mirror of
https://github.com/irmen/prog8.git
synced 2024-12-04 19:50:19 +00:00
286 lines
11 KiB
Python
286 lines
11 KiB
Python
"""
|
|
Programming Language for 6502/6510 microprocessors
|
|
This is the expression parser/evaluator.
|
|
|
|
Written by Irmen de Jong (irmen@razorvine.net)
|
|
License: GNU GPL 3.0, see LICENSE
|
|
"""
|
|
|
|
import ast
|
|
import attr
|
|
from typing import Union, Optional, List, Tuple, Any
|
|
from .symbols import FLOAT_MAX_POSITIVE, FLOAT_MAX_NEGATIVE, SourceRef, SymbolTable, SymbolError, PrimitiveType
|
|
|
|
|
|
class ParseError(Exception):
|
|
def __init__(self, message: str, sourcetext: str, sourceref: SourceRef) -> None:
|
|
self.sourceref = sourceref
|
|
self.msg = message
|
|
self.sourcetext = sourcetext
|
|
|
|
def __str__(self):
|
|
return "{} {:s}".format(self.sourceref, self.msg)
|
|
|
|
|
|
class SourceLine:
|
|
def __init__(self, text: str, sourceref: SourceRef) -> None:
|
|
self.sourceref = sourceref
|
|
self.text = text.strip()
|
|
|
|
def to_error(self, message: str) -> ParseError:
|
|
return ParseError(message, self.text, self.sourceref)
|
|
|
|
def preprocess(self) -> str:
|
|
# transforms the source text into valid Python syntax by bending some things, so ast can parse it.
|
|
# $d020 -> 0xd020
|
|
# %101001 -> 0xb101001
|
|
# #something -> __ptr@something (matmult operator)
|
|
text = ""
|
|
quotes_stack = ""
|
|
characters = enumerate(self.text + " ")
|
|
for i, c in characters:
|
|
if c in ("'", '"'):
|
|
if quotes_stack and quotes_stack[-1] == c:
|
|
quotes_stack = quotes_stack[:-1]
|
|
else:
|
|
quotes_stack += c
|
|
text += c
|
|
continue
|
|
if not quotes_stack:
|
|
if c == '%' and self.text[i + 1] in "01":
|
|
text += "0b"
|
|
continue
|
|
if c == '$' and self.text[i + 1] in "0123456789abcdefABCDEF":
|
|
text += "0x"
|
|
continue
|
|
if c == '&':
|
|
if i > 0:
|
|
text += " "
|
|
text += "__ptr@"
|
|
continue
|
|
text += c
|
|
return text
|
|
|
|
|
|
def parse_arguments(text: str, sourceref: SourceRef) -> List[Tuple[str, PrimitiveType]]:
|
|
src = SourceLine(text, sourceref)
|
|
text = src.preprocess()
|
|
try:
|
|
nodes = ast.parse("__func({:s})".format(text), sourceref.file, "eval")
|
|
except SyntaxError as x:
|
|
raise src.to_error(str(x))
|
|
|
|
args = [] # type: List[Tuple[str, Any]]
|
|
if isinstance(nodes, ast.Expression):
|
|
for arg in nodes.body.args:
|
|
reprvalue = astnode_to_repr(arg)
|
|
args.append((None, reprvalue))
|
|
for kwarg in nodes.body.keywords:
|
|
reprvalue = astnode_to_repr(kwarg.value)
|
|
args.append((kwarg.arg, reprvalue))
|
|
return args
|
|
else:
|
|
raise TypeError("ast.Expression expected")
|
|
|
|
|
|
def parse_expr_as_comparison(text: str, sourceref: SourceRef) -> Tuple[str, str, str]:
|
|
src = SourceLine(text, sourceref)
|
|
text = src.preprocess()
|
|
try:
|
|
node = ast.parse(text, sourceref.file, mode="eval")
|
|
except SyntaxError as x:
|
|
raise src.to_error(str(x))
|
|
if not isinstance(node, ast.Expression):
|
|
raise TypeError("ast.Expression expected")
|
|
if isinstance(node.body, ast.Compare):
|
|
if len(node.body.ops) != 1:
|
|
raise src.to_error("only one comparison operator at a time is supported")
|
|
operator = {
|
|
"Eq": "==",
|
|
"NotEq": "!=",
|
|
"Lt": "<",
|
|
"LtE": "<=",
|
|
"Gt": ">",
|
|
"GtE": ">=",
|
|
"Is": None,
|
|
"IsNot": None,
|
|
"In": None,
|
|
"NotIn": None
|
|
}[node.body.ops[0].__class__.__name__]
|
|
if not operator:
|
|
