| /* | |
| * msvcrt C++ exception handling | |
| * | |
| * Copyright 2002 Alexandre Julliard | |
| * | |
| * This library is free software; you can redistribute it and/or | |
| * modify it under the terms of the GNU Lesser General Public | |
| * License as published by the Free Software Foundation; either | |
| * version 2.1 of the License, or (at your option) any later version. | |
| * | |
| * This library is distributed in the hope that it will be useful, | |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
| * Lesser General Public License for more details. | |
| * | |
| * You should have received a copy of the GNU Lesser General Public | |
| * License along with this library; if not, write to the Free Software | |
| * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |
| * | |
| * NOTES | |
| * A good reference is the article "How a C++ compiler implements | |
| * exception handling" by Vishal Kochhar, available on | |
| * www.thecodeproject.com. | |
| */ | |
| #include "config.h" | |
| #include "wine/port.h" | |
| #include "winternl.h" | |
| #include "msvcrt.h" | |
| #include "wine/exception.h" | |
| #include "msvcrt/excpt.h" | |
| #include "wine/debug.h" | |
| WINE_DEFAULT_DEBUG_CHANNEL(seh); | |
| #define CXX_FRAME_MAGIC 0x19930520 | |
| #define CXX_EXCEPTION 0xe06d7363 | |
| typedef struct __type_info | |
| { | |
| void *vtable; | |
| void *data; | |
| char name[1]; | |
| } type_info; | |
| /* the exception frame used by CxxFrameHandler */ | |
| typedef struct __cxx_exception_frame | |
| { | |
| EXCEPTION_FRAME *prev; | |
| void (*handler)(PEXCEPTION_RECORD, PEXCEPTION_FRAME, PCONTEXT, PEXCEPTION_RECORD); | |
| int trylevel; | |
| DWORD ebp; | |
| } cxx_exception_frame; | |
| /* info about a single catch {} block */ | |
| typedef struct __catchblock_info | |
| { | |
| UINT flags; /* flags (see below) */ | |
| type_info *type_info; /* C++ type caught by this block */ | |
| int offset; /* stack offset to copy exception object to */ | |
| void (*handler)(); /* catch block handler code */ | |
| } catchblock_info; | |
| #define TYPE_FLAG_CONST 1 | |
| #define TYPE_FLAG_VOLATILE 2 | |
| #define TYPE_FLAG_REFERENCE 8 | |
| /* info about a single try {} block */ | |
| typedef struct __tryblock_info | |
| { | |
| int start_level; /* start trylevel of that block */ | |
| int end_level; /* end trylevel of that block */ | |
| int catch_level; /* initial trylevel of the catch block */ | |
| int catchblock_count; /* count of catch blocks in array */ | |
| catchblock_info *catchblock; /* array of catch blocks */ | |
| } tryblock_info; | |
| /* info about the unwind handler for a given trylevel */ | |
| typedef struct __unwind_info | |
| { | |
| int prev; /* prev trylevel unwind handler, to run after this one */ | |
| void (*handler)(); /* unwind handler */ | |
| } unwind_info; | |
| /* descriptor of all try blocks of a given function */ | |
| typedef struct __cxx_function_descr | |
| { | |
| UINT magic; /* must be CXX_FRAME_MAGIC */ | |
| UINT unwind_count; /* number of unwind handlers */ | |
| unwind_info *unwind_table; /* array of unwind handlers */ | |
| UINT tryblock_count; /* number of try blocks */ | |
| tryblock_info *tryblock; /* array of try blocks */ | |
| UINT unknown[3]; | |
| } cxx_function_descr; | |
| /* complete information about a C++ type */ | |
| typedef struct __cxx_type_info | |
| { | |
| UINT flags; /* flags (see CLASS_* flags below) */ | |
| type_info *type_info; /* C++ type info */ | |
| int this_offset; /* offset of base class this pointer from start of object */ | |
| int vbase_descr; /* offset of virtual base class descriptor */ | |
| int vbase_offset; /* offset of this pointer offset in virtual base class descriptor */ | |
| size_t size; /* object size */ | |
| void (*copy_ctor)(); /* copy constructor */ | |
| } cxx_type_info; | |
| #define CLASS_IS_SIMPLE_TYPE 1 | |
| #define CLASS_HAS_VIRTUAL_BASE_CLASS 4 | |
| /* table of C++ types that apply for a given object */ | |
