mirror of
https://github.com/python/cpython.git
synced 2024-11-21 21:09:37 +01:00
339 lines
11 KiB
Python
339 lines
11 KiB
Python
"""The Tab Nanny despises ambiguous indentation. She knows no mercy.
|
|
|
|
tabnanny -- Detection of ambiguous indentation
|
|
|
|
For the time being this module is intended to be called as a script.
|
|
However it is possible to import it into an IDE and use the function
|
|
check() described below.
|
|
|
|
Warning: The API provided by this module is likely to change in future
|
|
releases; such changes may not be backward compatible.
|
|
"""
|
|
|
|
# Released to the public domain, by Tim Peters, 15 April 1998.
|
|
|
|
# XXX Note: this is now a standard library module.
|
|
# XXX The API needs to undergo changes however; the current code is too
|
|
# XXX script-like. This will be addressed later.
|
|
|
|
__version__ = "6"
|
|
|
|
import os
|
|
import sys
|
|
import tokenize
|
|
|
|
__all__ = ["check", "NannyNag", "process_tokens"]
|
|
|
|
verbose = 0
|
|
filename_only = 0
|
|
|
|
def errprint(*args):
|
|
sep = ""
|
|
for arg in args:
|
|
sys.stderr.write(sep + str(arg))
|
|
sep = " "
|
|
sys.stderr.write("\n")
|
|
sys.exit(1)
|
|
|
|
def main():
|
|
import getopt
|
|
|
|
global verbose, filename_only
|
|
try:
|
|
opts, args = getopt.getopt(sys.argv[1:], "qv")
|
|
except getopt.error as msg:
|
|
errprint(msg)
|
|
for o, a in opts:
|
|
if o == '-q':
|
|
filename_only = filename_only + 1
|
|
if o == '-v':
|
|
verbose = verbose + 1
|
|
if not args:
|
|
errprint("Usage:", sys.argv[0], "[-v] file_or_directory ...")
|
|
for arg in args:
|
|
check(arg)
|
|
|
|
class NannyNag(Exception):
|
|
"""
|
|
Raised by process_tokens() if detecting an ambiguous indent.
|
|
Captured and handled in check().
|
|
"""
|
|
def __init__(self, lineno, msg, line):
|
|
self.lineno, self.msg, self.line = lineno, msg, line
|
|
def get_lineno(self):
|
|
return self.lineno
|
|
def get_msg(self):
|
|
return self.msg
|
|
def get_line(self):
|
|
return self.line
|
|
|
|
def check(file):
|
|
"""check(file_or_dir)
|
|
|
|
If file_or_dir is a directory and not a symbolic link, then recursively
|
|
descend the directory tree named by file_or_dir, checking all .py files
|
|
along the way. If file_or_dir is an ordinary Python source file, it is
|
|
checked for whitespace related problems. The diagnostic messages are
|
|
written to standard output using the print statement.
|
|
"""
|
|
|
|
if os.path.isdir(file) and not os.path.islink(file):
|
|
if verbose:
|
|
print("%r: listing directory" % (file,))
|
|
names = os.listdir(file)
|
|
for name in names:
|
|
fullname = os.path.join(file, name)
|
|
if (os.path.isdir(fullname) and
|
|
not os.path.islink(fullname) or
|
|
os.path.normcase(name[-3:]) == ".py"):
|
|
check(fullname)
|
|
return
|
|
|
|
try:
|
|
f = tokenize.open(file)
|
|
except OSError as msg:
|
|
errprint("%r: I/O Error: %s" % (file, msg))
|
|
return
|
|
|
|
if verbose > 1:
|
|
print("checking %r ..." % file)
|
|
|
|
try:
|
|
process_tokens(tokenize.generate_tokens(f.readline))
|
|
|
|
except tokenize.TokenError as msg:
|
|
errprint("%r: Token Error: %s" % (file, msg))
|
|
return
|
|
|
|
except IndentationError as msg:
|
|
errprint("%r: Indentation Error: %s" % (file, msg))
|
|
return
|
|
|
|
except SyntaxError as msg:
|
|
errprint("%r: Syntax Error: %s" % (file, msg))
|
|
return
|
|
|
|
except NannyNag as nag:
|
|
badline = nag.get_lineno()
|
|
line = nag.get_line()
|
|
if verbose:
|
|
print("%r: *** Line %d: trouble in tab city! ***" % (file, badline))
|
|
print("offending line: %r" % (line,))
|
|
print(nag.get_msg())
|
|
else:
|
|
if ' ' in file: file = '"' + file + '"'
|
|
if filename_only: print(file)
|
|
else: print(file, badline, repr(line))
|
|
return
|
|
|
|
finally:
|
|
f.close()
|
|
|
|
if verbose:
|
|
print("%r: Clean bill of health." % (file,))
|
|
|
|
class Whitespace:
|
|
# the characters used for space and tab
|
|
S, T = ' \t'
