configure.py

#!/usr/bin/env python
#
# Copyright 2014 Google Inc. All rights reserved.
#
# Use of this source code is governed by The MIT License.
# See the LICENSE file for details.

"""Script that generates the build.ninja file for SPF."""

__author__ = 'nicksay@google.com (Alex Nicksay)'

import errno
import distutils.version
import glob
import os
import shutil
import subprocess
import sys
import urllib
import zipfile


def check_requirements():
  # Closure Compiler after v20131014 requires Java 7.
  required_java = distutils.version.LooseVersion('1.7')
  try:
    cmd = subprocess.Popen(['java', '-version'],
                           stderr=subprocess.STDOUT,
                           stdout=subprocess.PIPE)
  except OSError:
    print('ERROR: Unable to find java.')
    print('Please install java and try again.')
    sys.exit(1)
  out = cmd.stdout.readlines()
  if len(out) <= 0:
    print('ERROR: Unable to get java version.')
    print('Please ensure java is properly installed and try again.')
    sys.exit(1)
  version_string = out[0].split(' ')[-1].strip('\n"')
  installed_java = distutils.version.LooseVersion(version_string)
  if installed_java < required_java:
    print('ERROR: Installed java version "%s" is less than the required "%s".' %
          (installed_java, required_java))
    print('Please upgrade java and try again.')
    sys.exit(1)


def fetch_dependencies():
  # Ninja v1.5.1
  ninja_dir = 'vendor/ninja'
  ninja_syntax = 'vendor/ninja/misc/ninja_syntax.py'
  ninja_syntax_url = 'https://github.com/martine/ninja/archive/v1.5.1.zip'
  ninja_syntax_zip = 'vendor/ninja/v1.5.1.zip'
  ninja_binary = 'vendor/ninja/ninja'
  if 'darwin' in sys.platform:
    ninja_binary_url = 'https://github.com/martine/ninja/releases/download/v1.5.1/ninja-mac.zip'
    ninja_binary_zip = 'vendor/ninja/ninja-mac.zip'
  elif 'win' in sys.platform:
    ninja_binary_url = 'https://github.com/martine/ninja/releases/download/v1.5.1/ninja-win.zip'
    ninja_binary_zip = 'vendor/ninja/ninja-win.zip'
  else:
    ninja_binary_url = 'https://github.com/martine/ninja/releases/download/v1.5.1/ninja-linux.zip'
    ninja_binary_zip = 'vendor/ninja/ninja-linux.zip'
  if not os.path.exists(ninja_dir):
    try:
      os.makedirs(ninja_dir)
    except OSError:
      print('ERROR: Could not create the Ninja directory.')
      print('Please run "mkdir %s" manually and try again.' % ninja_dir)
      sys.exit(1)
  if not os.path.exists(ninja_syntax_zip):
    print('Downloading Ninja syntax...')
    try:
      urllib.urlretrieve(ninja_syntax_url, ninja_syntax_zip)
    except (IOError, urllib.ContentTooShortError):
      print('ERROR: Unable to download Ninja syntax zip file.')
      print('Please download "%s" to "%s" and try again.' %
            (ninja_syntax_url, ninja_syntax_zip))
      sys.exit(1)
  if not os.path.exists(ninja_binary_zip):
    print('Downloading Ninja binary...')
    try:
      urllib.urlretrieve(ninja_binary_url, ninja_binary_zip)
    except (IOError, urllib.ContentTooShortError):
      print('ERROR: Unable to download Ninja binary zip file.')
      print('Please download "%s" to "%s" and try again.' %
            (ninja_binary_url, ninja_binary_zip))
      sys.exit(1)
  if not os.path.exists(ninja_syntax):
    try:
      if not os.path.exists(os.path.dirname(ninja_syntax)):
        os.makedirs(os.path.dirname(ninja_syntax))
      with zipfile.ZipFile(ninja_syntax_zip) as zf:
        # ZipFile.extract is simpler, but manually opening and copying
        # the file objects enables removing the version prefix.
        with zf.open('ninja-1.5.1/misc/ninja_syntax.py') as src:
          with open(ninja_syntax, 'w') as out:
            shutil.copyfileobj(src, out)
        with zf.open('ninja-1.5.1/README') as src:
          with open(os.path.join(ninja_dir, 'README'), 'w') as out:
            shutil.copyfileobj(src, out)
        with zf.open('ninja-1.5.1/COPYING') as src:
          with open(os.path.join(ninja_dir, 'COPYING'), 'w') as out:
            shutil.copyfileobj(src, out)
    except (OSError, IOError, RuntimeError, zipfile.BadZipfile,
            zipfile.LargeZipFile):
      print('ERROR: Unable to unzip Ninja syntax zip file.')
      print('Please delete "%s" and try again.' % ninja_syntax_zip)
  if not os.path.exists(ninja_binary):
    try:
      with zipfile.ZipFile(ninja_binary_zip) as zf:
        zf.extract('ninja', ninja_dir)
        os.chmod(ninja_binary, 0755)
    except (OSError, IOError, RuntimeError, zipfile.BadZipfile,
            zipfile.LargeZipFile):
      print('ERROR: Unable to unzip Ninja syntax zip file.')
      print('Please delete "%s" and try again.' % ninja_syntax_zip)


