1 /*
  2  * Copyright (c) 2016, 2025, Oracle and/or its affiliates. All rights reserved.
  3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  4  *
  5  * This code is free software; you can redistribute it and/or modify it
  6  * under the terms of the GNU General Public License version 2 only, as
  7  * published by the Free Software Foundation.
  8  *
  9  * This code is distributed in the hope that it will be useful, but WITHOUT
 10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 12  * version 2 for more details (a copy is included in the LICENSE file that
 13  * accompanied this code).
 14  *
 15  * You should have received a copy of the GNU General Public License version
 16  * 2 along with this work; if not, write to the Free Software Foundation,
 17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 18  *
 19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 20  * or visit www.oracle.com if you need additional information or have any
 21  * questions.
 22  */
 23 
 24 package requires;
 25 
 26 import java.io.BufferedInputStream;
 27 import java.io.FileInputStream;
 28 import java.io.IOException;
 29 import java.io.InputStream;
 30 import java.io.File;
 31 import java.nio.charset.Charset;
 32 import java.nio.file.Files;
 33 import java.nio.file.Path;
 34 import java.nio.file.Paths;
 35 import java.nio.file.StandardOpenOption;
 36 import java.time.Instant;
 37 import java.util.ArrayList;
 38 import java.util.Collections;
 39 import java.util.HashMap;
 40 import java.util.List;
 41 import java.util.Map;
 42 import java.util.Properties;
 43 import java.util.Set;
 44 import java.util.concurrent.Callable;
 45 import java.util.concurrent.TimeUnit;
 46 import java.util.function.Predicate;
 47 import java.util.function.Supplier;
 48 import java.util.regex.Matcher;
 49 import java.util.regex.Pattern;
 50 import java.util.stream.Stream;
 51 
 52 import jdk.internal.foreign.CABI;
 53 import jdk.internal.misc.PreviewFeatures;
 54 import jdk.test.whitebox.code.Compiler;
 55 import jdk.test.whitebox.cpuinfo.CPUInfo;
 56 import jdk.test.whitebox.gc.GC;
 57 import jdk.test.whitebox.WhiteBox;
 58 import jdk.test.lib.Platform;
 59 import jdk.test.lib.Container;
 60 
 61 /**
 62  * The Class to be invoked by jtreg prior Test Suite execution to
 63  * collect information about VM.
 64  * Do not use any APIs that may not be available in all target VMs.
 65  * Properties set by this Class will be available in the @requires expressions.
 66  */
 67 public class VMProps implements Callable<Map<String, String>> {
 68     // value known to jtreg as an indicator of error state
 69     private static final String ERROR_STATE = "__ERROR__";
 70 
 71     private static final String GC_PREFIX = "-XX:+Use";
 72     private static final String GC_SUFFIX = "GC";
 73 
 74     private static final WhiteBox WB = WhiteBox.getWhiteBox();
 75 
 76     private static class SafeMap {
 77         private final Map<String, String> map = new HashMap<>();
 78 
 79         public void put(String key, Supplier<String> s) {
 80             String value;
 81             try {
 82                 value = s.get();
 83             } catch (Throwable t) {
 84                 System.err.println("failed to get value for " + key);
 85                 t.printStackTrace(System.err);
 86                 value = ERROR_STATE + t;
 87             }
 88             map.put(key, value);
 89         }
 90     }
 91 
 92     /**
 93      * Collects information about VM properties.
 94      * This method will be invoked by jtreg.
 95      *
 96      * @return Map of property-value pairs.
 97      */
 98     @Override
 99     public Map<String, String> call() {
100         log("Entering call()");
101         SafeMap map = new SafeMap();
102         map.put("vm.flavor", this::vmFlavor);
103         map.put("vm.compMode", this::vmCompMode);
104         map.put("vm.bits", this::vmBits);
105         map.put("vm.flightRecorder", this::vmFlightRecorder);
106         map.put("vm.simpleArch", this::vmArch);
107         map.put("vm.debug", this::vmDebug);
108         map.put("vm.jvmci", this::vmJvmci);
109         map.put("vm.jvmci.enabled", this::vmJvmciEnabled);
110         map.put("vm.emulatedClient", this::vmEmulatedClient);
111         // vm.hasSA is "true" if the VM contains the serviceability agent
112         // and jhsdb.
