CODEWITHSUNDEEP
c++cclionmingw-w64
AGSoldier
AGSoldier

Reputation: 3

Cannot properly use C++ static library in C program (Mingw64 with CLion)

I'm trying to make a simple C++ static library to use with a C program. My files are the following.

// strarr.h
#pragma once

#include <stdio.h>

#ifdef __cplusplus
extern "C"
{
#endif
    typedef char **str_arr;
    str_arr new_str_arr(size_t size);
    void del_str_arr(str_arr arr, size_t size);
    str_arr resize_str_arr(str_arr arr, size_t arr_size, size_t new_size);
    size_t add_str(str_arr arr, size_t index, char *str);
#ifdef __cplusplus
}
#endif

void print_arr(str_arr arr, size_t size);

// strarr.c
#include "strarr.h"

#include <stdlib.h>

str_arr new_str_arr(size_t size)
{
    str_arr arr = (str_arr)calloc(size, sizeof(char*));
    if (arr == NULL) return NULL;

    for (size_t i = 0; i < size; i++)
    {
        arr[i] = (char*)calloc(1, sizeof(char));
        if (arr[i] == NULL) return NULL;
    }

    return arr;
}

void del_str_arr(str_arr arr, size_t size)
{
    for (size_t i = 0; i < size; i++)
    {
        free(arr[i]);
        arr[i] = NULL;
    }

    free(arr);
    arr = NULL;
}

str_arr resize_str_arr(str_arr arr, size_t arr_size, size_t new_size)
{
    return NULL;
}

size_t add_str(str_arr arr, size_t index, char* str)
{
    return 0;
}

// strarr.cpp
#include "strarr.h"

#include <iostream>

void print_arr(str_arr arr, size_t size)
{
    for (size_t i = 0; i < size; i++)
        std::cout << i << ": " << arr[i] << std::endl;
}

I'm compiling manually with the following commands

g++ -c strarr.c -o bin/static/strarr.o
g++ -lstdc++ -c strarr.cpp -o bin/static/strarrcpp.o
ar rvs bin/static/libqbb.a bin/static/strarr.o bin/static/strarrcpp.o

I've imported the successfully built library in a C project, but while building it spits out this error.

====================[ Build | all | Debug ]=====================================
C:\Users\AGSoldier\AppData\Local\JetBrains\Toolbox\apps\CLion\ch-0\202.6397.106\bin\cmake\win\bin\cmake.exe --build "D:\AGSoldier\Sidereal Works\Qbb\qbb_test\build" --target all -- -j 3
Scanning dependencies of target qbb_test
[ 50%] Building C object CMakeFiles/qbb_test.dir/main.c.obj
[100%] Linking C executable qbb_test.exe
CMakeFiles\qbb_test.dir/objects.a(main.c.obj): In function `main':
D:/AGSoldier/Sidereal Works/Qbb/qbb_test/main.c:468: undefined reference to `print_arr'
collect2.exe: error: ld returned 1 exit status
mingw32-make.exe[2]: *** [CMakeFiles\qbb_test.dir\build.make:107: qbb_test.exe] Error 1
mingw32-make.exe[1]: *** [CMakeFiles\Makefile2:95: CMakeFiles/qbb_test.dir/all] Error 2
mingw32-make.exe: *** [Makefile:103: all] Error 2

What an I doing wrong? I googled for a few hours without any result.

Upvotes: 0

Views: 101

Answers (1)

JSalaun
JSalaun

Reputation: 41

You need to put the declaration

void print_arr(str_arr arr, size_t size);

into the extern C scope if you are going to call that function from a *.c file.

Upvotes: 1

Related Questions