| typedef struct __cxx_type_info_table | |
| { | |
| UINT count; /* number of types */ | |
| cxx_type_info *info[1]; /* array of types */ | |
| } cxx_type_info_table; | |
| typedef DWORD (*cxx_exc_custom_handler)( PEXCEPTION_RECORD, cxx_exception_frame*, | |
| PCONTEXT, struct __EXCEPTION_FRAME**, | |
| cxx_function_descr*, DWORD unknown1, | |
| DWORD unknown2, DWORD unknown3 ); | |
| /* type information for an exception object */ | |
| typedef struct __cxx_exception_type | |
| { | |
| UINT flags; /* TYPE_FLAG flags */ | |
| void (*destructor)(); /* exception object destructor */ | |
| cxx_exc_custom_handler custom_handler; /* custom handler for this exception */ | |
| cxx_type_info_table *type_info_table; /* list of types for this exception object */ | |
| } cxx_exception_type; | |
| #ifdef __i386__ /* CxxFrameHandler is not supported on non-i386 */ | |
| /* call a function with a given ebp */ | |
| inline static void *call_ebp_func( void *func, void *ebp ) | |
| { | |
| void *ret; | |
| __asm__ __volatile__ ("pushl %%ebp; movl %2,%%ebp; call *%%eax;; popl %%ebp" \ | |
| : "=a" (ret) : "0" (func), "g" (ebp)); | |
| return ret; | |
| } | |
| /* call a copy constructor */ | |
| inline static void call_copy_ctor( void *func, void *this, void *src, int has_vbase ) | |
| { | |
| TRACE( "calling copy ctor %p object %p src %p\n", func, this, src ); | |
| if (has_vbase) | |
| /* in that case copy ctor takes an extra bool indicating whether to copy the base class */ | |
| __asm__ __volatile__("pushl $1; pushl %2; call *%0" | |
| : : "r" (func), "c" (this), "g" (src) ); | |
| else | |
| __asm__ __volatile__("pushl %2; call *%0" | |
| : : "r" (func), "c" (this), "g" (src) ); | |
| } | |
| /* call the destructor of the exception object */ | |
| inline static void call_dtor( void *func, void *object ) | |
| { | |
| __asm__ __volatile__("call *%0" : : "r" (func), "c" (object) ); | |
| } | |
| static void dump_type( cxx_type_info *type ) | |
| { | |
| DPRINTF( "flags %x type %p", type->flags, type->type_info ); | |
| if (type->type_info) DPRINTF( " (%p %s)", type->type_info->data, type->type_info->name ); | |
| DPRINTF( " offset %d vbase %d,%d size %d copy ctor %p\n", type->this_offset, | |
| type->vbase_descr, type->vbase_offset, type->size, type->copy_ctor ); | |
| } | |
| static void dump_exception_type( cxx_exception_type *type ) | |
| { | |
| int i; | |
| DPRINTF( "exception type:\n" ); | |
| DPRINTF( "flags %x destr %p handler %p type info %p\n", | |
| type->flags, type->destructor, type->custom_handler, type->type_info_table ); | |
| for (i = 0; i < type->type_info_table->count; i++) | |
| { | |
| DPRINTF( " %d: ", i ); | |
| dump_type( type->type_info_table->info[i] ); | |
| } | |
| } | |
| static void dump_function_descr( cxx_function_descr *descr, cxx_exception_type *info ) | |
| { | |
| int i, j; | |
| DPRINTF( "function descr:\n" ); | |
| DPRINTF( "magic %x\n", descr->magic ); | |
| DPRINTF( "unwind table: %p %d\n", descr->unwind_table, descr->unwind_count ); | |
| for (i = 0; i < descr->unwind_count; i++) | |
| { | |
| DPRINTF( " %d: prev %d func %p\n", i, | |
| descr->unwind_table[i].prev, descr->unwind_table[i].handler ); | |
| } | |
| DPRINTF( "try table: %p %d\n", descr->tryblock, descr->tryblock_count ); | |
| for (i = 0; i < descr->tryblock_count; i++) | |
| { | |
| DPRINTF( " %d: start %d end %d catchlevel %d catch %p %d\n", i, | |
| descr->tryblock[i].start_level, descr->tryblock[i].end_level, | |
| descr->tryblock[i].catch_level, descr->tryblock[i].catchblock, | |
| descr->tryblock[i].catchblock_count ); | |
| for (j = 0; j < descr->tryblock[i].catchblock_count; j++) | |
| { | |
| catchblock_info *ptr = &descr->tryblock[i].catchblock[j]; | |
| DPRINTF( " %d: flags %x offset %d handler %p type %p", | |
| j, ptr->flags, ptr->offset, ptr->handler, ptr->type_info ); | |
| if (ptr->type_info) DPRINTF( " (%p %s)", ptr->type_info->data, ptr->type_info->name ); | |
