gcc/data-streamer-out.c

   1 /* Routines for saving various data types to a file stream.  This deals
   2    with various data types like strings, integers, enums, etc.
   3
   4    Copyright (C) 2011-2015 Free Software Foundation, Inc.
   5    Contributed by Diego Novillo <dnovillo@google.com>
   6
   7 This file is part of GCC.
   8
   9 GCC is free software; you can redistribute it and/or modify it under
  10 the terms of the GNU General Public License as published by the Free
  11 Software Foundation; either version 3, or (at your option) any later
  12 version.
  13
  14 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  15 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  16 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  17 for more details.
  18
  19 You should have received a copy of the GNU General Public License
  20 along with GCC; see the file COPYING3.  If not see
  21 <http://www.gnu.org/licenses/>.  */
  22
  23 #include "config.h"
  24 #include "system.h"
  25 #include "coretypes.h"
  26 #include "alias.h"
  27 #include "backend.h"
  28 #include "tree.h"
  29 #include "gimple.h"
  30 #include "hard-reg-set.h"
  31 #include "options.h"
  32 #include "fold-const.h"
  33 #include "internal-fn.h"
  34 #include "cgraph.h"
  35 #include "data-streamer.h"
  36
  37
  38 /* Adds a new block to output stream OBS.  */
  39
  40 void
  41 lto_append_block (struct lto_output_stream *obs)
  42 {
  43   struct lto_char_ptr_base *new_block;
  44
  45   gcc_assert (obs->left_in_block == 0);
  46
  47   if (obs->first_block == NULL)
  48     {
  49       /* This is the first time the stream has been written
  50          into.  */
  51       obs->block_size = 1024;
  52       new_block = (struct lto_char_ptr_base*) xmalloc (obs->block_size);
  53       obs->first_block = new_block;
  54     }
  55   else
  56     {
  57       struct lto_char_ptr_base *tptr;
  58       /* Get a new block that is twice as big as the last block
  59          and link it into the list.  */
  60       obs->block_size *= 2;
  61       new_block = (struct lto_char_ptr_base*) xmalloc (obs->block_size);
  62       /* The first bytes of the block are reserved as a pointer to
  63          the next block.  Set the chain of the full block to the
  64          pointer to the new block.  */
  65       tptr = obs->current_block;
  66       tptr->ptr = (char *) new_block;
  67     }
  68
  69   /* Set the place for the next char at the first position after the
  70      chain to the next block.  */
  71   obs->current_pointer
  72     = ((char *) new_block) + sizeof (struct lto_char_ptr_base);
  73   obs->current_block = new_block;
  74   /* Null out the newly allocated block's pointer to the next block.  */
  75   new_block->ptr = NULL;
  76   obs->left_in_block = obs->block_size - sizeof (struct lto_char_ptr_base);
  77 }
  78
  79
  80 /* Return index used to reference STRING of LEN characters in the string table
  81    in OB.  The string might or might not include a trailing '\0'.
  82    Then put the index onto the INDEX_STREAM.
  83    When PERSISTENT is set, the string S is supposed to not change during
  84    duration of the OB and thus OB can keep pointer into it.  */
  85
  86 static unsigned
  87 streamer_string_index (struct output_block *ob, const char *s, unsigned int len,
  88                        bool persistent)
  89 {
  90   struct string_slot **slot;
  91   struct string_slot s_slot;
  92
  93   s_slot.s = s;
  94   s_slot.len = len;
  95   s_slot.slot_num = 0;
  96
  97   slot = ob->string_hash_table->find_slot (&s_slot, INSERT);
  98   if (*slot == NULL)
  99     {
 100       struct lto_output_stream *string_stream = ob->string_stream;
 101       unsigned int start = string_stream->total_size;
 102       struct string_slot *new_slot = XOBNEW (&ob->obstack, struct string_slot);
 103       const char *string;
 104
 105       if (!persistent)
 106         {
 107           char *tmp;
 108           string = tmp = XOBNEWVEC (&ob->obstack, char, len);
 109           memcpy (tmp, s, len);
 110         }
 111       else
 112         string = s;
 113
 114       new_slot->s = string;
 115       new_slot->len = len;
 116       new_slot->slot_num = start;
 117       *slot = new_slot;
 118       streamer_write_uhwi_stream (string_stream, len);
 119       streamer_write_data_stream (string_stream, string, len);
 120       return start + 1;
 121     }
 122   else
 123     {
 124       struct string_slot *old_slot = *slot;
 125       return old_slot->slot_num + 1;
 126     }
 127 }
 128
 129
 130 /* Output STRING of LEN characters to the string table in OB. The
 131    string might or might not include a trailing '\0'. Then put the
 132    index onto the INDEX_STREAM.
