Makefile for mex project: : .rodata' can not be used when making a shared object

I have a c-code which I can compile using makefile and run. Now, I want to convert it to mex file which I would like to compile using corresponding makefile. However, my makefile for mex code is not working. I would appreciate if someone can guide me.

I am working on *64 bit* system.

Structure of both C-codes and mex codes:

    C-codes                                Mex Code
    Test_tsnnls.c <--Main defined         Test_tsnnls_MEX.c <--mex defined here
    Include_4_TSNNLS.h                    Include_4_TSNNLS.h
    Include_4_TSNNLS.c                    Include_4_TSNNLS.c

Makefile (C-project) works:

    CXX       = gcc
    FLAGS     = 
    CFLAGS    = "-m64"   ## "-m32"
    INCLUDE_TSNNLS  = -I/home/dkumar/libtsnnls-2.3.3 -I/home/dkumar/libtsnnls-2.3.3/tsnnls  -I/home/dkumar/libtsnnls-2.3.3/tsnnls/taucs_basic

    #################### ALL TSNNLS lib related ##########################
    ## this is where all object file (*.o) generated by tsnnls library makefile are located.
    tsnnl_PATH = /home/dkumar/libtsnnls-2.3.3/tsnnls/

    # Here is a Make Macro that uses the backslash to extend to multiple lines.
    OBJS_tsnnls0 =   libtsnnls_la-taucs_malloc.o libtsnnls_la-taucs_ccs_order.o \
      libtsnnls_la-taucs_ccs_ops.o libtsnnls_la-taucs_vec_base.o \
      libtsnnls_la-taucs_complex.o libtsnnls_la-colamd.o \
      libtsnnls_la-amdbar.o libtsnnls_la-amdexa.o \
      libtsnnls_la-amdtru.o libtsnnls_la-genmmd.o \
      libtsnnls_la-taucs_timer.o libtsnnls_la-taucs_sn_llt.o \
      libtsnnls_la-taucs_ccs_base.o libtsnnls_la-tlsqr.o \
      libtsnnls_la-tsnnls.o libtsnnls_la-lsqr.o

     ## adding "$(OBJS_PATH)" to each word in "$(OBJS)"
    # which in our case is basically to add the same folder in front of all "*.o" object files.
    OBJS_tsnnls = $(addprefix $(tsnnl_PATH), $(OBJS_tsnnls0)) 

    # Libraries for tsnnls
    STLIB_tsnnls   = /usr/local/lib/taucs_full/lib/linux/libtaucs.a 
    LIBS_tsnnls   = -largtable2 -llapack -lblas -lquadmath -lm

    ########################################################################
    TARGET_WO_EXTN =   Test_tsnnls
    TARGET          =   $(TARGET_WO_EXTN)
    LIBS           =   $(LIBS_tsnnls)    $(STLIB_tsnnls)
    INCLUDE        =   $(INCLUDE_TSNNLS)
    REBUILDABLES   =   *.o       $(TARGET) 

    all : $(TARGET)
      echo All done

    clean : 
      rm -f $(REBUILDABLES)  
      echo Clean done

    Include_4_TSNNLS.o:  Include_4_TSNNLS.c
      $(CXX) -c -o Include_4_TSNNLS.o Include_4_TSNNLS.c

    $(TARGET_WO_EXTN).o: $(TARGET_WO_EXTN).c
      $(CXX) -c -o $(TARGET_WO_EXTN).o  $(TARGET_WO_EXTN).c

    # Final linking
    $(TARGET) : $(OBJS_tsnnls)   $(TARGET_WO_EXTN).o   Include_4_TSNNLS.o $(LIBS)
      $(CXX) -g -o $@ $(INCLUDE) $(CFLAGS) $^

Makefile (mex project) DOES NOT work:

    MEXSUFFIX  = mexa64
    MATLABHOME = /usr/local/MATLAB/R2014b
    MEX        = mex
    CXX        = gcc
    CFLAGS     = -fPIC -pthread -DMX_COMPAT_32 \
                   -DMATLAB_MEX_FILE

