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) 2011-2017 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 "backend.h"
  27 #include "tree.h"
  28 #include "gimple.h"
  29 #include "tree-streamer.h"
  30 #include "cgraph.h"
  31
  32 /* Table indexed by machine_mode, used for 2 different purposes.
  33    During streaming out we record there non-zero value for all modes
  34    that were streamed out.
  35    During streaming in, we translate the on the disk mode using this
  36    table.  For normal LTO it is set to identity, for ACCEL_COMPILER
  37    depending on the mode_table content.  */
  38 unsigned char streamer_mode_table[1 << 8];
  39
  40 /* Check that all the TS_* structures handled by the streamer_write_* and
  41    streamer_read_* routines are exactly ALL the structures defined in
  42    treestruct.def.  */
  43
  44 void
  45 streamer_check_handled_ts_structures (void)
  46 {
  47   bool handled_p[LAST_TS_ENUM];
  48   unsigned i;
  49
  50   memset (&handled_p, 0, sizeof (handled_p));
  51
  52   /* These are the TS_* structures that are either handled or
  53      explicitly ignored by the streamer routines.  */
  54   handled_p[TS_BASE] = true;
  55   handled_p[TS_TYPED] = true;
  56   handled_p[TS_COMMON] = true;
  57   handled_p[TS_INT_CST] = true;
  58   handled_p[TS_REAL_CST] = true;
  59   handled_p[TS_FIXED_CST] = true;
  60   handled_p[TS_VECTOR] = true;
  61   handled_p[TS_STRING] = true;
  62   handled_p[TS_COMPLEX] = true;
  63   handled_p[TS_IDENTIFIER] = true;
  64   handled_p[TS_DECL_MINIMAL] = true;
  65   handled_p[TS_DECL_COMMON] = true;
  66   handled_p[TS_DECL_WRTL] = true;
  67   handled_p[TS_DECL_NON_COMMON] = true;
  68   handled_p[TS_DECL_WITH_VIS] = true;
  69   handled_p[TS_FIELD_DECL] = true;
  70   handled_p[TS_VAR_DECL] = true;
  71   handled_p[TS_PARM_DECL] = true;
  72   handled_p[TS_LABEL_DECL] = true;
  73   handled_p[TS_RESULT_DECL] = true;
  74   handled_p[TS_CONST_DECL] = true;
  75   handled_p[TS_TYPE_DECL] = true;
  76   handled_p[TS_FUNCTION_DECL] = true;
  77   handled_p[TS_TYPE_COMMON] = true;
  78   handled_p[TS_TYPE_WITH_LANG_SPECIFIC] = true;
  79   handled_p[TS_TYPE_NON_COMMON] = true;
  80   handled_p[TS_LIST] = true;
  81   handled_p[TS_VEC] = true;
  82   handled_p[TS_EXP] = true;
  83   handled_p[TS_SSA_NAME] = true;
  84   handled_p[TS_BLOCK] = true;
  85   handled_p[TS_BINFO] = true;
  86   handled_p[TS_STATEMENT_LIST] = true;
  87   handled_p[TS_CONSTRUCTOR] = true;
  88   handled_p[TS_OMP_CLAUSE] = true;
  89   handled_p[TS_OPTIMIZATION] = true;
  90   handled_p[TS_TARGET_OPTION] = true;
  91   handled_p[TS_TRANSLATION_UNIT_DECL] = true;
  92
  93   /* Anything not marked above will trigger the following assertion.
