dlls/msvcrt/except.c

   1 /*
   2  * msvcrt.dll exception handling
   3  *
   4  * Copyright 2000 Jon Griffiths
   5  *
   6  * See http://www.microsoft.com/msj/0197/exception/exception.htm,
   7  * but don't believe all of it.
   8  *
   9  * FIXME: Incomplete support for nested exceptions/try block cleanup.
  10  */
  11 #include "ntddk.h"
  12 #include "wine/exception.h"
  13 #include "thread.h"
  14 #include "msvcrt.h"
  15
  16 DEFAULT_DEBUG_CHANNEL(msvcrt);
  17
  18 typedef void (*MSVCRT_sig_handler_func)(void);
  19
  20 /* VC++ extensions to Win32 SEH */
  21 typedef struct _SCOPETABLE
  22 {
  23   DWORD previousTryLevel;
  24   int (*lpfnFilter)(PEXCEPTION_POINTERS);
  25   int (*lpfnHandler)(void);
  26 } SCOPETABLE, *PSCOPETABLE;
  27
  28 typedef struct _MSVCRT_EXCEPTION_FRAME
  29 {
  30   EXCEPTION_FRAME *prev;
  31   void (*handler)(PEXCEPTION_RECORD, PEXCEPTION_FRAME,
  32                   PCONTEXT, PEXCEPTION_RECORD);
  33   PSCOPETABLE scopetable;
  34   DWORD trylevel;
  35   int _ebp;
  36   PEXCEPTION_POINTERS xpointers;
  37 } MSVCRT_EXCEPTION_FRAME;
  38
  39 #define TRYLEVEL_END 0xff /* End of trylevel list */
  40
  41 #if defined(__GNUC__) && defined(__i386__)
  42
  43 #define CALL_FINALLY_BLOCK(code_block, base_ptr) \
  44   __asm__ __volatile__ ("movl %0,%%eax; movl %1,%%ebp; call *%%eax" \
  45                         : : "g" (code_block), "g" (base_ptr))
  46
  47 static DWORD MSVCRT_nested_handler(PEXCEPTION_RECORD rec,
  48                                    struct __EXCEPTION_FRAME* frame,
  49                                    PCONTEXT context WINE_UNUSED,
  50                                    struct __EXCEPTION_FRAME** dispatch)
  51 {
  52   if (rec->ExceptionFlags & 0x6)
  53     return ExceptionContinueSearch;
  54   *dispatch = frame;
  55   return ExceptionCollidedUnwind;
  56 }
  57 #endif
  58
  59
  60 /*********************************************************************
  61  *              _XcptFilter (MSVCRT.@)
  62  */
  63 int _XcptFilter(int ex, PEXCEPTION_POINTERS ptr)
  64 {
  65   FIXME("(%d,%p)semi-stub\n", ex, ptr);
  66   return UnhandledExceptionFilter(ptr);
  67 }
  68
  69 /*********************************************************************
  70  *              _EH_prolog (MSVCRT.@)
  71  */
  72 #ifdef __i386__
  73 /* Provided for VC++ binary compatability only */
  74 __ASM_GLOBAL_FUNC(_EH_prolog,
  75                   "pushl $0xff\n\t"
  76                   "pushl %eax\n\t"
  77                   "pushl %fs:0\n\t"
  78                   "movl  %esp, %fs:0\n\t"
  79                   "movl  12(%esp), %eax\n\t"
  80                   "movl  %ebp, 12(%esp)\n\t"
  81                   "leal  12(%esp), %ebp\n\t"
  82                   "pushl %eax\n\t"
  83                   "ret");
  84 #endif
  85
  86 /*******************************************************************
  87  *              _global_unwind2 (MSVCRT.@)
  88  */
  89 void _global_unwind2(PEXCEPTION_FRAME frame)
  90 {
  91     TRACE("(%p)\n",frame);
  92     RtlUnwind( frame, 0, 0, 0 );
  93 }
  94
  95 /*******************************************************************
  96  *              _local_unwind2 (MSVCRT.@)
  97  */
  98 void _local_unwind2(MSVCRT_EXCEPTION_FRAME* frame,
  99                     DWORD trylevel)
 100 {
 101   MSVCRT_EXCEPTION_FRAME *curframe = frame;
 102   DWORD curtrylevel = 0xfe;
 103   EXCEPTION_FRAME reg;
 104
 105   TRACE("(%p,%ld,%ld)\n",frame, frame->trylevel, trylevel);
 106
 107   /* Register a handler in case of a nested exception */
 108   reg.Handler = (PEXCEPTION_HANDLER)MSVCRT_nested_handler;
 109   reg.Prev = NtCurrentTeb()->except;
 110   __wine_push_frame(&reg);
 111
 112   while (frame->trylevel != TRYLEVEL_END && frame->trylevel != trylevel)
 113   {
 114     curtrylevel = frame->scopetable[frame->trylevel].previousTryLevel;
 115     curframe = frame;
 116     curframe->trylevel = curtrylevel;
 117     if (!frame->scopetable[curtrylevel].lpfnFilter)
 118     {
 119       ERR("__try block cleanup not implemented - expect crash!\n");
 120       /* FIXME: Remove current frame, set ebp, call
 121        * frame->scopetable[curtrylevel].lpfnHandler()
 122        */
 123     }
 124   }
 125   __wine_pop_frame(&reg);
 126   TRACE("unwound OK\n");
 127 }
 128
 129 /*********************************************************************
 130  *              _except_handler2 (MSVCRT.@)
 131  */
 132 int _except_handler2(PEXCEPTION_RECORD rec,
 133                      PEXCEPTION_FRAME frame,
