prog8/il65/plyparse.py
2018-01-21 18:17:39 +01:00

1573 lines
54 KiB
Python

"""
Programming Language for 6502/6510 microprocessors, codename 'Sick'
This is the parser of the IL65 code, that generates a parse tree.
Written by Irmen de Jong (irmen@razorvine.net) - license: GNU GPL 3.0
"""
import math
import builtins
import inspect
import enum
from collections import defaultdict
from typing import Union, Generator, Tuple, Sequence, List, Optional, Dict, Any, no_type_check
import attr
from ply.yacc import yacc
from .plylex import SourceRef, tokens, lexer, find_tok_column, print_warning
from .datatypes import DataType, VarType, REGISTER_SYMBOLS, REGISTER_BYTES, REGISTER_WORDS, \
char_to_bytevalue, FLOAT_MAX_NEGATIVE, FLOAT_MAX_POSITIVE
class ProgramFormat(enum.Enum):
RAW = "raw"
PRG = "prg"
BASIC = "basicprg"
class ZpOptions(enum.Enum):
NOCLOBBER = "noclobber"
CLOBBER = "clobber"
CLOBBER_RESTORE = "clobber_restore"
math_functions = {name: func for name, func in vars(math).items() if inspect.isbuiltin(func)}
builtin_functions = {name: func for name, func in vars(builtins).items() if inspect.isbuiltin(func)}
class ParseError(Exception):
def __init__(self, message: str, sourceref: SourceRef) -> None:
super().__init__(message)
self.sourceref = sourceref
# @todo chain attribute, a list of other exceptions, so we can have more than 1 error at a time.
def __str__(self):
return "{} {:s}".format(self.sourceref, self.args[0])
class ExpressionEvaluationError(ParseError):
pass
class UndefinedSymbolError(LookupError):
pass
start = "start"
@attr.s(cmp=False, slots=True, frozen=False, repr=False)
class AstNode:
# all ast nodes have: sourceref, parent, and nodes (=list of zero or more sub-nodes)
sourceref = attr.ib(type=SourceRef)
parent = attr.ib(init=False, default=None) # will be hooked up later
nodes = attr.ib(type=list, init=False, default=attr.Factory(list)) # type: List['AstNode']
@property
def lineref(self) -> str:
return "src l. " + str(self.sourceref.line)
def my_scope(self) -> 'Scope':
# returns the closest Scope in the ancestry of this node, or raises LookupError if no scope is found
scope = self.parent
while scope:
if isinstance(scope, Scope):
return scope
scope = scope.parent
raise LookupError("no scope found in node ancestry", self)
def all_nodes(self, *nodetypes: type) -> Generator['AstNode', None, None]:
nodetypes = nodetypes or (AstNode, )
for node in list(self.nodes):
if isinstance(node, nodetypes): # type: ignore
yield node
for node in self.nodes:
if isinstance(node, AstNode):
yield from node.all_nodes(*nodetypes)
def remove_node(self, node: 'AstNode') -> None:
self.nodes.remove(node)
def replace_node(self, oldnode: 'AstNode', newnode: 'AstNode') -> None:
assert isinstance(newnode, AstNode)
idx = self.nodes.index(oldnode)
self.nodes[idx] = newnode
def add_node(self, newnode: 'AstNode', index: int = None) -> None:
assert isinstance(newnode, AstNode)
if index is None:
self.nodes.append(newnode)
else:
self.nodes.insert(index, newnode)
@attr.s(cmp=False)
class Directive(AstNode):
name = attr.ib(type=str)
args = attr.ib(type=list, default=attr.Factory(list))
# no subnodes.
@attr.s(cmp=False, slots=True, repr=False)
class Scope(AstNode):
# has zero or more subnodes
level = attr.ib(type=str, init=True)
nodes = attr.ib(type=list, init=True) # requires nodes in __init__
symbols = attr.ib(init=False)
name = attr.ib(init=False) # will be set by enclosing block, or subroutine etc.
parent_scope = attr.ib(init=False, default=None) # will be wired up later
_save_registers = attr.ib(type=bool, default=None, init=False)
@property
def save_registers(self) -> bool:
if self._save_registers is not None:
return self._save_registers
try:
return self.my_scope().save_registers
except LookupError:
return False
@save_registers.setter
def save_registers(self, save: bool) -> None:
self._save_registers = save
def __attrs_post_init__(self):
# populate the symbol table for this scope for fast lookups via scope.lookup("name") or scope.lookup("dotted.name")
self.symbols = {}
for node in self.nodes:
assert isinstance(node, AstNode)
self._populate_symboltable(node)
def _populate_symboltable(self, node: AstNode) -> None:
if isinstance(node, (Label, VarDef)):
if node.name in self.symbols:
raise ParseError("symbol already defined at {}".format(self.symbols[node.name].sourceref), node.sourceref)
self.symbols[node.name] = node
if isinstance(node, Subroutine):
if node.name in self.symbols:
raise ParseError("symbol already defined at {}".format(self.symbols[node.name].sourceref), node.sourceref)
self.symbols[node.name] = node
if node.scope:
node.scope.parent_scope = self
if isinstance(node, Block):
if node.name:
if node.name != "ZP" and node.name in self.symbols:
raise ParseError("symbol already defined at {}".format(self.symbols[node.name].sourceref), node.sourceref)
self.symbols[node.name] = node
node.scope.parent_scope = self
def lookup(self, name: str) -> AstNode:
assert isinstance(name, str)
if '.' in name:
# look up the dotted name starting from the topmost scope
scope = self
while scope.parent_scope:
scope = scope.parent_scope
for namepart in name.split('.'):
if isinstance(scope, (Block, Subroutine)):
scope = scope.scope
if not isinstance(scope, Scope):
raise UndefinedSymbolError("undefined symbol: " + name)
scope = scope.symbols.get(namepart, None)
if not scope:
raise UndefinedSymbolError("undefined symbol: " + name)
return scope
else:
# find the name in nested scope hierarchy
if name in self.symbols:
return self.symbols[name]
if self.parent_scope:
return self.parent_scope.lookup(name)
raise UndefinedSymbolError("undefined symbol: " + name)
def remove_node(self, node: AstNode) -> None:
if hasattr(node, "name"):
try:
del self.symbols[node.name] # type: ignore
except KeyError:
pass
super().remove_node(node)
def replace_node(self, oldnode: AstNode, newnode: AstNode) -> None:
if hasattr(oldnode, "name"):
del self.symbols[oldnode.name] # type: ignore
super().replace_node(oldnode, newnode)
def add_node(self, newnode: AstNode, index: int=None) -> None:
super().add_node(newnode, index)
self._populate_symboltable(newnode)
def validate_address(obj: AstNode, attrib: attr.Attribute, value: Optional[int]) -> None:
if value is None:
return
if isinstance(obj, Block) and obj.name == "ZP":
raise ParseError("zeropage block cannot have custom start {:s}".format(attrib.name), obj.sourceref)
if value < 0x0200 or value > 0xffff:
raise ParseError("invalid {:s} (must be from $0200 to $ffff)".format(attrib.name), obj.sourceref)
def dimensions_validator(obj: 'DatatypeNode', attrib: attr.Attribute, value: List[int]) -> None:
if not value:
return
dt = obj.to_enum()
if value and dt not in (DataType.MATRIX, DataType.WORDARRAY, DataType.BYTEARRAY):
raise ParseError("cannot use a dimension for this datatype", obj.sourceref)
if dt == DataType.WORDARRAY or dt == DataType.BYTEARRAY:
if len(value) == 1:
if value[0] <= 0 or value[0] > 256:
raise ParseError("array length must be 1..256", obj.sourceref)
else:
raise ParseError("array must have only one dimension", obj.sourceref)
if dt == DataType.MATRIX:
if len(value) < 2 or len(value) > 3:
raise ParseError("matrix must have two dimensions, with optional interleave", obj.sourceref)
if len(value) == 3:
if value[2] < 1 or value[2] > 256:
raise ParseError("matrix interleave must be 1..256", obj.sourceref)
if value[0] < 0 or value[0] > 128 or value[1] < 0 or value[1] > 128:
raise ParseError("matrix rows and columns must be 1..128", obj.sourceref)
@attr.s(cmp=False, repr=False)
class Block(AstNode):
