debugger/expr.c

   1 /*
   2  * File expr.c - expression handling for Wine internal debugger.
   3  *
   4  * Copyright (C) 1997, Eric Youngdale.
   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
  21 #include "config.h"
  22 #include <stdlib.h>
  23 #include <string.h>
  24 #include "winbase.h"
  25 #include "wine/winbase16.h"
  26 #include "debugger.h"
  27 #include "expr.h"
  28
  29 #include <stdarg.h>
  30
  31 struct expr
  32 {
  33   unsigned int  perm;
  34   unsigned int  type:31;
  35   union
  36   {
  37     struct
  38     {
  39       int value;
  40     } constant;
  41
  42     struct
  43     {
  44       const char * str;
  45     } string;
  46
  47     struct
  48     {
  49       unsigned int value;
  50     } u_const;
  51
  52     struct
  53     {
  54       const char * name;
  55     } symbol;
  56
  57     struct
  58     {
  59       const char * name;
  60     } intvar;
  61
  62     struct
  63     {
  64       int unop_type;
  65       struct expr * exp1;
  66       int             result;
  67     } unop;
  68
  69     struct
  70     {
  71       int binop_type;
  72       int result;
  73       struct expr * exp1;
  74       struct expr * exp2;
  75     } binop;
  76
  77     struct
  78     {
  79       struct datatype * cast;
  80       struct expr     * expr;
  81     } cast;
  82
  83     struct
  84     {
  85       struct expr * exp1;
  86       const char * element_name;
  87       int result;
  88     } structure;
  89
  90     struct
  91     {
  92       struct expr * base;
  93       struct expr * index;
  94     } array;
  95
  96     struct
  97     {
  98       const char  * funcname;
  99       int           nargs;
 100       int           result;
 101       struct expr * arg[5];
 102     } call;
 103
 104   } un;
 105 };
 106
 107 #define EXPR_TYPE_CONST         0
 108 #define EXPR_TYPE_US_CONST      1
 109 #define EXPR_TYPE_SYMBOL        2
 110 #define EXPR_TYPE_INTVAR        3
 111 #define EXPR_TYPE_BINOP         4
 112 #define EXPR_TYPE_UNOP          5
 113 #define EXPR_TYPE_STRUCT        6
 114 #define EXPR_TYPE_PSTRUCT       7
 115 #define EXPR_TYPE_ARRAY         8
 116 #define EXPR_TYPE_CALL          9
 117 #define EXPR_TYPE_STRING        10
 118 #define EXPR_TYPE_CAST          11
 119
 120 static char expr_list[4096];
 121 static unsigned int next_expr_free = 0;
 122
 123 /*
 124  * This is how we turn an expression address into the actual value.
 125  * This works well in the 32 bit domain - not sure at all about the
 126  * 16 bit world.
 127  */
 128 #define VAL(_exp)       DEBUG_GetExprValue(&_exp, NULL)
 129
 130 static
 131 struct expr *
 132 DEBUG_GetFreeExpr(void)
 133 {
 134   struct expr * rtn;
 135
 136   rtn =  (struct expr *) &expr_list[next_expr_free];
 137
 138   next_expr_free += sizeof(struct expr);
 139   assert(next_expr_free < sizeof(expr_list));
 140
 141   return rtn;
 142 }
 143
 144 void
 145 DEBUG_FreeExprMem(void)
 146 {
 147   next_expr_free = 0;
 148 }
 149
 150 struct expr *
 151 DEBUG_TypeCastExpr(struct datatype * dt, struct expr * exp)
 152 {
 153   struct expr * ex;
 154
 155   ex = DEBUG_GetFreeExpr();
 156
 157   ex->type        = EXPR_TYPE_CAST;
 158   ex->un.cast.cast = dt;
 159   ex->un.cast.expr = exp;
 160   return ex;
 161 }
 162
 163 struct expr *
 164 DEBUG_IntVarExpr(const char* name)
 165 {
 166   struct expr * ex;
 167
 168   ex = DEBUG_GetFreeExpr();
 169
