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

*** 24,42 ****
--- 24,45 ----
   */
  
  package jdk.internal.module;
  
  import java.io.File;
+ import java.io.IOException;
  import java.io.PrintStream;
+ import java.io.UncheckedIOException;
  import java.lang.module.Configuration;
  import java.lang.module.ModuleDescriptor;
  import java.lang.module.ModuleFinder;
  import java.lang.module.ModuleReference;
  import java.lang.module.ResolvedModule;
  import java.lang.reflect.Layer;
  import java.lang.reflect.Module;
  import java.net.URI;
+ import java.nio.file.Files;
  import java.nio.file.Path;
  import java.nio.file.Paths;
  import java.util.ArrayList;
  import java.util.Collections;
  import java.util.HashMap;
*** 44,53 ****
--- 47,57 ----
  import java.util.List;
  import java.util.Map;
  import java.util.Optional;
  import java.util.Set;
  import java.util.function.Function;
+ import java.util.stream.Stream;
  
  import jdk.internal.loader.BootLoader;
  import jdk.internal.loader.BuiltinClassLoader;
  import jdk.internal.misc.SharedSecrets;
  import jdk.internal.perf.PerfCounter;
*** 112,122 ****
      public static Layer boot() {
  
          long t0 = System.nanoTime();
  
          // system modules (may be patched)
!         ModuleFinder systemModules = ModuleFinder.ofSystem();
  
          PerfCounters.systemModulesTime.addElapsedTimeFrom(t0);
  
  
          long t1 = System.nanoTime();
--- 116,131 ----
      public static Layer boot() {
  
          long t0 = System.nanoTime();
  
          // system modules (may be patched)
!         ModuleFinder systemModules;
!         if (SystemModules.MODULE_NAMES.length > 0) {
!             systemModules = SystemModuleFinder.getInstance();
!         } else {
!             systemModules = ModuleFinder.ofSystem();
!         }
  
          PerfCounters.systemModulesTime.addElapsedTimeFrom(t0);
  
  
          long t1 = System.nanoTime();
*** 273,283 ****
          if (Boolean.getBoolean("jdk.launcher.traceResolver"))
              traceOutput = System.out;
  
          // run the resolver to create the configuration
          Configuration cf = SharedSecrets.getJavaLangModuleAccess()
!                 .resolveRequiresAndUses(finder,
                                          roots,
                                          needPostResolutionChecks,
                                          traceOutput);
  
          // time to create configuration
--- 282,292 ----
          if (Boolean.getBoolean("jdk.launcher.traceResolver"))
              traceOutput = System.out;
  
          // run the resolver to create the configuration
          Configuration cf = SharedSecrets.getJavaLangModuleAccess()
!                 .resolveAndBind(finder,
                                  roots,
                                  needPostResolutionChecks,
                                  traceOutput);
  
          // time to create configuration
*** 378,389 ****
      private static ModuleFinder limitFinder(ModuleFinder finder,
                                              Set<String> roots,
                                              Set<String> otherMods)
      {
          // resolve all root modules
!         Configuration cf = Configuration.empty()
!                 .resolveRequires(finder,
                                   ModuleFinder.of(),
                                   roots);
  
          // module name -> reference
          Map<String, ModuleReference> map = new HashMap<>();
--- 387,397 ----
      private static ModuleFinder limitFinder(ModuleFinder finder,
                                              Set<String> roots,
                                              Set<String> otherMods)
      {
          // resolve all root modules
!         Configuration cf = Configuration.empty().resolve(finder,
                                                           ModuleFinder.of(),
                                                           roots);
  
          // module name -> reference
          Map<String, ModuleReference> map = new HashMap<>();
*** 526,537 ****
--- 534,585 ----
          prefix = "jdk.module.addopens.";
          Map<String, List<String>> extraOpens = decode(prefix);
          if (!extraOpens.isEmpty()) {
              addExtraExportsOrOpens(bootLayer, extraOpens, true);
          }
+ 
+         // DEBUG_ADD_OPENS is for debugging purposes only
+         String home = System.getProperty("java.home");
+         Path file = Paths.get(home, "conf", "DEBUG_ADD_OPENS");
+         if (Files.exists(file)) {
+             warn(file + " detected; may break encapsulation");
+             try (Stream<String> lines = Files.lines(file)) {
+                 lines.map(line -> line.trim())
+                     .filter(line -> (!line.isEmpty() && !line.startsWith("#")))
+                     .forEach(line -> {
+                         String[] s = line.split("/");
+                         if (s.length != 2) {
+                             fail("Unable to parse as <module>/<package>: " + line);
+                         } else {
+                             String mn = s[0];
+                             String pkg = s[1];
+                             openPackage(bootLayer, mn, pkg);
+                         }
+                     });
+             } catch (IOException ioe) {
+                 throw new UncheckedIOException(ioe);
+             }
+         }
      }
  
+     private static void openPackage(Layer bootLayer, String mn, String pkg) {
+         if (mn.equals("ALL-RESOLVED") && pkg.equals("ALL-PACKAGES")) {
+             bootLayer.modules().stream().forEach(m ->
+                 m.getDescriptor().packages().forEach(pn -> openPackage(m, pn)));
+         } else {
+             bootLayer.findModule(mn)
+                      .filter(m -> m.getDescriptor().packages().contains(pkg))
+                      .ifPresent(m -> openPackage(m, pkg));
+         }
+     }
+ 
+     private static void openPackage(Module m, String pn) {
+         Modules.addOpensToAllUnnamed(m, pn);
+         warn("Opened for deep reflection: " + m.getName()  + "/" + pn);
+     }
+ 
+ 
      private static void addExtraExportsOrOpens(Layer bootLayer,
                                                 Map<String, List<String>> map,
                                                 boolean opens)
      {
          String option = opens ? ADD_OPENS : ADD_EXPORTS;