CGO undefined reference in included files

Question

Wraping up OpenJtalk in Go, files are successfully included and types are referenced without an issue, but functions trigger an undefined reference error.

jtalk.go:

package main

// #cgo CFLAGS: -I/home/vagrant/open_jtalk/njd [...etc]
/*
#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <string.h>
#include <math.h>

// Main headers 
#include "mecab.h"
#include "njd.h"
#include "jpcommon.h"
#include "HTS_engine.h"

// Sub headers 
#include "text2mecab.h"
#include "mecab2njd.h"
#include "njd_set_pronunciation.h"
#include "njd_set_digit.h"
#include "njd_set_accent_phrase.h"
#include "njd_set_accent_type.h"
#include "njd_set_unvoiced_vowel.h"
#include "njd_set_long_vowel.h"
#include "njd2jpcommon.h"
*/
import "C"

type Open_JTalk struct {
   mecab C.Mecab           each of these struct references are fine
   njd C.NJD 
   jpcommon C.JPCommon 
   engine C.HTS_Engine 
}

func (open_jtalk *Open_JTalk) Open_JTalk_initialize() {
   C.Mecab_initialize(&open_jtalk.mecab)             // when any function is called the error happens
   C.NJD_initialize(&open_jtalk.njd)
   C.JPCommon_initialize(&open_jtalk.jpcommon)
   C.HTS_Engine_initialize(&open_jtalk.engine)
}

func main() {

}

And the weird part is that those same functions are declared right after the types:

mecab.h

// line 1584
typedef struct _Mecab{
   char **feature;
   int size;
   mecab_t *mecab;
} Mecab;

BOOL Mecab_initialize(Mecab *m);

Project webpage: http://open-jtalk.sourceforge.net/

Answer 1

You need to add cgo linker options (LDFLAGS) with the path to and the name of your library. e.g.

// #cgo CFLAGS: -Iyour-include-path
// #cgo LDFLAGS: -Lyour-library-path -lyour-library-name-minus-the-lib-part