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   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 <stdarg.h>
  32
  33 #include "windef.h"
  34 #include "winbase.h"
  35 #include "winreg.h"
  36 #include "winternl.h"
  37 #include "wine/exception.h"
  38 #include "msvcrt.h"
  39 #include "excpt.h"
  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   int previousTryLevel;
  50   int (*lpfnFilter)(PEXCEPTION_POINTERS);
  51   int (*lpfnHandler)(void);
  52 } SCOPETABLE, *PSCOPETABLE;
  53
  54 typedef struct _MSVCRT_EXCEPTION_FRAME
  55 {
  56   EXCEPTION_REGISTRATION_RECORD *prev;
  57   void (*handler)(PEXCEPTION_RECORD, EXCEPTION_REGISTRATION_RECORD*,
  58                   PCONTEXT, PEXCEPTION_RECORD);
  59   PSCOPETABLE scopetable;
  60   int trylevel;
  61   int _ebp;
  62   PEXCEPTION_POINTERS xpointers;
  63 } MSVCRT_EXCEPTION_FRAME;
  64
  65 #define TRYLEVEL_END (-1) /* 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
  74 inline static DWORD call_filter( void *func, void *arg, void *ebp )
  75 {
  76     DWORD ret;
  77     __asm__ __volatile__ ("pushl %%ebp; pushl %3; movl %2,%%ebp; call *%%eax; popl %%ebp; popl %%ebp"
  78                           : "=a" (ret)
  79                           : "0" (func), "g" (ebp), "g" (arg)
  80                           : "ecx", "edx", "memory" );
  81     return ret;
  82 }
  83 #endif
  84
  85 static DWORD MSVCRT_nested_handler(PEXCEPTION_RECORD rec,
  86                                    EXCEPTION_REGISTRATION_RECORD* frame,
  87                                    PCONTEXT context,
  88                                    EXCEPTION_REGISTRATION_RECORD** dispatch)
  89 {
  90   if (rec->ExceptionFlags & 0x6)
  91     return ExceptionContinueSearch;
  92   *dispatch = frame;
  93   return ExceptionCollidedUnwind;
  94 }
  95
  96
  97 /*********************************************************************
  98  *              _XcptFilter (MSVCRT.@)
  99  */
 100 int _XcptFilter(int ex, PEXCEPTION_POINTERS ptr)
 101 {
 102   FIXME("(%d,%p)semi-stub\n", ex, ptr);
 103   return UnhandledExceptionFilter(ptr);
 104 }
 105
 106 /*********************************************************************
 107  *              _EH_prolog (MSVCRT.@)
 108  */
 109 #ifdef __i386__
 110 /* Provided for VC++ binary compatibility only */
 111 __ASM_GLOBAL_FUNC(_EH_prolog,
 112                   "pushl $-1\n\t"
 113                   "pushl %eax\n\t"
 114                   "pushl %fs:0\n\t"
 115                   "movl  %esp, %fs:0\n\t"
 116                   "movl  12(%esp), %eax\n\t"
 117                   "movl  %ebp, 12(%esp)\n\t"
 118                   "leal  12(%esp), %ebp\n\t"
 119                   "pushl %eax\n\t"
 120                   "ret");
 121 #endif
 122
 123 /*******************************************************************
 124  *              _global_unwind2 (MSVCRT.@)
 125  */
 126 void _global_unwind2(EXCEPTION_REGISTRATION_RECORD* frame)
 127 {
 128     TRACE("(%p)\n",frame);
 129     RtlUnwind( frame, 0, 0, 0 );
 130 }
 131
 132 /*******************************************************************
 133  *              _local_unwind2 (MSVCRT.@)
 134  */
 135 void _local_unwind2(MSVCRT_EXCEPTION_FRAME* frame, int trylevel)
 136 {
