C/C++调用Golang 一

(开发环境:

  1. 操作系统: windows 7 32位操作系统
  2. C++: visual studio 2010
  3. Golang:go version go1.9 windows/386 TDM-GCC-32)

用一个简单的例子演示如何在C++中调用golang程序。用golang编写一个简单的函数,编译成动态链接库,然后在C++中调用该go函数。

第一阶段将Golang代码编译成动态链接库 (涉及2个文件 main.go和godll.def)

Golang : main.go 一个简单的Add函数

package main

import "C"

//export Add

func Add(a, b int32) int32 {

return a + b

}

func main() {}

为动态链接库指定导出符号,创建godll.def

EXPORTS

Add

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将main.go编译成动态链接库,在命令行中执行如下操作:

go build -buildmode=c-archive

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go build 生成了两个文件:godll.a godll.h

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再执行gcc -m32 -shared -o godll.dll godll.def godll.a -static -lwinmm -lWs2_32

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(需要安装 TDM-GCC-32)

编译后生成godll.dll

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godll.h和godll.dll是C++工程需要的,godll.h的内容如下:

/* Created by "go tool cgo" - DO NOT EDIT. */

/* package _/Y_/godll */

/* Start of preamble from import "C" comments. */

/* End of preamble from import "C" comments. */

/* Start of boilerplate cgo prologue. */

#line 1 "cgo-gcc-export-header-prolog"

#ifndef GO_CGO_PROLOGUE_H

#define GO_CGO_PROLOGUE_H

typedef signed char GoInt8;

typedef unsigned char GoUint8;

typedef short GoInt16;

typedef unsigned short GoUint16;

typedef int GoInt32;

typedef unsigned int GoUint32;

typedef long long GoInt64;

typedef unsigned long long GoUint64;

typedef GoInt32 GoInt;

typedef GoUint32 GoUint;

typedef __SIZE_TYPE__ GoUintptr;

typedef float GoFloat32;

typedef double GoFloat64;

typedef float _Complex GoComplex64;

typedef double _Complex GoComplex128;

/*

static assertion to make sure the file is being used on architecture

at least with matching size of GoInt.

*/

typedef char _check_for_32_bit_pointer_matching_GoInt[sizeof(void*)==32/8 ? 1:-1];

typedef struct { const char *p; GoInt n; } GoString;

typedef void *GoMap;

typedef void *GoChan;

typedef struct { void *t; void *v; } GoInterface;

typedef struct { void *data; GoInt len; GoInt cap; } GoSlice;

#endif

/* End of boilerplate cgo prologue. */

#ifdef __cplusplus

extern "C" {

#endif

extern GoInt32 Add(GoInt32 p0, GoInt32 p1);

#ifdef __cplusplus

}

#endif

extern GoInt32 Add(GoInt32 p0, GoInt32 p1);是导出函数的签名。

用depends22_x86 查看 godll.dll

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第二阶段在C++工程中调用godll.dll

创建名为callgo的vs 2010工程,将godll.h加入到工程,新建main.cpp的源文件:

#include<Windows.h>

#include<stdio.h>

#include"godll.h"

typedefGoInt32 (*funcPtrAdd)(GoInt32 p0, GoInt32 p1);

intmain(){

HMODULE h = LoadLibraryA("godll.dll");

if(NULL == h || INVALID_HANDLE_VALUE == h)

{

return-1;

}

funcPtrAdd pfAdd = (funcPtrAdd)GetProcAddress(h,"Add");

if(pfAdd)

{

GoInt32 result = pfAdd(5,4);

printf("Add(5,4) = %d",result);

}

FreeLibrary(h);

return0;

}

将godll.h中的三行注释掉

//typedef __SIZE_TYPE__ GoUintptr;

typedeffloatGoFloat32;

typedefdoubleGoFloat64;

//typedef float _Complex GoComplex64;

//typedef double _Complex GoComplex128;

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编译运行,结果如下图:

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注意事项:

main.go中 import "C" 这一行一定要有,否则gcc编译时会报符号未定义的错误:

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