#!/usr/bin/env python

# Copyright (c) 2001-2004, MetaSlash Inc.  All rights reserved.
# Portions Copyright (c) 2005, Google, Inc.  All rights reserved.

"""
Check python source code files for possible errors and print warnings

Contact Info:
  http://pychecker.sourceforge.net/
  pychecker-list@lists.sourceforge.net
"""

import string
import types
import sys
import imp
import os
import glob
import traceback
import re

# see __init__.py for meaning, this must match the version there
LOCAL_MAIN_VERSION = 3


def setupNamespace(path) :
    # remove pychecker if it's the first component, it needs to be last
    if sys.path[0][-9:] == 'pychecker' :
        del sys.path[0]

    # make sure pychecker is last in path, so we can import
    checker_path = os.path.dirname(os.path.dirname(path))
    if checker_path not in sys.path :
        sys.path.append(checker_path)

if __name__ == '__main__' :
    setupNamespace(sys.argv[0])

from pychecker import utils
from pychecker import printer
from pychecker import warn
from pychecker import OP
from pychecker import Config
from pychecker import function
from pychecker import msgs
from pychecker.Warning import Warning

# Globals for storing a dictionary of info about modules and classes
_allModules = {}
_cfg = None

# Constants
_DEFAULT_MODULE_TOKENS = ('__builtins__', '__doc__', '__file__', '__name__',
                          '__path__')
_DEFAULT_CLASS_TOKENS = ('__doc__', '__name__', '__module__')

# When using introspection on objects from some C extension modules,
# the interpreter will crash.  Since pychecker exercises these bugs we
# need to blacklist the objects and ignore them.  For more info on how
# to determine what object is causing the crash, search for this
# comment below (ie, it is also several hundred lines down):
#
#     README if interpreter is crashing:

# FIXME: the values should indicate the versions of these modules
# that are broken.  We shouldn't ignore good modules.

_EVIL_C_OBJECTS = {
    'matplotlib.axes.BinOpType': None,  # broken on versions <= 0.83.2

    # broken on versions at least 2.5.5 up to 2.6
    'wx.TheClipboard': None,
    'wx._core.TheClipboard': None,
    'wx._misc.TheClipboard': None,
  }

_VERSION_MISMATCH_ERROR = '''
There seem to be two versions of PyChecker being used.
One is probably in python/site-packages, the other in a local directory.
If you want to run the local version, you must remove the version
from site-packages.  Or you can install the current version
by doing python setup.py install.
'''

def cfg() :
    return utils.cfg()

def _flattenList(list) :
    "Returns a list which contains no lists"

    new_list = []
    for element in list :
        if type(element) == types.ListType :
            new_list.extend(_flattenList(element))
        else :
            new_list.append(element)

    return new_list

def getModules(arg_list) :
    "Returns a list of module names that can be imported"

    new_arguments = []
    for arg in arg_list :
        # is this a wildcard filespec? (necessary for windows)
        if '*' in arg or '?' in arg or '[' in arg :
            arg = glob.glob(arg)
        new_arguments.append(arg)

    PY_SUFFIXES = ['.py']
    PY_SUFFIX_LENS = [3]
    if _cfg.quixote:
        PY_SUFFIXES.append('.ptl')
        PY_SUFFIX_LENS.append(4)
        
    modules = []
    for arg in _flattenList(new_arguments) :
        # is it a .py file?
        for suf, suflen in zip(PY_SUFFIXES, PY_SUFFIX_LENS):
            if len(arg) > suflen and arg[-suflen:] == suf:
                arg_dir = os.path.dirname(arg)
                if arg_dir and not os.path.exists(arg) :
                    print 'File or pathname element does not exist: "%s"' % arg
                    continue

                module_name = os.path.basename(arg)[:-suflen]
                if arg_dir not in sys.path :
                    sys.path.insert(0, arg_dir)
                arg = module_name
        modules.append(arg)

    return modules

def _q_file(f):
    # crude hack!!!
    # imp.load_module requires a real file object, so we can't just
    # fiddle def lines and yield them
    import tempfile
    fd, newfname = tempfile.mkstemp(suffix=".py", text=True)
    newf = os.fdopen(fd, 'r+')
    os.unlink(newfname)
    for line in f:
        mat = re.match(r'(\s*def\s+\w+\s*)\[(html|plain)\](.*)', line)
        if mat is None:
            newf.write(line)
        else:
            newf.write(mat.group(1)+mat.group(3)+'\n')
    newf.seek(0)
    return newf

