graalvm-expert

name	graalvm-expert
description	Expert knowledge for GraalVM, Native Image (AOT), Polyglot runtime, and reflection/resource configuration. Use for native compilation and multi-language JVM questions.
version	1.1.0
keywords	["graalvm","native-image","aot","polyglot","optimization","jvm"]

graalvm-expert

Keyword: graalvm | Platforms: gemini,claude,codex

High-Performance Polyglot & Native VM Expert Skill - Specialized in GraalVM AOT (Ahead-of-Time) compilation.

Core Mandates

• AOT Mindset: Understand that Native Image has a "Closed-world assumption" (all bytecode must be known at build time).
• Reflection Discipline: Mandate reflection-config.json for any dynamic class loading or reflection usage.
• Initialization Policy: Differentiate between Build-time initialization (faster startup, smaller image) and Runtime initialization (safer for classes with side effects).
• Polyglot Strategy: Leverage GraalVM SDK for high-performance interoperability between Java, JS, Python, and Ruby.

Native Image Mastery

• Native Image Agent: Using java -agentlib:native-image-agent to automatically generate configuration files.
• Resource Management: Config for resource-config.json to include static assets in the native binary.
• Dynamic Proxy: Configuring proxy-config.json for Java dynamic proxies.
• Substrate VM: Understanding memory management and GC options (G1 vs Serial) in native binaries.

GraalVM + Build Systems

• Maven/Gradle: Using the GraalVM Native Build Tools plugins.
• Bazel Integration: Configuring rules_graalvm and toolchains for hermetic native builds.
• Quarkus Native: Troubleshooting Quarkus-specific native image failures (often related to extensions or transitive libraries).

Optimization & Performance

• PGO (Profile-Guided Optimization): Collecting profiles from JIT runs to optimize AOT binaries.
• Graal JIT: Using Graal as a replacement for C2 compiler in standard JVM mode for better performance in modern Java.
• Static Analysis: Interpreting GraalVM build-time reports (reachability analysis).

Expert Tips

• Always check reflect-config.json if you get ClassNotFoundException in a native binary.
• Prefer quarkus.native.additional-build-args for passing low-level GraalVM flags.
• Use --trace-class-initialization to debug complex initialization order issues.

🌐 GraalVM Deep Dives

Directive: Use web_fetch to find specific configuration flags or reflection-config.json syntax if a native build fails or requires optimization.

• Native Image Agent: GraalVM Agent Guide - Automating metadata collection.
• Reflection Config: Reflection Config Reference - Manual reflection configuration.
• Dynamic Proxy: Dynamic Proxy metadata - Handling interface-based proxies.
• Static vs Runtime Init: Class Initialization in Native Image - Debugging --initialize-at-build-time.

References

• GraalVM Native Image Documentation
• Quarkus Native Image Guide
• GraalVM GitHub Repository

Skill Interoperability

The graalvm-expert 🚀 skill provides the native runtime and AOT compilation expertise for:

• quarkus-expert ⚡: Enables building Native Images for Quarkus applications. It depends on java-expert ☕ for understanding reflection and resource configuration.