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 "compiler.h"
  19
  20 #include <stdio.h>
  21 #include <stdlib.h>
  22 #include <string.h>
  23 #include <errno.h>
  24 #include <inttypes.h>
  25
  26 #define RDOFF_UTILS
  27
  28 #include "rdoff.h"
  29
  30 #define newstr(str) strcpy(malloc(strlen(str) + 1),str)
  31 #define newstrcat(s1,s2) strcat(strcpy(malloc(strlen(s1) + strlen(s2) + 1), \
  32                                        s1),s2)
  33
  34 /*
  35  * Comment this out to allow the module to read & write header record types
  36  * that it isn't aware of. With this defined, unrecognised header records
  37  * will generate error number 8, reported as 'unknown extended header record'.
  38  */
  39
  40 #define STRICT_ERRORS
  41
  42 /* ========================================================================
  43  * Code for memory buffers (for delayed writing of header until we know
  44  * how int32_t it is).
  45  * ======================================================================== */
  46
  47 memorybuffer *newmembuf()
  48 {
  49     memorybuffer *t;
  50
  51     t = malloc(sizeof(memorybuffer));
  52     if (!t)
  53         return NULL;
  54
  55     t->length = 0;
  56     t->next = NULL;
  57     return t;
  58 }
  59
  60 void membufwrite(memorybuffer * const b, void *data, int bytes)
  61 {
  62     uint16_t w;
  63     int32_t l;
  64     char *c;
  65
  66     if (b->next) {              /* memory buffer full - use next buffer */
  67         membufwrite(b->next, data, bytes);
  68         return;
  69     }
  70
  71     if ((bytes < 0 && b->length - bytes > BUF_BLOCK_LEN)
  72         || (bytes > 0 && b->length + bytes > BUF_BLOCK_LEN)) {
  73
  74         /* buffer full and no next allocated... allocate and initialise next
  75          * buffer */
  76         b->next = newmembuf();
  77         membufwrite(b->next, data, bytes);
  78         return;
  79     }
  80
  81     switch (bytes) {
  82     case -4:                   /* convert to little-endian */
  83         l = *(int32_t *)data;
  84         b->buffer[b->length++] = l & 0xFF;
  85         l >>= 8;
  86         b->buffer[b->length++] = l & 0xFF;
  87         l >>= 8;
  88         b->buffer[b->length++] = l & 0xFF;
  89         l >>= 8;
  90         b->buffer[b->length++] = l & 0xFF;
  91         break;
  92
  93     case -2:
  94         w = *(uint16_t *) data;
  95         b->buffer[b->length++] = w & 0xFF;
  96         w >>= 8;
  97         b->buffer[b->length++] = w & 0xFF;
  98         break;
  99
 100     default:
 101         c = data;
 102         while (bytes--)
 103             b->buffer[b->length++] = *c++;
 104         break;
 105     }
 106 }
 107
 108 void membufdump(memorybuffer * b, FILE * fp)
 109 {
 110     if (!b)
 111         return;
 112
 113     fwrite(b->buffer, 1, b->length, fp);
 114
 115     membufdump(b->next, fp);
 116 }
 117
 118 int membuflength(memorybuffer * b)
 119 {
 120     if (!b)
 121         return 0;
 122     return b->length + membuflength(b->next);
 123 }
 124
 125 void freemembuf(memorybuffer * b)
 126 {
 127     if (!b)
 128         return;
 129     freemembuf(b->next);
 130     free(b);
 131 }
 132
 133 /* =========================================================================
