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) 2011-2018 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 "backend.h"
  27 #include "tree.h"
  28 #include "gimple.h"
  29 #include "cgraph.h"
  30 #include "data-streamer.h"
  31
  32
  33 /* Adds a new block to output stream OBS.  */
  34
  35 void
  36 lto_append_block (struct lto_output_stream *obs)
  37 {
  38   struct lto_char_ptr_base *new_block;
  39
  40   gcc_assert (obs->left_in_block == 0);
  41
  42   if (obs->first_block == NULL)
  43     {
  44       /* This is the first time the stream has been written
  45          into.  */
  46       obs->block_size = 1024;
  47       new_block = (struct lto_char_ptr_base*) xmalloc (obs->block_size);
  48       obs->first_block = new_block;
  49     }
  50   else
  51     {
  52       struct lto_char_ptr_base *tptr;
  53       /* Get a new block that is twice as big as the last block
  54          and link it into the list.  */
  55       obs->block_size *= 2;
  56       new_block = (struct lto_char_ptr_base*) xmalloc (obs->block_size);
  57       /* The first bytes of the block are reserved as a pointer to
  58          the next block.  Set the chain of the full block to the
  59          pointer to the new block.  */
  60       tptr = obs->current_block;
  61       tptr->ptr = (char *) new_block;
  62     }
  63
  64   /* Set the place for the next char at the first position after the
  65      chain to the next block.  */
  66   obs->current_pointer
  67     = ((char *) new_block) + sizeof (struct lto_char_ptr_base);
  68   obs->current_block = new_block;
  69   /* Null out the newly allocated block's pointer to the next block.  */
  70   new_block->ptr = NULL;
  71   obs->left_in_block = obs->block_size - sizeof (struct lto_char_ptr_base);
  72 }
  73
  74
  75 /* Return index used to reference STRING of LEN characters in the string table
  76    in OB.  The string might or might not include a trailing '\0'.
  77    Then put the index onto the INDEX_STREAM.
  78    When PERSISTENT is set, the string S is supposed to not change during
  79    duration of the OB and thus OB can keep pointer into it.  */
  80
  81 static unsigned
  82 streamer_string_index (struct output_block *ob, const char *s, unsigned int len,
  83                        bool persistent)
  84 {
  85   struct string_slot **slot;
  86   struct string_slot s_slot;
  87
  88   s_slot.s = s;
  89   s_slot.len = len;
  90   s_slot.slot_num = 0;
  91
  92   slot = ob->string_hash_table->find_slot (&s_slot, INSERT);
  93   if (*slot == NULL)
  94     {
  95       struct lto_output_stream *string_stream = ob->string_stream;
  96       unsigned int start = string_stream->total_size;
  97       struct string_slot *new_slot = XOBNEW (&ob->obstack, struct string_slot);
  98       const char *string;
  99
 100       if (!persistent)
 101         {
 102           char *tmp;
 103           string = tmp = XOBNEWVEC (&ob->obstack, char, len);
 104           memcpy (tmp, s, len);
 105         }
 106       else
 107         string = s;
 108
 109       new_slot->s = string;
 110       new_slot->len = len;
 111       new_slot->slot_num = start;
 112       *slot = new_slot;
 113       streamer_write_uhwi_stream (string_stream, len);
 114       streamer_write_data_stream (string_stream, string, len);
 115       return start + 1;
 116     }
 117   else
 118     {
 119       struct string_slot *old_slot = *slot;
 120       return old_slot->slot_num + 1;
 121     }
 122 }
 123
 124
 125 /* Output STRING of LEN characters to the string table in OB. The
 126    string might or might not include a trailing '\0'. Then put the
 127    index onto the INDEX_STREAM.
 128    When PERSISTENT is set, the string S is supposed to not change during
 129    duration of the OB and thus OB can keep pointer into it.  */
 130
 131 void
 132 streamer_write_string_with_length (struct output_block *ob,
 133                                    struct lto_output_stream *index_stream,
 134                                    const char *s, unsigned int len,
 135                                    bool persistent)
 136 {
 137   if (s)
 138     streamer_write_uhwi_stream (index_stream,
 139                                 streamer_string_index (ob, s, len, persistent));
 140   else
 141     streamer_write_char_stream (index_stream, 0);
 142 }
 143
 144
 145 /* Output the '\0' terminated STRING to the string
 146    table in OB.  Then put the index onto the INDEX_STREAM.
