linux-imx

#!/usr/bin/python3

# SPDX-License-Identifier: GPL-2.0-only

#

# Copyright (C) 2018 Netronome Systems, Inc.

​

# In case user attempts to run with Python 2.

from __future__ import print_function

​

import argparse

import re

import sys, os

​

class NoHelperFound(BaseException):

    pass

​

class ParsingError(BaseException):

    def __init__(self, line='<line not provided>', reader=None):

        if reader:

            BaseException.__init__(self,

                                   'Error at file offset %d, parsing line: %s' %

                                   (reader.tell(), line))

        else:

            BaseException.__init__(self, 'Error parsing line: %s' % line)

​

class Helper(object):

    """

    An object representing the description of an eBPF helper function.

    @proto: function prototype of the helper function

    @desc: textual description of the helper function

    @ret: description of the return value of the helper function

    """

    def __init__(self, proto='', desc='', ret=''):

        self.proto = proto

        self.desc = desc

        self.ret = ret

​

    def proto_break_down(self):

        """

        Break down helper function protocol into smaller chunks: return type,

        name, distincts arguments.

        """

        arg_re = re.compile('((const )?(struct )?(\w+|...))( (\**)(\w+))?$')

        res = {}

        proto_re = re.compile('(.+) (\**)(\w+)\(((([^,]+)(, )?){1,5})\)$')

​

        capture = proto_re.match(self.proto)

        res['ret_type'] = capture.group(1)

        res['ret_star'] = capture.group(2)

        res['name']     = capture.group(3)

        res['args'] = []

​

        args    = capture.group(4).split(', ')

        for a in args:

            capture = arg_re.match(a)

            res['args'].append({

                'type' : capture.group(1),

                'star' : capture.group(6),

                'name' : capture.group(7)

            })

​

        return res

​

class HeaderParser(object):

    """

    An object used to parse a file in order to extract the documentation of a

    list of eBPF helper functions. All the helpers that can be retrieved are

    stored as Helper object, in the self.helpers() array.

    @filename: name of file to parse, usually include/uapi/linux/bpf.h in the

               kernel tree

    """

    def __init__(self, filename):

        self.reader = open(filename, 'r')

        self.line = ''

        self.helpers = []

​

    def parse_helper(self):

        proto    = self.parse_proto()

        desc     = self.parse_desc()

        ret      = self.parse_ret()

        return Helper(proto=proto, desc=desc, ret=ret)

​

    def parse_proto(self):

        # Argument can be of shape:

        #   - "void"

        #   - "type  name"

        #   - "type *name"

        #   - Same as above, with "const" and/or "struct" in front of type

        #   - "..." (undefined number of arguments, for bpf_trace_printk())

        # There is at least one term ("void"), and at most five arguments.

        p = re.compile(' \* ?((.+) \**\w+\((((const )?(struct )?(\w+|\.\.\.)( \**\w+)?)(, )?){1,5}\))$')

        capture = p.match(self.line)

        if not capture: