Example #1
0
        // Run Alias Analysis on a sequential Boogie program
        // and returned the pruned program
        public static PersistentProgram RunAliasAnalysis(PersistentProgram inp, bool pruneEP = true)
        {
            var newinp = inp;

            if (Options.unrollDepth > 0)
            {
                Stats.resume("unroll");

                var unrp = new cba.LoopUnrollingPass(Options.unrollDepth);
                newinp = unrp.run(newinp);

                Stats.stop("unroll");
            }

            var program = newinp.getProgram();

            //AliasAnalysis.AliasAnalysis.dbg = true;
            //AliasAnalysis.AliasConstraintSolver.dbg = true;
            AliasAnalysis.AliasAnalysisResults res = null;
            if (Options.UseAliasAnalysisForAssertions)
            {
                // Do SSA
                program =
                    SSA.Compute(program, PhiFunctionEncoding.Verifiable, new HashSet <string> {
                    "int"
                });

                if (Options.inlineDepth > 0)
                {
                    Stats.resume("inlining");

                    Stats.resume("read.write");
                    program = BoogieUtil.ReResolveInMem(program);
                    Stats.stop("read.write");

                    var op = CommandLineOptions.Clo.InlineDepth;
                    CommandLineOptions.Clo.InlineDepth = Options.inlineDepth;

                    cba.InliningPass.InlineToDepth(program);

                    CommandLineOptions.Clo.InlineDepth = op;

                    RemoveHavocs(program);

                    Stats.stop("inlining");
                }

                /* TODO: Is this needed?
                 * Stats.resume("read.write");
                 * program = BoogieUtil.ReResolveInMem(program);
                 * Stats.stop("read.write");
                 */

                // Make sure that aliasing queries are on identifiers only
                var af =
                    AliasAnalysis.SimplifyAliasingQueries.Simplify(program);

                Stats.resume("fixpoint");
                res =
                    AliasAnalysis.AliasAnalysis.DoAliasAnalysis(program);
                Stats.stop("fixpoint");
            }
            else
            {
                // Make sure that aliasing queries are on identifiers only
                var af =
                    AliasAnalysis.SimplifyAliasingQueries.Simplify(program);

                res = new AliasAnalysis.AliasAnalysisResults();
                af.Iter(s => res.aliases.Add(s, true));
            }

            var origProgram = inp.getProgram();

            AliasAnalysis.PruneAliasingQueries.Prune(origProgram, res);

            if (pruneEP)
            {
                PruneRedundantEntryPoints(origProgram);
            }

            return(new PersistentProgram(origProgram, inp.mainProcName, inp.contextBound));
        }
Example #2
0
        // Replace "assume x == NULL" with "assume x == NULL; assert false;"
        // provided x can indeed alias NULL
        // Also returns a map from allocation_site to possible branches affected by it
        public static Tuple <Program, Dictionary <int, HashSet <int> > > Run(Program program, string ep, bool useAA, bool injectAssert)
        {
            var ib = new InstrumentBranches(program, useAA, injectAssert);

            ib.instrument(ep);

            if (!useAA)
            {
                Console.WriteLine("For deadcode detection, we added {0} angelic assertions", ib.assertsAdded);
                return(Tuple.Create <Program, Dictionary <int, HashSet <int> > >(program, null));
            }

            var inp = new PersistentProgram(program, ep, 1);
            //inp.writeToFile("progbefore.bpl");

            // Make sure that aliasing queries are on identifiers only
            var af =
                AliasAnalysis.SimplifyAliasingQueries.Simplify(program);

            // Do SSA
            program =
                SSA.Compute(program, PhiFunctionEncoding.Verifiable, new HashSet <string> {
                "int"
            });

            //BoogieUtil.PrintProgram(program, "b3.bpl");

            // Run AA
            AliasAnalysis.AliasAnalysisResults res =
                AliasAnalysis.AliasAnalysis.DoAliasAnalysis(program);

            // allocation site of null
            var nil = res.allocationSites[ib.nullQuery.Name].FirstOrDefault();

            Debug.Assert(nil != null);

            var deadcodeAssertId = 0;

            // add the assert false OR assume reach(true)
            var MkAssertFalse = new Func <int, PredicateCmd>(i =>
            {
                var acmd = injectAssert ? BoogieAstFactory.MkAssert(Expr.False) as PredicateCmd :
                           new AssumeCmd(Token.NoToken,
                                         new NAryExpr(Token.NoToken, new FunctionCall(ib.reach), new List <Expr> {
                    Expr.True
                })) as PredicateCmd;

                acmd.Attributes = new QKeyValue(Token.NoToken,
                                                "deadcode", new List <object> {
                    Expr.Literal(i)
                }, null);

                return(acmd);
            });

