void createUnconditionalBranch(BasicBlock deadCodeBasicBlock, ITransformationMetadata basicBlockMetadata)
{
// Branch to some other basic block in our method (or to a newly created dead code block).
var exitBranch = new UnconditionalBranchTarget();
exitBranch.sourceBasicBlock = deadCodeBasicBlock;
deadCodeBasicBlock.exitBranch = exitBranch;
deadCodeBasicBlock.operations.Add(createNewOperation(OperationCode.Br, 0));
// TODO: Decrease possibility for dead code to be added?
if (prng.Next(2) == 0)
{
// Random BB as dead code block target.
var targetBlock = randomTargetBlock();
targetBlock.entryBranches.Add(exitBranch);
exitBranch.takenTarget = targetBlock;
}
else
{
// New dead code BB as dead code block target.
var targetBlock = new BasicBlock();
targetBlock.startIdx = targetBlock.endIdx = 0;
targetBlock.entryBranches.Add(exitBranch);
exitBranch.takenTarget = targetBlock;
generateDeadCode(targetBlock, basicBlockMetadata);
}
}
public void generateDeadCode(BasicBlock deadCodeBasicBlock, ITransformationMetadata basicBlockMetadata)
{
// Add the dead code to the basic block.
var result = generateDeadCode();
foreach (var operation in result)
{
deadCodeBasicBlock.operations.Add(operation);
}
// Add metadata, if necessary (TODO: Use a set for metadata handling?)
if (basicBlockMetadata != null && !deadCodeBasicBlock.transformationMetadata.Contains(basicBlockMetadata))
{
deadCodeBasicBlock.transformationMetadata.Add(basicBlockMetadata);
}
// Choose epilogue of dead code block.
int target = 1;
if (!debugging)
{
target = prng.Next(3);
if (prng.Next(1) == 0)
{
target = 0;
}
}
switch (target)
{
case 0: createUnconditionalBranch(deadCodeBasicBlock, basicBlockMetadata); break;
case 1: createExitBranch(deadCodeBasicBlock); break;
case 2: createNoBranch(deadCodeBasicBlock); break;
}
}
public void generateDeadCode(BasicBlock deadCodeBasicBlock, ITransformationMetadata basicBlockMetadata)
{
// Add the dead code to the basic block.
var result = generateDeadCode();
foreach(var operation in result) {
deadCodeBasicBlock.operations.Add(operation);
}
// Add metadata, if necessary (TODO: Use a set for metadata handling?)
if(basicBlockMetadata != null && !deadCodeBasicBlock.transformationMetadata.Contains(basicBlockMetadata)) {
deadCodeBasicBlock.transformationMetadata.Add(basicBlockMetadata);
}
// Choose epilogue of dead code block.
int target = 1;
if(!debugging) {
target = prng.Next(3);
if(prng.Next(1) == 0) {
target = 0;
}
}
switch(target) {
case 0: createUnconditionalBranch(deadCodeBasicBlock, basicBlockMetadata); break;
case 1: createExitBranch(deadCodeBasicBlock); break;
case 2: createNoBranch(deadCodeBasicBlock); break;
}
}
void createUnconditionalBranch(BasicBlock deadCodeBasicBlock, ITransformationMetadata basicBlockMetadata)
{
// Branch to some other basic block in our method (or to a newly created dead code block).
var exitBranch = new UnconditionalBranchTarget();
exitBranch.sourceBasicBlock = deadCodeBasicBlock;
deadCodeBasicBlock.exitBranch = exitBranch;
deadCodeBasicBlock.operations.Add(createNewOperation(OperationCode.Br, 0));
// TODO: Decrease possibility for dead code to be added?
if(prng.Next(2) == 0) {
// Random BB as dead code block target.
var targetBlock = randomTargetBlock();
targetBlock.entryBranches.Add(exitBranch);
exitBranch.takenTarget = targetBlock;
}
else {
// New dead code BB as dead code block target.
var targetBlock = new BasicBlock();
targetBlock.startIdx = targetBlock.endIdx = 0;
targetBlock.entryBranches.Add(exitBranch);
exitBranch.takenTarget = targetBlock;
generateDeadCode(targetBlock, basicBlockMetadata);
}
}
