如何在 Go 中使用 C++
在新的 Go 语言中，我如何调用 C++ 代码?换句话说，我如何包装我的 C++ 类并在 Go 中使用它们?
In the new Go language, how do I call C++ code? In other words, how can I wrap my C++ classes and use them in Go?
推荐答案
更新:我已经成功地将一个小型测试 C++ 类与 Go 链接起来
Update: I've succeeded in linking a small test C++ class with Go
如果您使用 C 接口包装 C++ 代码，您应该能够使用 cgo 调用您的库(请参阅 $GOROOT/misc/cgo/gmp 中的 gmp 示例).
If you wrap you C++ code with a C interface you should be able to call your library with cgo (see the example of gmp in $GOROOT/misc/cgo/gmp).
我不确定 C++ 中类的想法是否真的可以在 Go 中表达，因为它没有继承.
I'm not sure if the idea of a class in C++ is really expressible in Go, as it doesn't have inheritance.
这是一个例子:
我有一个 C++ 类定义为:
I have a C++ class defined as:
// foo.hpp
class cxxFoo {
public:
int a;
cxxFoo(int _a):a(_a){};
~cxxFoo(){};
void Bar();
};
// foo.cpp
#include <iostream>
#include "foo.hpp"
void
cxxFoo::Bar(void){
std::cout<<this->a<<std::endl;
}
我想在 Go 中使用.我会用C接口
which I want to use in Go. I'll use the C interface
// foo.h
#ifdef __cplusplus
extern "C" {
#endif
typedef void* Foo;
Foo FooInit(void);
void FooFree(Foo);
void FooBar(Foo);
#ifdef __cplusplus
}
#endif
(我使用 void* 而不是 C 结构，所以编译器知道 Foo 的大小)
(I use a void* instead of a C struct so the compiler knows the size of Foo)
实现是:
//cfoo.cpp
#include "foo.hpp"
#include "foo.h"
Foo FooInit()
{
cxxFoo * ret = new cxxFoo(1);
return (void*)ret;
}
void FooFree(Foo f)
{
cxxFoo * foo = (cxxFoo*)f;
delete foo;
}
void FooBar(Foo f)
{
cxxFoo * foo = (cxxFoo*)f;
foo->Bar();
}
完成所有这些后，Go 文件是:
with all that done, the Go file is:
// foo.go
package foo
// #include "foo.h"
import "C"
import "unsafe"
type GoFoo struct {
foo C.Foo;
}
func New()(GoFoo){
var ret GoFoo;
ret.foo = C.FooInit();
return ret;
}
func (f GoFoo)Free(){
C.FooFree(unsafe.Pointer(f.foo));
}
func (f GoFoo)Bar(){
C.FooBar(unsafe.Pointer(f.foo));
}
我用来编译这个的makefile是:
The makefile I used to compile this was:
// makefile
TARG=foo
CGOFILES=foo.go
include $(GOROOT)/src/Make.$(GOARCH)
include $(GOROOT)/src/Make.pkg
foo.o:foo.cpp
g++ $(_CGO_CFLAGS_$(GOARCH)) -fPIC -O2 -o $@ -c $(CGO_CFLAGS) $<
cfoo.o:cfoo.cpp
g++ $(_CGO_CFLAGS_$(GOARCH)) -fPIC -O2 -o $@ -c $(CGO_CFLAGS) $<
CGO_LDFLAGS+=-lstdc++
$(elem)_foo.so: foo.cgo4.o foo.o cfoo.o
gcc $(_CGO_CFLAGS_$(GOARCH)) $(_CGO_LDFLAGS_$(GOOS)) -o $@ $^ $(CGO_LDFLAGS)
尝试使用以下方法进行测试:
Try testing it with:
// foo_test.go
package foo
import "testing"
func TestFoo(t *testing.T){
foo := New();
foo.Bar();
foo.Free();
}
您需要使用 make install 安装共享库，然后运行 ??make test.预期输出为:
You'll need to install the shared library with make install, then run make test. Expected output is:
gotest
rm -f _test/foo.a _gotest_.6
6g -o _gotest_.6 foo.cgo1.go foo.cgo2.go foo_test.go
rm -f _test/foo.a
gopack grc _test/foo.a _gotest_.6 foo.cgo3.6
1
PASS