Develop Reference

C/C++: ld: error: found local symbol '__bss_start' in global part of symbol table in file

I am creating a project in android studio with using opencv library. my ndk is r23 and my cmake is 3.18.1.
this is my graddle.build(app):
plugins {
id 'com.android.application'
}
android {
namespace 'com.example.slam3'
compileSdk 33
defaultConfig {
applicationId "com.example.slam3"
minSdk 29
targetSdk 33
versionCode 1
versionName "1.0"
testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
externalNativeBuild {
cmake {
cppFlags '-std=c++11'
}
}
}
buildTypes {
release {
minifyEnabled false
proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
}
}
compileOptions {
sourceCompatibility JavaVersion.VERSION_1_8
targetCompatibility JavaVersion.VERSION_1_8
}
externalNativeBuild {
cmake {
path file('src/main/cpp/CMakeLists.txt')
version '3.18.1'
}
}
buildFeatures {
viewBinding true
}
}
dependencies {
implementation 'androidx.appcompat:appcompat:1.6.0'
implementation 'com.google.android.material:material:1.8.0'
implementation 'androidx.constraintlayout:constraintlayout:2.1.4'
implementation project(path: ':openCV')
testImplementation 'junit:junit:4.13.2'
androidTestImplementation 'androidx.test.ext:junit:1.1.5'
androidTestImplementation 'androidx.test.espresso:espresso-core:3.5.1'
}
i use CMakeLists.txt for using a simple native lib in my project. my CMakeLists.txt:
set(pathToProject C:/Users/HYPER_STOCK_TABRIZ/AndroidStudioProjects/Slam3)
set(pathToOpenCV C:/Users/HYPER_STOCK_TABRIZ/AndroidStudioProjects/OpenCV-android-sdk)
#For more information about using CMake with Android Studio, read the
# documentation: https://d.android.com/studio/projects/add-native-code.html
# Sets the minimum version of CMake required to build the native library.
cmake_minimum_required(VERSION 3.18.1)
set(CMAKE_VERBOSE_MAKEFILE on)
set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=gnu++11")
include_directories(${pathToOpenCV}/sdk/native/jni/include)
# Declares and names the project.
project("slam3")
# Creates and names a library, sets it as either STATIC
# or SHARED, and provides the relative paths to its source code.
# You can define multiple libraries, and CMake builds them for you.
# Gradle automatically packages shared libraries with your APK.
add_library( # Sets the name of the library.
slam3
# Sets the library as a shared library.
SHARED
# Provides a relative path to your source file(s).
native-lib.cpp)
add_library(lib_opencv SHARED IMPORTED)
set_target_properties(lib_opencv PROPERTIES IMPORTED_LOCATION ${pathToProject}/app/src/main/jniLibs/${ANDROID_ABI}/libopencv_java3.so)
# Searches for a specified prebuilt library and stores the path as a
# variable. Because CMake includes system libraries in the search path by
# default, you only need to specify the name of the public NDK library
# you want to add. CMake verifies that the library exists before
# completing its build.
find_library( # Sets the name of the path variable.
log-lib
# Specifies the name of the NDK library that
# you want CMake to locate.
log)
# Specifies libraries CMake should link to your target library. You
# can link multiple libraries, such as libraries you define in this
# build script, prebuilt third-party libraries, or system libraries.
target_link_libraries(slam3 ${log-lib} lib_opencv)
When i run project in device i see this error:
C/C++: ld: error: found local symbol '__bss_start' in global part of symbol table in file C:/Users/HYPER_STOCK_TABRIZ/AndroidStudioProjects/Slam3/app/src/main/jniLibs/arm64-v8a/libopencv_java3.so
i test this
but still i has the same error. how can i solve it?

