gcc/lto-section-in.c

   1 /* Input functions for reading LTO sections.
   2
   3    Copyright (C) 2009-2014 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 "tree.h"
  27 #include "basic-block.h"
  28 #include "tree-ssa-alias.h"
  29 #include "internal-fn.h"
  30 #include "gimple-expr.h"
  31 #include "is-a.h"
  32 #include "gimple.h"
  33 #include "expr.h"
  34 #include "flags.h"
  35 #include "params.h"
  36 #include "input.h"
  37 #include "hashtab.h"
  38 #include "function.h"
  39 #include "diagnostic-core.h"
  40 #include "except.h"
  41 #include "timevar.h"
  42 #include "lto-streamer.h"
  43 #include "lto-compress.h"
  44
  45 /* Section names.  These must correspond to the values of
  46    enum lto_section_type.  */
  47 const char *lto_section_name[LTO_N_SECTION_TYPES] =
  48 {
  49   "decls",
  50   "function_body",
  51   "statics",
  52   "symtab",
  53   "refs",
  54   "asm",
  55   "jmpfuncs",
  56   "pureconst",
  57   "reference",
  58   "profile",
  59   "symbol_nodes",
  60   "opts",
  61   "cgraphopt",
  62   "inline",
  63   "ipcp_trans"
  64 };
  65
  66
  67 /* Hooks so that the ipa passes can call into the lto front end to get
  68    sections.  */
  69
  70 static struct lto_file_decl_data ** file_decl_data;
  71 static lto_get_section_data_f* get_section_f;
  72 static lto_free_section_data_f* free_section_f;
  73
  74
  75 /* This is called from the lto front end to set up the hooks that are
  76    used by the ipa passes to get the data that they will
  77    deserialize.  */
  78
  79 void
  80 lto_set_in_hooks (struct lto_file_decl_data ** data,
  81                   lto_get_section_data_f* get_f,
  82                   lto_free_section_data_f* free_f)
  83 {
  84   file_decl_data = data;
  85   get_section_f = get_f;
  86   free_section_f = free_f;
  87 }
  88
  89
  90 /* Return an array of file decl datas for all of the files passed to
  91    this compilation.  */
  92
  93 struct lto_file_decl_data **
  94 lto_get_file_decl_data (void)
  95 {
  96   gcc_assert (file_decl_data);
  97   return file_decl_data;
  98 }
  99
 100 /* Buffer structure for accumulating data from compression callbacks.  */
 101
 102 struct lto_buffer
 103 {
 104   char *data;
 105   size_t length;
 106 };
 107
 108 /* Compression callback, append LENGTH bytes from DATA to the buffer pointed
 109    to by OPAQUE.  */
 110
 111 static void
 112 lto_append_data (const char *data, unsigned length, void *opaque)
 113 {
 114   struct lto_buffer *buffer = (struct lto_buffer *) opaque;
 115
 116   buffer->data = (char *) xrealloc (buffer->data, buffer->length + length);
 117   memcpy (buffer->data + buffer->length, data, length);
 118   buffer->length += length;
 119 }
 120
 121 /* Header placed in returned uncompressed data streams.  Allows the
 122    uncompressed allocated data to be mapped back to the underlying
 123    compressed data for use with free_section_f.  */
 124
 125 struct lto_data_header
 126 {
 127   const char *data;
 128   size_t len;
 129 };
 130
 131 /* Return a char pointer to the start of a data stream for an LTO pass
 132    or function.  FILE_DATA indicates where to obtain the data.
