japl/src/util/debug.nim

117 lines
3.8 KiB
Nim

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