113         map.put("vm.hasSA", this::vmHasSA);
114         // vm.hasJFR is "true" if JFR is included in the build of the VM and
115         // so tests can be executed.
116         map.put("vm.hasJFR", this::vmHasJFR);
117         map.put("vm.hasDTrace", this::vmHasDTrace);
118         map.put("vm.jvmti", this::vmHasJVMTI);
119         map.put("vm.cpu.features", this::cpuFeatures);
120         map.put("vm.pageSize", this::vmPageSize);
121         // vm.cds is true if the VM is compiled with cds support.
122         map.put("vm.cds", this::vmCDS);
123         map.put("vm.cds.default.archive.available", this::vmCDSDefaultArchiveAvailable);
124         map.put("vm.cds.nocoops.archive.available", this::vmCDSNocoopsArchiveAvailable);
125         map.put("vm.cds.custom.loaders", this::vmCDSForCustomLoaders);
126         map.put("vm.cds.supports.aot.class.linking", this::vmCDSSupportsAOTClassLinking);
127         map.put("vm.cds.supports.aot.code.caching", this::vmCDSSupportsAOTCodeCaching);
128         map.put("vm.cds.write.archived.java.heap", this::vmCDSCanWriteArchivedJavaHeap);
129         map.put("vm.continuations", this::vmContinuations);
130         // vm.graal.enabled is true if Graal is used as JIT
131         map.put("vm.graal.enabled", this::isGraalEnabled);
132         // jdk.hasLibgraal is true if the libgraal shared library file is present
133         map.put("jdk.hasLibgraal", this::hasLibgraal);
134         map.put("java.enablePreview", this::isPreviewEnabled);
135         map.put("vm.libgraal.jit", this::isLibgraalJIT);
136         map.put("vm.compiler1.enabled", this::isCompiler1Enabled);
137         map.put("vm.compiler2.enabled", this::isCompiler2Enabled);
138         map.put("container.support", this::containerSupport);
139         map.put("systemd.support", this::systemdSupport);
140         map.put("vm.musl", this::isMusl);
141         map.put("vm.asan", this::isAsanEnabled);
142         map.put("vm.ubsan", this::isUbsanEnabled);
143         map.put("release.implementor", this::implementor);
144         map.put("jdk.containerized", this::jdkContainerized);
145         map.put("vm.flagless", this::isFlagless);
146         map.put("jdk.foreign.linker", this::jdkForeignLinker);
147         map.put("jlink.packagedModules", this::packagedModules);
148         map.put("jdk.static", this::isStatic);
149         vmGC(map); // vm.gc.X = true/false
150         vmGCforCDS(map); // may set vm.gc
151         vmOptFinalFlags(map);
152 
153         dump(map.map);
154         log("Leaving call()");
155         return map.map;
156     }
157 
158     /**
159      * Print a stack trace before returning error state;
160      * Used by the various helper functions which parse information from
161      * VM properties in the case where they don't find an expected property
162      * or a property doesn't conform to an expected format.
163      *
164      * @return {@link #ERROR_STATE}
165      */
166     private String errorWithMessage(String message) {
167         new Exception(message).printStackTrace();
168         return ERROR_STATE + message;
169     }
170 
171     /**
172      * @return vm.simpleArch value of "os.simpleArch" property of tested JDK.
173      */
174     protected String vmArch() {
175         String arch = System.getProperty("os.arch");
176         if (arch.equals("x86_64") || arch.equals("amd64")) {
177             return "x64";
178         } else if (arch.contains("86")) {
179             return "x86";
180         } else {
181             return arch;
182         }
183     }
184 
185     /**
186      * @return VM type value extracted from the "java.vm.name" property.
