debugger/expr.c

   1 /*
   2  * File expr.c - expression handling for Wine internal debugger.
   3  *
   4  * Copyright (C) 1997, Eric Youngdale.
   5  *
   6  */
   7
   8 #include "config.h"
   9 #include <stdlib.h>
  10 #include <string.h>
  11 #include "winbase.h"
  12 #include "wine/winbase16.h"
  13 #include "task.h"
  14 #include "debugger.h"
  15 #include "expr.h"
  16
  17 #include <stdarg.h>
  18
  19 struct expr
  20 {
  21   unsigned int  perm;
  22   unsigned int  type:31;
  23   union
  24   {
  25     struct
  26     {
  27       int value;
  28     } constant;
  29
  30     struct
  31     {
  32       const char * str;
  33     } string;
  34
  35     struct
  36     {
  37       unsigned int value;
  38     } u_const;
  39
  40     struct
  41     {
  42       const char * name;
  43     } symbol;
  44
  45     struct
  46     {
  47       const char * name;
  48     } intvar;
  49
  50     struct
  51     {
  52       int unop_type;
  53       struct expr * exp1;
  54       int             result;
  55     } unop;
  56
  57     struct
  58     {
  59       int binop_type;
  60       int result;
  61       struct expr * exp1;
  62       struct expr * exp2;
  63     } binop;
  64
  65     struct
  66     {
  67       struct datatype * cast;
  68       struct expr     * expr;
  69     } cast;
  70
  71     struct
  72     {
  73       struct expr * exp1;
  74       const char * element_name;
  75       int result;
  76     } structure;
  77
  78     struct
  79     {
  80       struct expr * base;
  81       struct expr * index;
  82     } array;
  83
  84     struct
  85     {
  86       const char  * funcname;
  87       int           nargs;
  88       int           result;
  89       struct expr * arg[5];
  90     } call;
  91
  92   } un;
  93 };
  94
  95 #define EXPR_TYPE_CONST         0
  96 #define EXPR_TYPE_US_CONST      1
  97 #define EXPR_TYPE_SYMBOL        2
  98 #define EXPR_TYPE_INTVAR        3
  99 #define EXPR_TYPE_BINOP         4
 100 #define EXPR_TYPE_UNOP          5
 101 #define EXPR_TYPE_STRUCT        6
 102 #define EXPR_TYPE_PSTRUCT       7
 103 #define EXPR_TYPE_ARRAY         8
 104 #define EXPR_TYPE_CALL          9
 105 #define EXPR_TYPE_STRING        10
 106 #define EXPR_TYPE_CAST          11
 107
 108 static char expr_list[4096];
 109 static int next_expr_free = 0;
 110
 111 /*
 112  * This is how we turn an expression address into the actual value.
 113  * This works well in the 32 bit domain - not sure at all about the
 114  * 16 bit world.
 115  */
 116 #define VAL(_exp)       DEBUG_GetExprValue(&_exp, NULL)
 117
 118 static
 119 struct expr *
 120 DEBUG_GetFreeExpr(void)
 121 {
 122   struct expr * rtn;
 123
 124   rtn =  (struct expr *) &expr_list[next_expr_free];
 125
 126   next_expr_free += sizeof(struct expr);
 127   assert(next_expr_free < sizeof(expr_list));
 128
 129   return rtn;
 130 }
 131
 132 void
 133 DEBUG_FreeExprMem(void)
 134 {
 135   next_expr_free = 0;
