jdk/src/java.base/share/classes/jdk/internal/module/ModulePatcher.java

*** 56,95 ****
  import jdk.internal.misc.SharedSecrets;
  import sun.net.www.ParseUtil;
  
  
  /**
!  * Provides support for patching modules in the boot layer with -Xpatch.
   */
  
  public final class ModulePatcher {
  
      private static final JavaLangModuleAccess JLMA
          = SharedSecrets.getJavaLangModuleAccess();
  
!     // the prefix of the system properties that encode the value of -Xpatch
!     private static final String PATCH_PROPERTY_PREFIX = "jdk.launcher.patch.";
  
      // module name -> sequence of patches (directories or JAR files)
      private static final Map<String, List<Path>> PATCH_MAP = decodeProperties();
  
      private ModulePatcher() { }
  
- 
      /**
!      * Decodes the values of -Xpatch options, returning a Map of module name to
!      * list of file paths.
       *
       * @throws IllegalArgumentException if the the module name is missing or
!      *         -Xpatch is used more than once to patch the same module
       */
      private static Map<String, List<Path>> decodeProperties() {
  
          int index = 0;
!         String value = System.getProperty(PATCH_PROPERTY_PREFIX + index);
          if (value == null)
!             return Collections.emptyMap();  // -Xpatch not specified
  
          Map<String, List<Path>> map = new HashMap<>();
          while (value != null) {
  
              // <module>=<file>(:<file>)*
--- 56,94 ----
  import jdk.internal.misc.SharedSecrets;
  import sun.net.www.ParseUtil;
  
  
  /**
!  * Provides support for patching modules in the boot layer with --patch-module.
   */
  
  public final class ModulePatcher {
  
      private static final JavaLangModuleAccess JLMA
          = SharedSecrets.getJavaLangModuleAccess();
  
!     // the prefix of the system properties that encode the value of --patch-module
!     private static final String PATCH_PROPERTY_PREFIX = "jdk.module.patch.";
  
      // module name -> sequence of patches (directories or JAR files)
      private static final Map<String, List<Path>> PATCH_MAP = decodeProperties();
  
      private ModulePatcher() { }
  
      /**
!      * Decodes the values of --patch-module options, returning a Map of module
!      * name to list of file paths.
       *
       * @throws IllegalArgumentException if the the module name is missing or
!      *         --patch-module is used more than once to patch the same module
       */
      private static Map<String, List<Path>> decodeProperties() {
  
          int index = 0;
!         String value = getAndRemoveProperty(PATCH_PROPERTY_PREFIX + index);
          if (value == null)
!             return Collections.emptyMap();  // --patch-module not specified
  
          Map<String, List<Path>> map = new HashMap<>();
          while (value != null) {
  
              // <module>=<file>(:<file>)*
*** 113,130 ****
                      list.add(Paths.get(path));
                  }
              }
  
              index++;
!             value = System.getProperty(PATCH_PROPERTY_PREFIX + index);
          }
  
          return map;
      }
  
  
      /**
       * Returns a module reference that interposes on the given module if
       * needed. If there are no patches for the given module then the module
       * reference is simply returned. Otherwise the patches for the module
       * are scanned (to find any new concealed packages) and a new module
       * reference is returned.
--- 112,137 ----
                      list.add(Paths.get(path));
                  }
              }
  
              index++;
!             value = getAndRemoveProperty(PATCH_PROPERTY_PREFIX + index);
          }
  
          return map;
      }
  
  
      /**
+      * Returns {@code true} is --patch-module is specified to patch modules
+      * in the boot layer.
+      */
+     static boolean isBootLayerPatched() {
+         return !PATCH_MAP.isEmpty();
+     }
+ 
+     /**
       * Returns a module reference that interposes on the given module if
       * needed. If there are no patches for the given module then the module
       * reference is simply returned. Otherwise the patches for the module
       * are scanned (to find any new concealed packages) and a new module
       * reference is returned.
*** 535,544 ****
--- 542,558 ----
              return parent.toString().replace(File.separatorChar, '.');
          }
      }
  
      /**
+      * Gets and remove the named system property
+      */
+     private static String getAndRemoveProperty(String key) {
+         return (String)System.getProperties().remove(key);
+     }
+ 
+     /**
       * Derives a package name from the name of an entry in a JAR file.
       */
      private static String toPackageName(Path file, JarEntry entry) {
          String name = entry.getName();
          int index = name.lastIndexOf("/");