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) 2011-2019 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_POLY_INT_CST] = true;
  59   handled_p[TS_REAL_CST] = true;
  60   handled_p[TS_FIXED_CST] = true;
  61   handled_p[TS_VECTOR] = true;
  62   handled_p[TS_STRING] = true;
  63   handled_p[TS_COMPLEX] = true;
  64   handled_p[TS_IDENTIFIER] = true;
  65   handled_p[TS_DECL_MINIMAL] = true;
  66   handled_p[TS_DECL_COMMON] = true;
  67   handled_p[TS_DECL_WRTL] = true;
  68   handled_p[TS_DECL_NON_COMMON] = true;
  69   handled_p[TS_DECL_WITH_VIS] = true;
  70   handled_p[TS_FIELD_DECL] = true;
  71   handled_p[TS_VAR_DECL] = true;
  72   handled_p[TS_PARM_DECL] = true;
  73   handled_p[TS_LABEL_DECL] = true;
  74   handled_p[TS_RESULT_DECL] = true;
  75   handled_p[TS_CONST_DECL] = true;
  76   handled_p[TS_TYPE_DECL] = true;
  77   handled_p[TS_FUNCTION_DECL] = true;
  78   handled_p[TS_TYPE_COMMON] = true;
  79   handled_p[TS_TYPE_WITH_LANG_SPECIFIC] = true;
  80   handled_p[TS_TYPE_NON_COMMON] = true;
  81   handled_p[TS_LIST] = true;
  82   handled_p[TS_VEC] = true;
  83   handled_p[TS_EXP] = true;
  84   handled_p[TS_SSA_NAME] = true;
  85   handled_p[TS_BLOCK] = true;
  86   handled_p[TS_BINFO] = true;
  87   handled_p[TS_STATEMENT_LIST] = true;
  88   handled_p[TS_CONSTRUCTOR] = true;
  89   handled_p[TS_OMP_CLAUSE] = true;
  90   handled_p[TS_OPTIMIZATION] = true;
  91   handled_p[TS_TARGET_OPTION] = true;
  92   handled_p[TS_TRANSLATION_UNIT_DECL] = true;
  93
  94   /* Anything not marked above will trigger the following assertion.
  95      If this assertion triggers, it means that there is a new TS_*
  96      structure that should be handled by the streamer.  */
  97   for (i = 0; i < LAST_TS_ENUM; i++)
  98     gcc_assert (handled_p[i]);
  99 }
 100
 101
 102 /* Helper for streamer_tree_cache_insert_1.  Add T to CACHE->NODES at
 103    slot IX.  */
 104
 105 static void
 106 streamer_tree_cache_add_to_node_array (struct streamer_tree_cache_d *cache,
 107                                        unsigned ix, tree t, hashval_t hash)
 108 {
 109   /* We're either replacing an old element or appending consecutively.  */
 110   if (cache->nodes.exists ())
 111     {
 112       if (cache->nodes.length () == ix)
 113         cache->nodes.safe_push (t);
 114       else
 115         cache->nodes[ix] = t;
 116     }
 117   if (cache->hashes.exists ())
 118     {
 119       if (cache->hashes.length () == ix)
 120         cache->hashes.safe_push (hash);
 121       else
 122         cache->hashes[ix] = hash;
 123     }
 124 }
 125
 126
 127 /* Helper for streamer_tree_cache_insert and streamer_tree_cache_insert_at.
 128    CACHE, T, and IX_P are as in streamer_tree_cache_insert.
 129
 130    If INSERT_AT_NEXT_SLOT_P is true, T is inserted at the next available
 131    slot in the cache.  Otherwise, T is inserted at the position indicated
 132    in *IX_P.
 133
 134    If T already existed in CACHE, return true.  Otherwise,
 135    return false.  */
 136
 137 static bool
 138 streamer_tree_cache_insert_1 (struct streamer_tree_cache_d *cache,
 139                               tree t, hashval_t hash, unsigned *ix_p,
 140                               bool insert_at_next_slot_p)
 141 {
 142   bool existed_p;
 143
 144   gcc_assert (t);
 145
 146   unsigned int &ix = cache->node_map->get_or_insert (t, &existed_p);
 147   if (!existed_p)
 148     {
 149       /* Determine the next slot to use in the cache.  */
 150       if (insert_at_next_slot_p)
 151         ix = cache->next_idx++;
 152       else
 153         ix = *ix_p;
 154
 155       streamer_tree_cache_add_to_node_array (cache, ix, t, hash);
 156     }
 157   else
 158     {
 159       if (!insert_at_next_slot_p && ix != *ix_p)
 160         {
 161           /* If the caller wants to insert T at a specific slot
 162              location, and ENTRY->TO does not match *IX_P, add T to
 163              the requested location slot.  */
 164           ix = *ix_p;
 165           streamer_tree_cache_add_to_node_array (cache, ix, t, hash);
 166         }
 167     }
 168
 169   if (ix_p)
 170     *ix_p = ix;
 171
 172   return existed_p;
 173 }
 174
 175
 176 /* Insert tree node T in CACHE.  If T already existed in the cache
 177    return true.  Otherwise, return false.
