| #!/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 = get_headnode_dict(self.pre_order) |
| self.post_order = 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 as 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 as 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(chain(*self.pre_order.values()),\ |
| chain(*self.post_order.values())) |
| for fixer in all_fixers: |
| fixer.start_tree(tree, name) |
| |
| self.traverse_by(self.pre_order, tree.pre_order()) |
| self.traverse_by(self.post_order, 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 as 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 as err: |
| self.log_error("Can't create %s: %s", filename, err) |
| return |
| try: |
| try: |
| f.write(new_text) |
| except os.error as 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 as 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="") |