 136 }
 137
 138 struct expr *
 139 DEBUG_TypeCastExpr(struct datatype * dt, struct expr * exp)
 140 {
 141   struct expr * ex;
 142
 143   ex = DEBUG_GetFreeExpr();
 144
 145   ex->type        = EXPR_TYPE_CAST;
 146   ex->un.cast.cast = dt;
 147   ex->un.cast.expr = exp;
 148   return ex;
 149 }
 150
 151 struct expr *
 152 DEBUG_IntVarExpr(const char* name)
 153 {
 154   struct expr * ex;
 155
 156   ex = DEBUG_GetFreeExpr();
 157
 158   ex->type        = EXPR_TYPE_INTVAR;
 159   ex->un.intvar.name = name;
 160   return ex;
 161 }
 162
 163 struct expr *
 164 DEBUG_SymbolExpr(const char * name)
 165 {
 166   struct expr * ex;
 167
 168   ex = DEBUG_GetFreeExpr();
 169
 170   ex->type        = EXPR_TYPE_SYMBOL;
 171   ex->un.symbol.name = name;
 172   return ex;
 173 }
 174
 175 struct expr *
 176 DEBUG_ConstExpr(int value)
 177 {
 178   struct expr * ex;
 179
 180   ex = DEBUG_GetFreeExpr();
 181
 182   ex->type        = EXPR_TYPE_CONST;
 183   ex->un.constant.value = value;
 184   return ex;
 185 }
 186
 187 struct expr *
 188 DEBUG_StringExpr(const char * str)
 189 {
 190   struct expr * ex;
 191   char * pnt;
 192   ex = DEBUG_GetFreeExpr();
 193
 194   ex->type        = EXPR_TYPE_STRING;
 195   ex->un.string.str = str+1;
 196   pnt = strrchr(ex->un.string.str, '"');
 197   if( pnt != NULL )
 198     {
 199       *pnt =  '\0';
 200     }
 201   return ex;
 202 }
 203
 204 struct expr *
 205 DEBUG_USConstExpr(unsigned int value)
 206 {
 207   struct expr * ex;
 208
 209   ex = DEBUG_GetFreeExpr();
 210
 211   ex->type           = EXPR_TYPE_CONST;
 212   ex->un.u_const.value = value;
 213   return ex;
 214 }
 215
 216 struct expr *
 217 DEBUG_BinopExpr(int operator_type, struct expr * exp1, struct expr * exp2)
 218 {
 219   struct expr * ex;
 220
 221   ex = DEBUG_GetFreeExpr();
 222
 223   ex->type           = EXPR_TYPE_BINOP;
 224   ex->un.binop.binop_type = operator_type;
 225   ex->un.binop.exp1     = exp1;
 226   ex->un.binop.exp2     = exp2;
 227   return ex;
 228 }
 229
 230 struct expr *
 231 DEBUG_UnopExpr(int operator_type, struct expr * exp1)
 232 {
 233   struct expr * ex;
 234
 235   ex = DEBUG_GetFreeExpr();
 236
 237   ex->type           = EXPR_TYPE_UNOP;
 238   ex->un.unop.unop_type = operator_type;
 239   ex->un.unop.exp1      = exp1;
 240   return ex;
 241 }
 242
 243 struct expr *
 244 DEBUG_StructExpr(struct expr * exp, const char * element)
 245 {
 246   struct expr * ex;
 247
 248   ex = DEBUG_GetFreeExpr();
 249
 250   ex->type           = EXPR_TYPE_STRUCT;
 251   ex->un.structure.exp1 = exp;
 252   ex->un.structure.element_name = element;
 253   return ex;
 254 }
 255
 256 struct expr *
 257 DEBUG_StructPExpr(struct expr * exp, const char * element)
 258 {
 259   struct expr * ex;
 260
 261   ex = DEBUG_GetFreeExpr();
 262
 263   ex->type           = EXPR_TYPE_PSTRUCT;
 264   ex->un.structure.exp1 = exp;
 265   ex->un.structure.element_name = element;
 266   return ex;
