dlls/msvcrt/except.c

   1 /*
   2  * msvcrt.dll exception handling
   3  *
   4  * Copyright 2000 Jon Griffiths
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19  *
  20  * NOTES:
  21  *
  22  * See http://www.microsoft.com/msj/0197/exception/exception.htm,
  23  * but don't believe all of it.
  24  *
  25  * FIXME: Incomplete support for nested exceptions/try block cleanup.
  26  */
  27
  28 #include "config.h"
  29 #include "wine/port.h"
  30
  31 #include "ntddk.h"
  32 #include "wine/exception.h"
  33 #include "thread.h"
  34 #include "msvcrt.h"
  35
  36 #include "msvcrt/setjmp.h"
  37 #include "msvcrt/excpt.h"
  38
  39
  40 #include "wine/debug.h"
  41
  42 WINE_DEFAULT_DEBUG_CHANNEL(msvcrt);
  43
  44 typedef void (*MSVCRT_sig_handler_func)(void);
  45
  46 /* VC++ extensions to Win32 SEH */
  47 typedef struct _SCOPETABLE
  48 {
  49   DWORD previousTryLevel;
  50   int (*lpfnFilter)(PEXCEPTION_POINTERS);
  51   int (*lpfnHandler)(void);
  52 } SCOPETABLE, *PSCOPETABLE;
  53
  54 typedef struct _MSVCRT_EXCEPTION_FRAME
  55 {
  56   EXCEPTION_FRAME *prev;
  57   void (*handler)(PEXCEPTION_RECORD, PEXCEPTION_FRAME,
  58                   PCONTEXT, PEXCEPTION_RECORD);
  59   PSCOPETABLE scopetable;
  60   DWORD trylevel;
  61   int _ebp;
  62   PEXCEPTION_POINTERS xpointers;
  63 } MSVCRT_EXCEPTION_FRAME;
  64
  65 #define TRYLEVEL_END 0xffffffff /* End of trylevel list */
  66
  67 #if defined(__GNUC__) && defined(__i386__)
  68 inline static void call_finally_block( void *code_block, void *base_ptr )
  69 {
  70     __asm__ __volatile__ ("movl %1,%%ebp; call *%%eax" \
  71                           : : "a" (code_block), "g" (base_ptr));
  72 }
  73 #endif
  74
  75 static DWORD MSVCRT_nested_handler(PEXCEPTION_RECORD rec,
  76                                    struct __EXCEPTION_FRAME* frame,
  77                                    PCONTEXT context WINE_UNUSED,
  78                                    struct __EXCEPTION_FRAME** dispatch)
  79 {
  80   if (rec->ExceptionFlags & 0x6)
  81     return ExceptionContinueSearch;
  82   *dispatch = frame;
  83   return ExceptionCollidedUnwind;
  84 }
  85
  86
  87 /*********************************************************************
  88  *              _XcptFilter (MSVCRT.@)
  89  */
  90 int _XcptFilter(int ex, PEXCEPTION_POINTERS ptr)
  91 {
  92   FIXME("(%d,%p)semi-stub\n", ex, ptr);
  93   return UnhandledExceptionFilter(ptr);
  94 }
  95
  96 /*********************************************************************
  97  *              _EH_prolog (MSVCRT.@)
  98  */
  99 #ifdef __i386__
 100 /* Provided for VC++ binary compatability only */
 101 __ASM_GLOBAL_FUNC(_EH_prolog,
 102                   "pushl $0xff\n\t"
 103                   "pushl %eax\n\t"
 104                   "pushl %fs:0\n\t"
 105                   "movl  %esp, %fs:0\n\t"
 106                   "movl  12(%esp), %eax\n\t"
 107                   "movl  %ebp, 12(%esp)\n\t"
 108                   "leal  12(%esp), %ebp\n\t"
 109                   "pushl %eax\n\t"
 110                   "ret");
 111 #endif
 112
 113 /*******************************************************************
 114  *              _global_unwind2 (MSVCRT.@)
 115  */
 116 void _global_unwind2(PEXCEPTION_FRAME frame)
 117 {
 118     TRACE("(%p)\n",frame);
 119     RtlUnwind( frame, 0, 0, 0 );
 120 }
 121
 122 /*******************************************************************
 123  *              _local_unwind2 (MSVCRT.@)
 124  */
 125 void _local_unwind2(MSVCRT_EXCEPTION_FRAME* frame,
 126                     DWORD trylevel)
 127 {
 128   MSVCRT_EXCEPTION_FRAME *curframe = frame;
 129   DWORD curtrylevel = 0xfe;
 130   EXCEPTION_FRAME reg;
 131
 132   TRACE("(%p,%ld,%ld)\n",frame, frame->trylevel, trylevel);
 133
 134   /* Register a handler in case of a nested exception */
 135   reg.Handler = (PEXCEPTION_HANDLER)MSVCRT_nested_handler;
 136   reg.Prev = NtCurrentTeb()->except;
 137   __wine_push_frame(&reg);
 138
 139   while (frame->trylevel != TRYLEVEL_END && frame->trylevel != trylevel)
 140   {
 141     curtrylevel = frame->scopetable[frame->trylevel].previousTryLevel;
 142     curframe = frame;
 143     curframe->trylevel = curtrylevel;
 144     if (!frame->scopetable[curtrylevel].lpfnFilter)
 145     {
 146       ERR("__try block cleanup not implemented - expect crash!\n");