 170   ex->type        = EXPR_TYPE_INTVAR;
 171   ex->un.intvar.name = name;
 172   return ex;
 173 }
 174
 175 struct expr *
 176 DEBUG_SymbolExpr(const char * name)
 177 {
 178   struct expr * ex;
 179
 180   ex = DEBUG_GetFreeExpr();
 181
 182   ex->type        = EXPR_TYPE_SYMBOL;
 183   ex->un.symbol.name = name;
 184   return ex;
 185 }
 186
 187 struct expr *
 188 DEBUG_ConstExpr(int value)
 189 {
 190   struct expr * ex;
 191
 192   ex = DEBUG_GetFreeExpr();
 193
 194   ex->type        = EXPR_TYPE_CONST;
 195   ex->un.constant.value = value;
 196   return ex;
 197 }
 198
 199 struct expr *
 200 DEBUG_StringExpr(const char * str)
 201 {
 202   struct expr * ex;
 203   char * pnt;
 204   ex = DEBUG_GetFreeExpr();
 205
 206   ex->type        = EXPR_TYPE_STRING;
 207   ex->un.string.str = str+1;
 208   pnt = strrchr(ex->un.string.str, '"');
 209   if( pnt != NULL )
 210     {
 211       *pnt =  '\0';
 212     }
 213   return ex;
 214 }
 215
 216 struct expr *
 217 DEBUG_USConstExpr(unsigned int value)
 218 {
 219   struct expr * ex;
 220
 221   ex = DEBUG_GetFreeExpr();
 222
 223   ex->type           = EXPR_TYPE_CONST;
 224   ex->un.u_const.value = value;
 225   return ex;
 226 }
 227
 228 struct expr *
 229 DEBUG_BinopExpr(int operator_type, struct expr * exp1, struct expr * exp2)
 230 {
 231   struct expr * ex;
 232
 233   ex = DEBUG_GetFreeExpr();
 234
 235   ex->type           = EXPR_TYPE_BINOP;
 236   ex->un.binop.binop_type = operator_type;
 237   ex->un.binop.exp1     = exp1;
 238   ex->un.binop.exp2     = exp2;
 239   return ex;
 240 }
 241
 242 struct expr *
 243 DEBUG_UnopExpr(int operator_type, struct expr * exp1)
 244 {
 245   struct expr * ex;
 246
 247   ex = DEBUG_GetFreeExpr();
 248
 249   ex->type           = EXPR_TYPE_UNOP;
 250   ex->un.unop.unop_type = operator_type;
 251   ex->un.unop.exp1      = exp1;
 252   return ex;
 253 }
 254
 255 struct expr *
 256 DEBUG_StructExpr(struct expr * exp, const char * element)
 257 {
 258   struct expr * ex;
 259
 260   ex = DEBUG_GetFreeExpr();
 261
 262   ex->type           = EXPR_TYPE_STRUCT;
 263   ex->un.structure.exp1 = exp;
 264   ex->un.structure.element_name = element;
 265   return ex;
 266 }
 267
 268 struct expr *
 269 DEBUG_StructPExpr(struct expr * exp, const char * element)
 270 {
 271   struct expr * ex;
 272
 273   ex = DEBUG_GetFreeExpr();
 274
 275   ex->type           = EXPR_TYPE_PSTRUCT;
 276   ex->un.structure.exp1 = exp;
 277   ex->un.structure.element_name = element;
 278   return ex;
 279 }
 280
 281 struct expr *
 282 DEBUG_CallExpr(const char * funcname, int nargs, ...)
 283 {
 284   struct expr * ex;
 285   va_list ap;
 286   int i;
 287
 288   ex = DEBUG_GetFreeExpr();
 289
 290   ex->type           = EXPR_TYPE_CALL;
 291   ex->un.call.funcname = funcname;
 292   ex->un.call.nargs = nargs;
 293
 294   va_start(ap, nargs);
 295   for(i=0; i < nargs; i++)
 296     {
 297       ex->un.call.arg[i] = va_arg(ap, struct expr *);
 298     }
 299   va_end(ap);
 300   return ex;
 301 }
 302
 303 DBG_VALUE DEBUG_EvalExpr(struct expr * exp)
 304 {
 305   DBG_VALUE     rtn;
 306   int           i;
 307   DBG_VALUE     exp1;
 308   DBG_VALUE     exp2;
 309   unsigned int  cexp[5];
 310   int               scale1;
 311   int               scale2;
 312   int               scale3;
 313   struct datatype * type1;
 314   struct datatype * type2;
 315
 316   rtn.type = NULL;
 317   rtn.cookie = DV_INVALID;
 318   rtn.addr.off = 0;
