Added method "canReasonAbout" to ConstraintManager. This method returns true if

a ConstraintManager can usefully reason about the given SVal.

llvm-svn: 66624

clang/include/clang/Analysis/PathSensitive/ConstraintManager.h

@@ -51,6 +51,13 @@ public:
                      const char* nl, const char *sep) = 0;
 
   virtual void EndPath(const GRState* St) {}
+  
+  /// canReasonAbout - Not all ConstraintManagers can accurately reason about
+  ///  all SVal values.  This method returns true if the ConstraintManager can
+  ///  reasonably handle a given SVal value.  This is typically queried by
+  ///  GRExprEngine to determine if the value should be replaced with a
+  ///  conjured symbolic value in order to recover some precision.
+  virtual bool canReasonAbout(SVal X) const = 0;
 };
 
 ConstraintManager* CreateBasicConstraintManager(GRStateManager& statemgr);

clang/lib/Analysis/SimpleConstraintManager.cpp

@@ -20,6 +20,10 @@ namespace clang {
 
 SimpleConstraintManager::~SimpleConstraintManager() {}
 
+bool SimpleConstraintManager::canReasonAbout(SVal X) const {
+  return true;
+}
+  
 const GRState*
 SimpleConstraintManager::Assume(const GRState* St, SVal Cond, bool Assumption,
                                 bool& isFeasible) {

clang/lib/Analysis/SimpleConstraintManager.h

@@ -26,6 +26,9 @@ public:
   SimpleConstraintManager(GRStateManager& statemgr) 
     : StateMgr(statemgr) {}
   virtual ~SimpleConstraintManager();
+  
+  bool canReasonAbout(SVal X) const;
+  
   virtual const GRState* Assume(const GRState* St, SVal Cond, bool Assumption,
                                 bool& isFeasible);