Android ndk-build not generating gdb.setup file - android

I am currently trying to debug native code in Android via ndk-gdb but I am having some troubles.
Even if I start a very simple project (let's say for example a default cocos2d-x v3 project) and run
ndk-build NDK_DEBUG=1
I end up with the following folder structure inside my android project
...
libs/
armeabi/
libcocos2dcpp.so
...
instead of the expected:
...
libs/
armeabi/
gdb.setup
gdbserver
libcocos2dcpp.so
...
In order to use ndk-gdb I need those two gdb files.
I am using cocos version 3.2 and Android NDK version r9d.
Isn't NDK_DEBUG=1enough for the gdb files to be generated? I have also tried withandroid:debuggable="true" inside my manifest file but it didn't work.
Edit
After running the command suggested by Digit I found a very suspicious line
Android NDK: Application 'local' forced *not* debuggable through NDK_DEBUG
when running the command ndk-build NDK_LOG=1 NDK_DEBUG=1
BUT
if I change to ndk-build NDK_LOG=1 NDK_DEBUG=true I get
Android NDK: Application 'local' forced debuggable through NDK_DEBUG
So it is ok now, really weird though how =1 is not considered true.

Can you paste the output of 'ndk-build NDK_LOG=1 NDK_DEBUG=1', this should contain more information about what ndk-build is doing, and is likely to provide an explanation.