def find_js_sources():
  sources = ['src/client/stub.js']
  for root, dirs, files in os.walk('src/client'):
    if root.endswith('testing'):
      continue
    for file in files:
      if file.endswith('.js'):
        if file.startswith('stub') or file.endswith('test.js'):
          continue
        sources.append(os.path.join(root, file))
  return sources


def find_js_tests():
  tests = []
  for root, dirs, files in os.walk('src/client'):
    for file in files:
      if file.endswith('test.js'):
        tests.append(os.path.join(root, file))
  return tests


def find_demo_sources():
  sources = []
  for root, dirs, files in os.walk('src/server/demo'):
    for file in files:
      if os.path.splitext(file)[1]:  # Only grab source files.
        sources.append(os.path.join(root, file))
  return sources


def create_ninja_file():
  # Do this during execution to allow downloading the syntax file first.
  sys.path.insert(0, 'vendor/ninja/misc')
  import ninja_syntax

  os.chdir(os.path.dirname(os.path.abspath(__file__)))
  buildfile = open('build.ninja', 'w')
  return ninja_syntax.Writer(buildfile)


def write_header(ninja):
  ninja.comment('Copyright 2014 Google Inc. All rights reserved.')
  ninja.newline()
  ninja.comment('Use of this source code is governed by The MIT License.')
  ninja.comment('See the LICENSE file for details.')
  ninja.newline()
  ninja.comment('This generated file is used to build SPF.')
  ninja.comment('To update, run %s.' % os.path.basename(__file__))
  ninja.newline()


def write_variables(ninja):
  ninja.variable('builddir', 'build')
  ninja.variable('jscompiler_jar', 'vendor/closure-compiler/compiler.jar')
  ninja.variable('jslinter_bin', 'vendor/closure-linter/bin/gjslint')
  ninja.variable('jslinter_dir', 'vendor/closure-linter')
  ninja.variable('jsfixer_bin', 'vendor/closure-linter/bin/fixjsstyle')
  ninja.variable('jsfixer_dir', 'vendor/closure-linter')
  ninja.variable('license_js', 'src/license.js')
  ninja.variable('license', 'cat $license_js')
  ninja.variable('preamble', 'true')
  ninja.variable('wrapper_js', 'src/wrapper.js')

