./Ultimate.py --spec ../../sv-benchmarks/c/properties/unreach-call.prp --file ../../sv-benchmarks/c/weaver/popl20-horseshoe.wvr.c --full-output --architecture 32bit -------------------------------------------------------------------------------- Checking for ERROR reachability Using default analysis Version 527bcce2 Calling Ultimate with: /usr/lib/jvm/java-11-openjdk-amd64/bin/java -Dosgi.configuration.area=/tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_d18a002d-6fef-48c0-bc22-7b5491bf7185/bin/uautomizer-verify-bycVGegfSx/data/config -Xmx15G -Xms4m -jar /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_d18a002d-6fef-48c0-bc22-7b5491bf7185/bin/uautomizer-verify-bycVGegfSx/plugins/org.eclipse.equinox.launcher_1.5.800.v20200727-1323.jar -data @noDefault -ultimatedata /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_d18a002d-6fef-48c0-bc22-7b5491bf7185/bin/uautomizer-verify-bycVGegfSx/data -tc /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_d18a002d-6fef-48c0-bc22-7b5491bf7185/bin/uautomizer-verify-bycVGegfSx/config/AutomizerReach.xml -i ../../sv-benchmarks/c/weaver/popl20-horseshoe.wvr.c -s /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_d18a002d-6fef-48c0-bc22-7b5491bf7185/bin/uautomizer-verify-bycVGegfSx/config/svcomp-Reach-32bit-Automizer_Default.epf --cacsl2boogietranslator.entry.function main --witnessprinter.witness.directory /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_d18a002d-6fef-48c0-bc22-7b5491bf7185/bin/uautomizer-verify-bycVGegfSx --witnessprinter.witness.filename witness --witnessprinter.write.witness.besides.input.file false --witnessprinter.graph.data.specification CHECK( init(main()), LTL(G ! call(reach_error())) ) --witnessprinter.graph.data.producer Automizer --witnessprinter.graph.data.architecture 32bit --witnessprinter.graph.data.programhash ceb2af5016fd0ad74653237fbc44a2b3541e4ff971325e3807dab6f19c05af6d --- Real Ultimate output --- This is Ultimate 0.2.3-dev-527bcce [2023-11-21 22:23:24,420 INFO L188 SettingsManager]: Resetting all preferences to default values... [2023-11-21 22:23:24,501 INFO L114 SettingsManager]: Loading settings from /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_d18a002d-6fef-48c0-bc22-7b5491bf7185/bin/uautomizer-verify-bycVGegfSx/config/svcomp-Reach-32bit-Automizer_Default.epf [2023-11-21 22:23:24,507 WARN L101 SettingsManager]: Preference file contains the following unknown settings: [2023-11-21 22:23:24,508 WARN L103 SettingsManager]: * de.uni_freiburg.informatik.ultimate.core.Log level for class [2023-11-21 22:23:24,533 INFO L130 SettingsManager]: Preferences different from defaults after loading the file: [2023-11-21 22:23:24,534 INFO L151 SettingsManager]: Preferences of UltimateCore differ from their defaults: [2023-11-21 22:23:24,535 INFO L153 SettingsManager]: * Log level for class=de.uni_freiburg.informatik.ultimate.lib.smtlibutils.quantifier.QuantifierPusher=ERROR; [2023-11-21 22:23:24,536 INFO L151 SettingsManager]: Preferences of Boogie Preprocessor differ from their defaults: [2023-11-21 22:23:24,536 INFO L153 SettingsManager]: * Use memory slicer=true [2023-11-21 22:23:24,537 INFO L151 SettingsManager]: Preferences of Boogie Procedure Inliner differ from their defaults: [2023-11-21 22:23:24,538 INFO L153 SettingsManager]: * Ignore calls to procedures called more than once=ONLY_FOR_SEQUENTIAL_PROGRAMS [2023-11-21 22:23:24,539 INFO L151 SettingsManager]: Preferences of BlockEncodingV2 differ from their defaults: [2023-11-21 22:23:24,539 INFO L153 SettingsManager]: * Create parallel compositions if possible=false [2023-11-21 22:23:24,540 INFO L153 SettingsManager]: * Use SBE=true [2023-11-21 22:23:24,541 INFO L151 SettingsManager]: Preferences of CACSL2BoogieTranslator differ from their defaults: [2023-11-21 22:23:24,541 INFO L153 SettingsManager]: * Pointer base address is valid at dereference=IGNORE [2023-11-21 22:23:24,542 INFO L153 SettingsManager]: * sizeof long=4 [2023-11-21 22:23:24,542 INFO L153 SettingsManager]: * Overapproximate operations on floating types=true [2023-11-21 22:23:24,543 INFO L153 SettingsManager]: * sizeof POINTER=4 [2023-11-21 22:23:24,543 INFO L153 SettingsManager]: * Check division by zero=IGNORE [2023-11-21 22:23:24,544 INFO L153 SettingsManager]: * Pointer to allocated memory at dereference=IGNORE [2023-11-21 22:23:24,544 INFO L153 SettingsManager]: * If two pointers are subtracted or compared they have the same base address=IGNORE [2023-11-21 22:23:24,545 INFO L153 SettingsManager]: * Check array bounds for arrays that are off heap=IGNORE [2023-11-21 22:23:24,545 INFO L153 SettingsManager]: * sizeof long double=12 [2023-11-21 22:23:24,545 INFO L153 SettingsManager]: * Check if freed pointer was valid=false [2023-11-21 22:23:24,546 INFO L153 SettingsManager]: * Use constant arrays=true [2023-11-21 22:23:24,546 INFO L151 SettingsManager]: Preferences of RCFGBuilder differ from their defaults: [2023-11-21 22:23:24,547 INFO L153 SettingsManager]: * Size of a code block=SequenceOfStatements [2023-11-21 22:23:24,547 INFO L153 SettingsManager]: * Only consider context switches at boundaries of