Define Linux clang target as toolchain
This change configures the Linux clang -Og target as a toolchain with
args. To support this, all Pigweed variables from pw_vars_default are
made into build args, defined within their respective modules.
The Linux clang target/toolchain is the only one that currently works.
Pigweed's other targets will be ported in later changes.
Change-Id: I051e29fde7577e41a3184c37031a4e04936404e1
diff --git a/pw_tokenizer/backend.gni b/pw_tokenizer/backend.gni
new file mode 100644
index 0000000..dd00ac9
--- /dev/null
+++ b/pw_tokenizer/backend.gni
@@ -0,0 +1,20 @@
+# Copyright 2020 The Pigweed Authors
+#
+# 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
+#
+# https://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.
+
+declare_args() {
+ # Backends for the pw_tokenizer:global_handler and
+ # pw_tokenizer:global_handler_with_payload facades.
+ pw_tokenizer_GLOBAL_HANDLER_BACKEND = ""
+ pw_tokenizer_GLOBAL_HANDLER_WITH_PAYLOAD_BACKEND = ""
+}