  common_jsflags = [
      '--compilation_level ADVANCED_OPTIMIZATIONS',
      '--define "COMPILED=true"',
      '--manage_closure_dependencies true',
      '--process_closure_primitives true',
  ]
  prod_jsflags = common_jsflags + [
      '--define "SPF_DEBUG=false"',
      '--summary_detail_level 3',
      '--warning_level VERBOSE',
  ]
  debug_jsflags = common_jsflags + [
      '--debug true',
      '--formatting PRETTY_PRINT',
  ]
  trace_jsflags = common_jsflags + [
      '--define "SPF_DEBUG=false"',
      '--define "SPF_TRACING=true"',
  ]
  dev_jsflags = [
      '--compilation_level WHITESPACE_ONLY',
      '--formatting PRETTY_PRINT',
      '--manage_closure_dependencies true',
      '--closure_entry_point spf.main',
  ]
  main_jsflags = [
      '--closure_entry_point spf.main',
      '--output_wrapper_file $wrapper_js',
  ]
  bootloader_jsflags = [
      '--closure_entry_point spf.bootloader',
      '--output_wrapper "(function(){%output%})();"',
  ]
  ninja.variable('prod_jsflags', ' '.join(prod_jsflags))
  ninja.variable('debug_jsflags', ' '.join(debug_jsflags))
  ninja.variable('trace_jsflags', ' '.join(trace_jsflags))
  ninja.variable('dev_jsflags', ' '.join(dev_jsflags))
  ninja.variable('main_jsflags', ' '.join(main_jsflags))
  ninja.variable('bootloader_jsflags', ' '.join(bootloader_jsflags))
  ninja.newline()


def write_rules(ninja):
  ninja.newline()
  ninja.comment('Build JS files.');
  ninja.rule('jscompile',
             command='$license > $out '
                     '&& $preamble >> $out '
                     '&& java -jar $jscompiler_jar $flags $in >> $out '
                     '|| rm $out',
             description='jscompile $out')

  ninja.newline()
  ninja.comment('Lint and fix JS files.')
  ninja.rule('jslint',
             command='export PYTHONUSERBASE="$jslinter_dir" '
                     '&& python $jslinter_bin '
                     '    $flags $in',
             description='jslint $in')
  ninja.rule('jsfix',
             command='export PYTHONUSERBASE="$jsfixer_dir" '
                     '&& python $jsfixer_bin '
                     '    $flags $in',
             description='jsfix $in')

  ninja.newline()
  ninja.comment('Build the build file.')
  ninja.rule('configure',
             command='python ./configure.py',
             generator=True)

  ninja.newline()
  ninja.comment('Symlink.')
  ninja.rule('symlink',
             command='ln -sf $prefix$in $out',
             description='symlink $prefix$in -> $out')

  ninja.newline()
  ninja.comment('Download files.')
  ninja.rule('download',
             command='curl -L $url -o $out',
             generator=True,
             description='download $url -> $out')

  ninja.newline()
  ninja.comment('Unpack files.')
  ninja.rule('unzip',
             command='unzip -u $flags $in $paths -x $exclude -d $dest',
             restat=True,
             description='unzip $in -> $dest')
  ninja.rule('untgz',
             command='tar -xmz -f $in $flags -C $dest --exclude $exclude',
             description='untgz $in -> $dest')

  ninja.newline()
  ninja.comment('Generate test manifest.')
  ninja.rule('gen_test_manifest',
             command=('echo $in '
                      '| tr " " "\\n" '
                      '| sed "s,^,document.write(\'<script src=\\"$prefix,g" '
                      '| sed "s,$$,\\"></script>\');,g" '
                      '> $out'),
             description='generate $out')

  ninja.newline()
  ninja.comment('Setup python packages.')
  ninja.rule('setup',
             command=('cd $dir '
                      '&& export PYTHONUSERBASE="$$PWD" '
                      '&& python setup.py -q install --user '
                      '&& python setup.py -q clean --all'),
             generator=True,
             description='setup $dir')


def write_targets(ninja):
  license_js = '$license_js'
  wrapper_js = '$wrapper_js'

  ninja.newline()
  ninja.comment('Libraries.')
  # Closure Compiler v20140625
  jscompiler_jar = '$jscompiler_jar' # Globally defined to allow use in rules.
  jscompiler_url = 'http://dl.google.com/closure-compiler/compiler-20140625.zip'
  jscompiler_zip = 'vendor/closure-compiler/compiler-20140625.zip'
  jscompiler_zip_dest = 'vendor/closure-compiler'
  jscompiler_zip_outs = [
      'vendor/closure-compiler/COPYING',
      'vendor/closure-compiler/README.md',
      'vendor/closure-compiler/compiler.jar',
  ]
  ninja.build(jscompiler_zip, 'download',
              variables=[('url', jscompiler_url)])
  ninja.build(jscompiler_zip_outs, 'unzip', jscompiler_zip,
              variables=[('dest', jscompiler_zip_dest)])

