aboutsummaryrefslogtreecommitdiffstats
path: root/libraries.adb
blob: f06bd16e5ca64b6c5f293095e1d9c6ee3c33abf8 (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
--  VHDL libraries handling.
--  Copyright (C) 2002, 2003, 2004, 2005 Tristan Gingold
--
--  GHDL 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 2, or (at your option) any later
--  version.
--
--  GHDL 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 COPYING.  If not, write to the Free
--  Software Foundation, 59 Temple Place - Suite 330, Boston, MA
--  02111-1307, USA.
with Ada.Text_IO; use Ada.Text_IO;
with GNAT.Table;
with GNAT.OS_Lib;
with Errorout; use Errorout;
with Scan;
with Iirs_Utils;
with Parse;
with Back_End;
with Name_Table; use Name_Table;
with Str_Table;
with Sem_Scopes;
with Tokens;
with Files_Map;
with Flags;
with Std_Names;
with Std_Package;

package body Libraries is
   --  Chain of known libraries.  This is also the top node of all iir node.
   Libraries_Chain : Iir_Library_Declaration := Null_Iir;
   Libraries_Chain_Last : Iir_Library_Declaration := Null_Iir;

   --  A location for any implicit declarations (such as library WORK).
   Implicit_Location: Location_Type;

   --  Table of library pathes.
   package Pathes is new GNAT.Table
     (Table_Index_Type => Integer,
      Table_Component_Type => Name_Id,
      Table_Low_Bound => 1,
      Table_Initial => 4,
      Table_Increment => 100);

   --  Initialize pathes table.
   --  Set the local path.
   Name_Nil : Name_Id;
   procedure Init_Pathes
   is
   begin
      Name_Nil := Get_Identifier ("");
      Pathes.Append (Name_Nil);
      Local_Directory := Name_Nil;
      Work_Directory := Name_Nil;
   end Init_Pathes;

   function Path_To_Id (Path : String) return Name_Id is
   begin
      if Path (Path'Last) /= GNAT.OS_Lib.Directory_Separator then
         return Get_Identifier (Path & GNAT.OS_Lib.Directory_Separator);
      else
         return Get_Identifier (Path);
      end if;
   end Path_To_Id;

   procedure Add_Library_Path (Path : String)
   is
   begin
      if Path'Length = 0 then
         return;
      end if;
      Pathes.Increment_Last;
      Pathes.Table (Pathes.Last) := Path_To_Id (Path);
   end Add_Library_Path;

   function Get_Nbr_Pathes return Natural is
   begin
      return Pathes.Last;
   end Get_Nbr_Pathes;

   function Get_Path (N : Natural) return Name_Id is
   begin
      if N > Pathes.Last or N < Pathes.First then
         raise Constraint_Error;
      end if;
      return Pathes.Table (N);
   end Get_Path;

   --  Set PATH as the path of the work library.
   procedure Set_Work_Library_Path (Path : String) is
   begin
      Work_Directory := Path_To_Id (Path);
      if not GNAT.OS_Lib.Is_Directory (Get_Address (Work_Directory)) then
         --  This is a warning, since 'clean' action should not fail in
         --  this cases.
         Warning_Msg
           ("directory '" & Path & "' set by --workdir= does not exist");
         --  raise Option_Error;
      end if;
   end Set_Work_Library_Path;

   --  Open LIBRARY map file, return TRUE if successful.
   function Set_Library_File_Name (Dir : Name_Id;
                                   Library: Iir_Library_Declaration)
     return Boolean
   is
      File_Name : String := Back_End.Library_To_File_Name (Library);
      Fe : Source_File_Entry;
   begin
      Fe := Files_Map.Load_Source_File (Dir, Get_Identifier (File_Name));
      if Fe = No_Source_File_Entry then
         return False;
      end if;
      Scan.Set_File (Fe);
      return True;
   end Set_Library_File_Name;

   --  Every design unit is put in this hash table to be quickly found by
   --  its (primary) identifier.
   Unit_Hash_Length : constant Name_Id := 127;
   subtype Hash_Id is Name_Id range 0 .. Unit_Hash_Length - 1;
   Unit_Hash_Table : array (Hash_Id) of Iir := (others => Null_Iir);

   --  Get the hash value for DESIGN_UNIT.
   --  Architectures use the entity name.
   function Get_Hash_Id_For_Unit (Design_Unit : Iir_Design_Unit)
                                 return Hash_Id
   is
      Lib_Unit : Iir;
      Id : Name_Id;
   begin
      Lib_Unit := Get_Library_Unit (Design_Unit);
      case Get_Kind (Lib_Unit) is
         when Iir_Kind_Entity_Declaration
           | Iir_Kind_Configuration_Declaration
           | Iir_Kind_Package_Declaration
           | Iir_Kind_Package_Body =>
            Id := Get_Identifier (Lib_Unit);
         when Iir_Kind_Architecture_Declaration =>
            --  Architectures are put with the entity identifier.
            Id := Get_Identifier (Get_Entity (Lib_Unit));
         when others =>
            Error_Kind ("get_id_for_unit_hash", Lib_Unit);
      end case;
      return Id mod Unit_Hash_Length;
   end Get_Hash_Id_For_Unit;

   --  Put DESIGN_UNIT into the unit hash table.
   procedure Add_Unit_Hash (Design_Unit : Iir)
   is
      Id : Hash_Id;
   begin
      Id := Get_Hash_Id_For_Unit (Design_Unit);
      Set_Hash_Chain (Design_Unit, Unit_Hash_Table (Id));
      Unit_Hash_Table (Id) := Design_Unit;
   end Add_Unit_Hash;

   --  Remove DESIGN_UNIT from the unit hash table.
   procedure Remove_Unit_Hash (Design_Unit : Iir)
   is
      Id : Hash_Id;
      Unit, Prev, Next : Iir_Design_Unit;
   begin
      Id := Get_Hash_Id_For_Unit (Design_Unit);
      Unit := Unit_Hash_Table (Id);
      Prev := Null_Iir;
      while Unit /= Null_Iir loop
         Next := Get_Hash_Chain (Unit);
         if Unit = Design_Unit then
            if Prev = Null_Iir then
               Unit_Hash_Table (Id) := Next;
            else
               Set_Hash_Chain (Prev, Next);
            end if;
            return;
         end if;
         Prev := Unit;
         Unit := Next;
      end loop;
      --  Not found.
      raise Internal_Error;
   end Remove_Unit_Hash;

   procedure Purge_Design_File (Design_File : Iir_Design_File)
   is
      Prev, File, Next : Iir_Design_File;
      Unit : Iir_Design_Unit;

      File_Name : Name_Id;
      Dir_Name : Name_Id;
   begin
      File_Name := Get_Design_File_Filename (Design_File);
      Dir_Name := Get_Design_File_Directory (Design_File);

      File := Get_Design_File_Chain (Work_Library);
      Prev := Null_Iir;
      while File /= Null_Iir loop
         Next := Get_Chain (File);
         if Get_Design_File_Filename (File) = File_Name
           and then Get_Design_File_Directory (File) = Dir_Name
         then
            --  Remove from library.
            if Prev = Null_Iir then
               Set_Design_File_Chain (Work_Library, Next);
            else
               Set_Chain (Prev, Next);
            end if;

