Extracted a separate class to generate fresh variable names.

1 files changed, 17 insertions, 21 deletions

diff --git a/Source/Dafny/Compiler.cs b/Source/Dafny/Compiler.cs
index 1aa15145..a3312c4a 100644
--- a/Source/Dafny/Compiler.cs
+++ b/Source/Dafny/Compiler.cs
@@ -487,7 +487,7 @@ namespace Microsoft.Dafny {
 

         Indent(indent);  wr.WriteLine("}");

       }

-      constructorIndex ++;

+      constructorIndex++;

     }

 

     void CompileDatatypeStruct(DatatypeDecl dt, int indent) {

@@ -1179,7 +1179,7 @@ namespace Microsoft.Dafny {
               if (!(rhs is HavocRhs)) {

                 lvalues.Add(CreateLvalue(lhs, indent));

 

-                string target = "_rhs" + FreshTmpVarCount();

+                string target = VariableNameGenerator.FreshVariableName("_rhs");

                 rhss.Add(target);

                 TrRhs("var " + target, null, rhs, indent);

               }

@@ -1240,7 +1240,7 @@ namespace Microsoft.Dafny {
           Contract.Assert(s.Bounds != null);  // follows from s.MissingBounds == null

           var n = s.Lhss.Count;

           Contract.Assert(s.Bounds.Count == n);

-          var c = FreshTmpVarCount();

+          var c = VariableNameGenerator.FreshVariableCount();

           var doneLabel = "_ASSIGN_SUCH_THAT_" + c;

           var iterLimit = "_iterLimit_" + c;

 

@@ -1259,7 +1259,7 @@ namespace Microsoft.Dafny {
               Indent(ind);

               wr.WriteLine("var {0}_{1} = {0};", iterLimit, i);

             }

-            var tmpVar = "_assign_such_that_" + FreshTmpVarCount();

+            var tmpVar = VariableNameGenerator.FreshVariableName("_assign_such_that_");

             Indent(ind);

             if (bound is ComprehensionExpr.BoolBoundedPool) {

               wr.WriteLine("foreach (var {0} in Dafny.Helpers.AllBooleans) {{ @{1} = {0};", tmpVar, bv.CompileName);

@@ -1475,7 +1475,7 @@ namespace Microsoft.Dafny {
         // be nested.

 

         // Temporary names

-        var c = FreshTmpVarCount();

+        var c = VariableNameGenerator.FreshVariableCount();

         string ingredients = "_ingredients" + c;

         string tup = "_tup" + c;

 

@@ -1628,7 +1628,7 @@ namespace Microsoft.Dafny {
         //   ...

         // }

         if (s.Cases.Count != 0) {

-          string source = "_source" + FreshTmpVarCount();

+          string source = VariableNameGenerator.FreshVariableName("_source");

           Indent(indent);

           wr.Write("{0} {1} = ", TypeName(cce.NonNull(s.Source.Type)), source);

           TrExpr(s.Source);

@@ -1671,7 +1671,7 @@ namespace Microsoft.Dafny {
         return "@" + ll.Var.CompileName;

       } else if (lhs is MemberSelectExpr) {

         var ll = (MemberSelectExpr)lhs;

-        string obj = "_obj" + FreshTmpVarCount();

+        string obj = VariableNameGenerator.FreshVariableName("_obj");

         Indent(indent);

         wr.Write("var {0} = ", obj);

         TrExpr(ll.Obj);

@@ -1679,7 +1679,7 @@ namespace Microsoft.Dafny {
         return string.Format("{0}.@{1}", obj, ll.Member.CompileName);

       } else if (lhs is SeqSelectExpr) {

         var ll = (SeqSelectExpr)lhs;

-        var c = FreshTmpVarCount();

+        var c = VariableNameGenerator.FreshVariableCount();

         string arr = "_arr" + c;

         string index = "_index" + c;

         Indent(indent);

@@ -1693,7 +1693,7 @@ namespace Microsoft.Dafny {
         return string.Format("{0}[(int){1}]", arr, index);