 319   rtn.addr.seg = 0;
 320
 321   switch(exp->type)
 322     {
 323     case EXPR_TYPE_CAST:
 324       rtn = DEBUG_EvalExpr(exp->un.cast.expr);
 325       rtn.type = exp->un.cast.cast;
 326       if (!rtn.type)
 327       {
 328           DEBUG_Printf(DBG_CHN_MESG, "Can't cast to unknown type\n");
 329           RaiseException(DEBUG_STATUS_BAD_TYPE, 0, 0, NULL);
 330       }
 331       if (DEBUG_GetType(rtn.type) == DT_POINTER)
 332          rtn.cookie = DV_TARGET;
 333       break;
 334     case EXPR_TYPE_STRING:
 335       rtn.type = DEBUG_GetBasicType(DT_BASIC_STRING);
 336       rtn.cookie = DV_HOST;
 337       rtn.addr.off = (unsigned int) &exp->un.string.str;
 338       rtn.addr.seg = 0;
 339       break;
 340     case EXPR_TYPE_CONST:
 341       rtn.type = DEBUG_GetBasicType(DT_BASIC_CONST_INT);
 342       rtn.cookie = DV_HOST;
 343       rtn.addr.off = (unsigned int) &exp->un.constant.value;
 344       rtn.addr.seg = 0;
 345       break;
 346     case EXPR_TYPE_US_CONST:
 347       rtn.type = DEBUG_GetBasicType(DT_BASIC_USHORTINT);
 348       rtn.cookie = DV_HOST;
 349       rtn.addr.off = (unsigned int) &exp->un.u_const.value;
 350       rtn.addr.seg = 0;
 351       break;
 352     case EXPR_TYPE_SYMBOL:
 353       if( !DEBUG_GetSymbolValue(exp->un.symbol.name, -1, &rtn, FALSE) )
 354       {
 355           DEBUG_Printf(DBG_CHN_MESG, "%s\n", exp->un.symbol.name);
 356           RaiseException(DEBUG_STATUS_NO_SYMBOL, 0, 0, NULL);
 357       }
 358       break;
 359     case EXPR_TYPE_PSTRUCT:
 360       exp1 =  DEBUG_EvalExpr(exp->un.structure.exp1);
 361       if( exp1.type == NULL )
 362         {
 363            RaiseException(DEBUG_STATUS_BAD_TYPE, 0, 0, NULL);
 364         }
 365       rtn.cookie = DV_TARGET;
 366       rtn.addr.off = DEBUG_TypeDerefPointer(&exp1, &rtn.type);
 367       if( rtn.type == NULL )
 368         {
 369           RaiseException(DEBUG_STATUS_BAD_TYPE, 0, 0, NULL);
 370         }
 371       if (!DEBUG_FindStructElement(&rtn, exp->un.structure.element_name,
 372                                    &exp->un.structure.result))
 373       {
 374           DEBUG_Printf(DBG_CHN_MESG, "%s\n", exp->un.structure.element_name);
 375           RaiseException(DEBUG_STATUS_NO_FIELD, 0, 0, NULL);
 376       }
 377
 378       break;
 379     case EXPR_TYPE_STRUCT:
 380       exp1 =  DEBUG_EvalExpr(exp->un.structure.exp1);
 381       if( exp1.type == NULL )
 382       {
 383           RaiseException(DEBUG_STATUS_BAD_TYPE, 0, 0, NULL);
 384       }
 385       rtn = exp1;
 386       if (!DEBUG_FindStructElement(&rtn, exp->un.structure.element_name,
 387                                    &exp->un.structure.result))
 388       {
 389           DEBUG_Printf(DBG_CHN_MESG, "%s\n", exp->un.structure.element_name);
 390           RaiseException(DEBUG_STATUS_NO_FIELD, 0, 0, NULL);
 391       }
 392       break;
 393     case EXPR_TYPE_CALL:
 394       /*
 395        * First, evaluate all of the arguments.  If any of them are not
 396        * evaluable, then bail.
 397        */
 398       for(i=0; i < exp->un.call.nargs; i++)
 399         {
 400           exp1  = DEBUG_EvalExpr(exp->un.call.arg[i]);
 401           if( exp1.type == NULL )
 402             {
 403               return rtn;
 404             }
 405           cexp[i] = DEBUG_GetExprValue(&exp1, NULL);
 406         }
 407
 408       /*
 409        * Now look up the address of the function itself.
