win32/except.c

   1 /*
   2  * Win32 exception functions
   3  *
   4  * Copyright (c) 1996 Onno Hovers, (onno@stack.urc.tue.nl)
   5  * Copyright (c) 1999 Alexandre Julliard
   6  *
   7  * Notes:
   8  *  What really happens behind the scenes of those new
   9  *  __try{...}__except(..){....}  and
  10  *  __try{...}__finally{...}
  11  *  statements is simply not documented by Microsoft. There could be different
  12  *  reasons for this:
  13  *  One reason could be that they try to hide the fact that exception
  14  *  handling in Win32 looks almost the same as in OS/2 2.x.
  15  *  Another reason could be that Microsoft does not want others to write
  16  *  binary compatible implementations of the Win32 API (like us).
  17  *
  18  *  Whatever the reason, THIS SUCKS!! Ensuring portabilty or future
  19  *  compatability may be valid reasons to keep some things undocumented.
  20  *  But exception handling is so basic to Win32 that it should be
  21  *  documented!
  22  *
  23  */
  24
  25 #include <stdio.h>
  26 #include "windef.h"
  27 #include "winerror.h"
  28 #include "ntddk.h"
  29 #include "wine/exception.h"
  30 #include "ldt.h"
  31 #include "callback.h"
  32 #include "process.h"
  33 #include "thread.h"
  34 #include "stackframe.h"
  35 #include "server.h"
  36 #include "debugtools.h"
  37
  38 DEFAULT_DEBUG_CHANNEL(seh);
  39
  40
  41 /*******************************************************************
  42  *         RaiseException  (KERNEL32.418)
  43  */
  44 void WINAPI RaiseException( DWORD code, DWORD flags, DWORD nbargs, const LPDWORD args )
  45 {
  46     EXCEPTION_RECORD record;
  47
  48     /* Compose an exception record */
  49
  50     record.ExceptionCode    = code;
  51     record.ExceptionFlags   = flags & EH_NONCONTINUABLE;
  52     record.ExceptionRecord  = NULL;
  53     record.ExceptionAddress = RaiseException;
  54     if (nbargs && args)
  55     {
  56         if (nbargs > EXCEPTION_MAXIMUM_PARAMETERS) nbargs = EXCEPTION_MAXIMUM_PARAMETERS;
  57         record.NumberParameters = nbargs;
  58         memcpy( record.ExceptionInformation, args, nbargs * sizeof(*args) );
  59     }
  60     else record.NumberParameters = 0;
  61
  62     RtlRaiseException( &record );
  63 }
  64
  65
  66 /*******************************************************************
  67  *         UnhandledExceptionFilter   (KERNEL32.537)
  68  */
  69 DWORD WINAPI UnhandledExceptionFilter(PEXCEPTION_POINTERS epointers)
  70 {
  71     struct exception_event_request *req = get_req_buffer();
  72     PDB*                pdb = PROCESS_Current();
  73     char                format[256];
  74     char                buffer[256];
  75     HKEY                hDbgConf;
  76     DWORD               bAuto = FALSE;
  77     DWORD               ret = EXCEPTION_EXECUTE_HANDLER;
  78
  79     /* send a last chance event to the debugger */
  80     req->record  = *epointers->ExceptionRecord;
  81     req->first   = 0;
  82     req->context = *epointers->ContextRecord;
  83     if (!server_call_noerr( REQ_EXCEPTION_EVENT )) *epointers->ContextRecord = req->context;
  84     switch (req->status)
  85     {
  86     case DBG_CONTINUE:
  87        return EXCEPTION_CONTINUE_EXECUTION;
  88     case DBG_EXCEPTION_NOT_HANDLED:
  89        TerminateProcess( GetCurrentProcess(), epointers->ExceptionRecord->ExceptionCode );
  90        break; /* not reached */
  91     case 0: /* no debugger is present */
  92        break;
  93     default:
  94        FIXME("Unsupported yet debug continue value %d (please report)\n", req->status);
  95     }
  96
  97     if (pdb->top_filter)
  98     {
  99         DWORD ret = pdb->top_filter( epointers );
 100         if (ret != EXCEPTION_CONTINUE_SEARCH) return ret;
 101     }
 102
 103     /* FIXME: Should check the current error mode */
