Question

I can’t seem to get the following trivial code to compile/link and the problem seems specific to std::wstring and the gnustl_static C++ library. Any help would be appreciated.

main.cpp file:

#include <string>
int main(void)
{
    std::wstring wtest(L"Test");
    return 0;
}

Application.mk file:

APP_CFLAGS += -fexceptions
APP_STL := gnustl_static

Android.mk file:

LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
LOCAL_MODULE := TestWCharApp
LOCAL_CFLAGS := -D_GLIBCXX_USE_WCHAR_T
LOCAL_SRC_FILES := main.cpp
include $(BUILD_EXECUTABLE)

When attempting to link the above application using gnustl_static I get the following error message:

undefined reference to `std::basic_string<wchar_t, std::char_traits<wchar_t>, std::allocator<wchar_t> >::basic_string(wchar_t const*, std::allocator<wchar_t> const&)'

If I change APP_STL to stlport_static and define _STLP_HAS_WCHAR_T everything seems to compile/link/run fine. I verify it works by uploading the exe to the emulator and running it via the shell.

I’m going to need to use the gnustl implementation for c++ exception support otherwise I’d go with stlport_shared. Any clues as to why the above sample works for stlport_static but not gnustl_static?

Answer 1

It’s a problem with the file $NDK/sources/cxx-stl/gnu-libstdc++/Android.mk

Add the following line to that file:

LOCAL_MODULE_FILENAME := libstdc++