gcc/lto-streamer.c

   1 /* Miscellaneous utilities for GIMPLE streaming.  Things that are used
   2    in both input and output are here.
   3
   4    Copyright (C) 2009-2016 Free Software Foundation, Inc.
   5    Contributed by Doug Kwan <dougkwan@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 "tree-streamer.h"
  30 #include "cgraph.h"
  31 #include "lto-streamer.h"
  32 #include "toplev.h"
  33 #include "lto-section-names.h"
  34
  35 /* Statistics gathered during LTO, WPA and LTRANS.  */
  36 struct lto_stats_d lto_stats;
  37
  38 /* LTO uses bitmaps with different life-times.  So use a separate
  39    obstack for all LTO bitmaps.  */
  40 static bitmap_obstack lto_obstack;
  41 static bool lto_obstack_initialized;
  42
  43 const char *section_name_prefix = LTO_SECTION_NAME_PREFIX;
  44 /* Set when streaming LTO for offloading compiler.  */
  45 bool lto_stream_offload_p;
  46
  47 /* Return a string representing LTO tag TAG.  */
  48
  49 const char *
  50 lto_tag_name (enum LTO_tags tag)
  51 {
  52   if (lto_tag_is_tree_code_p (tag))
  53     {
  54       /* For tags representing tree nodes, return the name of the
  55          associated tree code.  */
  56       return get_tree_code_name (lto_tag_to_tree_code (tag));
  57     }
  58
  59   if (lto_tag_is_gimple_code_p (tag))
  60     {
  61       /* For tags representing gimple statements, return the name of
  62          the associated gimple code.  */
  63       return gimple_code_name[lto_tag_to_gimple_code (tag)];
  64     }
  65
  66   switch (tag)
  67     {
  68     case LTO_null:
  69       return "LTO_null";
  70     case LTO_bb0:
  71       return "LTO_bb0";
  72     case LTO_bb1:
  73       return "LTO_bb1";
  74     case LTO_eh_region:
  75       return "LTO_eh_region";
  76     case LTO_function:
  77       return "LTO_function";
  78     case LTO_eh_table:
  79       return "LTO_eh_table";
  80     case LTO_ert_cleanup:
  81       return "LTO_ert_cleanup";
  82     case LTO_ert_try:
  83       return "LTO_ert_try";
  84     case LTO_ert_allowed_exceptions:
  85       return "LTO_ert_allowed_exceptions";
  86     case LTO_ert_must_not_throw:
  87       return "LTO_ert_must_not_throw";
  88     case LTO_tree_pickle_reference:
  89       return "LTO_tree_pickle_reference";
  90     case LTO_field_decl_ref:
  91       return "LTO_field_decl_ref";
  92     case LTO_function_decl_ref:
  93       return "LTO_function_decl_ref";
  94     case LTO_label_decl_ref:
  95       return "LTO_label_decl_ref";
  96     case LTO_namespace_decl_ref:
  97       return "LTO_namespace_decl_ref";
  98     case LTO_result_decl_ref:
  99       return "LTO_result_decl_ref";
 100     case LTO_ssa_name_ref:
 101       return "LTO_ssa_name_ref";
 102     case LTO_type_decl_ref:
 103       return "LTO_type_decl_ref";
 104     case LTO_type_ref:
 105       return "LTO_type_ref";
 106     case LTO_global_decl_ref:
 107       return "LTO_global_decl_ref";
 108     default:
 109       return "LTO_UNKNOWN";
 110     }
 111 }
 112
 113
 114 /* Allocate a bitmap from heap.  Initializes the LTO obstack if necessary.  */
 115
 116 bitmap
 117 lto_bitmap_alloc (void)
 118 {
 119   if (!lto_obstack_initialized)
 120     {
 121       bitmap_obstack_initialize (&lto_obstack);
 122       lto_obstack_initialized = true;
 123     }
 124   return BITMAP_ALLOC (&lto_obstack);
 125 }
 126
 127 /* Free bitmap B.  */
 128
 129 void
 130 lto_bitmap_free (bitmap b)
 131 {
 132   BITMAP_FREE (b);
 133 }
 134
 135
 136 /* Get a section name for a particular type or name.  The NAME field
 137    is only used if SECTION_TYPE is LTO_section_function_body. For all
 138    others it is ignored.  The callee of this function is responsible
 139    to free the returned name.  */
 140
 141 char *
 142 lto_get_section_name (int section_type, const char *name, struct lto_file_decl_data *f)
 143 {
 144   const char *add;
 145   char post[32];
 146   const char *sep;
 147
 148   if (section_type == LTO_section_function_body)
 149     {
 150       gcc_assert (name != NULL);
 151       if (name[0] == '*')
 152         name++;
 153       add = name;
 154       sep = "";
 155     }
 156   else if (section_type < LTO_N_SECTION_TYPES)
 157     {
 158       add = lto_section_name[section_type];
 159       sep = ".";
 160     }
 161   else
 162     internal_error ("bytecode stream: unexpected LTO section %s", name);
 163
 164   /* Make the section name unique so that ld -r combining sections
 165      doesn't confuse the reader with merged sections.