def _q_find_module(p, path):
    if not _cfg.quixote:
        return imp.find_module(p, path)
    else:
        for direc in path:
            try:
                return imp.find_module(p, [direc])
            except ImportError:
                f = os.path.join(direc, p+".ptl")
                if os.path.exists(f):
                    return _q_file(file(f)), f, ('.ptl', 'U', 1)

def _findModule(name) :
    """Returns the result of an imp.find_module(), ie, (file, filename, smt)
       name can be a module or a package name.  It is *not* a filename."""

    path = sys.path[:]
    packages = string.split(name, '.')
    for p in packages :
        # smt = (suffix, mode, type)
        file, filename, smt = _q_find_module(p, path)
        if smt[-1] == imp.PKG_DIRECTORY :
            try :
                # package found - read path info from init file
                m = imp.load_module(p, file, filename, smt)
            finally :
                if file is not None :
                    file.close()

            # importing xml plays a trick, which replaces itself with _xmlplus
            # both have subdirs w/same name, but different modules in them
            # we need to choose the real (replaced) version
            if m.__name__ != p :
                try :
                    file, filename, smt = _q_find_module(m.__name__, path)
                    m = imp.load_module(p, file, filename, smt)
                finally :
                    if file is not None :
                        file.close()

            new_path = m.__path__
            if type(new_path) == types.ListType :
                new_path = filename
            if new_path not in path :
                path.insert(1, new_path)
        elif smt[-1] != imp.PY_COMPILED:
            if p is not packages[-1] :
                if file is not None :
                    file.close()
                raise ImportError, "No module named %s" % packages[-1]
            return file, filename, smt

    # in case we have been given a package to check
    return file, filename, smt


class Variable :
    "Class to hold all information about a variable"

    def __init__(self, name, type):
        self.name = name
        self.type = type
        self.value = None

    def __str__(self) :
        return self.name

    __repr__ = utils.std_repr


def _filterDir(object, ignoreList) :
    "Return a list of tokens (attributes) in a class, except for ignoreList"

    tokens = dir(object)
    for token in ignoreList :
        if token in tokens :
            tokens.remove(token)
    return tokens

def _getClassTokens(c) :
    return _filterDir(c, _DEFAULT_CLASS_TOKENS)


class Class :
    "Class to hold all information about a class"

    def __init__(self, name, module) :
        self.name = name
        self.classObject = getattr(module, name)

        modname = getattr(self.classObject, '__module__', None)
        if modname is None:
            # hm, some ExtensionClasses don't have a __module__ attribute
            # so try parsing the type output
            typerepr = repr(type(self.classObject))
            mo = re.match("^<type ['\"](.+)['\"]>$", typerepr)
            if mo:
                modname = ".".join(mo.group(1).split(".")[:-1])

        self.module = sys.modules.get(modname)
        if not self.module:
            self.module = module
            sys.stderr.write("warning: couldn't find real module "
                             "for class %s (module name: %s)\n"
                             % (self.classObject, modname))
        self.ignoreAttrs = 0
        self.methods = {}
        self.members = { '__class__': types.ClassType,
                         '__doc__': types.StringType,
                         '__dict__': types.DictType, }
        self.memberRefs = {}
        self.statics = {}
        self.lineNums = {}

    def __str__(self) :
        return self.name

    __repr__ = utils.std_repr

    def getFirstLine(self) :
        "Return first line we can find in THIS class, not any base classes"

        lineNums = []
        classDir = dir(self.classObject)
        for m in self.methods.values() :
            if m != None and m.function.func_code.co_name in classDir:
                lineNums.append(m.function.func_code.co_firstlineno)
        if lineNums :
            return min(lineNums)
        return 0


    def allBaseClasses(self, c = None) :
        "Return a list of all base classes for this class and it's subclasses"

        baseClasses = []
        if c == None :
            c = self.classObject
        for base in c.__bases__ :
            baseClasses = baseClasses + [ base ] + self.allBaseClasses(base)
        return baseClasses

    def __getMethodName(self, func_name, className = None) :
        if func_name[0:2] == '__' and func_name[-2:] != '__' :
            if className == None :
                className = self.name
            if className[0] != '_' :
                className = '_' + className
            func_name = className + func_name
        return func_name

    def addMethod(self, method, methodName = None) :
        if type(method) == types.StringType :
            self.methods[method] = None
        else :
            assert methodName is not None, "must supply methodName"
            self.methods[methodName] = function.Function(method, 1)
                
    def addMethods(self, classObject) :
        for classToken in _getClassTokens(classObject) :
            token = getattr(classObject, classToken, None)
            if token is None:
                continue

