2 * Win32 exception functions
4 * Copyright (c) 1996 Onno Hovers, (onno@stack.urc.tue.nl)
5 * Copyright (c) 1999 Alexandre Julliard
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
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).
18 * Whatever the reason, THIS SUCKS!! Ensuring portability or future
19 * compatibility may be valid reasons to keep some things undocumented.
20 * But exception handling is so basic to Win32 that it should be
31 #include "wine/exception.h"
33 #include "stackframe.h"
34 #include "wine/server.h"
35 #include "debugtools.h"
37 DEFAULT_DEBUG_CHANNEL(seh);
39 static PTOP_LEVEL_EXCEPTION_FILTER top_filter;
41 typedef INT (WINAPI *MessageBoxA_funcptr)(HWND,LPCSTR,LPCSTR,UINT);
42 typedef INT (WINAPI *MessageBoxW_funcptr)(HWND,LPCWSTR,LPCWSTR,UINT);
44 /*******************************************************************
45 * RaiseException (KERNEL32.@)
47 void WINAPI RaiseException( DWORD code, DWORD flags, DWORD nbargs, const LPDWORD args )
49 EXCEPTION_RECORD record;
51 /* Compose an exception record */
53 record.ExceptionCode = code;
54 record.ExceptionFlags = flags & EH_NONCONTINUABLE;
55 record.ExceptionRecord = NULL;
56 record.ExceptionAddress = RaiseException;
59 if (nbargs > EXCEPTION_MAXIMUM_PARAMETERS) nbargs = EXCEPTION_MAXIMUM_PARAMETERS;
60 record.NumberParameters = nbargs;
61 memcpy( record.ExceptionInformation, args, nbargs * sizeof(*args) );
63 else record.NumberParameters = 0;
65 RtlRaiseException( &record );
69 /*******************************************************************
70 * format_exception_msg
72 static int format_exception_msg( const EXCEPTION_POINTERS *ptr, char *buffer, int size )
74 const EXCEPTION_RECORD *rec = ptr->ExceptionRecord;
77 switch(rec->ExceptionCode)
79 case EXCEPTION_INT_DIVIDE_BY_ZERO:
80 len = snprintf( buffer, size, "Unhandled division by zero" );
82 case EXCEPTION_INT_OVERFLOW:
83 len = snprintf( buffer, size, "Unhandled overflow" );
85 case EXCEPTION_ARRAY_BOUNDS_EXCEEDED:
86 len = snprintf( buffer, size, "Unhandled array bounds" );
88 case EXCEPTION_ILLEGAL_INSTRUCTION:
89 len = snprintf( buffer, size, "Unhandled illegal instruction" );
91 case EXCEPTION_STACK_OVERFLOW:
92 len = snprintf( buffer, size, "Unhandled stack overflow" );
94 case EXCEPTION_PRIV_INSTRUCTION:
95 len = snprintf( buffer, size, "Unhandled privileged instruction" );
97 case EXCEPTION_ACCESS_VIOLATION:
98 if (rec->NumberParameters == 2)
99 len = snprintf( buffer, size, "Unhandled page fault on %s access to 0x%08lx",
100 rec->ExceptionInformation[0] ? "write" : "read",
101 rec->ExceptionInformation[1]);
103 len = snprintf( buffer, size, "Unhandled page fault");
105 case EXCEPTION_DATATYPE_MISALIGNMENT:
106 len = snprintf( buffer, size, "Unhandled alignment" );
109 len = snprintf( buffer, size, "Unhandled ^C");
111 case EXCEPTION_CRITICAL_SECTION_WAIT:
112 len = snprintf( buffer, size, "Critical section %08lx wait failed",
113 rec->ExceptionInformation[0]);
115 case EXCEPTION_WINE_STUB:
116 len = snprintf( buffer, size, "Unimplemented function %s.%s called",
117 (char *)rec->ExceptionInformation[0], (char *)rec->ExceptionInformation[1] );
119 case EXCEPTION_VM86_INTx:
120 len = snprintf( buffer, size, "Unhandled interrupt %02lx in vm86 mode",
121 rec->ExceptionInformation[0]);
123 case EXCEPTION_VM86_STI:
124 len = snprintf( buffer, size, "Unhandled sti in vm86 mode");
126 case EXCEPTION_VM86_PICRETURN:
127 len = snprintf( buffer, size, "Unhandled PIC return in vm86 mode");
130 len = snprintf( buffer, size, "Unhandled exception 0x%08lx", rec->ExceptionCode);
133 if ((len<0) || (len>=size))
136 if (ptr->ContextRecord->SegCs != __get_cs())
137 len2 = snprintf(buffer+len, size-len,
138 " at address 0x%04lx:0x%08lx.\nDo you wish to debug it ?",
139 ptr->ContextRecord->SegCs,
140 (DWORD)ptr->ExceptionRecord->ExceptionAddress);
143 len2 = snprintf(buffer+len, size-len,
144 " at address 0x%08lx.\nDo you wish to debug it ?",
145 (DWORD)ptr->ExceptionRecord->ExceptionAddress);
146 if ((len2<0) || (len>=size-len))
152 /**********************************************************************
155 * Send an EXCEPTION_DEBUG_EVENT event to the debugger.