            --  Remove all units from unit hash table.
            Unit := Get_First_Design_Unit (File);
            while Unit /= Null_Iir loop
               Remove_Unit_Hash (Unit);
               Unit := Get_Chain (Unit);
            end loop;

            return;
         end if;
         Prev := File;
         File := Next;
      end loop;
   end Purge_Design_File;

   -- Load the contents of a library from a map file.
   -- The format of this file, used by save_library and load_library is
   -- as follow:
   --
   -- file_format ::= header { design_file_format }
   -- header ::= v 3
   -- design_file_format ::=
   --      filename_format { design_unit_format  }
   -- filename_format ::=
   --      FILE directory "FILENAME" file_time_stamp analyze_time_stamp:
   -- design_unit_format ::= entity_format
   --                        | architecture_format
   --                        | package_format
   --                        | package_body_format
   --                        | configuration_format
   -- position_format ::= LINE(POS) + OFF on DATE
   -- entity_format ::=
   --      ENTITY identifier AT position_format ;
   -- architecture_format ::=
   --      ARCHITECTURE identifier of name AT position_format ;
   -- package_format ::=
   --      PACKAGE identifier AT position_format [BODY] ;
   -- package_body_format ::=
   --      PACKAGE BODY identifier AT position_format ;
   -- configuration_format ::=
   --      CONFIGURATION identifier AT position_format ;
   --
   -- The position_format meaning is:
   --       LINE is the line number (first line is number 1),
   --       POS is the offset of this line number, as a source_ptr value,
   --       OFF is the offset in the line, starting with 0.
   --       DATE is the symbolic date of analysis (order).
   --
   -- Return TRUE if the library was found.
   function Load_Library (Library: Iir_Library_Declaration)
     return Boolean
   is
      use Scan;
      use Tokens;
      use Iirs_Utils;

      File : Source_File_Entry;

      procedure Bad_Library_Format is
      begin
         Error_Msg (Image (Files_Map.Get_File_Name (File)) &
                    ": bad library format");
      end Bad_Library_Format;

      procedure Scan_Expect (Tok: Token_Type) is
      begin
         Scan.Scan;
         if Current_Token /= Tok then
            Bad_Library_Format;
            raise Compilation_Error;
         end if;
      end Scan_Expect;

      function Current_Time_Stamp return Time_Stamp_Id is
      begin
         if Current_String_Length /= Time_Stamp_String'Length then
            Bad_Library_Format;
            raise Compilation_Error;
         end if;
         return Time_Stamp_Id (Current_String_Id);
      end Current_Time_Stamp;

      function String_To_Name_Id return Name_Id
      is
         Len : Natural;
         Ptr : String_Fat_Acc;
      begin
         Len := Natural (Current_String_Length);
         Ptr := Str_Table.Get_String_Fat_Acc (Current_String_Id);
         for I in 1 .. Len loop
            Name_Table.Name_Buffer (I) := Ptr (I);
         end loop;
         Name_Table.Name_Length := Len;
         --  FIXME: should remove last string.
         return Get_Identifier;
      end String_To_Name_Id;

      Design_Unit, Last_Design_Unit : Iir_Design_Unit;
      Lib_Ident : Name_Id;

      function Scan_Unit_List return Iir_List is
      begin
         if Current_Token = Tok_Left_Paren then
            Scan_Expect (Tok_Identifier);
            loop
               Scan_Expect (Tok_Dot);
               Scan_Expect (Tok_Identifier);
               Scan.Scan;
               if Current_Token = Tok_Left_Paren then
                  --  This is an architecture.
                  Scan_Expect (Tok_Identifier);
                  Scan_Expect (Tok_Right_Paren);
                  Scan.Scan;
               end if;
               exit when Current_Token /= Tok_Comma;
               Scan.Scan;
            end loop;
            Scan.Scan;
         end if;
         return Null_Iir_List;
      end Scan_Unit_List;

      Design_File: Iir_Design_File;
      Library_Unit: Iir;
      Line, Col: Natural;
      File_Dir : Name_Id;
      Pos: Source_Ptr;
      Date: Date_Type;
      Max_Date: Date_Type := Date_Valid'First;
      Dir : Name_Id;
   begin
      Lib_Ident := Get_Identifier (Library);

      if False then
         Ada.Text_IO.Put_Line ("Load library " & Image (Lib_Ident));
      end if;

      -- Check the library was not already loaded.
      if Get_Design_File_Chain (Library) /= Null_Iir then
         raise Internal_Error;
      end if;

      -- Try to open the library file map.
      Dir := Get_Library_Directory (Library);
      if Dir = Null_Identifier then
         --  Search in the library path.
         declare
            File_Name : String := Back_End.Library_To_File_Name (Library);
            L : Natural;
         begin
            for I in Pathes.First .. Pathes.Last loop
               Image (Pathes.Table (I));
               L := Name_Length + File_Name'Length;
               Name_Buffer (Name_Length + 1 .. L) := File_Name;
               Name_Buffer (L + 1) := Character'Val (0);
               if GNAT.OS_Lib.Is_Regular_File (Name_Buffer'Address) then
                  Dir := Pathes.Table (I);
                  Set_Library_Directory (Library, Dir);
                  exit;
               end if;
            end loop;
         end;
      end if;
      if Dir = Null_Identifier
        or else not Set_Library_File_Name (Dir, Library)
      then
         --  Not found.
         Set_Date (Library, Date_Valid'First);
         return False;
      end if;
      File := Get_Current_Source_File;

      --  Parse header.
      Scan.Scan;
      if Current_Token /= Tok_Identifier
        or else Name_Length /= 1 or else Name_Buffer (1) /= 'v'
      then
         Bad_Library_Format;
         raise Compilation_Error;
      end if;
      Scan_Expect (Tok_Integer);
      if Current_Iir_Int64 not in 1 .. 3 then
         Bad_Library_Format;
         raise Compilation_Error;
      end if;
      Scan.Scan;

      Last_Design_Unit := Null_Iir;
      while Current_Token /= Tok_Eof loop
         if Current_Token = Tok_File then
            -- This is a new design file.
            Design_File := Create_Iir (Iir_Kind_Design_File);

            Scan.Scan;
            if Current_Token = Tok_Dot then
               --  The filename is local, use the directory of the library.
               if Dir = Name_Nil then
                  File_Dir := Files_Map.Get_Home_Directory;
               else
                  File_Dir := Dir;
               end if;
            elsif Current_Token = Tok_Slash then
               --  The filename is an absolute file.
               File_Dir := Null_Identifier;
            elsif Current_Token = Tok_String then
               --  Be compatible with version 1: an empty directory for
               --  an absolute filename.
               if Current_String_Length = 0 then
                  File_Dir := Null_Identifier;
               else
                  File_Dir := String_To_Name_Id;
               end if;
            else
               Bad_Library_Format;
               raise Compilation_Error;
            end if;

            Set_Design_File_Directory (Design_File, File_Dir);

            Scan_Expect (Tok_String);
            Set_Design_File_Filename (Design_File, String_To_Name_Id);

            -- FIXME: check the file name is uniq.

