symbian-qemu-0.9.1-12/python-2.6.1/Lib/lib2to3/refactor.py
changeset 1 2fb8b9db1c86
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/symbian-qemu-0.9.1-12/python-2.6.1/Lib/lib2to3/refactor.py	Fri Jul 31 15:01:17 2009 +0100
@@ -0,0 +1,519 @@
+#!/usr/bin/env python2.5
+# Copyright 2006 Google, Inc. All Rights Reserved.
+# Licensed to PSF under a Contributor Agreement.
+
+"""Refactoring framework.
+
+Used as a main program, this can refactor any number of files and/or
+recursively descend down directories.  Imported as a module, this
+provides infrastructure to write your own refactoring tool.
+"""
+
+__author__ = "Guido van Rossum <guido@python.org>"
+
+
+# Python imports
+import os
+import sys
+import difflib
+import logging
+import operator
+from collections import defaultdict
+from itertools import chain
+
+# Local imports
+from .pgen2 import driver
+from .pgen2 import tokenize
+
+from . import pytree
+from . import patcomp
+from . import fixes
+from . import pygram
+
+
+def get_all_fix_names(fixer_pkg, remove_prefix=True):
+    """Return a sorted list of all available fix names in the given package."""
+    pkg = __import__(fixer_pkg, [], [], ["*"])
+    fixer_dir = os.path.dirname(pkg.__file__)
+    fix_names = []
+    for name in sorted(os.listdir(fixer_dir)):
+        if name.startswith("fix_") and name.endswith(".py"):
+            if remove_prefix:
+                name = name[4:]
+            fix_names.append(name[:-3])
+    return fix_names
+
+def get_head_types(pat):
+    """ Accepts a pytree Pattern Node and returns a set
+        of the pattern types which will match first. """
+
+    if isinstance(pat, (pytree.NodePattern, pytree.LeafPattern)):
+        # NodePatters must either have no type and no content
+        #   or a type and content -- so they don't get any farther
+        # Always return leafs
+        return set([pat.type])
+
+    if isinstance(pat, pytree.NegatedPattern):
+        if pat.content:
+            return get_head_types(pat.content)
+        return set([None]) # Negated Patterns don't have a type
+
+    if isinstance(pat, pytree.WildcardPattern):
+        # Recurse on each node in content
+        r = set()
+        for p in pat.content:
+            for x in p:
+                r.update(get_head_types(x))
+        return r
+
+    raise Exception("Oh no! I don't understand pattern %s" %(pat))
+
+def get_headnode_dict(fixer_list):
+    """ Accepts a list of fixers and returns a dictionary
+        of head node type --> fixer list.  """
+    head_nodes = defaultdict(list)
+    for fixer in fixer_list:
+        if not fixer.pattern:
+            head_nodes[None].append(fixer)
+            continue
+        for t in get_head_types(fixer.pattern):
+            head_nodes[t].append(fixer)
+    return head_nodes
+
+def get_fixers_from_package(pkg_name):
+    """
+    Return the fully qualified names for fixers in the package pkg_name.
+    """
+    return [pkg_name + "." + fix_name
+            for fix_name in get_all_fix_names(pkg_name, False)]
+
+
+class FixerError(Exception):
+    """A fixer could not be loaded."""
+
+
+class RefactoringTool(object):
+
+    _default_options = {"print_function": False}
+
+    CLASS_PREFIX = "Fix" # The prefix for fixer classes
+    FILE_PREFIX = "fix_" # The prefix for modules with a fixer within
+
+    def __init__(self, fixer_names, options=None, explicit=None):
+        """Initializer.
+
+        Args:
+            fixer_names: a list of fixers to import
+            options: an dict with configuration.
+            explicit: a list of fixers to run even if they are explicit.
+        """
+        self.fixers = fixer_names
+        self.explicit = explicit or []
+        self.options = self._default_options.copy()
+        if options is not None:
+            self.options.update(options)
+        self.errors = []
+        self.logger = logging.getLogger("RefactoringTool")
+        self.fixer_log = []
+        self.wrote = False
+        if self.options["print_function"]:
+            del pygram.python_grammar.keywords["print"]
+        self.driver = driver.Driver(pygram.python_grammar,
+                                    convert=pytree.convert,
+                                    logger=self.logger)
+        self.pre_order, self.post_order = self.get_fixers()
+
+        self.pre_order_mapping = get_headnode_dict(self.pre_order)
+        self.post_order_mapping = get_headnode_dict(self.post_order)
+
+        self.files = []  # List of files that were or should be modified
+
+    def get_fixers(self):
+        """Inspects the options to load the requested patterns and handlers.
