rdoff/rdoff.c

   1 /* rdoff.c      library of routines for manipulating rdoff files
   2  *
   3  * The Netwide Assembler is copyright (C) 1996 Simon Tatham and
   4  * Julian Hall. All rights reserved. The software is
   5  * redistributable under the licence given in the file "Licence"
   6  * distributed in the NASM archive.
   7  *
   8  * Permission to use this file in your own projects is granted, as int32_t
   9  * as acknowledgement is given in an appropriate manner to its authors,
  10  * with instructions of how to obtain a copy via ftp.
  11  */
  12
  13 /* TODO:        The functions in this module assume they are running
  14  *              on a little-endian machine. This should be fixed to
  15  *              make it portable.
  16  */
  17
  18 #include <stdio.h>
  19 #include <stdlib.h>
  20 #include <string.h>
  21 #include <errno.h>
  22 #include <inttypes.h>
  23
  24 #define RDOFF_UTILS
  25
  26 #include "rdoff.h"
  27
  28 #define newstr(str) strcpy(malloc(strlen(str) + 1),str)
  29 #define newstrcat(s1,s2) strcat(strcpy(malloc(strlen(s1) + strlen(s2) + 1), \
  30                                        s1),s2)
  31
  32 /*
  33  * Comment this out to allow the module to read & write header record types
  34  * that it isn't aware of. With this defined, unrecognised header records
  35  * will generate error number 8, reported as 'unknown extended header record'.
  36  */
  37
  38 #define STRICT_ERRORS
  39
  40 /* ========================================================================
  41  * Code for memory buffers (for delayed writing of header until we know
  42  * how int32_t it is).
  43  * ======================================================================== */
  44
  45 memorybuffer *newmembuf()
  46 {
  47     memorybuffer *t;
  48
  49     t = malloc(sizeof(memorybuffer));
  50     if (!t)
  51         return NULL;
  52
  53     t->length = 0;
  54     t->next = NULL;
  55     return t;
  56 }
  57
  58 void membufwrite(memorybuffer * const b, void *data, int bytes)
  59 {
  60     uint16_t w;
  61     int32_t l;
  62
  63     if (b->next) {              /* memory buffer full - use next buffer */
  64         membufwrite(b->next, data, bytes);
  65         return;
  66     }
  67
  68     if ((bytes < 0 && b->length - bytes > BUF_BLOCK_LEN)
  69         || (bytes > 0 && b->length + bytes > BUF_BLOCK_LEN)) {
  70
  71         /* buffer full and no next allocated... allocate and initialise next
  72          * buffer */
  73         b->next = newmembuf();
  74         membufwrite(b->next, data, bytes);
  75         return;
  76     }
  77
  78     switch (bytes) {
  79     case -4:                   /* convert to little-endian */
  80         l = *(int32_t *)data;
  81         b->buffer[b->length++] = l & 0xFF;
  82         l >>= 8;
  83         b->buffer[b->length++] = l & 0xFF;
  84         l >>= 8;
  85         b->buffer[b->length++] = l & 0xFF;
  86         l >>= 8;
  87         b->buffer[b->length++] = l & 0xFF;
  88         break;
  89
  90     case -2:
  91         w = *(uint16_t *) data;
  92         b->buffer[b->length++] = w & 0xFF;
  93         w >>= 8;
  94         b->buffer[b->length++] = w & 0xFF;
  95         break;
  96
  97     default:
  98         while (bytes--) {
  99             b->buffer[b->length++] = *(*(uint8_t **)&data);
 100
 101             (*(uint8_t **)&data)++;
 102         }
 103         break;
 104     }
 105 }
 106
 107 void membufdump(memorybuffer * b, FILE * fp)