            Set_Parent (Design_File, Library);

            --  Prepend.
            Set_Chain (Design_File, Get_Design_File_Chain (Library));
            Set_Design_File_Chain (Library, Design_File);

            Scan_Expect (Tok_String);
            Set_File_Time_Stamp (Design_File, Current_Time_Stamp);

            Scan_Expect (Tok_String);
            Set_Analysis_Time_Stamp (Design_File, Current_Time_Stamp);

            Scan_Expect (Tok_Colon);
            Scan.Scan;
            Last_Design_Unit := Null_Iir;
         else
            -- This is a new design unit.
            Design_Unit := Create_Iir (Iir_Kind_Design_Unit);
            Set_Design_File (Design_Unit, Design_File);
            case Current_Token is
               when Tok_Entity =>
                  Library_Unit := Create_Iir (Iir_Kind_Entity_Declaration);
                  Scan.Scan;
               when Tok_Architecture =>
                  Library_Unit :=
                    Create_Iir (Iir_Kind_Architecture_Declaration);
                  Scan.Scan;
               when Tok_Configuration =>
                  Library_Unit :=
                    Create_Iir (Iir_Kind_Configuration_Declaration);
                  Scan.Scan;
               when Tok_Package =>
                  Scan.Scan;
                  if Current_Token = Tok_Body then
                     Library_Unit := Create_Iir (Iir_Kind_Package_Body);
                     Scan.Scan;
                  else
                     Library_Unit := Create_Iir (Iir_Kind_Package_Declaration);
                  end if;
               when Tok_With =>
                  if Library_Unit = Null_Iir
                    or else
                    Get_Kind (Library_Unit)
                    /= Iir_Kind_Architecture_Declaration
                  then
                     Put_Line ("load_library: invalid use of 'with'");
                     raise Internal_Error;
                  end if;
                  Scan_Expect (Tok_Configuration);
                  Scan_Expect (Tok_Colon);
                  Scan.Scan;
                  Set_Dependence_List (Design_Unit, Scan_Unit_List);
                  goto Next_Line;
               when others =>
                  Put_Line
                    ("load_library: line must start with " &
                     "'architecture', 'entity', 'package' or 'configuration'");
                  raise Internal_Error;
            end case;

            if Current_Token /= Tok_Identifier then
               raise Internal_Error;
            end if;
            Set_Identifier (Library_Unit, Current_Identifier);
            Set_Identifier (Design_Unit, Current_Identifier);
            Set_Visible_Flag (Design_Unit, True);

            if Get_Kind (Library_Unit) = Iir_Kind_Architecture_Declaration then
               Scan_Expect (Tok_Of);
               Scan_Expect (Tok_Identifier);
               Set_Entity (Library_Unit, Current_Text);
            end if;

            -- Scan position.
            Scan_Expect (Tok_Identifier); -- at
            Scan_Expect (Tok_Integer);
            Line := Natural (Current_Iir_Int64);
            Scan_Expect (Tok_Left_Paren);
            Scan_Expect (Tok_Integer);
            Pos := Source_Ptr (Current_Iir_Int64);
            Scan_Expect (Tok_Right_Paren);
            Scan_Expect (Tok_Plus);
            Scan_Expect (Tok_Integer);
            Col := Natural (Current_Iir_Int64);
            Scan_Expect (Tok_On);
            Scan_Expect (Tok_Integer);
            Date := Date_Type (Current_Iir_Int64);

            Scan.Scan;
            if Get_Kind (Library_Unit) = Iir_Kind_Package_Declaration
              and then Current_Token = Tok_Body
            then
               Set_Need_Body (Library_Unit, True);
               Scan.Scan;
            end if;
            if Current_Token /= Tok_Semi_Colon then
               raise Internal_Error;
            end if;
            Scan.Scan;

            if False then
               Put_Line ("line:" & Natural'Image (Line)
                         & ", pos:" & Source_Ptr'Image (Pos));
            end if;

            -- Scan dependence list.
            Set_Dependence_List (Design_Unit, Scan_Unit_List);

            -- Keep the position of the design unit.
            --Set_Location (Design_Unit, Location_Type (File));
            --Set_Location (Library_Unit, Location_Type (File));
            Set_Pos_Line_Off (Design_Unit, Pos, Line, Col);
            Set_Date (Design_Unit, Date);
            if Date > Max_Date then
               Max_Date := Date;
            end if;
            Set_Date_State (Design_Unit, Date_Disk);
            Set_Library_Unit (Design_Unit, Library_Unit);
            Set_Design_Unit (Library_Unit, Design_Unit);

            --  Add in the unit hash table.
            Add_Unit_Hash (Design_Unit);

            if Last_Design_Unit = Null_Iir then
               Set_First_Design_Unit (Design_File, Design_Unit);
            else
               Set_Chain (Last_Design_Unit, Design_Unit);
            end if;
            Last_Design_Unit := Design_Unit;
            Set_Last_Design_Unit (Design_File, Design_Unit);
         end if;
         << Next_Line >> null;
      end loop;
      Set_Date (Library, Max_Date);
      Close_File;
      return True;
   end Load_Library;

   procedure Create_Virtual_Locations
   is
      use Files_Map;
      use Name_Table;
      Implicit_Source_File : Source_File_Entry;
      Command_Source_File : Source_File_Entry;
   begin
      Implicit_Source_File := Create_Virtual_Source_File
        (Get_Identifier ("*implicit*"));
      Command_Source_File := Create_Virtual_Source_File
        (Get_Identifier ("*command line*"));
      Command_Line_Location := Source_File_To_Location (Command_Source_File);
      Implicit_Location := Source_File_To_Location (Implicit_Source_File);
   end Create_Virtual_Locations;

   -- Note: the scanner shouldn't be in use, since this procedure uses it.
   procedure Load_Std_Library (Build_Standard : Boolean := True)
   is
      use Std_Package;
      Dir : Name_Id;
   begin
      if Libraries_Chain /= Null_Iir then
         --  This procedure must not be called twice.
         raise Internal_Error;
      end if;

      Flags.Create_Flag_String;
      Create_Virtual_Locations;

      Std_Package.Create_First_Nodes;

      --  Create the library.
      Std_Library := Create_Iir (Iir_Kind_Library_Declaration);
      Set_Identifier (Std_Library, Std_Names.Name_Std);
      Set_Location (Std_Library, Implicit_Location);
      Libraries_Chain := Std_Library;
      Libraries_Chain_Last := Std_Library;

      if Build_Standard then
         Create_Std_Standard_Package (Std_Library);
         Add_Unit_Hash (Std_Standard_Unit);
      end if;

      if Flags.Bootstrap
        and then Work_Library_Name = Std_Names.Name_Std
      then
         Dir := Work_Directory;
      else
         Dir := Null_Identifier;
      end if;
      Set_Library_Directory (Std_Library, Dir);
      if Load_Library (Std_Library) = False
        and then not Flags.Bootstrap
      then
         Error_Msg_Option ("cannot find ""std"" library");
      end if;

      if Build_Standard then
         --  Add the standard_file into the library.
         --  This is done after Load_Library, because it checks there is no
         --  previous files in the library.
         Set_Parent (Std_Standard_File, Std_Library);
         Set_Chain (Std_Standard_File, Get_Design_File_Chain (Std_Library));
         Set_Design_File_Chain (Std_Library, Std_Standard_File);
      end if;

