1 files changed, 54 insertions, 0 deletions
diff --git a/cc/toolchains/feature_constraint.bzl b/cc/toolchains/feature_constraint.bzl
new file mode 100644
index 0000000..c6ae44a
--- /dev/null
+++ b/cc/toolchains/feature_constraint.bzl
@@ -0,0 +1,54 @@
+# Copyright 2024 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.
+"""Implementation of the cc_feature_constraint rule."""
+
+load(
+    "//cc/toolchains/impl:collect.bzl",
+    "collect_features",
+    "collect_provider",
+)
+load(
+    ":cc_toolchain_info.bzl",
+    "FeatureConstraintInfo",
+    "FeatureSetInfo",
+)
+
+def _cc_feature_constraint_impl(ctx):
+    if ctx.attr.features:
+        fail("Features is a reserved attribute in bazel. Use the attributes `all_of` and `none_of` for feature constraints")
+    all_of = collect_provider(ctx.attr.all_of, FeatureConstraintInfo)
+    none_of = [collect_features(ctx.attr.none_of)]
+    none_of.extend([fc.none_of for fc in all_of])
+    return [FeatureConstraintInfo(
+        label = ctx.label,
+        all_of = depset(transitive = [fc.all_of for fc in all_of]),
+        none_of = depset(transitive = none_of),
+    )]
+
+cc_feature_constraint = rule(
+    implementation = _cc_feature_constraint_impl,
+    attrs = {
+        "all_of": attr.label_list(
+            providers = [FeatureConstraintInfo],
+        ),
+        "none_of": attr.label_list(
+            providers = [FeatureSetInfo],
+        ),
+    },
+    provides = [FeatureConstraintInfo],
+    doc = """Defines a constraint on features.
+
+Can be used with require_any_of to specify that something is only enabled when
+a constraint is met.""",
+)