view contrib/byteify-strings.py @ 44763:94f4f2ec7dee stable

packaging: support building Inno installer with PyOxidizer

We want to start distributing Mercurial on Python 3 on
Windows. PyOxidizer will be our vehicle for achieving that.

This commit implements basic support for producing Inno
installers using PyOxidizer.

While it is an eventual goal of PyOxidizer to produce
installers, those features aren't yet implemented. So our
strategy for producing Mercurial installers is similar to
what we've been doing with py2exe: invoke a build system to
produce files then stage those files into a directory so they
can be turned into an installer.

We had to make significant alterations to the pyoxidizer.bzl
config file to get it to produce the files that we desire for
a Windows install. This meant differentiating the build targets
so we can target Windows specifically.

We've added a new module to hgpackaging to deal with interacting
with PyOxidizer. It is similar to pyexe: we invoke a build process
then copy files to a staging directory. Ideally these extra
files would be defined in pyoxidizer.bzl. But I don't think it
is worth doing at this time, as PyOxidizer's config files are
lacking some features to make this turnkey.

The rest of the change is introducing a variant of the
Inno installer code that invokes PyOxidizer instead of
py2exe.

Comparing the Python 2.7 based Inno installers with this
one, the following changes were observed:

* No lib/*.{pyd, dll} files
* No Microsoft.VC90.CRT.manifest
* No msvc{m,p,r}90.dll files
* python27.dll replaced with python37.dll
* Add vcruntime140.dll file

The disappearance of the .pyd and .dll files is acceptable, as
PyOxidizer has embedded these in hg.exe and loads them from
memory.

The disappearance of the *90* files is acceptable because those
provide the Visual C++ 9 runtime, as required by Python 2.7.
Similarly, the appearance of vcruntime140.dll is a requirement
of Python 3.7.

Differential Revision: https://phab.mercurial-scm.org/D8473

#!/usr/bin/env python3
#
# byteify-strings.py - transform string literals to be Python 3 safe
#
# Copyright 2015 Gregory Szorc <[e-mail]>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

from __future__ import absolute_import, print_function

import argparse
import contextlib
import errno
import os
import sys
import tempfile
import token
import tokenize


def adjusttokenpos(t, ofs):
    """Adjust start/end column of the given token"""
    return t._replace(
        start=(t.start[0], t.start[1] + ofs), end=(t.end[0], t.end[1] + ofs)
    )


def replacetokens(tokens, opts):
    """Transform a stream of tokens from raw to Python 3.

    Returns a generator of possibly rewritten tokens.

    The input token list may be mutated as part of processing. However,
    its changes do not necessarily match the output token stream.
    """
    sysstrtokens = set()

    # The following utility functions access the tokens list and i index of
    # the for i, t enumerate(tokens) loop below
    def _isop(j, *o):
        """Assert that tokens[j] is an OP with one of the given values"""
        try:
            return tokens[j].type == token.OP and tokens[j].string in o
        except IndexError:
            return False

    def _findargnofcall(n):
        """Find arg n of a call expression (start at 0)

        Returns index of the first token of that argument, or None if
        there is not that many arguments.

        Assumes that token[i + 1] is '('.

        """
        nested = 0
        for j in range(i + 2, len(tokens)):
            if _isop(j, ')', ']', '}'):
                # end of call, tuple, subscription or dict / set
                nested -= 1
                if nested < 0:
                    return None
            elif n == 0:
                # this is the starting position of arg
                return j
            elif _isop(j, '(', '[', '{'):
                nested += 1
            elif _isop(j, ',') and nested == 0:
                n -= 1

        return None

    def _ensuresysstr(j):
        """Make sure the token at j is a system string

        Remember the given token so the string transformer won't add
        the byte prefix.

        Ignores tokens that are not strings. Assumes bounds checking has
        already been done.