# has one subnode: the Scope.
name = attr.ib(type=str, default=None)
address = attr.ib(type=int, default=None, validator=validate_address)
_unnamed_block_labels = {} # type: Dict[Block, str]
@property
def scope(self) -> Scope:
return self.nodes[0] if self.nodes else None # type: ignore
@scope.setter
def scope(self, scope: Scope) -> None:
assert isinstance(scope, Scope)
self.nodes.clear()
self.nodes.append(scope)
scope.name = self.name
@property
def label(self) -> str:
if self.name:
return self.name
if self in self._unnamed_block_labels:
return self._unnamed_block_labels[self]
label = "il65_block_{:d}".format(len(self._unnamed_block_labels))
self._unnamed_block_labels[self] = label
return label
@attr.s(cmp=False, repr=False)
class Module(AstNode):
# has one subnode: the Scope.
name = attr.ib(type=str) # filename
subroutine_usage = attr.ib(type=defaultdict, init=False, default=attr.Factory(lambda: defaultdict(set))) # will be populated later
format = attr.ib(type=ProgramFormat, init=False, default=ProgramFormat.PRG) # can be set via directive
address = attr.ib(type=int, init=False, default=0xc000, validator=validate_address) # can be set via directive
zp_options = attr.ib(type=ZpOptions, init=False, default=ZpOptions.NOCLOBBER) # can be set via directive
@property
def scope(self) -> Scope:
return self.nodes[0] if self.nodes else None # type: ignore
@no_type_check
def zeropage(self) -> Optional[Block]:
# return the zeropage block (if defined)
first_block = next(self.scope.all_nodes(Block))
if first_block.name == "ZP":
return first_block
return None
@no_type_check
def main(self) -> Optional[Block]:
# return the 'main' block (if defined)
for block in self.scope.all_nodes(Block):
if block.name == "main":
return block
return None
@attr.s(cmp=False)
class Label(AstNode):
name = attr.ib(type=str)
# no subnodes.
@attr.s(cmp=False, slots=True)
class Register(AstNode):
name = attr.ib(type=str, validator=attr.validators.in_(REGISTER_SYMBOLS))
datatype = attr.ib(type=DataType, init=False)
# no subnodes.
def __attrs_post_init__(self):
if self.name in REGISTER_BYTES:
self.datatype = DataType.BYTE
elif self.name in REGISTER_WORDS:
self.datatype = DataType.WORD
else:
self.datatype = None # register 'SC' etc.
def __hash__(self) -> int:
return hash(self.name)
def __eq__(self, other) -> bool:
if not isinstance(other, Register):
return NotImplemented
return self.name == other.name
def __lt__(self, other) -> bool:
if not isinstance(other, Register):
return NotImplemented
return self.name < other.name
@attr.s(cmp=False)
class PreserveRegs(AstNode):
registers = attr.ib(type=str)
# no subnodes.
@attr.s(cmp=False)
class TargetRegisters(AstNode):
# subnodes is is a list of 1 or more registers.
# In it's multiple-register form it is only used to be able to parse
# the result of a subroutine call such as A,X = sub().
# It will be replaced by a regular Register node if it contains just one register.
pass
@attr.s(cmp=False, repr=False)
class InlineAssembly(AstNode):
# no subnodes.
assembly = attr.ib(type=str)
@attr.s(cmp=False, slots=True)
class DatatypeNode(AstNode):
# no subnodes.
name = attr.ib(type=str)
dimensions = attr.ib(type=list, default=None, validator=dimensions_validator) # if set, 1 or more dimensions (ints)
def to_enum(self):
return {
"byte": DataType.BYTE,
"word": DataType.WORD,
"float": DataType.FLOAT,
"text": DataType.STRING,
"ptext": DataType.STRING_P,
"stext": DataType.STRING_S,
"pstext": DataType.STRING_PS,
"matrix": DataType.MATRIX,
"array": DataType.BYTEARRAY,
"wordarray": DataType.WORDARRAY
}[self.name]
@attr.s(cmp=False, repr=False)
class Subroutine(AstNode):
# one subnode: the Scope.
name = attr.ib(type=str)
param_spec = attr.ib(type=list)
result_spec = attr.ib(type=list)
address = attr.ib(type=int, default=None, validator=validate_address)
@property
def scope(self) -> Scope:
return self.nodes[0] if self.nodes else None # type: ignore
@scope.setter
def scope(self, scope: Scope) -> None:
assert isinstance(scope, Scope)
self.nodes.clear()
self.nodes.append(scope)
scope.name = self.name
if self.address is not None:
raise ValueError("subroutine must have either a scope or an address, not both")
@attr.s(cmp=True, slots=True)
class LiteralValue(AstNode):