            // build a map from AA allocation sites to allocation_site id
            var as2id = new Dictionary <string, HashSet <int> >();

            foreach (var tup in ib.allocationSite2Func)
            {
                var asites = res.allocationSites[tup.Value.Name];
                asites.Where(s => !as2id.ContainsKey(s)).Iter(s => as2id.Add(s, new HashSet <int>()));
                asites.Iter(s => as2id[s].Add(tup.Key));
            }

            if (AliasAnalysis.AliasConstraintSolver.environmentPointersUnroll != 0)
            {
                Console.WriteLine("AA Warning: EnvironmentPointersUnroll is non-zero, which means that the dependency information for deadcode branches is not sound.");
                Console.WriteLine("AA Warning: We currently rely on: forall unknown allocation sites that return a, ReachableAllocationSitesViaFields(a) = {a}.");
            }

            // map from allocation_site to possible branches affected by it
            var depInfo = new Dictionary <int, HashSet <int> >();

            program = inp.getProgram();
            var id = 0; var added = 0;

            foreach (var impl in program.TopLevelDeclarations.OfType <Implementation>())
            {
                foreach (var blk in impl.Blocks)
                {
                    blk.Cmds.RemoveAll(c => (c is AssumeCmd) && QKeyValue.FindBoolAttribute((c as AssumeCmd).Attributes, "ForDeadCodeDetection"));

                    var ncmds = new List <Cmd>();
                    for (int i = 0; i < blk.Cmds.Count; i++)
                    {
                        ncmds.Add(blk.Cmds[i]);
                        var acmd = blk.Cmds[i] as AssumeCmd;
                        if (acmd == null)
                        {
                            continue;
                        }

                        id++;
                        if (!ib.id2Func.ContainsKey(id))
                        {
                            continue;
                        }

                        var asites = res.allocationSites[ib.id2Func[id].Name];
                        //if (!Options.disbleDeadcodeOpt || !asites.Contains(nil) && asites.Count != 0)
                        {
                            var assertid = deadcodeAssertId++;
                            ncmds.Add(MkAssertFalse(assertid));

                            // compute dependent allocations for this branch
                            var dep = new HashSet <int>();
                            asites.Where(a => as2id.ContainsKey(a))
                            .Iter(a => dep.UnionWith(as2id[a]));

                            dep.Where(d => !depInfo.ContainsKey(d))
                            .Iter(d => depInfo.Add(d, new HashSet <int>()));

                            dep.Iter(d => depInfo[d].Add(assertid));

                            added++;
                        }
                        //i++;
                    }
                    blk.Cmds = ncmds;
                }
            }
            //BoogieUtil.PrintProgram(program, "progafter.bpl");

            Console.WriteLine("For deadcode detection, we added {0} angelic assertions", added);
            return(Tuple.Create(program, depInfo));
        }
Example #3
0
        static void Main(string[] args)
        {
            System.Runtime.GCSettings.LatencyMode = System.Runtime.GCLatencyMode.Batch;

            if (args.Length < 2 || !args[0].EndsWith(".bpl") || !args[1].EndsWith(".bpl"))
            {
                Console.WriteLine("Usage: AvHarnessInstrumentation infile.bpl outfile.bpl [options]");
                return;
            }

            SetOptions(args);

            // Initialize Boogie
            CommandLineOptions.Install(new CommandLineOptions());
            CommandLineOptions.Clo.PrintInstrumented = true;
            BoogieUtil.InitializeBoogie("");
            ProgTransformation.PersistentProgramIO.useDuplicator = true;

            var sw = new Stopwatch();

            sw.Start();

            if (Options.killAfter > 0)
            {
                var timer = new System.Timers.Timer(Options.killAfter * 1000);
                timer.Elapsed += (sender, e) => HandleTimer(sw);
                timer.Start();
            }

            try
            {
                // Get the program, install the harness and do basic instrumentation
                var inprog = GetProgram(args[0]);


                Utils.Print(string.Format("#Procs : {0}", inprog.TopLevelDeclarations.OfType <Implementation>().Count()), Utils.PRINT_TAG.AV_STATS);
                Utils.Print(string.Format("#EntryPoints : {0}", harnessInstrumentation.entrypoints.Count), Utils.PRINT_TAG.AV_STATS);
                Utils.Print(string.Format("#AssertsBeforeAA : {0}", AssertCountVisitor.Count(inprog)), Utils.PRINT_TAG.AV_STATS);

                if (Options.delayAA)
                {
                    PruneRedundantEntryPoints(inprog);
                    BoogieUtil.PrintProgram(inprog, args[1]);
                }
                else
                {
                    var program = new PersistentProgram(inprog, AvnAnnotations.CORRAL_MAIN_PROC, 0);

