1/* Miscellaneous utilities for GIMPLE streaming.  Things that are used
2   in both input and output are here.
3
4   Copyright (C) 2009-2015 Free Software Foundation, Inc.
5   Contributed by Doug Kwan <dougkwan@google.com>
6
7This file is part of GCC.
8
9GCC is free software; you can redistribute it and/or modify it under
10the terms of the GNU General Public License as published by the Free
11Software Foundation; either version 3, or (at your option) any later
12version.
13
14GCC is distributed in the hope that it will be useful, but WITHOUT ANY
15WARRANTY; without even the implied warranty of MERCHANTABILITY or
16FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
17for more details.
18
19You should have received a copy of the GNU General Public License
20along 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 "tm.h"
27#include "toplev.h"
28#include "flags.h"
29#include "hash-set.h"
30#include "machmode.h"
31#include "vec.h"
32#include "double-int.h"
33#include "input.h"
34#include "alias.h"
35#include "symtab.h"
36#include "wide-int.h"
37#include "inchash.h"
38#include "tree.h"
39#include "fold-const.h"
40#include "predict.h"
41#include "hard-reg-set.h"
42#include "input.h"
43#include "function.h"
44#include "basic-block.h"
45#include "tree-ssa-alias.h"
46#include "internal-fn.h"
47#include "gimple-expr.h"
48#include "is-a.h"
49#include "gimple.h"
50#include "bitmap.h"
51#include "diagnostic-core.h"
52#include "hash-map.h"
53#include "plugin-api.h"
54#include "ipa-ref.h"
55#include "cgraph.h"
56#include "tree-streamer.h"
57#include "lto-streamer.h"
58#include "lto-section-names.h"
59#include "streamer-hooks.h"
60
61/* Statistics gathered during LTO, WPA and LTRANS.  */
62struct lto_stats_d lto_stats;
63
64/* LTO uses bitmaps with different life-times.  So use a separate
65   obstack for all LTO bitmaps.  */
66static bitmap_obstack lto_obstack;
67static bool lto_obstack_initialized;
68
69const char *section_name_prefix = LTO_SECTION_NAME_PREFIX;
70/* Set when streaming LTO for offloading compiler.  */
71bool lto_stream_offload_p;
72
73/* Return a string representing LTO tag TAG.  */
74
75const char *
76lto_tag_name (enum LTO_tags tag)
77{
78  if (lto_tag_is_tree_code_p (tag))
79    {
80      /* For tags representing tree nodes, return the name of the
81	 associated tree code.  */
82      return get_tree_code_name (lto_tag_to_tree_code (tag));
83    }
84
85  if (lto_tag_is_gimple_code_p (tag))
86    {
87      /* For tags representing gimple statements, return the name of
88	 the associated gimple code.  */
89      return gimple_code_name[lto_tag_to_gimple_code (tag)];
90    }
91
92  switch (tag)
93    {
94    case LTO_null:
95      return "LTO_null";
96    case LTO_bb0:
97      return "LTO_bb0";
98    case LTO_bb1:
99      return "LTO_bb1";
100    case LTO_eh_region:
101      return "LTO_eh_region";
102    case LTO_function:
103      return "LTO_function";
104    case LTO_eh_table:
105      return "LTO_eh_table";
106    case LTO_ert_cleanup:
107      return "LTO_ert_cleanup";
108    case LTO_ert_try:
109      return "LTO_ert_try";
110    case LTO_ert_allowed_exceptions:
111      return "LTO_ert_allowed_exceptions";
112    case LTO_ert_must_not_throw:
113      return "LTO_ert_must_not_throw";
114    case LTO_tree_pickle_reference:
115      return "LTO_tree_pickle_reference";
116    case LTO_field_decl_ref:
117      return "LTO_field_decl_ref";
118    case LTO_function_decl_ref:
119      return "LTO_function_decl_ref";
120    case LTO_label_decl_ref:
121      return "LTO_label_decl_ref";
122    case LTO_namespace_decl_ref:
123      return "LTO_namespace_decl_ref";
124    case LTO_result_decl_ref:
125      return "LTO_result_decl_ref";
126    case LTO_ssa_name_ref:
127      return "LTO_ssa_name_ref";
128    case LTO_type_decl_ref:
129      return "LTO_type_decl_ref";
130    case LTO_type_ref:
131      return "LTO_type_ref";
132    case LTO_global_decl_ref:
133      return "LTO_global_decl_ref";
134    default:
135      return "LTO_UNKNOWN";
136    }
137}
138
139
140/* Allocate a bitmap from heap.  Initializes the LTO obstack if necessary.  */
141
142bitmap
143lto_bitmap_alloc (void)
144{
145  if (!lto_obstack_initialized)
146    {
147      bitmap_obstack_initialize (&lto_obstack);
148      lto_obstack_initialized = true;
149    }
150  return BITMAP_ALLOC (&lto_obstack);
151}
152
153/* Free bitmap B.  */
154
155void
156lto_bitmap_free (bitmap b)
157{
158  BITMAP_FREE (b);
159}
160
161
162/* Get a section name for a particular type or name.  The NAME field
163   is only used if SECTION_TYPE is LTO_section_function_body. For all
164   others it is ignored.  The callee of this function is responsible
165   to free the returned name.  */
166
167char *
168lto_get_section_name (int section_type, const char *name, struct lto_file_decl_data *f)
169{
170  const char *add;
171  char post[32];
172  const char *sep;
173
174  if (section_type == LTO_section_function_body)
175    {
176      gcc_assert (name != NULL);
177      if (name[0] == '*')
178	name++;
179      add = name;
180      sep = "";
181    }
182  else if (section_type < LTO_N_SECTION_TYPES)
183    {
184      add = lto_section_name[section_type];
185      sep = ".";
186    }
187  else
188    internal_error ("bytecode stream: unexpected LTO section %s", name);
189
190  /* Make the section name unique so that ld -r combining sections
191     doesn't confuse the reader with merged sections.