|
|
|
|
# members:
|
|
# raw
|
|
# the original string
|
|
# n
|
|
# the number of leading whitespace characters in raw
|
|
# nt
|
|
# the number of tabs in raw[:n]
|
|
# norm
|
|
# the normal form as a pair (count, trailing), where:
|
|
# count
|
|
# a tuple such that raw[:n] contains count[i]
|
|
# instances of S * i + T
|
|
# trailing
|
|
# the number of trailing spaces in raw[:n]
|
|
# It's A Theorem that m.indent_level(t) ==
|
|
# n.indent_level(t) for all t >= 1 iff m.norm == n.norm.
|
|
# is_simple
|
|
# true iff raw[:n] is of the form (T*)(S*)
|
|
|
|
def __init__(self, ws):
|
|
self.raw = ws
|
|
S, T = Whitespace.S, Whitespace.T
|
|
count = []
|
|
b = n = nt = 0
|
|
for ch in self.raw:
|
|
if ch == S:
|
|
n = n + 1
|
|
b = b + 1
|
|
elif ch == T:
|
|
n = n + 1
|
|
nt = nt + 1
|
|
if b >= len(count):
|
|
count = count + [0] * (b - len(count) + 1)
|
|
count[b] = count[b] + 1
|
|
b = 0
|
|
else:
|
|
break
|
|
self.n = n
|
|
self.nt = nt
|
|
self.norm = tuple(count), b
|
|
self.is_simple = len(count) <= 1
|
|
|
|
# return length of longest contiguous run of spaces (whether or not
|
|
# preceding a tab)
|
|
def longest_run_of_spaces(self):
|
|
count, trailing = self.norm
|
|
return max(len(count)-1, trailing)
|
|
|
|
def indent_level(self, tabsize):
|
|
# count, il = self.norm
|
|
# for i in range(len(count)):
|
|
# if count[i]:
|
|
# il = il + (i//tabsize + 1)*tabsize * count[i]
|
|
# return il
|
|
|
|
# quicker:
|
|
# il = trailing + sum (i//ts + 1)*ts*count[i] =
|
|
# trailing + ts * sum (i//ts + 1)*count[i] =
|
|
# trailing + ts * sum i//ts*count[i] + count[i] =
|
|
# trailing + ts * [(sum i//ts*count[i]) + (sum count[i])] =
|
|
# trailing + ts * [(sum i//ts*count[i]) + num_tabs]
|
|
# and note that i//ts*count[i] is 0 when i < ts
|
|
|
|
count, trailing = self.norm
|
|
il = 0
|
|
for i in range(tabsize, len(count)):
|
|
il = il + i//tabsize * count[i]
|
|
return trailing + tabsize * (il + self.nt)
|
|
|
|
# return true iff self.indent_level(t) == other.indent_level(t)
|
|
# for all t >= 1
|
|
def equal(self, other):
|
|
return self.norm == other.norm
|
|
|
|
# return a list of tuples (ts, i1, i2) such that
|
|
# i1 == self.indent_level(ts) != other.indent_level(ts) == i2.
|
|
# Intended to be used after not self.equal(other) is known, in which
|
|
# case it will return at least one witnessing tab size.
|
|
def not_equal_witness(self, other):
|
|
n = max(self.longest_run_of_spaces(),
|
|
other.longest_run_of_spaces()) + 1
|
|
a = []
|
|
for ts in range(1, n+1):
|
|
if self.indent_level(ts) != other.indent_level(ts):
|
|
a.append( (ts,
|
|
self.indent_level(ts),
|
|
other.indent_level(ts)) )
