Refactored the generation of unique IDs for temporary variable names.

1 files changed, 27 insertions, 34 deletions

diff --git a/Source/Dafny/Compiler.cs b/Source/Dafny/Compiler.cs
index 0c670062..1aa15145 100644
--- a/Source/Dafny/Compiler.cs
+++ b/Source/Dafny/Compiler.cs
@@ -1179,8 +1179,7 @@ namespace Microsoft.Dafny {
               if (!(rhs is HavocRhs)) {

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

 

-                string target = "_rhs" + tmpVarCount;

-                tmpVarCount++;

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

                 rhss.Add(target);

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

               }

@@ -1241,9 +1240,9 @@ 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 doneLabel = "_ASSIGN_SUCH_THAT_" + tmpVarCount;

-          var iterLimit = "_iterLimit_" + tmpVarCount;

-          tmpVarCount++;

+          var c = FreshTmpVarCount();

+          var doneLabel = "_ASSIGN_SUCH_THAT_" + c;

+          var iterLimit = "_iterLimit_" + c;

 

           int ind = indent;

           bool needIterLimit = s.Lhss.Count != 1 && s.Bounds.Exists(bnd => !bnd.IsFinite);

@@ -1260,8 +1259,7 @@ namespace Microsoft.Dafny {
               Indent(ind);

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

             }

-            var tmpVar = "_assign_such_that_" + tmpVarCount;

-            tmpVarCount++;

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

             Indent(ind);

             if (bound is ComprehensionExpr.BoolBoundedPool) {

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

@@ -1477,9 +1475,9 @@ namespace Microsoft.Dafny {
         // be nested.

 

         // Temporary names

-        string ingredients = "_ingredients" + tmpVarCount;

-        string tup = "_tup" + tmpVarCount;

-        tmpVarCount++;

+        var c = FreshTmpVarCount();

+        string ingredients = "_ingredients" + c;

+        string tup = "_tup" + c;

 

         // Compute L

         int L;

@@ -1630,8 +1628,7 @@ namespace Microsoft.Dafny {
         //   ...

         // }

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

-          string source = "_source" + tmpVarCount;

-          tmpVarCount++;

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

           Indent(indent);

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

           TrExpr(s.Source);

@@ -1674,8 +1671,7 @@ namespace Microsoft.Dafny {
         return "@" + ll.Var.CompileName;

       } else if (lhs is MemberSelectExpr) {

         var ll = (MemberSelectExpr)lhs;

-        string obj = "_obj" + tmpVarCount;

-        tmpVarCount++;

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

         Indent(indent);

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

         TrExpr(ll.Obj);

@@ -1683,9 +1679,9 @@ namespace Microsoft.Dafny {
         return string.Format("{0}.@{1}", obj, ll.Member.CompileName);

       } else if (lhs is SeqSelectExpr) {

         var ll = (SeqSelectExpr)lhs;

-        string arr = "_arr" + tmpVarCount;

-        string index = "_index" + tmpVarCount;

-        tmpVarCount++;

+        var c = FreshTmpVarCount();

+        string arr = "_arr" + c;

+        string index = "_index" + c;

         Indent(indent);

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

         TrExpr(ll.Seq);

@@ -1697,7 +1693,8 @@ namespace Microsoft.Dafny {
         return string.Format("{0}[(int){1}]", arr, index);

       } else {

         var ll = (MultiSelectExpr)lhs;

-        string arr = "_arr" + tmpVarCount;

+        var c = FreshTmpVarCount();

+        string arr = "_arr" + c;

         Indent(indent);

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

         TrExpr(ll.Array);

@@ -1706,7 +1703,7 @@ namespace Microsoft.Dafny {
         string sep = "";

         int i = 0;

         foreach (var idx in ll.Indices) {

-          string index = "_index" + i + "_" + tmpVarCount;

+          string index = "_index" + i + "_" + c;

           Indent(indent);

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

           TrExpr(idx);

@@ -1715,7 +1712,6 @@ namespace Microsoft.Dafny {
           sep = ", ";

           i++;

         }

-        tmpVarCount++;

         return fullString + "]";

       }

     }

@@ -1724,8 +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" + tmpVarCount;

-        tmpVarCount++;

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

         Indent(indent);

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

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

@@ -1776,8 +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" + tmpVarCount;

-          tmpVarCount++;

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

           inTmps.Add(inTmp);

           Indent(indent);

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

@@ -1787,8 +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" + tmpVarCount;

-            tmpVarCount++;

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

             inTmps.Add(inTmp);

             Indent(indent);

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

@@ -1830,8 +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" + tmpVarCount;

-            tmpVarCount++;

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

             outTmps.Add(target);

             Indent(indent);

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

@@ -1888,6 +1880,10 @@ namespace Microsoft.Dafny {
     }

 

     int tmpVarCount = 0;

+    int FreshTmpVarCount()

+    {

+      return tmpVarCount++;

+    }

 

     /// <summary>

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

@@ -2253,8 +2249,7 @@ namespace Microsoft.Dafny {
               string arg;

               var fce = actual as FunctionCallExpr;

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

-                string varName = "_ac" + tmpVarCount;

-                tmpVarCount++;

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

                 arg = varName;

 

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

@@ -2263,8 +2258,7 @@ namespace Microsoft.Dafny {
               } else {

                 var sw = new StringWriter();

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

-                  string varName = "_ac" + tmpVarCount;

-                  tmpVarCount++;

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

                   sw.Write(varName);

 

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

@@ -2577,8 +2571,7 @@ namespace Microsoft.Dafny {
         //   }

         // }(src)

 

-        string source = "_source" + tmpVarCount;

-        tmpVarCount++;

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

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

 

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