How to compile Apache Avro C++ example

Question

Probably a newbie mistake, but can anyone please tell me what I'm doing wrong here?
Any help is much appreciated.

I wrote this simple Makefile:

CC=g++
INC=-I/usr/local/avro-cpp-1.7.2 -I/usr/local/boost_1_53_0

cpx : generated.cc
        $(CC) -o cpx generated.cc $(INC)

Which generates these the errors:

g++ -o cpx generated.cc -I/usr/local/avro-cpp-1.7.2 -I/usr/local/boost_1_53_0
/tmp/ccYymUVo.o: In function `main':
generated.cc:(.text+0x84): undefined reference to `avro::memoryOutputStream(unsigned long)'
generated.cc:(.text+0xb0): undefined reference to `avro::binaryEncoder()'
generated.cc:(.text+0x11e): undefined reference to `avro::memoryInputStream(avro::OutputStream const&)'
generated.cc:(.text+0x150): undefined reference to `avro::binaryDecoder()'
collect2: ld returned 1 exit status
make: *** [cpx] Error 1

Here's the source as supplied in the Avro examples directory:

#############################
# cpx.hh
#############################
#ifndef CPX_HH_1278398428__H_
#define CPX_HH_1278398428__H_

#include "boost/any.hpp"
#include "avro/Specific.hh"
#include "avro/Encoder.hh"
#include "avro/Decoder.hh"

namespace c {
struct cpx {
    double re;
    double im;
};

}
namespace avro {
template<> struct codec_traits<c::cpx> {
    static void encode(Encoder& e, const c::cpx& v) {
        avro::encode(e, v.re);
        avro::encode(e, v.im);
    }
    static void decode(Decoder& d, c::cpx& v) {
        avro::decode(d, v.re);
        avro::decode(d, v.im);
    }
};

}
#endif

and

#############################
# generated.cc
#############################
#include "cpx.hh"
#include "avro/Encoder.hh"
#include "avro/Decoder.hh"

int
main()
{
    std::auto_ptr<avro::OutputStream> out = avro::memoryOutputStream();
    avro::EncoderPtr e = avro::binaryEncoder();
    e->init(*out);
    c::cpx c1;
    c1.re = 1.0;
    c1.im = 2.13;
    avro::encode(*e, c1);

    std::auto_ptr<avro::InputStream> in = avro::memoryInputStream(*out);
    avro::DecoderPtr d = avro::binaryDecoder();
    d->init(*in);

    c::cpx c2;
    avro::decode(*d, c2);
    std::cout << '(' << c2.re << ", " << c2.im << ')' << std::endl;
    return 0;
}

Thanks.

Answer 1

1)

in your output, you don't link against the avrocpp library, although your comments about the LD_LIBRARY_PATH suggest that you got the link to work, but the example program failed to find the library when executing. Your compile line needs the linker option: -l avrocpp

2)

If the avrocpp library .so is not installed in a path that your runtime linker is configured to search, you can add the library path into the binary itself with the linker option -rpath.

Example 1: Assuming your avrocpp library is installed in /usr/local/lib (i.e. /usr/local/lib/libavrocpp.so), and your runtime linker doesn't look in /usr/local/lib, add the rpath by adding this option to your compiler command line:

-Wl,-rpath,/usr/local/lib

Example 2: Assuming your avrocpp library is installed in /usr/local/avro-cpp-1.7.2/lib (i.e. /usr/local/avro-cpp-1.7.2/lib/libavrocpp.so), add the rpath by adding this option to your compiler command line:

-Wl,-rpath,/usr/local/avro-cpp-1.7.2/lib