        """
        k = j
        currtoken = tokens[k]
        while currtoken.type in (token.STRING, token.NEWLINE, tokenize.NL):
            k += 1
            if currtoken.type == token.STRING and currtoken.string.startswith(
                ("'", '"')
            ):
                sysstrtokens.add(currtoken)
            try:
                currtoken = tokens[k]
            except IndexError:
                break

    def _isitemaccess(j):
        """Assert the next tokens form an item access on `tokens[j]` and that
        `tokens[j]` is a name.
        """
        try:
            return (
                tokens[j].type == token.NAME
                and _isop(j + 1, '[')
                and tokens[j + 2].type == token.STRING
                and _isop(j + 3, ']')
            )
        except IndexError:
            return False

    def _ismethodcall(j, *methodnames):
        """Assert the next tokens form a call to `methodname` with a string
        as first argument on `tokens[j]` and that `tokens[j]` is a name.
        """
        try:
            return (
                tokens[j].type == token.NAME
                and _isop(j + 1, '.')
                and tokens[j + 2].type == token.NAME
                and tokens[j + 2].string in methodnames
                and _isop(j + 3, '(')
                and tokens[j + 4].type == token.STRING
            )
        except IndexError:
            return False

    coldelta = 0  # column increment for new opening parens
    coloffset = -1  # column offset for the current line (-1: TBD)
    parens = [(0, 0, 0, -1)]  # stack of (line, end-column, column-offset, type)
    ignorenextline = False  # don't transform the next line
    insideignoreblock = False  # don't transform until turned off
    for i, t in enumerate(tokens):
        # Compute the column offset for the current line, such that
        # the current line will be aligned to the last opening paren
        # as before.
        if coloffset < 0:
            lastparen = parens[-1]
            if t.start[1] == lastparen[1]:
                coloffset = lastparen[2]
            elif t.start[1] + 1 == lastparen[1] and lastparen[3] not in (
                token.NEWLINE,
                tokenize.NL,
            ):
                # fix misaligned indent of s/util.Abort/error.Abort/
                coloffset = lastparen[2] + (lastparen[1] - t.start[1])
            else:
                coloffset = 0

        # Reset per-line attributes at EOL.
        if t.type in (token.NEWLINE, tokenize.NL):
            yield adjusttokenpos(t, coloffset)
            coldelta = 0
            coloffset = -1
            if not insideignoreblock:
                ignorenextline = (
                    tokens[i - 1].type == token.COMMENT
                    and tokens[i - 1].string == "# no-py3-transform"
                )
            continue

        if t.type == token.COMMENT:
            if t.string == "# py3-transform: off":
                insideignoreblock = True
            if t.string == "# py3-transform: on":
                insideignoreblock = False

        if ignorenextline or insideignoreblock:
            yield adjusttokenpos(t, coloffset)
            continue

        # Remember the last paren position.
        if _isop(i, '(', '[', '{'):
            parens.append(t.end + (coloffset + coldelta, tokens[i + 1].type))
        elif _isop(i, ')', ']', '}'):
            parens.pop()

        # Convert most string literals to byte literals. String literals
        # in Python 2 are bytes. String literals in Python 3 are unicode.
        # Most strings in Mercurial are bytes and unicode strings are rare.
        # Rather than rewrite all string literals to use ``b''`` to indicate
        # byte strings, we apply this token transformer to insert the ``b``
        # prefix nearly everywhere.
        if t.type == token.STRING and t not in sysstrtokens:
            s = t.string

            # Preserve docstrings as string literals. This is inconsistent
            # with regular unprefixed strings. However, the
            # "from __future__" parsing (which allows a module docstring to
            # exist before it) doesn't properly handle the docstring if it
            # is b''' prefixed, leading to a SyntaxError. We leave all
            # docstrings as unprefixed to avoid this. This means Mercurial
            # components touching docstrings need to handle unicode,
            # unfortunately.
            if s[0:3] in ("'''", '"""'):
                # If it's assigned to something, it's not a docstring
                if not _isop(i - 1, '='):
                    yield adjusttokenpos(t, coloffset)
                    continue

            # If the first character isn't a quote, it is likely a string
            # prefixing character (such as 'b', 'u', or 'r'. Ignore.
            if s[0] not in ("'", '"'):
                yield adjusttokenpos(t, coloffset)
                continue

            # String literal. Prefix to make a b'' string.
            yield adjusttokenpos(t._replace(string='b%s' % t.string), coloffset)
            coldelta += 1
            continue

        # This looks like a function call.
        if t.type == token.NAME and _isop(i + 1, '('):
            fn = t.string

            # *attr() builtins don't accept byte strings to 2nd argument.
            if fn in (
                'getattr',
                'setattr',
                'hasattr',
                'safehasattr',
                'wrapfunction',
                'wrapclass',
                'addattr',
            ) and (opts['allow-attr-methods'] or not _isop(i - 1, '.')):
                arg1idx = _findargnofcall(1)
                if arg1idx is not None:
                    _ensuresysstr(arg1idx)

            # .encode() and .decode() on str/bytes/unicode don't accept
            # byte strings on Python 3.
            elif fn in ('encode', 'decode') and _isop(i - 1, '.'):
                for argn in range(2):
                    argidx = _findargnofcall(argn)
                    if argidx is not None:
                        _ensuresysstr(argidx)

            # It changes iteritems/values to items/values as they are not
            # present in Python 3 world.
            elif opts['dictiter'] and fn in ('iteritems', 'itervalues'):
                yield adjusttokenpos(t._replace(string=fn[4:]), coloffset)
                continue

        if t.type == token.NAME and t.string in opts['treat-as-kwargs']:
            if _isitemaccess(i):
                _ensuresysstr(i + 2)
            if _ismethodcall(i, 'get', 'pop', 'setdefault', 'popitem'):
                _ensuresysstr(i + 4)

        # Looks like "if __name__ == '__main__'".
        if (
            t.type == token.NAME
            and t.string == '__name__'
            and _isop(i + 1, '==')
        ):
            _ensuresysstr(i + 2)

        # Emit unmodified token.
        yield adjusttokenpos(t, coloffset)


def process(fin, fout, opts):
    tokens = tokenize.tokenize(fin.readline)
    tokens = replacetokens(list(tokens), opts)
    fout.write(tokenize.untokenize(tokens))


def tryunlink(fname):
    try:
        os.unlink(fname)
    except OSError as err:
        if err.errno != errno.ENOENT:
            raise


@contextlib.contextmanager
def editinplace(fname):
    n = os.path.basename(fname)
    d = os.path.dirname(fname)
    fp = tempfile.NamedTemporaryFile(
        prefix='.%s-' % n, suffix='~', dir=d, delete=False
    )
    try:
        yield fp
        fp.close()
        if os.name == 'nt':
            tryunlink(fname)
        os.rename(fp.name, fname)
    finally:
        fp.close()
        tryunlink(fp.name)


def main():
    ap = argparse.ArgumentParser()
    ap.add_argument(
        '--version', action='version', version='Byteify strings 1.0'
    )
    ap.add_argument(
        '-i',
        '--inplace',
        action='store_true',
        default=False,
        help='edit files in place',
    )
    ap.add_argument(
        '--dictiter',
        action='store_true',
        default=False,
        help='rewrite iteritems() and itervalues()',
    ),
    ap.add_argument(
        '--allow-attr-methods',
        action='store_true',
        default=False,
        help='also handle attr*() when they are methods',
    ),
    ap.add_argument(
        '--treat-as-kwargs',
        nargs="+",
        default=[],
        help="ignore kwargs-like objects",
    ),
    ap.add_argument('files', metavar='FILE', nargs='+', help='source file')
    args = ap.parse_args()
    opts = {
        'dictiter': args.dictiter,
        'treat-as-kwargs': set(args.treat_as_kwargs),
        'allow-attr-methods': args.allow_attr_methods,
    }
    for fname in args.files:
        fname = os.path.realpath(fname)
        if args.inplace:
            with editinplace(fname) as fout:
                with open(fname, 'rb') as fin:
                    process(fin, fout, opts)
        else:
            with open(fname, 'rb') as fin:
                fout = sys.stdout.buffer
                process(fin, fout, opts)


if __name__ == '__main__':
    if sys.version_info[0:2] < (3, 7):
        print('This script must be run under Python 3.7+')
        sys.exit(3)
    main()