Made invariant of class 'IfThenElse' robust by changing the design

(replaced public field by private field + getter/setter)

2 files changed, 25 insertions, 5 deletions

diff --git a/Source/Core/AbsyExpr.cs b/Source/Core/AbsyExpr.cs
index 8918115b..e2113ab5 100644
--- a/Source/Core/AbsyExpr.cs
+++ b/Source/Core/AbsyExpr.cs
@@ -2530,16 +2530,30 @@ namespace Microsoft.Boogie {
 

   public class IfThenElse : IAppliable {

 

-    public IToken/*!*/ tok;

+    private IToken/*!*/ _tok;

+

+    public IToken/*!*/ tok

+    {

+      get

+      {

+        Contract.Ensures(Contract.Result<IToken>() != null);

+        return this._tok;

+      }

+      set

+      {

+        Contract.Requires(value != null);

+        this._tok = value;

+      }

+    }

+    

     [ContractInvariantMethod]

     void ObjectInvariant() {

-      Contract.Invariant(tok != null);

+      Contract.Invariant(this._tok != null);

     }

 

-

     public IfThenElse(IToken tok) {

       Contract.Requires(tok != null);

-      this.tok = tok;

+      this._tok = tok;

     }

 

     public string/*!*/ FunctionName {

@@ -2566,7 +2580,7 @@ namespace Microsoft.Boogie {
     public void Emit(List<Expr> args, TokenTextWriter stream, int contextBindingStrength, bool fragileContext) {

       //Contract.Requires(stream != null);

       //Contract.Requires(args != null);

-      stream.SetToken(ref this.tok);

+      stream.SetToken(this);

       Contract.Assert(args.Count == 3);

       stream.push();

       stream.Write("(if ");     

diff --git a/Source/Core/Util.cs b/Source/Core/Util.cs
index b28ac042..73008742 100644
--- a/Source/Core/Util.cs
+++ b/Source/Core/Util.cs
@@ -229,6 +229,12 @@ namespace Microsoft.Boogie {
       this.SetToken(t => absy.tok = t);

     }

 

+    public void SetToken(IfThenElse expr)

+    {

+      Contract.Requires(expr != null);

+      this.SetToken(t => expr.tok = t);

+    }

+

     public void SetToken(Action<IToken> setter) {

       Contract.Requires(setter != null);

       if (this.setTokens) {