       } else {

         var ll = (MultiSelectExpr)lhs;

-        var c = FreshTmpVarCount();

+        var c = VariableNameGenerator.FreshVariableCount();

         string arr = "_arr" + c;

         Indent(indent);

         wr.Write("var {0} = ", arr);

@@ -1720,7 +1720,7 @@ namespace Microsoft.Dafny {
       Contract.Requires((target == null) != (targetExpr == null));

       var tRhs = rhs as TypeRhs;

       if (tRhs != null && tRhs.InitCall != null) {

-        string nw = "_nw" + FreshTmpVarCount();

+        string nw = VariableNameGenerator.FreshVariableName("_nw");

         Indent(indent);

         wr.Write("var {0} = ", nw);

         TrAssignmentRhs(rhs);  // in this case, this call will not require us to spill any let variables first

@@ -1771,7 +1771,7 @@ namespace Microsoft.Dafny {
           // TODO:  What to do here?  When does this happen, what does it mean?

         } else if (!s.Method.IsStatic) {

 

-          string inTmp = "_in" + FreshTmpVarCount();

+          string inTmp = VariableNameGenerator.FreshVariableName("_in");

           inTmps.Add(inTmp);

           Indent(indent);

           wr.Write("var {0} = ", inTmp);

@@ -1781,7 +1781,7 @@ namespace Microsoft.Dafny {
         for (int i = 0; i < s.Method.Ins.Count; i++) {

           Formal p = s.Method.Ins[i];

           if (!p.IsGhost) {

-            string inTmp = "_in" + FreshTmpVarCount();

+            string inTmp = VariableNameGenerator.FreshVariableName("_in");

             inTmps.Add(inTmp);

             Indent(indent);

             wr.Write("var {0} = ", inTmp);

@@ -1823,7 +1823,7 @@ namespace Microsoft.Dafny {
         for (int i = 0; i < s.Method.Outs.Count; i++) {

           Formal p = s.Method.Outs[i];

           if (!p.IsGhost) {

-            string target = "_out" + FreshTmpVarCount();

+            string target = VariableNameGenerator.FreshVariableName("_out");

             outTmps.Add(target);

             Indent(indent);

             wr.WriteLine("{0} {1};", TypeName(s.Lhs[i].Type), target);

@@ -1879,11 +1879,7 @@ namespace Microsoft.Dafny {
       }

     }

 

-    int tmpVarCount = 0;

-    int FreshTmpVarCount()

-    {

-      return tmpVarCount++;

-    }

+    FreshVariableNameGenerator VariableNameGenerator = new FreshVariableNameGenerator();

 

     /// <summary>

     /// Before calling TrAssignmentRhs(rhs), the caller must have spilled the let variables declared in "rhs".

@@ -2249,7 +2245,7 @@ namespace Microsoft.Dafny {
               string arg;

               var fce = actual as FunctionCallExpr;

               if (fce == null || fce.CoCall != FunctionCallExpr.CoCallResolution.Yes) {

-                string varName = "_ac" + FreshTmpVarCount();

+                string varName = VariableNameGenerator.FreshVariableName("_ac");

                 arg = varName;

 

                 wr.Write("var {0} = ", varName);

@@ -2258,7 +2254,7 @@ namespace Microsoft.Dafny {
               } else {

                 var sw = new StringWriter();

                 CompileFunctionCallExpr(fce, sw, (exp) => {

-                  string varName = "_ac" + FreshTmpVarCount();

+                  string varName = VariableNameGenerator.FreshVariableName("_ac");

                   sw.Write(varName);

 

                   wr.Write("var {0} = ", varName);

@@ -2571,7 +2567,7 @@ namespace Microsoft.Dafny {
         //   }

         // }(src)

 

-        string source = "_source" + FreshTmpVarCount();

+        string source = VariableNameGenerator.FreshVariableName("_source");

         wr.Write("new Dafny.Helpers.Function<{0}, {1}>(delegate ({0} {2}) {{ ", TypeName(e.Source.Type), TypeName(e.Type), source);

 

         if (e.Cases.Count == 0) {