Support agent by attaching it at build time #9668

ziyilin · 2024-09-12T08:05:33Z

This PR enables GraalVM to accept java agents at build time and apply their class transformations in the native image.

The agent is passed to native-image by specifying -javaagent:<jarpath>[=<options>], the same as using with JVM.

vjovanov · 2024-09-12T08:35:03Z

substratevm/src/com.oracle.svm.hosted/src/com/oracle/svm/hosted/InstrumentFeature.java

+        // Read MANIFEST in agent jar
+        try {
+            JarFile agentJarFile = new JarFile(agent);
+            premainClass = agentJarFile.getManifest().getMainAttributes().getValue("Premain-Class");


What happens when there is no Manifest? There should be a special error message for that.

At this moment, the java agent has been already loaded and run by JVM.
If there is no Manifest, the JVM can't get started with -javaagent.
But in the proxy agent case, the actual agent will be loaded by -cp, we should check the existence of Manifest then.

vjovanov · 2024-09-12T08:49:27Z

substratevm/mx.substratevm/mx_substratevm.py

        native_agent_premain_options = ['-XXpremain:com.oracle.svm.test.javaagent.agent1.TestJavaAgent1:test.agent1=true', '-XXpremain:com.oracle.svm.test.javaagent.agent2.TestJavaAgent2:test.agent2=true']
-        image_args = ['-cp', test_cp, '-J-ea', '-J-esa', '-H:+ReportExceptionStackTraces', '-H:Class=com.oracle.svm.test.javaagent.AgentTest']
-        native_image(image_args + svm_experimental_options(['-H:PremainClasses=' + agents_arg]) + ['-o', binary_path] + args)
+        image_args = ['-cp', test_cp, '-J-ea', '-J-esa', '-H:+ReportExceptionStackTraces', '-J--add-exports=java.base/jdk.internal.org.objectweb.asm=ALL-UNNAMED', '-H:Class=com.oracle.svm.test.javaagent.AgentTest']


Why do we need -J--add-exports=java.base/jdk.internal.org.objectweb.asm=ALL-UNNAMED?

I transformed class in test agent with ASM.

Will users have to specify this?

vjovanov · 2024-09-12T08:50:07Z

substratevm/mx.substratevm/mx_substratevm.py

@@ -1756,18 +1761,23 @@ def build_and_test_java_agent_image(native_image, args):
            # Note: we are not using MX here to avoid polluting the suite.py and requiring extra build flags
            mx.log("Building agent jars from " + test_classpath)
            agents = []
-            for i in range(1, 2):
+            for i in range(1, 3):


I don't see the agent3 in the PR? Is it committed?

python's range(x, y) includes x but excludes y.

vjovanov · 2024-09-12T08:51:48Z

substratevm/mx.substratevm/mx_substratevm.py

-                mx.run([mx.get_jdk().jar, 'cmf', join(test_classpath, 'resources', 'javaagent' + str(i), 'MANIFEST.MF'), agent] + class_list, cwd = tmp_dir)
+                current_dir = os.getcwd()
+                # Change to test classpath to create agent jar file
+                os.chdir(test_classpath)


Why do we need to change the dir?

Running jar cmf xxx.jar package/SomeClass.class to pack a jar file requires changing working directory to the root of class package path.

vjovanov · 2024-09-12T09:03:18Z

....oracle.graal.pointsto/src/com/oracle/graal/pointsto/infrastructure/WrappedConstantPool.java

@@ -117,7 +120,26 @@ public JavaMethod lookupMethod(int cpi, int opcode) {
    @Override
    public JavaMethod lookupMethod(int cpi, int opcode, ResolvedJavaMethod caller) {
        try {
-            return universe.lookupAllowUnresolved(wrapped.lookupMethod(cpi, opcode, OriginalMethodProvider.getOriginalMethod(caller)));
+            JavaMethod ret = universe.lookupAllowUnresolved(wrapped.lookupMethod(cpi, opcode, OriginalMethodProvider.getOriginalMethod(caller)));


For which classes does this happen? Can you provide a concrete example?

Class com.oracle.svm.test.javaagent.agent1.TestJavaAgent1 has dependency on org.junit.Assert.

At build time, TestJavaAgent1 is loaded by appClassloader as part of java agent, while org.junit.Assert is loaded by NativeImageClassloader because its jar is specified by -cp. Therefore, appClassloader:TestJavaAgent1 depends on NativeImageClassloader:Assert. The following error is thrown during building:

