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