            # Looks like a method.  Need to code it this way to
            # accommodate ExtensionClass and Python 2.2.  Yecchh.
            if (hasattr(token, "func_code") and
                hasattr(token.func_code, "co_argcount")): 
                self.addMethod(token, token.__name__)

            elif hasattr(token, '__get__') and \
                 not hasattr(token, '__set__') and \
                 type(token) is not types.ClassType :
                self.addMethod(getattr(token, '__name__', classToken))
            else :
                self.members[classToken] = type(token)
                self.memberRefs[classToken] = None

        self.cleanupMemberRefs()
        # add standard methods
        for methodName in ('__class__',) :
            self.addMethod(methodName, classObject.__name__)

    def addMembers(self, classObject) :
        if not cfg().onlyCheckInitForMembers :
            for classToken in _getClassTokens(classObject) :
                method = getattr(classObject, classToken, None)
                if type(method) == types.MethodType :
                    self.addMembersFromMethod(method.im_func)
        else:
            try:
                self.addMembersFromMethod(classObject.__init__.im_func)
            except AttributeError:
                pass

    def addMembersFromMethod(self, method) :
        if not hasattr(method, 'func_code') :
            return

        func_code, code, i, maxCode, extended_arg = OP.initFuncCode(method)
        stack = []
        while i < maxCode :
            op, oparg, i, extended_arg = OP.getInfo(code, i, extended_arg)
            if op >= OP.HAVE_ARGUMENT :
                operand = OP.getOperand(op, func_code, oparg)
                if OP.LOAD_CONST(op) or OP.LOAD_FAST(op) or OP.LOAD_GLOBAL(op):
                    stack.append(operand)
                elif OP.LOAD_DEREF(op):
                    try:
                        operand = func_code.co_cellvars[oparg]
                    except IndexError:
                        index = oparg - len(func_code.co_cellvars)
                        operand = func_code.co_freevars[index]
                    stack.append(operand)
                elif OP.STORE_ATTR(op) :
                    if len(stack) > 0 :
                        if stack[-1] == cfg().methodArgName:
                            value = None
                            if len(stack) > 1 :
                                value = type(stack[-2])
                            self.members[operand] = value
                            self.memberRefs[operand] = None
                        stack = []

        self.cleanupMemberRefs()

    def cleanupMemberRefs(self) :
        try :
            del self.memberRefs[Config.CHECKER_VAR]
        except KeyError :
            pass

    def abstractMethod(self, m):
        """Return 1 if method is abstract, None if not
           An abstract method always raises an exception.
        """
        if not self.methods.get(m, None):
            return None
        func_code, bytes, i, maxCode, extended_arg = \
                   OP.initFuncCode(self.methods[m].function)
        # abstract if the first opcode is RAISE_VARARGS and it raises
        # NotImplementedError
        arg = ""
        while i < maxCode:
            op, oparg, i, extended_arg = OP.getInfo(bytes, i, extended_arg)
            if OP.LOAD_GLOBAL(op):
                arg = func_code.co_names[oparg]
            elif OP.RAISE_VARARGS(op):
                # if we saw NotImplementedError sometime before the raise
                # assume it's related to this raise stmt
                return arg == "NotImplementedError"
            if OP.conditional(op):
                break
        return None

    def isAbstract(self):
        """Return the method names that make a class abstract.
           An abstract class has at least one abstract method."""
        result = []
        for m in self.methods.keys():
            if self.abstractMethod(m):
                result.append(m)
        return result

def _getLineInFile(moduleName, linenum):
    line = ''
    file, filename, smt = _findModule(moduleName)
    try:
        lines = file.readlines()
        line = string.rstrip(lines[linenum - 1])
    except (IOError, IndexError):
        pass
    file.close()
    return line

def importError(moduleName):
    exc_type, exc_value, tb = sys.exc_info()