 166
 167      For options don't add a ID, the option reader cannot deal with them
 168      and merging should be ok here. */
 169   if (section_type == LTO_section_opts)
 170     strcpy (post, "");
 171   else if (f != NULL)
 172     sprintf (post, "." HOST_WIDE_INT_PRINT_HEX_PURE, f->id);
 173   else
 174     sprintf (post, "." HOST_WIDE_INT_PRINT_HEX_PURE, get_random_seed (false));
 175   return concat (section_name_prefix, sep, add, post, NULL);
 176 }
 177
 178
 179 /* Show various memory usage statistics related to LTO.  */
 180
 181 void
 182 print_lto_report (const char *s)
 183 {
 184   unsigned i;
 185
 186   fprintf (stderr, "[%s] # of input files: "
 187            HOST_WIDE_INT_PRINT_UNSIGNED "\n", s, lto_stats.num_input_files);
 188
 189   fprintf (stderr, "[%s] # of input cgraph nodes: "
 190            HOST_WIDE_INT_PRINT_UNSIGNED "\n", s,
 191            lto_stats.num_input_cgraph_nodes);
 192
 193   fprintf (stderr, "[%s] # of function bodies: "
 194            HOST_WIDE_INT_PRINT_UNSIGNED "\n", s,
 195            lto_stats.num_function_bodies);
 196
 197   for (i = 0; i < NUM_TREE_CODES; i++)
 198     if (lto_stats.num_trees[i])
 199       fprintf (stderr, "[%s] # of '%s' objects read: "
 200                HOST_WIDE_INT_PRINT_UNSIGNED "\n", s,
 201                get_tree_code_name ((enum tree_code) i), lto_stats.num_trees[i]);
 202
 203   if (flag_lto)
 204     {
 205       fprintf (stderr, "[%s] Compression: "
 206                HOST_WIDE_INT_PRINT_UNSIGNED " output bytes, "
 207                HOST_WIDE_INT_PRINT_UNSIGNED " compressed bytes", s,
 208                lto_stats.num_output_il_bytes,
 209                lto_stats.num_compressed_il_bytes);
 210       if (lto_stats.num_output_il_bytes > 0)
 211         {
 212           const float dividend = (float) lto_stats.num_compressed_il_bytes;
 213           const float divisor = (float) lto_stats.num_output_il_bytes;
 214           fprintf (stderr, " (ratio: %f)", dividend / divisor);
 215         }
 216       fprintf (stderr, "\n");
 217     }
 218
 219   if (flag_wpa)
 220     {
 221       fprintf (stderr, "[%s] # of output files: "
 222                HOST_WIDE_INT_PRINT_UNSIGNED "\n", s,
 223                lto_stats.num_output_files);
 224
 225       fprintf (stderr, "[%s] # of output symtab nodes: "
 226                HOST_WIDE_INT_PRINT_UNSIGNED "\n", s,
 227                lto_stats.num_output_symtab_nodes);
 228
 229       fprintf (stderr, "[%s] # of output tree pickle references: "
 230                HOST_WIDE_INT_PRINT_UNSIGNED "\n", s,
 231                lto_stats.num_pickle_refs_output);
 232       fprintf (stderr, "[%s] # of output tree bodies: "
 233                HOST_WIDE_INT_PRINT_UNSIGNED "\n", s,
 234                lto_stats.num_tree_bodies_output);
 235
 236       fprintf (stderr, "[%s] # callgraph partitions: "
 237                HOST_WIDE_INT_PRINT_UNSIGNED "\n", s,
 238                lto_stats.num_cgraph_partitions);
 239
 240       fprintf (stderr, "[%s] Compression: "
 241                HOST_WIDE_INT_PRINT_UNSIGNED " input bytes, "
 242                HOST_WIDE_INT_PRINT_UNSIGNED " uncompressed bytes", s,
 243                lto_stats.num_input_il_bytes,
 244                lto_stats.num_uncompressed_il_bytes);
 245       if (lto_stats.num_input_il_bytes > 0)
 246         {
 247           const float dividend = (float) lto_stats.num_uncompressed_il_bytes;
 248           const float divisor = (float) lto_stats.num_input_il_bytes;
 249           fprintf (stderr, " (ratio: %f)", dividend / divisor);
 250         }
 251       fprintf (stderr, "\n");
 252     }
 253
 254   for (i = 0; i < LTO_N_SECTION_TYPES; i++)
 255     fprintf (stderr, "[%s] Size of mmap'd section %s: "
 256              HOST_WIDE_INT_PRINT_UNSIGNED " bytes\n", s,
 257              lto_section_name[i], lto_stats.section_size[i]);
 258 }
 259
 260
 261 #ifdef LTO_STREAMER_DEBUG
 262 struct tree_hash_entry
 263 {
 264   tree key;
 265   intptr_t value;
 266 };
 267
 268 struct tree_entry_hasher : nofree_ptr_hash <tree_hash_entry>
