libiberty/simple-object-common.h

   1 /* simple-object-common.h -- common structs for object file manipulation.
   2    Copyright (C) 2010 Free Software Foundation, Inc.
   3
   4 This file is part of the libiberty library.
   5 Libiberty is free software; you can redistribute it and/or
   6 modify it under the terms of the GNU Library General Public
   7 License as published by the Free Software Foundation; either
   8 version 2 of the License, or (at your option) any later version.
   9
  10 Libiberty 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 GNU
  13 Library General Public License for more details.
  14
  15 You should have received a copy of the GNU Library General Public
  16 License along with libiberty; see the file COPYING.LIB.  If not,
  17 write to the Free Software Foundation, Inc., 51 Franklin Street - Fifth Floor,
  18 Boston, MA 02110-1301, USA.  */
  19
  20 /* Forward reference.  */
  21 struct simple_object_functions;
  22
  23 /* An object file opened for reading.  */
  24
  25 struct simple_object_read_struct
  26 {
  27   /* The file descriptor.  */
  28   int descriptor;
  29   /* The offset within the file.  */
  30   off_t offset;
  31   /* The functions which do the actual work.  */
  32   const struct simple_object_functions *functions;
  33   /* Private data for the object file format.  */
  34   void *data;
  35 };
  36
  37 /* Object file attributes.  */
  38
  39 struct simple_object_attributes_struct
  40 {
  41   /* The functions which do the actual work.  */
  42   const struct simple_object_functions *functions;
  43   /* Private data for the object file format.  */
  44   void *data;
  45 };
  46
  47 /* An object file being created.  */
  48
  49 struct simple_object_write_struct
  50 {
  51   /* The functions which do the actual work.  */
  52   const struct simple_object_functions *functions;
  53   /* The segment_name argument from the user.  */
  54   char *segment_name;
  55   /* The start of the list of sections.  */
  56   simple_object_write_section *sections;
  57   /* The last entry in the list of sections.  */
  58   simple_object_write_section *last_section;
  59   /* Private data for the object file format.  */
  60   void *data;
  61 };
  62
  63 /* A section in an object file being created.  */
  64
  65 struct simple_object_write_section_struct
  66 {
  67   /* Next in the list of sections attached to an
  68      simple_object_write.  */
  69   simple_object_write_section *next;
  70   /* The name of this section.  */
  71   char *name;
  72   /* The required alignment.  */
  73   unsigned int align;
  74   /* The first data attached to this section.  */
  75   struct simple_object_write_section_buffer *buffers;
  76   /* The last data attached to this section.  */
  77   struct simple_object_write_section_buffer *last_buffer;
  78 };
  79
  80 /* Data attached to a section.  */
  81
  82 struct simple_object_write_section_buffer
  83 {
  84   /* The next data for this section.  */
  85   struct simple_object_write_section_buffer *next;
  86   /* The size of the buffer.  */
  87   size_t size;
  88   /* The actual bytes.  */
  89   const void *buffer;
  90   /* A buffer to free, or NULL.  */
  91   void *free_buffer;
  92 };
  93
  94 /* The number of bytes we read from the start of the file to pass to
  95    the match function.  */
  96 #define SIMPLE_OBJECT_MATCH_HEADER_LEN (16)
  97
  98 /* Format-specific object file functions.  */
  99
 100 struct simple_object_functions
 101 {
 102   /* If this file matches these functions, return a new value for the
 103      private data for an simple_object_read.  HEADER is the first 16
 104      bytes of the file.  DESCRIPTOR, OFFSET, SEGMENT_NAME, ERRMSG, and
 105      ERR are as for simple_object_open_read.  If this file does not
 106      match, this function should return NULL with *ERRMSG set to
 107      NULL.  */
 108   void *(*match) (unsigned char header[SIMPLE_OBJECT_MATCH_HEADER_LEN],
 109                   int descriptor, off_t offset, const char *segment_name,
 110                   const char **errmsg, int *err);
 111
 112   /* Implement simple_object_find_sections.  */
 113   const char *(*find_sections) (simple_object_read *,
 114                                 int (*pfn) (void *, const char *,
 115                                             off_t offset, off_t length),
 116                                 void *data,
 117                                 int *err);
 118
 119   /* Return the private data for the attributes for SOBJ.  */
 120   void *(*fetch_attributes) (simple_object_read *sobj, const char **errmsg,
 121                              int *err);
 122
 123   /* Release the private data for an simple_object_read.  */
 124   void (*release_read) (void *);
 125
 126   /* Merge the private data for the attributes of two files.  If they
 127      could be linked together, return NULL.  Otherwise return an error
 128      message.  */
 129   const char *(*attributes_merge) (void *, void *, int *err);
 130
 131   /* Release the private data for an simple_object_attributes.  */
 132   void (*release_attributes) (void *);
 133
 134   /* Start creating an object file.  */
 135   void *(*start_write) (void *attributes_data, const char **errmsg,
 136                         int *err);
 137
 138   /* Write the complete object file.  */
 139   const char *(*write_to_file) (simple_object_write *sobj, int descriptor,
 140                                 int *err);
 141
 142   /* Release the private data for an simple_object_write.  */
 143   void (*release_write) (void *);
 144 };
 145
 146 /* The known object file formats.  */
 147
 148 extern const struct simple_object_functions simple_object_coff_functions;
 149 extern const struct simple_object_functions simple_object_elf_functions;
 150 extern const struct simple_object_functions simple_object_mach_o_functions;
 151
 152 /* Read SIZE bytes from DESCRIPTOR at file offset OFFSET into BUFFER.