atomic blocks=true [2023-11-21 22:23:24,548 INFO L153 SettingsManager]: * SMT solver=External_DefaultMode [2023-11-21 22:23:24,548 INFO L153 SettingsManager]: * Command for external solver=z3 SMTLIB2_COMPLIANT=true -memory:2024 -smt2 -in -t:2000 [2023-11-21 22:23:24,549 INFO L151 SettingsManager]: Preferences of TraceAbstraction differ from their defaults: [2023-11-21 22:23:24,549 INFO L153 SettingsManager]: * Compute Interpolants along a Counterexample=FPandBP [2023-11-21 22:23:24,550 INFO L153 SettingsManager]: * Positions where we compute the Hoare Annotation=LoopHeads [2023-11-21 22:23:24,550 INFO L153 SettingsManager]: * Trace refinement strategy=CAMEL [2023-11-21 22:23:24,550 INFO L153 SettingsManager]: * Command for external solver=z3 SMTLIB2_COMPLIANT=true -memory:2024 -smt2 -in [2023-11-21 22:23:24,551 INFO L153 SettingsManager]: * Apply one-shot large block encoding in concurrent analysis=false [2023-11-21 22:23:24,551 INFO L153 SettingsManager]: * Automaton type used in concurrency analysis=PETRI_NET [2023-11-21 22:23:24,552 INFO L153 SettingsManager]: * Compute Hoare Annotation of negated interpolant automaton, abstraction and CFG=true [2023-11-21 22:23:24,552 INFO L153 SettingsManager]: * Order on configurations for Petri net unfoldings=DBO [2023-11-21 22:23:24,553 INFO L153 SettingsManager]: * SMT solver=External_ModelsAndUnsatCoreMode [2023-11-21 22:23:24,553 INFO L153 SettingsManager]: * Looper check in Petri net analysis=SEMANTIC WARNING: An illegal reflective access operation has occurred WARNING: Illegal reflective access by com.sun.xml.bind.v2.runtime.reflect.opt.Injector$1 (file:/tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_d18a002d-6fef-48c0-bc22-7b5491bf7185/bin/uautomizer-verify-bycVGegfSx/plugins/com.sun.xml.bind_2.2.0.v201505121915.jar) to method java.lang.ClassLoader.defineClass(java.lang.String,byte[],int,int) WARNING: Please consider reporting this to the maintainers of com.sun.xml.bind.v2.runtime.reflect.opt.Injector$1 WARNING: Use --illegal-access=warn to enable warnings of further illegal reflective access operations WARNING: All illegal access operations will be denied in a future release Applying setting for plugin de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator: Entry function -> main Applying setting for plugin de.uni_freiburg.informatik.ultimate.witnessprinter: Witness directory -> /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_d18a002d-6fef-48c0-bc22-7b5491bf7185/bin/uautomizer-verify-bycVGegfSx Applying setting for plugin de.uni_freiburg.informatik.ultimate.witnessprinter: Witness filename -> witness Applying setting for plugin de.uni_freiburg.informatik.ultimate.witnessprinter: Write witness besides input file -> false Applying setting for plugin de.uni_freiburg.informatik.ultimate.witnessprinter: Graph data specification -> CHECK( init(main()), LTL(G ! call(reach_error())) ) Applying setting for plugin de.uni_freiburg.informatik.ultimate.witnessprinter: Graph data producer -> Automizer Applying setting for plugin de.uni_freiburg.informatik.ultimate.witnessprinter: Graph data architecture -> 32bit Applying setting for plugin de.uni_freiburg.informatik.ultimate.witnessprinter: Graph data programhash -> ceb2af5016fd0ad74653237fbc44a2b3541e4ff971325e3807dab6f19c05af6d [2023-11-21 22:23:24,822 INFO L75 nceAwareModelManager]: Repository-Root is: /tmp [2023-11-21 22:23:24,855 INFO L261 ainManager$Toolchain]: [Toolchain 1]: Applicable parser(s) successfully (re)initialized [2023-11-21 22:23:24,858 INFO L217 ainManager$Toolchain]: [Toolchain 1]: Toolchain selected. [2023-11-21 22:23:24,860 INFO L270 PluginConnector]: Initializing CDTParser... [2023-11-21 22:23:24,861 INFO L274 PluginConnector]: CDTParser initialized [2023-11-21 22:23:24,862 INFO L431 ainManager$Toolchain]: [Toolchain 1]: Parsing single file: /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_d18a002d-6fef-48c0-bc22-7b5491bf7185/bin/uautomizer-verify-bycVGegfSx/../../sv-benchmarks/c/weaver/popl20-horseshoe.wvr.c [2023-11-21 22:23:28,016 INFO L533 CDTParser]: Created temporary CDT project at NULL [2023-11-21 22:23:28,250 INFO L384 CDTParser]: Found 1 translation units. [2023-11-21 22:23:28,250 INFO L180 CDTParser]: Scanning /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_d18a002d-6fef-48c0-bc22-7b5491bf7185/sv-benchmarks/c/weaver/popl20-horseshoe.wvr.c [2023-11-21 22:23:28,259 INFO L427 CDTParser]: About to delete temporary CDT project at /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_d18a002d-6fef-48c0-bc22-7b5491bf7185/bin/uautomizer-verify-bycVGegfSx/data/eaefbbba8/d67b070343674d4b8430af97f02305c3/FLAG8930378cb [2023-11-21 22:23:28,271 INFO L435 CDTParser]: Successfully deleted /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_d18a002d-6fef-48c0-bc22-7b5491bf7185/bin/uautomizer-verify-bycVGegfSx/data/eaefbbba8/d67b070343674d4b8430af97f02305c3 [2023-11-21 22:23:28,274 INFO L299 ainManager$Toolchain]: ####################### [Toolchain 1] ####################### [2023-11-21 22:23:28,275 INFO L133 ToolchainWalker]: Walking toolchain with 6 elements. [2023-11-21 22:23:28,277 INFO