 410        */
 411       if( !DEBUG_GetSymbolValue(exp->un.call.funcname, -1, &rtn, FALSE ) )
 412         {
 413           RaiseException(DEBUG_STATUS_NO_SYMBOL, 0, 0, NULL);
 414         }
 415
 416 #if 0
 417       /* FIXME: NEWDBG NIY */
 418       /* Anyway, I wonder how this could work depending on the calling order of
 419        * the function (cdecl vs pascal for example)
 420        */
 421       int               (*fptr)();
 422
 423       fptr = (int (*)()) rtn.addr.off;
 424       switch(exp->un.call.nargs)
 425         {
 426         case 0:
 427           exp->un.call.result = (*fptr)();
 428           break;
 429         case 1:
 430           exp->un.call.result = (*fptr)(cexp[0]);
 431           break;
 432         case 2:
 433           exp->un.call.result = (*fptr)(cexp[0], cexp[1]);
 434           break;
 435         case 3:
 436           exp->un.call.result = (*fptr)(cexp[0], cexp[1], cexp[2]);
 437           break;
 438         case 4:
 439           exp->un.call.result = (*fptr)(cexp[0], cexp[1], cexp[2], cexp[3]);
 440           break;
 441         case 5:
 442           exp->un.call.result = (*fptr)(cexp[0], cexp[1], cexp[2], cexp[3], cexp[4]);
 443           break;
 444         }
 445 #else
 446       DEBUG_Printf(DBG_CHN_MESG, "Function call no longer implemented\n");
 447       /* would need to set up a call to this function, and then restore the current
 448        * context afterwards...
 449        */
 450       exp->un.call.result = 0;
 451 #endif
 452       rtn.type = DEBUG_GetBasicType(DT_BASIC_INT);
 453       rtn.cookie = DV_HOST;
 454       rtn.addr.off = (unsigned int) &exp->un.call.result;
 455
 456       break;
 457     case EXPR_TYPE_INTVAR:
 458       {
 459
 460          DBG_INTVAR*    div = DEBUG_GetIntVar(exp->un.intvar.name);
 461
 462          if (!div) RaiseException(DEBUG_STATUS_NO_SYMBOL, 0, 0, NULL);
 463          rtn.cookie = DV_HOST;
 464          rtn.type = div->type;
 465          rtn.addr.off = (unsigned int)div->pval;
 466          /* EPP FIXME rtn.addr.seg = ?? */
 467       }
 468       break;
 469     case EXPR_TYPE_BINOP:
 470       exp1 = DEBUG_EvalExpr(exp->un.binop.exp1);
 471       exp2 = DEBUG_EvalExpr(exp->un.binop.exp2);
 472       rtn.cookie = DV_HOST;
 473       if( exp1.type == NULL || exp2.type == NULL )
 474         {
 475           RaiseException(DEBUG_STATUS_BAD_TYPE, 0, 0, NULL);
 476         }
 477       if( exp1.type == DEBUG_GetBasicType(DT_BASIC_CONST_INT) &&
 478           exp2.type == DEBUG_GetBasicType(DT_BASIC_CONST_INT) )
 479         {
 480           rtn.type = exp1.type;
 481         }
 482       else
 483         {
 484           rtn.type = DEBUG_GetBasicType(DT_BASIC_INT);
 485         }
 486       rtn.addr.seg = 0;
 487       rtn.addr.off = (unsigned int) &exp->un.binop.result;
 488       switch(exp->un.binop.binop_type)
 489         {
 490         case EXP_OP_ADD:
 491           type1 = DEBUG_GetPointerType(exp1.type);
 492           type2 = DEBUG_GetPointerType(exp2.type);
 493           scale1 = 1;
 494           scale2 = 1;
 495           if( type1 != NULL && type2 != NULL )
 496             {
 497               RaiseException(DEBUG_STATUS_BAD_TYPE, 0, 0, NULL);
 498             }
 499           else if( type1 != NULL )
 500             {
 501               scale2 = DEBUG_GetObjectSize(type1);
 502               rtn.type = exp1.type;
 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) * scale1  + scale2 * VAL(exp2));
 510           break;
 511         case EXP_OP_SUB:
 512           type1 = DEBUG_GetPointerType(exp1.type);
 513           type2 = DEBUG_GetPointerType(exp2.type);
 514           scale1 = 1;
 515           scale2 = 1;
 516           scale3 = 1;
 517           if( type1 != NULL && type2 != NULL )
 518             {
 519               if( type1 != type2 )
 520                 {
 521                   RaiseException(DEBUG_STATUS_BAD_TYPE, 0, 0, NULL);
 522                 }
 523               scale3 = DEBUG_GetObjectSize(type1);
 524             }
 525           else if( type1 != NULL )
 526             {