 137   MSVCRT_EXCEPTION_FRAME *curframe = frame;
 138   EXCEPTION_REGISTRATION_RECORD reg;
 139
 140   TRACE("(%p,%d,%d)\n",frame, frame->trylevel, trylevel);
 141
 142   /* Register a handler in case of a nested exception */
 143   reg.Handler = (PEXCEPTION_HANDLER)MSVCRT_nested_handler;
 144   reg.Prev = NtCurrentTeb()->Tib.ExceptionList;
 145   __wine_push_frame(&reg);
 146
 147   while (frame->trylevel != TRYLEVEL_END && frame->trylevel != trylevel)
 148   {
 149     int curtrylevel = frame->scopetable[frame->trylevel].previousTryLevel;
 150     curframe = frame;
 151     curframe->trylevel = curtrylevel;
 152     if (!frame->scopetable[curtrylevel].lpfnFilter)
 153     {
 154       ERR("__try block cleanup not implemented - expect crash!\n");
 155       /* FIXME: Remove current frame, set ebp, call
 156        * frame->scopetable[curtrylevel].lpfnHandler()
 157        */
 158     }
 159   }
 160   __wine_pop_frame(&reg);
 161   TRACE("unwound OK\n");
 162 }
 163
 164 /*********************************************************************
 165  *              _except_handler2 (MSVCRT.@)
 166  */
 167 int _except_handler2(PEXCEPTION_RECORD rec,
 168                      EXCEPTION_REGISTRATION_RECORD* frame,
 169                      PCONTEXT context,
 170                      EXCEPTION_REGISTRATION_RECORD** dispatcher)
 171 {
 172   FIXME("exception %lx flags=%lx at %p handler=%p %p %p stub\n",
 173         rec->ExceptionCode, rec->ExceptionFlags, rec->ExceptionAddress,
 174         frame->Handler, context, dispatcher);
 175   return ExceptionContinueSearch;
 176 }
 177
 178 /*********************************************************************
 179  *              _except_handler3 (MSVCRT.@)
 180  */
 181 int _except_handler3(PEXCEPTION_RECORD rec,
 182                      MSVCRT_EXCEPTION_FRAME* frame,
 183                      PCONTEXT context, void* dispatcher)
 184 {
 185 #if defined(__GNUC__) && defined(__i386__)
 186   long retval;
 187   int trylevel;
 188   EXCEPTION_POINTERS exceptPtrs;
 189   PSCOPETABLE pScopeTable;
 190
 191   TRACE("exception %lx flags=%lx at %p handler=%p %p %p semi-stub\n",
 192         rec->ExceptionCode, rec->ExceptionFlags, rec->ExceptionAddress,
 193         frame->handler, context, dispatcher);
 194
 195   __asm__ __volatile__ ("cld");
 196
 197   if (rec->ExceptionFlags & (EH_UNWINDING | EH_EXIT_UNWIND))
 198   {
 199     /* Unwinding the current frame */
 200      _local_unwind2(frame, TRYLEVEL_END);
 201     return ExceptionContinueSearch;
 202   }
 203   else
 204   {
 205     /* Hunting for handler */
 206     exceptPtrs.ExceptionRecord = rec;
 207     exceptPtrs.ContextRecord = context;
 208     *((DWORD *)frame-1) = (DWORD)&exceptPtrs;
 209     trylevel = frame->trylevel;
 210     pScopeTable = frame->scopetable;
 211
 212     while (trylevel != TRYLEVEL_END)
 213     {
 214       if (pScopeTable[trylevel].lpfnFilter)
 215       {
 216         TRACE("filter = %p\n", pScopeTable[trylevel].lpfnFilter);
 217
 218         retval = call_filter( pScopeTable[trylevel].lpfnFilter, &exceptPtrs, &frame->_ebp );
 219
 220         TRACE("filter returned %s\n", retval == EXCEPTION_CONTINUE_EXECUTION ?
 221               "CONTINUE_EXECUTION" : retval == EXCEPTION_EXECUTE_HANDLER ?
