/// <summary>
/// Examines a CFG and removes the stack manipulating instructions by introducing
/// some explicit variables for stack locations. After this transformation, no more
/// Pop, Dup etc.
/// </summary>
/// <param name="cfg">Control Flow Graph that is modified by the transformation.
/// This argument WILL be mutated.</param>
/// <returns>A map that assigns to each block from <c>cfg</c> the stack depth at its
/// beginning. Useful as a pseudo-liveness information.</returns>
public static int[] Process(ControlFlowGraph cfg)
{
StackRemovalTransformation sd = new StackRemovalTransformation(cfg);
StackRemovalVisitor srv = new StackRemovalVisitor();
// should be in order.
foreach (CfgBlock block in cfg.PreOrder) {
int depth = sd.InitialDepthOfBlock(block, cfg);
if (depth < 0) {
continue;
}
// set block starting depth
srv.depth = depth;
StatementList stats = block.Statements;
for(int i = 0, n = stats.Count; i < n; i++) {
stats[i] = (Statement) srv.Visit(stats[i]);
if (cfg.GenericsUse == null) { cfg.GenericsUse = srv.GenericsUse; }
if (cfg.PointerUse == null) { cfg.PointerUse = srv.PointerUse; }
if (srv.SawMissingInfo) { cfg.HasMissingInfo = true; }
}
// push final depth onto successors.
foreach (CfgBlock succ in cfg.NormalSucc(block)) {
sd.PushDepth(succ, srv.depth);
}
}
// finalize stack depth info on each block
foreach (CfgBlock block in cfg.Blocks())
{
int depth = sd.block2depth[block.Index];
// cache depth on block
block.stackDepth = depth;
if (depth < 0) {
// unreachable
// set statementlist to null in case some backward analysis or other code gets to it
if (block.Statements.Count > 0) {
block.Statements = new StatementList(0);
}
}
}
return sd.block2depth;
}
/// <summary>
/// Examines a CFG and removes the stack manipulating instructions by introducing
/// some explicit variables for stack locations. After this transformation, no more
/// Pop, Dup etc.
/// </summary>
/// <param name="cfg">Control Flow Graph that is modified by the transformation.
/// This argument WILL be mutated.</param>
/// <returns>A map that assigns to each block from <c>cfg</c> the stack depth at its
/// beginning. Useful as a pseudo-liveness information.</returns>
public static int[] Process(ControlFlowGraph cfg)
{
StackRemovalTransformation sd = new StackRemovalTransformation(cfg);
StackRemovalVisitor srv = new StackRemovalVisitor();
// should be in order.
foreach (CfgBlock block in cfg.PreOrder)
{
int depth = sd.InitialDepthOfBlock(block, cfg);
if (depth < 0)
{
continue;
}
// set block starting depth
srv.depth = depth;
StatementList stats = block.Statements;
for (int i = 0, n = stats.Count; i < n; i++)
{
stats[i] = (Statement)srv.Visit(stats[i]);
if (cfg.GenericsUse == null)
{
cfg.GenericsUse = srv.GenericsUse;
}
if (cfg.PointerUse == null)
{
cfg.PointerUse = srv.PointerUse;
}
if (srv.SawMissingInfo)
{
cfg.HasMissingInfo = true;
}
}
// push final depth onto successors.
foreach (CfgBlock succ in cfg.NormalSucc(block))
{
sd.PushDepth(succ, srv.depth);
}
}
// finalize stack depth info on each block
foreach (CfgBlock block in cfg.Blocks())
{
int depth = sd.block2depth[block.Index];
// cache depth on block
block.stackDepth = depth;
if (depth < 0)
{
// unreachable
// set statementlist to null in case some backward analysis or other code gets to it
if (block.Statements.Count > 0)
{
block.Statements = new StatementList(0);
}
}
}
return(sd.block2depth);
}