 108 {
 109     if (!b)
 110         return;
 111
 112     fwrite(b->buffer, 1, b->length, fp);
 113
 114     membufdump(b->next, fp);
 115 }
 116
 117 int membuflength(memorybuffer * b)
 118 {
 119     if (!b)
 120         return 0;
 121     return b->length + membuflength(b->next);
 122 }
 123
 124 void freemembuf(memorybuffer * b)
 125 {
 126     if (!b)
 127         return;
 128     freemembuf(b->next);
 129     free(b);
 130 }
 131
 132 /* =========================================================================
 133    General purpose routines and variables used by the library functions
 134    ========================================================================= */
 135
 136 /*
 137  * translateint32_t() and translateint16_t()
 138  *
 139  * translate from little endian to local representation
 140  */
 141 int32_t translateint32_t(int32_t in)
 142 {
 143     int32_t r;
 144     uint8_t *i;
 145
 146     i = (uint8_t *)&in;
 147     r = i[3];
 148     r = (r << 8) + i[2];
 149     r = (r << 8) + i[1];
 150     r = (r << 8) + *i;
 151
 152     return r;
 153 }
 154
 155 uint16_t translateint16_t(uint16_t in)
 156 {
 157     uint16_t r;
 158     uint8_t *i;
 159
 160     i = (uint8_t *)&in;
 161     r = (i[1] << 8) + i[0];
 162
 163     return r;
 164 }
 165
 166 /* Segment types */
 167 static char *knownsegtypes[8] = {
 168     "NULL", "text", "data", "object comment",
 169     "linked comment", "loader comment",
 170     "symbolic debug", "line number debug"
 171 };
 172
 173 /* Get a textual string describing the segment type */
 174 char *translatesegmenttype(uint16_t type)
 175 {
 176     if (type < 8)
 177         return knownsegtypes[type];
 178     if (type < 0x0020)
 179         return "reserved";
 180     if (type < 0x1000)
 181         return "reserved - Moscow";
 182     if (type < 0x8000)
 183         return "reserved - system dependant";
 184     if (type < 0xFFFF)
 185         return "reserved - other";
 186     if (type == 0xFFFF)
 187         return "invalid type code";
 188     return "type code out of range";
 189 }
 190
 191 /* This signature is written to the start of RDOFF files */
 192 const char *RDOFFId = RDOFF2_SIGNATURE;
 193
 194 /* Error messages. Must correspond to the codes defined in rdoff.h */
 195 const char *rdf_errors[11] = {
 196     /* 0 */ "no error occurred",
 197     /* 1 */ "could not open file",
 198     /* 2 */ "invalid file format",
 199     /* 3 */ "error reading file",
 200     /* 4 */ "unknown error",
 201     /* 5 */ "header not read",
 202     /* 6 */ "out of memory",
 203     /* 7 */ "RDOFF v1 not supported",
 204     /* 8 */ "unknown extended header record",
 205     /* 9 */ "header record of known type but unknown length",
 206     /* 10 */ "no such segment"
 207 };
 208
 209 int rdf_errno = 0;
 210
 211 /* ========================================================================
 212    The library functions
 213    ======================================================================== */
 214
 215 int rdfopen(rdffile * f, const char *name)
 216 {
 217     FILE *fp;
 218
 219     fp = fopen(name, "rb");
 220     if (!fp)
 221         return rdf_errno = RDF_ERR_OPEN;
 222
 223     return rdfopenhere(f, fp, NULL, name);
 224 }
 225
 226 int rdfopenhere(rdffile * f, FILE * fp, int *refcount, const char *name)
 227 {
 228     char buf[8];
 229     int32_t initpos;
 230     int32_t l;
 231     uint16_t s;
 232
 233     if (translateint32_t(0x01020304) != 0x01020304) {
