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

*** 151,163 ****
  
          // additional module(s) specified by --add-modules
          boolean addAllDefaultModules = false;
          boolean addAllSystemModules = false;
          boolean addAllApplicationModules = false;
!         String propValue = getAndRemoveProperty("jdk.module.addmods");
!         if (propValue != null) {
!             for (String mod: propValue.split(",")) {
                  switch (mod) {
                      case ALL_DEFAULT:
                          addAllDefaultModules = true;
                          break;
                      case ALL_SYSTEM:
--- 151,161 ----
  
          // additional module(s) specified by --add-modules
          boolean addAllDefaultModules = false;
          boolean addAllSystemModules = false;
          boolean addAllApplicationModules = false;
!         for (String mod: getExtraAddModules()) {
              switch (mod) {
                  case ALL_DEFAULT:
                      addAllDefaultModules = true;
                      break;
                  case ALL_SYSTEM:
*** 168,181 ****
                          break;
                      default :
                          roots.add(mod);
                  }
              }
-         }
  
          // --limit-modules
!         propValue = getAndRemoveProperty("jdk.module.limitmods");
          if (propValue != null) {
              Set<String> mods = new HashSet<>();
              for (String mod: propValue.split(",")) {
                  mods.add(mod);
              }
--- 166,178 ----
                      break;
                  default :
                      roots.add(mod);
              }
          }
  
          // --limit-modules
!         String propValue = getAndRemoveProperty("jdk.module.limitmods");
          if (propValue != null) {
              Set<String> mods = new HashSet<>();
              for (String mod: propValue.split(",")) {
                  mods.add(mod);
              }
*** 390,399 ****
--- 387,422 ----
              }
              return ModuleFinder.of(paths);
          }
      }
  
+     /**
+      * Returns the set of module names specified via --add-modules options
+      * on the command line
+      */
+     private static Set<String> getExtraAddModules() {
+         String prefix = "jdk.module.addmods.";
+         int index = 0;
+ 
+         // the system property is removed after decoding
+         String value = getAndRemoveProperty(prefix + index);
+         if (value == null) {
+             return Collections.emptySet();
+         }
+ 
+         Set<String> modules = new HashSet<>();
+         while (value != null) {
+             for (String s : value.split(",")) {
+                 if (s.length() > 0) modules.add(s);
+             }
+ 
+             index++;
+             value = getAndRemoveProperty(prefix + index);
+         }
+ 
+         return modules;
+     }
  
      /**
       * Process the --add-reads options to add any additional read edges that
       * are specified on the command-line.
       */