  # Closure Linter v2.3.13
  jslinter_bin = '$jslinter_bin' # Globally defined to allow use in rules.
  jslinter_url = 'https://closure-linter.googlecode.com/files/closure_linter-2.3.13.tar.gz'
  jslinter_tgz = 'vendor/closure-linter/closure_linter-2.3.13.tar.gz'
  jslinter_tgz_dest = 'vendor/closure-linter'
  jslinter_tgz_outs = [
      'vendor/closure-linter/PKG-INFO',
      'vendor/closure-linter/setup.py',
      'vendor/closure-linter/closure_linter/',
      'vendor/closure-linter/closure_linter/requireprovidesorter.py',
      'vendor/closure-linter/closure_linter/scopeutil.py',
      'vendor/closure-linter/closure_linter/ecmalintrules.py',
      'vendor/closure-linter/closure_linter/error_fixer.py',
      'vendor/closure-linter/closure_linter/javascripttokenizer.py',
      'vendor/closure-linter/closure_linter/runner.py',
      'vendor/closure-linter/closure_linter/checkerbase.py',
      'vendor/closure-linter/closure_linter/common/',
      'vendor/closure-linter/closure_linter/common/simplefileflags.py',
      'vendor/closure-linter/closure_linter/common/tokenizer.py',
      'vendor/closure-linter/closure_linter/common/error.py',
      'vendor/closure-linter/closure_linter/common/erroraccumulator.py',
      'vendor/closure-linter/closure_linter/common/htmlutil.py',
      'vendor/closure-linter/closure_linter/common/tokens.py',
      'vendor/closure-linter/closure_linter/common/lintrunner.py',
      'vendor/closure-linter/closure_linter/common/position.py',
      'vendor/closure-linter/closure_linter/common/matcher.py',
      'vendor/closure-linter/closure_linter/common/__init__.py',
      'vendor/closure-linter/closure_linter/common/erroroutput.py',
      'vendor/closure-linter/closure_linter/common/errorhandler.py',
      'vendor/closure-linter/closure_linter/common/filetestcase.py',
      'vendor/closure-linter/closure_linter/javascriptstatetracker.py',
      'vendor/closure-linter/closure_linter/__init__.py',
      'vendor/closure-linter/closure_linter/statetracker.py',
      'vendor/closure-linter/closure_linter/error_check.py',
      'vendor/closure-linter/closure_linter/fixjsstyle.py',
      'vendor/closure-linter/closure_linter/errorrules.py',
      'vendor/closure-linter/closure_linter/errorrecord.py',
      'vendor/closure-linter/closure_linter/gjslint.py',
      'vendor/closure-linter/closure_linter/checker.py',
      'vendor/closure-linter/closure_linter/closurizednamespacesinfo.py',
      'vendor/closure-linter/closure_linter/aliaspass.py',
      'vendor/closure-linter/closure_linter/ecmametadatapass.py',
      'vendor/closure-linter/closure_linter/testutil.py',
      'vendor/closure-linter/closure_linter/errors.py',
      'vendor/closure-linter/closure_linter/javascripttokens.py',
      'vendor/closure-linter/closure_linter/indentation.py',
      'vendor/closure-linter/closure_linter/javascriptlintrules.py',
      'vendor/closure-linter/closure_linter/tokenutil.py',
      'vendor/closure-linter/README',
  ]
  jslinter_setup_outs = [
      'vendor/closure-linter/bin/fixjsstyle',
      'vendor/closure-linter/bin/gjslint',
      'vendor/closure-linter/closure_linter.egg-info/dependency_links.txt',
      'vendor/closure-linter/closure_linter.egg-info/entry_points.txt',
      'vendor/closure-linter/closure_linter.egg-info/PKG-INFO',
      'vendor/closure-linter/closure_linter.egg-info/requires.txt',
      'vendor/closure-linter/closure_linter.egg-info/SOURCES.txt',
      'vendor/closure-linter/closure_linter.egg-info/top_level.txt',
      'vendor/closure-linter/dist/closure_linter-2.3.13-py2.7.egg',
      'vendor/closure-linter/lib/python/site-packages/closure_linter-2.3.13-py2.7.egg',
      'vendor/closure-linter/lib/python/site-packages/easy-install.pth',
      'vendor/closure-linter/lib/python/site-packages/python_gflags-2.0-py2.7.egg',
  ]
  ninja.build(jslinter_tgz, 'download',
              variables=[('url', jslinter_url)])
  ninja.build(jslinter_tgz_outs, 'untgz', jslinter_tgz,
              variables=[('flags', '--strip-components 1'),
                         ('exclude', '"*_test*"'),
                         ('dest', jslinter_tgz_dest)])
  ninja.build(jslinter_setup_outs, 'setup', jslinter_tgz_outs,
              variables=[('dir', 'vendor/closure-linter')])

