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 <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
  40 #include "msvcrt/setjmp.h"
  41 #include "excpt.h"
  42
  43
  44 #include "wine/debug.h"
  45
  46 WINE_DEFAULT_DEBUG_CHANNEL(msvcrt);
  47
  48 typedef void (*MSVCRT_sig_handler_func)(void);
  49
  50 /* VC++ extensions to Win32 SEH */
  51 typedef struct _SCOPETABLE
  52 {
  53   int previousTryLevel;
  54   int (*lpfnFilter)(PEXCEPTION_POINTERS);
  55   int (*lpfnHandler)(void);
  56 } SCOPETABLE, *PSCOPETABLE;
  57
  58 typedef struct _MSVCRT_EXCEPTION_FRAME
  59 {
  60   EXCEPTION_REGISTRATION_RECORD *prev;
  61   void (*handler)(PEXCEPTION_RECORD, PEXCEPTION_REGISTRATION_RECORD,
  62                   PCONTEXT, PEXCEPTION_RECORD);
  63   PSCOPETABLE scopetable;
  64   int trylevel;
  65   int _ebp;
  66   PEXCEPTION_POINTERS xpointers;
  67 } MSVCRT_EXCEPTION_FRAME;
  68
  69 #define TRYLEVEL_END (-1) /* End of trylevel list */
  70
  71 #if defined(__GNUC__) && defined(__i386__)
  72 inline static void call_finally_block( void *code_block, void *base_ptr )
  73 {
  74     __asm__ __volatile__ ("movl %1,%%ebp; call *%%eax" \
  75                           : : "a" (code_block), "g" (base_ptr));
  76 }
  77
  78 inline static DWORD call_filter( void *func, void *arg, void *ebp )
  79 {
  80     DWORD ret;
  81     __asm__ __volatile__ ("pushl %%ebp; pushl %3; movl %2,%%ebp; call *%%eax; popl %%ebp; popl %%ebp"
  82                           : "=a" (ret)
  83                           : "0" (func), "g" (ebp), "g" (arg)
  84                           : "ecx", "edx", "memory" );
  85     return ret;
  86 }
  87 #endif
  88
  89 static DWORD MSVCRT_nested_handler(PEXCEPTION_RECORD rec,
  90                                    EXCEPTION_REGISTRATION_RECORD* frame,
  91                                    PCONTEXT context WINE_UNUSED,
  92                                    EXCEPTION_REGISTRATION_RECORD** dispatch)
  93 {
  94   if (rec->ExceptionFlags & 0x6)
  95     return ExceptionContinueSearch;
  96   *dispatch = frame;
  97   return ExceptionCollidedUnwind;
  98 }
  99
 100
 101 /*********************************************************************
 102  *              _XcptFilter (MSVCRT.@)
 103  */
 104 int _XcptFilter(int ex, PEXCEPTION_POINTERS ptr)
 105 {
 106   FIXME("(%d,%p)semi-stub\n", ex, ptr);
 107   return UnhandledExceptionFilter(ptr);
 108 }
 109
 110 /*********************************************************************
 111  *              _EH_prolog (MSVCRT.@)
 112  */
 113 #ifdef __i386__
 114 /* Provided for VC++ binary compatibility only */
 115 __ASM_GLOBAL_FUNC(_EH_prolog,
 116                   "pushl $-1\n\t"
 117                   "pushl %eax\n\t"
 118                   "pushl %fs:0\n\t"
 119                   "movl  %esp, %fs:0\n\t"
 120                   "movl  12(%esp), %eax\n\t"
 121                   "movl  %ebp, 12(%esp)\n\t"
 122                   "leal  12(%esp), %ebp\n\t"
 123                   "pushl %eax\n\t"
 124                   "ret");
 125 #endif
 126
 127 /*******************************************************************
 128  *              _global_unwind2 (MSVCRT.@)
 129  */
 130 void _global_unwind2(PEXCEPTION_REGISTRATION_RECORD frame)
 131 {
 132     TRACE("(%p)\n",frame);
 133     RtlUnwind( frame, 0, 0, 0 );
 134 }
 135
 136 /*******************************************************************
