From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Sat, 18 Dec 2021 12:50:15 +0530
Subject: Rename build.py to prevent name conflict with the build package

---
 MANIFEST.in   |   2 +-
 build.py      | 305 ----------------------------------------------------------
 setup.py      |   2 +-
 unix_build.py | 305 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 307 insertions(+), 307 deletions(-)
 delete mode 100755 build.py
 create mode 100755 unix_build.py

diff --git a/MANIFEST.in b/MANIFEST.in
index 3d9654a..76b71c5 100644
--- a/MANIFEST.in
+++ b/MANIFEST.in
@@ -1,5 +1,5 @@
 exclude *.py
-include setup.py build.py run_tests.py gen*.py win-ci.py
+include setup.py unix_build.py run_tests.py gen*.py win-ci.py
 include LICENSE README.rst
 include gumbo/*.c gumbo/*.h gumbo/*.py gumbo/*.rl
 include src/*.c src/*.h
diff --git a/build.py b/build.py
deleted file mode 100755
index 83f916f..0000000
--- a/build.py
+++ /dev/null
@@ -1,305 +0,0 @@
-#!/usr/bin/env python
-# vim:fileencoding=utf-8
-# License: Apache 2.0 Copyright: 2017, Kovid Goyal <kovid at kovidgoyal.net>
-
-from __future__ import (absolute_import, division, print_function, unicode_literals)
-
-import argparse
-import errno
-import glob
-import os
-import re
-import shlex
-import shutil
-import subprocess
-import sys
-import sysconfig
-from collections import namedtuple
-from copy import deepcopy
-from itertools import chain
-try:
-    import configparser
-except ImportError:
-    import ConfigParser as configparser
-
-self_path = os.path.abspath(__file__)
-base = os.path.dirname(self_path)
-build_dir = os.path.join(base, 'build', 'custom')
-freeze_dir = os.path.join(base, 'build', 'html5_parser')
-_plat = sys.platform.lower()
-isosx = 'darwin' in _plat
-iswindows = hasattr(sys, 'getwindowsversion')
-is_ci = os.environ.get('CI') == 'true'
-Env = namedtuple('Env', 'cc cflags ldflags linker debug cc_name cc_ver')
-PKGCONFIG = os.environ.get('PKGCONFIG_EXE', 'pkg-config')
-cfg = configparser.ConfigParser()
-cfg.read(os.path.join(base, 'setup.cfg'))
-version = namedtuple('Version', 'major minor patch')(
-    *map(int, cfg.get('metadata', 'version').split('.')))
-
-
-def safe_makedirs(path):
-    try:
-        os.makedirs(path)
-    except EnvironmentError as err:
-        if err.errno != errno.EEXIST:
-            raise
-
-
-def add_python_flags(env, return_libs=False):
-    env.cflags.extend('-I' + sysconfig.get_path(x) for x in 'include platinclude'.split())
-    libs = []
-    libs += sysconfig.get_config_var('LIBS').split()
-    libs += sysconfig.get_config_var('SYSLIBS').split()
-    fw = sysconfig.get_config_var('PYTHONFRAMEWORK')
-    if fw:
-        for var in 'data include stdlib'.split():
-            val = sysconfig.get_path(var)
-            if val and '/{}.framework'.format(fw) in val:
-                fdir = val[:val.index('/{}.framework'.format(fw))]
-                if os.path.isdir(os.path.join(fdir, '{}.framework'.format(fw))):
-                    framework_dir = fdir
-                    break
-        else:
-            raise SystemExit('Failed to find Python framework')
-        libs.append(os.path.join(framework_dir, sysconfig.get_config_var('LDLIBRARY')))
-    else:
-        libs += ['-L' + sysconfig.get_config_var('LIBDIR')]
-        libs += ['-lpython' + sysconfig.get_config_var('VERSION') + getattr(sys, 'abiflags', '')]
-        libs += sysconfig.get_config_var('LINKFORSHARED').split()
-    env.ldflags.extend(libs)
-    return libs if return_libs else env