 267 }
 268
 269 struct expr *
 270 DEBUG_CallExpr(const char * funcname, int nargs, ...)
 271 {
 272   struct expr * ex;
 273   va_list ap;
 274   int i;
 275
 276   ex = DEBUG_GetFreeExpr();
 277
 278   ex->type           = EXPR_TYPE_CALL;
 279   ex->un.call.funcname = funcname;
 280   ex->un.call.nargs = nargs;
 281
 282   va_start(ap, nargs);
 283   for(i=0; i < nargs; i++)
 284     {
 285       ex->un.call.arg[i] = va_arg(ap, struct expr *);
 286     }
 287   va_end(ap);
 288   return ex;
 289 }
 290
 291 DBG_VALUE DEBUG_EvalExpr(struct expr * exp)
 292 {
 293   DBG_VALUE     rtn;
 294   int           i;
 295   DBG_VALUE     exp1;
 296   DBG_VALUE     exp2;
 297   unsigned int  cexp[5];
 298   int               scale1;
 299   int               scale2;
 300   int               scale3;
 301   struct datatype * type1;
 302   struct datatype * type2;
 303
 304   rtn.type = NULL;
 305   rtn.cookie = DV_INVALID;
 306   rtn.addr.off = 0;
 307   rtn.addr.seg = 0;
 308
 309   switch(exp->type)
 310     {
 311     case EXPR_TYPE_CAST:
 312       rtn = DEBUG_EvalExpr(exp->un.cast.expr);
 313       rtn.type = exp->un.cast.cast;
 314       if (DEBUG_GetType(rtn.type) == DT_POINTER)
 315          rtn.cookie = DV_TARGET;
 316       break;
 317     case EXPR_TYPE_STRING:
 318       rtn.type = DEBUG_TypeString;
 319       rtn.cookie = DV_HOST;
 320       rtn.addr.off = (unsigned int) &exp->un.string.str;
 321       rtn.addr.seg = 0;
 322       break;
 323     case EXPR_TYPE_CONST:
 324       rtn.type = DEBUG_TypeIntConst;
 325       rtn.cookie = DV_HOST;
 326       rtn.addr.off = (unsigned int) &exp->un.constant.value;
 327       rtn.addr.seg = 0;
 328       break;
 329     case EXPR_TYPE_US_CONST:
 330       rtn.type = DEBUG_TypeUSInt;
 331       rtn.cookie = DV_HOST;
 332       rtn.addr.off = (unsigned int) &exp->un.u_const.value;
 333       rtn.addr.seg = 0;
 334       break;
 335     case EXPR_TYPE_SYMBOL:
 336       if( !DEBUG_GetSymbolValue(exp->un.symbol.name, -1, &rtn, FALSE) )
 337         {
 338            RaiseException(DEBUG_STATUS_NO_SYMBOL, 0, 0, NULL);
 339         }
 340       break;
 341     case EXPR_TYPE_PSTRUCT:
 342       exp1 =  DEBUG_EvalExpr(exp->un.structure.exp1);
 343       if( exp1.type == NULL )
 344         {
 345            RaiseException(DEBUG_STATUS_BAD_TYPE, 0, 0, NULL);
 346         }
 347       rtn.cookie = DV_TARGET;
 348       rtn.addr.off = DEBUG_TypeDerefPointer(&exp1, &type1);
 349       if( type1 == NULL )
 350         {
 351           RaiseException(DEBUG_STATUS_BAD_TYPE, 0, 0, NULL);
 352         }
 353       rtn.type = type1;
 354       DEBUG_FindStructElement(&rtn, exp->un.structure.element_name,
 355                               &exp->un.structure.result);
 356       break;
 357     case EXPR_TYPE_STRUCT:
 358       exp1 =  DEBUG_EvalExpr(exp->un.structure.exp1);
 359       if( exp1.type == NULL )
 360         {
 361           RaiseException(DEBUG_STATUS_BAD_TYPE, 0, 0, NULL);
 362         }
 363       rtn = exp1;
 364       DEBUG_FindStructElement(&rtn, exp->un.structure.element_name,
 365                               &exp->un.structure.result);
 366       break;
 367     case EXPR_TYPE_CALL:
 368       /*
 369        * First, evaluate all of the arguments.  If any of them are not
 370        * evaluable, then bail.
 371        */
 372       for(i=0; i < exp->un.call.nargs; i++)
 373         {
 374           exp1  = DEBUG_EvalExpr(exp->un.call.arg[i]);
 375           if( exp1.type == NULL )
 376             {
 377               return rtn;
 378             }
 379           cexp[i] = DEBUG_GetExprValue(&exp1, NULL);
 380         }
 381
 382       /*
 383        * Now look up the address of the function itself.
 384        */
 385       if( !DEBUG_GetSymbolValue(exp->un.call.funcname, -1, &rtn, FALSE ) )
 386         {
 387           RaiseException(DEBUG_STATUS_NO_SYMBOL, 0, 0, NULL);
 388         }
 389
 390 #if 0
 391       /* FIXME: NEWDBG NIY */
 392       /* Anyway, I wonder how this could work depending on the calling order of
 393        * the function (cdecl vs pascal for example)
 394        */
 395       int               (*fptr)();
 396
 397       fptr = (int (*)()) rtn.addr.off;
 398       switch(exp->un.call.nargs)
 399         {
 400         case 0:
 401           exp->un.call.result = (*fptr)();
 402           break;
 403         case 1:
 404           exp->un.call.result = (*fptr)(cexp[0]);
 405           break;
 406         case 2:
 407           exp->un.call.result = (*fptr)(cexp[0], cexp[1]);
 408           break;
 409         case 3:
 410           exp->un.call.result = (*fptr)(cexp[0], cexp[1], cexp[2]);
 411           break;
 412         case 4:
 413           exp->un.call.result = (*fptr)(cexp[0], cexp[1], cexp[2], cexp[3]);
 414           break;
 415         case 5:
 416           exp->un.call.result = (*fptr)(cexp[0], cexp[1], cexp[2], cexp[3], cexp[4]);
 417           break;
 418         }
 419 #else
 420       DEBUG_Printf(DBG_CHN_MESG, "Function call no longer implemented\n");
 421       /* would need to set up a call to this function, and then restore the current
 422        * context afterwards...