 137  *              _local_unwind2 (MSVCRT.@)
 138  */
 139 void _local_unwind2(MSVCRT_EXCEPTION_FRAME* frame, int trylevel)
 140 {
 141   MSVCRT_EXCEPTION_FRAME *curframe = frame;
 142   EXCEPTION_REGISTRATION_RECORD reg;
 143
 144   TRACE("(%p,%d,%d)\n",frame, frame->trylevel, trylevel);
 145
 146   /* Register a handler in case of a nested exception */
 147   reg.Handler = (PEXCEPTION_HANDLER)MSVCRT_nested_handler;
 148   reg.Prev = NtCurrentTeb()->Tib.ExceptionList;
 149   __wine_push_frame(&reg);
 150
 151   while (frame->trylevel != TRYLEVEL_END && frame->trylevel != trylevel)
 152   {
 153     int curtrylevel = frame->scopetable[frame->trylevel].previousTryLevel;
 154     curframe = frame;
 155     curframe->trylevel = curtrylevel;
 156     if (!frame->scopetable[curtrylevel].lpfnFilter)
 157     {
 158       ERR("__try block cleanup not implemented - expect crash!\n");
 159       /* FIXME: Remove current frame, set ebp, call
 160        * frame->scopetable[curtrylevel].lpfnHandler()
 161        */
 162     }
 163   }
 164   __wine_pop_frame(&reg);
 165   TRACE("unwound OK\n");
 166 }
 167
 168 /*********************************************************************
 169  *              _except_handler2 (MSVCRT.@)
 170  */
 171 int _except_handler2(PEXCEPTION_RECORD rec,
 172                      PEXCEPTION_REGISTRATION_RECORD frame,
 173                      PCONTEXT context,
 174                      PEXCEPTION_REGISTRATION_RECORD* dispatcher)
 175 {
 176   FIXME("exception %lx flags=%lx at %p handler=%p %p %p stub\n",
 177         rec->ExceptionCode, rec->ExceptionFlags, rec->ExceptionAddress,
 178         frame->Handler, context, dispatcher);
 179   return ExceptionContinueSearch;
 180 }
 181
 182 /*********************************************************************
 183  *              _except_handler3 (MSVCRT.@)
 184  */
 185 int _except_handler3(PEXCEPTION_RECORD rec,
 186                      MSVCRT_EXCEPTION_FRAME* frame,
 187                      PCONTEXT context, void* dispatcher)
 188 {
 189 #if defined(__GNUC__) && defined(__i386__)
 190   long retval;
 191   int trylevel;
 192   EXCEPTION_POINTERS exceptPtrs;
 193   PSCOPETABLE pScopeTable;
 194
 195   TRACE("exception %lx flags=%lx at %p handler=%p %p %p semi-stub\n",
 196         rec->ExceptionCode, rec->ExceptionFlags, rec->ExceptionAddress,
 197         frame->handler, context, dispatcher);
 198
 199   __asm__ __volatile__ ("cld");
 200
 201   if (rec->ExceptionFlags & (EH_UNWINDING | EH_EXIT_UNWIND))
 202   {
 203     /* Unwinding the current frame */
 204      _local_unwind2(frame, TRYLEVEL_END);
 205     return ExceptionContinueSearch;
 206   }
 207   else
 208   {
 209     /* Hunting for handler */
 210     exceptPtrs.ExceptionRecord = rec;
 211     exceptPtrs.ContextRecord = context;
 212     *((DWORD *)frame-1) = (DWORD)&exceptPtrs;
 213     trylevel = frame->trylevel;
 214     pScopeTable = frame->scopetable;
 215
 216     while (trylevel != TRYLEVEL_END)
 217     {
 218       if (pScopeTable[trylevel].lpfnFilter)
 219       {
 220         TRACE("filter = %p\n", pScopeTable[trylevel].lpfnFilter);
 221
 222         retval = call_filter( pScopeTable[trylevel].lpfnFilter, &exceptPtrs, &frame->_ebp );
 223
 224         TRACE("filter returned %s\n", retval == EXCEPTION_CONTINUE_EXECUTION ?
 225               "CONTINUE_EXECUTION" : retval == EXCEPTION_EXECUTE_HANDLER ?
