예제 #1
0
        /// <summary>
        /// Processes procedures individually, building complex expression trees out
        /// of the simple, close-to-the-machine code generated by the disassembly.
        /// </summary>
        /// <param name="rl"></param>
		public void BuildExpressionTrees()
		{
            int i = 0;
			foreach (Procedure proc in program.Procedures.Values)
			{
                eventListener.ShowProgress("Building complex expressions.", i, program.Procedures.Values.Count);
                ++i;

                try
                {
                    var larw = new LongAddRewriter(proc, program.Architecture);
                    larw.Transform();

                    Aliases alias = new Aliases(proc, program.Architecture, flow);
                    alias.Transform();

                    var doms = new DominatorGraph<Block>(proc.ControlGraph, proc.EntryBlock);
                    var sst = new SsaTransform(flow, proc, doms);
                    var ssa = sst.SsaState;

                    var cce = new ConditionCodeEliminator(ssa.Identifiers, program.Platform);
                    cce.Transform();
                    DeadCode.Eliminate(proc, ssa);

                    var vp = new ValuePropagator(ssa.Identifiers, proc);
                    vp.Transform();
                    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 (KeyValuePair<LinearInductionVariable, LinearInductionVariableContext> de in liv.Contexts)
                    {
                        var str = new StrengthReduction(ssa, de.Key, de.Value);
                        str.ClassifyUses();
                        str.ModifyUses();
                    }
                    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);
                }
                catch (Exception ex)
                {
                    eventListener.Error(new NullCodeLocation(proc.Name), ex, "An error occurred during data flow analysis.");
                }
			} 
		}
예제 #2
0
        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
            {

            }
        }
예제 #3
0
		protected override void RunTest(Program prog, TextWriter fut)
		{
			DataFlowAnalysis dfa = new DataFlowAnalysis(prog, new FakeDecompilerEventListener());
			dfa.UntangleProcedures();
			
			foreach (Procedure proc in prog.Procedures.Values)
			{
				Aliases alias = new Aliases(proc, prog.Architecture);
				alias.Transform();
				SsaTransform sst = new SsaTransform(dfa.ProgramDataFlow, proc, proc.CreateBlockDominatorGraph());
				SsaState ssa = sst.SsaState;
				
                ConditionCodeEliminator cce = new ConditionCodeEliminator(ssa.Identifiers, prog.Platform);
				cce.Transform();
				DeadCode.Eliminate(proc, ssa);

				ValuePropagator vp = new ValuePropagator(ssa.Identifiers, proc);
				vp.Transform();
				DeadCode.Eliminate(proc, ssa);
				Coalescer co = new Coalescer(proc, ssa);
				co.Transform();

				ssa.Write(fut);
				proc.Write(false, fut);
				fut.WriteLine();
			}
		}
예제 #4
0
		private void Build(Procedure proc, IProcessorArchitecture arch)
		{
            var platform = new DefaultPlatform(null, arch);
			this.proc = proc;
			Aliases alias = new Aliases(proc, arch);
			alias.Transform();
			var gr = proc.CreateBlockDominatorGraph();
			SsaTransform sst = new SsaTransform(new ProgramDataFlow(), proc, gr);
			SsaState ssa = sst.SsaState;
			this.ssaIds = ssa.Identifiers;

			ConditionCodeEliminator cce = new ConditionCodeEliminator(ssa.Identifiers, platform);
			cce.Transform();
			DeadCode.Eliminate(proc, ssa);

			ValuePropagator vp = new ValuePropagator(ssa.Identifiers, proc);
			vp.Transform();

			Coalescer coa = new Coalescer(proc, ssa);
			coa.Transform();

			DeadCode.Eliminate(proc, ssa);
            proc.Dump(true, false); //$DEBUG
		}
예제 #5
0
		private void Build(Program prog)
		{
			DataFlowAnalysis dfa = new DataFlowAnalysis(prog, new FakeDecompilerEventListener());
			dfa.UntangleProcedures();
			foreach (Procedure proc in prog.Procedures.Values)
			{
				Aliases alias = new Aliases(proc, prog.Architecture);
				alias.Transform();
				var gr = proc.CreateBlockDominatorGraph();
				SsaTransform sst = new SsaTransform(dfa.ProgramDataFlow, proc, gr);
				SsaState ssa = sst.SsaState;

				ConditionCodeEliminator cce = new ConditionCodeEliminator(ssa.Identifiers, prog.Platform);
				cce.Transform();

				DeadCode.Eliminate(proc, ssa);

				var vp = new ValuePropagator(ssa.Identifiers, proc);
				vp.Transform();

				DeadCode.Eliminate(proc, ssa);

				Coalescer coa = new Coalescer(proc, ssa);
				coa.Transform();

				DeadCode.Eliminate(proc, ssa);

				LiveCopyInserter lci = new LiveCopyInserter(proc, ssa.Identifiers);
				lci.Transform();

				WebBuilder web = new WebBuilder(proc, ssa.Identifiers, new Dictionary<Identifier,LinearInductionVariable>());
				web.Transform();

				ssa.ConvertBack(false);
			}

		}
예제 #6
0
		private void Build(Procedure proc, IProcessorArchitecture arch)
		{
            var platform = new DefaultPlatform(null, arch);
			this.proc = proc;
			Aliases alias = new Aliases(proc, arch);
			alias.Transform();
			SsaTransform sst = new SsaTransform(new ProgramDataFlow(), proc, proc.CreateBlockDominatorGraph());
			ssa = sst.SsaState;
			ConditionCodeEliminator cce = new ConditionCodeEliminator(ssa.Identifiers, platform);
			cce.Transform();
			ValuePropagator vp = new ValuePropagator(ssa.Identifiers, proc);
			vp.Transform();
			DeadCode.Eliminate(proc, ssa);
			Coalescer coa = new Coalescer(proc, ssa);
			coa.Transform();
			DeadCode.Eliminate(proc, ssa);

			sla = new SsaLivenessAnalysis(proc, ssa.Identifiers);
			sla2 = new SsaLivenessAnalysis2(proc, ssa.Identifiers);
			sla2.Analyze();
		}