[Patches] New checkappend.py tool

[Tim Peters]

New script (akin to tabnanny.py) for finding multi-argument .append() calls.
Much easier than trying to wade thru a gazillion false positives via e.g.
grep.


I confirm that, to the best of my knowledge and belief, this
contribution is free of any claims of third parties under
copyright, patent or other rights or interests ("claims").  To
the extent that I have any such claims, I hereby grant to CNRI a
nonexclusive, irrevocable, royalty-free, worldwide license to
reproduce, distribute, perform and/or display publicly, prepare
derivative versions, and otherwise use this contribution as part
of the Python software and its related documentation, or any
derivative versions thereof, at no cost to CNRI or its licensed
users, and to authorize others to do so.

I acknowledge that CNRI may, at its sole discretion, decide
whether or not to incorporate this contribution in the Python
software and its related documentation.  I further grant CNRI
permission to use my name and other identifying information
provided to CNRI by me for use in connection with the Python
software and its related documentation.


#! /usr/bin/env python

# Released to the public domain, by Tim Peters, 28 February 2000.

"""checkappend.py -- search for multi-argument .append() calls.

Usage:  specify one or more file or directory paths:
    checkappend [-v] file_or_dir [file_or_dir] ...

Each file_or_dir is checked for multi-argument .append() calls.  When
a directory, all .py files in the directory, and recursively in its
subdirectories, are checked.

Use -v for status msgs.  Use -vv for more status msgs.

In the absence of -v, the only output is pairs of the form

    filename(linenumber):
    line containing the suspicious append

Note that this finds multi-argument append calls regardless of whether
they're attached to list objects.  If a module defines a class with an
append method that takes more than one argument, calls to that method
will be listed.

Note that this will not find multi-argument list.append calls made via a
bound method object.  For example, this is not caught:

    somelist = []
    push = somelist.append
    push(1, 2, 3)
"""

__version__ = 1, 0, 0

import os
import sys
import string
import getopt
import tokenize

verbose = 0

def errprint(*args):
    msg = string.join(args)
    sys.stderr.write(msg)
    sys.stderr.write("\n")

def main():
    args = sys.argv[1:]
    global verbose
    try:
        opts, args = getopt.getopt(sys.argv[1:], "v")
    except getopt.error, msg:
        errprint(msg + "\n\n" + __doc__)
        return
    for opt, optarg in opts:
        if opt == '-v':
            verbose = verbose + 1
    if not args:
        errprint(__doc__)
        return
    for arg in args:
        check(arg)

def check(file):
    if os.path.isdir(file) and not os.path.islink(file):
        if verbose:
            print "%s: 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 = open(file)
    except IOError, msg:
        errprint("%s: I/O Error: %s" % (`file`, str(msg)))
        return

    if verbose > 1:
        print "checking", `file`, "..."

    ok = AppendChecker(file, f).run()
    if verbose and ok:
        print "%s: Clean bill of health." % `file`

[FIND_DOT,
 FIND_APPEND,
 FIND_LPAREN,
 FIND_COMMA,
 FIND_STMT]   = range(5)

class AppendChecker:
    def __init__(self, fname, file):
        self.fname = fname
        self.file = file
        self.state = FIND_DOT
        self.nerrors = 0

    def run(self):
        try:
            tokenize.tokenize(self.file.readline, self.tokeneater)
        except tokenize.TokenError, msg:
            errprint("%s: Token Error: %s" % (`self.fname`, str(msg)))
            self.nerrors = self.nerrors + 1
        return self.nerrors == 0

    def tokeneater(self, type, token, start, end, line,
                NEWLINE=tokenize.NEWLINE,
                JUNK=(tokenize.COMMENT, tokenize.NL),
                OP=tokenize.OP,
                NAME=tokenize.NAME):

        state = self.state

        if type in JUNK:
            pass

        elif state is FIND_DOT:
            if type is OP and token == ".":
                state = FIND_APPEND

        elif state is FIND_APPEND:
            if type is NAME and token == "append":
                self.line = line
                self.lineno = start[0]
                state = FIND_LPAREN
            else:
                state = FIND_DOT

        elif state is FIND_LPAREN:
            if type is OP and token == "(":
                self.level = 1
                state = FIND_COMMA
            else:
                state = FIND_DOT

        elif state is FIND_COMMA:
            if type is OP:
                if token in ("(", "{", "["):
                    self.level = self.level + 1
                elif token in (")", "}", "]"):
                    self.level = self.level - 1
                    if self.level == 0:
                        state = FIND_DOT
                elif token == "," and self.level == 1:
                    self.nerrors = self.nerrors + 1
                    print "%s(%d):\n%s" % (self.fname, self.lineno,
                                           self.line)
                    # don't gripe about this stmt again
                    state = FIND_STMT

        elif state is FIND_STMT:
            if type is NEWLINE:
                state = FIND_DOT

        else:
            raise SystemError("unknown internal state '%s'" % `state`)

        self.state = state

if __name__ == '__main__':
    main()