2 * msvcrt C++ exception handling
4 * Copyright 2002 Alexandre Julliard
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.
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.
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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
21 * A good reference is the article "How a C++ compiler implements
22 * exception handling" by Vishal Kochhar, available on
23 * www.thecodeproject.com.
26 #define __WINE_DEBUG_CHANNEL__
30 #include <wine/exception.h>
31 #include <internal/wine/msvcrt.h>
32 #include <internal/wine/cppexcept.h>
34 #ifdef __i386__ /* CxxFrameHandler is not supported on non-i386 */
36 WINE_DEFAULT_DEBUG_CHANNEL(seh
);
38 DWORD CDECL
cxx_frame_handler( PEXCEPTION_RECORD rec
, cxx_exception_frame
* frame
,
39 PCONTEXT context
, EXCEPTION_REGISTRATION_RECORD
** dispatch
,
40 const cxx_function_descr
*descr
,
41 EXCEPTION_REGISTRATION_RECORD
* nested_frame
, int nested_trylevel
);
43 /* call a function with a given ebp */
44 static inline void *call_ebp_func( void *func
, void *ebp
)
48 __asm__
__volatile__ ("pushl %%ebx\n\t"
54 : "=a" (ret
), "=S" (dummy
), "=D" (dummy
)
55 : "0" (func
), "1" (ebp
) : "ecx", "edx", "memory" );
59 /* call a copy constructor */
60 static inline void call_copy_ctor( void *func
, void *this, void *src
, int has_vbase
)
62 TRACE( "calling copy ctor %p object %p src %p\n", func
, this, src
);
64 /* in that case copy ctor takes an extra bool indicating whether to copy the base class */
65 __asm__
__volatile__("pushl $1; pushl %2; call *%0"
66 : : "r" (func
), "c" (this), "r" (src
) : "eax", "edx", "memory" );
68 __asm__
__volatile__("pushl %2; call *%0"
69 : : "r" (func
), "c" (this), "r" (src
) : "eax", "edx", "memory" );
72 /* call the destructor of the exception object */
73 static inline void call_dtor( void *func
, void *object
)
75 __asm__
__volatile__("call *%0" : : "r" (func
), "c" (object
) : "eax", "edx", "memory" );
78 /* continue execution to the specified address after exception is caught */
79 static inline void DECLSPEC_NORETURN
continue_after_catch( cxx_exception_frame
* frame
, void *addr
)
81 __asm__
__volatile__("movl -4(%0),%%esp; leal 12(%0),%%ebp; jmp *%1"
82 : : "r" (frame
), "a" (addr
) );
83 for (;;) ; /* unreached */
86 static inline void dump_type( const cxx_type_info
*type
)
88 TRACE( "flags %x type %p %s offsets %d,%d,%d size %d copy ctor %p\n",
89 type
->flags
, type
->type_info
, dbgstr_type_info(type
->type_info
),
90 type
->offsets
.this_offset
, type
->offsets
.vbase_descr
, type
->offsets
.vbase_offset
,
91 type
->size
, type
->copy_ctor
);
94 static void dump_exception_type( const cxx_exception_type
*type
)
98 TRACE( "flags %x destr %p handler %p type info %p\n",
99 type
->flags
, type
->destructor
, type
->custom_handler
, type
->type_info_table
);
100 for (i
= 0; i
< type
->type_info_table
->count
; i
++)
103 dump_type( type
->type_info_table
->info
[i
] );
107 static void dump_function_descr( const cxx_function_descr
*descr
)
109 #ifndef WINE_NO_TRACE_MSGS
113 TRACE( "magic %x\n", descr
->magic
);
114 TRACE( "unwind table: %p %d\n", descr
->unwind_table
, descr
->unwind_count
);
115 for (i
= 0; i
< descr
->unwind_count
; i
++)
117 TRACE( " %d: prev %d func %p\n", i
,
118 descr
->unwind_table
[i
].prev