 133    When PERSISTENT is set, the string S is supposed to not change during
 134    duration of the OB and thus OB can keep pointer into it.  */
 135
 136 void
 137 streamer_write_string_with_length (struct output_block *ob,
 138                                    struct lto_output_stream *index_stream,
 139                                    const char *s, unsigned int len,
 140                                    bool persistent)
 141 {
 142   if (s)
 143     streamer_write_uhwi_stream (index_stream,
 144                                 streamer_string_index (ob, s, len, persistent));
 145   else
 146     streamer_write_char_stream (index_stream, 0);
 147 }
 148
 149
 150 /* Output the '\0' terminated STRING to the string
 151    table in OB.  Then put the index onto the INDEX_STREAM.
 152    When PERSISTENT is set, the string S is supposed to not change during
 153    duration of the OB and thus OB can keep pointer into it.  */
 154
 155 void
 156 streamer_write_string (struct output_block *ob,
 157                        struct lto_output_stream *index_stream,
 158                        const char *string, bool persistent)
 159 {
 160   if (string)
 161     streamer_write_string_with_length (ob, index_stream, string,
 162                                        strlen (string) + 1,
 163                                        persistent);
 164   else
 165     streamer_write_char_stream (index_stream, 0);
 166 }
 167
 168
 169 /* Output STRING of LEN characters to the string table in OB.  Then
 170    put the index into BP.
 171    When PERSISTENT is set, the string S is supposed to not change during
 172    duration of the OB and thus OB can keep pointer into it.  */
 173
 174 void
 175 bp_pack_string_with_length (struct output_block *ob, struct bitpack_d *bp,
 176                             const char *s, unsigned int len, bool persistent)
 177 {
 178   unsigned index = 0;
 179   if (s)
 180     index = streamer_string_index (ob, s, len, persistent);
 181   bp_pack_var_len_unsigned (bp, index);
 182 }
 183
 184
 185 /* Output the '\0' terminated STRING to the string
 186    table in OB.  Then put the index onto the bitpack BP.
 187    When PERSISTENT is set, the string S is supposed to not change during
 188    duration of the OB and thus OB can keep pointer into it.  */
 189
 190 void
 191 bp_pack_string (struct output_block *ob, struct bitpack_d *bp,
 192                 const char *s, bool persistent)
 193 {
 194   unsigned index = 0;
 195   if (s)
 196     index = streamer_string_index (ob, s, strlen (s) + 1, persistent);
 197   bp_pack_var_len_unsigned (bp, index);
 198 }
 199
 200
 201
 202 /* Write a zero to the output stream.  */
 203
 204 void
 205 streamer_write_zero (struct output_block *ob)
 206 {
 207   streamer_write_char_stream (ob->main_stream, 0);
 208 }
 209
 210
 211 /* Write an unsigned HOST_WIDE_INT value WORK to OB->main_stream.  */
 212
 213 void
 214 streamer_write_uhwi (struct output_block *ob, unsigned HOST_WIDE_INT work)
 215 {
 216   streamer_write_uhwi_stream (ob->main_stream, work);
 217 }
 218
 219
 220 /* Write a HOST_WIDE_INT value WORK to OB->main_stream.  */
 221
 222 void
 223 streamer_write_hwi (struct output_block *ob, HOST_WIDE_INT work)
 224 {
 225   streamer_write_hwi_stream (ob->main_stream, work);
 226 }
 227
 228 /* Write a gcov counter value WORK to OB->main_stream.  */
 229
 230 void
 231 streamer_write_gcov_count (struct output_block *ob, gcov_type work)
 232 {
 233   streamer_write_gcov_count_stream (ob->main_stream, work);
 234 }
 235
 236 /* Write an unsigned HOST_WIDE_INT value WORK to OBS.  */
 237
 238 void
 239 streamer_write_uhwi_stream (struct lto_output_stream *obs,
 240                             unsigned HOST_WIDE_INT work)
 241 {
 242   if (obs->left_in_block == 0)
 243     lto_append_block (obs);
 244   char *current_pointer = obs->current_pointer;
 245   unsigned int left_in_block = obs->left_in_block;
