Develop Reference

ndk_build.cmd in cygwin not recognizing included mk files

I have multiple static libs that are built using jni. I have a scheme that includes other mk files, etc to allow me to share compile settings, include files from other dependent projects, etc.
I have set it up successfully on the mac and have been building it. However, when I tried to do the same in windows under cygwin I'm running into issues...
Here is my jni/Android.mk file..
LOCAL_PATH := $(call my-dir)
INJ_PROJECT_PATH := $(PWD)
include $(INJ_PROJECT_PATH)/jni/Project.mk
The problem I'm seeing is that ndk-build is complaining about the Project.mk file. Here is what I'm seeing..
shammi#SHAMMIDEV /cygdrive/c/projects/injitiProjects/injitiEngine/Engine/Core
$ ndk-build.cmd NDK_APP_OUT=../../build/Android/Engine/release
jni/Android.mk:5: /cygdrive/c/projects/injitiProjects/injitiEngine/Engine/Core/jni/Project.mk: No such file or directory
jni/Android.mk:5: /cygdrive/c/projects/injitiProjects/injitiEngine/Engine/Core/jni/Project.mk: No such file or directory
jni/Android.mk:5: /cygdrive/c/projects/injitiProjects/injitiEngine/Engine/Core/jni/Project.mk: No such file or directory
jni/Android.mk:5: /cygdrive/c/projects/injitiProjects/injitiEngine/Engine/Core/jni/Project.mk: No such file or directory
C:/projects/Android/sdk/ndk-bundle/build//../build/core/build-all.mk:89: Android NDK: WARNING: There are no modules to build in this project!
make: *** No rule to make target `/cygdrive/c/projects/injitiProjects/injitiEngine/Engine/Core/jni/Project.mk'. Stop.
I have confirmed that /cygdrive/c/projects/injitiProjects/injitiEngine/Engine/Core/jni/Project.mk does exist, and I am the owner and it has read permissions for user/group/other.
Again, this exact same setup works absolutely fine on the mac. I'm just looking at having a portable dev environment.
What am I missing here..?

I guess I forgot that ndk-build.cmd was a windows shell batch script (DOH).
The answer was that I was able to call /build/ndk-build which is a sh script that is comfortable running in cygwin.

You probably need to use LOCAL_PATH instead of PWD. I'm not really sure how PWD gets set (I think it's a make builtin?), but we actually have control over LOCAL_PATH and can make sure it gets set in the right way for cygwin.

Instead of include what if you define it to be APP_BUILD_SCRIPT?
for ex.
APP_BUILD_SCRIPT := jni/Android.mk
Also Id try $(shell $pwd) instead of $(PWD) if the above doesn't work, usually ndk doesn't interpret shell commands for me if I don't use the shell in the parenthesis.

How to use a custom toolchain with ndk-build?