 134                      PCONTEXT context,
 135                      PEXCEPTION_FRAME* dispatcher)
 136 {
 137   FIXME("exception %lx flags=%lx at %p handler=%p %p %p stub\n",
 138         rec->ExceptionCode, rec->ExceptionFlags, rec->ExceptionAddress,
 139         frame->Handler, context, dispatcher);
 140   return ExceptionContinueSearch;
 141 }
 142
 143 /*********************************************************************
 144  *              _except_handler3 (MSVCRT.@)
 145  */
 146 int _except_handler3(PEXCEPTION_RECORD rec,
 147                      MSVCRT_EXCEPTION_FRAME* frame,
 148                      PCONTEXT context, void* dispatcher)
 149 {
 150 #if defined(__GNUC__) && defined(__i386__)
 151   long retval, trylevel;
 152   EXCEPTION_POINTERS exceptPtrs;
 153   PSCOPETABLE pScopeTable;
 154
 155   TRACE("exception %lx flags=%lx at %p handler=%p %p %p semi-stub\n",
 156         rec->ExceptionCode, rec->ExceptionFlags, rec->ExceptionAddress,
 157         frame->handler, context, dispatcher);
 158
 159   __asm__ __volatile__ ("cld");
 160
 161   if (rec->ExceptionFlags & (EH_UNWINDING | EH_EXIT_UNWIND))
 162   {
 163     /* Unwinding the current frame */
 164      _local_unwind2(frame, TRYLEVEL_END);
 165     return ExceptionContinueSearch;
 166   }
 167   else
 168   {
 169     /* Hunting for handler */
 170     exceptPtrs.ExceptionRecord = rec;
 171     exceptPtrs.ContextRecord = context;
 172     *((DWORD *)frame-1) = (DWORD)&exceptPtrs;
 173     trylevel = frame->trylevel;
 174     pScopeTable = frame->scopetable;
 175
 176     while (trylevel != TRYLEVEL_END)
 177     {
 178       if (pScopeTable[trylevel].lpfnFilter)
 179       {
 180         TRACE("filter = %p\n", pScopeTable[trylevel].lpfnFilter);
 181
 182         retval = pScopeTable[trylevel].lpfnFilter(&exceptPtrs);
 183
 184         TRACE("filter returned %s\n", retval == EXCEPTION_CONTINUE_EXECUTION ?
 185               "CONTINUE_EXECUTION" : retval == EXCEPTION_EXECUTE_HANDLER ?
 186               "EXECUTE_HANDLER" : "CONTINUE_SEARCH");
 187
 188         if (retval == EXCEPTION_CONTINUE_EXECUTION)
 189           return ExceptionContinueExecution;
 190
 191         if (retval == EXCEPTION_EXECUTE_HANDLER)
 192         {
 193           /* Unwind all higher frames, this one will handle the exception */
 194           _global_unwind2((PEXCEPTION_FRAME)frame);
 195           _local_unwind2(frame, trylevel);
 196
 197           /* Set our trylevel to the enclosing block, and call the __finally
 198            * code, which won't return
 199            */
 200           frame->trylevel = pScopeTable->previousTryLevel;
 201           TRACE("__finally block %p\n",pScopeTable[trylevel].lpfnHandler);
 202           CALL_FINALLY_BLOCK(pScopeTable[trylevel].lpfnHandler, frame->_ebp);
 203           ERR("Returned from __finally block - expect crash!\n");
 204        }
 205       }
 206       trylevel = pScopeTable->previousTryLevel;
 207     }
 208   }
 209 #else
 210   TRACE("exception %lx flags=%lx at %p handler=%p %p %p stub\n",
 211         rec->ExceptionCode, rec->ExceptionFlags, rec->ExceptionAddress,
 212         frame->handler, context, dispatcher);
 213 #endif
 214   return ExceptionContinueSearch;
 215 }
 216
 217 /*********************************************************************
 218  *              _abnormal_termination (MSVCRT.@)
 219  */
 220 int _abnormal_termination(void)
 221 {
 222   FIXME("(void)stub\n");
 223   return 0;
 224 }
 225
 226 /*******************************************************************
 227  *              _setjmp (MSVCRT.@)
 228  */
 229 int MSVCRT__setjmp(LPDWORD* jmpbuf)
 230 {
 231   FIXME(":(%p): stub\n",jmpbuf);
 232   return 0;
 233 }
 234
 235 /*******************************************************************
 236  *              _setjmp3 (MSVCRT.@)
 237  */
 238 int __cdecl MSVCRT__setjmp3(LPDWORD *jmpbuf, int x)
 239 {
 240   FIXME(":(%p %x): stub\n",jmpbuf,x);
 241   return 0;
 242 }
 243
 244 /*********************************************************************
 245  *              longjmp (MSVCRT.@)
 246  */
 247 void MSVCRT_longjmp(jmp_buf env, int val)
 248 {
 249   FIXME("MSVCRT_longjmp semistub, expect crash\n");
 250   longjmp(env, val);
 251 }
 252
 253 /*********************************************************************
 254  *              signal (MSVCRT.@)
 255  */
 256 void* MSVCRT_signal(int sig, MSVCRT_sig_handler_func func)
 257 {
 258   FIXME("(%d %p):stub\n", sig, func);
 259   return (void*)-1;
 260 }