-
-
-def pkg_config(pkg, *args):
-    try:
-        val = subprocess.check_output([PKGCONFIG, pkg] + list(args)).decode('utf-8')
-    except EnvironmentError as err:
-        if err.errno == errno.ENOENT:
-            raise SystemExit('pkg-config is required to build html5-parser')
-        raise
-    return list(filter(None, map(str, shlex.split(val))))
-
-
-def env_var(which, default='', split=os.pathsep):
-    val = str(os.environ.get(which, default))
-    if not split:
-        return val
-    return list(filter(None, val.split(split)))
-
-
-def include_dirs():
-    if 'LIBXML_INCLUDE_DIRS' in os.environ:
-        return env_var('LIBXML_INCLUDE_DIRS')
-    return [x[2:] for x in pkg_config('libxml-2.0', '--cflags-only-I')]
-
-
-def libraries():
-    if iswindows:
-        return env_var('LIBXML_LIBS', 'libxml2')
-    if 'LIBXML_LIBS' in os.environ:
-        return env_var('LIBXML_LIBS')
-    return [x[2:] for x in pkg_config('libxml-2.0', '--libs-only-l')]
-
-
-def library_dirs():
-    if 'LIBXML_LIB_DIRS' in os.environ:
-        return env_var('LIBXML_LIB_DIRS')
-    return [x[2:] for x in pkg_config('libxml-2.0', '--libs-only-L')]
-
-
-def cc_version():
-    cc = os.environ.get('CC', 'gcc')
-    raw = subprocess.check_output([cc, '-dM', '-E', '-'], stdin=open(os.devnull, 'rb'))
-    m = re.search(br'^#define __clang__ 1', raw, flags=re.M)
-    cc_name = 'gcc' if m is None else 'clang'
-    ver = int(re.search(br'#define __GNUC__ (\d+)', raw, flags=re.M).group(1)), int(
-        re.search(br'#define __GNUC_MINOR__ (\d+)', raw, flags=re.M).group(1))
-    return cc, ver, cc_name
-
-
-def get_sanitize_args(cc, ccver):
-    sanitize_args = set()
-    if cc == 'gcc' and ccver < (4, 8):
-        return sanitize_args
-    sanitize_args.add('-fno-omit-frame-pointer')
-    sanitize_args.add('-fsanitize=address')
-    if (cc == 'gcc' and ccver >= (5, 0)) or (cc == 'clang' and not isosx):
-        # clang on macOS does not support -fsanitize=undefined
-        sanitize_args.add('-fsanitize=undefined')
-        # if cc == 'gcc' or (cc == 'clang' and ccver >= (4, 2)):
-        #     sanitize_args.add('-fno-sanitize-recover=all')
-    return sanitize_args
-
-
-def init_env(debug=False, sanitize=False, native_optimizations=False, add_python=True):
-    native_optimizations = (native_optimizations and not sanitize and not debug)
-    cc, ccver, cc_name = cc_version()
-    stack_protector = '-fstack-protector'
-    if ccver >= (4, 9) and cc_name == 'gcc':
-        stack_protector += '-strong'
-    missing_braces = ''
-    if ccver < (5, 2) and cc_name == 'gcc':
-        missing_braces = '-Wno-missing-braces'
-    optimize = '-ggdb' if debug or sanitize else '-O3'
-    sanitize_args = get_sanitize_args(cc_name, ccver) if sanitize else set()
-    cflags = os.environ.get(
-        'OVERRIDE_CFLAGS', (
-            '-Wextra -Wno-missing-field-initializers -Wall -std=c99 -fvisibility=hidden'
-            ' -pedantic-errors -Werror {} {} -D{}DEBUG -fwrapv {} {} -pipe {}').format(
-                optimize, ' '.join(sanitize_args), ('' if debug else 'N'), stack_protector,
-                missing_braces, '-march=native' if native_optimizations else ''))
-    libxml_cflags = pkg_config('libxml-2.0', '--cflags')
-    cflags = shlex.split(cflags) + libxml_cflags + shlex.split(sysconfig.get_config_var('CCSHARED'))
-    ldflags = os.environ.get(
-        'OVERRIDE_LDFLAGS', '-Wall -shared ' + ' '.join(sanitize_args) + ('' if debug else ' -O3'))
-    libxml_ldflags = pkg_config('libxml-2.0', '--libs')
-    ldflags = shlex.split(ldflags) + libxml_ldflags
-    cflags += shlex.split(os.environ.get('CFLAGS', ''))
-    ldflags += shlex.split(os.environ.get('LDFLAGS', ''))
-    cflags.append('-pthread')
-    cflags.extend((
-        '-DMAJOR=' + str(version.major),
-        '-DMINOR=' + str(version.minor),
-        '-DPATCH=' + str(version.patch),
-    ))
-    ans = Env(cc, cflags, ldflags, cc, debug, cc_name, ccver)
-    return add_python_flags(ans) if add_python else ans
-
-
-def run_tool(cmd):
-    if hasattr(cmd, 'lower'):
-        cmd = shlex.split(cmd)
-    print(' '.join(cmd))
-    p = subprocess.Popen(cmd)
-    ret = p.wait()
-    if ret != 0:
-        raise SystemExit(ret)
-
-
-def newer(dest, *sources):
-    try:
-        dtime = os.path.getmtime(dest)
-    except EnvironmentError:
-        return True
-    for s in chain(sources, (self_path, )):
-        if os.path.getmtime(s) >= dtime:
-            return True
-    return False
-
-
-def find_c_files(src_dir):
-    ans, headers = [], []
-    for x in sorted(os.listdir(src_dir)):
-        ext = os.path.splitext(x)[1]
-        if ext == '.c' and not x.endswith('-check.c'):
-            ans.append(os.path.join(src_dir, x))
-        elif ext == '.h':
-            headers.append(os.path.join(src_dir, x))
-    ans.sort(key=os.path.getmtime, reverse=True)
-    return tuple(ans), tuple(headers)
-
-
-def build_obj(src, env, headers):
-    suffix = '-debug' if env.debug else ''
-    obj = os.path.join(build_dir, os.path.basename(src).rpartition('.')[0] + suffix + '.o')
-    if newer(obj, src, *headers):
-        cflags = list(env.cflags)
-        if src.endswith('char_ref.c'):
-            cflags.append('-Wno-unused-const-variable')
-        cmd = [env.cc] + cflags + ['-c', src] + ['-o', obj]
-        run_tool(cmd)
-    return obj
-
-
-TEST_EXE = os.path.join(build_dir, 'test')
-MEMLEAK_EXE = os.path.join(build_dir, 'mem-leak-check')
-if is_ci:
-    TEST_EXE = os.path.join(os.path.dirname(os.path.abspath(sys.executable)), 'test-html5-parser')
-SRC_DIRS = 'src gumbo'.split()
-MOD_EXT = '.so'
-
-
-def link(objects, env):
-    dest = os.path.join(build_dir, 'html_parser' + MOD_EXT)
-    o = ['-o', dest]
-    cmd = [env.linker] + objects + o + env.ldflags
-    if newer(dest, *objects):
-        run_tool(cmd)
-    return dest
-
-
-def build(args, build_leak_check=False):
-    debug_objects = []
-    debug_env = init_env(debug=True, sanitize=True)
-    for sdir in SRC_DIRS:
-        sources, headers = find_c_files(sdir)
-        if sdir == 'src':
-            headers += ('gumbo/gumbo.h', )
-        debug_objects.extend(build_obj(c, debug_env, headers) for c in sources)
-    link(debug_objects, debug_env)
-    ldflags = add_python_flags(deepcopy(debug_env), return_libs=True)
-    if newer(TEST_EXE, *debug_objects):
-        cmd = ([debug_env.cc] + debug_env.cflags + ['test.c'] + ['-o', TEST_EXE] + ldflags)
-        run_tool(cmd)
-    if build_leak_check and newer(MEMLEAK_EXE, 'mem-leak-check.c', *debug_objects):
-        cmd = ([debug_env.cc] + debug_env.cflags + ['mem-leak-check.c'] + [
-            '-o', MEMLEAK_EXE] + debug_objects + debug_env.ldflags)
-        cmd = [x for x in cmd if x not in {'-fPIC', '-pthread', '-shared'}]
-        run_tool(cmd)
-    for mod in glob.glob(os.path.join(build_dir, '*' + MOD_EXT)):
-        shutil.copy2(mod, freeze_dir)
-    for mod in glob.glob(os.path.join('src', 'html5_parser', '*.py')):
