feat: Validate file extensions on devicetree source attributes

devicetree/private/devicetree_library.bzl

@@ -50,7 +50,7 @@ devicetree_library = rule(
             providers = [DevicetreeLibraryInfo],
         ),
         "hdrs": attr.label_list(
-            allow_files = True,
+            allow_files = [".h", ".dtsi", ".dts", ".dtso"],
             doc = """List of exported included files (`.h`, `.dtsi`).
 
                 These files are visible to all targets that transitively depend

devicetree/private/dtb.bzl

@@ -360,7 +360,7 @@ dtb = rule(
             [`devicetree_library()`](devicetree_library.md#devicetree_library)
             and add them to [`deps`](#dtb-deps).
         """,
-            allow_files = True,
+            allow_files = [".dts", ".dtsi", ".h"],
         ),
     },
     toolchains = [
@@ -452,7 +452,7 @@ dtbo = rule(
             [`devicetree_library()`](devicetree_library.md#devicetree_library)
             and add them to [`deps`](#dtb-deps).
         """,
-            allow_files = True,
+            allow_files = [".dtso", ".dtsi", ".h"],
         ),
     },
     toolchains = [

devicetree/private/dtb_composite.bzl

@@ -60,7 +60,7 @@ dtb_composite = rule(
     doc = "Builds a composite dtb by applying overlays on a base dtb.",
     attrs = {
         "base": attr.label(
-            allow_single_file = True,
+            allow_single_file = [".dtb"],
             doc = """Base `.dtb` to apply overlays on.
 
                 This usually comes from a `dtb()` target with
@@ -74,7 +74,7 @@ dtb_composite = rule(
                 Default is `name + ".dtb"` if missing extension, otherwise `name`.""",
         ),
         "overlays": attr.label_list(
-            allow_files = True,
+            allow_files = [".dtbo"],
             doc = "List of `.dtbo` overlays to apply.",
         ),
     },

e2e/smoke/include_test/srcs_include_test/BUILD.bazel

@@ -0,0 +1,35 @@
+# Copyright (C) 2026 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.
+
+"""Test that `.dtsi` and `.h` files may be listed directly in `srcs`."""
+
+load("@bazel_skylib//rules:build_test.bzl", "build_test")
+load("@rules_devicetree//devicetree:dtb.bzl", "dtb")
+
+dtb(
+    name = "srcs_include",
+    srcs = [
+        "srcs_include.dts",
+        "sub/dt-bindings.h",
+        "sub/srcs_include.dtsi",
+    ],
+)
+
+build_test(
+    name = "srcs_include_test",
+    targets = [
+        # keep sorted
+        ":srcs_include",
+    ],
+)

e2e/smoke/include_test/srcs_include_test/srcs_include.dts

@@ -0,0 +1,7 @@
+/dts-v1/;
+
+#include "sub/dt-bindings.h"
+#include "sub/srcs_include.dtsi"
+
+/ {
+};

e2e/smoke/include_test/srcs_include_test/sub/dt-bindings.h

@@ -0,0 +1 @@
+#define SRCS_INCLUDE_VALUE 1

e2e/smoke/include_test/srcs_include_test/sub/srcs_include.dtsi

@@ -0,0 +1,3 @@
+/ {
+	srcs-include-value = <SRCS_INCLUDE_VALUE>;
+};