Related

Error when attempting to configure cmake for cross compilation to android

I have been trying to build a c++ library for android using cmake cross compilation.
The library itself is a trivial test I made purely for testing the androind build process.
I have been using the cmake gui (v 3.25.0) on a windows machine.
I use a visual studio 2019 generator in cmake and specify a toolchain file.
Unfortunately, I seem to get the same error whatever I try. I tried searching for similar problems and trouble shooting, but have so far been unable to make any progress. If anyone with more experience could lend a hand, I would be very grateful!
I have attempted setting many different variables in the toolchain file in an attempt to resolve the problem, but the basic version of what I am working with is:
set(CMAKE_SYSTEM_NAME Android)
set(CMAKE_ANDROID_ARCH_ABI armeabi-v7a)
set(CMAKE_ANDROID_NDK C:/Microsoft/AndroidNDK64/android-ndk-r16b/)
The error I run into happens whenever I configure cmake. The outut I get from cmake looks something like this:
Android: Targeting API '27' with architecture 'arm', ABI 'armeabi-v7a', and processor 'armv7-a'
Android: Selected Clang toolchain 'arm-linux-androideabi-clang' with GCC toolchain 'arm-linux-androideabi-4.9'
The C compiler identification is Clang 5.0.300080
The CXX compiler identification is Clang 5.0.300080
Detecting C compiler ABI info
Detecting C compiler ABI info - failed
Check for working C compiler: C:/Microsoft/AndroidNDK64/android-ndk-r16b//toolchains/llvm/prebuilt/windows-x86_64/bin/clang.exe
Check for working C compiler: C:/Microsoft/AndroidNDK64/android-ndk-r16b//toolchains/llvm/prebuilt/windows-x86_64/bin/clang.exe - broken
CMake Error at C:/Program Files/CMake/share/cmake-3.25/Modules/CMakeTestCCompiler.cmake:70 (message):
The C compiler
"C:/Microsoft/AndroidNDK64/android-ndk-r16b//toolchains/llvm/prebuilt/windows-x86_64/bin/clang.exe"
is not able to compile a simple test program.
It fails with the following output:
Change Dir: C:/Users/username/Documents/Code Projects/Android Test/build/CMakeFiles/CMakeScratch/TryCompile-zqgcqm
Run Build Command(s):C:/Program Files (x86)/Microsoft Visual Studio/2019/Community/MSBuild/Current/Bin/MSBuild.exe cmTC_b0f1d.vcxproj /p:Configuration=Debug /p:Platform=x64 /p:VisualStudioVersion=16.0 /v:m && Microsoft (R) Build Engine version 16.11.2+f32259642 for .NET Framework
Copyright (C) Microsoft Corporation. All rights reserved.
ANDROID_HOME=C:\\Microsoft\AndroidSDK\25
ANT_HOME=C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\Apps\apache-ant-1.9.3
JAVA_HOME=C:\Program Files\Eclipse Foundation\jdk-8.0.302.8-hotspot
NDK_ROOT=C:\\Microsoft\AndroidNDK64\android-ndk-r16b
testCCompiler.c
clang.exe : warning : argument unused during compilation: '-mthumb' [-Wunused-command-line-argument] [C:\Users\username\Documents\Code Projects\Android Test\build\CMakeFiles\CMakeScratch\TryCompile-zqgcqm\cmTC_b0f1d.vcxproj]
clang.exe : warning : argument unused during compilation: '-mfpu=vfpv3-d16' [-Wunused-command-line-argument] [C:\Users\username\Documents\Code Projects\Android Test\build\CMakeFiles\CMakeScratch\TryCompile-zqgcqm\cmTC_b0f1d.vcxproj]
clang.exe : warning : argument unused during compilation: '-mfloat-abi=softfp' [-Wunused-command-line-argument] [C:\Users\username\Documents\Code Projects\Android Test\build\CMakeFiles\CMakeScratch\TryCompile-zqgcqm\cmTC_b0f1d.vcxproj]
CLANGCOMPILE : error : unknown target CPU 'armv7-a' [C:\Users\username\Documents\Code Projects\Android Test\build\CMakeFiles\CMakeScratch\TryCompile-zqgcqm\cmTC_b0f1d.vcxproj]
CMake will not be able to correctly generate this project.
Call Stack (most recent call first):
CMakeLists.txt:4 (project)
Configuring incomplete, errors occurred!
I initially used used the NDK version found in the android tools for visual studio found at: "C:/Microsoft/AndroidNDK64/android-ndk-r16b/"
as an NDK version.
I have also tried directly downloading the latest version of the NDK and pointing to that with CMAKE_ANDROID_NDK in the toolchain file, though this did not seem to make any change.
I have tried directly using the toolchain.cmake files found at "NDK/build/cmake/android.toolchain.cmake"
for both the NDK versions described above. This too gave the same error.
Any ideas what could be causing this or how to fix?
Ok, so I was misunderstanding a few things about cross-compiling to android.
First, if I want to be able to use the static library (e.g in android studio), I will need to generate and build a solution for more than one android ABI.
The ABI's to build for are: armeabi-v7a, arm64-v8a, x86_64, x86. I then need to check for each android ABI in the CMakeLists.txt file of Android studio (e.g. elseif(ANDROID_ABI STREQUAL arm64-v8a)) and swap out the location of the library to import to the build folder of that particular ABI.
As far as I am aware, it is unfortunately not possible to generate for all these ABI's as seperate platforms within the same visual studio solution. Given that, cmake must be run 4 seperate times to different build folders, each time targeting a different ABI and generator platform. To save the hassle of doing this manually, creating a batch (.bat) script to automate the process seems the best way to go. This will involve using cmake from the command line instead of the GUI version. The script can also be made to build the generated projects to save opening each one in visual studio and building there.
The batch script I have made to generate and build cross-compilation projects for android is as follows:
#echo OFF
set BUILD_DIR=build
set ANDROID_NDK=C:\Microsoft\AndroidNDK\android-ndk-r23c
set GENERATOR="Visual Studio 17 2022"
set CMAKE_GENERATOR=-G %GENERATOR%
set CMAKE_TOOLCHAIN_FILE=-DCMAKE_TOOLCHAIN_FILE=%ANDROID_NDK%\build\cmake\android.toolchain.cmake
set CMAKE_SYSTEM_NAME=-DCMAKE_SYSTEM_NAME=Android
set EXTRA_CMAKE_ARGS=-DBUILD_SHARED_LIBS=true -DANDROID_TOOLCHAIN=clang -DANDROID_STL=c++_static
CALL :build_android armeabi-v7a ARM 16
CALL :build_android arm64-v8a ARM64 21
CALL :build_android x86_64 x64 21
CALL :build_android x86 x86 16
EXIT /B %ERRORLEVEL%
:build_android
set ABI_VERSION=%~1
set GENERATOR_PLATFORM=%~2
set MINIMUM_API_LEVEL=%~3
set CMAKE_ANDROID_ARCH_ABI=-DANDROID_ABI=%ABI_VERSION%
set ABI_BUILD_DIR=%BUILD_DIR%\%ABI_VERSION%
set CMAKE_GENERATOR_PLATFORM=-A %GENERATOR_PLATFORM%
set CMAKE_BUILD_DIR=-B %ABI_BUILD_DIR%
set CMAKE_MIN_API=-DANDROID_PLATFORM=android-%MINIMUM_API_LEVEL%
set CMAKE_ARGS=%CMAKE_BUILD_DIR% %CMAKE_ANDROID_ARCH_ABI% %CMAKE_GENERATOR% %CMAKE_GENERATOR_PLATFORM% %CMAKE_SYSTEM_NAME% %CMAKE_TOOLCHAIN_FILE% %CMAKE_MIN_API%
echo building for android ABI: %ABI_VERSION%
echo cmake arguments = %CMAKE_ARGS%
echo:
cmake %CMAKE_ARGS% %EXTRA_CMAKE_ARGS%
echo:
cmake --build %ABI_BUILD_DIR% --target ALL_BUILD
echo:
echo:
EXIT /B 0
This worked for my simple test library, but I guess depending on the project the arguments to the cmake commands may need to be tweaked.