# no subnodes.
value = attr.ib()
@attr.s(cmp=False)
class AddressOf(AstNode):
# no subnodes.
name = attr.ib(type=str)
@attr.s(cmp=False, slots=True)
class SymbolName(AstNode):
# no subnodes.
name = attr.ib(type=str)
@attr.s(cmp=False)
class Dereference(AstNode):
# one subnode: operand (SymbolName, int or register name)
datatype = attr.ib()
size = attr.ib(type=int, default=None)
@property
def operand(self) -> Union[SymbolName, int, str]:
return self.nodes[0] # type: ignore
def __attrs_post_init__(self):
# convert datatype node to enum + size
if self.datatype is None:
assert self.size is None
self.size = 1
self.datatype = DataType.BYTE
elif isinstance(self.datatype, DatatypeNode):
assert self.size is None
self.size = self.datatype.dimensions
if not self.datatype.to_enum().isnumeric():
raise ParseError("dereference target value must be byte, word, float", self.datatype.sourceref)
self.datatype = self.datatype.to_enum()
@attr.s(cmp=False)
class IncrDecr(AstNode):
# increment or decrement something by a CONSTANT value (1 or more)
# one subnode: target (TargetRegisters, Register, SymbolName, or Dereference).
operator = attr.ib(type=str, validator=attr.validators.in_(["++", "--"]))
howmuch = attr.ib(default=1)
@property
def target(self) -> Union[TargetRegisters, Register, SymbolName, Dereference]:
return self.nodes[0] # type: ignore
@target.setter
def target(self, target: Union[TargetRegisters, Register, SymbolName, Dereference]) -> None:
if isinstance(target, Register):
if target.name not in REGISTER_BYTES | REGISTER_WORDS:
raise ParseError("cannot incr/decr that register", self.sourceref)
if isinstance(target, TargetRegisters):
raise ParseError("cannot incr/decr multiple registers at once", self.sourceref)
assert isinstance(target, (Register, SymbolName, Dereference))
self.nodes.clear()
self.nodes.append(target)
def __attrs_post_init__(self):
# make sure the amount is always >= 0
if self.howmuch < 0:
self.howmuch = -self.howmuch
self.operator = "++" if self.operator == "--" else "--"
@attr.s(cmp=False, slots=True, repr=False)
class Expression(AstNode):
left = attr.ib()
operator = attr.ib(type=str)
right = attr.ib()
unary = attr.ib(type=bool, default=False)
# when evaluating an expression, does it have to be a constant value?
must_be_constant = attr.ib(type=bool, init=False, default=False)
def __attrs_post_init__(self):
assert self.operator not in ("++", "--"), "incr/decr should not be an expression"
if self.operator == "mod":
self.operator = "%" # change it back to the more common '%'
def evaluate_primitive_constants(self, scope: Scope, sourceref: SourceRef) -> LiteralValue:
# make sure the lvalue and rvalue are primitives, and the operator is allowed
assert isinstance(self.left, LiteralValue)
assert isinstance(self.right, LiteralValue)
if self.operator not in {'+', '-', '*', '/', '//', '~', '|', '&', '%', '<<', '>>', '<', '>', '<=', '>=', '==', '!='}:
raise ValueError("operator", self.operator)
estr = "{} {} {}".format(repr(self.left.value), self.operator, repr(self.right.value))
try:
return LiteralValue(value=eval(estr, {}, {}), sourceref=sourceref) # type: ignore # safe because of checks above
except Exception as x:
raise ExpressionEvaluationError("expression error: " + str(x), self.sourceref) from None
def print_tree(self) -> None:
def tree(expr: Any, level: int) -> str:
indent = " "*level
if not isinstance(expr, Expression):
return indent + str(expr) + "\n"
if expr.unary:
return indent + "{}{}".format(expr.operator, tree(expr.left, level+1))
else:
return indent + "{}".format(tree(expr.left, level+1)) + \
indent + str(expr.operator) + "\n" + \
indent + "{}".format(tree(expr.right, level + 1))
print(tree(self, 0))
@attr.s(cmp=False, repr=False)
class Goto(AstNode):
# one or two subnodes: target (SymbolName, int or Dereference) and optionally: condition (Expression)
if_stmt = attr.ib(default=None)
@property
def target(self) -> Union[SymbolName, int, Dereference]:
return self.nodes[0] # type: ignore
@property
def condition(self) -> Expression:
return self.nodes[1] if len(self.nodes) == 2 else None # type: ignore
@attr.s(cmp=False, slots=True, repr=False)
class CallArgument(AstNode):
# one subnode: the value (Expression)
name = attr.ib(type=str, default=None)
@property
def value(self) -> Expression:
return self.nodes[0] # type: ignore
@attr.s(cmp=False)
class CallArguments(AstNode):
# subnodes are zero or more subroutine call arguments (CallArgument)
nodes = attr.ib(type=list, init=True) # requires nodes in __init__
@attr.s(cmp=False, repr=False)
class SubCall(AstNode):
# has three subnodes:
# 0: target (Symbolname, int, or Dereference),
# 1: preserve_regs (PreserveRegs)
# 2: arguments (CallArguments).
@property
def target(self) -> Union[SymbolName, int, Dereference]:
return self.nodes[0] # type: ignore
@property
def preserve_regs(self) -> PreserveRegs:
return self.nodes[1] # type: ignore
@property
def arguments(self) -> CallArguments:
return self.nodes[2] # type: ignore
@attr.s(cmp=False, slots=True, repr=False)
class VarDef(AstNode):