 222               "EXECUTE_HANDLER" : "CONTINUE_SEARCH");
 223
 224         if (retval == EXCEPTION_CONTINUE_EXECUTION)
 225           return ExceptionContinueExecution;
 226
 227         if (retval == EXCEPTION_EXECUTE_HANDLER)
 228         {
 229           /* Unwind all higher frames, this one will handle the exception */
 230           _global_unwind2((EXCEPTION_REGISTRATION_RECORD*)frame);
 231           _local_unwind2(frame, trylevel);
 232
 233           /* Set our trylevel to the enclosing block, and call the __finally
 234            * code, which won't return
 235            */
 236           frame->trylevel = pScopeTable->previousTryLevel;
 237           TRACE("__finally block %p\n",pScopeTable[trylevel].lpfnHandler);
 238           call_finally_block(pScopeTable[trylevel].lpfnHandler, &frame->_ebp);
 239           ERR("Returned from __finally block - expect crash!\n");
 240        }
 241       }
 242       trylevel = pScopeTable->previousTryLevel;
 243     }
 244   }
 245 #else
 246   TRACE("exception %lx flags=%lx at %p handler=%p %p %p stub\n",
 247         rec->ExceptionCode, rec->ExceptionFlags, rec->ExceptionAddress,
 248         frame->handler, context, dispatcher);
 249 #endif
 250   return ExceptionContinueSearch;
 251 }
 252
 253 /*********************************************************************
 254  *              _abnormal_termination (MSVCRT.@)
 255  */
 256 int _abnormal_termination(void)
 257 {
 258   FIXME("(void)stub\n");
 259   return 0;
 260 }
 261
 262 /*
 263  * setjmp/longjmp implementation
 264  */
 265
 266 #ifdef __i386__
 267 #define MSVCRT_JMP_MAGIC 0x56433230 /* ID value for new jump structure */
 268 typedef void (*MSVCRT_unwind_function)(const void*);
 269
 270 /*
 271  * The signatures of the setjmp/longjmp functions do not match that
 272  * declared in the setjmp header so they don't follow the regular naming
 273  * convention to avoid conflicts.
 274  */
 275
 276 /*******************************************************************
 277  *              _setjmp (MSVCRT.@)
 278  */
 279 DEFINE_REGS_ENTRYPOINT( MSVCRT__setjmp, _MSVCRT__setjmp, 4, 0 );
 280 void _MSVCRT__setjmp(struct MSVCRT___JUMP_BUFFER *jmp, CONTEXT86* context)
 281 {
 282     TRACE("(%p)\n",jmp);
 283     jmp->Ebp = context->Ebp;
 284     jmp->Ebx = context->Ebx;
 285     jmp->Edi = context->Edi;
 286     jmp->Esi = context->Esi;
 287     jmp->Esp = context->Esp;
 288     jmp->Eip = context->Eip;
 289     jmp->Registration = (unsigned long)NtCurrentTeb()->Tib.ExceptionList;
 290     if (jmp->Registration == TRYLEVEL_END)
 291         jmp->TryLevel = TRYLEVEL_END;
 292     else
 293         jmp->TryLevel = ((MSVCRT_EXCEPTION_FRAME*)jmp->Registration)->trylevel;
 294     TRACE("returning 0\n");
 295     context->Eax=0;
 296 }
 297
 298 /*******************************************************************
 299  *              _setjmp3 (MSVCRT.@)
 300  */
 301 DEFINE_REGS_ENTRYPOINT( MSVCRT__setjmp3, _MSVCRT__setjmp3, 8, 0 );
 302 void _MSVCRT__setjmp3(struct MSVCRT___JUMP_BUFFER *jmp, int nb_args, CONTEXT86* context)
 303 {
 304     TRACE("(%p,%d)\n",jmp,nb_args);
 305     jmp->Ebp = context->Ebp;