 423        */
 424       exp->un.call.result = 0;
 425 #endif
 426       rtn.type = DEBUG_TypeInt;
 427       rtn.cookie = DV_HOST;
 428       rtn.addr.off = (unsigned int) &exp->un.call.result;
 429
 430       break;
 431     case EXPR_TYPE_INTVAR:
 432       {
 433
 434          DBG_INTVAR*    div = DEBUG_GetIntVar(exp->un.intvar.name);
 435
 436          if (!div) RaiseException(DEBUG_STATUS_NO_SYMBOL, 0, 0, NULL);
 437          rtn.cookie = DV_HOST;
 438          rtn.type = div->type;
 439          rtn.addr.off = (unsigned int)div->pval;
 440          /* EPP FIXME rtn.addr.seg = ?? */
 441       }
 442       break;
 443     case EXPR_TYPE_BINOP:
 444       exp1 = DEBUG_EvalExpr(exp->un.binop.exp1);
 445       exp2 = DEBUG_EvalExpr(exp->un.binop.exp2);
 446       rtn.cookie = DV_HOST;
 447       if( exp1.type == NULL || exp2.type == NULL )
 448         {
 449           RaiseException(DEBUG_STATUS_BAD_TYPE, 0, 0, NULL);
 450         }
 451       if( exp1.type == DEBUG_TypeIntConst && exp2.type == DEBUG_TypeIntConst )
 452         {
 453           rtn.type = exp1.type;
 454         }
 455       else
 456         {
 457           rtn.type = DEBUG_TypeInt;
 458         }
 459       rtn.addr.seg = 0;
 460       rtn.addr.off = (unsigned int) &exp->un.binop.result;
 461       switch(exp->un.binop.binop_type)
 462         {
 463         case EXP_OP_ADD:
 464           type1 = DEBUG_GetPointerType(exp1.type);
 465           type2 = DEBUG_GetPointerType(exp2.type);
 466           scale1 = 1;
 467           scale2 = 1;
 468           if( type1 != NULL && type2 != NULL )
 469             {
 470               RaiseException(DEBUG_STATUS_BAD_TYPE, 0, 0, NULL);
 471             }
 472           else if( type1 != NULL )
 473             {
 474               scale2 = DEBUG_GetObjectSize(type1);
 475               rtn.type = exp1.type;
 476             }
 477           else if( type2 != NULL )
 478             {
 479               scale1 = DEBUG_GetObjectSize(type2);
 480               rtn.type = exp2.type;
 481             }
 482           exp->un.binop.result = (VAL(exp1) * scale1  + scale2 * VAL(exp2));
 483           break;
 484         case EXP_OP_SUB:
 485           type1 = DEBUG_GetPointerType(exp1.type);
 486           type2 = DEBUG_GetPointerType(exp2.type);
 487           scale1 = 1;
 488           scale2 = 1;
 489           scale3 = 1;
 490           if( type1 != NULL && type2 != NULL )
 491             {
 492               if( type1 != type2 )
 493                 {
 494                   RaiseException(DEBUG_STATUS_BAD_TYPE, 0, 0, NULL);
 495                 }
 496               scale3 = DEBUG_GetObjectSize(type1);
 497             }
 498           else if( type1 != NULL )
 499             {
 500               scale2 = DEBUG_GetObjectSize(type1);
 501               rtn.type = exp1.type;
 502             }
 503
 504           else if( type2 != NULL )
 505             {
 506               scale1 = DEBUG_GetObjectSize(type2);
 507               rtn.type = exp2.type;
 508             }
 509           exp->un.binop.result = (VAL(exp1) - VAL(exp2)) / scale3;
 510           break;
 511         case EXP_OP_SEG:
 512           rtn.cookie = DV_TARGET;
 513           rtn.addr.seg = VAL(exp1);
 514           exp->un.binop.result = VAL(exp2);
 515 #ifdef __i386__
 516           DEBUG_FixSegment(&rtn.addr);
 517 #endif
 518           break;