# zero or one subnode: value (an Expression).
name = attr.ib(type=str)
vartype = attr.ib()
datatype = attr.ib()
size = attr.ib(type=list, default=None)
zp_address = attr.ib(type=int, default=None, init=False) # the address in the zero page if this var is there, will be set later
@property
def value(self) -> Union[LiteralValue, Expression, AddressOf, SymbolName]:
return self.nodes[0] if self.nodes else None # type: ignore
@value.setter
def value(self, value: Union[LiteralValue, Expression, AddressOf, SymbolName]) -> None:
assert isinstance(value, (LiteralValue, Expression, AddressOf, SymbolName))
if self.nodes:
self.nodes[0] = value
else:
self.nodes.append(value)
# if the value is an expression, mark it as a *constant* expression here
if isinstance(value, Expression):
value.must_be_constant = True
def __attrs_post_init__(self):
# convert vartype to enum
if self.vartype == "const":
self.vartype = VarType.CONST
elif self.vartype == "var":
self.vartype = VarType.VAR
elif self.vartype == "memory":
self.vartype = VarType.MEMORY
else:
raise ValueError("invalid vartype", self.vartype)
# convert datatype node to enum + size
if self.datatype is None:
assert self.size is None
self.size = [1]
self.datatype = DataType.BYTE
elif isinstance(self.datatype, DatatypeNode):
assert self.size is None
self.size = self.datatype.dimensions or [1]
self.datatype = self.datatype.to_enum()
if self.datatype.isarray() and sum(self.size) in (0, 1):
print("warning: {}: array/matrix with size 1, use normal byte/word instead for efficiency".format(self.sourceref))
if self.value is None and (self.datatype.isnumeric() or self.datatype.isarray()):
self.value = LiteralValue(value=0, sourceref=self.sourceref)
# if it's a matrix with interleave, it must be memory mapped
if self.datatype == DataType.MATRIX and len(self.size) == 3:
if self.vartype != VarType.MEMORY:
raise ParseError("matrix with interleave can only be a memory-mapped variable", self.sourceref)
# note: value coercion is done later, when all expressions are evaluated
@attr.s(cmp=False, repr=False)
class Return(AstNode):
# one, two or three subnodes: value_A, value_X, value_Y (all three Expression)
@property
def value_A(self) -> Expression:
return self.nodes[0] if self.nodes else None # type: ignore
@property
def value_X(self) -> Expression:
return self.nodes[0] if self.nodes else None # type: ignore
@property
def value_Y(self) -> Expression:
return self.nodes[0] if self.nodes else None # type: ignore
@attr.s(cmp=False, slots=True, repr=False)
class AssignmentTargets(AstNode):
# a list of one or more assignment targets (TargetRegisters, Register, SymbolName, or Dereference).
nodes = attr.ib(type=list, init=True) # requires nodes in __init__
@attr.s(cmp=False, slots=True, repr=False)
class Assignment(AstNode):
# can be single- or multi-assignment
# has two subnodes: left (=AssignmentTargets) and right (=reg/literal/expr
# or another Assignment but those will be converted to multi assign)
@property
def left(self) -> AssignmentTargets:
return self.nodes[0] # type: ignore
@property
def right(self) -> Union[Register, LiteralValue, Expression]:
return self.nodes[1] # type: ignore
@right.setter
def right(self, rvalue: Union[Register, LiteralValue, Expression, Dereference, SymbolName, SubCall]) -> None:
assert isinstance(rvalue, (Register, LiteralValue, Expression, Dereference, SymbolName, SubCall))
self.nodes[1] = rvalue
@attr.s(cmp=False, slots=True, repr=False)
class AugAssignment(AstNode):
# has two subnodes: left (=TargetRegisters, Register, SymbolName, or Dereference) and right (=Expression)
operator = attr.ib(type=str)
@property
def left(self) -> Union[TargetRegisters, Register, SymbolName, Dereference]:
return self.nodes[0] # type: ignore
@property
def right(self) -> Expression:
return self.nodes[1] # type: ignore
def datatype_of(assignmenttarget: AstNode, scope: Scope) -> DataType:
# tries to determine the DataType of an assignment target node
if isinstance(assignmenttarget, (VarDef, Dereference, Register)):
return assignmenttarget.datatype
elif isinstance(assignmenttarget, SymbolName):
symdef = scope.lookup(assignmenttarget.name)
if isinstance(symdef, VarDef):
return symdef.datatype
elif isinstance(assignmenttarget, TargetRegisters):
if len(assignmenttarget.nodes) == 1:
return datatype_of(assignmenttarget.nodes[0], scope)
raise TypeError("cannot determine datatype", assignmenttarget)
def coerce_constant_value(datatype: DataType, value: AstNode,
sourceref: SourceRef=None) -> Tuple[bool, AstNode]:
# if we're a BYTE type, and the value is a single character, convert it to the numeric value
assert isinstance(value, AstNode)
def verify_bounds(value: Union[int, float, str]) -> None:
# if the value is out of bounds, raise an overflow exception
if isinstance(value, (int, float)):
if datatype == DataType.BYTE and not (0 <= value <= 0xff): # type: ignore
raise OverflowError("value out of range for byte: " + str(value))
if datatype == DataType.WORD and not (0 <= value <= 0xffff): # type: ignore
raise OverflowError("value out of range for word: " + str(value))
if datatype == DataType.FLOAT and not (FLOAT_MAX_NEGATIVE <= value <= FLOAT_MAX_POSITIVE): # type: ignore
raise OverflowError("value out of range for float: " + str(value))
if isinstance(value, LiteralValue):
if type(value.value) is str and len(value.value) == 1 and (datatype.isnumeric() or datatype.isarray()):
# convert a string of length 1 to its numeric character value
return True, LiteralValue(value=char_to_bytevalue(value.value), sourceref=value.sourceref) # type: ignore
# if we're an integer value and the passed value is float, truncate it (and give a warning)
if datatype in (DataType.BYTE, DataType.WORD, DataType.MATRIX) and isinstance(value.value, float):
frac = math.modf(value.value)
if frac != 0:
print_warning("float value truncated ({} to datatype {})".format(value.value, datatype.name), sourceref=sourceref)
v2 = int(value.value)
verify_bounds(v2)
return True, LiteralValue(value=v2, sourceref=value.sourceref) # type: ignore
if type(value.value) in (int, float):
verify_bounds(value.value)
if datatype == DataType.WORD:
if type(value.value) not in (int, float, str):
raise TypeError("cannot assign '{:s}' to {:s}".format(type(value.value).__name__, datatype.name.lower()), sourceref)
elif datatype in (DataType.BYTE, DataType.WORD, DataType.FLOAT):
if type(value.value) not in (int, float):
raise TypeError("cannot assign '{:s}' to {:s}".format(type(value.value).__name__, datatype.name.lower()), sourceref)
elif isinstance(value, (Expression, SubCall)):
return False, value
elif isinstance(value, SymbolName):
symboldef = value.my_scope().lookup(value.name)
if isinstance(symboldef, VarDef) and symboldef.vartype == VarType.CONST:
return True, symboldef.value
elif isinstance(value, AddressOf):
raise NotImplementedError("addressof const coerce", value) # XXX implement this
if datatype == DataType.WORD and not isinstance(value, (LiteralValue, Dereference, Register, SymbolName, AddressOf)):
raise TypeError("cannot assign '{:s}' to {:s}".format(type(value).__name__, datatype.name.lower()), sourceref)
elif datatype in (DataType.BYTE, DataType.WORD, DataType.FLOAT) \
and not isinstance(value, (LiteralValue, Dereference, Register, SymbolName, AddressOf)):
raise TypeError("cannot assign '{:s}' to {:s}".format(type(value).__name__, datatype.name.lower()), sourceref)
return False, value
def process_expression(expr: Expression, scope: Scope, sourceref: SourceRef) -> Any:
# process/simplify all expressions (constant folding etc)
if expr.must_be_constant:
return process_constant_expression(expr, sourceref, scope)
else:
return process_dynamic_expression(expr, sourceref, scope)
def process_constant_expression(expr: Any, sourceref: SourceRef, symbolscope: Scope) -> LiteralValue:
