From 3492831d48712047cf75404620dfaac228c59485 Mon Sep 17 00:00:00 2001
From: Ivan Ristovic <ivan.ristovic@oracle.com>
Date: Tue, 23 Jul 2024 17:45:11 +0200
Subject: [PATCH] Add system modules implicitly required by the application to
 the image builder module graph

---
 .../com/oracle/svm/driver/NativeImage.java    | 43 +++++++++++++++++++
 1 file changed, 43 insertions(+)

diff --git a/substratevm/src/com.oracle.svm.driver/src/com/oracle/svm/driver/NativeImage.java b/substratevm/src/com.oracle.svm.driver/src/com/oracle/svm/driver/NativeImage.java
index 2f2c9001f8d0..afb540d1e768 100644
--- a/substratevm/src/com.oracle.svm.driver/src/com/oracle/svm/driver/NativeImage.java
+++ b/substratevm/src/com.oracle.svm.driver/src/com/oracle/svm/driver/NativeImage.java
@@ -29,9 +29,12 @@
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.InputStreamReader;
+import java.lang.module.Configuration;
 import java.lang.module.FindException;
+import java.lang.module.ModuleDescriptor;
 import java.lang.module.ModuleFinder;
 import java.lang.module.ModuleReference;
+import java.lang.module.ResolvedModule;
 import java.lang.reflect.Method;
 import java.net.URI;
 import java.nio.charset.StandardCharsets;
@@ -60,6 +63,7 @@
 import java.util.function.BiFunction;
 import java.util.function.Consumer;
 import java.util.function.Function;
+import java.util.function.Predicate;
 import java.util.jar.Attributes;
 import java.util.jar.JarFile;
 import java.util.jar.Manifest;
@@ -1626,6 +1630,15 @@ protected int buildImage(List<String> javaArgs, LinkedHashSet<Path> cp, LinkedHa
         }
         List<Path> finalImageModulePath = applicationModules.values().stream().toList();
 
+        /*
+         * Make sure to add all system modules required by the application that might not be part of
+         * the boot module layer of image builder. If we do not do this, the image builder will fail
+         * to create the image-build module layer, as it will attempt to define system modules to
+         * the host VM.
+         */
+        Set<String> implicitlyRequiredSystemModules = getImplicitlyRequiredSystemModules(finalImageModulePath);
+        addModules.addAll(implicitlyRequiredSystemModules);
+
         if (!addModules.isEmpty()) {
 
             arguments.add("-D" + ModuleSupport.PROPERTY_IMAGE_EXPLICITLY_ADDED_MODULES + "=" +
@@ -1825,6 +1838,36 @@ private Map<String, Path> getModulesFromPath(Collection<Path> modulePath) {
         return mrefs;
     }
 
+    private Set<String> getImplicitlyRequiredSystemModules(Collection<Path> modulePath) {
+        if (!config.modulePathBuild || modulePath.isEmpty()) {
+            return Set.of();
+        }
+
+        ModuleFinder finder = ModuleFinder.of(modulePath.toArray(Path[]::new));
+        Set<ModuleReference> modules = finder.findAll();
+
+        Set<String> systemModules = getBuiltInModules();
+        Set<String> applicationModulePathRequiredModules = new HashSet<>();
+
+        int priorSize;
+        do {
+            priorSize = applicationModulePathRequiredModules.size();
+            for (ModuleReference mref : modules) {
+                Set<String> requiredModules = getRequiredModules(mref);
+                applicationModulePathRequiredModules.addAll(requiredModules);
+            }
+        } while (priorSize < applicationModulePathRequiredModules.size());
+
+        applicationModulePathRequiredModules.retainAll(systemModules);
+        return applicationModulePathRequiredModules;
+    }
+
+    private Set<String> getRequiredModules(ModuleReference mref) {
+        return mref.descriptor().requires().stream()
+                .map(ModuleDescriptor.Requires::name)
+                .collect(Collectors.toSet());
+    }
+
     boolean useBundle() {
         return bundleSupport != null;
     }