import autopath
from pypy.translator.translator import Translator
from pypy.objspace.flow.model import Variable, Constant, Block, Link
from pypy.objspace.flow.model import traverse, mkentrymap, checkgraph


def valueset_variables(graph):
    entrymap = mkentrymap(graph)
    consider_blocks = entrymap

    while consider_blocks:
        blocklist = consider_blocks.keys()
        consider_blocks = {}
        for block in blocklist:
            if block is graph.startblock:
                continue
            links = entrymap[block]
            assert links
            mapping = {}
            for i in range(len(block.inputargs)):
                # list of possible vars that can arrive in i'th position
                v1 = block.inputargs[i]
                names = {v1.name: True}
                key = []
                for link in links:
                    v = link.args[i]
                    if not isinstance(v, Variable):
                        break
                    names[v.name] = True
                else:
                    if len(names) == 2:
                        del names[v1.name]
                        v1._name, = names.keys()
                        # mark all the following block as subject to
                        # possible further optimization
                        for link in block.exits:
                            consider_blocks[link.target] = True


# ____________________________________________________________

if __name__ == '__main__':

    def is_perfect_number(n=int):
        div = 1
        sum = 0
        while div < n:
            if n % div == 0:
                sum += div
            div += 1
        return n == sum


    t = Translator(is_perfect_number)
    #a = t.annotate([int])
    #a.simplify()
    #a.specialize()
    valueset_variables(t.getflowgraph())
    t.view()
    #f = t.ccompile()
    #for i in range(1, 33):
    #    print '%3d' % i, is_perfect_number(i)