496 lines
18 KiB
C
496 lines
18 KiB
C
/*
|
|
* 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 "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 frame; /* the standard exception frame */
|
|
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*, int nested_trylevel,
|
|
EXCEPTION_FRAME *nested_frame, 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 */
|
|
|
|
static DWORD cxx_frame_handler( PEXCEPTION_RECORD rec, cxx_exception_frame* frame,
|
|
PCONTEXT exc_context, EXCEPTION_FRAME** dispatch,
|
|
cxx_function_descr *descr, EXCEPTION_FRAME* nested_frame,
|
|
int nested_trylevel, CONTEXT86 *context );
|
|
|
|
/* 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) : "ecx", "edx", "memory" );
|
|
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) : "eax", "edx", "memory" );
|
|
else
|
|
__asm__ __volatile__("pushl %2; call *%0"
|
|
: : "r" (func), "c" (this), "g" (src) : "eax", "edx", "memory" );
|
|
}
|
|
|
|
/* call the destructor of the exception object */
|
|
inline static void call_dtor( void *func, void *object )
|
|
{
|
|
__asm__ __volatile__("call *%0" : : "r" (func), "c" (object) : "eax", "edx", "memory" );
|
|
}
|
|
|
|
|
|
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;
|
|
}
|
|
|
|
/* exception frame for nested exceptions in catch block */
|
|
struct catch_func_nested_frame
|
|
{
|
|
EXCEPTION_FRAME frame; /* standard exception frame */
|
|
EXCEPTION_RECORD *prev_rec; /* previous record to restore in thread data */
|
|
cxx_exception_frame *cxx_frame; /* frame of parent exception */
|
|
cxx_function_descr *descr; /* descriptor of parent exception */
|
|
int trylevel; /* current try level */
|
|
};
|
|
|
|
/* handler for exceptions happening while calling a catch function */
|
|
static DWORD catch_function_nested_handler( EXCEPTION_RECORD *rec, EXCEPTION_FRAME *frame,
|
|
CONTEXT *context, EXCEPTION_FRAME **dispatcher )
|
|
{
|
|
struct catch_func_nested_frame *nested_frame = (struct catch_func_nested_frame *)frame;
|
|
|
|
if (rec->ExceptionFlags & (EH_UNWINDING | EH_EXIT_UNWIND))
|
|
{
|
|
msvcrt_get_thread_data()->exc_record = nested_frame->prev_rec;
|
|
return ExceptionContinueSearch;
|
|
}
|
|
else
|
|
{
|
|
TRACE( "got nested exception in catch function\n" );
|
|
return cxx_frame_handler( rec, nested_frame->cxx_frame, context,
|
|
NULL, nested_frame->descr, &nested_frame->frame,
|
|
nested_frame->trylevel, context );
|
|
}
|
|
}
|
|
|
|
/* 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,
|
|
cxx_function_descr *descr, int nested_trylevel,
|
|
cxx_exception_type *info )
|
|
{
|
|
int i, j;
|
|
void *addr, *object = (void *)rec->ExceptionInformation[1];
|
|
struct catch_func_nested_frame nested_frame;
|
|
int trylevel = frame->trylevel;
|
|
MSVCRT_thread_data *thread_data = msvcrt_get_thread_data();
|
|
|
|
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( 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 );
|
|
|
|
/* setup an exception block for nested exceptions */
|
|
|
|
nested_frame.frame.Handler = catch_function_nested_handler;
|
|
nested_frame.prev_rec = thread_data->exc_record;
|
|
nested_frame.cxx_frame = frame;
|
|
nested_frame.descr = descr;
|
|
nested_frame.trylevel = nested_trylevel + 1;
|
|
|
|
__wine_push_frame( &nested_frame.frame );
|
|
thread_data->exc_record = rec;
|
|
addr = call_ebp_func( catchblock->handler, &frame->ebp );
|
|
thread_data->exc_record = nested_frame.prev_rec;
|
|
__wine_pop_frame( &nested_frame.frame );
|
|
|
|
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, EXCEPTION_FRAME* nested_frame,
|
|
int nested_trylevel, 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 && !nested_trylevel) 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 &&
|
|
rec->ExceptionInformation[0] > CXX_FRAME_MAGIC &&
|
|
exc_type->custom_handler)
|
|
{
|
|
return exc_type->custom_handler( rec, frame, exc_context, dispatch,
|
|
descr, nested_trylevel, nested_frame, 0 );
|
|
}
|
|
|
|
if (!exc_type) /* nested exception, fetch info from original exception */
|
|
{
|
|
rec = msvcrt_get_thread_data()->exc_record;
|
|
exc_type = (cxx_exception_type *)rec->ExceptionInformation[2];
|
|
}
|
|
|
|
if (TRACE_ON(seh))
|
|
{
|
|
TRACE("handling C++ exception rec %p frame %p trylevel %d descr %p nested_frame %p\n",
|
|
rec, frame, frame->trylevel, descr, nested_frame );
|
|
dump_exception_type( exc_type );
|
|
dump_function_descr( descr, exc_type );
|
|
}
|
|
|
|
next_ip = call_catch_block( rec, frame, descr, frame->trylevel, exc_type );
|
|
|
|
if (!next_ip) return ExceptionContinueSearch;
|
|
rec->ExceptionFlags &= ~EH_NONCONTINUABLE;
|
|
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, NULL, 0, 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 );
|
|
}
|