      Set_Visible_Flag (Std_Library, True);
   end Load_Std_Library;

   procedure Load_Work_Library (Empty : Boolean := False)
   is
      use Std_Names;
   begin
      if Work_Library_Name = Name_Std then
         if not Flags.Bootstrap then
            Error_Msg_Option ("the WORK library cannot be STD");
            return;
         end if;
         Work_Library := Std_Library;
      else
         Work_Library := Create_Iir (Iir_Kind_Library_Declaration);
         Set_Location (Work_Library, Implicit_Location);
         --Set_Visible_Flag (Work_Library, True);
         Set_Library_Directory (Work_Library, Work_Directory);

         Set_Identifier (Work_Library, Work_Library_Name);

         if not Empty then
            if Load_Library (Work_Library) = False then
               null;
            end if;
         end if;

         --  Add it to the list of libraries.
         Set_Chain (Libraries_Chain_Last, Work_Library);
         Libraries_Chain_Last := Work_Library;
      end if;
      Set_Visible_Flag (Work_Library, True);
   end Load_Work_Library;

--    procedure Unload_Library (Library : Iir_Library_Declaration)
--    is
--       File : Iir_Design_File;
--       Unit : Iir_Design_Unit;
--    begin
--       loop
--          File := Get_Design_File_Chain (Library);
--          exit when File = Null_Iir;
--          Set_Design_File_Chain (Library, Get_Chain (File));

--          loop
--             Unit := Get_Design_Unit_Chain (File);
--             exit when Unit = Null_Iir;
--             Set_Design_Unit_Chain (File, Get_Chain (Unit));

--             --  Units should not be loaded.
--             if Get_Loaded_Flag (Unit) then
--                raise Internal_Error;
--             end if;

--             --  Free dependences list.
--          end loop;
--       end loop;
--    end Unload_Library;

--    procedure Unload_All_Libraries
--    is
--       Library : Iir_Library_Declaration;
--    begin
--       if Get_Identifier (Std_Library) /= Name_Std then
--          raise Internal_Error;
--       end if;
--       if Std_Library /= Libraries_Chain then
--          raise Internal_Error;
--       end if;
--       loop
--          Library := Get_Chain (Libraries_Chain);
--          exit when Library = Null_Iir;
--          Set_Chain (Libraries_Chain, Get_Chain (Libraries_Chain));
--          Unload_Library (Library);
--       end loop;
--    end Unload_All_Libraries;

   -- Get or create a library from an identifier.
   function Get_Library (Ident: Name_Id; Loc : Location_Type)
                        return Iir_Library_Declaration
   is
      Library: Iir_Library_Declaration;
   begin
      -- library work is a little bit special.
      if Ident = Std_Names.Name_Work or else Ident = Work_Library_Name then
         if Work_Library = Null_Iir then
            --  load_work_library must have been called before.
            raise Internal_Error;
         end if;
         return Work_Library;
      end if;

      --  Check if the library has already been loaded.
      Library := Iirs_Utils.Find_Name_In_Chain (Libraries_Chain, Ident);
      if Library /= Null_Iir then
         return Library;
      end if;

      --  This is a new library.
      if Ident = Std_Names.Name_Std then
         --  Load_std_library must have been called before.
         raise Internal_Error;
      end if;

      Library := Create_Iir (Iir_Kind_Library_Declaration);
      Set_Location (Library, Scan.Get_Token_Location);
      Set_Library_Directory (Library, Null_Identifier);
      Set_Identifier (Library, Ident);
      if Load_Library (Library) = False then
         Error_Msg_Sem ("cannot find resource library """
                        & Name_Table.Image (Ident) & """", Loc);
      end if;
      Set_Visible_Flag (Library, True);

      Set_Chain (Libraries_Chain_Last, Library);
      Libraries_Chain_Last := Library;

      return Library;
   end Get_Library;

   -- Return TRUE if LIBRARY_UNIT and UNIT have identifiers for the same
   -- design unit identifier.
   -- eg: 'entity A' and 'package A' returns TRUE.
   function Is_Same_Library_Unit (Library_Unit, Unit: Iir) return Boolean
   is
      Entity_Name1, Entity_Name2: Name_Id;
      Library_Unit_Kind, Unit_Kind : Iir_Kind;
   begin
      if Get_Identifier (Unit) /= Get_Identifier (Library_Unit) then
         return False;
      end if;

      Library_Unit_Kind := Get_Kind (Library_Unit);
      Unit_Kind := Get_Kind (Unit);

      --  Package and package body are never the same library unit.
      if Library_Unit_Kind = Iir_Kind_Package_Declaration
        and then Unit_Kind = Iir_Kind_Package_Body
      then
         return False;
      end if;
      if Unit_Kind = Iir_Kind_Package_Declaration
        and then Library_Unit_Kind = Iir_Kind_Package_Body
      then
         return False;
      end if;

      --  Two architecture declarations are identical only if they also have
      --  the same entity name.
      if Unit_Kind = Iir_Kind_Architecture_Declaration
        and then Library_Unit_Kind = Iir_Kind_Architecture_Declaration
      then
         Entity_Name1 := Get_Identifier (Get_Entity (Unit));
         Entity_Name2 := Get_Identifier (Get_Entity (Library_Unit));
         if Entity_Name1 /= Entity_Name2 then
            return False;
         end if;
      end if;

      --  An architecture declaration never conflits with a library unit that
      --  is not an architecture declaration.
      if (Unit_Kind = Iir_Kind_Architecture_Declaration
          and then Library_Unit_Kind /= Iir_Kind_Architecture_Declaration)
        or else
        (Unit_Kind /= Iir_Kind_Architecture_Declaration
         and then Library_Unit_Kind = Iir_Kind_Architecture_Declaration)
      then
         return False;
      end if;

      return True;
   end Is_Same_Library_Unit;

   procedure Free_Dependence_List (Design : Iir_Design_Unit)
   is
      List : Iir_List;
      El : Iir;
   begin
      List := Get_Dependence_List (Design);
      if List /= Null_Iir_List then
         for I in Natural loop
            El := Get_Nth_Element (List, I);
            exit when El = Null_Iir;
            Iirs_Utils.Free_Recursive (El);
         end loop;
         Destroy_Iir_List (List);
      end if;
   end Free_Dependence_List;

   procedure Free_Design_Unit (Design_Unit : Iir_Design_Unit)
   is
      Lib : Iir;
      Unit : Iir_Design_Unit;
      Dep_List : Iir_List;
   begin
      Dep_List := Get_Dependence_List (Design_Unit);
      Destroy_Iir_List (Dep_List);
      Lib := Get_Library_Unit (Design_Unit);
      if Lib /= Null_Iir
        and then Get_Kind (Lib) = Iir_Kind_Architecture_Declaration
      then
         Unit := Get_Default_Configuration_Declaration (Lib);
         if Unit /= Null_Iir then
            Free_Design_Unit (Unit);
         end if;
      end if;
      Iirs_Utils.Free_Old_Iir (Lib);
   end Free_Design_Unit;

   procedure Remove_Unit_From_File
     (Unit_Ref : Iir_Design_Unit; File : Iir_Design_File)
   is
      Prev : Iir_Design_Unit;
      Unit, Next : Iir_Design_Unit;
   begin
      Prev := Null_Iir;
      Unit := Get_First_Design_Unit (File);
      while Unit /= Null_Iir loop
         Next := Get_Chain (Unit);
         if Unit = Unit_Ref then
            if Prev = Null_Iir then
               Set_First_Design_Unit (File, Next);
            else
               Set_Chain (Prev, Next);
            end if;
            if Next = Null_Iir then
               Set_Last_Design_Unit (File, Prev);
            end if;
            return;
         end if;
         Prev := Unit;
         Unit := Next;
      end loop;
      --  Not found.
      raise Internal_Error;
   end Remove_Unit_From_File;

