libiberty/simple-object-xcoff.c

   1 /* simple-object-coff.c -- routines to manipulate XCOFF object files.
   2    Copyright 2013 Free Software Foundation, Inc.
   3    Written by Ian Lance Taylor, Google and David Edelsohn, IBM.
   4
   5 This program is free software; you can redistribute it and/or modify it
   6 under the terms of the GNU General Public License as published by the
   7 Free Software Foundation; either version 2, or (at your option) any
   8 later version.
   9
  10 This program is distributed in the hope that it will be useful,
  11 but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 GNU General Public License for more details.
  14
  15 You should have received a copy of the GNU General Public License
  16 along with this program; if not, write to the Free Software
  17 Foundation, 51 Franklin Street - Fifth Floor,
  18 Boston, MA 02110-1301, USA.  */
  19
  20 #include "config.h"
  21 #include "libiberty.h"
  22 #include "simple-object.h"
  23
  24 #include <errno.h>
  25 #include <stddef.h>
  26
  27 #ifdef HAVE_STDLIB_H
  28 #include <stdlib.h>
  29 #endif
  30
  31 #ifdef HAVE_STDINT_H
  32 #include <stdint.h>
  33 #endif
  34
  35 #ifdef HAVE_STRING_H
  36 #include <string.h>
  37 #endif
  38
  39 #ifdef HAVE_INTTYPES_H
  40 #include <inttypes.h>
  41 #endif
  42
  43 #include "simple-object-common.h"
  44
  45 /* XCOFF structures and constants.  */
  46
  47 /* XCOFF file header.  */
  48
  49 struct external_filehdr
  50 {
  51   unsigned char f_magic[2];     /* magic number                 */
  52   unsigned char f_nscns[2];     /* number of sections           */
  53   unsigned char f_timdat[4];    /* time & date stamp            */
  54   union
  55   {
  56     struct
  57     {
  58       unsigned char f_symptr[4];        /* file pointer to symtab       */
  59       unsigned char f_nsyms[4]; /* number of symtab entries     */
  60       unsigned char f_opthdr[2];        /* sizeof(optional hdr)         */
  61       unsigned char f_flags[2]; /* flags                        */
  62     } xcoff32;
  63     struct
  64     {
  65       unsigned char f_symptr[8];        /* file pointer to symtab       */
  66       unsigned char f_opthdr[2];        /* sizeof(optional hdr)         */
  67       unsigned char f_flags[2]; /* flags                        */
  68       unsigned char f_nsyms[4]; /* number of symtab entries     */
  69     } xcoff64;
  70   } u;
  71 };
  72
  73 /* Bits for filehdr f_flags field.  */
  74
  75 #define F_EXEC                  (0x0002)
  76
  77 /* The known values of f_magic in an XCOFF file header.  */
  78
  79 #define U802WRMAGIC 0730        /* Writeable text segments.  */
  80 #define U802ROMAGIC 0735        /* Readonly sharable text segments.  */
  81 #define U802TOCMAGIC 0737       /* Readonly text segments and TOC.  */
  82 #define U803XTOCMAGIC 0757      /* Aix 4.3 64-bit XCOFF.  */
  83 #define U64_TOCMAGIC 0767       /* AIX 5+ 64-bit XCOFF.  */
  84
  85 /* XCOFF section header.  */
  86
  87 struct external_scnhdr
  88 {
  89   unsigned char s_name[8];      /* section name                         */
  90   union
  91   {
  92     struct
  93     {
  94       unsigned char s_paddr[4]; /* physical address, aliased s_nlib     */
  95       unsigned char s_vaddr[4]; /* virtual address                      */
  96       unsigned char s_size[4];  /* section size                         */
  97       unsigned char s_scnptr[4];        /* file ptr to raw data for section */
  98       unsigned char s_relptr[4];        /* file ptr to relocation       */
  99       unsigned char s_lnnoptr[4];       /* file ptr to line numbers     */
 100       unsigned char s_nreloc[2];        /* number of relocation entries */
 101       unsigned char s_nlnno[2]; /* number of line number entries        */
 102       unsigned char s_flags[4]; /* flags                                */
 103     } xcoff32;
 104     struct
 105     {
 106       unsigned char s_paddr[8]; /* physical address, aliased s_nlib     */
 107       unsigned char s_vaddr[8]; /* virtual address                      */
 108       unsigned char s_size[8];  /* section size                         */
