关于调用intermediates下中间文件流程分析

关于调用intermediates下中间文件流程分析

最近查看安卓源码在分析其Oberlay机制，无意中发现call intermediates-dir-for 方法的调用，其后面跟了好许参数，就在这里深入的分析了解一下，原代码文件基于Mstar定制的android6.0分析

• $(call intermediates-dir-for,,,,)/src

• 代码：build/core/definitions.mk

  # $(1): target class, like "APPS"
  # $(2): target name, like "NotePad"
  # $(3): if non-empty, this is a HOST target.
  # $(4): if non-empty, force the intermediates to be COMMON
  # $(5): if non-empty, force the intermedistes to be for the 2nd arch
  define intermediates-dir-for
  $(strip \
      $(eval _idfClass := $(strip $(1))) \
      $(if $(_idfClass),, \
          $(error $(LOCAL_PATH): Class not defined in call to intermediates-dir-for)) \
      $(eval _idfName := $(strip $(2))) \
      $(if $(_idfName),, \
          $(error $(LOCAL_PATH): Name not defined in call to intermediates-dir-for)) \
      $(eval _idfPrefix := $(if $(strip $(3)),HOST,TARGET)) \
      $(eval _idf2ndArchPrefix := $(if $(strip $(5)),$(TARGET_2ND_ARCH_VAR_PREFIX))) \
      $(if $(filter $(_idfPrefix)-$(_idfClass),$(COMMON_MODULE_CLASSES))$(4), \
          $(eval _idfIntBase := $($(_idfPrefix)_OUT_COMMON_INTERMEDIATES)) \
        ,$(if $(filter $(_idfClass),SHARED_LIBRARIES STATIC_LIBRARIES EXECUTABLES GYP),\
            $(eval _idfIntBase := $($(_idf2ndArchPrefix)$(_idfPrefix)_OUT_INTERMEDIATES)) \
         ,$(eval _idfIntBase := $($(_idfPrefix)_OUT_INTERMEDIATES)) \
         ) \
       ) \
      $(_idfIntBase)/$(_idfClass)/$(_idfName)_intermediates \
  )
  endef
  
  代码中接受的几个重要参数如下：
  参数1: _idfClass
  参数2: _idfName
  参数3: _idfPrefix
  参数4: _idfIntBase
  参数5：_idf2ndArchPrefix
  

• 示例：

  framework_GENERATED_SOURCE_DIR := $(call intermediates-dir-for,JAVA_LIBRARIES,framework,,COMMON)/src
  
  示例传入参数如下：
  参数1：JAVA_LIBRARIES
  参数2: framework
  参数3: 
  参数4: COMMON
  参数5:
  

1. 参数1赋值过程

   $(eval _idfClass := $(strip $(1))) \
       $(if $(_idfClass),, \
           $(error $(LOCAL_PATH): Class not defined in call to intermediates-dir-for)) \
   
   获取第一个参数，直接赋值给_idfClass=JAVA_LIBRARIES;如果为空，直接报错
   

2. 参数2赋值过程

   $(eval _idfName := $(strip $(2))) \
       $(if $(_idfName),, \
           $(error $(LOCAL_PATH): Name not defined in call to intermediates-dir-for)) \
   
   获取传入的第二个参数，赋值到_idfName=framework;如果为空，直接报错
   

3. 参数3赋值过程

   $(eval _idfPrefix := $(if $(strip $(3)),HOST,TARGET)) \
   
   获取传入的第三个参数，如果不为空，则为“HOST”，否则是“TARGET”，这里传入的为空，即_idfPrefix=TARGET
   

4. 参数4赋值过程

   $(if $(filter $(_idfPrefix)-$(_idfClass),$(COMMON_MODULE_CLASSES))$(4), \
           $(eval _idfIntBase := $($(_idfPrefix)_OUT_COMMON_INTERMEDIATES)) \
         ,$(if $(filter $(_idfClass),SHARED_LIBRARIES STATIC_LIBRARIES EXECUTABLES GYP),\
             $(eval _idfIntBase := $($(_idf2ndArchPrefix)$(_idfPrefix)_OUT_INTERMEDIATES)) \
          ,$(eval _idfIntBase := $($(_idfPrefix)_OUT_INTERMEDIATES)) \
          ) \
        ) \
   
   判断1: 
       过滤在  $(_idfPrefix)-$(_idfClass) 中存在匹配条件 TARGET-NOTICE_FILES HOST-NOTICE_FILES HOST-JAVA_LIBRARIES中任意项目，如果存在不为空，直接取值$(4)；
       否则，_idfIntBase=(_idfPrefix)_OUT_COMMON_INTERMEDIATES
   判断2: 
       过滤 _idfClass 中存在 SHARED_LIBRARIES STATIC_LIBRARIES EXECUTABLES GYP 中任意值，如结果不为空，_idfIntBase := $($(_idf2ndArchPrefix)$(_idfPrefix)_OUT_INTERMEDIATES)) ；
       否则，_idfIntBase := $($(_idfPrefix)_OUT_INTERMEDIATES))
   此处由上此处传入的是“COMMMON”，分析得出 _idfIntBase=TARGET_OUT_COMMON_INTERMEDIATES
   

5. 参数5赋值过程

   $(eval _idf2ndArchPrefix := $(if $(strip $(5)),$(TARGET_2ND_ARCH_VAR_PREFIX))) \
   
   如果存在参数5不为空，直接取值 _idf2ndArchPrefix ：= $(TARGET_2ND_ARCH_VAR_PREFIX)
   

6. 具体路径查找替换

   $(_idfIntBase)/$(_idfClass)/$(_idfName)_intermediates \)
   
   由上分析这里可以替换出具体路径如下：
   TARGET_OUT_COMMON_INTERMEDIATES/JAVA_LIBRARIES/framework_intermediates
   
   下面具体找到TARGET_OUT_COMMON_INTERMEDIATES的具体路径
   

7. 关于TARGET_OUT_COMMON_INTERMEDIATES的具体路径

   相关Makefile路径代码：build/envsetup.mk
   
   TARGET_OUT_COMMON_INTERMEDIATES := $(TARGET_COMMON_OUT_ROOT)/obj
   
   TARGET_COMMON_OUT_ROOT := $(TARGET_OUT_ROOT)/common
   
   TARGET_OUT_ROOT := $(TARGET_OUT_ROOT_$(TARGET_BUILD_TYPE))
   
       ifneq ($(TARGET_BUILD_TYPE),debug)
       TARGET_BUILD_TYPE := release
       endif
   此处默认为release
   
   TARGET_OUT_ROOT_release := $(OUT_DIR)/target
   TARGET_OUT_ROOT_debug := $(DEBUG_OUT_DIR)/target
   
   ifeq (,$(strip $(OUT_DIR)))
   ifeq (,$(strip $(OUT_DIR_COMMON_BASE)))
   OUT_DIR := $(TOPDIR)out
   else
   OUT_DIR := $(OUT_DIR_COMMON_BASE)/$(notdir $(PWD))
   endif
   endif
   此处OUT_DIR为源码的根目录
   
   因此，TARGET_OUT_COMMON_INTERMEDIATES=out/target/common/obj
   

8. 综上分析得出最终的路径如下：

   /out/target/common/obj/JAVA_LIBRARIES/framework_intermediates/src
   

• 相关拓展

  Makefile函数集锦及条件判断