvm::Twine());
+    OS << "')";
+  } else if (const auto *ImplicitCast = dyn_cast<ImplicitCastExpr>(S)) {
+    OS << "implicit cast (from '";
+    QualType::print(ImplicitCast->getSubExpr()->getType().getTypePtr(),
+                    Qualifiers(), OS, LangOpts, llvm::Twine());
+    OS << "' to '";
+    QualType::print(ImplicitCast->getType().getTypePtr(), Qualifiers(), OS,
+                    LangOpts, llvm::Twine());
+    OS << "')";
+  } else {
+    OS << "this context";
+  }
+
+  // Generate the extra diagnostic.
+  PathDiagnosticLocation Pos(S, BRC.getSourceManager(),
+                             N->getLocationContext());
+  return new PathDiagnosticEventPiece(Pos, OS.str(), true, nullptr);
+}
+
+// TODO: consider checking explicit casts?
+void DynamicTypeChecker::checkPostStmt(const ImplicitCastExpr *CE,
+                                       CheckerContext &C) const {
+  // TODO: C++ support.
+  if (CE->getCastKind() != CK_BitCast)
+    return;
+
+  const MemRegion *Region = C.getSVal(CE).getAsRegion();
+  if (!Region)
+    return;
+
+  ProgramStateRef State = C.getState();
+  DynamicTypeInfo DynTypeInfo = getDynamicTypeInfo(State, Region);
+
+  if (!DynTypeInfo.isValid())
+    return;
+
+  QualType DynType = DynTypeInfo.getType();
+  QualType StaticType = CE->getType();
+
+  const auto *DynObjCType = DynType->getAs<ObjCObjectPointerType>();
+  const auto *StaticObjCType = StaticType->getAs<ObjCObjectPointerType>();
+
+  if (!DynObjCType || !StaticObjCType)
+    return;
+
+  ASTContext &ASTCtxt = C.getASTContext();
+
+  // Strip kindeofness to correctly detect subtyping relationships.
+  DynObjCType = DynObjCType->stripObjCKindOfTypeAndQuals(ASTCtxt);
+  StaticObjCType = StaticObjCType->stripObjCKindOfTypeAndQuals(ASTCtxt);
+
+  // Specialized objects are handled by the generics checker.
+  if (StaticObjCType->isSpecialized())
+    return;
+
+  if (ASTCtxt.canAssignObjCInterfaces(StaticObjCType, DynObjCType))
+    return;
+
+  if (DynTypeInfo.canBeASubClass() &&
+      ASTCtxt.canAssignObjCInterfaces(DynObjCType, StaticObjCType))
+    return;
+
+  reportTypeError(DynType, StaticType, Region, CE, C);
+}
+
+void ento::registerDynamicTypeChecker(CheckerManager &mgr) {
+  mgr.registerChecker<DynamicTypeChecker>();
+}

cfe/trunk/lib/StaticAnalyzer/Checkers/DynamicTypePropagation.cpp

 // Generics Checker for Objective-C:
 // This checker tries to find type errors that the compiler is not able to catch
 // due to the implicit conversions that were introduced for backward
 // compatibility.
 //
 //===----------------------------------------------------------------------===//
 
 #include "ClangSACheckers.h"
-#include "clang/AST/ParentMap.h"
 #include "clang/AST/RecursiveASTVisitor.h"
 #include "clang/Basic/Builtins.h"
 #include "clang/StaticAnalyzer/Core/BugReporter/BugType.h"
 #include "clang/StaticAnalyzer/Core/Checker.h"
 #include "clang/StaticAnalyzer/Core/CheckerManager.h"
 #include "clang/StaticAnalyzer/Core/PathSensitive/CallEvent.h"
 #include "clang/StaticAnalyzer/Core/PathSensitive/DynamicTypeMap.h"
 #include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h"
private:
     // The tracked symbol.
     SymbolRef Sym;
   };
 
   void reportGenericsBug(const ObjCObjectPointerType *From,
                          const ObjCObjectPointerType *To, ExplodedNode *N,
                          SymbolRef Sym, CheckerContext &C,
                          const Stmt *ReportedNode = nullptr) const;
-
-  bool isReturnValueMisused(const ObjCMessageExpr *MessageExpr,
-                            const ObjCObjectPointerType *TrackedType,
-                            SymbolRef Sym, const ObjCMethodDecl *Method,
-                            ArrayRef<QualType> TypeArgs,
-                            bool SubscriptOrProperty, CheckerContext &C) const;
-
 public:
   void checkPreCall(const CallEvent &Call, CheckerContext &C) const;
   void checkPostCall(const CallEvent &Call, CheckerContext &C) const;
   void checkPostStmt(const CastExpr *CastE, CheckerContext &C) const;
   void checkPostStmt(const CXXNewExpr *NewE, CheckerContext &C) const;
   void checkDeadSymbols(SymbolReaper &SR, CheckerContext &C) const;
   void checkPreObjCMessage(const ObjCMethodCall &M, CheckerContext &C) const;
   void checkPostObjCMessage(const ObjCMethodCall &M, CheckerContext &C) const;
if (!isObjCTypeParamDependent(StaticResultType))
     return QualType();
 
   QualType ResultType = StaticResultType.substObjCTypeArgs(
       C, TypeArgs, ObjCSubstitutionContext::Result);
 
   return ResultType;
 }
 
-/// Validate that the return type of a message expression is used correctly.
-/// Returns true in case an error is detected.
-bool DynamicTypePropagation::isReturnValueMisused(
-    const ObjCMessageExpr *MessageExpr,
-    const ObjCObjectPointerType *ResultPtrType, SymbolRef Sym,
-    const ObjCMethodDecl *Method, ArrayRef<QualType> TypeArgs,
-    bool SubscriptOrProperty, CheckerContext &C) const {
-  if (!ResultPtrType)
-    return false;
-
-  ASTContext &ASTCtxt = C.getASTContext();
-  const Stmt *Parent =
-      C.getCurrentAnalysisDeclContext()->getParentMap().getParent(MessageExpr);
-  if (SubscriptOrProperty) {
-    // Properties and subscripts are not direct parents.
-    Parent =
-        C.getCurrentAnalysisDeclContext()->getParentMap().getParent(Parent);
-  }
-
-  const auto *ImplicitCast = dyn_cast_or_null<ImplicitCastExpr>(Parent);
-  if (!ImplicitCast || ImplicitCast->getCastKind() != CK_BitCast)
-    return false;
-
-  const auto *ExprTypeAboveCast =
-      ImplicitCast->getType()->getAs<ObjCObjectPointerType>();
-  if (!ExprTypeAboveCast)
-    return false;
-
-  // Only warn on unrelated types to avoid too many false positives on
-  // downcasts.
-  if (!ASTCtxt.canAssignObjCInterfaces(ExprTypeAboveCast, ResultPtrType) &&
-      !ASTCtxt.canAssignObjCInterfaces(ResultPtrType, ExprTypeAboveCast)) {
-    static CheckerProgramPointTag Tag(this, "ReturnTypeMismatch");
-    ExplodedNode *N = C.addTransition(C.getState(), &Tag);
-    reportGenericsBug(ResultPtrType, ExprTypeAboveCast, N, Sym, C);
-    return true;
-  }
-  return false;
-}
-
 /// When the receiver has a tracked type, use that type to validate the
 /// argumments of the message expression and the return value.
 void DynamicTypePropagation::checkPreObjCMessage(const ObjCMethodCall &M,
                                                  CheckerContext &C) const {
   ProgramStateRef State = C.getState();
   SymbolRef Sym = M.getReceiverSVal().getAsSymbol();
   if (!Sym)
     return;
if (RetRegion && !State->get<DynamicTypeMap>(RetRegion)) {
     // the stored data differs from the one stored in the former.
     State = setDynamicTypeInfo(State, RetRegion, ResultType,
                                /*CanBeSubclass=*/true);
     Pred = C.addTransition(State);
   }
 
   const auto *ResultPtrType = ResultType->getAs<ObjCObjectPointerType>();
 
