从c调用go函数时出错

Question

新来这里。试图从C调用go函数，但遇到了一些编译问题

这是go脚本

package main
// #cgo CFLAGS: -Wno-error=implicit-function-declaration
// #include <stdlib.h> 
// #include "wrapper.c"
import "C"
//import "unsafe"
import "fmt"
//import "time"

//export dummy
func dummy() int {
    fmt.Println("hi you");
    return 0
}

func main() {
    C.testc()
}

这是包装器

#include <sys/types.h>
#include <stdio.h>
#include <errno.h>
#include <string.h>

extern int dummy();

void testc(){
    dummy();
}

运行时，会出现错误

xyz@xyz-HP:~/learn/go$ go run reader.go 
# command-line-arguments
In file included from $WORK/command-line-arguments/_obj/_cgo_export.c:2:0:
reader.go:30:14: error: conflicting types for ‘dummy’
In file included from reader.go:3:0,
                 from $WORK/command-line-arguments/_obj/_cgo_export.c:2:
./wrapper.c:6:12: note: previous declaration of ‘dummy’ was here
/tmp/go-build528677551/command-line-arguments/_obj/_cgo_export.c:8:7: error: conflicting types for ‘dummy’
In file included from reader.go:3:0,
                 from $WORK/command-line-arguments/_obj/_cgo_export.c:2:
./wrapper.c:6:12: note: previous declaration of ‘dummy’ was here

Answer 1

您不需要在C文件中声明dummy。下面是我如何拆分您的代码以使其工作。我将C函数导出到一个.h文件中，体本身放在一个.c文件中，并且只在go代码中包含h文件。

杜梅(dumy.h)

void testc();

dumy.c

#include <sys/types.h>
#include <stdio.h>
#include <errno.h>
#include <string.h>


void testc(){
    dummy();
}

main.go

package main

// #cgo CFLAGS: -Wno-error=implicit-function-declaration
// #include <stdlib.h>
// #include "dummy.h"
import "C"

import "fmt"

//export dummy
func dummy() int {
    fmt.Println("hi you")
    return 0
}

func main() {
    C.testc()
}