[analyzer] Only allow CallEvents to be created by CallEventManager.

This ensures that it is valid to reference-count any CallEvents, and we
won't accidentally try to reclaim a CallEvent that lives on the stack.
It also hides an ugly switch statement for handling CallExprs!

There should be no functionality change here.

llvm-svn: 160986

1 files changed, 22 insertions, 17 deletions

diff --git a/clang/lib/StaticAnalyzer/Core/ExprEngineObjC.cpp b/clang/lib/StaticAnalyzer/Core/ExprEngineObjC.cpp
index e61ea795943..e3bc498b51e 100644
--- a/clang/lib/StaticAnalyzer/Core/ExprEngineObjC.cpp
+++ b/clang/lib/StaticAnalyzer/Core/ExprEngineObjC.cpp
@@ -140,17 +140,20 @@ static bool isSubclass(const ObjCInterfaceDecl *Class, IdentifierInfo *II) {
   return isSubclass(Class->getSuperClass(), II);
 }
 
-void ExprEngine::VisitObjCMessage(const ObjCMethodCall &msg,
+void ExprEngine::VisitObjCMessage(const ObjCMessageExpr *ME,
                                   ExplodedNode *Pred,
                                   ExplodedNodeSet &Dst) {
-  
+  CallEventManager &CEMgr = getStateManager().getCallEventManager();
+  CallEventRef<ObjCMethodCall> Msg =
+    CEMgr.getObjCMethodCall(ME, Pred->getState(), Pred->getLocationContext());
+
   // Handle the previsits checks.
   ExplodedNodeSet dstPrevisit;
   getCheckerManager().runCheckersForPreObjCMessage(dstPrevisit, Pred,
-                                                   msg, *this);
+                                                   *Msg, *this);
   ExplodedNodeSet dstGenericPrevisit;
   getCheckerManager().runCheckersForPreCall(dstGenericPrevisit, dstPrevisit,
-                                            msg, *this);
+                                            *Msg, *this);
 
   // Proceed with evaluate the message expression.
   ExplodedNodeSet dstEval;
@@ -159,16 +162,17 @@ void ExprEngine::VisitObjCMessage(const ObjCMethodCall &msg,
   for (ExplodedNodeSet::iterator DI = dstGenericPrevisit.begin(),
        DE = dstGenericPrevisit.end(); DI != DE; ++DI) {
     ExplodedNode *Pred = *DI;
+    ProgramStateRef State = Pred->getState();
+    CallEventRef<ObjCMethodCall> UpdatedMsg = Msg.cloneWithState(State);
     
-    if (msg.isInstanceMessage()) {
-      SVal recVal = msg.getReceiverSVal();
+    if (UpdatedMsg->isInstanceMessage()) {
+      SVal recVal = UpdatedMsg->getReceiverSVal();
       if (!recVal.isUndef()) {
         // Bifurcate the state into nil and non-nil ones.
         DefinedOrUnknownSVal receiverVal = cast<DefinedOrUnknownSVal>(recVal);
         
-        ProgramStateRef state = Pred->getState();
         ProgramStateRef notNilState, nilState;
-        llvm::tie(notNilState, nilState) = state->assume(receiverVal);
+        llvm::tie(notNilState, nilState) = State->assume(receiverVal);
         
         // There are three cases: can be nil or non-nil, must be nil, must be
         // non-nil. We ignore must be nil, and merge the rest two into non-nil.
@@ -180,20 +184,20 @@ void ExprEngine::VisitObjCMessage(const ObjCMethodCall &msg,
         
         // Check if the "raise" message was sent.
         assert(notNilState);
-        if (msg.getSelector() == RaiseSel) {
+        if (Msg->getSelector() == RaiseSel) {
           // If we raise an exception, for now treat it as a sink.
           // Eventually we will want to handle exceptions properly.
-          Bldr.generateNode(currentStmt, Pred, Pred->getState(), true);
+          Bldr.generateNode(currentStmt, Pred, State, true);
           continue;
         }
         
         // Generate a transition to non-Nil state.
-        if (notNilState != state)
+        if (notNilState != State)
           Pred = Bldr.generateNode(currentStmt, Pred, notNilState);
       }
     } else {
       // Check for special class methods.
-      if (const ObjCInterfaceDecl *Iface = msg.getReceiverInterface()) {
+      if (const ObjCInterfaceDecl *Iface = Msg->getReceiverInterface()) {
         if (!NSExceptionII) {
           ASTContext &Ctx = getContext();
           NSExceptionII = &Ctx.Idents.get("NSException");
@@ -222,7 +226,7 @@ void ExprEngine::VisitObjCMessage(const ObjCMethodCall &msg,
               Ctx.Selectors.getSelector(II.size(), &II[0]);
           }
           
-          Selector S = msg.getSelector();
+          Selector S = Msg->getSelector();
           bool RaisesException = false;
           for (unsigned i = 0; i < NUM_RAISE_SELECTORS; ++i) {
             if (S == NSExceptionInstanceRaiseSelectors[i]) {
@@ -240,16 +244,17 @@ void ExprEngine::VisitObjCMessage(const ObjCMethodCall &msg,
         }
       }
     }
-    // Evaluate the call.
-    defaultEvalCall(Bldr, Pred, msg);
 
+    // Evaluate the call.
+    defaultEvalCall(Bldr, Pred, *UpdatedMsg);
   }
   
   ExplodedNodeSet dstPostvisit;
-  getCheckerManager().runCheckersForPostCall(dstPostvisit, dstEval, msg, *this);
+  getCheckerManager().runCheckersForPostCall(dstPostvisit, dstEval,
+                                             *Msg, *this);
 
   // Finally, perform the post-condition check of the ObjCMessageExpr and store
   // the created nodes in 'Dst'.
   getCheckerManager().runCheckersForPostObjCMessage(Dst, dstPostvisit,
-                                                    msg, *this);
+                                                    *Msg, *this);
 }