1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
|
// 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(cif unsafe.Pointer, impl unsafe.Pointer)
// The makeCIF function, implemented in the runtime package, allocates a CIF.
func makeCIF(ft *funcType) 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)
typedmemmove(rt, p, *(*unsafe.Pointer)(ap))
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.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)
// Convert v to type typ if v is assignable to a variable
// of type t in the language spec.
// See issue 28761.
v = v.assignTo("reflect.MakeFunc", typ, addr)
if v.flag&flagIndir == 0 && (v.kind() == Ptr || v.kind() == UnsafePointer) {
*(*unsafe.Pointer)(addr) = v.ptr
} else {
typedmemmove(typ, addr, v.ptr)
}
off += typ.size
}
}
|