 133    SECTION_TYPE is the type of information to be obtained.  NAME is
 134    the name of the function and is only used when finding a function
 135    body; otherwise it is NULL.  LEN is the size of the data
 136    returned.  */
 137
 138 const char *
 139 lto_get_section_data (struct lto_file_decl_data *file_data,
 140                       enum lto_section_type section_type,
 141                       const char *name,
 142                       size_t *len)
 143 {
 144   const char *data = (get_section_f) (file_data, section_type, name, len);
 145   const size_t header_length = sizeof (struct lto_data_header);
 146   struct lto_data_header *header;
 147   struct lto_buffer buffer;
 148   struct lto_compression_stream *stream;
 149   lto_stats.section_size[section_type] += *len;
 150
 151   if (data == NULL)
 152     return NULL;
 153
 154   /* FIXME lto: WPA mode does not write compressed sections, so for now
 155      suppress uncompression if flag_ltrans.  */
 156   if (!flag_ltrans)
 157     {
 158       /* Create a mapping header containing the underlying data and length,
 159          and prepend this to the uncompression buffer.  The uncompressed data
 160          then follows, and a pointer to the start of the uncompressed data is
 161          returned.  */
 162       header = (struct lto_data_header *) xmalloc (header_length);
 163       header->data = data;
 164       header->len = *len;
 165
 166       buffer.data = (char *) header;
 167       buffer.length = header_length;
 168
 169       stream = lto_start_uncompression (lto_append_data, &buffer);
 170       lto_uncompress_block (stream, data, *len);
 171       lto_end_uncompression (stream);
 172
 173       *len = buffer.length - header_length;
 174       data = buffer.data + header_length;
 175     }
 176
 177   lto_check_version (((const lto_header *)data)->major_version,
 178                      ((const lto_header *)data)->minor_version);
 179   return data;
 180 }
 181
 182
 183 /* Free the data found from the above call.  The first three
 184    parameters are the same as above.  DATA is the data to be freed and
 185    LEN is the length of that data.  */
 186
 187 void
 188 lto_free_section_data (struct lto_file_decl_data *file_data,
 189                        enum lto_section_type section_type,
 190                        const char *name,
 191                        const char *data,
 192                        size_t len)
 193 {
 194   const size_t header_length = sizeof (struct lto_data_header);
 195   const char *real_data = data - header_length;
 196   const struct lto_data_header *header
 197     = (const struct lto_data_header *) real_data;
 198
 199   gcc_assert (free_section_f);
 200
 201   /* FIXME lto: WPA mode does not write compressed sections, so for now
 202      suppress uncompression mapping if flag_ltrans.  */
 203   if (flag_ltrans)
 204     {
 205       (free_section_f) (file_data, section_type, name, data, len);
 206       return;
 207     }
 208
 209   /* The underlying data address has been extracted from the mapping header.
 210      Free that, then free the allocated uncompression buffer.  */
 211   (free_section_f) (file_data, section_type, name, header->data, header->len);
 212   free (CONST_CAST (char *, real_data));
 213 }
 214
 215
 216 /* Load a section of type SECTION_TYPE from FILE_DATA, parse the
 217    header and then return an input block pointing to the section.  The
 218    raw pointer to the section is returned in DATAR and LEN.  These are
 219    used to free the section.  Return NULL if the section is not present.  */
 220
 221 struct lto_input_block *
 222 lto_create_simple_input_block (struct lto_file_decl_data *file_data,
 223                                enum lto_section_type section_type,
 224                                const char **datar, size_t *len)
 225 {
 226   const char *data = lto_get_section_data (file_data, section_type, NULL, len);
