C/C++生成静态库动态库及语言交互

• C++静态库与动态库（比较透彻）
• Go中调用C的动态库与静态库

我的示例

• 文件结构

    |- sample
        |- c
            |- libsample
                |- libsample.h
                |- libsample.cpp
        |- g
            |- main.go

• libsample.h

#ifdef __cplusplus
extern "C" {
#endif
int add(int a, int b);
#ifdef __cplusplus
}
#endif

• libsample.cpp

#include "libsample.h"

int add(int a, int b)
{
    return a + b;
}

• 编译生成静态库

g++ -c libsample.cpp -o libsample.o
ar -crv libsample.a libsample.o

• main.go

package main

/*
#cgo CFLAGS: -I../c/libsample
#cgo LDFLAGS: -L../c/libsample -lsample
#include "libsample.h"
*/
import "C"
import "fmt"

func main() {
	fmt.Println("hello world")
	ret := C.add(11, 23)
	fmt.Println(ret)
}

• 运行一下看看效果

$ go run main.go
hello world
34

• 编译成动态（共享）库

g++ -fPIC -shared -o libsample.so libsample.cpp

• 运行一下看看效果

$ go run main.go
dyld: Library not loaded: libsample.so
  Referenced from: /var/folders/t0/4pythctd2ygbjp8sprsxp4vh0000gp/T/go-build106945710/b001/exe/main
  Reason: image not found
signal: abort trap

• 这是因为在Go的目录里面找不到libsample.so,需要把动态库文件拷贝到和Go生成的main同目录下，再次运行即可。