def getCoveragePaths(fgraph, maxpath=None):
    '''
    Get a set of paths which will cover every block, but will
    *end* on branches which re-merge with previously traversed
    paths.  This allows a full coverage of the graph with as
    little work as possible, but *will* omit possible states.

    Returns: yield based path generator ( where path is list if (nid,edge) tuples )
    '''
    pathcnt = 0
    nodedone = {}

    for root in fgraph.getHierRootNodes():

        proot = vg_pathcore.newPathNode(nid=root[0], eid=None)
        todo = [(root,proot), ]

        while todo:

            node,cpath = todo.pop()
            refsfrom = fgraph.getRefsFrom(node)

            # Record that we have visited this node...
            nodedone[node[0]] = True

            # This is a leaf node!
            if not refsfrom:
                path = vg_pathcore.getPathToNode(cpath)
                yield [ _nodeedge(n) for n in path ]

                pathcnt += 1
                if maxpath != None and pathcnt >= maxpath:
                    return

            for eid, fromid, toid, einfo in refsfrom:

                # If we're branching to a visited node, return the path as is
                if nodedone.get(toid):
                    path = vg_pathcore.getPathToNode(cpath)
                    yield [ _nodeedge(n) for n in path ]

                    # Check if that was the last path we should yield
                    pathcnt += 1
                    if maxpath != None and pathcnt >= maxpath:
                        return

                    # If we're at a completed node, take no further branches
                    continue

                npath = vg_pathcore.newPathNode(parent=cpath, nid=toid, eid=eid)
                tonode = fgraph.getNode(toid)
                todo.append((tonode,npath))

def getLoopPaths(fgraph):
    '''
    Similar to getCodePaths(), however, getLoopPaths() will return path lists
    which loop.  The last element in the (node,edge) list will be the first
    "looped" block.
    '''
    for root in fgraph.getHierRootNodes():
        proot = vg_pathcore.newPathNode(nid=root[0], eid=None)
        todo = [ (root[0],proot,0), ]

        while todo:
            node,cpath,loopcnt = todo.pop()

            count = 0
            free = []
            if loopcnt == 1:
                yield [ _nodeedge(n) for n in vg_pathcore.getPathToNode(npath) ]

            else:
                for eid, fromid, toid, einfo in fgraph.getRefsFromByNid(node):

                    loopcnt = vg_pathcore.getPathLoopCount(cpath, 'nid', toid)
                    if loopcnt > 1:
                        continue

                    count += 1
                    npath = vg_pathcore.newPathNode(parent=cpath, nid=toid, eid=eid)
                    todo.append((toid,npath,loopcnt))

            if not count:
                vg_pathcore.trimPath(cpath)

def _getCodePathsThru2(fgraph, tgtcbva, path, firstpath, loopcnt=0, pathcnt=0, maxpath=None):

    tgtnode = fgraph.getNode(tgtcbva)
    todo = [ (tgtnode,firstpath), ]

    while todo:

        node,cpath = todo.pop()

        refsfrom = fgraph.getRefsFrom(node)

        # This is a leaf node!
        if not refsfrom:
            path = vg_pathcore.getPathToNode(cpath)
            yield path, pathcnt
            vg_pathcore.trimPath(cpath)

            pathcnt += 1
            if maxpath and pathcnt >= maxpath:
                return

        for eid, fromid, toid, einfo in refsfrom:
            # Skip loops if they are "deeper" than we are allowed
            loops = vg_pathcore.getPathLoopCount(cpath, 'nid', toid)
            if loops > loopcnt:
                continue

            npath = vg_pathcore.newPathNode(parent=cpath, nid=toid, eid=eid)
            tonode = fgraph.getNode(toid)
            todo.append((tonode,npath))

def getLoopPaths(fgraph):
    '''
    Similar to getCodePaths(), however, getLoopPaths() will return path lists
    which loop.  The last element in the (node,edge) list will be the first
    "looped" block.
    '''
    loops = []
    for root in fgraph.getRootNodes():
        proot = vg_pathcore.newPathNode(nid=root, eid=None)
        todo = [ (root,proot), ]

        while todo:
            nodeid,cpath = todo.pop()

            for eid, fromid, toid, einfo in fgraph.getRefsFrom(nodeid):

                loopcnt = vg_pathcore.getPathLoopCount(cpath, 'nid', toid)
                if loopcnt > 1:
                    continue

                npath = vg_pathcore.newPathNode(parent=cpath, nid=toid, eid=eid)
                if loopcnt == 1:
                    loops.append(npath)
                else:
                    todo.append((toid,npath))

    for lnode in loops:
        yield [ _nodeedge(n) for n in vg_pathcore.getPathToNode(lnode) ]

def getCodePathsThru(fgraph, tgtcbva, loopcnt=0, maxpath=None):
    '''
    Yields all the paths through the hierarchical graph which pass through
    the target codeblock "tgtcb".  Each "root" node is traced to the target, 
    and all paths are traversed from there to the end.  Specify a loopcnt
    to allow loop paths to be generated with the given "loop iteration count"

