private static Block[] BuildBlocks(Node[] statementNodes)
{
// a mapping from each target node to the block it begins
IDictionary<Node, Block.FatBlock> theTargetBlocks = new Dictionary<Node, Block.FatBlock>();
ObjArray theBlocks = new ObjArray();
// there's a block that starts at index 0
int beginNodeIndex = 0;
for (int i = 0; i < statementNodes.Length; i++)
{
switch (statementNodes[i].GetType())
{
case Token.TARGET:
{
if (i != beginNodeIndex)
{
Block.FatBlock fb = NewFatBlock(beginNodeIndex, i - 1);
if (statementNodes[beginNodeIndex].GetType() == Token.TARGET)
{
theTargetBlocks.Put(statementNodes[beginNodeIndex], fb);
}
theBlocks.Add(fb);
// start the next block at this node
beginNodeIndex = i;
}
break;
}
case Token.IFNE:
case Token.IFEQ:
case Token.GOTO:
{
Block.FatBlock fb = NewFatBlock(beginNodeIndex, i);
if (statementNodes[beginNodeIndex].GetType() == Token.TARGET)
{
theTargetBlocks.Put(statementNodes[beginNodeIndex], fb);
}
theBlocks.Add(fb);
// start the next block at the next node
beginNodeIndex = i + 1;
break;
}
}
}
if (beginNodeIndex != statementNodes.Length)
{
Block.FatBlock fb = NewFatBlock(beginNodeIndex, statementNodes.Length - 1);
if (statementNodes[beginNodeIndex].GetType() == Token.TARGET)
{
theTargetBlocks.Put(statementNodes[beginNodeIndex], fb);
}
theBlocks.Add(fb);
}
// build successor and predecessor links
for (int i_1 = 0; i_1 < theBlocks.Size(); i_1++)
{
Block.FatBlock fb = (Block.FatBlock)(theBlocks.Get(i_1));
Node blockEndNode = statementNodes[fb.realBlock.itsEndNodeIndex];
int blockEndNodeType = blockEndNode.GetType();
if ((blockEndNodeType != Token.GOTO) && (i_1 < (theBlocks.Size() - 1)))
{
Block.FatBlock fallThruTarget = (Block.FatBlock)(theBlocks.Get(i_1 + 1));
fb.AddSuccessor(fallThruTarget);
fallThruTarget.AddPredecessor(fb);
}
if ((blockEndNodeType == Token.IFNE) || (blockEndNodeType == Token.IFEQ) || (blockEndNodeType == Token.GOTO))
{
Node target = ((Jump)blockEndNode).target;
Block.FatBlock branchTargetBlock = theTargetBlocks.Get(target);
target.PutProp(Node.TARGETBLOCK_PROP, branchTargetBlock.realBlock);
fb.AddSuccessor(branchTargetBlock);
branchTargetBlock.AddPredecessor(fb);
}
}
Block[] result = new Block[theBlocks.Size()];
for (int i_2 = 0; i_2 < theBlocks.Size(); i_2++)
{
Block.FatBlock fb = (Block.FatBlock)(theBlocks.Get(i_2));
Block b = fb.realBlock;
b.itsSuccessors = fb.GetSuccessors();
b.itsPredecessors = fb.GetPredecessors();
b.itsBlockID = i_2;
result[i_2] = b;
}
return result;
}
