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What does "try {" compile to in machine instructions or any intermediate language? I always thought of it as an annotation on a scope but now I'm curious. Edit

What does "try {" compile to in machine instructions or any intermediate language? I always thought of it as an annotation on a scope but now I'm curious. Edit- from reading https://stackoverflow.com/questions/25007427/how-are-exceptions-caught-and-dealt-with-at-the-low-assembly-level https://stackoverflow.com/questions/25007427/how-are-excepti... it appears my suspicion was correct. try{ is effectively an annotation that has no impact on the sequence of instructions you are authoring. So it's surprising to me that it breaks the this/super first rule. OTOH it seems to me there should always be a rule to not allow execution paths that never call super nor this, and since try could break that one I'd always be leery of using it in constructors.

tsimionescu 4y ago
The JEP itself explains the reason why this limitation exists: > try { } Blocks > The restriction that super() and this() may not appear inside a try { } block comes from the JVM itself, and is due to how StackMaps are represented. The logic is that when a superclass constructor throws an exception, the new instance on the stack is neither fully uninitialized nor fully initialized, so it should be considered unusable, and therefore such a constructor must never return. However, the JVM doesn't allow the bytecode to discard the unusable instance and throw another exception; instead, it doesn't allow it to exist on the stack at all. The net effect is that constructors can't catch exceptions thrown by superclass initialization, even if rethrown. [emphasis mine]