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.addr.off = 0;
 306   rtn.addr.seg = 0;
 307
 308   switch(exp->type)
 309     {
 310     case EXPR_TYPE_CAST:
 311       rtn = DEBUG_EvalExpr(exp->un.cast.expr);
 312       rtn.type = exp->un.cast.cast;
 313       if (DEBUG_GetType(rtn.type) == DT_POINTER)
 314          rtn.cookie = DV_TARGET;
 315       break;
 316     case EXPR_TYPE_STRING:
 317       rtn.type = DEBUG_TypeString;
 318       rtn.cookie = DV_HOST;
 319       rtn.addr.off = (unsigned int) &exp->un.string.str;
 320       rtn.addr.seg = 0;
 321       break;
 322     case EXPR_TYPE_CONST:
 323       rtn.type = DEBUG_TypeIntConst;
 324       rtn.cookie = DV_HOST;
 325       rtn.addr.off = (unsigned int) &exp->un.constant.value;
 326       rtn.addr.seg = 0;
 327       break;
 328     case EXPR_TYPE_US_CONST:
 329       rtn.type = DEBUG_TypeUSInt;
 330       rtn.cookie = DV_HOST;
 331       rtn.addr.off = (unsigned int) &exp->un.u_const.value;
 332       rtn.addr.seg = 0;
 333       break;
 334     case EXPR_TYPE_SYMBOL:
 335       if( !DEBUG_GetSymbolValue(exp->un.symbol.name, -1, &rtn, FALSE) )
 336         {
 337            RaiseException(DEBUG_STATUS_NO_SYMBOL, 0, 0, NULL);
 338         }
 339       break;
 340     case EXPR_TYPE_PSTRUCT:
 341       exp1 =  DEBUG_EvalExpr(exp->un.structure.exp1);
 342       if( exp1.type == NULL )
 343         {
 344            RaiseException(DEBUG_STATUS_BAD_TYPE, 0, 0, NULL);
 345         }
 346       rtn.cookie = DV_TARGET;
 347       rtn.addr.off = DEBUG_TypeDerefPointer(&exp1, &type1);
 348       if( type1 == NULL )
 349         {
 350           RaiseException(DEBUG_STATUS_BAD_TYPE, 0, 0, NULL);
 351         }
 352       rtn.type = type1;
 353       DEBUG_FindStructElement(&rtn, exp->un.structure.element_name,
 354                               &exp->un.structure.result);
 355       break;
 356     case EXPR_TYPE_STRUCT:
 357       exp1 =  DEBUG_EvalExpr(exp->un.structure.exp1);
 358       if( exp1.type == NULL )
 359         {
 360           RaiseException(DEBUG_STATUS_BAD_TYPE, 0, 0, NULL);
 361         }
 362       rtn = exp1;
 363       DEBUG_FindStructElement(&rtn, exp->un.structure.element_name,
 364                               &exp->un.structure.result);
 365       break;
 366     case EXPR_TYPE_CALL:
 367       /*
 368        * First, evaluate all of the arguments.  If any of them are not
 369        * evaluable, then bail.
 370        */
 371       for(i=0; i < exp->un.call.nargs; i++)
 372         {
 373           exp1  = DEBUG_EvalExpr(exp->un.call.arg[i]);
 374           if( exp1.type == NULL )
 375             {
 376               return rtn;
 377             }
 378           cexp[i] = DEBUG_GetExprValue(&exp1, NULL);
 379         }
 380
 381       /*
 382        * Now look up the address of the function itself.
 383        */
 384       if( !DEBUG_GetSymbolValue(exp->un.call.funcname, -1, &rtn, FALSE ) )
 385         {
 386           RaiseException(DEBUG_STATUS_NO_SYMBOL, 0, 0, NULL);
 387         }
 388
 389 #if 0
 390       /* FIXME: NEWDBG NIY */
 391       /* Anyway, I wonder how this could work depending on the calling order of
 392        * the function (cdecl vs pascal for example)
 393        */
 394       int               (*fptr)();
 395
 396       fptr = (int (*)()) rtn.addr.off;
 397       switch(exp->un.call.nargs)
 398         {
 399         case 0:
 400           exp->un.call.result = (*fptr)();
 401           break;
 402         case 1:
 403           exp->un.call.result = (*fptr)(cexp[0]);
 404           break;
 405         case 2:
 406           exp->un.call.result = (*fptr)(cexp[0], cexp[1]);
 407           break;
 408         case 3:
 409           exp->un.call.result = (*fptr)(cexp[0], cexp[1], cexp[2]);
 410           break;
 411         case 4:
 412           exp->un.call.result = (*fptr)(cexp[0], cexp[1], cexp[2], cexp[3]);
 413           break;
 414         case 5:
 415           exp->un.call.result = (*fptr)(cexp[0], cexp[1], cexp[2], cexp[3], cexp[4]);
 416           break;
 417         }
 418 #else
 419       DEBUG_Printf(DBG_CHN_MESG, "Function call no longer implemented\n");
 420       /* would need to set up a call to this function, and then restore the current
 421        * context afterwards...
