gcc/lto-section-in.c

   1 /* Input functions for reading LTO sections.
   2
   3    Copyright (C) 2009-2015 Free Software Foundation, Inc.
   4    Contributed by Kenneth Zadeck <zadeck@naturalbridge.com>
   5
   6 This file is part of GCC.
   7
   8 GCC is free software; you can redistribute it and/or modify it under
   9 the terms of the GNU General Public License as published by the Free
  10 Software Foundation; either version 3, or (at your option) any later
  11 version.
  12
  13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  15 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  16 for more details.
  17
  18 You should have received a copy of the GNU General Public License
  19 along with GCC; see the file COPYING3.  If not see
  20 <http://www.gnu.org/licenses/>.  */
  21
  22 #include "config.h"
  23 #include "system.h"
  24 #include "coretypes.h"
  25 #include "tm.h"
  26 #include "hash-set.h"
  27 #include "machmode.h"
  28 #include "vec.h"
  29 #include "double-int.h"
  30 #include "input.h"
  31 #include "alias.h"
  32 #include "symtab.h"
  33 #include "wide-int.h"
  34 #include "inchash.h"
  35 #include "tree.h"
  36 #include "fold-const.h"
  37 #include "predict.h"
  38 #include "hard-reg-set.h"
  39 #include "function.h"
  40 #include "basic-block.h"
  41 #include "tree-ssa-alias.h"
  42 #include "internal-fn.h"
  43 #include "gimple-expr.h"
  44 #include "is-a.h"
  45 #include "gimple.h"
  46 #include "hashtab.h"
  47 #include "rtl.h"
  48 #include "flags.h"
  49 #include "statistics.h"
  50 #include "real.h"
  51 #include "fixed-value.h"
  52 #include "insn-config.h"
  53 #include "expmed.h"
  54 #include "dojump.h"
  55 #include "explow.h"
  56 #include "calls.h"
  57 #include "emit-rtl.h"
  58 #include "varasm.h"
  59 #include "stmt.h"
  60 #include "expr.h"
  61 #include "params.h"
  62 #include "diagnostic-core.h"
  63 #include "except.h"
  64 #include "timevar.h"
  65 #include "hash-map.h"
  66 #include "plugin-api.h"
  67 #include "ipa-ref.h"
  68 #include "cgraph.h"
  69 #include "lto-streamer.h"
  70 #include "lto-compress.h"
  71
  72 /* Section names.  These must correspond to the values of
  73    enum lto_section_type.  */
  74 const char *lto_section_name[LTO_N_SECTION_TYPES] =
  75 {
  76   "decls",
  77   "function_body",
  78   "statics",
  79   "symtab",
  80   "refs",
  81   "asm",
  82   "jmpfuncs",
  83   "pureconst",
  84   "reference",
  85   "profile",
  86   "symbol_nodes",
  87   "opts",
  88   "cgraphopt",
  89   "inline",
  90   "ipcp_trans",
  91   "icf",
  92   "offload_table"
  93 };
  94
  95
  96 /* Hooks so that the ipa passes can call into the lto front end to get
  97    sections.  */
  98
  99 static struct lto_file_decl_data ** file_decl_data;
 100 static lto_get_section_data_f* get_section_f;
 101 static lto_free_section_data_f* free_section_f;
 102
 103
 104 /* This is called from the lto front end to set up the hooks that are
 105    used by the ipa passes to get the data that they will
 106    deserialize.  */
 107
 108 void
 109 lto_set_in_hooks (struct lto_file_decl_data ** data,
 110                   lto_get_section_data_f* get_f,
 111                   lto_free_section_data_f* free_f)
 112 {
 113   file_decl_data = data;
 114   get_section_f = get_f;
 115   free_section_f = free_f;
 116 }
 117
 118
 119 /* Return an array of file decl datas for all of the files passed to
 120    this compilation.  */
 121
 122 struct lto_file_decl_data **
 123 lto_get_file_decl_data (void)
 124 {
 125   gcc_assert (file_decl_data);
 126   return file_decl_data;
 127 }
 128
 129 /* Buffer structure for accumulating data from compression callbacks.  */
 130
 131 struct lto_buffer
 132 {
 133   char *data;
 134   size_t length;
 135 };
 136
 137 /* Compression callback, append LENGTH bytes from DATA to the buffer pointed
 138    to by OPAQUE.  */
 139
 140 static void
 141 lto_append_data (const char *data, unsigned length, void *opaque)
 142 {
 143   struct lto_buffer *buffer = (struct lto_buffer *) opaque;
 144
 145   buffer->data = (char *) xrealloc (buffer->data, buffer->length + length);
 146   memcpy (buffer->data + buffer->length, data, length);
 147   buffer->length += length;
 148 }
 149
 150 /* Header placed in returned uncompressed data streams.  Allows the
 151    uncompressed allocated data to be mapped back to the underlying
 152    compressed data for use with free_section_f.  */
 153
 154 struct lto_data_header
 155 {
 156   const char *data;
 157   size_t len;
 158 };
 159
 160 /* Return a char pointer to the start of a data stream for an LTO pass
 161    or function.  FILE_DATA indicates where to obtain the data.