157 static int send_debug_event( EXCEPTION_RECORD *rec, int first_chance, CONTEXT *context )
162 SERVER_START_VAR_REQ( queue_exception_event, sizeof(*rec) + sizeof(*context) )
164 CONTEXT *context_ptr = server_data_ptr(req);
165 EXCEPTION_RECORD *rec_ptr = (EXCEPTION_RECORD *)(context_ptr + 1);
166 req->first = first_chance;
168 *context_ptr = *context;
169 if (!SERVER_CALL()) handle = req->handle;
172 if (!handle) return 0; /* no debugger present or other error */
174 /* No need to wait on the handle since the process gets suspended
175 * once the event is passed to the debugger, so when we get back
176 * here the event has been continued already.
178 SERVER_START_VAR_REQ( get_exception_status, sizeof(*context) )
180 req->handle = handle;
181 if (!SERVER_CALL()) *context = *(CONTEXT *)server_data_ptr(req);
189 /******************************************************************
192 * Does the effective debugger startup according to 'format'
194 static BOOL start_debugger(PEXCEPTION_POINTERS epointers, HANDLE hEvent)
198 PROCESS_INFORMATION info;
199 STARTUPINFOA startup;
200 char* cmdline = NULL;
205 MESSAGE("wine: Unhandled exception, starting debugger...\n");
207 if (!RegOpenKeyA(HKEY_LOCAL_MACHINE,
208 "Software\\Microsoft\\Windows NT\\CurrentVersion\\AeDebug", &hDbgConf)) {
213 if (!RegQueryValueExA(hDbgConf, "Debugger", 0, &type, NULL, &format_size)) {
214 format = HeapAlloc(GetProcessHeap(), 0, format_size);
215 RegQueryValueExA(hDbgConf, "Debugger", 0, &type, format, &format_size);
216 if (type==REG_EXPAND_SZ) {
219 /* Expand environment variable references */
220 format_size=ExpandEnvironmentStringsA(format,NULL,0);
221 tmp=HeapAlloc(GetProcessHeap(), 0, format_size);
222 ExpandEnvironmentStringsA(format,tmp,format_size);
223 HeapFree(GetProcessHeap(), 0, format);
228 count = sizeof(bAuto);
229 if (RegQueryValueExA(hDbgConf, "Auto", 0, &type, (char*)&bAuto, &count))
231 else if (type == REG_SZ)
234 count = sizeof(autostr);
235 if (!RegQueryValueExA(hDbgConf, "Auto", 0, &type, autostr, &count))
236 bAuto = atoi(autostr);
238 RegCloseKey(hDbgConf);
240 /* try a default setup... */
241 strcpy( format, "winedbg --debugmsg -all -- --auto %ld %ld" );
246 HMODULE mod = GetModuleHandleA( "user32.dll" );
247 MessageBoxA_funcptr pMessageBoxA = NULL;
249 if (mod) pMessageBoxA = (MessageBoxA_funcptr)GetProcAddress( mod, "MessageBoxA" );
253 format_exception_msg( epointers, buffer, sizeof(buffer) );
254 if (pMessageBoxA( 0, buffer, "Exception raised", MB_YESNO | MB_ICONHAND ) == IDNO)
256 TRACE("Killing process\n");
263 TRACE("Starting debugger (fmt=%s)\n", format);
264 cmdline=HeapAlloc(GetProcessHeap(), 0, format_size+2*20);
265 sprintf(cmdline, format, GetCurrentProcessId(), hEvent);
266 memset(&startup, 0, sizeof(startup));
267 startup.cb = sizeof(startup);
268 startup.dwFlags = STARTF_USESHOWWINDOW;
269 startup.wShowWindow = SW_SHOWNORMAL;
270 if (CreateProcessA(NULL, cmdline, NULL, NULL, TRUE, 0, NULL, NULL, &startup, &info)) {
271 /* wait for debugger to come up... */
272 WaitForSingleObject(hEvent, INFINITE);
279 ERR("Couldn't start debugger (%s) (%ld)\n"
280 "Read the Wine Developers Guide on how to set up winedbg or another debugger\n",
281 debugstr_a(cmdline), GetLastError());
285 HeapFree(GetProcessHeap(), 0, cmdline);
287 HeapFree(GetProcessHeap(), 0, format);
291 /******************************************************************
292 * start_debugger_atomic
294 * starts the debugger in an atomic way:
295 * - either the debugger is not started and it is started
296 * - or the debugger has already been started by another thread
297 * - or the debugger couldn't be started
299 * returns TRUE for the two first conditions, FALSE for the last
301 static int start_debugger_atomic(PEXCEPTION_POINTERS epointers)