 269 {
 270   static inline hashval_t hash (const tree_hash_entry *);
 271   static inline bool equal (const tree_hash_entry *, const tree_hash_entry *);
 272 };
 273
 274 inline hashval_t
 275 tree_entry_hasher::hash (const tree_hash_entry *e)
 276 {
 277   return htab_hash_pointer (e->key);
 278 }
 279
 280 inline bool
 281 tree_entry_hasher::equal (const tree_hash_entry *e1, const tree_hash_entry *e2)
 282 {
 283   return (e1->key == e2->key);
 284 }
 285
 286 static hash_table<tree_entry_hasher> *tree_htab;
 287 #endif
 288
 289 /* Initialization common to the LTO reader and writer.  */
 290
 291 void
 292 lto_streamer_init (void)
 293 {
 294   /* Check that all the TS_* handled by the reader and writer routines
 295      match exactly the structures defined in treestruct.def.  When a
 296      new TS_* astructure is added, the streamer should be updated to
 297      handle it.  */
 298   if (flag_checking)
 299     streamer_check_handled_ts_structures ();
 300
 301 #ifdef LTO_STREAMER_DEBUG
 302   tree_htab = new hash_table<tree_entry_hasher> (31);
 303 #endif
 304 }
 305
 306
 307 /* Gate function for all LTO streaming passes.  */
 308
 309 bool
 310 gate_lto_out (void)
 311 {
 312   return ((flag_generate_lto || flag_generate_offload || in_lto_p)
 313           /* Don't bother doing anything if the program has errors.  */
 314           && !seen_error ());
 315 }
 316
 317
 318 #ifdef LTO_STREAMER_DEBUG
 319 /* Add a mapping between T and ORIG_T, which is the numeric value of
 320    the original address of T as it was seen by the LTO writer.  This
 321    mapping is useful when debugging streaming problems.  A debugging
 322    session can be started on both reader and writer using ORIG_T
 323    as a breakpoint value in both sessions.
 324
 325    Note that this mapping is transient and only valid while T is
 326    being reconstructed.  Once T is fully built, the mapping is
 327    removed.  */
 328
 329 void
 330 lto_orig_address_map (tree t, intptr_t orig_t)
 331 {
 332   struct tree_hash_entry ent;
 333   struct tree_hash_entry **slot;
 334
 335   ent.key = t;
 336   ent.value = orig_t;
 337   slot = tree_htab->find_slot (&ent, INSERT);
 338   gcc_assert (!*slot);
 339   *slot = XNEW (struct tree_hash_entry);
 340   **slot = ent;
 341 }
 342
 343
 344 /* Get the original address of T as it was seen by the writer.  This
 345    is only valid while T is being reconstructed.  */
 346
 347 intptr_t
 348 lto_orig_address_get (tree t)
 349 {
 350   struct tree_hash_entry ent;
 351   struct tree_hash_entry **slot;
 352
 353   ent.key = t;
 354   slot = tree_htab->find_slot (&ent, NO_INSERT);
 355   return (slot ? (*slot)->value : 0);
 356 }
 357
 358
 359 /* Clear the mapping of T to its original address.  */
 360
 361 void
 362 lto_orig_address_remove (tree t)
 363 {
 364   struct tree_hash_entry ent;
 365   struct tree_hash_entry **slot;
 366
 367   ent.key = t;
 368   slot = tree_htab->find_slot (&ent, NO_INSERT);
 369   gcc_assert (slot);
 370   free (*slot);
 371   tree_htab->clear_slot (slot);
 372 }
 373 #endif
 374
 375
 376 /* Check that the version MAJOR.MINOR is the correct version number.  */
 377
 378 void
 379 lto_check_version (int major, int minor, const char *file_name)
 380 {
 381   if (major != LTO_major_version || minor != LTO_minor_version)
 382     fatal_error (input_location,
 383                  "bytecode stream in file '%s' generated with LTO version "
 384                  "%d.%d instead of the expected %d.%d",
 385                  file_name,
 386                  major, minor,
 387                  LTO_major_version, LTO_minor_version);
 388 }
 389
 390
 391 /* Initialize all the streamer hooks used for streaming GIMPLE.  */
 392
 393 void
 394 lto_streamer_hooks_init (void)
 395 {
 396   streamer_hooks_init ();
 397   streamer_hooks.write_tree = lto_output_tree;
 398   streamer_hooks.read_tree = lto_input_tree;
 399   streamer_hooks.input_location = lto_input_location;
 400   streamer_hooks.output_location = lto_output_location;
 401 }