Files
nx_post_support/server/libs/tclint/parser.py
T
2026-06-18 17:21:58 +02:00

915 lines
28 KiB
Python

import io
import re
import string
from typing import Optional, Tuple
from tclint.commands import CommandArgError
from tclint.commands import builtin as _builtin
from tclint.commands.checks import check_command
from tclint.lexer import (
STATE_BRACEDWORD,
TOK_ALPHA_CHARS,
TOK_ARG_EXPANSION,
TOK_BACKSLASH_NEWLINE,
TOK_DOLLAR,
TOK_EOF,
TOK_HASH,
TOK_LBRACE,
TOK_LBRACKET,
TOK_LPAREN,
TOK_NAMESPACE_SEP,
TOK_NEWLINE,
TOK_NUM_CHARS,
TOK_QUOTE,
TOK_RBRACE,
TOK_RBRACKET,
TOK_RPAREN,
TOK_SEMI,
TOK_WS,
Lexer,
TclSyntaxError,
)
from tclint.syntax_tree import (
ArgExpansion,
BareWord,
BinaryOp,
BracedExpression,
BracedWord,
Command,
CommandSub,
Comment,
CompoundBareWord,
Expression,
Function,
List,
Node,
ParenExpression,
QuotedWord,
Script,
TernaryOp,
UnaryOp,
VarSub,
)
from tclint.violations import Rule, Violation
def _strip_ws(parse_func):
"""Decorator used by expression parser for stripping whitespace around a node."""
def func(parser, ts):
while ts.type() in {TOK_WS, TOK_BACKSLASH_NEWLINE, TOK_NEWLINE}:
ts.next()
node = parse_func(parser, ts)
while ts.type() in {TOK_WS, TOK_BACKSLASH_NEWLINE, TOK_NEWLINE}:
ts.next()
return node
return func
class _Word:
"""Helper class for constructing Word nodes out of multiple segments."""
def __init__(self):
self.segments = []
self.current_segment = ""
self.current_start = None
def add_tok(self, tok):
if self.current_start is None:
self.current_start = tok.value[1]
self.current_segment += tok.value[0]
def add_node(self, node):
if self.current_segment != "":
self.segments.append(
BareWord(self.current_segment, pos=self.current_start, end_pos=node.pos)
)
self.current_segment = ""
self.current_start = None
self.segments.append(node)
def resolve(self, end_pos):
if self.current_segment:
self.segments.append(
BareWord(self.current_segment, pos=self.current_start, end_pos=end_pos)
)
return self.segments
class Parser:
def __init__(self, debug=False, commands: Optional[dict] = None):
self._debug = debug
self._debug_indent = 0
# TODO: better way to handle this?
self.violations: list[Violation] = []
if commands is None:
commands = _builtin.commands
self._commands = commands
# Used to normalize newlines consistently with open()'s universal newlines mode.
self._decoder = io.IncrementalNewlineDecoder(None, True)
def debug(self, *msg):
if self._debug:
print(" " * self._debug_indent, end="")
print(*msg)
def parse(self, script: str, pos: Optional[Tuple[int, int]] = None):
script = self._decoder.decode(script, True)
lexer = Lexer(pos=pos)
lexer.input(script)
tree = self._parse_script(lexer, in_command_sub=False)
assert (
lexer.type() == TOK_EOF
), "Didn't reach EOF parsing script, please file a bug report."
return tree
def _parse_command_args(self, routine, args):
"""Since many built-in Tcl commands take in Tcl scripts or expressions
as arguments, building a complete parse tree requires checking command
names and possibly parsing their arguments.
The node of any argument that gets parsed by this method is replaced with
the parse tree of that argument. Since this process requires checking
the arguments provided to these commands, this method may report lint
violations.
This parsing process is analogous to how the Tcl interpreter interprets
scripts, and better handles weird edge cases compared to a traditional
parsing technique. For example, this may look like valid Tcl:
proc foo {a} {
# output }
puts "}"
}
But really, it is invalid since the } in the comment terminates the body
of the proc - Tcl blindly constructs the body of the proc until it
reaches the first }. tclint handles this correctly.