187      */
188     protected String vmFlavor() {
189         // E.g. "Java HotSpot(TM) 64-Bit Server VM"
190         String vmName = System.getProperty("java.vm.name");
191         if (vmName == null) {
192             return errorWithMessage("Can't get 'java.vm.name' property");
193         }
194 
195         Pattern startP = Pattern.compile(".* (\\S+) VM");
196         Matcher m = startP.matcher(vmName);
197         if (m.matches()) {
198             return m.group(1).toLowerCase();
199         }
200         return errorWithMessage("Can't get VM flavor from 'java.vm.name'");
201     }
202 
203     /**
204      * @return VM compilation mode extracted from the "java.vm.info" property.
205      */
206     protected String vmCompMode() {
207         // E.g. "mixed mode"
208         String vmInfo = System.getProperty("java.vm.info");
209         if (vmInfo == null) {
210             return errorWithMessage("Can't get 'java.vm.info' property");
211         }
212         vmInfo = vmInfo.toLowerCase();
213         if (vmInfo.contains("mixed mode")) {
214             return "Xmixed";
215         } else if (vmInfo.contains("compiled mode")) {
216             return "Xcomp";
217         } else if (vmInfo.contains("interpreted mode")) {
218             return "Xint";
219         } else {
220             return errorWithMessage("Can't get compilation mode from 'java.vm.info'");
221         }
222     }
223 
224     /**
225      * @return VM bitness, the value of the "sun.arch.data.model" property.
226      */
227     protected String vmBits() {
228         String dataModel = System.getProperty("sun.arch.data.model");
229         if (dataModel != null) {
230             return dataModel;
231         } else {
232             return errorWithMessage("Can't get 'sun.arch.data.model' property");
233         }
234     }
235 
236     /**
237      * @return "true" if Flight Recorder is enabled, "false" if is disabled.
238      */
239     protected String vmFlightRecorder() {
240         Boolean isFlightRecorder = WB.getBooleanVMFlag("FlightRecorder");
241         String startFROptions = WB.getStringVMFlag("StartFlightRecording");
242         if (isFlightRecorder != null && isFlightRecorder) {
243             return "true";
244         }
245         if (startFROptions != null && !startFROptions.isEmpty()) {
246             return "true";
247         }
248         return "false";
249     }
250 
251     /**
252      * @return debug level value extracted from the "jdk.debug" property.
253      */
254     protected String vmDebug() {
255         String debug = System.getProperty("jdk.debug");
256         if (debug != null) {
257             return "" + debug.contains("debug");
258         } else {
259             return errorWithMessage("Can't get 'jdk.debug' property");
260         }
261     }
262 
263     /**
264      * @return true if VM supports JVMCI and false otherwise
265      */
266     protected String vmJvmci() {
267         // builds with jvmci have this flag
268         if (WB.getBooleanVMFlag("EnableJVMCI") == null) {
269             return "false";
270         }
271 
272         // Not all GCs have full JVMCI support
273         if (!WB.isJVMCISupportedByGC()) {
274           return "false";
275         }
276 
277         // Interpreted mode cannot enable JVMCI
278         if (vmCompMode().equals("Xint")) {
279           return "false";
280         }
281 
282         return "true";
283     }
284 
285 
286     /**
287      * @return true if JVMCI is enabled
288      */
289     protected String vmJvmciEnabled() {
290         // builds with jvmci have this flag
291         if ("false".equals(vmJvmci())) {
292             return "false";
293         }
294 
295         return "" + Compiler.isJVMCIEnabled();
296     }
297 
298 
299     /**
300      * @return true if VM runs in emulated-client mode and false otherwise.
301      */
302     protected String vmEmulatedClient() {
303         String vmInfo = System.getProperty("java.vm.info");
304         if (vmInfo == null) {
305             return errorWithMessage("Can't get 'java.vm.info' property");
306         }
307         return "" + vmInfo.contains(" emulated-client");
308     }
309 
310     /**
311      * @return supported CPU features
312      */
313     protected String cpuFeatures() {
314         return CPUInfo.getFeatures().toString();
315     }
316 
317     /**
318      * For all existing GC sets vm.gc.X property.