   --  Last design_file used.  Kept to speed-up operations.
   Last_Design_File : Iir_Design_File := Null_Iir;

   -- Add or replace a design unit in the working library.
   procedure Add_Design_Unit_Into_Library (Unit : Iir_Design_Unit)
   is
      Design_File: Iir_Design_File;
      Design_Unit, Prev_Design_Unit : Iir_Design_Unit;
      Last_Unit : Iir_Design_Unit;
      Library_Unit: Iir;
      New_Library_Unit: Iir;
      Unit_Id : Name_Id;
      Date: Date_Type;
      New_Lib_Time_Stamp : Time_Stamp_Id;
      Id : Hash_Id;

      --  File name and dir name of DECL.
      File_Name : Name_Id;
      Dir_Name : Name_Id;
   begin
      pragma Assert (Get_Chain (Unit) = Null_Iir);

      if Get_Date_State (Unit) /= Date_Extern then
         raise Internal_Error;
      end if;

      --  Mark this design unit as being loaded.
      New_Library_Unit := Get_Library_Unit (Unit);
      Unit_Id := Get_Identifier (New_Library_Unit);

      --  Set the date of the design unit as the most recently analyzed
      --  design unit.
      case Get_Date (Unit) is
         when Date_Parsed =>
            Set_Date_State (Unit, Date_Parse);
         when Date_Analyzed =>
            Date := Get_Date (Work_Library) + 1;
            Set_Date (Unit, Date);
            Set_Date (Work_Library, Date);
            Set_Date_State (Unit, Date_Analyze);
         when Date_Valid =>
            raise Internal_Error;
         when others =>
            raise Internal_Error;
      end case;

      --  Set file time stamp.
      declare
         File : Source_File_Entry;
         Pos : Source_Ptr;
      begin
         Files_Map.Location_To_File_Pos (Get_Location (New_Library_Unit),
                                         File, Pos);
         New_Lib_Time_Stamp := Files_Map.Get_File_Time_Stamp (File);
         File_Name := Files_Map.Get_File_Name (File);
         Image (File_Name);
         if Files_Map.Is_Absolute_Pathname (Name_Buffer (1 .. Name_Length))
         then
            Dir_Name := Null_Identifier;
         else
            Dir_Name := Files_Map.Get_Home_Directory;
         end if;
      end;

      --  Try to find a design unit with the same name in the work library.
      Id := Get_Hash_Id_For_Unit (Unit);
      Design_Unit := Unit_Hash_Table (Id);
      Prev_Design_Unit := Null_Iir;
      while Design_Unit /= Null_Iir loop
         Design_File := Get_Design_File (Design_Unit);
         Library_Unit := Get_Library_Unit (Design_Unit);
         if Get_Identifier (Design_Unit) = Unit_Id
           and then Get_Library (Design_File) = Work_Library
           and then Is_Same_Library_Unit (New_Library_Unit, Library_Unit)
         then
            --  LIBRARY_UNIT and UNIT designate the same design unit.
            --  Remove the old one.
            Set_Date (Design_Unit, Date_Obsolete);
            declare
               Next_Design : Iir;
            begin
               --  Remove DESIGN_UNIT from the unit_hash.
               Next_Design := Get_Hash_Chain (Design_Unit);
               if Prev_Design_Unit = Null_Iir then
                  Unit_Hash_Table (Id) := Next_Design;
               else
                  Set_Hash_Chain (Prev_Design_Unit, Next_Design);
               end if;

               --  Remove DESIGN_UNIT from the design_file.
               Remove_Unit_From_File (Design_Unit, Design_File);
            end;

            -- UNIT *must* replace library_unit if they don't belong
            -- to the same file.
            if Get_Design_File_Filename (Design_File) = File_Name
              and then Get_Design_File_Directory (Design_File) = Dir_Name
            then
               --  In the same file.
               if Get_Date_State (Design_Unit) = Date_Analyze then
                  --  Warns only if we are not re-analyzing the file.
                  if Flags.Warn_Library then
                     Warning_Msg_Sem
                       ("redefinition of a library unit in "
                        & "same design file:", Unit);
                     Warning_Msg_Sem
                       (Disp_Node (Library_Unit) & " defined at "
                        & Disp_Location (Library_Unit) & " is now "
                        & Disp_Node (New_Library_Unit), Unit);
                  end if;
               else
                  --  Free the stub.
                  Free_Design_Unit (Design_Unit);
               end if;

               --  Note: the current design unit should not be freed if
               --  in use; unfortunatly, this is not obvious to check.
            else
               if Flags.Warn_Library then
                  if Get_Kind (Library_Unit) /= Get_Kind (New_Library_Unit)
                  then
                     Warning_Msg ("changing definition of a library unit:");
                     Warning_Msg (Disp_Node (Library_Unit) & " is now "
                                  & Disp_Node (New_Library_Unit));
                  end if;
                  Warning_Msg
                    ("library unit '"
                     & Iirs_Utils.Image_Identifier (Library_Unit)
                     & "' was also defined in file '"
                     & Image (Get_Design_File_Filename (Design_File))
                     & ''');
               end if;
            end if;
            exit;
         end if;
         Prev_Design_Unit := Design_Unit;
         Design_Unit := Get_Hash_Chain (Design_Unit);
      end loop;

      --  Try to find the design file in the library.
      --  First try the last one found.
      if Last_Design_File /= Null_Iir
        and then Get_Library (Last_Design_File) = Work_Library
        and then Get_Design_File_Filename (Last_Design_File) = File_Name
        and then Get_Design_File_Directory (Last_Design_File) = Dir_Name
      then
         Design_File := Last_Design_File;
      else
         --  Search.
         Design_File := Get_Design_File_Chain (Work_Library);
         while Design_File /= Null_Iir loop
            if Get_Design_File_Filename (Design_File) = File_Name
              and then Get_Design_File_Directory (Design_File) = Dir_Name
            then
               exit;
            end if;
            Design_File := Get_Chain (Design_File);
         end loop;
      end if;

      if Design_File /= Null_Iir
        and then not Files_Map.Is_Eq (New_Lib_Time_Stamp,
                                      Get_File_Time_Stamp (Design_File))
      then
         -- FIXME: this test is not enough: what about reanalyzing
         --  unmodified files (this works only because the order is not
         --  changed).
         -- Design file is updated.
         -- Outdate all other units, overwrite the design_file.
         Set_File_Time_Stamp (Design_File, New_Lib_Time_Stamp);
         Design_Unit := Get_First_Design_Unit (Design_File);
         while Design_Unit /= Null_Iir loop
            if Design_Unit /= Unit then
               --  Mark other design unit as obsolete.
               Set_Date (Design_Unit, Date_Obsolete);
               Remove_Unit_Hash (Design_Unit);
            else
               raise Internal_Error;
            end if;
            Design_Unit := Get_Chain (Design_Unit);
         end loop;
         Set_First_Design_Unit (Design_File, Null_Iir);
         Set_Last_Design_Unit (Design_File, Null_Iir);
      end if;

      if Design_File = Null_Iir then
         -- This is the first apparition of the design file.
         Design_File := Create_Iir (Iir_Kind_Design_File);
         Location_Copy (Design_File, Unit);