"""
if routine not in self._commands:
return args
spec = self._commands[routine]
try:
new_args = check_command(routine, args, self, spec)
except TclSyntaxError as e:
raise e
except CommandArgError as e:
raise e
except Exception:
if self._debug:
raise
raise CommandArgError(
f"error parsing command arguments, possibly malformed {routine} command"
)
if new_args is None:
return args
return new_args
def parse_script(self, node):
if node.contents is None:
raise CommandArgError(
"expected braced word or word without substitutions in argument"
" interpreted as script"
)
script = self.parse(node.contents, pos=node.contents_pos)
if isinstance(node, BracedWord):
script.braced = True
script.line = node.line
script.col = node.col
script.end_pos = node.end_pos
return script
def _parse_script(self, ts, in_command_sub):
self.debug(f"parse_script({ts.current})")
self._debug_indent += 1
pos = ts.pos()
script: Script | CommandSub
if in_command_sub:
script = CommandSub(pos=pos)
else:
script = Script(pos=pos)
while ts.type() is not TOK_EOF:
if ts.type() in {TOK_WS, TOK_BACKSLASH_NEWLINE}:
# strip whitespace at start of command
ts.next()
continue
if ts.type() == TOK_HASH:
script.add(self.parse_comment(ts))
else:
cmd = self.parse_command(ts, in_command_sub=in_command_sub)
if cmd is not None:
script.add(cmd)
# when in command sub mode, a script is terminated by ]
if in_command_sub and ts.type() == TOK_RBRACKET:
return script
ts.expect(
TOK_EOF,
TOK_NEWLINE,
TOK_SEMI,
message=f"expected newline or semicolon, got {ts.value()}",
pos=ts.pos(),
)
if in_command_sub and ts.type() is TOK_EOF:
raise TclSyntaxError(
"reached EOF without finding end of command substitution", pos, ts.pos()
)
self._debug_indent -= 1
script.end_pos = ts.pos()
return script
def parse_comment(self, ts):
self.debug(f"parse_comment({ts.current})")
pos = ts.pos()
ts.assert_(TOK_HASH)
value = ""
while ts.type() not in {TOK_NEWLINE, TOK_EOF}:
value += ts.value()
ts.next()
# Stripping trailing whitespace from comments here allows tclfmt to clean it up
# without affecting the AST.
value = value.rstrip()
return Comment(value, pos=pos, end_pos=ts.pos())
def parse_command(self, ts, in_command_sub):
self.debug(f"parse_command({ts.current})")
self._debug_indent += 1
pos = ts.pos()
routine = self.parse_word(ts, in_command_sub)
if routine is None:
self._debug_indent -= 1
return None
args = []
while True:
if ts.type() not in {TOK_WS, TOK_BACKSLASH_NEWLINE}:
break
while ts.type() in {TOK_WS, TOK_BACKSLASH_NEWLINE}:
ts.next()
word = self.parse_word(ts, in_command_sub)
if word is None:
break
args.append(word)
self._debug_indent -= 1
try:
parsed_args = self._parse_command_args(routine.contents, args)
except CommandArgError as e:
self.violations.append(Violation(Rule.COMMAND_ARGS, str(e), pos, ts.pos()))
parsed_args = args
children = [routine, *parsed_args]
