gcc/tree-streamer.c

   1 /* Miscellaneous utilities for tree streaming.  Things that are used
   2    in both input and output are here.
   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 "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 "options.h"
  34 #include "wide-int.h"
  35 #include "inchash.h"
  36 #include "tree.h"
  37 #include "fold-const.h"
  38 #include "predict.h"
  39 #include "tm.h"
  40 #include "hard-reg-set.h"
  41 #include "input.h"
  42 #include "function.h"
  43 #include "basic-block.h"
  44 #include "tree-ssa-alias.h"
  45 #include "internal-fn.h"
  46 #include "gimple-expr.h"
  47 #include "hash-map.h"
  48 #include "is-a.h"
  49 #include "gimple.h"
  50 #include "streamer-hooks.h"
  51 #include "plugin-api.h"
  52 #include "ipa-ref.h"
  53 #include "cgraph.h"
  54 #include "tree-streamer.h"
  55
  56 /* Check that all the TS_* structures handled by the streamer_write_* and
  57    streamer_read_* routines are exactly ALL the structures defined in
  58    treestruct.def.  */
  59
  60 void
  61 streamer_check_handled_ts_structures (void)
  62 {
  63   bool handled_p[LAST_TS_ENUM];
  64   unsigned i;
  65
  66   memset (&handled_p, 0, sizeof (handled_p));
  67
  68   /* These are the TS_* structures that are either handled or
  69      explicitly ignored by the streamer routines.  */
  70   handled_p[TS_BASE] = true;
  71   handled_p[TS_TYPED] = true;
  72   handled_p[TS_COMMON] = true;
  73   handled_p[TS_INT_CST] = true;
  74   handled_p[TS_REAL_CST] = true;
  75   handled_p[TS_FIXED_CST] = true;
  76   handled_p[TS_VECTOR] = true;
  77   handled_p[TS_STRING] = true;
  78   handled_p[TS_COMPLEX] = true;
  79   handled_p[TS_IDENTIFIER] = true;
  80   handled_p[TS_DECL_MINIMAL] = true;
  81   handled_p[TS_DECL_COMMON] = true;
  82   handled_p[TS_DECL_WRTL] = true;
  83   handled_p[TS_DECL_NON_COMMON] = true;
  84   handled_p[TS_DECL_WITH_VIS] = true;
  85   handled_p[TS_FIELD_DECL] = true;
  86   handled_p[TS_VAR_DECL] = true;
  87   handled_p[TS_PARM_DECL] = true;
  88   handled_p[TS_LABEL_DECL] = true;
  89   handled_p[TS_RESULT_DECL] = true;
  90   handled_p[TS_CONST_DECL] = true;
  91   handled_p[TS_TYPE_DECL] = true;
  92   handled_p[TS_FUNCTION_DECL] = true;
  93   handled_p[TS_TYPE_COMMON] = true;
  94   handled_p[TS_TYPE_WITH_LANG_SPECIFIC] = true;
  95   handled_p[TS_TYPE_NON_COMMON] = true;
  96   handled_p[TS_LIST] = true;
  97   handled_p[TS_VEC] = true;
  98   handled_p[TS_EXP] = true;
  99   handled_p[TS_SSA_NAME] = true;
 100   handled_p[TS_BLOCK] = true;
 101   handled_p[TS_BINFO] = true;
 102   handled_p[TS_STATEMENT_LIST] = true;
 103   handled_p[TS_CONSTRUCTOR] = true;
 104   handled_p[TS_OMP_CLAUSE] = true;
 105   handled_p[TS_OPTIMIZATION] = true;
 106   handled_p[TS_TARGET_OPTION] = true;
 107   handled_p[TS_TRANSLATION_UNIT_DECL] = true;
 108
 109   /* Anything not marked above will trigger the following assertion.
 110      If this assertion triggers, it means that there is a new TS_*
 111      structure that should be handled by the streamer.  */
 112   for (i = 0; i < LAST_TS_ENUM; i++)
 113     gcc_assert (handled_p[i]);
 114 }
 115
 116
 117 /* Helper for streamer_tree_cache_insert_1.  Add T to CACHE->NODES at
 118    slot IX.  */
 119
 120 static void
 121 streamer_tree_cache_add_to_node_array (struct streamer_tree_cache_d *cache,
 122                                        unsigned ix, tree t, hashval_t hash)
 123 {
 124   /* We're either replacing an old element or appending consecutively.  */
 125   if (cache->nodes.exists ())
 126     {
 127       if (cache->nodes.length () == ix)
 128         cache->nodes.safe_push (t);
 129       else
 130         cache->nodes[ix] = t;
 131     }
 132   if (cache->hashes.exists ())
 133     {
 134       if (cache->hashes.length () == ix)
 135         cache->hashes.safe_push (hash);
 136       else
 137         cache->hashes[ix] = hash;
 138     }
 139 }
 140
 141
 142 /* Helper for streamer_tree_cache_insert and streamer_tree_cache_insert_at.