, descr
->unwind_table
[i
].handler
);
120 TRACE( "try table: %p %d\n", descr
->tryblock
, descr
->tryblock_count
);
121 for (i
= 0; i
< descr
->tryblock_count
; i
++)
123 TRACE( " %d: start %d end %d catchlevel %d catch %p %d\n", i
,
124 descr
->tryblock
[i
].start_level
, descr
->tryblock
[i
].end_level
,
125 descr
->tryblock
[i
].catch_level
, descr
->tryblock
[i
].catchblock
,
126 descr
->tryblock
[i
].catchblock_count
);
127 for (j
= 0; j
< descr
->tryblock
[i
].catchblock_count
; j
++)
129 const catchblock_info
*ptr
= &descr
->tryblock
[i
].catchblock
[j
];
130 TRACE( " %d: flags %x offset %d handler %p type %p %s\n",
131 j
, ptr
->flags
, ptr
->offset
, ptr
->handler
,
132 ptr
->type_info
, dbgstr_type_info( ptr
->type_info
) );
136 if (descr
->magic
<= CXX_FRAME_MAGIC_VC6
) return;
137 TRACE( "expect list: %p\n", descr
->expect_list
);
138 if (descr
->magic
<= CXX_FRAME_MAGIC_VC7
) return;
139 TRACE( "flags: %08x\n", descr
->flags
);
142 /* check if the exception type is caught by a given catch block, and return the type that matched */
143 static const cxx_type_info
*find_caught_type( cxx_exception_type
*exc_type
,
144 const catchblock_info
*catchblock
)
148 for (i
= 0; i
< exc_type
->type_info_table
->count
; i
++)
150 const cxx_type_info
*type
= exc_type
->type_info_table
->info
[i
];
152 if (!catchblock
->type_info
) return type
; /* catch(...) matches any type */
153 if (catchblock
->type_info
!= type
->type_info
)
155 if (strcmp( catchblock
->type_info
->mangled
, type
->type_info
->mangled
)) continue;
157 /* type is the same, now check the flags */
158 if ((exc_type
->flags
& TYPE_FLAG_CONST
) &&
159 !(catchblock
->flags
& TYPE_FLAG_CONST
)) continue;
160 if ((exc_type
->flags
& TYPE_FLAG_VOLATILE
) &&
161 !(catchblock
->flags
& TYPE_FLAG_VOLATILE
)) continue;
162 return type
; /* it matched */
168 /* copy the exception object where the catch block wants it */
169 static void copy_exception( void *object
, cxx_exception_frame
*frame
,
170 const catchblock_info
*catchblock
, const cxx_type_info
*type
)
174 if (!catchblock
->type_info
|| !catchblock
->type_info
->mangled
[0]) return;
175 if (!catchblock
->offset
) return;
176 dest_ptr
= (void **)((char *)&frame
->ebp
+ catchblock
->offset
);
178 if (catchblock
->flags
& TYPE_FLAG_REFERENCE
)
180 *dest_ptr
= get_this_pointer( &type
->offsets
, object
);
182 else if (type
->flags
& CLASS_IS_SIMPLE_TYPE
)
184 memmove( dest_ptr
, object
, type
->size
);
185 /* if it is a pointer, adjust it */
186 if (type
->size
== sizeof(void *)) *dest_ptr
= get_this_pointer( &type
->offsets
, *dest_ptr
);
188 else /* copy the object */
191 call_copy_ctor( type
->copy_ctor
, dest_ptr
, get_this_pointer(&type
->offsets
,object
),
192 (type
->flags
& CLASS_HAS_VIRTUAL_BASE_CLASS
) );
194 memmove( dest_ptr
, get_this_pointer(&type
->offsets
,object
), type
->size
);
198 /* unwind the local function up to a given trylevel */
199 static void cxx_local_unwind( cxx_exception_frame
* frame
, const cxx_function_descr
*descr
, int last_level
)
201 void (*handler
)(void);
202 int trylevel
= frame
->trylevel
;
204 while (trylevel
!= last_level
)
206 if (trylevel
< 0 || trylevel
>= descr
->unwind_count
)
208 ERR( "invalid trylevel %d\n", trylevel
);
211 handler
= descr
->unwind_table
[trylevel
