prog8/python-prototype/tinyvm/parse.py
Irmen de Jong 6d343bd75d moved
2018-09-30 23:13:35 +02:00

219 lines
7.3 KiB
Python

"""
Simplistic 8/16 bit Virtual Machine to execute a stack based instruction language.
Parser for the simplistic text based program representation
Written by Irmen de Jong (irmen@razorvine.net) - license: GNU GPL 3.0
"""
import array
from typing import Optional, List, Tuple, Dict, Any
from .program import Opcode, Program, Block, Variable, Instruction, Value
from .vm import StackValueType
from .core import DataType
class ParseError(Exception):
pass
class Parser:
def __init__(self, source: str) -> None:
self.source = source.splitlines()
self.lineno = 0
def parse(self) -> Program:
blocklist = []
while self.lineno < len(self.source):
self.skip_empty()
blocklist.append(self.parse_block(None))
return Program(blocklist)
def skip_empty(self) -> None:
while self.lineno < len(self.source):
line = self.source[self.lineno].strip()
if not line or line.startswith(";"):
self.lineno += 1
else:
break
def parse_block(self, parent: Optional[Block]) -> Block:
assert self.source[self.lineno].startswith("%block")
blockname = self.source[self.lineno].split()[1]
variables = [] # type: List[Variable]
instructions = [] # type: List[Instruction]
labels = {} # type: Dict[str, Instruction]
self.lineno += 1
self.skip_empty()
if self.source[self.lineno].startswith("%vardefs"):
variables = self.parse_vardefs()
self.skip_empty()
if self.source[self.lineno].startswith("%instructions"):
instructions, labels = self.parse_instructions()
block = Block(blockname, parent, variables, instructions, labels, [])
self.skip_empty()
if self.source[self.lineno].startswith("%subblocks"):
block.blocks = self.parse_subblocks(block)
self.skip_empty()
assert self.source[self.lineno].startswith("%end_block")
self.lineno += 1
return block
def get_array_type(self, dtype: DataType) -> str:
return {
DataType.ARRAY_BYTE: 'B',
DataType.ARRAY_SBYTE: 'b',
DataType.ARRAY_WORD: 'H',
DataType.ARRAY_SWORD: 'h',
DataType.MATRIX_BYTE: 'B',
DataType.MATRIX_SBYTE: 'b'
}[dtype]
def parse_vardefs(self) -> List[Variable]:
assert self.source[self.lineno].startswith("%vardefs")
self.lineno += 1
variables = []
while not self.source[self.lineno].startswith("%"):
vartype, datatype, name, argstr = self.source[self.lineno].split(maxsplit=3)
dtype = DataType[datatype.upper()]
length = height = 0
value = None # type: StackValueType
if dtype in (DataType.BYTE, DataType.WORD, DataType.SBYTE, DataType.SWORD):
value = Value(dtype, int(argstr))
elif dtype == DataType.FLOAT:
value = Value(dtype, float(argstr))
elif dtype == DataType.BOOL:
value = Value(dtype, argstr.lower() not in ("0", "false"))
elif dtype in (DataType.ARRAY_BYTE, DataType.ARRAY_SBYTE, DataType.ARRAY_WORD, DataType.ARRAY_SWORD):
args = argstr.split(maxsplit=1)
length = int(args[0])
valuestr = args[1]
typecode = self.get_array_type(dtype)
if valuestr[0] == '[' and valuestr[-1] == ']':
value = Value(dtype, array.array(typecode, [int(v) for v in valuestr[1:-1].split()]))
else:
value = Value(dtype, array.array(typecode, [int(valuestr)]) * length)
elif dtype in (DataType.MATRIX_BYTE, DataType.MATRIX_SBYTE):
args = argstr.split(maxsplit=2)
length = int(args[0])
height = int(args[1])
valuestr = args[2]
typecode = self.get_array_type(dtype)
if valuestr[0] == '[' and valuestr[-1] == ']':
value = Value(dtype, array.array(typecode, [int(v) for v in valuestr[1:-1].split()]))
else:
value = Value(dtype, array.array(typecode, [int(valuestr)] * length * height))
else:
raise TypeError("weird dtype", dtype)
variables.append(Variable(name, dtype, value, vartype == "const"))
self.lineno += 1
self.skip_empty()
assert self.source[self.lineno].startswith("%end_vardefs")
self.lineno += 1
return variables
def parse_instructions(self) -> Tuple[List[Instruction], Dict[str, Instruction]]:
assert self.source[self.lineno].startswith("%instructions")
self.lineno += 1
instructions = []
labels = {} # type: Dict[str, Instruction]
def parse_instruction(ln: str) -> Instruction:
parts = ln.split(maxsplit=1)
opcode = Opcode[parts[0].upper()]
args = [] # type: List[Any]
if len(parts) == 2:
args = parts[1].split()
else:
args = []
if opcode in (Opcode.CALL, Opcode.RETURN):
args[0] = int(args[0]) # the number of arguments/parameters
return Instruction(opcode, args, None, None)
while not self.source[self.lineno].startswith("%"):
line = self.source[self.lineno].strip()
if line.endswith(":"):
# a label that points to an instruction
label = line[:-1].rstrip()
self.lineno += 1
line = self.source[self.lineno]
next_instruction = parse_instruction(line)
labels[label] = next_instruction
instructions.append(next_instruction)
self.lineno += 1
else:
instructions.append(parse_instruction(line))
self.lineno += 1
self.skip_empty()
assert self.source[self.lineno].startswith("%end_instructions")
self.lineno += 1
return instructions, labels
def parse_subblocks(self, parent: Block) -> List[Block]:
assert self.source[self.lineno].startswith("%subblocks")
self.lineno += 1
blocks = []
while not self.source[self.lineno].startswith("%end_subblocks"):
self.lineno += 1
while True:
if self.source[self.lineno].startswith("%block"):
blocks.append(self.parse_block(parent))
else:
break
self.skip_empty()
self.lineno += 1
return blocks
if __name__ == "__main__":
src = """
%block b1
%vardefs
var byte v1 0
var word w1 2222
var sword ws -3333
const byte c1 99
const sword cws -5444
var array_byte ba 10 33
var array_byte ba2 10 [1 2 3 4 5 6 7 8 9 10]
var matrix_byte mxb 4 5 33
var matrix_byte mxb2 3 2 [1 2 3 4 5 6]
%end_vardefs
%instructions
nop
nop
l1:
nop
push c1
push2 c1 cws
call 3 l1
return 2
%end_instructions
%subblocks
%block b2
%vardefs
%end_vardefs
%end_block ; b2
%end_subblocks
%end_block ;b1
%block b3
%vardefs
%end_vardefs
%instructions
nop
nop
l1:
nop
return 99
%end_instructions
%end_block ; b3
"""
parser = Parser(src)
program = parser.parse()