private void UntangleProcedureScc(IList<Procedure> procs)
{
if (procs.Count == 1)
{
var proc = procs[0];
Aliases alias = new Aliases(proc, program.Architecture, flow);
alias.Transform();
// Transform the procedure to SSA state. When encountering 'call' instructions,
// they can be to functions already visited. If so, they have a "ProcedureFlow"
// associated with them. If they have not been visited, or are computed destinations
// (e.g. vtables) they will have no "ProcedureFlow" associated with them yet, in
// which case the the SSA treats the call as a "hell node".
var doms = proc.CreateBlockDominatorGraph();
var sst = new SsaTransform(flow, proc, doms);
var ssa = sst.SsaState;
// Propagate condition codes and registers. At the end, the hope is that
// all statements like (x86) mem[esp_42+4] will have been converted to
// mem[fp - 30]. We also hope that procedure constants kept in registers
// are propagated to the corresponding call sites.
var cce = new ConditionCodeEliminator(ssa.Identifiers, program.Platform);
cce.Transform();
var vp = new ValuePropagator(ssa.Identifiers, proc);
vp.Transform();
// Now compute SSA for the stack-based variables as well. That is:
// mem[fp - 30] becomes wLoc30, while
// mem[fp + 30] becomes wArg30.
// This allows us to compute the dataflow of this procedure.
sst.RenameFrameAccesses = true;
sst.AddUseInstructions = true;
sst.Transform();
// Propagate those newly discovered identifiers.
vp.Transform();
// At this point, the computation of _actual_ ProcedureFlow should be possible.
var tid = new TrashedRegisterFinder2(program.Architecture, flow, proc, ssa.Identifiers, this.eventListener);
tid.Compute();
DeadCode.Eliminate(proc, ssa);
// Build expressions. A definition with a single use can be subsumed
// into the using expression.
var coa = new Coalescer(proc, ssa);
coa.Transform();
DeadCode.Eliminate(proc, ssa);
var liv = new LinearInductionVariableFinder(
proc,
ssa.Identifiers,
new BlockDominatorGraph(proc.ControlGraph, proc.EntryBlock));
liv.Find();
foreach (var de in liv.Contexts)
{
var str = new StrengthReduction(ssa, de.Key, de.Value);
str.ClassifyUses();
str.ModifyUses();
}
proc.Dump(true, false);
//var opt = new OutParameterTransformer(proc, ssa.Identifiers);
//opt.Transform();
DeadCode.Eliminate(proc, ssa);
// Definitions with multiple uses and variables joined by PHI functions become webs.
var web = new WebBuilder(proc, ssa.Identifiers, program.InductionVariables);
web.Transform();
ssa.ConvertBack(false);
}
else
{
}
}
private Procedure RunTest(string sExp, IProcessorArchitecture arch, Func<Procedure> mkProc)
{
var proc = mkProc();
progBuilder.ResolveUnresolved();
var ssa = new SsaTransform(pf, proc, proc.CreateBlockDominatorGraph());
var vp = new ValuePropagator(ssa.SsaState.Identifiers, proc);
vp.Transform();
ssa.RenameFrameAccesses = true;
ssa.AddUseInstructions = true;
ssa.Transform();
vp.Transform();
var trf = new TrashedRegisterFinder2(
arch,
pf,
proc,
ssa.SsaState.Identifiers,
NullDecompilerEventListener.Instance);
var flow = trf.Compute();
var sw = new StringWriter();
sw.Write("Preserved: ");
sw.WriteLine(string.Join(",", flow.Preserved.OrderBy(p => p.ToString())));
sw.Write("Trashed: ");
sw.WriteLine(string.Join(",", flow.Trashed.OrderBy(p => p.ToString())));
if (flow.Constants.Count > 0)
{
sw.Write("Constants: ");
sw.WriteLine(string.Join(
",",
flow.Constants
.OrderBy(kv => kv.Key.ToString())
.Select(kv => string.Format(
"{0}:{1}", kv.Key, kv.Value))));
}
var sActual = sw.ToString();
if (sActual != sExp)
{
proc.Dump(true, false);
Debug.WriteLine(sActual);
Assert.AreEqual(sExp, sActual);
}
pf.ProcedureFlows2.Add(proc, flow);
return proc;
}