在cgo中，如何用go func arg调用c方法

Question

以下是我的代码，希望go能捕获c代码的进度

package main

/*
#cgo CFLAGS: -I/home/roroco/Downloads/go/test_cgo/submodule/test_cgo_cpp/include
#cgo LDFLAGS: -L/home/roroco/Downloads/go/test_cgo/submodule/test_cgo_cpp/cmake-build-debug -ltest_cgo -Wl,-rpath=/home/roroco/Downloads/go/test_cgo/submodule/test_cgo_cpp/cmake-build-debug
#include "test_cgo.h"
*/
import "C"
import (
    "fmt"
    "unsafe"
)

//export goProgressCallbackHandler
func goProgressCallbackHandler(progress C.uint32_t) {
    fmt.Printf("Progress: %d%%\n", progress)
}

func main() {
    C.simulateProgress(unsafe.Pointer(C.goProgressCallbackHandler))
}

test_cgo.h

#ifndef PROGRESS_H
#define PROGRESS_H

#include <stdint.h>

#ifdef __cplusplus
extern "C" {
#endif

// Function prototype for the callback
typedef void (*progressCallback)(uint32_t);

// Function to simulate progress update in C++
void simulateProgress(void *fnHandle);

#ifdef __cplusplus
}
#endif

#endif // PROGRESS_H

test_cgo.cpp

#include "test_cgo.h"

extern "C" {
void simulateProgress(void *fnHandle) {
    progressCallback cb = (progressCallback) fnHandle;
    for (uint32_t i = 0; i <= 100; i += 10) {
        cb(i);  // Call the callback function with the current progress
    }
}
}

cgo 抛出错误

# command-line-arguments
./test_cgo.go:20:36: could not determine kind of name for C.goProgressCallbackHandler

如何使cgo代码工作

Answer 1

我修复了它，我应该添加

extern void goProgressCallbackHandlerProxy(uint32_t progress);

以使

C.goProgressCallbackHandlerProxy

存在

以下是完整代码

package main

/*
#cgo CFLAGS: -I/home/roroco/Downloads/go/test_cgo/submodule/test_cgo_cpp/include
#cgo LDFLAGS: -L/home/roroco/Downloads/go/test_cgo/submodule/test_cgo_cpp/cmake-build-debug -ltest_cgo -Wl,-rpath=/home/roroco/Downloads/go/test_cgo/submodule/test_cgo_cpp/cmake-build-debug
#include "test_cgo.h"

// Define a proxy function to call the Go callback handler from C
extern void goProgressCallbackHandlerProxy(uint32_t progress);
*/
import "C"
import (
    "fmt"
    "unsafe"
)

//export goProgressCallbackHandlerProxy
func goProgressCallbackHandlerProxy(progress C.uint32_t) {
    fmt.Printf("Progress: %d%%\n", uint32(progress))
}

func main() {
    // Convert Go function to a C function pointer (void*)
    callbackPointer := unsafe.Pointer(C.goProgressCallbackHandlerProxy)

    // Call C++ function via CGO with the callback function pointer
    C.simulateProgress(callbackPointer)
}