adtools/clib2

/*
 * $Id: amiga_callhooka.c,v 1.3 2006-01-08 12:04:22 obarthel Exp $
 *
 * :ts=4
 *
 * Portable ISO 'C' (1994) runtime library for the Amiga computer
 * Copyright (c) 2002-2015 by Olaf Barthel <obarthel (at) gmx.net>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *   - Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *
 *   - Neither the name of Olaf Barthel nor the names of contributors
 *     may be used to endorse or promote products derived from this
 *     software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#if (defined(__GNUC__) && !defined(__PPC__))

/****************************************************************************/

asm("

h_Entry = 8

    .text
    .even

|---------------------------------------------------------------------------
| new hook standard
| use struct Hook (with minnode at the top)
|
| *** register calling convention: ***
|    A0 - pointer to hook itself
|    A1 - pointer to parameter packed ('message')
|    A2 - Hook specific address data ('object,' e.g, gadget )
|
| ***  C conventions: ***
| Note that parameters are in unusual register order: a0, a2, a1.
| This is to provide a performance boost for assembly language
| programming (the object in a2 is most frequently untouched).
| It is also no problem in 'register direct' C function parameters.
|
| calling through a hook
|    CallHook( hook, object, msgid, p1, p2, ... );
|    CallHookA( hook, object, msgpkt );
|
| using a C function:    CFunction( hook, object, message );
|    hook.h_Entry = HookEntry;
|    hook.h_SubEntry = CFunction;
|
|---------------------------------------------------------------------------

| C calling hook interface for prepared message packet

    .globl    _CallHookA

_CallHookA:

    moveml    a2/a6,sp@-
    moveal    sp@(12),a0
    moveal    sp@(16),a2
    moveal    sp@(20),a1
    pea        callhooka_return
    movel    a0@(h_Entry),sp@-
    rts

callhooka_return:

    moveml    sp@+,a2/a6
    rts

");

/****************************************************************************/

#endif /* __GNUC__ && !__PPC__ */