Add duplicate java.base check

Author: ivan-ristovic

substratevm/mx.substratevm/suite.py

@@ -200,7 +200,8 @@
             "dependencies": ["com.oracle.svm.core"],
             "requires" : [
                 "java.logging",
-                "jdk.unsupported"
+                "jdk.unsupported",
+                "java.compiler",
             ],
             "requiresConcealed" : {
                 "java.base" : [

substratevm/src/com.oracle.svm.core.jdk11/src/com/oracle/svm/core/jdk/Target_java_lang_Module.java

@@ -71,6 +71,13 @@ private static void defineModule0(Module module, boolean isOpen, String version,
             if (module.getClassLoader() != null) {
                 throw new IllegalArgumentException("Class loader must be the boot class loader");
             }
+
+            // TODO (ivan-ristovic) is synchronization nececary?
+            boolean duplicateJavaBase = ModuleUtil.bootLayerContainsModule("java.base");
+            if (duplicateJavaBase) {
+                throw new InternalError("Module java.base is already defined");
+            }
+
             return;
         }
 
@@ -90,7 +97,7 @@ private static void defineModule0(Module module, boolean isOpen, String version,
             }
         }
 
-        // TODO is synchronization nececary?
+        // TODO (ivan-ristovic) is synchronization necessary?
         Package existingPackage = null;
         boolean moduleAlreadyExists = false;
         for (String pn : pns) {
@@ -140,7 +147,6 @@ private static void addExportsToAll0(Module from, String pn) {
     @Substitute
     private static void addExportsToAllUnnamed0(Module from, String pn) {
         ModuleUtil.checkFromModuleAndPackageNullability(from, pn);
-
         if (from.isNamed()) {
             ModuleUtil.checkIsPackageContainedInModule(pn, from);
         }
@@ -165,30 +171,42 @@ static void checkFromModuleAndPackageNullability(Module from, String pn) {
     }
 
     static void checkIsPackageContainedInModule(String pn, Module module) {
+        ClassLoader loader = module.getClassLoader() == null ? ClassLoader.getPlatformClassLoader() : module.getClassLoader();
+        Package definedPackage = loader.getDefinedPackage(pn);
+        if (definedPackage != null) {
+            Target_java_lang_NamedPackage namedPackage = SubstrateUtil.cast(definedPackage, Target_java_lang_NamedPackage.class);
+            Module actualModule = namedPackage.module;
+            if (!actualModule.equals(module)) {
+                throw new IllegalArgumentException("Package " + pn + " found in module " + actualModule.getName() +
+                        ", not in module: " + module.getName());
+            }
+        }
+
         if (module.getPackages().stream().noneMatch(p -> p.equals(pn))) {
             throw new IllegalArgumentException("Package " + pn + " not found in from_module " + module.getName());
         }
-
-        // module.getClassLoader().getDefinedPackage(pn);
-        // TODO print message if package is not in from_module but is in another module
     }
 
     static boolean isPackageNameForbidden(String pn) {
         if (!pn.startsWith("java")) {
             return false;
         }
-        char trailingChar = pn.length() < 5 ? '/' : pn.charAt("java".length());
-        return trailingChar == '/';
+        char trailingChar = pn.length() < 5 ? '.' : pn.charAt("java".length());
+        return trailingChar == '.';
     }
 
     static boolean isValidPackageName(String pn) {
         // It is OK to use SourceVersion.isName here even though it calls String.split()
         // because pattern "\\." will take the fast path in the String.split() method
-        return Objects.nonNull(pn) && !pn.isEmpty() && SourceVersion.isName(pn);
+        return Objects.nonNull(pn) && SourceVersion.isName(pn);
     }
 
     static boolean moduleAlreadyExists(Module module) {
-        // TODO
+        // TODO (ivan-ristovic)
         return false;
     }
+
+    public static boolean bootLayerContainsModule(String name) {
+        return ModuleLayer.boot().modules().stream().anyMatch(m -> m.getName().equals(name));
+    }
 }