CMake add_subdirectory given source which is not an existing directory

I'm following this tutorial in order to implement firebase in my android project using C++. I've followed all the steps as the tutorial shows, but when I run my project, I'm getting this error message:
CMake Error at CMakeLists.txt:46 (add_subdirectory):
add_subdirectory given source "olympic/firebase_cpp_sdk" which is not an
existing directory.
CMakeLists.txt:
# For more information about using CMake with Android Studio, read the
# documentation: https://d.android.com/studio/projects/add-native-code.html
# Sets the minimum version of CMake required to build the native library.
cmake_minimum_required(VERSION 3.4.1)
# Creates and names a library, sets it as either STATIC
# or SHARED, and provides the relative paths to its source code.
# You can define multiple libraries, and CMake builds them for you.
# Gradle automatically packages shared libraries with your APK.
add_library( # Sets the name of the library.
native-lib
# Sets the library as a shared library.
SHARED
# Provides a relative path to your source file(s).
native-lib.cpp)
# Searches for a specified prebuilt library and stores the path as a
# variable. Because CMake includes system libraries in the search path by
# default, you only need to specify the name of the public NDK library
# you want to add. CMake verifies that the library exists before
# completing its build.
find_library( # Sets the name of the path variable.
log-lib
# Specifies the name of the NDK library that
# you want CMake to locate.
log)
# Specifies libraries CMake should link to your target library. You
# can link multiple libraries, such as libraries you define in this
# build script, prebuilt third-party libraries, or system libraries.
target_link_libraries( # Specifies the target library.
native-lib
# Links the target library to the log library
# included in the NDK.
${log-lib})
# Add Firebase libraries to the target using the function from the SDK.
add_subdirectory(${FIREBASE_CPP_SDK_DIR} bin/ EXCLUDE_FROM_ALL)
# The core Firebase library (firebase_app) is required to use any Firebase product,
# and it must always be listed last.
set(firebase_libs firebase_analytics firebase_app)
target_link_libraries(${target_name} "${firebase_libs}")
Build.gradle
apply plugin: 'com.android.library'
android {
compileSdkVersion 29
buildToolsVersion "29.0.2"
defaultConfig {
minSdkVersion 16
targetSdkVersion 29
versionCode 1
versionName "1.0"
testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
}
compileOptions {
sourceCompatibility JavaVersion.VERSION_1_8
targetCompatibility JavaVersion.VERSION_1_8
}
buildTypes {
release {
minifyEnabled false
proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
}
}
externalNativeBuild {
cmake {
path "src/main/cpp/CMakeLists.txt"
version "3.10.2"
}
}
}
dependencies {
implementation fileTree(dir: 'libs', include: ['*.jar'])
implementation 'androidx.appcompat:appcompat:1.1.0'
implementation 'androidx.constraintlayout:constraintlayout:1.1.3'
implementation 'com.deltadna.android:deltadna-sdk:4.11.3.1'
implementation 'com.helpshift:android-helpshift-aar:7.+'
implementation "com.mixpanel.android:mixpanel-android:5.+"
testImplementation 'junit:junit:4.12'
androidTestImplementation 'androidx.test:runner:1.2.0'
androidTestImplementation 'androidx.test.espresso:espresso-core:3.2.0'
}
apply plugin: 'com.google.gms.google-services'
android.defaultConfig.externalNativeBuild.cmake {
arguments "-DFIREBASE_CPP_SDK_DIR=$gradle.firebase_cpp_sdk_dir"
}
apply from: "firebase_cpp_sdk/Android/firebase_dependencies.gradle"
firebaseCpp.dependencies {
analytics
}

The error complains that the directory olympic/firebase_cpp_sdk does not exist. From the documentation for add_subdirectory(), the first argument to this command can be a relative or absolute path:
If it is a relative path it will be evaluated with respect to the current directory (the typical usage), but it may also be an absolute path.
Since you have provided a relative path, CMake will look for olympic/firebase_cpp_sdk relative to the current CMakeLists.txt file being processed; this path does not exist on your system. To ensure CMake can locate the firebase_cpp_sdk directory, try specifying an absolute path instead, as suggested in the tutorial in this step:
Specify the location of the unzipped SDK in your project's gradle.properties file:
systemProp.firebase_cpp_sdk.dir=full-path-to-SDK
So try the full path:
systemProp.firebase_cpp_sdk.dir=/your/full/path/to/SDK

You have to specify path to the "firebase sdk" before:
# Add Firebase libraries to the target using the function from the SDK.
add_subdirectory(${FIREBASE_CPP_SDK_DIR} bin/ EXCLUDE_FROM_ALL)
and then set this path to the cmake variable "FIREBASE_CPP_SDK_DIR":
set(FIREBASE_CPP_SDK_DIR "${CMAKE_CURRENT_LIST_DIR}/<some relative path inside of your project>")
where CMAKE_CURRENT_LIST_DIR - path where located current CMakeLists.txt.