303 static HANDLE hRunOnce /* = 0 */;
307 OBJECT_ATTRIBUTES attr;
310 attr.Length = sizeof(attr);
311 attr.RootDirectory = 0;
312 attr.Attributes = OBJ_INHERIT;
313 attr.ObjectName = NULL;
314 attr.SecurityDescriptor = NULL;
315 attr.SecurityQualityOfService = NULL;
317 /* ask for manual reset, so that once the debugger is started,
318 * every thread will know it */
319 NtCreateEvent( &hEvent, EVENT_ALL_ACCESS, &attr, TRUE, FALSE );
320 if (InterlockedCompareExchange( (LPLONG)&hRunOnce, hEvent, 0 ) == 0)
322 /* ok, our event has been set... we're the winning thread */
323 BOOL ret = start_debugger( epointers, hRunOnce );
328 /* so that the other threads won't be stuck */
329 NtSetEvent( hRunOnce, &tmp );
334 /* someone beat us here... */
335 CloseHandle( hEvent );
338 /* and wait for the winner to have actually created the debugger */
339 WaitForSingleObject( hRunOnce, INFINITE );
340 /* in fact, here, we only know that someone has tried to start the debugger,
341 * we'll know by reposting the exception if it has actually attached
342 * to the current process */
347 /*******************************************************************
348 * UnhandledExceptionFilter (KERNEL32.@)
350 DWORD WINAPI UnhandledExceptionFilter(PEXCEPTION_POINTERS epointers)
355 for (loop = 0; loop <= 1; loop++)
357 /* send a last chance event to the debugger */
358 status = send_debug_event( epointers->ExceptionRecord, FALSE, epointers->ContextRecord );
362 return EXCEPTION_CONTINUE_EXECUTION;
363 case DBG_EXCEPTION_NOT_HANDLED:
364 TerminateProcess( GetCurrentProcess(), epointers->ExceptionRecord->ExceptionCode );
365 break; /* not reached */
366 case 0: /* no debugger is present */
367 if (epointers->ExceptionRecord->ExceptionCode == CONTROL_C_EXIT)
369 /* do not launch the debugger on ^C, simply terminate the process */
370 TerminateProcess( GetCurrentProcess(), 1 );
372 /* second try, the debugger isn't present... */
373 if (loop == 1) return EXCEPTION_EXECUTE_HANDLER;
376 FIXME("Unsupported yet debug continue value %d (please report)\n", status);
377 return EXCEPTION_EXECUTE_HANDLER;
380 /* should only be there when loop == 0 */
384 DWORD ret = top_filter( epointers );
385 if (ret != EXCEPTION_CONTINUE_SEARCH) return ret;
388 /* FIXME: Should check the current error mode */
390 if (!start_debugger_atomic( epointers ))
391 return EXCEPTION_EXECUTE_HANDLER;
392 /* now that we should have a debugger attached, try to resend event */
395 return EXCEPTION_EXECUTE_HANDLER;
399 /***********************************************************************
400 * SetUnhandledExceptionFilter (KERNEL32.@)
402 LPTOP_LEVEL_EXCEPTION_FILTER WINAPI SetUnhandledExceptionFilter(
403 LPTOP_LEVEL_EXCEPTION_FILTER filter )
405 LPTOP_LEVEL_EXCEPTION_FILTER old = top_filter;
411 /**************************************************************************
412 * FatalAppExitA (KERNEL32.@)
414 void WINAPI FatalAppExitA( UINT action, LPCSTR str )
416 HMODULE mod = GetModuleHandleA( "user32.dll" );
417 MessageBoxA_funcptr pMessageBoxA = NULL;
421 if (mod) pMessageBoxA = (MessageBoxA_funcptr)GetProcAddress( mod, "MessageBoxA" );
422 if (pMessageBoxA) pMessageBoxA( 0, str, NULL, MB_SYSTEMMODAL | MB_OK );
423 else ERR( "%s\n", debugstr_a(str) );
428 /**************************************************************************
429 * FatalAppExitW (KERNEL32.@)
431 void WINAPI FatalAppExitW( UINT action, LPCWSTR str )
433 HMODULE mod = GetModuleHandleA( "user32.dll" );
434 MessageBoxW_funcptr pMessageBoxW = NULL;
438 if (mod) pMessageBoxW = (MessageBoxW_funcptr)GetProcAddress( mod, "MessageBoxW" );
439 if (pMessageBoxW) pMessageBoxW( 0, str, NULL, MB_SYSTEMMODAL | MB_OK );
440 else ERR( "%s\n", debugstr_w(str) );