 162    SECTION_TYPE is the type of information to be obtained.  NAME is
 163    the name of the function and is only used when finding a function
 164    body; otherwise it is NULL.  LEN is the size of the data
 165    returned.  */
 166
 167 const char *
 168 lto_get_section_data (struct lto_file_decl_data *file_data,
 169                       enum lto_section_type section_type,
 170                       const char *name,
 171                       size_t *len)
 172 {
 173   const char *data = (get_section_f) (file_data, section_type, name, len);
 174   const size_t header_length = sizeof (struct lto_data_header);
 175   struct lto_data_header *header;
 176   struct lto_buffer buffer;
 177   struct lto_compression_stream *stream;
 178   lto_stats.section_size[section_type] += *len;
 179
 180   if (data == NULL)
 181     return NULL;
 182
 183   /* FIXME lto: WPA mode does not write compressed sections, so for now
 184      suppress uncompression if flag_ltrans.  */
 185   if (!flag_ltrans)
 186     {
 187       /* Create a mapping header containing the underlying data and length,
 188          and prepend this to the uncompression buffer.  The uncompressed data
 189          then follows, and a pointer to the start of the uncompressed data is
 190          returned.  */
 191       header = (struct lto_data_header *) xmalloc (header_length);
 192       header->data = data;
 193       header->len = *len;
 194
 195       buffer.data = (char *) header;
 196       buffer.length = header_length;
 197
 198       stream = lto_start_uncompression (lto_append_data, &buffer);
 199       lto_uncompress_block (stream, data, *len);
 200       lto_end_uncompression (stream);
 201
 202       *len = buffer.length - header_length;
 203       data = buffer.data + header_length;
 204     }
 205
 206   lto_check_version (((const lto_header *)data)->major_version,
 207                      ((const lto_header *)data)->minor_version);
 208   return data;
 209 }
 210
 211
 212 /* Free the data found from the above call.  The first three
 213    parameters are the same as above.  DATA is the data to be freed and
 214    LEN is the length of that data.  */
 215
 216 void
 217 lto_free_section_data (struct lto_file_decl_data *file_data,
 218                        enum lto_section_type section_type,
 219                        const char *name,
 220                        const char *data,
 221                        size_t len)
 222 {
 223   const size_t header_length = sizeof (struct lto_data_header);
 224   const char *real_data = data - header_length;
 225   const struct lto_data_header *header
 226     = (const struct lto_data_header *) real_data;
 227
 228   gcc_assert (free_section_f);
 229
 230   /* FIXME lto: WPA mode does not write compressed sections, so for now
 231      suppress uncompression mapping if flag_ltrans.  */
 232   if (flag_ltrans)
 233     {
 234       (free_section_f) (file_data, section_type, name, data, len);
 235       return;
 236     }
 237
 238   /* The underlying data address has been extracted from the mapping header.