L112 PluginConnector]: ------------------------CACSL2BoogieTranslator---------------------------- [2023-11-21 22:23:28,277 INFO L270 PluginConnector]: Initializing CACSL2BoogieTranslator... [2023-11-21 22:23:28,281 INFO L274 PluginConnector]: CACSL2BoogieTranslator initialized [2023-11-21 22:23:28,282 INFO L184 PluginConnector]: Executing the observer ACSLObjectContainerObserver from plugin CACSL2BoogieTranslator for "CDTParser AST 21.11 10:23:28" (1/1) ... [2023-11-21 22:23:28,283 INFO L204 PluginConnector]: Invalid model from CACSL2BoogieTranslator for observer de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator.ACSLObjectContainerObserver@3b19fd00 and model type de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 21.11 10:23:28, skipping insertion in model container [2023-11-21 22:23:28,284 INFO L184 PluginConnector]: Executing the observer CACSL2BoogieTranslatorObserver from plugin CACSL2BoogieTranslator for "CDTParser AST 21.11 10:23:28" (1/1) ... [2023-11-21 22:23:28,310 INFO L177 MainTranslator]: Built tables and reachable declarations [2023-11-21 22:23:28,507 WARN L240 ndardFunctionHandler]: Function reach_error is already implemented but we override the implementation for the call at /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_d18a002d-6fef-48c0-bc22-7b5491bf7185/sv-benchmarks/c/weaver/popl20-horseshoe.wvr.c[3463,3476] [2023-11-21 22:23:28,515 INFO L209 PostProcessor]: Analyzing one entry point: main [2023-11-21 22:23:28,526 INFO L202 MainTranslator]: Completed pre-run [2023-11-21 22:23:28,551 WARN L240 ndardFunctionHandler]: Function reach_error is already implemented but we override the implementation for the call at /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_d18a002d-6fef-48c0-bc22-7b5491bf7185/sv-benchmarks/c/weaver/popl20-horseshoe.wvr.c[3463,3476] [2023-11-21 22:23:28,555 INFO L209 PostProcessor]: Analyzing one entry point: main [2023-11-21 22:23:28,565 WARN L675 CHandler]: The function __VERIFIER_atomic_begin is called, but not defined or handled by StandardFunctionHandler. [2023-11-21 22:23:28,565 WARN L675 CHandler]: The function __VERIFIER_atomic_end is called, but not defined or handled by StandardFunctionHandler. [2023-11-21 22:23:28,571 INFO L206 MainTranslator]: Completed translation [2023-11-21 22:23:28,571 INFO L201 PluginConnector]: Adding new model de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 21.11 10:23:28 WrapperNode [2023-11-21 22:23:28,572 INFO L131 PluginConnector]: ------------------------ END CACSL2BoogieTranslator---------------------------- [2023-11-21 22:23:28,573 INFO L112 PluginConnector]: ------------------------Boogie Procedure Inliner---------------------------- [2023-11-21 22:23:28,573 INFO L270 PluginConnector]: Initializing Boogie Procedure Inliner... [2023-11-21 22:23:28,573 INFO L274 PluginConnector]: Boogie Procedure Inliner initialized [2023-11-21 22:23:28,582 INFO L184 PluginConnector]: Executing the observer TypeChecker from plugin Boogie Procedure Inliner for "de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 21.11 10:23:28" (1/1) ... [2023-11-21 22:23:28,600 INFO L184 PluginConnector]: Executing the observer Inliner from plugin Boogie Procedure Inliner for "de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 21.11 10:23:28" (1/1) ... [2023-11-21 22:23:28,643 INFO L138 Inliner]: procedures = 25, calls = 55, calls flagged for inlining = 16, calls inlined = 18, statements flattened = 257 [2023-11-21 22:23:28,644 INFO L131 PluginConnector]: ------------------------ END Boogie Procedure Inliner---------------------------- [2023-11-21 22:23:28,648 INFO L112 PluginConnector]: ------------------------Boogie Preprocessor---------------------------- [2023-11-21 22:23:28,648 INFO L270 PluginConnector]: Initializing Boogie Preprocessor... [2023-11-21 22:23:28,648 INFO L274 PluginConnector]: Boogie Preprocessor initialized [2023-11-21 22:23:28,661 INFO L184 PluginConnector]: Executing the observer EnsureBoogieModelObserver from plugin Boogie Preprocessor for "de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 21.11 10:23:28" (1/1) ... [2023-11-21 22:23:28,662 INFO L184 PluginConnector]: Executing the observer TypeChecker from plugin Boogie Preprocessor for "de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 21.11 10:23:28" (1/1) ... [2023-11-21 22:23:28,666 INFO L184 PluginConnector]: Executing the observer HeapSplitter from plugin Boogie Preprocessor for "de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 21.11 10:23:28" (1/1) ... [2023-11-21 22:23:28,679 FATAL L? ?]: The Plugin de.uni_freiburg.informatik.ultimate.boogie.preprocessor has thrown an exception: java.lang.ArrayIndexOutOfBoundsException: Index 0 out of bounds for length 0 at de.uni_freiburg.informatik.ultimate.boogie.preprocessor.memoryslicer.AliasAnalysis.processJoinStatement(AliasAnalysis.java:175) at de.uni_freiburg.informatik.ultimate.boogie.preprocessor.memoryslicer.AliasAnalysis.processStatementList(AliasAnalysis.java:161) at de.uni_freiburg.informatik.ultimate.boogie.preprocessor.memoryslicer.AliasAnalysis.processBody(AliasAnalysis.java:128) at