 227   const struct lto_simple_header * header
 228     = (const struct lto_simple_header *) data;
 229
 230   int main_offset = sizeof (struct lto_simple_header);
 231
 232   if (!data)
 233     return NULL;
 234
 235   *datar = data;
 236   return new lto_input_block (data + main_offset, header->main_size);
 237 }
 238
 239
 240 /* Close the section returned from a call to
 241    LTO_CREATE_SIMPLE_INPUT_BLOCK.  IB is the input block returned from
 242    that call.  The FILE_DATA and SECTION_TYPE are the same as what was
 243    passed to that call and the DATA and LEN are what was returned from
 244    that call.  */
 245
 246 void
 247 lto_destroy_simple_input_block (struct lto_file_decl_data *file_data,
 248                                 enum lto_section_type section_type,
 249                                 struct lto_input_block *ib,
 250                                 const char *data, size_t len)
 251 {
 252   delete ib;
 253   lto_free_section_data (file_data, section_type, NULL, data, len);
 254 }
 255
 256 /*****************************************************************************/
 257 /* Record renamings of static declarations                                   */
 258 /*****************************************************************************/
 259
 260 struct lto_renaming_slot
 261 {
 262   const char *old_name;
 263   const char *new_name;
 264 };
 265
 266 /* Returns a hash code for P.  */
 267
 268 static hashval_t
 269 hash_name (const void *p)
 270 {
 271   const struct lto_renaming_slot *ds = (const struct lto_renaming_slot *) p;
 272   return (hashval_t) htab_hash_string (ds->new_name);
 273 }
 274
 275 /* Returns nonzero if P1 and P2 are equal.  */
 276
 277 static int
 278 eq_name (const void *p1, const void *p2)
 279 {
 280   const struct lto_renaming_slot *s1 =
 281     (const struct lto_renaming_slot *) p1;
 282   const struct lto_renaming_slot *s2 =
 283     (const struct lto_renaming_slot *) p2;
 284
 285   return strcmp (s1->new_name, s2->new_name) == 0;
 286 }
 287
 288 /* Free a renaming table entry.  */
 289
 290 static void
 291 renaming_slot_free (void *slot)
 292 {
 293   struct lto_renaming_slot *s = (struct lto_renaming_slot *) slot;
 294
 295   free (CONST_CAST (void *, (const void *) s->old_name));
 296   free (CONST_CAST (void *, (const void *) s->new_name));
 297   free ((void *) s);
 298 }
 299
 300 /* Create an empty hash table for recording declaration renamings.  */
 301
 302 htab_t
 303 lto_create_renaming_table (void)
 304 {
 305   return htab_create (37, hash_name, eq_name, renaming_slot_free);
 306 }
 307
 308 /* Record a declaration name mapping OLD_NAME -> NEW_NAME.  DECL_DATA
 309    holds the renaming hash table to use.  */
 310
 311 void
 312 lto_record_renamed_decl (struct lto_file_decl_data *decl_data,
 313                          const char *old_name, const char *new_name)
 314 {
 315   void **slot;
 316   struct lto_renaming_slot r_slot;
 317
 318   r_slot.new_name = new_name;
 319   slot = htab_find_slot (decl_data->renaming_hash_table, &r_slot, INSERT);
 320   if (*slot == NULL)
 321     {
 322       struct lto_renaming_slot *new_slot = XNEW (struct lto_renaming_slot);
 323       new_slot->old_name = xstrdup (old_name);
 324       new_slot->new_name = xstrdup (new_name);
 325       *slot = new_slot;
 326     }
 327   else
 328     gcc_unreachable ();
 329 }
 330
 331
 332 /* Given a string NAME, return the string that it has been mapped to
 333    by lto_record_renamed_decl.  If NAME was not renamed, it is
 334    returned unchanged.  DECL_DATA holds the renaming hash table to use.  */
 335
 336 const char *
 337 lto_get_decl_name_mapping (struct lto_file_decl_data *decl_data,
 338                            const char *name)
 339 {
 340   htab_t renaming_hash_table = decl_data->renaming_hash_table;
 341   struct lto_renaming_slot *slot;
 342   struct lto_renaming_slot r_slot;
 343
 344   r_slot.new_name = name;