    Example:
        for path in getCodePathsThru(fgraph, tgtcb):
            for node,edge in path:
                ...etc...
    '''    
    # this starts with the "To" side, finding a path back from tgtcbva to root
    pathcnt = 0
    looptrack = []
    pnode = vg_pathcore.newPathNode(nid=tgtcbva, eid=None)
    rootnodes = fgraph.getHierRootNodes()

    tgtnode = fgraph.getNode(tgtcbva)
    todo = [(tgtnode,pnode), ]

    while todo:

        node,cpath = todo.pop()

        refsto = fgraph.getRefsTo(node)

        # This is the root node!
        if node in rootnodes:
            path = vg_pathcore.getPathToNode(cpath)
            path.reverse()
            # build the path in the right direction
            newcpath = None
            lastnk = {'eid':None}
            for np,nc,nk in path:
                newcpath = vg_pathcore.newPathNode(parent=newcpath, nid=nk['nid'], eid=lastnk['eid'])
                lastnk = nk

            for fullpath, count in _getCodePathsThru2(fgraph, tgtcbva, path, newcpath, loopcnt=loopcnt, pathcnt=pathcnt, maxpath=maxpath):
                yield [ _nodeedge(n) for n in fullpath ]
            vg_pathcore.trimPath(cpath)

            pathcnt += count
            if maxpath and pathcnt >= maxpath:
                return

        for eid, fromid, toid, einfo in refsto:
            # Skip loops if they are "deeper" than we are allowed
            loops = vg_pathcore.getPathLoopCount(cpath, 'nid', fromid)
            if loops > loopcnt:
                continue

            #vg_pathcore.setNodeProp(cpath, 'eid', eid)
            #print "-e: %d %x %x %s" % (eid, fromid, toid, repr(einfo))
            npath = vg_pathcore.newPathNode(parent=cpath, nid=fromid, eid=eid)
            fromnode = fgraph.getNode(fromid)
            todo.append((fromnode,npath))

    def do_argtrack(self, line):
        """
        Track input arguments to the given function by name or address.

        Usage: argtrack <func_addr_expr> <arg_idx>
        """
        if not line:
            return self.do_help("argtrack")

        argv = e_cli.splitargs(line)
        if len(argv) != 2:
            return self.do_help("argtrack")

        try:
            fva = self.parseExpression(argv[0])
        except Exception as e:
            self.vprint("Invalid Address Expression: %s" % argv[0])
            return

        try:
            idx = self.parseExpression(argv[1])
        except Exception as e:
            self.vprint("Invalid Index Expression: %s" % argv[1])
            return

        if self.getFunction(fva) != fva:
            self.vprint("Invalid Function Address: (0x%.8x) %s" % (fva, line))

        for pleaf in viv_vector.trackArgOrigin(self, fva, idx):

            self.vprint('='*80)

            path = vg_path.getPathToNode(pleaf)
            path.reverse()

            for pnode in path:
                fva = vg_path.getNodeProp(pnode, 'fva')
                argv = vg_path.getNodeProp(pnode, 'argv')
                callva = vg_path.getNodeProp(pnode, 'cva')
                argidx = vg_path.getNodeProp(pnode, 'argidx')
                if callva != None:
                    aval, amagic = argv[argidx]
                    arepr = '0x%.8x' % aval
                    if amagic != None:
                        arepr = repr(amagic)
                    frepr = 'UNKNOWN'
                    if fva != None:
                        frepr = '0x%.8x' % fva
                    self.vprint('func: %s calls at: 0x%.8x with his own: %s' % (frepr, callva, arepr))
            self.vprint("="*80)

def getCodePathsTo(fgraph, tocbva, loopcnt=0, maxpath=None):
    '''
    Yields all the paths through the hierarchical graph starting at the 
    "root nodes" and ending at tocbva.  Specify a loopcnt to allow loop 
    paths to be generated with the given "loop iteration count"