 147    When PERSISTENT is set, the string S is supposed to not change during
 148    duration of the OB and thus OB can keep pointer into it.  */
 149
 150 void
 151 streamer_write_string (struct output_block *ob,
 152                        struct lto_output_stream *index_stream,
 153                        const char *string, bool persistent)
 154 {
 155   if (string)
 156     streamer_write_string_with_length (ob, index_stream, string,
 157                                        strlen (string) + 1,
 158                                        persistent);
 159   else
 160     streamer_write_char_stream (index_stream, 0);
 161 }
 162
 163
 164 /* Output STRING of LEN characters to the string table in OB.  Then
 165    put the index into BP.
 166    When PERSISTENT is set, the string S is supposed to not change during
 167    duration of the OB and thus OB can keep pointer into it.  */
 168
 169 void
 170 bp_pack_string_with_length (struct output_block *ob, struct bitpack_d *bp,
 171                             const char *s, unsigned int len, bool persistent)
 172 {
 173   unsigned index = 0;
 174   if (s)
 175     index = streamer_string_index (ob, s, len, persistent);
 176   bp_pack_var_len_unsigned (bp, index);
 177 }
 178
 179
 180 /* Output the '\0' terminated STRING to the string
 181    table in OB.  Then put the index onto the bitpack BP.
 182    When PERSISTENT is set, the string S is supposed to not change during
 183    duration of the OB and thus OB can keep pointer into it.  */
 184
 185 void
 186 bp_pack_string (struct output_block *ob, struct bitpack_d *bp,
 187                 const char *s, bool persistent)
 188 {
 189   unsigned index = 0;
 190   if (s)
 191     index = streamer_string_index (ob, s, strlen (s) + 1, persistent);
 192   bp_pack_var_len_unsigned (bp, index);
 193 }
 194
 195
 196
 197 /* Write a zero to the output stream.  */
 198
 199 void
 200 streamer_write_zero (struct output_block *ob)
 201 {
 202   streamer_write_char_stream (ob->main_stream, 0);
 203 }
 204
 205
 206 /* Write an unsigned HOST_WIDE_INT value WORK to OB->main_stream.  */
 207
 208 void
 209 streamer_write_uhwi (struct output_block *ob, unsigned HOST_WIDE_INT work)
 210 {
 211   streamer_write_uhwi_stream (ob->main_stream, work);
 212 }
 213
 214
 215 /* Write a HOST_WIDE_INT value WORK to OB->main_stream.  */
 216
 217 void
 218 streamer_write_hwi (struct output_block *ob, HOST_WIDE_INT work)
 219 {
 220   streamer_write_hwi_stream (ob->main_stream, work);
 221 }
 222
 223 /* Write a gcov counter value WORK to OB->main_stream.  */
 224
 225 void
 226 streamer_write_gcov_count (struct output_block *ob, gcov_type work)
 227 {
 228   streamer_write_gcov_count_stream (ob->main_stream, work);
 229 }
 230
 231 /* Write an unsigned HOST_WIDE_INT value WORK to OBS.  */
 232
 233 void
 234 streamer_write_uhwi_stream (struct lto_output_stream *obs,
 235                             unsigned HOST_WIDE_INT work)
 236 {
 237   if (obs->left_in_block == 0)
 238     lto_append_block (obs);
 239   char *current_pointer = obs->current_pointer;
 240   unsigned int left_in_block = obs->left_in_block;
 241   unsigned int size = 0;
 242   do
 243     {
 244       unsigned int byte = (work & 0x7f);
 245       work >>= 7;
 246       if (work != 0)
 247         /* More bytes to follow.  */
 248         byte |= 0x80;
 249
 250       *(current_pointer++) = byte;
 251       left_in_block--;
 252       size++;
 253     }
 254   while (work != 0 && left_in_block > 0);
 255   if (work != 0)
 256     {
 257       obs->left_in_block = 0;
 258       lto_append_block (obs);
 259       current_pointer = obs->current_pointer;
 260       left_in_block = obs->left_in_block;
 261       do
 262         {
 263           unsigned int byte = (work & 0x7f);
 264           work >>= 7;
 265           if (work != 0)
 266             /* More bytes to follow.  */
 267             byte |= 0x80;
 268
