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Added wrapper to replace llseek+lread to avoid HANDLE/HFILE
[wine/multimedia.git] / dlls / msvcrt / cppexcept.c
blob23075cc4d27b3dd1d588b68f930bc6ed263d32d2
1 /*
2 * msvcrt C++ exception handling
3 *
4 * Copyright 2002 Alexandre Julliard
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 * A good reference is the article "How a C++ compiler implements
22 * exception handling" by Vishal Kochhar, available on
23 * www.thecodeproject.com.
24 */
25
26 #include "config.h"
27 #include "wine/port.h"
28
29 #include "winternl.h"
30 #include "msvcrt.h"
31 #include "wine/exception.h"
32 #include "msvcrt/excpt.h"
33 #include "wine/debug.h"
34
35 WINE_DEFAULT_DEBUG_CHANNEL(seh);
36
37 #define CXX_FRAME_MAGIC 0x19930520
38 #define CXX_EXCEPTION 0xe06d7363
39
40 typedef struct __type_info
41 {
42 void *vtable;
43 void *data;
44 char name[1];
45 } type_info;
46
47 /* the exception frame used by CxxFrameHandler */
48 typedef struct __cxx_exception_frame
49 {
50 EXCEPTION_FRAME frame; /* the standard exception frame */
51 int trylevel;
52 DWORD ebp;
53 } cxx_exception_frame;
54
55 /* info about a single catch {} block */
56 typedef struct __catchblock_info
57 {
58 UINT flags; /* flags (see below) */
59 type_info *type_info; /* C++ type caught by this block */
60 int offset; /* stack offset to copy exception object to */
61 void (*handler)(); /* catch block handler code */
62 } catchblock_info;
63 #define TYPE_FLAG_CONST 1
64 #define TYPE_FLAG_VOLATILE 2
65 #define TYPE_FLAG_REFERENCE 8
66
67 /* info about a single try {} block */
68 typedef struct __tryblock_info
69 {
70 int start_level; /* start trylevel of that block */
71 int end_level; /* end trylevel of that block */
72 int catch_level; /* initial trylevel of the catch block */
73 int catchblock_count; /* count of catch blocks in array */
74 catchblock_info *catchblock; /* array of catch blocks */
75 } tryblock_info;
76
77 /* info about the unwind handler for a given trylevel */
78 typedef struct __unwind_info
79 {
80 int prev; /* prev trylevel unwind handler, to run after this one */
81 void (*handler)(); /* unwind handler */
82 } unwind_info;
83
84 /* descriptor of all try blocks of a given function */
85 typedef struct __cxx_function_descr
86 {
87 UINT magic; /* must be CXX_FRAME_MAGIC */
88 UINT unwind_count; /* number of unwind handlers */
89 unwind_info *unwind_table; /* array of unwind handlers */
90 UINT tryblock_count; /* number of try blocks */
91 tryblock_info *tryblock; /* array of try blocks */
92 UINT unknown[3];
93 } cxx_function_descr;
94
95 /* complete information about a C++ type */
96 typedef struct __cxx_type_info
97 {
98 UINT flags; /* flags (see CLASS_* flags below) */
99 type_info *type_info; /* C++ type info */
100 int this_offset; /* offset of base class this pointer from start of object */
101 int vbase_descr; /* offset of virtual base class descriptor */
102 int vbase_offset; /* offset of this pointer offset in virtual base class descriptor */
103 size_t size; /* object size */
104 void (*copy_ctor)(); /* copy constructor */
105 } cxx_type_info;
106 #define CLASS_IS_SIMPLE_TYPE 1
107 #define CLASS_HAS_VIRTUAL_BASE_CLASS 4
108
109 /* table of C++ types that apply for a given object */
110 typedef struct __cxx_type_info_table
111 {
112 UINT count; /* number of types */
113 cxx_type_info *info[1]; /* array of types */
114 } cxx_type_info_table;
115
116 typedef DWORD (*cxx_exc_custom_handler)( PEXCEPTION_RECORD, cxx_exception_frame*,
117 PCONTEXT, struct __EXCEPTION_FRAME**,
118 cxx_function_descr*, int nested_trylevel,