    Example:
        for path in getCodePathsTo(fgraph, tocbva):
            for node,edge in path:
                ...etc...
    '''
    pathcnt = 0
    looptrack = []
    pnode = vg_pathcore.newPathNode(nid=tocbva, eid=None)

    #rootnodes = fgraph.getHierRootNodes()
    cbnode = fgraph.getNode(tocbva)
    todo = [(cbnode,pnode), ]

    while todo:

        node,cpath = todo.pop()

        refsto = fgraph.getRefsTo(node)

        # Is this is the root node?
        if node[1].get('rootnode'):
            path = vg_pathcore.getPathToNode(cpath)
            path.reverse()
            yield [ _nodeedge(n) for n in path ]
            vg_pathcore.trimPath(cpath)

            pathcnt += 1
            if maxpath and pathcnt >= maxpath:
                return

        for eid, n1, n2, einfo in refsto:
            # Skip loops if they are "deeper" than we are allowed
            loops = vg_pathcore.getPathLoopCount(cpath, 'nid', n1)
            if loops > loopcnt:
                continue

            vg_pathcore.setNodeProp(cpath, 'eid', eid)
            npath = vg_pathcore.newPathNode(parent=cpath, nid=n1, eid=None)
            node1 = fgraph.getNode(n1)
            todo.append((node1,npath))

def getCodePathsFrom(fgraph, fromcbva, loopcnt=0, maxpath=None):
    '''
    Yields all the paths through the hierarchical graph beginning with 
    "fromcbva", which is traced to all terminating points.  Specify a loopcnt
    to allow loop paths to be generated with the given "loop iteration count"

    Example:
        for path in getCodePathsFrom(fgraph, fromcbva):
            for node,edge in path:
                ...etc...
    '''
    pathcnt = 0
    proot = vg_pathcore.newPathNode(nid=fromcbva, eid=None)

    cbnid,cbnode = fgraph.getNode(fromcbva)
    todo = [(cbnid,proot), ]

    while todo:

        nid,cpath = todo.pop()

        refsfrom = fgraph.getRefsFromByNid(nid)

        # This is a leaf node!
        if not refsfrom:
            path = vg_pathcore.getPathToNode(cpath)
            yield [ _nodeedge(n) for n in path ]
            vg_pathcore.trimPath(cpath)

            pathcnt += 1
            if maxpath and pathcnt >= maxpath:
                return

        for eid, fromid, n2, einfo in refsfrom:
            # Skip loops if they are "deeper" than we are allowed
            loops = vg_pathcore.getPathLoopCount(cpath, 'nid', n2)
            if loops > loopcnt:
                continue

            npath = vg_pathcore.newPathNode(parent=cpath, nid=n2, eid=eid)
            todo.append((n2,npath))

def getCodePaths(fgraph, loopcnt=0, maxpath=None):
    '''
    Yields all the paths through the hierarchical graph.  Each
    "root" node is traced to all terminating points.  Specify a loopcnt
    to allow loop paths to be generated with the given "loop iteration count"

    Example:
        for path in getCodePaths(fgraph):
            for node,edge in path:
                ...etc...
    '''
    pathcnt = 0
    for root in fgraph.getHierRootNodes():
        proot = vg_pathcore.newPathNode(nid=root[0], eid=None)
        todo = [(root,proot), ]

        while todo:

            node,cpath = todo.pop()

            refsfrom = fgraph.getRefsFrom(node)

            # This is a leaf node!
            if not refsfrom:
                path = vg_pathcore.getPathToNode(cpath)
                yield [ _nodeedge(n) for n in path ]
                vg_pathcore.trimPath(cpath)

                pathcnt += 1
                if maxpath and pathcnt >= maxpath:
                    return

            for eid, fromid, toid, einfo in refsfrom:
                # Skip loops if they are "deeper" than we are allowed
                if vg_pathcore.getPathLoopCount(cpath, 'nid', toid) > loopcnt:
                    continue

                npath = vg_pathcore.newPathNode(parent=cpath, nid=toid, eid=eid)
                tonode = fgraph.getNode(toid)
                todo.append((tonode,npath))

            return

        try:
            idx = self.parseExpression(argv[1])
        except Exception, e:
            self.vprint("Invalid Index Expression: %s" % argv[1])
            return

        if self.getFunction(fva) != fva:
            self.vprint("Invalid Function Address: (0x%.8x) %s" % (fva, line))

        for pleaf in viv_vector.trackArgOrigin(self, fva, idx):

            self.vprint('='*80)

            path = vg_path.getPathToNode(pleaf)
            path.reverse()