                    // Run alias analysis
                    Stats.resume("alias.analysis");
                    Console.WriteLine("Running alias analysis");
                    program = RunAliasAnalysis(program);
                    Stats.stop("alias.analysis");

                    var assertCnt = AssertCountVisitor.Count(program.getProgram());
                    Utils.Print(string.Format("#AssertsAfterAA : {0}", assertCnt), Utils.PRINT_TAG.AV_STATS);

                    // run Houdini pass
                    if (Options.HoudiniPass)
                    {
                        Utils.Print("Running Houdini Pass");
                        program   = RunHoudiniPass(program);
                        assertCnt = AssertCountVisitor.Count(program.getProgram());
                        Utils.Print(string.Format("#Asserts : {0}", assertCnt), Utils.PRINT_TAG.AV_STATS);
                    }

                    if (assertCnt == 0)
                    {
                        // program has been proved correct
                        // Write a trivial program
                        System.IO.File.WriteAllLines(args[1], new string[]
                        {
                            "procedure {:entrypoint} {:NoVerificationNecessary} dummy() { }"
                        });
                    }
                    else
                    {
                        program.writeToFile(args[1]);
                    }
                }
            }
            catch (Exception e)
            {
                //stacktrace containts source locations, confuses regressions that looks for AV_OUTPUT
                Utils.Print(String.Format("AngelicVerifier failed with: {0}", e.Message), Utils.PRINT_TAG.AV_OUTPUT);
                Utils.Print(String.Format("AngelicVerifier failed with: {0}", e.Message + e.StackTrace), Utils.PRINT_TAG.AV_DEBUG);
            }
            finally
            {
                Stats.printStats();
                Utils.Print(string.Format("TotalTime(ms) : {0}", sw.ElapsedMilliseconds), Utils.PRINT_TAG.AV_STATS);
            }
        }
Example #4
0
        static void Main(string[] args)
        {
            System.Runtime.GCSettings.LatencyMode = System.Runtime.GCLatencyMode.Batch;

            if (args.Length < 2 || !args[0].EndsWith(".bpl") || !args[1].EndsWith(".bpl"))
            {
                Console.WriteLine("Usage: AvHarnessInstrumentation infile.bpl outfile.bpl [options]");
                return;
            }

            SetOptions(args);

            // Initialize Boogie
            CommandLineOptions.Install(new CommandLineOptions());
            CommandLineOptions.Clo.PrintInstrumented = true;
            BoogieUtil.InitializeBoogie("");
            ProgTransformation.PersistentProgramIO.useDuplicator = true;

            var sw = new Stopwatch();

            sw.Start();

            try
            {
                // Get the program, install the harness and do basic instrumentation
                var inprog  = GetProgram(args[0]);
                var program = new PersistentProgram(inprog, AvnAnnotations.CORRAL_MAIN_PROC, 0);

                Utils.Print(string.Format("#Procs : {0}", inprog.TopLevelDeclarations.OfType <Implementation>().Count()), Utils.PRINT_TAG.AV_STATS);
                Utils.Print(string.Format("#EntryPoints : {0}", harnessInstrumentation.entrypoints.Count), Utils.PRINT_TAG.AV_STATS);
                Utils.Print(string.Format("#AssertsBeforeAA : {0}", AssertCountVisitor.Count(inprog)), Utils.PRINT_TAG.AV_STATS);

                // Run alias analysis
                Stats.resume("alias.analysis");
                Console.WriteLine("Running alias analysis");
                program = RunAliasAnalysis(program);
                Stats.stop("alias.analysis");

                Utils.Print(string.Format("#AssertsAfterAA : {0}", AssertCountVisitor.Count(program.getProgram())), Utils.PRINT_TAG.AV_STATS);

                // run Houdini pass
                if (Options.HoudiniPass)
                {
                    Utils.Print("Running Houdini Pass");
                    program = RunHoudiniPass(program);
                    Utils.Print(string.Format("#Asserts : {0}", AssertCountVisitor.Count(program.getProgram())), Utils.PRINT_TAG.AV_STATS);
                }

                program.writeToFile(args[1]);
            }
            catch (Exception e)
            {
                //stacktrace containts source locations, confuses regressions that looks for AV_OUTPUT
                Utils.Print(String.Format("AngelicVerifier failed with: {0}", e.Message), Utils.PRINT_TAG.AV_OUTPUT);
                Utils.Print(String.Format("AngelicVerifier failed with: {0}", e.Message + e.StackTrace), Utils.PRINT_TAG.AV_DEBUG);
            }
            finally
            {
                Stats.printStats();
                Utils.Print(string.Format("TotalTime(ms) : {0}", sw.ElapsedMilliseconds), Utils.PRINT_TAG.AV_STATS);
            }
        }