 345   slot = (struct lto_renaming_slot *) htab_find (renaming_hash_table, &r_slot);
 346   if (slot)
 347     return slot->old_name;
 348   else
 349     return name;
 350 }
 351
 352 /*****************************************************************************/
 353 /* Input decl state object.                                                  */
 354 /*****************************************************************************/
 355
 356 /* Return a newly created in-decl state object. */
 357
 358 struct lto_in_decl_state *
 359 lto_new_in_decl_state (void)
 360 {
 361   return ggc_cleared_alloc<lto_in_decl_state> ();
 362 }
 363
 364 /* Delete STATE and its components. */
 365
 366 void
 367 lto_delete_in_decl_state (struct lto_in_decl_state *state)
 368 {
 369   int i;
 370
 371   for (i = 0; i < LTO_N_DECL_STREAMS; i++)
 372     if (state->streams[i].trees)
 373       ggc_free (state->streams[i].trees);
 374   ggc_free (state);
 375 }
 376
 377 /* Hashtable helpers. lto_in_decl_states are hash by their function decls. */
 378
 379 hashval_t
 380 lto_hash_in_decl_state (const void *p)
 381 {
 382   const struct lto_in_decl_state *state = (const struct lto_in_decl_state *) p;
 383   return htab_hash_pointer (state->fn_decl);
 384 }
 385
 386 /* Return true if the fn_decl field of the lto_in_decl_state pointed to by
 387    P1 equals to the function decl P2. */
 388
 389 int
 390 lto_eq_in_decl_state (const void *p1, const void *p2)
 391 {
 392   const struct lto_in_decl_state *state1 =
 393    (const struct lto_in_decl_state *) p1;
 394   const struct lto_in_decl_state *state2 =
 395    (const struct lto_in_decl_state *) p2;
 396   return state1->fn_decl == state2->fn_decl;
 397 }
 398
 399
 400 /* Search the in-decl state of a function FUNC contained in the file
 401    associated with FILE_DATA.  Return NULL if not found.  */
 402
 403 struct lto_in_decl_state*
 404 lto_get_function_in_decl_state (struct lto_file_decl_data *file_data,
 405                                 tree func)
 406 {
 407   struct lto_in_decl_state temp;
 408   void **slot;
 409
 410   temp.fn_decl = func;
 411   slot = htab_find_slot (file_data->function_decl_states, &temp, NO_INSERT);
 412   return slot? ((struct lto_in_decl_state*) *slot) : NULL;
 413 }
 414
 415 /* Free decl_states.  */
 416
 417 void
 418 lto_free_function_in_decl_state (struct lto_in_decl_state *state)
 419 {
 420   int i;
 421   for (i = 0; i < LTO_N_DECL_STREAMS; i++)
 422     ggc_free (state->streams[i].trees);
 423   ggc_free (state);
 424 }
 425
 426 /* Free decl_states associated with NODE.  This makes it possible to furhter
 427    release trees needed by the NODE's body.  */
 428
 429 void
 430 lto_free_function_in_decl_state_for_node (symtab_node *node)
 431 {
 432   struct lto_in_decl_state temp;
 433   void **slot;
 434
 435   if (!node->lto_file_data)
 436     return;
 437
 438   temp.fn_decl = node->decl;
 439   slot = htab_find_slot (node->lto_file_data->function_decl_states,
 440                          &temp, NO_INSERT);
 441   if (slot && *slot)
 442     {
 443       lto_free_function_in_decl_state ((struct lto_in_decl_state*) *slot);
 444       htab_clear_slot (node->lto_file_data->function_decl_states,
 445                        slot);
 446     }
 447   node->lto_file_data = NULL;
 448 }
 449
 450
 451 /* Report read pass end of the section.  */
 452
 453 void
 454 lto_section_overrun (struct lto_input_block *ib)
 455 {
 456   fatal_error ("bytecode stream: trying to read %d bytes "
 457                "after the end of the input buffer", ib->p - ib->len);
 458 }
 459
 460 /* Report out of range value.  */
 461
 462 void
 463 lto_value_range_error (const char *purpose, HOST_WIDE_INT val,
 464                        HOST_WIDE_INT min, HOST_WIDE_INT max)
 465 {
 466   fatal_error ("%s out of range: Range is %i to %i, value is %i",
 467                purpose, (int)min, (int)max, (int)val);
 468 }