[gn] introduce build_root variable (project-chip#4352)

* [gn] introduce build_root variable

* [nrfconnect] build from CHIP root directory

* [pigweed] bump version

* [nrfconnect] ensure the minimum gn version is installed

* Restyled by gn

Co-authored-by: Restyled.io <commits@restyled.io>

.gn

@@ -12,14 +12,15 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import("//build_overrides/build.gni")
+import("//build_overrides/pigweed.gni")
+
 # The location of the build configuration file.
-buildconfig = "//build/config/BUILDCONFIG.gn"
+buildconfig = "${build_root}/config/BUILDCONFIG.gn"
 
 # CHIP uses angle bracket includes.
 check_system_includes = true
 
-import("//build_overrides/pigweed.gni")
-
 script_executable = "python3"
 
 default_args = {

BUILD.gn

@@ -12,20 +12,22 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import("//build_overrides/build.gni")
 import("//build_overrides/chip.gni")
 import("//build_overrides/mbedtls.gni")
 import("//build_overrides/nlassert.gni")
 import("//build_overrides/nlio.gni")
 import("//build_overrides/nlunit_test.gni")
 import("//build_overrides/pigweed.gni")
+
 import("//src/platform/device.gni")
 import("$dir_pw_build/python.gni")
 
 # This build file should not be used in superproject builds.
 assert(chip_root == "//")
 
-import("${chip_root}/build/chip/tests.gni")
-import("${chip_root}/build/chip/tools.gni")
+import("${build_root}/chip/tests.gni")
+import("${build_root}/chip/tools.gni")
 
 if (current_toolchain != "${dir_pw_toolchain}/dummy:dummy") {
   declare_args() {
@@ -115,7 +117,7 @@ if (current_toolchain != "${dir_pw_toolchain}/dummy:dummy") {
   }
 } else {
   # This is the unified build. Configure various real toolchains.
-  import("${chip_root}/build/chip/chip_build.gni")
+  import("${build_root}/chip/chip_build.gni")
   declare_args() {
     # Set this to false to disable all builds by default.
     enable_default_builds = true
@@ -179,13 +181,13 @@ if (current_toolchain != "${dir_pw_toolchain}/dummy:dummy") {
 
   if (enable_host_clang_build) {
     chip_build("host_clang") {
-      toolchain = "//build/toolchain/host:${host_os}_${host_cpu}_clang"
+      toolchain = "${build_root}/toolchain/host:${host_os}_${host_cpu}_clang"
     }
   }
 
   if (enable_host_gcc_build) {
     chip_build("host_gcc") {
-      toolchain = "//build/toolchain/host:${host_os}_${host_cpu}_gcc"
+      toolchain = "${build_root}/toolchain/host:${host_os}_${host_cpu}_gcc"
     }
   }
 
@@ -197,19 +199,19 @@ if (current_toolchain != "${dir_pw_toolchain}/dummy:dummy") {
 
   if (enable_android_builds) {
     chip_build("android_arm") {
-      toolchain = "//build/toolchain/android:android_arm"
+      toolchain = "${build_root}/toolchain/android:android_arm"
     }
 
     chip_build("android_arm64") {
-      toolchain = "//build/toolchain/android:android_arm64"
+      toolchain = "${build_root}/toolchain/android:android_arm64"
     }
 
     chip_build("android_x64") {
-      toolchain = "//build/toolchain/android:android_x64"
+      toolchain = "${build_root}/toolchain/android:android_x64"
     }
 
     chip_build("android_x86") {
-      toolchain = "//build/toolchain/android:android_x86"
+      toolchain = "${build_root}/toolchain/android:android_x86"
     }
   }
 

build/chip/buildconfig_header.gni

@@ -101,14 +101,15 @@
 #     ]
 #   }
 
+import("//build_overrides/build.gni")
 import("//build_overrides/chip.gni")
 
 template("buildconfig_header") {
   source_set_name = target_name
   gen_target_name = "gen_${target_name}"
 
   action(gen_target_name) {
-    script = "${chip_root}/build/chip/write_buildconfig_header.py"
+    script = "${build_root}/chip/write_buildconfig_header.py"
 
     if (defined(invoker.header_dir)) {
       header_file = "${invoker.header_dir}/${invoker.header}"

build/chip/chip_build.gni

@@ -12,9 +12,9 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-import("//build_overrides/chip.gni")
+import("//build_overrides/build.gni")
 
