我在一个项目中使用cgo,我想导出一个函数供使用.这是我想要实现的一个例子：
package csplit
import (
"C"
"strings"
)
//export Split
/* The Split function takes two C strings,the second of which represents
a substring to split on,and returns an array of strings. Example:
Split("1,2",",") // gives ["1","2"]
*/
func Split(original *C.char,split *C.char) []*C.char {
goResult := strings.Split(C.GoString(original),C.GoString(split))
cResult := make([]*C.char,len(goResult))
for idx,substring := range goResult {
cResult[idx] = C.CString(substring)
}
return cResult
}
问题是返回类型是Go分配数据,而不是移入C堆.这有点恐慌：运行时错误：cgo结果有Go指针
解决方法
您将返回在Go中分配的Go切片,并且是与C数组不同的结构.你需要在C中分配一个数组：
//export Split
func Split(original *C.char,split *C.char) **C.char {
goResult := strings.Split(C.GoString(original),C.GoString(split))
cArray := C.malloc(C.size_t(len(goResult)) * C.size_t(unsafe.Sizeof(uintptr(0))))
// convert the C array to a Go Array so we can index it
a := (*[1<<30 - 1]*C.char)(cArray)
for idx,substring := range goResult {
a[idx] = C.CString(substring)
}
return (**C.char)(cArray)
}