-  if (isReturnValueMisused(MessageExpr, ResultPtrType, RecSym, Method,
-                           *TypeArgs, M.getMessageKind() != OCM_Message, C))
-    return;
-
   if (!ResultPtrType || ResultPtrType->isUnspecialized())
     return;
 
   // When the result is a specialized type and it is not tracked yet, track it
   // for the result symbol.
   if (!State->get<MostSpecializedTypeArgsMap>(RetSym)) {
     State = State->set<MostSpecializedTypeArgsMap>(RetSym, ResultPtrType);
     C.addTransition(State, Pred);

cfe/trunk/test/Analysis/dynamic_type_check.m

+// RUN: %clang_cc1 -analyze -analyzer-checker=core,alpha.core.DynamicTypeChecker -verify %s
+
+
+#define nil 0
+typedef unsigned long NSUInteger;
+typedef int BOOL;
+
+@protocol NSObject
++ (id)alloc;
+- (id)init;
+@end
+
+@protocol NSCopying
+@end
+
+__attribute__((objc_root_class))
+@interface NSObject <NSObject>
+@end
+
+@interface NSString : NSObject <NSCopying>
+@end
+
+@interface NSMutableString : NSString
+@end
+
+@interface NSNumber : NSObject <NSCopying>
+@end
+
+void testTypeCheck(NSString* str) {
+  id obj = str;
+  NSNumber *num = obj; // expected-warning {{}}
+  (void)num;
+}

cfe/trunk/test/Analysis/generics.m

-// RUN: %clang_cc1 -analyze -analyzer-checker=core,alpha.osx.cocoa.ObjCGenerics -verify -Wno-objc-method-access %s
-// RUN: %clang_cc1 -analyze -analyzer-checker=core,alpha.osx.cocoa.ObjCGenerics -verify -Wno-objc-method-access %s -analyzer-output=plist -o %t.plist
+// RUN: %clang_cc1 -analyze -analyzer-checker=core,alpha.osx.cocoa.ObjCGenerics,alpha.core.DynamicTypeChecker -verify -Wno-objc-method-access %s
+// RUN: %clang_cc1 -analyze -analyzer-checker=core,alpha.osx.cocoa.ObjCGenerics,alpha.core.DynamicTypeChecker -verify -Wno-objc-method-access %s -analyzer-output=plist -o %t.plist
 // RUN: FileCheck --input-file %t.plist %s
 
 #if !__has_feature(objc_generics)
 #  error Compiler does not support Objective-C generics?
 #endif
 
 #if !__has_feature(objc_generics_variance)
 #  error Compiler does not support co- and contr-variance?
void enforceDynamicRulesInsteadOfStatic(NSArray<NSNumber *> *a) {
   NSArray *b = a;
   // Valid uses of NSArray of NSNumbers.
   b = getStrings();
   // Valid uses of NSArray of NSStrings.
 }
 
 void workWithProperties(NSArray<NSNumber *> *a) {
   NSArray *b = a;
-  NSString *str = [b getObjAtIndex: 0]; // expected-warning {{Conversion}}
+  NSString *str = [b getObjAtIndex: 0]; // expected-warning {{Object has a dynamic type 'NSNumber *' which is incompatible with static type 'NSString *'}}
   NSNumber *num = [b getObjAtIndex: 0];
-  str = [b firstObject]; // expected-warning {{Conversion}}
+  str = [b firstObject]; // expected-warning {{Object has a dynamic type 'NSNumber *' which is incompatible with static type 'NSString *'}}
   num = [b firstObject];
-  str = b.firstObject; // expected-warning {{Conversion}}
+  str = b.firstObject; // expected-warning {{Object has a dynamic type 'NSNumber *' which is incompatible with static type 'NSString *'}}
   num = b.firstObject;
-  str = b[0]; // expected-warning {{Conversion}}
+  str = b[0]; // expected-warning {{Object has a dynamic type 'NSNumber *' which is incompatible with static type 'NSString *'}}
   num = b[0];
 }
 
 void findMethodDeclInTrackedType(id m, NSArray<NSMutableString *> *a,
                                  MutableArray<NSMutableString *> *b) {
   a = b;
   if (getUnknown() == 5) {
     m = a;  

 void eraseSpecialization(NSArray<NSArray<NSString *> *> *arr) {
   NSArray *erased = arr;
   NSArray* a = [erased firstObject];
   NSArray<NSNumber *> *res = a; // expected-warning {{Conversion}}
 }
 
 void returnToUnrelatedType(NSArray<NSArray<NSString *> *> *arr) {
   NSArray *erased = arr;
-  NSSet* a = [erased firstObject]; // expected-warning {{Conversion}}
+  NSSet* a = [erased firstObject]; // expected-warning {{Object has a dynamic type 'NSArray<NSString *> *' which is incompatible with static type 'NSSet *'}}
   (void)a;
 }
 
 void returnToIdVariable(NSArray<NSString *> *arr) {
   NSArray *erased = arr;
   id a = [erased firstObject];
-  // TODO: Warn in this case. Possibly in a separate checker.
-  NSNumber *res = a;
+  NSNumber *res = a; // expected-warning {{Object has a dynamic type 'NSString *' which is incompatible with static type 'NSNumber *'}}
 }
 
 // CHECK:  <array>
 // CHECK:   <dict>
 // CHECK:    <key>path</key>
 // CHECK:    <array>
 // CHECK:     <dict>
 // CHECK:      <key>kind</key><string>event</string>

 // CHECK:    <key>col</key><integer>27</integer>
 // CHECK:    <key>file</key><integer>0</integer>
 // CHECK:   </dict>
 // CHECK:   </dict>
 // CHECK:   <dict>
 // CHECK:    <key>path</key>
 // CHECK:    <array>
 // CHECK:     <dict>
-// CHECK:      <key>kind</key><string>event</string>
-// CHECK:      <key>location</key>
-// CHECK:      <dict>
-// CHECK:       <key>line</key><integer>238</integer>
-// CHECK:       <key>col</key><integer>16</integer>
-// CHECK:       <key>file</key><integer>0</integer>
-// CHECK:      </dict>
-// CHECK:      <key>ranges</key>
-// CHECK:      <array>
-// CHECK:        <array>
-// CHECK:         <dict>
-// CHECK:          <key>line</key><integer>238</integer>
-// CHECK:          <key>col</key><integer>16</integer>
-// CHECK:          <key>file</key><integer>0</integer>
-// CHECK:         </dict>
-// CHECK:         <dict>
-// CHECK:          <key>line</key><integer>238</integer>
-// CHECK:          <key>col</key><integer>16</integer>
-// CHECK:          <key>file</key><integer>0</integer>
-// CHECK:         </dict>
-// CHECK:        </array>
-// CHECK:      </array>
-// CHECK:      <key>depth</key><integer>0</integer>
-// CHECK:      <key>extended_message</key>
-// CHECK:      <string>Type &apos;NSArray&lt;NSNumber *&gt; *&apos; is inferred from implicit cast (from &apos;NSArray&lt;NSNumber *&gt; *&apos; to &apos;NSArray *&apos;)</string>
-// CHECK:      <key>message</key>
-// CHECK:      <string>Type &apos;NSArray&lt;NSNumber *&gt; *&apos; is inferred from implicit cast (from &apos;NSArray&lt;NSNumber *&gt; *&apos; to &apos;NSArray *&apos;)</string>
-// CHECK:     </dict>
-// CHECK:     <dict>
 // CHECK:      <key>kind</key><string>control</string>
 // CHECK:      <key>edges</key>
 // CHECK:       <array>
 // CHECK:        <dict>
 // CHECK:         <key>start</key>
 // CHECK:          <array>
 // CHECK:           <dict>
 // CHECK:            <key>line</key><integer>238</integer>