-import("${chip_root}/build/chip/tests.gni")
+import("${build_root}/chip/tests.gni")
 
 template("chip_build") {
   _build_name = target_name

build/chip/chip_test.gni

@@ -12,11 +12,13 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import("//build_overrides/build.gni")
 import("//build_overrides/chip.gni")
 import("//build_overrides/pigweed.gni")
+
 import("$dir_pw_build/python_action.gni")
 
-import("${chip_root}/build/chip/tests.gni")
+import("${build_root}/chip/tests.gni")
 import("${chip_root}/src/platform/device.gni")
 import("${dir_pw_unit_test}/test.gni")
 

build/chip/chip_test_group.gni

@@ -12,9 +12,9 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-import("//build_overrides/chip.gni")
+import("//build_overrides/build.gni")
 
-import("${chip_root}/build/chip/tests.gni")
+import("${build_root}/chip/tests.gni")
 
 assert(chip_build_tests)
 

build/chip/chip_test_suite.gni

@@ -12,10 +12,11 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import("//build_overrides/build.gni")
 import("//build_overrides/chip.gni")
 
-import("${chip_root}/build/chip/chip_test.gni")
-import("${chip_root}/build/chip/tests.gni")
+import("${build_root}/chip/chip_test.gni")
+import("${build_root}/chip/tests.gni")
 import("${dir_pw_unit_test}/test.gni")
 
 assert(chip_build_tests)

build/chip/happy_test.gni

@@ -12,9 +12,10 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import("//build_overrides/build.gni")
 import("//build_overrides/chip.gni")
 
-import("${chip_root}/build/chip/tests.gni")
+import("${build_root}/chip/tests.gni")
 
 assert(chip_build_tests)
 assert(chip_enable_happy_tests)

build/chip/java/BUILD.gn

@@ -12,10 +12,10 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-import("//build_overrides/chip.gni")
+import("//build_overrides/build.gni")
 
-import("//build/config/android/config.gni")
-import("//build/config/android_abi.gni")
+import("${build_root}/config/android/config.gni")
+import("${build_root}/config/android_abi.gni")
 
 # Place a copy of the shared c++ support library in the jni output directory
 # See:

build/chip/java/rules.gni

@@ -12,12 +12,12 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-import("//build_overrides/chip.gni")
+import("//build_overrides/build.gni")
 
-import("//build/config/android/config.gni")
+import("${build_root}/config/android/config.gni")
 
-javac_runner = "${chip_root}/build/chip/java/javac_runner.py"
-jar_runner = "${chip_root}/build/chip/java/jar_runner.py"
+javac_runner = "${build_root}/chip/java/javac_runner.py"
+jar_runner = "${build_root}/chip/java/jar_runner.py"
 
 assert(android_sdk_root != "", "android_sdk_root must be specified")
 

build/chip/linux/BUILD.gn

@@ -12,7 +12,9 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-import("//build/config/linux/pkg_config.gni")
+import("//build_overrides/build.gni")
+
+import("${build_root}/config/linux/pkg_config.gni")
 
 pkg_config("glib") {
   packages = [

build/config/BUILDCONFIG.gn

@@ -32,16 +32,16 @@ if (current_os == "") {
   current_os = target_os
 }
 
-_chip_overrides = {
-  import("//build_overrides/chip.gni")
+_build_overrides = {
+  import("//build_overrides/build.gni")
 }
 