].handler
;
214 TRACE( "calling unwind handler %p trylevel %d last %d ebp %p\n",
215 handler
, trylevel
, last_level
, &frame
->ebp
);
216 call_ebp_func( handler
, &frame
->ebp
);
218 trylevel
= descr
->unwind_table
[trylevel
].prev
;
220 frame
->trylevel
= last_level
;
223 /* exception frame for nested exceptions in catch block */
224 struct catch_func_nested_frame
226 EXCEPTION_REGISTRATION_RECORD frame
; /* standard exception frame */
227 EXCEPTION_RECORD
*prev_rec
; /* previous record to restore in thread data */
228 cxx_exception_frame
*cxx_frame
; /* frame of parent exception */
229 const cxx_function_descr
*descr
; /* descriptor of parent exception */
230 int trylevel
; /* current try level */
231 EXCEPTION_RECORD
*rec
; /* rec associated with frame */
234 /* handler for exceptions happening while calling a catch function */
235 static DWORD
catch_function_nested_handler( EXCEPTION_RECORD
*rec
, EXCEPTION_REGISTRATION_RECORD
*frame
,
236 CONTEXT
*context
, EXCEPTION_REGISTRATION_RECORD
**dispatcher
)
238 struct catch_func_nested_frame
*nested_frame
= (struct catch_func_nested_frame
*)frame
;
240 if (rec
->ExceptionFlags
& (EH_UNWINDING
| EH_EXIT_UNWIND
))
242 msvcrt_get_thread_data()->exc_record
= nested_frame
->prev_rec
;
243 return ExceptionContinueSearch
;
246 TRACE( "got nested exception in catch function\n" );
248 if(rec
->ExceptionCode
== CXX_EXCEPTION
)
250 PEXCEPTION_RECORD prev_rec
= nested_frame
->rec
;
251 if(rec
->ExceptionInformation
[1] == 0 && rec
->ExceptionInformation
[2] == 0)
253 /* exception was rethrown */
254 rec
->ExceptionInformation
[1] = prev_rec
->ExceptionInformation
[1];
255 rec
->ExceptionInformation
[2] = prev_rec
->ExceptionInformation
[2];
256 TRACE("detect rethrow: re-propagate: obj: %lx, type: %lx\n",
257 rec
->ExceptionInformation
[1], rec
->ExceptionInformation
[2]);
260 /* new exception in exception handler, destroy old */
261 void *object
= (void*)prev_rec
->ExceptionInformation
[1];
262 cxx_exception_type
*info
= (cxx_exception_type
*) prev_rec
->ExceptionInformation
[2];
263 TRACE("detect threw new exception in catch block - destroy old(obj: %p type: %p)\n",
265 if(info
&& info
->destructor
)
266 call_dtor( info
->destructor
, object
);
270 return cxx_frame_handler( rec
, nested_frame
->cxx_frame
, context
,
271 NULL
, nested_frame
->descr
, &nested_frame
->frame
,
272 nested_frame
->trylevel
);
275 /* find and call the appropriate catch block for an exception */
276 /* returns the address to continue execution to after the catch block was called */
277 static inline void call_catch_block( PEXCEPTION_RECORD rec
, cxx_exception_frame
*frame
,
278 const cxx_function_descr
*descr
, int nested_trylevel
,
279 cxx_exception_type
*info
)
283 void *addr
, *object
= (void *)rec
->ExceptionInformation
[1];
284 struct catch_func_nested_frame nested_frame
;
285 int trylevel
= frame
->trylevel
;
286 MSVCRT_thread_data
*thread_data
= msvcrt_get_thread_data();
287 DWORD save_esp
= ((DWORD
*)frame
)[-1];
289 for (i
= 0; i
< descr
->tryblock_count
; i
++)
291 const tryblock_info
*tryblock
= &descr
->tryblock
[i
];
293 if (trylevel
< tryblock
->start_level
) continue;
294 if (trylevel
> tryblock
->end_level
) continue;
296 /* got a try block */
297 for (j
= 0; j
< tryblock
->catchblock_count