    INCLUDE_Matlab  = -I$(MATLABHOME)/extern/include
    MEXFLAGS   = -cxx CC='$(CXX)' CXX='$(CXX)' LD='$(CXX)'

    INCLUDE_TSNNLS  = -I/home/dkumar/libtsnnls-2.3.3 -I/home/dkumar/libtsnnls-2.3.3/tsnnls  -I/home/dkumar/libtsnnls-2.3.3/tsnnls/taucs_basic

    #################### ALL TSNNLS lib related ##########################
    ## this is where all object file (*.o) generated by tsnnls library makefile are located.
    tsnnl_PATH = /home/dkumar/libtsnnls-2.3.3/tsnnls/

    # Here is a Make Macro that uses the backslash to extend to multiple lines.
    OBJS_tsnnls0 =   libtsnnls_la-taucs_malloc.o libtsnnls_la-taucs_ccs_order.o \
      libtsnnls_la-taucs_ccs_ops.o libtsnnls_la-taucs_vec_base.o \
      libtsnnls_la-taucs_complex.o libtsnnls_la-colamd.o \
      libtsnnls_la-amdbar.o libtsnnls_la-amdexa.o \
      libtsnnls_la-amdtru.o libtsnnls_la-genmmd.o \
      libtsnnls_la-taucs_timer.o libtsnnls_la-taucs_sn_llt.o \
      libtsnnls_la-taucs_ccs_base.o libtsnnls_la-tlsqr.o \
      libtsnnls_la-tsnnls.o libtsnnls_la-lsqr.o

     ## adding "$(OBJS_PATH)" to each word in "$(OBJS)"
    # which in our case is basically to add the same folder in front of all "*.o" object files.
    OBJS_tsnnls = $(addprefix $(tsnnl_PATH), $(OBJS_tsnnls0)) 

    # Libraries for tsnnls
    STLIB_tsnnls   = /usr/local/lib/taucs_full/lib/linux/libtaucs.a 
    LIBS_tsnnls   = -largtable2 -llapack -lblas -lquadmath -lm

    ########################################################################
    TARGET_WO_EXTN =  Test_tsnnls_Mex
    TARGET         = $(TARGET_WO_EXTN).$(MEXSUFFIX)
    LIBS           = $(LIBS_tsnnls)    $(STLIB_tsnnls)
    INCLUDE        = $(INCLUDE_Matlab)   $(INCLUDE_TSNNLS)
    REBUILDABLES   = *.o       $(TARGET)  

    all : $(TARGET)
      echo All done

    clean : 
      rm -f $(REBUILDABLES)  
      echo Clean done

    Include_4_TSNNLS.o:  Include_4_TSNNLS.c
      $(CXX) $(CFLAGS) $(INCLUDE) -c $^
    ##  $(CXX) -c -o Include_4_TSNNLS.o Include_4_TSNNLS.c

    $(TARGET_WO_EXTN).o: $(TARGET_WO_EXTN).c
      $(CXX) $(CFLAGS) $(INCLUDE) -c $^

    # Final linking
    $(TARGET): $(OBJS_tsnnls)   $(TARGET_WO_EXTN).o   Include_4_TSNNLS.o $(LIBS)
      $(MEX) $(MEXFLAGS) $(LIBS) -output $(TARGET_WO_EXTN) $^

