Remove unnecessary USE_CLANG_PLATFORM_BUILD.

This build variable is unnecessary now that GCC is completely
unsupported for Android platform builds.

Bug: http://b/64032869
Test: Builds
Change-Id: I9d44ebd7129cb2bdfbb26d37922db19c6fb9efc9

Changes.md

@@ -92,6 +92,11 @@ Specify Framework Compatibility Matrix Version in device manifest by adding a `t
 attribute to the root element `<manifest>`. If `PRODUCT_COMPATIBILITY_MATRIX_LEVEL_OVERRIDE`
 is 26 or 27, you can add `"target-level"="1"` to your device manifest instead.
 
+### Stop using USE_CLANG_PLATFORM_BUILD {#USE_CLANG_PLATFORM_BUILD}
+
+Clang is the default and only supported Android compiler, so there is no reason
+for this option to exist.
+
 ### Other envsetup.sh variables  {#other_envsetup_variables}
 
 * ANDROID_TOOLCHAIN

core/binary.mk

@@ -354,11 +354,6 @@ ifdef LOCAL_IS_HOST_MODULE
             my_clang := true
         endif
     endif
-# Add option to make gcc the default for device build
-else ifeq ($(USE_CLANG_PLATFORM_BUILD),false)
-    ifeq ($(my_clang),)
-        my_clang := false
-    endif
 else ifeq ($(my_clang),)
     my_clang := true
 endif

core/config.mk

@@ -76,6 +76,7 @@ $(KATI_obsolete_var \
   ANDROID_PRE_BUILD_PATHS \
   ,See $(CHANGES_URL)#other_envsetup_variables)
 $(KATI_obsolete_var PRODUCT_COMPATIBILITY_MATRIX_LEVEL_OVERRIDE,Set FCM Version in device manifest instead. See $(CHANGES_URL)#PRODUCT_COMPATIBILITY_MATRIX_LEVEL_OVERRIDE)
+$(KATI_obsolete_var USE_CLANG_PLATFORM_BUILD,Clang is the only supported Android compiler. See $(CHANGES_URL)#USE_CLANG_PLATFORM_BUILD)
 
 CHANGES_URL :=
 

core/envsetup.mk

@@ -657,13 +657,3 @@ endif
 ifeq ($(CALLED_FROM_SETUP),true)
 PRINT_BUILD_CONFIG ?= true
 endif
-
-ifeq ($(USE_CLANG_PLATFORM_BUILD),)
-USE_CLANG_PLATFORM_BUILD := true
-endif
-
-ifneq ($(USE_CLANG_PLATFORM_BUILD),true)
-ifneq ($(USE_CLANG_PLATFORM_BUILD),false)
-$(error USE_CLANG_PLATFORM_BUILD must be true or false)
-endif
-endif

core/soong_config.mk

@@ -110,7 +110,6 @@ $(call add_json_str,  BtConfigIncludeDir,                $(BOARD_BLUETOOTH_BDROI
 $(call add_json_bool, Device_uses_hwc2,                  $(filter true,$(TARGET_USES_HWC2)))
 $(call add_json_list, DeviceKernelHeaders,               $(TARGET_PROJECT_SYSTEM_INCLUDES))
 $(call add_json_bool, DevicePrefer32BitExecutables,      $(filter true,$(TARGET_PREFER_32_BIT_EXECUTABLES)))
-$(call add_json_val,  DeviceUsesClang,                   $(if $(USE_CLANG_PLATFORM_BUILD),$(USE_CLANG_PLATFORM_BUILD),false))
 $(call add_json_str,  DeviceVndkVersion,                 $(BOARD_VNDK_VERSION))
 $(call add_json_str,  Platform_vndk_version,             $(PLATFORM_VNDK_VERSION))
 $(call add_json_list, ExtraVndkVersions,                 $(PRODUCT_EXTRA_VNDK_VERSIONS))