hello.h

#ifndef HELLO_H_
#define HELLO_H_

#ifdef __cplusplus
extern "C" {
#endif

extern int hello(char *name, int age);

#ifdef __cplusplus
}
#endif

#endif // HELLO_H_

hello.c

#include <stdio.h>
#include "hello.h"

int hello(char *name, int age) {
    printf("Hello %s, your age is %d.\n"
 
, name, age);
    return age;
}

test.go

package main

/*
#cgo CFLAGS: -I.
#cgo LDFLAGS: -L. -lhello
#include <stdio.h>
#include <stdlib.h>
#include "hello.h"
*/
import "C"
import (
    "fmt"
    "unsafe"
)

func main() {
    name := C.CString("Jack")
    defer C.free(unsafe.Pointer(name)
 
)
    age := C.int(18)

    result := C.hello(name, age)
    fmt.Println(result)
}

編譯 C 程式碼：

gcc -Wall -c hello.c
ar -rv libhello.a hello.o

遇到的報錯

could not determine kind of name for C.free

• /* ... */ cgo 註釋部分和 import "C" 之間存在空行
• 沒有匯入 #include <stdlib.h>

參考

https://golang.org/cmd/cgo/