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