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