Compiling against C++ standard libraries on the android toolchain

Issue

I have a really simple helloworld.cpp program

#include <iostream>
using namespace std;
int main ()
{
  cout << "Hello World!";
  return 0;
}

And I'm trying to compile it for android x86 with the cross-compiler from the toolchain:

/Users/me/android-ndk-r8/toolchains/x86-4.4.3/prebuilt/darwin-x86/bin/i686-android-linux-g++ helloworld.cpp -L "/Users/me/android-ndk-r8/sources/cxx-stl/stlport/libs/x86/" -lstlport_static

However, I get errors:

helloworld.cpp:2:20: error: iostream: No such file or directory

Any idea why?

Solution

Check the documentation.html file included with the NDK, under "Standalone Toolchain". It says that if you invoke the compiler in this way you won't be able to "use any C++ STL". However it is possible, as the documentation explains, if you first create a "customized" toolchain installation, using something like the following command:

$NDK/build/tools/make-standalone-toolchain.sh --platform=android-8 --install-dir=/tmp/my-android-toolchain --arch=x86

where $NDK is the path to your NDK directory. Note the --arch=x86 which means that the toolchain is prepared specifically for the x86 Android. This prepares what you need in one directory, including the STL headers and folders. You should then be able to use -lstdc++ to link against the STL (static version), i.e. something like:

/tmp/my-android-toolchain/bin/i686-android-linux-g++ helloworld.cpp -lstdc++

For a more complete explanation, please see the NDK documentation.

Answered By - simon