119 EXCEPTION_FRAME *nested_frame, DWORD unknown3 );
120
121 /* type information for an exception object */
122 typedef struct __cxx_exception_type
123 {
124 UINT flags; /* TYPE_FLAG flags */
125 void (*destructor)(); /* exception object destructor */
126 cxx_exc_custom_handler custom_handler; /* custom handler for this exception */
127 cxx_type_info_table *type_info_table; /* list of types for this exception object */
128 } cxx_exception_type;
129
130
131 #ifdef __i386__ /* CxxFrameHandler is not supported on non-i386 */
132
133 static DWORD cxx_frame_handler( PEXCEPTION_RECORD rec, cxx_exception_frame* frame,
134 PCONTEXT exc_context, EXCEPTION_FRAME** dispatch,
135 cxx_function_descr *descr, EXCEPTION_FRAME* nested_frame,
136 int nested_trylevel, CONTEXT86 *context );
137
138 /* call a function with a given ebp */
139 inline static void *call_ebp_func( void *func, void *ebp )
140 {
141 void *ret;
142 __asm__ __volatile__ ("pushl %%ebp; movl %2,%%ebp; call *%%eax; popl %%ebp" \
143 : "=a" (ret) : "0" (func), "g" (ebp) : "ecx", "edx", "memory" );
144 return ret;
145 }
146
147 /* call a copy constructor */
148 inline static void call_copy_ctor( void *func, void *this, void *src, int has_vbase )
149 {
150 TRACE( "calling copy ctor %p object %p src %p\n", func, this, src );
151 if (has_vbase)
152 /* in that case copy ctor takes an extra bool indicating whether to copy the base class */
153 __asm__ __volatile__("pushl $1; pushl %2; call *%0"
154 : : "r" (func), "c" (this), "g" (src) : "eax", "edx", "memory" );
155 else
156 __asm__ __volatile__("pushl %2; call *%0"
157 : : "r" (func), "c" (this), "g" (src) : "eax", "edx", "memory" );
158 }
159
160 /* call the destructor of the exception object */
161 inline static void call_dtor( void *func, void *object )
162 {
163 __asm__ __volatile__("call *%0" : : "r" (func), "c" (object) : "eax", "edx", "memory" );
164 }
165
166
167 static void dump_type( cxx_type_info *type )
168 {
169 DPRINTF( "flags %x type %p", type->flags, type->type_info );
170 if (type->type_info) DPRINTF( " (%p %s)", type->type_info->data, type->type_info->name );
171 DPRINTF( " offset %d vbase %d,%d size %d copy ctor %p\n", type->this_offset,
172 type->vbase_descr, type->vbase_offset, type->size, type->copy_ctor );
173 }
174
175 static void dump_exception_type( cxx_exception_type *type )
176 {
177 int i;
178
179 DPRINTF( "exception type:\n" );
180 DPRINTF( "flags %x destr %p handler %p type info %p\n",
181 type->flags, type->destructor, type->custom_handler, type->type_info_table );
182 for (i = 0; i < type->type_info_table->count; i++)
183 {
184 DPRINTF( " %d: ", i );
185 dump_type( type->type_info_table->info[i] );
186 }
187 }
188
189 static void dump_function_descr( cxx_function_descr *descr, cxx_exception_type *info )
190 {
191 int i, j;
192
193 DPRINTF( "function descr:\n" );
194 DPRINTF( "magic %x\n", descr->magic );
195 DPRINTF( "unwind table: %p %d\n", descr->unwind_table, descr->unwind_count );
196 for (i = 0; i < descr->unwind_count; i++)
197 {
198 DPRINTF( " %d: prev %d func %p\n", i,
199 descr->unwind_table[i].prev, descr->unwind_table[i].handler );
200 }
201 DPRINTF( "try table: %p %d\n", descr->tryblock, descr->tryblock_count );
202 for (i = 0; i < descr->tryblock_count; i++)
203 {
204 DPRINTF( " %d: start %d end %d catchlevel %d catch %p %d\n", i,
205 descr->tryblock[i].start_level, descr->tryblock[i].end_level,
206 descr->tryblock[i].catch_level, descr->tryblock[i].catchblock,
207 descr->tryblock[i].catchblock_count );
208 for (j = 0; j < descr->tryblock[i].catchblock_count; j++)
209 {
210 catchblock_info *ptr = &descr->tryblock[i].catchblock[j];
