Start build target config files
This change defines the build target system used by Pigweed, where the
build is configured using per-target globals imported from a target .gni
file. A single build arg specifying the path to the target file replaces
the previous args.
A default build variables file is provided in the Pigweed root. This
file defines and documents all of the build variables used by Pigweed.
A top-level targets directory is added to define the targets used by
Pigweed developers. Currently, only a "host" target is added, which
configures the build for a development system based on the host OS.
Change-Id: Ie62b8d41e5789bfe7fffe20462160142c79076c4
diff --git a/pw_vars_default.gni b/pw_vars_default.gni
new file mode 100644
index 0000000..f0fd89f
--- /dev/null
+++ b/pw_vars_default.gni
@@ -0,0 +1,46 @@
+# Copyright 2019 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.
+
+# This file defines default values for all of the build variables used by
+# Pigweed.
+#
+# Each individual variable can be overriden by a target to configure the system
+# to build for it. This is done in a .gni file specific to the target by first
+# importing this file, then changing the variables as desired.
+
+# Options which configure the executable targets created in Pigweed builds.
+pw_executable_config = {
+ # The name of the GN target type used to build Pigweed executables.
+ #
+ # If this is a custom template, the .gni file containing the template must
+ # be imported at the top of this file to make it globally available.
+ target_type = "executable"
+
+ # Path to an instantiation of the "linker_script" GN template defining the
+ # linker script configuration for the target.
+ linker_script_target = ""
+
+ # Path to the Bloaty configuration file that defines the memory layout and
+ # capacities for the target binaries.
+ bloaty_config_file = ""
+}
+
+# Default toolchain for the build target.
+#
+# If this is changed, you must run `ninja -t clean` to remove any files from
+# the previous toolchain's build before building again.
+pw_target_toolchain = ""
+
+# Implementation of a main function for "pw_test" unit test binaries.
+pw_unit_test_main = "$dir_pw_unit_test:main"