-        shutil.copy2(mod, freeze_dir)
-
-
-TEST_COMMAND = ['run_tests.py']
-
-
-def add_python_path(env, path):
-    pp = env.get('PYTHONPATH', '')
-    to_join = filter(None, [os.path.abspath(path), pp])
-    env['PYTHONPATH'] = os.pathsep.join(to_join)
-    return env
-
-
-def option_parser():
-    p = argparse.ArgumentParser()
-    p.add_argument(
-        'action',
-        nargs='?',
-        default='test',
-        choices='build test try leak'.split(),
-        help='Action to perform (default is build)')
-    p.add_argument('rest', nargs='*')
-    return p
-
-
-def main():
-    args = option_parser().parse_args()
-    os.chdir(base)
-    safe_makedirs(build_dir), safe_makedirs(freeze_dir)
-    if args.action == 'build':
-        build(args)
-    elif args.action == 'test':
-        build(args)
-        os.environ['ASAN_OPTIONS'] = 'leak_check_at_exit=0'
-        add_python_path(os.environ, os.path.dirname(freeze_dir))
-        print('\nrunning tests...')
-        os.execlp(TEST_EXE, TEST_EXE, 'run_tests.py', *args.rest)
-    elif args.action == 'try':
-        build(args)
-        os.environ['ASAN_OPTIONS'] = 'leak_check_at_exit=0'
-        add_python_path(os.environ, os.path.dirname(freeze_dir))
-        os.execlp(
-            TEST_EXE, TEST_EXE, '-c', 'from html5_parser import *; ' + args.rest[0], *args.rest[1:])
-    elif args.action == 'leak':
-        build(args, build_leak_check=True)
-        os.environ['MEMLEAK_EXE'] = os.path.abspath(MEMLEAK_EXE)
-        os.environ['ASAN_OPTIONS'] = 'leak_check_at_exit=0'
-        add_python_path(os.environ, os.path.dirname(freeze_dir))
-        os.execlp(TEST_EXE, TEST_EXE, 'run_tests.py')
-
-
-if __name__ == '__main__':
-    main()
diff --git a/setup.py b/setup.py
index a67c33f..c20b154 100755
--- a/setup.py
+++ b/setup.py
@@ -12,7 +12,7 @@ self_path = os.path.abspath(__file__)
 base = os.path.dirname(self_path)
 sys.path.insert(0, base)
 if True:
-    from build import (
+    from unix_build import (
         SRC_DIRS, TEST_COMMAND, add_python_path, find_c_files, include_dirs, iswindows, libraries,
         library_dirs, version
     )
diff --git a/unix_build.py b/unix_build.py
new file mode 100755
index 0000000..83f916f
--- /dev/null
+++ b/unix_build.py
@@ -0,0 +1,305 @@
+#!/usr/bin/env python
+# vim:fileencoding=utf-8
+# License: Apache 2.0 Copyright: 2017, Kovid Goyal <kovid at kovidgoyal.net>
+
+from __future__ import (absolute_import, division, print_function, unicode_literals)
+
+import argparse
+import errno
+import glob
+import os
+import re
+import shlex
+import shutil
+import subprocess
+import sys
+import sysconfig
+from collections import namedtuple
+from copy import deepcopy
+from itertools import chain
+try:
+    import configparser
+except ImportError:
+    import ConfigParser as configparser
+
+self_path = os.path.abspath(__file__)
+base = os.path.dirname(self_path)
+build_dir = os.path.join(base, 'build', 'custom')
+freeze_dir = os.path.join(base, 'build', 'html5_parser')
+_plat = sys.platform.lower()
+isosx = 'darwin' in _plat
+iswindows = hasattr(sys, 'getwindowsversion')
+is_ci = os.environ.get('CI') == 'true'
+Env = namedtuple('Env', 'cc cflags ldflags linker debug cc_name cc_ver')
+PKGCONFIG = os.environ.get('PKGCONFIG_EXE', 'pkg-config')
+cfg = configparser.ConfigParser()
+cfg.read(os.path.join(base, 'setup.cfg'))
+version = namedtuple('Version', 'major minor patch')(
+    *map(int, cfg.get('metadata', 'version').split('.')))
