Added lval::FieldOffset, which represents symbolic lvalues for field offsets from other Lvalues.
This removes the failure in null-deref-ps.c (test suite).


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@50449 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/BasicValueFactory.cpp b/lib/Analysis/BasicValueFactory.cpp
index 22fb2d1..b0aa79e 100644
--- a/lib/Analysis/BasicValueFactory.cpp
+++ b/lib/Analysis/BasicValueFactory.cpp
@@ -18,18 +18,18 @@
 
 using namespace clang;
 
-typedef std::pair<RVal, unsigned> SizedRVal;
+typedef std::pair<RVal, uintptr_t> RValData;
 
 namespace llvm {
-template<> struct FoldingSetTrait<SizedRVal> {
-  static inline void Profile(const SizedRVal& X, llvm::FoldingSetNodeID& ID) {
+template<> struct FoldingSetTrait<RValData> {
+  static inline void Profile(const RValData& X, llvm::FoldingSetNodeID& ID) {
     X.first.Profile(ID);
-    ID.AddInteger(X.second);
+    ID.AddPointer( (void*) X.second);
   }
 };
 }
 
-typedef llvm::FoldingSet<llvm::FoldingSetNodeWrapper<SizedRVal> >
+typedef llvm::FoldingSet<llvm::FoldingSetNodeWrapper<RValData> >
   PersistentRValsTy;
 
 BasicValueFactory::~BasicValueFactory() {
@@ -184,8 +184,8 @@
 }
 
 
-const std::pair<RVal, unsigned>&
-BasicValueFactory::getPersistentSizedRVal(const RVal& V, unsigned Bits) {
+const std::pair<RVal, uintptr_t>&
+BasicValueFactory::getPersistentRValWithData(const RVal& V, uintptr_t Data) {
   
   // Lazily create the folding set.
   if (!PersistentRVals) PersistentRVals = new PersistentRValsTy();
@@ -193,18 +193,18 @@
   llvm::FoldingSetNodeID ID;
   void* InsertPos;
   V.Profile(ID);
-  ID.AddInteger(Bits);
+  ID.AddPointer((void*) Data);
   
   PersistentRValsTy& Map = *((PersistentRValsTy*) PersistentRVals);
   
-  typedef llvm::FoldingSetNodeWrapper<SizedRVal> FoldNodeTy;
+  typedef llvm::FoldingSetNodeWrapper<RValData> FoldNodeTy;
   FoldNodeTy* P = Map.FindNodeOrInsertPos(ID, InsertPos);
   
   if (!P) {  
     P = (FoldNodeTy*) BPAlloc.Allocate<FoldNodeTy>();
-    new (P) FoldNodeTy(std::make_pair(V, Bits));
+    new (P) FoldNodeTy(std::make_pair(V, Data));
     Map.InsertNode(P, InsertPos);
   }
 
-  return *P;
+  return P->getValue();
 }
diff --git a/lib/Analysis/GRExprEngine.cpp b/lib/Analysis/GRExprEngine.cpp
index 2353058..a4f1a05 100644
--- a/lib/Analysis/GRExprEngine.cpp
+++ b/lib/Analysis/GRExprEngine.cpp
@@ -856,16 +856,12 @@
     // This is a redunant copy; we do this as a placeholder for future logic.
     for (NodeSet::iterator I=Tmp.begin(), E=Tmp.end(); I!=E; ++I) {
       ValueState* St = GetState(*I);
-      RVal V = GetRVal(St, Base);
+      RVal BaseV = GetRVal(St, Base);      
 
-      // TODO: Compute the LVal for the field.  This will enable field
-      //  sensitivity for the analysis.
+      RVal V = lval::FieldOffset::Make(BasicVals, GetRVal(St, Base),
+                                       M->getMemberDecl());
       
-      if (!(V.isUndef() || V.isUnknown() || isa<lval::ConcreteInt>(V)))
-        V = UnknownVal();      
-      
-      MakeNode(Dst, M, *I, SetRVal(St, M, V)); 
-      
+      MakeNode(Dst, M, *I, SetRVal(St, M, V));      
     }
 
     return;
@@ -879,13 +875,8 @@
   for (NodeSet::iterator I=Tmp.begin(), E=Tmp.end(); I!=E; ++I) {
     ValueState* St = GetState(*I);
     
-    RVal V = GetRVal(St, Base);
-    
-    // TODO: Compute the LVal for the field.  This will enable field
-    //  sensitivity for the analysis.
-    
-    if (!(V.isUndef() || V.isUnknown() || isa<lval::ConcreteInt>(V)))
-      V = UnknownVal();
+    RVal V = lval::FieldOffset::Make(BasicVals, GetRVal(St, Base),
+                                     M->getMemberDecl());
     
     EvalLoad(Dst, M, *I, St, V, true);
   }
@@ -2034,7 +2025,11 @@
     case lval::StringLiteralValKind:
       isFeasible = Assumption;
       return St;
-
+      
+    case lval::FieldOffsetKind:
+      return AssumeAux(St, cast<lval::FieldOffset>(Cond).getBase(),
+                       Assumption, isFeasible);
+      
     case lval::ConcreteIntKind: {
       bool b = cast<lval::ConcreteInt>(Cond).getValue() != 0;
       isFeasible = b ? Assumption : !Assumption;      
diff --git a/lib/Analysis/RValues.cpp b/lib/Analysis/RValues.cpp
index 5e161f3..ab1cf6a 100644
--- a/lib/Analysis/RValues.cpp
+++ b/lib/Analysis/RValues.cpp
@@ -25,6 +25,9 @@
 //===----------------------------------------------------------------------===//
 
 RVal::symbol_iterator RVal::symbol_begin() const {
+  
+  // FIXME: This is a rat's nest.  Cleanup.
+
   if (isa<lval::SymbolVal>(this))
     return (symbol_iterator) (&Data);
   else if (isa<nonlval::SymbolVal>(this))
@@ -39,7 +42,10 @@
     const nonlval::LValAsInteger& V = cast<nonlval::LValAsInteger>(*this);
     return  V.getPersistentLVal().symbol_begin();
   }
-  
+  else if (isa<lval::FieldOffset>(this)) {
+    const lval::FieldOffset& V = cast<lval::FieldOffset>(*this);
+    return V.getPersistentBase().symbol_begin();
+  }
   return NULL;
 }
 
@@ -402,6 +408,13 @@
           << "\"";
       break;
       
+    case lval::FieldOffsetKind: {
+      const lval::FieldOffset& C = *cast<lval::FieldOffset>(this);
+      C.getBase().print(Out);
+      Out << "." << C.getFieldDecl()->getName() << " (field LVal)";
+      break;
+    }
+      
     default:
       assert (false && "Pretty-printing not implemented for this LVal.");
       break;
diff --git a/lib/Analysis/ValueState.cpp b/lib/Analysis/ValueState.cpp
index cba0253..e51366d 100644
--- a/lib/Analysis/ValueState.cpp
+++ b/lib/Analysis/ValueState.cpp
@@ -212,6 +212,9 @@
       return UnknownVal();
     }
       
+    case lval::FieldOffsetKind:
+      return UnknownVal();
+      
     case lval::FuncValKind:
       return LV;