 226               "EXECUTE_HANDLER" : "CONTINUE_SEARCH");
 227
 228         if (retval == EXCEPTION_CONTINUE_EXECUTION)
 229           return ExceptionContinueExecution;
 230
 231         if (retval == EXCEPTION_EXECUTE_HANDLER)
 232         {
 233           /* Unwind all higher frames, this one will handle the exception */
 234           _global_unwind2((PEXCEPTION_REGISTRATION_RECORD)frame);
 235           _local_unwind2(frame, trylevel);
 236
 237           /* Set our trylevel to the enclosing block, and call the __finally
 238            * code, which won't return
 239            */
 240           frame->trylevel = pScopeTable->previousTryLevel;
 241           TRACE("__finally block %p\n",pScopeTable[trylevel].lpfnHandler);
 242           call_finally_block(pScopeTable[trylevel].lpfnHandler, &frame->_ebp);
 243           ERR("Returned from __finally block - expect crash!\n");
 244        }
 245       }
 246       trylevel = pScopeTable->previousTryLevel;
 247     }
 248   }
 249 #else
 250   TRACE("exception %lx flags=%lx at %p handler=%p %p %p stub\n",
 251         rec->ExceptionCode, rec->ExceptionFlags, rec->ExceptionAddress,
 252         frame->handler, context, dispatcher);
 253 #endif
 254   return ExceptionContinueSearch;
 255 }
 256
 257 /*********************************************************************
 258  *              _abnormal_termination (MSVCRT.@)
 259  */
 260 int _abnormal_termination(void)
 261 {
 262   FIXME("(void)stub\n");
 263   return 0;
 264 }
 265
 266 /*
 267  * setjmp/longjmp implementation
 268  */
 269
 270 #ifdef __i386__
 271 #define MSVCRT_JMP_MAGIC 0x56433230 /* ID value for new jump structure */
 272 typedef void (*MSVCRT_unwind_function)(const void*);
 273
 274 /*
 275  * The signatures of the setjmp/longjmp functions do not match that
 276  * declared in the setjmp header so they don't follow the regular naming
 277  * convention to avoid conflicts.
 278  */
 279
 280 /*******************************************************************
 281  *              _setjmp (MSVCRT.@)
 282  */
 283 DEFINE_REGS_ENTRYPOINT( MSVCRT__setjmp, _MSVCRT__setjmp, 4, 0 );
 284 void _MSVCRT__setjmp(_JUMP_BUFFER *jmp, CONTEXT86* context)
 285 {
 286     TRACE("(%p)\n",jmp);
 287     jmp->Ebp = context->Ebp;
 288     jmp->Ebx = context->Ebx;
 289     jmp->Edi = context->Edi;
 290     jmp->Esi = context->Esi;
 291     jmp->Esp = context->Esp;
 292     jmp->Eip = context->Eip;
 293     jmp->Registration = (unsigned long)NtCurrentTeb()->Tib.ExceptionList;
 294     if (jmp->Registration == TRYLEVEL_END)
 295         jmp->TryLevel = TRYLEVEL_END;
 296     else
 297         jmp->TryLevel = ((MSVCRT_EXCEPTION_FRAME*)jmp->Registration)->trylevel;
 298     TRACE("returning 0\n");
 299     context->Eax=0;
 300 }
 301
 302 /*******************************************************************
 303  *              _setjmp3 (MSVCRT.@)
 304  */
 305 DEFINE_REGS_ENTRYPOINT( MSVCRT__setjmp3, _MSVCRT__setjmp3, 8, 0 );
 306 void _MSVCRT__setjmp3(_JUMP_BUFFER *jmp, int nb_args, CONTEXT86* context)
 307 {
 308     TRACE("(%p,%d)\n",jmp,nb_args);
 309     jmp->Ebp = context->Ebp;