 422        */
 423       exp->un.call.result = 0;
 424 #endif
 425       rtn.type = DEBUG_TypeInt;
 426       rtn.cookie = DV_HOST;
 427       rtn.addr.off = (unsigned int) &exp->un.call.result;
 428
 429       break;
 430     case EXPR_TYPE_INTVAR:
 431       {
 432
 433          DBG_INTVAR*    div = DEBUG_GetIntVar(exp->un.intvar.name);
 434
 435          if (!div) RaiseException(DEBUG_STATUS_NO_SYMBOL, 0, 0, NULL);
 436          rtn.cookie = DV_HOST;
 437          rtn.type = div->type;
 438          rtn.addr.off = (unsigned int)div->pval;
 439          /* EPP FIXME rtn.addr.seg = ?? */
 440       }
 441       break;
 442     case EXPR_TYPE_BINOP:
 443       exp1 = DEBUG_EvalExpr(exp->un.binop.exp1);
 444       exp2 = DEBUG_EvalExpr(exp->un.binop.exp2);
 445       rtn.cookie = DV_HOST;
 446       if( exp1.type == NULL || exp2.type == NULL )
 447         {
 448           RaiseException(DEBUG_STATUS_BAD_TYPE, 0, 0, NULL);
 449         }
 450       if( exp1.type == DEBUG_TypeIntConst && exp2.type == DEBUG_TypeIntConst )
 451         {
 452           rtn.type = exp1.type;
 453         }
 454       else
 455         {
 456           rtn.type = DEBUG_TypeInt;
 457         }
 458       rtn.addr.seg = 0;
 459       rtn.addr.off = (unsigned int) &exp->un.binop.result;
 460       switch(exp->un.binop.binop_type)
 461         {
 462         case EXP_OP_ADD:
 463           type1 = DEBUG_GetPointerType(exp1.type);
 464           type2 = DEBUG_GetPointerType(exp2.type);
 465           scale1 = 1;
 466           scale2 = 1;
 467           if( type1 != NULL && type2 != NULL )
 468             {
 469               RaiseException(DEBUG_STATUS_BAD_TYPE, 0, 0, NULL);
 470             }
 471           else if( type1 != NULL )
 472             {
 473               scale2 = DEBUG_GetObjectSize(type1);
 474               rtn.type = exp1.type;
 475             }
 476           else if( type2 != NULL )
 477             {
 478               scale1 = DEBUG_GetObjectSize(type2);
 479               rtn.type = exp2.type;
 480             }
 481           exp->un.binop.result = (VAL(exp1) * scale1  + scale2 * VAL(exp2));
 482           break;
 483         case EXP_OP_SUB:
 484           type1 = DEBUG_GetPointerType(exp1.type);
 485           type2 = DEBUG_GetPointerType(exp2.type);
 486           scale1 = 1;
 487           scale2 = 1;
 488           scale3 = 1;
 489           if( type1 != NULL && type2 != NULL )
 490             {
 491               if( type1 != type2 )
 492                 {
 493                   RaiseException(DEBUG_STATUS_BAD_TYPE, 0, 0, NULL);
 494                 }
 495               scale3 = DEBUG_GetObjectSize(type1);
 496             }
 497           else if( type1 != NULL )
 498             {
 499               scale2 = DEBUG_GetObjectSize(type1);
 500               rtn.type = exp1.type;
 501             }
 502
 503           else if( type2 != NULL )
 504             {
 505               scale1 = DEBUG_GetObjectSize(type2);
 506               rtn.type = exp2.type;
 507             }
 508           exp->un.binop.result = (VAL(exp1) - VAL(exp2)) / scale3;
 509           break;
 510         case EXP_OP_SEG:
 511           rtn.cookie = DV_TARGET;
 512           rtn.addr.seg = VAL(exp1);
 513           exp->un.binop.result = VAL(exp2);
 514 #ifdef __i386__
 515           DEBUG_FixSegment(&rtn.addr);
 516 #endif
 517           break;
