unit.c

   1 /*
   2  * $Id: unit.c,v 1.4 2007/07/22 13:33:26 khansen Exp $
   3  * $Log: unit.c,v $
   4  * Revision 1.4  2007/07/22 13:33:26  khansen
   5  * convert tabs to whitespaces
   6  *
   7  * Revision 1.3  2004/12/18 17:00:35  kenth
   8  * improved error reporting slightly
   9  *
  10  * Revision 1.2  2004/12/16 13:20:07  kenth
  11  * xorcyst 1.3.5
  12  *
  13  * Revision 1.1  2004/06/30 07:56:00  kenth
  14  * Initial revision
  15  *
  16  */
  17
  18 /**
  19  *    (C) 2004 Kent Hansen
  20  *
  21  *    The XORcyst is free software; you can redistribute it and/or modify
  22  *    it under the terms of the GNU General Public License as published by
  23  *    the Free Software Foundation; either version 2 of the License, or
  24  *    (at your option) any later version.
  25  *
  26  *    The XORcyst is distributed in the hope that it will be useful,
  27  *    but WITHOUT ANY WARRANTY; without even the implied warranty of
  28  *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  29  *    GNU General Public License for more details.
  30  *
  31  *    You should have received a copy of the GNU General Public License
  32  *    along with The XORcyst; if not, write to the Free Software
  33  *    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  34  */
  35
  36 #include <stdio.h>
  37 #include <stdlib.h>
  38 #include "unit.h"
  39 #include "objdef.h"
  40
  41 #define SAFE_FREE(m) if ((m) != NULL) { free(m); m = NULL; }
  42
  43 /*---------------------------------------------------------------------------*/
  44
  45 /* Reads a byte */
  46 #define get_1(f) (unsigned char)fgetc(fp)
  47 /* Reads a short (big-endian) */
  48 static unsigned short get_2(FILE *fp)
  49 {
  50     unsigned short result;
  51     result = get_1(fp) << 8;    /* High byte */
  52     result |= get_1(fp);        /* Low byte */
  53     return result;
  54 }
  55 /* Reads a 24-bit integer (big-endian) */
  56 static unsigned int get_3(FILE *fp)
  57 {
  58     unsigned int result;
  59     result = get_2(fp) << 8;    /* High 16 bits */
  60     result |= get_1(fp);        /* Low byte */
  61     return result;
  62 }
  63 /* Reads an int (big-endian) */
  64 static unsigned int get_4(FILE *fp)
  65 {
  66     unsigned int result;
  67     /* Assumes little-endian machine!! */
  68     result = get_2(fp) << 16;   /* High 16 bits */
  69     result |= get_2(fp);        /* Low 16 bits */
  70     return result;
  71 }
  72 /* Reads a string prepended by 8-bit length */
  73 static char *get_str_8(FILE *fp)
  74 {
  75     char *s;
  76     int len = get_1(fp) + 1;
  77     s = (char *)malloc(len + 1);
  78     if (s != NULL) {
  79         fread(s, 1, len, fp);
  80         s[len] = '\0';
  81     }
  82     return s;
  83 }
  84 /* Reads a string prepended by 16-bit length */
  85 static char *get_str_16(FILE *fp)
  86 {
  87     char *s;
  88     int len = get_2(fp) + 1;
  89     s = (char *)malloc(len + 1);
  90     if (s != NULL) {
  91         fread(s, 1, len, fp);
  92         s[len] = '\0';
  93     }
  94     return s;
  95 }
  96 #define get_bytes_8(f) (unsigned char *)get_str_8(f)
  97 #define get_bytes_16(f) (unsigned char *)get_str_16(f)
  98
  99 /*--------------------------------------------------------------------------*/
 100
 101 /**
 102  * Reads a constant from file.