# We need to inherit end pos of last child to prevent us from counting
# extra whitespace at end of command, which is important for
# spaces-in-braces check.
return Command(*children, pos=pos, end_pos=children[-1].end_pos)
def parse_word(self, ts, in_command_sub):
self.debug(f"parse_word({ts.current})")
if ts.type() == TOK_ARG_EXPANSION:
return self.parse_arg_expansion(ts, in_command_sub)
elif ts.type() == TOK_LBRACE:
return self.parse_braced_word(ts)
elif ts.type() == TOK_QUOTE:
return self.parse_quoted_word(ts)
else:
return self.parse_bare_word(ts, in_command_sub)
def parse_arg_expansion(self, ts, in_command_sub):
self.debug(f"parse_arg_expansion({ts.current})")
pos = ts.pos()
ts.assert_(TOK_ARG_EXPANSION)
delimiters = [TOK_WS, TOK_BACKSLASH_NEWLINE, TOK_NEWLINE, TOK_SEMI, TOK_EOF]
if in_command_sub:
delimiters.append(TOK_RBRACKET)
# Arg expansion is just a regular braced word if followed by whitespace,
# or other word boundaries such as semicolon or right bracket
# (in command substitution)
if ts.type() in delimiters:
return BracedWord("*", pos=pos, end_pos=ts.pos())
return ArgExpansion(
self.parse_word(ts, in_command_sub), pos=pos, end_pos=ts.pos()
)
def parse_quoted_word(self, ts):
self.debug(f"parse_quoted_word({ts.current})")
self._debug_indent += 1
pos = ts.pos()
ts.assert_(TOK_QUOTE)
word = _Word()
while ts.type() not in {TOK_QUOTE, TOK_EOF}:
if ts.type() == TOK_DOLLAR:
dollar_tok = ts.current
var_sub = self.parse_var_sub(ts)
if var_sub:
word.add_node(var_sub)
else:
word.add_tok(dollar_tok)
elif ts.type() == TOK_LBRACKET:
command_sub = self.parse_command_sub(ts)
word.add_node(command_sub)
else:
word.add_tok(ts.current)
ts.next()
res = word.resolve(ts.pos())
ts.expect(
TOK_QUOTE, message="reached EOF without finding match for quote", pos=pos
)
self._debug_indent -= 1
if not res:
res = []
return QuotedWord(*res, pos=pos, end_pos=ts.pos())
def parse_braced_word(self, ts):
self.debug(f"parse_braced_word({ts.current})")
pos = ts.pos()
ts.lexer.push_state(STATE_BRACEDWORD)
ts.assert_(TOK_LBRACE)
word = ""
# store position for each brace we want to match, facilitating good
# error messages
expected_braces = [pos]
while True:
toktype = ts.type()
if toktype == TOK_EOF:
raise TclSyntaxError(
"reached EOF without finding match for brace",
expected_braces[-1],
ts.pos(),
)
if toktype == TOK_LBRACE:
expected_braces.append(ts.pos())
elif toktype == TOK_RBRACE:
try:
expected_braces.pop()
except IndexError:
start = ts.pos()
ts.next()
end = ts.pos()
raise TclSyntaxError(
"found closing brace without matching open brace", start, end
)
if len(expected_braces) == 0:
ts.lexer.pop_state()
ts.next()
break
word += ts.value()
ts.next()
end_pos = ts.pos()
return BracedWord(word, pos=pos, end_pos=end_pos)
def parse_bare_word(self, ts, in_command_sub):
self.debug(f"parse_bare_word({ts.current})")
self._debug_indent += 1
pos = ts.pos()
word = _Word()
delimiters = [TOK_WS, TOK_BACKSLASH_NEWLINE, TOK_NEWLINE, TOK_SEMI, TOK_EOF]
# In command sub mode, words are ended by ]
if in_command_sub:
delimiters.append(TOK_RBRACKET)
while ts.type() not in delimiters:
if ts.type() == TOK_DOLLAR:
dollar_tok = ts.current
var_sub = self.parse_var_sub(ts)
if var_sub:
word.add_node(var_sub)
else:
word.add_tok(dollar_tok)
elif ts.type() == TOK_LBRACKET:
command_sub = self.parse_command_sub(ts)