App works fine on emulators, but crashes on device with: java.lang.UnsatisfiedLinkError: dlopen failed: cannot locate symbol "__aeabi_memcpy"

I'm trying to implement yctung's AndroidLibSvm into my project with Android Studio 3.2.1. While the app works fine on any emulated device (I tried Android 23 and 28, both worked flawlessly), it crashes on my real device (a lenovo tablet with Android 6.0) with the following error:
java.lang.UnsatisfiedLinkError: dlopen failed: cannot locate symbol "__aeabi_memcpy" referenced by "/data/app/com.krautkremer.nils.mymirror-2/lib/arm/libjnilibsvm.so"
as soon as the app tries to run the part of the code that uses cytung's lib.
There are a few similar cases on SO e.g. here or here but setting my
arguments "-DANDROID_PLATFORM=android-23"
or any other android-x and my targetSdkVersion to 23 in the build.gradle didn't solve it.
this is my build.gradle:
apply plugin: 'com.android.application'
android {
compileSdkVersion 28
defaultConfig {
applicationId "com.krautkremer.nils.mymirror"
minSdkVersion 23
targetSdkVersion 28
versionCode 1
versionName "1.0"
testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
externalNativeBuild {
cmake {
cppFlags ""
arguments "-DANDROID_PLATFORM=android-23"
}
}
}
buildTypes {
release {
minifyEnabled false
proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
}
}
packagingOptions {
//exclude 'META-INF/proguard/androidx-annotations.pro'
}
externalNativeBuild {
cmake {
path "CMakeLists.txt"
}
}
}
dependencies {
implementation fileTree(include: ['*.jar'], dir: 'libs')
implementation 'androidx.appcompat:appcompat:1.1.0-alpha01'
implementation 'androidx.media:media:1.1.0-alpha01'
implementation 'androidx.legacy:legacy-support-v4:1.0.0'
implementation 'androidx.constraintlayout:constraintlayout:2.0.0-alpha2'
implementation 'com.google.android.material:material:1.1.0-alpha01'
implementation 'androidx.annotation:annotation:1.0.1'
implementation 'com.google.firebase:firebase-core:16.0.6'
implementation 'com.google.firebase:firebase-ml-vision:18.0.2'
implementation 'com.google.firebase:firebase-ml-common:16.1.6'
implementation 'com.google.firebase:firebase-ml-vision-face-model:17.0.2'
testImplementation 'junit:junit:4.12'
androidTestImplementation 'androidx.test:runner:1.1.1-alpha01'
androidTestImplementation 'androidx.test.espresso:espresso-core:3.1.1-alpha01'
implementation project(':androidlibsvm-release')
}
apply plugin: 'com.google.gms.google-services'
I even downgraded my NDK version from 18 to 15 with no success.
Any ideas what might be the problem?
Help me, Obi-Wan Kenobi. You're my only hope.
EDIT:
This is my CMakeLists.txt, if it is of any help. I didn't change anything, should I?
# For more information about using CMake with Android Studio, read the
# documentation: https://d.android.com/studio/projects/add-native-code.html
# Sets the minimum version of CMake required to build the native library.
cmake_minimum_required(VERSION 3.4.1)
# Creates and names a library, sets it as either STATIC
# or SHARED, and provides the relative paths to its source code.
# You can define multiple libraries, and CMake builds them for you.
# Gradle automatically packages shared libraries with your APK.
add_library( # Sets the name of the library.
native-lib
# Sets the library as a shared library.
SHARED
# Provides a relative path to your source file(s).
src/main/cpp/native-lib.cpp)
# Searches for a specified prebuilt library and stores the path as a
# variable. Because CMake includes system libraries in the search path by
# default, you only need to specify the name of the public NDK library
# you want to add. CMake verifies that the library exists before
# completing its build.
find_library( # Sets the name of the path variable.
log-lib
# Specifies the name of the NDK library that
# you want CMake to locate.
log)
# Specifies libraries CMake should link to your target library. You
# can link multiple libraries, such as libraries you define in this
# build script, prebuilt third-party libraries, or system libraries.
target_link_libraries( # Specifies the target library.
native-lib
# Links the target library to the log library
# included in the NDK.
${log-lib})

Try to change your minSdkVersion and targetSdkVersion, i.e.
minSdkVersion 15
targetSdkVersion 23

How to import openCV with contrib on Android using CMake?

