Merge pull request project-chip#91 from lukgni/fix_warning_number

Fix too many warnings in Mbed variant of CHIP build

build/config/compiler/BUILD.gn

@@ -136,7 +136,6 @@ config("optimize_default") {
 config("disabled_warnings") {
   cflags = [
     "-Wno-deprecated-declarations",
-    "-Wno-unknown-warning-option",
     "-Wno-missing-field-initializers",
     "-Wno-unused-parameter",
   ]
@@ -150,6 +149,9 @@ config("disabled_warnings") {
       "-Wno-cast-function-type",
     ]
   }
+  else {
+    cflags += [ "-Wno-unknown-warning-option" ]
+  }
 }
 
 config("strict_warnings") {

config/mbed/chip-gn/.gn

@@ -12,6 +12,8 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import("//build_overrides/build.gni")
+
 # The location of the build configuration file.
 buildconfig = "//build/config/BUILDCONFIG.gn"
 
@@ -22,5 +24,10 @@ default_args = {
   target_cpu = "arm"
   target_os = "mbed"
 
+  default_configs_warnings = [
+    "${build_root}/config/compiler:warnings_default",
+    "//:chip_custom_cflags_config"
+    ]
+
   import("//args.gni")
 }

config/mbed/chip-gn/BUILD.gn

@@ -19,6 +19,11 @@ assert(current_os == "mbed")
 
 declare_args() {
   chip_build_libshell = false
+  chip_custom_build_cflags = []
+}
+
+config("chip_custom_cflags_config") {
+  cflags = chip_custom_build_cflags
 }
 
 group("mbed") {

config/mbed/chip-gn/args.gni

@@ -21,6 +21,13 @@ chip_project_config_include = ""
 chip_system_project_config_include = ""
 chip_device_project_config_include = ""
 
+chip_custom_build_cflags = [
+    "-Wno-shadow",
+    "-Wno-conversion",
+    "-Wno-maybe-uninitialized",
+    "-Wno-return-type"
+    ]
+
 custom_toolchain = "//toolchain:mbed"
 mbedtls_target = "//mbedtls:mbedtls"