I've spent a day on this and can't seem to configure my dev environment for a NDK toolchain that will support standard C++ libraries. The story is I'm trying to cross compile libnfnetlink and libnetfilter_queue for ARM (Android).
First I'm using the following:
Nexus 5 with CyanogenMod 11 (I forget, doesn't matter I'm not even on the device yet)
Ubuntu 12.04 32-bit
Android SDK bundle: adt-bundle-linux-x86-20140702
Android NDK: android-ndk-r10c
There is a great blog on doing this here but its incomplete as Netfilter uses stlc++ and there's no word on a NDK install/setup that would work with simply calling ndk-build. Just copying the files into /jni and calling ndk-build won't work alone.
Anyways, my specific problem is when I straight copy the Netfilter lib source structure into an empty Project's /jni directory, I get this:
user#ubuntu:~/Projects/NetfilterTest/NetfilterNativeTest/jni$ ndk-build
[armeabi] Compile thumb : netfilter_queue <= libnetfilter_queue.c
In file included from /home/user/Projects/NetfilterTest/NetfilterNativeTest/jni/libnetfilter_queue/src/libnetfilter_queue.c:35:0:
/home/user/Projects/NetfilterTest/NetfilterNativeTest/jni/libnetfilter_queue/src/internal.h:4:20: fatal error: config.h: No such file or directory
compilation terminated.
make: *** [/home/user/Projects/NetfilterTest/NetfilterNativeTest/obj/local/armeabi/objs/netfilter_queue/libnetfilter_queue/src/libnetfilter_queue.o] Error 1
The config.h file can't be found. After some googling I realize its because the standard C++ libraries aren't available in the prebuilt tool chains.
Everything points to me creating my own tool chain. So I build my own cross compiler using the scripts that the NDK includes.
cd /home/user/android-ndk-r10c/build/tools
./make-standalone-toolchain.sh --platform=android-19 --ndk-dir=/home/user/android-ndk-r10c/ --install-dir=/home/user/android-ndk-r10c/prebuilt/android-arm/android-19
To confirm that config.h is included in my tool chain I searched for it. It's there:
user#ubuntu:~/Projects/NetfilterTest/NetfilterNativeTest/jni$ find /home/user/android-ndk-r10c/prebuilt/android-arm/android-19/ -iname config.h
/home/user/android-ndk-r10c/prebuilt/android-arm/android-19/sysroot/usr/include/linux/config.h
Naturally I need to setup my environment and the Android.mk
JAVA_HOME=/usr/local/java/jdk1.6.0_45
JRE_HOME=$JAVA_HOME/jre
ANDROID_SDK=/home/user/adt-bundle-linux-x86-20140702
ANDROID_NDK=/home/user/android-ndk-r10c
ANDROID_CHAIN=/home/user/android-ndk-r10c/prebuilt/android-arm/android-19
PATH=$PATH:$JAVA_HOME/bin:$JRE_HOME/bin:$ANDROID_SDK/sdk/platform-tools:$ANDROID_SDK/sdk/tools:$ANDROID_NDK:$ANDROID_CHAIN/bin
SYSROOT=$ANDROID_NDK/platforms/android-19/arch-arm
CC=arm-linux-androideabi-gcc
export CC
export ANDROID_SDK
export ANDROID_NDK
export SYSROOT
export JAVA_HOME
export JRE_HOME
export PATH
Here's my Android.mk (based on Roman10's blog:
LOCAL_PATH:=$(call my-dir)
#####################################################################
# build libnflink #
#####################################################################
include $(CLEAR_VARS)
LOCAL_MODULE:=nflink
LOCAL_C_INCLUDES:= $(LOCAL_PATH)/libnfnetlink/include
LOCAL_SRC_FILES:=\
libnfnetlink/src/iftable.c \
libnfnetlink/src/rtnl.c \
libnfnetlink/src/libnfnetlink.c
include $(BUILD_STATIC_LIBRARY)
#####################################################################
# build libnetfilter_queue #
#####################################################################
include $(CLEAR_VARS)
LOCAL_C_INCLUDES := $(LOCAL_PATH)/libnfnetlink/include \
$(LOCAL_PATH)/libnetfilter_queue/include
LOCAL_MODULE:=netfilter_queue
LOCAL_SRC_FILES:=libnetfilter_queue/src/libnetfilter_queue.c
LOCAL_STATIC_LIBRARIES:=libnflink
include $(BUILD_STATIC_LIBRARY)
#####################################################################
# build our code #
#####################################################################
include $(CLEAR_VARS)
LOCAL_C_INCLUDES := $(LOCAL_PATH)/libnfnetlink/include \
$(LOCAL_PATH)/libnetfilter_queue/include
LOCAL_MODULE:=nfqnltest
#LOCAL_LDLIBS:=-lstdc++
LOCAL_SRC_FILES:=nfqnl_test.c
LOCAL_STATIC_LIBRARIES:=libnetfilter_queue
LOCAL_LDLIBS:=-llog -lm
include $(BUILD_EXECUTABLE)
I still get config.h not found using ndk-build.
I've read that the ndk-build command leverages a config.mk/setup.mk that Google includes in the NDK and has to be modified to point to an alternative toolchain.
I'm completely floored that Google's own tools can't simply point to a custom toolchain that they give you scripts to create. If anyone has any suggestions on how I can use my toolchain to compile Netfilter or just in general it would be a great help.
Thanks in advance!

I can't find any reference to either internal.h or config.h when I search for a version of libnetfilter_queue.c on the web, so I'm not sure what version of the file you're using - can you point to which one you have?
Also, the config.h it looks for isn't the one you found in your toolchain (which should be included as linux/config.h) but most probably is one that you're expected to generate by running a configure script. So unless you've run the configure script (or have a pregenerated config.h from elsewhere) you can't really build it.
Finally, nothing of this has anything to do with libstdc++ since all your source files seem to be pure C, not C++.

