| #!/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 optparse |
| import logging |
| 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 main(fixer_dir, args=None): |
| """Main program. |
| |
| Args: |
| fixer_dir: directory where fixer modules are located. |
| args: optional; a list of command line arguments. If omitted, |
| sys.argv[1:] is used. |
| |
| Returns a suggested exit status (0, 1, 2). |
| """ |
| # Set up option parser |
| parser = optparse.OptionParser(usage="refactor.py [options] file|dir ...") |
| parser.add_option("-d", "--doctests_only", action="store_true", |
| help="Fix up doctests only") |
| parser.add_option("-f", "--fix", action="append", default=[], |
| help="Each FIX specifies a transformation; default all") |
| parser.add_option("-l", "--list-fixes", action="store_true", |
| help="List available transformations (fixes/fix_*.py)") |
| parser.add_option("-p", "--print-function", action="store_true", |
| help="Modify the grammar so that print() is a function") |
| parser.add_option("-v", "--verbose", action="store_true", |
| help="More verbose logging") |
| parser.add_option("-w", "--write", action="store_true", |
| help="Write back modified files") |
| |
| # Parse command line arguments |
| options, args = parser.parse_args(args) |
| if options.list_fixes: |
| print "Available transformations for the -f/--fix option:" |
| for fixname in get_all_fix_names(fixer_dir): |
| print fixname |
| if not args: |
| return 0 |
| if not args: |
| print >>sys.stderr, "At least one file or directory argument required." |
| print >>sys.stderr, "Use --help to show usage." |
| return 2 |
| |
| # Set up logging handler |
| if sys.version_info < (2, 4): |
| hdlr = logging.StreamHandler() |
| fmt = logging.Formatter('%(name)s: %(message)s') |
| hdlr.setFormatter(fmt) |
| logging.root.addHandler(hdlr) |
| else: |
| logging.basicConfig(format='%(name)s: %(message)s', level=logging.INFO) |
| |
| # Initialize the refactoring tool |
| rt = RefactoringTool(fixer_dir, options) |
| |
| # Refactor all files and directories passed as arguments |
| if not rt.errors: |
| rt.refactor_args(args) |
| rt.summarize() |
| |
| # Return error status (0 if rt.errors is zero) |
| return int(bool(rt.errors)) |
| |
| |
| def get_all_fix_names(fixer_dir): |
| """Return a sorted list of all available fix names.""" |
| fix_names = [] |
| names = os.listdir(fixer_dir) |
| names.sort() |
| for name in names: |
| if name.startswith("fix_") and name.endswith(".py"): |
| fix_names.append(name[4:-3]) |
| fix_names.sort() |
| 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 |
| |
| |
| class RefactoringTool(object): |
| |
| def __init__(self, fixer_dir, options): |
| """Initializer. |
| |
| Args: |
| fixer_dir: directory in which to find fixer modules. |
| options: an optparse.Values instance. |
| """ |
| self.fixer_dir = fixer_dir |
| self.options = options |
| self.errors = [] |
| self.logger = logging.getLogger("RefactoringTool") |
| self.fixer_log = [] |
| 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. |
| """ |
| fixer_pkg = self.fixer_dir.replace(os.path.sep, ".") |
| if os.path.altsep: |
| fixer_pkg = fixer_pkg.replace(os.path.altsep, ".") |
| pre_order_fixers = [] |
| post_order_fixers = [] |
| fix_names = self.options.fix |
| if not fix_names or "all" in fix_names: |
| fix_names = get_all_fix_names(self.fixer_dir) |
| for fix_name in fix_names: |
| try: |
| mod = __import__(fixer_pkg + ".fix_" + fix_name, {}, {}, ["*"]) |
| except ImportError: |
| self.log_error("Can't find transformation %s", fix_name) |
| continue |
| parts = fix_name.split("_") |
| class_name = "Fix" + "".join([p.title() for p in parts]) |
| try: |
| fix_class = getattr(mod, class_name) |
| except AttributeError: |
| self.log_error("Can't find fixes.fix_%s.%s", |
| fix_name, class_name) |
| continue |
| try: |
| fixer = fix_class(self.options, self.fixer_log) |
| except Exception, err: |
| self.log_error("Can't instantiate fixes.fix_%s.%s()", |
| fix_name, class_name, exc_info=True) |
| continue |
| if fixer.explicit and fix_name not in self.options.fix: |
| self.log_message("Skipping implicit fixer: %s", fix_name) |
| continue |
| |
| if self.options.verbose: |
| self.log_message("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 ValueError("Illegal fixer order: %r" % fixer.order) |