 519         case EXP_OP_LOR:
 520           exp->un.binop.result = (VAL(exp1) || VAL(exp2));
 521           break;
 522         case EXP_OP_LAND:
 523           exp->un.binop.result = (VAL(exp1) && VAL(exp2));
 524           break;
 525         case EXP_OP_OR:
 526           exp->un.binop.result = (VAL(exp1) | VAL(exp2));
 527           break;
 528         case EXP_OP_AND:
 529           exp->un.binop.result = (VAL(exp1) & VAL(exp2));
 530           break;
 531         case EXP_OP_XOR:
 532           exp->un.binop.result = (VAL(exp1) ^ VAL(exp2));
 533           break;
 534         case EXP_OP_EQ:
 535           exp->un.binop.result = (VAL(exp1) == VAL(exp2));
 536           break;
 537         case EXP_OP_GT:
 538           exp->un.binop.result = (VAL(exp1) > VAL(exp2));
 539           break;
 540         case EXP_OP_LT:
 541           exp->un.binop.result = (VAL(exp1) < VAL(exp2));
 542           break;
 543         case EXP_OP_GE:
 544           exp->un.binop.result = (VAL(exp1) >= VAL(exp2));
 545           break;
 546         case EXP_OP_LE:
 547           exp->un.binop.result = (VAL(exp1) <= VAL(exp2));
 548           break;
 549         case EXP_OP_NE:
 550           exp->un.binop.result = (VAL(exp1) != VAL(exp2));
 551           break;
 552         case EXP_OP_SHL:
 553           exp->un.binop.result = ((unsigned) VAL(exp1) << VAL(exp2));
 554           break;
 555         case EXP_OP_SHR:
 556           exp->un.binop.result = ((unsigned) VAL(exp1) >> VAL(exp2));
 557           break;
 558         case EXP_OP_MUL:
 559           exp->un.binop.result = (VAL(exp1) * VAL(exp2));
 560           break;
 561         case EXP_OP_DIV:
 562           if( VAL(exp2) == 0 )
 563             {
 564                RaiseException(DEBUG_STATUS_DIV_BY_ZERO, 0, 0, NULL);
 565             }
 566           exp->un.binop.result = (VAL(exp1) / VAL(exp2));
 567           break;
 568         case EXP_OP_REM:
 569           if( VAL(exp2) == 0 )
 570             {
 571                RaiseException(DEBUG_STATUS_DIV_BY_ZERO, 0, 0, NULL);
 572             }
 573           exp->un.binop.result = (VAL(exp1) % VAL(exp2));
 574           break;
 575         case EXP_OP_ARR:
 576           DEBUG_ArrayIndex(&exp1, &rtn, VAL(exp2));
 577           break;
 578         default:
 579           RaiseException(DEBUG_STATUS_INTERNAL_ERROR, 0, 0, NULL);
 580           break;
 581         }
 582       break;
 583     case EXPR_TYPE_UNOP:
 584       exp1 = DEBUG_EvalExpr(exp->un.unop.exp1);
 585       rtn.cookie = DV_HOST;
 586       if( exp1.type == NULL )
 587         {
 588           RaiseException(DEBUG_STATUS_BAD_TYPE, 0, 0, NULL);
 589         }
 590       rtn.addr.seg = 0;
 591       rtn.addr.off = (unsigned int) &exp->un.unop.result;
 592       if( exp1.type == DEBUG_TypeIntConst )
 593         {
 594           rtn.type = exp1.type;
 595         }
 596       else
 597         {
 598           rtn.type = DEBUG_TypeInt;
 599         }
 600       switch(exp->un.unop.unop_type)
 601         {
 602         case EXP_OP_NEG:
 603           exp->un.unop.result = -VAL(exp1);
 604           break;
 605         case EXP_OP_NOT:
 606           exp->un.unop.result = !VAL(exp1);
 607           break;
 608         case EXP_OP_LNOT:
 609           exp->un.unop.result = ~VAL(exp1);
 610           break;
 611         case EXP_OP_DEREF:
 612           rtn.cookie = exp1.cookie;
