我遇到的這個例子

# Copyright 2011 The Android Open Source Project

ifneq ($(BUILD_TINY_ANDROID),true)

LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)

LOCAL_SRC_FILES := \
charger.c

ifeq ($(SIMCOM_PROJECT), MX3)        ###這個地方定義了一個字元用以控制編譯進行
LOCAL_CFLAGS := -DMX3
endif

ifeq ($(strip $(BOARD_CHARGER_DISABLE_INIT_BLANK)),true)
LOCAL_CFLAGS := -DCHARGER_DISABLE_INIT_BLANK
endif


ifeq ($(strip $(BOARD_CHARGER_ENABLE_SUSPEND)),true)
LOCAL_CFLAGS += -DCHARGER_ENABLE_SUSPEND

endif