reactos/lib/crt/wine/cppexcept.c

   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 "wine/config.h"
  27 #include "wine/port.h"
  28
  29 #include <stdarg.h>
  30
  31 #include "windef.h"
  32 #include "winbase.h"
  33 #include "winreg.h"
  34 #include "winternl.h"
  35 #include <internal/wine/msvcrt.h>
  36 #include "wine/exception.h"
  37 #include "excpt.h"
  38 #include "wine/debug.h"
  39
  40 #include <internal/wine/cppexcept.h>
  41
  42 WINE_DEFAULT_DEBUG_CHANNEL(seh);
  43
  44 #ifdef __i386__  /* CxxFrameHandler is not supported on non-i386 */
  45 #define CONTEXT86 CONTEXT //Mingw Hack
  46
  47 static DWORD cxx_frame_handler( PEXCEPTION_RECORD rec, cxx_exception_frame* frame,
  48                                 PCONTEXT exc_context, EXCEPTION_REGISTRATION_RECORD** dispatch,
  49                                 cxx_function_descr *descr, EXCEPTION_REGISTRATION_RECORD* nested_frame,
  50                                 int nested_trylevel, CONTEXT86 *context );
  51
  52 /* call a function with a given ebp */
  53 inline static void *call_ebp_func( void *func, void *ebp )
  54 {
  55     void *ret;
  56     __asm__ __volatile__ ("pushl %%ebp; movl %2,%%ebp; call *%%eax; popl %%ebp" \
  57                           : "=a" (ret) : "0" (func), "g" (ebp) : "ecx", "edx", "memory" );
  58     return ret;
  59 }
  60
  61 /* call a copy constructor */
  62 inline static void call_copy_ctor( void *func, void *this, void *src, int has_vbase )
  63 {
  64     TRACE( "calling copy ctor %p object %p src %p\n", func, this, src );
  65     if (has_vbase)
  66         /* in that case copy ctor takes an extra bool indicating whether to copy the base class */
  67         __asm__ __volatile__("pushl $1; pushl %2; call *%0"
  68                              : : "r" (func), "c" (this), "g" (src) : "eax", "edx", "memory" );
  69     else
  70         __asm__ __volatile__("pushl %2; call *%0"
  71                              : : "r" (func), "c" (this), "g" (src) : "eax", "edx", "memory" );
  72 }
  73
  74 /* call the destructor of the exception object */
  75 inline static void call_dtor( void *func, void *object )
  76 {
  77     __asm__ __volatile__("call *%0" : : "r" (func), "c" (object) : "eax", "edx", "memory" );
  78 }
  79
  80 static void dump_type( const cxx_type_info *type )
  81 {
  82     DPRINTF( "flags %x type %p", type->flags, type->type_info );
  83     if (type->type_info) DPRINTF( " (%p %s)", type->type_info->name, type->type_info->mangled );
  84     DPRINTF( " offset %d vbase %d,%d size %d copy ctor %p\n", type->this_offset,
  85              type->vbase_descr, type->vbase_offset, type->size, type->copy_ctor );
  86 }
  87
  88 static void dump_exception_type( const cxx_exception_type *type )
  89 {
  90     UINT i;
  91
  92     DPRINTF( "exception type:\n" );
  93     DPRINTF( "flags %x destr %p handler %p type info %p\n",
  94              type->flags, type->destructor, type->custom_handler, type->type_info_table );
  95     for (i = 0; i < type->type_info_table->count; i++)
  96     {
  97         DPRINTF( "    %d: ", i );
  98         dump_type( type->type_info_table->info[i] );
  99     }
 100 }
 101
 102 static void dump_function_descr( const cxx_function_descr *descr, const cxx_exception_type *info )
 103 {
 104     UINT i;
 105     int j;
 106
 107     DPRINTF( "function descr:\n" );
 108     DPRINTF( "magic %x\n", descr->magic );
 109     DPRINTF( "unwind table: %p %d\n", descr->unwind_table, descr->unwind_count );
 110     for (i = 0; i < descr->unwind_count; i++)
 111     {
 112         DPRINTF( "    %d: prev %d func %p\n", i,
 113                  descr->unwind_table[i].prev, descr->unwind_table[i].handler );
 114     }
 115     DPRINTF( "try table: %p %d\n", descr->tryblock, descr->tryblock_count );
 116     for (i = 0; i < descr->tryblock_count; i++)
 117     {
 118         DPRINTF( "    %d: start %d end %d catchlevel %d catch %p %d\n", i,
 119                  descr->tryblock[i].start_level, descr->tryblock[i].end_level,
 120                  descr->tryblock[i].catch_level, descr->tryblock[i].catchblock,
 121                  descr->tryblock[i].catchblock_count );
 122         for (j = 0; j < descr->tryblock[i].catchblock_count; j++)
 123         {
 124             catchblock_info *ptr = &descr->tryblock[i].catchblock[j];
 125             DPRINTF( "        %d: flags %x offset %d handler %p type %p",