# the expression must result in a single (constant) value (int, float, whatever) wrapped as LiteralValue.
if isinstance(expr, (int, float, str, bool)):
raise TypeError("expr node should not be a python primitive value", expr, sourceref)
elif expr is None or isinstance(expr, LiteralValue):
return expr
elif isinstance(expr, SymbolName):
value = check_symbol_definition(expr.name, symbolscope, expr.sourceref)
if isinstance(value, VarDef):
if value.vartype == VarType.MEMORY:
raise ExpressionEvaluationError("can't take a memory value, must be a constant", expr.sourceref)
value = value.value
if isinstance(value, Expression):
raise ExpressionEvaluationError("circular reference?", expr.sourceref)
elif isinstance(value, LiteralValue):
return value
elif isinstance(value, (int, float, str, bool)):
raise TypeError("symbol value node should not be a python primitive value", expr)
else:
raise ExpressionEvaluationError("constant symbol required, not {}".format(value.__class__.__name__), expr.sourceref)
elif isinstance(expr, AddressOf):
assert isinstance(expr.name, SymbolName)
value = check_symbol_definition(expr.name.name, symbolscope, expr.sourceref)
if isinstance(value, VarDef):
if value.vartype == VarType.MEMORY:
if isinstance(value.value, LiteralValue):
return value.value
else:
raise ExpressionEvaluationError("constant literal value required", value.sourceref)
if value.vartype == VarType.CONST:
raise ExpressionEvaluationError("can't take the address of a constant", expr.name.sourceref)
raise ExpressionEvaluationError("address-of this {} isn't a compile-time constant"
.format(value.__class__.__name__), expr.name.sourceref)
else:
raise ExpressionEvaluationError("constant address required, not {}"
.format(value.__class__.__name__), expr.name.sourceref)
elif isinstance(expr, SubCall):
if isinstance(expr.target, SymbolName): # 'function(1,2,3)'
funcname = expr.target.name
if funcname in math_functions or funcname in builtin_functions:
func_args = []
for a in (process_constant_expression(callarg.value, sourceref, symbolscope) for callarg in expr.arguments.nodes):
if isinstance(a, LiteralValue):
func_args.append(a.value)
else:
func_args.append(a)
func = math_functions.get(funcname, builtin_functions.get(funcname))
try:
return LiteralValue(value=func(*func_args), sourceref=expr.arguments.sourceref) # type: ignore
except Exception as x:
raise ExpressionEvaluationError(str(x), expr.sourceref)
else:
raise ExpressionEvaluationError("can only use math- or builtin function", expr.sourceref)
elif isinstance(expr.target, Dereference): # '[...](1,2,3)'
raise ExpressionEvaluationError("dereferenced value call is not a constant value", expr.sourceref)
elif type(expr.target) is int: # '64738()'
raise ExpressionEvaluationError("immediate address call is not a constant value", expr.sourceref)
else:
raise NotImplementedError("weird call target", expr.target)
elif not isinstance(expr, Expression):
raise ExpressionEvaluationError("constant value required, not {}".format(expr.__class__.__name__), expr.sourceref)
if expr.unary:
left_sourceref = expr.left.sourceref if isinstance(expr.left, AstNode) else sourceref
expr.left = process_constant_expression(expr.left, left_sourceref, symbolscope)
if isinstance(expr.left, LiteralValue) and type(expr.left.value) in (int, float):
try:
if expr.operator == '-':
return LiteralValue(value=-expr.left.value, sourceref=expr.left.sourceref) # type: ignore
elif expr.operator == '~':
return LiteralValue(value=~expr.left.value, sourceref=expr.left.sourceref) # type: ignore
elif expr.operator in ("++", "--"):
raise ValueError("incr/decr should not be an expression")
raise ValueError("invalid unary operator", expr.operator)
except TypeError as x:
raise ParseError(str(x), expr.sourceref) from None
raise ValueError("invalid operand type for unary operator", expr.left, expr.operator)
else:
left_sourceref = expr.left.sourceref if isinstance(expr.left, AstNode) else sourceref
expr.left = process_constant_expression(expr.left, left_sourceref, symbolscope)
right_sourceref = expr.right.sourceref if isinstance(expr.right, AstNode) else sourceref
expr.right = process_constant_expression(expr.right, right_sourceref, symbolscope)
if isinstance(expr.left, LiteralValue):
if isinstance(expr.right, LiteralValue):
return expr.evaluate_primitive_constants(symbolscope, expr.right.sourceref)
else:
raise ExpressionEvaluationError("constant literal value required on right, not {}"
.format(expr.right.__class__.__name__), right_sourceref)
else:
raise ExpressionEvaluationError("constant literal value required on left, not {}"
.format(expr.left.__class__.__name__), left_sourceref)
def process_dynamic_expression(expr: Any, sourceref: SourceRef, symbolscope: Scope) -> Any:
# constant-fold a dynamic expression
if isinstance(expr, (int, float, str, bool)):
raise TypeError("expr node should not be a python primitive value", expr, sourceref)
elif expr is None or isinstance(expr, LiteralValue):
return expr
elif isinstance(expr, SymbolName):
try:
return process_constant_expression(expr, sourceref, symbolscope)
except ExpressionEvaluationError:
return expr
elif isinstance(expr, AddressOf):
try:
return process_constant_expression(expr, sourceref, symbolscope)
except ExpressionEvaluationError:
return expr
elif isinstance(expr, SubCall):
try:
return process_constant_expression(expr, sourceref, symbolscope)
except ExpressionEvaluationError:
if isinstance(expr.target, SymbolName):
check_symbol_definition(expr.target.name, symbolscope, expr.target.sourceref)
return expr
elif isinstance(expr, Register):
return expr
elif isinstance(expr, Dereference):
if isinstance(expr.operand, SymbolName):
check_symbol_definition(expr.operand.name, symbolscope, expr.operand.sourceref)
return expr
elif not isinstance(expr, Expression):
raise ParseError("expression required, not {}".format(expr.__class__.__name__), expr.sourceref)
if expr.unary:
left_sourceref = expr.left.sourceref if isinstance(expr.left, AstNode) else sourceref
expr.left = process_dynamic_expression(expr.left, left_sourceref, symbolscope)
try:
return process_constant_expression(expr, sourceref, symbolscope)
except ExpressionEvaluationError:
return expr
else:
left_sourceref = expr.left.sourceref if isinstance(expr.left, AstNode) else sourceref
expr.left = process_dynamic_expression(expr.left, left_sourceref, symbolscope)
right_sourceref = expr.right.sourceref if isinstance(expr.right, AstNode) else sourceref
expr.right = process_dynamic_expression(expr.right, right_sourceref, symbolscope)
try:
return process_constant_expression(expr, sourceref, symbolscope)
except ExpressionEvaluationError:
return expr
def check_symbol_definition(name: str, scope: Scope, sref: SourceRef) -> Any:
try:
return scope.lookup(name)
except UndefinedSymbolError as x:
raise ParseError(str(x), sref)
# ----------------- PLY parser definition follows ----------------------
def p_start(p):
"""
start : empty
| module_elements
"""
if p[1]:
scope = Scope(nodes=p[1], level="module", sourceref=_token_sref(p, 1))
scope.name = "<" + p.lexer.source_filename + " global scope>"
p[0] = Module(name=p.lexer.source_filename, sourceref=_token_sref(p, 1))
p[0].nodes.append(scope)
else:
scope = Scope(nodes=[], level="module", sourceref=_token_sref(p, 1))
scope.name = "<" + p.lexer.source_filename + " global scope>"
p[0] = Module(name=p.lexer.source_filename, sourceref=SourceRef(lexer.source_filename, 1, 1))
p[0].nodes.append(scope)
def p_module(p):
"""
module_elements : module_elt
| module_elements module_elt
"""
if len(p) == 2:
if p[1] is None:
p[0] = []
else:
p[0] = [p[1]]
else:
if p[2] is None:
p[0] = p[1]
else:
p[0] = p[1] + [p[2]]
def p_module_elt(p):
"""
module_elt : ENDL
| directive
| block
"""
if p[1] != '\n':
p[0] = p[1]
def p_directive(p):
"""
directive : DIRECTIVE ENDL
| DIRECTIVE directive_args ENDL
"""
if len(p) == 3:
p[0] = Directive(name=p[1], sourceref=_token_sref(p, 1))
else:
p[0] = Directive(name=p[1], args=p[2], sourceref=_token_sref(p, 1))
def p_directive_args(p):
"""
directive_args : directive_arg
| directive_args ',' directive_arg
"""
if len(p) == 2:
p[0] = [p[1]]
else:
p[0] = p[1] + [p[3]]
def p_directive_arg(p):
"""
directive_arg : NAME
| INTEGER
| STRING
| BOOLEAN
"""
p[0] = p[1]
def p_block_name_addr(p):
"""
block : BITINVERT NAME INTEGER endl_opt scope
"""
p[0] = Block(name=p[2], address=p[3], sourceref=_token_sref(p, 2))
p[0].scope = p[5]
def p_block_name(p):
"""
block : BITINVERT NAME endl_opt scope
"""
p[0] = Block(name=p[2], sourceref=_token_sref(p, 2))
p[0].scope = p[4]
def p_block(p):
"""
block : BITINVERT endl_opt scope
"""
p[0] = Block(sourceref=_token_sref(p, 1))
p[0].scope = p[3]
def p_endl_opt(p):
"""
endl_opt : empty
| ENDL
"""
pass
def p_scope(p):
"""
scope : '{' scope_elements_opt '}'
"""
p[0] = Scope(nodes=p[2] or [], level="block", sourceref=_token_sref(p, 1))
def p_scope_elements_opt(p):
"""
scope_elements_opt : empty
| scope_elements
"""
p[0] = p[1]
def p_scope_elements(p):
"""
scope_elements : scope_element
| scope_elements scope_element
"""
if len(p) == 2:
p[0] = [] if p[1] in (None, '\n') else [p[1]]
else:
if p[2] in (None, '\n'):
p[0] = p[1]
else:
p[0] = p[1] + [p[2]]
def p_scope_element(p):
"""
scope_element : ENDL
| label
| directive
| vardef
| subroutine
| inlineasm
| statement
"""
if p[1] != '\n':
p[0] = p[1]
else:
p[0] = None
def p_label(p):
"""
label : LABEL
"""
p[0] = Label(name=p[1], sourceref=_token_sref(p, 1))
def p_inlineasm(p):
"""
inlineasm : INLINEASM ENDL
"""
p[0] = InlineAssembly(assembly=p[1], sourceref=_token_sref(p, 1))
def p_vardef(p):
"""
vardef : VARTYPE type_opt NAME ENDL
"""
p[0] = VarDef(name=p[3], vartype=p[1], datatype=p[2], sourceref=_token_sref(p, 3))
def p_vardef_value(p):
"""
vardef : VARTYPE type_opt NAME IS expression
"""
p[0] = VarDef(name=p[3], vartype=p[1], datatype=p[2], sourceref=_token_sref(p, 3))
p[0].value = p[5]
def p_type_opt(p):
"""
type_opt : DATATYPE '(' dimensions ')'
| DATATYPE
| empty
"""
if len(p) == 5:
p[0] = DatatypeNode(name=p[1], dimensions=p[3], sourceref=_token_sref(p, 1))
elif len(p) == 2 and p[1]:
p[0] = DatatypeNode(name=p[1], sourceref=_token_sref(p, 1))
def p_dimensions(p):
"""
dimensions : INTEGER
| dimensions ',' INTEGER
"""
if len(p) == 2:
p[0] = [p[1]]
else:
p[0] = p[1] + [p[3]]
def p_literal_value(p):
"""literal_value : INTEGER
| FLOATINGPOINT
| STRING
| CHARACTER
| BOOLEAN"""
tok = p.slice[-1]
if tok.type == "CHARACTER":
p[1] = char_to_bytevalue(p[1]) # character literals are converted to byte value.