Error: Discovered unresolved type during parsing: org.junit.Assert. This error is reported at image build time because class com.oracle.svm.test.javaagent.agent1.TestJavaAgent1 is registered for linking at image build time by system default. Error encountered while parsing com.oracle.svm.test.javaagent.agent1.TestJavaAgent1.premain(TestJavaAgent1.java:48) Parsing context: at static root method.(Unknown Source) Detailed message: Caused by: com.oracle.graal.pointsto.constraints.UnsupportedFeatureException: Discovered unresolved type during parsing: org.junit.Assert. This error is reported at image build time because class com.oracle.svm.test.javaagent.agent1.TestJavaAgent1 is registered for linking at image build time by system default. Error encountered while parsing com.oracle.svm.test.javaagent.agent1.TestJavaAgent1.premain(TestJavaAgent1.java:48) Parsing context: at static root method.(Unknown Source) Detailed message: at org.graalvm.nativeimage.pointsto/com.oracle.graal.pointsto.constraints.UnsupportedFeatures.report(UnsupportedFeatures.java:126) at org.graalvm.nativeimage.builder/com.oracle.svm.hosted.NativeImageGenerator.runPointsToAnalysis(NativeImageGenerator.java:867) at org.graalvm.nativeimage.builder/com.oracle.svm.hosted.NativeImageGenerator.doRun(NativeImageGenerator.java:593) at org.graalvm.nativeimage.builder/com.oracle.svm.hosted.NativeImageGenerator.run(NativeImageGenerator.java:555) at org.graalvm.nativeimage.builder/com.oracle.svm.hosted.NativeImageGeneratorRunner.buildImage(NativeImageGeneratorRunner.java:544) at org.graalvm.nativeimage.builder/com.oracle.svm.hosted.NativeImageGeneratorRunner.build(NativeImageGeneratorRunner.java:731) at org.graalvm.nativeimage.builder/com.oracle.svm.hosted.NativeImageGeneratorRunner.start(NativeImageGeneratorRunner.java:151) at org.graalvm.nativeimage.builder/com.oracle.svm.hosted.NativeImageGeneratorRunner.main(NativeImageGeneratorRunner.java:99) Caused by: com.oracle.graal.pointsto.constraints.UnresolvedElementException: Discovered unresolved type during parsing: org.junit.Assert. This error is reported at image build time because class com.oracle.svm.test.javaagent.agent1.TestJavaAgent1 is registered for linking at image build time by system default. at org.graalvm.nativeimage.builder/com.oracle.svm.hosted.phases.SharedGraphBuilderPhase$SharedBytecodeParser.reportUnresolvedElement(SharedGraphBuilderPhase.java:604) at org.graalvm.nativeimage.builder/com.oracle.svm.hosted.phases.SharedGraphBuilderPhase$SharedBytecodeParser.reportUnresolvedElement(SharedGraphBuilderPhase.java:598) at org.graalvm.nativeimage.builder/com.oracle.svm.hosted.phases.SharedGraphBuilderPhase$SharedBytecodeParser.handleUnresolvedType(SharedGraphBuilderPhase.java:490) at org.graalvm.nativeimage.builder/com.oracle.svm.hosted.phases.SharedGraphBuilderPhase$SharedBytecodeParser.handleUnresolvedMethod(SharedGraphBuilderPhase.java:518) at org.graalvm.nativeimage.builder/com.oracle.svm.hosted.phases.SharedGraphBuilderPhase$SharedBytecodeParser.handleUnresolvedInvoke(SharedGraphBuilderPhase.java:411) at jdk.graal.compiler/jdk.graal.compiler.java.BytecodeParser.genInvokeStatic(BytecodeParser.java:1864) at jdk.graal.compiler/jdk.graal.compiler.java.BytecodeParser.genInvokeStatic(BytecodeParser.java:1843) at jdk.graal.compiler/jdk.graal.compiler.java.BytecodeParser.processBytecode(BytecodeParser.java:5807) at jdk.graal.compiler/jdk.graal.compiler.java.BytecodeParser.iterateBytecodesForBlock(BytecodeParser.java:3769) at org.graalvm.nativeimage.builder/com.oracle.svm.hosted.phases.SharedGraphBuilderPhase$SharedBytecodeParser.iterateBytecodesForBlock(SharedGraphBuilderPhase.java:954) at jdk.graal.compiler/jdk.graal.compiler.java.BytecodeParser.handleBytecodeBlock(BytecodeParser.java:3729) at jdk.graal.compiler/jdk.graal.compiler.java.BytecodeParser.processBlock(BytecodeParser.java:3576) at jdk.graal.compiler/jdk.graal.compiler.java.BytecodeParser.build(BytecodeParser.java:1162) at org.graalvm.nativeimage.builder/com.oracle.svm.hosted.phases.SharedGraphBuilderPhase$SharedBytecodeParser.build(SharedGraphBuilderPhase.java:205) at jdk.graal.compiler/jdk.graal.compiler.java.BytecodeParser.buildRootMethod(BytecodeParser.java:1054) at jdk.graal.compiler/jdk.graal.compiler.java.GraphBuilderPhase$Instance.run(GraphBuilderPhase.java:103) at org.graalvm.nativeimage.builder/com.oracle.svm.hosted.phases.SharedGraphBuilderPhase.run(SharedGraphBuilderPhase.java:157) at jdk.graal.compiler/jdk.graal.compiler.phases.Phase.run(Phase.java:49) at jdk.graal.compiler/jdk.graal.compiler.phases.BasePhase.apply(BasePhase.java:468) at jdk.graal.compiler/jdk.graal.compiler.phases.Phase.apply(Phase.java:42) at jdk.graal.compiler/jdk.graal.compiler.phases.Phase.apply(Phase.java:38) at org.graalvm.nativeimage.pointsto/com.oracle.graal.pointsto.flow.AnalysisParsedGraph.parseBytecode(AnalysisParsedGraph.java:144) at org.graalvm.nativeimage.pointsto/com.oracle.graal.pointsto.meta.AnalysisMethod.lambda$parseGraph$5(AnalysisMethod.java:986) at org.graalvm.nativeimage.pointsto/com.oracle.graal.pointsto.meta.AnalysisMethod.setGraph(AnalysisMethod.java:1002) at