 527               scale2 = DEBUG_GetObjectSize(type1);
 528               rtn.type = exp1.type;
 529             }
 530
 531           else if( type2 != NULL )
 532             {
 533               scale1 = DEBUG_GetObjectSize(type2);
 534               rtn.type = exp2.type;
 535             }
 536           exp->un.binop.result = (VAL(exp1) - VAL(exp2)) / scale3;
 537           break;
 538         case EXP_OP_SEG:
 539           rtn.cookie = DV_TARGET;
 540           rtn.type = NULL;
 541           rtn.addr.seg = VAL(exp1);
 542           rtn.addr.off = VAL(exp2);
 543           break;
 544         case EXP_OP_LOR:
 545           exp->un.binop.result = (VAL(exp1) || VAL(exp2));
 546           break;
 547         case EXP_OP_LAND:
 548           exp->un.binop.result = (VAL(exp1) && VAL(exp2));
 549           break;
 550         case EXP_OP_OR:
 551           exp->un.binop.result = (VAL(exp1) | VAL(exp2));
 552           break;
 553         case EXP_OP_AND:
 554           exp->un.binop.result = (VAL(exp1) & VAL(exp2));
 555           break;
 556         case EXP_OP_XOR:
 557           exp->un.binop.result = (VAL(exp1) ^ VAL(exp2));
 558           break;
 559         case EXP_OP_EQ:
 560           exp->un.binop.result = (VAL(exp1) == VAL(exp2));
 561           break;
 562         case EXP_OP_GT:
 563           exp->un.binop.result = (VAL(exp1) > VAL(exp2));
 564           break;
 565         case EXP_OP_LT:
 566           exp->un.binop.result = (VAL(exp1) < VAL(exp2));
 567           break;
 568         case EXP_OP_GE:
 569           exp->un.binop.result = (VAL(exp1) >= VAL(exp2));
 570           break;
 571         case EXP_OP_LE:
 572           exp->un.binop.result = (VAL(exp1) <= VAL(exp2));
 573           break;
 574         case EXP_OP_NE:
 575           exp->un.binop.result = (VAL(exp1) != VAL(exp2));
 576           break;
 577         case EXP_OP_SHL:
 578           exp->un.binop.result = ((unsigned) VAL(exp1) << VAL(exp2));
 579           break;
 580         case EXP_OP_SHR:
 581           exp->un.binop.result = ((unsigned) VAL(exp1) >> VAL(exp2));
 582           break;
 583         case EXP_OP_MUL:
 584           exp->un.binop.result = (VAL(exp1) * VAL(exp2));
 585           break;
 586         case EXP_OP_DIV:
 587           if( VAL(exp2) == 0 )
 588             {
 589                RaiseException(DEBUG_STATUS_DIV_BY_ZERO, 0, 0, NULL);
 590             }
 591           exp->un.binop.result = (VAL(exp1) / VAL(exp2));
 592           break;
 593         case EXP_OP_REM:
 594           if( VAL(exp2) == 0 )
 595             {
 596                RaiseException(DEBUG_STATUS_DIV_BY_ZERO, 0, 0, NULL);
 597             }
 598           exp->un.binop.result = (VAL(exp1) % VAL(exp2));
 599           break;
 600         case EXP_OP_ARR:
 601           DEBUG_ArrayIndex(&exp1, &rtn, VAL(exp2));
 602           break;
 603         default:
 604           RaiseException(DEBUG_STATUS_INTERNAL_ERROR, 0, 0, NULL);
 605           break;
 606         }
 607       break;
 608     case EXPR_TYPE_UNOP:
 609       exp1 = DEBUG_EvalExpr(exp->un.unop.exp1);
 610       rtn.cookie = DV_HOST;
 611       if( exp1.type == NULL )
 612         {
 613           RaiseException(DEBUG_STATUS_BAD_TYPE, 0, 0, NULL);
 614         }
 615       rtn.addr.seg = 0;
 616       rtn.addr.off = (unsigned int) &exp->un.unop.result;
 617       if( exp1.type == DEBUG_GetBasicType(DT_BASIC_CONST_INT) )
 618         {
 619           rtn.type = exp1.type;
 620         }
 621       else
 622         {
 623           rtn.type = DEBUG_GetBasicType(DT_BASIC_INT);
 624         }
 625       switch(exp->un.unop.unop_type)
 626         {
 627         case EXP_OP_NEG:
 628           exp->un.unop.result = -VAL(exp1);
 629           break;
 630         case EXP_OP_NOT:
 631           exp->un.unop.result = !VAL(exp1);
 632           break;
 633         case EXP_OP_LNOT:
 634           exp->un.unop.result = ~VAL(exp1);
 635           break;
 636         case EXP_OP_DEREF:
 637           /* FIXME: this is currently buggy.
 638            * there is no way to tell were the deref:ed value is...