| DPRINTF( "\n" ); | |
| } | |
| } | |
| } | |
| /* compute the this pointer for a base class of a given type */ | |
| static void *get_this_pointer( cxx_type_info *type, void *object ) | |
| { | |
| void *this_ptr; | |
| int *offset_ptr; | |
| if (!object) return NULL; | |
| this_ptr = (char *)object + type->this_offset; | |
| if (type->vbase_descr >= 0) | |
| { | |
| /* move this ptr to vbase descriptor */ | |
| this_ptr = (char *)this_ptr + type->vbase_descr; | |
| /* and fetch additional offset from vbase descriptor */ | |
| offset_ptr = (int *)(*(char **)this_ptr + type->vbase_offset); | |
| this_ptr = (char *)this_ptr + *offset_ptr; | |
| } | |
| return this_ptr; | |
| } | |
| /* check if the exception type is caught by a given catch block, and return the type that matched */ | |
| static cxx_type_info *find_caught_type( cxx_exception_type *exc_type, catchblock_info *catchblock ) | |
| { | |
| UINT i; | |
| for (i = 0; i < exc_type->type_info_table->count; i++) | |
| { | |
| cxx_type_info *type = exc_type->type_info_table->info[i]; | |
| if (!catchblock->type_info) return type; /* catch(...) matches any type */ | |
| if (catchblock->type_info != type->type_info) | |
| { | |
| if (strcmp( catchblock->type_info->name, type->type_info->name )) continue; | |
| } | |
| /* type is the same, now check the flags */ | |
| if ((exc_type->flags & TYPE_FLAG_CONST) && | |
| !(catchblock->flags & TYPE_FLAG_CONST)) continue; | |
| if ((exc_type->flags & TYPE_FLAG_VOLATILE) && | |
| !(catchblock->flags & TYPE_FLAG_VOLATILE)) continue; | |
| return type; /* it matched */ | |
| } | |
| return NULL; | |
| } | |
| /* copy the exception object where the catch block wants it */ | |
| static void copy_exception( void *object, cxx_exception_frame *frame, | |
| catchblock_info *catchblock, cxx_type_info *type ) | |
| { | |
| void **dest_ptr; | |
| if (!catchblock->type_info || !catchblock->type_info->name[0]) return; | |
| if (!catchblock->offset) return; | |
| dest_ptr = (void **)((char *)&frame->ebp + catchblock->offset); | |
| if (catchblock->flags & TYPE_FLAG_REFERENCE) | |
| { | |
| *dest_ptr = get_this_pointer( type, object ); | |
| } | |
| else if (type->flags & CLASS_IS_SIMPLE_TYPE) | |
| { | |
| memmove( dest_ptr, object, type->size ); | |
| /* if it is a pointer, adjust it */ | |
| if (type->size == sizeof(void *)) *dest_ptr = get_this_pointer( type, *dest_ptr ); | |
| } | |
| else /* copy the object */ | |
| { | |
| if (type->copy_ctor) | |
| call_copy_ctor( type->copy_ctor, dest_ptr, get_this_pointer(type,object), | |
| (type->flags & CLASS_HAS_VIRTUAL_BASE_CLASS) ); | |
| else | |
| memmove( dest_ptr, get_this_pointer(type,object), type->size ); | |
| } | |
| } | |
| /* unwind the local function up to a given trylevel */ | |
| static void cxx_local_unwind( cxx_exception_frame* frame, cxx_function_descr *descr, int last_level) | |
| { | |
| void (*handler)(); | |
| int trylevel = frame->trylevel; | |
| while (trylevel != last_level) | |
| { | |
| if (trylevel < 0 || trylevel >= descr->unwind_count) | |
| { | |
| ERR( "invalid trylevel %d\n", trylevel ); | |
| MSVCRT_terminate(); | |
| } | |
| handler = descr->unwind_table[trylevel].handler; | |
| if (handler) | |
| { | |
| TRACE( "calling unwind handler %p trylevel %d last %d ebp %p\n", | |
| handler, trylevel, last_level, &frame->ebp ); | |
| call_ebp_func( handler, &frame->ebp ); | |
| } | |
| trylevel = descr->unwind_table[trylevel].prev; | |
| } | |
| frame->trylevel = last_level; | |
| } | |
| /* find and call the appropriate catch block for an exception */ | |
| /* returns the address to continue execution to after the catch block was called */ | |
| inline static void *call_catch_block( PEXCEPTION_RECORD rec, cxx_exception_frame *frame, | |
| EXCEPTION_FRAME *unwind_frame, | |
| cxx_function_descr *descr, int trylevel, | |
| cxx_exception_type *info ) | |
| { | |
| int i, j; | |
| void *addr, *object = (void *)rec->ExceptionInformation[1]; | |