Checking preprocessor directives with Android Studio Gradle Build, NDK and CMake

I'm passing in preprocessor directives via CMakeLists.txt for the build of a native android library using android NDK.
add_definitions(-DMY_DIRECTIVE=1)
It would be great to double check that those preprocessor directives are actually finding their way into the calls to the compiler (llvm ?)
But the gradle build output doesn't seem to include the calls to the compiler, I just get:
Building C object CMakeFiles/my_project.dir/home/me/projects/my_proj/src/my_native.c.o
Is there a means to make the gradle output more verbose such that I can see the actual compiler calls and check those preprocessor directives are present?
The answer is to understand that Gradle utilises CMake to build the android NDK component (shared library) of an android project, and CMake utilises Ninja as a build system to handle the calls to the compiler. The compiler used by android NDK now defaults to LLVM->Clang.
So in order to actually see the Clang calls you have to find the build.ninja files for each target of your android project.
In my case I am only building for an armeabi-v7a target architecture. Therefore the relevant build.ninja files are found in:
/home/me/projects/my_proj/app/.externalNativeBuild/cmake/debug/armeabi-v7a
/home/me/projects/my_proj/app/.externalNativeBuild/cmake/release/armeabi-v7a
cd to either directory and run:
ninja -v
i.e. the -v option is the key to see all the calls to the clang compiler that the native build (android NDK) part of your android project generates.
Note if you have installed CMake via the android package manager, you may find that ninja is not installed in a location that is on your PATH. For me the ninja binary is located as follows:
~/Android/Sdk/cmake/3.6.3155560/bin/ninja
(same directory as cmake binary)
Therefore for me to see all the clang compiler calls for my android project's debug armeabi-v7a build I have to run:
cd /home/me/projects/my_proj/app/.externalNativeBuild/cmake/debug/armeabi-v7a
~/Android/Sdk/cmake/3.6.3155560/bin/ninja -v
Note if ninja tells you ninja: no work to do.
Then run:
~/Android/Sdk/cmake/3.6.3155560/bin/ninja clean
Relevant ninja documentation is -> https://ninja-build.org/manual.html#_extra_tools

How to use ndk-build without jni directory?