 178
 179    If IX_P is non-null, update it with the index into the cache where
 180    T has been stored.  */
 181
 182 bool
 183 streamer_tree_cache_insert (struct streamer_tree_cache_d *cache, tree t,
 184                             hashval_t hash, unsigned *ix_p)
 185 {
 186   return streamer_tree_cache_insert_1 (cache, t, hash, ix_p, true);
 187 }
 188
 189
 190 /* Replace the tree node with T in CACHE at slot IX.  */
 191
 192 void
 193 streamer_tree_cache_replace_tree (struct streamer_tree_cache_d *cache,
 194                                   tree t, unsigned ix)
 195 {
 196   hashval_t hash = 0;
 197   if (cache->hashes.exists ())
 198     hash = streamer_tree_cache_get_hash (cache, ix);
 199   if (!cache->node_map)
 200     streamer_tree_cache_add_to_node_array (cache, ix, t, hash);
 201   else
 202     streamer_tree_cache_insert_1 (cache, t, hash, &ix, false);
 203 }
 204
 205
 206 /* Appends tree node T to CACHE, even if T already existed in it.  */
 207
 208 void
 209 streamer_tree_cache_append (struct streamer_tree_cache_d *cache,
 210                             tree t, hashval_t hash)
 211 {
 212   unsigned ix = cache->next_idx++;
 213   if (!cache->node_map)
 214     streamer_tree_cache_add_to_node_array (cache, ix, t, hash);
 215   else
 216     streamer_tree_cache_insert_1 (cache, t, hash, &ix, false);
 217 }
 218
 219 /* Return true if tree node T exists in CACHE, otherwise false.  If IX_P is
 220    not NULL, write to *IX_P the index into the cache where T is stored
 221    ((unsigned)-1 if T is not found).  */
 222
 223 bool
 224 streamer_tree_cache_lookup (struct streamer_tree_cache_d *cache, tree t,
 225                             unsigned *ix_p)
 226 {
 227   unsigned *slot;
 228   bool retval;
 229   unsigned ix;
 230
 231   gcc_assert (t);
 232
 233   slot = cache->node_map->get (t);
 234   if (slot == NULL)
 235     {
 236       retval = false;
 237       ix = -1;
 238     }
 239   else
 240     {
 241       retval = true;
 242       ix = *slot;
 243     }
 244
 245   if (ix_p)
 246     *ix_p = ix;
 247
 248   return retval;
 249 }
 250
 251
 252 /* Verify that NODE is in CACHE.  */
 253
 254 static void
 255 verify_common_node_recorded (struct streamer_tree_cache_d *cache, tree node)
 256 {
 257   /* Restrict this to flag_checking only because in general violating it is
 258      harmless plus we never know what happens on all targets/frontend/flag(!)
 259      combinations.  */
 260   if (!flag_checking)
 261     return;
 262
 263   if (cache->node_map)
 264     gcc_assert (streamer_tree_cache_lookup (cache, node, NULL));
 265   else
 266     {
 267       bool found = false;
 268       gcc_assert (cache->nodes.exists ());
 269       /* Linear search...  */
 270       for (unsigned i = 0; !found && i < cache->nodes.length (); ++i)
 271         if (cache->nodes[i] == node)
 272           found = true;
 273       gcc_assert (found);
 274     }
 275 }
 276
 277
 278 /* Record NODE in CACHE.  */
 279
 280 static void
 281 record_common_node (struct streamer_tree_cache_d *cache, tree node)
 282 {
 283   /* If we recursively end up at nodes we do not want to preload simply don't.
 284      ???  We'd want to verify that this doesn't happen, or alternatively
 285      do not recurse at all.  */
 286   if (node == char_type_node)
 287     return;
 288
 289   gcc_checking_assert (node != boolean_type_node
 290                        && node != boolean_true_node
 291                        && node != boolean_false_node);
 292
 293   /* We have to make sure to fill exactly the same number of
 294      elements for all frontends.  That can include NULL trees.
 295      As our hash table can't deal with zero entries we'll simply stream
 296      a random other tree.  A NULL tree never will be looked up so it
 297      doesn't matter which tree we replace it with, just to be sure
 298      use error_mark_node.  */
 299   if (!node)
 300     node = error_mark_node;
 301
 302   /* ???  FIXME, devise a better hash value.  But the hash needs to be equal
 303      for all frontend and lto1 invocations.  So just use the position
 304      in the cache as hash value.  */
 305   streamer_tree_cache_append (cache, node, cache->nodes.length ());
 306
 307   switch (TREE_CODE (node))
 308     {
 309     case ERROR_MARK:
 310     case FIELD_DECL:
 311     case FIXED_POINT_TYPE:
 312     case IDENTIFIER_NODE:
 313     case INTEGER_CST:
 314     case INTEGER_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 }