elif tok.type == "BOOLEAN":
p[1] = int(p[1]) # boolean literals are converted to integer form (true=1, false=0).
p[0] = LiteralValue(value=p[1], sourceref=_token_sref(p, 1))
def p_subroutine(p):
"""
subroutine : SUB NAME '(' sub_param_spec ')' RARROW '(' sub_result_spec ')' subroutine_body ENDL
"""
body = p[10]
if isinstance(body, Scope):
p[0] = Subroutine(name=p[2], param_spec=p[4] or [], result_spec=p[8] or [], sourceref=_token_sref(p, 1))
p[0].scope = body
elif type(body) is int:
p[0] = Subroutine(name=p[2], param_spec=p[4] or [], result_spec=p[8] or [], address=body, sourceref=_token_sref(p, 1))
else:
raise TypeError("subroutine_body", p.slice)
def p_sub_param_spec(p):
"""
sub_param_spec : empty
| sub_param_list
"""
p[0] = p[1]
def p_sub_param_list(p):
"""
sub_param_list : sub_param
| sub_param_list ',' sub_param
"""
if len(p) == 2:
p[0] = [p[1]]
else:
p[0] = p[1] + [p[3]]
def p_sub_param(p):
"""
sub_param : LABEL REGISTER
| REGISTER
"""
if len(p) == 3:
p[0] = (p[1], p[2])
elif len(p) == 2:
p[0] = (None, p[1])
def p_sub_result_spec(p):
"""
sub_result_spec : empty
| '?'
| sub_result_list
"""
if p[1] == '?':
p[0] = ['A', 'X', 'Y'] # '?' means: all registers clobbered
else:
p[0] = p[1]
def p_sub_result_list(p):
"""
sub_result_list : sub_result_reg
| sub_result_list ',' sub_result_reg
"""
if len(p) == 2:
p[0] = [p[1]]
else:
p[0] = p[1] + [p[3]]
def p_sub_result_reg(p):
"""
sub_result_reg : REGISTER
| CLOBBEREDREGISTER
"""
p[0] = p[1]
def p_subroutine_body(p):
"""
subroutine_body : scope
| IS INTEGER
"""
if len(p) == 2:
p[0] = p[1]
else:
p[0] = p[2]
def p_statement(p):
"""
statement : assignment ENDL
| aug_assignment ENDL
| subroutine_call ENDL
| goto ENDL
| conditional_goto ENDL
| incrdecr ENDL
| return ENDL
"""
p[0] = p[1]
def p_incrdecr(p):
"""
incrdecr : assignment_target INCR
| assignment_target DECR
"""
p[0] = IncrDecr(operator=p[2], sourceref=_token_sref(p, 2))
p[0].target = p[1]
def p_call_subroutine(p):
"""
subroutine_call : calltarget preserveregs_opt '(' call_arguments_opt ')'
"""
sref = _token_sref(p, 3)
p[0] = SubCall(sourceref=sref)
p[0].nodes.append(p[1])
p[0].nodes.append(p[2])
p[0].nodes.append(CallArguments(nodes=p[4] or [], sourceref=sref))
def p_preserveregs_opt(p):
"""
preserveregs_opt : empty
| preserveregs
"""
p[0] = p[1]
def p_preserveregs(p):
"""
preserveregs : PRESERVEREGS
"""
p[0] = PreserveRegs(registers=p[1], sourceref=_token_sref(p, 1))
def p_call_arguments_opt(p):
"""
call_arguments_opt : empty
| call_arguments
"""
p[0] = p[1]
def p_call_arguments(p):
"""
call_arguments : call_argument
| call_arguments ',' call_argument
"""
if len(p) == 2:
p[0] = [p[1]]
else:
p[0] = p[1] + [p[3]]
def p_call_argument(p):
"""
call_argument : expression
| register IS expression
| NAME IS expression
"""
if len(p) == 2:
p[0] = CallArgument(sourceref=_token_sref(p, 1))
p[0].nodes.append(p[1])
elif len(p) == 4:
if isinstance(p[1], AstNode):
sref = p[1].sourceref
else:
sref = _token_sref(p, 2)
p[0] = CallArgument(name=p[1], sourceref=sref)
p[0].nodes.append(p[3])
def p_return(p):
"""
return : RETURN
| RETURN expression
| RETURN expression ',' expression
| RETURN expression ',' expression ',' expression
"""
if len(p) == 2:
p[0] = Return(sourceref=_token_sref(p, 1))
elif len(p) == 3:
p[0] = Return(sourceref=_token_sref(p, 1))
p[0].nodes.append(p[2]) # A
elif len(p) == 5:
p[0] = Return(sourceref=_token_sref(p, 1))
p[0].nodes.append(p[2]) # A
p[0].nodes.append(p[4]) # X
elif len(p) == 7:
p[0] = Return(sourceref=_token_sref(p, 1))
p[0].nodes.append(p[2]) # A
p[0].nodes.append(p[4]) # X
p[0].nodes.append(p[6]) # Y
def p_register(p):
"""
register : REGISTER
"""
p[0] = Register(name=p[1], sourceref=_token_sref(p, 1))
def p_goto(p):
"""
goto : GOTO calltarget
"""
p[0] = Goto(sourceref=_token_sref(p, 1))
p[0].nodes.append(p[2])
def p_conditional_goto_plain(p):
"""
conditional_goto : IF GOTO calltarget
"""
p[0] = Goto(if_stmt=p[1], sourceref=_token_sref(p, 1))
p[0].nodes.append(p[3])
def p_conditional_goto_expr(p):
"""
conditional_goto : IF expression GOTO calltarget
"""
p[0] = Goto(if_stmt=p[1], sourceref=_token_sref(p, 1))
p[0].nodes.append(p[4])
p[0].nodes.append(p[2])
def p_calltarget(p):
"""
calltarget : symbolname
| INTEGER
| dereference
"""
p[0] = p[1]
def p_dereference(p):
"""
dereference : '[' dereference_operand ']'
"""
p[0] = Dereference(datatype=p[2][1], sourceref=_token_sref(p, 1))
p[0].nodes.append(p[2][0])
def p_dereference_operand(p):
"""
dereference_operand : symbolname type_opt
| REGISTER type_opt
| INTEGER type_opt
"""
p[0] = (p[1], p[2])
def p_symbolname(p):
"""
symbolname : NAME
| DOTTEDNAME
"""
p[0] = SymbolName(name=p[1], sourceref=_token_sref(p, 1))
def p_assignment(p):
"""
assignment : assignment_target IS expression
| assignment_target IS assignment
"""
p[0] = Assignment(sourceref=_token_sref(p, 2))
p[0].nodes.append(AssignmentTargets(nodes=[p[1]], sourceref=p[0].sourceref))
p[0].nodes.append(p[3])
def p_aug_assignment(p):
"""