 518         case EXP_OP_LOR:
 519           exp->un.binop.result = (VAL(exp1) || VAL(exp2));
 520           break;
 521         case EXP_OP_LAND:
 522           exp->un.binop.result = (VAL(exp1) && VAL(exp2));
 523           break;
 524         case EXP_OP_OR:
 525           exp->un.binop.result = (VAL(exp1) | VAL(exp2));
 526           break;
 527         case EXP_OP_AND:
 528           exp->un.binop.result = (VAL(exp1) & VAL(exp2));
 529           break;
 530         case EXP_OP_XOR:
 531           exp->un.binop.result = (VAL(exp1) ^ VAL(exp2));
 532           break;
 533         case EXP_OP_EQ:
 534           exp->un.binop.result = (VAL(exp1) == VAL(exp2));
 535           break;
 536         case EXP_OP_GT:
 537           exp->un.binop.result = (VAL(exp1) > VAL(exp2));
 538           break;
 539         case EXP_OP_LT:
 540           exp->un.binop.result = (VAL(exp1) < VAL(exp2));
 541           break;
 542         case EXP_OP_GE:
 543           exp->un.binop.result = (VAL(exp1) >= VAL(exp2));
 544           break;
 545         case EXP_OP_LE:
 546           exp->un.binop.result = (VAL(exp1) <= VAL(exp2));
 547           break;
 548         case EXP_OP_NE:
 549           exp->un.binop.result = (VAL(exp1) != VAL(exp2));
 550           break;
 551         case EXP_OP_SHL:
 552           exp->un.binop.result = ((unsigned) VAL(exp1) << VAL(exp2));
 553           break;
 554         case EXP_OP_SHR:
 555           exp->un.binop.result = ((unsigned) VAL(exp1) >> VAL(exp2));
 556           break;
 557         case EXP_OP_MUL:
 558           exp->un.binop.result = (VAL(exp1) * VAL(exp2));
 559           break;
 560         case EXP_OP_DIV:
 561           if( VAL(exp2) == 0 )
 562             {
 563                RaiseException(DEBUG_STATUS_DIV_BY_ZERO, 0, 0, NULL);
 564             }
 565           exp->un.binop.result = (VAL(exp1) / VAL(exp2));
 566           break;
 567         case EXP_OP_REM:
 568           if( VAL(exp2) == 0 )
 569             {
 570                RaiseException(DEBUG_STATUS_DIV_BY_ZERO, 0, 0, NULL);
 571             }
 572           exp->un.binop.result = (VAL(exp1) % VAL(exp2));
 573           break;
 574         case EXP_OP_ARR:
 575           DEBUG_ArrayIndex(&exp1, &rtn, VAL(exp2));
 576           break;
 577         default:
 578           RaiseException(DEBUG_STATUS_INTERNAL_ERROR, 0, 0, NULL);
 579           break;
 580         }
 581       break;
 582     case EXPR_TYPE_UNOP:
 583       exp1 = DEBUG_EvalExpr(exp->un.unop.exp1);
 584       rtn.cookie = DV_HOST;
 585       if( exp1.type == NULL )
 586         {
 587           RaiseException(DEBUG_STATUS_BAD_TYPE, 0, 0, NULL);
 588         }
 589       rtn.addr.seg = 0;
 590       rtn.addr.off = (unsigned int) &exp->un.unop.result;
 591       if( exp1.type == DEBUG_TypeIntConst )
 592         {
 593           rtn.type = exp1.type;
 594         }
 595       else
 596         {
 597           rtn.type = DEBUG_TypeInt;
 598         }
 599       switch(exp->un.unop.unop_type)
 600         {
 601         case EXP_OP_NEG:
 602           exp->un.unop.result = -VAL(exp1);
 603           break;
 604         case EXP_OP_NOT:
 605           exp->un.unop.result = !VAL(exp1);
 606           break;
 607         case EXP_OP_LNOT:
 608           exp->un.unop.result = ~VAL(exp1);
 609           break;
 610         case EXP_OP_DEREF:
 611           rtn.cookie = exp1.cookie;
