How to use a static library created by a custom task?

Question

I want use waf to trigger a makefile to build an other library. For this I created the following task:

def build(bld):
    def run(self):
        bld_dir = self.generator.bld.path.get_bld()
        src_dir = self.inputs[0].parent
        tgt = self.outputs[0]
        tgt_dir = bld_dir.make_node(os.path.splitext(tgt.name)[0])
        cmd = 'BUILDDIR="{tgt_dir}" make config gdb=1 debug=1 cc={cc} && BUILDDIR="    {tgt_dir}" make'.format(
        tgt_dir = tgt_dir.abspath(),
        cc = self.env.get_flat("CC"))
        self.exec_command(cmd, cwd=src_dir.abspath())
        return self.exec_command(['cp', lib.abspath(), tgt.abspath()],
                                 cwd=tgt_dir.abspath())

    bld(
            rule = run,
            source = "Makefile",
            target = 'metis',
    )

How can I tell waf that the task created a static library, so that I can use "metis" in a use keyword:

    bld(
            features = "cxx cxxprogramm"
            source = "main.cpp",
            target = 'main',
            use = 'metis'
    )    

Answer 1

To finally solve the problem I created a on link_task, that basicly does notthing (similar to the fake_lib in ccroot.py):

from waflib.TaskGen import feature, after_method
from waflib.Tools.ccroot import stlink_task

class custom_stlib(stlink_task):
    """ Dummy link task """
    pass

@feature("custom_stlib")
def custom_lib(self):
    self.env['custom_stlib_PATTERN']    = 'lib%s.a'
    self.link_task = self.create_task('custom_stlib', [])
    self.link_task.add_target(self.target)


def build(bld):
    # ...
    bld(
            features = "cxx custom_stlib",
            target = 'metis',
            after = "metis_bld",
    )