思路
将 C++ 库包装成 C 库 -> golang 通过 cgo 调用 C 库
C ++ 相关文件
目录列表
- include/
- some.h C++ 库头文件
- some_wrapper.h <= 用于将 C++ 库包装成 C 库的头文件
- lib/
- libsome.a C++ 库
- src/
- some_wrapper.cpp <= 用于将 C++ 库包装成 C 库的源码文件
源码示例
some.h
#ifndef SOME_H
#define SOME_H
#include <string>
#include <utility>
#include <vector>
namespace Some {
struct DeviceInfo {
std::string id;
};
std::vector<std::pair<std::string, std::string>> Generate(const DeviceInfo& device);
}
#endif // SOME_H
some_wrapper.h
#ifndef SOME_WRAPPER_H
#define SOME_WRAPPER_H
#ifdef __cplusplus
extern "C" {
#endif
struct some_item {
char version[8];
char value[32];
};
struct some_result {
struct some_item data[1];
int size;
};
int generate(struct some_result* result, char* id);
#ifdef __cplusplus
}
#endif
#endif // SOME_WRAPPER_H
some_wrapper.cpp
#include <string.h>
#include "some.h"
#include "some_wrapper.h"
#ifdef __cplusplus
extern "C" {
#endif
int generate(struct some_result* result, char* id) {
Some::DeviceInfo deviceInfo;
deviceInfo.id = id;
auto v = Some::Generate(deviceInfo);
strcpy(result->data[0].version, v.first.data());
strcpy(result->data[0].value, v.second.data());
result->size = 1;
return 0;
}
#ifdef __cplusplus
}
#endif
将 C++ 库包装成 C 库
# 编译生成 src/some_wrapper.o 临时目标文件 g++ -c -Iinclude src/some_wrapper.cpp -o src/some_wrapper.o # 生成静态库 lib/libsomewrapper.a ar -cr lib/libsomewrapper.a src/some_wrapper.o # 删除临时目标文件 rm -rf src/some_wrapper.o
Golang CGO 调用 C 库
package main
// #cgo CFLAGS: -I ${SRCDIR}/include
// #cgo LDFLAGS: -L ${SRCDIR}/lib -lsomewrapper -lsome -lstdc++
// #include <stdlib.h>
// #include "some_wrapper.h"
import "C"
import (
"unsafe"
)
type DeviceInfo struct {
ID string `json:"id"`
}
func main() {
di := DeviceInfo{
ID: "123456",
}
cID:= C.CString(di.ID)
defer C.free(unsafe.Pointer(cID))
some := &C.struct_some_result{}
C.generate(some, cId)
if len(some.data) > 0 {
item := some.data[0]
version := C.GoStringN(&(item.version[0]), 8)
value := C.GoStringN(&(item.value[0]), 32)
result := make(map[string]string, someSize)
result[version] = value
someSize := int(some.size)
fmt.Println(result, someSize)
}
}
# 编译 go 文件 go install -v # 运行 $GOPATH/bin/demo
参考
- https://pkg.go.dev/cmd/cgo
- https://stackoverflow.com/questions/41811563/do-i-have-to-free-structs-created-with-cgo