            for pnode in path:
                fva = vg_path.getNodeProp(pnode, 'fva')
                argv = vg_path.getNodeProp(pnode, 'argv')
                callva = vg_path.getNodeProp(pnode, 'cva')
                argidx = vg_path.getNodeProp(pnode, 'argidx')
                if callva != None:
                    aval, amagic = argv[argidx]
                    arepr = '0x%.8x' % aval
                    if amagic != None:
                        arepr = repr(amagic)
                    frepr = 'UNKNOWN'
                    if fva != None:
                        frepr = '0x%.8x' % fva

    def getFuncCbRoutedPaths(self, fromva, tova, loopcnt=0, maxpath=None, maxsec=None):
        '''
        Yields all the paths through the hierarchical graph starting at the 
        "root nodes" and ending at tocbva.  Specify a loopcnt to allow loop 
        paths to be generated with the given "loop iteration count"

        Example:
            for path in getCodePathsTo(fgraph, tocbva):
                for node,edge in path:
                    ...etc...
        '''
        fgraph = self.graph
        self.__update = 0
        self.__go__ = True
        pathcnt = 0
        tocbva = getGraphNodeByVa(fgraph, tova)
        frcbva = getGraphNodeByVa(fgraph, fromva)

        preRouteGraph(fgraph, fromva, tova)
        
        pnode = vg_pathcore.newPathNode(nid=frcbva, eid=None)

        todo = [(frcbva, pnode), ]

        if maxsec:
            self.watchdog(maxsec)

        while todo:
            if not self.__go__:
                raise PathForceQuitException()

            nodeid,cpath = todo.pop()

            refsfrom = fgraph.getRefsFrom((nodeid, None))

            # This is the root node!
            if nodeid == tocbva:
                path = vg_pathcore.getPathToNode(cpath)
                yield [ _nodeedge(n) for n in path ]
                vg_pathcore.trimPath(cpath)

                pathcnt += 1
                self.__update = 1
                if maxpath and pathcnt >= maxpath:
                    return

            for eid, fromid, toid, einfo in refsfrom:
                if fgraph.getNodeProps(fromid).get('down') != True:
                    #sys.stderr.write('.')
                    # TODO: drop the bad edges from graph in preprocessing? instead of "if" here
                    continue

                # Skip loops if they are "deeper" than we are allowed
                loops = vg_pathcore.getPathLoopCount(cpath, 'nid', fromid)
                if loops > loopcnt:
                    vg_pathcore.trimPath(cpath)
                    #sys.stderr.write('o')

                    # as long as we have at least one path, we count loops as paths, lest we die.
                    if pathcnt: 
                        pathcnt += 1
                    continue

                npath = vg_pathcore.newPathNode(parent=cpath, nid=toid, eid=eid)
                todo.append((toid,npath))

            vg_pathcore.trimPath(cpath)

    def getFuncCbRoutedPaths_genback(self, fromva, tova, loopcnt=0, maxpath=None, maxsec=None):
        '''
        Yields all the paths through the hierarchical graph starting at the 
        "root nodes" and ending at tocbva.  Specify a loopcnt to allow loop 
        paths to be generated with the given "loop iteration count"

        Example:
            for path in getCodePathsTo(fgraph, tocbva):
                for node,edge in path:
                    ...etc...
        '''
        fgraph = self.graph
        self.__update = 0
        self.__go__ = True
        pathcnt = 0
        tocbva = getGraphNodeByVa(fgraph, tova)
        frcbva = getGraphNodeByVa(fgraph, fromva)

        preRouteGraph(fgraph, fromva, tova)
        
        pnode = vg_pathcore.newPathNode(nid=tocbva, eid=None)

        todo = [(tocbva,pnode), ]

        if maxsec:
            self.watchdog(maxsec)

        while todo:
            if not self.__go__:
                raise PathForceQuitException()

            nodeid,cpath = todo.pop()

            refsto = fgraph.getRefsTo((nodeid, None))

            # This is the root node!
            if nodeid == frcbva:
                path = vg_pathcore.getPathToNode(cpath)
                path.reverse()
                self.__steplock.acquire()
                yield [ viv_graph._nodeedge(n) for n in path ]
                vg_pathcore.trimPath(cpath)

                pathcnt += 1
                self.__update = 1
                self.__steplock.release()
                if maxpath and pathcnt >= maxpath:
                    return

            for eid, fromid, toid, einfo in refsto:
                if fgraph.getNodeProps(fromid).get('up') != True:
                    # TODO: drop the bad edges from graph in preprocessing? instead of "if" here
                    vg_pathcore.trimPath(cpath)
                    continue