+
+        Returns:
+          (pre_order, post_order), where pre_order is the list of fixers that
+          want a pre-order AST traversal, and post_order is the list that want
+          post-order traversal.
+        """
+        pre_order_fixers = []
+        post_order_fixers = []
+        for fix_mod_path in self.fixers:
+            mod = __import__(fix_mod_path, {}, {}, ["*"])
+            fix_name = fix_mod_path.rsplit(".", 1)[-1]
+            if fix_name.startswith(self.FILE_PREFIX):
+                fix_name = fix_name[len(self.FILE_PREFIX):]
+            parts = fix_name.split("_")
+            class_name = self.CLASS_PREFIX + "".join([p.title() for p in parts])
+            try:
+                fix_class = getattr(mod, class_name)
+            except AttributeError:
+                raise FixerError("Can't find %s.%s" % (fix_name, class_name))
+            fixer = fix_class(self.options, self.fixer_log)
+            if fixer.explicit and self.explicit is not True and \
+                    fix_mod_path not in self.explicit:
+                self.log_message("Skipping implicit fixer: %s", fix_name)
+                continue
+
+            self.log_debug("Adding transformation: %s", fix_name)
+            if fixer.order == "pre":
+                pre_order_fixers.append(fixer)
+            elif fixer.order == "post":
+                post_order_fixers.append(fixer)
+            else:
+                raise FixerError("Illegal fixer order: %r" % fixer.order)
+
+        key_func = operator.attrgetter("run_order")
+        pre_order_fixers.sort(key=key_func)
+        post_order_fixers.sort(key=key_func)
+        return (pre_order_fixers, post_order_fixers)
+
+    def log_error(self, msg, *args, **kwds):
+        """Called when an error occurs."""
+        raise
+
+    def log_message(self, msg, *args):
+        """Hook to log a message."""
+        if args:
+            msg = msg % args
+        self.logger.info(msg)
+
+    def log_debug(self, msg, *args):
+        if args:
+            msg = msg % args
+        self.logger.debug(msg)
+
+    def print_output(self, lines):
+        """Called with lines of output to give to the user."""
+        pass
+
+    def refactor(self, items, write=False, doctests_only=False):
+        """Refactor a list of files and directories."""
+        for dir_or_file in items:
+            if os.path.isdir(dir_or_file):
+                self.refactor_dir(dir_or_file, write, doctests_only)
+            else:
+                self.refactor_file(dir_or_file, write, doctests_only)
+
+    def refactor_dir(self, dir_name, write=False, doctests_only=False):
+        """Descends down a directory and refactor every Python file found.
+
+        Python files are assumed to have a .py extension.
+
+        Files and subdirectories starting with '.' are skipped.
+        """
+        for dirpath, dirnames, filenames in os.walk(dir_name):
+            self.log_debug("Descending into %s", dirpath)
+            dirnames.sort()
+            filenames.sort()
+            for name in filenames:
+                if not name.startswith(".") and name.endswith("py"):
+                    fullname = os.path.join(dirpath, name)
+                    self.refactor_file(fullname, write, doctests_only)
+            # Modify dirnames in-place to remove subdirs with leading dots
+            dirnames[:] = [dn for dn in dirnames if not dn.startswith(".")]
+
+    def refactor_file(self, filename, write=False, doctests_only=False):
+        """Refactors a file."""
+        try:
+            f = open(filename)
+        except IOError, err:
+            self.log_error("Can't open %s: %s", filename, err)
+            return
+        try:
+            input = f.read() + "\n" # Silence certain parse errors
+        finally:
+            f.close()
+        if doctests_only:
+            self.log_debug("Refactoring doctests in %s", filename)
+            output = self.refactor_docstring(input, filename)
+            if output != input:
+                self.processed_file(output, filename, input, write=write)
+            else:
+                self.log_debug("No doctest changes in %s", filename)
+        else:
+            tree = self.refactor_string(input, filename)
+            if tree and tree.was_changed:
+                # The [:-1] is to take off the \n we added earlier
+                self.processed_file(str(tree)[:-1], filename, write=write)
+            else:
+                self.log_debug("No changes in %s", filename)
+
+    def refactor_string(self, data, name):
+        """Refactor a given input string.
+
+        Args:
+            data: a string holding the code to be refactored.
+            name: a human-readable name for use in error/log messages.
+
+        Returns:
+            An AST corresponding to the refactored input stream; None if
+            there were errors during the parse.