319      * Example vm.gc.G1=true means:
320      *    VM supports G1
321      *    User either set G1 explicitely (-XX:+UseG1GC) or did not set any GC
322      *    G1 can be selected, i.e. it doesn't conflict with other VM flags
323      *
324      * @param map - property-value pairs
325      */
326     protected void vmGC(SafeMap map) {
327         var isJVMCIEnabled = Compiler.isJVMCIEnabled();
328         Predicate<GC> vmGCProperty = (GC gc) -> (gc.isSupported()
329                                         && (!isJVMCIEnabled || gc.isSupportedByJVMCICompiler())
330                                         && (gc.isSelected() || GC.isSelectedErgonomically()));
331         for (GC gc: GC.values()) {
332             map.put("vm.gc." + gc.name(), () -> "" + vmGCProperty.test(gc));
333         }
334     }
335 
336     /**
337      * "jtreg -vmoptions:-Dtest.cds.runtime.options=..." can be used to specify
338      * the GC type to be used when running with a CDS archive. Set "vm.gc" accordingly,
339      * so that tests that need to explicitly choose the GC type can be excluded
340      * with "@requires vm.gc == null".
341      *
342      * @param map - property-value pairs
343      */
344     protected void vmGCforCDS(SafeMap map) {
345         if (!GC.isSelectedErgonomically()) {
346             // The GC has been explicitly specified on the command line, so
347             // jtreg will set the "vm.gc" property. Let's not interfere with it.
348             return;
349         }
350 
351         String jtropts = System.getProperty("test.cds.runtime.options");
352         if (jtropts != null) {
353             for (String opt : jtropts.split(",")) {
354                 if (opt.startsWith(GC_PREFIX) && opt.endsWith(GC_SUFFIX)) {
355                     String gc = opt.substring(GC_PREFIX.length(), opt.length() - GC_SUFFIX.length());
356                     map.put("vm.gc", () -> gc);
357                 }
358             }
359         }
360     }
361 
362     /**
363      * Selected final flag.
364      *
365      * @param map - property-value pairs
366      * @param flagName - flag name
367      */
368     private void vmOptFinalFlag(SafeMap map, String flagName) {
369         map.put("vm.opt.final." + flagName,
370                 () -> String.valueOf(WB.getBooleanVMFlag(flagName)));
371     }
372 
373     /**
374      * Selected sets of final flags.
375      *
376      * @param map - property-value pairs
377      */
378     protected void vmOptFinalFlags(SafeMap map) {
379         vmOptFinalFlag(map, "ClassUnloading");
380         vmOptFinalFlag(map, "ClassUnloadingWithConcurrentMark");
381         vmOptFinalFlag(map, "CriticalJNINatives");
382         vmOptFinalFlag(map, "EnableJVMCI");
383         vmOptFinalFlag(map, "EliminateAllocations");
384         vmOptFinalFlag(map, "TieredCompilation");
385         vmOptFinalFlag(map, "UnlockExperimentalVMOptions");
386         vmOptFinalFlag(map, "UseCompressedOops");
387         vmOptFinalFlag(map, "UseLargePages");
388         vmOptFinalFlag(map, "UseTransparentHugePages");
389         vmOptFinalFlag(map, "UseVectorizedMismatchIntrinsic");
390     }
391 
392     /**
393      * @return "true" if VM has a serviceability agent.
394      */
395     protected String vmHasSA() {
396         return "" + Platform.hasSA();
397     }
398 
399     /**
400      * @return "true" if the VM is compiled with Java Flight Recorder (JFR)
401      * support.
402      */
403     protected String vmHasJFR() {
404         return "" + WB.isJFRIncluded();
405     }
406 
407     /**
408      * @return "true" if the VM is compiled with JVMTI
409      */
410     protected String vmHasJVMTI() {
411         return "" + WB.isJVMTIIncluded();
412     }
413 
414     /**
415      * @return "true" if the VM is compiled with DTrace
416      */
417     protected String vmHasDTrace() {
418         return "" + WB.isDTraceIncluded();
419     }
420 
421     /**
422      * Check for CDS support.
423      *
424      * @return true if CDS is supported by the VM to be tested.
425      */
426     protected String vmCDS() {
427         boolean noJvmtiAdded = allFlags()
428                 .filter(s -> s.startsWith("-agentpath"))
429                 .findAny()
430                 .isEmpty();
431 
432         return "" + (noJvmtiAdded && WB.isCDSIncluded());
433     }
434 
435     /**
436      * Check for CDS default archive existence.