| for (i = 0; i < descr->tryblock_count; i++) | |
| { | |
| tryblock_info *tryblock = &descr->tryblock[i]; | |
| if (trylevel < tryblock->start_level) continue; | |
| if (trylevel > tryblock->end_level) continue; | |
| /* got a try block */ | |
| for (j = 0; j < tryblock->catchblock_count; j++) | |
| { | |
| catchblock_info *catchblock = &tryblock->catchblock[j]; | |
| cxx_type_info *type = find_caught_type( info, catchblock ); | |
| if (!type) continue; | |
| TRACE( "matched type %p in tryblock %d catchblock %d\n", type, i, j ); | |
| /* copy the exception to its destination on the stack */ | |
| copy_exception( object, frame, catchblock, type ); | |
| /* unwind the stack */ | |
| RtlUnwind( unwind_frame, 0, rec, 0 ); | |
| cxx_local_unwind( frame, descr, tryblock->start_level ); | |
| frame->trylevel = tryblock->end_level + 1; | |
| /* call the catch block */ | |
| TRACE( "calling catch block %p for type %p addr %p ebp %p\n", | |
| catchblock, type, catchblock->handler, &frame->ebp ); | |
| addr = call_ebp_func( catchblock->handler, &frame->ebp ); | |
| if (info->destructor) call_dtor( info->destructor, object ); | |
| TRACE( "done, continuing at %p\n", addr ); | |
| return addr; | |
| } | |
| } | |
| return NULL; | |
| } | |
| /********************************************************************* | |
| * cxx_frame_handler | |
| * | |
| * Implementation of __CxxFrameHandler. | |
| */ | |
| static DWORD cxx_frame_handler( PEXCEPTION_RECORD rec, cxx_exception_frame* frame, | |
| PCONTEXT exc_context, EXCEPTION_FRAME** dispatch, | |
| cxx_function_descr *descr, CONTEXT86 *context ) | |
| { | |
| cxx_exception_type *exc_type; | |
| void *next_ip; | |
| if (descr->magic != CXX_FRAME_MAGIC) | |
| { | |
| ERR( "invalid frame magic %x\n", descr->magic ); | |
| return ExceptionContinueSearch; | |
| } | |
| if (rec->ExceptionFlags & (EH_UNWINDING|EH_EXIT_UNWIND)) | |
| { | |
| if (descr->unwind_count) cxx_local_unwind( frame, descr, -1 ); | |
| return ExceptionContinueSearch; | |
| } | |
| if (!descr->tryblock_count) return ExceptionContinueSearch; | |
| exc_type = (cxx_exception_type *)rec->ExceptionInformation[2]; | |
| if (rec->ExceptionCode != CXX_EXCEPTION) goto normal_handler; | |
| if (rec->ExceptionInformation[0] != CXX_FRAME_MAGIC) goto normal_handler; | |
| if (exc_type->custom_handler) | |
| return exc_type->custom_handler( rec, frame, exc_context, dispatch, descr, 0, 0, 0 ); | |
| normal_handler: | |
| if (TRACE_ON(seh)) | |
| { | |
| TRACE("handling C++ exception rec %p frame %p trylevel %d descr %p\n", | |
| rec, frame, frame->trylevel, descr ); | |
| dump_exception_type( exc_type ); | |
| dump_function_descr( descr, exc_type ); | |
| } | |
| next_ip = call_catch_block( rec, frame, (EXCEPTION_FRAME *)frame, | |
| descr, frame->trylevel, exc_type ); | |
| if (!next_ip) return ExceptionContinueSearch; | |
| context->Eip = (DWORD)next_ip; | |
| context->Ebp = (DWORD)&frame->ebp; | |
| context->Esp = ((DWORD*)frame)[-1]; | |
| return ExceptionContinueExecution; | |
| } | |
| /********************************************************************* | |
| * __CxxFrameHandler (MSVCRT.@) | |
| */ | |
| void __CxxFrameHandler( PEXCEPTION_RECORD rec, EXCEPTION_FRAME* frame, | |
| PCONTEXT exc_context, EXCEPTION_FRAME** dispatch, | |
| CONTEXT86 *context ) | |
| { | |
| cxx_function_descr *descr = (cxx_function_descr *)context->Eax; | |
| context->Eax = cxx_frame_handler( rec, (cxx_exception_frame *)frame, | |
| exc_context, dispatch, descr, context ); | |
| } | |
| #endif /* __i386__ */ | |
| /********************************************************************* | |
| * _CxxThrowException (MSVCRT.@) | |
| */ | |
| void _CxxThrowException( void *object, cxx_exception_type *type ) | |
| { | |
| DWORD args[3]; | |
| args[0] = CXX_FRAME_MAGIC; | |
| args[1] = (DWORD)object; | |
| args[2] = (DWORD)type; | |
| RaiseException( CXX_EXCEPTION, EH_NONCONTINUABLE, 3, args ); | |
| } |