Android编译系统变量打印

每次launch完，一些系统的变量会打印出来，如下，

============================================

    PLATFORM_VERSION_CODENAME=REL
    PLATFORM_VERSION=6.0
    TARGET_PRODUCT=sp7731c_c7301_fwvga_lm_oversea
    TARGET_BUILD_VARIANT=user
    TARGET_BUILD_TYPE=release
    TARGET_BUILD_APPS=
    TARGET_ARCH=arm
    TARGET_ARCH_VARIANT=armv7-a-neon
    TARGET_CPU_VARIANT=cortex-a7
    TARGET_2ND_ARCH=
    TARGET_2ND_ARCH_VARIANT=
    TARGET_2ND_CPU_VARIANT=
    HOST_ARCH=x86_64
    HOST_OS=linux
    HOST_OS_EXTRA=Linux-3.2.0-32-generic-x86_64-with-Ubuntu-12.04-precise
    HOST_BUILD_TYPE=release
    BUILD_ID=MRA58K
    OUT_DIR=out
    PRODUCT_LOCALES=en_US sv_SE nb_NO da_DK is_IS de_DE nl_NL pl_PL cs_CZ sk_SK ru_RU uk_UA sr_RS hr_HR sl_SI mk_MK es_US pt_PT fr_FR lt_LT lv_LV fi_FI el_GR fi_FI et_EE hu_HU tr_TR ro_RO zh_CN


如果我们想debug一些变量的值，可以在build\core\dumpvar.mk里自行添加，


ifneq ($(PRINT_BUILD_CONFIG),)
HOST_OS_EXTRA:=$(shell python -c "import platform; print(platform.platform())")
$(info ============================================)
$(info   PLATFORM_VERSION_CODENAME=$(PLATFORM_VERSION_CODENAME))
$(info   PLATFORM_VERSION=$(PLATFORM_VERSION))
$(info   TARGET_PRODUCT=$(TARGET_PRODUCT))
$(info   TARGET_BUILD_VARIANT=$(TARGET_BUILD_VARIANT))
$(info   TARGET_BUILD_TYPE=$(TARGET_BUILD_TYPE))
$(info   TARGET_BUILD_APPS=$(TARGET_BUILD_APPS))
$(info   TARGET_ARCH=$(TARGET_ARCH))
$(info   TARGET_ARCH_VARIANT=$(TARGET_ARCH_VARIANT))
$(info   TARGET_CPU_VARIANT=$(TARGET_CPU_VARIANT))
$(info   TARGET_2ND_ARCH=$(TARGET_2ND_ARCH))
$(info   TARGET_2ND_ARCH_VARIANT=$(TARGET_2ND_ARCH_VARIANT))
$(info   TARGET_2ND_CPU_VARIANT=$(TARGET_2ND_CPU_VARIANT))
$(info   HOST_ARCH=$(HOST_ARCH))
$(info   HOST_OS=$(HOST_OS))
$(info   HOST_OS_EXTRA=$(HOST_OS_EXTRA))
$(info   HOST_BUILD_TYPE=$(HOST_BUILD_TYPE))
$(info   BUILD_ID=$(BUILD_ID))
$(info   OUT_DIR=$(OUT_DIR))
$(info   PRODUCT_LOCALES=$(PRODUCT_LOCALES))
$(info ============================================)
endif