437      *
438      * @return true if CDS default archive classes.jsa exists in the JDK to be tested.
439      */
440     protected String vmCDSDefaultArchiveAvailable() {
441         Path archive = Paths.get(System.getProperty("java.home"), "lib", "server", "classes.jsa");
442         return "" + ("true".equals(vmCDS()) && Files.exists(archive));
443     }
444 
445     /**
446      * Check for CDS no compressed oops archive existence.
447      *
448      * @return true if CDS archive classes_nocoops.jsa exists in the JDK to be tested.
449      */
450     protected String vmCDSNocoopsArchiveAvailable() {
451         Path archive = Paths.get(System.getProperty("java.home"), "lib", "server", "classes_nocoops.jsa");
452         return "" + ("true".equals(vmCDS()) && Files.exists(archive));
453     }
454 
455     /**
456      * Check for CDS support for custom loaders.
457      *
458      * @return true if CDS provides support for customer loader in the VM to be tested.
459      */
460     protected String vmCDSForCustomLoaders() {
461         return "" + ("true".equals(vmCDS()) && Platform.areCustomLoadersSupportedForCDS());
462     }
463 
464     /**
465      * @return true if it's possible for "java -Xshare:dump" to write Java heap objects
466      *         with the current set of jtreg VM options. For example, false will be returned
467      *         if -XX:-UseCompressedClassPointers is specified,
468      */
469     protected String vmCDSCanWriteArchivedJavaHeap() {
470         return "" + ("true".equals(vmCDS()) && WB.canWriteJavaHeapArchive()
471                      && isCDSRuntimeOptionsCompatible());
472     }
473 
474     /**
475      * @return true if this VM can support the -XX:AOTClassLinking option
476      */
477     protected String vmCDSSupportsAOTClassLinking() {
478       // Currently, the VM supports AOTClassLinking as long as it's able to write archived java heap.
479       return vmCDSCanWriteArchivedJavaHeap();
480     }
481 
482     /**
483      * @return true if this VM can support the AOT Code Caching
484      */
485     protected String vmCDSSupportsAOTCodeCaching() {
486       if ("true".equals(vmCDSSupportsAOTClassLinking()) &&
487           !"zero".equals(vmFlavor()) &&
488           "false".equals(vmJvmciEnabled()) &&
489           (Platform.isX64() || Platform.isAArch64())) {
490         return "true";
491       } else {
492         return "false";
493       }
494     }
495 
496     /**
497      * @return true if the VM options specified via the "test.cds.runtime.options"
498      * property is compatible with writing Java heap objects into the CDS archive
499      */
500     protected boolean isCDSRuntimeOptionsCompatible() {
501         String jtropts = System.getProperty("test.cds.runtime.options");
502         if (jtropts == null) {
503             return true;
504         }
505         String CCP_DISABLED = "-XX:-UseCompressedClassPointers";
506         String G1GC_ENABLED = "-XX:+UseG1GC";
507         String PARALLELGC_ENABLED = "-XX:+UseParallelGC";
508         String SERIALGC_ENABLED = "-XX:+UseSerialGC";
509         for (String opt : jtropts.split(",")) {
510             if (opt.equals(CCP_DISABLED)) {
511                 return false;
512             }
513             if (opt.startsWith(GC_PREFIX) && opt.endsWith(GC_SUFFIX) &&
514                 !opt.equals(G1GC_ENABLED) && !opt.equals(PARALLELGC_ENABLED) && !opt.equals(SERIALGC_ENABLED)) {
515                 return false;
516             }
517         }
518         return true;
519     }
520 
521     /**
522      * @return "true" if this VM supports continuations.
523      */
524     protected String vmContinuations() {
525         if (WB.getBooleanVMFlag("VMContinuations")) {
526             return "true";
527         } else {
528             return "false";
529         }
530     }
531 
532     /**
533      * @return System page size in bytes.
534      */
535     protected String vmPageSize() {
536         return "" + WB.getVMPageSize();
537     }
538 
539     /**
540      * Check if Graal is used as JIT compiler.
541      *
542      * @return true if Graal is used as JIT compiler.