 153    Return non-zero on success.  On failure return 0 and set *ERRMSG
 154    and *ERR.  */
 155
 156 extern int
 157 simple_object_internal_read (int descriptor, off_t offset,
 158                              unsigned char *buffer, size_t size,
 159                              const char **errmsg, int *err);
 160
 161 /* Write SIZE bytes from BUFFER to DESCRIPTOR at file offset OFFSET.
 162    Return non-zero on success.  On failure return 0 and set *ERRMSG
 163    and *ERR.  */
 164
 165 extern int
 166 simple_object_internal_write (int descriptor, off_t offset,
 167                               const unsigned char *buffer, size_t size,
 168                               const char **errmsg, int *err);
 169
 170 /* Define ulong_type as an unsigned 64-bit type if available.
 171    Otherwise just make it unsigned long.  */
 172
 173 #ifdef UNSIGNED_64BIT_TYPE
 174 __extension__ typedef UNSIGNED_64BIT_TYPE ulong_type;
 175 #else
 176 typedef unsigned long ulong_type;
 177 #endif
 178
 179 /* Fetch a big-endian 16-bit value.  */
 180
 181 static inline unsigned short
 182 simple_object_fetch_big_16 (const unsigned char *buf)
 183 {
 184   return ((unsigned short) buf[0] << 8) | (unsigned short) buf[1];
 185 }
 186
 187 /* Fetch a little-endian 16-bit value.  */
 188
 189 static inline unsigned short
 190 simple_object_fetch_little_16 (const unsigned char *buf)
 191 {
 192   return ((unsigned short) buf[1] << 8) | (unsigned short) buf[0];
 193 }
 194
 195 /* Fetch a big-endian 32-bit value.  */
 196
 197 static inline unsigned int
 198 simple_object_fetch_big_32 (const unsigned char *buf)
 199 {
 200   return (((unsigned int) buf[0] << 24)
 201           | ((unsigned int) buf[1] << 16)
 202           | ((unsigned int) buf[2] << 8)
 203           | (unsigned int) buf[3]);
 204 }
 205
 206 /* Fetch a little-endian 32-bit value.  */
 207
 208 static inline unsigned int
 209 simple_object_fetch_little_32 (const unsigned char *buf)
 210 {
 211   return (((unsigned int) buf[3] << 24)
 212           | ((unsigned int) buf[2] << 16)
 213           | ((unsigned int) buf[1] << 8)
 214           | (unsigned int) buf[0]);
 215 }
 216
 217 /* Fetch a big-endian 32-bit value as a ulong_type.  */
 218
 219 static inline ulong_type
 220 simple_object_fetch_big_32_ulong (const unsigned char *buf)
 221 {
 222   return (ulong_type) simple_object_fetch_big_32 (buf);
 223 }
 224
 225 /* Fetch a little-endian 32-bit value as a ulong_type.  */
 226
 227 static inline ulong_type
 228 simple_object_fetch_little_32_ulong (const unsigned char *buf)
 229 {
 230   return (ulong_type) simple_object_fetch_little_32 (buf);
 231 }
 232
 233 #ifdef UNSIGNED_64BIT_TYPE
 234
 235 /* Fetch a big-endian 64-bit value.  */
 236
 237 static inline ulong_type
 238 simple_object_fetch_big_64 (const unsigned char *buf)
 239 {
 240   return (((ulong_type) buf[0] << 56)
 241           | ((ulong_type) buf[1] << 48)
 242           | ((ulong_type) buf[2] << 40)
 243           | ((ulong_type) buf[3] << 32)
 244           | ((ulong_type) buf[4] << 24)
 245           | ((ulong_type) buf[5] << 16)
