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