 // CHECK:          <key>line</key><integer>239</integer>
 // CHECK:          <key>col</key><integer>38</integer>
 // CHECK:          <key>file</key><integer>0</integer>
 // CHECK:         </dict>
 // CHECK:        </array>
 // CHECK:      </array>
 // CHECK:      <key>depth</key><integer>0</integer>
 // CHECK:      <key>extended_message</key>
-// CHECK:      <string>Conversion from value of type &apos;NSNumber *&apos; to incompatible type &apos;NSString *&apos;</string>
+// CHECK:      <string>Type &apos;NSNumber *&apos; is inferred from this context</string>
 // CHECK:      <key>message</key>
-// CHECK:      <string>Conversion from value of type &apos;NSNumber *&apos; to incompatible type &apos;NSString *&apos;</string>
+// CHECK:      <string>Type &apos;NSNumber *&apos; is inferred from this context</string>
 // CHECK:     </dict>
-// CHECK:    </array>
-// CHECK:    <key>description</key><string>Conversion from value of type &apos;NSNumber *&apos; to incompatible type &apos;NSString *&apos;</string>
-// CHECK:    <key>category</key><string>Core Foundation/Objective-C</string>
-// CHECK:    <key>type</key><string>Generics</string>
-// CHECK:    <key>check_name</key><string>core.DynamicTypePropagation</string>
-// CHECK:   <key>issue_context_kind</key><string>function</string>
-// CHECK:   <key>issue_context</key><string>workWithProperties</string>
-// CHECK:   <key>issue_hash</key><string>2</string>
-// CHECK:   <key>location</key>
-// CHECK:   <dict>
-// CHECK:    <key>line</key><integer>239</integer>
-// CHECK:    <key>col</key><integer>19</integer>
-// CHECK:    <key>file</key><integer>0</integer>
-// CHECK:   </dict>
-// CHECK:   </dict>
-// CHECK:   <dict>
-// CHECK:    <key>path</key>
-// CHECK:    <array>
 // CHECK:     <dict>
 // CHECK:      <key>kind</key><string>event</string>
 // CHECK:      <key>location</key>
 // CHECK:      <dict>
-// CHECK:       <key>line</key><integer>238</integer>
-// CHECK:       <key>col</key><integer>16</integer>
+// CHECK:       <key>line</key><integer>239</integer>
+// CHECK:       <key>col</key><integer>19</integer>
 // CHECK:       <key>file</key><integer>0</integer>
 // CHECK:      </dict>
 // CHECK:      <key>ranges</key>
 // CHECK:      <array>
 // CHECK:        <array>
 // CHECK:         <dict>
-// CHECK:          <key>line</key><integer>238</integer>
-// CHECK:          <key>col</key><integer>16</integer>
+// CHECK:          <key>line</key><integer>239</integer>
+// CHECK:          <key>col</key><integer>19</integer>
 // CHECK:          <key>file</key><integer>0</integer>
 // CHECK:         </dict>
 // CHECK:         <dict>
-// CHECK:          <key>line</key><integer>238</integer>
-// CHECK:          <key>col</key><integer>16</integer>
+// CHECK:          <key>line</key><integer>239</integer>
+// CHECK:          <key>col</key><integer>38</integer>
 // CHECK:          <key>file</key><integer>0</integer>
 // CHECK:         </dict>
 // CHECK:        </array>
 // CHECK:      </array>
 // CHECK:      <key>depth</key><integer>0</integer>
 // CHECK:      <key>extended_message</key>
-// CHECK:      <string>Type &apos;NSArray&lt;NSNumber *&gt; *&apos; is inferred from implicit cast (from &apos;NSArray&lt;NSNumber *&gt; *&apos; to &apos;NSArray *&apos;)</string>
+// CHECK:      <string>Object has a dynamic type &apos;NSNumber *&apos; which is incompatible with static type &apos;NSString *&apos;</string>
 // CHECK:      <key>message</key>
-// CHECK:      <string>Type &apos;NSArray&lt;NSNumber *&gt; *&apos; is inferred from implicit cast (from &apos;NSArray&lt;NSNumber *&gt; *&apos; to &apos;NSArray *&apos;)</string>
-// CHECK:     </dict>
-// CHECK:     <dict>
+// CHECK:      <string>Object has a dynamic type &apos;NSNumber *&apos; which is incompatible with static type &apos;NSString *&apos;</string>
+// CHECK:     </dict>
+// CHECK:    </array>
+// CHECK:    <key>description</key><string>Object has a dynamic type &apos;NSNumber *&apos; which is incompatible with static type &apos;NSString *&apos;</string>
+// CHECK:    <key>category</key><string>Type Error</string>
+// CHECK:    <key>type</key><string>Dynamic and static type mismatch</string>
+// CHECK:    <key>check_name</key><string>alpha.core.DynamicTypeChecker</string>
+// CHECK:   <key>issue_context_kind</key><string>function</string>
+// CHECK:   <key>issue_context</key><string>workWithProperties</string>
+// CHECK:   <key>issue_hash</key><string>2</string>
+// CHECK:   <key>location</key>
+// CHECK:   <dict>
+// CHECK:    <key>line</key><integer>239</integer>
+// CHECK:    <key>col</key><integer>19</integer>
+// CHECK:    <key>file</key><integer>0</integer>
+// CHECK:   </dict>
+// CHECK:   </dict>
+// CHECK:   <dict>
+// CHECK:    <key>path</key>
+// CHECK:    <array>
+// CHECK:     <dict>
 // CHECK:      <key>kind</key><string>control</string>
 // CHECK:      <key>edges</key>
 // CHECK:       <array>
 // CHECK:        <dict>
 // CHECK:         <key>start</key>
 // CHECK:          <array>
 // CHECK:           <dict>
 // CHECK:            <key>line</key><integer>238</integer>