Problems compiling avahi into Android NDK project

Over the last few days I've been having a difficult time trying to build avahi into a static or shared library for use with an existing Android NDK project.
We have a few games in the App and Play stores and my task is to get multiplayer working in the Android versions.
Specifically the task involves replacing the Bonjour component so that these games can connect to each other via zeroconf.
Research seemed to indicate that avahi is the lib that we're looking for, but at this point I'm open to anything that will work!
I'm hoping that someone here can either help me get avahi compiling or suggest another more appropriate (and easier to install) lib.
Project uses android-ndk-r8b and is being built on OSX 10.7.4 using command line (not eclipse)
Got the latest Avahi source from here:
http://www.linuxfromscratch.org/blfs/view/svn/basicnet/avahi.html
homebrewed all the necessary libs to get ./configure to run without errors.
./configure --prefix=/usr --sysconfdir=/etc --localstatedir=/var --disable-static --disable-mono --disable-monodoc --disable-gdbm --disable-libdaemon --disable-nls --disable-gtk --disable-gtk3 --disable-python --disable-qt3 --disable-qt4 --enable-core-docs --with-distro=none
./configure runs with no apparent red flags.
make results in this compile error:
socket.c: In function 'ipv6_pktinfo':
socket.c:271: warning: unused variable 'yes' [-Wunused-variable]
socket.c:270: warning: unused parameter 'fd' [-Wunused-parameter]
socket.c: In function 'avahi_send_dns_packet_ipv6':
socket.c:609: error: 'IPV6_PKTINFO' undeclared (first use in this function)
socket.c:609: error: (Each undeclared identifier is reported only once
socket.c:609: error: for each function it appears in.)
socket.c: In function 'avahi_recv_dns_packet_ipv6':
socket.c:869: error: 'IPV6_HOPLIMIT' undeclared (first use in this function)
socket.c:878: error: 'IPV6_PKTINFO' undeclared (first use in this function)
make[2]: *** [libavahi_core_la-socket.lo] Error 1
make[1]: *** [all-recursive] Error 1
make: *** [all] Error 2
Figured that it's not building against the android-ndk-r8b libs or finding ipv6.h or something.
Checked my .bash_profile.sh file:
export PATH=/Users/Muy01/Projects/Development/Android/android-sdks/tools/:$PATH
export PATH=/Users/Muy01/Projects/Development/Android/android-sdks/platform-tools/:$PATH
export PATH=/Users/Muy01/Projects/Development/Android/android-ndk-r8b/:$PATH
added --host=arm-linux-androideabi to the ./configure arguments list
resulting in this error:
checking host system type... Invalid configuration `arm-linux-androideabi': system `androideabi' not recognized
Couldn't figure out how to get a list of available host system types so changed direction and decided to try and build the static lib via Android.mk file.
Found this post on creating an appropriate Android.mk file:
can't compile avahi on android
Realized that I don't have Android.mk files within all the subdirectories.
Researched, downloaded, built, Androgenizer to try and convert all the Makefile.am files into Android.mk files.
http://cgit.collabora.com/git/user/derek/androgenizer.git/
Couldn't figure out or find info on how to do that though =/
Decided to try and create my own Android.mk file:
LOCAL_PATH := $(call my-dir)
ROOT_LOCAL_PATH :=$(call my-dir)
#Build avahi into a static lib
include $(CLEAR_VARS)
AVAHI_TOP := $(ROOT_LOCAL_PATH)/../avahi-0.6.31
MY_SOURCES := $(wildcard $(AVAHI_TOP)/avahi-core/*.c*)
MY_SOURCES += $(wildcard $(AVAHI_TOP)/avahi-common/*.c*)
LOCAL_C_INCLUDES := $(AVAHI_TOP)
LOCAL_SRC_FILES := $(MY_SOURCES:$(LOCAL_PATH)%=%)
LOCAL_MODULE := avahi
include $(BUILD_STATIC_LIBRARY)
Results in compile time errors for avahi-core/iface-linux.c:33:0:
/avahi-0.6.31/avahi-core/iface-linux.h:27:8: Redefinition of 'struct AvahiInterfaceMonitorOSDep'
/avahi-0.6.31/avahi-core/iface.h:46:16: Originally defined here
/avahi-0.6.31/avahi-core/iface-linux.h:33:9: Redeclaration of enumerator 'LIST_IFACE'
/avahi-0.6.31/avahi-core/iface.h:52:9: Previous definition of 'LIST_IFACE' was here
/avahi-0.6.31/avahi-core/iface-linux.h:34:9: Redeclaration of enumerator 'LIST_ADDR'
/avahi-0.6.31/avahi-core/iface.h:53:9: Previous definition of 'LIST_ADDR' was here
/avahi-0.6.31/avahi-core/iface-linux.h:35:9: Redeclaration of enumerator 'LIST_DONE'
/avahi-0.6.31/avahi-core/iface.h:54:9: Previous definition of 'LIST_DONE' was here
/jni//../avahi-0.6.31/avahi-core/iface-linux.c: In function 'netlink_callback':
And now I'm pretty much stuck.
I tried #if 0'ing out the iface-linux.c and h files resulting in a cascading slew of other errors, so prob a bad idea.
Thinking that it may be something I've done wrong with the ./configure command?
Perhaps an issue with my Android.mk file?
I figure this must be something that quite a few developers are dealing with so I'm probably missing something because I can't seem to find any good information via google.
Any help would be much appreciated!
I've sent this out to the avhi mailing list as well, if I get a response there I will post here for posterity.
Thanks,
Chris