word.add_node(command_sub)
else:
word.add_tok(ts.current)
ts.next()
res = word.resolve(ts.pos())
self._debug_indent -= 1
if not res:
return None
if len(res) == 1:
return res[0]
return CompoundBareWord(*res, pos=pos, end_pos=ts.pos())
def parse_var_sub(self, ts):
self.debug(f"parse_var_sub({ts.current})")
pos = ts.pos()
ts.assert_(TOK_DOLLAR)
var = ""
if ts.type() == TOK_LBRACE:
brace_pos = ts.pos()
ts.next()
while ts.type() != TOK_RBRACE:
if ts.type() is TOK_EOF:
raise TclSyntaxError(
"reached EOF without finding match for brace",
brace_pos,
ts.pos(),
)
var += ts.value()
ts.next()
ts.next()
return VarSub(var, pos=pos, end_pos=ts.pos(), braced=True)
while ts.type() in {TOK_ALPHA_CHARS, TOK_NUM_CHARS, TOK_NAMESPACE_SEP}:
var += ts.value()
ts.next()
if not var:
return None
index_nodes = []
if ts.type() == TOK_LPAREN:
paren_pos = ts.pos()
index = _Word()
ts.next()
while ts.type() != TOK_RPAREN:
if ts.type() == TOK_EOF:
raise TclSyntaxError(
"reached EOF without finding match for paren",
paren_pos,
ts.pos(),
)
if ts.type() == TOK_DOLLAR:
dollar_tok = ts.current
var_sub = self.parse_var_sub(ts)
if var_sub:
index.add_node(var_sub)
else:
index.add_tok(dollar_tok)
elif ts.type() == TOK_LBRACKET:
command_sub = self.parse_command_sub(ts)
index.add_node(command_sub)
else:
index.add_tok(ts.current)
ts.next()
index_nodes = index.resolve(ts.pos())
ts.next()
var_sub = VarSub(var, pos=pos, end_pos=ts.pos())
for index_segment in index_nodes:
var_sub.add(index_segment)
return var_sub
def parse_command_sub(self, ts):
self.debug(f"parse_command_sub({ts.current})")
self._debug_indent += 1
pos = ts.pos()
ts.assert_(TOK_LBRACKET)
script = self._parse_script(ts, in_command_sub=True)
ts.assert_(TOK_RBRACKET)
end_pos = ts.pos()
script.line = pos[0]
script.col = pos[1]
script.end_pos = end_pos
self._debug_indent -= 1
return script
def parse_list(self, node: Node) -> List:
"""Parse contents of node as Tcl list. This is a distinct entry point
that doesn't get used when generating the main syntax tree, but is used
in command-specific argument parsing.
"""
if isinstance(node, List):
return node
if node.contents is None:
raise CommandArgError(
"expected braced word or word without substitutions in argument"
" interpreted as list"
)
ts = Lexer(pos=node.contents_pos)
ts.input(node.contents)
DELIMITERS = {TOK_WS, TOK_BACKSLASH_NEWLINE, TOK_NEWLINE}
list_node = List(pos=node.pos, end_pos=node.end_pos)
while ts.type() is not TOK_EOF:
while ts.type() in DELIMITERS:
ts.next()
if ts.type() is TOK_EOF:
break
if ts.type() == TOK_LBRACE:
# we can reuse parse_braced_word, since it doesn't use
# substitutions in any case
list_node.add(self.parse_braced_word(ts))
elif ts.type() == TOK_QUOTE:
quote_word_pos = ts.pos()
ts.assert_(TOK_QUOTE)
bare_word_pos = ts.pos()
contents = ""
while ts.type() not in {TOK_QUOTE, TOK_EOF}:
contents += ts.value()
ts.next()
word = BareWord(contents, pos=bare_word_pos, end_pos=ts.pos())
ts.expect(
TOK_QUOTE,
message="reached EOF without finding match for quote",
pos=quote_word_pos,
)
list_node.add(QuotedWord(word, pos=quote_word_pos, end_pos=ts.pos()))
else:
pos = ts.pos()
contents = ""
while ts.type() not in {*DELIMITERS, TOK_EOF}:
contents += ts.value()
ts.next()
list_node.add(BareWord(contents, pos=pos, end_pos=ts.pos()))
return list_node
def parse_expression(self, node):
if node.contents is None:
raise CommandArgError(
"expected braced word or word without substitutions in argument"
" interpreted as expr"
)
ts = Lexer(pos=node.contents_pos)
ts.input(node.contents)
contents = self._parse_expression(ts)
ts.expect(
TOK_EOF,
message=f"expected end of expression, got {ts.value()}",
pos=ts.pos(),
)
if isinstance(node, BracedWord):
return BracedExpression(contents, pos=node.pos, end_pos=node.end_pos)
return Expression(contents, pos=node.pos, end_pos=node.end_pos)
@_strip_ws
def _parse_expression(self, ts):
op1 = self._parse_operand(ts)
expr = op1
# last condition is hack to break out of expression in case we're in ternary op
if ts.type() not in {TOK_EOF, TOK_RPAREN} and ts.value() not in {":", ","}:
if ts.value() == "?":
# weird hack to record operator
start = ts.pos()
ts.next()
q = BareWord("?", pos=start, end_pos=ts.pos())
op2 = self._parse_expression(ts)
if ts.value() != ":":
start = ts.pos()
ts.next()
end = ts.pos()
raise TclSyntaxError(
"expected ':' to continue ternary expression", start, end
)
# weird hack again
start = ts.pos()
ts.next()
colon = BareWord(":", pos=start, end_pos=ts.pos())
op3 = self._parse_expression(ts)
expr = TernaryOp(
op1, q, op2, colon, op3, pos=op1.pos, end_pos=op3.end_pos
)
else:
operator = self._parse_operator(ts)
op2 = self._parse_expression(ts)
expr = BinaryOp(op1, operator, op2, pos=op1.pos, end_pos=op2.end_pos)
if ts.type() != TOK_RPAREN and ts.value() not in {":", ","}:
ts.expect(TOK_EOF, message="expected end of expression", pos=ts.pos())
return expr
@_strip_ws
def _parse_operand(self, ts):
if ts.type() == TOK_DOLLAR:
return self.parse_var_sub(ts)
if ts.type() == TOK_QUOTE:
return self.parse_quoted_word(ts)
if ts.type() == TOK_LBRACE:
return self.parse_braced_word(ts)
if ts.type() == TOK_LBRACKET:
return self.parse_command_sub(ts)
if ts.type() == TOK_LPAREN:
start = ts.pos()
ts.next()
expr = self._parse_expression(ts)
ts.expect(
TOK_RPAREN,
message="reached EOF without finding match for paren",
pos=expr.pos,
)
end = ts.pos()
return ParenExpression(expr, start, end)
if ts.value() in {"-", "+", "~", "!"}:
operator_val = ts.value()
operator_pos = ts.pos()
ts.next()
operator = BareWord(operator_val, pos=operator_pos, end_pos=ts.pos())
operand = self._parse_operand(ts)
# Since _parse_operand() munches whitespace after the operand, we
# set the end of the UnaryOp to the end of the operand rather than
# ts.pos(). Otherwise, the bounds of the UnaryOp would include all
# that whitespace.
return UnaryOp(operator, operand, pos=operator_pos, end_pos=operand.end_pos)
# If none of these, collect tokens that may comprise an operand
operand = ""
operand_pos = ts.pos()
# First, we want to check for numeric operands (either ints or numeric
# floats) by consuming tokens as long as they comprise the prefix of a
# numeric operand
while ts.type() != TOK_EOF and (
_is_int_prefix(operand + ts.value())
or _is_float_prefix(operand + ts.value())
):
operand += ts.value()
ts.next()
# Next, we check if we've consumed an entire numeric literal. If so, we
# move on. If not, we keep consuming tokens that may correspond to a
# valid bareword (pretty much just alphanumeric chars).
if not (_is_int_literal(operand) or _is_float_literal(operand)):
while ts.type() in {TOK_ALPHA_CHARS, TOK_NUM_CHARS}:
operand += ts.value()
ts.next()