I try import openCV with contrib on Android. I referenced this site:
http://www.cnblogs.com/fx-blog/p/8206737.html
I failed to build opencv with contrib for Android, so I downloaded opencv with contrib sdk. I imported module, set dependency and write CMakeLists and build.gradle
Here is my CMakeLists and build.gradle
CMakeLists.txt
# For more information about using CMake with Android Studio, read the
# documentation: https://d.android.com/studio/projects/add-native-code.html
# Sets the minimum version of CMake required to build the native library.
cmake_minimum_required(VERSION 3.4.1)
set(pathOPENCV E:/opencv/opencv3-android-sdk-with-contrib-master/OpenCV-android-sdk)
set(pathPROJECT C:/Users/sms28/Downloads/artoolkit-android-studio-example- master/MyApplication7)
set(pathLIBOPENCV_JAVA C:/Users/sms28/Downloads/artoolkit-android-studio-example- master/MyApplication7/app/src/main/JniLibs/${ANDROID_ABI}/libopencv_java3.so)
set(CMAKE_VERBOSE_MAKEFILE on)
# set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=gnu++11")
include_directories(${pathOPENCV}/sdk/native/jni/include)
# Creates and names a library, sets it as either STATIC
# or SHARED, and provides the relative paths to its source code.
# You can define multiple libraries, and CMake builds them for you.
# Gradle automatically packages shared libraries with your APK.
add_library(libopencv_java3 SHARED IMPORTED )
set_target_properties(libopencv_java3 PROPERTIES
IMPORTED_LOCATION "${pathLIBOPENCV_JAVA}")
add_library( # Sets the name of the library.
xfeatures2d
# Sets the library as a shared library.
SHARED
# Provides a relative path to your source file(s).
src/main/cpp/xfeatures2d_init.cpp
src/main/cpp/sift.cpp
src/main/cpp/surf.cpp
src/main/cpp/freak.cpp )
# Searches for a specified prebuilt library and stores the path as a
# variable. Because CMake includes system libraries in the search path by
# default, you only need to specify the name of the public NDK library
# you want to add. CMake verifies that the library exists before
# completing its build.
find_library( # Sets the name of the path variable.
log-lib
# Specifies the name of the NDK library that
# you want CMake to locate.
log )
# Specifies libraries CMake should link to your target library. You
# can link multiple libraries, such as libraries you define in this
# build script, prebuilt third-party libraries, or system libraries.
target_link_libraries( # Specifies the target library.
xfeatures2d android log libopencv_java3
# Links the target library to the log library
# included in the NDK.
${log-lib} )
build.gradle (app)
apply plugin: 'com.android.application'
android {
compileSdkVersion 27
defaultConfig {
applicationId "com.example.sms28.myapplication"
minSdkVersion 16
targetSdkVersion 27
versionCode 1
versionName "1.0"
testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
externalNativeBuild {
cmake {
cppFlags "-std=c++11", "-frtti", "-fexceptions"
abiFilters 'x86', 'x86_64','armeabi-v7a', 'arm64-v8a'
}
}
}
sourceSets {
main {
jniLibs.srcDirs = ['src/main/jniLibs']
}
}
buildTypes {
release {
minifyEnabled false
proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
}
}
externalNativeBuild {
cmake {
path "CMakeLists.txt"
}
}
}
dependencies {
implementation fileTree(include: ['*.jar'], dir: 'libs')
implementation 'com.android.support:appcompat-v7:27.1.1'
implementation 'com.android.support.constraint:constraint-layout:1.1.0'
testImplementation 'junit:junit:4.12'
androidTestImplementation 'com.android.support.test:runner:1.0.2'
androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
implementation project(':openCVLibrary340dev')
}
And I build it, but I got errors:
click and show error image

