clang.py

import os.path
import re
import subprocess
import SCons.Action
from SCons.Tool import cc


def detect_version(env, clang):
    clang = env.subst(clang)
    if not clang:
        return None
    version = None
    pipe = SCons.Action._subproc(env, SCons.Util.CLVar(clang) + ['--version'],
                                 stdin='devnull',
                                 stderr='devnull',
                                 stdout=subprocess.PIPE)
    line = pipe.stdout.readline()
    match = re.search(r'version ([^\s])', line)
    if match:
        version = match.group(0)

    while pipe.stdout.readline():
        pass
    ret = pipe.wait()
    if ret != 0:
        return None
    return version


def generate(env):
    if 'CC' not in env:
        env['CC'] = env.Detect('clang')
    if 'CXX' not in env:
        env['CXX'] = env.Detect('clang++')

    cc.generate(env)

    env['CCVERSION'] = detect_version(env, env.subst('$CC'))
    env['CXXVERSION'] = detect_version(env, env.subst('$CXX'))


def exists(env):
    return env.Detect('clang')