mirror of https://github.com/japl-lang/japl.git
81 lines
3.0 KiB
Nim
81 lines
3.0 KiB
Nim
# Copyright 2020 Mattia Giambirtone
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#
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# Licensed under the Apache License, Version 2.0 (the "License");
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# you may not use this file except in compliance with the License.
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# You may obtain a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS,
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# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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# See the License for the specific language governing permissions and
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# limitations under the License.
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## This module takes chunks of bytecode, and prints their contents to the
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## screen.
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import ../meta/opcode
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import ../types/baseObject
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import ../types/methods
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import ../types/arraylist
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import strformat
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proc simpleInstruction(name: string, index: int): int =
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echo &"DEBUG - VM:\tInstruction -> {name}"
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return index + 1
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proc byteInstruction(name: string, chunk: Chunk, offset: int): int =
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var slot = chunk.code[offset + 1]
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echo &"DEBUG - VM:\tInstruction -> {name}, points to slot {slot}"
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return offset + 2
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proc constantInstruction(name: string, chunk: Chunk, offset: int): int =
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# Rebuild the index
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var constantArray: array[3, uint8] = [chunk.code[offset + 1], chunk.code[offset + 2], chunk.code[offset + 3]]
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var constant: int
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copyMem(constant.addr, constantArray.addr, sizeof(constantArray))
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echo &"DEBUG - VM:\tInstruction -> {name}, points to slot {constant}"
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let obj = chunk.consts[constant]
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echo &"DEBUG - VM:\tOperand -> {stringify(obj)}\nDEBUG - VM:\tValue kind -> {obj.kind}"
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return offset + 4
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proc jumpInstruction(name: string, chunk: Chunk, offset: int): int =
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var jumpArray: array[2, uint8] = [chunk.code[offset + 1], chunk.code[offset + 2]]
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var jump: int
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copyMem(jump.addr, jumpArray.addr, sizeof(uint16))
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echo &"DEBUG - VM:\tInstruction -> {name}\nDEBUG - VM:\tJump size -> {jump}"
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return offset + 3
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proc disassembleInstruction*(chunk: Chunk, offset: int): int =
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## Takes one bytecode instruction and prints it
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echo &"DEBUG - VM:\tOffset: {offset}\nDEBUG - VM:\tLine: {chunk.lines[offset]}"
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var opcode = OpCode(chunk.code[offset])
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case opcode:
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of simpleInstructions:
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result = simpleInstruction($opcode, offset)
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of constantInstructions:
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result = constantInstruction($opcode, chunk, offset)
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of byteInstructions:
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result = byteInstruction($opcode, chunk, offset)
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of jumpInstructions:
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result = jumpInstruction($opcode, chunk, offset)
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else:
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echo &"DEBUG - Unknown opcode {opcode} at index {offset}"
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result = offset + 1
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proc disassembleChunk*(chunk: Chunk, name: string) =
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## Takes a chunk of bytecode, and prints it
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echo &"==== JAPL VM Debugger - Chunk '{name}' ====\n"
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var index = 0
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while index < chunk.code.len:
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index = disassembleInstruction(chunk, index)
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echo &"==== Debug session ended - Chunk '{name}' ===="
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