 612           rtn.addr.off = (unsigned int) DEBUG_TypeDerefPointer(&exp1, &rtn.type);
 613           if (!rtn.type)
 614             {
 615               RaiseException(DEBUG_STATUS_BAD_TYPE, 0, 0, NULL);
 616             }
 617           break;
 618         case EXP_OP_FORCE_DEREF:
 619           rtn.cookie = exp1.cookie;
 620           rtn.addr.seg = exp1.addr.seg;
 621           if (exp1.cookie == DV_TARGET)
 622              DEBUG_READ_MEM((void*)exp1.addr.off, &rtn.addr.off, sizeof(rtn.addr.off));
 623           else
 624              memcpy(&rtn.addr.off, (void*)exp1.addr.off, sizeof(rtn.addr.off));
 625           break;
 626         case EXP_OP_ADDR:
 627           /* FIXME: even for a 16 bit entity ? */
 628           rtn.cookie = DV_TARGET;
 629           rtn.type = DEBUG_FindOrMakePointerType(exp1.type);
 630           exp->un.unop.result = exp1.addr.off;
 631           break;
 632         default:
 633            RaiseException(DEBUG_STATUS_INTERNAL_ERROR, 0, 0, NULL);
 634         }
 635       break;
 636     default:
 637       DEBUG_Printf(DBG_CHN_MESG,"Unexpected expression (%d).\n", exp->type);
 638       RaiseException(DEBUG_STATUS_INTERNAL_ERROR, 0, 0, NULL);
 639       break;
 640     }
 641
 642   assert(rtn.cookie == DV_TARGET || rtn.cookie == DV_HOST);
 643
 644   return rtn;
 645 }
 646
 647
 648 int
 649 DEBUG_DisplayExpr(const struct expr * exp)
 650 {
 651   int           i;
 652
 653   switch(exp->type)
 654     {
 655     case EXPR_TYPE_CAST:
 656       DEBUG_Printf(DBG_CHN_MESG, "((");
 657       DEBUG_PrintTypeCast(exp->un.cast.cast);
 658       DEBUG_Printf(DBG_CHN_MESG, ")");
 659       DEBUG_DisplayExpr(exp->un.cast.expr);
 660       DEBUG_Printf(DBG_CHN_MESG, ")");
 661       break;
 662     case EXPR_TYPE_INTVAR:
 663       DEBUG_Printf(DBG_CHN_MESG, "$%s", exp->un.intvar.name);
 664       break;
 665     case EXPR_TYPE_US_CONST:
 666       DEBUG_Printf(DBG_CHN_MESG, "%ud", exp->un.u_const.value);
 667       break;
 668     case EXPR_TYPE_CONST:
 669       DEBUG_Printf(DBG_CHN_MESG, "%d", exp->un.u_const.value);
 670       break;
 671     case EXPR_TYPE_STRING:
 672       DEBUG_Printf(DBG_CHN_MESG, "\"%s\"", exp->un.string.str);
 673       break;
 674     case EXPR_TYPE_SYMBOL:
 675       DEBUG_Printf(DBG_CHN_MESG, "%s" , exp->un.symbol.name);
 676       break;
 677     case EXPR_TYPE_PSTRUCT:
 678       DEBUG_DisplayExpr(exp->un.structure.exp1);
 679       DEBUG_Printf(DBG_CHN_MESG, "->%s", exp->un.structure.element_name);
 680       break;
 681     case EXPR_TYPE_STRUCT:
 682       DEBUG_DisplayExpr(exp->un.structure.exp1);
 683       DEBUG_Printf(DBG_CHN_MESG, ".%s", exp->un.structure.element_name);
 684       break;
 685     case EXPR_TYPE_CALL:
 686       DEBUG_Printf(DBG_CHN_MESG, "%s(",exp->un.call.funcname);
 687       for(i=0; i < exp->un.call.nargs; i++)
 688         {
 689           DEBUG_DisplayExpr(exp->un.call.arg[i]);
 690           if( i != exp->un.call.nargs - 1 )
 691             {
 692               DEBUG_Printf(DBG_CHN_MESG, ", ");
 693             }
 694         }
 695       DEBUG_Printf(DBG_CHN_MESG, ")");
 696       break;
 697     case EXPR_TYPE_BINOP:
 698       DEBUG_Printf(DBG_CHN_MESG, "( ");
 699       DEBUG_DisplayExpr(exp->un.binop.exp1);
 700       switch(exp->un.binop.binop_type)
 701         {
 702         case EXP_OP_ADD:
 703           DEBUG_Printf(DBG_CHN_MESG, " + ");
 704           break;
