Question

I am trying to build libraw as a Android shared library. It looks the lib is too complex to use with Android.mk etc, or better: I am not capable yet of doing that.

I tried the route of using a standalone toolchain from the NDK, but I am getting stuck when compiling this lib.

This is the path I take to compile the lib. Please point out if I am making obvious errors:

1. I downloaded the ndk.
2. ran: make-standalone-toolchain.sh
3. Added the bin folder of that standalone toolchain as first item in my PATH.
4. Ran ./configure with --host=arm-linux-androideabi. This succeeded
5. Ran make, here it crashed very fast.

    LibRaw-0.14.4$ make
    depbase=`echo internal/dcraw_common.lo | sed 's|[^/]*$|.deps/&|;s|\.lo$||'`;\
        /bin/bash ./libtool --tag=CXX   --mode=compile arm-linux-androideabi-g++ -DPACKAGE_NAME=\"LibRaw\" -DPACKAGE_TARNAME=\"libraw\" -DPACKAGE_VERSION=\"0.14.4\" -DPACKAGE_STRING=\"LibRaw\ 0.14.4\" -DPACKAGE_BUGREPORT=\"[e-mail]\" -DPACKAGE_URL=\"http://www.libraw.org\" -DSTDC_HEADERS=1 -DHAVE_SYS_TYPES_H=1 -DHAVE_SYS_STAT_H=1 -DHAVE_STDLIB_H=1 -DHAVE_STRING_H=1 -DHAVE_MEMORY_H=1 -DHAVE_STRINGS_H=1 -DHAVE_INTTYPES_H=1 -DHAVE_STDINT_H=1 -DHAVE_UNISTD_H=1 -DHAVE_DLFCN_H=1 -DLT_OBJDIR=\".libs/\" -I.   -I/usr/local/include  -g -O2 -MT internal/dcraw_common.lo -MD -MP -MF $depbase.Tpo -c -o internal/dcraw_common.lo internal/dcraw_common.cpp &&\
        mv -f $depbase.Tpo $depbase.Plo
    libtool: compile:  arm-linux-androideabi-g++ -DPACKAGE_NAME=\"LibRaw\" -DPACKAGE_TARNAME=\"libraw\" -DPACKAGE_VERSION=\"0.14.4\" "-DPACKAGE_STRING=\"LibRaw 0.14.4\"" -DPACKAGE_BUGREPORT=\"[e-mail]\" -DPACKAGE_URL=\"http://www.libraw.org\" -DSTDC_HEADERS=1 -DHAVE_SYS_TYPES_H=1 -DHAVE_SYS_STAT_H=1 -DHAVE_STDLIB_H=1 -DHAVE_STRING_H=1 -DHAVE_MEMORY_H=1 -DHAVE_STRINGS_H=1 -DHAVE_INTTYPES_H=1 -DHAVE_STDINT_H=1 -DHAVE_UNISTD_H=1 -DHAVE_DLFCN_H=1 -DLT_OBJDIR=\".libs/\" -I. -I/usr/local/include -g -O2 -MT internal/dcraw_common.lo -MD -MP -MF internal/.deps/dcraw_common.Tpo -c internal/dcraw_common.cpp  -fPIC -DPIC -o internal/.libs/dcraw_common.o
    internal/dcraw_common.cpp: In member function 'void LibRaw::read_shorts(ushort*, int)':
    internal/dcraw_common.cpp:119: error: 'swab' was not declared in this scope
    internal/dcraw_common.cpp: In member function 'void LibRaw::write_ppm_tiff()':
    internal/dcraw_common.cpp:9235: error: 'swab' was not declared in this scope
    make: *** [internal/dcraw_common.lo] Error 1

I doubt this error message is helpfull here at stackoverflow, but I am left wondering if I should have applied some additional flags or configuration to get this to work?

Note that I am able to compile this lib succesfully if just compiling for my system without crosscompiling. (linux 32bit).

When I am looking to a instruction for building GDAL for Android (here), it uses a additional setting of LIBS="-lsupc++ -lstdc++". This links the STL and C++ exceptions?
However, when I set those before running my configure I get immediately errors like:

configure:3018: checking whether the C++ compiler works
configure:3040: arm-linux-androideabi-g++    conftest.cpp -lsupc++ -lstdc++ >&5
/tmp/android-chain/bin/../lib/gcc/arm-linux-androideabi/4.4.3/../../../../arm-linux-androideabi/bin/ld: cannot find -lsupc++
collect2: ld returned 1 exit status

So, I am a bit stuck. Someone an idea?

Answer 1

I had to add an implementation of the swab function, since the NDK does not have that one.
Afterwards this compiled fine (but I used the crystax ndk).

A better way toolwise was to just use a Android.mk file and use ndk-build to compile it.