 239      Free that, then free the allocated uncompression buffer.  */
 240   (free_section_f) (file_data, section_type, name, header->data, header->len);
 241   free (CONST_CAST (char *, real_data));
 242 }
 243
 244
 245 /* Load a section of type SECTION_TYPE from FILE_DATA, parse the
 246    header and then return an input block pointing to the section.  The
 247    raw pointer to the section is returned in DATAR and LEN.  These are
 248    used to free the section.  Return NULL if the section is not present.  */
 249
 250 struct lto_input_block *
 251 lto_create_simple_input_block (struct lto_file_decl_data *file_data,
 252                                enum lto_section_type section_type,
 253                                const char **datar, size_t *len)
 254 {
 255   const char *data = lto_get_section_data (file_data, section_type, NULL, len);
 256   const struct lto_simple_header * header
 257     = (const struct lto_simple_header *) data;
 258
 259   int main_offset = sizeof (struct lto_simple_header);
 260
 261   if (!data)
 262     return NULL;
 263
 264   *datar = data;
 265   return new lto_input_block (data + main_offset, header->main_size);
 266 }
 267
 268
 269 /* Close the section returned from a call to
 270    LTO_CREATE_SIMPLE_INPUT_BLOCK.  IB is the input block returned from
 271    that call.  The FILE_DATA and SECTION_TYPE are the same as what was
 272    passed to that call and the DATA and LEN are what was returned from
 273    that call.  */
 274
 275 void
 276 lto_destroy_simple_input_block (struct lto_file_decl_data *file_data,
 277                                 enum lto_section_type section_type,
 278                                 struct lto_input_block *ib,
 279                                 const char *data, size_t len)
 280 {
 281   delete ib;
 282   lto_free_section_data (file_data, section_type, NULL, data, len);
 283 }
 284
 285 /*****************************************************************************/
 286 /* Record renamings of static declarations                                   */
 287 /*****************************************************************************/
 288
 289 struct lto_renaming_slot
 290 {
 291   const char *old_name;
 292   const char *new_name;
 293 };
 294
 295 /* Returns a hash code for P.  */
 296
 297 static hashval_t
 298 hash_name (const void *p)
 299 {
 300   const struct lto_renaming_slot *ds = (const struct lto_renaming_slot *) p;
 301   return (hashval_t) htab_hash_string (ds->new_name);
 302 }
 303
 304 /* Returns nonzero if P1 and P2 are equal.  */
 305
 306 static int
 307 eq_name (const void *p1, const void *p2)
 308 {
 309   const struct lto_renaming_slot *s1 =
 310     (const struct lto_renaming_slot *) p1;
 311   const struct lto_renaming_slot *s2 =
 312     (const struct lto_renaming_slot *) p2;
 313
 314   return strcmp (s1->new_name, s2->new_name) == 0;
 315 }
 316
 317 /* Free a renaming table entry.  */
 318
 319 static void
 320 renaming_slot_free (void *slot)
 321 {
 322   struct lto_renaming_slot *s = (struct lto_renaming_slot *) slot;
 323
 324   free (CONST_CAST (void *, (const void *) s->old_name));
 325   free (CONST_CAST (void *, (const void *) s->new_name));
 326   free ((void *) s);
 327 }
 328
 329 /* Create an empty hash table for recording declaration renamings.  */
 330
 331 htab_t
 332 lto_create_renaming_table (void)
 333 {
 334   return htab_create (37, hash_name, eq_name, renaming_slot_free);
 335 }
 336
 337 /* Record a declaration name mapping OLD_NAME -> NEW_NAME.  DECL_DATA
 338    holds the renaming hash table to use.  */
 339
 340 void
 341 lto_record_renamed_decl (struct lto_file_decl_data *decl_data,
 342                          const char *old_name, const char *new_name)
 343 {
 344   void **slot;
 345   struct lto_renaming_slot r_slot;
 346
 347   r_slot.new_name = new_name;
 348   slot = htab_find_slot (decl_data->renaming_hash_table, &r_slot, INSERT);