543      */
544     protected String isGraalEnabled() {
545         return "" + Compiler.isGraalEnabled();
546     }
547 
548     /**
549      * Check if the libgraal shared library file is present.
550      *
551      * @return true if the libgraal shared library file is present.
552      */
553     protected String hasLibgraal() {
554         return "" + WB.hasLibgraal();
555     }
556 
557     /**
558      * Check if libgraal is used as JIT compiler.
559      *
560      * @return true if libgraal is used as JIT compiler.
561      */
562     protected String isLibgraalJIT() {
563         return "" + Compiler.isLibgraalJIT();
564     }
565 
566     /**
567      * Check if Compiler1 is present.
568      *
569      * @return true if Compiler1 is used as JIT compiler, either alone or as part of the tiered system.
570      */
571     protected String isCompiler1Enabled() {
572         return "" + Compiler.isC1Enabled();
573     }
574 
575     /**
576      * Check if Compiler2 is present.
577      *
578      * @return true if Compiler2 is used as JIT compiler, either alone or as part of the tiered system.
579      */
580     protected String isCompiler2Enabled() {
581         return "" + Compiler.isC2Enabled();
582     }
583 
584     protected String isPreviewEnabled() {
585         return "" + PreviewFeatures.isEnabled();
586     }
587     /**
588      * A simple check for container support
589      *
590      * @return true if container is supported in a given environment
591      */
592     protected String containerSupport() {
593         log("Entering containerSupport()");
594 
595         boolean isSupported = false;
596         if (Platform.isLinux()) {
597            // currently container testing is only supported for Linux,
598            // on certain platforms
599 
600            String arch = System.getProperty("os.arch");
601 
602            if (Platform.isX64()) {
603               isSupported = true;
604            } else if (Platform.isAArch64()) {
605               isSupported = true;
606            } else if (Platform.isS390x()) {
607               isSupported = true;
608            } else if (arch.equals("ppc64le")) {
609               isSupported = true;
610            }
611         }
612 
613         log("containerSupport(): platform check: isSupported = " + isSupported);
614 
615         if (isSupported) {
616            try {
617               isSupported = checkProgramSupport("checkContainerSupport()", Container.ENGINE_COMMAND);
618            } catch (Exception e) {
619               isSupported = false;
620            }
621          }
622 
623         log("containerSupport(): returning isSupported = " + isSupported);
624         return "" + isSupported;
625     }
626 
627     /**
628      * A simple check for systemd support
629      *
630      * @return true if systemd is supported in a given environment
631      */
632     protected String systemdSupport() {
633         log("Entering systemdSupport()");
634 
635         boolean isSupported = Platform.isLinux();
636         if (isSupported) {
637            try {
638               isSupported = checkProgramSupport("checkSystemdSupport()", "systemd-run");
639            } catch (Exception e) {
640               isSupported = false;
641            }
642          }
643 
644         log("systemdSupport(): returning isSupported = " + isSupported);
645         return "" + isSupported;
646     }
647 
648     // Configures process builder to redirect process stdout and stderr to a file.
649     // Returns file names for stdout and stderr.