| |
| pre_order_fixers.sort(key=lambda x: x.run_order) |
| post_order_fixers.sort(key=lambda x: x.run_order) |
| return (pre_order_fixers, post_order_fixers) |
| |
| def log_error(self, msg, *args, **kwds): |
| """Increments error count and log a message.""" |
| self.errors.append((msg, args, kwds)) |
| self.logger.error(msg, *args, **kwds) |
| |
| def log_message(self, msg, *args): |
| """Hook to log a message.""" |
| if args: |
| msg = msg % args |
| self.logger.info(msg) |
| |
| def refactor_args(self, args): |
| """Refactors files and directories from an argument list.""" |
| for arg in args: |
| if arg == "-": |
| self.refactor_stdin() |
| elif os.path.isdir(arg): |
| self.refactor_dir(arg) |
| else: |
| self.refactor_file(arg) |
| |
| def refactor_dir(self, arg): |
| """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(arg): |
| if self.options.verbose: |
| self.log_message("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) |
| # 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): |
| """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 self.options.doctests_only: |
| if self.options.verbose: |
| self.log_message("Refactoring doctests in %s", filename) |
| output = self.refactor_docstring(input, filename) |
| if output != input: |
| self.write_file(output, filename, input) |
| elif self.options.verbose: |
| self.log_message("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.write_file(str(tree)[:-1], filename) |
| elif self.options.verbose: |
| self.log_message("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,1) |
| except Exception, err: |
| self.log_error("Can't parse %s: %s: %s", |
| name, err.__class__.__name__, err) |
| return |
| if self.options.verbose: |
| self.log_message("Refactoring %s", name) |
| self.refactor_tree(tree, name) |
| return tree |
| |
| def refactor_stdin(self): |
| if self.options.write: |
| self.log_error("Can't write changes back to stdin") |
| return |
| input = sys.stdin.read() |
| if self.options.doctests_only: |
| if self.options.verbose: |
| self.log_message("Refactoring doctests in stdin") |
| output = self.refactor_docstring(input, "<stdin>") |
| if output != input: |
| self.write_file(output, "<stdin>", input) |
| elif self.options.verbose: |
| self.log_message("No doctest changes in stdin") |
| else: |
| tree = self.refactor_string(input, "<stdin>") |
| if tree and tree.was_changed: |
| self.write_file(str(tree), "<stdin>", input) |
| elif self.options.verbose: |
| self.log_message("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 write_file(self, new_text, filename, old_text=None): |
| """Writes a string to a file. |
| |
| If there are no changes, this is a no-op. |
| |
| Otherwise, 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. |
| """ |
| 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: |
| if self.options.verbose: |
| self.log_message("No changes to %s", filename) |
| return |
| diff_texts(old_text, new_text, filename) |
| if not self.options.write: |
| if self.options.verbose: |
| self.log_message("Not writing changes to %s", filename) |
| return |
| backup = filename + ".bak" |
| if os.path.lexists(backup): |
| try: |
| os.remove(backup) |
| except os.error, err: |
| self.log_message("Can't remove backup %s", backup) |
| try: |
| os.rename(filename, backup) |
| except os.error, err: |
| self.log_message("Can't rename %s to %s", filename, backup) |
| try: |
| f = open(filename, "w") |
| except os.error, err: |
| self.log_error("Can't create %s: %s", filename, err) |
| return |
| try: |
| try: |
| f.write(new_text) |
| except os.error, err: |
| self.log_error("Can't write %s: %s", filename, err) |
| finally: |
| f.close() |
| if self.options.verbose: |
| self.log_message("Wrote changes to %s", filename) |
| |
| 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.options.verbose: |
| for line in block: |
| self.log_message("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.options.write: |
| 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): |
| """Prints a unified diff of two strings.""" |
| a = a.splitlines() |
| b = b.splitlines() |
| for line in difflib.unified_diff(a, b, filename, filename, |
| "(original)", "(refactored)", |
| lineterm=""): |
| print line |
| |
| |
| if __name__ == "__main__": |
| sys.exit(main()) |