Crash on stl string assignment NDK

Question

My code crashes here:

void setText(const string & s) 
{ 
    needsReload = true; 
    _text = s; //<-- SIGSEGV here
}

_text is a std::string

This makes absolutely no sense. this, _text and s are in valid memory. I can't try portstl because I need exceptions. There is simply nothing that can go wrong. I'm currently compiling for armeabi-v7a. Any suggestions?

After some more fiddling I discovered that it crashes whenever I assign something to a string that was the empty string beforehand. I think it has something to do with my libstdc++. Here are my compilation and linking flags:

[ 50%] Building CXX object CMakeFiles/Mathrix.dir/main.cpp.o
/opt/android-ndk/toolchains/arm-linux-androideabi-4.6/prebuilt/linux-x86/bin/arm-linux-androideabi-g++   -DMathrix_EXPORTS -DANDROID -D__ARM_ARCH_5__ -D__ARM_ARCH_5T__ -D__ARM_ARCH_5E__ -D__ARM_ARCH_5TE__ --sysroot=/opt/android-ndk/platforms/android-9/arch-arm -fsigned-char -march=armv7-a -mfloat-abi=softfp -mfpu=vfp -fdata-sections -ffunction-sections -fPIC -Wno-psabi -frtti -fexceptions -marm -Os -finline-limit=64 -fno-strict-aliasing -fno-omit-frame-pointer -DDEBUG -D_DEBUG -DDEBUG -fPIC -isystem /opt/android-ndk/platforms/android-9/arch-arm/usr/include -isystem /opt/android-ndk/sources/cxx-stl/gnu-libstdc++/4.6/include -isystem /opt/android-ndk/sources/cxx-stl/gnu-libstdc++/4.6/libs/armeabi-v7a/include -I/home/da_petcu21/src/Porkholt/Examples/Mathrix/../../Engine/include -I/home/da_petcu21/src/Porkholt/Examples/Mathrix/../../Engine/../Externals/lua/src -I/home/da_petcu21/src/Porkholt/Examples/Mathrix/../../Engine/../Externals/libpng -I/home/da_petcu21/src/Porkholt/Examples/Mathrix/../../Engine/../Externals/zlib -I/home/da_petcu21/src/Porkholt/Examples/Mathrix/../../Engine/../Externals/uremote/include -I/home/da_petcu21/src/Porkholt/Examples/Mathrix/../../Engine/../Externals/openal-soft/include    -o CMakeFiles/Mathrix.dir/main.cpp.o -c /home/da_petcu21/src/Porkholt/Examples/Mathrix/main.cpp
Linking CXX shared library ../libs/armeabi-v7a/libMathrix.so
/usr/bin/cmake -E cmake_link_script CMakeFiles/Mathrix.dir/link.txt --verbose=Yes
/opt/android-ndk/toolchains/arm-linux-androideabi-4.6/prebuilt/linux-x86/bin/arm-linux-androideabi-g++  -fPIC --sysroot=/opt/android-ndk/platforms/android-9/arch-arm -fsigned-char -march=armv7-a -mfloat-abi=softfp -mfpu=vfp -fdata-sections -ffunction-sections -fPIC -Wno-psabi -frtti -fexceptions -marm -Os -finline-limit=64 -fno-strict-aliasing -fno-omit-frame-pointer -DDEBUG -D_DEBUG -DDEBUG -Wl,--fix-cortex-a8 -Wl,--gc-sections -Wl,--no-undefined   -shared -Wl,-soname,libMathrix.so -o ../libs/armeabi-v7a/libMathrix.so CMakeFiles/Mathrix.dir/main.cpp.o -L/opt/android-ndk/toolchains/arm-linux-androideabi-4.6/prebuilt/linux-x86/user/libs/armeabi-v7a -L/home/da_petcu21/src/Porkholt/Examples/Mathrix/build-android/armeabi-v7a/CMakeFiles/ndklibs/armeabi-v7a -L/home/da_petcu21/src/Porkholt/Examples/Mathrix/build-android/libs/armeabi-v7a -lPorkholt -llua -Wl,-rpath,/opt/android-ndk/toolchains/arm-linux-androideabi-4.6/prebuilt/linux-x86/user/libs/armeabi-v7a:/home/da_petcu21/src/Porkholt/Examples/Mathrix/build-android/armeabi-v7a/CMakeFiles/ndklibs/armeabi-v7a:/home/da_petcu21/src/Porkholt/Examples/Mathrix/build-android/libs/armeabi-v7a

The build script I'm using copies libgnustl_static to /home/da_petcu21/src/Porkholt/Examples/Mathrix/build-android/armeabi-v7a/CMakeFiles/ndklibs/armeabi-v7a/libstdc++.a

I suspect it uses the one in /opt/android-ndk/platforms/android-9/arm/lib instead

Not enough context. The code looks innocent. The bug cannot be found using what few info you've posted. — Seva Alekseyev, Sep 25 '12 at 21:11
CLearly there is _something_ that's going wrong - since it is. I agree with Seva; please post a self-contained example. — Marshall Clow, Sep 25 '12 at 22:10

score 4 · Accepted Answer · edited May 23 '17 at 12:13

4

The problem was that stl was linked statically with each of my libraries, thus creating copies of certain globals it required to be shared. (see Can't load native shared library with dependencies in a native activity app for a look over my apk's library layout).

For future reference, here is a pretty good explanation on why this happens: http://www.trilithium.com/johan/2005/06/static-libstdc/

I managed to solve the problem by simply linking stl dynamically.

edited May 23 '17 at 12:13

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answered Sep 26 '12 at 09:30

da_petcu21

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have to explicitly choose 'stl=c++_shared' gnustl and stlport not working for me – fastr.de Oct 08 '15 at 21:56

Crash on stl string assignment NDK

1 Answers1