650     private Map<String, String> redirectOutputToLogFile(String msg, ProcessBuilder pb, String fileNameBase) {
651         Map<String, String> result = new HashMap<>();
652         String timeStamp = Instant.now().toString().replace(":", "-").replace(".", "-");
653 
654         String stdoutFileName = String.format("./%s-stdout--%s.log", fileNameBase, timeStamp);
655         pb.redirectOutput(new File(stdoutFileName));
656         log(msg + ": child process stdout redirected to " + stdoutFileName);
657         result.put("stdout", stdoutFileName);
658 
659         String stderrFileName = String.format("./%s-stderr--%s.log", fileNameBase, timeStamp);
660         pb.redirectError(new File(stderrFileName));
661         log(msg + ": child process stderr redirected to " + stderrFileName);
662         result.put("stderr", stderrFileName);
663 
664         return result;
665     }
666 
667     private void printLogfileContent(Map<String, String> logFileNames) {
668         logFileNames.entrySet().stream()
669             .forEach(entry ->
670                 {
671                     log("------------- " + entry.getKey());
672                     try {
673                         Files.lines(Path.of(entry.getValue()))
674                             .forEach(line -> log(line));
675                     } catch (IOException ie) {
676                         log("Exception while reading file: " + ie);
677                     }
678                     log("-------------");
679                 });
680     }
681 
682     private boolean checkProgramSupport(String logString, String cmd) throws IOException, InterruptedException {
683         log(logString + ": entering");
684         ProcessBuilder pb = new ProcessBuilder("which", cmd);
685         Map<String, String> logFileNames =
686             redirectOutputToLogFile(logString + ": which " + cmd,
687                                                       pb, "which-cmd");
688         Process p = pb.start();
689         p.waitFor(10, TimeUnit.SECONDS);
690         int exitValue = p.exitValue();
691 
692         log(String.format("%s: exitValue = %s, pid = %s", logString, exitValue, p.pid()));
693         if (exitValue != 0) {
694             printLogfileContent(logFileNames);
695         }
696 
697         return (exitValue == 0);
698     }
699 
700     /**
701      * Checks musl libc.
702      *
703      * @return true if musl libc is used.
704      */
705     protected String isMusl() {
706         return Boolean.toString(WB.getLibcName().contains("musl"));
707     }
708 
709     // Sanitizer support
710     protected String isAsanEnabled() {
711         return "" + WB.isAsanEnabled();
712     }
713 
714     protected String isUbsanEnabled() {
715         return "" + WB.isUbsanEnabled();
716     }
717 
718     private String implementor() {
719         try (InputStream in = new BufferedInputStream(new FileInputStream(
720                 System.getProperty("java.home") + "/release"))) {
721             Properties properties = new Properties();
722             properties.load(in);
723             String implementorProperty = properties.getProperty("IMPLEMENTOR");
724             if (implementorProperty != null) {
725                 return implementorProperty.replace("\"", "");
726             }
727             return errorWithMessage("Can't get 'IMPLEMENTOR' property from 'release' file");
728         } catch (IOException e) {
729             e.printStackTrace();
730             return errorWithMessage("Failed to read 'release' file " + e);
731         }
732     }
733 
734     private String jdkContainerized() {
735         String isEnabled = System.getenv("TEST_JDK_CONTAINERIZED");
736         return "" + "true".equalsIgnoreCase(isEnabled);
737     }
738 
739     private String packagedModules() {
740         // Some jlink tests require packaged modules being present (jmods).
741         // For a runtime linkable image build packaged modules aren't present
742         try {
743             Path jmodsDir = Path.of(System.getProperty("java.home"), "jmods");
744             if (jmodsDir.toFile().exists()) {
745                 return Boolean.TRUE.toString();
746             } else {
747                 return Boolean.FALSE.toString();
748             }
749         } catch (Throwable t) {
750             return Boolean.FALSE.toString();
751         }
752     }
753 
754     /**
755      * Checks if we are in <i>almost</i> out-of-box configuration, i.e. the flags
756      * which JVM is started with don't affect its behavior "significantly".
757      * {@code TEST_VM_FLAGLESS} enviroment variable can be used to force this
758      * method to return true or false and allow or reject any flags.
