svm: introduce HostModuleUtil#addReads

Author: zapster

substratevm/src/com.oracle.svm.util/src/com/oracle/svm/util/HostModuleUtil.java

@@ -0,0 +1,50 @@
+/*
+ * Copyright (c) 2025, 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
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+package com.oracle.svm.util;
+
+/**
+ * Utilities to access {@linkplain ResolvedJavaModule runtime modules} from hosted code.
+ */
+public abstract class HostModuleUtil {
+
+    /**
+     * Updates the module of {@code hostedClass} to read {@code runtimeModule} during the image
+     * build. This method is not meant to change any runtime property of {@code runtimeModule}.
+     */
+    public static void addReads(Class<?> hostedClass, ResolvedJavaModule runtimeModule) {
+        addReads(hostedClass.getModule(), runtimeModule);
+    }
+
+    /**
+     * Updates a {@code hostedModule} to read {@code runtimeModule} during the image build. This
+     * method is not meant to change any runtime property of {@code runtimeModule}.
+     */
+    private static void addReads(Module hostedModule, ResolvedJavaModule runtimeModule) {
+        ResolvedJavaModuleImpl.addReads(hostedModule, runtimeModule);
+    }
+
+    private HostModuleUtil() {
+    }
+}

substratevm/src/com.oracle.svm.util/src/com/oracle/svm/util/ModuleSupport.java

@@ -161,7 +161,10 @@ public static void accessModuleByClass(Access access, Class<?> accessingClass, M
     }
 
     @Platforms(Platform.HOSTED_ONLY.class)
-    public static void accessModule(Access access, Module accessingModule, Module declaringModule, String packageName) {
-        access.giveAccess(accessingModule, declaringModule, packageName);
+    public static void accessModule(Access access, Module accessingModule, Module declaringModule, String... packageNames) {
+        Set<String> packages = packageNames.length > 0 ? Set.of(packageNames) : declaringModule.getPackages();
+        for (String packageName : packages) {
+            access.giveAccess(accessingModule, declaringModule, packageName);
+        }
     }
 }

substratevm/src/com.oracle.svm.util/src/com/oracle/svm/util/ResolvedJavaModuleImpl.java

@@ -99,4 +99,8 @@ private static ResolvedJavaModuleImpl toImpl(ResolvedJavaModule module) {
         }
         throw new IllegalArgumentException("Unsupported ResolvedJavaModule implementation: " + module.getClass().getName());
     }
+
+    static void addReads(Module accessingModule, ResolvedJavaModule declaringModule) {
+        ModuleSupport.accessModule(ModuleSupport.Access.OPEN, accessingModule, toImpl(declaringModule).module);
+    }
 }