summaryrefslogtreecommitdiffstats
path: root/servo/components/style/gecko/regen_atoms.py
blob: 61f2fc4c63591ac4f0a3d5f602a57b267bc6fa05 (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
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
#!/usr/bin/env python

# This Source Code Form is subject to the terms of the Mozilla Public
# License, v. 2.0. If a copy of the MPL was not distributed with this
# file, You can obtain one at https://mozilla.org/MPL/2.0/.

import re
import os
import sys

from io import BytesIO

GECKO_DIR = os.path.dirname(__file__.replace("\\", "/"))
sys.path.insert(0, os.path.join(os.path.dirname(GECKO_DIR), "properties"))

import build


# Matches lines like `GK_ATOM(foo, "foo", 0x12345678, true, nsStaticAtom, PseudoElementAtom)`.
PATTERN = re.compile(
    '^GK_ATOM\(([^,]*),[^"]*"([^"]*)",\s*(0x[0-9a-f]+),\s*[^,]*,\s*([^,]*),\s*([^)]*)\)',
    re.MULTILINE,
)
FILE = "include/nsGkAtomList.h"


def map_atom(ident):
    if ident in {
        "box",
        "loop",
        "match",
        "mod",
        "ref",
        "self",
        "type",
        "use",
        "where",
        "in",
    }:
        return ident + "_"
    return ident


class Atom:
    def __init__(self, ident, value, hash, ty, atom_type):
        self.ident = "nsGkAtoms_{}".format(ident)
        self.original_ident = ident
        self.value = value
        self.hash = hash
        # The Gecko type: "nsStaticAtom", "nsCSSPseudoElementStaticAtom", or
        # "nsAnonBoxPseudoStaticAtom".
        self.ty = ty
        # The type of atom: "Atom", "PseudoElement", "NonInheritingAnonBox",
        # or "InheritingAnonBox".
        self.atom_type = atom_type

        if (
            self.is_pseudo_element()
            or self.is_anon_box()
            or self.is_tree_pseudo_element()
        ):
            self.pseudo_ident = (ident.split("_", 1))[1]

        if self.is_anon_box():
            assert self.is_inheriting_anon_box() or self.is_non_inheriting_anon_box()

    def type(self):
        return self.ty

    def capitalized_pseudo(self):
        return self.pseudo_ident[0].upper() + self.pseudo_ident[1:]

    def is_pseudo_element(self):
        return self.atom_type == "PseudoElementAtom"

    def is_anon_box(self):
        if self.is_tree_pseudo_element():
            return False
        return self.is_non_inheriting_anon_box() or self.is_inheriting_anon_box()

    def is_non_inheriting_anon_box(self):
        assert not self.is_tree_pseudo_element()
        return self.atom_type == "NonInheritingAnonBoxAtom"

    def is_inheriting_anon_box(self):
        if self.is_tree_pseudo_element():
            return False
        return self.atom_type == "InheritingAnonBoxAtom"

    def is_tree_pseudo_element(self):
        return self.value.startswith(":-moz-tree-")

    def is_simple_pseudo_element(self) -> bool:
        return not (self.is_tree_pseudo_element() or self.pseudo_ident == "highlight")


def collect_atoms(objdir):
    atoms = []
    path = os.path.abspath(os.path.join(objdir, FILE))
    print("cargo:rerun-if-changed={}".format(path))
    with open(path) as f:
        content = f.read()
        for result in PATTERN.finditer(content):
            atoms.append(
                Atom(
                    result.group(1),
                    result.group(2),
                    result.group(3),
                    result.group(4),
                    result.group(5),
                )
            )
    return atoms


class FileAvoidWrite(BytesIO):
    """File-like object that buffers output and only writes if content changed."""

    def __init__(self, filename):
        BytesIO.__init__(self)
        self.name = filename

    def write(self, buf):
        if isinstance(buf, str):
            buf = buf.encode("utf-8")
        BytesIO.write(self, buf)

    def close(self):
        buf = self.getvalue()
        BytesIO.close(self)
        try:
            with open(self.name, "rb") as f:
                old_content = f.read()
                if old_content == buf:
                    print("{} is not changed, skip".format(self.name))
                    return
        except IOError:
            pass
        with open(self.name, "wb") as f:
            f.write(buf)

    def __enter__(self):
        return self

    def __exit__(self, type, value, traceback):
        if not self.closed:
            self.close()


PRELUDE = """
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at https://mozilla.org/MPL/2.0/. */

// Autogenerated file created by components/style/gecko/regen_atoms.py.
// DO NOT EDIT DIRECTLY
"""[
    1:
]

RULE_TEMPLATE = """
    ("{atom}") => {{{{
        #[allow(unsafe_code)] #[allow(unused_unsafe)]
        unsafe {{ $crate::string_cache::Atom::from_index_unchecked({index}) }}
    }}}};
"""[
    1:
]

MACRO_TEMPLATE = """
/// Returns a static atom by passing the literal string it represents.
#[macro_export]
macro_rules! atom {{
{body}\
}}
"""


def write_atom_macro(atoms, file_name):
    with FileAvoidWrite(file_name) as f:
        f.write(PRELUDE)
        macro_rules = [
            RULE_TEMPLATE.format(atom=atom.value, name=atom.ident, index=i)
            for (i, atom) in enumerate(atoms)
        ]
        f.write(MACRO_TEMPLATE.format(body="".join(macro_rules)))


def write_pseudo_elements(atoms, target_filename):
    pseudos = []
    for atom in atoms:
        if (
            atom.type() == "nsCSSPseudoElementStaticAtom"
            or atom.type() == "nsCSSAnonBoxPseudoStaticAtom"
        ):
            pseudos.append(atom)

    pseudo_definition_template = os.path.join(
        GECKO_DIR, "pseudo_element_definition.mako.rs"
    )
    print("cargo:rerun-if-changed={}".format(pseudo_definition_template))
    contents = build.render(pseudo_definition_template, PSEUDOS=pseudos)

    with FileAvoidWrite(target_filename) as f:
        f.write(contents)


def generate_atoms(dist, out):
    atoms = collect_atoms(dist)
    write_atom_macro(atoms, os.path.join(out, "atom_macro.rs"))
    write_pseudo_elements(atoms, os.path.join(out, "pseudo_element_definition.rs"))


if __name__ == "__main__":
    if len(sys.argv) != 3:
        print("Usage: {} dist out".format(sys.argv[0]))
        exit(2)
    generate_atoms(sys.argv[1], sys.argv[2])