|
|
return a
|
|
|
|
# Return True iff self.indent_level(t) < other.indent_level(t)
|
|
# for all t >= 1.
|
|
# The algorithm is due to Vincent Broman.
|
|
# Easy to prove it's correct.
|
|
# XXXpost that.
|
|
# Trivial to prove n is sharp (consider T vs ST).
|
|
# Unknown whether there's a faster general way. I suspected so at
|
|
# first, but no longer.
|
|
# For the special (but common!) case where M and N are both of the
|
|
# form (T*)(S*), M.less(N) iff M.len() < N.len() and
|
|
# M.num_tabs() <= N.num_tabs(). Proof is easy but kinda long-winded.
|
|
# XXXwrite that up.
|
|
# Note that M is of the form (T*)(S*) iff len(M.norm[0]) <= 1.
|
|
def less(self, other):
|
|
if self.n >= other.n:
|
|
return False
|
|
if self.is_simple and other.is_simple:
|
|
return self.nt <= other.nt
|
|
n = max(self.longest_run_of_spaces(),
|
|
other.longest_run_of_spaces()) + 1
|
|
# the self.n >= other.n test already did it for ts=1
|
|
for ts in range(2, n+1):
|
|
if self.indent_level(ts) >= other.indent_level(ts):
|
|
return False
|
|
return True
|
|
|
|
# return a list of tuples (ts, i1, i2) such that
|
|
# i1 == self.indent_level(ts) >= other.indent_level(ts) == i2.
|
|
# Intended to be used after not self.less(other) is known, in which
|
|
# case it will return at least one witnessing tab size.
|
|
def not_less_witness(self, other):
|
|
n = max(self.longest_run_of_spaces(),
|
|
other.longest_run_of_spaces()) + 1
|
|
a = []
|
|
for ts in range(1, n+1):
|
|
if self.indent_level(ts) >= other.indent_level(ts):
|
|
a.append( (ts,
|
|
self.indent_level(ts),
|
|
other.indent_level(ts)) )
|
|
return a
|
|
|
|
def format_witnesses(w):
|
|
firsts = (str(tup[0]) for tup in w)
|
|
prefix = "at tab size"
|
|
if len(w) > 1:
|
|
prefix = prefix + "s"
|
|
return prefix + " " + ', '.join(firsts)
|
|
|
|
def process_tokens(tokens):
|
|
try:
|
|
_process_tokens(tokens)
|
|
except TabError as e:
|
|
raise NannyNag(e.lineno, e.msg, e.text)
|
|
|
|
def _process_tokens(tokens):
|
|
INDENT = tokenize.INDENT
|
|
DEDENT = tokenize.DEDENT
|
|
NEWLINE = tokenize.NEWLINE
|
|
JUNK = tokenize.COMMENT, tokenize.NL
|
|
indents = [Whitespace("")]
|
|
check_equal = 0
|
|
|
|
for (type, token, start, end, line) in tokens:
|
|
if type == NEWLINE:
|
|
# a program statement, or ENDMARKER, will eventually follow,
|
|
# after some (possibly empty) run of tokens of the form
|
|
# (NL | COMMENT)* (INDENT | DEDENT+)?
|
|
# If an INDENT appears, setting check_equal is wrong, and will
|
|
# be undone when we see the INDENT.
|
|
check_equal = 1
|
|
|
|
elif type == INDENT:
|
|
check_equal = 0
|
|
thisguy = Whitespace(token)
|
|
if not indents[-1].less(thisguy):
|
|
witness = indents[-1].not_less_witness(thisguy)
|
|
msg = "indent not greater e.g. " + format_witnesses(witness)
|
|
raise NannyNag(start[0], msg, line)
|
|
indents.append(thisguy)
|
|
|
|
elif type == DEDENT:
|
|
# there's nothing we need to check here! what's important is
|
|
# that when the run of DEDENTs ends, the indentation of the
|
|
# program statement (or ENDMARKER) that triggered the run is
|
|
# equal to what's left at the top of the indents stack
|
|
|
|
# Ouch! This assert triggers if the last line of the source
|
|
# is indented *and* lacks a newline -- then DEDENTs pop out
|
|
# of thin air.
|
|
# assert check_equal # else no earlier NEWLINE, or an earlier INDENT
|
|
check_equal = 1
|
|
|
|
del indents[-1]
|
|
|
|
elif check_equal and type not in JUNK:
|
|
# this is the first "real token" following a NEWLINE, so it
|
|
# must be the first token of the next program statement, or an
|
|
# ENDMARKER; the "line" argument exposes the leading whitespace
|
|
# for this statement; in the case of ENDMARKER, line is an empty
|
|
# string, so will properly match the empty string with which the
|
|
# "indents" stack was seeded
|
|
check_equal = 0
|
|
thisguy = Whitespace(line)
|
|
if not indents[-1].equal(thisguy):
|
|
witness = indents[-1].not_equal_witness(thisguy)
|
|
msg = "indent not equal e.g. " + format_witnesses(witness)
|
|
raise NannyNag(start[0], msg, line)
|
|
|
|
|
|
if __name__ == '__main__':
|
|
main()
|