 246           | ((ulong_type) buf[6] << 8)
 247           | (ulong_type) buf[7]);
 248 }
 249
 250 /* Fetch a little-endian 64-bit value.  */
 251
 252 static inline ulong_type
 253 simple_object_fetch_little_64 (const unsigned char *buf)
 254 {
 255   return (((ulong_type) buf[7] << 56)
 256           | ((ulong_type) buf[6] << 48)
 257           | ((ulong_type) buf[5] << 40)
 258           | ((ulong_type) buf[4] << 32)
 259           | ((ulong_type) buf[3] << 24)
 260           | ((ulong_type) buf[2] << 16)
 261           | ((ulong_type) buf[1] << 8)
 262           | (ulong_type) buf[0]);
 263 }
 264
 265 #endif
 266
 267 /* Store a big-endian 16-bit value.  */
 268
 269 static inline void
 270 simple_object_set_big_16 (unsigned char *buf, unsigned short val)
 271 {
 272   buf[0] = (val >> 8) & 0xff;
 273   buf[1] = val & 0xff;
 274 }
 275
 276 /* Store a little-endian 16-bit value.  */
 277
 278 static inline void
 279 simple_object_set_little_16 (unsigned char *buf, unsigned short val)
 280 {
 281   buf[1] = (val >> 8) & 0xff;
 282   buf[0] = val & 0xff;
 283 }
 284
 285 /* Store a big-endian 32-bit value.  */
 286
 287 static inline void
 288 simple_object_set_big_32 (unsigned char *buf, unsigned int val)
 289 {
 290   buf[0] = (val >> 24) & 0xff;
 291   buf[1] = (val >> 16) & 0xff;
 292   buf[2] = (val >> 8) & 0xff;
 293   buf[3] = val & 0xff;
 294 }
 295
 296 /* Store a little-endian 32-bit value.  */
 297
 298 static inline void
 299 simple_object_set_little_32 (unsigned char *buf, unsigned int val)
 300 {
 301   buf[3] = (val >> 24) & 0xff;
 302   buf[2] = (val >> 16) & 0xff;
 303   buf[1] = (val >> 8) & 0xff;
 304   buf[0] = val & 0xff;
 305 }
 306
 307 /* Store a big-endian 32-bit value coming in as a ulong_type.  */
 308
 309 static inline void
 310 simple_object_set_big_32_ulong (unsigned char *buf, ulong_type val)
 311 {
 312   simple_object_set_big_32 (buf, val);
 313 }
 314
 315 /* Store a little-endian 32-bit value coming in as a ulong_type.  */
 316
 317 static inline void
 318 simple_object_set_little_32_ulong (unsigned char *buf, ulong_type val)
 319 {
 320   simple_object_set_little_32 (buf, val);
 321 }
 322
 323 #ifdef UNSIGNED_64BIT_TYPE
 324
 325 /* Store a big-endian 64-bit value.  */
 326
 327 static inline void
 328 simple_object_set_big_64 (unsigned char *buf, ulong_type val)
 329 {
 330   buf[0] = (val >> 56) & 0xff;
 331   buf[1] = (val >> 48) & 0xff;
 332   buf[2] = (val >> 40) & 0xff;
 333   buf[3] = (val >> 32) & 0xff;
 334   buf[4] = (val >> 24) & 0xff;
 335   buf[5] = (val >> 16) & 0xff;
 336   buf[6] = (val >> 8) & 0xff;
 337   buf[7] = val & 0xff;
 338 }
 339
 340 /* Store a little-endian 64-bit value.  */
 341
 342 static inline void
 343 simple_object_set_little_64 (unsigned char *buf, ulong_type val)
 344 {
 345   buf[7] = (val >> 56) & 0xff;
 346   buf[6] = (val >> 48) & 0xff;
 347   buf[5] = (val >> 40) & 0xff;
 348   buf[4] = (val >> 32) & 0xff;
 349   buf[3] = (val >> 24) & 0xff;
 350   buf[2] = (val >> 16) & 0xff;
 351   buf[1] = (val >> 8) & 0xff;
 352   buf[0] = val & 0xff;
 353 }
 354
 355 #endif