192
193     For options don't add a ID, the option reader cannot deal with them
194     and merging should be ok here. */
195  if (section_type == LTO_section_opts)
196    strcpy (post, "");
197  else if (f != NULL)
198    sprintf (post, "." HOST_WIDE_INT_PRINT_HEX_PURE, f->id);
199  else
200    sprintf (post, "." HOST_WIDE_INT_PRINT_HEX_PURE, get_random_seed (false));
201  return concat (section_name_prefix, sep, add, post, NULL);
202}
203
204
205/* Show various memory usage statistics related to LTO.  */
206
207void
208print_lto_report (const char *s)
209{
210  unsigned i;
211
212  fprintf (stderr, "[%s] # of input files: "
213	   HOST_WIDE_INT_PRINT_UNSIGNED "\n", s, lto_stats.num_input_files);
214
215  fprintf (stderr, "[%s] # of input cgraph nodes: "
216	   HOST_WIDE_INT_PRINT_UNSIGNED "\n", s,
217	   lto_stats.num_input_cgraph_nodes);
218
219  fprintf (stderr, "[%s] # of function bodies: "
220	   HOST_WIDE_INT_PRINT_UNSIGNED "\n", s,
221	   lto_stats.num_function_bodies);
222
223  for (i = 0; i < NUM_TREE_CODES; i++)
224    if (lto_stats.num_trees[i])
225      fprintf (stderr, "[%s] # of '%s' objects read: "
226	       HOST_WIDE_INT_PRINT_UNSIGNED "\n", s,
227	       get_tree_code_name ((enum tree_code) i), lto_stats.num_trees[i]);
228
229  if (flag_lto)
230    {
231      fprintf (stderr, "[%s] Compression: "
232	       HOST_WIDE_INT_PRINT_UNSIGNED " output bytes, "
233	       HOST_WIDE_INT_PRINT_UNSIGNED " compressed bytes", s,
234	       lto_stats.num_output_il_bytes,
235	       lto_stats.num_compressed_il_bytes);
236      if (lto_stats.num_output_il_bytes > 0)
237	{
238	  const float dividend = (float) lto_stats.num_compressed_il_bytes;
239	  const float divisor = (float) lto_stats.num_output_il_bytes;
240	  fprintf (stderr, " (ratio: %f)", dividend / divisor);
241	}
242      fprintf (stderr, "\n");
243    }
244
245  if (flag_wpa)
246    {
247      fprintf (stderr, "[%s] # of output files: "
248	       HOST_WIDE_INT_PRINT_UNSIGNED "\n", s,
249	       lto_stats.num_output_files);
250
251      fprintf (stderr, "[%s] # of output symtab nodes: "
252	       HOST_WIDE_INT_PRINT_UNSIGNED "\n", s,
253	       lto_stats.num_output_symtab_nodes);
254
255      fprintf (stderr, "[%s] # of output tree pickle references: "
256	       HOST_WIDE_INT_PRINT_UNSIGNED "\n", s,
257	       lto_stats.num_pickle_refs_output);
258      fprintf (stderr, "[%s] # of output tree bodies: "
259	       HOST_WIDE_INT_PRINT_UNSIGNED "\n", s,
260	       lto_stats.num_tree_bodies_output);
261
262      fprintf (stderr, "[%s] # callgraph partitions: "
263	       HOST_WIDE_INT_PRINT_UNSIGNED "\n", s,
264	       lto_stats.num_cgraph_partitions);
265
266      fprintf (stderr, "[%s] Compression: "
267	       HOST_WIDE_INT_PRINT_UNSIGNED " input bytes, "
268	       HOST_WIDE_INT_PRINT_UNSIGNED " uncompressed bytes", s,
269	       lto_stats.num_input_il_bytes,
270	       lto_stats.num_uncompressed_il_bytes);
271      if (lto_stats.num_input_il_bytes > 0)
272	{
273	  const float dividend = (float) lto_stats.num_uncompressed_il_bytes;
274	  const float divisor = (float) lto_stats.num_input_il_bytes;
275	  fprintf (stderr, " (ratio: %f)", dividend / divisor);
276	}
277      fprintf (stderr, "\n");
278    }
279
280  for (i = 0; i < LTO_N_SECTION_TYPES; i++)
281    fprintf (stderr, "[%s] Size of mmap'd section %s: "
282	     HOST_WIDE_INT_PRINT_UNSIGNED " bytes\n", s,
283	     lto_section_name[i], lto_stats.section_size[i]);
284}
285
286
287#ifdef LTO_STREAMER_DEBUG
288struct tree_hash_entry
289{
290  tree key;
291  intptr_t value;
292};
293
294struct tree_entry_hasher : typed_noop_remove <tree_hash_entry>
295{
296  typedef tree_hash_entry value_type;