  94      If this assertion triggers, it means that there is a new TS_*
  95      structure that should be handled by the streamer.  */
  96   for (i = 0; i < LAST_TS_ENUM; i++)
  97     gcc_assert (handled_p[i]);
  98 }
  99
 100
 101 /* Helper for streamer_tree_cache_insert_1.  Add T to CACHE->NODES at
 102    slot IX.  */
 103
 104 static void
 105 streamer_tree_cache_add_to_node_array (struct streamer_tree_cache_d *cache,
 106                                        unsigned ix, tree t, hashval_t hash)
 107 {
 108   /* We're either replacing an old element or appending consecutively.  */
 109   if (cache->nodes.exists ())
 110     {
 111       if (cache->nodes.length () == ix)
 112         cache->nodes.safe_push (t);
 113       else
 114         cache->nodes[ix] = t;
 115     }
 116   if (cache->hashes.exists ())
 117     {
 118       if (cache->hashes.length () == ix)
 119         cache->hashes.safe_push (hash);
 120       else
 121         cache->hashes[ix] = hash;
 122     }
 123 }
 124
 125
 126 /* Helper for streamer_tree_cache_insert and streamer_tree_cache_insert_at.
 127    CACHE, T, and IX_P are as in streamer_tree_cache_insert.
 128
 129    If INSERT_AT_NEXT_SLOT_P is true, T is inserted at the next available
 130    slot in the cache.  Otherwise, T is inserted at the position indicated
 131    in *IX_P.
 132
 133    If T already existed in CACHE, return true.  Otherwise,
 134    return false.  */
 135
 136 static bool
 137 streamer_tree_cache_insert_1 (struct streamer_tree_cache_d *cache,
 138                               tree t, hashval_t hash, unsigned *ix_p,
 139                               bool insert_at_next_slot_p)
 140 {
 141   bool existed_p;
 142
 143   gcc_assert (t);
 144
 145   unsigned int &ix = cache->node_map->get_or_insert (t, &existed_p);
 146   if (!existed_p)
 147     {
 148       /* Determine the next slot to use in the cache.  */
 149       if (insert_at_next_slot_p)
 150         ix = cache->next_idx++;
 151       else
 152         ix = *ix_p;
 153
 154       streamer_tree_cache_add_to_node_array (cache, ix, t, hash);
 155     }
 156   else
 157     {
 158       if (!insert_at_next_slot_p && ix != *ix_p)
 159         {
 160           /* If the caller wants to insert T at a specific slot
 161              location, and ENTRY->TO does not match *IX_P, add T to
 162              the requested location slot.  */
 163           ix = *ix_p;
 164           streamer_tree_cache_add_to_node_array (cache, ix, t, hash);
 165         }
 166     }
 167
 168   if (ix_p)
 169     *ix_p = ix;
 170
 171   return existed_p;
 172 }
 173
 174
 175 /* Insert tree node T in CACHE.  If T already existed in the cache
 176    return true.  Otherwise, return false.
 177
 178    If IX_P is non-null, update it with the index into the cache where
 179    T has been stored.  */
 180
 181 bool
 182 streamer_tree_cache_insert (struct streamer_tree_cache_d *cache, tree t,
 183                             hashval_t hash, unsigned *ix_p)
 184 {
 185   return streamer_tree_cache_insert_1 (cache, t, hash, ix_p, true);
 186 }
 187
 188
 189 /* Replace the tree node with T in CACHE at slot IX.  */
 190
 191 void
 192 streamer_tree_cache_replace_tree (struct streamer_tree_cache_d *cache,
 193                                   tree t, unsigned ix)
 194 {
 195   hashval_t hash = 0;
 196   if (cache->hashes.exists ())
 197     hash = streamer_tree_cache_get_hash (cache, ix);
 198   if (!cache->node_map)
 199     streamer_tree_cache_add_to_node_array (cache, ix, t, hash);
 200   else
 201     streamer_tree_cache_insert_1 (cache, t, hash, &ix, false);
 202 }
 203
 204
 205 /* Appends tree node T to CACHE, even if T already existed in it.  */
 206
 207 void
 208 streamer_tree_cache_append (struct streamer_tree_cache_d *cache,
 209                             tree t, hashval_t hash)
 210 {
 211   unsigned ix = cache->next_idx++;
 212   if (!cache->node_map)
 213     streamer_tree_cache_add_to_node_array (cache, ix, t, hash);
 214   else
 215     streamer_tree_cache_insert_1 (cache, t, hash, &ix, false);
 216 }
 217
 218 /* Return true if tree node T exists in CACHE, otherwise false.  If IX_P is
 219    not NULL, write to *IX_P the index into the cache where T is stored
 220    ((unsigned)-1 if T is not found).  */
 221
 222 bool
 223 streamer_tree_cache_lookup (struct streamer_tree_cache_d *cache, tree t,
 224                             unsigned *ix_p)
 225 {
 226   unsigned *slot;
 227   bool retval;
 228   unsigned ix;
 229
 230   gcc_assert (t);
 231
 232   slot = cache->node_map->get (t);
 233   if (slot == NULL)
 234     {
 235       retval = false;
 236       ix = -1;
 237     }
 238   else
 239     {
 240       retval = true;
 241       ix = *slot;
 242     }
 243
 244   if (ix_p)
 245     *ix_p = ix;
 246
 247   return retval;
 248 }
 249
 250
 251 /* Verify that NODE is in CACHE.  */
 252
 253 static void
 254 verify_common_node_recorded (struct streamer_tree_cache_d *cache, tree node)
 255 {
 256   /* Restrict this to flag_checking only because in general violating it is
 257      harmless plus we never know what happens on all targets/frontend/flag(!)
