diff --git a/lib/Analysis/Environment.cpp b/lib/Analysis/Environment.cpp
index 86fd12c..dd5caef 100644
--- a/lib/Analysis/Environment.cpp
+++ b/lib/Analysis/Environment.cpp
@@ -16,14 +16,101 @@
 
 using namespace clang;
 
-//===----------------------------------------------------------------------===//
-// Environment.
-//===----------------------------------------------------------------------===//
+RVal Environment::GetRVal(Expr* E, BasicValueFactory& BasicVals) const {
+  
+  for (;;) {
+    
+    switch (E->getStmtClass()) {
+        
+      case Stmt::AddrLabelExprClass:        
+        return LVal::MakeVal(cast<AddrLabelExpr>(E));
+        
+        // ParenExprs are no-ops.
+        
+      case Stmt::ParenExprClass:        
+        E = cast<ParenExpr>(E)->getSubExpr();
+        continue;
+        
+      case Stmt::CharacterLiteralClass: {
+        CharacterLiteral* C = cast<CharacterLiteral>(E);
+        return NonLVal::MakeVal(BasicVals, C->getValue(), C->getType());
+      }
+        
+      case Stmt::IntegerLiteralClass: {
+        return NonLVal::MakeVal(BasicVals, cast<IntegerLiteral>(E));
+      }
+        
+      case Stmt::StringLiteralClass:
+        return LVal::MakeVal(cast<StringLiteral>(E));
+        
+        // Casts where the source and target type are the same
+        // are no-ops.  We blast through these to get the descendant
+        // subexpression that has a value.
+        
+      case Stmt::ImplicitCastExprClass: {
+        ImplicitCastExpr* C = cast<ImplicitCastExpr>(E);
+        QualType CT = C->getType();
+        
+        if (CT->isVoidType())
+          return UnknownVal();
+        
+        QualType ST = C->getSubExpr()->getType();
+        
+        break;
+      }
+        
+      case Stmt::CastExprClass: {
+        CastExpr* C = cast<CastExpr>(E);
+        QualType CT = C->getType();
+        QualType ST = C->getSubExpr()->getType();
+        
+        if (CT->isVoidType())
+          return UnknownVal();
+        
+        break;
+      }
+        
+        // Handle all other Expr* using a lookup.
+        
+      default:
+        break;
+    };
+    
+    break;
+  }
+  
+  return LookupExpr(E);
+}
 
+RVal Environment::GetBlkExprRVal(Expr* E, BasicValueFactory& BasicVals) const {
+  
+  E = E->IgnoreParens();
+  
+  switch (E->getStmtClass()) {
+    case Stmt::CharacterLiteralClass: {
+      CharacterLiteral* C = cast<CharacterLiteral>(E);
+      return NonLVal::MakeVal(BasicVals, C->getValue(), C->getType());
+    }
+      
+    case Stmt::IntegerLiteralClass: {
+      return NonLVal::MakeVal(BasicVals, cast<IntegerLiteral>(E));
+    }
+      
+    default:
+      return LookupBlkExpr(E);
+  }
+}
 
+Environment EnvironmentManager::SetRVal(const Environment& Env, Expr* E, RVal V,
+                                        bool isBlkExpr, bool Invalidate) {  
+  assert (E);
+  
+  if (V.isUnknown()) {    
+    if (Invalidate)
+      return isBlkExpr ? RemoveBlkExpr(Env, E) : RemoveSubExpr(Env, E);
+    else
+      return Env;
+  }
 
-
-
-//===----------------------------------------------------------------------===//
-// Environment Manager.
-//===----------------------------------------------------------------------===//
\ No newline at end of file
+  return isBlkExpr ? AddBlkExpr(Env, E, V) : AddSubExpr(Env, E, V);
+}