We are attempting to add first class build support for Android to a C++ library. We want to supply a stock Android.mk, and disgorge it from dependencies like a jni subfolder in an Eclipse or Android Studio project directory. That is, we want to:
cd library-src
ndk-build <options>
In the above, library-src is not NDK_PROJECT_PATH. Rather, its the root folder for the library.
We visited the NDK's help (ndk-build -?), but it did not tell us how to remove the assumptions. We tried the following, but it produced an errors:
$ ndk-build -f Android.mk
Android NDK: Could not find application project directory !
Android NDK: Please define the NDK_PROJECT_PATH variable to point to it.
/opt/android-ndk-r10e/build/core/build-local.mk:143: *** Android NDK: Aborting
Stop.
Attempting to set NDK_PROJECT_PATH results in a similar error:
$ NDK_PROJECT_PATH=. ndk-build -f Android.mk
Android NDK: Your APP_BUILD_SCRIPT points to an unknown file: ./jni/Android.mk
/opt/android-ndk-r10e/.../add-application.mk:199: *** Android NDK: Aborting...
Stop.
And attempting to set APP_BUILD_SCRIPT results in a similar error:
$ NDK_PROJECT_PATH=. APP_BUILD_SCRIPT=Android.mk ndk-build -f Android.mk
Android NDK: Your APP_BUILD_SCRIPT points to an unknown file: ./jni/Android.mk
/opt/android-ndk-r10e/.../add-application.mk:199: *** Android NDK: Aborting...
Stop.
How do we use ndk-build without the jni directory?
Its important that we remove the limitations/assumptions. If we can't remove them, then we can't automate building and testing. If we can't automate building and testing, then we can't add the support because our governance has some QA and testing gates that we won't be able to pass through. (I'm willing to tolerate a manual adb push to test on-device).
I must admit that I don't understand your limitations. Why adding file library-src/Android.mk is OK, but library-src/jni/Android.mk breaks your QA and testing gates. Furthermore, Android.mk is usually not enough to launch a build. Whether you want to choose the STL variation, or ABI, or toolchain, it is natural to define these settings in a different file, Application.mk, which also goes to the jni directory by convention. Add library-src/jni directory, and Android developers will thank you when their tools of trade get upgrades and they can stay with the standard configuration.
But Android build is a very flexible system, and you can achieve literally what you ask for.
The experiments that you made did not work because ndk-build is simply a thin wrapper around GNU make, and treats environment variables with low priority.
ndk-build APP_BUILD_SCRIPT=Android.mk NDK_PROJECT_PATH=.
will most likely simply work for you. If you need more control, you can use something like
ndk-build APP_BUILD_SCRIPT=Android.mk NDK_PROJECT_PATH=. APP_STL=gnustl_static APP_ABI=armeabi-v7a APP_PLATFORM=android-19 NDK_TOOLCHAIN_VERSION=4.9
You can control the output directories, too. See NDK_APP_OUT, NDK_APP_LIBS_OUT.
One last hint: if your global build process is based on make, you can invoke $(MAKE) directly instead of going through ndk-build. It is also OK if you require standalone toolchain to keep platform-independent make logic.

Openh264 compiling using PJSIP

I am trying to build pjsip project with openh264 lib. Everything works fine except openh264 is not being detected by pjsip ./configure-android
this is my config_site.h
/* Activate Android specific settings in the 'config_site_sample.h' */
#define PJ_CONFIG_ANDROID 1
#include <pj/config_site_sample.h>
#define PJMEDIA_HAS_VIDEO 1
#define PJMEDIA_HAS_OPENH264_CODEC 1
I am getting following log
Using OpenH264 prefix... /home/user_name/PJSIPTOOLS/openh264-1.0.0/openlib/
checking OpenH264 usability... no
As it is not detected by ./configure-android my app is crashing at runtime saying lib not found for openh264.
I am on ubuntu 14.04 32 bit.
Any suggestions.
I just encountered a similar issue. In the following, I refer to the directory, I downloaded and extracted OpenH264 to, as path-to-openh264. I created a subdirectory android within that folder and modified OpenH264's Makefile by setting PREFIX=android. Afterwards running the following commands to build OpenH264 solved the issue for me:
make OS=android NDKROOT=<path-to-ndk> TARGET=android-14 APP_ABI=armeabi ARCH=arm
make OS=android NDKROOT=<path-to-ndk> TARGET=android-14 APP_ABI=armeabi ARCH=arm clean
make install OS=android NDKROOT=<path-to-ndk> TARGET=android-14 APP_ABI=armeabi ARCH=arm
The resulting libopenh264.so file should end up in the directory path-to-openh264/android/lib/. In order to configure pjsip I used the following command:
APP_PLATFORM=android-14 ./configure-android --with-openh264=<path-to-openh264>/android
The following StackOverflow thread lead me to the right direction:
building openh264 for android platform in x86
The reason for this issue was, that I ran the make install command without the command line parameters at first. This caused the native library file to be created for the wrong ABI (the default one, which is armeabi-v7a). When building pjsip for the armeabi ABI, it didn't recognize the library, because it was built for a different ABI. At least this is what I suppose.
Actually i faced that problem too.
Solution:
step 1:go to your openh264 directory and create a folder named "android"
step 2: open makefile and set prefix
PREFIX=/your_path/openh264-1.0.0/android
step3:then build openh264 using this command
make OS=android NDKROOT=/your_path/android-ndk-r10d TARGET=android-17 APP_ABI=armeabi
step4: now build pjsip using this command
TARGET_ABI=armeabi APP_PLATFORM=android-12 ./configure-android --use-ndk-cflags --with-openh264=/your_path/openh264-1.0.0/android
hope this time you will see
Using OpenH264 prefix...
/home/user_name/PJSIPTOOLS/openh264-1.0.0/openlib/
checking OpenH264 usability... ok
http://trac.pjsip.org/repos/ticket/1758
modify the "prefix" in Makefile
run "make install ARCH=armeabi"
run "./configure-android --with_openh264=/path/to/prefix/folder"