 103  * @param fp File handle
 104  * @param u Unit in which constant is loaded
 105  * @param i Index of constant in unit's constant array
 106  */
 107 static void get_const(FILE *fp, xasm_unit *u, int i)
 108 {
 109     xasm_constant *cnst = &u->constants[i];
 110     cnst->name = get_str_8(fp);
 111     cnst->type = get_1(fp);
 112     switch (cnst->type) {
 113         case XASM_INT_8: cnst->integer = get_1(fp);  cnst->type = XASM_INTEGER_CONSTANT;  break;
 114         case XASM_INT_16:    cnst->integer = get_2(fp);  cnst->type = XASM_INTEGER_CONSTANT;  break;
 115         case XASM_INT_24:    cnst->integer = get_3(fp);  cnst->type = XASM_INTEGER_CONSTANT;  break;
 116         case XASM_INT_32:    cnst->integer = get_4(fp);  cnst->type = XASM_INTEGER_CONSTANT;  break;
 117         case XASM_STR_8: cnst->string = get_str_8(fp);   cnst->type = XASM_STRING_CONSTANT;   break;
 118         case XASM_STR_16:    cnst->string = get_str_16(fp);  cnst->type = XASM_STRING_CONSTANT;   break;
 119
 120         default:
 121         fprintf(stderr, "%s(0x%lx): get_const(): bad constant type (%.2X)\n", u->name, ftell(fp), cnst->type);
 122         break;
 123     }
 124     cnst->unit = u;
 125 }
 126
 127 /**
 128  * Reads constant array from file.
 129  * @param fp File handle
 130  * @param u Unit whose constants array will be populated
 131  */
 132 static void get_constants(FILE *fp, xasm_unit *u)
 133 {
 134     int i;
 135     int count = get_2(fp);
 136     if (count > 0) {
 137         u->constants = (xasm_constant *)malloc(sizeof(xasm_constant) * count);
 138     } else {
 139         u->constants = NULL;
 140     }
 141     for (i=0; i<count; i++) {
 142         get_const(fp, u, i);
 143     }
 144     u->const_count = count;
 145 }
 146
 147 /**
 148  * Reads imported symbol from file.
 149  * @param fp File handle
 150  * @param u Unit
 151  * @param i External index
 152  */
 153 static void get_ext(FILE *fp, xasm_unit *u, int i)
 154 {
 155     xasm_external *ext = &u->externals[i];
 156     ext->unit = get_1(fp);
 157     ext->name = get_str_8(fp);
 158     ext->from = u;
 159 }
 160
 161 /**
 162  * Reads imported symbol array from file.
 163  * @param fp File handle
 164  * @param u Unit whose externals array will be populated
 165  */
 166 static void get_externals(FILE *fp, xasm_unit *u)
 167 {
 168     int i;
 169     int count;
 170     count = get_2(fp);
 171     if (count > 0) {
 172         u->externals = (xasm_external *)malloc(sizeof(xasm_external) * count);
 173     } else {
 174         u->externals = NULL;
 175     }
 176     for (i=0; i<count; i++) {
 177         get_ext(fp, u, i);
 178     }
 179     u->ext_count = count;
 180 }
 181
 182 /**
 183  * Reads an expression from file.
 184  * @param fp File handle
 185  * @param dest Pointer to pointer where expression should be stored
 186  * @param u Owner unit
 187  */
 188 static void get_expr_recursive(FILE *fp, xasm_expression **dest, xasm_unit *u)
 189 {
 190     unsigned char type;
 191     xasm_expression *exp = (xasm_expression *)malloc( sizeof(xasm_expression) );
 192     if (exp != NULL) {
 193         type = get_1(fp);
 194         switch (type) {
 195             case XASM_INT_8: exp->integer = get_1(fp);   exp->type = XASM_INTEGER_EXPRESSION; break;
 196             case XASM_INT_16:    exp->integer = get_2(fp);   exp->type = XASM_INTEGER_EXPRESSION; break;
 197             case XASM_INT_24:    exp->integer = get_3(fp);   exp->type = XASM_INTEGER_EXPRESSION; break;
 198             case XASM_INT_32:    exp->integer = get_4(fp);   exp->type = XASM_INTEGER_EXPRESSION; break;
 199             case XASM_STR_8: exp->string = get_str_8(fp);    exp->type = XASM_STRING_EXPRESSION;  break;
 200             case XASM_STR_16:    exp->string = get_str_16(fp);   exp->type = XASM_STRING_EXPRESSION;  break;
 201
 202             case XASM_LOCAL: exp->local_id = get_2(fp);  exp->type = XASM_LOCAL_EXPRESSION;   break;
 203             case XASM_EXTRN: exp->extrn_id = get_2(fp);  exp->type = XASM_EXTERNAL_EXPRESSION;break;
 204
 205             case XASM_PC:    ;               exp->type = XASM_PC_EXPRESSION;  break;
 206
 207             case XASM_OP_PLUS:
 208             case XASM_OP_MINUS:
 209             case XASM_OP_MUL:
