cgo：体系结构 x86_64 的未定义符号

Question

我想从 C 函数空间调用 go func，但程序抛出构建错误。

例子.go

package main

/*

#include "test.c"

*/

import "C"

import "fmt"

func Example() {

    fmt.Println("this is go")

    fmt.Println(C.GoString(C.myprint(C.CString("go!!"))))

}

// export receiveC              (remove the extra space between // and export)

func receiveC(msg *C.char) {

    fmt.Println(C.GoString(msg))

}

func main() {

    Example()

}

测试.c

#include <stdio.h>

extern void receiveC(char *msg);

char* myprint(char *msg) {

    receiveC(msg);  // calling the exported go function

    return msg;     

    }

当我执行命令来运行/构建（go build或go run example.go或go build example.go）程序时，它会抛出错误：

# github.com/subh007/goodl/cgo

Undefined symbols for architecture x86_64:

  "_receiveC", referenced from:

      _myprint in example.cgo2.o

      __cgo_6037ec60b2ba_Cfunc_myprint in example.cgo2.o

      _myprint in test.o

ld: symbol(s) not found for architecture x86_64

clang: error: linker command failed with exit code 1 (use -v to see invocation)

我正在按照cgo 幻灯片编写程序。请让我知道这里的任何错误。

编辑 1：我使用的是 OS-X 10.9 操作系统。

EDIT2：我之间的一个额外的空间// export，应该有之间没有空格//和export。但是现在我在构建时遇到以下错误：

# github.com/subh007/goodl/cgo

duplicate symbol _myprint in:

    $WORK/github.com/subh007/goodl/cgo/_obj/_cgo_export.o

    $WORK/github.com/subh007/goodl/cgo/_obj/example.cgo2.o

duplicate symbol _receiver_go in:

    $WORK/github.com/subh007/goodl/cgo/_obj/_cgo_export.o

    $WORK/github.com/subh007/goodl/cgo/_obj/example.cgo2.o

duplicate symbol _myprint in:

    $WORK/github.com/subh007/goodl/cgo/_obj/_cgo_export.o

    $WORK/github.com/subh007/goodl/cgo/_obj/test.o

duplicate symbol _receiver_go in:

    $WORK/github.com/subh007/goodl/cgo/_obj/_cgo_export.o

    $WORK/github.com/subh007/goodl/cgo/_obj/test.o

ld: 4 duplicate symbols for architecture x86_64

clang: error: linker command failed with exit code 1 (use -v to see invocation)