de.uni_freiburg.informatik.ultimate.boogie.preprocessor.memoryslicer.AliasAnalysis.aliasAnalysis(AliasAnalysis.java:117) at de.uni_freiburg.informatik.ultimate.boogie.preprocessor.memoryslicer.HeapSplitter.tryToSliceMemory(HeapSplitter.java:116) at de.uni_freiburg.informatik.ultimate.boogie.preprocessor.memoryslicer.HeapSplitter.process(HeapSplitter.java:102) at de.uni_freiburg.informatik.ultimate.core.coreplugin.modelwalker.DFSTreeWalker.runObserver(DFSTreeWalker.java:65) at de.uni_freiburg.informatik.ultimate.core.coreplugin.modelwalker.BaseWalker.runObserver(BaseWalker.java:93) at de.uni_freiburg.informatik.ultimate.core.coreplugin.modelwalker.BaseWalker.run(BaseWalker.java:86) at de.uni_freiburg.informatik.ultimate.core.coreplugin.PluginConnector.runObserver(PluginConnector.java:166) at de.uni_freiburg.informatik.ultimate.core.coreplugin.PluginConnector.runTool(PluginConnector.java:155) at de.uni_freiburg.informatik.ultimate.core.coreplugin.PluginConnector.run(PluginConnector.java:127) at de.uni_freiburg.informatik.ultimate.core.coreplugin.ToolchainWalker.executePluginConnector(ToolchainWalker.java:233) at de.uni_freiburg.informatik.ultimate.core.coreplugin.ToolchainWalker.processPlugin(ToolchainWalker.java:227) at de.uni_freiburg.informatik.ultimate.core.coreplugin.ToolchainWalker.walkUnprotected(ToolchainWalker.java:144) at de.uni_freiburg.informatik.ultimate.core.coreplugin.ToolchainWalker.walk(ToolchainWalker.java:106) at de.uni_freiburg.informatik.ultimate.core.coreplugin.ToolchainManager$Toolchain.processToolchain(ToolchainManager.java:319) at de.uni_freiburg.informatik.ultimate.core.coreplugin.toolchain.DefaultToolchainJob.run(DefaultToolchainJob.java:145) at org.eclipse.core.internal.jobs.Worker.run(Worker.java:63) [2023-11-21 22:23:28,684 INFO L158 Benchmark]: Toolchain (without parser) took 407.49ms. Allocated memory is still 146.8MB. Free memory was 106.7MB in the beginning and 90.2MB in the end (delta: 16.5MB). Peak memory consumption was 16.8MB. Max. memory is 16.1GB. [2023-11-21 22:23:28,685 INFO L158 Benchmark]: CDTParser took 0.32ms. Allocated memory is still 100.7MB. Free memory was 51.8MB in the beginning and 51.7MB in the end (delta: 134.4kB). There was no memory consumed. Max. memory is 16.1GB. [2023-11-21 22:23:28,685 INFO L158 Benchmark]: CACSL2BoogieTranslator took 295.69ms. Allocated memory is still 146.8MB. Free memory was 106.3MB in the beginning and 93.7MB in the end (delta: 12.6MB). Peak memory consumption was 12.6MB. Max. memory is 16.1GB. [2023-11-21 22:23:28,686 INFO L158 Benchmark]: Boogie Procedure Inliner took 74.22ms. Allocated memory is still 146.8MB. Free memory was 93.7MB in the beginning and 91.3MB in the end (delta: 2.4MB). Peak memory consumption was 2.1MB. Max. memory is 16.1GB. [2023-11-21 22:23:28,687 INFO L158 Benchmark]: Boogie Preprocessor took 34.06ms. Allocated memory is still 146.8MB. Free memory was 91.3MB in the beginning and 90.2MB in the end (delta: 1.1MB). Peak memory consumption was 2.1MB. Max. memory is 16.1GB. [2023-11-21 22:23:28,691 INFO L338 ainManager$Toolchain]: ####################### End [Toolchain 1] ####################### --- Results --- * Results from de.uni_freiburg.informatik.ultimate.core: - StatisticsResult: Toolchain Benchmarks Benchmark results are: * CDTParser took 0.32ms. Allocated memory is still 100.7MB. Free memory was 51.8MB in the beginning and 51.7MB in the end (delta: 134.4kB). There was no memory consumed. Max. memory is 16.1GB. * CACSL2BoogieTranslator took 295.69ms. Allocated memory is still 146.8MB. Free memory was 106.3MB in the beginning and 93.7MB in the end (delta: 12.6MB). Peak memory consumption was 12.6MB. Max. memory is 16.1GB. * Boogie Procedure Inliner took 74.22ms. Allocated memory is still 146.8MB. Free memory was 93.7MB in the beginning and 91.3MB in the end (delta: 2.4MB). Peak memory consumption was 2.1MB. Max. memory is 16.1GB. * Boogie Preprocessor took 34.06ms. Allocated memory is still 146.8MB. Free memory was 91.3MB in the beginning and 90.2MB in the end (delta: 1.1MB). Peak memory consumption was 2.1MB. Max. memory is 16.1GB. * Results from de.uni_freiburg.informatik.ultimate.boogie.preprocessor: - ExceptionOrErrorResult: ArrayIndexOutOfBoundsException: Index 0 out of bounds for length 0 de.uni_freiburg.informatik.ultimate.boogie.preprocessor: ArrayIndexOutOfBoundsException: Index 0 out of bounds for length 0: de.uni_freiburg.informatik.ultimate.boogie.preprocessor.memoryslicer.AliasAnalysis.processJoinStatement(AliasAnalysis.java:175) RESULT: Ultimate could not prove your program: Toolchain returned no result. Received shutdown request... --- End real Ultimate output --- Execution finished normally Using bit-precise analysis Retrying with bit-precise analysis ### Bit-precise run ### Calling Ultimate with: /usr/lib/jvm/java-11-openjdk-amd64/bin/java -Dosgi.configuration.area=/tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_d18a002d-6fef-48c0-bc22-7b5491bf7185/bin/uautomizer-verify-bycVGegfSx/data/config -Xmx15G -Xms4m -jar /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_d18a002d-6fef-48c0-bc22-7b5491bf7185/bin/uautomizer-verify-bycVGegfSx/plugins/org.eclipse.equinox.launcher_1.5.800.v20200727-1323.jar -data @noDefault -ultimatedata /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_d18a002d-6fef-48c0-bc22-7b5491bf7185/bin/uautomizer-verify-bycVGegfSx/data -tc /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_d18a002d-6fef-48c0-bc22-7b5491bf7185/bin/uautomizer-verify-bycVGegfSx/config/AutomizerReach.xml -i ../../sv-benchmarks/c/weaver/popl20-horseshoe.wvr.c -s /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_d18a002d-6fef-48c0-bc22-7b5491bf7185/bin/uautomizer-verify-bycVGegfSx/config/svcomp-Reach-32bit-Automizer_Bitvector.epf --cacsl2boogietranslator.entry.function main --witnessprinter.witness.directory /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_d18a002d-6fef-48c0-bc22-7b5491bf7185/bin/uautomizer-verify-bycVGegfSx --witnessprinter.witness.filename witness --witnessprinter.write.witness.besides.input.file false --witnessprinter.graph.data.specification CHECK( init(main()), LTL(G ! call(reach_error())) ) --witnessprinter.graph.data.producer Automizer --witnessprinter.graph.data.architecture 32bit --witnessprinter.graph.data.programhash ceb2af5016fd0ad74653237fbc44a2b3541e4ff971325e3807dab6f19c05af6d --- Real Ultimate output --- This is Ultimate 0.2.3-dev-527bcce [2023-11-21 22:23:31,206 INFO L188 SettingsManager]: Resetting all preferences to default values... [2023-11-21 22:23:31,343 INFO L114 SettingsManager]: Loading settings from /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_d18a002d-6fef-48c0-bc22-7b5491bf7185/bin/uautomizer-verify-bycVGegfSx/config/svcomp-Reach-32bit-Automizer_Bitvector.epf [2023-11-21 22:23:31,352 WARN L101 SettingsManager]: Preference file contains the following unknown settings: [2023-11-21 22:23:31,353 WARN L103 SettingsManager]: * de.uni_freiburg.informatik.ultimate.core.Log level for class [2023-11-21 22:23:31,398 INFO L130 SettingsManager]: Preferences different from defaults after loading the file: [2023-11-21 22:23:31,400 INFO L151 SettingsManager]: Preferences of UltimateCore differ from their defaults: [2023-11-21 22:23:31,400 INFO L153 SettingsManager]: * Log level for class=de.uni_freiburg.informatik.ultimate.lib.smtlibutils.quantifier.QuantifierPusher=ERROR; [2023-11-21 22:23:31,401 INFO L151 SettingsManager]: Preferences of Boogie Preprocessor differ from their defaults: [2023-11-21 22:23:31,406 INFO L153 SettingsManager]: * Use memory slicer=true [2023-11-21 22:23:31,407 INFO L151 SettingsManager]: Preferences of Boogie Procedure Inliner differ from their defaults: [2023-11-21 22:23:31,408 INFO L153 SettingsManager]: * Ignore calls to procedures called more than once=ONLY_FOR_SEQUENTIAL_PROGRAMS [2023-11-21 22:23:31,408 INFO L151 SettingsManager]: Preferences of BlockEncodingV2 differ from their defaults: [2023-11-21 22:23:31,410 INFO L153 SettingsManager]: * Create parallel compositions if possible=false [2023-11-21 22:23:31,411 INFO L153 SettingsManager]: * Use SBE=true [2023-11-21 22:23:31,411 INFO L151 SettingsManager]: Preferences of CACSL2BoogieTranslator differ from their defaults: [2023-11-21 22:23:31,412 INFO L153 SettingsManager]: * Pointer base address is valid at dereference=IGNORE [2023-11-21 22:23:31,412 INFO L153 SettingsManager]: * sizeof long=4 [2023-11-21 22:23:31,413 INFO L153 SettingsManager]: * sizeof POINTER=4 [2023-11-21 22:23:31,414 INFO L153 SettingsManager]: * Check division by zero=IGNORE [2023-11-21 22:23:31,414 INFO L153 SettingsManager]: * Pointer to allocated memory at dereference=IGNORE [2023-11-21 22:23:31,415 INFO L153 SettingsManager]: * If two pointers are subtracted or compared they have the same base address=IGNORE [2023-11-21 22:23:31,416 INFO L153 SettingsManager]: * Check array bounds for arrays that are off heap=IGNORE [2023-11-21 22:23:31,416 INFO L153 SettingsManager]: * Adapt memory model on pointer casts if necessary=true [2023-11-21 22:23:31,416 INFO L153 SettingsManager]: * Use bitvectors instead of ints=true [2023-11-21 22:23:31,417 INFO L153 SettingsManager]: * Memory model=HoenickeLindenmann_4ByteResolution [2023-11-21 22:23:31,417 INFO L153 SettingsManager]: * sizeof long double=12 [2023-11-21 22:23:31,418 INFO L153 SettingsManager]: * Check if freed pointer was valid=false [2023-11-21 22:23:31,418 INFO L153 SettingsManager]: * Use constant arrays=true [2023-11-21 22:23:31,419 INFO L151 SettingsManager]: Preferences of RCFGBuilder differ from their defaults: [2023-11-21 22:23:31,421 INFO L153 SettingsManager]: * Size of a code block=SequenceOfStatements [2023-11-21 22:23:31,421 INFO L153 SettingsManager]: * Only consider context switches at boundaries of atomic blocks=true [2023-11-21 22:23:31,421 INFO L153 SettingsManager]: * SMT solver=External_DefaultMode [2023-11-21 22:23:31,421 INFO L153 SettingsManager]: * Command for external solver=z3 SMTLIB2_COMPLIANT=true -memory:2024 -smt2 -in -t:2000 [2023-11-21 22:23:31,422 INFO L151 SettingsManager]: Preferences of TraceAbstraction differ from their defaults: [2023-11-21 22:23:31,422 INFO L153 SettingsManager]: * Compute Interpolants along a Counterexample=FPandBP [2023-11-21 22:23:31,423 INFO L153 SettingsManager]: * Positions where we compute the Hoare Annotation=LoopHeads [2023-11-21 22:23:31,423 INFO L153 SettingsManager]: * Trace refinement strategy=WOLF [2023-11-21 22:23:31,424 INFO L153 SettingsManager]: * Command for external solver=cvc4 --incremental --print-success --lang smt [2023-11-21 22:23:31,424 INFO L153 SettingsManager]: * Apply one-shot large block encoding in concurrent analysis=false [2023-11-21 22:23:31,424 INFO L153 SettingsManager]: * Automaton type used in concurrency analysis=PETRI_NET [2023-11-21 22:23:31,425 INFO L153 SettingsManager]: * Compute Hoare Annotation of negated interpolant automaton, abstraction and CFG=true [2023-11-21 22:23:31,425 INFO L153 SettingsManager]: * Order on configurations for Petri net unfoldings=DBO [2023-11-21 22:23:31,425 INFO L153 SettingsManager]: * SMT solver=External_ModelsAndUnsatCoreMode [2023-11-21 22:23:31,426 INFO L153 SettingsManager]: * Logic for external solver=AUFBV [2023-11-21 22:23:31,426 INFO L153 SettingsManager]: * Looper check in Petri net analysis=SEMANTIC WARNING: An illegal reflective access operation has occurred WARNING: Illegal reflective access by com.sun.xml.bind.v2.runtime.reflect.opt.Injector$1 (file:/tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_d18a002d-6fef-48c0-bc22-7b5491bf7185/bin/uautomizer-verify-bycVGegfSx/plugins/com.sun.xml.bind_2.2.0.v201505121915.jar) to method java.lang.ClassLoader.defineClass(java.lang.String,byte[],int,int) WARNING: Please consider reporting this to the maintainers of com.sun.xml.bind.v2.runtime.reflect.opt.Injector$1 WARNING: Use --illegal-access=warn to enable warnings of further illegal reflective access operations WARNING: All illegal access operations will be denied in a future release Applying setting for plugin de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator: Entry function -> main Applying setting for plugin de.uni_freiburg.informatik.ultimate.witnessprinter: Witness directory -> /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_d18a002d-6fef-48c0-bc22-7b5491bf7185/bin/uautomizer-verify-bycVGegfSx Applying setting for plugin de.uni_freiburg.informatik.ultimate.witnessprinter: Witness filename -> witness Applying setting for plugin de.uni_freiburg.informatik.ultimate.witnessprinter: Write witness besides input file -> false Applying setting for plugin de.uni_freiburg.informatik.ultimate.witnessprinter: Graph data specification -> CHECK( init(main()), LTL(G ! call(reach_error())) ) Applying setting for plugin de.uni_freiburg.informatik.ultimate.witnessprinter: Graph data producer -> Automizer Applying setting for plugin de.uni_freiburg.informatik.ultimate.witnessprinter: Graph data architecture -> 32bit Applying setting for plugin de.uni_freiburg.informatik.ultimate.witnessprinter: Graph data programhash -> ceb2af5016fd0ad74653237fbc44a2b3541e4ff971325e3807dab6f19c05af6d [2023-11-21 22:23:31,798 INFO L75 nceAwareModelManager]: Repository-Root is: /tmp [2023-11-21 22:23:31,820 INFO L261 ainManager$Toolchain]: [Toolchain 1]: Applicable parser(s) successfully (re)initialized [2023-11-21 22:23:31,823 INFO L217 ainManager$Toolchain]: [Toolchain 1]: Toolchain selected. [2023-11-21 22:23:31,825 INFO L270 PluginConnector]: Initializing CDTParser... [2023-11-21 22:23:31,825 INFO L274 PluginConnector]: CDTParser initialized [2023-11-21 22:23:31,827 INFO L431 ainManager$Toolchain]: [Toolchain 1]: Parsing single file: /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_d18a002d-6fef-48c0-bc22-7b5491bf7185/bin/uautomizer-verify-bycVGegfSx/../../sv-benchmarks/c/weaver/popl20-horseshoe.wvr.c [2023-11-21 22:23:35,201 INFO L533 CDTParser]: Created temporary CDT project at NULL [2023-11-21 22:23:35,532 INFO L384 CDTParser]: Found 1 translation units. [2023-11-21 22:23:35,533 INFO L180 CDTParser]: Scanning /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_d18a002d-6fef-48c0-bc22-7b5491bf7185/sv-benchmarks/c/weaver/popl20-horseshoe.wvr.c [2023-11-21 22:23:35,545 INFO L427 CDTParser]: About to delete temporary CDT project at /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_d18a002d-6fef-48c0-bc22-7b5491bf7185/bin/uautomizer-verify-bycVGegfSx/data/d7a1b5e85/d992fe7624a147d4995e341d62e628ba/FLAG3330fc8b6 [2023-11-21 22:23:35,574 INFO L435 CDTParser]: Successfully deleted /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_d18a002d-6fef-48c0-bc22-7b5491bf7185/bin/uautomizer-verify-bycVGegfSx/data/d7a1b5e85/d992fe7624a147d4995e341d62e628ba [2023-11-21 22:23:35,582 INFO L299 ainManager$Toolchain]: ####################### [Toolchain 1] ####################### [2023-11-21 22:23:35,584 INFO L133 ToolchainWalker]: Walking toolchain with 6 elements. [2023-11-21 22:23:35,587 INFO L112 PluginConnector]: ------------------------CACSL2BoogieTranslator---------------------------- [2023-11-21 22:23:35,588 INFO L270 PluginConnector]: Initializing CACSL2BoogieTranslator... [2023-11-21 22:23:35,593 INFO L274 PluginConnector]: CACSL2BoogieTranslator initialized [2023-11-21 22:23:35,594 INFO L184 PluginConnector]: Executing the observer ACSLObjectContainerObserver