211 DPRINTF( " %d: flags %x offset %d handler %p type %p",
212 j, ptr->flags, ptr->offset, ptr->handler, ptr->type_info );
213 if (ptr->type_info) DPRINTF( " (%p %s)", ptr->type_info->data, ptr->type_info->name );
214 DPRINTF( "\n" );
215 }
216 }
217 }
218
219 /* compute the this pointer for a base class of a given type */
220 static void *get_this_pointer( cxx_type_info *type, void *object )
221 {
222 void *this_ptr;
223 int *offset_ptr;
224
225 if (!object) return NULL;
226 this_ptr = (char *)object + type->this_offset;
227 if (type->vbase_descr >= 0)
228 {
229 /* move this ptr to vbase descriptor */
230 this_ptr = (char *)this_ptr + type->vbase_descr;
231 /* and fetch additional offset from vbase descriptor */
232 offset_ptr = (int *)(*(char **)this_ptr + type->vbase_offset);
233 this_ptr = (char *)this_ptr + *offset_ptr;
234 }
235 return this_ptr;
236 }
237
238 /* check if the exception type is caught by a given catch block, and return the type that matched */
239 static cxx_type_info *find_caught_type( cxx_exception_type *exc_type, catchblock_info *catchblock )
240 {
241 UINT i;
242
243 for (i = 0; i < exc_type->type_info_table->count; i++)
244 {
245 cxx_type_info *type = exc_type->type_info_table->info[i];
246
247 if (!catchblock->type_info) return type; /* catch(...) matches any type */
248 if (catchblock->type_info != type->type_info)
249 {
250 if (strcmp( catchblock->type_info->name, type->type_info->name )) continue;
251 }
252 /* type is the same, now check the flags */
253 if ((exc_type->flags & TYPE_FLAG_CONST) &&
254 !(catchblock->flags & TYPE_FLAG_CONST)) continue;
255 if ((exc_type->flags & TYPE_FLAG_VOLATILE) &&
256 !(catchblock->flags & TYPE_FLAG_VOLATILE)) continue;
257 return type; /* it matched */
258 }
259 return NULL;
260 }
261
262
263 /* copy the exception object where the catch block wants it */
264 static void copy_exception( void *object, cxx_exception_frame *frame,
265 catchblock_info *catchblock, cxx_type_info *type )
266 {
267 void **dest_ptr;
268
269 if (!catchblock->type_info || !catchblock->type_info->name[0]) return;
270 if (!catchblock->offset) return;
271 dest_ptr = (void **)((char *)&frame->ebp + catchblock->offset);
272
273 if (catchblock->flags & TYPE_FLAG_REFERENCE)
274 {
275 *dest_ptr = get_this_pointer( type, object );
276 }
277 else if (type->flags & CLASS_IS_SIMPLE_TYPE)
278 {
279 memmove( dest_ptr, object, type->size );
280 /* if it is a pointer, adjust it */
281 if (type->size == sizeof(void *)) *dest_ptr = get_this_pointer( type, *dest_ptr );
282 }
283 else /* copy the object */
284 {
285 if (type->copy_ctor)
286 call_copy_ctor( type->copy_ctor, dest_ptr, get_this_pointer(type,object),
287 (type->flags & CLASS_HAS_VIRTUAL_BASE_CLASS) );
288 else
289 memmove( dest_ptr, get_this_pointer(type,object), type->size );
290 }
291 }
292
293 /* unwind the local function up to a given trylevel */
294 static void cxx_local_unwind( cxx_exception_frame* frame, cxx_function_descr *descr, int last_level)
295 {
296 void (*handler)();
297 int trylevel = frame->trylevel;
298
299 while (trylevel != last_level)
300 {
301 if (trylevel < 0 || trylevel >= descr->unwind_count)
302 {
303 ERR( "invalid trylevel %d\n", trylevel );
304 MSVCRT_terminate();
305 }
306 handler = descr->unwind_table[trylevel].handler;
307 if (handler)
308 {
309 TRACE( "calling unwind handler %p trylevel %d last %d ebp %p\n",
310 handler, trylevel, last_level, &frame->ebp );
311 call_ebp_func( handler, &frame->ebp );
312 }
313 trylevel = descr->unwind_table[trylevel].prev;
314 }
315 frame->trylevel = last_level;
316 }