 // CHECK:          <key>line</key><integer>241</integer>
 // CHECK:          <key>col</key><integer>23</integer>
 // CHECK:          <key>file</key><integer>0</integer>
 // CHECK:         </dict>
 // CHECK:        </array>
 // CHECK:      </array>
 // CHECK:      <key>depth</key><integer>0</integer>
 // CHECK:      <key>extended_message</key>
-// CHECK:      <string>Conversion from value of type &apos;NSNumber *&apos; to incompatible type &apos;NSString *&apos;</string>
+// CHECK:      <string>Type &apos;NSNumber *&apos; is inferred from this context</string>
 // CHECK:      <key>message</key>
-// CHECK:      <string>Conversion from value of type &apos;NSNumber *&apos; to incompatible type &apos;NSString *&apos;</string>
-// CHECK:     </dict>
-// CHECK:    </array>
-// CHECK:    <key>description</key><string>Conversion from value of type &apos;NSNumber *&apos; to incompatible type &apos;NSString *&apos;</string>
-// CHECK:    <key>category</key><string>Core Foundation/Objective-C</string>
-// CHECK:    <key>type</key><string>Generics</string>
-// CHECK:    <key>check_name</key><string>core.DynamicTypePropagation</string>
-// CHECK:   <key>issue_context_kind</key><string>function</string>
-// CHECK:   <key>issue_context</key><string>workWithProperties</string>
-// CHECK:   <key>issue_hash</key><string>4</string>
-// CHECK:   <key>location</key>
-// CHECK:   <dict>
-// CHECK:    <key>line</key><integer>241</integer>
-// CHECK:    <key>col</key><integer>9</integer>
-// CHECK:    <key>file</key><integer>0</integer>
-// CHECK:   </dict>
-// CHECK:   </dict>
-// CHECK:   <dict>
-// CHECK:    <key>path</key>
-// CHECK:    <array>
-// CHECK:     <dict>
+// CHECK:      <string>Type &apos;NSNumber *&apos; is inferred from this context</string>
+// CHECK:     </dict>
+// CHECK:     <dict>
 // CHECK:      <key>kind</key><string>event</string>
 // CHECK:      <key>location</key>
 // CHECK:      <dict>
-// CHECK:       <key>line</key><integer>238</integer>
-// CHECK:       <key>col</key><integer>16</integer>
+// CHECK:       <key>line</key><integer>241</integer>
+// CHECK:       <key>col</key><integer>9</integer>
 // CHECK:       <key>file</key><integer>0</integer>
 // CHECK:      </dict>
 // CHECK:      <key>ranges</key>
 // CHECK:      <array>
 // CHECK:        <array>
 // CHECK:         <dict>
-// CHECK:          <key>line</key><integer>238</integer>
-// CHECK:          <key>col</key><integer>16</integer>
+// CHECK:          <key>line</key><integer>241</integer>
+// CHECK:          <key>col</key><integer>9</integer>
 // CHECK:          <key>file</key><integer>0</integer>
 // CHECK:         </dict>
 // CHECK:         <dict>
-// CHECK:          <key>line</key><integer>238</integer>
-// CHECK:          <key>col</key><integer>16</integer>
+// CHECK:          <key>line</key><integer>241</integer>
+// CHECK:          <key>col</key><integer>23</integer>
 // CHECK:          <key>file</key><integer>0</integer>
 // CHECK:         </dict>
 // CHECK:        </array>
 // CHECK:      </array>
 // CHECK:      <key>depth</key><integer>0</integer>
 // CHECK:      <key>extended_message</key>
-// CHECK:      <string>Type &apos;NSArray&lt;NSNumber *&gt; *&apos; is inferred from implicit cast (from &apos;NSArray&lt;NSNumber *&gt; *&apos; to &apos;NSArray *&apos;)</string>
+// CHECK:      <string>Object has a dynamic type &apos;NSNumber *&apos; which is incompatible with static type &apos;NSString *&apos;</string>
 // CHECK:      <key>message</key>
-// CHECK:      <string>Type &apos;NSArray&lt;NSNumber *&gt; *&apos; is inferred from implicit cast (from &apos;NSArray&lt;NSNumber *&gt; *&apos; to &apos;NSArray *&apos;)</string>
-// CHECK:     </dict>
-// CHECK:     <dict>
+// CHECK:      <string>Object has a dynamic type &apos;NSNumber *&apos; which is incompatible with static type &apos;NSString *&apos;</string>
+// CHECK:     </dict>
+// CHECK:    </array>
+// CHECK:    <key>description</key><string>Object has a dynamic type &apos;NSNumber *&apos; which is incompatible with static type &apos;NSString *&apos;</string>
+// CHECK:    <key>category</key><string>Type Error</string>
+// CHECK:    <key>type</key><string>Dynamic and static type mismatch</string>
+// CHECK:    <key>check_name</key><string>alpha.core.DynamicTypeChecker</string>
+// CHECK:   <key>issue_context_kind</key><string>function</string>
+// CHECK:   <key>issue_context</key><string>workWithProperties</string>
+// CHECK:   <key>issue_hash</key><string>4</string>
+// CHECK:   <key>location</key>
+// CHECK:   <dict>
+// CHECK:    <key>line</key><integer>241</integer>
+// CHECK:    <key>col</key><integer>9</integer>
+// CHECK:    <key>file</key><integer>0</integer>
+// CHECK:   </dict>
+// CHECK:   </dict>
+// CHECK:   <dict>
+// CHECK:    <key>path</key>
+// CHECK:    <array>
+// CHECK:     <dict>
 // CHECK:      <key>kind</key><string>control</string>
 // CHECK:      <key>edges</key>
 // CHECK:       <array>
 // CHECK:        <dict>
 // CHECK:         <key>start</key>
 // CHECK:          <array>
 // CHECK:           <dict>
 // CHECK:            <key>line</key><integer>238</integer>

 // CHECK:          <key>line</key><integer>243</integer>
 // CHECK:          <key>col</key><integer>21</integer>
 // CHECK:          <key>file</key><integer>0</integer>
 // CHECK:         </dict>
 // CHECK:        </array>
 // CHECK:      </array>
 // CHECK:      <key>depth</key><integer>0</integer>
 // CHECK:      <key>extended_message</key>
-// CHECK:      <string>Conversion from value of type &apos;NSNumber *&apos; to incompatible type &apos;NSString *&apos;</string>
+// CHECK:      <string>Type &apos;NSNumber *&apos; is inferred from this context</string>
 // CHECK:      <key>message</key>
-// CHECK:      <string>Conversion from value of type &apos;NSNumber *&apos; to incompatible type &apos;NSString *&apos;</string>
+// CHECK:      <string>Type &apos;NSNumber *&apos; is inferred from this context</string>
 // CHECK:     </dict>
-// CHECK:    </array>
-// CHECK:    <key>description</key><string>Conversion from value of type &apos;NSNumber *&apos; to incompatible type &apos;NSString *&apos;</string>
-// CHECK:    <key>category</key><string>Core Foundation/Objective-C</string>
-// CHECK:    <key>type</key><string>Generics</string>
-// CHECK:    <key>check_name</key><string>core.DynamicTypePropagation</string>
-// CHECK:   <key>issue_context_kind</key><string>function</string>
-// CHECK:   <key>issue_context</key><string>workWithProperties</string>
-// CHECK:   <key>issue_hash</key><string>6</string>
-// CHECK:   <key>location</key>
-// CHECK:   <dict>
-// CHECK:    <key>line</key><integer>243</integer>
-// CHECK:    <key>col</key><integer>11</integer>
-// CHECK:    <key>file</key><integer>0</integer>
-// CHECK:   </dict>
-// CHECK:   </dict>
-// CHECK:   <dict>
-// CHECK:    <key>path</key>
-// CHECK:    <array>
 // CHECK:     <dict>
 // CHECK:      <key>kind</key><string>event</string>
 // CHECK:      <key>location</key>
 // CHECK:      <dict>
-// CHECK:       <key>line</key><integer>238</integer>
-// CHECK:       <key>col</key><integer>16</integer>
+// CHECK:       <key>line</key><integer>243</integer>
+// CHECK:       <key>col</key><integer>9</integer>
 // CHECK:       <key>file</key><integer>0</integer>
 // CHECK:      </dict>
 // CHECK:      <key>ranges</key>
 // CHECK:      <array>
 // CHECK:        <array>
 // CHECK:         <dict>
-// CHECK:          <key>line</key><integer>238</integer>
-// CHECK:          <key>col</key><integer>16</integer>
+// CHECK:          <key>line</key><integer>243</integer>
+// CHECK:          <key>col</key><integer>9</integer>
 // CHECK:          <key>file</key><integer>0</integer>
 // CHECK:         </dict>
 // CHECK:         <dict>
-// CHECK:          <key>line</key><integer>238</integer>
-// CHECK:          <key>col</key><integer>16</integer>
+// CHECK:          <key>line</key><integer>243</integer>
+// CHECK:          <key>col</key><integer>21</integer>
 // CHECK:          <key>file</key><integer>0</integer>
 // CHECK:         </dict>
 // CHECK:        </array>
 // CHECK:      </array>
 // CHECK:      <key>depth</key><integer>0</integer>
 // CHECK:      <key>extended_message</key>
-// CHECK:      <string>Type &apos;NSArray&lt;NSNumber *&gt; *&apos; is inferred from implicit cast (from &apos;NSArray&lt;NSNumber *&gt; *&apos; to &apos;NSArray *&apos;)</string>
+// CHECK:      <string>Object has a dynamic type &apos;NSNumber *&apos; which is incompatible with static type &apos;NSString *&apos;</string>
 // CHECK:      <key>message</key>
-// CHECK:      <string>Type &apos;NSArray&lt;NSNumber *&gt; *&apos; is inferred from implicit cast (from &apos;NSArray&lt;NSNumber *&gt; *&apos; to &apos;NSArray *&apos;)</string>
-// CHECK:     </dict>
-// CHECK:     <dict>
+// CHECK:      <string>Object has a dynamic type &apos;NSNumber *&apos; which is incompatible with static type &apos;NSString *&apos;</string>
+// CHECK:     </dict>
+// CHECK:    </array>
+// CHECK:    <key>description</key><string>Object has a dynamic type &apos;NSNumber *&apos; which is incompatible with static type &apos;NSString *&apos;</string>
+// CHECK:    <key>category</key><string>Type Error</string>
+// CHECK:    <key>type</key><string>Dynamic and static type mismatch</string>
+// CHECK:    <key>check_name</key><string>alpha.core.DynamicTypeChecker</string>
+// CHECK:   <key>issue_context_kind</key><string>function</string>
+// CHECK:   <key>issue_context</key><string>workWithProperties</string>
+// CHECK:   <key>issue_hash</key><string>6</string>
+// CHECK:   <key>location</key>
+// CHECK:   <dict>
+// CHECK:    <key>line</key><integer>243</integer>
+// CHECK:    <key>col</key><integer>9</integer>
+// CHECK:    <key>file</key><integer>0</integer>
+// CHECK:   </dict>
+// CHECK:   </dict>
+// CHECK:   <dict>
+// CHECK:    <key>path</key>
+// CHECK:    <array>
+// CHECK:     <dict>
 // CHECK:      <key>kind</key><string>control</string>
 // CHECK:      <key>edges</key>
 // CHECK:       <array>
 // CHECK:        <dict>
 // CHECK:         <key>start</key>
 // CHECK:          <array>
 // CHECK:           <dict>
 // CHECK:            <key>line</key><integer>238</integer>