297  typedef tree_hash_entry compare_type;
298  static inline hashval_t hash (const value_type *);
299  static inline bool equal (const value_type *, const compare_type *);
300};
301
302inline hashval_t
303tree_entry_hasher::hash (const value_type *e)
304{
305  return htab_hash_pointer (e->key);
306}
307
308inline bool
309tree_entry_hasher::equal (const value_type *e1, const compare_type *e2)
310{
311  return (e1->key == e2->key);
312}
313
314static hash_table<tree_hash_entry> *tree_htab;
315#endif
316
317/* Initialization common to the LTO reader and writer.  */
318
319void
320lto_streamer_init (void)
321{
322#ifdef ENABLE_CHECKING
323  /* Check that all the TS_* handled by the reader and writer routines
324     match exactly the structures defined in treestruct.def.  When a
325     new TS_* astructure is added, the streamer should be updated to
326     handle it.  */
327  streamer_check_handled_ts_structures ();
328#endif
329
330#ifdef LTO_STREAMER_DEBUG
331  tree_htab = new hash_table<tree_hash_entry> (31);
332#endif
333}
334
335
336/* Gate function for all LTO streaming passes.  */
337
338bool
339gate_lto_out (void)
340{
341  return ((flag_generate_lto || flag_generate_offload || in_lto_p)
342	  /* Don't bother doing anything if the program has errors.  */
343	  && !seen_error ());
344}
345
346
347#ifdef LTO_STREAMER_DEBUG
348/* Add a mapping between T and ORIG_T, which is the numeric value of
349   the original address of T as it was seen by the LTO writer.  This
350   mapping is useful when debugging streaming problems.  A debugging
351   session can be started on both reader and writer using ORIG_T
352   as a breakpoint value in both sessions.
353
354   Note that this mapping is transient and only valid while T is
355   being reconstructed.  Once T is fully built, the mapping is
356   removed.  */
357
358void
359lto_orig_address_map (tree t, intptr_t orig_t)
360{
361  struct tree_hash_entry ent;
362  struct tree_hash_entry **slot;
363
364  ent.key = t;
365  ent.value = orig_t;
366  slot = tree_htab->find_slot (&ent, INSERT);
367  gcc_assert (!*slot);
368  *slot = XNEW (struct tree_hash_entry);
369  **slot = ent;
370}
371
372
373/* Get the original address of T as it was seen by the writer.  This
374   is only valid while T is being reconstructed.  */
375
376intptr_t
377lto_orig_address_get (tree t)
378{
379  struct tree_hash_entry ent;
380  struct tree_hash_entry **slot;
381
382  ent.key = t;
383  slot = tree_htab->find_slot (&ent, NO_INSERT);
384  return (slot ? (*slot)->value : 0);
385}
386
387
388/* Clear the mapping of T to its original address.  */
389
390void
391lto_orig_address_remove (tree t)
392{
393  struct tree_hash_entry ent;
394  struct tree_hash_entry **slot;
395
396  ent.key = t;
397  slot = tree_htab->find_slot (&ent, NO_INSERT);
398  gcc_assert (slot);
399  free (*slot);
400  tree_htab->clear_slot (slot);
401}
402#endif
403
404
405/* Check that the version MAJOR.MINOR is the correct version number.  */
406
407void
408lto_check_version (int major, int minor)
409{
410  if (major != LTO_major_version || minor != LTO_minor_version)
411    fatal_error (input_location,
412		 "bytecode stream generated with LTO version %d.%d instead "
413	         "of the expected %d.%d",
414		 major, minor,
415		 LTO_major_version, LTO_minor_version);
416}
417
418
419/* Initialize all the streamer hooks used for streaming GIMPLE.  */
420
421void
422lto_streamer_hooks_init (void)
423{
424  streamer_hooks_init ();
425  streamer_hooks.write_tree = lto_output_tree;
426  streamer_hooks.read_tree = lto_input_tree;
427  streamer_hooks.input_location = lto_input_location;
428  streamer_hooks.output_location = lto_output_location;
429}
430