raise src.to_error("unsupported comparison operator")
|
|
left = text[node.body.left.col_offset:node.body.comparators[0].col_offset].rstrip()[:-len(operator)]
|
|
right = text[node.body.comparators[0].col_offset:]
|
|
return left.strip(), operator, right.strip()
|
|
left = astnode_to_repr(node.body)
|
|
return left, "", ""
|
|
|
|
|
|
def parse_expr_as_int(text: str, context: Optional[SymbolTable], ppcontext: Optional[SymbolTable], sourceref: SourceRef, *,
|
|
minimum: int=0, maximum: int=0xffff) -> int:
|
|
result = parse_expr_as_primitive(text, context, ppcontext, sourceref, minimum=minimum, maximum=maximum)
|
|
if isinstance(result, int):
|
|
return result
|
|
src = SourceLine(text, sourceref)
|
|
raise src.to_error("int expected, not " + type(result).__name__)
|
|
|
|
|
|
def parse_expr_as_number(text: str, context: Optional[SymbolTable], ppcontext: Optional[SymbolTable], sourceref: SourceRef, *,
|
|
minimum: float=FLOAT_MAX_NEGATIVE, maximum: float=FLOAT_MAX_POSITIVE) -> Union[int, float]:
|
|
result = parse_expr_as_primitive(text, context, ppcontext, sourceref, minimum=minimum, maximum=maximum)
|
|
if isinstance(result, (int, float)):
|
|
return result
|
|
src = SourceLine(text, sourceref)
|
|
raise src.to_error("int or float expected, not " + type(result).__name__)
|
|
|
|
|
|
def parse_expr_as_string(text: str, context: Optional[SymbolTable], ppcontext: Optional[SymbolTable], sourceref: SourceRef) -> str:
|
|
result = parse_expr_as_primitive(text, context, ppcontext, sourceref)
|
|
if isinstance(result, str):
|
|
return result
|
|
src = SourceLine(text, sourceref)
|
|
raise src.to_error("string expected, not " + type(result).__name__)
|
|
|
|
|
|
def parse_expr_as_primitive(text: str, context: Optional[SymbolTable], ppcontext: Optional[SymbolTable], sourceref: SourceRef, *,
|
|
minimum: float = FLOAT_MAX_NEGATIVE, maximum: float = FLOAT_MAX_POSITIVE) -> PrimitiveType:
|
|
src = SourceLine(text, sourceref)
|
|
text = src.preprocess()
|
|
try:
|
|
node = ast.parse(text, sourceref.file, mode="eval")
|
|
except SyntaxError as x:
|
|
raise src.to_error(str(x))
|
|
if isinstance(node, ast.Expression):
|
|
result = ExpressionTransformer(src, context, ppcontext).evaluate(node)
|
|
else:
|
|
raise TypeError("ast.Expression expected")
|
|
if isinstance(result, bool):
|
|
return int(result)
|
|
if isinstance(result, (int, float)):
|
|
if minimum <= result <= maximum:
|
|
return result
|
|
raise src.to_error("number too large")
|
|
if isinstance(result, str):
|
|
return result
|
|
raise src.to_error("int or float or string expected, not " + type(result).__name__)
|
|
|
|
|
|
class EvaluatingTransformer(ast.NodeTransformer):
|
|
def __init__(self, src: SourceLine, context: SymbolTable, ppcontext: SymbolTable) -> None:
|
|
super().__init__()
|
|
self.src = src
|
|
self.context = context
|
|
self.ppcontext = ppcontext
|
|
|
|
def error(self, message: str, column: int=0) -> ParseError:
|
|
ref = attr.evolve(self.src.sourceref, column=column)
|
|
return ParseError(message, self.src.text, ref)
|
|
|
|
def evaluate(self, node: ast.Expression) -> PrimitiveType:
|
|
node = self.visit(node)
|
|
code = compile(node, self.src.sourceref.file, mode="eval")
|
|
if self.context:
|
|
globals = None
|
|
locals = self.context.as_eval_dict(self.ppcontext)
|
|
else:
|
|
globals = {"__builtins__": {}}
|
|
locals = None
|
|
try:
|
|
result = eval(code, globals, locals) # XXX unsafe...