 258      combinations.  */
 259   if (!flag_checking)
 260     return;
 261
 262   if (cache->node_map)
 263     gcc_assert (streamer_tree_cache_lookup (cache, node, NULL));
 264   else
 265     {
 266       bool found = false;
 267       gcc_assert (cache->nodes.exists ());
 268       /* Linear search...  */
 269       for (unsigned i = 0; !found && i < cache->nodes.length (); ++i)
 270         if (cache->nodes[i] == node)
 271           found = true;
 272       gcc_assert (found);
 273     }
 274 }
 275
 276
 277 /* Record NODE in CACHE.  */
 278
 279 static void
 280 record_common_node (struct streamer_tree_cache_d *cache, tree node)
 281 {
 282   /* If we recursively end up at nodes we do not want to preload simply don't.
 283      ???  We'd want to verify that this doesn't happen, or alternatively
 284      do not recurse at all.  */
 285   if (node == char_type_node)
 286     return;
 287
 288   gcc_checking_assert (node != boolean_type_node
 289                        && node != boolean_true_node
 290                        && node != boolean_false_node);
 291
 292   /* We have to make sure to fill exactly the same number of
 293      elements for all frontends.  That can include NULL trees.
 294      As our hash table can't deal with zero entries we'll simply stream
 295      a random other tree.  A NULL tree never will be looked up so it
 296      doesn't matter which tree we replace it with, just to be sure
 297      use error_mark_node.  */
 298   if (!node)
 299     node = error_mark_node;
 300
 301   /* ???  FIXME, devise a better hash value.  But the hash needs to be equal
 302      for all frontend and lto1 invocations.  So just use the position
 303      in the cache as hash value.  */
 304   streamer_tree_cache_append (cache, node, cache->nodes.length ());
 305
 306   switch (TREE_CODE (node))
 307     {
 308     case ERROR_MARK:
 309     case FIELD_DECL:
 310     case FIXED_POINT_TYPE:
 311     case IDENTIFIER_NODE:
 312     case INTEGER_CST:
 313     case INTEGER_TYPE:
 314     case POINTER_BOUNDS_TYPE:
 315     case REAL_TYPE:
 316     case TREE_LIST:
 317     case VOID_CST:
 318     case VOID_TYPE:
 319       /* No recursive trees.  */
 320       break;
 321     case ARRAY_TYPE:
 322     case POINTER_TYPE:
 323     case REFERENCE_TYPE:
 324       record_common_node (cache, TREE_TYPE (node));
 325       break;
 326     case COMPLEX_TYPE:
 327       /* Verify that a complex type's component type (node_type) has been
 328          handled already (and we thus don't need to recurse here).  */
 329       verify_common_node_recorded (cache, TREE_TYPE (node));
 330       break;
 331     case RECORD_TYPE:
 332       /* The FIELD_DECLs of structures should be shared, so that every
 333          COMPONENT_REF uses the same tree node when referencing a field.
 334          Pointer equality between FIELD_DECLs is used by the alias
 335          machinery to compute overlapping component references (see
 336          nonoverlapping_component_refs_p and
 337          nonoverlapping_component_refs_of_decl_p).  */
 338       for (tree f = TYPE_FIELDS (node); f; f = TREE_CHAIN (f))
 339         record_common_node (cache, f);
 340       break;
 341     default:
 342       /* Unexpected tree code.  */
 343       gcc_unreachable ();
 344     }
 345 }
 346
 347
 348 /* Preload common nodes into CACHE and make sure they are merged
 349    properly according to the gimple type table.  */
 350
 351 static void
 352 preload_common_nodes (struct streamer_tree_cache_d *cache)
 353 {
 354   unsigned i;
 355
 356   for (i = 0; i < itk_none; i++)
 357     /* Skip itk_char.  char_type_node is dependent on -f[un]signed-char.  */
 358     if (i != itk_char)
 359       record_common_node (cache, integer_types[i]);
 360
 361   for (i = 0; i < stk_type_kind_last; i++)
 362     record_common_node (cache, sizetype_tab[i]);
 363
 364   for (i = 0; i < TI_MAX; i++)
 365     /* Skip boolean type and constants, they are frontend dependent.  */
 366     if (i != TI_BOOLEAN_TYPE
 367         && i != TI_BOOLEAN_FALSE
 368         && i != TI_BOOLEAN_TRUE
 369         /* MAIN_IDENTIFIER is not always initialized by Fortran FE.  */
 370         && i != TI_MAIN_IDENTIFIER
 371         /* PID_TYPE is initialized only by C family front-ends.  */
 372         && i != TI_PID_TYPE
 373         /* Skip optimization and target option nodes; they depend on flags.  */
 374         && i != TI_OPTIMIZATION_DEFAULT
 375         && i != TI_OPTIMIZATION_CURRENT
 376         && i != TI_TARGET_OPTION_DEFAULT
 377         && i != TI_TARGET_OPTION_CURRENT
 378         && i != TI_CURRENT_TARGET_PRAGMA
 379         && i != TI_CURRENT_OPTIMIZE_PRAGMA
 380         /* Skip va_list* related nodes if offloading.  For native LTO
 381            we want them to be merged for the stdarg pass, for offloading
 382            they might not be identical between host and offloading target.  */
 383         && (!lto_stream_offload_p
 384             || (i != TI_VA_LIST_TYPE
 385                 && i != TI_VA_LIST_GPR_COUNTER_FIELD
 386                 && i != TI_VA_LIST_FPR_COUNTER_FIELD)))
 387       record_common_node (cache, global_trees[i]);
 388 }
 389
 390
 391 /* Create a cache of pickled nodes.  */
 392
 393 struct streamer_tree_cache_d *
 394 streamer_tree_cache_create (bool with_hashes, bool with_map, bool with_vec)
 395 {
 396   struct streamer_tree_cache_d *cache;
 397
 398   cache = XCNEW (struct streamer_tree_cache_d);
 399
 400   if (with_map)
 401     cache->node_map = new hash_map<tree, unsigned> (251);
 402   cache->next_idx = 0;
 403   if (with_vec)
 404     cache->nodes.create (165);
 405   if (with_hashes)
 406     cache->hashes.create (165);
 407
 408   /* Load all the well-known tree nodes that are always created by
 409      the compiler on startup.  This prevents writing them out
 410      unnecessarily.  */
 411   preload_common_nodes (cache);
 412
 413   return cache;
 414 }
 415
 416
 417 /* Delete the streamer cache C.  */
 418
 419 void
 420 streamer_tree_cache_delete (struct streamer_tree_cache_d *c)
 421 {
 422   if (c == NULL)
 423     return;
 424
 425   delete c->node_map;
 426   c->node_map = NULL;
 427   c->nodes.release ();
 428   c->hashes.release ();
 429   free (c);
 430 }