org.graalvm.nativeimage.pointsto/com.oracle.graal.pointsto.meta.AnalysisMethod.parseGraph(AnalysisMethod.java:986) at org.graalvm.nativeimage.pointsto/com.oracle.graal.pointsto.meta.AnalysisMethod.ensureGraphParsedHelper(AnalysisMethod.java:958) at org.graalvm.nativeimage.pointsto/com.oracle.graal.pointsto.meta.AnalysisMethod.ensureGraphParsed(AnalysisMethod.java:937) at org.graalvm.nativeimage.pointsto/com.oracle.graal.pointsto.flow.MethodTypeFlowBuilder.parse(MethodTypeFlowBuilder.java:190) at org.graalvm.nativeimage.pointsto/com.oracle.graal.pointsto.flow.MethodTypeFlowBuilder.apply(MethodTypeFlowBuilder.java:658) at org.graalvm.nativeimage.pointsto/com.oracle.graal.pointsto.flow.MethodTypeFlow.createFlowsGraph(MethodTypeFlow.java:167) at org.graalvm.nativeimage.pointsto/com.oracle.graal.pointsto.flow.MethodTypeFlow.ensureFlowsGraphCreated(MethodTypeFlow.java:152) at org.graalvm.nativeimage.pointsto/com.oracle.graal.pointsto.flow.MethodTypeFlow.getOrCreateMethodFlowsGraphInfo(MethodTypeFlow.java:110) at org.graalvm.nativeimage.pointsto/com.oracle.graal.pointsto.typestate.DefaultAnalysisPolicy.staticRootMethodGraph(DefaultAnalysisPolicy.java:208) at org.graalvm.nativeimage.pointsto/com.oracle.graal.pointsto.PointsToAnalysis.lambda$addRootMethod$1(PointsToAnalysis.java:339) at org.graalvm.nativeimage.pointsto/com.oracle.graal.pointsto.AbstractAnalysisEngine$1.run(AbstractAnalysisEngine.java:338) at org.graalvm.nativeimage.pointsto/com.oracle.graal.pointsto.util.CompletionExecutor.executeCommand(CompletionExecutor.java:166) at org.graalvm.nativeimage.pointsto/com.oracle.graal.pointsto.util.CompletionExecutor.lambda$executeService$0(CompletionExecutor.java:152) at java.base/java.util.concurrent.ForkJoinTask$RunnableExecuteAction.exec(ForkJoinTask.java:1423) at java.base/java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:387) at java.base/java.util.concurrent.ForkJoinPool$WorkQueue.topLevelExec(ForkJoinPool.java:1312) at java.base/java.util.concurrent.ForkJoinPool.scan(ForkJoinPool.java:1843) at java.base/java.util.concurrent.ForkJoinPool.runWorker(ForkJoinPool.java:1808) at java.base/java.util.concurrent.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:188) Caused by: com.oracle.graal.pointsto.constraints.UnresolvedElementException: Discovered unresolved type during parsing: org.junit.Assert. This error is reported at image build time because class com.oracle.svm.test.javaagent.agent1.TestJavaAgent1 is registered for linking at image build time by system default. at org.graalvm.nativeimage.builder/com.oracle.svm.hosted.phases.SharedGraphBuilderPhase$SharedBytecodeParser.reportUnresolvedElement(SharedGraphBuilderPhase.java:604) at org.graalvm.nativeimage.builder/com.oracle.svm.hosted.phases.SharedGraphBuilderPhase$SharedBytecodeParser.reportUnresolvedElement(SharedGraphBuilderPhase.java:598) at org.graalvm.nativeimage.builder/com.oracle.svm.hosted.phases.SharedGraphBuilderPhase$SharedBytecodeParser.handleUnresolvedType(SharedGraphBuilderPhase.java:490) at org.graalvm.nativeimage.builder/com.oracle.svm.hosted.phases.SharedGraphBuilderPhase$SharedBytecodeParser.handleUnresolvedMethod(SharedGraphBuilderPhase.java:518) at org.graalvm.nativeimage.builder/com.oracle.svm.hosted.phases.SharedGraphBuilderPhase$SharedBytecodeParser.handleUnresolvedInvoke(SharedGraphBuilderPhase.java:411) at jdk.graal.compiler/jdk.graal.compiler.java.BytecodeParser.genInvokeStatic(BytecodeParser.java:1864) at jdk.graal.compiler/jdk.graal.compiler.java.BytecodeParser.genInvokeStatic(BytecodeParser.java:1843) at jdk.graal.compiler/jdk.graal.compiler.java.BytecodeParser.processBytecode(BytecodeParser.java:5807) at jdk.graal.compiler/jdk.graal.compiler.java.BytecodeParser.iterateBytecodesForBlock(BytecodeParser.java:3769) at org.graalvm.nativeimage.builder/com.oracle.svm.hosted.phases.SharedGraphBuilderPhase$SharedBytecodeParser.iterateBytecodesForBlock(SharedGraphBuilderPhase.java:954) at jdk.graal.compiler/jdk.graal.compiler.java.BytecodeParser.handleBytecodeBlock(BytecodeParser.java:3729) at jdk.graal.compiler/jdk.graal.compiler.java.BytecodeParser.processBlock(BytecodeParser.java:3576) at jdk.graal.compiler/jdk.graal.compiler.java.BytecodeParser.build(BytecodeParser.java:1162) at org.graalvm.nativeimage.builder/com.oracle.svm.hosted.phases.SharedGraphBuilderPhase$SharedBytecodeParser.build(SharedGraphBuilderPhase.java:205) at jdk.graal.compiler/jdk.graal.compiler.java.BytecodeParser.buildRootMethod(BytecodeParser.java:1054) at jdk.graal.compiler/jdk.graal.compiler.java.GraphBuilderPhase$Instance.run(GraphBuilderPhase.java:103) at org.graalvm.nativeimage.builder/com.oracle.svm.hosted.phases.SharedGraphBuilderPhase.run(SharedGraphBuilderPhase.java:157) at jdk.graal.compiler/jdk.graal.compiler.phases.Phase.run(Phase.java:49) at jdk.graal.compiler/jdk.graal.compiler.phases.BasePhase.apply(BasePhase.java:468) at jdk.graal.compiler/jdk.graal.compiler.phases.Phase.apply(Phase.java:42) at jdk.graal.compiler/jdk.graal.compiler.phases.Phase.apply(Phase.java:38) at org.graalvm.nativeimage.pointsto/com.oracle.graal.pointsto.flow.AnalysisParsedGraph.parseBytecode(AnalysisParsedGraph.java:144) at