 126                      j, ptr->flags, ptr->offset, ptr->handler, ptr->type_info );
 127             if (ptr->type_info) DPRINTF( " (%p %s)", ptr->type_info->name, ptr->type_info->mangled );
 128             DPRINTF( "\n" );
 129         }
 130     }
 131 }
 132
 133 /* compute the this pointer for a base class of a given type */
 134 static void *get_this_pointer( const cxx_type_info *type, void *object )
 135 {
 136     void *this_ptr;
 137     int *offset_ptr;
 138
 139     if (!object) return NULL;
 140     this_ptr = (char *)object + type->this_offset;
 141     if (type->vbase_descr >= 0)
 142     {
 143         /* move this ptr to vbase descriptor */
 144         this_ptr = (char *)this_ptr + type->vbase_descr;
 145         /* and fetch additional offset from vbase descriptor */
 146         offset_ptr = (int *)(*(char **)this_ptr + type->vbase_offset);
 147         this_ptr = (char *)this_ptr + *offset_ptr;
 148     }
 149     return this_ptr;
 150 }
 151
 152 /* check if the exception type is caught by a given catch block, and return the type that matched */
 153 static const cxx_type_info *find_caught_type( cxx_exception_type *exc_type, catchblock_info *catchblock )
 154 {
 155     UINT i;
 156
 157     for (i = 0; i < exc_type->type_info_table->count; i++)
 158     {
 159         const cxx_type_info *type = exc_type->type_info_table->info[i];
 160
 161         if (!catchblock->type_info) return type;   /* catch(...) matches any type */
 162         if (catchblock->type_info != type->type_info)
 163         {
 164             if (strcmp( catchblock->type_info->mangled, type->type_info->mangled )) continue;
 165         }
 166         /* type is the same, now check the flags */
 167         if ((exc_type->flags & TYPE_FLAG_CONST) &&
 168             !(catchblock->flags & TYPE_FLAG_CONST)) continue;
 169         if ((exc_type->flags & TYPE_FLAG_VOLATILE) &&
 170             !(catchblock->flags & TYPE_FLAG_VOLATILE)) continue;
 171         return type;  /* it matched */
 172     }
 173     return NULL;
 174 }
 175
 176
 177 /* copy the exception object where the catch block wants it */
 178 static void copy_exception( void *object, cxx_exception_frame *frame,
 179                             catchblock_info *catchblock, const cxx_type_info *type )
 180 {
 181     void **dest_ptr;
 182
 183     if (!catchblock->type_info || !catchblock->type_info->mangled[0]) return;
 184     if (!catchblock->offset) return;
 185     dest_ptr = (void **)((char *)&frame->ebp + catchblock->offset);
 186
 187     if (catchblock->flags & TYPE_FLAG_REFERENCE)
 188     {
 189         *dest_ptr = get_this_pointer( type, object );
 190     }
 191     else if (type->flags & CLASS_IS_SIMPLE_TYPE)
 192     {
 193         memmove( dest_ptr, object, type->size );
 194         /* if it is a pointer, adjust it */
 195         if (type->size == sizeof(void *)) *dest_ptr = get_this_pointer( type, *dest_ptr );
 196     }
 197     else  /* copy the object */
 198     {
 199         if (type->copy_ctor)
 200             call_copy_ctor( type->copy_ctor, dest_ptr, get_this_pointer(type,object),
 201                             (type->flags & CLASS_HAS_VIRTUAL_BASE_CLASS) );
 202         else
 203             memmove( dest_ptr, get_this_pointer(type,object), type->size );
 204     }
 205 }
 206
 207 /* unwind the local function up to a given trylevel */
 208 static void cxx_local_unwind( cxx_exception_frame* frame, cxx_function_descr *descr, int last_level)
 209 {
 210     void (*handler)();
 211     int trylevel = frame->trylevel;
 212
 213     while (trylevel != last_level)
 214     {
 215         if (trylevel < 0 || trylevel >= (int)descr->unwind_count)
 216         {
 217             ERR( "invalid trylevel %d\n", trylevel );
 218             MSVCRT_terminate();
 219         }
 220         handler = descr->unwind_table[trylevel].handler;
 221         if (handler)
 222         {
 223             TRACE( "calling unwind handler %p trylevel %d last %d ebp %p\n",
 224                    handler, trylevel, last_level, &frame->ebp );
 225             call_ebp_func( handler, &frame->ebp );
 226         }
 227         trylevel = descr->unwind_table[trylevel].prev;
 228     }
 229     frame->trylevel = last_level;
 230 }
 231
 232 /* exception frame for nested exceptions in catch block */
 233 struct catch_func_nested_frame
 234 {
 235     EXCEPTION_REGISTRATION_RECORD frame;     /* standard exception frame */