 134    General purpose routines and variables used by the library functions
 135    ========================================================================= */
 136
 137 /*
 138  * translateint32_t() and translateint16_t()
 139  *
 140  * translate from little endian to local representation
 141  */
 142 int32_t translateint32_t(int32_t in)
 143 {
 144     int32_t r;
 145     uint8_t *i;
 146
 147     i = (uint8_t *)&in;
 148     r = i[3];
 149     r = (r << 8) + i[2];
 150     r = (r << 8) + i[1];
 151     r = (r << 8) + *i;
 152
 153     return r;
 154 }
 155
 156 uint16_t translateint16_t(uint16_t in)
 157 {
 158     uint16_t r;
 159     uint8_t *i;
 160
 161     i = (uint8_t *)&in;
 162     r = (i[1] << 8) + i[0];
 163
 164     return r;
 165 }
 166
 167 /* Segment types */
 168 static char *knownsegtypes[8] = {
 169     "NULL", "text", "data", "object comment",
 170     "linked comment", "loader comment",
 171     "symbolic debug", "line number debug"
 172 };
 173
 174 /* Get a textual string describing the segment type */
 175 char *translatesegmenttype(uint16_t type)
 176 {
 177     if (type < 8)
 178         return knownsegtypes[type];
 179     if (type < 0x0020)
 180         return "reserved";
 181     if (type < 0x1000)
 182         return "reserved - Moscow";
 183     if (type < 0x8000)
 184         return "reserved - system dependant";
 185     if (type < 0xFFFF)
 186         return "reserved - other";
 187     if (type == 0xFFFF)
 188         return "invalid type code";
 189     return "type code out of range";
 190 }
 191
 192 /* This signature is written to the start of RDOFF files */
 193 const char *RDOFFId = RDOFF2_SIGNATURE;
 194
 195 /* Error messages. Must correspond to the codes defined in rdoff.h */
 196 const char *rdf_errors[11] = {
 197     /* 0 */ "no error occurred",
 198     /* 1 */ "could not open file",
 199     /* 2 */ "invalid file format",
 200     /* 3 */ "error reading file",
 201     /* 4 */ "unknown error",
 202     /* 5 */ "header not read",
 203     /* 6 */ "out of memory",
 204     /* 7 */ "RDOFF v1 not supported",
 205     /* 8 */ "unknown extended header record",
 206     /* 9 */ "header record of known type but unknown length",
 207     /* 10 */ "no such segment"
 208 };
 209
 210 int rdf_errno = 0;
 211
 212 /* ========================================================================
 213    The library functions
 214    ======================================================================== */
 215
 216 int rdfopen(rdffile * f, const char *name)
 217 {
 218     FILE *fp;
 219
 220     fp = fopen(name, "rb");
 221     if (!fp)
 222         return rdf_errno = RDF_ERR_OPEN;
 223
 224     return rdfopenhere(f, fp, NULL, name);
 225 }
 226
 227 int rdfopenhere(rdffile * f, FILE * fp, int *refcount, const char *name)
 228 {
 229     char buf[8];
 230     int32_t initpos;
 231     int32_t l;
 232     uint16_t s;
 233
 234     if (translateint32_t(0x01020304) != 0x01020304) {
 235         /* fix this to be portable! */
 236         fputs("*** this program requires a little endian machine\n",
 237               stderr);
 238         fprintf(stderr, "01020304h = %08"PRIx32"h\n", translateint32_t(0x01020304));
 239         exit(3);
 240     }
 241
 242     f->fp = fp;
 243     initpos = ftell(fp);
 244
 245     fread(buf, 6, 1, f->fp);    /* read header */
 246     buf[6] = 0;
 247
 248     if (strcmp(buf, RDOFFId)) {
 249         fclose(f->fp);
 250         if (!strcmp(buf, "RDOFF1"))
 251             return rdf_errno = RDF_ERR_VER;
 252         return rdf_errno = RDF_ERR_FORMAT;
 253     }
 254
 255     if (fread(&l, 1, 4, f->fp) != 4
 256         || fread(&f->header_len, 1, 4, f->fp) != 4) {
 257         fclose(f->fp);
 258         return rdf_errno = RDF_ERR_READ;
 259     }
 260
 261     f->header_ofs = ftell(f->fp);
 262     f->eof_offset = f->header_ofs + translateint32_t(l) - 4;
 263
 264     if (fseek(f->fp, f->header_len, SEEK_CUR)) {
 265         fclose(f->fp);
 266         return rdf_errno = RDF_ERR_FORMAT;      /* seek past end of file...? */
 267     }
 268
 269     if (fread(&s, 1, 2, f->fp) != 2) {
 270         fclose(f->fp);
 271         return rdf_errno = RDF_ERR_READ;
 272     }
 273
 274     f->nsegs = 0;
 275
 276     while (s != 0) {
 277         f->seg[f->nsegs].type = s;
 278         if (fread(&f->seg[f->nsegs].number, 1, 2, f->fp) != 2 ||
 279             fread(&f->seg[f->nsegs].reserved, 1, 2, f->fp) != 2 ||
 280             fread(&f->seg[f->nsegs].length, 1, 4, f->fp) != 4) {
 281             fclose(f->fp);
 282             return rdf_errno = RDF_ERR_READ;
 283         }
 284
 285         f->seg[f->nsegs].offset = ftell(f->fp);
 286         if (fseek(f->fp, f->seg[f->nsegs].length, SEEK_CUR)) {
 287             fclose(f->fp);
 288             return rdf_errno = RDF_ERR_FORMAT;
 289         }
 290         f->nsegs++;
 291
 292         if (fread(&s, 1, 2, f->fp) != 2) {
 293             fclose(f->fp);
 294             return rdf_errno = RDF_ERR_READ;
 295         }
 296     }
 297
 298     if (f->eof_offset != ftell(f->fp) + 8) {    /* +8 = skip null segment header */
 299         fprintf(stderr, "warning: eof_offset [%"PRId32"] and actual eof offset "
 300                 "[%ld] don't match\n", f->eof_offset, ftell(f->fp) + 8);
 301     }
 302     fseek(f->fp, initpos, SEEK_SET);
 303     f->header_loc = NULL;
 304
 305     f->name = newstr(name);
 306     f->refcount = refcount;
 307     if (refcount)
 308         (*refcount)++;
 309     return RDF_OK;
 310 }
 311
 312 int rdfclose(rdffile * f)
 313 {
 314     if (!f->refcount || !--(*f->refcount)) {
 315         fclose(f->fp);
 316         f->fp = NULL;
 317     }
 318     free(f->name);
 319
 320     return 0;
 321 }
 322
 323 /*
 324  * Print the message for last error (from rdf_errno)
 325  */
 326 void rdfperror(const char *app, const char *name)
 327 {
 328     fprintf(stderr, "%s:%s: %s\n", app, name, rdf_errors[rdf_errno]);
 329     if (rdf_errno == RDF_ERR_OPEN || rdf_errno == RDF_ERR_READ) {
 330         perror(app);
 331     }
 332 }
 333
 334 /*
 335  * Find the segment by its number.
 336  * Returns segment array index, or -1 if segment with such number was not found.
 337  */
 338 int rdffindsegment(rdffile * f, int segno)
 339 {
 340     int i;
 341     for (i = 0; i < f->nsegs; i++)
 342         if (f->seg[i].number == segno)
 343             return i;
 344     return -1;
 345 }
 346
 347 /*
 348  * Load the segment. Returns status.
 349  */
 350 int rdfloadseg(rdffile * f, int segment, void *buffer)
 351 {
 352     int32_t fpos;
 353     size_t slen;
 354
 355     switch (segment) {
 356     case RDOFF_HEADER:
 357         fpos = f->header_ofs;
 358         slen = f->header_len;
 359         f->header_loc = (uint8_t *) buffer;
 360         f->header_fp = 0;
 361         break;
 362     default:
 363         if (segment < f->nsegs) {
 364             fpos = f->seg[segment].offset;
 365             slen = f->seg[segment].length;
 366             f->seg[segment].data = (uint8_t *) buffer;
 367         } else {
 368             return rdf_errno = RDF_ERR_SEGMENT;
 369         }
 370     }
 371
 372     if (fseek(f->fp, fpos, SEEK_SET))
 373         return rdf_errno = RDF_ERR_UNKNOWN;
 374
 375     if (fread(buffer, 1, slen, f->fp) != slen)
 376         return rdf_errno = RDF_ERR_READ;
 377
 378     return RDF_OK;
 379 }
 380
 381 /* Macros for reading integers from header in memory */
 382
 383 #define RI8(v) v = f->header_loc[f->header_fp++]
 384 #define RI16(v) { v = (f->header_loc[f->header_fp] + \
 385                        (f->header_loc[f->header_fp+1] << 8)); \
 386                   f->header_fp += 2; }
 387
 388 #define RI32(v) { v = (f->header_loc[f->header_fp] + \
 389                        (f->header_loc[f->header_fp+1] << 8) + \
 390                        (f->header_loc[f->header_fp+2] << 16) + \
 391                        (f->header_loc[f->header_fp+3] << 24)); \
 392                   f->header_fp += 4; }
 393
 394 #define RS(str,max) { for(i=0;i<max;i++){\
 395   RI8(str[i]); if (!str[i]) break;} str[i]=0; }
 396
 397 /*
 398  * Read a header record.
 399  * Returns the address of record, or NULL in case of error.
 400  */
 401 rdfheaderrec *rdfgetheaderrec(rdffile * f)
 402 {
 403     static rdfheaderrec r;
 404     int i;
 405
 406     if (!f->header_loc) {
 407         rdf_errno = RDF_ERR_HEADER;
 408         return NULL;
 409     }
 410
 411     if (f->header_fp >= f->header_len)
 412         return 0;
 413
 414     RI8(r.type);
 415     RI8(r.g.reclen);
 416
 417     switch (r.type) {
 418     case RDFREC_RELOC:         /* Relocation record */
 419     case RDFREC_SEGRELOC:
 420         if (r.r.reclen != 8) {
 421             rdf_errno = RDF_ERR_RECLEN;
 422             return NULL;
 423         }
 424         RI8(r.r.segment);
 425         RI32(r.r.offset);
 426         RI8(r.r.length);
 427         RI16(r.r.refseg);
 428         break;
 429
 430     case RDFREC_IMPORT:        /* Imported symbol record */
 431     case RDFREC_FARIMPORT:
 432         RI8(r.i.flags);
 433         RI16(r.i.segment);
 434         RS(r.i.label, EXIM_LABEL_MAX);
 435         break;
 436
 437     case RDFREC_GLOBAL:        /* Exported symbol record */
 438         RI8(r.e.flags);
 439         RI8(r.e.segment);
 440         RI32(r.e.offset);
 441         RS(r.e.label, EXIM_LABEL_MAX);
 442         break;
 443
 444     case RDFREC_DLL:           /* DLL record */
 445         RS(r.d.libname, MODLIB_NAME_MAX);
 446         break;
 447
 448     case RDFREC_BSS:           /* BSS reservation record */
 449         if (r.r.reclen != 4) {
 450             rdf_errno = RDF_ERR_RECLEN;
 451             return NULL;
 452         }
 453         RI32(r.b.amount);
 454         break;
 455
 456     case RDFREC_MODNAME:       /* Module name record */
 457         RS(r.m.modname, MODLIB_NAME_MAX);
 458         break;
 459
 460     case RDFREC_COMMON:        /* Common variable */
 461         RI16(r.c.segment);
 462         RI32(r.c.size);
 463         RI16(r.c.align);
 464         RS(r.c.label, EXIM_LABEL_MAX);
 465         break;
 466
 467     default:
 468 #ifdef STRICT_ERRORS
 469         rdf_errno = RDF_ERR_RECTYPE;    /* unknown header record */
 470         return NULL;
 471 #else
 472         for (i = 0; i < r.g.reclen; i++)
 473             RI8(r.g.data[i]);
 474 #endif
 475     }
 476     return &r;
 477 }
 478
 479 /*
 480  * Rewind to the beginning of the file
 481  */
 482 void rdfheaderrewind(rdffile * f)
 483 {
 484     f->header_fp = 0;
 485 }
 486
 487 rdf_headerbuf *rdfnewheader(void)
 488 {
 489     rdf_headerbuf *hb = malloc(sizeof(rdf_headerbuf));
 490     if (hb == NULL)
 491         return NULL;
 492
 493     hb->buf = newmembuf();
 494     hb->nsegments = 0;
 495     hb->seglength = 0;
 496
 497     return hb;
 498 }
 499
 500 int rdfaddheader(rdf_headerbuf * h, rdfheaderrec * r)
 501 {
 502 #ifndef STRICT_ERRORS
 503     int i;
 504 #endif
 505     membufwrite(h->buf, &r->type, 1);
 506     membufwrite(h->buf, &r->g.reclen, 1);
 507
 508     switch (r->type) {
 509     case RDFREC_GENERIC:       /* generic */
 510         membufwrite(h->buf, &r->g.data, r->g.reclen);
 511         break;
 512     case RDFREC_RELOC:
 513     case RDFREC_SEGRELOC:
 514         membufwrite(h->buf, &r->r.segment, 1);
 515         membufwrite(h->buf, &r->r.offset, -4);
 516         membufwrite(h->buf, &r->r.length, 1);
 517         membufwrite(h->buf, &r->r.refseg, -2);  /* 9 bytes written */
 518         break;
 519
 520     case RDFREC_IMPORT:        /* import */
 521     case RDFREC_FARIMPORT:
 522         membufwrite(h->buf, &r->i.flags, 1);
 523         membufwrite(h->buf, &r->i.segment, -2);
 524         membufwrite(h->buf, &r->i.label, strlen(r->i.label) + 1);
 525         break;
 526
 527     case RDFREC_GLOBAL:        /* export */
 528         membufwrite(h->buf, &r->e.flags, 1);
 529         membufwrite(h->buf, &r->e.segment, 1);
 530         membufwrite(h->buf, &r->e.offset, -4);
 531         membufwrite(h->buf, &r->e.label, strlen(r->e.label) + 1);
 532         break;
 533
 534     case RDFREC_DLL:           /* DLL */
 535         membufwrite(h->buf, &r->d.libname, strlen(r->d.libname) + 1);
 536         break;
 537
 538     case RDFREC_BSS:           /* BSS */
 539         membufwrite(h->buf, &r->b.amount, -4);
 540         break;
 541
 542     case RDFREC_MODNAME:       /* Module name */
 543         membufwrite(h->buf, &r->m.modname, strlen(r->m.modname) + 1);
 544         break;
 545
 546     default:
 547 #ifdef STRICT_ERRORS
 548         return rdf_errno = RDF_ERR_RECTYPE;
 549 #else
 550         for (i = 0; i < r->g.reclen; i++)
 551             membufwrite(h->buf, r->g.data[i], 1);
 552 #endif
 553     }
 554     return 0;
 555 }
 556
 557 int rdfaddsegment(rdf_headerbuf * h, int32_t seglength)
 558 {
 559     h->nsegments++;
 560     h->seglength += seglength;
 561     return 0;
 562 }
 563
 564 int rdfwriteheader(FILE * fp, rdf_headerbuf * h)
 565 {
 566     int32_t l, l2;
 567
 568     fwrite(RDOFFId, 1, strlen(RDOFFId), fp);
 569
 570     l = membuflength(h->buf);
 571     l2 = l + 14 + 10 * h->nsegments + h->seglength;
 572     l = translateint32_t(l);
 573     l2 = translateint32_t(l2);
 574     fwrite(&l2, 4, 1, fp);      /* object length */
 575     fwrite(&l, 4, 1, fp);       /* header length */
 576
 577     membufdump(h->buf, fp);
 578
 579     return 0;                   /* no error handling in here... CHANGE THIS! */
 580 }
 581
 582 void rdfdoneheader(rdf_headerbuf * h)
 583 {
 584     freemembuf(h->buf);
 585     free(h);
 586 }