  # WebPy @73f1119649
  webpy_url = 'https://github.com/webpy/webpy/archive/73f1119649ffe54ba26ddaf6a612aaf1dab79b7f.zip'
  webpy_zip = 'vendor/webpy/webpy-73f1119649ffe54ba26ddaf6a612aaf1dab79b7f.zip'
  webpy_zip_root_dest = 'vendor/webpy'
  webpy_zip_root_outs = [
      'vendor/webpy/LICENSE.txt',
      'vendor/webpy/README.md',
  ]
  webpy_zip_web_dest = 'vendor/webpy/web'
  webpy_zip_web_outs = [
      'vendor/webpy/web/',
      'vendor/webpy/web/__init__.py',
      'vendor/webpy/web/application.py',
      'vendor/webpy/web/browser.py',
      'vendor/webpy/web/db.py',
      'vendor/webpy/web/debugerror.py',
      'vendor/webpy/web/form.py',
      'vendor/webpy/web/http.py',
      'vendor/webpy/web/httpserver.py',
      'vendor/webpy/web/net.py',
      'vendor/webpy/web/python23.py',
      'vendor/webpy/web/session.py',
      'vendor/webpy/web/template.py',
      'vendor/webpy/web/test.py',
      'vendor/webpy/web/utils.py',
      'vendor/webpy/web/webapi.py',
      'vendor/webpy/web/webopenid.py',
      'vendor/webpy/web/wsgi.py',
  ]
  webpy_zip_web_contrib_dest = 'vendor/webpy/web/contrib'
  webpy_zip_web_contrib_outs = [
      'vendor/webpy/web/contrib/',
      'vendor/webpy/web/contrib/__init__.py',
      'vendor/webpy/web/contrib/template.py',
  ]
  webpy_zip_web_wsgiserver_dest = 'vendor/webpy/web/wsgiserver'
  webpy_zip_web_wsgiserver_outs = [
      'vendor/webpy/web/wsgiserver/',
      'vendor/webpy/web/wsgiserver/LICENSE.txt',
      'vendor/webpy/web/wsgiserver/__init__.py',
      'vendor/webpy/web/wsgiserver/ssl_builtin.py',
      'vendor/webpy/web/wsgiserver/ssl_pyopenssl.py',
  ]
  webpy_zip_outs = (webpy_zip_root_outs + webpy_zip_web_outs +
                    webpy_zip_web_contrib_outs + webpy_zip_web_wsgiserver_outs)
  ninja.build(webpy_zip, 'download',
              variables=[('url', webpy_url)])
  # Extracting each level individually enables removing the version prefix.
  ninja.build(webpy_zip_root_outs, 'unzip', webpy_zip,
              variables=[('flags', '-j'),
                         ('paths', '"*LICENSE.txt" "*README.md"'),
                         ('dest', webpy_zip_root_dest)])
  ninja.build(webpy_zip_web_outs, 'unzip', webpy_zip,
              variables=[('flags', '-j'),
                         ('paths', '"*/web/*"'),
                         ('exclude', '"*/web/contrib/*" "*/web/wsgiserver/*"'),
                         ('dest', webpy_zip_web_dest)])
  ninja.build(webpy_zip_web_contrib_outs, 'unzip', webpy_zip,
              variables=[('flags', '-j'),
                         ('paths', '"*/web/contrib/*"'),
                         ('dest', webpy_zip_web_contrib_dest)])
  ninja.build(webpy_zip_web_wsgiserver_outs, 'unzip', webpy_zip,
              variables=[('flags', '-j'),
                         ('paths', '"*/web/wsgiserver/*"'),
                         ('dest', webpy_zip_web_wsgiserver_dest)])