aug_assignment : assignment_target AUGASSIGN expression
"""
p[0] = AugAssignment(operator=p[2], sourceref=_token_sref(p, 2))
p[0].nodes.append(p[1])
p[0].nodes.append(p[3])
precedence = (
# following the python operator precedence rules mostly; https://docs.python.org/3/reference/expressions.html#operator-precedence
('left', 'LOGICOR'),
('left', 'LOGICAND'),
('right', 'LOGICNOT'),
('left', "LT", "GT", "LE", "GE", "EQUALS", "NOTEQUALS"),
('left', 'BITOR'),
('left', 'BITXOR'),
('left', 'BITAND'),
('left', 'SHIFTLEFT', 'SHIFTRIGHT'),
('left', '+', '-'),
('left', '*', '/', 'INTEGERDIVIDE', 'MODULO'),
('right', 'UNARY_MINUS', 'BITINVERT', "UNARY_ADDRESSOF"),
('left', 'POWER'),
('nonassoc', "COMMENT"),
)
def p_expression(p):
"""
expression : expression '+' expression
| expression '-' expression
| expression '*' expression
| expression '/' expression
| expression MODULO expression
| expression BITOR expression
| expression BITXOR expression
| expression BITAND expression
| expression SHIFTLEFT expression
| expression SHIFTRIGHT expression
| expression LOGICOR expression
| expression LOGICAND expression
| expression POWER expression
| expression INTEGERDIVIDE expression
| expression LT expression
| expression GT expression
| expression LE expression
| expression GE expression
| expression EQUALS expression
| expression NOTEQUALS expression
"""
p[0] = Expression(left=p[1], operator=p[2], right=p[3], sourceref=_token_sref(p, 2))
def p_expression_uminus(p):
"""
expression : '-' expression %prec UNARY_MINUS
"""
p[0] = Expression(left=p[2], operator=p[1], right=None, unary=True, sourceref=_token_sref(p, 1))
def p_expression_addressof(p):
"""
expression : BITAND symbolname %prec UNARY_ADDRESSOF
"""
p[0] = AddressOf(name=p[2], sourceref=_token_sref(p, 1))
def p_unary_expression_bitinvert(p):
"""
expression : BITINVERT expression
"""
p[0] = Expression(left=p[2], operator=p[1], right=None, unary=True, sourceref=_token_sref(p, 1))
def p_unary_expression_logicnot(p):
"""
expression : LOGICNOT expression
"""
p[0] = Expression(left=p[2], operator=p[1], right=None, unary=True, sourceref=_token_sref(p, 1))
def p_expression_group(p):
"""
expression : '(' expression ')'
"""
p[0] = p[2]
def p_expression_expr_value(p):
"""expression : expression_value"""
p[0] = p[1]
def p_expression_value(p):
"""
expression_value : literal_value
| symbolname
| register
| subroutine_call
| dereference
"""
p[0] = p[1]
def p_assignment_target(p):
"""
assignment_target : target_registers
| symbolname
| dereference
"""
if isinstance(p[1], TargetRegisters):
# if the target registers is just a single register, use that instead
if len(p[1].nodes) == 1:
assert isinstance(p[1].nodes[0], Register)
p[1] = p[1].nodes[0]
p[0] = p[1]
def p_target_registers(p):
"""
target_registers : register
| target_registers ',' register
"""
if len(p) == 2:
p[0] = TargetRegisters(sourceref=_token_sref(p, 1))
p[0].nodes.append(p[1])
else:
p[1].nodes.append(p[3])
p[0] = p[1]
def p_empty(p):
"""empty :"""
pass
def p_error(p):
stack_state_str = ' '.join([symbol.type for symbol in parser.symstack][1:])
print('\n[ERROR DEBUG: parser state={:d} stack: {} . {} ]'.format(parser.state, stack_state_str, p))
if p:
sref = SourceRef(p.lexer.source_filename, p.lineno, find_tok_column(p))
if p.value in ("", "\n"):
p.lexer.error_function(sref, "syntax error before end of line")
else:
p.lexer.error_function(sref, "syntax error before or at '{:.20s}'", str(p.value).rstrip())
else:
lexer.error_function(None, "syntax error at end of input", lexer.source_filename)
def _token_sref(p, token_idx):
""" Returns the coordinates for the YaccProduction object 'p' indexed
with 'token_idx'. The coordinate includes the 'lineno' and 'column', starting from 1.
"""
last_cr = p.lexer.lexdata.rfind('\n', 0, p.lexpos(token_idx))
if last_cr < 0:
last_cr = -1
chunk = p.lexer.lexdata[last_cr:p.lexpos(token_idx)]
column = len(chunk.expandtabs())
return SourceRef(p.lexer.source_filename, p.lineno(token_idx), column)
class TokenFilter:
def __init__(self, lexer):
self.lexer = lexer
self.prev_was_EOL = False
assert "ENDL" in tokens
def token(self):
# make sure we only ever emit ONE "ENDL" token in sequence
if self.prev_was_EOL:
# skip all EOLS that might follow
while True:
tok = self.lexer.token()
if not tok or tok.type != "ENDL":
break
self.prev_was_EOL = False
else:
tok = self.lexer.token()
self.prev_was_EOL = tok and tok.type == "ENDL"
return tok
parser = yacc(write_tables=True)
def connect_parents(node: AstNode, parent: AstNode) -> None:
node.parent = parent
for childnode in node.nodes:
if isinstance(childnode, AstNode):
connect_parents(childnode, node)
def parse_file(filename: str, lexer_error_func=None) -> Module:
lexer.error_function = lexer_error_func
lexer.lineno = 1
lexer.source_filename = filename
tfilter = TokenFilter(lexer)
with open(filename, "rU") as inf:
sourcecode = inf.read()
result = parser.parse(input=sourcecode, tokenfunc=tfilter.token)
connect_parents(result, None)
return result