 613           rtn.addr.off = (unsigned int) DEBUG_TypeDerefPointer(&exp1, &rtn.type);
 614           if (!rtn.type)
 615             {
 616               RaiseException(DEBUG_STATUS_BAD_TYPE, 0, 0, NULL);
 617             }
 618           break;
 619         case EXP_OP_FORCE_DEREF:
 620           rtn.cookie = exp1.cookie;
 621           rtn.addr.seg = exp1.addr.seg;
 622           if (exp1.cookie == DV_TARGET)
 623              DEBUG_READ_MEM((void*)exp1.addr.off, &rtn.addr.off, sizeof(rtn.addr.off));
 624           else
 625              memcpy(&rtn.addr.off, (void*)exp1.addr.off, sizeof(rtn.addr.off));
 626           break;
 627         case EXP_OP_ADDR:
 628           /* FIXME: even for a 16 bit entity ? */
 629           rtn.cookie = DV_TARGET;
 630           rtn.type = DEBUG_FindOrMakePointerType(exp1.type);
 631           exp->un.unop.result = exp1.addr.off;
 632           break;
 633         default:
 634            RaiseException(DEBUG_STATUS_INTERNAL_ERROR, 0, 0, NULL);
 635         }
 636       break;
 637     default:
 638       DEBUG_Printf(DBG_CHN_MESG,"Unexpected expression (%d).\n", exp->type);
 639       RaiseException(DEBUG_STATUS_INTERNAL_ERROR, 0, 0, NULL);
 640       break;
 641     }
 642
 643   assert(rtn.cookie == DV_TARGET || rtn.cookie == DV_HOST);
 644
 645   return rtn;
 646 }
 647
 648
 649 int
 650 DEBUG_DisplayExpr(const struct expr * exp)
 651 {
 652   int           i;
 653
 654   switch(exp->type)
 655     {
 656     case EXPR_TYPE_CAST:
 657       DEBUG_Printf(DBG_CHN_MESG, "((");
 658       DEBUG_PrintTypeCast(exp->un.cast.cast);
 659       DEBUG_Printf(DBG_CHN_MESG, ")");
 660       DEBUG_DisplayExpr(exp->un.cast.expr);
 661       DEBUG_Printf(DBG_CHN_MESG, ")");
 662       break;
 663     case EXPR_TYPE_INTVAR:
 664       DEBUG_Printf(DBG_CHN_MESG, "$%s", exp->un.intvar.name);
 665       break;
 666     case EXPR_TYPE_US_CONST:
 667       DEBUG_Printf(DBG_CHN_MESG, "%ud", exp->un.u_const.value);
 668       break;
 669     case EXPR_TYPE_CONST:
 670       DEBUG_Printf(DBG_CHN_MESG, "%d", exp->un.u_const.value);
 671       break;
 672     case EXPR_TYPE_STRING:
 673       DEBUG_Printf(DBG_CHN_MESG, "\"%s\"", exp->un.string.str);
 674       break;
 675     case EXPR_TYPE_SYMBOL:
 676       DEBUG_Printf(DBG_CHN_MESG, "%s" , exp->un.symbol.name);
 677       break;
 678     case EXPR_TYPE_PSTRUCT:
 679       DEBUG_DisplayExpr(exp->un.structure.exp1);
 680       DEBUG_Printf(DBG_CHN_MESG, "->%s", exp->un.structure.element_name);
 681       break;
 682     case EXPR_TYPE_STRUCT:
 683       DEBUG_DisplayExpr(exp->un.structure.exp1);
 684       DEBUG_Printf(DBG_CHN_MESG, ".%s", exp->un.structure.element_name);
 685       break;
 686     case EXPR_TYPE_CALL:
 687       DEBUG_Printf(DBG_CHN_MESG, "%s(",exp->un.call.funcname);
 688       for(i=0; i < exp->un.call.nargs; i++)
 689         {
 690           DEBUG_DisplayExpr(exp->un.call.arg[i]);
 691           if( i != exp->un.call.nargs - 1 )
 692             {
 693               DEBUG_Printf(DBG_CHN_MESG, ", ");
 694             }
 695         }
 696       DEBUG_Printf(DBG_CHN_MESG, ")");
 697       break;
 698     case EXPR_TYPE_BINOP:
 699       DEBUG_Printf(DBG_CHN_MESG, "( ");
 700       DEBUG_DisplayExpr(exp->un.binop.exp1);
 701       switch(exp->un.binop.binop_type)
 702         {
 703         case EXP_OP_ADD:
 704           DEBUG_Printf(DBG_CHN_MESG, " + ");
 705           break;