 349   if (*slot == NULL)
 350     {
 351       struct lto_renaming_slot *new_slot = XNEW (struct lto_renaming_slot);
 352       new_slot->old_name = xstrdup (old_name);
 353       new_slot->new_name = xstrdup (new_name);
 354       *slot = new_slot;
 355     }
 356   else
 357     gcc_unreachable ();
 358 }
 359
 360
 361 /* Given a string NAME, return the string that it has been mapped to
 362    by lto_record_renamed_decl.  If NAME was not renamed, it is
 363    returned unchanged.  DECL_DATA holds the renaming hash table to use.  */
 364
 365 const char *
 366 lto_get_decl_name_mapping (struct lto_file_decl_data *decl_data,
 367                            const char *name)
 368 {
 369   htab_t renaming_hash_table = decl_data->renaming_hash_table;
 370   struct lto_renaming_slot *slot;
 371   struct lto_renaming_slot r_slot;
 372
 373   r_slot.new_name = name;
 374   slot = (struct lto_renaming_slot *) htab_find (renaming_hash_table, &r_slot);
 375   if (slot)
 376     return slot->old_name;
 377   else
 378     return name;
 379 }
 380
 381 /*****************************************************************************/
 382 /* Input decl state object.                                                  */
 383 /*****************************************************************************/
 384
 385 /* Return a newly created in-decl state object. */
 386
 387 struct lto_in_decl_state *
 388 lto_new_in_decl_state (void)
 389 {
 390   return ggc_cleared_alloc<lto_in_decl_state> ();
 391 }
 392
 393 /* Delete STATE and its components. */
 394
 395 void
 396 lto_delete_in_decl_state (struct lto_in_decl_state *state)
 397 {
 398   int i;
 399
 400   for (i = 0; i < LTO_N_DECL_STREAMS; i++)
 401     vec_free (state->streams[i]);
 402   ggc_free (state);
 403 }
 404
 405 /* Search the in-decl state of a function FUNC contained in the file
 406    associated with FILE_DATA.  Return NULL if not found.  */
 407
 408 struct lto_in_decl_state*
 409 lto_get_function_in_decl_state (struct lto_file_decl_data *file_data,
 410                                 tree func)
 411 {
 412   struct lto_in_decl_state temp;
 413   lto_in_decl_state **slot;
 414
 415   temp.fn_decl = func;
 416   slot = file_data->function_decl_states->find_slot (&temp, NO_INSERT);
 417   return slot? *slot : NULL;
 418 }
 419
 420 /* Free decl_states.  */
 421
 422 void
 423 lto_free_function_in_decl_state (struct lto_in_decl_state *state)
 424 {
 425   int i;
 426   for (i = 0; i < LTO_N_DECL_STREAMS; i++)
 427     vec_free (state->streams[i]);
 428   ggc_free (state);
 429 }
 430
 431 /* Free decl_states associated with NODE.  This makes it possible to furhter
 432    release trees needed by the NODE's body.  */
 433
 434 void
 435 lto_free_function_in_decl_state_for_node (symtab_node *node)
 436 {
 437   struct lto_in_decl_state temp;
 438   lto_in_decl_state **slot;
 439
 440   if (!node->lto_file_data)
 441     return;
 442
 443   temp.fn_decl = node->decl;
 444   slot
 445     = node->lto_file_data->function_decl_states->find_slot (&temp, NO_INSERT);
 446   if (slot && *slot)
 447     {
 448       lto_free_function_in_decl_state (*slot);
 449       node->lto_file_data->function_decl_states->clear_slot (slot);
 450     }
 451   node->lto_file_data = NULL;
 452 }
 453
 454
 455 /* Report read pass end of the section.  */
 456
 457 void
 458 lto_section_overrun (struct lto_input_block *ib)
 459 {
 460   fatal_error (input_location, "bytecode stream: trying to read %d bytes "
 461                "after the end of the input buffer", ib->p - ib->len);
 462 }
 463
 464 /* Report out of range value.  */
 465
 466 void
 467 lto_value_range_error (const char *purpose, HOST_WIDE_INT val,
 468                        HOST_WIDE_INT min, HOST_WIDE_INT max)
 469 {
 470   fatal_error (input_location,
 471                "%s out of range: Range is %i to %i, value is %i",
 472                purpose, (int)min, (int)max, (int)val);
 473 }