+        """
+        try:
+            tree = self.driver.parse_string(data)
+        except Exception, err:
+            self.log_error("Can't parse %s: %s: %s",
+                           name, err.__class__.__name__, err)
+            return
+        self.log_debug("Refactoring %s", name)
+        self.refactor_tree(tree, name)
+        return tree
+
+    def refactor_stdin(self, doctests_only=False):
+        input = sys.stdin.read()
+        if doctests_only:
+            self.log_debug("Refactoring doctests in stdin")
+            output = self.refactor_docstring(input, "<stdin>")
+            if output != input:
+                self.processed_file(output, "<stdin>", input)
+            else:
+                self.log_debug("No doctest changes in stdin")
+        else:
+            tree = self.refactor_string(input, "<stdin>")
+            if tree and tree.was_changed:
+                self.processed_file(str(tree), "<stdin>", input)
+            else:
+                self.log_debug("No changes in stdin")
+
+    def refactor_tree(self, tree, name):
+        """Refactors a parse tree (modifying the tree in place).
+
+        Args:
+            tree: a pytree.Node instance representing the root of the tree
+                  to be refactored.
+            name: a human-readable name for this tree.
+
+        Returns:
+            True if the tree was modified, False otherwise.
+        """
+        # Two calls to chain are required because pre_order.values()
+        #   will be a list of lists of fixers:
+        #   [[<fixer ...>, <fixer ...>], [<fixer ...>]]
+        all_fixers = chain(self.pre_order, self.post_order)
+        for fixer in all_fixers:
+            fixer.start_tree(tree, name)
+
+        self.traverse_by(self.pre_order_mapping, tree.pre_order())
+        self.traverse_by(self.post_order_mapping, tree.post_order())
+
+        for fixer in all_fixers:
+            fixer.finish_tree(tree, name)
+        return tree.was_changed
+
+    def traverse_by(self, fixers, traversal):
+        """Traverse an AST, applying a set of fixers to each node.
+
+        This is a helper method for refactor_tree().
+
+        Args:
+            fixers: a list of fixer instances.
+            traversal: a generator that yields AST nodes.
+
+        Returns:
+            None
+        """
+        if not fixers:
+            return
+        for node in traversal:
+            for fixer in fixers[node.type] + fixers[None]:
+                results = fixer.match(node)
+                if results:
+                    new = fixer.transform(node, results)
+                    if new is not None and (new != node or
+                                            str(new) != str(node)):
+                        node.replace(new)
+                        node = new
+
+    def processed_file(self, new_text, filename, old_text=None, write=False):
+        """
+        Called when a file has been refactored, and there are changes.
+        """
+        self.files.append(filename)
+        if old_text is None:
+            try:
+                f = open(filename, "r")
+            except IOError, err:
+                self.log_error("Can't read %s: %s", filename, err)
+                return
+            try:
+                old_text = f.read()
+            finally:
+                f.close()
+        if old_text == new_text:
+            self.log_debug("No changes to %s", filename)
+            return
+        self.print_output(diff_texts(old_text, new_text, filename))
+        if write:
+            self.write_file(new_text, filename, old_text)
+        else:
+            self.log_debug("Not writing changes to %s", filename)
+
+    def write_file(self, new_text, filename, old_text):
+        """Writes a string to a file.
+
+        It first shows a unified diff between the old text and the new text, and
+        then rewrites the file; the latter is only done if the write option is
+        set.
+        """
+        try:
+            f = open(filename, "w")
+        except os.error, err:
+            self.log_error("Can't create %s: %s", filename, err)
+            return
+        try:
+            f.write(new_text)
+        except os.error, err:
+            self.log_error("Can't write %s: %s", filename, err)
+        finally:
+            f.close()
+        self.log_debug("Wrote changes to %s", filename)
+        self.wrote = True
+
+    PS1 = ">>> "
+    PS2 = "... "
+
+    def refactor_docstring(self, input, filename):
+        """Refactors a docstring, looking for doctests.
+
+        This returns a modified version of the input string.  It looks
+        for doctests, which start with a ">>>" prompt, and may be
+        continued with "..." prompts, as long as the "..." is indented
+        the same as the ">>>".
+
+        (Unfortunately we can't use the doctest module's parser,
+        since, like most parsers, it is not geared towards preserving
+        the original source.)