 104
 105     if (!RegOpenKeyA(HKEY_LOCAL_MACHINE,
 106                      "Software\\Microsoft\\Windows NT\\CurrentVersion\\AeDebug",
 107                      &hDbgConf)) {
 108        DWORD    type;
 109        DWORD    count;
 110
 111        count = sizeof(format);
 112        if (RegQueryValueExA(hDbgConf, "Debugger", 0, &type, format, &count))
 113           format[0] = 0;
 114
 115        count = sizeof(bAuto);
 116        if (RegQueryValueExA(hDbgConf, "Auto", 0, &type, (char*)&bAuto, &count))
 117           bAuto = FALSE;
 118
 119        RegCloseKey(hDbgConf);
 120     } else {
 121        /* format[0] = 0; */
 122        strcpy(format, "debugger/winedbg %ld %ld");
 123     }
 124
 125     if (!bAuto && Callout.MessageBoxA) {
 126        sprintf( buffer, "Unhandled exception 0x%08lx at address 0x%08lx.\n"
 127                         "Do you wish to debug it ?",
 128                 epointers->ExceptionRecord->ExceptionCode,
 129                 (DWORD)epointers->ExceptionRecord->ExceptionAddress );
 130        if (Callout.MessageBoxA( 0, buffer, "Error", MB_YESNO | MB_ICONHAND ) == IDNO) {
 131           TRACE("Killing process\n");
 132           return EXCEPTION_EXECUTE_HANDLER;
 133        }
 134     }
 135
 136     if (format[0]) {
 137        HANDLE                   hEvent;
 138        PROCESS_INFORMATION      info;
 139        STARTUPINFOA             startup;
 140
 141        TRACE("Starting debugger (fmt=%s)\n", format);
 142        hEvent = ConvertToGlobalHandle(CreateEventA(NULL, FALSE, FALSE, NULL));
 143        sprintf(buffer, format, GetCurrentProcessId(), hEvent);
 144        memset(&startup, 0, sizeof(startup));
 145        startup.cb = sizeof(startup);
 146        startup.dwFlags = STARTF_USESHOWWINDOW;
 147        startup.wShowWindow = SW_SHOWNORMAL;
 148        if (CreateProcessA(NULL, buffer, NULL, NULL,
 149                           TRUE, 0, NULL, NULL, &startup, &info)) {
 150           WaitForSingleObject(hEvent, INFINITE);
 151           ret = EXCEPTION_CONTINUE_SEARCH;
 152        } else {
 153           ERR("Couldn't start debugger (%s) (%ld)\n", buffer, GetLastError());
 154        }
 155        CloseHandle(hEvent);
 156     } else {
 157        ERR("No standard debugger defined in the registry => no debugging session\n");
 158     }
 159
 160     return ret;
 161 }
 162
 163
 164 /***********************************************************************
 165  *            SetUnhandledExceptionFilter   (KERNEL32.516)
 166  */
 167 LPTOP_LEVEL_EXCEPTION_FILTER WINAPI SetUnhandledExceptionFilter(
 168                                           LPTOP_LEVEL_EXCEPTION_FILTER filter )
 169 {
 170     PDB *pdb = PROCESS_Current();
 171     LPTOP_LEVEL_EXCEPTION_FILTER old = pdb->top_filter;
 172     pdb->top_filter = filter;
 173     return old;
 174 }
 175
 176
 177 /**************************************************************************
 178  *           FatalAppExit16   (KERNEL.137)
 179  */
 180 void WINAPI FatalAppExit16( UINT16 action, LPCSTR str )
 181 {
 182     WARN("AppExit\n");
 183     FatalAppExitA( action, str );
 184 }
 185
 186
 187 /**************************************************************************
 188  *           FatalAppExitA   (KERNEL32.108)
 189  */
 190 void WINAPI FatalAppExitA( UINT action, LPCSTR str )
 191 {
 192     WARN("AppExit\n");
 193     Callout.MessageBoxA( 0, str, NULL, MB_SYSTEMMODAL | MB_OK );
 194     ExitProcess(0);
 195 }
 196
 197
 198 /**************************************************************************
 199  *           FatalAppExitW   (KERNEL32.109)
 200  */
 201 void WINAPI FatalAppExitW( UINT action, LPCWSTR str )
 202 {
 203     WARN("AppExit\n");
 204     Callout.MessageBoxW( 0, str, NULL, MB_SYSTEMMODAL | MB_OK );
 205     ExitProcess(0);
 206 }