 // CHECK:          <key>line</key><integer>245</integer>
 // CHECK:          <key>col</key><integer>9</integer>
 // CHECK:          <key>file</key><integer>0</integer>
 // CHECK:         </dict>
 // CHECK:        </array>
 // CHECK:      </array>
 // CHECK:      <key>depth</key><integer>0</integer>
 // CHECK:      <key>extended_message</key>
-// CHECK:      <string>Conversion from value of type &apos;NSNumber *&apos; to incompatible type &apos;NSString *&apos;</string>
+// CHECK:      <string>Type &apos;NSNumber *&apos; is inferred from this context</string>
 // CHECK:      <key>message</key>
-// CHECK:      <string>Conversion from value of type &apos;NSNumber *&apos; to incompatible type &apos;NSString *&apos;</string>
-// CHECK:     </dict>
-// CHECK:    </array>
-// CHECK:    <key>description</key><string>Conversion from value of type &apos;NSNumber *&apos; to incompatible type &apos;NSString *&apos;</string>
-// CHECK:    <key>category</key><string>Core Foundation/Objective-C</string>
-// CHECK:    <key>type</key><string>Generics</string>
-// CHECK:    <key>check_name</key><string>core.DynamicTypePropagation</string>
+// CHECK:      <string>Type &apos;NSNumber *&apos; is inferred from this context</string>
+// CHECK:     </dict>
+// CHECK:     <dict>
+// CHECK:      <key>kind</key><string>event</string>
+// CHECK:      <key>location</key>
+// CHECK:      <dict>
+// CHECK:       <key>line</key><integer>245</integer>
+// CHECK:       <key>col</key><integer>9</integer>
+// CHECK:       <key>file</key><integer>0</integer>
+// CHECK:      </dict>
+// CHECK:      <key>ranges</key>
+// CHECK:      <array>
+// CHECK:        <array>
+// CHECK:         <dict>
+// CHECK:          <key>line</key><integer>245</integer>
+// CHECK:          <key>col</key><integer>9</integer>
+// CHECK:          <key>file</key><integer>0</integer>
+// CHECK:         </dict>
+// CHECK:         <dict>
+// CHECK:          <key>line</key><integer>245</integer>
+// CHECK:          <key>col</key><integer>12</integer>
+// CHECK:          <key>file</key><integer>0</integer>
+// CHECK:         </dict>
+// CHECK:        </array>
+// CHECK:      </array>
+// CHECK:      <key>depth</key><integer>0</integer>
+// CHECK:      <key>extended_message</key>
+// CHECK:      <string>Object has a dynamic type &apos;NSNumber *&apos; which is incompatible with static type &apos;NSString *&apos;</string>
+// CHECK:      <key>message</key>
+// CHECK:      <string>Object has a dynamic type &apos;NSNumber *&apos; which is incompatible with static type &apos;NSString *&apos;</string>
+// CHECK:     </dict>
+// CHECK:    </array>
+// CHECK:    <key>description</key><string>Object has a dynamic type &apos;NSNumber *&apos; which is incompatible with static type &apos;NSString *&apos;</string>
+// CHECK:    <key>category</key><string>Type Error</string>
+// CHECK:    <key>type</key><string>Dynamic and static type mismatch</string>
+// CHECK:    <key>check_name</key><string>alpha.core.DynamicTypeChecker</string>
 // CHECK:   <key>issue_context_kind</key><string>function</string>
 // CHECK:   <key>issue_context</key><string>workWithProperties</string>
 // CHECK:   <key>issue_hash</key><string>8</string>
 // CHECK:   <key>location</key>
 // CHECK:   <dict>
 // CHECK:    <key>line</key><integer>245</integer>
 // CHECK:    <key>col</key><integer>9</integer>
 // CHECK:    <key>file</key><integer>0</integer>

 // CHECK:    <key>col</key><integer>3</integer>
 // CHECK:    <key>file</key><integer>0</integer>
 // CHECK:   </dict>
 // CHECK:   </dict>
 // CHECK:   <dict>
 // CHECK:    <key>path</key>
 // CHECK:    <array>
 // CHECK:     <dict>
-// CHECK:      <key>kind</key><string>event</string>
-// CHECK:      <key>location</key>
-// CHECK:      <dict>
-// CHECK:       <key>line</key><integer>289</integer>
-// CHECK:       <key>col</key><integer>13</integer>
-// CHECK:       <key>file</key><integer>0</integer>
-// CHECK:      </dict>
-// CHECK:      <key>ranges</key>
-// CHECK:      <array>
-// CHECK:        <array>
-// CHECK:         <dict>
-// CHECK:          <key>line</key><integer>289</integer>
-// CHECK:          <key>col</key><integer>13</integer>
-// CHECK:          <key>file</key><integer>0</integer>
-// CHECK:         </dict>
-// CHECK:         <dict>
-// CHECK:          <key>line</key><integer>289</integer>
-// CHECK:          <key>col</key><integer>39</integer>
-// CHECK:          <key>file</key><integer>0</integer>
-// CHECK:         </dict>
-// CHECK:        </array>
-// CHECK:      </array>
-// CHECK:      <key>depth</key><integer>0</integer>
-// CHECK:      <key>extended_message</key>
-// CHECK:      <string>Type &apos;NSArray&lt;NSString *&gt; *&apos; is inferred from this context</string>
-// CHECK:      <key>message</key>
-// CHECK:      <string>Type &apos;NSArray&lt;NSString *&gt; *&apos; is inferred from this context</string>
-// CHECK:     </dict>
-// CHECK:     <dict>
 // CHECK:      <key>kind</key><string>control</string>
 // CHECK:      <key>edges</key>
 // CHECK:       <array>
 // CHECK:        <dict>
 // CHECK:         <key>start</key>
 // CHECK:          <array>
 // CHECK:           <dict>
 // CHECK:            <key>line</key><integer>289</integer>

