fix zipped core file support

Author: plummercj

test/lib/jdk/test/lib/util/CoreUtils.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2020, 2023, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2020, 2025, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -203,8 +203,9 @@ public static String getCoreFileLocation(String crashOutputString, long pid) thr
 
     private static final String CORE_PATTERN_FILE_NAME = "/proc/sys/kernel/core_pattern";
     private static final String LOCATION_STRING = "location: ";
-
-    private static String parseCoreFileLocationFromOutput(String crashOutputString) {
+    private static final String ALT_LOCATION_STRING = "alternatively, falling back to";
+    
+    private static String parseCoreFileLocationFromOutput(String crashOutputString) throws IOException {
         System.out.println("crashOutputString = [" + crashOutputString + "]");
 
         // Find the line of output that contains LOCATION_STRING
@@ -220,12 +221,25 @@ private static String parseCoreFileLocationFromOutput(String crashOutputString)
 
         // Find the core file name in the output.
         String coreWithPid;
-        if (stringWithLocation.contains("or ") && !Platform.isWindows()) {
-            Matcher m = Pattern.compile("or.* ([^ ]+[^\\)])\\)?").matcher(stringWithLocation);
+        if (Platform.isLinux() && stringWithLocation.contains(ALT_LOCATION_STRING)) {
+            /*
+             * If hotspot detects that /proc/sys/kernel/core_pattern starts with a "|",
+             * it generates a messages something like the following:
+             * # Core dump will be written. Default location: Determined by the following:
+             *   "/var/bin/core.sh %p" (alternatively, falling back to
+             *   /ws/jdk/build/linux-x64/test-support/jtreg_open_test_hotspot_jtreg_serviceability_sa_ClhsdbFindPC_java/scratch/2/core.10353)
+             * We try to detect this and glean this alternative path from the message. The
+             * hope here is that either this is where the core file actually ends up, or that
+             * the script referenced by the core_pattern is just zipping the core file, in
+             * which case a call to unzipCores() will have already unzipped the core file
+             * into this path.
+             */
+            Matcher m = Pattern.compile(ALT_LOCATION_STRING + ".* ([^ ]+[^\\)])\\)?").matcher(stringWithLocation);
             if (!m.find()) {
                 throw new RuntimeException("Couldn't find path to core inside location string");
             }
             coreWithPid = m.group(1);
+            System.out.println("getCoreFileLocation found alt coreWithPid = " + coreWithPid);
         } else {
             coreWithPid = stringWithLocation.trim();
         }