2 files changed, 27 insertions, 8 deletions
diff --git a/lib/StaticAnalyzer/Core/ConstraintManager.cpp b/lib/StaticAnalyzer/Core/ConstraintManager.cpp
index 5dd1392bde..4dec526005 100644
--- a/lib/StaticAnalyzer/Core/ConstraintManager.cpp
+++ b/lib/StaticAnalyzer/Core/ConstraintManager.cpp
@@ -12,7 +12,6 @@
 //===----------------------------------------------------------------------===//
 
 #include "clang/StaticAnalyzer/Core/PathSensitive/ProgramState.h"
-#include "llvm/Support/SaveAndRestore.h"
 
 using namespace clang;
 using namespace ento;
@@ -26,13 +25,8 @@ static DefinedSVal getLocFromSymbol(const ProgramStateRef &State,
   return loc::MemRegionVal(R);
 }
 
-/// Convenience method to query the state to see if a symbol is null or
-/// not null, or neither assumption can be made.
-ConditionTruthVal ConstraintManager::isNull(ProgramStateRef State,
-                                            SymbolRef Sym) {
-  // Disable recursive notification of clients.
-  llvm::SaveAndRestore<bool> DisableNotify(NotifyAssumeClients, false);
-  
+ConditionTruthVal ConstraintManager::checkNull(ProgramStateRef State,
+                                               SymbolRef Sym) {  
   QualType Ty = Sym->getType();
   DefinedSVal V = Loc::isLocType(Ty) ? getLocFromSymbol(State, Sym)
                                      : nonloc::SymbolVal(Sym);
diff --git a/lib/StaticAnalyzer/Core/RangeConstraintManager.cpp b/lib/StaticAnalyzer/Core/RangeConstraintManager.cpp
index a4c841eb6b..467abd0837 100644
--- a/lib/StaticAnalyzer/Core/RangeConstraintManager.cpp
+++ b/lib/StaticAnalyzer/Core/RangeConstraintManager.cpp
@@ -324,6 +324,7 @@ public:
                              const llvm::APSInt& Adjustment);
 
   const llvm::APSInt* getSymVal(ProgramStateRef St, SymbolRef sym) const;
+  ConditionTruthVal checkNull(ProgramStateRef State, SymbolRef Sym);
 
   ProgramStateRef removeDeadBindings(ProgramStateRef St, SymbolReaper& SymReaper);
 
@@ -347,6 +348,30 @@ const llvm::APSInt* RangeConstraintManager::getSymVal(ProgramStateRef St,
   return T ? T->getConcreteValue() : NULL;
 }
 
+ConditionTruthVal RangeConstraintManager::checkNull(ProgramStateRef State,
+                                                    SymbolRef Sym) {
+  const RangeSet *Ranges = State->get<ConstraintRange>(Sym);
+
+  // If we don't have any information about this symbol, it's underconstrained.
+  if (!Ranges)
+    return ConditionTruthVal();
+
+  // If we have a concrete value, see if it's zero.
+  if (const llvm::APSInt *Value = Ranges->getConcreteValue())
+    return *Value == 0;
+
+  BasicValueFactory &BV = getBasicVals();
+  APSIntType IntType = BV.getAPSIntType(Sym->getType());
+  llvm::APSInt Zero = IntType.getZeroValue();
+
+  // Check if zero is in the set of possible values.
+  if (Ranges->Intersect(BV, F, Zero, Zero).isEmpty())
+    return false;
+
+  // Zero is a possible value, but it is not the /only/ possible value.
+  return ConditionTruthVal();
+}
+
 /// Scan all symbols referenced by the constraints. If the symbol is not alive
 /// as marked in LSymbols, mark it as dead in DSymbols.
 ProgramStateRef