 705         case EXP_OP_SUB:
 706           DEBUG_Printf(DBG_CHN_MESG, " - ");
 707           break;
 708         case EXP_OP_SEG:
 709           DEBUG_Printf(DBG_CHN_MESG, ":");
 710           break;
 711         case EXP_OP_LOR:
 712           DEBUG_Printf(DBG_CHN_MESG, " || ");
 713           break;
 714         case EXP_OP_LAND:
 715           DEBUG_Printf(DBG_CHN_MESG, " && ");
 716           break;
 717         case EXP_OP_OR:
 718           DEBUG_Printf(DBG_CHN_MESG, " | ");
 719           break;
 720         case EXP_OP_AND:
 721           DEBUG_Printf(DBG_CHN_MESG, " & ");
 722           break;
 723         case EXP_OP_XOR:
 724           DEBUG_Printf(DBG_CHN_MESG, " ^ ");
 725           break;
 726         case EXP_OP_EQ:
 727           DEBUG_Printf(DBG_CHN_MESG, " == ");
 728           break;
 729         case EXP_OP_GT:
 730           DEBUG_Printf(DBG_CHN_MESG, " > ");
 731           break;
 732         case EXP_OP_LT:
 733           DEBUG_Printf(DBG_CHN_MESG, " < ");
 734           break;
 735         case EXP_OP_GE:
 736           DEBUG_Printf(DBG_CHN_MESG, " >= ");
 737           break;
 738         case EXP_OP_LE:
 739           DEBUG_Printf(DBG_CHN_MESG, " <= ");
 740           break;
 741         case EXP_OP_NE:
 742           DEBUG_Printf(DBG_CHN_MESG, " != ");
 743           break;
 744         case EXP_OP_SHL:
 745           DEBUG_Printf(DBG_CHN_MESG, " << ");
 746           break;
 747         case EXP_OP_SHR:
 748           DEBUG_Printf(DBG_CHN_MESG, " >> ");
 749           break;
 750         case EXP_OP_MUL:
 751           DEBUG_Printf(DBG_CHN_MESG, " * ");
 752           break;
 753         case EXP_OP_DIV:
 754           DEBUG_Printf(DBG_CHN_MESG, " / ");
 755           break;
 756         case EXP_OP_REM:
 757           DEBUG_Printf(DBG_CHN_MESG, " %% ");
 758           break;
 759         case EXP_OP_ARR:
 760           DEBUG_Printf(DBG_CHN_MESG, "[");
 761           break;
 762         default:
 763           break;
 764         }
 765       DEBUG_DisplayExpr(exp->un.binop.exp2);
 766       if( exp->un.binop.binop_type == EXP_OP_ARR )
 767         {
 768           DEBUG_Printf(DBG_CHN_MESG, "]");
 769         }
 770       DEBUG_Printf(DBG_CHN_MESG, " )");
 771       break;
 772     case EXPR_TYPE_UNOP:
 773       switch(exp->un.unop.unop_type)
 774         {
 775         case EXP_OP_NEG:
 776           DEBUG_Printf(DBG_CHN_MESG, "-");
 777           break;
 778         case EXP_OP_NOT:
 779           DEBUG_Printf(DBG_CHN_MESG, "!");
 780           break;
 781         case EXP_OP_LNOT:
 782           DEBUG_Printf(DBG_CHN_MESG, "~");
 783           break;
 784         case EXP_OP_DEREF:
 785           DEBUG_Printf(DBG_CHN_MESG, "*");
 786           break;
 787         case EXP_OP_ADDR:
 788           DEBUG_Printf(DBG_CHN_MESG, "&");
 789           break;
 790         }
 791       DEBUG_DisplayExpr(exp->un.unop.exp1);
 792       break;
 793     default:
 794       DEBUG_Printf(DBG_CHN_MESG,"Unexpected expression.\n");
 795       RaiseException(DEBUG_STATUS_INTERNAL_ERROR, 0, 0, NULL);
 796       break;
 797     }
 798
 799   return TRUE;
 800 }
 801
 802 struct expr *
 803 DEBUG_CloneExpr(const struct expr * exp)
 804 {
 805   int           i;
 806   struct expr * rtn;
 807
 808   rtn = (struct expr *) DBG_alloc(sizeof(struct expr));
 809
 810   /*
 811    * First copy the contents of the expression itself.
