Undefined reference errors when including external library libxml2 in android ndk

Question

I'm trying to use libxml2 with android ndk. When I run the make file, I got errors saying that file 'unicode/ucnv.h' does not exist. I've seen 'unicode/ucnv.h' is included in one of the files and no such header file is present. So I downloaded unicode header files from http://site.icu-project.org/ and placed them in include folder.

Now the previous error is gone but I've got these errors.

SharedLibrary : libxml2.so

./obj/local/armeabi/objs-debug/xml2/encoding.o: In function `openIcuConverter':
C:\test\hello-jni/jni/encoding.c:109: undefined reference to `ucnv_open_49'
C:\test\hello-jni/jni/encoding.c:115: undefined reference to `ucnv_setToUCallBack_49'
C:\test\hello-jni/jni/encoding.c:119: undefined reference to `ucnv_setFromUCallBack_49'
C:\test\hello-jni/jni/encoding.c:126: undefined reference to `ucnv_open_49'
C:\test\hello-jni/jni/encoding.c:132: undefined reference to `ucnv_close_49'
C:\test\hello-jni/jni/encoding.c:135: undefined reference to `UCNV_TO_U_CALLBACK_STOP_49'
C:\test\hello-jni/jni/encoding.c:135: undefined reference to `UCNV_FROM_U_CALLBACK_STOP_49'
./obj/local/armeabi/objs-debug/xml2/encoding.o: In function `closeIcuConverter':
C:\test\hello-jni/jni/encoding.c:141: undefined reference to `ucnv_close_49'
C:\test\hello-jni/jni/encoding.c:142: undefined reference to `ucnv_close_49'
./obj/local/armeabi/objs-debug/xml2/encoding.o: In function `xmlUconvWrapper':
C:\test\hello-jni/jni/encoding.c:1865: undefined reference to `ucnv_convertEx_49'
C:\test\hello-jni/jni/encoding.c:1870: undefined reference to `ucnv_convertEx_49'

collect2: ld returned 1 exit status make: * [obj/local/armeabi/libxml2.so] Error 1

I didn't find function ucnv_open_49 in any of the files. Am I the only one who is facing this problem?

Answer 1

Build unicode library (icu) along with libxml2 and mention in LOCAL_SHARED_LIBRARIES. That's it!

Answer 2

Are you intending to link libxml2 against ICU (e.g. use it for conversion)? It's optional but currently you have it enabled. With such you'll need ICU to be linked in as well rather static or dynamic. See the libxml2's configure script for options. Some of which are iconv or even no converters if you intend to work with UTF-8 only.