+
+
+def safe_makedirs(path):
+    try:
+        os.makedirs(path)
+    except EnvironmentError as err:
+        if err.errno != errno.EEXIST:
+            raise
+
+
+def add_python_flags(env, return_libs=False):
+    env.cflags.extend('-I' + sysconfig.get_path(x) for x in 'include platinclude'.split())
+    libs = []
+    libs += sysconfig.get_config_var('LIBS').split()
+    libs += sysconfig.get_config_var('SYSLIBS').split()
+    fw = sysconfig.get_config_var('PYTHONFRAMEWORK')
+    if fw:
+        for var in 'data include stdlib'.split():
+            val = sysconfig.get_path(var)
+            if val and '/{}.framework'.format(fw) in val:
+                fdir = val[:val.index('/{}.framework'.format(fw))]
+                if os.path.isdir(os.path.join(fdir, '{}.framework'.format(fw))):
+                    framework_dir = fdir
+                    break
+        else:
+            raise SystemExit('Failed to find Python framework')
+        libs.append(os.path.join(framework_dir, sysconfig.get_config_var('LDLIBRARY')))
+    else:
+        libs += ['-L' + sysconfig.get_config_var('LIBDIR')]
+        libs += ['-lpython' + sysconfig.get_config_var('VERSION') + getattr(sys, 'abiflags', '')]
+        libs += sysconfig.get_config_var('LINKFORSHARED').split()
+    env.ldflags.extend(libs)
+    return libs if return_libs else env
+
+
+def pkg_config(pkg, *args):
+    try:
+        val = subprocess.check_output([PKGCONFIG, pkg] + list(args)).decode('utf-8')
+    except EnvironmentError as err:
+        if err.errno == errno.ENOENT:
+            raise SystemExit('pkg-config is required to build html5-parser')
+        raise
+    return list(filter(None, map(str, shlex.split(val))))
+
+
+def env_var(which, default='', split=os.pathsep):
+    val = str(os.environ.get(which, default))
+    if not split:
+        return val
+    return list(filter(None, val.split(split)))
+
+
+def include_dirs():
+    if 'LIBXML_INCLUDE_DIRS' in os.environ:
+        return env_var('LIBXML_INCLUDE_DIRS')
+    return [x[2:] for x in pkg_config('libxml-2.0', '--cflags-only-I')]
+
+
+def libraries():
+    if iswindows:
+        return env_var('LIBXML_LIBS', 'libxml2')
+    if 'LIBXML_LIBS' in os.environ:
+        return env_var('LIBXML_LIBS')
+    return [x[2:] for x in pkg_config('libxml-2.0', '--libs-only-l')]
+
+
+def library_dirs():
+    if 'LIBXML_LIB_DIRS' in os.environ:
+        return env_var('LIBXML_LIB_DIRS')
+    return [x[2:] for x in pkg_config('libxml-2.0', '--libs-only-L')]
+
+
+def cc_version():
+    cc = os.environ.get('CC', 'gcc')
+    raw = subprocess.check_output([cc, '-dM', '-E', '-'], stdin=open(os.devnull, 'rb'))
+    m = re.search(br'^#define __clang__ 1', raw, flags=re.M)
+    cc_name = 'gcc' if m is None else 'clang'
+    ver = int(re.search(br'#define __GNUC__ (\d+)', raw, flags=re.M).group(1)), int(
+        re.search(br'#define __GNUC_MINOR__ (\d+)', raw, flags=re.M).group(1))
+    return cc, ver, cc_name
+
+
+def get_sanitize_args(cc, ccver):
+    sanitize_args = set()
+    if cc == 'gcc' and ccver < (4, 8):
+        return sanitize_args
+    sanitize_args.add('-fno-omit-frame-pointer')
+    sanitize_args.add('-fsanitize=address')
+    if (cc == 'gcc' and ccver >= (5, 0)) or (cc == 'clang' and not isosx):
+        # clang on macOS does not support -fsanitize=undefined
