Detect `InvocationTargetException` when initializing global variables outside setup

Created by: mglst

Current Behavior

Whilst coding I ran into RuntimeException: java.lang.reflect.InvocationTargetException. It only took a google search to find another user on the Processing Foundation Forum with the same issue, and a well explained fix: https://discourse.processing.org/t/just-starting-to-code-and-code-returns-java-lang-reflect-invocationtargetexception-error/14615/2.
There are many weird exception catching things that the Processing IDE already does to mitigate the most common of these Processing-specific oddities. The post that I link to has 2.1k, so I can safely say I'm neither the first nor last person to run into this. I find that the way Java errors are thrown is quite confusing. For instance, it complains about code at a specified line, but this refers to the 'java' file rather than the 'pde' file that I'm working on - this is not obvious and can be a source for more confusion still if I go looking for a bug at the wrong place in my code ("what even are .java files? and what do you mean I have to 'export' as application to get a glimpse at it?")

Steps to Reproduce

1. see code from https://discourse.processing.org/t/just-starting-to-code-and-code-returns-java-lang-reflect-invocationtargetexception-error/14615

Your Environment

• Processing version: 4.0a5
• Operating System and OS version: macOS 12.0B5

Solutions

I would like the IDE to detect when making such errors and warn me that I'm likely doing something wrong by defining initialising global variables outside of setup - especially since this seems like something which is fine for ints, booleans, bytes, ... (as I understand, all primitives - although confusingly also Strings)
The fact that this is a RunTime error makes me believe that this might be a tricky suggestion to implement, but I'd hope that it would be a useful enough feature to be worth the cost

从链接的 Processing Forum 复现案例以及 IDE 现有的异常处理行为入手。确定在 setup 之外初始化全局变量为何会产生 InvocationTargetException，然后定义 IDE 应如何检测到这一点，并显示指向用户 PDE 代码的警告。完成的标准是：所报告的案例能够获得清晰且针对 Processing 的诊断。