org.graalvm.nativeimage.pointsto/com.oracle.graal.pointsto.meta.AnalysisMethod.lambda$parseGraph$5(AnalysisMethod.java:986) at org.graalvm.nativeimage.pointsto/com.oracle.graal.pointsto.meta.AnalysisMethod.setGraph(AnalysisMethod.java:1002) at org.graalvm.nativeimage.pointsto/com.oracle.graal.pointsto.meta.AnalysisMethod.parseGraph(AnalysisMethod.java:986) at org.graalvm.nativeimage.pointsto/com.oracle.graal.pointsto.meta.AnalysisMethod.ensureGraphParsedHelper(AnalysisMethod.java:958) at org.graalvm.nativeimage.pointsto/com.oracle.graal.pointsto.meta.AnalysisMethod.ensureGraphParsed(AnalysisMethod.java:937) at org.graalvm.nativeimage.pointsto/com.oracle.graal.pointsto.flow.MethodTypeFlowBuilder.parse(MethodTypeFlowBuilder.java:190) at org.graalvm.nativeimage.pointsto/com.oracle.graal.pointsto.flow.MethodTypeFlowBuilder.apply(MethodTypeFlowBuilder.java:658) at org.graalvm.nativeimage.pointsto/com.oracle.graal.pointsto.flow.MethodTypeFlow.createFlowsGraph(MethodTypeFlow.java:167) at org.graalvm.nativeimage.pointsto/com.oracle.graal.pointsto.flow.MethodTypeFlow.ensureFlowsGraphCreated(MethodTypeFlow.java:152) at org.graalvm.nativeimage.pointsto/com.oracle.graal.pointsto.flow.MethodTypeFlow.getOrCreateMethodFlowsGraphInfo(MethodTypeFlow.java:110) at org.graalvm.nativeimage.pointsto/com.oracle.graal.pointsto.typestate.DefaultAnalysisPolicy.staticRootMethodGraph(DefaultAnalysisPolicy.java:208) at org.graalvm.nativeimage.pointsto/com.oracle.graal.pointsto.PointsToAnalysis.lambda$addRootMethod$1(PointsToAnalysis.java:339) at org.graalvm.nativeimage.pointsto/com.oracle.graal.pointsto.AbstractAnalysisEngine$1.run(AbstractAnalysisEngine.java:338) at org.graalvm.nativeimage.pointsto/com.oracle.graal.pointsto.util.CompletionExecutor.executeCommand(CompletionExecutor.java:166) at org.graalvm.nativeimage.pointsto/com.oracle.graal.pointsto.util.CompletionExecutor.lambda$executeService$0(CompletionExecutor.java:152) at java.base/java.util.concurrent.ForkJoinTask$RunnableExecuteAction.exec(ForkJoinTask.java:1423) at java.base/java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:387) at java.base/java.util.concurrent.ForkJoinPool$WorkQueue.topLevelExec(ForkJoinPool.java:1312) at java.base/java.util.concurrent.ForkJoinPool.scan(ForkJoinPool.java:1843) at java.base/java.util.concurrent.ForkJoinPool.runWorker(ForkJoinPool.java:1808) at java.base/java.util.concurrent.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:188) Internal exception: com.oracle.svm.core.util.UserError$UserException: Discovered unresolved type during parsing: org.junit.Assert. This error is reported at image build time because class com.oracle.svm.test.javaagent.agent1.TestJavaAgent1 is registered for linking at image build time by system default. Error encountered while parsing com.oracle.svm.test.javaagent.agent1.TestJavaAgent1.premain(TestJavaAgent1.java:48) Parsing context: at static root method.(Unknown Source) Detailed message: at org.graalvm.nativeimage.builder/com.oracle.svm.core.util.UserError.abort(UserError.java:97) at org.graalvm.nativeimage.builder/com.oracle.svm.hosted.FallbackFeature.reportAsFallback(FallbackFeature.java:248) at org.graalvm.nativeimage.builder/com.oracle.svm.hosted.NativeImageGenerator.runPointsToAnalysis(NativeImageGenerator.java:872) at org.graalvm.nativeimage.builder/com.oracle.svm.hosted.NativeImageGenerator.doRun(NativeImageGenerator.java:593) at org.graalvm.nativeimage.builder/com.oracle.svm.hosted.NativeImageGenerator.run(NativeImageGenerator.java:555) at org.graalvm.nativeimage.builder/com.oracle.svm.hosted.NativeImageGeneratorRunner.buildImage(NativeImageGeneratorRunner.java:544) at org.graalvm.nativeimage.builder/com.oracle.svm.hosted.NativeImageGeneratorRunner.build(NativeImageGeneratorRunner.java:731) at org.graalvm.nativeimage.builder/com.oracle.svm.hosted.NativeImageGeneratorRunner.start(NativeImageGeneratorRunner.java:151) at org.graalvm.nativeimage.builder/com.oracle.svm.hosted.NativeImageGeneratorRunner.main(NativeImageGeneratorRunner.java:99) Caused by: com.oracle.graal.pointsto.constraints.UnsupportedFeatureException: Discovered unresolved type during parsing: org.junit.Assert. This error is reported at image build time because class com.oracle.svm.test.javaagent.agent1.TestJavaAgent1 is registered for linking at image build time by system default. Error encountered while parsing com.oracle.svm.test.javaagent.agent1.TestJavaAgent1.premain(TestJavaAgent1.java:48) Parsing context: at static root method.(Unknown Source) Detailed message: at org.graalvm.nativeimage.pointsto/com.oracle.graal.pointsto.constraints.UnsupportedFeatures.report(UnsupportedFeatures.java:126) at org.graalvm.nativeimage.builder/com.oracle.svm.hosted.NativeImageGenerator.runPointsToAnalysis(NativeImageGenerator.java:867) ... 