Errors that I get

    dkumar@dkumar-Precision-WorkStation-T7500 ~/Mex_Codes_DKU/Using_tsnnls_DKU_copy_MEX/Pure_Mex $ make
    cc -fPIC -pthread -DMX_COMPAT_32 -DMATLAB_MEX_FILE   -c -o Test_tsnnls_Mex.o Test_tsnnls_Mex.c
    gcc -c -o Include_4_TSNNLS.o Include_4_TSNNLS.c
    In file included from Include_4_TSNNLS.c:1:0:
    Include_4_TSNNLS.h:72:15: warning: useless storage class specifier in empty declaration [enabled by default]
       extern enum STYPE;
                   ^
    mex -cxx CC='gcc' CXX='gcc' LD='gcc' -largtable2 -llapack -lblas -lquadmath -lm    /usr/local/lib/taucs_full/lib/linux/libtaucs.a  -output Test_tsnnls_Mex /home/dkumar/libtsnnls-2.3.3/tsnnls/libtsnnls_la-taucs_malloc.o /home/dkumar/libtsnnls-2.3.3/tsnnls/libtsnnls_la-taucs_ccs_order.o /home/dkumar/libtsnnls-2.3.3/tsnnls/libtsnnls_la-taucs_ccs_ops.o /home/dkumar/libtsnnls-2.3.3/tsnnls/libtsnnls_la-taucs_vec_base.o /home/dkumar/libtsnnls-2.3.3/tsnnls/libtsnnls_la-taucs_complex.o /home/dkumar/libtsnnls-2.3.3/tsnnls/libtsnnls_la-colamd.o /home/dkumar/libtsnnls-2.3.3/tsnnls/libtsnnls_la-amdbar.o /home/dkumar/libtsnnls-2.3.3/tsnnls/libtsnnls_la-amdexa.o /home/dkumar/libtsnnls-2.3.3/tsnnls/libtsnnls_la-amdtru.o /home/dkumar/libtsnnls-2.3.3/tsnnls/libtsnnls_la-genmmd.o /home/dkumar/libtsnnls-2.3.3/tsnnls/libtsnnls_la-taucs_timer.o /home/dkumar/libtsnnls-2.3.3/tsnnls/libtsnnls_la-taucs_sn_llt.o /home/dkumar/libtsnnls-2.3.3/tsnnls/libtsnnls_la-taucs_ccs_base.o /home/dkumar/libtsnnls-2.3.3/tsnnls/libtsnnls_la-tlsqr.o /home/dkumar/libtsnnls-2.3.3/tsnnls/libtsnnls_la-tsnnls.o /home/dkumar/libtsnnls-2.3.3/tsnnls/libtsnnls_la-lsqr.o Test_tsnnls_Mex.o Include_4_TSNNLS.o /usr/local/lib/libargtable2.so /usr/lib/liblapack.so /usr/lib/libblas.so /usr/lib/libquadmath.so /usr/lib/x86_64-linux-gnu/libm.so /usr/local/lib/taucs_full/lib/linux/libtaucs.a
    Building with 'g++'.
    Warning: You are using gcc version '4.8.2'. The version of gcc is not supported. The version currently supported with MEX is '4.7.x'. For a list of currently supported compilers see: http://www.mathworks.com/support/compilers/current_release.
    Warning: You are using gcc version '4.8.2-19ubuntu1)'. The version of gcc is not supported. The version currently supported with MEX is '4.7.x'. For a list of currently supported compilers see: http://www.mathworks.com/support/compilers/current_release.
    /usr/bin/ld: /home/dkumar/libtsnnls-2.3.3/tsnnls/libtsnnls_la-taucs_ccs_order.o: relocation R_X86_64_32 against `.rodata' can not be used when making a shared object; recompile with -fPIC
    /home/dkumar/libtsnnls-2.3.3/tsnnls/libtsnnls_la-taucs_ccs_order.o: error adding symbols: Bad value
    collect2: error: ld returned 1 exit status

    make: *** [Test_tsnnls_Mex.mexa64] Error 255

I think that I am already compiling with -fPIC. My understanding is that `$(OBJS_tsnnls)` may not properly included in my mex project.

OR, issue could be with 32-bit vs 64 bit platform [http://stackoverflow.com/questions/9637551/relocation-r-x86-64-32s-against-rodata-while-compiling-on-64-bit-platform]. I have no idea how to fix this.

Any help would be so very much appreciated.