 639            * for example:
 640            *    x is a pointer to struct s, x being on the stack
 641            *            => exp1 is target, result is target
 642            *    x is a pointer to struct s, x being optimized into a reg
 643            *            => exp1 is host, result is target
 644            *    x is a pointer to internal variable x
 645            *            => exp1 is host, result is host
 646            * so we force DV_TARGET, because dereferencing pointers to
 647            * internal variables is very unlikely. a correct fix would be
 648            * rather large.
 649            */
 650           rtn.cookie = DV_TARGET;
 651           rtn.addr.off = (unsigned int) DEBUG_TypeDerefPointer(&exp1, &rtn.type);
 652           if (!rtn.type)
 653             {
 654               RaiseException(DEBUG_STATUS_BAD_TYPE, 0, 0, NULL);
 655             }
 656           break;
 657         case EXP_OP_FORCE_DEREF:
 658           rtn.cookie = exp1.cookie;
 659           rtn.addr.seg = exp1.addr.seg;
 660           if (exp1.cookie == DV_TARGET)
 661              DEBUG_READ_MEM((void*)exp1.addr.off, &rtn.addr.off, sizeof(rtn.addr.off));
 662           else
 663              memcpy(&rtn.addr.off, (void*)exp1.addr.off, sizeof(rtn.addr.off));
 664           break;
 665         case EXP_OP_ADDR:
 666           /* FIXME: even for a 16 bit entity ? */
 667           rtn.type = DEBUG_FindOrMakePointerType(exp1.type);
 668           exp->un.unop.result = exp1.addr.off;
 669           break;
 670         default:
 671            RaiseException(DEBUG_STATUS_INTERNAL_ERROR, 0, 0, NULL);
 672         }
 673       break;
 674     default:
 675       DEBUG_Printf(DBG_CHN_MESG,"Unexpected expression (%d).\n", exp->type);
 676       RaiseException(DEBUG_STATUS_INTERNAL_ERROR, 0, 0, NULL);
 677       break;
 678     }
 679
 680   assert(rtn.cookie == DV_TARGET || rtn.cookie == DV_HOST);
 681
 682   return rtn;
 683 }
 684
 685
 686 int
 687 DEBUG_DisplayExpr(const struct expr * exp)
 688 {
 689   int           i;
 690
 691   switch(exp->type)
 692     {
 693     case EXPR_TYPE_CAST:
 694       DEBUG_Printf(DBG_CHN_MESG, "((");
 695       DEBUG_PrintTypeCast(exp->un.cast.cast);
 696       DEBUG_Printf(DBG_CHN_MESG, ")");
 697       DEBUG_DisplayExpr(exp->un.cast.expr);
 698       DEBUG_Printf(DBG_CHN_MESG, ")");
 699       break;
 700     case EXPR_TYPE_INTVAR:
 701       DEBUG_Printf(DBG_CHN_MESG, "$%s", exp->un.intvar.name);
 702       break;
 703     case EXPR_TYPE_US_CONST:
 704       DEBUG_Printf(DBG_CHN_MESG, "%ud", exp->un.u_const.value);
 705       break;
 706     case EXPR_TYPE_CONST:
 707       DEBUG_Printf(DBG_CHN_MESG, "%d", exp->un.u_const.value);
 708       break;
 709     case EXPR_TYPE_STRING:
 710       DEBUG_Printf(DBG_CHN_MESG, "\"%s\"", exp->un.string.str);
 711       break;
 712     case EXPR_TYPE_SYMBOL:
 713       DEBUG_Printf(DBG_CHN_MESG, "%s" , exp->un.symbol.name);
 714       break;
 715     case EXPR_TYPE_PSTRUCT:
 716       DEBUG_DisplayExpr(exp->un.structure.exp1);
 717       DEBUG_Printf(DBG_CHN_MESG, "->%s", exp->un.structure.element_name);
 718       break;
 719     case EXPR_TYPE_STRUCT:
 720       DEBUG_DisplayExpr(exp->un.structure.exp1);
 721       DEBUG_Printf(DBG_CHN_MESG, ".%s", exp->un.structure.element_name);
 722       break;
 723     case EXPR_TYPE_CALL:
 724       DEBUG_Printf(DBG_CHN_MESG, "%s(",exp->un.call.funcname);
 725       for(i=0; i < exp->un.call.nargs; i++)
 726         {
 727           DEBUG_DisplayExpr(exp->un.call.arg[i]);
 728           if( i != exp->un.call.nargs - 1 )
 729             {
 730               DEBUG_Printf(DBG_CHN_MESG, ", ");
 731             }
 732         }