I'll follow up here with the solution that worked for me.
My solution was to use JMDNS instead of Avahi.
There's not much traffic on the Avahi mailing list.
JMDNS has working examples available.
JMDNS took me about 4 hours to set up within my NDK environment and about a day to work out some "kinks."

tar avahi-0.6.31
patch -p1 < 0001-Add-Android-support.patch
patch -p1 < 0002-Add-uninstalled.pc.in-files.patch
cd avahi-0.6.31
./configure --sysconfdir=/etc --localstatedir=/var
make
cd the subdirectories: make Android.mk
then, you will see Android.mk in all the subdirectories.
ndk-build V=1 NDK_LOG=2 APP_ABI="armeabi armeabi-v7a"

Want to compile native Android binary I can run in terminal on the phone

I've been trying for a couple days to compile a native ARM Android binary that will execute on my phone using a terminal application. I want to generate the same type of binary as the standard Posix binaries installed on the phone like ls, mkdir etc. I've downloaded the Android NDK under Mac OS X and have been able to compile simple ELF binaries without errors. However, when I transfer them to the phone, they always segfault. That is, they segfault when compiled with -static in GCC. If I don't use -static, they complain about not being linked, etc. Put simply, they don't work.
My hypothesis is that they are not linking to the Android standard C library properly. Even though I am linking my binaries with the libc provided by the NDK, they still don't work. I read that Android uses the Bionic C library, and tried to download source for it but I'm not sure how to build a library from it (it's all ARM assembly, it seems).
Is it true that the Android C library on the phone is different from the one provided with the Android NDK? Will the one included with the NDK not allow me to compile native binaries I can execute through a terminal? Any guidance here is greatly appreciated!
Update:
I finally got this to work using GCC 4.7.0 on Mac OS X. I downloaded the Bionic headers and then compiled a dynamically linked binary using the C library that comes with the Android NDK. I was able to get a test app to work on the phone using the phone's C lib (the binary was 33K). I also tried to statically link against the NDK's C library, and that also worked.
In order to get this all working I had to pass -nostdlib to GCC and then manually add crtbegin_dynamic.o and crtend_android.o to GCC's command line. It works something like this:
$CC \
$NDK_PATH/usr/lib/crtbegin_dynamic.o \
hello.c -o hello \
$CFLAGS \
$NDK_PATH/usr/lib/crtend_android.o
For static binaries, use "crtbegin_static.o." This is explained in the crtbegin_dynamic.S/crtbegin_static.S source.
For this experiment, I only used plain 'ol GCC 4.7.0 and Binutils 2.22. I also compiled GCC with newlib, but I am not actually linking my ARM binaries with newlib at all. I am forcing GCC/ld to link directly to the libc provided with the Android NDK, or in the case of dynamic binaries, to the libc on the phone.

Just use the android-ndk. And build a Android.mk like so.
include $(BUILD_EXECUTABLE) is what tells it build a executable instead of a JNI .lib
Android.mk
ifneq ($(TARGET_SIMULATOR),true)
LOCAL_PATH:= $(call my-dir)
include $(CLEAR_VARS)
LOCAL_CFLAGS += -Wall
LOCAL_LDLIBS := -L$(LOCAL_PATH)/lib -llog -g
LOCAL_C_INCLUDES := bionic
LOCAL_C_INCLUDES += $(LOCAL_PATH)/include
LOCAL_SRC_FILES:= main.cpp
LOCAL_MODULE := mycmd
include $(BUILD_EXECUTABLE)
endif # TARGET_SIMULATOR != true