 109       unsigned char s_scnptr[8];        /* file ptr to raw data for section */
 110       unsigned char s_relptr[8];        /* file ptr to relocation       */
 111       unsigned char s_lnnoptr[8];       /* file ptr to line numbers     */
 112       unsigned char s_nreloc[4];        /* number of relocation entries */
 113       unsigned char s_nlnno[4]; /* number of line number entries        */
 114       unsigned char s_flags[4]; /* flags                                */
 115     } xcoff64;
 116   } u;
 117 };
 118
 119 #define SCNHSZ32        (40)
 120 #define SCNHSZ64        (68)
 121
 122 /* The length of the s_name field in struct external_scnhdr.  */
 123
 124 #define SCNNMLEN        (8)
 125
 126 /* Bits for scnhdr s_flags field.  */
 127
 128 #define STYP_DATA                       0x40
 129
 130 /* XCOFF symbol table entry.  */
 131
 132
 133 #define N_SYMNMLEN      (8)     /* # characters in a symbol name        */
 134
 135 /* The format of an XCOFF symbol-table entry.  */
 136 struct external_syment
 137 {
 138   union {
 139     struct {
 140       union {
 141         /* The name of the symbol.  There is an implicit null character
 142            after the end of the array.  */
 143         char n_name[N_SYMNMLEN];
 144         struct {
 145           /* If n_zeroes is zero, n_offset is the offset the name from
 146              the start of the string table.  */
 147           unsigned char n_zeroes[4];
 148           unsigned char n_offset[4];
 149         } n;
 150       } n;
 151
 152       /* The symbol's value.  */
 153       unsigned char n_value[4];
 154     } xcoff32;
 155     struct {
 156       /* The symbol's value.  */
 157       unsigned char n_value[8];
 158
 159       /* The offset of the symbol from the start of the string table.  */
 160       unsigned char n_offset[4];
 161     } xcoff64;
 162   } u;
 163
 164   /* The number of the section to which this symbol belongs.  */
 165   unsigned char n_scnum[2];
 166
 167   /* The type of symbol.  (It can be interpreted as an n_lang
 168      and an n_cpu byte, but we don't care about that here.)  */
 169   unsigned char n_type[2];
 170
 171   /* The class of symbol (a C_* value).  */
 172   unsigned char n_sclass[1];
 173
 174   /* The number of auxiliary symbols attached to this entry.  */
 175   unsigned char n_numaux[1];
 176 };
 177
 178 #define SYMESZ          (18)
 179
 180 /* Length allowed for filename in aux sym format 4.  */
 181
 182 #define FILNMLEN        (14)
 183
 184 /* Omits x_sym and other unused variants.  */
 185
 186 union external_auxent
 187 {
 188   /* Aux sym format 4: file.  */
 189   union
 190   {
 191     char x_fname[FILNMLEN];
 192     struct
 193     {
 194       unsigned char x_zeroes[4];
 195       unsigned char x_offset[4];
 196       unsigned char x_pad[FILNMLEN-8];
 197       unsigned char x_ftype;
 198     } _x;
 199   } x_file;
 200   /* Aux sym format 5: section.  */
 201   struct
 202   {
 203     unsigned char x_scnlen[4];          /* section length               */
 204     unsigned char x_nreloc[2];          /* # relocation entries         */
 205     unsigned char x_nlinno[2];          /* # line numbers               */
 206   } x_scn;
 207   /* CSECT auxiliary entry.  */
 208   union
 209   {
 210     struct
 211     {
 212       struct
 213       {
 214         unsigned char x_scnlen[4];      /* csect length */
 215         unsigned char x_parmhash[4];    /* parm type hash index */
 216         unsigned char x_snhash[2];      /* sect num with parm hash */
 217         unsigned char x_smtyp;          /* symbol align and type */
 218         unsigned char x_smclas;         /* storage mapping class */
 219         unsigned char x_stab;           /* dbx stab info index */
 220         unsigned char x_snstab[2];      /* sect num with dbx stab */
 221       } x_csect;
 222     } xcoff32;
 223     struct
 224     {
 225       struct
 226       {
 227         unsigned char x_scnlen_lo[4];   /* csect length */
 228         unsigned char x_parmhash[4];    /* parm type hash index */
 229         unsigned char x_snhash[2];      /* sect num with parm hash */
 230         unsigned char x_smtyp;          /* symbol align and type */
 231         unsigned char x_smclas;         /* storage mapping class */
 232         unsigned char x_scnlen_hi[4];
 233         unsigned char pad;
 234         unsigned char x_auxtype;
 235       } x_csect;
 236     } xcoff64;
 237   } u;
 238   /* SECTION/DWARF auxiliary entry.  */
 239   struct
 240   {
 241     unsigned char x_scnlen[4];          /* section length */
 242     unsigned char pad1[4];
 243     unsigned char x_nreloc[4];          /* number RLDs */
 244   } x_sect;
 245 };
 246
 247 /* Symbol-related constants.  */
 248
 249 #define N_DEBUG         (-2)
 250 #define IMAGE_SYM_TYPE_NULL     (0)
 251 #define IMAGE_SYM_DTYPE_NULL    (0)
 252 #define IMAGE_SYM_CLASS_STATIC  (3)
 253 #define IMAGE_SYM_CLASS_FILE    (103)
 254
 255 #define IMAGE_SYM_TYPE \
 256   ((IMAGE_SYM_DTYPE_NULL << 4) | IMAGE_SYM_TYPE_NULL)
 257
 258 #define C_STAT          (3)
 259 #define C_FILE          (103)
 260
 261 /* Private data for an simple_object_read.  */
 262
 263 struct simple_object_xcoff_read
 264 {
 265   /* Magic number.  */
 266   unsigned short magic;
 267   /* Number of sections.  */
 268   unsigned short nscns;
 269   /* File offset of symbol table.  */
 270   off_t symptr;
 271   /* Number of symbol table entries.  */
 272   unsigned int nsyms;
 273   /* Flags.  */
 274   unsigned short flags;
 275   /* Offset of section headers in file.  */
 276   off_t scnhdr_offset;
 277 };
 278
 279 /* Private data for an simple_object_attributes.  */
 280
 281 struct simple_object_xcoff_attributes
 282 {
 283   /* Magic number.  */
 284   unsigned short magic;
 285   /* Flags.  */
 286   unsigned short flags;
 287 };
 288
 289 /* See if we have a XCOFF file.  */
 290
 291 static void *
 292 simple_object_xcoff_match (unsigned char header[SIMPLE_OBJECT_MATCH_HEADER_LEN],
 293                            int descriptor, off_t offset,
 294                            const char *segment_name ATTRIBUTE_UNUSED,
 295                            const char **errmsg, int *err)
 296 {
 297   unsigned short magic;
 298   unsigned short (*fetch_16) (const unsigned char *);
 299   unsigned int (*fetch_32) (const unsigned char *);
 300   ulong_type (*fetch_64) (const unsigned char *);
 301   unsigned char hdrbuf[sizeof (struct external_filehdr)];
 302   struct simple_object_xcoff_read *ocr;
 303   int u64;
 304
 305   magic = simple_object_fetch_big_16 (header);
 306
 307   if (magic != U802TOCMAGIC && magic != U64_TOCMAGIC)
 308     {
 309       *errmsg = NULL;
 310       *err = 0;
 311       return NULL;
 312     }
 313
 314   fetch_16 = simple_object_fetch_big_16;
 315   fetch_32 = simple_object_fetch_big_32;
 316   fetch_64 = simple_object_fetch_big_64;
 317
 318   if (!simple_object_internal_read (descriptor, offset, hdrbuf, sizeof hdrbuf,
 319                                     errmsg, err))
 320     return NULL;
 321
 322   u64 = magic == U64_TOCMAGIC;
 323
 324   ocr = XNEW (struct simple_object_xcoff_read);
 325   ocr->magic = magic;
 326   ocr->nscns = fetch_16 (hdrbuf + offsetof (struct external_filehdr, f_nscns));
 327   if (u64)
 328     {
 329       ocr->symptr = fetch_64 (hdrbuf
 330                               + offsetof (struct external_filehdr,
 331                                           u.xcoff64.f_symptr));
 332       ocr->nsyms = fetch_32 (hdrbuf + offsetof (struct external_filehdr,
 333                                                 u.xcoff64.f_nsyms));
 334       ocr->scnhdr_offset = (sizeof (struct external_filehdr)
 335                             + fetch_16 (hdrbuf + offsetof (struct external_filehdr,
 336                                                            u.xcoff64.f_opthdr)));
 337
 338     }
 339   else
 340     {
 341       ocr->symptr = fetch_32 (hdrbuf
 342                               + offsetof (struct external_filehdr,
 343                                           u.xcoff32.f_symptr));
 344       ocr->nsyms = fetch_32 (hdrbuf + offsetof (struct external_filehdr,
 345                                                 u.xcoff32.f_nsyms));
 346       ocr->scnhdr_offset = (sizeof (struct external_filehdr) - 4
 347                             + fetch_16 (hdrbuf + offsetof (struct external_filehdr,
 348                                                            u.xcoff32.f_opthdr)));
 349
 350     }
 351
 352   return (void *) ocr;
 353 }
 354
 355 /* Read the string table in a XCOFF file.  */
 356
 357 static char *
 358 simple_object_xcoff_read_strtab (simple_object_read *sobj, size_t *strtab_size,
 359                                  const char **errmsg, int *err)
 360 {
 361   struct simple_object_xcoff_read *ocr =
 362     (struct simple_object_xcoff_read *) sobj->data;
 363   off_t strtab_offset;
 364   unsigned char strsizebuf[4];
 365   size_t strsize;
 366   char *strtab;
 367
 368   strtab_offset = sobj->offset + ocr->symptr
 369     + ocr->nsyms * SYMESZ;
 370   if (!simple_object_internal_read (sobj->descriptor, strtab_offset,
 371                                     strsizebuf, 4, errmsg, err))
 372     return NULL;
 373   strsize = simple_object_fetch_big_32 (strsizebuf);
 374   strtab = XNEWVEC (char, strsize);
 375   if (!simple_object_internal_read (sobj->descriptor, strtab_offset,
 376                                     (unsigned char *) strtab, strsize, errmsg,
 377                                     err))
 378     {
 379       XDELETEVEC (strtab);
 380       return NULL;
 381     }
 382   *strtab_size = strsize;
 383   return strtab;
 384 }
 385
 386 /* Find all sections in a XCOFF file.  */
 387
 388 static const char *
 389 simple_object_xcoff_find_sections (simple_object_read *sobj,
 390                                   int (*pfn) (void *, const char *,
 391                                               off_t offset, off_t length),
 392                                   void *data,
 393                                   int *err)
 394 {
 395   struct simple_object_xcoff_read *ocr =
 396     (struct simple_object_xcoff_read *) sobj->data;
 397   int u64 = ocr->magic == U64_TOCMAGIC;
 398   size_t scnhdr_size;
 399   unsigned char *scnbuf;
 400   const char *errmsg;
 401   unsigned int (*fetch_32) (const unsigned char *);
 402   ulong_type (*fetch_64) (const unsigned char *);
 403   unsigned int nscns;
 404   char *strtab;
 405   size_t strtab_size;
 406   unsigned int i;
 407
 408   scnhdr_size = u64 ? SCNHSZ64 : SCNHSZ32;
 409   scnbuf = XNEWVEC (unsigned char, scnhdr_size * ocr->nscns);
 410   if (!simple_object_internal_read (sobj->descriptor,
 411                                     sobj->offset + ocr->scnhdr_offset,
 412                                     scnbuf, scnhdr_size * ocr->nscns, &errmsg,
 413                                     err))
 414     {
 415       XDELETEVEC (scnbuf);
 416       return errmsg;
 417     }
 418
 419   fetch_32 = simple_object_fetch_big_32;
 420   fetch_64 = simple_object_fetch_big_64;
 421
 422   nscns = ocr->nscns;
 423   strtab = NULL;
 424   strtab_size = 0;
 425   for (i = 0; i < nscns; ++i)
 426     {
 427       unsigned char *scnhdr;
 428       unsigned char *scnname;
 429       char namebuf[SCNNMLEN + 1];
 430       char *name;
 431       off_t scnptr;
 432       unsigned int size;
 433
 434       scnhdr = scnbuf + i * scnhdr_size;
 435       scnname = scnhdr + offsetof (struct external_scnhdr, s_name);
 436       memcpy (namebuf, scnname, SCNNMLEN);
 437       namebuf[SCNNMLEN] = '\0';
 438       name = &namebuf[0];
 439       if (namebuf[0] == '/')
 440         {
 441           size_t strindex;
 442           char *end;
 443
 444           strindex = strtol (namebuf + 1, &end, 10);
 445           if (*end == '\0')
 446             {
 447               /* The real section name is found in the string
 448                  table.  */
 449               if (strtab == NULL)
 450                 {
 451                   strtab = simple_object_xcoff_read_strtab (sobj,
 452                                                            &strtab_size,
 453                                                            &errmsg, err);
 454                   if (strtab == NULL)
 455                     {
 456                       XDELETEVEC (scnbuf);
 457                       return errmsg;
 458                     }
 459                 }
 460
 461               if (strindex < 4 || strindex >= strtab_size)
 462                 {
 463                   XDELETEVEC (strtab);
 464                   XDELETEVEC (scnbuf);
 465                   *err = 0;
 466                   return "section string index out of range";
 467                 }
 468
 469               name = strtab + strindex;
 470             }
 471         }
 472
 473       if (u64)
 474         {
 475           scnptr = fetch_64 (scnhdr + offsetof (struct external_scnhdr,
 476                                                 u.xcoff64.s_scnptr));
 477           size = fetch_64 (scnhdr + offsetof (struct external_scnhdr,
 478                                               u.xcoff64.s_size));
 479         }
 480       else
 481         {
 482           scnptr = fetch_32 (scnhdr + offsetof (struct external_scnhdr,
 483                                                 u.xcoff32.s_scnptr));
 484           size = fetch_32 (scnhdr + offsetof (struct external_scnhdr,
 485                                               u.xcoff32.s_size));
 486         }
 487
 488       if (!(*pfn) (data, name, scnptr, size))
 489         break;
 490     }
 491
 492   if (strtab != NULL)
 493     XDELETEVEC (strtab);
 494   XDELETEVEC (scnbuf);
 495
 496   return NULL;
 497 }
 498
 499 /* Fetch the attributes for an simple_object_read.  */
 500
 501 static void *
 502 simple_object_xcoff_fetch_attributes (simple_object_read *sobj,
 503                                      const char **errmsg ATTRIBUTE_UNUSED,
 504                                      int *err ATTRIBUTE_UNUSED)
 505 {
 506   struct simple_object_xcoff_read *ocr =
 507     (struct simple_object_xcoff_read *) sobj->data;
 508   struct simple_object_xcoff_attributes *ret;
 509
 510   ret = XNEW (struct simple_object_xcoff_attributes);
 511   ret->magic = ocr->magic;
 512   ret->flags = ocr->flags;
 513   return ret;
 514 }
 515
 516 /* Release the private data for an simple_object_read.  */
 517
 518 static void
 519 simple_object_xcoff_release_read (void *data)
 520 {
 521   XDELETE (data);
 522 }
 523
 524 /* Compare two attributes structures.  */
 525
 526 static const char *
 527 simple_object_xcoff_attributes_merge (void *todata, void *fromdata, int *err)
 528 {
 529   struct simple_object_xcoff_attributes *to =
 530     (struct simple_object_xcoff_attributes *) todata;
 531   struct simple_object_xcoff_attributes *from =
 532     (struct simple_object_xcoff_attributes *) fromdata;
 533
 534   if (to->magic != from->magic)
 535     {
 536       *err = 0;
 537       return "XCOFF object format mismatch";
 538     }
 539   return NULL;
 540 }
 541
 542 /* Release the private data for an attributes structure.  */
 543
 544 static void
 545 simple_object_xcoff_release_attributes (void *data)
 546 {
 547   XDELETE (data);
 548 }
 549
 550 /* Prepare to write out a file.  */
 551
 552 static void *
 553 simple_object_xcoff_start_write (void *attributes_data,
 554                                 const char **errmsg ATTRIBUTE_UNUSED,
 555                                 int *err ATTRIBUTE_UNUSED)
 556 {
 557   struct simple_object_xcoff_attributes *attrs =
 558     (struct simple_object_xcoff_attributes *) attributes_data;
 559   struct simple_object_xcoff_attributes *ret;
 560
 561   /* We're just going to record the attributes, but we need to make a
 562      copy because the user may delete them.  */
 563   ret = XNEW (struct simple_object_xcoff_attributes);
 564   *ret = *attrs;
 565   return ret;
 566 }
 567
 568 /* Write out a XCOFF filehdr.  */
 569
 570 static int
 571 simple_object_xcoff_write_filehdr (simple_object_write *sobj, int descriptor,
 572                                   unsigned int nscns, size_t symtab_offset,
 573                                   unsigned int nsyms, const char **errmsg,
 574                                   int *err)
 575 {
 576   struct simple_object_xcoff_attributes *attrs =
 577     (struct simple_object_xcoff_attributes *) sobj->data;
 578   int u64 = attrs->magic == U64_TOCMAGIC;
 579   unsigned char hdrbuf[sizeof (struct external_filehdr)];
 580   unsigned char *hdr;
 581   void (*set_16) (unsigned char *, unsigned short);
 582   void (*set_32) (unsigned char *, unsigned int);
 583   void (*set_64) (unsigned char *, ulong_type);
 584
 585   hdr = &hdrbuf[0];
 586
 587   set_16 = simple_object_set_big_16;
 588   set_32 = simple_object_set_big_32;
 589   set_64 = simple_object_set_big_64;
 590
 591   memset (hdr, 0, sizeof (struct external_filehdr));
 592
 593   set_16 (hdr + offsetof (struct external_filehdr, f_magic), attrs->magic);
 594   set_16 (hdr + offsetof (struct external_filehdr, f_nscns), nscns);
 595   /* f_timdat left as zero.  */
 596   if (u64)
 597     {
 598       set_64 (hdr + offsetof (struct external_filehdr, u.xcoff64.f_symptr),
 599               symtab_offset);
 600       set_32 (hdr + offsetof (struct external_filehdr, u.xcoff64.f_nsyms),
 601               nsyms);
 602       /* f_opthdr left as zero.  */
 603       set_16 (hdr + offsetof (struct external_filehdr, u.xcoff64.f_flags),
 604               attrs->flags);
 605     }
 606   else
 607     {
 608       set_32 (hdr + offsetof (struct external_filehdr, u.xcoff64.f_symptr),
 609               symtab_offset);
 610       set_32 (hdr + offsetof (struct external_filehdr, u.xcoff64.f_nsyms),
 611               nsyms);
 612       /* f_opthdr left as zero.  */
 613       set_16 (hdr + offsetof (struct external_filehdr, u.xcoff64.f_flags),
 614               attrs->flags);
 615     }
 616
 617   return simple_object_internal_write (descriptor, 0, hdrbuf,
 618                                        sizeof (struct external_filehdr),
 619                                        errmsg, err);
 620 }
 621
 622 /* Write out a XCOFF section header.  */
 623
 624 static int
 625 simple_object_xcoff_write_scnhdr (simple_object_write *sobj,
 626                                   int descriptor,
 627                                   const char *name, size_t *name_offset,
 628                                   off_t scnhdr_offset, size_t scnsize,
 629                                   off_t offset, unsigned int align,
 630                                   const char **errmsg, int *err)
 631 {
 632   struct simple_object_xcoff_read *ocr =
 633     (struct simple_object_xcoff_read *) sobj->data;
 634   int u64 = ocr->magic == U64_TOCMAGIC;
 635   void (*set_32) (unsigned char *, unsigned int);
 636   void (*set_64) (unsigned char *, unsigned int);
 637   unsigned char hdrbuf[sizeof (struct external_scnhdr)];
 638   unsigned char *hdr;
 639   size_t namelen;
 640   unsigned int flags;
 641
 642   set_32 = simple_object_set_big_32;
 643   set_64 = simple_object_set_big_32;
 644
 645   memset (hdrbuf, 0, sizeof hdrbuf);
 646   hdr = &hdrbuf[0];
 647
 648   namelen = strlen (name);
 649   if (namelen <= SCNNMLEN)
 650     strncpy ((char *) hdr + offsetof (struct external_scnhdr, s_name),
 651              name, SCNNMLEN);
 652   else
 653     {
 654       snprintf ((char *) hdr + offsetof (struct external_scnhdr, s_name),
 655                 SCNNMLEN, "/%lu", (unsigned long) *name_offset);
 656       *name_offset += namelen + 1;
 657     }
 658
 659   /* s_paddr left as zero.  */
 660   /* s_vaddr left as zero.  */
 661   if (u64)
 662     {
 663       set_64 (hdr + offsetof (struct external_scnhdr, u.xcoff64.s_size),
 664               scnsize);
 665       set_64 (hdr + offsetof (struct external_scnhdr, u.xcoff64.s_scnptr),
 666               offset);
 667     }
 668   else
 669     {
 670       set_32 (hdr + offsetof (struct external_scnhdr, u.xcoff32.s_size),
 671               scnsize);
 672       set_32 (hdr + offsetof (struct external_scnhdr, u.xcoff32.s_scnptr),
 673               offset);
 674     }
 675   /* s_relptr left as zero.  */
 676   /* s_lnnoptr left as zero.  */
 677   /* s_nreloc left as zero.  */
 678   /* s_nlnno left as zero.  */
 679   flags = STYP_DATA;
 680   if (align > 13)
 681     align = 13;
 682   if (u64)
 683     set_32 (hdr + offsetof (struct external_scnhdr, u.xcoff64.s_flags), flags);
 684   else
 685     set_32 (hdr + offsetof (struct external_scnhdr, u.xcoff32.s_flags), flags);
 686
 687   return simple_object_internal_write (descriptor, scnhdr_offset, hdrbuf,
 688                                        u64 ? SCNHSZ64 : SCNHSZ32,
 689                                        errmsg, err);
 690 }
 691
 692 /* Write out a complete XCOFF file.  */
 693
 694 static const char *
 695 simple_object_xcoff_write_to_file (simple_object_write *sobj, int descriptor,
 696                                   int *err)
 697 {
 698   struct simple_object_xcoff_read *ocr =
 699     (struct simple_object_xcoff_read *) sobj->data;
 700   int u64 = ocr->magic == U64_TOCMAGIC;
 701   unsigned int nscns, secnum;
 702   simple_object_write_section *section;
 703   off_t scnhdr_offset;
 704   size_t symtab_offset;
 705   off_t secsym_offset;
 706   unsigned int nsyms;
 707   size_t offset;
 708   size_t name_offset;
 709   const char *errmsg;
 710   unsigned char strsizebuf[4];
 711   /* The interface doesn't give us access to the name of the input file
 712      yet.  We want to use its basename for the FILE symbol.  This is
 713      what 'gas' uses when told to assemble from stdin.  */
 714   const char *source_filename = "fake";
 715   size_t sflen;
 716   union
 717   {
 718     struct external_syment sym;
 719     union external_auxent aux;
 720   } syms[2];
 721   void (*set_16) (unsigned char *, unsigned short);
 722   void (*set_32) (unsigned char *, unsigned int);
 723
 724   set_16 = simple_object_set_big_16;
 725   set_32 = simple_object_set_big_32;
 726
 727   nscns = 0;
 728   for (section = sobj->sections; section != NULL; section = section->next)
 729     ++nscns;
 730
 731   scnhdr_offset = sizeof (struct external_filehdr) - (u64 ? 4 : 0);
 732   offset = scnhdr_offset + nscns * (u64 ? SCNHSZ64 : SCNHSZ32);
 733   name_offset = 4;
 734   for (section = sobj->sections; section != NULL; section = section->next)
 735     {
 736       size_t mask;
 737       size_t new_offset;
 738       size_t scnsize;
 739       struct simple_object_write_section_buffer *buffer;
 740
 741       mask = (1U << section->align) - 1;
 742       new_offset = offset & mask;
 743       new_offset &= ~ mask;
 744       while (new_offset > offset)
 745         {
 746           unsigned char zeroes[16];
 747           size_t write;
 748
 749           memset (zeroes, 0, sizeof zeroes);
 750           write = new_offset - offset;
 751           if (write > sizeof zeroes)
 752             write = sizeof zeroes;
 753           if (!simple_object_internal_write (descriptor, offset, zeroes, write,
 754                                              &errmsg, err))
 755             return errmsg;
 756         }
 757
 758       scnsize = 0;
 759       for (buffer = section->buffers; buffer != NULL; buffer = buffer->next)
 760         {
 761           if (!simple_object_internal_write (descriptor, offset + scnsize,
 762                                              ((const unsigned char *)
 763                                               buffer->buffer),
 764                                              buffer->size, &errmsg, err))
 765             return errmsg;
 766           scnsize += buffer->size;
 767         }
 768
 769       if (!simple_object_xcoff_write_scnhdr (sobj, descriptor, section->name,
 770                                             &name_offset, scnhdr_offset,
 771                                             scnsize, offset, section->align,
 772                                             &errmsg, err))
 773         return errmsg;
 774
 775       scnhdr_offset += u64 ? SCNHSZ64 : SCNHSZ32;
 776       offset += scnsize;
 777     }
 778
 779   /* Symbol table is always half-word aligned.  */
 780   offset += (offset & 1);
 781   /* There is a file symbol and a section symbol per section,
 782      and each of these has a single auxiliary symbol following.  */
 783   nsyms = 2 * (nscns + 1);
 784   symtab_offset = offset;
 785   /* Advance across space reserved for symbol table to locate
 786      start of string table.  */
 787   offset += nsyms * SYMESZ;
 788
 789   /* Write out file symbol.  */
 790   memset (&syms[0], 0, sizeof (syms));
 791   if (!u64)
 792     strcpy ((char *)&syms[0].sym.u.xcoff32.n.n_name[0], ".file");
 793   set_16 (&syms[0].sym.n_scnum[0], N_DEBUG);
 794   set_16 (&syms[0].sym.n_type[0], IMAGE_SYM_TYPE);
 795   syms[0].sym.n_sclass[0] = C_FILE;
 796   syms[0].sym.n_numaux[0] = 1;
 797   /* The name need not be nul-terminated if it fits into the x_fname field
 798      directly, but must be if it has to be placed into the string table.  */
 799   sflen = strlen (source_filename);
 800   if (sflen <= FILNMLEN)
 801     memcpy (&syms[1].aux.x_file.x_fname[0], source_filename, sflen);
 802   else
 803     {
 804       set_32 (&syms[1].aux.x_file._x.x_offset[0], name_offset);
 805       if (!simple_object_internal_write (descriptor, offset + name_offset,
 806                                          ((const unsigned char *)
 807                                           source_filename),
 808                                          sflen + 1, &errmsg, err))
 809         return errmsg;
 810       name_offset += strlen (source_filename) + 1;
 811     }
 812   if (!simple_object_internal_write (descriptor, symtab_offset,
 813                                      (const unsigned char *) &syms[0],
 814                                      sizeof (syms), &errmsg, err))
 815     return errmsg;
 816
 817   /* Write the string table length, followed by the strings and section
 818      symbols in step with each other.  */
 819   set_32 (strsizebuf, name_offset);
 820   if (!simple_object_internal_write (descriptor, offset, strsizebuf, 4,
 821                                      &errmsg, err))
 822     return errmsg;
 823
 824   name_offset = 4;
 825   secsym_offset = symtab_offset + sizeof (syms);
 826   memset (&syms[0], 0, sizeof (syms));
 827   set_16 (&syms[0].sym.n_type[0], IMAGE_SYM_TYPE);
 828   syms[0].sym.n_sclass[0] = C_STAT;
 829   syms[0].sym.n_numaux[0] = 1;
 830   secnum = 1;
 831
 832   for (section = sobj->sections; section != NULL; section = section->next)
 833     {
 834       size_t namelen;
 835       size_t scnsize;
 836       struct simple_object_write_section_buffer *buffer;
 837
 838       namelen = strlen (section->name);
 839       set_16 (&syms[0].sym.n_scnum[0], secnum++);
 840       scnsize = 0;
 841       for (buffer = section->buffers; buffer != NULL; buffer = buffer->next)
 842         scnsize += buffer->size;
 843       set_32 (&syms[1].aux.x_scn.x_scnlen[0], scnsize);
 844       if (namelen > SCNNMLEN)
 845         {
 846           set_32 (&syms[0].sym.u.xcoff32.n.n.n_zeroes[0], 0);
 847           set_32 (&syms[0].sym.u.xcoff32.n.n.n_offset[0], name_offset);
 848           if (!simple_object_internal_write (descriptor, offset + name_offset,
 849                                              ((const unsigned char *)
 850                                               section->name),
 851                                              namelen + 1, &errmsg, err))
 852             return errmsg;
 853           name_offset += namelen + 1;
 854         }
 855       else
 856         {
 857           memcpy (&syms[0].sym.u.xcoff32.n.n_name[0], section->name,
 858                   strlen (section->name));
 859           memset (&syms[0].sym.u.xcoff32.n.n_name[strlen (section->name)], 0,
 860                   N_SYMNMLEN - strlen (section->name));
 861         }
 862
 863       if (!simple_object_internal_write (descriptor, secsym_offset,
 864                                          (const unsigned char *) &syms[0],
 865                                          sizeof (syms), &errmsg, err))
 866         return errmsg;
 867       secsym_offset += sizeof (syms);
 868     }
 869
 870   if (!simple_object_xcoff_write_filehdr (sobj, descriptor, nscns,
 871                                          symtab_offset, nsyms, &errmsg, err))
 872     return errmsg;
 873
 874   return NULL;
 875 }
 876
 877 /* Release the private data for an simple_object_write structure.  */
 878
 879 static void
 880 simple_object_xcoff_release_write (void *data)
 881 {
 882   XDELETE (data);
 883 }
 884
 885 /* The XCOFF functions.  */
 886
 887 const struct simple_object_functions simple_object_xcoff_functions =
 888 {
 889   simple_object_xcoff_match,
 890   simple_object_xcoff_find_sections,
 891   simple_object_xcoff_fetch_attributes,
 892   simple_object_xcoff_release_read,
 893   simple_object_xcoff_attributes_merge,
 894   simple_object_xcoff_release_attributes,
 895   simple_object_xcoff_start_write,
 896   simple_object_xcoff_write_to_file,
 897   simple_object_xcoff_release_write
 898 };