 143    CACHE, T, and IX_P are as in streamer_tree_cache_insert.
 144
 145    If INSERT_AT_NEXT_SLOT_P is true, T is inserted at the next available
 146    slot in the cache.  Otherwise, T is inserted at the position indicated
 147    in *IX_P.
 148
 149    If T already existed in CACHE, return true.  Otherwise,
 150    return false.  */
 151
 152 static bool
 153 streamer_tree_cache_insert_1 (struct streamer_tree_cache_d *cache,
 154                               tree t, hashval_t hash, unsigned *ix_p,
 155                               bool insert_at_next_slot_p)
 156 {
 157   bool existed_p;
 158
 159   gcc_assert (t);
 160
 161   unsigned int &ix = cache->node_map->get_or_insert (t, &existed_p);
 162   if (!existed_p)
 163     {
 164       /* Determine the next slot to use in the cache.  */
 165       if (insert_at_next_slot_p)
 166         ix = cache->next_idx++;
 167       else
 168         ix = *ix_p;
 169
 170       streamer_tree_cache_add_to_node_array (cache, ix, t, hash);
 171     }
 172   else
 173     {
 174       if (!insert_at_next_slot_p && ix != *ix_p)
 175         {
 176           /* If the caller wants to insert T at a specific slot
 177              location, and ENTRY->TO does not match *IX_P, add T to
 178              the requested location slot.  */
 179           ix = *ix_p;
 180           streamer_tree_cache_add_to_node_array (cache, ix, t, hash);
 181         }
 182     }
 183
 184   if (ix_p)
 185     *ix_p = ix;
 186
 187   return existed_p;
 188 }
 189
 190
 191 /* Insert tree node T in CACHE.  If T already existed in the cache
 192    return true.  Otherwise, return false.
 193
 194    If IX_P is non-null, update it with the index into the cache where
 195    T has been stored.  */
 196
 197 bool
 198 streamer_tree_cache_insert (struct streamer_tree_cache_d *cache, tree t,
 199                             hashval_t hash, unsigned *ix_p)
 200 {
 201   return streamer_tree_cache_insert_1 (cache, t, hash, ix_p, true);
 202 }
 203
 204
 205 /* Replace the tree node with T in CACHE at slot IX.  */
 206
 207 void
 208 streamer_tree_cache_replace_tree (struct streamer_tree_cache_d *cache,
 209                                   tree t, unsigned ix)
 210 {
 211   hashval_t hash = 0;
 212   if (cache->hashes.exists ())
 213     hash = streamer_tree_cache_get_hash (cache, ix);
 214   if (!cache->node_map)
 215     streamer_tree_cache_add_to_node_array (cache, ix, t, hash);
 216   else
 217     streamer_tree_cache_insert_1 (cache, t, hash, &ix, false);
 218 }
 219
 220
 221 /* Appends tree node T to CACHE, even if T already existed in it.  */
 222
 223 void
 224 streamer_tree_cache_append (struct streamer_tree_cache_d *cache,
 225                             tree t, hashval_t hash)
 226 {
 227   unsigned ix = cache->next_idx++;
 228   if (!cache->node_map)
 229     streamer_tree_cache_add_to_node_array (cache, ix, t, hash);
 230   else
 231     streamer_tree_cache_insert_1 (cache, t, hash, &ix, false);
 232 }
 233
 234 /* Return true if tree node T exists in CACHE, otherwise false.  If IX_P is
 235    not NULL, write to *IX_P the index into the cache where T is stored
 236    ((unsigned)-1 if T is not found).  */
 237
 238 bool
 239 streamer_tree_cache_lookup (struct streamer_tree_cache_d *cache, tree t,
 240                             unsigned *ix_p)
 241 {
 242   unsigned *slot;
 243   bool retval;
 244   unsigned ix;
 245
 246   gcc_assert (t);
 247
 248   slot = cache->node_map->get (t);
 249   if (slot == NULL)
 250     {
 251       retval = false;
 252       ix = -1;
 253     }
 254   else
 255     {
 256       retval = true;
 257       ix = *slot;
 258     }
 259
 260   if (ix_p)
 261     *ix_p = ix;
 262
 263   return retval;
 264 }
 265
 266
 267 /* Record NODE in CACHE.  */
 268
 269 static void
 270 record_common_node (struct streamer_tree_cache_d *cache, tree node)
 271 {
 272   /* If we recursively end up at nodes we do not want to preload simply don't.
