gcc/lto-section-out.c

   1 /* Functions for writing LTO sections.
   2
   3    Copyright (C) 2009-2020 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 "backend.h"
  26 #include "rtl.h"
  27 #include "tree.h"
  28 #include "gimple.h"
  29 #include "cgraph.h"
  30 #include "data-streamer.h"
  31 #include "langhooks.h"
  32 #include "lto-compress.h"
  33 #include "print-tree.h"
  34
  35 static vec<lto_out_decl_state_ptr> decl_state_stack;
  36
  37 /* List of out decl states used by functions.  We use this to
  38    generate the decl directory later. */
  39
  40 vec<lto_out_decl_state_ptr> lto_function_decl_states;
  41
  42
  43 /*****************************************************************************
  44    Output routines shared by all of the serialization passes.
  45 *****************************************************************************/
  46
  47
  48 /* Flush compressed stream data function, sends NUM_CHARS from CHARS
  49    to the append lang hook, OPAQUE is currently always NULL.  */
  50
  51 static void
  52 lto_append_data (const char *chars, unsigned int num_chars, void *opaque)
  53 {
  54   gcc_assert (opaque == NULL);
  55   lang_hooks.lto.append_data (chars, num_chars, opaque);
  56 }
  57
  58 /* Pointer to the current compression stream.  */
  59
  60 static struct lto_compression_stream *compression_stream = NULL;
  61
  62 /* Begin a new output section named NAME. If COMPRESS is true, zlib compress
  63    the section. */
  64
  65 void
  66 lto_begin_section (const char *name, bool compress)
  67 {
  68   lang_hooks.lto.begin_section (name);
  69
  70   if (streamer_dump_file)
  71     {
  72       if (flag_dump_unnumbered || flag_dump_noaddr)
  73           fprintf (streamer_dump_file, "Creating %ssection\n",
  74                    compress ? "compressed " : "");
  75         else
  76           fprintf (streamer_dump_file, "Creating %ssection %s\n",
  77                    compress ? "compressed " : "", name);
  78     }
  79   gcc_assert (compression_stream == NULL);
  80   if (compress)
  81     compression_stream = lto_start_compression (lto_append_data, NULL);
  82 }
  83
  84
  85 /* End the current output section.  */
  86
  87 void
  88 lto_end_section (void)
  89 {
  90   if (compression_stream)
  91     {
  92       lto_end_compression (compression_stream);
  93       compression_stream = NULL;
  94     }
  95   lang_hooks.lto.end_section ();
  96 }
  97
  98 /* Write SIZE bytes starting at DATA to the assembler.  */
  99
 100 void
 101 lto_write_data (const void *data, unsigned int size)
 102 {
 103   if (compression_stream)
 104     lto_compress_block (compression_stream, (const char *)data, size);
 105   else
 106     lang_hooks.lto.append_data ((const char *)data, size, NULL);
 107 }
 108
 109 /* Write SIZE bytes starting at DATA to the assembler.  */
 110
 111 void
 112 lto_write_raw_data (const void *data, unsigned int size)
 113 {
 114   lang_hooks.lto.append_data ((const char *)data, size, NULL);
 115 }
 116
 117 /* Write all of the chars in OBS to the assembler.  Recycle the blocks
 118    in obs as this is being done.  */
 119
 120 void
 121 lto_write_stream (struct lto_output_stream *obs)
 122 {
 123   unsigned int block_size = 1024;
 124   struct lto_char_ptr_base *block;
 125   struct lto_char_ptr_base *next_block;
 126   if (!obs->first_block)
 127     return;
 128
 129   for (block = obs->first_block; block; block = next_block)
 130     {
 131       const char *base = ((char *)block) + sizeof (struct lto_char_ptr_base);
 132       unsigned int num_chars = block_size - sizeof (struct lto_char_ptr_base);
 133
 134       /* If this is not the last block, it is full.  If it is the last
 135          block, left_in_block indicates how many chars are unoccupied in
 136          this block; subtract from num_chars to obtain occupancy.  */
 137       next_block = (struct lto_char_ptr_base *) block->ptr;
 138       if (!next_block)
 139         num_chars -= obs->left_in_block;
 140
 141       if (compression_stream)
 142         lto_compress_block (compression_stream, base, num_chars);
 143       else
 144         lang_hooks.lto.append_data (base, num_chars, block);
 145       free (block);
 146       block_size *= 2;