6 more Caused by: com.oracle.graal.pointsto.constraints.UnresolvedElementException: Discovered unresolved type during parsing: org.junit.Assert. This error is reported at image build time because class com.oracle.svm.test.javaagent.agent1.TestJavaAgent1 is registered for linking at image build time by system default. at org.graalvm.nativeimage.builder/com.oracle.svm.hosted.phases.SharedGraphBuilderPhase$SharedBytecodeParser.reportUnresolvedElement(SharedGraphBuilderPhase.java:604) at org.graalvm.nativeimage.builder/com.oracle.svm.hosted.phases.SharedGraphBuilderPhase$SharedBytecodeParser.reportUnresolvedElement(SharedGraphBuilderPhase.java:598) at org.graalvm.nativeimage.builder/com.oracle.svm.hosted.phases.SharedGraphBuilderPhase$SharedBytecodeParser.handleUnresolvedType(SharedGraphBuilderPhase.java:490) at org.graalvm.nativeimage.builder/com.oracle.svm.hosted.phases.SharedGraphBuilderPhase$SharedBytecodeParser.handleUnresolvedMethod(SharedGraphBuilderPhase.java:518) at org.graalvm.nativeimage.builder/com.oracle.svm.hosted.phases.SharedGraphBuilderPhase$SharedBytecodeParser.handleUnresolvedInvoke(SharedGraphBuilderPhase.java:411) at jdk.graal.compiler/jdk.graal.compiler.java.BytecodeParser.genInvokeStatic(BytecodeParser.java:1864) at jdk.graal.compiler/jdk.graal.compiler.java.BytecodeParser.genInvokeStatic(BytecodeParser.java:1843) at jdk.graal.compiler/jdk.graal.compiler.java.BytecodeParser.processBytecode(BytecodeParser.java:5807) at jdk.graal.compiler/jdk.graal.compiler.java.BytecodeParser.iterateBytecodesForBlock(BytecodeParser.java:3769) at org.graalvm.nativeimage.builder/com.oracle.svm.hosted.phases.SharedGraphBuilderPhase$SharedBytecodeParser.iterateBytecodesForBlock(SharedGraphBuilderPhase.java:954) at jdk.graal.compiler/jdk.graal.compiler.java.BytecodeParser.handleBytecodeBlock(BytecodeParser.java:3729) at jdk.graal.compiler/jdk.graal.compiler.java.BytecodeParser.processBlock(BytecodeParser.java:3576) at jdk.graal.compiler/jdk.graal.compiler.java.BytecodeParser.build(BytecodeParser.java:1162) at org.graalvm.nativeimage.builder/com.oracle.svm.hosted.phases.SharedGraphBuilderPhase$SharedBytecodeParser.build(SharedGraphBuilderPhase.java:205) at jdk.graal.compiler/jdk.graal.compiler.java.BytecodeParser.buildRootMethod(BytecodeParser.java:1054) at jdk.graal.compiler/jdk.graal.compiler.java.GraphBuilderPhase$Instance.run(GraphBuilderPhase.java:103) at org.graalvm.nativeimage.builder/com.oracle.svm.hosted.phases.SharedGraphBuilderPhase.run(SharedGraphBuilderPhase.java:157) at jdk.graal.compiler/jdk.graal.compiler.phases.Phase.run(Phase.java:49) at jdk.graal.compiler/jdk.graal.compiler.phases.BasePhase.apply(BasePhase.java:468) at jdk.graal.compiler/jdk.graal.compiler.phases.Phase.apply(Phase.java:42) at jdk.graal.compiler/jdk.graal.compiler.phases.Phase.apply(Phase.java:38) at org.graalvm.nativeimage.pointsto/com.oracle.graal.pointsto.flow.AnalysisParsedGraph.parseBytecode(AnalysisParsedGraph.java:144) at org.graalvm.nativeimage.pointsto/com.oracle.graal.pointsto.meta.AnalysisMethod.lambda$parseGraph$5(AnalysisMethod.java:986) at org.graalvm.nativeimage.pointsto/com.oracle.graal.pointsto.meta.AnalysisMethod.setGraph(AnalysisMethod.java:1002) at org.graalvm.nativeimage.pointsto/com.oracle.graal.pointsto.meta.AnalysisMethod.parseGraph(AnalysisMethod.java:986) at org.graalvm.nativeimage.pointsto/com.oracle.graal.pointsto.meta.AnalysisMethod.ensureGraphParsedHelper(AnalysisMethod.java:958) at org.graalvm.nativeimage.pointsto/com.oracle.graal.pointsto.meta.AnalysisMethod.ensureGraphParsed(AnalysisMethod.java:937) at org.graalvm.nativeimage.pointsto/com.oracle.graal.pointsto.flow.MethodTypeFlowBuilder.parse(MethodTypeFlowBuilder.java:190) at org.graalvm.nativeimage.pointsto/com.oracle.graal.pointsto.flow.MethodTypeFlowBuilder.apply(MethodTypeFlowBuilder.java:658) at org.graalvm.nativeimage.pointsto/com.oracle.graal.pointsto.flow.MethodTypeFlow.createFlowsGraph(MethodTypeFlow.java:167) at org.graalvm.nativeimage.pointsto/com.oracle.graal.pointsto.flow.MethodTypeFlow.ensureFlowsGraphCreated(MethodTypeFlow.java:152) at org.graalvm.nativeimage.pointsto/com.oracle.graal.pointsto.flow.MethodTypeFlow.getOrCreateMethodFlowsGraphInfo(MethodTypeFlow.java:110) at org.graalvm.nativeimage.pointsto/com.oracle.graal.pointsto.typestate.DefaultAnalysisPolicy.staticRootMethodGraph(DefaultAnalysisPolicy.java:208) at org.graalvm.nativeimage.pointsto/com.oracle.graal.pointsto.PointsToAnalysis.lambda$addRootMethod$1(PointsToAnalysis.java:339) at org.graalvm.nativeimage.pointsto/com.oracle.graal.pointsto.AbstractAnalysisEngine$1.run(AbstractAnalysisEngine.java:338) at org.graalvm.nativeimage.pointsto/com.oracle.graal.pointsto.util.CompletionExecutor.executeCommand(CompletionExecutor.java:166) at org.graalvm.nativeimage.pointsto/com.oracle.graal.pointsto.util.CompletionExecutor.lambda$executeService$0(CompletionExecutor.java:152) at java.base/java.util.concurrent.ForkJoinTask$RunnableExecuteAction.exec(ForkJoinTask.java:1423) at java.base/java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:387) at java.base/java.util.concurrent.ForkJoinPool$WorkQueue.topLevelExec(ForkJoinPool.java:1312) at java.base/java.util.concurrent.ForkJoinPool.scan(ForkJoinPool.java:1843) at java.base/java.util.concurrent.ForkJoinPool.runWorker(ForkJoinPool.java:1808) at java.base/java.util.concurrent.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:188)