+        sanitize_args.add('-fsanitize=undefined')
+        # if cc == 'gcc' or (cc == 'clang' and ccver >= (4, 2)):
+        #     sanitize_args.add('-fno-sanitize-recover=all')
+    return sanitize_args
+
+
+def init_env(debug=False, sanitize=False, native_optimizations=False, add_python=True):
+    native_optimizations = (native_optimizations and not sanitize and not debug)
+    cc, ccver, cc_name = cc_version()
+    stack_protector = '-fstack-protector'
+    if ccver >= (4, 9) and cc_name == 'gcc':
+        stack_protector += '-strong'
+    missing_braces = ''
+    if ccver < (5, 2) and cc_name == 'gcc':
+        missing_braces = '-Wno-missing-braces'
+    optimize = '-ggdb' if debug or sanitize else '-O3'
+    sanitize_args = get_sanitize_args(cc_name, ccver) if sanitize else set()
+    cflags = os.environ.get(
+        'OVERRIDE_CFLAGS', (
+            '-Wextra -Wno-missing-field-initializers -Wall -std=c99 -fvisibility=hidden'
+            ' -pedantic-errors -Werror {} {} -D{}DEBUG -fwrapv {} {} -pipe {}').format(
+                optimize, ' '.join(sanitize_args), ('' if debug else 'N'), stack_protector,
+                missing_braces, '-march=native' if native_optimizations else ''))
+    libxml_cflags = pkg_config('libxml-2.0', '--cflags')
+    cflags = shlex.split(cflags) + libxml_cflags + shlex.split(sysconfig.get_config_var('CCSHARED'))
+    ldflags = os.environ.get(
+        'OVERRIDE_LDFLAGS', '-Wall -shared ' + ' '.join(sanitize_args) + ('' if debug else ' -O3'))
+    libxml_ldflags = pkg_config('libxml-2.0', '--libs')
+    ldflags = shlex.split(ldflags) + libxml_ldflags
+    cflags += shlex.split(os.environ.get('CFLAGS', ''))
+    ldflags += shlex.split(os.environ.get('LDFLAGS', ''))
+    cflags.append('-pthread')
+    cflags.extend((
+        '-DMAJOR=' + str(version.major),
+        '-DMINOR=' + str(version.minor),
+        '-DPATCH=' + str(version.patch),
+    ))
+    ans = Env(cc, cflags, ldflags, cc, debug, cc_name, ccver)
+    return add_python_flags(ans) if add_python else ans
+
+
+def run_tool(cmd):
+    if hasattr(cmd, 'lower'):
+        cmd = shlex.split(cmd)
+    print(' '.join(cmd))
+    p = subprocess.Popen(cmd)
+    ret = p.wait()
+    if ret != 0:
+        raise SystemExit(ret)
+
+
+def newer(dest, *sources):
+    try:
+        dtime = os.path.getmtime(dest)
+    except EnvironmentError:
+        return True
+    for s in chain(sources, (self_path, )):
+        if os.path.getmtime(s) >= dtime:
+            return True
+    return False
+
+
+def find_c_files(src_dir):
+    ans, headers = [], []
+    for x in sorted(os.listdir(src_dir)):
+        ext = os.path.splitext(x)[1]
+        if ext == '.c' and not x.endswith('-check.c'):
+            ans.append(os.path.join(src_dir, x))
+        elif ext == '.h':
+            headers.append(os.path.join(src_dir, x))
+    ans.sort(key=os.path.getmtime, reverse=True)
+    return tuple(ans), tuple(headers)
+
+
+def build_obj(src, env, headers):
+    suffix = '-debug' if env.debug else ''
+    obj = os.path.join(build_dir, os.path.basename(src).rpartition('.')[0] + suffix + '.o')
+    if newer(obj, src, *headers):
+        cflags = list(env.cflags)
+        if src.endswith('char_ref.c'):
+            cflags.append('-Wno-unused-const-variable')
+        cmd = [env.cc] + cflags + ['-c', src] + ['-o', obj]
+        run_tool(cmd)
+    return obj