 147     }
 148 }
 149
 150
 151 /* Lookup NAME in ENCODER.  If NAME is not found, create a new entry in
 152    ENCODER for NAME with the next available index of ENCODER,  then
 153    print the index to OBS.  True is returned if NAME was added to
 154    ENCODER.  The resulting index is stored in THIS_INDEX.
 155
 156    If OBS is NULL, the only action is to add NAME to the encoder. */
 157
 158 bool
 159 lto_output_decl_index (struct lto_output_stream *obs,
 160                        struct lto_tree_ref_encoder *encoder,
 161                        tree name, unsigned int *this_index)
 162 {
 163   bool new_entry_p = FALSE;
 164   bool existed_p;
 165
 166   unsigned int &index
 167     = encoder->tree_hash_table->get_or_insert (name, &existed_p);
 168   if (!existed_p)
 169     {
 170       index = encoder->trees.length ();
 171       if (streamer_dump_file)
 172         {
 173           print_node_brief (streamer_dump_file, "    Encoding indexable ",
 174                             name, 4);
 175           fprintf (streamer_dump_file, "  as %i \n", index);
 176         }
 177       encoder->trees.safe_push (name);
 178       new_entry_p = TRUE;
 179     }
 180
 181   if (obs)
 182     streamer_write_uhwi_stream (obs, index);
 183   *this_index = index;
 184   return new_entry_p;
 185 }
 186
 187 /* Output a field DECL to OBS.  */
 188
 189 void
 190 lto_output_field_decl_index (struct lto_out_decl_state *decl_state,
 191                              struct lto_output_stream * obs, tree decl)
 192 {
 193   unsigned int index;
 194   lto_output_decl_index (obs, &decl_state->streams[LTO_DECL_STREAM_FIELD_DECL],
 195                          decl, &index);
 196 }
 197
 198 /* Output a function DECL to OBS.  */
 199
 200 void
 201 lto_output_fn_decl_index (struct lto_out_decl_state *decl_state,
 202                           struct lto_output_stream * obs, tree decl)
 203 {
 204   unsigned int index;
 205   lto_output_decl_index (obs, &decl_state->streams[LTO_DECL_STREAM_FN_DECL],
 206                          decl, &index);
 207 }
 208
 209 /* Output a namespace DECL to OBS.  */
 210
 211 void
 212 lto_output_namespace_decl_index (struct lto_out_decl_state *decl_state,
 213                                  struct lto_output_stream * obs, tree decl)
 214 {
 215   unsigned int index;
 216   lto_output_decl_index (obs,
 217                          &decl_state->streams[LTO_DECL_STREAM_NAMESPACE_DECL],
 218                          decl, &index);
 219 }
 220
 221 /* Output a static or extern var DECL to OBS.  */
 222
 223 void
 224 lto_output_var_decl_index (struct lto_out_decl_state *decl_state,
 225                            struct lto_output_stream * obs, tree decl)
 226 {
 227   unsigned int index;
 228   lto_output_decl_index (obs, &decl_state->streams[LTO_DECL_STREAM_VAR_DECL],
 229                          decl, &index);
 230 }
 231
 232 /* Output a type DECL to OBS.  */
 233
 234 void
 235 lto_output_type_decl_index (struct lto_out_decl_state *decl_state,
 236                             struct lto_output_stream * obs, tree decl)
 237 {
 238   unsigned int index;
 239   lto_output_decl_index (obs, &decl_state->streams[LTO_DECL_STREAM_TYPE_DECL],
 240                          decl, &index);
 241 }
 242
 243 /* Output a type REF to OBS.  */
 244
 245 void
 246 lto_output_type_ref_index (struct lto_out_decl_state *decl_state,
 247                            struct lto_output_stream *obs, tree ref)
 248 {
 249   unsigned int index;
 250   lto_output_decl_index (obs, &decl_state->streams[LTO_DECL_STREAM_TYPE],
 251                          ref, &index);