         Set_Design_File_Filename (Design_File, File_Name);
         Set_Design_File_Directory (Design_File, Dir_Name);

         Set_File_Time_Stamp (Design_File, New_Lib_Time_Stamp);
         Set_Parent (Design_File, Work_Library);
         Set_Chain (Design_File, Get_Design_File_Chain (Work_Library));
         Set_Design_File_Chain (Work_Library, Design_File);
      end if;

      --  Add DECL to DESIGN_FILE.
      Last_Unit := Get_Last_Design_Unit (Design_File);
      if Last_Unit = Null_Iir then
         if Get_First_Design_Unit (Design_File) /= Null_Iir then
            raise Internal_Error;
         end if;
         Set_First_Design_Unit (Design_File, Unit);
      else
         if Get_First_Design_Unit (Design_File) = Null_Iir then
            raise Internal_Error;
         end if;
         Set_Chain (Last_Unit, Unit);
      end if;
      Set_Last_Design_Unit (Design_File, Unit);
      Set_Design_File (Unit, Design_File);

      --  Add DECL in unit hash table.
      Set_Hash_Chain (Unit, Unit_Hash_Table (Id));
      Unit_Hash_Table (Id) := Unit;

      --  Update the analyzed time stamp.
      Set_Analysis_Time_Stamp (Design_File, Files_Map.Get_Os_Time_Stamp);
   end Add_Design_Unit_Into_Library;

   procedure Add_Design_File_Into_Library (File : in out Iir_Design_File)
   is
      Unit : Iir_Design_Unit;
      Next_Unit : Iir_Design_Unit;
      First_Unit : Iir_Design_Unit;
   begin
      Unit := Get_First_Design_Unit (File);
      First_Unit := Unit;
      Set_First_Design_Unit (File, Null_Iir);
      Set_Last_Design_Unit (File, Null_Iir);
      while Unit /= Null_Iir loop
         Next_Unit := Get_Chain (Unit);
         Set_Chain (Unit, Null_Iir);
         Libraries.Add_Design_Unit_Into_Library (Unit);
         Unit := Next_Unit;
      end loop;
      if First_Unit /= Null_Iir then
         File := Get_Design_File (First_Unit);
      end if;
   end Add_Design_File_Into_Library;

   -- Save the file map of library LIBRARY.
   procedure Save_Library (Library: Iir_Library_Declaration) is
      File: File_Type;

      Design_File: Iir_Design_File;
      Design_Unit: Iir_Design_Unit;
      Library_Unit: Iir;
      Dir : Name_Id;

      Off, Line: Natural;
      Pos: Source_Ptr;
      Source_File : Source_File_Entry;
   begin
      -- FIXME: directory
      declare
         use Files_Map;
         File_Name: String := Image (Work_Directory)
           & Back_End.Library_To_File_Name (Library);
      begin
         Create (File, Out_File, File_Name);
      exception
         when Use_Error =>
            Open (File, Out_File, File_Name);
         when Name_Error =>
            Error_Msg ("cannot create library file """ & File_Name & """");
            raise Option_Error;
      end;

      --  Header: version.
      Put_Line (File, "v 3");

      Design_File := Get_Design_File_Chain (Library);
      while Design_File /= Null_Iir loop
         if Design_File = Std_Package.Std_Standard_File then
            goto Continue;
         end if;
         Design_Unit := Get_First_Design_Unit (Design_File);

         if Design_Unit /= Null_Iir then
            Put (File, "file ");
            Dir := Get_Design_File_Directory (Design_File);
            if Dir = Null_Identifier then
               --  Absolute filenames.
               Put (File, "/");
            elsif Work_Directory = Name_Nil
              and then Dir = Files_Map.Get_Home_Directory
            then
               --  If the library is in the current directory, do not write
               --  it.  This allows to move the library file.
               Put (File, ".");
            else
               Image (Dir);
               Put (File, """");
               Put (File, Name_Buffer (1 .. Name_Length));
               Put (File, """");
            end if;
            Put (File, " """);
            Image (Get_Design_File_Filename (Design_File));
            Put (File, Name_Buffer (1 .. Name_Length));
            Put (File, """ """);
            Put (File, Files_Map.Get_Time_Stamp_String
                 (Get_File_Time_Stamp (Design_File)));
            Put (File, """ """);
            Put (File, Files_Map.Get_Time_Stamp_String
                 (Get_Analysis_Time_Stamp (Design_File)));
            Put_Line (File, """:");
         end if;

         while Design_Unit /= Null_Iir loop
            Library_Unit := Get_Library_Unit (Design_Unit);

            Put (File, "  ");
            case Get_Kind (Library_Unit) is
               when Iir_Kind_Entity_Declaration =>
                  Put (File, "entity ");
                  Put (File, Iirs_Utils.Image_Identifier (Library_Unit));
               when Iir_Kind_Architecture_Declaration =>
                  Put (File, "architecture ");
                  Put (File, Iirs_Utils.Image_Identifier (Library_Unit));
                  Put (File, " of ");
                  Put (File, Iirs_Utils.Image_Identifier
                       (Get_Entity (Library_Unit)));
               when Iir_Kind_Package_Declaration =>
                  Put (File, "package ");
                  Put (File, Iirs_Utils.Image_Identifier (Library_Unit));
               when Iir_Kind_Package_Body =>
                  Put (File, "package body ");
                  Put (File, Iirs_Utils.Image_Identifier (Library_Unit));
               when Iir_Kind_Configuration_Declaration =>
                  Put (File, "configuration ");
                  Put (File, Iirs_Utils.Image_Identifier (Library_Unit));
               when others =>
                  Error_Kind ("save_library", Library_Unit);
            end case;

            if Get_Date_State (Design_Unit) = Date_Disk then
               Get_Pos_Line_Off (Design_Unit, Pos, Line, Off);
            else
               Files_Map.Location_To_Coord (Get_Location (Design_Unit),
                                            Source_File, Pos, Line, Off);
            end if;

            Put (File, " at");
            Put (File, Natural'Image (Line));
            Put (File, "(");
            Put (File, Source_Ptr'Image (Pos));
            Put (File, ") +");
            Put (File, Natural'Image (Off));
            Put (File, " on");
            case Get_Date (Design_Unit) is
               when Date_Valid
                 | Date_Analyzed
                 | Date_Parsed =>
                  Put (File, Date_Type'Image (Get_Date (Design_Unit)));
               when others =>
                  Put_Line (Date_Type'Image (Get_Date (Design_Unit)));
                  raise Internal_Error;
            end case;
            if Get_Kind (Library_Unit) = Iir_Kind_Package_Declaration
              and then Get_Need_Body (Library_Unit)
            then
               Put (File, " body");
            end if;
            Put_Line (File, ";");

            Design_Unit := Get_Chain (Design_Unit);
         end loop;
         << Continue >> null;
         Design_File := Get_Chain (Design_File);
      end loop;

      Close (File);
   end Save_Library;

