blob: e319094a456ba4118445e7e579c9bf2196867b7a [file] [log] [blame]
// Copyright 2009 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.
#include "textflag.h"
#include "abi_amd64.h"
// Set the x_crosscall2_ptr C function pointer variable point to crosscall2.
// It's such a pointer chain: _crosscall2_ptr -> x_crosscall2_ptr -> crosscall2
// Use a local trampoline, to avoid taking the address of a dynamically exported
// function.
TEXT ·set_crosscall2(SB),NOSPLIT,$0-0
MOVQ _crosscall2_ptr(SB), AX
MOVQ $crosscall2_trampoline<>(SB), BX
MOVQ BX, (AX)
RET
TEXT crosscall2_trampoline<>(SB),NOSPLIT,$0-0
JMP crosscall2(SB)
// Called by C code generated by cmd/cgo.
// func crosscall2(fn, a unsafe.Pointer, n int32, ctxt uintptr)
// Saves C callee-saved registers and calls cgocallback with three arguments.
// fn is the PC of a func(a unsafe.Pointer) function.
// This signature is known to SWIG, so we can't change it.
TEXT crosscall2(SB),NOSPLIT|NOFRAME,$0-0
PUSH_REGS_HOST_TO_ABI0()
// Make room for arguments to cgocallback.
ADJSP $0x18
#ifndef GOOS_windows
MOVQ DI, 0x0(SP) /* fn */
MOVQ SI, 0x8(SP) /* arg */
// Skip n in DX.
MOVQ CX, 0x10(SP) /* ctxt */
#else
MOVQ CX, 0x0(SP) /* fn */
MOVQ DX, 0x8(SP) /* arg */
// Skip n in R8.
MOVQ R9, 0x10(SP) /* ctxt */
#endif
CALL runtime·cgocallback(SB)
ADJSP $-0x18
POP_REGS_HOST_TO_ABI0()
RET