 733       DEBUG_Printf(DBG_CHN_MESG, ")");
 734       break;
 735     case EXPR_TYPE_BINOP:
 736       DEBUG_Printf(DBG_CHN_MESG, "( ");
 737       DEBUG_DisplayExpr(exp->un.binop.exp1);
 738       switch(exp->un.binop.binop_type)
 739         {
 740         case EXP_OP_ADD:
 741           DEBUG_Printf(DBG_CHN_MESG, " + ");
 742           break;
 743         case EXP_OP_SUB:
 744           DEBUG_Printf(DBG_CHN_MESG, " - ");
 745           break;
 746         case EXP_OP_SEG:
 747           DEBUG_Printf(DBG_CHN_MESG, ":");
 748           break;
 749         case EXP_OP_LOR:
 750           DEBUG_Printf(DBG_CHN_MESG, " || ");
 751           break;
 752         case EXP_OP_LAND:
 753           DEBUG_Printf(DBG_CHN_MESG, " && ");
 754           break;
 755         case EXP_OP_OR:
 756           DEBUG_Printf(DBG_CHN_MESG, " | ");
 757           break;
 758         case EXP_OP_AND:
 759           DEBUG_Printf(DBG_CHN_MESG, " & ");
 760           break;
 761         case EXP_OP_XOR:
 762           DEBUG_Printf(DBG_CHN_MESG, " ^ ");
 763           break;
 764         case EXP_OP_EQ:
 765           DEBUG_Printf(DBG_CHN_MESG, " == ");
 766           break;
 767         case EXP_OP_GT:
 768           DEBUG_Printf(DBG_CHN_MESG, " > ");
 769           break;
 770         case EXP_OP_LT:
 771           DEBUG_Printf(DBG_CHN_MESG, " < ");
 772           break;
 773         case EXP_OP_GE:
 774           DEBUG_Printf(DBG_CHN_MESG, " >= ");
 775           break;
 776         case EXP_OP_LE:
 777           DEBUG_Printf(DBG_CHN_MESG, " <= ");
 778           break;
 779         case EXP_OP_NE:
 780           DEBUG_Printf(DBG_CHN_MESG, " != ");
 781           break;
 782         case EXP_OP_SHL:
 783           DEBUG_Printf(DBG_CHN_MESG, " << ");
 784           break;
 785         case EXP_OP_SHR:
 786           DEBUG_Printf(DBG_CHN_MESG, " >> ");
 787           break;
 788         case EXP_OP_MUL:
 789           DEBUG_Printf(DBG_CHN_MESG, " * ");
 790           break;
 791         case EXP_OP_DIV:
 792           DEBUG_Printf(DBG_CHN_MESG, " / ");
 793           break;
 794         case EXP_OP_REM:
 795           DEBUG_Printf(DBG_CHN_MESG, " %% ");
 796           break;
 797         case EXP_OP_ARR:
 798           DEBUG_Printf(DBG_CHN_MESG, "[");
 799           break;
 800         default:
 801           break;
 802         }
 803       DEBUG_DisplayExpr(exp->un.binop.exp2);
 804       if( exp->un.binop.binop_type == EXP_OP_ARR )
 805         {
 806           DEBUG_Printf(DBG_CHN_MESG, "]");
 807         }
 808       DEBUG_Printf(DBG_CHN_MESG, " )");
 809       break;
 810     case EXPR_TYPE_UNOP:
 811       switch(exp->un.unop.unop_type)
 812         {
 813         case EXP_OP_NEG:
 814           DEBUG_Printf(DBG_CHN_MESG, "-");
 815           break;
 816         case EXP_OP_NOT:
 817           DEBUG_Printf(DBG_CHN_MESG, "!");
 818           break;
 819         case EXP_OP_LNOT:
 820           DEBUG_Printf(DBG_CHN_MESG, "~");
 821           break;
 822         case EXP_OP_DEREF:
 823           DEBUG_Printf(DBG_CHN_MESG, "*");
 824           break;
 825         case EXP_OP_ADDR:
 826           DEBUG_Printf(DBG_CHN_MESG, "&");
 827           break;
 828         }
 829       DEBUG_DisplayExpr(exp->un.unop.exp1);
 830       break;
 831     default:
 832       DEBUG_Printf(DBG_CHN_MESG,"Unexpected expression.\n");
 833       RaiseException(DEBUG_STATUS_INTERNAL_ERROR, 0, 0, NULL);
 834       break;
 835     }
 836
 837   return TRUE;
 838 }
 839
 840 struct expr *
 841 DEBUG_CloneExpr(const struct expr * exp)
 842 {
 843   int           i;
 844   struct expr * rtn;
 845
 846   rtn = (struct expr *) DBG_alloc(sizeof(struct expr));
 847
 848   /*
 849    * First copy the contents of the expression itself.