 273      ???  We'd want to verify that this doesn't happen, or alternatively
 274      do not recurse at all.  */
 275   if (node == char_type_node)
 276     return;
 277
 278   gcc_checking_assert (node != boolean_type_node
 279                        && node != boolean_true_node
 280                        && node != boolean_false_node);
 281
 282   /* We have to make sure to fill exactly the same number of
 283      elements for all frontends.  That can include NULL trees.
 284      As our hash table can't deal with zero entries we'll simply stream
 285      a random other tree.  A NULL tree never will be looked up so it
 286      doesn't matter which tree we replace it with, just to be sure
 287      use error_mark_node.  */
 288   if (!node)
 289     node = error_mark_node;
 290
 291   /* ???  FIXME, devise a better hash value.  But the hash needs to be equal
 292      for all frontend and lto1 invocations.  So just use the position
 293      in the cache as hash value.  */
 294   streamer_tree_cache_append (cache, node, cache->nodes.length ());
 295
 296   if (POINTER_TYPE_P (node)
 297       || TREE_CODE (node) == COMPLEX_TYPE
 298       || TREE_CODE (node) == ARRAY_TYPE)
 299     record_common_node (cache, TREE_TYPE (node));
 300   else if (TREE_CODE (node) == RECORD_TYPE)
 301     {
 302       /* The FIELD_DECLs of structures should be shared, so that every
 303          COMPONENT_REF uses the same tree node when referencing a field.
 304          Pointer equality between FIELD_DECLs is used by the alias
 305          machinery to compute overlapping component references (see
 306          nonoverlapping_component_refs_p and
 307          nonoverlapping_component_refs_of_decl_p).  */
 308       for (tree f = TYPE_FIELDS (node); f; f = TREE_CHAIN (f))
 309         record_common_node (cache, f);
 310     }
 311 }
 312
 313
 314 /* Preload common nodes into CACHE and make sure they are merged
 315    properly according to the gimple type table.  */
 316
 317 static void
 318 preload_common_nodes (struct streamer_tree_cache_d *cache)
 319 {
 320   unsigned i;
 321
 322   for (i = 0; i < itk_none; i++)
 323     /* Skip itk_char.  char_type_node is dependent on -f[un]signed-char.  */
 324     if (i != itk_char)
 325       record_common_node (cache, integer_types[i]);
 326
 327   for (i = 0; i < stk_type_kind_last; i++)
 328     record_common_node (cache, sizetype_tab[i]);
 329
 330   for (i = 0; i < TI_MAX; i++)
 331     /* Skip boolean type and constants, they are frontend dependent.  */
 332     if (i != TI_BOOLEAN_TYPE
 333         && i != TI_BOOLEAN_FALSE
 334         && i != TI_BOOLEAN_TRUE
 335         /* MAIN_IDENTIFIER is not always initialized by Fortran FE.  */
 336         && i != TI_MAIN_IDENTIFIER
 337         /* PID_TYPE is initialized only by C family front-ends.  */
 338         && i != TI_PID_TYPE
 339         /* Skip optimization and target option nodes; they depend on flags.  */
 340         && i != TI_OPTIMIZATION_DEFAULT
 341         && i != TI_OPTIMIZATION_CURRENT
 342         && i != TI_TARGET_OPTION_DEFAULT
 343         && i != TI_TARGET_OPTION_CURRENT
 344         && i != TI_CURRENT_TARGET_PRAGMA
 345         && i != TI_CURRENT_OPTIMIZE_PRAGMA)
 346       record_common_node (cache, global_trees[i]);
 347 }
 348
 349
 350 /* Create a cache of pickled nodes.  */
 351
 352 struct streamer_tree_cache_d *
 353 streamer_tree_cache_create (bool with_hashes, bool with_map, bool with_vec)
 354 {
 355   struct streamer_tree_cache_d *cache;
 356
 357   cache = XCNEW (struct streamer_tree_cache_d);
 358
 359   if (with_map)
 360     cache->node_map = new hash_map<tree, unsigned> (251);
 361   cache->next_idx = 0;
 362   if (with_vec)
 363     cache->nodes.create (165);
 364   if (with_hashes)
 365     cache->hashes.create (165);
 366
 367   /* Load all the well-known tree nodes that are always created by
 368      the compiler on startup.  This prevents writing them out
 369      unnecessarily.  */
 370   preload_common_nodes (cache);
 371
 372   return cache;
 373 }
 374
 375
 376 /* Delete the streamer cache C.  */
 377
 378 void
 379 streamer_tree_cache_delete (struct streamer_tree_cache_d *c)
 380 {
 381   if (c == NULL)
 382     return;
 383
 384   delete c->node_map;
 385   c->node_map = NULL;
 386   c->nodes.release ();
 387   c->hashes.release ();
 388   free (c);
 389 }