 252 }
 253
 254
 255 /* Create the output block and return it.  */
 256
 257 struct lto_simple_output_block *
 258 lto_create_simple_output_block (enum lto_section_type section_type)
 259 {
 260   struct lto_simple_output_block *ob
 261     = ((struct lto_simple_output_block *)
 262        xcalloc (1, sizeof (struct lto_simple_output_block)));
 263
 264   ob->section_type = section_type;
 265   ob->decl_state = lto_get_out_decl_state ();
 266   ob->main_stream = ((struct lto_output_stream *)
 267                      xcalloc (1, sizeof (struct lto_output_stream)));
 268
 269   return ob;
 270 }
 271
 272
 273 /* Produce a simple section for one of the ipa passes.  */
 274
 275 void
 276 lto_destroy_simple_output_block (struct lto_simple_output_block *ob)
 277 {
 278   char *section_name;
 279   struct lto_simple_header header;
 280
 281   section_name = lto_get_section_name (ob->section_type, NULL, 0, NULL);
 282   lto_begin_section (section_name, !flag_wpa);
 283   free (section_name);
 284
 285   /* Write the header which says how to decode the pieces of the
 286      t.  */
 287   memset (&header, 0, sizeof (struct lto_simple_header));
 288   header.main_size = ob->main_stream->total_size;
 289   lto_write_data (&header, sizeof header);
 290
 291   lto_write_stream (ob->main_stream);
 292
 293   /* Put back the assembly section that was there before we started
 294      writing lto info.  */
 295   lto_end_section ();
 296
 297   free (ob->main_stream);
 298   free (ob);
 299 }
 300
 301
 302 /* Return a new lto_out_decl_state. */
 303
 304 struct lto_out_decl_state *
 305 lto_new_out_decl_state (void)
 306 {
 307   struct lto_out_decl_state *state = XCNEW (struct lto_out_decl_state);
 308   int i;
 309
 310   for (i = 0; i < LTO_N_DECL_STREAMS; i++)
 311     lto_init_tree_ref_encoder (&state->streams[i]);
 312
 313   /* At WPA time we do not compress sections by default.  */
 314   state->compressed = !flag_wpa;
 315
 316   return state;
 317 }
 318
 319
 320 /* Delete STATE and components.  */
 321
 322 void
 323 lto_delete_out_decl_state (struct lto_out_decl_state *state)
 324 {
 325   int i;
 326
 327   for (i = 0; i < LTO_N_DECL_STREAMS; i++)
 328     lto_destroy_tree_ref_encoder (&state->streams[i]);
 329
 330   free (state);
 331 }
 332
 333
 334 /* Get the currently used lto_out_decl_state structure. */
 335
 336 struct lto_out_decl_state *
 337 lto_get_out_decl_state (void)
 338 {
 339   return decl_state_stack.last ();
 340 }
 341
 342 /* Push STATE to top of out decl stack. */
 343
 344 void
 345 lto_push_out_decl_state (struct lto_out_decl_state *state)
 346 {
 347   decl_state_stack.safe_push (state);
 348 }
 349
 350 /* Pop the currently used out-decl state from top of stack. */
 351
 352 struct lto_out_decl_state *
 353 lto_pop_out_decl_state (void)
 354 {
 355   return decl_state_stack.pop ();
 356 }
 357
 358 /* Record STATE after it has been used in serializing the body of
 359    FN_DECL.  STATE should no longer be used by the caller.  The ownership
 360    of it is taken over from this point.  */
 361
 362 void
 363 lto_record_function_out_decl_state (tree fn_decl,
 364                                     struct lto_out_decl_state *state)
 365 {
 366   int i;
 367
 368   /* Strip all hash tables to save some memory. */
 369   for (i = 0; i < LTO_N_DECL_STREAMS; i++)
 370     if (state->streams[i].tree_hash_table)
 371       {
 372         delete state->streams[i].tree_hash_table;
 373         state->streams[i].tree_hash_table = NULL;
 374       }
 375   state->fn_decl = fn_decl;
 376   lto_function_decl_states.safe_push (state);
 377 }