317
318 /* exception frame for nested exceptions in catch block */
319 struct catch_func_nested_frame
320 {
321 EXCEPTION_FRAME frame; /* standard exception frame */
322 EXCEPTION_RECORD *prev_rec; /* previous record to restore in thread data */
323 cxx_exception_frame *cxx_frame; /* frame of parent exception */
324 cxx_function_descr *descr; /* descriptor of parent exception */
325 int trylevel; /* current try level */
326 };
327
328 /* handler for exceptions happening while calling a catch function */
329 static DWORD catch_function_nested_handler( EXCEPTION_RECORD *rec, EXCEPTION_FRAME *frame,
330 CONTEXT *context, EXCEPTION_FRAME **dispatcher )
331 {
332 struct catch_func_nested_frame *nested_frame = (struct catch_func_nested_frame *)frame;
333
334 if (rec->ExceptionFlags & (EH_UNWINDING | EH_EXIT_UNWIND))
335 {
336 msvcrt_get_thread_data()->exc_record = nested_frame->prev_rec;
337 return ExceptionContinueSearch;
338 }
339 else
340 {
341 TRACE( "got nested exception in catch function\n" );
342 return cxx_frame_handler( rec, nested_frame->cxx_frame, context,
343 NULL, nested_frame->descr, &nested_frame->frame,
344 nested_frame->trylevel, context );
345 }
346 }
347
348 /* find and call the appropriate catch block for an exception */
349 /* returns the address to continue execution to after the catch block was called */
350 inline static void *call_catch_block( PEXCEPTION_RECORD rec, cxx_exception_frame *frame,
351 cxx_function_descr *descr, int nested_trylevel,
352 cxx_exception_type *info )
353 {
354 int i, j;
355 void *addr, *object = (void *)rec->ExceptionInformation[1];
356 struct catch_func_nested_frame nested_frame;
357 int trylevel = frame->trylevel;
358 MSVCRT_thread_data *thread_data = msvcrt_get_thread_data();
359
360 for (i = 0; i < descr->tryblock_count; i++)
361 {
362 tryblock_info *tryblock = &descr->tryblock[i];
363
364 if (trylevel < tryblock->start_level) continue;
365 if (trylevel > tryblock->end_level) continue;
366
367 /* got a try block */
368 for (j = 0; j < tryblock->catchblock_count; j++)
369 {
370 catchblock_info *catchblock = &tryblock->catchblock[j];
371 cxx_type_info *type = find_caught_type( info, catchblock );
372 if (!type) continue;
373
374 TRACE( "matched type %p in tryblock %d catchblock %d\n", type, i, j );
375
376 /* copy the exception to its destination on the stack */
377 copy_exception( object, frame, catchblock, type );
378
379 /* unwind the stack */
380 RtlUnwind( frame, 0, rec, 0 );
381 cxx_local_unwind( frame, descr, tryblock->start_level );
382 frame->trylevel = tryblock->end_level + 1;
383
384 /* call the catch block */
385 TRACE( "calling catch block %p for type %p addr %p ebp %p\n",
386 catchblock, type, catchblock->handler, &frame->ebp );
387
388 /* setup an exception block for nested exceptions */
389
390 nested_frame.frame.Handler = catch_function_nested_handler;
391 nested_frame.prev_rec = thread_data->exc_record;
392 nested_frame.cxx_frame = frame;
393 nested_frame.descr = descr;
394 nested_frame.trylevel = nested_trylevel + 1;
395
396 __wine_push_frame( &nested_frame.frame );
397 thread_data->exc_record = rec;
398 addr = call_ebp_func( catchblock->handler, &frame->ebp );
399 thread_data->exc_record = nested_frame.prev_rec;
400 __wine_pop_frame( &nested_frame.frame );
401
402 if (info->destructor) call_dtor( info->destructor, object );
403 TRACE( "done, continuing at %p\n", addr );
404 return addr;
405 }
406 }
407 return NULL;
408 }
409
410
411 /*********************************************************************
412 * cxx_frame_handler
413 *
414 * Implementation of __CxxFrameHandler.