+        """
+        result = []
+        block = None
+        block_lineno = None
+        indent = None
+        lineno = 0
+        for line in input.splitlines(True):
+            lineno += 1
+            if line.lstrip().startswith(self.PS1):
+                if block is not None:
+                    result.extend(self.refactor_doctest(block, block_lineno,
+                                                        indent, filename))
+                block_lineno = lineno
+                block = [line]
+                i = line.find(self.PS1)
+                indent = line[:i]
+            elif (indent is not None and
+                  (line.startswith(indent + self.PS2) or
+                   line == indent + self.PS2.rstrip() + "\n")):
+                block.append(line)
+            else:
+                if block is not None:
+                    result.extend(self.refactor_doctest(block, block_lineno,
+                                                        indent, filename))
+                block = None
+                indent = None
+                result.append(line)
+        if block is not None:
+            result.extend(self.refactor_doctest(block, block_lineno,
+                                                indent, filename))
+        return "".join(result)
+
+    def refactor_doctest(self, block, lineno, indent, filename):
+        """Refactors one doctest.
+
+        A doctest is given as a block of lines, the first of which starts
+        with ">>>" (possibly indented), while the remaining lines start
+        with "..." (identically indented).
+
+        """
+        try:
+            tree = self.parse_block(block, lineno, indent)
+        except Exception, err:
+            if self.log.isEnabledFor(logging.DEBUG):
+                for line in block:
+                    self.log_debug("Source: %s", line.rstrip("\n"))
+            self.log_error("Can't parse docstring in %s line %s: %s: %s",
+                           filename, lineno, err.__class__.__name__, err)
+            return block
+        if self.refactor_tree(tree, filename):
+            new = str(tree).splitlines(True)
+            # Undo the adjustment of the line numbers in wrap_toks() below.
+            clipped, new = new[:lineno-1], new[lineno-1:]
+            assert clipped == ["\n"] * (lineno-1), clipped
+            if not new[-1].endswith("\n"):
+                new[-1] += "\n"
+            block = [indent + self.PS1 + new.pop(0)]
+            if new:
+                block += [indent + self.PS2 + line for line in new]
+        return block
+
+    def summarize(self):
+        if self.wrote:
+            were = "were"
+        else:
+            were = "need to be"
+        if not self.files:
+            self.log_message("No files %s modified.", were)
+        else:
+            self.log_message("Files that %s modified:", were)
+            for file in self.files:
+                self.log_message(file)
+        if self.fixer_log:
+            self.log_message("Warnings/messages while refactoring:")
+            for message in self.fixer_log:
+                self.log_message(message)
+        if self.errors:
+            if len(self.errors) == 1:
+                self.log_message("There was 1 error:")
+            else:
+                self.log_message("There were %d errors:", len(self.errors))
+            for msg, args, kwds in self.errors:
+                self.log_message(msg, *args, **kwds)
+
+    def parse_block(self, block, lineno, indent):
+        """Parses a block into a tree.
+
+        This is necessary to get correct line number / offset information
+        in the parser diagnostics and embedded into the parse tree.
+        """
+        return self.driver.parse_tokens(self.wrap_toks(block, lineno, indent))
+
+    def wrap_toks(self, block, lineno, indent):
+        """Wraps a tokenize stream to systematically modify start/end."""
+        tokens = tokenize.generate_tokens(self.gen_lines(block, indent).next)
+        for type, value, (line0, col0), (line1, col1), line_text in tokens:
+            line0 += lineno - 1
+            line1 += lineno - 1
+            # Don't bother updating the columns; this is too complicated
+            # since line_text would also have to be updated and it would
+            # still break for tokens spanning lines.  Let the user guess
+            # that the column numbers for doctests are relative to the
+            # end of the prompt string (PS1 or PS2).
+            yield type, value, (line0, col0), (line1, col1), line_text
+
+
+    def gen_lines(self, block, indent):
+        """Generates lines as expected by tokenize from a list of lines.
+
+        This strips the first len(indent + self.PS1) characters off each line.
+        """
+        prefix1 = indent + self.PS1
+        prefix2 = indent + self.PS2
+        prefix = prefix1
+        for line in block:
+            if line.startswith(prefix):
+                yield line[len(prefix):]
+            elif line == prefix.rstrip() + "\n":
+                yield "\n"
+            else:
+                raise AssertionError("line=%r, prefix=%r" % (line, prefix))
+            prefix = prefix2
+        while True:
+            yield ""
+
+
+def diff_texts(a, b, filename):
+    """Return a unified diff of two strings."""
+    a = a.splitlines()
+    b = b.splitlines()
+    return difflib.unified_diff(a, b, filename, filename,
+                                "(original)", "(refactored)",
+                                lineterm="")