xref: /aosp_15_r20/external/bazel-skylib/rules/private/maprule_util.bzl (revision bcb5dc7965af6ee42bf2f21341a2ec00233a8c8a)
1# Copyright 2019 The Bazel Authors. All rights reserved.
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
15"""Utilities for maprule."""
16
17def resolve_locations(ctx, strategy, d):
18    """Resolve $(location) references in the values of a dictionary.
19
20    Args:
21      ctx: the 'ctx' argument of the rule implementation function
22      strategy: a struct with an 'as_path(string) -> string' function
23      d: {string: string} dictionary; values may contain $(location) references
24        for labels declared in the rule's 'srcs' and 'tools' attributes
25
26    Returns:
27      {string: string} dict, same as 'd' except "$(location)" references are
28      resolved.
29    """
30    location_expressions = []
31    parts = {}
32    was_anything_to_resolve = False
33    for k, v in d.items():
34        # Look for "$(location ...)" or "$(locations ...)", resolve if found.
35        # _validate_attributes already ensured that there's at most one $(location/s ...) in "v".
36        if "$(location" in v:
37            tokens = v.split("$(location")
38            was_anything_to_resolve = True
39            closing_paren = tokens[1].find(")")
40            location_expressions.append("$(location" + tokens[1][:closing_paren + 1])
41            parts[k] = (tokens[0], tokens[1][closing_paren + 1:])
42        else:
43            location_expressions.append("")
44
45    resolved = {}
46    if was_anything_to_resolve:
47        # Resolve all $(location) expressions in one go.  Should be faster than resolving them
48        # one-by-one.
49        all_location_expressions = "<split_here>".join(location_expressions)
50        all_resolved_locations = ctx.expand_location(all_location_expressions)
51        resolved_locations = strategy.as_path(all_resolved_locations).split("<split_here>")
52
53        i = 0
54
55        # Starlark dictionaries have a deterministic order of iteration, so the element order in
56        # "resolved_locations" matches the order in "location_expressions", i.e. the previous
57        # iteration order of "d".
58        for k, v in d.items():
59            if location_expressions[i]:
60                head, tail = parts[k]
61                resolved[k] = head + resolved_locations[i] + tail
62            else:
63                resolved[k] = v
64            i += 1
65    else:
66        resolved = d
67
68    return resolved
69
70def fail_if_errors(errors):
71    """Reports errors and fails the rule.
72
73    Args:
74        errors: list of strings; the errors to report. At most 10 are reported.
75    """
76    if errors:
77        # Don't overwhelm the user; report up to ten errors.
78        fail("\n".join(errors[:10]))
79
80def _as_windows_path(s):
81    """Returns the input path as a Windows path (replaces all of "/" with "\")."""
82    return s.replace("/", "\\")
83
84def _unchanged_path(s):
85    """Returns the input string (path) unchanged."""
86    return s
87
88def _create_cmd_action(
89        ctx,
90        outputs,
91        command,
92        inputs = None,
93        env = None,
94        progress_message = None,
95        mnemonic = None,
96        manifests_from_tools = None):
97    """Create one action using cmd.exe."""
98    ctx.actions.run(
99        inputs = inputs or [],
100        outputs = outputs,
101        executable = "cmd.exe",
102        env = env,
103        arguments = ["/C", command],
104        progress_message = progress_message or "Running cmd.exe command",
105        mnemonic = mnemonic or "CmdExeCommand",
106        input_manifests = manifests_from_tools,
107    )
108
109def _create_bash_action(
110        ctx,
111        outputs,
112        command,
113        inputs = None,
114        env = None,
115        progress_message = None,
116        mnemonic = None,
117        manifests_from_tools = None):
118    """Create one action using Bash."""
119    ctx.actions.run_shell(
120        inputs = inputs or [],
121        outputs = outputs,
122        env = env,
123        command = command,
124        progress_message = progress_message or "Running Bash command",
125        mnemonic = mnemonic or "BashCommand",
126        input_manifests = manifests_from_tools,
127    )
128
129# Action creation utilities for cmd.exe actions.
130CMD_STRATEGY = struct(
131    as_path = _as_windows_path,
132    create_action = _create_cmd_action,
133)
134
135# Action creation utilities for Bash actions.
136BASH_STRATEGY = struct(
137    as_path = _unchanged_path,
138    create_action = _create_bash_action,
139)
140