 706         case EXP_OP_SUB:
 707           DEBUG_Printf(DBG_CHN_MESG, " - ");
 708           break;
 709         case EXP_OP_SEG:
 710           DEBUG_Printf(DBG_CHN_MESG, ":");
 711           break;
 712         case EXP_OP_LOR:
 713           DEBUG_Printf(DBG_CHN_MESG, " || ");
 714           break;
 715         case EXP_OP_LAND:
 716           DEBUG_Printf(DBG_CHN_MESG, " && ");
 717           break;
 718         case EXP_OP_OR:
 719           DEBUG_Printf(DBG_CHN_MESG, " | ");
 720           break;
 721         case EXP_OP_AND:
 722           DEBUG_Printf(DBG_CHN_MESG, " & ");
 723           break;
 724         case EXP_OP_XOR:
 725           DEBUG_Printf(DBG_CHN_MESG, " ^ ");
 726           break;
 727         case EXP_OP_EQ:
 728           DEBUG_Printf(DBG_CHN_MESG, " == ");
 729           break;
 730         case EXP_OP_GT:
 731           DEBUG_Printf(DBG_CHN_MESG, " > ");
 732           break;
 733         case EXP_OP_LT:
 734           DEBUG_Printf(DBG_CHN_MESG, " < ");
 735           break;
 736         case EXP_OP_GE:
 737           DEBUG_Printf(DBG_CHN_MESG, " >= ");
 738           break;
 739         case EXP_OP_LE:
 740           DEBUG_Printf(DBG_CHN_MESG, " <= ");
 741           break;
 742         case EXP_OP_NE:
 743           DEBUG_Printf(DBG_CHN_MESG, " != ");
 744           break;
 745         case EXP_OP_SHL:
 746           DEBUG_Printf(DBG_CHN_MESG, " << ");
 747           break;
 748         case EXP_OP_SHR:
 749           DEBUG_Printf(DBG_CHN_MESG, " >> ");
 750           break;
 751         case EXP_OP_MUL:
 752           DEBUG_Printf(DBG_CHN_MESG, " * ");
 753           break;
 754         case EXP_OP_DIV:
 755           DEBUG_Printf(DBG_CHN_MESG, " / ");
 756           break;
 757         case EXP_OP_REM:
 758           DEBUG_Printf(DBG_CHN_MESG, " %% ");
 759           break;
 760         case EXP_OP_ARR:
 761           DEBUG_Printf(DBG_CHN_MESG, "[");
 762           break;
 763         default:
 764           break;
 765         }
 766       DEBUG_DisplayExpr(exp->un.binop.exp2);
 767       if( exp->un.binop.binop_type == EXP_OP_ARR )
 768         {
 769           DEBUG_Printf(DBG_CHN_MESG, "]");
 770         }
 771       DEBUG_Printf(DBG_CHN_MESG, " )");
 772       break;
 773     case EXPR_TYPE_UNOP:
 774       switch(exp->un.unop.unop_type)
 775         {
 776         case EXP_OP_NEG:
 777           DEBUG_Printf(DBG_CHN_MESG, "-");
 778           break;
 779         case EXP_OP_NOT:
 780           DEBUG_Printf(DBG_CHN_MESG, "!");
 781           break;
 782         case EXP_OP_LNOT:
 783           DEBUG_Printf(DBG_CHN_MESG, "~");
 784           break;
 785         case EXP_OP_DEREF:
 786           DEBUG_Printf(DBG_CHN_MESG, "*");
 787           break;
 788         case EXP_OP_ADDR:
 789           DEBUG_Printf(DBG_CHN_MESG, "&");
 790           break;
 791         }
 792       DEBUG_DisplayExpr(exp->un.unop.exp1);
 793       break;
 794     default:
 795       DEBUG_Printf(DBG_CHN_MESG,"Unexpected expression.\n");
 796       RaiseException(DEBUG_STATUS_INTERNAL_ERROR, 0, 0, NULL);
 797       break;
 798     }
 799
 800   return TRUE;
 801 }
 802
 803 struct expr *
 804 DEBUG_CloneExpr(const struct expr * exp)
 805 {
 806   int           i;
 807   struct expr * rtn;
 808
 809   rtn = (struct expr *) DBG_alloc(sizeof(struct expr));
 810
 811   /*
 812    * First copy the contents of the expression itself.