                # Skip loops if they are "deeper" than we are allowed
                loops = vg_pathcore.getPathLoopCount(cpath, 'nid', fromid)
                if loops > loopcnt:
                    continue

                vg_pathcore.setNodeProp(cpath, 'eid', eid)
                npath = vg_pathcore.newPathNode(parent=cpath, nid=fromid, eid=None)
                todo.append((fromid,npath))

    def pathSearch(self, n1, n2=None, edgecb=None, tocb=None):
        '''
        Search for the shortest path from one node to another
        with the option to filter based on edges using
        edgecb.  edgecb should be a function:

        def myedgecb(graph, eid, n1, n2, depth)

        which returns True if it's OK to traverse this node
        in the search.

        Additionally, n2 may be None and the caller may specify
        tocb with a function such as:

        def mytocb(graph, nid)

        which must return True on finding the target node

        Returns a list of edge ids...
        '''

        if n2 == None and tocb == None:
            raise Exception('You must use either n2 or tocb!')

        root = vg_pathcore.newPathNode(nid=n1, eid=None)

        todo = [(root, 0),]

        # FIXME make this a deque so it can be FIFO
        while len(todo):

            pnode,depth = todo.pop() # popleft()
            ppnode, pkids, pprops = pnode

            nid = pprops.get('nid')
            for edge in self.getRefsFromByNid(nid):

                eid, srcid, dstid, eprops = edge

                if vg_pathcore.isPathLoop(pnode, 'nid', dstid):
                    continue

                # Check if the callback is present and likes us...
                if edgecb != None:
                    if not edgecb(self, edge, depth):
                        continue

                # Are we the match?
                match = False
                if dstid == n2:
                    match = True

                if tocb and tocb(self, dstid):
                    match = True

                if match:

                    m = vg_pathcore.newPathNode(pnode, nid=dstid, eid=eid)
                    path = vg_pathcore.getPathToNode(m)

                    ret = []
                    for ppnode, pkids, pprops in path:
                        eid = pprops.get('eid')
                        if eid != None:
                            ret.append(eid)

                    yield ret

                # Add the next set of choices to evaluate.
                branch = vg_pathcore.newPathNode(pnode, nid=dstid, eid=eid)
                todo.append((branch, depth+1))

def getCodePaths(vw, fromva, tova, trim=True):
    """
    Return a list of paths, where each path is a list
    of code blocks from fromva to tova.

    Usage: getCodePaths(vw, <fromva>, <tova>) -> [ [frblock, ..., toblock], ...]

    NOTE: "trim" causes an optimization which may not reveal *all* the paths,
          but is much faster to run.  It will never return no paths when there
          are some, but may not return all of them... (based on path overlap)
    """

    done = {}
    res = []

    frcb = vw.getCodeBlock(fromva)
    tocb = vw.getCodeBlock(tova)
    if frcb == None:
        raise viv_exc.InvalidLocation(fromva)
    if tocb == None:
        raise viv_exc.InvalidLocation(tova)

    frva = frcb[0] # For compare speed

    root = vg_path.newPathNode(cb=tocb, cbva=tocb[0])
    todo = [root, ]
    done[tova] = tocb

    cbcache = {}

    while len(todo):

        path = todo.pop()
        cbva = vg_path.getNodeProp(path, 'cbva')

        codeblocks = cbcache.get(cbva)
        if codeblocks == None:
            codeblocks = getCodeFlow(vw, cbva)
            cbcache[cbva] = codeblocks

        for cblock in codeblocks:

            bva,bsize,bfva = cblock

            # Don't follow loops...
            if vg_path.isPathLoop(path, 'cbva', bva):
                continue

            # If we have been here before and it's *not* the answer,
            # skip out...
            if trim and done.get(bva) != None: continue

            done[bva] = cblock

            newpath = vg_path.newPathNode(parent=path, cb=cblock, cbva=bva)

            # If this one is a match, we don't need to
            # track past it.  Also, put it in the results list
            # so we don't have to do it later....
            if bva == frva:
                res.append(newpath)
            else:
                todo.append(newpath)


    # Now...  if we have some results, lets build the block list.
    ret = []
    for cpath in res:
        fullpath = vg_path.getPathToNode(cpath)
        # We actually do it by inbound references, so reverse the result!
        fullpath.reverse()
        ret.append([vg_path.getNodeProp(path, 'cb') for path in fullpath])

    return ret