+
+
+TEST_EXE = os.path.join(build_dir, 'test')
+MEMLEAK_EXE = os.path.join(build_dir, 'mem-leak-check')
+if is_ci:
+    TEST_EXE = os.path.join(os.path.dirname(os.path.abspath(sys.executable)), 'test-html5-parser')
+SRC_DIRS = 'src gumbo'.split()
+MOD_EXT = '.so'
+
+
+def link(objects, env):
+    dest = os.path.join(build_dir, 'html_parser' + MOD_EXT)
+    o = ['-o', dest]
+    cmd = [env.linker] + objects + o + env.ldflags
+    if newer(dest, *objects):
+        run_tool(cmd)
+    return dest
+
+
+def build(args, build_leak_check=False):
+    debug_objects = []
+    debug_env = init_env(debug=True, sanitize=True)
+    for sdir in SRC_DIRS:
+        sources, headers = find_c_files(sdir)
+        if sdir == 'src':
+            headers += ('gumbo/gumbo.h', )
+        debug_objects.extend(build_obj(c, debug_env, headers) for c in sources)
+    link(debug_objects, debug_env)
+    ldflags = add_python_flags(deepcopy(debug_env), return_libs=True)
+    if newer(TEST_EXE, *debug_objects):
+        cmd = ([debug_env.cc] + debug_env.cflags + ['test.c'] + ['-o', TEST_EXE] + ldflags)
+        run_tool(cmd)
+    if build_leak_check and newer(MEMLEAK_EXE, 'mem-leak-check.c', *debug_objects):
+        cmd = ([debug_env.cc] + debug_env.cflags + ['mem-leak-check.c'] + [
+            '-o', MEMLEAK_EXE] + debug_objects + debug_env.ldflags)
+        cmd = [x for x in cmd if x not in {'-fPIC', '-pthread', '-shared'}]
+        run_tool(cmd)
+    for mod in glob.glob(os.path.join(build_dir, '*' + MOD_EXT)):
+        shutil.copy2(mod, freeze_dir)
+    for mod in glob.glob(os.path.join('src', 'html5_parser', '*.py')):
+        shutil.copy2(mod, freeze_dir)
+
+
+TEST_COMMAND = ['run_tests.py']
+
+
+def add_python_path(env, path):
+    pp = env.get('PYTHONPATH', '')
+    to_join = filter(None, [os.path.abspath(path), pp])
+    env['PYTHONPATH'] = os.pathsep.join(to_join)
+    return env
+
+
+def option_parser():
+    p = argparse.ArgumentParser()
+    p.add_argument(
+        'action',
+        nargs='?',
+        default='test',
+        choices='build test try leak'.split(),
+        help='Action to perform (default is build)')
+    p.add_argument('rest', nargs='*')
+    return p
+
+
+def main():
+    args = option_parser().parse_args()
+    os.chdir(base)
+    safe_makedirs(build_dir), safe_makedirs(freeze_dir)
+    if args.action == 'build':
+        build(args)
+    elif args.action == 'test':
+        build(args)
+        os.environ['ASAN_OPTIONS'] = 'leak_check_at_exit=0'
+        add_python_path(os.environ, os.path.dirname(freeze_dir))
+        print('\nrunning tests...')
+        os.execlp(TEST_EXE, TEST_EXE, 'run_tests.py', *args.rest)
+    elif args.action == 'try':
+        build(args)
+        os.environ['ASAN_OPTIONS'] = 'leak_check_at_exit=0'
+        add_python_path(os.environ, os.path.dirname(freeze_dir))
+        os.execlp(
+            TEST_EXE, TEST_EXE, '-c', 'from html5_parser import *; ' + args.rest[0], *args.rest[1:])
+    elif args.action == 'leak':
+        build(args, build_leak_check=True)
+        os.environ['MEMLEAK_EXE'] = os.path.abspath(MEMLEAK_EXE)
+        os.environ['ASAN_OPTIONS'] = 'leak_check_at_exit=0'
+        add_python_path(os.environ, os.path.dirname(freeze_dir))
+        os.execlp(TEST_EXE, TEST_EXE, 'run_tests.py')
+
+
+if __name__ == '__main__':
+    main()