 _pigweed_overrides = {
   import("//build_overrides/pigweed.gni")
 }
 
 _chip_defaults = {
-  import("//build/config/defaults.gni")
+  import("${_build_overrides.build_root}/config/defaults.gni")
 }
 
 declare_args() {
@@ -51,9 +51,9 @@ declare_args() {
 
 if (host_toolchain == "") {
   if (_chip_defaults.is_clang) {
-    host_toolchain = "//build/toolchain/host:${host_os}_${host_cpu}_clang"
+    host_toolchain = "${_build_overrides.build_root}/toolchain/host:${host_os}_${host_cpu}_clang"
   } else {
-    host_toolchain = "//build/toolchain/host:${host_os}_${host_cpu}_gcc"
+    host_toolchain = "${_build_overrides.build_root}/toolchain/host:${host_os}_${host_cpu}_gcc"
   }
 }
 
@@ -65,24 +65,29 @@ if (_chip_defaults.custom_toolchain != "") {
   _default_toolchain = "${_pigweed_overrides.dir_pw_toolchain}/dummy"
 } else if (target_os == "freertos") {
   if (target_cpu == "arm") {
-    _default_toolchain = "//build/toolchain/arm_gcc"
+    _default_toolchain = "${_build_overrides.build_root}/toolchain/arm_gcc"
   } else {
     assert(false, "Unsupported target_cpu: ${target_cpu}")
   }
 } else if (target_os == "android") {
   if (current_cpu == "arm") {
-    _default_toolchain = "//build/toolchain/android:android_arm"
+    _default_toolchain =
+        "${_build_overrides.build_root}/toolchain/android:android_arm"
   } else if (current_cpu == "arm64") {
-    _default_toolchain = "//build/toolchain/android:android_arm64"
+    _default_toolchain =
+        "${_build_overrides.build_root}/toolchain/android:android_arm64"
   } else if (current_cpu == "x64") {
-    _default_toolchain = "//build/toolchain/android:android_x64"
+    _default_toolchain =
+        "${_build_overrides.build_root}/toolchain/android:android_x64"
   } else if (current_cpu == "x86") {
-    _default_toolchain = "//build/toolchain/android:android_x86"
+    _default_toolchain =
+        "${_build_overrides.build_root}/toolchain/android:android_x86"
   } else {
     assert(false, "Unsupported target_cpu: ${current_cpu}")
   }
 } else if (target_os == "ios") {
-  _default_toolchain = "//build/toolchain/ios:ios_${target_cpu}"
+  _default_toolchain =
+      "${_build_overrides.build_root}/toolchain/ios:ios_${target_cpu}"
 } else {
   assert(false, "No toolchain specified, please specify custom_toolchain")
 }

build/config/arm.gni

@@ -12,6 +12,8 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import("//build_overrides/build.gni")
+
 if (current_cpu == "arm" || current_cpu == "arm64") {
   declare_args() {
     # Build file to import for ARM defaults.
@@ -20,7 +22,7 @@ if (current_cpu == "arm" || current_cpu == "arm64") {
 
   if (arm_platform_config == "") {
     if (current_os == "android") {
-      arm_platform_config = "//build/toolchain/android/android_arm.gni"
+      arm_platform_config = "${build_root}/toolchain/android/android_arm.gni"
     }
   }
 

build/config/compiler/BUILD.gn

@@ -12,11 +12,11 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-import("//build_overrides/chip.gni")
+import("//build_overrides/build.gni")
 import("//build_overrides/pigweed.gni")
 
-import("//build/config/compiler/compiler.gni")
-import("//build/config/target.gni")
+import("${build_root}/config/compiler/compiler.gni")
+import("${build_root}/config/target.gni")
 
 declare_args() {
   # Enable -Werror. This can be disabled if using a different compiler
@@ -28,9 +28,9 @@ _is_embedded_arm = current_os != "ios" && current_os != "mac_os" &&
                    (current_cpu == "arm" || current_cpu == "arm64")
 
 if (_is_embedded_arm) {
-  import("//build/config/arm.gni")
+  import("${build_root}/config/arm.gni")
 } else if (current_cpu == "x86" || current_cpu == "x86_64") {
-  import("//build/config/x86.gni")
+  import("${build_root}/config/x86.gni")
 }
 
 config("release") {