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// Copyright 2014 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package reflect
import (
"unsafe"
)
// The makeFuncFFI function, written in C, fills in an FFI closure.
// It arranges for ffiCall to be invoked directly from FFI.
func makeFuncFFI(ftyp *funcType, impl unsafe.Pointer)
// FFICallbackGo implements the Go side of the libffi callback.
// It is exported so that C code can call it.
//
// The call chain arriving here looks like
// some_go_caller
// ->some_ffi_internals
// ->ffi_callback (in C)
// ->FFICallbackGo
//
// The ffi_callback handles __go_makefunc_can_recover, and
// then passes off the data as received from ffi here.
func FFICallbackGo(results unsafe.Pointer, params unsafe.Pointer, impl *makeFuncImpl) {
ftyp := impl.typ
in := make([]Value, 0, len(ftyp.in))
ap := params
for _, rt := range ftyp.in {
p := unsafe_New(rt)
memmove(p, *(*unsafe.Pointer)(ap), rt.size)
v := Value{rt, p, flag(rt.Kind()) | flagIndir}
in = append(in, v)
ap = (unsafe.Pointer)(uintptr(ap) + ptrSize)
}
out := impl.call(in)
off := uintptr(0)
for i, typ := range ftyp.out {
v := out[i]
if v.typ != typ {
panic("reflect: function created by MakeFunc using " + funcName(impl.fn) +
" returned wrong type: have " +
out[i].typ.String() + " for " + typ.String())
}
if v.flag&flagRO != 0 {
panic("reflect: function created by MakeFunc using " + funcName(impl.fn) +
" returned value obtained from unexported field")
}
off = align(off, uintptr(typ.fieldAlign))
addr := unsafe.Pointer(uintptr(results) + off)
if v.flag&flagIndir == 0 && (v.kind() == Ptr || v.kind() == UnsafePointer) {
*(*unsafe.Pointer)(addr) = v.ptr
} else {
memmove(addr, v.ptr, typ.size)
}
off += typ.size
}
}
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