759      *
760      * @return true if there are no JVM flags
761      */
762     private String isFlagless() {
763         boolean result = true;
764         String flagless = System.getenv("TEST_VM_FLAGLESS");
765         if (flagless != null) {
766             return "" + "true".equalsIgnoreCase(flagless);
767         }
768 
769         List<String> allFlags = allFlags().toList();
770 
771         // check -XX flags
772         var ignoredXXFlags = Set.of(
773                 // added by run-test framework
774                 "MaxRAMPercentage",
775                 // added by test environment
776                 "CreateCoredumpOnCrash"
777         );
778         result &= allFlags.stream()
779                           .filter(s -> s.startsWith("-XX:"))
780                           // map to names:
781                               // remove -XX:
782                               .map(s -> s.substring(4))
783                               // remove +/- from bool flags
784                               .map(s -> s.charAt(0) == '+' || s.charAt(0) == '-' ? s.substring(1) : s)
785                               // remove =.* from others
786                               .map(s -> s.contains("=") ? s.substring(0, s.indexOf('=')) : s)
787                           // skip known-to-be-there flags
788                           .filter(s -> !ignoredXXFlags.contains(s))
789                           .findAny()
790                           .isEmpty();
791 
792         // check -X flags
793         var ignoredXFlags = Set.of(
794                 // default, yet still seen to be explicitly set
795                 "mixed",
796                 // -XmxmNNNm added by run-test framework for non-hotspot tests
797                 "mx"
798         );
799         result &= allFlags.stream()
800                           .filter(s -> s.startsWith("-X") && !s.startsWith("-XX:"))
801                           // map to names:
802                           // remove -X
803                           .map(s -> s.substring(2))
804                           // remove :.* from flags with values
805                           .map(s -> s.contains(":") ? s.substring(0, s.indexOf(':')) : s)
806                           // remove size like 4G, 768m which might be set for non-hotspot tests
807                           .map(s -> s.replaceAll("(\\d+)[mMgGkK]", ""))
808                           // skip known-to-be-there flags
809                           .filter(s -> !ignoredXFlags.contains(s))
810                           .findAny()
811                           .isEmpty();
812 
813         return "" + result;
814     }
815 
816     private Stream<String> allFlags() {
817         return Stream.of((System.getProperty("test.vm.opts", "") + " " + System.getProperty("test.java.opts", "")).trim().split("\\s+"));
818     }
819 
820     /*
821      * A string indicating the foreign linker that is currently being used. See jdk.internal.foreign.CABI
822      * for valid values.
823      *
824      * "FALLBACK" and "UNSUPPORTED" are special values. The former indicates the fallback linker is
825      * being used. The latter indicates an unsupported platform.
826      */
827     private String jdkForeignLinker() {
828         return String.valueOf(CABI.current());
829     }
830 
831     private String isStatic() {
832         return Boolean.toString(WB.isStatic());
833     }
834 
835     /**
836      * Dumps the map to the file if the file name is given as the property.
837      * This functionality could be helpful to know context in the real
838      * execution.
839      *
840      * @param map
841      */
842     protected static void dump(Map<String, String> map) {
843         String dumpFileName = System.getProperty("vmprops.dump");
844         if (dumpFileName == null) {
845             return;
846         }
847         List<String> lines = new ArrayList<>();
848         map.forEach((k, v) -> lines.add(k + ":" + v));
849         Collections.sort(lines);
850         try {
851             Files.write(Paths.get(dumpFileName), lines,
852                     StandardOpenOption.APPEND, StandardOpenOption.CREATE);
853         } catch (IOException e) {
854             throw new RuntimeException("Failed to dump properties into '"
855                     + dumpFileName + "'", e);
856         }
857     }
858 
859     /**
860      * Log diagnostic message.
861      *
862      * @param msg
863      */
864     protected static void log(String msg) {
865         // Always log to a file.
866         logToFile(msg);
867 
868         // Also log to stderr; guarded by property to avoid excessive verbosity.
869         // By jtreg design stderr produced here will be visible
870         // in the output of a parent process. Note: stdout should not be used
871         // for logging as jtreg parses that output directly and only echoes it
872         // in the event of a failure.
873         if (Boolean.getBoolean("jtreg.log.vmprops")) {
874             System.err.println("VMProps: " + msg);
875         }
876     }
877 
878     /**
879      * Log diagnostic message to a file.
880      *
881      * @param msg
882      */
883     protected static void logToFile(String msg) {
884         String fileName = "./vmprops.log";
885         try {
886             Files.writeString(Paths.get(fileName), msg + "\n", Charset.forName("ISO-8859-1"),
887                     StandardOpenOption.APPEND, StandardOpenOption.CREATE);
888         } catch (IOException e) {
889             throw new RuntimeException("Failed to log into '" + fileName + "'", e);
890         }
891     }
892 
893     /**
894      * This method is for the testing purpose only.
895      *
896      * @param args
897      */
898     public static void main(String args[]) {
899         Map<String, String> map = new VMProps().call();
900         map.forEach((k, v) -> System.out.println(k + ": '" + v + "'"));
901     }
902 }
--- EOF ---