#!/usr/bin/python

# metabuild: Generic build system wrapper
# Copyright 2010 Colin Walters <walters@verbum.org>
# Licensed under the new-BSD license (http://www.opensource.org/licenses/bsd-license.php)

# metabuild currently just wraps autotools (configure+make).
# To use it, you must first use the "inroot" tool to enter an alternative
# buildroot.
#
# $ inroot /path/to/buildroot bash
#
# Next, just type:
# $ metabuild
# This will:
#  1) Run ./configure if necessary
#  2) Run make
#
# The build output is automatically logged to $TMPDIR/build-$(PWD).log.
# For example, invoking metabuild in a directory named "foo" will log
# to /tmp/build-foo.log
#
# You can pass arguments to metabuild; if they start with '--', they're
# given to configure.  Otherwise, they're passed to make.
#
# $ metabuild --enable-libfoo  # passed to configure
# $ metabuild -j 1             # passed to make

import os,sys,subprocess,tempfile
from multiprocessing import cpu_count
import glib,gio

if 'INROOT_DIR' not in os.environ:
    print "INROOT_DIR not set; run under inroot"
    sys.exit(1)
root = os.environ['INROOT_DIR']
if os.path.isdir('/lib64'):
    libdir=os.path.join(root, 'lib64')
else:
    libdir=os.path.join(root, 'lib')

configargs = ['--prefix=' + root, '--libdir=' + libdir]
makeargs = ['make', '-j', '%d' % (cpu_count() * 2, )]
for arg in sys.argv[1:]:
    if arg.startswith('--'):
        configargs.append(arg)
    else:
        makeargs.append(arg)

have_configure=(os.path.exists('configure.ac') or os.path.exists('configure.in'))
if have_configure and not os.path.exists('configure'):
    if os.path.exists('autogen.sh'):
        args = ['./autogen.sh']
        args.extend(configargs)
        subprocess.check_call(args, stdout=sys.stdout, stderr=sys.stderr)
    else:
        subprocess.check_call(['autoreconf', '-f', '-i'], stdout=sys.stdout, stderr=sys.stderr)
        args = ['./configure']
        args.extend(configargs)
        subprocess.check_call(args, stdout=sys.stdout, stderr=sys.stderr)
prefix_matches=True
if have_configure and os.path.exists('config.log'):
    previous_prefix = None
    f = open('config.log')
    for line in f:
        if line.startswith('prefix=\''):
            previous_prefix = line[8:-2]
            break
    f.close()
    if previous_prefix != root:
        print "Reruning configure due to prefix change (%r -> %r)" % (root, previous_prefix)
        prefix_matches=False

if have_configure and (not os.path.exists('Makefile') or not prefix_matches):
    args = ['./configure']
    args.extend(configargs)
    subprocess.check_call(args, stdout=sys.stdout, stderr=sys.stderr)

class Tail(object):
    def __init__(self, filename, output):
        self.filename = filename
        self.output = output
        self._gfile = gio.File(path=filename)
        self._mon = self._gfile.monitor(gio.FILE_MONITOR_NONE)
        self._fd = os.open(self.filename, os.O_RDONLY)
        self._position = 0
        self._mon.connect('changed', self._on_changed)
        self._do_read()

    def _do_read(self):
        buf = os.read(self._fd, 8192)
        while buf != '':
            self._position += len(buf)
            self.output.write(buf)
            buf = os.read(self._fd, 8192)

    def _on_changed(self, mon, gfile, other, event):
        self._do_read()

    def finish(self):
        self._do_read()

loop = glib.MainLoop()
build_condition = None

tempdir = os.environ.get('TMPDIR', '/tmp')
logfile_path = os.path.join(tempdir, 'build-%s.log' % (os.path.basename(os.getcwd()), ))
try:
    os.unlink(logfile_path)
except OSError, e:
    pass
logfile_write_fd = os.open(logfile_path, os.O_WRONLY | os.O_CREAT | os.O_EXCL)
sys.stdout.write('metabuild: logging to %r\n' % (logfile_path, ))
sys.stdout.flush()
def child_setup(*args):
    os.dup2(logfile_write_fd, 1)
    os.dup2(logfile_write_fd, 2)
(make_pid, stdin_fd, stdout_fd, stderr_fd) = \
    glib.spawn_async(makeargs,
                     flags=(glib.SPAWN_DO_NOT_REAP_CHILD | glib.SPAWN_SEARCH_PATH),
                     child_setup=child_setup)
os.close(logfile_write_fd)
tail = Tail(logfile_path, sys.stdout)
def on_child(pid, condition):
    global loop
    global build_condition
    build_condition = condition
    loop.quit()
glib.child_watch_add(make_pid, on_child)
loop.run()
tail.finish()
print "metabuild: make exited with status %r, logfile=%r" % (build_condition, logfile_path)
sys.exit(0 if build_condition == 0 else 1)