First, make sure you have the NDK:
http://developer.android.com/tools/sdk/ndk/index.html
Here is the easiest way to compile a C binary for your phone:
http://developer.android.com/tools/sdk/ndk/index.html
http://www.kandroid.org/ndk/docs/STANDALONE-TOOLCHAIN.html
Usually $NDK(may be different) =
Linux:
/home/<user>/android-ndk
Mac OS X:
/Users/<user>/android-ndk
In Terminal:
# create tool-chain - one line
# New method in ndk 12.
$NDK/build/tools/make_standalone_toolchain.py --arch arm --install-dir=/tmp/my-android-toolchain
# Old method.
#$NDK/build/tools/make-standalone-toolchain.sh --platform=android-3 --install-dir=/tmp/my-android-toolchain
# add to terminal PATH variable
export PATH=/tmp/my-android-toolchain/bin:$PATH
# make alias CC be the new gcc binary
export CC=arm-linux-androideabi-gcc
# compile your C code(I tried hello world)
$CC -o foo.o -c foo.c
# push binary to phone
adb push foo.o /data/local/tmp
# execute binary
adb /data/local/tmp/foo.o

Using CMake with the Android NDK is a nice way to compile Android console applications.
Download CMake and android-cmake (set it up like this). If your program is called main.c, then write the following in file CMakeLists.txt:
project(test)
cmake_minimum_required(VERSION 2.8)
add_executable(test ./main.c)
and run cmake -DCMAKE_TOOLCHAIN_FILE=$ANDTOOLCHAIN .
You will then have a Makefile for your program, you can run make to have your test executable.

In CMake, you can cross build using toolchain files.
From google developers:
cmake \
    -DCMAKE_TOOLCHAIN_FILE=$NDK/build/cmake/android.toolchain.cmake \
    -DANDROID_ABI=$ABI \
    -DANDROID_PLATFORM=android-$MINSDKVERSION \
    $OTHER_ARGS
CMake has its own built-in NDK support. Before CMake 3.21, this workflow is not supported by Android and is often broken with new NDK releases. Starting from CMake 3.21, the implementations are merged.
Starting from cmake 3.21 you can:
mkdir build
cd build
cmake ..
-DCMAKE_SYSTEM_NAME=Android
-DCMAKE_SYSTEM_VERSION=23 # API level. optional, recommanded
-DCMAKE_ANDROID_NDK=path/to/ndk
-DCMAKE_ANDROID_ARCH=arm # optional, recommanded
-DCMAKE_ANDROID_ARCH_ABI=armeabi # optional, recommanded
Note: in the command above, line endings (<line feed>) are not escaped, please don't copy-paste this command directly in your shell
See Cross Compiling for Android with the NDK for more information about variables, possible values, and determenation algorithms.

Try if if the agcc wrapper can help you as referenced in the Android-tricks blog. According to the blog post you want to use the bionic library, but the one already installed on the phone, not some separately compiled version.

hello-jni NDK sample - ndk-build fails

I am following the steps on http://developer.android.com/sdk/ndk/overview.html to build the hello-jni sample, however when I get to Step 2 to run
cd $NDK-ROOT/samples/hello-jni
$NDK-ROOT/ndk-build
in the Cygwin command prompt, I receive the following error messages:
/bin/sh: -c: line 0: unexpected EOF while looking for matching `''
/bin/sh: -c: line 1: syntax error: unexpected end of file
Android NDK: Host awk tool is outdated. Please define HOST_AWK to point to Gawk
or Nawk !
I have Cygwin 1.7.9, Gnu Make 3.8.2, and Gawk 3.1.8 on my Windows machine, along with the r5b release of the Android NDK.
I also have set the HOST_AWK environment variable, which points to my Gawk folder.
Unfortunatley the sample cannot run successfully without this step, (if I run hello-jni, I immediately receive an UnsatisfiedLinkError exception).
Below is the portion of the init.mk file on my machine (found in NDK_ROOT/build/core) which creates this error:
# Location of all awk scripts we use
BUILD_AWK := $(NDK_ROOT)/build/awk
AWK_TEST := $(shell $(HOST_AWK) -f $(BUILD_AWK)/check-awk.awk)
$(call ndk_log,Host awk test returned: $(AWK_TEST))
ifneq ($(AWK_TEST),Pass)
$(call __ndk_info,Host awk tool is outdated. Please define HOST_AWK to point to Gawk or Nawk !)
$(call __ndk_error,Aborting.)
endif
Thank-you for your help

Try updating your awk tool. Seems to an an outdated version (perhaps). Also ensure that NDK root is defined to where you have your NDK source and ensure that your awk tool is located in the build directory of your NDK Source.
NDK_ROOT
Try settings this environment variable to where your NDK root is. Whenever this is defined (Typically at the top)

Instead of HOST_AWK=gawk.exe, just do HOST_AWK=gawk

It turns out there was an apostrophe in my HOST_AWK path, which was causing the problem.

reference
https://stackoverflow.com/q/8121153/411522
mine worked fine now.what to do is: just rename the prebuilt awk in ndk