 // CHECK:          <key>line</key><integer>290</integer>
 // CHECK:          <key>col</key><integer>39</integer>
 // CHECK:          <key>file</key><integer>0</integer>
 // CHECK:         </dict>
 // CHECK:        </array>
 // CHECK:      </array>
 // CHECK:      <key>depth</key><integer>0</integer>
 // CHECK:      <key>extended_message</key>
-// CHECK:      <string>Conversion from value of type &apos;NSArray&lt;NSString *&gt; *&apos; to incompatible type &apos;NSArray&lt;NSNumber *&gt; *&apos;</string>
+// CHECK:      <string>Type &apos;NSArray&lt;NSString *&gt; *&apos; is inferred from this context</string>
 // CHECK:      <key>message</key>
-// CHECK:      <string>Conversion from value of type &apos;NSArray&lt;NSString *&gt; *&apos; to incompatible type &apos;NSArray&lt;NSNumber *&gt; *&apos;</string>
-// CHECK:     </dict>
-// CHECK:    </array>
-// CHECK:    <key>description</key><string>Conversion from value of type &apos;NSArray&lt;NSString *&gt; *&apos; to incompatible type &apos;NSArray&lt;NSNumber *&gt; *&apos;</string>
-// CHECK:    <key>category</key><string>Core Foundation/Objective-C</string>
-// CHECK:    <key>type</key><string>Generics</string>
-// CHECK:    <key>check_name</key><string>core.DynamicTypePropagation</string>
-// CHECK:   <key>issue_context_kind</key><string>function</string>
-// CHECK:   <key>issue_context</key><string>trackedClassVariables</string>
-// CHECK:   <key>issue_hash</key><string>2</string>
-// CHECK:   <key>location</key>
-// CHECK:   <dict>
-// CHECK:    <key>line</key><integer>290</integer>
-// CHECK:    <key>col</key><integer>28</integer>
-// CHECK:    <key>file</key><integer>0</integer>
-// CHECK:   </dict>
-// CHECK:   </dict>
-// CHECK:   <dict>
-// CHECK:    <key>path</key>
-// CHECK:    <array>
-// CHECK:     <dict>
+// CHECK:      <string>Type &apos;NSArray&lt;NSString *&gt; *&apos; is inferred from this context</string>
+// CHECK:     </dict>
+// CHECK:     <dict>
 // CHECK:      <key>kind</key><string>event</string>
 // CHECK:      <key>location</key>
 // CHECK:      <dict>
-// CHECK:       <key>line</key><integer>289</integer>
-// CHECK:       <key>col</key><integer>13</integer>
+// CHECK:       <key>line</key><integer>290</integer>
+// CHECK:       <key>col</key><integer>28</integer>
 // CHECK:       <key>file</key><integer>0</integer>
 // CHECK:      </dict>
 // CHECK:      <key>ranges</key>
 // CHECK:      <array>
 // CHECK:        <array>
 // CHECK:         <dict>
-// CHECK:          <key>line</key><integer>289</integer>
-// CHECK:          <key>col</key><integer>13</integer>
+// CHECK:          <key>line</key><integer>290</integer>
+// CHECK:          <key>col</key><integer>28</integer>
 // CHECK:          <key>file</key><integer>0</integer>
 // CHECK:         </dict>
 // CHECK:         <dict>
-// CHECK:          <key>line</key><integer>289</integer>
+// CHECK:          <key>line</key><integer>290</integer>
 // CHECK:          <key>col</key><integer>39</integer>
 // CHECK:          <key>file</key><integer>0</integer>
 // CHECK:         </dict>
 // CHECK:        </array>
 // CHECK:      </array>
 // CHECK:      <key>depth</key><integer>0</integer>
 // CHECK:      <key>extended_message</key>
-// CHECK:      <string>Type &apos;NSArray&lt;NSString *&gt; *&apos; is inferred from this context</string>
+// CHECK:      <string>Conversion from value of type &apos;NSArray&lt;NSString *&gt; *&apos; to incompatible type &apos;NSArray&lt;NSNumber *&gt; *&apos;</string>
 // CHECK:      <key>message</key>
-// CHECK:      <string>Type &apos;NSArray&lt;NSString *&gt; *&apos; is inferred from this context</string>
+// CHECK:      <string>Conversion from value of type &apos;NSArray&lt;NSString *&gt; *&apos; to incompatible type &apos;NSArray&lt;NSNumber *&gt; *&apos;</string>
 // CHECK:     </dict>
+// CHECK:    </array>
+// CHECK:    <key>description</key><string>Conversion from value of type &apos;NSArray&lt;NSString *&gt; *&apos; to incompatible type &apos;NSArray&lt;NSNumber *&gt; *&apos;</string>
+// CHECK:    <key>category</key><string>Core Foundation/Objective-C</string>
+// CHECK:    <key>type</key><string>Generics</string>
+// CHECK:    <key>check_name</key><string>core.DynamicTypePropagation</string>
+// CHECK:   <key>issue_context_kind</key><string>function</string>
+// CHECK:   <key>issue_context</key><string>trackedClassVariables</string>
+// CHECK:   <key>issue_hash</key><string>2</string>
+// CHECK:   <key>location</key>
+// CHECK:   <dict>
+// CHECK:    <key>line</key><integer>290</integer>
+// CHECK:    <key>col</key><integer>28</integer>
+// CHECK:    <key>file</key><integer>0</integer>
+// CHECK:   </dict>
+// CHECK:   </dict>
+// CHECK:   <dict>
+// CHECK:    <key>path</key>
+// CHECK:    <array>
 // CHECK:     <dict>
 // CHECK:      <key>kind</key><string>control</string>
 // CHECK:      <key>edges</key>
 // CHECK:       <array>
 // CHECK:        <dict>
 // CHECK:         <key>start</key>
 // CHECK:          <array>
 // CHECK:           <dict>

 // CHECK:          <key>line</key><integer>291</integer>
 // CHECK:          <key>col</key><integer>19</integer>
 // CHECK:          <key>file</key><integer>0</integer>
 // CHECK:         </dict>
 // CHECK:        </array>
 // CHECK:      </array>
 // CHECK:      <key>depth</key><integer>0</integer>
 // CHECK:      <key>extended_message</key>
+// CHECK:      <string>Type &apos;NSArray&lt;NSString *&gt; *&apos; is inferred from this context</string>
+// CHECK:      <key>message</key>
+// CHECK:      <string>Type &apos;NSArray&lt;NSString *&gt; *&apos; is inferred from this context</string>
+// CHECK:     </dict>
+// CHECK:     <dict>
+// CHECK:      <key>kind</key><string>event</string>
+// CHECK:      <key>location</key>
+// CHECK:      <dict>
+// CHECK:       <key>line</key><integer>291</integer>
+// CHECK:       <key>col</key><integer>7</integer>
+// CHECK:       <key>file</key><integer>0</integer>
+// CHECK:      </dict>
+// CHECK:      <key>ranges</key>
+// CHECK:      <array>
+// CHECK:        <array>
+// CHECK:         <dict>
+// CHECK:          <key>line</key><integer>291</integer>
+// CHECK:          <key>col</key><integer>7</integer>
+// CHECK:          <key>file</key><integer>0</integer>
+// CHECK:         </dict>
+// CHECK:         <dict>
+// CHECK:          <key>line</key><integer>291</integer>
+// CHECK:          <key>col</key><integer>19</integer>
+// CHECK:          <key>file</key><integer>0</integer>
+// CHECK:         </dict>
+// CHECK:        </array>
+// CHECK:      </array>
+// CHECK:      <key>depth</key><integer>0</integer>
+// CHECK:      <key>extended_message</key>
 // CHECK:      <string>Conversion from value of type &apos;NSArray&lt;NSString *&gt; *&apos; to incompatible type &apos;NSArray&lt;NSNumber *&gt; *&apos;</string>
 // CHECK:      <key>message</key>
 // CHECK:      <string>Conversion from value of type &apos;NSArray&lt;NSString *&gt; *&apos; to incompatible type &apos;NSArray&lt;NSNumber *&gt; *&apos;</string>
 // CHECK:     </dict>
 // CHECK:    </array>
 // CHECK:    <key>description</key><string>Conversion from value of type &apos;NSArray&lt;NSString *&gt; *&apos; to incompatible type &apos;NSArray&lt;NSNumber *&gt; *&apos;</string>
 // CHECK:    <key>category</key><string>Core Foundation/Objective-C</string>
 // CHECK:    <key>type</key><string>Generics</string>