 850    */
 851   *rtn = *exp;
 852
 853
 854   switch(exp->type)
 855     {
 856     case EXPR_TYPE_CAST:
 857       rtn->un.cast.expr = DEBUG_CloneExpr(exp->un.cast.expr);
 858       break;
 859     case EXPR_TYPE_INTVAR:
 860       rtn->un.intvar.name = DBG_strdup(exp->un.intvar.name);
 861       break;
 862     case EXPR_TYPE_US_CONST:
 863     case EXPR_TYPE_CONST:
 864       break;
 865     case EXPR_TYPE_STRING:
 866       rtn->un.string.str = DBG_strdup(exp->un.string.str);
 867       break;
 868     case EXPR_TYPE_SYMBOL:
 869       rtn->un.symbol.name = DBG_strdup(exp->un.symbol.name);
 870       break;
 871     case EXPR_TYPE_PSTRUCT:
 872     case EXPR_TYPE_STRUCT:
 873       rtn->un.structure.exp1 = DEBUG_CloneExpr(exp->un.structure.exp1);
 874       rtn->un.structure.element_name = DBG_strdup(exp->un.structure.element_name);
 875       break;
 876     case EXPR_TYPE_CALL:
 877       for(i=0; i < exp->un.call.nargs; i++)
 878         {
 879           rtn->un.call.arg[i]  = DEBUG_CloneExpr(exp->un.call.arg[i]);
 880         }
 881       rtn->un.call.funcname = DBG_strdup(exp->un.call.funcname);
 882       break;
 883     case EXPR_TYPE_BINOP:
 884       rtn->un.binop.exp1 = DEBUG_CloneExpr(exp->un.binop.exp1);
 885       rtn->un.binop.exp2 = DEBUG_CloneExpr(exp->un.binop.exp2);
 886       break;
 887     case EXPR_TYPE_UNOP:
 888       rtn->un.unop.exp1 = DEBUG_CloneExpr(exp->un.unop.exp1);
 889       break;
 890     default:
 891       DEBUG_Printf(DBG_CHN_MESG,"Unexpected expression.\n");
 892       RaiseException(DEBUG_STATUS_INTERNAL_ERROR, 0, 0, NULL);
 893       break;
 894     }
 895
 896   return rtn;
 897 }
 898
 899
 900 /*
 901  * Recursively go through an expression tree and free all memory associated
 902  * with it.
 903  */
 904 int
 905 DEBUG_FreeExpr(struct expr * exp)
 906 {
 907   int i;
 908
 909   switch(exp->type)
 910     {
 911     case EXPR_TYPE_CAST:
 912       DEBUG_FreeExpr(exp->un.cast.expr);
 913       break;
 914     case EXPR_TYPE_INTVAR:
 915       DBG_free((char *) exp->un.intvar.name);
 916       break;
 917     case EXPR_TYPE_US_CONST:
 918     case EXPR_TYPE_CONST:
 919       break;
 920     case EXPR_TYPE_STRING:
 921       DBG_free((char *) exp->un.string.str);
 922       break;
 923     case EXPR_TYPE_SYMBOL:
 924       DBG_free((char *) exp->un.symbol.name);
 925       break;
 926     case EXPR_TYPE_PSTRUCT:
 927     case EXPR_TYPE_STRUCT:
 928       DEBUG_FreeExpr(exp->un.structure.exp1);
 929       DBG_free((char *) exp->un.structure.element_name);
 930       break;
 931     case EXPR_TYPE_CALL:
 932       for(i=0; i < exp->un.call.nargs; i++)
 933         {
 934           DEBUG_FreeExpr(exp->un.call.arg[i]);
 935         }
 936       DBG_free((char *) exp->un.call.funcname);
 937       break;
 938     case EXPR_TYPE_BINOP:
 939       DEBUG_FreeExpr(exp->un.binop.exp1);
 940       DEBUG_FreeExpr(exp->un.binop.exp2);
 941       break;
 942     case EXPR_TYPE_UNOP:
 943       DEBUG_FreeExpr(exp->un.unop.exp1);
 944       break;
 945     default:
 946       DEBUG_Printf(DBG_CHN_MESG,"Unexpected expression.\n");
 947       RaiseException(DEBUG_STATUS_INTERNAL_ERROR, 0, 0, NULL);
 948       break;
 949     }
 950
 951   DBG_free(exp);
 952   return TRUE;
 953 }