 236     EXCEPTION_RECORD             *prev_rec;  /* previous record to restore in thread data */
 237     cxx_exception_frame          *cxx_frame; /* frame of parent exception */
 238     cxx_function_descr           *descr;     /* descriptor of parent exception */
 239     int                           trylevel;  /* current try level */
 240 };
 241
 242 /* handler for exceptions happening while calling a catch function */
 243 static DWORD catch_function_nested_handler( EXCEPTION_RECORD *rec, EXCEPTION_REGISTRATION_RECORD *frame,
 244                                             CONTEXT *context, EXCEPTION_REGISTRATION_RECORD **dispatcher )
 245 {
 246     struct catch_func_nested_frame *nested_frame = (struct catch_func_nested_frame *)frame;
 247
 248     if (rec->ExceptionFlags & (EH_UNWINDING | EH_EXIT_UNWIND))
 249     {
 250         msvcrt_get_thread_data()->exc_record = nested_frame->prev_rec;
 251         return ExceptionContinueSearch;
 252     }
 253     else
 254     {
 255         TRACE( "got nested exception in catch function\n" );
 256         return cxx_frame_handler( rec, nested_frame->cxx_frame, context,
 257                                   NULL, nested_frame->descr, &nested_frame->frame,
 258                                   nested_frame->trylevel, context );
 259     }
 260 }
 261
 262 /* find and call the appropriate catch block for an exception */
 263 /* returns the address to continue execution to after the catch block was called */
 264 inline static void *call_catch_block( PEXCEPTION_RECORD rec, cxx_exception_frame *frame,
 265                                       cxx_function_descr *descr, int nested_trylevel,
 266                                       cxx_exception_type *info )
 267 {
 268     UINT i;
 269     int j;
 270     void *addr, *object = (void *)rec->ExceptionInformation[1];
 271     struct catch_func_nested_frame nested_frame;
 272     int trylevel = frame->trylevel;
 273     MSVCRT_thread_data *thread_data = msvcrt_get_thread_data();
 274
 275     for (i = 0; i < descr->tryblock_count; i++)
 276     {
 277         tryblock_info *tryblock = &descr->tryblock[i];
 278
 279         if (trylevel < tryblock->start_level) continue;
 280         if (trylevel > tryblock->end_level) continue;
 281
 282         /* got a try block */
 283         for (j = 0; j < tryblock->catchblock_count; j++)
 284         {
 285             catchblock_info *catchblock = &tryblock->catchblock[j];
 286             const cxx_type_info *type = find_caught_type( info, catchblock );
 287             if (!type) continue;
 288
 289             TRACE( "matched type %p in tryblock %d catchblock %d\n", type, i, j );
 290
 291             /* copy the exception to its destination on the stack */
 292             copy_exception( object, frame, catchblock, type );
 293
 294             /* unwind the stack */
 295             RtlUnwind( frame, 0, rec, 0 );
 296             cxx_local_unwind( frame, descr, tryblock->start_level );
 297             frame->trylevel = tryblock->end_level + 1;
 298
 299             /* call the catch block */
 300             TRACE( "calling catch block %p for type %p addr %p ebp %p\n",
 301                    catchblock, type, catchblock->handler, &frame->ebp );
 302
 303             /* setup an exception block for nested exceptions */
 304
 305             //nested_frame.frame.Handler = catch_function_nested_handler;
 306             nested_frame.frame.handler = (PEXCEPTION_HANDLER)catch_function_nested_handler;
 307             nested_frame.prev_rec  = thread_data->exc_record;
 308             nested_frame.cxx_frame = frame;
 309             nested_frame.descr     = descr;
 310             nested_frame.trylevel  = nested_trylevel + 1;
 311
 312             __wine_push_frame( &nested_frame.frame );
 313             thread_data->exc_record = rec;
 314             addr = call_ebp_func( catchblock->handler, &frame->ebp );
 315             thread_data->exc_record = nested_frame.prev_rec;
 316             __wine_pop_frame( &nested_frame.frame );
 317
 318             if (info->destructor) call_dtor( info->destructor, object );
 319             TRACE( "done, continuing at %p\n", addr );
 320             return addr;
 321         }
 322     }
 323     return NULL;
 324 }
 325
 326
 327 /*********************************************************************
 328  *              cxx_frame_handler
 329  *
 330  * Implementation of __CxxFrameHandler.