 234         /* fix this to be portable! */
 235         fputs("*** this program requires a little endian machine\n",
 236               stderr);
 237         fprintf(stderr, "01020304h = %08"PRIx32"h\n", translateint32_t(0x01020304));
 238         exit(3);
 239     }
 240
 241     f->fp = fp;
 242     initpos = ftell(fp);
 243
 244     fread(buf, 6, 1, f->fp);    /* read header */
 245     buf[6] = 0;
 246
 247     if (strcmp(buf, RDOFFId)) {
 248         fclose(f->fp);
 249         if (!strcmp(buf, "RDOFF1"))
 250             return rdf_errno = RDF_ERR_VER;
 251         return rdf_errno = RDF_ERR_FORMAT;
 252     }
 253
 254     if (fread(&l, 1, 4, f->fp) != 4
 255         || fread(&f->header_len, 1, 4, f->fp) != 4) {
 256         fclose(f->fp);
 257         return rdf_errno = RDF_ERR_READ;
 258     }
 259
 260     f->header_ofs = ftell(f->fp);
 261     f->eof_offset = f->header_ofs + translateint32_t(l) - 4;
 262
 263     if (fseek(f->fp, f->header_len, SEEK_CUR)) {
 264         fclose(f->fp);
 265         return rdf_errno = RDF_ERR_FORMAT;      /* seek past end of file...? */
 266     }
 267
 268     if (fread(&s, 1, 2, f->fp) != 2) {
 269         fclose(f->fp);
 270         return rdf_errno = RDF_ERR_READ;
 271     }
 272
 273     f->nsegs = 0;
 274
 275     while (s != 0) {
 276         f->seg[f->nsegs].type = s;
 277         if (fread(&f->seg[f->nsegs].number, 1, 2, f->fp) != 2 ||
 278             fread(&f->seg[f->nsegs].reserved, 1, 2, f->fp) != 2 ||
 279             fread(&f->seg[f->nsegs].length, 1, 4, f->fp) != 4) {
 280             fclose(f->fp);
 281             return rdf_errno = RDF_ERR_READ;
 282         }
 283
 284         f->seg[f->nsegs].offset = ftell(f->fp);
 285         if (fseek(f->fp, f->seg[f->nsegs].length, SEEK_CUR)) {
 286             fclose(f->fp);
 287             return rdf_errno = RDF_ERR_FORMAT;
 288         }
 289         f->nsegs++;
 290
 291         if (fread(&s, 1, 2, f->fp) != 2) {
 292             fclose(f->fp);
 293             return rdf_errno = RDF_ERR_READ;
 294         }
 295     }
 296
 297     if (f->eof_offset != ftell(f->fp) + 8) {    /* +8 = skip null segment header */
 298         fprintf(stderr, "warning: eof_offset [%"PRId32"] and actual eof offset "
 299                 "[%ld] don't match\n", f->eof_offset, ftell(f->fp) + 8);
 300     }
 301     fseek(f->fp, initpos, SEEK_SET);
 302     f->header_loc = NULL;
 303
 304     f->name = newstr(name);
 305     f->refcount = refcount;
 306     if (refcount)
 307         (*refcount)++;
 308     return RDF_OK;
 309 }
 310
 311 int rdfclose(rdffile * f)
 312 {
 313     if (!f->refcount || !--(*f->refcount)) {
 314         fclose(f->fp);
 315         f->fp = NULL;
 316     }
 317     free(f->name);
 318
 319     return 0;
 320 }
 321
 322 /*
 323  * Print the message for last error (from rdf_errno)
 324  */
 325 void rdfperror(const char *app, const char *name)
 326 {
 327     fprintf(stderr, "%s:%s: %s\n", app, name, rdf_errors[rdf_errno]);
 328     if (rdf_errno == RDF_ERR_OPEN || rdf_errno == RDF_ERR_READ) {
 329         perror(app);
 330     }
 331 }
 332
 333 /*
 334  * Find the segment by its number.
 335  * Returns segment array index, or -1 if segment with such number was not found.
 336  */
 337 int rdffindsegment(rdffile * f, int segno)
 338 {
 339     int i;
 340     for (i = 0; i < f->nsegs; i++)
 341         if (f->seg[i].number == segno)
 342             return i;
 343     return -1;
 344 }
 345
 346 /*
 347  * Load the segment. Returns status.
