talk/site_scons/site_tools/talk_libjingle.py

# Copyright 2010 Google Inc.
# All Rights Reserved.
# Author: thaloun@google.com (Tim Haloun)

"""Tools that we need to include with libjingle."""

import subprocess

# We need this in libjingle because main.scons depends on it and
# libjingle depends on main.scons.
def EnableFeatureWherePackagePresent(env, bit, cpp_flag, package):
  """Enable a feature if a required pkg-config package is present.

  Args:
    env: The current SCons environment.
    bit: The name of the Bit to enable when the package is present.
    cpp_flag: The CPP flag to enable when the package is present.
    package: The name of the package.
  """
  if not env.Bit('host_linux'):
    return
  if _HavePackage(package):
    env.SetBits(bit)
    env.Append(CPPDEFINES = [cpp_flag])
  else:
    print ("Warning: Package \"%s\" not found. Feature \"%s\" will not be "
           "built. To build with this feature, install the package that "
           "provides the \"%s.pc\" file.") % (package, bit, package)

def _HavePackage(package):
  """Whether the given pkg-config package name is present on the build system.

  Args:
    package: The name of the package.

  Return:
    True if the package is present, else False
  """
  return subprocess.call(["pkg-config", "--exists", package]) == 0

def generate(env):
  env.AddMethod(EnableFeatureWherePackagePresent)

def exists(env):
  return 1