Convert a gcc command to CMake for android ndk

I need to add a c project which can be compiled with gcc as follows
gcc -I/usr/include/epic5.1 -I/usr/include/i386-linux-gnu/epic5.1 -I./smproject/ -o code code.c ./smproject/smlib.so -lepic5.1
I have moved the code.c files content to my Android NDK .cpp file (src/main/cpp/native-lib.cpp) and also moved all files inside smproject directory to src/main/cpp/smproject/ directory
Here is my CMakeList.txt content
# For more information about using CMake with Android Studio, read the
# documentation: https://d.android.com/studio/projects/add-native-code.html
# Sets the minimum version of CMake required to build the native library.
cmake_minimum_required(VERSION 3.4.1)
# Creates and names a library, sets it as either STATIC
# or SHARED, and provides the relative paths to its source code.
# You can define multiple libraries, and CMake builds them for you.
# Gradle automatically packages shared libraries with your APK.
include_directories( /usr/include/epic5.1 )
include_directories( /usr/include/i386-linux-gnu/epic5.1 )
include_directories( src/main/cpp )
set_target_properties( delorean PROPERTIES IMPORTED_LOCATION
src/main/cpp/smlib.so
)
add_library( smlib STATIC IMPORTED )
add_library( # Sets the name of the library.
native-lib
# Sets the library as a shared library.
SHARED
# Provides a relative path to your source file(s).
src/main/cpp/native-lib.cpp
)
# Searches for a specified prebuilt library and stores the path as a
# variable. Because CMake includes system libraries in the search path by
# default, you only need to specify the name of the public NDK library
# you want to add. CMake verifies that the library exists before
# completing its build.
find_library( # Sets the name of the path variable.
log-lib
# Specifies the name of the NDK library that
# you want CMake to locate.
log)
# Specifies libraries CMake should link to your target library. You
# can link multiple libraries, such as libraries you define in this
# build script, pre-built third-party libraries, or system libraries.
target_link_libraries( # Specifies the target library.
native-lib
# Links the target library to the log library
# included in the NDK.
${log-lib}
smlib
)
I tried to follow Android NDK, CMake with other libraries but that didn't work for me it started throwing gradle error
tried following in build.gradle file
apply plugin: 'com.android.application'
android {
compileSdkVersion 25
buildToolsVersion "25.0.2"
defaultConfig {
applicationId "in.etpg.sampleapp"
minSdkVersion 15
targetSdkVersion 25
versionCode 1
versionName "1.0"
testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
externalNativeBuild {
cmake {
cppFlags "-I/usr/include/epic5.1 -I/usr/include/i386-linux-gnu/epic5.1 -lepic5.1 -frtti -fexceptions"
}
}
}
buildTypes {
release {
minifyEnabled false
proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
}
}
externalNativeBuild {
cmake {
path "CMakeLists.txt"
}
}
}
dependencies {
compile fileTree(dir: 'libs', include: ['*.jar'])
androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
exclude group: 'com.android.support', module: 'support-annotations'
})
compile 'com.android.support:appcompat-v7:25.3.1'
compile 'com.android.support.constraint:constraint-layout:1.0.2'
testCompile 'junit:junit:4.12'
}
Errors
Error:cannot find -lepic5.1
Error:error: linker command failed with exit code 1 (use -v to see
Warning:warning: -lepic5.1: 'linker' input unused
Error:A problem occurred configuring project ':app'.
> executing external native build for cmake /Users/laptop.user/AndroidStudioProjects/SampleApp/app/CMakeLists.txt

You simply need to add something to your module build.gradle, like this
ndk {
moduleName "code"
cFlags "-I/usr/include/epic5.1 -I/usr/include/i386-linux-gnu/epic5.1 -lepic5.1 -frtti -fexceptions"
ldLibs "log"
}
and place the source files in main/jni.
Perhaps, you need to change cFlags to cppFlags, but I recommend that you search for more information about this, the suggestion is based on the fact that you have -fnoexceptions flag, which is for c++.
You need of course libepic5.1.so binary to use it for compilation, if you can add it's source code it will work.