when export go func to c, the interface type port to GoInterface, and int to GoInt. How to port my c funcs to go with these types?
a.h
void *SomeFunc(GoInterface arg);
a.c
void *SomeFunc(GoInterface arg) {
}
a.go
package main
// #include "a.h"
import "C"
type A struct {
}
func main() {
var a = new(A)
}
when I go build:
cc errors for preamble:
In file included from ./a.go:3:0:
a.h:1:16: error: unknown type name 'GoInterface'
void *SomeFunc(GoInterface arg)
Is there a header file for go like jni.h for java, So I can include there types.
No, Go doesn't have any way to export types as "C readable". Further, you cannot reference a Go struct from within C, and it is not safe to try and finagle a C struct to "look like" a Go struct since you have no control over memory layout.
The "right" way to do this is to create a type in a C file and add it as a field in the Go struct:
// from C
typedef struct x {
// fields
} x;
// From Go, include your .h file that defines this type.
type X struct {
c C.x
}
Then operate on your type that way, and pass C.x into all your C functions instead of x.
There are a couple other ways, (for instance, converting between them any time you want to use it as one or the other), but this one is the best in a vague general sense.
Edit: a FEW Go types can be represented in C, for instance, int64 will be defined in code that's compiled via cgo, but for the most part what I said holds.