cgo turns typedef void* function arguments into unsafe.Pointer #254
Description
by eden.li:
What steps will reproduce the problem?
$ cat <<EOF > lazy_func_arg.go
package cgo_lazy_func_args
/*
struct st { int i; };
typedef struct st *st_st;
typedef void *vptr;
void testArgs(vptr expectVptr, st_st expectStructPtr) { };
*/
import "C"
func main() {
var (
a C.vptr = nil;
b C.st_st = nil;
);
C.testArgs(a, b)
}
EOF
$ cgo lazy_func_arg.go
$ 6g -o /dev/null lazy_func_arg.cgo[12].go
lazy_func_arg.cgo1.go:18: cannot use a (type _C_vptr) as type unsafe.Pointer
What is the expected output? What do you see instead?
Since Go treats unsafe.Pointer in a special way, the lax C rule-emulation
in cgo/gcc.go is too aggressive in this case. It should leave vptr alone
and render the Go-side declaration as:
func _C_testArgs(_C_vptr, *_Cstruct_st)
Instead of:
func _C_testArgs(unsafe.Pointer, *_Cstruct_st)
What is your $GOOS? $GOARCH?
darwin amd64
Which revision are you sync'ed to? (hg log -l 1)
changeset: 4110:89320216c4da
date: Tue Nov 17 20:44:35 2009 -0800