This doesn't happen in JVM because both TestJavaAgent1 and Assert are loaded by appClassloader in JVM mode.

@cstancu or @Zeavee : please have a look at the code part below.

Based on documentation here (and the JVM code) the agents should be loaded by the system class loader. However, in Native Image we do provide the NativeImageClassLoader as the system class loader.

That is why I am confused. What is the output of System.out.println(TestJavaAgent1.class.getClassLoader()) at build time? Did the agent run before we set the system class loader in Native Image?

Figured it out together with @olpaw. There is a paragraph in the documentation:

If a custom system class loader is configured (by means of the system property java.system.class.loader as specified in the getSystemClassLoader method) then it must define the appendToClassPathForInstrumentation method as specified in appendToSystemClassLoaderSearch. In other words, a custom system class loader must support the mechanism to add an agent JAR file to the system class loader search.

Since we don't do that correctly in the NativeImageSystemClassLoader we get a wrong class loader.

To make this work we need to fix the implementation of NativeImageSystemClassLoader.

So what's the plan? Should I wait for the fix first?

It is best to do the fix as the part of this PR as it is related to java agents.

I have fixed the NativeImageSystemClassLoader.
The nativeImageClassLoader was created in the main method of NativeImageGeneratorRunner. It was too late for agent loading. So I move the creation into the NativeImageSystemClassLoader.appendToClassPathForInstrumentation.

vjovanov · 2024-09-12T09:32:00Z

substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/SubstrateOptions.java

@@ -202,6 +202,10 @@ protected void onValueUpdate(EconomicMap<OptionKey<?>, Object> values, String ol
    public static OptionEnabledHandler<Boolean> imageLayerEnabledHandler;
    public static OptionEnabledHandler<Boolean> imageLayerCreateEnabledHandler;

+    @APIOption(name = "-javaagent", valueSeparator = ':')//
+    @Option(help = "Enable the given java agent in native image.", type = User, stability = OptionStability.EXPERIMENTAL)//


Please specify the expected format here.

vjovanov · 2024-09-12T09:32:58Z

substratevm/src/com.oracle.svm.hosted/src/com/oracle/svm/hosted/InstrumentFeature.java

        try {
            Class<?> clazz = Class.forName(premainClass, false, cl);
            Method premain = null;
            List<Object> args = new ArrayList<>();
-            args.add(""); // First argument is options which will be set at runtime
+            args.add(options); // First argument is options which will be set at runtime


Can the options be overridden at run time?

