android编译系统的Android.mk,里面还有条件判断， 但是到了Android.bp之后， android.bp是类似JSON的纯文本形式. 对于Android.mk里面条件判断部分,在Android.bp里要借助使用go语言文件去进行控制.

有条件判断的宏开关添加Demo

在Android.mk中添加的宏开关:

ifeq ($(ENABLE_USER2ENG),true)
LOCAL_CFLAGS += -DALLOW_ADBD_DISABLE_VERITY=1
LOCAL_CFLAGS += -DENABLE_USER2ENG=1
endif

如果要将以上的宏开关添加到Android.bp中去要通过使用go语言书写一个新文件:

比如我的修改是在

system/core/fs_mgr/Android.bp

,那么要在添加

system/core/fs_mgr/fs_mgr.go

:

package fs_mgr
 
import (
        "android/soong/android"
        "android/soong/cc"
        "fmt"
)
 
func init() {
    // for DEBUG
    fmt.Println("init start")
    android.RegisterModuleType("AAA", fs_mgrDefaultsFactory)
}
 
func fs_mgrDefaultsFactory() (android.Module) {
    module := cc.DefaultsFactory()
    android.AddLoadHook(module, fs_mgrDefaults)
    return module
}
 
func fs_mgrDefaults(ctx android.LoadHookContext) {
    type props struct {
        Cflags []string
    }
    p := &props{}
    p.Cflags = globalDefaults(ctx)
    ctx.AppendProperties(p)
}
 
func globalDefaults(ctx android.BaseContext) ([]string) {
    var cppflags []string
 
    fmt.Println("ENABLE_USER2ENG:",
        ctx.AConfig().IsEnvTrue("ENABLE_USER2ENG"))
    if ctx.AConfig().IsEnvTrue("ENABLE_USER2ENG") {
          cppflags = append(cppflags,
                         "-DALLOW_ADBD_DISABLE_VERITY=1",
                         "-DENABLE_USER2ENG=1")
    }
 
    return cppflags
}


Android.bp

需要修改的地方:

/// add start
bootstrap_go_package {
    // name and pkgPath need to  according to your module
    name: "soong-fs_mgr",
    pkgPath: "android/soong/fs_mgr",
    deps: [
        "blueprint",
        "blueprint-pathtools",
        "soong",
        "soong-android",
        "soong-cc",
        "soong-genrule",
    ],
    srcs: [
          // include new add .go file
          "fs_mgr.go",
    ],
    pluginFor: ["soong_build"],
}
 
// AAA is a module
AAA {
    name: "BBB",
}
/// add end
 
cc_defaults {
    name: "fs_mgr_defaults",
    defaults: ["BBB"],// new add
    sanitize: {
        misc_undefined: ["integer"],
    },
    local_include_dirs: ["include/"],
    cppflags: ["-Werror", "-DMTK_FSTAB_FLAGS"],
}

参照该例子修改时注意

AAA

,

BBB

的对应关系即可.

refers:

https://blog.csdn.net/weixin_33807284/article/details/86032658