 // CHECK:    <key>col</key><integer>30</integer>
 // CHECK:    <key>file</key><integer>0</integer>
 // CHECK:   </dict>
 // CHECK:   </dict>
 // CHECK:   <dict>
 // CHECK:    <key>path</key>
 // CHECK:    <array>
 // CHECK:     <dict>
-// CHECK:      <key>kind</key><string>event</string>
-// CHECK:      <key>location</key>
-// CHECK:      <dict>
-// CHECK:       <key>line</key><integer>320</integer>
-// CHECK:       <key>col</key><integer>21</integer>
-// CHECK:       <key>file</key><integer>0</integer>
-// CHECK:      </dict>
-// CHECK:      <key>ranges</key>
-// CHECK:      <array>
-// CHECK:        <array>
-// CHECK:         <dict>
-// CHECK:          <key>line</key><integer>320</integer>
-// CHECK:          <key>col</key><integer>21</integer>
-// CHECK:          <key>file</key><integer>0</integer>
-// CHECK:         </dict>
-// CHECK:         <dict>
-// CHECK:          <key>line</key><integer>320</integer>
-// CHECK:          <key>col</key><integer>23</integer>
-// CHECK:          <key>file</key><integer>0</integer>
-// CHECK:         </dict>
-// CHECK:        </array>
-// CHECK:      </array>
-// CHECK:      <key>depth</key><integer>0</integer>
-// CHECK:      <key>extended_message</key>
-// CHECK:      <string>Type &apos;NSArray&lt;NSArray&lt;NSString *&gt; *&gt; *&apos; is inferred from implicit cast (from &apos;NSArray&lt;NSArray&lt;NSString *&gt; *&gt; *&apos; to &apos;NSArray *&apos;)</string>
-// CHECK:      <key>message</key>
-// CHECK:      <string>Type &apos;NSArray&lt;NSArray&lt;NSString *&gt; *&gt; *&apos; is inferred from implicit cast (from &apos;NSArray&lt;NSArray&lt;NSString *&gt; *&gt; *&apos; to &apos;NSArray *&apos;)</string>
-// CHECK:     </dict>
-// CHECK:     <dict>
 // CHECK:      <key>kind</key><string>control</string>
 // CHECK:      <key>edges</key>
 // CHECK:       <array>
 // CHECK:        <dict>
 // CHECK:         <key>start</key>
 // CHECK:          <array>
 // CHECK:           <dict>
 // CHECK:            <key>line</key><integer>320</integer>

