aboutsummaryrefslogtreecommitdiffstats
path: root/docs/_scripts/siphon/parsers.py
blob: 162205de4ca4947153eef43e8e048cd111342ec0 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at:
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

import html
import pyparsing as pp

# Some useful primitives
ident = pp.Word(pp.alphas + "_", pp.alphas + pp.nums + "_")
intNum = pp.Word(pp.nums)
hexNum = pp.Literal("0x") + pp.Word(pp.hexnums)
octalNum = pp.Literal("0") + pp.Word("01234567")
integer = (hexNum | octalNum | intNum) + \
    pp.Optional(pp.Literal("ULL") | pp.Literal("LL") | pp.Literal("L"))
floatNum = pp.Regex(r'\d+(\.\d*)?([eE]\d+)?') + pp.Optional(pp.Literal("f"))
char = pp.Literal("'") + pp.Word(pp.printables, exact=1) + pp.Literal("'")
arrayIndex = integer | ident

lbracket = pp.Literal("(").suppress()
rbracket = pp.Literal(")").suppress()
lbrace = pp.Literal("{").suppress()
rbrace = pp.Literal("}").suppress()
comma = pp.Literal(",").suppress()
equals = pp.Literal("=").suppress()
dot = pp.Literal(".").suppress()
semicolon = pp.Literal(";").suppress()

# initializer := { [member = ] (variable | expression | { initializer } ) }
typeName = ident
varName = ident
typeSpec = pp.Optional("unsigned") + \
           pp.oneOf("int long short float double char u8 i8 void") + \
           pp.Optional(pp.Word("*"), default="")
typeCast = pp.Combine( "(" + ( typeSpec | typeName ) + ")" ).suppress()

string = pp.Combine(pp.OneOrMore(pp.QuotedString(quoteChar='"',
    escChar='\\', multiline=True)), adjacent=False)
literal = pp.Optional(typeCast) + (integer | floatNum | char | string)
var = pp.Combine(pp.Optional(typeCast) + varName +
    pp.Optional("[" + arrayIndex + "]"))

# This could be more complete, but suffices for our uses
expr = (literal | var)

"""Parse and render a block of text into a Python dictionary."""
class Parser(object):
    """Compiled PyParsing BNF"""
    _parser = None

    def __init__(self):
        super(Parser, self).__init__()
        self._parser = self.BNF()

    def BNF(self):
        raise NotImplementedError

    def item(self, item):
        raise NotImplementedError

    def parse(self, input):
        item = self._parser.parseString(input).asList()
        return self.item(item)


"""Parser for function-like macros - without the closing semi-colon."""
class ParserFunctionMacro(Parser):
    def BNF(self):
        # VLIB_CONFIG_FUNCTION (unix_config, "unix")
        macroName = ident
        params = pp.Group(pp.ZeroOrMore(expr + comma) + expr)
        macroParams = lbracket + params + rbracket

        return macroName + macroParams

    def item(self, item):
        r = {
            "macro": item[0],
            "name": item[1][1],
            "function": item[1][0],
        }

        return r


"""Parser for function-like macros with a closing semi-colon."""
class ParseFunctionMacroStmt(ParserFunctionMacro):
    def BNF(self):
        # VLIB_CONFIG_FUNCTION (unix_config, "unix");
        function_macro = super(ParseFunctionMacroStmt, self).BNF()
        mi = function_macro + semicolon
        mi.ignore(pp.cppStyleComment)

        return mi


"""
Parser for our struct initializers which are composed from a
function-like macro, equals sign, and then a normal C struct initializer
block.
"""
class MacroInitializer(ParserFunctionMacro):
    def BNF(self):
        # VLIB_CLI_COMMAND (show_sr_tunnel_command, static) = {
        #    .path = "show sr tunnel",
        #    .short_help = "show sr tunnel [name <sr-tunnel-name>]",
        #    .function = show_sr_tunnel_fn,
        # };
        cs = pp.Forward()


        member = pp.Combine(dot + varName + pp.Optional("[" + arrayIndex + "]"),
            adjacent=False)
        value = (expr | cs)

        entry = pp.Group(pp.Optional(member + equals, default="") + value)
        entries = (pp.ZeroOrMore(entry + comma) + entry + pp.Optional(comma)) | \
                  (pp.ZeroOrMore(entry + comma))

        cs << (lbrace + entries + rbrace)

        macroName = ident
        params = pp.Group(pp.ZeroOrMore(expr + comma) + expr)
        macroParams = lbracket + params + rbracket

        function_macro = super(MacroInitializer, self).BNF()
        mi = function_macro + equals + pp.Group(cs) + semicolon
        mi.ignore(pp.cppStyleComment)

        return mi

    def item(self, item):
        r = {
            "macro": item[0],
            "name": item[1][0],
            "params": item[2],
            "value": {},
        }

        for param in item[2]:
            r["value"][param[0]] = html.escape(param[1])

        return r