contrib/packaging/hgpackaging/inno.py

packaging: process Inno Setup files with Jinja2

I want to make the Inno Setup files dynamically generated.
This will enable us to do things like automatically derive the
set of files to be packaged instead of having to manually
keep lists of files in sync across installers.

As the first step towards this, we process the Inno Setup
files with Jinja2.

As part of this conversion, we had to escape syntax in
mercurial.iss that conflicts with Jinja2. I also took the
opportunity to include modpath.iss via Jinja2 instead of
using Inno's preprocessor. This keeps the Python code a
bit simpler.

Differential Revision: https://phab.mercurial-scm.org/D7158

# inno.py - Inno Setup functionality.
#
# Copyright 2019 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.

# no-check-code because Python 3 native.

import os
import pathlib
import shutil
import subprocess

import jinja2

from .py2exe import build_py2exe
from .util import find_vc_runtime_files

EXTRA_PACKAGES = {
    'dulwich',
    'keyring',
    'pygments',
    'win32ctypes',
}


def build(
    source_dir: pathlib.Path,
    build_dir: pathlib.Path,
    python_exe: pathlib.Path,
    iscc_exe: pathlib.Path,
    version=None,
):
    """Build the Inno installer.

    Build files will be placed in ``build_dir``.

    py2exe's setup.py doesn't use setuptools. It doesn't have modern logic
    for finding the Python 2.7 toolchain. So, we require the environment
    to already be configured with an active toolchain.
    """
    if not iscc_exe.exists():
        raise Exception('%s does not exist' % iscc_exe)

    vc_x64 = r'\x64' in os.environ.get('LIB', '')
    arch = 'x64' if vc_x64 else 'x86'
    inno_source_dir = source_dir / 'contrib' / 'packaging' / 'inno'
    inno_build_dir = build_dir / ('inno-%s' % arch)

    requirements_txt = (
        source_dir / 'contrib' / 'packaging' / 'inno' / 'requirements.txt'
    )

    inno_build_dir.mkdir(parents=True, exist_ok=True)

    build_py2exe(
        source_dir,
        build_dir,
        python_exe,
        'inno',
        requirements_txt,
        extra_packages=EXTRA_PACKAGES,
    )

    # hg.exe depends on VC9 runtime DLLs. Copy those into place.
    for f in find_vc_runtime_files(vc_x64):
        if f.name.endswith('.manifest'):
            basename = 'Microsoft.VC90.CRT.manifest'
        else:
            basename = f.name

        dest_path = source_dir / 'dist' / basename

        print('copying %s to %s' % (f, dest_path))
        shutil.copyfile(f, dest_path)

    print('creating installer')

    # Install Inno files by rendering a template.
    jinja_env = jinja2.Environment(
        loader=jinja2.FileSystemLoader(str(inno_source_dir)),
        # Need to change these to prevent conflict with Inno Setup.
        comment_start_string='{##',
        comment_end_string='##}',
    )

    try:
        template = jinja_env.get_template('mercurial.iss')
    except jinja2.TemplateSyntaxError as e:
        raise Exception(
            'template syntax error at %s:%d: %s'
            % (e.name, e.lineno, e.message,)
        )

    content = template.render()

    with (inno_build_dir / 'mercurial.iss').open('w', encoding='utf-8') as fh:
        fh.write(content)

    args = [str(iscc_exe)]

    if vc_x64:
        args.append('/dARCH=x64')

    if version:
        args.append('/dVERSION=%s' % version)

    args.append('/Odist')
    args.append(str(inno_build_dir / 'mercurial.iss'))

    subprocess.run(args, cwd=str(source_dir), check=True)