; j
++)
299 const catchblock_info
*catchblock
= &tryblock
->catchblock
[j
];
302 const cxx_type_info
*type
= find_caught_type( info
, catchblock
);
305 TRACE( "matched type %p in tryblock %d catchblock %d\n", type
, i
, j
);
307 /* copy the exception to its destination on the stack */
308 copy_exception( object
, frame
, catchblock
, type
);
312 /* no CXX_EXCEPTION only proceed with a catch(...) block*/
313 if(catchblock
->type_info
)
315 TRACE("found catch(...) block\n");
318 /* unwind the stack */
319 RtlUnwind( frame
, 0, rec
, 0 );
320 cxx_local_unwind( frame
, descr
, tryblock
->start_level
);
321 frame
->trylevel
= tryblock
->end_level
+ 1;
323 /* call the catch block */
324 TRACE( "calling catch block %p addr %p ebp %p\n",
325 catchblock
, catchblock
->handler
, &frame
->ebp
);
327 /* setup an exception block for nested exceptions */
329 nested_frame
.frame
.Handler
= (PEXCEPTION_ROUTINE
)catch_function_nested_handler
;
330 nested_frame
.prev_rec
= thread_data
->exc_record
;
331 nested_frame
.cxx_frame
= frame
;
332 nested_frame
.descr
= descr
;
333 nested_frame
.trylevel
= nested_trylevel
+ 1;
334 nested_frame
.rec
= rec
;
336 __wine_push_frame( &nested_frame
.frame
);
337 thread_data
->exc_record
= rec
;
338 addr
= call_ebp_func( catchblock
->handler
, &frame
->ebp
);
339 thread_data
->exc_record
= nested_frame
.prev_rec
;
340 __wine_pop_frame( &nested_frame
.frame
);
342 ((DWORD
*)frame
)[-1] = save_esp
;
343 if (info
&& info
->destructor
) call_dtor( info
->destructor
, object
);
344 TRACE( "done, continuing at %p\n", addr
);
346 continue_after_catch( frame
, addr
);
352 /*********************************************************************
355 * Implementation of __CxxFrameHandler.
357 DWORD CDECL
cxx_frame_handler( PEXCEPTION_RECORD rec
, cxx_exception_frame
* frame
,
358 PCONTEXT context
, EXCEPTION_REGISTRATION_RECORD
** dispatch
,
359 const cxx_function_descr
*descr
,
360 EXCEPTION_REGISTRATION_RECORD
* nested_frame
,
361 int nested_trylevel
)
363 cxx_exception_type
*exc_type
;
365 if (descr
->magic
< CXX_FRAME_MAGIC_VC6
|| descr
->magic
> CXX_FRAME_MAGIC_VC8
)
367 ERR( "invalid frame magic %x\n", descr
->magic
);
368 return ExceptionContinueSearch
;
370 if (descr
->magic
>= CXX_FRAME_MAGIC_VC8
&&
371 (descr
->flags
& FUNC_DESCR_SYNCHRONOUS
) &&
372 (rec
->ExceptionCode
!= CXX_EXCEPTION
))
373 return ExceptionContinueSearch
; /* handle only c++ exceptions */
375 if (rec
->ExceptionFlags
& (EH_UNWINDING
|EH_EXIT_UNWIND
))
377 if (descr
->unwind_count
&& !nested_trylevel
) cxx_local_unwind( frame
, descr
, -1 );
378 return ExceptionContinueSearch
;
380 if (!descr
->tryblock_count
) return ExceptionContinueSearch
;
382 if(rec
->ExceptionCode
== CXX_EXCEPTION
)
384 exc_type
= (cxx_exception_type
*)rec
->ExceptionInformation
[2];
386 if (rec
->ExceptionInformation
[0] > CXX_FRAME_MAGIC_VC8
&&
387 exc_type
->custom_handler
)
389 return exc_type
->custom_handler( rec
, frame
, context
, dispatch
,
390 descr
, nested_trylevel
, nested_frame
, 0 );
395 TRACE("handling C++ exception rec %p frame %p trylevel %d descr %p nested_frame %p\n",
396 rec
, frame
, frame
->trylevel
, descr
, nested_frame
);
397 dump_exception_type( exc_type
);
398 dump_function_descr( descr
);
404 TRACE("handling C exception code %x rec %p frame %p trylevel %d descr %p nested_frame %p\n",
