blob: badceb97cc86fbe447e531e0a9e30257ac1968e0 [file] [log] [blame]
# Copyright 2022 Google LLC
#
# 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.
"""Rule for simple expansion of template files."""
def _template_rule_impl(ctx):
"""Modifies ctx.file.src keys in ctx.attr.substitutions with corresponding values."""
ctx.actions.expand_template(
template = ctx.file.src,
output = ctx.outputs.out,
substitutions = ctx.attr.substitutions,
)
# Rule for simple expansion of template files. Modifies the templates in src substituting the keys
# in substitutions with the corresponding values; the result is output to out.
#
# Borrowed from TensorFlow (https://github.com/tensorflow/tensorflow)
#
# Typical usage:
# template_rule(
# name = "ExpandMyTemplate",
# src = "my.template",
# out = "my.txt",
# substitutions = {
# "$VAR1": "foo",
# "$VAR2": "bar",
# }
# )
#
# Args:
# name: The name of the rule.
# src: The template file to expand
# out: The destination of the expanded file
# substitutions: A dictionary mapping strings to their substitutions
template_rule = rule(
attrs = {
"src": attr.label(
mandatory = True,
allow_single_file = True,
),
"substitutions": attr.string_dict(mandatory = True),
"out": attr.output(mandatory = True),
},
# output_to_genfiles is required for header files.
output_to_genfiles = True,
implementation = _template_rule_impl,
)