WI #2022 Change Review

Author: mayanje

TypeCobol.Analysis/Cfg/ControlFlowGraphBuilder.CfgAfterIterativePerformProcedureTransformer.cs

@@ -12,15 +12,15 @@ public partial class ControlFlowGraphBuilder<D>
         private class CfgAfterIterativePerformProcedureTransformer : ICfgTransform<Node, D>
         {
             private HashSet<BasicBlockForNodeGroup> _visitedGroups;
-            private ControlFlowGraphBuilder<D> Builder;
+            private ControlFlowGraph<Node, D> _cfg;
 
             /// <summary>
             /// Constructor
             /// </summary>
             /// <param name="builder"></param>
-            public CfgAfterIterativePerformProcedureTransformer(ControlFlowGraphBuilder<D> builder)
+            public CfgAfterIterativePerformProcedureTransformer(ControlFlowGraph<Node, D> cfg)
             {
-                this.Builder = builder;
+                this._cfg = cfg;
             }
             private bool Callback(BasicBlock<Node, D> block, int incomingEdge, BasicBlock<Node, D> predecessorBlock, ControlFlowGraph<Node, D> cfg)
             {
@@ -48,18 +48,20 @@ private bool Callback(BasicBlock<Node, D> block, int incomingEdge, BasicBlock<No
                 //If an after iterative group has been found, we must break the edge pointing to the PERFORM
                 //and replace it with a new edge pointing to the first instruction of the group.
                 if (iterativeGroup != null)
-                {                    
+                {
                     //Remove incoming edge
                     block.SuccessorEdges.RemoveAt(removedIndex);
 
                     //Create an edge to the first block of the iterative group.
                     int entranceEdge = cfg.SuccessorEdges.Count;
                     cfg.SuccessorEdges.Add(iterativeGroup.Group.First.Value);
                     block.SuccessorEdges.Add(entranceEdge);
-                    if(block.Context != null)
-                    {
-                        ((MultiBranchContext)block.Context).ChangeSuccessor(Builder, iterativeGroup, iterativeGroup.Group.First.Value);
-                    }
+                    System.Diagnostics.Debug.Assert(block.Context == null);
+                    //If the assert above fails (it should not be case), then it will be necessay to exeute the commented code bellow.
+                    //if(block.Context != null)
+                    //{
+                    //    ((MultiBranchContext)block.Context).ChangeSuccessor(_cfg, iterativeGroup, iterativeGroup.Group.First.Value);
+                    //}
                 }
 
                 //If the current block is a group, we must also traverse blocks of the group

TypeCobol.Analysis/Cfg/ControlFlowGraphBuilder.MultiBranchContext.cs

@@ -85,6 +85,7 @@ internal MultiBranchContext(Node instruction)
             internal void Start(BasicBlockForNode originBlock)
             {
                 this.OriginBlock = originBlock;
+                this.OriginBlock.Context = this;
             }
 
             /// <summary>
@@ -135,9 +136,10 @@ internal void End(ControlFlowGraphBuilder<D> builder, bool branchToNext, BasicBl
             /// <summary>
             /// Change the successors
             /// </summary>
+            /// <param name="cfg">The target CFG graph</param>
             /// <param name="currentSucc">The current Successor</param>
             /// <param name="newSucc">The new Successor</param>
-            internal void ChangeSuccessor(ControlFlowGraphBuilder<D> builder, BasicBlock<Node, D> currentSucc, BasicBlock<Node, D> newSucc)
+            internal void ChangeSuccessor(ControlFlowGraph<Node, D> cfg, BasicBlock<Node, D> currentSucc, BasicBlock<Node, D> newSucc)
             {
                 if (NextFlowBlock == currentSucc)
                     NextFlowBlock = newSucc;
@@ -150,12 +152,12 @@ internal void ChangeSuccessor(ControlFlowGraphBuilder<D> builder, BasicBlock<Nod
                     {
                         if (branches[i] == currentSucc)
                         {
-                            System.Diagnostics.Debug.Assert(builder.Cfg.SuccessorEdges[branchIndices[i]] == currentSucc);
+                            System.Diagnostics.Debug.Assert(cfg.SuccessorEdges[branchIndices[i]] == currentSucc);
                             branches[i] = newSucc;
                             RootBlockForEnd.SuccessorEdges.Remove(branchIndices[i]);
-                            branchIndices[i] = builder.Cfg.SuccessorEdges.Count;
-                            RootBlockForEnd.SuccessorEdges.Add(builder.Cfg.SuccessorEdges.Count);
-                            builder.Cfg.SuccessorEdges.Add(newSucc);
+                            branchIndices[i] = cfg.SuccessorEdges.Count;
+                            RootBlockForEnd.SuccessorEdges.Add(cfg.SuccessorEdges.Count);
+                            cfg.SuccessorEdges.Add(newSucc);
                             break;
                         }
                     }

TypeCobol.Analysis/Cfg/ControlFlowGraphBuilder.cs

@@ -1333,7 +1333,7 @@ private void HandlePerformsWithTestAfter()
             {
                 //Transform graph to replace edge in performs with test after.
                 //Transformation is directly applied to the graph, no new instance created.
-                ICfgTransform<Node, D> transform = new CfgAfterIterativePerformProcedureTransformer(this.CurrentProgramCfgBuilder);
+                ICfgTransform<Node, D> transform = new CfgAfterIterativePerformProcedureTransformer(this.CurrentProgramCfgBuilder.Cfg);
                 transform.Transform(this.CurrentProgramCfgBuilder.Cfg);
             }
         }
@@ -1733,7 +1733,7 @@ protected virtual void LeaveEvaluate(Evaluate evaluate)
                 var nextBlock = this.CurrentProgramCfgBuilder.CreateBlock(null, true);
                 ctx.End(this.CurrentProgramCfgBuilder, branchToNext, nextBlock);
                 this.CurrentProgramCfgBuilder.CurrentBasicBlock = nextBlock;
-            }            
+            }
         }
 
         /// <summary>
@@ -2061,7 +2061,7 @@ public virtual void LeaveSearch(Search node)
                     else
                     {
                         ctx.End(this.CurrentProgramCfgBuilder, branchToNext, nextBlock);
-                    }                    
+                    }
                     this.CurrentProgramCfgBuilder.CurrentBasicBlock = nextBlock;
                     ctx = this.CurrentProgramCfgBuilder.MultiBranchContextStack.Pop();
                 }
@@ -2081,7 +2081,7 @@ public virtual void LeaveSearch(Search node)
                 var nextBlock = this.CurrentProgramCfgBuilder.CreateBlock(null, true);
                 ctx.End(this.CurrentProgramCfgBuilder, branchToNext, nextBlock);
                 this.CurrentProgramCfgBuilder.CurrentBasicBlock = nextBlock;
-            }            
+            }
         }
 
         /// <summary>