 147       /* FIXME: Remove current frame, set ebp, call
 148        * frame->scopetable[curtrylevel].lpfnHandler()
 149        */
 150     }
 151   }
 152   __wine_pop_frame(&reg);
 153   TRACE("unwound OK\n");
 154 }
 155
 156 /*********************************************************************
 157  *              _except_handler2 (MSVCRT.@)
 158  */
 159 int _except_handler2(PEXCEPTION_RECORD rec,
 160                      PEXCEPTION_FRAME frame,
 161                      PCONTEXT context,
 162                      PEXCEPTION_FRAME* dispatcher)
 163 {
 164   FIXME("exception %lx flags=%lx at %p handler=%p %p %p stub\n",
 165         rec->ExceptionCode, rec->ExceptionFlags, rec->ExceptionAddress,
 166         frame->Handler, context, dispatcher);
 167   return ExceptionContinueSearch;
 168 }
 169
 170 /*********************************************************************
 171  *              _except_handler3 (MSVCRT.@)
 172  */
 173 int _except_handler3(PEXCEPTION_RECORD rec,
 174                      MSVCRT_EXCEPTION_FRAME* frame,
 175                      PCONTEXT context, void* dispatcher)
 176 {
 177 #if defined(__GNUC__) && defined(__i386__)
 178   long retval, trylevel;
 179   EXCEPTION_POINTERS exceptPtrs;
 180   PSCOPETABLE pScopeTable;
 181
 182   TRACE("exception %lx flags=%lx at %p handler=%p %p %p semi-stub\n",
 183         rec->ExceptionCode, rec->ExceptionFlags, rec->ExceptionAddress,
 184         frame->handler, context, dispatcher);
 185
 186   __asm__ __volatile__ ("cld");
 187
 188   if (rec->ExceptionFlags & (EH_UNWINDING | EH_EXIT_UNWIND))
 189   {
 190     /* Unwinding the current frame */
 191      _local_unwind2(frame, TRYLEVEL_END);
 192     return ExceptionContinueSearch;
 193   }
 194   else
 195   {
 196     /* Hunting for handler */
 197     exceptPtrs.ExceptionRecord = rec;
 198     exceptPtrs.ContextRecord = context;
 199     *((DWORD *)frame-1) = (DWORD)&exceptPtrs;
 200     trylevel = frame->trylevel;
 201     pScopeTable = frame->scopetable;
 202
 203     while (trylevel != TRYLEVEL_END)
 204     {
 205       if (pScopeTable[trylevel].lpfnFilter)
 206       {
 207         TRACE("filter = %p\n", pScopeTable[trylevel].lpfnFilter);
 208
 209         retval = pScopeTable[trylevel].lpfnFilter(&exceptPtrs);
 210
 211         TRACE("filter returned %s\n", retval == EXCEPTION_CONTINUE_EXECUTION ?
 212               "CONTINUE_EXECUTION" : retval == EXCEPTION_EXECUTE_HANDLER ?
 213               "EXECUTE_HANDLER" : "CONTINUE_SEARCH");
 214
 215         if (retval == EXCEPTION_CONTINUE_EXECUTION)
 216           return ExceptionContinueExecution;
 217
 218         if (retval == EXCEPTION_EXECUTE_HANDLER)
 219         {
 220           /* Unwind all higher frames, this one will handle the exception */
 221           _global_unwind2((PEXCEPTION_FRAME)frame);
 222           _local_unwind2(frame, trylevel);
 223
 224           /* Set our trylevel to the enclosing block, and call the __finally
 225            * code, which won't return
 226            */
 227           frame->trylevel = pScopeTable->previousTryLevel;
 228           TRACE("__finally block %p\n",pScopeTable[trylevel].lpfnHandler);
 229           call_finally_block(pScopeTable[trylevel].lpfnHandler, &frame->_ebp);
 230           ERR("Returned from __finally block - expect crash!\n");
 231        }
 232       }
 233       trylevel = pScopeTable->previousTryLevel;
 234     }
 235   }
 236 #else
 237   TRACE("exception %lx flags=%lx at %p handler=%p %p %p stub\n",
 238         rec->ExceptionCode, rec->ExceptionFlags, rec->ExceptionAddress,
 239         frame->handler, context, dispatcher);
 240 #endif
 241   return ExceptionContinueSearch;
 242 }
 243
 244 /*********************************************************************
 245  *              _abnormal_termination (MSVCRT.@)
 246  */
 247 int _abnormal_termination(void)
 248 {
 249   FIXME("(void)stub\n");
 250   return 0;
 251 }
 252
 253 /*
 254  * setjmp/longjmp implementation
 255  */
 256
 257 #ifdef __i386__
 258 #define MSVCRT_JMP_MAGIC 0x56433230 /* ID value for new jump structure */
 259 typedef void (*MSVCRT_unwind_function)(const void*);
 260
 261 /*
 262  * The signatures of the setjmp/longjmp functions do not match that
 263  * declared in the setjmp header so they don't follow the regular naming
 264  * convention to avoid conflicts.