 306     jmp->Ebx = context->Ebx;
 307     jmp->Edi = context->Edi;
 308     jmp->Esi = context->Esi;
 309     jmp->Esp = context->Esp;
 310     jmp->Eip = context->Eip;
 311     jmp->Cookie = MSVCRT_JMP_MAGIC;
 312     jmp->UnwindFunc = 0;
 313     jmp->Registration = (unsigned long)NtCurrentTeb()->Tib.ExceptionList;
 314     if (jmp->Registration == TRYLEVEL_END)
 315     {
 316         jmp->TryLevel = TRYLEVEL_END;
 317     }
 318     else
 319     {
 320         void **args = ((void**)context->Esp)+2;
 321
 322         if (nb_args > 0) jmp->UnwindFunc = (unsigned long)*args++;
 323         if (nb_args > 1) jmp->TryLevel = (unsigned long)*args++;
 324         else jmp->TryLevel = ((MSVCRT_EXCEPTION_FRAME*)jmp->Registration)->trylevel;
 325         if (nb_args > 2)
 326         {
 327             size_t size = (nb_args - 2) * sizeof(DWORD);
 328             memcpy( jmp->UnwindData, args, min( size, sizeof(jmp->UnwindData) ));
 329         }
 330     }
 331     TRACE("returning 0\n");
 332     context->Eax = 0;
 333 }
 334
 335 /*********************************************************************
 336  *              longjmp (MSVCRT.@)
 337  */
 338 DEFINE_REGS_ENTRYPOINT( MSVCRT_longjmp, _MSVCRT_longjmp, 8, 0 );
 339 void _MSVCRT_longjmp(struct MSVCRT___JUMP_BUFFER *jmp, int retval, CONTEXT86* context)
 340 {
 341     unsigned long cur_frame = 0;
 342
 343     TRACE("(%p,%d)\n", jmp, retval);
 344
 345     cur_frame=(unsigned long)NtCurrentTeb()->Tib.ExceptionList;
 346     TRACE("cur_frame=%lx\n",cur_frame);
 347
 348     if (cur_frame != jmp->Registration)
 349         _global_unwind2((EXCEPTION_REGISTRATION_RECORD*)jmp->Registration);
 350
 351     if (jmp->Registration)
 352     {
 353         if (!IsBadReadPtr(&jmp->Cookie, sizeof(long)) &&
 354             jmp->Cookie == MSVCRT_JMP_MAGIC && jmp->UnwindFunc)
 355         {
 356             MSVCRT_unwind_function unwind_func;
 357
 358             unwind_func=(MSVCRT_unwind_function)jmp->UnwindFunc;
 359             unwind_func(jmp);
 360         }
 361         else
 362             _local_unwind2((MSVCRT_EXCEPTION_FRAME*)jmp->Registration,
 363                            jmp->TryLevel);
 364     }
 365
 366     if (!retval)
 367         retval = 1;
 368
 369     TRACE("Jump to %lx returning %d\n",jmp->Eip,retval);
 370     context->Ebp = jmp->Ebp;
 371     context->Ebx = jmp->Ebx;
 372     context->Edi = jmp->Edi;
 373     context->Esi = jmp->Esi;
 374     context->Esp = jmp->Esp;
 375     context->Eip = jmp->Eip;
 376     context->Eax = retval;
 377 }
 378
 379 /*********************************************************************
 380  *              _seh_longjmp_unwind (MSVCRT.@)
 381  */
 382 void __stdcall _seh_longjmp_unwind(struct MSVCRT___JUMP_BUFFER *jmp)
 383 {
 384     _local_unwind2( (MSVCRT_EXCEPTION_FRAME *)jmp->Registration, jmp->TryLevel );
 385 }
 386 #endif /* i386 */
 387
 388 /*********************************************************************
 389  *              signal (MSVCRT.@)
 390  */
 391 void* MSVCRT_signal(int sig, MSVCRT_sig_handler_func func)
 392 {
 393   FIXME("(%d %p):stub\n", sig, func);
 394   return (void*)-1;
 395 }