bazel-skylib/rules/private/maprule_util.bzl

140 lines
4.6 KiB
Python

# Copyright 2019 The Bazel Authors. All rights reserved.
#
# 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.
"""Utilities for maprule."""
def resolve_locations(ctx, strategy, d):
"""Resolve $(location) references in the values of a dictionary.
Args:
ctx: the 'ctx' argument of the rule implementation function
strategy: a struct with an 'as_path(string) -> string' function
d: {string: string} dictionary; values may contain $(location) references
for labels declared in the rule's 'srcs' and 'tools' attributes
Returns:
{string: string} dict, same as 'd' except "$(location)" references are
resolved.
"""
location_expressions = []
parts = {}
was_anything_to_resolve = False
for k, v in d.items():
# Look for "$(location ...)" or "$(locations ...)", resolve if found.
# _validate_attributes already ensured that there's at most one $(location/s ...) in "v".
if "$(location" in v:
tokens = v.split("$(location")
was_anything_to_resolve = True
closing_paren = tokens[1].find(")")
location_expressions.append("$(location" + tokens[1][:closing_paren + 1])
parts[k] = (tokens[0], tokens[1][closing_paren + 1:])
else:
location_expressions.append("")
resolved = {}
if was_anything_to_resolve:
# Resolve all $(location) expressions in one go. Should be faster than resolving them
# one-by-one.
all_location_expressions = "<split_here>".join(location_expressions)
all_resolved_locations = ctx.expand_location(all_location_expressions)
resolved_locations = strategy.as_path(all_resolved_locations).split("<split_here>")
i = 0
# Starlark dictionaries have a deterministic order of iteration, so the element order in
# "resolved_locations" matches the order in "location_expressions", i.e. the previous
# iteration order of "d".
for k, v in d.items():
if location_expressions[i]:
head, tail = parts[k]
resolved[k] = head + resolved_locations[i] + tail
else:
resolved[k] = v
i += 1
else:
resolved = d
return resolved
def fail_if_errors(errors):
"""Reports errors and fails the rule.
Args:
errors: list of strings; the errors to report. At most 10 are reported.
"""
if errors:
# Don't overwhelm the user; report up to ten errors.
fail("\n".join(errors[:10]))
def _as_windows_path(s):
"""Returns the input path as a Windows path (replaces all of "/" with "\")."""
return s.replace("/", "\\")
def _unchanged_path(s):
"""Returns the input string (path) unchanged."""
return s
def _create_cmd_action(
ctx,
outputs,
command,
inputs = None,
env = None,
progress_message = None,
mnemonic = None,
manifests_from_tools = None):
"""Create one action using cmd.exe."""
ctx.actions.run(
inputs = inputs or [],
outputs = outputs,
executable = "cmd.exe",
env = env,
arguments = ["/C", command],
progress_message = progress_message or "Running cmd.exe command",
mnemonic = mnemonic or "CmdExeCommand",
input_manifests = manifests_from_tools,
)
def _create_bash_action(
ctx,
outputs,
command,
inputs = None,
env = None,
progress_message = None,
mnemonic = None,
manifests_from_tools = None):
"""Create one action using Bash."""
ctx.actions.run_shell(
inputs = inputs or [],
outputs = outputs,
env = env,
command = command,
progress_message = progress_message or "Running Bash command",
mnemonic = mnemonic or "BashCommand",
input_manifests = manifests_from_tools,
)
# Action creation utilities for cmd.exe actions.
CMD_STRATEGY = struct(
as_path = _as_windows_path,
create_action = _create_cmd_action,
)
# Action creation utilities for Bash actions.
BASH_STRATEGY = struct(
as_path = _unchanged_path,
create_action = _create_bash_action,
)