 812    */
 813   *rtn = *exp;
 814
 815
 816   switch(exp->type)
 817     {
 818     case EXPR_TYPE_CAST:
 819       rtn->un.cast.expr = DEBUG_CloneExpr(exp->un.cast.expr);
 820       break;
 821     case EXPR_TYPE_INTVAR:
 822       rtn->un.intvar.name = DBG_strdup(exp->un.intvar.name);
 823       break;
 824     case EXPR_TYPE_US_CONST:
 825     case EXPR_TYPE_CONST:
 826       break;
 827     case EXPR_TYPE_STRING:
 828       rtn->un.string.str = DBG_strdup(exp->un.string.str);
 829       break;
 830     case EXPR_TYPE_SYMBOL:
 831       rtn->un.symbol.name = DBG_strdup(exp->un.symbol.name);
 832       break;
 833     case EXPR_TYPE_PSTRUCT:
 834     case EXPR_TYPE_STRUCT:
 835       rtn->un.structure.exp1 = DEBUG_CloneExpr(exp->un.structure.exp1);
 836       rtn->un.structure.element_name = DBG_strdup(exp->un.structure.element_name);
 837       break;
 838     case EXPR_TYPE_CALL:
 839       for(i=0; i < exp->un.call.nargs; i++)
 840         {
 841           rtn->un.call.arg[i]  = DEBUG_CloneExpr(exp->un.call.arg[i]);
 842         }
 843       rtn->un.call.funcname = DBG_strdup(exp->un.call.funcname);
 844       break;
 845     case EXPR_TYPE_BINOP:
 846       rtn->un.binop.exp1 = DEBUG_CloneExpr(exp->un.binop.exp1);
 847       rtn->un.binop.exp2 = DEBUG_CloneExpr(exp->un.binop.exp2);
 848       break;
 849     case EXPR_TYPE_UNOP:
 850       rtn->un.unop.exp1 = DEBUG_CloneExpr(exp->un.unop.exp1);
 851       break;
 852     default:
 853       DEBUG_Printf(DBG_CHN_MESG,"Unexpected expression.\n");
 854       RaiseException(DEBUG_STATUS_INTERNAL_ERROR, 0, 0, NULL);
 855       break;
 856     }
 857
 858   return rtn;
 859 }
 860
 861
 862 /*
 863  * Recursively go through an expression tree and free all memory associated
 864  * with it.
 865  */
 866 int
 867 DEBUG_FreeExpr(struct expr * exp)
 868 {
 869   int i;
 870
 871   switch(exp->type)
 872     {
 873     case EXPR_TYPE_CAST:
 874       DEBUG_FreeExpr(exp->un.cast.expr);
 875       break;
 876     case EXPR_TYPE_INTVAR:
 877       DBG_free((char *) exp->un.intvar.name);
 878       break;
 879     case EXPR_TYPE_US_CONST:
 880     case EXPR_TYPE_CONST:
 881       break;
 882     case EXPR_TYPE_STRING:
 883       DBG_free((char *) exp->un.string.str);
 884       break;
 885     case EXPR_TYPE_SYMBOL:
 886       DBG_free((char *) exp->un.symbol.name);
 887       break;
 888     case EXPR_TYPE_PSTRUCT:
 889     case EXPR_TYPE_STRUCT:
 890       DEBUG_FreeExpr(exp->un.structure.exp1);
 891       DBG_free((char *) exp->un.structure.element_name);
 892       break;
 893     case EXPR_TYPE_CALL:
 894       for(i=0; i < exp->un.call.nargs; i++)
 895         {
 896           DEBUG_FreeExpr(exp->un.call.arg[i]);
 897         }
 898       DBG_free((char *) exp->un.call.funcname);
 899       break;
 900     case EXPR_TYPE_BINOP:
 901       DEBUG_FreeExpr(exp->un.binop.exp1);
 902       DEBUG_FreeExpr(exp->un.binop.exp2);
 903       break;
 904     case EXPR_TYPE_UNOP:
 905       DEBUG_FreeExpr(exp->un.unop.exp1);
 906       break;
 907     default:
 908       DEBUG_Printf(DBG_CHN_MESG,"Unexpected expression.\n");
 909       RaiseException(DEBUG_STATUS_INTERNAL_ERROR, 0, 0, NULL);
 910       break;
 911     }
 912
 913   DBG_free(exp);
 914   return TRUE;
 915 }