 210             case XASM_OP_DIV:
 211             case XASM_OP_MOD:
 212             case XASM_OP_SHL:
 213             case XASM_OP_SHR:
 214             case XASM_OP_AND:
 215             case XASM_OP_OR:
 216             case XASM_OP_XOR:
 217             case XASM_OP_EQ:
 218             case XASM_OP_NE:
 219             case XASM_OP_LT:
 220             case XASM_OP_GT:
 221             case XASM_OP_LE:
 222             case XASM_OP_GE:
 223             get_expr_recursive(fp, &exp->op_expr.lhs, u);
 224             get_expr_recursive(fp, &exp->op_expr.rhs, u);
 225             exp->op_expr.operator = type;
 226             exp->type = XASM_OPERATOR_EXPRESSION;
 227             break;
 228
 229             case XASM_OP_NOT:
 230             case XASM_OP_NEG:
 231             case XASM_OP_LO:
 232             case XASM_OP_HI:
 233             case XASM_OP_UMINUS:
 234             case XASM_OP_BANK:
 235             get_expr_recursive(fp, &exp->op_expr.lhs, u);
 236             exp->op_expr.rhs = NULL;
 237             exp->op_expr.operator = type;
 238             exp->type = XASM_OPERATOR_EXPRESSION;
 239             break;
 240
 241             default:
 242             fprintf(stderr, "%s(0x%lx): get_expr(): invalid expression type (%.2X)\n", u->name, ftell(fp), type);
 243             exp->integer = 0;
 244             exp->type = XASM_INTEGER_EXPRESSION;
 245             break;
 246         }
 247     }
 248     exp->unit = u;
 249     *dest = exp;
 250 }
 251
 252 /**
 253  * Reads expressions from file.
 254  * @param fp File handle
 255  * @param u Unit whose expressions array to populate
 256  */
 257 static void get_expressions(FILE *fp, xasm_unit *u)
 258 {
 259     int i;
 260     int count;
 261     count = get_2(fp);
 262     if (count > 0) {
 263         u->expressions = (xasm_expression **)malloc(sizeof(xasm_expression *) * count);
 264     } else {
 265         u->expressions = NULL;
 266     }
 267     for (i=0; i<count; i++) {
 268         get_expr_recursive(fp, &u->expressions[i], u);
 269     }
 270     u->expr_count = count;
 271 }
 272
 273 /**
 274  * Reads a segment from file.
 275  * @param fp File handle
 276  * @param seg Where to store segment
 277  */
 278 static void get_segment(FILE *fp, xasm_segment *seg)
 279 {
 280     seg->size = get_3(fp);
 281     if (seg->size > 0) {
 282         seg->bytes = (unsigned char *)malloc(seg->size);
 283         if (seg->bytes != NULL) {
 284             fread(seg->bytes, 1, seg->size, fp);
 285         }
 286     } else {
 287         seg->bytes = NULL;
 288     }
 289 }
 290
 291 /*--------------------------------------------------------------------------*/
 292
 293 /**
 294  * Reads a unit from file.
 295  * @param filename Name of the unit
 296  * @param u Pointer to struct to fill in
 297  */
 298 int xasm_unit_read(const char *filename, xasm_unit *u)
 299 {
 300     FILE *fp;
 301     int count, i;
 302     unsigned short magic;
 303     unsigned char version;
 304
 305     u->name = filename;
 306     fp = fopen(filename, "rb");
 307     if (fp == NULL) {
 308         u->const_count = 0;
 309         u->ext_count = 0;
 310         u->expr_count = 0;
 311         u->dataseg.size = 0;
 312         u->dataseg.bytes = NULL;
 313         u->codeseg.size = 0;
 314         u->codeseg.bytes = NULL;
 315         return 0;
 316     }
 317
 318     magic = get_2(fp);
 319     if (magic != XASM_MAGIC) {
 320         /* Error, bad magic number */
 321         return 0;
 322     }
 323
 324     version = get_1(fp);
 325     if (version != XASM_OBJ_VERSION) {
 326         /* Error, bad version */
 327         return 0;
 328     }
 329
 330     get_constants(fp, u);
 331
 332     /* Read # of units explicitly imported from */
 333     count = get_1(fp);
 334     /* Read unit names */
 335     for (i=0; i<count; i++) {
 336         get_str_8(fp);
 337     }
 338
 339     get_externals(fp, u);
 340     get_segment(fp, &u->dataseg);
 341     get_segment(fp, &u->codeseg);
 342     get_expressions(fp, u);
 343
 344     fclose(fp);
 345
 346     /* Success */
 347     return 1;
 348 }
 349
 350 /*--------------------------------------------------------------------------*/
 351
 352 /**
 353  * Finalizes a constant.
