runtime/error.h

   1 /*
   2  * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * Portions Copyright (c) 1999 Apple Computer, Inc.  All Rights
   7  * Reserved.  This file contains Original Code and/or Modifications of
   8  * Original Code as defined in and that are subject to the Apple Public
   9  * Source License Version 1.1 (the "License").  You may not use this file
  10  * except in compliance with the License.  Please obtain a copy of the
  11  * License at http://www.apple.com/publicsource and read it before using
  12  * this file.
  13  *
  14  * The Original Code and all software distributed under the License are
  15  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  16  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  17  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE OR NON- INFRINGEMENT.  Please see the
  19  * License for the specific language governing rights and limitations
  20  * under the License.
  21  *
  22  * @APPLE_LICENSE_HEADER_END@
  23  */
  24
  25 /*
  26     error.h
  27
  28     This file defines the interface to the exception raising scheme.
  29
  30     Copyright (c) 1988-1996 NeXT Software, Inc. as an unpublished work.
  31     All rights reserved.
  32 */
  33
  34 #warning the API in this header is obsolete
  35
  36 #ifndef _OBJC_ERROR_H_
  37 #define _OBJC_ERROR_H_
  38
  39 #include <setjmp.h>
  40 #import <objc/objc-api.h>
  41
  42 #if defined(__svr4__)
  43     #define _setjmp setjmp
  44     #define _longjmp longjmp
  45 #endif
  46
  47 typedef struct _NXHandler {     /* a node in the handler chain */
  48     jmp_buf jumpState;                  /* place to longjmp to */
  49     struct _NXHandler *next;            /* ptr to next handler */
  50     int code;                           /* error code of exception */
  51     const void *data1, *data2;          /* blind data for describing error */
  52 } NXHandler;
  53
  54
  55 /* Handles RAISE's with nowhere to longjmp to */
  56 typedef void NXUncaughtExceptionHandler(int code, const void *data1,
  57                                                 const void *data2);
  58 OBJC_EXPORT NXUncaughtExceptionHandler *_NXUncaughtExceptionHandler;
  59 #define NXGetUncaughtExceptionHandler() _NXUncaughtExceptionHandler
  60 #define NXSetUncaughtExceptionHandler(proc) \
  61                         (_NXUncaughtExceptionHandler = (proc))
  62
  63 /* NX_DURING, NX_HANDLER and NX_ENDHANDLER are always used like:
  64
  65         NX_DURING
  66             some code which might raise an error
  67         NX_HANDLER
  68             code that will be jumped to if an error occurs
  69         NX_ENDHANDLER
  70
  71    If any error is raised within the first block of code, the second block
  72    of code will be jumped to.  Typically, this code will clean up any
  73    resources allocated in the routine, possibly case on the error code
  74    and perform special processing, and default to RERAISE the error to
  75    the next handler.  Within the scope of the handler, a local variable
  76    called NXLocalHandler of type NXHandler holds information about the
  77    error raised.
  78
  79    It is illegal to exit the first block of code by any other means than
  80    NX_VALRETURN, NX_VOIDRETURN, or just falling out the bottom.
  81  */
  82
  83 /* private support routines.  Do not call directly. */
  84 OBJC_EXPORT void _NXAddHandler( NXHandler *handler );
  85 OBJC_EXPORT void _NXRemoveHandler( NXHandler *handler );
  86
  87 #define NX_DURING { NXHandler NXLocalHandler;                   \
  88                     _NXAddHandler(&NXLocalHandler);             \
  89                     if( !_setjmp(NXLocalHandler.jumpState) ) {
  90
  91 #define NX_HANDLER _NXRemoveHandler(&NXLocalHandler); } else {
  92
  93 #define NX_ENDHANDLER }}
  94
  95 #define NX_VALRETURN(val)  do { typeof(val) temp = (val);       \
  96                         _NXRemoveHandler(&NXLocalHandler);      \
  97                         return(temp); } while (0)
  98
  99 #define NX_VOIDRETURN   do { _NXRemoveHandler(&NXLocalHandler); \
 100                         return; } while (0)
 101
 102 /* RAISE and RERAISE are called to indicate an error condition.  They
 103    initiate the process of jumping up the chain of handlers.
 104  */
 105
 106 OBJC_EXPORT
 107 #if defined(__GNUC__) && !defined(__STRICT_ANSI__) && !defined(NeXT_PDO)
 108     volatile    /* never returns */
 109 #endif
 110 void _NXRaiseError(int code, const void *data1, const void *data2)
 111 #if defined(__GNUC__)
 112   __attribute__ ((noreturn))
 113 #endif
 114 ;
 115
 116 #define NX_RAISE( code, data1, data2 )  \
 117                 _NXRaiseError( (code), (data1), (data2) )
 118
 119 #define NX_RERAISE()    _NXRaiseError( NXLocalHandler.code,     \
 120                                 NXLocalHandler.data1, NXLocalHandler.data2 )
 121
 122 /* These routines set and return the procedure which is called when
 123    exceptions are raised.  This procedure must NEVER return.  It will
 124    usually either longjmp, or call the uncaught exception handler.
 125    The default exception raiser is also declared
 126  */
 127 typedef volatile void NXExceptionRaiser(int code, const void *data1, const void *data2);
 128 OBJC_EXPORT void NXSetExceptionRaiser(NXExceptionRaiser *proc);
 129 OBJC_EXPORT NXExceptionRaiser *NXGetExceptionRaiser(void);
 130 OBJC_EXPORT NXExceptionRaiser NXDefaultExceptionRaiser;
 131
 132
 133 /* The error buffer is used to allocate data which is passed up to other
 134    handlers.  Clients should clear the error buffer in their top level
 135    handler.  The Application Kit does this.
 136  */
 137 OBJC_EXPORT void NXAllocErrorData(int size, void **data);
 138 OBJC_EXPORT void NXResetErrorData(void);
 139
 140 #endif /* _OBJC_ERROR_H_ */