from plugin CACSL2BoogieTranslator for "CDTParser AST 21.11 10:23:35" (1/1) ... [2023-11-21 22:23:35,595 INFO L204 PluginConnector]: Invalid model from CACSL2BoogieTranslator for observer de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator.ACSLObjectContainerObserver@7e089155 and model type de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 21.11 10:23:35, skipping insertion in model container [2023-11-21 22:23:35,596 INFO L184 PluginConnector]: Executing the observer CACSL2BoogieTranslatorObserver from plugin CACSL2BoogieTranslator for "CDTParser AST 21.11 10:23:35" (1/1) ... [2023-11-21 22:23:35,642 INFO L177 MainTranslator]: Built tables and reachable declarations [2023-11-21 22:23:35,916 WARN L240 ndardFunctionHandler]: Function reach_error is already implemented but we override the implementation for the call at /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_d18a002d-6fef-48c0-bc22-7b5491bf7185/sv-benchmarks/c/weaver/popl20-horseshoe.wvr.c[3463,3476] [2023-11-21 22:23:35,942 INFO L209 PostProcessor]: Analyzing one entry point: main [2023-11-21 22:23:35,963 INFO L199 MainTranslator]: Restarting translation with changed settings: SettingsChange [mNewPreferredMemoryModel=HoenickeLindenmann_1ByteResolution] [2023-11-21 22:23:35,975 INFO L177 MainTranslator]: Built tables and reachable declarations [2023-11-21 22:23:36,021 WARN L240 ndardFunctionHandler]: Function reach_error is already implemented but we override the implementation for the call at /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_d18a002d-6fef-48c0-bc22-7b5491bf7185/sv-benchmarks/c/weaver/popl20-horseshoe.wvr.c[3463,3476] [2023-11-21 22:23:36,025 INFO L209 PostProcessor]: Analyzing one entry point: main [2023-11-21 22:23:36,032 INFO L202 MainTranslator]: Completed pre-run [2023-11-21 22:23:36,079 WARN L240 ndardFunctionHandler]: Function reach_error is already implemented but we override the implementation for the call at /tmp/vcloud_worker_vcloud-master_on_vcloud-master/run_dir_d18a002d-6fef-48c0-bc22-7b5491bf7185/sv-benchmarks/c/weaver/popl20-horseshoe.wvr.c[3463,3476] [2023-11-21 22:23:36,089 INFO L209 PostProcessor]: Analyzing one entry point: main [2023-11-21 22:23:36,101 WARN L675 CHandler]: The function __VERIFIER_atomic_begin is called, but not defined or handled by StandardFunctionHandler. [2023-11-21 22:23:36,103 WARN L675 CHandler]: The function __VERIFIER_atomic_end is called, but not defined or handled by StandardFunctionHandler. [2023-11-21 22:23:36,111 INFO L206 MainTranslator]: Completed translation [2023-11-21 22:23:36,112 INFO L201 PluginConnector]: Adding new model de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 21.11 10:23:36 WrapperNode [2023-11-21 22:23:36,112 INFO L131 PluginConnector]: ------------------------ END CACSL2BoogieTranslator---------------------------- [2023-11-21 22:23:36,114 INFO L112 PluginConnector]: ------------------------Boogie Procedure Inliner---------------------------- [2023-11-21 22:23:36,114 INFO L270 PluginConnector]: Initializing Boogie Procedure Inliner... [2023-11-21 22:23:36,114 INFO L274 PluginConnector]: Boogie Procedure Inliner initialized [2023-11-21 22:23:36,122 INFO L184 PluginConnector]: Executing the observer TypeChecker from plugin Boogie Procedure Inliner for "de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 21.11 10:23:36" (1/1) ... [2023-11-21 22:23:36,150 INFO L184 PluginConnector]: Executing the observer Inliner from plugin Boogie Procedure Inliner for "de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 21.11 10:23:36" (1/1) ... [2023-11-21 22:23:36,195 INFO L138 Inliner]: procedures = 27, calls = 55, calls flagged for inlining = 16, calls inlined = 18, statements flattened = 250 [2023-11-21 22:23:36,196 INFO L131 PluginConnector]: ------------------------ END Boogie Procedure Inliner---------------------------- [2023-11-21 22:23:36,198 INFO L112 PluginConnector]: ------------------------Boogie Preprocessor---------------------------- [2023-11-21 22:23:36,198 INFO L270 PluginConnector]: Initializing Boogie Preprocessor... [2023-11-21 22:23:36,199 INFO L274 PluginConnector]: Boogie Preprocessor initialized [2023-11-21 22:23:36,211 INFO L184 PluginConnector]: Executing the observer EnsureBoogieModelObserver from plugin Boogie Preprocessor for "de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 21.11 10:23:36" (1/1) ... [2023-11-21 22:23:36,212 INFO L184 PluginConnector]: Executing the observer TypeChecker from plugin Boogie Preprocessor for "de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 21.11 10:23:36" (1/1) ... [2023-11-21 22:23:36,228 INFO L184 PluginConnector]: Executing the observer HeapSplitter from plugin Boogie Preprocessor for "de.uni_freiburg.informatik.ultimate.plugins.generator.cacsl2boogietranslator AST 21.11 10:23:36" (1/1) ... [2023-11-21 22:23:36,238 FATAL L? ?]: The Plugin de.uni_freiburg.informatik.ultimate.boogie.preprocessor has thrown an exception: java.lang.ArrayIndexOutOfBoundsException: Index 0 out of bounds for length 0 at de.uni_freiburg.informatik.ultimate.boogie.preprocessor.memoryslicer.AliasAnalysis.processJoinStatement(AliasAnalysis.java:175) at