 331  */
 332 static DWORD cxx_frame_handler( PEXCEPTION_RECORD rec, cxx_exception_frame* frame,
 333                                 PCONTEXT exc_context, EXCEPTION_REGISTRATION_RECORD** dispatch,
 334                                 cxx_function_descr *descr, EXCEPTION_REGISTRATION_RECORD* nested_frame,
 335                                 int nested_trylevel, CONTEXT86 *context )
 336 {
 337     cxx_exception_type *exc_type;
 338     void *next_ip;
 339
 340     if (descr->magic != CXX_FRAME_MAGIC)
 341     {
 342         ERR( "invalid frame magic %x\n", descr->magic );
 343         return ExceptionContinueSearch;
 344     }
 345     if (rec->ExceptionFlags & (EH_UNWINDING|EH_EXIT_UNWIND))
 346     {
 347         if (descr->unwind_count && !nested_trylevel) cxx_local_unwind( frame, descr, -1 );
 348         return ExceptionContinueSearch;
 349     }
 350     if (!descr->tryblock_count) return ExceptionContinueSearch;
 351
 352     exc_type = (cxx_exception_type *)rec->ExceptionInformation[2];
 353     if (rec->ExceptionCode == CXX_EXCEPTION &&
 354         rec->ExceptionInformation[0] > CXX_FRAME_MAGIC &&
 355         exc_type->custom_handler)
 356     {
 357         return exc_type->custom_handler( rec, frame, exc_context, dispatch,
 358                                          descr, nested_trylevel, nested_frame, 0 );
 359     }
 360
 361     if (!exc_type)  /* nested exception, fetch info from original exception */
 362     {
 363         rec = msvcrt_get_thread_data()->exc_record;
 364         exc_type = (cxx_exception_type *)rec->ExceptionInformation[2];
 365     }
 366
 367     if (TRACE_ON(seh))
 368     {
 369         TRACE("handling C++ exception rec %p frame %p trylevel %d descr %p nested_frame %p\n",
 370               rec, frame, frame->trylevel, descr, nested_frame );
 371         dump_exception_type( exc_type );
 372         dump_function_descr( descr, exc_type );
 373     }
 374
 375     next_ip = call_catch_block( rec, frame, descr, frame->trylevel, exc_type );
 376
 377     if (!next_ip) return ExceptionContinueSearch;
 378     rec->ExceptionFlags &= ~EH_NONCONTINUABLE;
 379     context->Eip = (DWORD)next_ip;
 380     context->Ebp = (DWORD)&frame->ebp;
 381     context->Esp = ((DWORD*)frame)[-1];
 382     return ExceptionContinueExecution;
 383 }
 384
 385
 386 /*********************************************************************
 387  *              __CxxFrameHandler (MSVCRT.@)
 388  */
 389 void __CxxFrameHandler( PEXCEPTION_RECORD rec, EXCEPTION_REGISTRATION_RECORD* frame,
 390                               PCONTEXT exc_context, EXCEPTION_REGISTRATION_RECORD** dispatch,
 391                               CONTEXT86 *context )
 392 {
 393     cxx_function_descr *descr = (cxx_function_descr *)context->Eax;
 394     context->Eax = cxx_frame_handler( rec, (cxx_exception_frame *)frame,
 395                                       exc_context, dispatch, descr, NULL, 0, context );
 396 }
 397 //DEFINE_REGS_ENTRYPOINT( __CxxFrameHandler, MSVCRT__CxxFrameHandler, 16, 0 );
 398 // ROS
 399 #endif  /* __i386__ */
 400
 401 /*********************************************************************
 402  *              _CxxThrowException (MSVCRT.@)
 403  */
 404 void _CxxThrowException( void *object, const cxx_exception_type *type )
 405 {
 406     DWORD args[3];
 407
 408     args[0] = CXX_FRAME_MAGIC;
 409     args[1] = (DWORD)object;
 410     args[2] = (DWORD)type;
 411     RaiseException( CXX_EXCEPTION, EH_NONCONTINUABLE, 3, args );
 412 }
 413
 414 /*********************************************************************
 415  *              __CxxDetectRethrow (MSVCRT.@)
 416  */
 417 BOOL __CxxDetectRethrow(PEXCEPTION_POINTERS ptrs)
 418 {
 419   PEXCEPTION_RECORD rec;
 420
 421   if (!ptrs)
 422     return FALSE;
 423
 424   rec = ptrs->ExceptionRecord;
 425
 426   if (rec->ExceptionCode == CXX_EXCEPTION &&
 427       rec->NumberParameters == 3 &&
 428       rec->ExceptionInformation[0] == CXX_FRAME_MAGIC &&
 429       rec->ExceptionInformation[2])
 430   {
 431     ptrs->ExceptionRecord = msvcrt_get_thread_data()->exc_record;
 432     return TRUE;
 433   }
 434   return (msvcrt_get_thread_data()->exc_record == rec);
 435 }
 436
 437 /*********************************************************************
 438  *              __CxxQueryExceptionSize (MSVCRT.@)
 439  */
 440 unsigned int __CxxQueryExceptionSize(void)
 441 {
 442   return sizeof(cxx_exception_type);
 443 }