Removing Services from Native Image without Special Flags

[vjovanov]

As recently discussed with @vjovanov, I would like to target a developer experience where we don't have any warning anymore when building native application with Spring Boot 4 to be released end of the year. The main blocker identified is this one:

 1 experimental option(s) unlocked:
 - '-H:ServiceLoaderFeatureExcludeServices' (origin(s): 'META-INF/native-image/org.springframework/spring-orm/native-image.properties' in 'file:///Users/sdeleuze/.m2/repository/org/springframework/spring-orm/7.0.0-SNAPSHOT/spring-orm-7.0.0-SNAPSHOT.jar')

I think this feature that allows us to ignore some service loader services is mandatory as we don't use build time init (following GraalVM best practices), but we need such mechanism to cut the reachability of some code (here ByteBuddy Hibernate support).

That said, we are totally open to specify it with something else than the current experimental expert undocumented command line flag, could be some other JSON based configuration, a GraalVM feature, or something else. Also we are going to use a Java 25 baseline for native in Spring Framework 7 so my hope is that we can provide this warning-free experience in one of the GraalVM for JDK 25 update (if too late for the initial launch).

Could we discuss a better way to enable this feature and move forward on making it available in GraalVM for JDK 25? Would be reassuring both from a GraalVM and Spring perspective to have a warning free experience out of the box with Spring Boot.

[vjovanov]

I will state the alternatives I see as viable to start the discussion:

1. Remove the META-INF/services/org.hibernate.bytecode.spi.BytecodeProvider file altogether with a build task.

   • Pro: works smoothly in all cases irrespective of Native Image.
   • Con: Each framework needs to apply it separately. Cumbersome as the tools for achieving this are not widely available.

2. Introduce an new type of entry in native-image.properties.

   • Pro: Works for everybody.
   • Con: Works for everybody and someone might not like the behavior. Doesn't work on previous GraalVM versions.

3. Make the flag for ignoring services an API flag (or at least not report a warning). Also, make sure that the services file removed by the flag is never seen via resource lookup.

   • Pro: Everyone can choose if they want to have this feature enabled.
   • Con: We need a special flag for Native Image to make programs work. This moves Native Image away from the Java semantics.

4. Modify the code of the library to ignore this service when Native Image is used, this has an added benefit that it could be configured as well.

   • Pro: Works for everyone (even on Java).
   • Con: We need to change the library code.

For reference, all the usages of the flag in the community are on the following link:

https://github.com/search?q=%22-H%3AServiceLoaderFeatureExcludeServices%3D%22&type=code&p=1

[vjovanov]

After reviewing the code in hibernate I am considering to add the following system property org.graalvm.nativeimage.closedWorld to Native Image. The new property would allow for the enhanced version of the hibernate queries to work once Crema is introduced into Native Image.

With this property we could easily check in hibernate code if bytecode providers are allowed.

The diff for fixing this in hibernate would then be:

diff --git i/hibernate-core/src/main/java/org/hibernate/bytecode/internal/BytecodeProviderInitiator.java w/hibernate-core/src/main/java/org/hibernate/bytecode/internal/BytecodeProviderInitiator.java
index a7433e1507..ff0021f70b 100644
--- i/hibernate-core/src/main/java/org/hibernate/bytecode/internal/BytecodeProviderInitiator.java
+++ w/hibernate-core/src/main/java/org/hibernate/bytecode/internal/BytecodeProviderInitiator.java
@@ -52,8 +52,9 @@ public static BytecodeProvider buildDefaultBytecodeProvider() {
 
 	@Internal
 	public static BytecodeProvider getBytecodeProvider(Iterable<BytecodeProvider> bytecodeProviders) {
+		final boolean classDefinitionUnsupported = Boolean.parseBoolean(System.getProperty("org.graalvm.nativeimage.closedWorld"));
 		final Iterator<BytecodeProvider> iterator = bytecodeProviders.iterator();
-		if ( !iterator.hasNext() ) {
+		if ( classDefinitionUnsupported || !iterator.hasNext() ) {
 			// If no BytecodeProvider service is available, default to the "no-op" enhancer
 			return new org.hibernate.bytecode.internal.none.BytecodeProviderImpl();
 		}