 348  */
 349 int rdfloadseg(rdffile * f, int segment, void *buffer)
 350 {
 351     int32_t fpos, slen;
 352
 353     switch (segment) {
 354     case RDOFF_HEADER:
 355         fpos = f->header_ofs;
 356         slen = f->header_len;
 357         f->header_loc = (uint8_t *) buffer;
 358         f->header_fp = 0;
 359         break;
 360     default:
 361         if (segment < f->nsegs) {
 362             fpos = f->seg[segment].offset;
 363             slen = f->seg[segment].length;
 364             f->seg[segment].data = (uint8_t *) buffer;
 365         } else {
 366             return rdf_errno = RDF_ERR_SEGMENT;
 367         }
 368     }
 369
 370     if (fseek(f->fp, fpos, SEEK_SET))
 371         return rdf_errno = RDF_ERR_UNKNOWN;
 372
 373     if (fread(buffer, 1, slen, f->fp) != slen)
 374         return rdf_errno = RDF_ERR_READ;
 375
 376     return RDF_OK;
 377 }
 378
 379 /* Macros for reading integers from header in memory */
 380
 381 #define RI8(v) v = f->header_loc[f->header_fp++]
 382 #define RI16(v) { v = (f->header_loc[f->header_fp] + \
 383                        (f->header_loc[f->header_fp+1] << 8)); \
 384                   f->header_fp += 2; }
 385
 386 #define RI32(v) { v = (f->header_loc[f->header_fp] + \
 387                        (f->header_loc[f->header_fp+1] << 8) + \
 388                        (f->header_loc[f->header_fp+2] << 16) + \
 389                        (f->header_loc[f->header_fp+3] << 24)); \
 390                   f->header_fp += 4; }
 391
 392 #define RS(str,max) { for(i=0;i<max;i++){\
 393   RI8(str[i]); if (!str[i]) break;} str[i]=0; }
 394
 395 /*
 396  * Read a header record.
 397  * Returns the address of record, or NULL in case of error.
 398  */
 399 rdfheaderrec *rdfgetheaderrec(rdffile * f)
 400 {
 401     static rdfheaderrec r;
 402     int i;
 403
 404     if (!f->header_loc) {
 405         rdf_errno = RDF_ERR_HEADER;
 406         return NULL;
 407     }
 408
 409     if (f->header_fp >= f->header_len)
 410         return 0;
 411
 412     RI8(r.type);
 413     RI8(r.g.reclen);
 414
 415     switch (r.type) {
 416     case RDFREC_RELOC:         /* Relocation record */
 417     case RDFREC_SEGRELOC:
 418         if (r.r.reclen != 8) {
 419             rdf_errno = RDF_ERR_RECLEN;
 420             return NULL;
 421         }
 422         RI8(r.r.segment);
 423         RI32(r.r.offset);
 424         RI8(r.r.length);
 425         RI16(r.r.refseg);
 426         break;
 427
 428     case RDFREC_IMPORT:        /* Imported symbol record */
 429     case RDFREC_FARIMPORT:
 430         RI8(r.i.flags);
 431         RI16(r.i.segment);
 432         RS(r.i.label, EXIM_LABEL_MAX);
 433         break;
 434
 435     case RDFREC_GLOBAL:        /* Exported symbol record */
 436         RI8(r.e.flags);
 437         RI8(r.e.segment);
 438         RI32(r.e.offset);
 439         RS(r.e.label, EXIM_LABEL_MAX);
 440         break;
 441
 442     case RDFREC_DLL:           /* DLL record */
 443         RS(r.d.libname, MODLIB_NAME_MAX);
 444         break;
 445
 446     case RDFREC_BSS:           /* BSS reservation record */
 447         if (r.r.reclen != 4) {
 448             rdf_errno = RDF_ERR_RECLEN;
 449             return NULL;
 450         }
 451         RI32(r.b.amount);
 452         break;
 453
 454     case RDFREC_MODNAME:       /* Module name record */
 455         RS(r.m.modname, MODLIB_NAME_MAX);
 456         break;
 457
 458     case RDFREC_COMMON:        /* Common variable */
 459         RI16(r.c.segment);
 460         RI32(r.c.size);
 461         RI16(r.c.align);
