| /* |
| * 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 "ntddk.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 ); |
| } |