 354  * @param c Constant to finalize
 355  */
 356 static void finalize_constant(xasm_constant *c)
 357 {
 358     if (c->type == XASM_STRING_CONSTANT) {
 359         SAFE_FREE(c->string);
 360     }
 361     SAFE_FREE(c->name);
 362 }
 363
 364 /**
 365  * Finalizes an external.
 366  * @param e External to finalize
 367  */
 368 static void finalize_external(xasm_external *e)
 369 {
 370     SAFE_FREE(e->name);
 371 }
 372
 373 /**
 374  * Finalizes an expression.
 375  * @param e Expression to finalize
 376  */
 377 static void finalize_expression(xasm_expression *e)
 378 {
 379     if (e == NULL) { return; }
 380     switch (e->type) {
 381         case XASM_STRING_EXPRESSION:
 382         SAFE_FREE(e->string);
 383         break;
 384
 385         case XASM_OPERATOR_EXPRESSION:
 386         finalize_expression(e->op_expr.lhs);
 387         finalize_expression(e->op_expr.rhs);
 388         break;
 389
 390         default:
 391         /* Nada */
 392         break;
 393     }
 394     SAFE_FREE(e);
 395 }
 396
 397 /**
 398  * Finalizes a bytecode segment.
 399  * @param s Segment to finalize
 400  */
 401 static void finalize_segment(xasm_segment *s)
 402 {
 403     SAFE_FREE(s->bytes);
 404 }
 405
 406 /*--------------------------------------------------------------------------*/
 407
 408 /**
 409  * Finalizes a unit.
 410  * @param u Unit to finalize
 411  */
 412 void xasm_unit_finalize(xasm_unit *u)
 413 {
 414     int i;
 415     for (i=0; i<u->const_count; i++) {
 416         finalize_constant(&u->constants[i]);
 417     }
 418     SAFE_FREE(u->constants);
 419
 420     for (i=0; i<u->ext_count; i++) {
 421         finalize_external(&u->externals[i]);
 422     }
 423     SAFE_FREE(u->externals);
 424
 425     for (i=0; i<u->expr_count; i++) {
 426         finalize_expression(u->expressions[i]);
 427     }
 428     SAFE_FREE(u->expressions);
 429
 430     finalize_segment(&u->dataseg);
 431     finalize_segment(&u->codeseg);
 432 }
 433
 434 /**
 435  * Gets string representation of an operator (OP_*, see objdef.h).
 436  * @param op Operator
 437  * @return String representation of operator
 438  */
 439 const char *xasm_operator_to_string(int op)
 440 {
 441     switch (op) {
 442         case XASM_OP_PLUS:   return "+";
 443         case XASM_OP_MINUS:  return "-";
 444         case XASM_OP_MUL:    return "*";
 445         case XASM_OP_DIV:    return "/";
 446         case XASM_OP_MOD:    return "%";
 447         case XASM_OP_SHL:    return "<<";
 448         case XASM_OP_SHR:    return ">>";
 449         case XASM_OP_AND:    return "&";
 450         case XASM_OP_OR: return "|";
 451         case XASM_OP_XOR:    return "^";
 452         case XASM_OP_EQ: return "==";
 453         case XASM_OP_NE: return "!=";
 454         case XASM_OP_LT: return "<";
 455         case XASM_OP_GT: return ">";
 456         case XASM_OP_LE: return "<=";
 457         case XASM_OP_GE: return ">=";
 458         case XASM_OP_NOT:    return "!";
 459         case XASM_OP_NEG:    return "~";
 460         case XASM_OP_LO: return "<";
 461         case XASM_OP_HI: return ">";
 462         case XASM_OP_UMINUS: return "-";
 463         case XASM_OP_BANK:   return "^";
 464     }
 465     return "";
 466 }