    # First, try to get a nice-looking name for this exception type.
    exc_name = getattr(exc_type, '__name__', None)
    if not exc_name:
        # either it's a string exception or a user-defined exception class
        # show string or fully-qualified class name
        exc_name = utils.safestr(exc_type)
        
    # Print a traceback, unless this is an ImportError.  ImportError is
    # presumably the most common import-time exception, so this saves
    # the clutter of a traceback most of the time.  Also, the locus of
    # the error is usually irrelevant for ImportError, so the lack of
    # traceback shouldn't be a problem.
    if exc_type is SyntaxError:
        # SyntaxErrors are special, we want to control how we format
        # the output and make it consistent for all versions of Python
        e = exc_value
        msg = '%s (%s, line %d)' % (e.msg, e.filename, e.lineno)
        line = _getLineInFile(moduleName, e.lineno)
        offset = e.offset
        if type(offset) is not types.IntType:
            offset = 0
        exc_value = '%s\n    %s\n   %s^' % (msg, line, ' ' * offset)
    elif exc_type is not ImportError:
        sys.stderr.write("  Caught exception importing module %s:\n" %
                         moduleName)

        try:
            tbinfo = traceback.extract_tb(tb)
        except:
            tbinfo = []
            sys.stderr.write("      Unable to format traceback\n")
        for filename, line, func, text in tbinfo[1:]:
            sys.stderr.write("    File \"%s\", line %d" % (filename, line))
            if func != "?":
                sys.stderr.write(", in %s()" % func)
            sys.stderr.write("\n")
            if text:
                sys.stderr.write("      %s\n" % text)

    # And finally print the exception type and value.
    # Careful formatting exc_value -- can fail for some user exceptions
    sys.stderr.write("  %s: " % exc_name)
    try:
        sys.stderr.write(utils.safestr(exc_value) + '\n')
    except:
        sys.stderr.write('**error formatting exception value**\n')


def _getPyFile(filename):
    """Return the file and '.py' filename from a filename which could
    end with .py, .pyc, or .pyo"""

    if filename[-1] in 'oc' and filename[-4:-1] == '.py':
        return filename[:-1]
    return filename

class PyCheckerModule :
    "Class to hold all information for a module"

    def __init__(self, moduleName, check = 1) :
        self.moduleName = moduleName
        self.variables = {}
        self.functions = {}
        self.classes = {}
        self.modules = {}
        self.moduleLineNums = {}
        self.attributes = [ '__dict__' ]
        self.main_code = None
        self.module = None
        self.check = check
        _allModules[moduleName] = self

    def __str__(self) :
        return self.moduleName

    __repr__ = utils.std_repr

    def addVariable(self, var, varType) :
        self.variables[var] = Variable(var, varType)

    def addFunction(self, func) :
        self.functions[func.__name__] = function.Function(func)

    def __addAttributes(self, c, classObject) :
        for base in classObject.__bases__ :
            self.__addAttributes(c, base)
        c.addMethods(classObject)
        c.addMembers(classObject)

    def addClass(self, name) :
        self.classes[name] = c = Class(name, self.module)
        try:
            objName = utils.safestr(c.classObject)
        except TypeError:
            # this can happen if there is a goofy __getattr__
            c.ignoreAttrs = 1
        else:
            packages = string.split(objName, '.')
            c.ignoreAttrs = packages[0] in cfg().blacklist
        if not c.ignoreAttrs :
            self.__addAttributes(c, c.classObject)

    def addModule(self, name) :
        module = _allModules.get(name, None)
        if module is None :
            self.modules[name] = module = PyCheckerModule(name, 0)
            if imp.is_builtin(name) == 0:
                module.load()
            else :
                globalModule = globals().get(name)
                if globalModule :
                    module.attributes.extend(dir(globalModule))
        else :
            self.modules[name] = module

    def filename(self) :
        try :
            filename = self.module.__file__
        except AttributeError :
            filename = self.moduleName
        return _getPyFile(filename)