 // CHECK:          <key>line</key><integer>321</integer>
 // CHECK:          <key>col</key><integer>33</integer>
 // CHECK:          <key>file</key><integer>0</integer>
 // CHECK:         </dict>
 // CHECK:        </array>
 // CHECK:      </array>
 // CHECK:      <key>depth</key><integer>0</integer>
 // CHECK:      <key>extended_message</key>
-// CHECK:      <string>Conversion from value of type &apos;NSArray&lt;NSString *&gt; *&apos; to incompatible type &apos;NSSet *&apos;</string>
+// CHECK:      <string>Type &apos;NSArray&lt;NSString *&gt; *&apos; is inferred from this context</string>
 // CHECK:      <key>message</key>
-// CHECK:      <string>Conversion from value of type &apos;NSArray&lt;NSString *&gt; *&apos; to incompatible type &apos;NSSet *&apos;</string>
-// CHECK:     </dict>
-// CHECK:    </array>
-// CHECK:    <key>description</key><string>Conversion from value of type &apos;NSArray&lt;NSString *&gt; *&apos; to incompatible type &apos;NSSet *&apos;</string>
-// CHECK:    <key>category</key><string>Core Foundation/Objective-C</string>
-// CHECK:    <key>type</key><string>Generics</string>
-// CHECK:    <key>check_name</key><string>core.DynamicTypePropagation</string>
+// CHECK:      <string>Type &apos;NSArray&lt;NSString *&gt; *&apos; is inferred from this context</string>
+// CHECK:     </dict>
+// CHECK:     <dict>
+// CHECK:      <key>kind</key><string>event</string>
+// CHECK:      <key>location</key>
+// CHECK:      <dict>
+// CHECK:       <key>line</key><integer>321</integer>
+// CHECK:       <key>col</key><integer>14</integer>
+// CHECK:       <key>file</key><integer>0</integer>
+// CHECK:      </dict>
+// CHECK:      <key>ranges</key>
+// CHECK:      <array>
+// CHECK:        <array>
+// CHECK:         <dict>
+// CHECK:          <key>line</key><integer>321</integer>
+// CHECK:          <key>col</key><integer>14</integer>
+// CHECK:          <key>file</key><integer>0</integer>
+// CHECK:         </dict>
+// CHECK:         <dict>
+// CHECK:          <key>line</key><integer>321</integer>
+// CHECK:          <key>col</key><integer>33</integer>
+// CHECK:          <key>file</key><integer>0</integer>
+// CHECK:         </dict>
+// CHECK:        </array>
+// CHECK:      </array>
+// CHECK:      <key>depth</key><integer>0</integer>
+// CHECK:      <key>extended_message</key>
+// CHECK:      <string>Object has a dynamic type &apos;NSArray&lt;NSString *&gt; *&apos; which is incompatible with static type &apos;NSSet *&apos;</string>
+// CHECK:      <key>message</key>
+// CHECK:      <string>Object has a dynamic type &apos;NSArray&lt;NSString *&gt; *&apos; which is incompatible with static type &apos;NSSet *&apos;</string>
+// CHECK:     </dict>
+// CHECK:    </array>
+// CHECK:    <key>description</key><string>Object has a dynamic type &apos;NSArray&lt;NSString *&gt; *&apos; which is incompatible with static type &apos;NSSet *&apos;</string>
+// CHECK:    <key>category</key><string>Type Error</string>
+// CHECK:    <key>type</key><string>Dynamic and static type mismatch</string>
+// CHECK:    <key>check_name</key><string>alpha.core.DynamicTypeChecker</string>
 // CHECK:   <key>issue_context_kind</key><string>function</string>
 // CHECK:   <key>issue_context</key><string>returnToUnrelatedType</string>
 // CHECK:   <key>issue_hash</key><string>2</string>
 // CHECK:   <key>location</key>
 // CHECK:   <dict>
 // CHECK:    <key>line</key><integer>321</integer>
 // CHECK:    <key>col</key><integer>14</integer>
 // CHECK:    <key>file</key><integer>0</integer>
 // CHECK:   </dict>
 // CHECK:   </dict>
+// CHECK:   <dict>
+// CHECK:    <key>path</key>
+// CHECK:    <array>
+// CHECK:     <dict>
+// CHECK:      <key>kind</key><string>control</string>
+// CHECK:      <key>edges</key>
+// CHECK:       <array>
+// CHECK:        <dict>
+// CHECK:         <key>start</key>
+// CHECK:          <array>
+// CHECK:           <dict>
+// CHECK:            <key>line</key><integer>326</integer>
+// CHECK:            <key>col</key><integer>3</integer>
+// CHECK:            <key>file</key><integer>0</integer>
+// CHECK:           </dict>
+// CHECK:           <dict>
+// CHECK:            <key>line</key><integer>326</integer>
+// CHECK:            <key>col</key><integer>9</integer>
+// CHECK:            <key>file</key><integer>0</integer>
+// CHECK:           </dict>
+// CHECK:          </array>
+// CHECK:         <key>end</key>
+// CHECK:          <array>
+// CHECK:           <dict>
+// CHECK:            <key>line</key><integer>327</integer>
+// CHECK:            <key>col</key><integer>3</integer>
+// CHECK:            <key>file</key><integer>0</integer>
+// CHECK:           </dict>
+// CHECK:           <dict>
+// CHECK:            <key>line</key><integer>327</integer>
+// CHECK:            <key>col</key><integer>4</integer>
+// CHECK:            <key>file</key><integer>0</integer>
+// CHECK:           </dict>
+// CHECK:          </array>
+// CHECK:        </dict>
+// CHECK:       </array>
+// CHECK:     </dict>
+// CHECK:     <dict>
+// CHECK:      <key>kind</key><string>event</string>
+// CHECK:      <key>location</key>
+// CHECK:      <dict>
+// CHECK:       <key>line</key><integer>327</integer>
+// CHECK:       <key>col</key><integer>10</integer>
+// CHECK:       <key>file</key><integer>0</integer>
+// CHECK:      </dict>
+// CHECK:      <key>ranges</key>
+// CHECK:      <array>
+// CHECK:        <array>
+// CHECK:         <dict>
+// CHECK:          <key>line</key><integer>327</integer>
+// CHECK:          <key>col</key><integer>10</integer>
+// CHECK:          <key>file</key><integer>0</integer>
+// CHECK:         </dict>
+// CHECK:         <dict>
+// CHECK:          <key>line</key><integer>327</integer>
+// CHECK:          <key>col</key><integer>29</integer>
+// CHECK:          <key>file</key><integer>0</integer>
+// CHECK:         </dict>
+// CHECK:        </array>
+// CHECK:      </array>
+// CHECK:      <key>depth</key><integer>0</integer>
+// CHECK:      <key>extended_message</key>
+// CHECK:      <string>Type &apos;NSString *&apos; is inferred from this context</string>
+// CHECK:      <key>message</key>
+// CHECK:      <string>Type &apos;NSString *&apos; is inferred from this context</string>
+// CHECK:     </dict>
+// CHECK:     <dict>
+// CHECK:      <key>kind</key><string>control</string>
+// CHECK:      <key>edges</key>
+// CHECK:       <array>
+// CHECK:        <dict>
+// CHECK:         <key>start</key>
+// CHECK:          <array>
+// CHECK:           <dict>
+// CHECK:            <key>line</key><integer>327</integer>
+// CHECK:            <key>col</key><integer>3</integer>
+// CHECK:            <key>file</key><integer>0</integer>
+// CHECK:           </dict>
+// CHECK:           <dict>
+// CHECK:            <key>line</key><integer>327</integer>
+// CHECK:            <key>col</key><integer>4</integer>
+// CHECK:            <key>file</key><integer>0</integer>
+// CHECK:           </dict>
+// CHECK:          </array>
+// CHECK:         <key>end</key>
+// CHECK:          <array>
+// CHECK:           <dict>
+// CHECK:            <key>line</key><integer>328</integer>
+// CHECK:            <key>col</key><integer>3</integer>
+// CHECK:            <key>file</key><integer>0</integer>
+// CHECK:           </dict>
+// CHECK:           <dict>
+// CHECK:            <key>line</key><integer>328</integer>
+// CHECK:            <key>col</key><integer>10</integer>
+// CHECK:            <key>file</key><integer>0</integer>
+// CHECK:           </dict>
+// CHECK:          </array>
+// CHECK:        </dict>
+// CHECK:       </array>
+// CHECK:     </dict>
+// CHECK:     <dict>
+// CHECK:      <key>kind</key><string>control</string>
+// CHECK:      <key>edges</key>
+// CHECK:       <array>
+// CHECK:        <dict>
+// CHECK:         <key>start</key>
+// CHECK:          <array>
+// CHECK:           <dict>
+// CHECK:            <key>line</key><integer>328</integer>
+// CHECK:            <key>col</key><integer>3</integer>
+// CHECK:            <key>file</key><integer>0</integer>
+// CHECK:           </dict>
+// CHECK:           <dict>
+// CHECK:            <key>line</key><integer>328</integer>
+// CHECK:            <key>col</key><integer>10</integer>
+// CHECK:            <key>file</key><integer>0</integer>
+// CHECK:           </dict>
+// CHECK:          </array>
+// CHECK:         <key>end</key>
+// CHECK:          <array>
+// CHECK:           <dict>
+// CHECK:            <key>line</key><integer>328</integer>
+// CHECK:            <key>col</key><integer>19</integer>
+// CHECK:            <key>file</key><integer>0</integer>
+// CHECK:           </dict>
+// CHECK:           <dict>
+// CHECK:            <key>line</key><integer>328</integer>
+// CHECK:            <key>col</key><integer>19</integer>
+// CHECK:            <key>file</key><integer>0</integer>
+// CHECK:           </dict>
+// CHECK:          </array>
+// CHECK:        </dict>
+// CHECK:       </array>
+// CHECK:     </dict>
+// CHECK:     <dict>
+// CHECK:      <key>kind</key><string>event</string>
+// CHECK:      <key>location</key>
+// CHECK:      <dict>
+// CHECK:       <key>line</key><integer>328</integer>
+// CHECK:       <key>col</key><integer>19</integer>
+// CHECK:       <key>file</key><integer>0</integer>
+// CHECK:      </dict>
+// CHECK:      <key>ranges</key>
+// CHECK:      <array>
+// CHECK:        <array>
+// CHECK:         <dict>
+// CHECK:          <key>line</key><integer>328</integer>
+// CHECK:          <key>col</key><integer>19</integer>
+// CHECK:          <key>file</key><integer>0</integer>
+// CHECK:         </dict>
+// CHECK:         <dict>
+// CHECK:          <key>line</key><integer>328</integer>
+// CHECK:          <key>col</key><integer>19</integer>
+// CHECK:          <key>file</key><integer>0</integer>
+// CHECK:         </dict>
+// CHECK:        </array>
+// CHECK:      </array>
+// CHECK:      <key>depth</key><integer>0</integer>
+// CHECK:      <key>extended_message</key>
+// CHECK:      <string>Object has a dynamic type &apos;NSString *&apos; which is incompatible with static type &apos;NSNumber *&apos;</string>
+// CHECK:      <key>message</key>
+// CHECK:      <string>Object has a dynamic type &apos;NSString *&apos; which is incompatible with static type &apos;NSNumber *&apos;</string>
+// CHECK:     </dict>
+// CHECK:    </array>
+// CHECK:    <key>description</key><string>Object has a dynamic type &apos;NSString *&apos; which is incompatible with static type &apos;NSNumber *&apos;</string>
+// CHECK:    <key>category</key><string>Type Error</string>
+// CHECK:    <key>type</key><string>Dynamic and static type mismatch</string>
+// CHECK:    <key>check_name</key><string>alpha.core.DynamicTypeChecker</string>
+// CHECK:   <key>issue_context_kind</key><string>function</string>
+// CHECK:   <key>issue_context</key><string>returnToIdVariable</string>
+// CHECK:   <key>issue_hash</key><string>3</string>
+// CHECK:   <key>location</key>
+// CHECK:   <dict>
+// CHECK:    <key>line</key><integer>328</integer>
+// CHECK:    <key>col</key><integer>19</integer>
+// CHECK:    <key>file</key><integer>0</integer>
+// CHECK:   </dict>
+// CHECK:   </dict>
 // CHECK:  </array>