   -- Save the map of the work library.
   procedure Save_Work_Library is
   begin
      Save_Library (Work_Library);
   end Save_Work_Library;

   -- Return the name of the latest architecture analysed for an entity.
   function Get_Latest_Architecture (Entity: Iir_Entity_Declaration)
     return Iir_Architecture_Declaration
   is
      Entity_Id : Name_Id;
      Lib : Iir_Library_Declaration;
      Design_File: Iir_Design_File;
      Design_Unit: Iir_Design_Unit;
      Library_Unit: Iir;
      Res: Iir_Design_Unit;
   begin
      --  FIXME: use hash
      Entity_Id := Get_Identifier (Entity);
      Lib := Get_Library (Get_Design_File (Get_Design_Unit (Entity)));
      Design_File := Get_Design_File_Chain (Lib);
      Res := Null_Iir;
      while Design_File /= Null_Iir loop
         Design_Unit := Get_First_Design_Unit (Design_File);
         while Design_Unit /= Null_Iir loop
            Library_Unit := Get_Library_Unit (Design_Unit);

            if Get_Kind (Library_Unit) = Iir_Kind_Architecture_Declaration
              and then Get_Identifier (Get_Entity (Library_Unit)) = Entity_Id
            then
               if Res = Null_Iir then
                  Res := Design_Unit;
               elsif Get_Date (Design_Unit) > Get_Date (Res) then
                  Res := Design_Unit;
               end if;
            end if;
            Design_Unit := Get_Chain (Design_Unit);
         end loop;
         Design_File := Get_Chain (Design_File);
      end loop;
      if Res = Null_Iir then
         return Null_Iir;
      else
         return Get_Library_Unit (Res);
      end if;
   end Get_Latest_Architecture;

   function Load_File (File : Source_File_Entry) return Iir_Design_File
   is
      Res : Iir_Design_File;
   begin
      Scan.Set_File (File);
      Res := Parse.Parse_Design_File;
      Scan.Close_File;
      if Res /= Null_Iir then
         Set_Parent (Res, Work_Library);
         Set_Design_File_Filename (Res, Files_Map.Get_File_Name (File));
      end if;
      return Res;
   end Load_File;

   -- parse a file.
   -- Return a design_file without putting it into the library
   -- (because it was not semantized).
   function Load_File (File_Name: Name_Id) return Iir_Design_File
   is
      Fe : Source_File_Entry;
   begin
      Fe := Files_Map.Load_Source_File (Local_Directory, File_Name);
      if Fe = No_Source_File_Entry then
         Error_Msg_Option ("cannot open " & Image (File_Name));
         return Null_Iir;
      end if;
      return Load_File (Fe);
   end Load_File;

   function Find_Design_Unit (Unit : Iir) return Iir_Design_Unit is
   begin
      case Get_Kind (Unit) is
         when Iir_Kind_Design_Unit =>
            return Unit;
         when Iir_Kind_Selected_Name =>
            declare
               Lib : Iir_Library_Declaration;
            begin
               Lib := Get_Library (Get_Identifier (Get_Prefix (Unit)),
                                   Get_Location (Unit));
               return Find_Primary_Unit (Lib, Get_Suffix_Identifier (Unit));
            end;
         when Iir_Kind_Entity_Aspect_Entity =>
            declare
               Prim : Iir_Design_Unit;
            begin
               Prim := Find_Design_Unit (Get_Entity (Unit));
               if Prim = Null_Iir then
                  return Null_Iir;
               end if;
               return Find_Secondary_Unit
                 (Prim, Get_Identifier (Get_Architecture (Unit)));
            end;
         when others =>
            Error_Kind ("find_design_unit", Unit);
      end case;
   end Find_Design_Unit;

   function Is_Obsolete (Design_Unit : Iir_Design_Unit; Loc : Iir)
     return Boolean
   is
      procedure Error_Obsolete (Msg : String) is
      begin
         if not Flags.Flag_Elaborate_With_Outdated then
            Error_Msg_Sem (Msg, Loc);
         end if;
      end Error_Obsolete;

      List : Iir_List;
      El : Iir;
      Unit : Iir_Design_Unit;
      U_Ts : Time_Stamp_Id;
      Du_Ts : Time_Stamp_Id;
   begin
      if Get_Date (Design_Unit) = Date_Obsolete then
         Error_Obsolete (Disp_Node (Design_Unit) & " is obsolete");
         return True;
      end if;
      List := Get_Dependence_List (Design_Unit);
      if List = Null_Iir_List then
         return False;
      end if;
      Du_Ts := Get_Analysis_Time_Stamp (Get_Design_File (Design_Unit));
      for I in Natural loop
         El := Get_Nth_Element (List, I);
         exit when El = Null_Iir;
         Unit := Find_Design_Unit (El);
         if Unit /= Null_Iir then
            U_Ts := Get_Analysis_Time_Stamp (Get_Design_File (Unit));
            if Files_Map.Is_Gt (U_Ts, Du_Ts) then
               Error_Obsolete
                 (Disp_Node (Design_Unit) & " is obsoleted by " &
                  Disp_Node (Unit));
               return True;
            elsif Is_Obsolete (Unit, Loc) then
               Error_Obsolete
                 (Disp_Node (Design_Unit) & " depends on obsolete unit");
               return True;
            end if;
         end if;
      end loop;
      return False;
   end Is_Obsolete;

   procedure Load_Parse_Design_Unit (Design_Unit: Iir_Design_Unit; Loc : Iir)
   is
      use Scan;
      Line, Off: Natural;
      Pos: Source_Ptr;
      Res: Iir;
      Library : Iir_Library_Declaration;
      Design_File : Iir_Design_File;
      Fe : Source_File_Entry;
   begin
      if Get_Date_State (Design_Unit) /= Date_Disk then
         raise Internal_Error;
      end if;

      --  Load and parse the unit.
      Design_File := Get_Design_File (Design_Unit);
      Library := Get_Library (Design_File);
      Fe := Files_Map.Load_Source_File
        (Get_Design_File_Directory (Design_File),
         Get_Design_File_Filename (Design_File));
      if Fe = No_Source_File_Entry then
         Error_Msg
           ("cannot load " & Disp_Node (Get_Library_Unit (Design_Unit)));
         raise Compilation_Error;
      end if;
      Set_File (Fe);

      if not Files_Map.Is_Eq
        (Files_Map.Get_File_Time_Stamp (Get_Current_Source_File),
         Get_File_Time_Stamp (Design_File))
      then
         Error_Msg_Sem
           ("file " & Image (Get_Design_File_Filename (Design_File))
            & " has changed and must be reanalysed", Loc);
         raise Compilation_Error;
      elsif Get_Date (Design_Unit) = Date_Obsolete then
         Error_Msg_Sem
           (''' & Disp_Node (Get_Library_Unit (Design_Unit))
            & "' is not anymore in the file",
            Design_Unit);
         raise Compilation_Error;
      end if;
      Get_Pos_Line_Off (Design_Unit, Pos, Line, Off);
      Files_Map.File_Add_Line_Number (Get_Current_Source_File, Line, Pos);
      Set_Current_Position (Pos + Source_Ptr (Off));
      Res := Parse.Parse_Design_Unit;
      Close_File;
      if Res = Null_Iir then
         raise Compilation_Error;
      end if;
      Set_Date_State (Design_Unit, Date_Parse);
      --  FIXME: check the library unit read is the one expected.
      --  Copy node.
      Iirs_Utils.Free_Recursive (Get_Library_Unit (Design_Unit));
      Set_Library_Unit (Design_Unit, Get_Library_Unit (Res));
      Set_Design_Unit (Get_Library_Unit (Res), Design_Unit);
      Set_Parent (Get_Library_Unit (Res), Design_Unit);
      Set_Context_Items (Design_Unit, Get_Context_Items (Res));
      Location_Copy (Design_Unit, Res);
      Free_Dependence_List (Design_Unit);
      Set_Dependence_List (Design_Unit, Get_Dependence_List (Res));
      Set_Dependence_List (Res, Null_Iir_List);
      Free_Iir (Res);
   end Load_Parse_Design_Unit;

   -- Load, parse, semantize, back-end a design_unit if necessary.
   procedure Load_Design_Unit (Design_Unit: Iir_Design_Unit; Loc : Iir) is
   begin
      if Get_Date_State (Design_Unit) = Date_Disk then
         Load_Parse_Design_Unit (Design_Unit, Loc);
      end if;

      if Get_Date_State (Design_Unit) = Date_Parse then
         --  Analyze the design unit.

         if Get_Date (Design_Unit) = Date_Analyzed then
            --  Work-around for an internal check in sem.
            --  FIXME: to be removed ?
            Set_Date (Design_Unit, Date_Parsed);
         end if;

         --  Avoid infinite recursion, if the unit is self-referenced.
         Set_Date_State (Design_Unit, Date_Analyze);

         Sem_Scopes.Push_Interpretations;
         Back_End.Finish_Compilation (Design_Unit);
         Sem_Scopes.Pop_Interpretations;

      end if;

      case Get_Date (Design_Unit) is
         when Date_Parsed =>
            raise Internal_Error;
         when Date_Analyzing =>
            --  Self-referenced unit.
            return;
         when Date_Analyzed =>
            --  FIXME: Accept it silently ?
            --  Note: this is used when Flag_Elaborate_With_Outdated is set.
            --  This is also used by anonymous configuration declaration.
            null;
         when Date_Uptodate =>
            return;
         when Date_Valid =>
            null;
         when Date_Obsolete =>
            if not Flags.Flag_Elaborate_With_Outdated then
               Error_Msg_Sem (Disp_Node (Design_Unit) & " is obsolete", Loc);
               return;
            end if;
         when others =>
            raise Internal_Error;
      end case;

      if not Flags.Flag_Elaborate_With_Outdated
        and then Is_Obsolete (Design_Unit, Loc)
      then
         Set_Date (Design_Unit, Date_Obsolete);
      end if;
   end Load_Design_Unit;

   --  Return the declaration of primary unit NAME of LIBRARY.
   function Find_Primary_Unit
     (Library: Iir_Library_Declaration; Name: Name_Id)
      return Iir_Design_Unit
   is
      Unit : Iir_Design_Unit;
   begin
      Unit := Unit_Hash_Table (Name mod Unit_Hash_Length);
      while Unit /= Null_Iir loop
         if Get_Identifier (Unit) = Name
           and then Get_Library (Get_Design_File (Unit)) = Library
         then
            case Get_Kind (Get_Library_Unit (Unit)) is
               when Iir_Kind_Package_Declaration
                 | Iir_Kind_Entity_Declaration
                 | Iir_Kind_Configuration_Declaration =>
                  --  Only return a primary unit.
                  return Unit;
               when others =>
                  null;
            end case;
         end if;
         Unit := Get_Hash_Chain (Unit);
      end loop;

      -- The primary unit is not in the library, return null.
      return Null_Iir;
   end Find_Primary_Unit;

   function Load_Primary_Unit
     (Library: Iir_Library_Declaration; Name: Name_Id; Loc : Iir)
      return Iir_Design_Unit
   is
      Design_Unit: Iir_Design_Unit;
   begin
      Design_Unit := Find_Primary_Unit (Library, Name);
      if Design_Unit /= Null_Iir then
         Load_Design_Unit (Design_Unit, Loc);
      end if;
      return Design_Unit;
   end Load_Primary_Unit;

   -- Return the declaration of secondary unit NAME for PRIMARY, or null if
   -- not found.
   function Find_Secondary_Unit (Primary: Iir_Design_Unit; Name: Name_Id)
      return Iir_Design_Unit
   is
      Design_Unit: Iir_Design_Unit;
      Library_Unit: Iir;
      Primary_Ident: Name_Id;
      Ident: Name_Id;
      Lib_Prim : Iir;
   begin
      Lib_Prim := Get_Library (Get_Design_File (Primary));
      Primary_Ident := Get_Identifier (Get_Library_Unit (Primary));
      Design_Unit := Unit_Hash_Table (Primary_Ident mod Unit_Hash_Length);
      while Design_Unit /= Null_Iir loop
         Library_Unit := Get_Library_Unit (Design_Unit);

         --  The secondary is always in the same library as the primary.
         if Get_Library (Get_Design_File (Design_Unit)) = Lib_Prim then
            -- Set design_unit to null iff this is not the correct
            -- design unit.
            case Get_Kind (Library_Unit) is
               when Iir_Kind_Architecture_Declaration =>
                  -- The entity field can be either an identifier (if the
                  -- library unit was not loaded) or an access to the entity
                  -- unit.
                  Ident := Get_Identifier (Get_Entity (Library_Unit));
                  if Ident = Primary_Ident
                    and then Get_Identifier (Library_Unit) = Name
                  then
                     return Design_Unit;
                  end if;
               when Iir_Kind_Package_Body =>
                  if Name = Null_Identifier
                    and then Get_Identifier (Library_Unit) = Primary_Ident
                  then
                     return Design_Unit;
                  end if;
               when others =>
                  null;
            end case;
         end if;
         Design_Unit := Get_Hash_Chain (Design_Unit);
      end loop;

      -- The architecture or the body is not in the library, return null.
      return Null_Iir;
   end Find_Secondary_Unit;

   -- Load an secondary unit and analyse it.
   function Load_Secondary_Unit
     (Primary: Iir_Design_Unit; Name: Name_Id; Loc : Iir)
      return Iir_Design_Unit
   is
      Design_Unit: Iir_Design_Unit;
   begin
      Design_Unit := Find_Secondary_Unit (Primary, Name);
      if Design_Unit /= Null_Iir then
         Load_Design_Unit (Design_Unit, Loc);
      end if;
      return Design_Unit;
   end Load_Secondary_Unit;

   function Find_Entity_For_Component (Name: Name_Id) return Iir_Design_Unit
   is
      Res : Iir_Design_Unit := Null_Iir;
      Unit : Iir_Design_Unit;
   begin
      Unit := Unit_Hash_Table (Name mod Unit_Hash_Length);
      while Unit /= Null_Iir loop
         if Get_Identifier (Unit) = Name
           and then (Get_Kind (Get_Library_Unit (Unit))
                     = Iir_Kind_Entity_Declaration)
         then
            if Res = Null_Iir then
               Res := Unit;
            else
               --  Many entities.
               return Null_Iir;
            end if;
         end if;
         Unit := Get_Hash_Chain (Unit);
      end loop;

      return Res;
   end Find_Entity_For_Component;

end Libraries;