de.uni_freiburg.informatik.ultimate.boogie.preprocessor.memoryslicer.AliasAnalysis.processStatementList(AliasAnalysis.java:161) at de.uni_freiburg.informatik.ultimate.boogie.preprocessor.memoryslicer.AliasAnalysis.processBody(AliasAnalysis.java:128) at de.uni_freiburg.informatik.ultimate.boogie.preprocessor.memoryslicer.AliasAnalysis.aliasAnalysis(AliasAnalysis.java:117) at de.uni_freiburg.informatik.ultimate.boogie.preprocessor.memoryslicer.HeapSplitter.tryToSliceMemory(HeapSplitter.java:116) at de.uni_freiburg.informatik.ultimate.boogie.preprocessor.memoryslicer.HeapSplitter.process(HeapSplitter.java:102) at de.uni_freiburg.informatik.ultimate.core.coreplugin.modelwalker.DFSTreeWalker.runObserver(DFSTreeWalker.java:65) at de.uni_freiburg.informatik.ultimate.core.coreplugin.modelwalker.BaseWalker.runObserver(BaseWalker.java:93) at de.uni_freiburg.informatik.ultimate.core.coreplugin.modelwalker.BaseWalker.run(BaseWalker.java:86) at de.uni_freiburg.informatik.ultimate.core.coreplugin.PluginConnector.runObserver(PluginConnector.java:166) at de.uni_freiburg.informatik.ultimate.core.coreplugin.PluginConnector.runTool(PluginConnector.java:155) at de.uni_freiburg.informatik.ultimate.core.coreplugin.PluginConnector.run(PluginConnector.java:127) at de.uni_freiburg.informatik.ultimate.core.coreplugin.ToolchainWalker.executePluginConnector(ToolchainWalker.java:233) at de.uni_freiburg.informatik.ultimate.core.coreplugin.ToolchainWalker.processPlugin(ToolchainWalker.java:227) at de.uni_freiburg.informatik.ultimate.core.coreplugin.ToolchainWalker.walkUnprotected(ToolchainWalker.java:144) at de.uni_freiburg.informatik.ultimate.core.coreplugin.ToolchainWalker.walk(ToolchainWalker.java:106) at de.uni_freiburg.informatik.ultimate.core.coreplugin.ToolchainManager$Toolchain.processToolchain(ToolchainManager.java:319) at de.uni_freiburg.informatik.ultimate.core.coreplugin.toolchain.DefaultToolchainJob.run(DefaultToolchainJob.java:145) at org.eclipse.core.internal.jobs.Worker.run(Worker.java:63) [2023-11-21 22:23:36,244 INFO L158 Benchmark]: Toolchain (without parser) took 659.38ms. Allocated memory is still 83.9MB. Free memory was 60.2MB in the beginning and 41.3MB in the end (delta: 18.9MB). Peak memory consumption was 18.9MB. Max. memory is 16.1GB. [2023-11-21 22:23:36,245 INFO L158 Benchmark]: CDTParser took 0.36ms. Allocated memory is still 83.9MB. Free memory was 60.1MB in the beginning and 59.9MB in the end (delta: 139.9kB). There was no memory consumed. Max. memory is 16.1GB. [2023-11-21 22:23:36,245 INFO L158 Benchmark]: CACSL2BoogieTranslator took 524.87ms. Allocated memory is still 83.9MB. Free memory was 59.9MB in the beginning and 45.2MB in the end (delta: 14.7MB). Peak memory consumption was 14.7MB. Max. memory is 16.1GB. [2023-11-21 22:23:36,246 INFO L158 Benchmark]: Boogie Procedure Inliner took 83.14ms. Allocated memory is still 83.9MB. Free memory was 45.2MB in the beginning and 42.9MB in the end (delta: 2.4MB). Peak memory consumption was 2.1MB. Max. memory is 16.1GB. [2023-11-21 22:23:36,252 INFO L158 Benchmark]: Boogie Preprocessor took 43.62ms. Allocated memory is still 83.9MB. Free memory was 42.6MB in the beginning and 41.3MB in the end (delta: 1.3MB). Peak memory consumption was 2.1MB. Max. memory is 16.1GB. [2023-11-21 22:23:36,257 INFO L338 ainManager$Toolchain]: ####################### End [Toolchain 1] ####################### --- Results --- * Results from de.uni_freiburg.informatik.ultimate.core: - StatisticsResult: Toolchain Benchmarks Benchmark results are: * CDTParser took 0.36ms. Allocated memory is still 83.9MB. Free memory was 60.1MB in the beginning and 59.9MB in the end (delta: 139.9kB). There was no memory consumed. Max. memory is 16.1GB. * CACSL2BoogieTranslator took 524.87ms. Allocated memory is still 83.9MB. Free memory was 59.9MB in the beginning and 45.2MB in the end (delta: 14.7MB). Peak memory consumption was 14.7MB. Max. memory is 16.1GB. * Boogie Procedure Inliner took 83.14ms. Allocated memory is still 83.9MB. Free memory was 45.2MB in the beginning and 42.9MB in the end (delta: 2.4MB). Peak memory consumption was 2.1MB. Max. memory is 16.1GB. * Boogie Preprocessor took 43.62ms. Allocated memory is still 83.9MB. Free memory was 42.6MB in the beginning and 41.3MB in the end (delta: 1.3MB). Peak memory consumption was 2.1MB. Max. memory is 16.1GB. * Results from de.uni_freiburg.informatik.ultimate.boogie.preprocessor: - ExceptionOrErrorResult: ArrayIndexOutOfBoundsException: Index 0 out of bounds for length 0 de.uni_freiburg.informatik.ultimate.boogie.preprocessor: ArrayIndexOutOfBoundsException: Index 0 out of bounds for length 0: de.uni_freiburg.informatik.ultimate.boogie.preprocessor.memoryslicer.AliasAnalysis.processJoinStatement(AliasAnalysis.java:175) RESULT: Ultimate could not prove your program: Toolchain returned no result. Received shutdown request... --- End real Ultimate output --- Execution finished normally Writing output log to file Ultimate.log Result: ERROR: ExceptionOrErrorResult: ArrayIndexOutOfBoundsException: Index 0 out of bounds for length 0