405 rec
->ExceptionCode
, rec
, frame
, frame
->trylevel
, descr
, nested_frame
);
408 call_catch_block( rec
, frame
, descr
, frame
->trylevel
, exc_type
);
409 return ExceptionContinueSearch
;
413 /*********************************************************************
414 * __CxxFrameHandler (MSVCRT.@)
416 extern DWORD CDECL
__CxxFrameHandler( PEXCEPTION_RECORD rec
, EXCEPTION_REGISTRATION_RECORD
* frame
,
417 PCONTEXT context
, EXCEPTION_REGISTRATION_RECORD
** dispatch
);
418 __ASM_GLOBAL_FUNC( __CxxFrameHandler
,
419 "pushl $0\n\t" /* nested_trylevel */
420 __ASM_CFI(".cfi_adjust_cfa_offset 4\n\t")
421 "pushl $0\n\t" /* nested_frame */
422 __ASM_CFI(".cfi_adjust_cfa_offset 4\n\t")
423 "pushl %eax\n\t" /* descr */
424 __ASM_CFI(".cfi_adjust_cfa_offset 4\n\t")
425 "pushl 28(%esp)\n\t" /* dispatch */
426 __ASM_CFI(".cfi_adjust_cfa_offset 4\n\t")
427 "pushl 28(%esp)\n\t" /* context */
428 __ASM_CFI(".cfi_adjust_cfa_offset 4\n\t")
429 "pushl 28(%esp)\n\t" /* frame */
430 __ASM_CFI(".cfi_adjust_cfa_offset 4\n\t")
431 "pushl 28(%esp)\n\t" /* rec */
432 __ASM_CFI(".cfi_adjust_cfa_offset 4\n\t")
433 "call " __ASM_NAME("cxx_frame_handler") "\n\t"
435 __ASM_CFI(".cfi_adjust_cfa_offset -28\n\t")
439 /*********************************************************************
440 * __CxxLongjmpUnwind (MSVCRT.@)
442 * Callback meant to be used as UnwindFunc for setjmp/longjmp.
444 void __stdcall
__CxxLongjmpUnwind( const struct MSVCRT___JUMP_BUFFER
*buf
)
446 cxx_exception_frame
*frame
= (cxx_exception_frame
*)buf
->Registration
;
447 const cxx_function_descr
*descr
= (const cxx_function_descr
*)buf
->UnwindData
[0];
449 TRACE( "unwinding frame %p descr %p trylevel %ld\n", frame
, descr
, buf
->TryLevel
);
450 cxx_local_unwind( frame
, descr
, buf
->TryLevel
);
453 #endif /* __i386__ */
456 /*********************************************************************
457 * __CppXcptFilter (MSVCRT.@)
459 int CDECL
__CppXcptFilter(NTSTATUS ex
, PEXCEPTION_POINTERS ptr
)
461 /* only filter c++ exceptions */
462 if (ex
!= CXX_EXCEPTION
) return EXCEPTION_CONTINUE_SEARCH
;
463 return _XcptFilter( ex
, ptr
);
466 /*********************************************************************
467 * _CxxThrowException (MSVCRT.@)
469 void CDECL
_CxxThrowException( exception
*object
, const cxx_exception_type
*type
)
473 args
[0] = CXX_FRAME_MAGIC_VC6
;
474 args
[1] = (ULONG_PTR
)object
;
475 args
[2] = (ULONG_PTR
)type
;
476 RaiseException( CXX_EXCEPTION
, EH_NONCONTINUABLE
, 3, args
);
479 /*********************************************************************
480 * __CxxDetectRethrow (MSVCRT.@)
482 BOOL CDECL
__CxxDetectRethrow(PEXCEPTION_POINTERS ptrs
)
484 PEXCEPTION_RECORD rec
;
489 rec
= ptrs
->ExceptionRecord
;
491 if (rec
->ExceptionCode
== CXX_EXCEPTION
&&
492 rec
->NumberParameters
== 3 &&
493 rec
->ExceptionInformation
[0] == CXX_FRAME_MAGIC_VC6
&&
494 rec
->ExceptionInformation
[2])
496 ptrs
->ExceptionRecord
= msvcrt_get_thread_data()->exc_record
;
499 return (msvcrt_get_thread_data()->exc_record
== rec
);
502 /*********************************************************************
503 * __CxxQueryExceptionSize (MSVCRT.@)
505 unsigned int CDECL
__CxxQueryExceptionSize(void)
507 return sizeof(cxx_exception_type
);