 269           *(current_pointer++) = byte;
 270           left_in_block--;
 271           size++;
 272         }
 273       while (work != 0);
 274     }
 275   obs->current_pointer = current_pointer;
 276   obs->left_in_block = left_in_block;
 277   obs->total_size += size;
 278 }
 279
 280
 281 /* Write a HOST_WIDE_INT value WORK to OBS.  */
 282
 283 void
 284 streamer_write_hwi_stream (struct lto_output_stream *obs, HOST_WIDE_INT work)
 285 {
 286   if (obs->left_in_block == 0)
 287     lto_append_block (obs);
 288   char *current_pointer = obs->current_pointer;
 289   unsigned int left_in_block = obs->left_in_block;
 290   unsigned int size = 0;
 291   bool more;
 292   do
 293     {
 294       unsigned int byte = (work & 0x7f);
 295       /* If the lower 7-bits are sign-extended 0 or -1 we are finished.  */
 296       work >>= 6;
 297       more = !(work == 0 || work == -1);
 298       if (more)
 299         {
 300           /* More bits to follow.  */
 301           work >>= 1;
 302           byte |= 0x80;
 303         }
 304
 305       *(current_pointer++) = byte;
 306       left_in_block--;
 307       size++;
 308     }
 309   while (more && left_in_block > 0);
 310   if (more)
 311     {
 312       obs->left_in_block = 0;
 313       lto_append_block (obs);
 314       current_pointer = obs->current_pointer;
 315       left_in_block = obs->left_in_block;
 316       do
 317         {
 318           unsigned int byte = (work & 0x7f);
 319           work >>= 6;
 320           more = !(work == 0 || work == -1);
 321           if (more)
 322             {
 323               work >>= 1;
 324               byte |= 0x80;
 325             }
 326
 327           *(current_pointer++) = byte;
 328           left_in_block--;
 329           size++;
 330         }
 331       while (more);
 332     }
 333   obs->current_pointer = current_pointer;
 334   obs->left_in_block = left_in_block;
 335   obs->total_size += size;
 336 }
 337
 338 /* Write a GCOV counter value WORK to OBS.  */
 339
 340 void
 341 streamer_write_gcov_count_stream (struct lto_output_stream *obs, gcov_type work)
 342 {
 343   gcc_assert ((HOST_WIDE_INT) work == work);
 344   streamer_write_hwi_stream (obs, work);
 345 }
 346
 347 /* Write raw DATA of length LEN to the output block OB.  */
 348
 349 void
 350 streamer_write_data_stream (struct lto_output_stream *obs, const void *data,
 351                             size_t len)
 352 {
 353   while (len)
 354     {
 355       size_t copy;
 356
 357       /* No space left.  */
 358       if (obs->left_in_block == 0)
 359         lto_append_block (obs);
 360
 361       /* Determine how many bytes to copy in this loop.  */
 362       if (len <= obs->left_in_block)
 363         copy = len;
 364       else
 365         copy = obs->left_in_block;
 366
 367       /* Copy the data and do bookkeeping.  */
 368       memcpy (obs->current_pointer, data, copy);
 369       obs->current_pointer += copy;
 370       obs->total_size += copy;
 371       obs->left_in_block -= copy;
 372       data = (const char *) data + copy;
 373       len -= copy;
 374     }
 375 }
 376
 377 /* Emit the physical representation of wide_int VAL to output block OB.  */
 378
 379 void
 380 streamer_write_wide_int (struct output_block *ob, const wide_int &val)
 381 {
 382   int len = val.get_len ();
 383
 384   streamer_write_uhwi (ob, val.get_precision ());
 385   streamer_write_uhwi (ob, len);
 386   for (int i = 0; i < len; i++)
 387     streamer_write_hwi (ob, val.elt (i));
 388 }
 389
 390 /* Emit the physical representation of widest_int W to output block OB.  */
 391
 392 void
 393 streamer_write_widest_int (struct output_block *ob,
 394                            const widest_int &w)
 395 {
 396   int len = w.get_len ();
 397
 398   streamer_write_uhwi (ob, w.get_precision ());
 399   streamer_write_uhwi (ob, len);
 400   for (int i = 0; i < len; i++)
 401     streamer_write_hwi (ob, w.elt (i));
 402 }
 403