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