Plugin ASM

中文

Plugin ASM

PASM 是一个轻量级、Mixin 风格的字节码注入框架，专为 Paper / Folia 服务端设计。
它允许你通过简单的注解，在运行时修改任意类的字节码——无需反射，无需继承，无性能损耗。

🎯 目标：让 Bukkit/Paper 插件开发者能像写普通 Java 一样实现热修补、API 增强、事件拦截等操作，而不触碰复杂的 ASM 细节。

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✨ 核心特性

| 特性 | 说明 |
|—————|————————————————————————|
| 🚀 Mixin 式注入 | @Pasm + @Inject 定义目标类与方法，框架自动合并字节码 |
| 🩸全注入类型 | BEFORE / AFTER / REPLACE / HEAD / TAIL（AROUND 降级为 REPLACE） |
| 🏗️ 构造函数注入 | 支持 ，自动插入 super() 之后 |
| 🔥异常处理兼容 | try-catch-finally 完整复制，标签映射正确 |
| 📏宽类型自动偏移 | long / double 参数自动处理双槽位，无需手动计算 this 偏移 |
| ⚔️ REPLACE 独占 | 同一方法若存在 REPLACE，自动忽略其他注入（符合 Mixin 规范） |
| 🧩 ASM 处理器钩子 | 在 pasm.json 中声明 asms 数组，实现 PasmAsmProcessor 接口，可在 premain 前后执行自定义字节码操作 |
| 📦插件式扫描 | 将 pasm.json 放入插件 Jar 根目录，PASM 自动扫描所有注入点 |

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📋 环境要求

• Java 8 – 21

• Minecraft 1.0+

• Maven 或 Gradle（仅编译插件时需要）

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📥 使用方法

1. 去Github或Modrinth下载最新的Plugin ASM

1. 添加到服务器根目录，添加后，结构应该如下：

server
| -> paper-1.xx.x-xx.jar
| -> pasm-x.x.x.jar
| -> plugins
    | -> 一些插件.jar

1. 修改你的启动命令，修改后，应该如下：

java -javaagent:pasm-x.x.x.jar -jar paper-1.xx.x-xx.jar

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使用Plugin ASM来字节码注入

参考Wiki

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🧪 测试与兼容性

PASM 已在以下场景通过完整测试：

• ✅ BEFORE、AFTER、REPLACE、HEAD、TAIL全类型覆盖

• ✅ 构造函数 <init> 注入

• ✅ 包含 try-catch-finally 的复杂方法

• ✅ 参数含 long / double 的宽类型方法（静态→非静态、静态→静态）

• ✅ 同一方法的多个 REPLACE 冲突检测（仅执行优先级最高者）

• ✅ 无 pasms 仅有 asms 的配置

• ✅ Paper 1.21.11 / Java 21

已知限制（将在后续版本改进）：

• AROUND 注入暂未实现，使用时会降级为 REPLACE 并输出警告。

• 热加载功能尚不稳定，不建议生产环境使用。

• 不支持修改 native 方法或抽象方法。

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📦 如何构建 PASM 本体（仅框架维护者）

git clone https://github.com/laolizhennui/Plugin-ASM.git
cd Plugin-ASM
mvn clean package

生成产物：target/pasm-x.x.x.jar（这就是 Java Agent）

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🤝 参与贡献

PASM 还是一个年轻的项目，欢迎任何形式的贡献！
你可以：

• 提交 Issue：报告 Bug 或提议新功能

• Pull Request：修复代码、完善文档

• 分享你的使用案例

期待你的 Star ⭐ 和 Fork 🍴！

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📄 许可证

LGPL License

Copyright © 2026 laolizhennui

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最后——PASM 并不是要取代 Mixin，而是为 Paper 开发者提供一个更简单、更符合直觉的字节码注入选择。

如果你喜欢它，请告诉你的朋友；如果你遇到问题，请告诉我们。

Happy Coding! 🎮🔧

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English

Plugin ASM

PASM is a lightweight, Mixin‑style bytecode injection framework designed specifically for Paper / Folia server
environments.
It allows you to modify the bytecode of arbitrary classes at runtime using simple annotations—**no reflection, no
inheritance, zero performance penalty**.

🎯 Goal: Let Bukkit/Paper plugin developers implement hot‑patches, API enhancements, event interceptors, and more—*

*just by writing plain Java, without touching complex ASM internals**.

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✨ Core Features

| Feature | Description |
|————————————|——————————————————————————————————————————-|
| 🚀 Mixin‑style injection | @Pasm + @Inject define target class & method; the framework merges bytecode automatically. |
| 🩸 Full injection types | BEFORE / AFTER / REPLACE / HEAD / TAIL (AROUND falls back to REPLACE with a warning). |
| 🏗️ Constructor injection | Supports ; automatically inserted after super() call. |
| 🔥 Exception‑handler compatibility | Full replication of try‑catch‑finally blocks; correct label mapping. |
| 📏 Automatic wide‑type offset | long / double parameters are handled as double‑slots; no manual calculation of this offset. |
| ⚔️ Exclusive REPLACE | If a method has multiple REPLACE injections, only the one with highest priority is applied. |
| 🧩 ASM processor hooks | Declare asms array in pasm.json; implement PasmAsmProcessor interface to run custom bytecode operations before/after premain. |
| 📦 Plugin‑style scanning | Place pasm.json in your plugin JAR root; PASM automatically discovers all injection points. |

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📋 Environment Requirements

• Java 8–21

• Minecraft 1.0+

• Maven or Gradle(only needed when compiling your plugin)

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📥 Installation & Setup

1. Download the latest Plugin ASM from GitHub or Modrinth

1. Place it in your server root directory. The structure should look like this:

server
| -> paper-1.xx.x-xx.jar
| -> pasm-x.x.x.jar
| -> plugins
    | -> some-plugin.jar

1. Modify your startup command accordingly:

java -javaagent:pasm-x.x.x.jar -jar paper-1.xx.x-xx.jar

🛠️ Using Plugin ASM for Bytecode Injection

Refer to the Wiki for detailed usage and examples.

🧪 Testing & Compatibility

PASM has been fully tested in the following scenarios:

• ✅ BEFORE, AFTER, REPLACE, HEAD, TAIL–all types covered

• ✅ Constructor(<init>) injection

• ✅ Methods containing try‑catch‑finally blocks

• ✅ Methods with long / double parameters(static → non‑static, static → static)

• ✅ Conflict detection for multiple REPLACE injectors on the same method(only the highest priority runs)

• ✅ Configuration with asms only(no pasms)

• ✅ Paper 1.21.11 / Java 21

Known limitations(to be improved in future versions):

• AROUND injection is not yet implemented; using it will fall back to REPLACE and emit a warning.

• Hot‑reload is experimental and not recommended for production.

• Native methods and abstract methods cannot be modified.

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📦 How to Build PASM Itself(Framework Maintainers Only)

git clone https://github.com/laolizhennui/Plugin-ASM.git
cd Plugin-ASM
mvn clean package

Output artifact: target/pasm-x.x.x.jar–this is the Java Agent.

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🤝 Contributing

PASM is still a young project, and contributions of any form are welcome!
You can:

• Submit an issue: report bugs or suggest new features

• Pull Request: fix code, improve documentation

• Share your use cases

We look forward to your Star ⭐ and Fork 🍴!

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📄 License

LGPL License

Copyright © 2026 laolizhennui

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Finally–PASM is not meant to replace Mixin, but to offer Paper developers a simpler, more intuitive choice for

bytecode injection.

If you like it, tell your friends; if you encounter problems, tell us.

Happy Coding! 🎮🔧