Yes. Options set at runtime can override the build time options.

christianhaeubl · 2024-09-23T15:50:52Z

substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/SubstrateOptions.java

@@ -202,6 +202,10 @@ protected void onValueUpdate(EconomicMap<OptionKey<?>, Object> values, String ol
    public static OptionEnabledHandler<Boolean> imageLayerEnabledHandler;
    public static OptionEnabledHandler<Boolean> imageLayerCreateEnabledHandler;

+    @APIOption(name = "-javaagent", valueSeparator = ':')//
+    @Option(help = "Enable the specified java agent in native image. Usage: -javaagent:<jarpath>[=<options>]. It's the same as using javaagent in JVM", type = User, stability = OptionStability.EXPERIMENTAL)//
+    public static final HostedOptionKey<AccumulatingLocatableMultiOptionValue.Strings> JavaAgent = new HostedOptionKey<>(AccumulatingLocatableMultiOptionValue.Strings.build());


This partially conflicts with the basic JVMTI runtime support that was merged a couple weeks ago (see #9558). I will need to think about that a bit and I will try to come up with an approach to unify the JVMTI build- and runtime support.

Where does the conflict come from? Feels to me that with javaagent transformations happen mostly at build time (except the premain), while JVMTI provides hooks for run-time events.

I don't think there is a conflict, as you said they are working on different phases. Class transformation has nothing to do with JVMTI events.

Both JVMTI and Java agents can be used to instrument Java classes. I was worried about those approaches conflicting. However, I think that you are right, this probably shouldn't result in worse situations than on HotSpot. Besides that, the same restrictions apply to both instrumentation approaches, so there is also no difference in terms of behavior there:

It is impossible to instrument most of the GraalVM-internal classes.

It is impossible to instrument certain JDK code (e.g., code that native image calls internally in low-level code, such as Throwable, java.lang.String, ...)

It is impossible to instrument code that Native Image substitutes (@TargetClass and similar annotations)

christianhaeubl

Thanks for this PR. I added a few comments.

I wasn't aware that some premain-related changes were already merged. So, I did a post merge review of those changes and opened a PR with cleanups: #9747

christianhaeubl · 2024-09-24T13:31:48Z

substratevm/src/com.oracle.graal.pointsto/src/com/oracle/graal/pointsto/api/HostVM.java

@@ -336,6 +336,11 @@ public boolean isClosedTypeWorld() {
        return true;
    }

+    @SuppressWarnings("unused")


Please use the following instead:
public boolean isFromJavaAgent(@SuppressWarnings("unused") Class<?> clazz) {

christianhaeubl · 2024-09-24T13:48:09Z

substratevm/src/com.oracle.svm.hosted/src/com/oracle/svm/hosted/InstrumentFeature.java

+        } catch (IOException e) {
+            // This shall not happen, because at this moment GraalVM is running with -javaagent.
+            // If the agent doesn't exist, the JVM shall fail to start.
+            UserError.abort(e, "Can't read the agent jar %s. Please check option %s", agent,


throw UserError...

christianhaeubl · 2024-09-24T13:48:58Z

substratevm/src/com.oracle.svm.hosted/src/com/oracle/svm/hosted/InstrumentFeature.java

@@ -94,12 +97,34 @@ public void afterRegistration(AfterRegistrationAccess access) {
     * is absent. <br>
     * So this method looks for them in the same order.
     */
-    private void addPremainClass(String premainClass) {
+    private void addPremainClass(String javaagentOption) {
+        int separatorIndex = javaagentOption.indexOf("=");


You can probably use SubstrateUtil.split(...) instead.

The jar file path which is prior to the first = is extracted here, while rest of the option that may contain more = should be kept in one piece for latter parsing.

christianhaeubl · 2024-09-24T13:54:26Z

substratevm/src/com.oracle.svm.hosted/src/com/oracle/svm/hosted/InstrumentFeature.java

+            JarFile agentJarFile = new JarFile(agent);
+            premainClass = agentJarFile.getManifest().getMainAttributes().getValue("Premain-Class");
+        } catch (IOException e) {
+            // This shall not happen, because at this moment GraalVM is running with -javaagent.


This should never happen because the image build process (HotSpot) already loaded the agent during startup.

christianhaeubl · 2024-09-24T14:05:01Z

...tratevm/src/com.oracle.svm.test/src/com/oracle/svm/test/javaagent/agent2/TestJavaAgent2.java

@@ -33,10 +33,9 @@ public class TestJavaAgent2 {
    public static void premain(String agentArgs) {
        AgentPremainHelper.parseOptions(agentArgs);
        System.setProperty("instrument.enable", "true");
+        AgentPremainHelper.load(TestJavaAgent2.class);
        if (!ImageInfo.inImageRuntimeCode()) {


I think you can remove this empty block.

christianhaeubl · 2024-09-24T14:15:30Z

substratevm/src/com.oracle.svm.hosted/src/com/oracle/svm/hosted/InstrumentFeature.java

+        // Read MANIFEST in agent jar
+        try {
+            JarFile agentJarFile = new JarFile(agent);
+            premainClass = agentJarFile.getManifest().getMainAttributes().getValue("Premain-Class");


So, HotSpot already executed the method PremainClass.premain during the image build but native image should execute the same method again at run-time?

I think that this will only work for a very small number of Java agents (i.e., agents that contain Native Image-specific logic or that hardly execute any code in premain). If so, then I don't think that we should register the premain method automatically and use an opt-in approach instead.

Ideally, the agent manifest would contained some information to identify if the premain method supports re-execution at run-time. Alternatively, we could execute a different method as the Java agent probably needs to explicitly support native image anyways?

From users' aspect, they need to manually isolate premain logic in JVM runtime and native image runtime anyway, a smoother and more convenient approach would be better.
Some of the agent premain logic could be shared between these two runtimes. Take OT agent for example, we carefully isolated class transformation and other staffs by runtime environment. The modifications are adding runtime environment checks for a few code sections, and most of the premain code is untouched. In this case, using a different method from premain will reduce the reusing of existing code.