 462         RS(r.c.label, EXIM_LABEL_MAX);
 463         break;
 464
 465     default:
 466 #ifdef STRICT_ERRORS
 467         rdf_errno = RDF_ERR_RECTYPE;    /* unknown header record */
 468         return NULL;
 469 #else
 470         for (i = 0; i < r.g.reclen; i++)
 471             RI8(r.g.data[i]);
 472 #endif
 473     }
 474     return &r;
 475 }
 476
 477 /*
 478  * Rewind to the beginning of the file
 479  */
 480 void rdfheaderrewind(rdffile * f)
 481 {
 482     f->header_fp = 0;
 483 }
 484
 485 rdf_headerbuf *rdfnewheader(void)
 486 {
 487     rdf_headerbuf *hb = malloc(sizeof(rdf_headerbuf));
 488     if (hb == NULL)
 489         return NULL;
 490
 491     hb->buf = newmembuf();
 492     hb->nsegments = 0;
 493     hb->seglength = 0;
 494
 495     return hb;
 496 }
 497
 498 int rdfaddheader(rdf_headerbuf * h, rdfheaderrec * r)
 499 {
 500 #ifndef STRICT_ERRORS
 501     int i;
 502 #endif
 503     membufwrite(h->buf, &r->type, 1);
 504     membufwrite(h->buf, &r->g.reclen, 1);
 505
 506     switch (r->type) {
 507     case RDFREC_GENERIC:       /* generic */
 508         membufwrite(h->buf, &r->g.data, r->g.reclen);
 509         break;
 510     case RDFREC_RELOC:
 511     case RDFREC_SEGRELOC:
 512         membufwrite(h->buf, &r->r.segment, 1);
 513         membufwrite(h->buf, &r->r.offset, -4);
 514         membufwrite(h->buf, &r->r.length, 1);
 515         membufwrite(h->buf, &r->r.refseg, -2);  /* 9 bytes written */
 516         break;
 517
 518     case RDFREC_IMPORT:        /* import */
 519     case RDFREC_FARIMPORT:
 520         membufwrite(h->buf, &r->i.flags, 1);
 521         membufwrite(h->buf, &r->i.segment, -2);
 522         membufwrite(h->buf, &r->i.label, strlen(r->i.label) + 1);
 523         break;
 524
 525     case RDFREC_GLOBAL:        /* export */
 526         membufwrite(h->buf, &r->e.flags, 1);
 527         membufwrite(h->buf, &r->e.segment, 1);
 528         membufwrite(h->buf, &r->e.offset, -4);
 529         membufwrite(h->buf, &r->e.label, strlen(r->e.label) + 1);
 530         break;
 531
 532     case RDFREC_DLL:           /* DLL */
 533         membufwrite(h->buf, &r->d.libname, strlen(r->d.libname) + 1);
 534         break;
 535
 536     case RDFREC_BSS:           /* BSS */
 537         membufwrite(h->buf, &r->b.amount, -4);
 538         break;
 539
 540     case RDFREC_MODNAME:       /* Module name */
 541         membufwrite(h->buf, &r->m.modname, strlen(r->m.modname) + 1);
 542         break;
 543
 544     default:
 545 #ifdef STRICT_ERRORS
 546         return rdf_errno = RDF_ERR_RECTYPE;
 547 #else
 548         for (i = 0; i < r->g.reclen; i++)
 549             membufwrite(h->buf, r->g.data[i], 1);
 550 #endif
 551     }
 552     return 0;
 553 }
 554
 555 int rdfaddsegment(rdf_headerbuf * h, int32_t seglength)
 556 {
 557     h->nsegments++;
 558     h->seglength += seglength;
 559     return 0;
 560 }
 561
 562 int rdfwriteheader(FILE * fp, rdf_headerbuf * h)
 563 {
 564     int32_t l, l2;
 565
 566     fwrite(RDOFFId, 1, strlen(RDOFFId), fp);
 567
 568     l = membuflength(h->buf);
 569     l2 = l + 14 + 10 * h->nsegments + h->seglength;
 570     l = translateint32_t(l);
 571     l2 = translateint32_t(l2);
 572     fwrite(&l2, 4, 1, fp);      /* object length */
 573     fwrite(&l, 4, 1, fp);       /* header length */
 574
 575     membufdump(h->buf, fp);
 576
 577     return 0;                   /* no error handling in here... CHANGE THIS! */
 578 }
 579
 580 void rdfdoneheader(rdf_headerbuf * h)
 581 {
 582     freemembuf(h->buf);
 583     free(h);
 584 }