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