415 */
416 static DWORD cxx_frame_handler( PEXCEPTION_RECORD rec, cxx_exception_frame* frame,
417 PCONTEXT exc_context, EXCEPTION_FRAME** dispatch,
418 cxx_function_descr *descr, EXCEPTION_FRAME* nested_frame,
419 int nested_trylevel, CONTEXT86 *context )
420 {
421 cxx_exception_type *exc_type;
422 void *next_ip;
423
424 if (descr->magic != CXX_FRAME_MAGIC)
425 {
426 ERR( "invalid frame magic %x\n", descr->magic );
427 return ExceptionContinueSearch;
428 }
429 if (rec->ExceptionFlags & (EH_UNWINDING|EH_EXIT_UNWIND))
430 {
431 if (descr->unwind_count && !nested_trylevel) cxx_local_unwind( frame, descr, -1 );
432 return ExceptionContinueSearch;
433 }
434 if (!descr->tryblock_count) return ExceptionContinueSearch;
435
436 exc_type = (cxx_exception_type *)rec->ExceptionInformation[2];
437 if (rec->ExceptionCode == CXX_EXCEPTION &&
438 rec->ExceptionInformation[0] > CXX_FRAME_MAGIC &&
439 exc_type->custom_handler)
440 {
441 return exc_type->custom_handler( rec, frame, exc_context, dispatch,
442 descr, nested_trylevel, nested_frame, 0 );
443 }
444
445 if (!exc_type) /* nested exception, fetch info from original exception */
446 {
447 rec = msvcrt_get_thread_data()->exc_record;
448 exc_type = (cxx_exception_type *)rec->ExceptionInformation[2];
449 }
450
451 if (TRACE_ON(seh))
452 {
453 TRACE("handling C++ exception rec %p frame %p trylevel %d descr %p nested_frame %p\n",
454 rec, frame, frame->trylevel, descr, nested_frame );
455 dump_exception_type( exc_type );
456 dump_function_descr( descr, exc_type );
457 }
458
459 next_ip = call_catch_block( rec, frame, descr, frame->trylevel, exc_type );
460
461 if (!next_ip) return ExceptionContinueSearch;
462 rec->ExceptionFlags &= ~EH_NONCONTINUABLE;
463 context->Eip = (DWORD)next_ip;
464 context->Ebp = (DWORD)&frame->ebp;
465 context->Esp = ((DWORD*)frame)[-1];
466 return ExceptionContinueExecution;
467 }
468
469
470 /*********************************************************************
471 * __CxxFrameHandler (MSVCRT.@)
472 */
473 void __CxxFrameHandler( PEXCEPTION_RECORD rec, EXCEPTION_FRAME* frame,
474 PCONTEXT exc_context, EXCEPTION_FRAME** dispatch,
475 CONTEXT86 *context )
476 {
477 cxx_function_descr *descr = (cxx_function_descr *)context->Eax;
478 context->Eax = cxx_frame_handler( rec, (cxx_exception_frame *)frame,
479 exc_context, dispatch, descr, NULL, 0, context );
480 }
481
482 #endif /* __i386__ */
483
484 /*********************************************************************
485 * _CxxThrowException (MSVCRT.@)
486 */
487 void _CxxThrowException( void *object, cxx_exception_type *type )
488 {
489 DWORD args[3];
490
491 args[0] = CXX_FRAME_MAGIC;
492 args[1] = (DWORD)object;
493 args[2] = (DWORD)type;
494 RaiseException( CXX_EXCEPTION, EH_NONCONTINUABLE, 3, args );
495 }
Maarten's multimedia branch