    def load(self):
        try :
            # there's no need to reload modules we already have
            module = sys.modules.get(self.moduleName)
            if module :
                if not _allModules[self.moduleName].module :
                    return self._initModule(module)
                return 1

            return self._initModule(self.setupMainCode())
        except (SystemExit, KeyboardInterrupt) :
            exc_type, exc_value, exc_tb = sys.exc_info()
            raise exc_type, exc_value
        except :
            importError(self.moduleName)
            return 0

    def initModule(self, module) :
        if not self.module:
            filename = _getPyFile(module.__file__)
            if string.lower(filename[-3:]) == '.py':
                try:
                    file = open(filename)
                except IOError:
                    pass
                else:
                    self._setupMainCode(file, filename, module)
            return self._initModule(module)
        return 1

    def _initModule(self, module):
        self.module = module
        self.attributes = dir(self.module)

        pychecker_attr = getattr(module, Config.CHECKER_VAR, None)
        if pychecker_attr is not None :
            utils.pushConfig()
            utils.updateCheckerArgs(pychecker_attr, 'suppressions', 0, [])

        for tokenName in _filterDir(self.module, _DEFAULT_MODULE_TOKENS) :
            if _EVIL_C_OBJECTS.has_key('%s.%s' % (self.moduleName, tokenName)):
                continue

            # README if interpreter is crashing:
            # Change 0 to 1 if the interpretter is crashing and re-run.
            # Follow the instructions from the last line printed.
            if 0:
                print "Add the following line to _EVIL_C_OBJECTS:\n" \
                      "    '%s.%s': None, " % (self.moduleName, tokenName)

            token = getattr(self.module, tokenName)
            if isinstance(token, types.ModuleType) :
                # get the real module name, tokenName could be an alias
                self.addModule(token.__name__)
            elif isinstance(token, types.FunctionType) :
                self.addFunction(token)
            elif isinstance(token, types.ClassType) or \
                 hasattr(token, '__bases__') :
                self.addClass(tokenName)
            else :
                self.addVariable(tokenName, type(token))

        if pychecker_attr is not None :
            utils.popConfig()
        return 1

    def setupMainCode(self) :
        file, filename, smt = _findModule(self.moduleName)
        # FIXME: if the smt[-1] == imp.PKG_DIRECTORY : load __all__
        module = imp.load_module(self.moduleName, file, filename, smt)
        self._setupMainCode(file, filename, module)
        return module

    def _setupMainCode(self, file, filename, module):
        try :
            self.main_code = function.create_from_file(file, filename, module)
        finally :
            if file != None :
                file.close()


def getAllModules() :
    "Returns a list of all modules that should be checked."
    modules = []
    for module in _allModules.values() :
        if module.check :
            modules.append(module)
    return modules

_BUILTIN_MODULE_ATTRS = { 'sys': [ 'ps1', 'ps2', 'tracebacklimit', 
                                   'exc_type', 'exc_value', 'exc_traceback',
                                   'last_type', 'last_value', 'last_traceback',
                                 ],
                        }

def fixupBuiltinModules(needs_init=0):
    for moduleName in sys.builtin_module_names :
        if needs_init:
            _ = PyCheckerModule(moduleName, 0)
        module = _allModules.get(moduleName, None)
        if module is not None :
            try :
                m = imp.init_builtin(moduleName)
            except ImportError :
                pass
            else :
                extra_attrs = _BUILTIN_MODULE_ATTRS.get(moduleName, [])
                module.attributes = [ '__dict__' ] + dir(m) + extra_attrs


def _printWarnings(warnings, stream=None):
    if stream is None:
        stream = sys.stdout
    
    warnings.sort()
    lastWarning = None
    for warning in warnings :
        if lastWarning is not None:
            # ignore duplicate warnings
            if cmp(lastWarning, warning) == 0:
                continue
            # print blank line between files
            if lastWarning.file != warning.file:
                stream.write("\n")

        lastWarning = warning
        warning.output(stream)


def processFiles(files, cfg = None, pre_process_cb = None) :
    # insert this here, so we find files in the local dir before std library
    if sys.path[0] != '' :
        sys.path.insert(0, '')

