1# Copyright (C) 2023 The Android Open Source Project
2#
3# Licensed under the Apache License, Version 2.0 (the "License");
4# you may not use this file except in compliance with the License.
5# You may obtain a copy of the License at
6#
7#      http://www.apache.org/licenses/LICENSE-2.0
8#
9# Unless required by applicable law or agreed to in writing, software
10# distributed under the License is distributed on an "AS IS" BASIS,
11# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12# See the License for the specific language governing permissions and
13# limitations under the License.
14"""
15Export build flags (with values) to make.
16"""
17
18load("//build/bazel/utils:schema_validation.scl", "validate")
19
20# Partitions that get build system flag summaries
21_flag_partitions = [
22    "product",
23    "system",
24    "system_ext",
25    "vendor",
26]
27
28ALL = ["all"]
29PRODUCT = ["product"]
30SYSTEM = ["system"]
31SYSTEM_EXT = ["system_ext"]
32VENDOR = ["vendor"]
33
34_valid_types = ["NoneType", "bool", "list", "string", "int"]
35
36_all_flags_schema = {
37    "type": "list",
38    "of": {
39        "type": "dict",
40        "required_keys": {
41            "name": {"type": "string"},
42            "partitions": {
43                "type": "list",
44                "of": {
45                    "type": "string",
46                    "choices": _flag_partitions + ["all"],
47                },
48                "unique": True,
49            },
50            "default": {
51                "or": [
52                    {"type": t}
53                    for t in _valid_types
54                ],
55            },
56            "origin": {"type": "string"},
57            "declared_in": {"type": "string"},
58        },
59        "optional_keys": {
60            "appends": {
61                "type": "bool",
62            },
63        },
64    },
65}
66
67_all_values_schema = {
68    "type": "list",
69    "of": {
70        "type": "dict",
71        "required_keys": {
72            "name": {"type": "string"},
73            "value": {
74                "or": [
75                    {"type": t}
76                    for t in _valid_types
77                ],
78            },
79            "set_in": {"type": "string"},
80        },
81    },
82}
83
84def flag(name, partitions, default, *, origin = "Unknown", appends = False):
85    """Declare a flag.
86
87    Args:
88      name: name of the flag
89      partitions: the partitions where this should be recorded.
90      default: the default value of the flag.
91      origin: The origin of this flag.
92      appends: Whether new values should be append (not replace) the old.
93
94    Returns:
95      A dictionary containing the flag declaration.
96    """
97    if not partitions:
98        fail("At least 1 partition is required")
99    if not name.startswith("RELEASE_"):
100        fail("Release flag names must start with RELEASE_")
101    if " " in name or "\t" in name or "\n" in name:
102        fail("Flag names must not contain whitespace: \"" + name + "\"")
103    for partition in partitions:
104        if partition == "all":
105            if len(partitions) > 1:
106                fail("\"all\" can't be combined with other partitions: " + str(partitions))
107        elif partition not in _flag_partitions:
108            fail("Invalid partition: " + partition + ", allowed partitions: " +
109                 str(_flag_partitions))
110    if type(default) not in _valid_types:
111        fail("Invalid type of default for flag \"" + name + "\" (" + type(default) + ")")
112    return {
113        "name": name,
114        "partitions": partitions,
115        "default": default,
116        "appends": appends,
117        "origin": origin,
118    }
119
120def value(name, value):
121    """Define the flag value for a particular configuration.
122
123    Args:
124      name: The name of the flag.
125      value: The value for the flag.
126
127    Returns:
128      A dictionary containing the name and value to be used.
129    """
130    return {
131        "name": name,
132        "value": value,
133    }
134
135def _format_value(val):
136    """Format the starlark type correctly for make.
137
138    Args:
139      val: The value to format
140
141    Returns:
142      The value, formatted correctly for make.
143    """
144    if type(val) == "NoneType":
145        return ""
146    elif type(val) == "bool":
147        return "true" if val else ""
148    else:
149        return val
150
151def equal_flag_declaration(flag, other):
152    """Return true if the flag declarations are equal.
153
154    Args:
155      flag: This flag declaration.
156      other: Another flag declaration.
157
158    Returns:
159      Whether the declarations are the same.
160    """
161    for key in "name", "partitions", "default", "appends":
162        if flag[key] != other[key]:
163            return False
164    # For now, allow Unknown to match any other origin.
165    if flag["origin"] == "Unknown" or other["origin"] == "Unknown":
166        return True
167    return flag["origin"] == other["origin"]
168
169def release_config(all_flags, all_values):
170    """Return the make variables that should be set for this release config.
171
172    Args:
173      all_flags: A list of flag objects (from flag() calls).
174      all_values: A list of value objects (from value() calls).
175
176    Returns:
177      A dictionary of {name: value} variables for make.
178    """
179    validate(all_flags, _all_flags_schema)
180    validate(all_values, _all_values_schema)
181
182    # Final values.
183    values = {}
184    # Validate flags
185    flag_names = []
186    flags_dict = {}
187    for flag in all_flags:
188        name = flag["name"]
189        if name in flag_names:
190            if equal_flag_declaration(flag, flags_dict[name]):
191                continue
192            else:
193                fail(flag["declared_in"] + ": Duplicate declaration of flag " + name +
194                     " (declared first in " + flags_dict[name]["declared_in"] + ")")
195        flag_names.append(name)
196        flags_dict[name] = flag
197        # Set the flag value to the default value.
198        values[name] = {"name": name, "value": _format_value(flag["default"]), "set_in": flag["declared_in"]}
199
200    # Record which flags go on which partition
201    partitions = {}
202    for flag in all_flags:
203        for partition in flag["partitions"]:
204            if partition == "all":
205                if len(flag["partitions"]) > 1:
206                    fail("\"all\" can't be combined with other partitions: " + str(flag["partitions"]))
207                for partition in _flag_partitions:
208                    partitions.setdefault(partition, []).append(flag["name"])
209            else:
210                partitions.setdefault(partition, []).append(flag["name"])
211
212    # Generate final values.
213    # Only declared flags may have a value.
214    for value in all_values:
215        name = value["name"]
216        if name not in flag_names:
217            fail(value["set_in"] + ": Value set for undeclared build flag: " + name)
218        if flags_dict[name]["appends"]:
219            if name in values:
220                values[name]["value"] += " " + value["value"]
221                values[name]["set_in"] += " " + value["set_in"]
222            else:
223                values[name] = value
224        else:
225            values[name] = value
226
227    # Collect values
228    result = {
229        "_ALL_RELEASE_FLAGS": sorted(flag_names),
230    }
231    for partition, names in partitions.items():
232        result["_ALL_RELEASE_FLAGS.PARTITIONS." + partition] = names
233    for flag in all_flags:
234        val = _format_value(values[flag["name"]]["value"])
235        result[flag["name"]] = val
236        result["_ALL_RELEASE_FLAGS." + flag["name"] + ".PARTITIONS"] = flag["partitions"]
237        result["_ALL_RELEASE_FLAGS." + flag["name"] + ".DEFAULT"] = _format_value(flag["default"])
238        result["_ALL_RELEASE_FLAGS." + flag["name"] + ".VALUE"] = val
239        result["_ALL_RELEASE_FLAGS." + flag["name"] + ".DECLARED_IN"] = flag["declared_in"]
240        result["_ALL_RELEASE_FLAGS." + flag["name"] + ".SET_IN"] = values[flag["name"]]["set_in"]
241        result["_ALL_RELEASE_FLAGS." + flag["name"] + ".ORIGIN"] = flag["origin"]
242
243    return result
244