summaryrefslogtreecommitdiff
path: root/gcc/symtab.c
blob: ded6ecc17d53f1b69a7fae6cc702e430bfe3717c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
2164
2165
2166
2167
2168
2169
2170
2171
2172
2173
2174
2175
2176
2177
2178
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188
2189
2190
2191
2192
2193
2194
2195
2196
2197
2198
2199
2200
2201
2202
2203
2204
2205
2206
2207
2208
2209
2210
2211
2212
2213
2214
2215
2216
2217
2218
2219
2220
2221
2222
2223
2224
2225
2226
2227
2228
2229
2230
2231
2232
2233
2234
2235
2236
2237
2238
2239
2240
2241
2242
2243
2244
2245
2246
2247
2248
2249
2250
2251
2252
2253
2254
2255
2256
2257
2258
2259
2260
2261
2262
2263
2264
/* Symbol table.
   Copyright (C) 2012-2016 Free Software Foundation, Inc.
   Contributed by Jan Hubicka

This file is part of GCC.

GCC is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 3, or (at your option) any later
version.

GCC is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
for more details.

You should have received a copy of the GNU General Public License
along with GCC; see the file COPYING3.  If not see
<http://www.gnu.org/licenses/>.  */

#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "backend.h"
#include "target.h"
#include "rtl.h"
#include "tree.h"
#include "gimple.h"
#include "timevar.h"
#include "cgraph.h"
#include "lto-streamer.h"
#include "print-tree.h"
#include "varasm.h"
#include "langhooks.h"
#include "output.h"
#include "ipa-utils.h"
#include "calls.h"

static const char *ipa_ref_use_name[] = {"read","write","addr","alias","chkp"};

const char * const ld_plugin_symbol_resolution_names[]=
{
  "",
  "undef",
  "prevailing_def",
  "prevailing_def_ironly",
  "preempted_reg",
  "preempted_ir",
  "resolved_ir",
  "resolved_exec",
  "resolved_dyn",
  "prevailing_def_ironly_exp"
};

/* Follow the IDENTIFIER_TRANSPARENT_ALIAS chain starting at ALIAS
   until we find an identifier that is not itself a transparent alias.  */

static inline tree
ultimate_transparent_alias_target (tree alias)
{
  tree target = alias;

  while (IDENTIFIER_TRANSPARENT_ALIAS (target))
    {
      gcc_checking_assert (TREE_CHAIN (target));
      target = TREE_CHAIN (target);
    }
  gcc_checking_assert (! IDENTIFIER_TRANSPARENT_ALIAS (target)
		       && ! TREE_CHAIN (target));

  return target;
}


/* Hash asmnames ignoring the user specified marks.  */

hashval_t
symbol_table::decl_assembler_name_hash (const_tree asmname)
{
  if (IDENTIFIER_POINTER (asmname)[0] == '*')
    {
      const char *decl_str = IDENTIFIER_POINTER (asmname) + 1;
      size_t ulp_len = strlen (user_label_prefix);

      if (ulp_len == 0)
	;
      else if (strncmp (decl_str, user_label_prefix, ulp_len) == 0)
	decl_str += ulp_len;

      return htab_hash_string (decl_str);
    }

  return htab_hash_string (IDENTIFIER_POINTER (asmname));
}

/* Return true if assembler names NAME1 and NAME2 leads to the same symbol
   name.  */

bool
symbol_table::assembler_names_equal_p (const char *name1, const char *name2)
{
  if (name1 != name2)
    {
      if (name1[0] == '*')
	{
	  size_t ulp_len = strlen (user_label_prefix);

	  name1 ++;

	  if (ulp_len == 0)
	    ;
	  else if (strncmp (name1, user_label_prefix, ulp_len) == 0)
	    name1 += ulp_len;
	  else
	    return false;
	}
      if (name2[0] == '*')
	{
	  size_t ulp_len = strlen (user_label_prefix);

	  name2 ++;

	  if (ulp_len == 0)
	    ;
	  else if (strncmp (name2, user_label_prefix, ulp_len) == 0)
	    name2 += ulp_len;
	  else
	    return false;
	}
      return !strcmp (name1, name2);
    }
  return true;
}

/* Compare ASMNAME with the DECL_ASSEMBLER_NAME of DECL.  */

bool
symbol_table::decl_assembler_name_equal (tree decl, const_tree asmname)
{
  tree decl_asmname = DECL_ASSEMBLER_NAME (decl);
  const char *decl_str;
  const char *asmname_str;

  if (decl_asmname == asmname)
    return true;

  decl_str = IDENTIFIER_POINTER (decl_asmname);
  asmname_str = IDENTIFIER_POINTER (asmname);
  return assembler_names_equal_p (decl_str, asmname_str);
}


/* Returns nonzero if P1 and P2 are equal.  */

/* Insert NODE to assembler name hash.  */

void
symbol_table::insert_to_assembler_name_hash (symtab_node *node,
					     bool with_clones)
{
  if (is_a <varpool_node *> (node) && DECL_HARD_REGISTER (node->decl))
    return;
  gcc_checking_assert (!node->previous_sharing_asm_name
		       && !node->next_sharing_asm_name);
  if (assembler_name_hash)
    {
      symtab_node **aslot;
      cgraph_node *cnode;
      tree decl = node->decl;

      tree name = DECL_ASSEMBLER_NAME (node->decl);

      /* C++ FE can produce decls without associated assembler name and insert
	 them to symtab to hold section or TLS information.  */
      if (!name)
	return;

      hashval_t hash = decl_assembler_name_hash (name);
      aslot = assembler_name_hash->find_slot_with_hash (name, hash, INSERT);
      gcc_assert (*aslot != node);
      node->next_sharing_asm_name = (symtab_node *)*aslot;
      if (*aslot != NULL)
	(*aslot)->previous_sharing_asm_name = node;
      *aslot = node;

      /* Update also possible inline clones sharing a decl.  */
      cnode = dyn_cast <cgraph_node *> (node);
      if (cnode && cnode->clones && with_clones)
	for (cnode = cnode->clones; cnode; cnode = cnode->next_sibling_clone)
	  if (cnode->decl == decl)
	    insert_to_assembler_name_hash (cnode, true);
    }

}

/* Remove NODE from assembler name hash.  */

void
symbol_table::unlink_from_assembler_name_hash (symtab_node *node,
					       bool with_clones)
{
  if (assembler_name_hash)
    {
      cgraph_node *cnode;
      tree decl = node->decl;

      if (node->next_sharing_asm_name)
	node->next_sharing_asm_name->previous_sharing_asm_name
	  = node->previous_sharing_asm_name;
      if (node->previous_sharing_asm_name)
	{
	  node->previous_sharing_asm_name->next_sharing_asm_name
	    = node->next_sharing_asm_name;
	}
      else
	{
	  tree name = DECL_ASSEMBLER_NAME (node->decl);
          symtab_node **slot;

	  if (!name)
	    return;

	  hashval_t hash = decl_assembler_name_hash (name);
	  slot = assembler_name_hash->find_slot_with_hash (name, hash,
							   NO_INSERT);
	  gcc_assert (*slot == node);
	  if (!node->next_sharing_asm_name)
	    assembler_name_hash->clear_slot (slot);
	  else
	    *slot = node->next_sharing_asm_name;
	}
      node->next_sharing_asm_name = NULL;
      node->previous_sharing_asm_name = NULL;

      /* Update also possible inline clones sharing a decl.  */
      cnode = dyn_cast <cgraph_node *> (node);
      if (cnode && cnode->clones && with_clones)
	for (cnode = cnode->clones; cnode; cnode = cnode->next_sibling_clone)
	  if (cnode->decl == decl)
	    unlink_from_assembler_name_hash (cnode, true);
    }
}

/* Arrange node to be first in its entry of assembler_name_hash.  */

void
symbol_table::symtab_prevail_in_asm_name_hash (symtab_node *node)
{
  unlink_from_assembler_name_hash (node, false);
  insert_to_assembler_name_hash (node, false);
}

/* Initalize asm name hash unless.  */

void
symbol_table::symtab_initialize_asm_name_hash (void)
{
  symtab_node *node;
  if (!assembler_name_hash)
    {
      assembler_name_hash = hash_table<asmname_hasher>::create_ggc (10);
      FOR_EACH_SYMBOL (node)
	insert_to_assembler_name_hash (node, false);
    }
}

/* Set the DECL_ASSEMBLER_NAME and update symtab hashtables.  */

void
symbol_table::change_decl_assembler_name (tree decl, tree name)
{
  symtab_node *node = NULL;

  /* We can have user ASM names on things, like global register variables, that
     are not in the symbol table.  */
  if ((TREE_CODE (decl) == VAR_DECL
       && (TREE_STATIC (decl) || DECL_EXTERNAL (decl)))
      || TREE_CODE (decl) == FUNCTION_DECL)
    node = symtab_node::get (decl);
  if (!DECL_ASSEMBLER_NAME_SET_P (decl))
    {
      SET_DECL_ASSEMBLER_NAME (decl, name);
      if (node)
	insert_to_assembler_name_hash (node, true);
    }
  else
    {
      if (name == DECL_ASSEMBLER_NAME (decl))
	return;

      tree alias = (IDENTIFIER_TRANSPARENT_ALIAS (DECL_ASSEMBLER_NAME (decl))
		    ? TREE_CHAIN (DECL_ASSEMBLER_NAME (decl))
		    : NULL);
      if (node)
	unlink_from_assembler_name_hash (node, true);

      const char *old_name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
      if (TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (decl))
	  && DECL_RTL_SET_P (decl))
	warning (0, "%D renamed after being referenced in assembly", decl);

      SET_DECL_ASSEMBLER_NAME (decl, name);
      if (alias)
	{
	  IDENTIFIER_TRANSPARENT_ALIAS (name) = 1;
	  TREE_CHAIN (name) = alias;
	}
      /* If we change assembler name, also all transparent aliases must
	 be updated.  There are three kinds - those having same assembler name,
	 those being renamed in varasm.c and weakref being renamed by the
	 assembler.  */
      if (node)
	{
	  insert_to_assembler_name_hash (node, true);
	  ipa_ref *ref;
	  for (unsigned i = 0; node->iterate_direct_aliases (i, ref); i++)
	    {
	      struct symtab_node *alias = ref->referring;
	      if (alias->transparent_alias && !alias->weakref
		  && symbol_table::assembler_names_equal_p
			 (old_name, IDENTIFIER_POINTER (
				      DECL_ASSEMBLER_NAME (alias->decl))))
		change_decl_assembler_name (alias->decl, name);
	      else if (alias->transparent_alias
		       && IDENTIFIER_TRANSPARENT_ALIAS (alias->decl))
		{
		  gcc_assert (TREE_CHAIN (DECL_ASSEMBLER_NAME (alias->decl))
			      && IDENTIFIER_TRANSPARENT_ALIAS
				     (DECL_ASSEMBLER_NAME (alias->decl)));

		  TREE_CHAIN (DECL_ASSEMBLER_NAME (alias->decl)) = 
		    ultimate_transparent_alias_target
			 (DECL_ASSEMBLER_NAME (node->decl));
		}
#ifdef ASM_OUTPUT_WEAKREF
	     else gcc_assert (!alias->transparent_alias || alias->weakref);
#else
	     else gcc_assert (!alias->transparent_alias);
#endif
	    }
	  gcc_assert (!node->transparent_alias || !node->definition
		      || node->weakref
		      || TREE_CHAIN (DECL_ASSEMBLER_NAME (decl))
		      || symbol_table::assembler_names_equal_p
			  (IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl)),
			   IDENTIFIER_POINTER
			     (DECL_ASSEMBLER_NAME
				 (node->get_alias_target ()->decl))));
	}
    }
}

/* Hash sections by their names.  */

hashval_t
section_name_hasher::hash (section_hash_entry *n)
{
  return htab_hash_string (n->name);
}

/* Return true if section P1 name equals to P2.  */

bool
section_name_hasher::equal (section_hash_entry *n1, const char *name)
{
  return n1->name == name || !strcmp (n1->name, name);
}

/* Add node into symbol table.  This function is not used directly, but via
   cgraph/varpool node creation routines.  */

void
symtab_node::register_symbol (void)
{
  symtab->register_symbol (this);

  if (!decl->decl_with_vis.symtab_node)
    decl->decl_with_vis.symtab_node = this;

  ref_list.clear ();

  /* Be sure to do this last; C++ FE might create new nodes via
     DECL_ASSEMBLER_NAME langhook!  */
  symtab->insert_to_assembler_name_hash (this, false);
}

/* Remove NODE from same comdat group.   */

void
symtab_node::remove_from_same_comdat_group (void)
{
  if (same_comdat_group)
    {
      symtab_node *prev;
      for (prev = same_comdat_group;
	   prev->same_comdat_group != this;
	   prev = prev->same_comdat_group)
	;
      if (same_comdat_group == prev)
	prev->same_comdat_group = NULL;
      else
	prev->same_comdat_group = same_comdat_group;
      same_comdat_group = NULL;
      set_comdat_group (NULL);
    }
}

/* Remove node from symbol table.  This function is not used directly, but via
   cgraph/varpool node removal routines.  */

void
symtab_node::unregister (void)
{
  remove_all_references ();
  remove_all_referring ();

  /* Remove reference to section.  */
  set_section_for_node (NULL);

  remove_from_same_comdat_group ();

  symtab->unregister (this);

  /* During LTO symtab merging we temporarily corrupt decl to symtab node
     hash.  */
  gcc_assert (decl->decl_with_vis.symtab_node || in_lto_p);
  if (decl->decl_with_vis.symtab_node == this)
    {
      symtab_node *replacement_node = NULL;
      if (cgraph_node *cnode = dyn_cast <cgraph_node *> (this))
	replacement_node = cnode->find_replacement ();
      decl->decl_with_vis.symtab_node = replacement_node;
    }
  if (!is_a <varpool_node *> (this) || !DECL_HARD_REGISTER (decl))
    symtab->unlink_from_assembler_name_hash (this, false);
  if (in_init_priority_hash)
    symtab->init_priority_hash->remove (this);
}


/* Remove symbol from symbol table.  */

void
symtab_node::remove (void)
{
  if (cgraph_node *cnode = dyn_cast <cgraph_node *> (this))
    cnode->remove ();
  else if (varpool_node *vnode = dyn_cast <varpool_node *> (this))
    vnode->remove ();
}

/* Add NEW_ to the same comdat group that OLD is in.  */

void
symtab_node::add_to_same_comdat_group (symtab_node *old_node)
{
  gcc_assert (old_node->get_comdat_group ());
  gcc_assert (!same_comdat_group);
  gcc_assert (this != old_node);

  set_comdat_group (old_node->get_comdat_group ());
  same_comdat_group = old_node;
  if (!old_node->same_comdat_group)
    old_node->same_comdat_group = this;
  else
    {
      symtab_node *n;
      for (n = old_node->same_comdat_group;
	   n->same_comdat_group != old_node;
	   n = n->same_comdat_group)
	;
      n->same_comdat_group = this;
    }
}

/* Dissolve the same_comdat_group list in which NODE resides.  */

void
symtab_node::dissolve_same_comdat_group_list (void)
{
  symtab_node *n = this;
  symtab_node *next;

  if (!same_comdat_group)
    return;
  do
    {
      next = n->same_comdat_group;
      n->same_comdat_group = NULL;
      /* Clear comdat_group for comdat locals, since
         make_decl_local doesn't.  */
      if (!TREE_PUBLIC (n->decl))
	n->set_comdat_group (NULL);
      n = next;
    }
  while (n != this);
}

/* Return printable assembler name of NODE.
   This function is used only for debugging.  When assembler name
   is unknown go with identifier name.  */

const char *
symtab_node::asm_name () const
{
  if (!DECL_ASSEMBLER_NAME_SET_P (decl))
    return name ();
  return IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
}

/* Return printable identifier name.  */

const char *
symtab_node::name () const
{
  if (!DECL_NAME (decl))
    {
      if (DECL_ASSEMBLER_NAME_SET_P (decl))
	return asm_name ();
      else
        return "<unnamed>";
    }
  return lang_hooks.decl_printable_name (decl, 2);
}

/* Return ipa reference from this symtab_node to
   REFERED_NODE or REFERED_VARPOOL_NODE. USE_TYPE specify type
   of the use.  */

ipa_ref *
symtab_node::create_reference (symtab_node *referred_node,
			       enum ipa_ref_use use_type)
{
  return create_reference (referred_node, use_type, NULL);
}


/* Return ipa reference from this symtab_node to
   REFERED_NODE or REFERED_VARPOOL_NODE. USE_TYPE specify type
   of the use and STMT the statement (if it exists).  */

ipa_ref *
symtab_node::create_reference (symtab_node *referred_node,
			       enum ipa_ref_use use_type, gimple *stmt)
{
  ipa_ref *ref = NULL, *ref2 = NULL;
  ipa_ref_list *list, *list2;
  ipa_ref_t *old_references;

  gcc_checking_assert (!stmt || is_a <cgraph_node *> (this));
  gcc_checking_assert (use_type != IPA_REF_ALIAS || !stmt);

  list = &ref_list;
  old_references = vec_safe_address (list->references);
  vec_safe_grow (list->references, vec_safe_length (list->references) + 1);
  ref = &list->references->last ();

  list2 = &referred_node->ref_list;

  /* IPA_REF_ALIAS is always inserted at the beginning of the list.   */
  if(use_type == IPA_REF_ALIAS)
    {
      list2->referring.safe_insert (0, ref);
      ref->referred_index = 0;

      for (unsigned int i = 1; i < list2->referring.length (); i++)
	list2->referring[i]->referred_index = i;
    }
  else
    {
      list2->referring.safe_push (ref);
      ref->referred_index = list2->referring.length () - 1;
    }

  ref->referring = this;
  ref->referred = referred_node;
  ref->stmt = stmt;
  ref->lto_stmt_uid = 0;
  ref->use = use_type;
  ref->speculative = 0;

  /* If vector was moved in memory, update pointers.  */
  if (old_references != list->references->address ())
    {
      int i;
      for (i = 0; iterate_reference(i, ref2); i++)
	ref2->referred_ref_list ()->referring[ref2->referred_index] = ref2;
    }
  return ref;
}

/* If VAL is a reference to a function or a variable, add a reference from
   this symtab_node to the corresponding symbol table node.  USE_TYPE specify
   type of the use and STMT the statement (if it exists).  Return the new
   reference or NULL if none was created.  */

ipa_ref *
symtab_node::maybe_create_reference (tree val, enum ipa_ref_use use_type,
				     gimple *stmt)
{
  STRIP_NOPS (val);
  if (TREE_CODE (val) != ADDR_EXPR)
    return NULL;
  val = get_base_var (val);
  if (val && (TREE_CODE (val) == FUNCTION_DECL
	       || TREE_CODE (val) == VAR_DECL))
    {
      symtab_node *referred = symtab_node::get (val);
      gcc_checking_assert (referred);
      return create_reference (referred, use_type, stmt);
    }
  return NULL;
}

/* Clone all references from symtab NODE to this symtab_node.  */

void
symtab_node::clone_references (symtab_node *node)
{
  ipa_ref *ref = NULL, *ref2 = NULL;
  int i;
  for (i = 0; node->iterate_reference (i, ref); i++)
    {
      bool speculative = ref->speculative;
      unsigned int stmt_uid = ref->lto_stmt_uid;

      ref2 = create_reference (ref->referred, ref->use, ref->stmt);
      ref2->speculative = speculative;
      ref2->lto_stmt_uid = stmt_uid;
    }
}

/* Clone all referring from symtab NODE to this symtab_node.  */

void
symtab_node::clone_referring (symtab_node *node)
{
  ipa_ref *ref = NULL, *ref2 = NULL;
  int i;
  for (i = 0; node->iterate_referring(i, ref); i++)
    {
      bool speculative = ref->speculative;
      unsigned int stmt_uid = ref->lto_stmt_uid;

      ref2 = ref->referring->create_reference (this, ref->use, ref->stmt);
      ref2->speculative = speculative;
      ref2->lto_stmt_uid = stmt_uid;
    }
}

/* Clone reference REF to this symtab_node and set its stmt to STMT.  */

ipa_ref *
symtab_node::clone_reference (ipa_ref *ref, gimple *stmt)
{
  bool speculative = ref->speculative;
  unsigned int stmt_uid = ref->lto_stmt_uid;
  ipa_ref *ref2;

  ref2 = create_reference (ref->referred, ref->use, stmt);
  ref2->speculative = speculative;
  ref2->lto_stmt_uid = stmt_uid;
  return ref2;
}

/* Find the structure describing a reference to REFERRED_NODE
   and associated with statement STMT.  */

ipa_ref *
symtab_node::find_reference (symtab_node *referred_node,
			     gimple *stmt, unsigned int lto_stmt_uid)
{
  ipa_ref *r = NULL;
  int i;

  for (i = 0; iterate_reference (i, r); i++)
    if (r->referred == referred_node
	&& !r->speculative
	&& ((stmt && r->stmt == stmt)
	    || (lto_stmt_uid && r->lto_stmt_uid == lto_stmt_uid)
	    || (!stmt && !lto_stmt_uid && !r->stmt && !r->lto_stmt_uid)))
      return r;
  return NULL;
}

/* Remove all references that are associated with statement STMT.  */

void
symtab_node::remove_stmt_references (gimple *stmt)
{
  ipa_ref *r = NULL;
  int i = 0;

  while (iterate_reference (i, r))
    if (r->stmt == stmt)
      r->remove_reference ();
    else
      i++;
}

/* Remove all stmt references in non-speculative references.
   Those are not maintained during inlining & clonning.
   The exception are speculative references that are updated along
   with callgraph edges associated with them.  */

void
symtab_node::clear_stmts_in_references (void)
{
  ipa_ref *r = NULL;
  int i;

  for (i = 0; iterate_reference (i, r); i++)
    if (!r->speculative)
      {
	r->stmt = NULL;
	r->lto_stmt_uid = 0;
      }
}

/* Remove all references in ref list.  */

void
symtab_node::remove_all_references (void)
{
  while (vec_safe_length (ref_list.references))
    ref_list.references->last ().remove_reference ();
  vec_free (ref_list.references);
}

/* Remove all referring items in ref list.  */

void
symtab_node::remove_all_referring (void)
{
  while (ref_list.referring.length ())
    ref_list.referring.last ()->remove_reference ();
  ref_list.referring.release ();
}

/* Dump references in ref list to FILE.  */

void
symtab_node::dump_references (FILE *file)
{
  ipa_ref *ref = NULL;
  int i;
  for (i = 0; iterate_reference (i, ref); i++)
    {
      fprintf (file, "%s/%i (%s)",
               ref->referred->asm_name (),
               ref->referred->order,
	       ipa_ref_use_name [ref->use]);
      if (ref->speculative)
	fprintf (file, " (speculative)");
    }
  fprintf (file, "\n");
}

/* Dump referring in list to FILE.  */

void
symtab_node::dump_referring (FILE *file)
{
  ipa_ref *ref = NULL;
  int i;
  for (i = 0; iterate_referring(i, ref); i++)
    {
      fprintf (file, "%s/%i (%s)",
               ref->referring->asm_name (),
               ref->referring->order,
	       ipa_ref_use_name [ref->use]);
      if (ref->speculative)
	fprintf (file, " (speculative)");
    }
  fprintf (file, "\n");
}

static const char * const symtab_type_names[] = {"symbol", "function", "variable"};

/* Dump base fields of symtab nodes to F.  Not to be used directly.  */

void
symtab_node::dump_base (FILE *f)
{
  static const char * const visibility_types[] = {
    "default", "protected", "hidden", "internal"
  };

  fprintf (f, "%s/%i (%s)", asm_name (), order, name ());
  dump_addr (f, " @", (void *)this);
  fprintf (f, "\n  Type: %s", symtab_type_names[type]);

  if (definition)
    fprintf (f, " definition");
  if (analyzed)
    fprintf (f, " analyzed");
  if (alias)
    fprintf (f, " alias");
  if (transparent_alias)
    fprintf (f, " transparent_alias");
  if (weakref)
    fprintf (f, " weakref");
  if (cpp_implicit_alias)
    fprintf (f, " cpp_implicit_alias");
  if (alias_target)
    fprintf (f, " target:%s",
	     DECL_P (alias_target)
	     ? IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME
				     (alias_target))
	     : IDENTIFIER_POINTER (alias_target));
  if (body_removed)
    fprintf (f, "\n  Body removed by symtab_remove_unreachable_nodes");
  fprintf (f, "\n  Visibility:");
  if (in_other_partition)
    fprintf (f, " in_other_partition");
  if (used_from_other_partition)
    fprintf (f, " used_from_other_partition");
  if (force_output)
    fprintf (f, " force_output");
  if (forced_by_abi)
    fprintf (f, " forced_by_abi");
  if (externally_visible)
    fprintf (f, " externally_visible");
  if (no_reorder)
    fprintf (f, " no_reorder");
  if (resolution != LDPR_UNKNOWN)
    fprintf (f, " %s",
 	     ld_plugin_symbol_resolution_names[(int)resolution]);
  if (TREE_ASM_WRITTEN (decl))
    fprintf (f, " asm_written");
  if (DECL_EXTERNAL (decl))
    fprintf (f, " external");
  if (TREE_PUBLIC (decl))
    fprintf (f, " public");
  if (DECL_COMMON (decl))
    fprintf (f, " common");
  if (DECL_WEAK (decl))
    fprintf (f, " weak");
  if (DECL_DLLIMPORT_P (decl))
    fprintf (f, " dll_import");
  if (DECL_COMDAT (decl))
    fprintf (f, " comdat");
  if (get_comdat_group ())
    fprintf (f, " comdat_group:%s",
	     IDENTIFIER_POINTER (get_comdat_group_id ()));
  if (DECL_ONE_ONLY (decl))
    fprintf (f, " one_only");
  if (get_section ())
    fprintf (f, " section:%s",
	     get_section ());
  if (implicit_section)
    fprintf (f," (implicit_section)");
  if (DECL_VISIBILITY_SPECIFIED (decl))
    fprintf (f, " visibility_specified");
  if (DECL_VISIBILITY (decl))
    fprintf (f, " visibility:%s",
	     visibility_types [DECL_VISIBILITY (decl)]);
  if (DECL_VIRTUAL_P (decl))
    fprintf (f, " virtual");
  if (DECL_ARTIFICIAL (decl))
    fprintf (f, " artificial");
  if (TREE_CODE (decl) == FUNCTION_DECL)
    {
      if (DECL_STATIC_CONSTRUCTOR (decl))
	fprintf (f, " constructor");
      if (DECL_STATIC_DESTRUCTOR (decl))
	fprintf (f, " destructor");
    }
  fprintf (f, "\n");
  
  if (same_comdat_group)
    fprintf (f, "  Same comdat group as: %s/%i\n",
	     same_comdat_group->asm_name (),
	     same_comdat_group->order);
  if (next_sharing_asm_name)
    fprintf (f, "  next sharing asm name: %i\n",
	     next_sharing_asm_name->order);
  if (previous_sharing_asm_name)
    fprintf (f, "  previous sharing asm name: %i\n",
	     previous_sharing_asm_name->order);

  if (address_taken)
    fprintf (f, "  Address is taken.\n");
  if (aux)
    {
      fprintf (f, "  Aux:");
      dump_addr (f, " @", (void *)aux);
    }

  fprintf (f, "  References: ");
  dump_references (f);
  fprintf (f, "  Referring: ");
  dump_referring (f);
  if (lto_file_data)
    fprintf (f, "  Read from file: %s\n",
	     lto_file_data->file_name);
}

/* Dump symtab node to F.  */

void
symtab_node::dump (FILE *f)
{
  if (cgraph_node *cnode = dyn_cast <cgraph_node *> (this))
    cnode->dump (f);
  else if (varpool_node *vnode = dyn_cast <varpool_node *> (this))
    vnode->dump (f);
}

/* Dump symbol table to F.  */

void
symtab_node::dump_table (FILE *f)
{
  symtab_node *node;
  fprintf (f, "Symbol table:\n\n");
  FOR_EACH_SYMBOL (node)
    node->dump (f);
}


/* Return the cgraph node that has ASMNAME for its DECL_ASSEMBLER_NAME.
   Return NULL if there's no such node.  */

symtab_node *
symtab_node::get_for_asmname (const_tree asmname)
{
  symtab_node *node;

  symtab->symtab_initialize_asm_name_hash ();
  hashval_t hash = symtab->decl_assembler_name_hash (asmname);
  symtab_node **slot
    = symtab->assembler_name_hash->find_slot_with_hash (asmname, hash,
							NO_INSERT);

  if (slot)
    {
      node = *slot;
      return node;
    }
  return NULL;
}

/* Dump symtab node NODE to stderr.  */

DEBUG_FUNCTION void
symtab_node::debug (void)
{
  dump (stderr);
}

/* Verify common part of symtab nodes.  */

DEBUG_FUNCTION bool
symtab_node::verify_base (void)
{
  bool error_found = false;
  symtab_node *hashed_node;

  if (is_a <cgraph_node *> (this))
    {
      if (TREE_CODE (decl) != FUNCTION_DECL)
	{
          error ("function symbol is not function");
          error_found = true;
	}
    }
  else if (is_a <varpool_node *> (this))
    {
      if (TREE_CODE (decl) != VAR_DECL)
	{
          error ("variable symbol is not variable");
          error_found = true;
	}
    }
  else
    {
      error ("node has unknown type");
      error_found = true;
    }
   
  if (symtab->state != LTO_STREAMING)
    {
      hashed_node = symtab_node::get (decl);
      if (!hashed_node)
	{
	  error ("node not found node->decl->decl_with_vis.symtab_node");
	  error_found = true;
	}
      if (hashed_node != this
	  && (!is_a <cgraph_node *> (this)
	      || !dyn_cast <cgraph_node *> (this)->clone_of
	      || dyn_cast <cgraph_node *> (this)->clone_of->decl != decl))
	{
	  error ("node differs from node->decl->decl_with_vis.symtab_node");
	  error_found = true;
	}
    }
  if (symtab->assembler_name_hash)
    {
      hashed_node = symtab_node::get_for_asmname (DECL_ASSEMBLER_NAME (decl));
      if (hashed_node && hashed_node->previous_sharing_asm_name)
	{
          error ("assembler name hash list corrupted");
          error_found = true;
	}
      while (hashed_node)
	{
	  if (hashed_node == this)
	    break;
	  hashed_node = hashed_node->next_sharing_asm_name;
	}
      if (!hashed_node
	  && !(is_a <varpool_node *> (this)
	       && DECL_HARD_REGISTER (decl)))
	{
          error ("node not found in symtab assembler name hash");
          error_found = true;
	}
    }
  if (previous_sharing_asm_name
      && previous_sharing_asm_name->next_sharing_asm_name != this)
    {
      error ("double linked list of assembler names corrupted");
      error_found = true;
    }
  if (body_removed && definition)
    {
      error ("node has body_removed but is definition");
      error_found = true;
    }
  if (analyzed && !definition)
    {
      error ("node is analyzed byt it is not a definition");
      error_found = true;
    }
  if (cpp_implicit_alias && !alias)
    {
      error ("node is alias but not implicit alias");
      error_found = true;
    }
  if (alias && !definition && !weakref)
    {
      error ("node is alias but not definition");
      error_found = true;
    }
  if (weakref && !transparent_alias)
    {
      error ("node is weakref but not an transparent_alias");
      error_found = true;
    }
  if (transparent_alias && !alias)
    {
      error ("node is transparent_alias but not an alias");
      error_found = true;
    }
  if (same_comdat_group)
    {
      symtab_node *n = same_comdat_group;

      if (!n->get_comdat_group ())
	{
	  error ("node is in same_comdat_group list but has no comdat_group");
	  error_found = true;
	}
      if (n->get_comdat_group () != get_comdat_group ())
	{
	  error ("same_comdat_group list across different groups");
	  error_found = true;
	}
      if (n->type != type)
	{
	  error ("mixing different types of symbol in same comdat groups is not supported");
	  error_found = true;
	}
      if (n == this)
	{
	  error ("node is alone in a comdat group");
	  error_found = true;
	}
      do
	{
	  if (!n->same_comdat_group)
	    {
	      error ("same_comdat_group is not a circular list");
	      error_found = true;
	      break;
	    }
	  n = n->same_comdat_group;
	}
      while (n != this);
      if (comdat_local_p ())
	{
	  ipa_ref *ref = NULL;

	  for (int i = 0; iterate_referring (i, ref); ++i)
	    {
	      if (!in_same_comdat_group_p (ref->referring))
		{
		  error ("comdat-local symbol referred to by %s outside its "
			 "comdat",
			 identifier_to_locale (ref->referring->name()));
		  error_found = true;
		}
	    }
	}
    }
  if (implicit_section && !get_section ())
    {
      error ("implicit_section flag is set but section isn't");
      error_found = true;
    }
  if (get_section () && get_comdat_group ()
      && !implicit_section
      && !lookup_attribute ("section", DECL_ATTRIBUTES (decl)))
    {
      error ("Both section and comdat group is set");
      error_found = true;
    }
  /* TODO: Add string table for sections, so we do not keep holding duplicated
     strings.  */
  if (alias && definition
      && get_section () != get_alias_target ()->get_section ()
      && (!get_section()
	  || !get_alias_target ()->get_section ()
	  || strcmp (get_section(),
		     get_alias_target ()->get_section ())))
    {
      error ("Alias and target's section differs");
      get_alias_target ()->dump (stderr);
      error_found = true;
    }
  if (alias && definition
      && get_comdat_group () != get_alias_target ()->get_comdat_group ())
    {
      error ("Alias and target's comdat groups differs");
      get_alias_target ()->dump (stderr);
      error_found = true;
    }
  if (transparent_alias && definition && !weakref)
    {
      symtab_node *to = get_alias_target ();
      const char *name1
	= IDENTIFIER_POINTER (
	    ultimate_transparent_alias_target (DECL_ASSEMBLER_NAME (decl)));
      const char *name2
	= IDENTIFIER_POINTER (
	    ultimate_transparent_alias_target (DECL_ASSEMBLER_NAME (to->decl)));
      if (!symbol_table::assembler_names_equal_p (name1, name2))
	{
	  error ("Transparent alias and target's assembler names differs");
	  get_alias_target ()->dump (stderr);
	  error_found = true;
	}
    }
  if (transparent_alias && definition
      && get_alias_target()->transparent_alias && get_alias_target()->analyzed)
    {
      error ("Chained transparent aliases");
      get_alias_target ()->dump (stderr);
      error_found = true;
    }

  return error_found;
}

/* Verify consistency of NODE.  */

DEBUG_FUNCTION void
symtab_node::verify (void)
{
  if (seen_error ())
    return;

  timevar_push (TV_CGRAPH_VERIFY);
  if (cgraph_node *node = dyn_cast <cgraph_node *> (this))
    node->verify_node ();
  else
    if (verify_base ())
      {
	debug ();
	internal_error ("symtab_node::verify failed");
      }
  timevar_pop (TV_CGRAPH_VERIFY);
}

/* Verify symbol table for internal consistency.  */

DEBUG_FUNCTION void
symtab_node::verify_symtab_nodes (void)
{
  symtab_node *node;
  hash_map<tree, symtab_node *> comdat_head_map (251);

  FOR_EACH_SYMBOL (node)
    {
      node->verify ();
      if (node->get_comdat_group ())
	{
	  symtab_node **entry, *s;
	  bool existed;

	  entry = &comdat_head_map.get_or_insert (node->get_comdat_group (),
						  &existed);
	  if (!existed)
	    *entry = node;
	  else if (!DECL_EXTERNAL (node->decl))
	    {
	      for (s = (*entry)->same_comdat_group;
		   s != NULL && s != node && s != *entry;
		   s = s->same_comdat_group)
		;
	      if (!s || s == *entry)
		{
		  error ("Two symbols with same comdat_group are not linked by "
			 "the same_comdat_group list.");
		  (*entry)->debug ();
		  node->debug ();
		  internal_error ("symtab_node::verify failed");
		}
	    }
	}
    }
}

/* Make DECL local.  FIXME: We shouldn't need to mess with rtl this early,
   but other code such as notice_global_symbol generates rtl.  */

void
symtab_node::make_decl_local (void)
{
  rtx rtl, symbol;

  if (weakref)
    {
      weakref = false;
      IDENTIFIER_TRANSPARENT_ALIAS (DECL_ASSEMBLER_NAME (decl)) = 0;
      TREE_CHAIN (DECL_ASSEMBLER_NAME (decl)) = NULL_TREE;
      symtab->change_decl_assembler_name
	 (decl, DECL_ASSEMBLER_NAME (get_alias_target ()->decl));
      DECL_ATTRIBUTES (decl) = remove_attribute ("weakref",
						 DECL_ATTRIBUTES (decl));
    }
  /* Avoid clearing comdat_groups on comdat-local decls.  */
  else if (TREE_PUBLIC (decl) == 0)
    return;

  /* Localizing a symbol also make all its transparent aliases local.  */
  ipa_ref *ref;
  for (unsigned i = 0; iterate_direct_aliases (i, ref); i++)
    {
      struct symtab_node *alias = ref->referring;
      if (alias->transparent_alias)
	alias->make_decl_local ();
    }

  if (TREE_CODE (decl) == VAR_DECL)
    {
      DECL_COMMON (decl) = 0;
      /* ADDRESSABLE flag is not defined for public symbols.  */
      TREE_ADDRESSABLE (decl) = 1;
      TREE_STATIC (decl) = 1;
    }
  else gcc_assert (TREE_CODE (decl) == FUNCTION_DECL);

  DECL_COMDAT (decl) = 0;
  DECL_WEAK (decl) = 0;
  DECL_EXTERNAL (decl) = 0;
  DECL_VISIBILITY_SPECIFIED (decl) = 0;
  DECL_VISIBILITY (decl) = VISIBILITY_DEFAULT;
  TREE_PUBLIC (decl) = 0;
  DECL_DLLIMPORT_P (decl) = 0;
  if (!DECL_RTL_SET_P (decl))
    return;

  /* Update rtl flags.  */
  make_decl_rtl (decl);

  rtl = DECL_RTL (decl);
  if (!MEM_P (rtl))
    return;

  symbol = XEXP (rtl, 0);
  if (GET_CODE (symbol) != SYMBOL_REF)
    return;

  SYMBOL_REF_WEAK (symbol) = DECL_WEAK (decl);
}

/* Copy visibility from N.
   This is useful when THIS becomes a transparent alias of N.  */

void
symtab_node::copy_visibility_from (symtab_node *n)
{
  gcc_checking_assert (n->weakref == weakref);

  ipa_ref *ref;
  for (unsigned i = 0; iterate_direct_aliases (i, ref); i++)
    {
      struct symtab_node *alias = ref->referring;
      if (alias->transparent_alias)
	alias->copy_visibility_from (n);
    }

  if (TREE_CODE (decl) == VAR_DECL)
    {
      DECL_COMMON (decl) = DECL_COMMON (n->decl);
      /* ADDRESSABLE flag is not defined for public symbols.  */
      if (TREE_PUBLIC (decl) && !TREE_PUBLIC (n->decl))
        TREE_ADDRESSABLE (decl) = 1;
      TREE_STATIC (decl) = TREE_STATIC (n->decl);
    }
  else gcc_assert (TREE_CODE (decl) == FUNCTION_DECL);

  DECL_COMDAT (decl) = DECL_COMDAT (n->decl);
  DECL_WEAK (decl) = DECL_WEAK (n->decl);
  DECL_EXTERNAL (decl) = DECL_EXTERNAL (n->decl);
  DECL_VISIBILITY_SPECIFIED (decl) = DECL_VISIBILITY_SPECIFIED (n->decl);
  DECL_VISIBILITY (decl) = DECL_VISIBILITY (n->decl);
  TREE_PUBLIC (decl) = TREE_PUBLIC (n->decl);
  DECL_DLLIMPORT_P (decl) = DECL_DLLIMPORT_P (n->decl);
  resolution = n->resolution;
  set_comdat_group (n->get_comdat_group ());
  call_for_symbol_and_aliases (symtab_node::set_section,
			     const_cast<char *>(n->get_section ()), true);
  externally_visible = n->externally_visible;
  if (!DECL_RTL_SET_P (decl))
    return;

  /* Update rtl flags.  */
  make_decl_rtl (decl);

  rtx rtl = DECL_RTL (decl);
  if (!MEM_P (rtl))
    return;

  rtx symbol = XEXP (rtl, 0);
  if (GET_CODE (symbol) != SYMBOL_REF)
    return;

  SYMBOL_REF_WEAK (symbol) = DECL_WEAK (decl);
}

/* Walk the alias chain to return the symbol NODE is alias of.
   If NODE is not an alias, return NODE.
   Assumes NODE is known to be alias.  */

symtab_node *
symtab_node::ultimate_alias_target_1 (enum availability *availability,
				      symtab_node *ref)
{
  bool transparent_p = false;

  /* To determine visibility of the target, we follow ELF semantic of aliases.
     Here alias is an alternative assembler name of a given definition. Its
     availability prevails the availability of its target (i.e. static alias of
     weak definition is available.

     Transaparent alias is just alternative anme of a given symbol used within
     one compilation unit and is translated prior hitting the object file.  It
     inherits the visibility of its target.
     Weakref is a different animal (and noweak definition is weak).

     If we ever get into supporting targets with different semantics, a target
     hook will be needed here.  */

  if (availability)
    {
      transparent_p = transparent_alias;
      if (!transparent_p)
	*availability = get_availability (ref);
      else
	*availability = AVAIL_NOT_AVAILABLE;
    }

  symtab_node *node = this;
  while (node)
    {
      if (node->alias && node->analyzed)
	node = node->get_alias_target ();
      else
	{
	  if (!availability || (!transparent_p && node->analyzed))
	    ;
	  else if (node->analyzed && !node->transparent_alias)
	    *availability = node->get_availability (ref);
	  else
	    *availability = AVAIL_NOT_AVAILABLE;
	  return node;
	}
      if (node && availability && transparent_p
	  && node->transparent_alias)
	{
	  *availability = node->get_availability (ref);
	  transparent_p = false;
	}
    }
  if (availability)
    *availability = AVAIL_NOT_AVAILABLE;
  return NULL;
}

/* C++ FE sometimes change linkage flags after producing same body aliases.

   FIXME: C++ produce implicit aliases for virtual functions and vtables that
   are obviously equivalent.  The way it is doing so is however somewhat
   kludgy and interferes with the visibility code. As a result we need to
   copy the visibility from the target to get things right.  */

void
symtab_node::fixup_same_cpp_alias_visibility (symtab_node *target)
{
  if (is_a <cgraph_node *> (this))
    {
      DECL_DECLARED_INLINE_P (decl)
	 = DECL_DECLARED_INLINE_P (target->decl);
      DECL_DISREGARD_INLINE_LIMITS (decl)
	 = DECL_DISREGARD_INLINE_LIMITS (target->decl);
    }
  /* FIXME: It is not really clear why those flags should not be copied for
     functions, too.  */
  else
    {
      DECL_WEAK (decl) = DECL_WEAK (target->decl);
      DECL_EXTERNAL (decl) = DECL_EXTERNAL (target->decl);
      DECL_VISIBILITY (decl) = DECL_VISIBILITY (target->decl);
    }
  if (TREE_PUBLIC (decl))
    {
      tree group;

      DECL_EXTERNAL (decl) = DECL_EXTERNAL (target->decl);
      DECL_COMDAT (decl) = DECL_COMDAT (target->decl);
      group = target->get_comdat_group ();
      set_comdat_group (group);
      if (group && !same_comdat_group)
	add_to_same_comdat_group (target);
    }
  externally_visible = target->externally_visible;
}

/* Set section, do not recurse into aliases.
   When one wants to change section of symbol and its aliases,
   use set_section.  */

void
symtab_node::set_section_for_node (const char *section)
{
  const char *current = get_section ();
  section_hash_entry **slot;

  if (current == section
      || (current && section
	  && !strcmp (current, section)))
    return;

  if (current)
    {
      x_section->ref_count--;
      if (!x_section->ref_count)
	{
	  hashval_t hash = htab_hash_string (x_section->name);
	  slot = symtab->section_hash->find_slot_with_hash (x_section->name,
							    hash, INSERT);
	  ggc_free (x_section);
	  symtab->section_hash->clear_slot (slot);
	}
      x_section = NULL;
    }
  if (!section)
    {
      implicit_section = false;
      return;
    }
  if (!symtab->section_hash)
    symtab->section_hash = hash_table<section_name_hasher>::create_ggc (10);
  slot = symtab->section_hash->find_slot_with_hash (section,
						    htab_hash_string (section),
						    INSERT);
  if (*slot)
    x_section = (section_hash_entry *)*slot;
  else
    {
      int len = strlen (section);
      *slot = x_section = ggc_cleared_alloc<section_hash_entry> ();
      x_section->name = ggc_vec_alloc<char> (len + 1);
      memcpy (x_section->name, section, len + 1);
    }
  x_section->ref_count++;
}

/* Worker for set_section.  */

bool
symtab_node::set_section (symtab_node *n, void *s)
{
  n->set_section_for_node ((char *)s);
  return false;
}

/* Set section of symbol and its aliases.  */

void
symtab_node::set_section (const char *section)
{
  gcc_assert (!this->alias);
  call_for_symbol_and_aliases
    (symtab_node::set_section, const_cast<char *>(section), true);
}

/* Return the initialization priority.  */

priority_type
symtab_node::get_init_priority ()
{
  if (!this->in_init_priority_hash)
    return DEFAULT_INIT_PRIORITY;

  symbol_priority_map *h = symtab->init_priority_hash->get (this);
  return h ? h->init : DEFAULT_INIT_PRIORITY;
}

/* Return the finalization priority.  */

priority_type
cgraph_node::get_fini_priority ()
{
  if (!this->in_init_priority_hash)
    return DEFAULT_INIT_PRIORITY;
  symbol_priority_map *h = symtab->init_priority_hash->get (this);
  return h ? h->fini : DEFAULT_INIT_PRIORITY;
}

/* Return the initialization and finalization priority information for
   DECL.  If there is no previous priority information, a freshly
   allocated structure is returned.  */

symbol_priority_map *
symtab_node::priority_info (void)
{
  if (!symtab->init_priority_hash)
    symtab->init_priority_hash = hash_map<symtab_node *, symbol_priority_map>::create_ggc (13);

  bool existed;
  symbol_priority_map *h
    = &symtab->init_priority_hash->get_or_insert (this, &existed);
  if (!existed)
    {
      h->init = DEFAULT_INIT_PRIORITY;
      h->fini = DEFAULT_INIT_PRIORITY;
      in_init_priority_hash = true;
    }

  return h;
}

/* Set initialization priority to PRIORITY.  */

void
symtab_node::set_init_priority (priority_type priority)
{
  symbol_priority_map *h;

  if (is_a <cgraph_node *> (this))
    gcc_assert (DECL_STATIC_CONSTRUCTOR (this->decl));

  if (priority == DEFAULT_INIT_PRIORITY)
    {
      gcc_assert (get_init_priority() == priority);
      return;
    }
  h = priority_info ();
  h->init = priority;
}

/* Set fialization priority to PRIORITY.  */

void
cgraph_node::set_fini_priority (priority_type priority)
{
  symbol_priority_map *h;

  gcc_assert (DECL_STATIC_DESTRUCTOR (this->decl));

  if (priority == DEFAULT_INIT_PRIORITY)
    {
      gcc_assert (get_fini_priority() == priority);
      return;
    }
  h = priority_info ();
  h->fini = priority;
}

/* Worker for symtab_resolve_alias.  */

bool
symtab_node::set_implicit_section (symtab_node *n,
				   void *data ATTRIBUTE_UNUSED)
{
  n->implicit_section = true;
  return false;
}

/* Add reference recording that symtab node is alias of TARGET.
   The function can fail in the case of aliasing cycles; in this case
   it returns false.  */

bool
symtab_node::resolve_alias (symtab_node *target, bool transparent)
{
  symtab_node *n;

  gcc_assert (!analyzed && !vec_safe_length (ref_list.references));

  /* Never let cycles to creep into the symbol table alias references;
     those will make alias walkers to be infinite.  */
  for (n = target; n && n->alias;
       n = n->analyzed ? n->get_alias_target () : NULL)
    if (n == this)
       {
	 if (is_a <cgraph_node *> (this))
	   error ("function %q+D part of alias cycle", decl);
	 else if (is_a <varpool_node *> (this))
	   error ("variable %q+D part of alias cycle", decl);
	 else
	   gcc_unreachable ();
	 alias = false;
	 return false;
       }

  /* "analyze" the node - i.e. mark the reference.  */
  definition = true;
  alias = true;
  analyzed = true;
  transparent |= transparent_alias;
  transparent_alias = transparent;
  if (transparent)
    while (target->transparent_alias && target->analyzed)
      target = target->get_alias_target ();
  create_reference (target, IPA_REF_ALIAS, NULL);

  /* Add alias into the comdat group of its target unless it is already there.  */
  if (same_comdat_group)
    remove_from_same_comdat_group ();
  set_comdat_group (NULL);
  if (target->get_comdat_group ())
    add_to_same_comdat_group (target);

  if ((get_section () != target->get_section ()
       || target->get_comdat_group ()) && get_section () && !implicit_section)
    {
      error ("section of alias %q+D must match section of its target", decl);
    }
  call_for_symbol_and_aliases (symtab_node::set_section,
			     const_cast<char *>(target->get_section ()), true);
  if (target->implicit_section)
    call_for_symbol_and_aliases (set_implicit_section, NULL, true);

  /* Alias targets become redundant after alias is resolved into an reference.
     We do not want to keep it around or we would have to mind updating them
     when renaming symbols.  */
  alias_target = NULL;

  if (!transparent && cpp_implicit_alias && symtab->state >= CONSTRUCTION)
    fixup_same_cpp_alias_visibility (target);

  /* If alias has address taken, so does the target.  */
  if (address_taken)
    target->ultimate_alias_target ()->address_taken = true;

  /* All non-transparent aliases of THIS are now in fact aliases of TARGET.
     If alias is transparent, also all transparent aliases of THIS are now
     aliases of TARGET.
     Also merge same comdat group lists.  */
  ipa_ref *ref;
  for (unsigned i = 0; iterate_direct_aliases (i, ref);)
    {
      struct symtab_node *alias_alias = ref->referring;
      if (alias_alias->get_comdat_group ())
	{
	  alias_alias->remove_from_same_comdat_group ();
	  alias_alias->set_comdat_group (NULL);
	  if (target->get_comdat_group ())
	    alias_alias->add_to_same_comdat_group (target);
	}
      if (!alias_alias->transparent_alias || transparent)
	{
	  alias_alias->remove_all_references ();
	  alias_alias->create_reference (target, IPA_REF_ALIAS, NULL);
	}
      else i++;
    }
  return true;
}

/* Worker searching noninterposable alias.  */

bool
symtab_node::noninterposable_alias (symtab_node *node, void *data)
{
  if (!node->transparent_alias && decl_binds_to_current_def_p (node->decl))
    {
      symtab_node *fn = node->ultimate_alias_target ();

      /* Ensure that the alias is well formed this may not be the case
	 of user defined aliases and currently it is not always the case
	 of C++ same body aliases (that is a bug).  */
      if (TREE_TYPE (node->decl) != TREE_TYPE (fn->decl)
	  || DECL_CONTEXT (node->decl) != DECL_CONTEXT (fn->decl)
	  || (TREE_CODE (node->decl) == FUNCTION_DECL
	      && flags_from_decl_or_type (node->decl)
		 != flags_from_decl_or_type (fn->decl))
	  || DECL_ATTRIBUTES (node->decl) != DECL_ATTRIBUTES (fn->decl))
	return false;
      *(symtab_node **)data = node;
      return true;
    }
  return false;
}

/* If node can not be overwriten by static or dynamic linker to point to
   different definition, return NODE. Otherwise look for alias with such
   property and if none exists, introduce new one.  */

symtab_node *
symtab_node::noninterposable_alias (void)
{
  tree new_decl;
  symtab_node *new_node = NULL;

  /* First try to look up existing alias or base object
     (if that is already non-overwritable).  */
  symtab_node *node = ultimate_alias_target ();
  gcc_assert (!node->alias && !node->weakref);
  node->call_for_symbol_and_aliases (symtab_node::noninterposable_alias,
				   (void *)&new_node, true);
  if (new_node)
    return new_node;
#ifndef ASM_OUTPUT_DEF
  /* If aliases aren't supported by the assembler, fail.  */
  return NULL;
#endif

  /* Otherwise create a new one.  */
  new_decl = copy_node (node->decl);
  DECL_DLLIMPORT_P (new_decl) = 0;
  DECL_NAME (new_decl) = clone_function_name (node->decl, "localalias");
  if (TREE_CODE (new_decl) == FUNCTION_DECL)
    DECL_STRUCT_FUNCTION (new_decl) = NULL;
  DECL_INITIAL (new_decl) = NULL;
  SET_DECL_ASSEMBLER_NAME (new_decl, DECL_NAME (new_decl));
  SET_DECL_RTL (new_decl, NULL);

  /* Update the properties.  */
  DECL_EXTERNAL (new_decl) = 0;
  TREE_PUBLIC (new_decl) = 0;
  DECL_COMDAT (new_decl) = 0;
  DECL_WEAK (new_decl) = 0;

  /* Since the aliases can be added to vtables, keep DECL_VIRTUAL flag.  */
  DECL_VIRTUAL_P (new_decl) = DECL_VIRTUAL_P (node->decl);
  if (TREE_CODE (new_decl) == FUNCTION_DECL)
    {
      DECL_STATIC_CONSTRUCTOR (new_decl) = 0;
      DECL_STATIC_DESTRUCTOR (new_decl) = 0;
      new_node = cgraph_node::create_alias (new_decl, node->decl);
    }
  else
    {
      TREE_READONLY (new_decl) = TREE_READONLY (node->decl);
      DECL_INITIAL (new_decl) = error_mark_node;
      new_node = varpool_node::create_alias (new_decl, node->decl);
    }
  new_node->resolve_alias (node);
  gcc_assert (decl_binds_to_current_def_p (new_decl)
	      && targetm.binds_local_p (new_decl));
  return new_node;
}

/* Return true if symtab node and TARGET represents
   semantically equivalent symbols.  */

bool
symtab_node::semantically_equivalent_p (symtab_node *target)
{
  enum availability avail;
  symtab_node *ba;
  symtab_node *bb;

  /* Equivalent functions are equivalent.  */
  if (decl == target->decl)
    return true;

  /* If symbol is not overwritable by different implementation,
     walk to the base object it defines.  */
  ba = ultimate_alias_target (&avail);
  if (avail >= AVAIL_AVAILABLE)
    {
      if (target == ba)
	return true;
    }
  else
    ba = this;
  bb = target->ultimate_alias_target (&avail);
  if (avail >= AVAIL_AVAILABLE)
    {
      if (this == bb)
	return true;
    }
  else
    bb = target;
  return bb == ba;
}

/* Classify symbol symtab node for partitioning.  */

enum symbol_partitioning_class
symtab_node::get_partitioning_class (void)
{
  /* Inline clones are always duplicated.
     This include external delcarations.   */
  cgraph_node *cnode = dyn_cast <cgraph_node *> (this);

  if (DECL_ABSTRACT_P (decl))
    return SYMBOL_EXTERNAL;

  if (cnode && cnode->global.inlined_to)
    return SYMBOL_DUPLICATE;

  /* Transparent aliases are always duplicated.  */
  if (transparent_alias)
    return definition ? SYMBOL_DUPLICATE : SYMBOL_EXTERNAL;

  /* External declarations are external.  */
  if (DECL_EXTERNAL (decl))
    return SYMBOL_EXTERNAL;

  if (varpool_node *vnode = dyn_cast <varpool_node *> (this))
    {
      if (alias && definition && !ultimate_alias_target ()->definition)
	return SYMBOL_EXTERNAL;
      /* Constant pool references use local symbol names that can not
         be promoted global.  We should never put into a constant pool
         objects that can not be duplicated across partitions.  */
      if (DECL_IN_CONSTANT_POOL (decl))
	return SYMBOL_DUPLICATE;
      if (DECL_HARD_REGISTER (decl))
	return SYMBOL_DUPLICATE;
      gcc_checking_assert (vnode->definition);
    }
  /* Functions that are cloned may stay in callgraph even if they are unused.
     Handle them as external; compute_ltrans_boundary take care to make
     proper things to happen (i.e. to make them appear in the boundary but
     with body streamed, so clone can me materialized).  */
  else if (!dyn_cast <cgraph_node *> (this)->function_symbol ()->definition)
    return SYMBOL_EXTERNAL;

  /* Linker discardable symbols are duplicated to every use unless they are
     keyed.  */
  if (DECL_ONE_ONLY (decl)
      && !force_output
      && !forced_by_abi
      && !used_from_object_file_p ())
    return SYMBOL_DUPLICATE;

  return SYMBOL_PARTITION;
}

/* Return true when symbol is known to be non-zero.  */

bool
symtab_node::nonzero_address ()
{
  /* Weakrefs may be NULL when their target is not defined.  */
  if (alias && weakref)
    {
      if (analyzed)
	{
	  symtab_node *target = ultimate_alias_target ();

	  if (target->alias && target->weakref)
	    return false;
	  /* We can not recurse to target::nonzero.  It is possible that the
	     target is used only via the alias.
	     We may walk references and look for strong use, but we do not know
	     if this strong use will survive to final binary, so be
	     conservative here.  
	     ??? Maybe we could do the lookup during late optimization that
	     could be useful to eliminate the NULL pointer checks in LTO
	     programs.  */
	  if (target->definition && !DECL_EXTERNAL (target->decl))
	      return true;
	  if (target->resolution != LDPR_UNKNOWN
	      && target->resolution != LDPR_UNDEF
	      && !target->can_be_discarded_p ()
	      && flag_delete_null_pointer_checks)
	    return true;
	  return false;
	}
      else
        return false;
    }

  /* With !flag_delete_null_pointer_checks we assume that symbols may
     bind to NULL. This is on by default on embedded targets only.

     Otherwise all non-WEAK symbols must be defined and thus non-NULL or
     linking fails.  Important case of WEAK we want to do well are comdats.
     Those are handled by later check for definition.

     When parsing, beware the cases when WEAK attribute is added later.  */
  if (!DECL_WEAK (decl)
      && flag_delete_null_pointer_checks)
    {
      refuse_visibility_changes = true;
      return true;
    }

  /* If target is defined and not extern, we know it will be output and thus
     it will bind to non-NULL.
     Play safe for flag_delete_null_pointer_checks where weak definition maye
     be re-defined by NULL.  */
  if (definition && !DECL_EXTERNAL (decl)
      && (flag_delete_null_pointer_checks || !DECL_WEAK (decl)))
    {
      if (!DECL_WEAK (decl))
        refuse_visibility_changes = true;
      return true;
    }

  /* As the last resort, check the resolution info.  */
  if (resolution != LDPR_UNKNOWN
      && resolution != LDPR_UNDEF
      && !can_be_discarded_p ()
      && flag_delete_null_pointer_checks)
    return true;
  return false;
}

/* Return 0 if symbol is known to have different address than S2,
   Return 1 if symbol is known to have same address as S2,
   return -1 otherwise.  

   If MEMORY_ACCESSED is true, assume that both memory pointer to THIS
   and S2 is going to be accessed.  This eliminates the situations when
   either THIS or S2 is NULL and is seful for comparing bases when deciding
   about memory aliasing.  */
int
symtab_node::equal_address_to (symtab_node *s2, bool memory_accessed)
{
  enum availability avail1, avail2;

  /* A Shortcut: equivalent symbols are always equivalent.  */
  if (this == s2)
    return 1;

  /* Unwind transparent aliases first; those are always equal to their
     target.  */
  if (this->transparent_alias && this->analyzed)
    return this->get_alias_target ()->equal_address_to (s2);
  while (s2->transparent_alias && s2->analyzed)
    s2 = s2->get_alias_target();

  if (this == s2)
    return 1;

  /* For non-interposable aliases, lookup and compare their actual definitions.
     Also check if the symbol needs to bind to given definition.  */
  symtab_node *rs1 = ultimate_alias_target (&avail1);
  symtab_node *rs2 = s2->ultimate_alias_target (&avail2);
  bool binds_local1 = rs1->analyzed && decl_binds_to_current_def_p (this->decl);
  bool binds_local2 = rs2->analyzed && decl_binds_to_current_def_p (s2->decl);
  bool really_binds_local1 = binds_local1;
  bool really_binds_local2 = binds_local2;

  /* Addresses of vtables and virtual functions can not be used by user
     code and are used only within speculation.  In this case we may make
     symbol equivalent to its alias even if interposition may break this
     rule.  Doing so will allow us to turn speculative inlining into
     non-speculative more agressively.  */
  if (DECL_VIRTUAL_P (this->decl) && avail1 >= AVAIL_AVAILABLE)
    binds_local1 = true;
  if (DECL_VIRTUAL_P (s2->decl) && avail2 >= AVAIL_AVAILABLE)
    binds_local2 = true;

  /* If both definitions are available we know that even if they are bound
     to other unit they must be defined same way and therefore we can use
     equivalence test.  */
  if (rs1 != rs2 && avail1 >= AVAIL_AVAILABLE && avail2 >= AVAIL_AVAILABLE)
    binds_local1 = binds_local2 = true;

  if ((binds_local1 ? rs1 : this)
       == (binds_local2 ? rs2 : s2))
    {
      /* We made use of the fact that alias is not weak.  */
      if (binds_local1 && rs1 != this)
        refuse_visibility_changes = true;
      if (binds_local2 && rs2 != s2)
        s2->refuse_visibility_changes = true;
      return 1;
    }

  /* If both symbols may resolve to NULL, we can not really prove them
     different.  */
  if (!memory_accessed && !nonzero_address () && !s2->nonzero_address ())
    return -1;

  /* Except for NULL, functions and variables never overlap.  */
  if (TREE_CODE (decl) != TREE_CODE (s2->decl))
    return 0;

  /* If one of the symbols is unresolved alias, punt.  */
  if (rs1->alias || rs2->alias)
    return -1;

  /* If we have a non-interposale definition of at least one of the symbols
     and the other symbol is different, we know other unit can not interpose
     it to the first symbol; all aliases of the definition needs to be 
     present in the current unit.  */
  if (((really_binds_local1 || really_binds_local2)
      /* If we have both definitions and they are different, we know they
	 will be different even in units they binds to.  */
       || (binds_local1 && binds_local2))
      && rs1 != rs2)
    {
      /* We make use of the fact that one symbol is not alias of the other
	 and that the definition is non-interposable.  */
      refuse_visibility_changes = true;
      s2->refuse_visibility_changes = true;
      rs1->refuse_visibility_changes = true;
      rs2->refuse_visibility_changes = true;
      return 0;
    }

  /* TODO: Alias oracle basically assume that addresses of global variables
     are different unless they are declared as alias of one to another while
     the code folding comparsions doesn't.
     We probably should be consistent and use this fact here, too, but for
     the moment return false only when we are called from the alias oracle.  */

  return memory_accessed && rs1 != rs2 ? 0 : -1;
}

/* Worker for call_for_symbol_and_aliases.  */

bool
symtab_node::call_for_symbol_and_aliases_1 (bool (*callback) (symtab_node *,
							      void *),
					    void *data,
					    bool include_overwritable)
{
  ipa_ref *ref;
  FOR_EACH_ALIAS (this, ref)
    {
      symtab_node *alias = ref->referring;
      if (include_overwritable
	  || alias->get_availability () > AVAIL_INTERPOSABLE)
	if (alias->call_for_symbol_and_aliases (callback, data,
					      include_overwritable))
	  return true;
    }
  return false;
}

/* Return true if address of N is possibly compared.  */

static bool
address_matters_1 (symtab_node *n, void *)
{
  struct ipa_ref *ref;

  if (!n->address_can_be_compared_p ())
    return false;
  if (n->externally_visible || n->force_output)
    return true;

  for (unsigned int i = 0; n->iterate_referring (i, ref); i++)
    if (ref->address_matters_p ())
      return true;
  return false;
}

/* Return true if symbol's address may possibly be compared to other
   symbol's address.  */

bool
symtab_node::address_matters_p ()
{
  gcc_assert (!alias);
  return call_for_symbol_and_aliases (address_matters_1, NULL, true);
}

/* Return true if symbol's alignment may be increased.  */

bool
symtab_node::can_increase_alignment_p (void)
{
  symtab_node *target = ultimate_alias_target ();

  /* For now support only variables.  */
  if (TREE_CODE (decl) != VAR_DECL)
    return false;

  /* With -fno-toplevel-reorder we may have already output the constant.  */
  if (TREE_ASM_WRITTEN (target->decl))
    return false;

  /* If target is already placed in an anchor, we can not touch its
     alignment.  */
  if (DECL_RTL_SET_P (target->decl)
      && MEM_P (DECL_RTL (target->decl))
      && SYMBOL_REF_HAS_BLOCK_INFO_P (XEXP (DECL_RTL (target->decl), 0)))
    return false;

  /* Constant pool entries may be shared.  */
  if (DECL_IN_CONSTANT_POOL (target->decl))
    return false;

  /* We cannot change alignment of symbols that may bind to symbols
     in other translation unit that may contain a definition with lower
     alignment.  */
  if (!decl_binds_to_current_def_p (decl))
    return false;

  /* When compiling partition, be sure the symbol is not output by other
     partition.  */
  if (flag_ltrans
      && (target->in_other_partition
	  || target->get_partitioning_class () == SYMBOL_DUPLICATE))
    return false;

  /* Do not override the alignment as specified by the ABI when the used
     attribute is set.  */
  if (DECL_PRESERVE_P (decl) || DECL_PRESERVE_P (target->decl))
    return false;

  /* Do not override explicit alignment set by the user when an explicit
     section name is also used.  This is a common idiom used by many
     software projects.  */
  if (DECL_SECTION_NAME (target->decl) != NULL && !target->implicit_section)
    return false;

  return true;
}

/* Worker for symtab_node::increase_alignment.  */

static bool
increase_alignment_1 (symtab_node *n, void *v)
{
  unsigned int align = (size_t)v;
  if (DECL_ALIGN (n->decl) < align
      && n->can_increase_alignment_p ())
    {
      SET_DECL_ALIGN (n->decl, align);
      DECL_USER_ALIGN (n->decl) = 1;
    }
  return false;
}

/* Increase alignment of THIS to ALIGN.  */

void
symtab_node::increase_alignment (unsigned int align)
{
  gcc_assert (can_increase_alignment_p () && align < MAX_OFILE_ALIGNMENT);
  ultimate_alias_target()->call_for_symbol_and_aliases (increase_alignment_1,
						        (void *)(size_t) align,
						        true);
  gcc_assert (DECL_ALIGN (decl) >= align);
}

/* Helper for symtab_node::definition_alignment.  */

static bool
get_alignment_1 (symtab_node *n, void *v)
{
  *((unsigned int *)v) = MAX (*((unsigned int *)v), DECL_ALIGN (n->decl));
  return false;
}

/* Return desired alignment of the definition.  This is NOT alignment useful
   to access THIS, because THIS may be interposable and DECL_ALIGN should
   be used instead.  It however must be guaranteed when output definition
   of THIS.  */

unsigned int
symtab_node::definition_alignment ()
{
  unsigned int align = 0;
  gcc_assert (!alias);
  call_for_symbol_and_aliases (get_alignment_1, &align, true);
  return align;
}

/* Return symbol used to separate symbol name from suffix.  */

char 
symbol_table::symbol_suffix_separator ()
{
#ifndef NO_DOT_IN_LABEL
  return '.';
#elif !defined NO_DOLLAR_IN_LABEL
  return '$';
#else
  return '_';
#endif
}

/* Return true when references to this symbol from REF must bind to current
   definition in final executable.  */

bool
symtab_node::binds_to_current_def_p (symtab_node *ref)
{
  if (!definition)
    return false;
  if (decl_binds_to_current_def_p (decl))
    return true;

  /* Inline clones always binds locally.  */
  cgraph_node *cnode = dyn_cast <cgraph_node *> (this);
  if (cnode && cnode->global.inlined_to)
    return true;

  if (DECL_EXTERNAL (decl))
    return false;

  if (!externally_visible)
    debug ();
  gcc_assert (externally_visible);

  if (ref)
    {
      cgraph_node *cref = dyn_cast <cgraph_node *> (ref);
      if (cref)
	ref = cref->global.inlined_to;
    }

  /* If this is a reference from symbol itself and there are no aliases, we
     may be sure that the symbol was not interposed by something else because
     the symbol itself would be unreachable otherwise.  This is important
     to optimize recursive functions well.

     This assumption may be broken by inlining: if symbol is interposable
     but the body is available (i.e. declared inline), inliner may make
     the body reachable even with interposition.  */
  if (this == ref && !has_aliases_p ()
      && (!cnode
	  || symtab->state >= IPA_SSA_AFTER_INLINING
	  || get_availability () >= AVAIL_INTERPOSABLE))
    return true;


  /* References within one comdat group are always bound in a group.  */
  if (ref
      && symtab->state >= IPA_SSA_AFTER_INLINING
      && get_comdat_group ()
      && get_comdat_group () == ref->get_comdat_group ())
    return true;

  return false;
}