Remove ProgramState::getSymVal(). It was being misused by Checkers,

with at least one subtle bug in MacOSXKeyChainAPIChecker where the
calling the method was a substitute for assuming a symbolic value
was null (which is not the case).

We still keep ConstraintManager::getSymVal(), but we use that as
an optimization in SValBuilder and ProgramState::getSVal() to
constant-fold SVals.  This is only if the ConstraintManager can
provide us with that information, which is no longer a requirement.
As part of this, introduce a default implementation of
ConstraintManager::getSymVal() which returns null.

For Checkers, introduce ConstraintManager::isNull(), which queries
the state to see if the symbolic value is constrained to be a null
value.  It does this without assuming it has been implicitly constant
folded.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@163428 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 10 insertions, 11 deletions

diff --git a/include/clang/StaticAnalyzer/Core/PathSensitive/ProgramState.h b/include/clang/StaticAnalyzer/Core/PathSensitive/ProgramState.h
index 264c6106db..4279504487 100644
--- a/include/clang/StaticAnalyzer/Core/PathSensitive/ProgramState.h
+++ b/include/clang/StaticAnalyzer/Core/PathSensitive/ProgramState.h
@@ -105,7 +105,12 @@ public:
   ~ProgramState();
 
   /// Return the ProgramStateManager associated with this state.
-  ProgramStateManager &getStateManager() const { return *stateMgr; }
+  ProgramStateManager &getStateManager() const {
+    return *stateMgr;
+  }
+  
+  /// Return the ConstraintManager.
+  ConstraintManager &getConstraintManager() const;
 
   /// getEnvironment - Return the environment associated with this state.
   ///  The environment is the mapping from expressions to values.
@@ -246,8 +251,6 @@ public:
   /// Get the lvalue for an array index.
   SVal getLValue(QualType ElementType, SVal Idx, SVal Base) const;
 
-  const llvm::APSInt *getSymVal(SymbolRef sym) const;
-
   /// Returns the SVal bound to the statement 'S' in the state's environment.
   SVal getSVal(const Stmt *S, const LocationContext *LCtx,
                bool useOnlyDirectBindings = false) const;
@@ -592,10 +595,6 @@ public:
     return ProgramStateTrait<T>::MakeContext(p);
   }
 
-  const llvm::APSInt* getSymVal(ProgramStateRef St, SymbolRef sym) {
-    return ConstraintMgr->getSymVal(St, sym);
-  }
-
   void EndPath(ProgramStateRef St) {
     ConstraintMgr->EndPath(St);
   }
@@ -606,6 +605,10 @@ public:
 // Out-of-line method definitions for ProgramState.
 //===----------------------------------------------------------------------===//
 
+inline ConstraintManager &ProgramState::getConstraintManager() const {
+  return stateMgr->getConstraintManager();
+}
+  
 inline const VarRegion* ProgramState::getRegion(const VarDecl *D,
                                                 const LocationContext *LC) const 
 {
@@ -670,10 +673,6 @@ inline SVal ProgramState::getLValue(QualType ElementType, SVal Idx, SVal Base) c
   return UnknownVal();
 }
 
-inline const llvm::APSInt *ProgramState::getSymVal(SymbolRef sym) const {
-  return getStateManager().getSymVal(this, sym);
-}
-
 inline SVal ProgramState::getSVal(const Stmt *Ex, const LocationContext *LCtx,
                                   bool useOnlyDirectBindings) const{
   return Env.getSVal(EnvironmentEntry(Ex, LCtx),