NEWS APPS DOCS ABOUT | ||||
Autodocs Include classes clib datatypes devices diskfont dos exec gadgets graphics hardware images intuition libraries pragma pragmas prefs proto reaction resources rexx utility date.h / .i hooks.h / .i name.h / .i pack.h / .i tagitem.h / .i utility.h / .i workbench GuruMeditation | #ifndef UTILITY_HOOKS_H #define UTILITY_HOOKS_H /* ** $VER: hooks.h 39.2 (16.6.1993) ** Includes Release 45.1 ** ** Callback hooks ** ** (C) Copyright 1989-2001 Amiga, Inc. ** All Rights Reserved */ /*****************************************************************************/ #ifndef EXEC_TYPES_H #include <exec/types.h> #endif #ifndef EXEC_NODES_H #include <exec/nodes.h> #endif /*****************************************************************************/ struct Hook { struct MinNode h_MinNode; ULONG (*h_Entry)(); /* assembler entry point */ ULONG (*h_SubEntry)(); /* often HLL entry point */ APTR h_Data; /* owner specific */ }; /* Useful definition for casting function pointers: * hook.h_SubEntry = (HOOKFUNC)AFunction */ typedef unsigned long (*HOOKFUNC)(); /* Hook calling conventions. * * The function pointed to by Hook.h_Entry is called with the following * parameters: * * A0 - pointer to hook data structure itself * A1 - pointer to parameter structure ("message") * A2 - Hook specific address data ("object") * * Control will be passed to the routine h_Entry. For many * High-Level Languages (HLL), this will be an assembly language * stub which pushes registers on the stack, does other setup, * and then calls the function at h_SubEntry. * * The standard C receiving code is: * * HookFunc(struct Hook *hook, APTR object, APTR message) * * Note that register natural order differs from this convention for C * parameter order, which is A0,A2,A1. * * The assembly language stub for "vanilla" C parameter conventions * could be: * * _hookEntry: * move.l a1,-(sp) ; push message packet pointer * move.l a2,-(sp) ; push object pointer * move.l a0,-(sp) ; push hook pointer * move.l h_SubEntry(a0),a0 ; fetch C entry point ... * jsr (a0) ; ... and call it * lea 12(sp),sp ; fix stack * rts * * With this function as your interface stub, you can write a Hook setup * function as: * * InitHook(struct Hook *hook, ULONG (*c_function)(), APTR userdata) * { * ULONG (*hookEntry)(); * * hook->h_Entry = hookEntry; * hook->h_SubEntry = c_function; * hook->h_Data = userdata; * } * * With a compiler capable of registerized parameters, such as SAS C, you * can put the C function in the h_Entry field directly. For example, for * SAS C: * * ULONG __saveds __asm HookFunc(register __a0 struct Hook *hook, * register __a2 APTR object, * register __a1 APTR message); * */ /*****************************************************************************/ #endif /* UTILITY_HOOKS_H */ Comments |
$VER: d0.se 1.14 Copyright © 2011-2024 Tobias Geijersson support at d0 dot se |