# The above method is a little hacky. Note that it doesn't parse things
# exactly the same as Tcl. E.g. if a script includes `expr {1foo}`,
# tclint will report an invalid operator "foo", whereas tclsh will
# report an invalid bareword "1foo". Despite reporting them differently
# both tools should still catch the same syntax errors, since there are
# no legal barewords that begin with a numeric literal prefix, and tclsh
# will stop parsing numeric operands if they're actually followed by a
# legal operator (e.g. `expr {1eq1}` will be handled properly).
is_func = _is_function(operand)
if not (
_is_int_literal(operand)
or _is_float_literal(operand)
or _is_bool_literal(operand)
or is_func
):
raise TclSyntaxError(
f"invalid bareword in expression: {operand}", operand_pos, ts.pos()
)
node = BareWord(operand, pos=operand_pos, end_pos=ts.pos())
if is_func:
node = self._parse_function(ts, node)
return node
def _parse_operator(self, ts):
pos = ts.pos()
# hacky logic to handle parsing legal operators
if ts.value() in {"*", "&", "|"}:
# one or two of these characters are legal operators
operator = ts.value()
ts.next()
if ts.value() == operator:
operator += ts.value()
ts.next()
elif ts.value() in {"<", ">"}:
operator = ts.value()
ts.next()
if ts.value() in {operator, "="}:
operator += ts.value()
ts.next()
elif ts.value() in {"=", "!"}:
operator = ts.value()
ts.next()
if ts.value() != "=":
raise TclSyntaxError(
f"invalid operator in expression: {operator}", pos, ts.pos()
)
operator += ts.value()
ts.next()
elif ts.value() in {"*", "/", "%", "+", "-", "^", "eq", "ne", "in", "ni"}:
operator = ts.value()
ts.next()
else:
message = "invalid operator in expression: "
if ts.value() == "\\ ":
message += (
"\\ (check for trailing whitespace if it's the end of the line)"
)
else:
message += ts.value()
raise TclSyntaxError(message, pos, ts.pos())
return BareWord(operator, pos=pos, end_pos=ts.pos())
def _parse_function(self, ts, name):
while ts.type() in {TOK_WS, TOK_BACKSLASH_NEWLINE}:
ts.next()
ts.expect(
TOK_LPAREN,
message="expected open paren after function name",
pos=name.pos,
)
delims = {TOK_RPAREN, TOK_EOF}
arguments = []
if ts.type() not in delims:
arguments.append(self._parse_expression(ts))
while ts.type() not in delims:
if ts.value() != ",":
start = ts.pos()
ts.next()
end = ts.pos()
raise TclSyntaxError(
"expected comma between function arguments", start, end
)
ts.next()
arguments.append(self._parse_expression(ts))
ts.expect(
TOK_RPAREN,
message="expected close paren after function arguments",
pos=name.pos,
)
return Function(name, *arguments, pos=name.pos, end_pos=ts.pos())
def _all(_list, non_empty=False):
"""Like all(), but if non_empty is True, list must also have at least 1 element."""
if non_empty and len(_list) == 0:
return False
return all(_list)
def _is_int(operand, full=False):
"""Returns whether operand is a valid Tcl integer literal.
If full is False, will also return True if operand is the prefix of an
integer literal. An empty string is not a valid full literal, but is a
valid prefix.
"""
# prefixes
if operand.startswith("0b"):
return _all([digit in "01" for digit in operand[2:]], non_empty=full)
if operand.startswith("0o"):
return _all(
[digit in string.octdigits for digit in operand[2:]], non_empty=full
)
if operand.startswith("0x"):
return _all(
[digit in string.hexdigits for digit in operand[2:]], non_empty=full
)
if operand.startswith("0"):
# fun fact: apparently a lone 0 prefix is interpreted as octal
return _all(
[digit in string.octdigits for digit in operand[1:]], non_empty=full
)
return _all([digit in string.digits for digit in operand], non_empty=full)
def _is_int_literal(operand):
return _is_int(operand, full=True)
def _is_int_prefix(operand):
return _is_int(operand, full=False)
def _is_float_literal(operand):
if operand.lower() in {"nan", "inf"}:
return True
return (
operand != "" and re.fullmatch(r"\d*\.?\d*([Ee][+-]?\d+)?", operand) is not None
)
def _is_float_prefix(operand):
"""Returns whether operand is the prefix of a valid numeric float literal."""
return re.fullmatch(r"\d*\.?\d*([Ee][+-]?)?\d*", operand) is not None
def _is_bool_literal(operand):
return operand in {"false", "no", "off", "true", "yes", "on"}
# map of function names to # arguments accepted
# None indicates 1 or more arguments
# TODO: use these values in an actual separate check. they might want to live elsewhere
_FUNCTIONS = {
"abs": 1,
"acos": 1,
"asin": 1,
"atan": 1,
"atan2": 2,
"bool": 1,
"ceil": 1,
"cos": 1,
"cosh": 1,
"double": 1,
"entier": 1,
"exp": 1,
"floor": 1,
"fmod": 2,
"hypot": 2,
"int": 1,
"isqrt": 1,
"log": 1,
"log10": 1,
"max": None,
"min": None,
"pow": 2,
"rand": 0,
"round": 1,
"sin": 1,
"sinh": 1,
"sqrt": 1,
"srand": 1,
"tan": 1,
"tanh": 1,
"wide": 1,
}
def _is_function(operand):
return operand in _FUNCTIONS.keys()