  # Jasmine v1.3.1
  jasmine_url = 'https://github.com/pivotal/jasmine/raw/ea76a30d85218954625d4685b246218d9ca2dfe1/dist/jasmine-standalone-1.3.1.zip'
  jasmine_zip = 'vendor/jasmine/jasmine-standalone-1.3.1.zip'
  jasmine_zip_dest = 'vendor/jasmine'
  jasmine_zip_outs = [
      'vendor/jasmine/MIT.LICENSE',
      'vendor/jasmine/jasmine.css',
      'vendor/jasmine/jasmine.js',
      'vendor/jasmine/jasmine-html.js',
  ]
  ninja.build(jasmine_zip, 'download',
              variables=[('url', jasmine_url)])
  ninja.build(jasmine_zip_outs, 'unzip', jasmine_zip,
              variables=[('flags', '-j'),
                         ('paths', '"lib/*"'),
                         ('dest', jasmine_zip_dest)])

  wtf_shim = 'third-party/tracing-framework/shims/wtf-trace-closure.js'
  js_srcs = find_js_sources() + [wtf_shim]

  ninja.newline()
  ninja.comment('Main.')
  ninja.build('$builddir/spf.js', 'jscompile', js_srcs,
              variables=[('flags', '$prod_jsflags $main_jsflags')],
              implicit=[jscompiler_jar, license_js, wrapper_js])
  ninja.build('$builddir/spf-debug.js', 'jscompile', js_srcs,
              variables=[('flags', '$debug_jsflags $main_jsflags')],
              implicit=[jscompiler_jar, license_js, wrapper_js])
  ninja.build('$builddir/spf-trace.js', 'jscompile', js_srcs,
              variables=[('flags', '$trace_jsflags $main_jsflags'),
                         ('preamble', 'head -n 6 ' + wtf_shim)],
              implicit=[jscompiler_jar, license_js, wrapper_js])

  ninja.newline()
  ninja.comment('Bootloader.')
  ninja.build('$builddir/boot.js', 'jscompile', js_srcs,
              variables=[('flags', '$prod_jsflags $bootloader_jsflags')],
              implicit=[jscompiler_jar, license_js])
  ninja.build('$builddir/boot-debug.js', 'jscompile', js_srcs,
              variables=[('flags', '$debug_jsflags $bootloader_jsflags')],
              implicit=[jscompiler_jar, license_js])
  ninja.build('$builddir/boot-trace.js', 'jscompile', js_srcs,
              variables=[('flags', '$trace_jsflags $bootloader_jsflags'),
                         ('preamble', 'head -n 6 ' + wtf_shim)],
              implicit=[jscompiler_jar, license_js])

  ninja.newline()
  ninja.comment('Development.')
  dev_out = '$builddir/dev-spf-bundle.js'
  ninja.build(dev_out, 'jscompile', js_srcs,
              variables=[('flags', '$dev_jsflags')],
              implicit=[jscompiler_jar, license_js])

