How to build openjdk mobile project android platform successfully and how does the mobile project adapt to bionic C ?

[gary.adams at oracle.com]

Only the java runtime libraries were ported to run in the Android app 
environment.
You can not build a full jdk image.

The mobile repos already has the needed "#if defined(__ANDROID__) ..."
directives with alternate implementations for missing bionic functions.

To debug build errors it helps to add "LOG=debug" to your make command line.
The error may be in the creation of a local build-jdk image prior to the 
building
of the target platform jre libraries.

On 8/24/18 4:13 AM, guoge (A) wrote:
> Hi mobile-dev,
>
>                  I want to build an android openjdk from the mobile project.(http://hg.openjdk.java.net/mobile/jdk9/)
>                  I followed the guide(http://openjdk.java.net/projects/mobile/android.html) but failed in the "make images" phase.
>                  I tried two versions of NDK toolchains(android-ndk32-r10b-linux-x86_64 and  android-ndk-r10e-linux-x86_64) and the followings are the configure and make images command outputs, could you help figure out why the project can't be built successfully?
>
>                  In addition, could you tell me how the mobile project adapts to the bionic C when bionic C lacks some functions the openjdk needs(such as ucontext.h, getpwuid_r etc.)?
>
>                  Thanks.
>
>
> android-ndk-r10b
> --------------------------------------------------------------------------
> configure:
> Configuration summary:
> * Debug level:    release
> * HS debug level: product
> * JDK variant:    normal
> * JVM variants:   zero
> * OpenJDK target: OS: android, CPU architecture: arm, address length: 32
> * Version string: 9-internal+0-adhoc.zhangfan.mobile-jdk9 (9-internal)
>
> Tools summary:
> * Boot JDK:       java version "1.8.0_192-ea" Java(TM) SE Runtime Environment (build 1.8.0_192-ea-b04) Java HotSpot(TM) 64-Bit Server VM (build 25.192-b04, mixed mode)  (at /home/zhangfan/tools/openjdk-builds/jdk1.8.0_192)
> * Toolchain:      gcc (GNU Compiler Collection)
> * C Compiler:     Version 4.6 (at /home/zhangfan/code/dev/jdk9mobile/android-ndk-r10b/generated-toolchains/android-arm-toolchain/bin/arm-linux-androideabi-gcc)
> * C++ Compiler:   Version 4.6 (at /home/zhangfan/code/dev/jdk9mobile/android-ndk-r10b/generated-toolchains/android-arm-toolchain/bin/arm-linux-androideabi-g++)
>
> make images:
> /home/zhangfan/code/dev/jdk9mobile/mobile-jdk9/hotspot/src/share/vm/utilities/globalDefinitions_gcc.hpp:79:22: fatal error: ucontext.h: No such file or directory
> compilation terminated.
>
>
> android-ndk-r10e
> --------------------------------------------------------------------------
> configure:
> Configuration summary:
> * Debug level:    release
> * HS debug level: product
> * JDK variant:    normal
> * JVM variants:   zero
> * OpenJDK target: OS: android, CPU architecture: arm, address length: 32
> * Version string: 9-internal+0-adhoc.zhangfan.mobile-jdk9 (9-internal)
>
> Tools summary:
> * Boot JDK:       java version "1.8.0_192-ea" Java(TM) SE Runtime Environment (build 1.8.0_192-ea-b04) Java HotSpot(TM) 64-Bit Server VM (build 25.192-b04, mixed mode)  (at /home/zhangfan/tools/openjdk-builds/jdk1.8.0_192)
> * Toolchain:      gcc (GNU Compiler Collection)
> * C Compiler:     Version 4.8 (at /home/zhangfan/code/dev/jdk9mobile/android-ndk-r10e/generated-toolchains/android-arm-toolchain/bin/arm-linux-androideabi-gcc)
> * C++ Compiler:   Version 4.8 (at /home/zhangfan/code/dev/jdk9mobile/android-ndk-r10e/generated-toolchains/android-arm-toolchain/bin/arm-linux-androideabi-g++)
>
> make images:
> /home/zhangfan/code/dev/jdk9mobile/mobile-jdk9/hotspot/src/os/linux/vm/perfMemory_linux.cpp: In function 'char* get_user_name(uid_t)':
> /home/zhangfan/code/dev/jdk9mobile/mobile-jdk9/hotspot/src/os/linux/vm/perfMemory_linux.cpp:458:66: error: 'getpwuid_r' was not declared in this scope
>     int result = getpwuid_r(uid, &pwent, pwbuf, (size_t)bufsize, &p);
> 	
> Best Regards,
> Guoge