    # ensure we have a config object, it's necessary
    global _cfg
    if cfg is not None :
        _cfg = cfg
    elif _cfg is None :
        _cfg = Config.Config()

    warnings = []
    utils.initConfig(_cfg)
    for moduleName in getModules(files) :
        if callable(pre_process_cb) :
            pre_process_cb(moduleName)
        module = PyCheckerModule(moduleName)
        if not module.load() :
            w = Warning(module.filename(), 1,
                        msgs.Internal("NOT PROCESSED UNABLE TO IMPORT"))
            warnings.append(w)
    utils.popConfig()
    return warnings


def getWarnings(files, cfg = None, suppressions = None):
    warnings = processFiles(files, cfg)
    fixupBuiltinModules()
    return warnings + warn.find(getAllModules(), _cfg, suppressions)


def _print_processing(name) :
    if not _cfg.quiet :
        sys.stderr.write("Processing %s...\n" % name)


def main(argv) :
    __pychecker__ = 'no-miximport'
    import pychecker
    if LOCAL_MAIN_VERSION != pychecker.MAIN_MODULE_VERSION :
        sys.stderr.write(_VERSION_MISMATCH_ERROR)
        sys.exit(100)

    # remove empty arguments
    argv = filter(None, argv)
        
    # if the first arg starts with an @, read options from the file
    # after the @ (this is mostly for windows)
    if len(argv) >= 2 and argv[1][0] == '@':
        # read data from the file
        command_file = argv[1][1:]
        try:
            f = open(command_file, 'r')
            command_line = f.read()
            f.close()
        except IOError, err:
            sys.stderr.write("Unable to read commands from file: %s\n  %s\n" % \
                             (command_file, err))
            sys.exit(101)

        # convert to an argv list, keeping argv[0] and the files to process
        argv = argv[:1] + string.split(command_line) + argv[2:]
 
    global _cfg
    _cfg, files, suppressions = Config.setupFromArgs(argv[1:])
    if not files :
        return 0

    # Now that we've got the args, update the list of evil C objects
    for evil_doer in _cfg.evil:
        _EVIL_C_OBJECTS[evil_doer] = None

    # insert this here, so we find files in the local dir before std library
    sys.path.insert(0, '')

    importWarnings = processFiles(files, _cfg, _print_processing)
    fixupBuiltinModules()
    if _cfg.printParse :
        for module in getAllModules() :
            printer.module(module)

    warnings = warn.find(getAllModules(), _cfg, suppressions)
    if not _cfg.quiet :
        print "\nWarnings...\n"
    if warnings or importWarnings :
        _printWarnings(importWarnings + warnings)
        return 1

    if not _cfg.quiet :
        print "None"
    return 0


if __name__ == '__main__' :
    try :
        sys.exit(main(sys.argv))
    except Config.UsageError :
        sys.exit(127)

else :
    _orig__import__ = None
    _suppressions = None
    _warnings_cache = {}

    def _get_unique_warnings(warnings):
        for i in range(len(warnings)-1, -1, -1):
            w = warnings[i].format()
            if _warnings_cache.has_key(w):
                del warnings[i]
            else:
                _warnings_cache[w] = 1
        return warnings

    def __import__(name, globals=None, locals=None, fromlist=None):
        if globals is None:
            globals = {}
        if locals is None:
            locals = {}
        if fromlist is None:
            fromlist = []

        check = not sys.modules.has_key(name) and name[:10] != 'pychecker.'
        pymodule = _orig__import__(name, globals, locals, fromlist)
        if check :
            try :
                module = PyCheckerModule(pymodule.__name__)
                if module.initModule(pymodule):
                    warnings = warn.find([module], _cfg, _suppressions)
                    _printWarnings(_get_unique_warnings(warnings))
                else :
                    print 'Unable to load module', pymodule.__name__
            except Exception:
                name = getattr(pymodule, '__name__', utils.safestr(pymodule))
                importError(name)

        return pymodule

    def _init() :
        global _cfg, _suppressions, _orig__import__

        args = string.split(os.environ.get('PYCHECKER', ''))
        _cfg, files, _suppressions = Config.setupFromArgs(args)
        utils.initConfig(_cfg)
        fixupBuiltinModules(1)

        # keep the orig __import__ around so we can call it
        import __builtin__
        _orig__import__ = __builtin__.__import__
        __builtin__.__import__ = __import__

    if not os.environ.get('PYCHECKER_DISABLED') :
        _init()