  ninja.newline()
  ninja.comment('Tests.')
  js_tests = find_js_tests()
  jasmine_test_srcs = jasmine_zip_outs[1:]
  jasmine_test_outs = [
      '$builddir/test/jasmine.css',
      '$builddir/test/jasmine.js',
      '$builddir/test/jasmine-html.js',
  ]
  manifest_srcs = [dev_out] + js_tests
  manifest_out = '$builddir/test/manifest.js'
  phantomjs_run_jasmine_src = 'third-party/phantomjs/examples/run-jasmine.js'
  phantomjs_run_jasmine_out = '$builddir/test/run-jasmine.js'
  test_outs = jasmine_test_outs + [manifest_out, phantomjs_run_jasmine_out]
  runner_src = 'src/client/testing/runner.html'
  runner_out = '$builddir/test/runner.html'
  for test_src, test_out in zip(jasmine_test_srcs, jasmine_test_outs):
    ninja.build(test_out, 'symlink', test_src,
                variables=[('prefix', '../' * test_out.count('/'))])
  ninja.build(manifest_out, 'gen_test_manifest', manifest_srcs,
              variables=[('prefix', '../' * manifest_out.count('/'))])
  ninja.build(phantomjs_run_jasmine_out, 'symlink', phantomjs_run_jasmine_src,
              variables=[('prefix',
                         '../' * phantomjs_run_jasmine_out.count('/'))])
  ninja.build(runner_out, 'symlink', runner_src,
              variables=[('prefix', '../' * runner_out.count('/'))],
              implicit=test_outs)

  ninja.newline()
  ninja.comment('Demo.')
  demo_srcs = find_demo_sources()
  demo_app_src = 'src/server/demo/app.py'
  demo_app_out = '$builddir/demo/app.py'
  demo_srcs.remove(demo_app_src)
  demo_outs = [s.replace('src/server/', '$builddir/') for s in demo_srcs]
  demo_srcs.append('vendor/webpy/web')
  demo_outs.append('$builddir/demo/web')
  demo_srcs.append(dev_out)
  demo_outs.append(dev_out.replace('$builddir/', '$builddir/demo/static/'))
  for demo_src, demo_out in zip(demo_srcs, demo_outs):
    if demo_src == 'vendor/webpy/web':
      implicit_deps = webpy_zip_outs
    else:
      implicit_deps = None
    ninja.build(demo_out, 'symlink', demo_src,
                variables=[('prefix', '../' * demo_out.count('/'))],
                implicit=implicit_deps)
  ninja.build(demo_app_out, 'symlink', demo_app_src,
              variables=[('prefix', '../' * demo_app_out.count('/'))],
              implicit=demo_outs)

  ninja.newline()
  ninja.comment('Generate build file.')
  # Update the build file if this script or the build syntax changes.
  ninja.build('build.ninja', 'configure',
              implicit=['./configure.py'])


def write_aliases(ninja):
  ninja.newline()
  ninja.comment('Tools.')
  ninja.build('lint', 'jslint', 'src/client',
              variables=[('flags', '--recurse')],
              implicit=['$jslinter_bin'])
  ninja.build('fix', 'jsfix', 'src/client',
              variables=[('flags', '--recurse')],
              implicit=['$jsfixer_bin'])

  ninja.newline()
  ninja.comment('Aliases.')
  aliases = [
      ninja.build('spf', 'phony',
                  '$builddir/spf.js'),
      ninja.build('spf-debug', 'phony',
                  '$builddir/spf-debug.js'),
      ninja.build('spf-trace', 'phony',
                  '$builddir/spf-trace.js'),
      ninja.build('bootloader', 'phony',
                  '$builddir/boot.js'),
      ninja.build('debug-bootloader', 'phony',
                  '$builddir/boot-debug.js'),
      ninja.build('tracing-bootloader', 'phony',
                  '$builddir/boot-trace.js'),
      ninja.build('tests', 'phony',
                  '$builddir/test/runner.html'),
      ninja.build('demo', 'phony',
                  '$builddir/demo/app.py'),
  ]
  aliases = [a for outs in aliases for a in outs]  # Reduce to a single list.
  ninja.build('all', 'phony', aliases)

  ninja.newline()
  ninja.comment('Default.')
  ninja.default('spf')


def main():
  check_requirements()
  fetch_dependencies()
  ninja = create_ninja_file()
  write_header(ninja)
  write_variables(ninja)
  write_rules(ninja)
  write_targets(ninja)
  write_aliases(ninja)
  print('Wrote %s' % ninja.output.name)


if __name__ == '__main__':
  main()