Android ndk-build command does nothing

I have a similar question to that posted here:
Android NDK: why ndk-build doesn't generate .so file and a new libs folder in Eclipse?
...though I am running Windows 7, not Mac os. Essentially the ndk-build command is run, gives no error but doesn't create an .so file (also, since I'm on windows this should create a .dll and not an .so?). I tried running the command from the root, jni, src folders etc. but got the same result; cmd just returns to the prompter after a few seconds. I ran it again from the jni folder with NDK_LOG=1 parameter to see what was happening. Here is a portion of the transcript of the log results after running ndk-build in the jni folder (after it successfully identified the platform, etc.)...
Android NDK: Looking for jni/Android.mk in /workspace/NdkFooActivity/jni
Android NDK: Looking for jni/Android.mk in /workspace/NdkFooActivity
Android NDK: Found it !
Android NDK: Found project path: /workspace/NdkFooActivity
Android NDK: Ouput path: /workspace/NdkFooActivity/obj
Android NDK: Parsing /cygdrive/c/android-ndk-r8/build/core/default-application.mk
Android NDK: Found APP_PLATFORM=android-15 in /workspace/NdkFooActivity/project.properties
Android NDK: Application local targets unknown platform 'android-15'
Android NDK: Switching to android-14
Android NDK: Using build script /workspace/NdkFooActivity/jni/Android.mk
Android NDK: Application 'local' is not debuggable
Android NDK: Selecting release optimization mode (app is not debuggable)
Android NDK: Adding import directory: /cygdrive/c/android-ndk-r8/sources
Android NDK: Building application 'local' for ABI 'armeabi'
Android NDK: Using target toolchain 'arm-linux-androideabi-4.4.3' for 'armeabi' ABI
Android NDK: Looking for imported module with tag 'cxx-stl/system'
Android NDK: Probing /cygdrive/c/android-ndk-r8/sources/cxx-stl/system/Android.mk
Android NDK: Found in /cygdrive/c/android-ndk-r8/sources/cxx-stl/system
Android NDK: Cygwin dependency file conversion script:
...after which point it just runs the script mentioned in the last line, then terminates. Any ideas? Thanks!
Set up a builder. Refer to following article for how to do that:
http://maxters.net/2011/02/android-ndk-builder-for-eclipse-in-windows/
There is a "small" change beginning NDK r8 – Cygwin is not necessary anymore and I had a trouble when building native libraries with Cygwin and NDK r8 – there was some error message about cxx-stl...
Almost everything in the link above is OK, but leave Arguments in the Main tab blank and change Location to:
${env_var:ANDROID_NDK_ROOT}/ndk-build.cmd
I use system variable path ANDROID_NDK_ROOT, but you can provide a full path to the ndk-build.cmd.
Also, there is no need to set any variable in the Environment tab.
Set up your builder this way and you will be fine.
Just a note, Android is built on the top of the Linux OS, so even if you are on Windows you will get Linux libraries with .so extension.
Following link was instructive but missing a detail if you are configuring NDK support in Eclipse after CDT it already depricated (summer of 2017 already).
http://maxters.net/2011/02/android-ndk-builder-for-eclipse-in-windows/
Where you need to configure your external builder Location, instead of pointing to cygwin\bin\bash.exe and adding as Argument your ndk-build.cmd location this is what worked for me on Windows 7 and 10.
In "Edit Configuration" dialog for external builder do following:
- for Location -> specify where your "ndk-build.cmd" is. i.e "D:\Android\NDK\ndk-build.cmd"
- for Arguments -> just specify "all"
The NDK build system relies on wildcards to find the sources to compile. If you have a path wrong somewhere, it will find no sources and do nothing. Check Android.mk very carefully. More can't be said unless you post Android.mk and a description of the source tree.

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