|
|
except Exception as x:
|
|
raise self.src.to_error(str(x)) from x
|
|
else:
|
|
if type(result) is bool:
|
|
return int(result)
|
|
return result
|
|
|
|
|
|
class ExpressionTransformer(EvaluatingTransformer):
|
|
def _dotted_name_from_attr(self, node: ast.Attribute) -> str:
|
|
if isinstance(node.value, ast.Name):
|
|
return node.value.id + '.' + node.attr
|
|
if isinstance(node.value, ast.Attribute):
|
|
return self._dotted_name_from_attr(node.value) + '.' + node.attr
|
|
raise self.error("dotted name error")
|
|
|
|
def visit_Name(self, node: ast.Name):
|
|
# convert true/false names to True/False constants
|
|
if node.id == "true":
|
|
return ast.copy_location(ast.NameConstant(True), node)
|
|
if node.id == "false":
|
|
return ast.copy_location(ast.NameConstant(False), node)
|
|
return node
|
|
|
|
def visit_UnaryOp(self, node):
|
|
if isinstance(node.operand, ast.Num):
|
|
if isinstance(node.op, ast.USub):
|
|
node = self.generic_visit(node)
|
|
return ast.copy_location(ast.Num(-node.operand.n), node)
|
|
if isinstance(node.op, ast.UAdd):
|
|
node = self.generic_visit(node)
|
|
return ast.copy_location(ast.Num(node.operand.n), node)
|
|
if isinstance(node.op, ast.Invert):
|
|
if isinstance(node.operand, ast.Num):
|
|
node = self.generic_visit(node)
|
|
return ast.copy_location(ast.Num(~node.operand.n), node)
|
|
else:
|
|
raise self.error("can only bitwise invert a number")
|
|
raise self.error("expected unary + or - or ~")
|
|
elif isinstance(node.operand, ast.UnaryOp):
|
|
# nested unary ops, for instance: "~-2" = invert(minus(2))
|
|
node = self.generic_visit(node)
|
|
return self.visit_UnaryOp(node)
|
|
else:
|
|
print(node.operand)
|
|
raise self.error("expected constant numeric operand for unary operator")
|
|
|
|
def visit_BinOp(self, node):
|
|
node = self.generic_visit(node)
|
|
if isinstance(node.op, ast.MatMult):
|
|
if isinstance(node.left, ast.Name) and node.left.id == "__ptr":
|
|
if isinstance(node.right, ast.Attribute):
|
|
symbolname = self._dotted_name_from_attr(node.right)
|
|
elif isinstance(node.right, ast.Name):
|
|
symbolname = node.right.id
|
|
else:
|
|
raise self.error("can only take address of a named variable")
|
|
try:
|
|
address = self.context.get_address(symbolname)
|
|
except SymbolError as x:
|
|
raise self.error(str(x))
|
|
else:
|
|
return ast.copy_location(ast.Num(address), node)
|
|
else:
|
|
raise self.error("invalid MatMult/Pointer node in AST")
|
|
return node
|
|
|
|
|
|
def astnode_to_repr(node: ast.AST) -> str:
|
|
if isinstance(node, ast.Name):
|
|
return node.id
|
|
if isinstance(node, ast.Num):
|
|
return repr(node.n)
|
|
if isinstance(node, ast.Str):
|
|
return repr(node.s)
|
|
if isinstance(node, ast.BinOp):
|
|
if node.left.id == "__ptr" and isinstance(node.op, ast.MatMult): # type: ignore
|
|
return '&' + astnode_to_repr(node.right)
|
|
else:
|
|
print("error", ast.dump(node))
|
|
raise TypeError("invalid arg ast node type", node)
|
|
if isinstance(node, ast.Attribute):
|
|
return astnode_to_repr(node.value) + "." + node.attr
|
|
if isinstance(node, ast.UnaryOp):
|
|
if isinstance(node.op, ast.USub):
|
|
return "-" + astnode_to_repr(node.operand)
|
|
if isinstance(node.op, ast.UAdd):
|
|
return "+" + astnode_to_repr(node.operand)
|
|
if isinstance(node.op, ast.Invert):
|
|
return "~" + astnode_to_repr(node.operand)
|
|
if isinstance(node.op, ast.Not):
|
|
return "not " + astnode_to_repr(node.operand)
|
|
if isinstance(node, ast.List):
|
|
# indirect values get turned into a list...
|
|
return "[" + ",".join(astnode_to_repr(elt) for elt in node.elts) + "]"
|
|
raise TypeError("invalid arg ast node type", node)
|