 813    */
 814   *rtn = *exp;
 815
 816
 817   switch(exp->type)
 818     {
 819     case EXPR_TYPE_CAST:
 820       rtn->un.cast.expr = DEBUG_CloneExpr(exp->un.cast.expr);
 821       break;
 822     case EXPR_TYPE_INTVAR:
 823       rtn->un.intvar.name = DBG_strdup(exp->un.intvar.name);
 824       break;
 825     case EXPR_TYPE_US_CONST:
 826     case EXPR_TYPE_CONST:
 827       break;
 828     case EXPR_TYPE_STRING:
 829       rtn->un.string.str = DBG_strdup(exp->un.string.str);
 830       break;
 831     case EXPR_TYPE_SYMBOL:
 832       rtn->un.symbol.name = DBG_strdup(exp->un.symbol.name);
 833       break;
 834     case EXPR_TYPE_PSTRUCT:
 835     case EXPR_TYPE_STRUCT:
 836       rtn->un.structure.exp1 = DEBUG_CloneExpr(exp->un.structure.exp1);
 837       rtn->un.structure.element_name = DBG_strdup(exp->un.structure.element_name);
 838       break;
 839     case EXPR_TYPE_CALL:
 840       for(i=0; i < exp->un.call.nargs; i++)
 841         {
 842           rtn->un.call.arg[i]  = DEBUG_CloneExpr(exp->un.call.arg[i]);
 843         }
 844       rtn->un.call.funcname = DBG_strdup(exp->un.call.funcname);
 845       break;
 846     case EXPR_TYPE_BINOP:
 847       rtn->un.binop.exp1 = DEBUG_CloneExpr(exp->un.binop.exp1);
 848       rtn->un.binop.exp2 = DEBUG_CloneExpr(exp->un.binop.exp2);
 849       break;
 850     case EXPR_TYPE_UNOP:
 851       rtn->un.unop.exp1 = DEBUG_CloneExpr(exp->un.unop.exp1);
 852       break;
 853     default:
 854       DEBUG_Printf(DBG_CHN_MESG,"Unexpected expression.\n");
 855       RaiseException(DEBUG_STATUS_INTERNAL_ERROR, 0, 0, NULL);
 856       break;
 857     }
 858
 859   return rtn;
 860 }
 861
 862
 863 /*
 864  * Recursively go through an expression tree and free all memory associated
 865  * with it.
 866  */
 867 int
 868 DEBUG_FreeExpr(struct expr * exp)
 869 {
 870   int i;
 871
 872   switch(exp->type)
 873     {
 874     case EXPR_TYPE_CAST:
 875       DEBUG_FreeExpr(exp->un.cast.expr);
 876       break;
 877     case EXPR_TYPE_INTVAR:
 878       DBG_free((char *) exp->un.intvar.name);
 879       break;
 880     case EXPR_TYPE_US_CONST:
 881     case EXPR_TYPE_CONST:
 882       break;
 883     case EXPR_TYPE_STRING:
 884       DBG_free((char *) exp->un.string.str);
 885       break;
 886     case EXPR_TYPE_SYMBOL:
 887       DBG_free((char *) exp->un.symbol.name);
 888       break;
 889     case EXPR_TYPE_PSTRUCT:
 890     case EXPR_TYPE_STRUCT:
 891       DEBUG_FreeExpr(exp->un.structure.exp1);
 892       DBG_free((char *) exp->un.structure.element_name);
 893       break;
 894     case EXPR_TYPE_CALL:
 895       for(i=0; i < exp->un.call.nargs; i++)
 896         {
 897           DEBUG_FreeExpr(exp->un.call.arg[i]);
 898         }
 899       DBG_free((char *) exp->un.call.funcname);
 900       break;
 901     case EXPR_TYPE_BINOP:
 902       DEBUG_FreeExpr(exp->un.binop.exp1);
 903       DEBUG_FreeExpr(exp->un.binop.exp2);
 904       break;
 905     case EXPR_TYPE_UNOP:
 906       DEBUG_FreeExpr(exp->un.unop.exp1);
 907       break;
 908     default:
 909       DEBUG_Printf(DBG_CHN_MESG,"Unexpected expression.\n");
 910       RaiseException(DEBUG_STATUS_INTERNAL_ERROR, 0, 0, NULL);
 911       break;
 912     }
 913
 914   DBG_free(exp);
 915   return TRUE;
 916 }