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     PDB*                pdb = PROCESS_Current();
  72     char                format[256];
  73     char                buffer[256];
  74     HKEY                hDbgConf;
  75     DWORD               bAuto = FALSE;
  76     DWORD               ret = EXCEPTION_EXECUTE_HANDLER;
  77     int status;
  78
  79     /* send a last chance event to the debugger */
  80     SERVER_START_REQ
  81     {
  82         struct exception_event_request *req = server_alloc_req( sizeof(*req),
  83                                                   sizeof(EXCEPTION_RECORD)+sizeof(CONTEXT) );
  84         CONTEXT *context_ptr = server_data_ptr(req);
  85         EXCEPTION_RECORD *rec_ptr = (EXCEPTION_RECORD *)(context_ptr + 1);
  86         req->first   = 0;
  87         *rec_ptr     = *epointers->ExceptionRecord;
  88         *context_ptr = *epointers->ContextRecord;
  89         if (!server_call_noerr( REQ_EXCEPTION_EVENT )) *epointers->ContextRecord = *context_ptr;
  90         status = req->status;
  91     }
  92     SERVER_END_REQ;
  93
  94     switch (status)
  95     {
  96     case DBG_CONTINUE:
  97         return EXCEPTION_CONTINUE_EXECUTION;
  98     case DBG_EXCEPTION_NOT_HANDLED:
  99         TerminateProcess( GetCurrentProcess(), epointers->ExceptionRecord->ExceptionCode );
 100         break; /* not reached */
 101     case 0: /* no debugger is present */
 102         break;
 103     default:
 104         FIXME("Unsupported yet debug continue value %d (please report)\n", status);
 105     }
 106
 107     if (pdb->top_filter)
 108     {
 109         DWORD ret = pdb->top_filter( epointers );
 110         if (ret != EXCEPTION_CONTINUE_SEARCH) return ret;
 111     }
 112
 113     /* FIXME: Should check the current error mode */
 114
 115     if (!RegOpenKeyA(HKEY_LOCAL_MACHINE,
 116                      "Software\\Microsoft\\Windows NT\\CurrentVersion\\AeDebug",
 117                      &hDbgConf)) {
 118        DWORD    type;
 119        DWORD    count;
 120
 121        count = sizeof(format);
 122        if (RegQueryValueExA(hDbgConf, "Debugger", 0, &type, format, &count))
 123           format[0] = 0;
 124
 125        count = sizeof(bAuto);
 126        if (RegQueryValueExA(hDbgConf, "Auto", 0, &type, (char*)&bAuto, &count))
 127           bAuto = TRUE;
 128
 129        RegCloseKey(hDbgConf);
 130     } else {
 131        /* format[0] = 0; */
 132        strcpy(format, "debugger/winedbg %ld %ld");
 133     }
 134
 135     if (!bAuto && Callout.MessageBoxA) {
 136        sprintf( buffer, "Unhandled exception 0x%08lx at address 0x%04lx:0x%08lx.\n"
 137                         "Do you wish to debug it ?",
 138                 epointers->ExceptionRecord->ExceptionCode,
 139                 epointers->ContextRecord->SegCs,
 140                 (DWORD)epointers->ExceptionRecord->ExceptionAddress );
 141        if (Callout.MessageBoxA( 0, buffer, "Error", MB_YESNO | MB_ICONHAND ) == IDNO) {
 142           TRACE("Killing process\n");
 143           return EXCEPTION_EXECUTE_HANDLER;
 144        }
 145     }
 146
 147     if (format[0]) {
 148        HANDLE                   hEvent;
 149        PROCESS_INFORMATION      info;
 150        STARTUPINFOA             startup;
 151        OBJECT_ATTRIBUTES        attr;
 152
 153        attr.Length                   = sizeof(attr);
 154        attr.RootDirectory            = 0;
 155        attr.Attributes               = OBJ_INHERIT;
 156        attr.ObjectName               = NULL;
 157        attr.SecurityDescriptor       = NULL;
 158        attr.SecurityQualityOfService = NULL;
 159
 160        TRACE("Starting debugger (fmt=%s)\n", format);
 161        NtCreateEvent( &hEvent, EVENT_ALL_ACCESS, &attr, FALSE, FALSE );
 162        sprintf(buffer, format, GetCurrentProcessId(), hEvent);
 163        memset(&startup, 0, sizeof(startup));
 164        startup.cb = sizeof(startup);
 165        startup.dwFlags = STARTF_USESHOWWINDOW;
 166        startup.wShowWindow = SW_SHOWNORMAL;
 167        if (CreateProcessA(NULL, buffer, NULL, NULL,
 168                           TRUE, 0, NULL, NULL, &startup, &info)) {
 169           WaitForSingleObject(hEvent, INFINITE);
 170           ret = EXCEPTION_CONTINUE_SEARCH;
 171        } else {
 172            ERR("Couldn't start debugger (%s) (%ld)\n"
 173                "Read the documentation on how to set up winedbg or another debugger\n",
 174                buffer, GetLastError());
 175        }
 176        CloseHandle(hEvent);
 177     } else {
 178        ERR("No standard debugger defined in the registry => no debugging session\n");
 179     }
 180
 181     return ret;
 182 }
 183
 184
 185 /***********************************************************************
 186  *            SetUnhandledExceptionFilter   (KERNEL32.516)
 187  */
 188 LPTOP_LEVEL_EXCEPTION_FILTER WINAPI SetUnhandledExceptionFilter(
 189                                           LPTOP_LEVEL_EXCEPTION_FILTER filter )
 190 {
 191     PDB *pdb = PROCESS_Current();
 192     LPTOP_LEVEL_EXCEPTION_FILTER old = pdb->top_filter;
 193     pdb->top_filter = filter;
 194     return old;
 195 }
 196
 197
 198 /**************************************************************************
 199  *           FatalAppExit16   (KERNEL.137)
 200  */
 201 void WINAPI FatalAppExit16( UINT16 action, LPCSTR str )
 202 {
 203     WARN("AppExit\n");
 204     FatalAppExitA( action, str );
 205 }
 206
 207
 208 /**************************************************************************
 209  *           FatalAppExitA   (KERNEL32.108)
 210  */
 211 void WINAPI FatalAppExitA( UINT action, LPCSTR str )
 212 {
 213     WARN("AppExit\n");
 214     Callout.MessageBoxA( 0, str, NULL, MB_SYSTEMMODAL | MB_OK );
 215     ExitProcess(0);
 216 }
 217
 218
 219 /**************************************************************************
 220  *           FatalAppExitW   (KERNEL32.109)
 221  */
 222 void WINAPI FatalAppExitW( UINT action, LPCWSTR str )
 223 {
 224     WARN("AppExit\n");
 225     Callout.MessageBoxW( 0, str, NULL, MB_SYSTEMMODAL | MB_OK );
 226     ExitProcess(0);
 227 }