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Implement a Minimal JVM That Runs Hello World

hard3/8

Parse a .class File Format Manually Understand JVM Class Loading: Bootstrap, Platform, Application

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Compiler

2.0s Limit 256MB

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Implementation

Write a C program that implements a minimal JVM interpreter executing a Hello World bytecode sequence.

Requirements:

Define operand stack and local variable arrays
Implement a fetch-decode-execute loop
Support at least these opcodes: iconst, istore, iload, iadd, getstatic, ldc, invokevirtual, return
Execute a hardcoded bytecode sequence that conceptually prints Hello World
Print an execution trace showing PC, opcode name, and stack state after each instruction
Output must contain: mini JVM, Hello World, operand stack, and execute

Why This Matters

iconst, iload, iadd, and invokevirtual are the real opcodes defined in the JVM Specification's instruction set, and the fetch-decode-execute loop you're writing is a miniature version of what HotSpot's bytecode interpreter (the C++ templateInterpreter) does before a method gets hot enough for JIT compilation. This is the same exercise behind small educational JVMs like avian and the various 'write your own JVM' community projects.

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main.c

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