 265  */
 266
 267 /*******************************************************************
 268  *              _setjmp (MSVCRT.@)
 269  */
 270 void _MSVCRT__setjmp(_JUMP_BUFFER *jmp, CONTEXT86* context)
 271 {
 272     TRACE("(%p)\n",jmp);
 273     jmp->Ebp = context->Ebp;
 274     jmp->Ebx = context->Ebx;
 275     jmp->Edi = context->Edi;
 276     jmp->Esi = context->Esi;
 277     jmp->Esp = context->Esp;
 278     jmp->Eip = context->Eip;
 279     jmp->Registration = (unsigned long)NtCurrentTeb()->except;
 280     if (jmp->Registration == TRYLEVEL_END)
 281         jmp->TryLevel = TRYLEVEL_END;
 282     else
 283         jmp->TryLevel = ((MSVCRT_EXCEPTION_FRAME*)jmp->Registration)->trylevel;
 284     TRACE("returning 0\n");
 285     context->Eax=0;
 286 }
 287
 288 /*******************************************************************
 289  *              _setjmp3 (MSVCRT.@)
 290  */
 291 void _MSVCRT__setjmp3(_JUMP_BUFFER *jmp, int nb_args, CONTEXT86* context)
 292 {
 293     TRACE("(%p,%d)\n",jmp,nb_args);
 294     jmp->Ebp = context->Ebp;
 295     jmp->Ebx = context->Ebx;
 296     jmp->Edi = context->Edi;
 297     jmp->Esi = context->Esi;
 298     jmp->Esp = context->Esp;
 299     jmp->Eip = context->Eip;
 300     jmp->Cookie = MSVCRT_JMP_MAGIC;
 301     jmp->UnwindFunc = 0;
 302     jmp->Registration = (unsigned long)NtCurrentTeb()->except;
 303     if (jmp->Registration == TRYLEVEL_END)
 304     {
 305         jmp->TryLevel = TRYLEVEL_END;
 306     }
 307     else
 308     {
 309         void **args = ((void**)context->Esp)+2;
 310
 311         if (nb_args > 0) jmp->UnwindFunc = (unsigned long)*args++;
 312         if (nb_args > 1) jmp->TryLevel = (unsigned long)*args++;
 313         else jmp->TryLevel = ((MSVCRT_EXCEPTION_FRAME*)jmp->Registration)->trylevel;
 314         if (nb_args > 2)
 315         {
 316             size_t size = (nb_args - 2) * sizeof(DWORD);
 317             memcpy( jmp->UnwindData, args, min( size, sizeof(jmp->UnwindData) ));
 318         }
 319     }
 320     TRACE("returning 0\n");
 321     context->Eax = 0;
 322 }
 323
 324 /*********************************************************************
 325  *              longjmp (MSVCRT.@)
 326  */
 327 void _MSVCRT_longjmp(_JUMP_BUFFER *jmp, int retval, CONTEXT86* context)
 328 {
 329     unsigned long cur_frame = 0;
 330
 331     TRACE("(%p,%d)\n", jmp, retval);
 332
 333     cur_frame=(unsigned long)NtCurrentTeb()->except;
 334     TRACE("cur_frame=%lx\n",cur_frame);
 335
 336     if (cur_frame != jmp->Registration)
 337         _global_unwind2((PEXCEPTION_FRAME)jmp->Registration);
 338
 339     if (jmp->Registration)
 340     {
 341         if (!IsBadReadPtr(&jmp->Cookie, sizeof(long)) &&
 342             jmp->Cookie == MSVCRT_JMP_MAGIC && jmp->UnwindFunc)
 343         {
 344             MSVCRT_unwind_function unwind_func;
 345
 346             unwind_func=(MSVCRT_unwind_function)jmp->UnwindFunc;
 347             unwind_func(jmp);
 348         }
 349         else
 350             _local_unwind2((MSVCRT_EXCEPTION_FRAME*)jmp->Registration,
 351                            jmp->TryLevel);
 352     }
 353
 354     if (!retval)
 355         retval = 1;
 356
 357     TRACE("Jump to %lx returning %d\n",jmp->Eip,retval);
 358     context->Ebp = jmp->Ebp;
 359     context->Ebx = jmp->Ebx;
 360     context->Edi = jmp->Edi;
 361     context->Esi = jmp->Esi;
 362     context->Esp = jmp->Esp;
 363     context->Eip = jmp->Eip;
 364     context->Eax = retval;
 365 }
 366 #endif /* i386 */
 367
 368 /*********************************************************************
 369  *              signal (MSVCRT.@)
 370  */
 371 void* MSVCRT_signal(int sig, MSVCRT_sig_handler_func func)
 372 {
 373   FIXME("(%d %p):stub\n", sig, func);
 374   return (void*)-1;
 375 }