It is possible some simple agents don't have complicated framework to init in premain as OT agent. It is not necessary to re-execute the premain in native image. But the end users may not know such details. We should not try to educate them when to use which option to enable premain and when to omit it. It should leave to agent developer to decide how to implement the premain, and the end users just use it as what they do in JVM mode.

@christianhaeubl the correct solution here would be that the Java agents don't do both transformation and initialization from the premain method, but have two methods instead. However, this would require a spec change which we can't do that easily.

We are hoping here that most of the users won't need to re-write their agents as the Instrumentation we pass ignores all the method calls and says that no classes are transformable.

We are implementing this as an experimental feature to experiment, and if it works great. If most of the agents need to be rewritten, then I would go with a two-method solution that you propose.

christianhaeubl · 2024-09-24T14:53:37Z

substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/SubstrateOptions.java

@@ -202,6 +202,10 @@ protected void onValueUpdate(EconomicMap<OptionKey<?>, Object> values, String ol
    public static OptionEnabledHandler<Boolean> imageLayerEnabledHandler;
    public static OptionEnabledHandler<Boolean> imageLayerCreateEnabledHandler;

+    @APIOption(name = "-javaagent", valueSeparator = ':')//
+    @Option(help = "Enable the specified java agent in native image. Usage: -javaagent:<jarpath>[=<options>]. It's the same as using javaagent in JVM", type = User, stability = OptionStability.EXPERIMENTAL)//
+    public static final HostedOptionKey<AccumulatingLocatableMultiOptionValue.Strings> JavaAgent = new HostedOptionKey<>(AccumulatingLocatableMultiOptionValue.Strings.build());


Both JVMTI and Java agents can be used to instrument Java classes. I was worried about those approaches conflicting. However, I think that you are right, this probably shouldn't result in worse situations than on HotSpot. Besides that, the same restrictions apply to both instrumentation approaches, so there is also no difference in terms of behavior there:

It is impossible to instrument most of the GraalVM-internal classes.

It is impossible to instrument certain JDK code (e.g., code that native image calls internally in low-level code, such as Throwable, java.lang.String, ...)

It is impossible to instrument code that Native Image substitutes (@TargetClass and similar annotations)

christianhaeubl · 2024-09-24T14:57:55Z

substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/SubstrateOptions.java

@@ -202,6 +202,10 @@ protected void onValueUpdate(EconomicMap<OptionKey<?>, Object> values, String ol
    public static OptionEnabledHandler<Boolean> imageLayerEnabledHandler;
    public static OptionEnabledHandler<Boolean> imageLayerCreateEnabledHandler;

+    @APIOption(name = "-javaagent", valueSeparator = ':')//
+    @Option(help = "Enable the specified java agent in native image. Usage: -javaagent:<jarpath>[=<options>]. It's the same as using javaagent in JVM", type = User, stability = OptionStability.EXPERIMENTAL)//


This option needs a longer explanation because its behavior is not the same as on HotSpot:

the Java agent is used during the image build

premain of the Java agent is re-executed at run-time

christianhaeubl · 2024-09-25T08:18:46Z

....oracle.graal.pointsto/src/com/oracle/graal/pointsto/infrastructure/WrappedConstantPool.java

@@ -117,7 +120,26 @@ public JavaMethod lookupMethod(int cpi, int opcode) {
    @Override
    public JavaMethod lookupMethod(int cpi, int opcode, ResolvedJavaMethod caller) {
        try {
-            return universe.lookupAllowUnresolved(wrapped.lookupMethod(cpi, opcode, OriginalMethodProvider.getOriginalMethod(caller)));
+            JavaMethod ret = universe.lookupAllowUnresolved(wrapped.lookupMethod(cpi, opcode, OriginalMethodProvider.getOriginalMethod(caller)));


@cstancu or @Zeavee : please have a look at the code part below.

GraalVM now can apply the class transformation in the native image by attaching the java agent at build time. User can attach the java agent to native-image with -javaagent option.

oracle-contributor-agreement bot added the OCA Verified All contributors have signed the Oracle Contributor Agreement. label Sep 12, 2024

ziyilin force-pushed the staticInstrument-buildtime-transform branch from 76036af to 94cf30e Compare September 12, 2024 08:19

vjovanov requested review from vjovanov and fniephaus September 12, 2024 08:32

vjovanov reviewed Sep 12, 2024

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fniephaus requested review from christianhaeubl and removed request for fniephaus September 13, 2024 09:44

ziyilin force-pushed the staticInstrument-buildtime-transform branch 3 times, most recently from 0726b1e to 386d5b0 Compare September 14, 2024 08:54

christianhaeubl reviewed Sep 23, 2024

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christianhaeubl reviewed Sep 25, 2024

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ziyilin force-pushed the staticInstrument-buildtime-transform branch 2 times, most recently from 8c427e6 to 86dfaa5 Compare October 8, 2024 06:08

ziyilin force-pushed the staticInstrument-buildtime-transform branch 2 times, most recently from 6b84b48 to fc6e0c5 Compare November 6, 2024 08:07

Support agent by attaching it at build time

aa36797

GraalVM now can apply the class transformation in the native image by attaching the java agent at build time. User can attach the java agent to native-image with -javaagent option.

ziyilin force-pushed the staticInstrument-buildtime-transform branch from fc6e0c5 to aa36797 Compare November 6, 2024 08:23

Support agent by attaching it at build time #9668

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Support agent by attaching it at build time #9668

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ziyilin commented Sep 12, 2024

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