 310     jmp->Ebx = context->Ebx;
 311     jmp->Edi = context->Edi;
 312     jmp->Esi = context->Esi;
 313     jmp->Esp = context->Esp;
 314     jmp->Eip = context->Eip;
 315     jmp->Cookie = MSVCRT_JMP_MAGIC;
 316     jmp->UnwindFunc = 0;
 317     jmp->Registration = (unsigned long)NtCurrentTeb()->Tib.ExceptionList;
 318     if (jmp->Registration == TRYLEVEL_END)
 319     {
 320         jmp->TryLevel = TRYLEVEL_END;
 321     }
 322     else
 323     {
 324         void **args = ((void**)context->Esp)+2;
 325
 326         if (nb_args > 0) jmp->UnwindFunc = (unsigned long)*args++;
 327         if (nb_args > 1) jmp->TryLevel = (unsigned long)*args++;
 328         else jmp->TryLevel = ((MSVCRT_EXCEPTION_FRAME*)jmp->Registration)->trylevel;
 329         if (nb_args > 2)
 330         {
 331             size_t size = (nb_args - 2) * sizeof(DWORD);
 332             memcpy( jmp->UnwindData, args, min( size, sizeof(jmp->UnwindData) ));
 333         }
 334     }
 335     TRACE("returning 0\n");
 336     context->Eax = 0;
 337 }
 338
 339 /*********************************************************************
 340  *              longjmp (MSVCRT.@)
 341  */
 342 DEFINE_REGS_ENTRYPOINT( MSVCRT_longjmp, _MSVCRT_longjmp, 8, 0 );
 343 void _MSVCRT_longjmp(_JUMP_BUFFER *jmp, int retval, CONTEXT86* context)
 344 {
 345     unsigned long cur_frame = 0;
 346
 347     TRACE("(%p,%d)\n", jmp, retval);
 348
 349     cur_frame=(unsigned long)NtCurrentTeb()->Tib.ExceptionList;
 350     TRACE("cur_frame=%lx\n",cur_frame);
 351
 352     if (cur_frame != jmp->Registration)
 353         _global_unwind2((PEXCEPTION_REGISTRATION_RECORD)jmp->Registration);
 354
 355     if (jmp->Registration)
 356     {
 357         if (!IsBadReadPtr(&jmp->Cookie, sizeof(long)) &&
 358             jmp->Cookie == MSVCRT_JMP_MAGIC && jmp->UnwindFunc)
 359         {
 360             MSVCRT_unwind_function unwind_func;
 361
 362             unwind_func=(MSVCRT_unwind_function)jmp->UnwindFunc;
 363             unwind_func(jmp);
 364         }
 365         else
 366             _local_unwind2((MSVCRT_EXCEPTION_FRAME*)jmp->Registration,
 367                            jmp->TryLevel);
 368     }
 369
 370     if (!retval)
 371         retval = 1;
 372
 373     TRACE("Jump to %lx returning %d\n",jmp->Eip,retval);
 374     context->Ebp = jmp->Ebp;
 375     context->Ebx = jmp->Ebx;
 376     context->Edi = jmp->Edi;
 377     context->Esi = jmp->Esi;
 378     context->Esp = jmp->Esp;
 379     context->Eip = jmp->Eip;
 380     context->Eax = retval;
 381 }
 382
 383 /*********************************************************************
 384  *              _seh_longjmp_unwind (MSVCRT.@)
 385  */
 386 void __stdcall _seh_longjmp_unwind(_JUMP_BUFFER *jmp)
 387 {
 388     _local_unwind2( (MSVCRT_EXCEPTION_FRAME *)jmp->Registration, jmp->TryLevel );
 389 }
 390 #endif /* i386 */
 391
 392 /*********************************************************************
 393  *              signal (MSVCRT.@)
 394  */
 395 void* MSVCRT_signal(int sig, MSVCRT_sig_handler_func func)
 396 {
 397   FIXME("(%d %p):stub\n", sig, func);
 398   return (void*)-1;
 399 }