 246   unsigned int size = 0;
 247   do
 248     {
 249       unsigned int byte = (work & 0x7f);
 250       work >>= 7;
 251       if (work != 0)
 252         /* More bytes to follow.  */
 253         byte |= 0x80;
 254
 255       *(current_pointer++) = byte;
 256       left_in_block--;
 257       size++;
 258     }
 259   while (work != 0 && left_in_block > 0);
 260   if (work != 0)
 261     {
 262       obs->left_in_block = 0;
 263       lto_append_block (obs);
 264       current_pointer = obs->current_pointer;
 265       left_in_block = obs->left_in_block;
 266       do
 267         {
 268           unsigned int byte = (work & 0x7f);
 269           work >>= 7;
 270           if (work != 0)
 271             /* More bytes to follow.  */
 272             byte |= 0x80;
 273
 274           *(current_pointer++) = byte;
 275           left_in_block--;
 276           size++;
 277         }
 278       while (work != 0);
 279     }
 280   obs->current_pointer = current_pointer;
 281   obs->left_in_block = left_in_block;
 282   obs->total_size += size;
 283 }
 284
 285
 286 /* Write a HOST_WIDE_INT value WORK to OBS.  */
 287
 288 void
 289 streamer_write_hwi_stream (struct lto_output_stream *obs, HOST_WIDE_INT work)
 290 {
 291   if (obs->left_in_block == 0)
 292     lto_append_block (obs);
 293   char *current_pointer = obs->current_pointer;
 294   unsigned int left_in_block = obs->left_in_block;
 295   unsigned int size = 0;
 296   bool more;
 297   do
 298     {
 299       unsigned int byte = (work & 0x7f);
 300       /* If the lower 7-bits are sign-extended 0 or -1 we are finished.  */
 301       work >>= 6;
 302       more = !(work == 0 || work == -1);
 303       if (more)
 304         {
 305           /* More bits to follow.  */
 306           work >>= 1;
 307           byte |= 0x80;
 308         }
 309
 310       *(current_pointer++) = byte;
 311       left_in_block--;
 312       size++;
 313     }
 314   while (more && left_in_block > 0);
 315   if (more)
 316     {
 317       obs->left_in_block = 0;
 318       lto_append_block (obs);
 319       current_pointer = obs->current_pointer;
 320       left_in_block = obs->left_in_block;
 321       do
 322         {
 323           unsigned int byte = (work & 0x7f);
 324           work >>= 6;
 325           more = !(work == 0 || work == -1);
 326           if (more)
 327             {
 328               work >>= 1;
 329               byte |= 0x80;
 330             }
 331
 332           *(current_pointer++) = byte;
 333           left_in_block--;
 334           size++;
 335         }
 336       while (more);
 337     }
 338   obs->current_pointer = current_pointer;
 339   obs->left_in_block = left_in_block;
 340   obs->total_size += size;
 341 }
 342
 343 /* Write a GCOV counter value WORK to OBS.  */
 344
 345 void
 346 streamer_write_gcov_count_stream (struct lto_output_stream *obs, gcov_type work)
 347 {
 348   gcc_assert (work >= 0);
 349   gcc_assert ((HOST_WIDE_INT) work == work);
 350   streamer_write_hwi_stream (obs, work);
 351 }
 352
 353 /* Write raw DATA of length LEN to the output block OB.  */
 354
 355 void
 356 streamer_write_data_stream (struct lto_output_stream *obs, const void *data,
 357                             size_t len)
 358 {
 359   while (len)
 360     {
 361       size_t copy;
 362
 363       /* No space left.  */
 364       if (obs->left_in_block == 0)
 365         lto_append_block (obs);
 366
 367       /* Determine how many bytes to copy in this loop.  */
 368       if (len <= obs->left_in_block)
 369         copy = len;
 370       else
 371         copy = obs->left_in_block;
 372
 373       /* Copy the data and do bookkeeping.  */
 374       memcpy (obs->current_pointer, data, copy);
 375       obs->current_pointer += copy;
 376       obs->total_size += copy;
 377       obs->left_in_block -= copy;
 378       data = (const char *) data + copy;
 379       len -= copy;
 380     }
 381 }
 382