summaryrefslogtreecommitdiff
path: root/gcc/ada/errout.adb
blob: 66b6c3b6c41d9d2349fa19d2e240f4c58ff7e8b4 (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
2265
2266
2267
2268
2269
2270
2271
2272
2273
2274
2275
2276
2277
2278
2279
2280
2281
2282
2283
2284
2285
2286
2287
2288
2289
2290
2291
2292
2293
2294
2295
2296
2297
2298
2299
2300
2301
2302
2303
2304
2305
2306
2307
2308
2309
2310
2311
2312
2313
2314
2315
2316
2317
2318
2319
2320
2321
2322
2323
2324
2325
2326
2327
2328
2329
2330
2331
2332
2333
2334
2335
2336
2337
2338
2339
2340
2341
2342
2343
2344
2345
2346
2347
2348
2349
2350
2351
2352
2353
2354
2355
2356
2357
2358
2359
2360
2361
2362
2363
2364
2365
2366
2367
2368
2369
2370
2371
2372
2373
2374
2375
2376
2377
2378
2379
2380
2381
2382
2383
2384
2385
2386
2387
2388
2389
2390
2391
2392
2393
2394
2395
2396
2397
2398
2399
2400
2401
2402
2403
2404
2405
2406
2407
2408
2409
2410
2411
2412
2413
2414
2415
2416
2417
2418
2419
2420
2421
2422
2423
2424
2425
2426
2427
2428
2429
2430
2431
2432
2433
2434
2435
2436
2437
2438
2439
2440
2441
2442
2443
2444
2445
2446
2447
2448
2449
2450
2451
2452
2453
2454
2455
2456
2457
2458
2459
2460
2461
2462
2463
2464
2465
2466
2467
2468
2469
2470
2471
2472
2473
2474
2475
2476
2477
2478
2479
2480
2481
2482
2483
2484
2485
2486
2487
2488
2489
2490
2491
2492
2493
2494
2495
2496
2497
2498
2499
2500
2501
2502
2503
2504
2505
2506
2507
2508
2509
2510
2511
2512
2513
2514
2515
2516
2517
2518
2519
2520
2521
2522
2523
2524
2525
2526
2527
2528
2529
2530
2531
2532
2533
2534
2535
2536
2537
2538
2539
2540
2541
2542
2543
2544
2545
2546
2547
2548
2549
2550
2551
2552
2553
2554
2555
2556
2557
2558
2559
2560
2561
2562
2563
------------------------------------------------------------------------------
--                                                                          --
--                         GNAT COMPILER COMPONENTS                         --
--                                                                          --
--                               E R R O U T                                --
--                                                                          --
--                                 B o d y                                  --
--                                                                          --
--          Copyright (C) 1992-2005 Free Software Foundation, Inc.          --
--                                                                          --
-- GNAT is free software;  you can  redistribute it  and/or modify it under --
-- terms of the  GNU General Public License as published  by the Free Soft- --
-- ware  Foundation;  either version 2,  or (at your option) any later ver- --
-- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
-- OUT 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  distributed with GNAT;  see file COPYING.  If not, write --
-- to  the  Free Software Foundation,  51  Franklin  Street,  Fifth  Floor, --
-- Boston, MA 02110-1301, USA.                                              --
--                                                                          --
-- GNAT was originally developed  by the GNAT team at  New York University. --
-- Extensive contributions were provided by Ada Core Technologies Inc.      --
--                                                                          --
------------------------------------------------------------------------------

--  Warning! Error messages can be generated during Gigi processing by direct
--  calls to error message routines, so it is essential that the processing
--  in this body be consistent with the requirements for the Gigi processing
--  environment, and that in particular, no disallowed table expansion is
--  allowed to occur.

with Atree;    use Atree;
with Casing;   use Casing;
with Csets;    use Csets;
with Debug;    use Debug;
with Einfo;    use Einfo;
with Erroutc;  use Erroutc;
with Fname;    use Fname;
with Hostparm; use Hostparm;
with Lib;      use Lib;
with Namet;    use Namet;
with Opt;      use Opt;
with Nlists;   use Nlists;
with Output;   use Output;
with Scans;    use Scans;
with Sinput;   use Sinput;
with Sinfo;    use Sinfo;
with Snames;   use Snames;
with Stand;    use Stand;
with Style;
with Uintp;    use Uintp;
with Uname;    use Uname;

with Unchecked_Conversion;

package body Errout is

   Errors_Must_Be_Ignored : Boolean := False;
   --  Set to True by procedure Set_Ignore_Errors (True), when calls to
   --  error message procedures should be ignored (when parsing irrelevant
   --  text in sources being preprocessed).

   Warn_On_Instance : Boolean;
   --  Flag set true for warning message to be posted on instance

   ------------------------------------
   -- Table of Non-Instance Messages --
   ------------------------------------

   --  This table contains an entry for every error message processed by the
   --  Error_Msg routine that is not posted on generic (or inlined) instance.
   --  As explained in further detail in the Error_Msg procedure body, this
   --  table is used to avoid posting redundant messages on instances.

   type NIM_Record is record
      Msg : String_Ptr;
      Loc : Source_Ptr;
   end record;
   --  Type used to store text and location of one message

   package Non_Instance_Msgs is new Table.Table (
     Table_Component_Type => NIM_Record,
     Table_Index_Type     => Int,
     Table_Low_Bound      => 1,
     Table_Initial        => 100,
     Table_Increment      => 100,
     Table_Name           => "Non_Instance_Msgs");

   -----------------------
   -- Local Subprograms --
   -----------------------

   procedure Error_Msg_Internal
     (Msg      : String;
      Sptr     : Source_Ptr;
      Optr     : Source_Ptr;
      Msg_Cont : Boolean);
   --  This is the low level routine used to post messages after dealing with
   --  the issue of messages placed on instantiations (which get broken up
   --  into separate calls in Error_Msg). Sptr is the location on which the
   --  flag will be placed in the output. In the case where the flag is on
   --  the template, this points directly to the template, not to one of the
   --  instantiation copies of the template. Optr is the original location
   --  used to flag the error, and this may indeed point to an instantiation
   --  copy. So typically we can see Optr pointing to the template location
   --  in an instantiation copy when Sptr points to the source location of
   --  the actual instantiation (i.e the line with the new). Msg_Cont is
   --  set true if this is a continuation message.

   function No_Warnings (N : Node_Or_Entity_Id) return Boolean;
   --  Determines if warnings should be suppressed for the given node

   function OK_Node (N : Node_Id) return Boolean;
   --  Determines if a node is an OK node to place an error message on (return
   --  True) or if the error message should be suppressed (return False). A
   --  message is suppressed if the node already has an error posted on it,
   --  or if it refers to an Etype that has an error posted on it, or if
   --  it references an Entity that has an error posted on it.

   procedure Output_Source_Line
     (L     : Physical_Line_Number;
      Sfile : Source_File_Index;
      Errs  : Boolean);
   --  Outputs text of source line L, in file S, together with preceding line
   --  number, as described above for Output_Line_Number. The Errs parameter
   --  indicates if there are errors attached to the line, which forces
   --  listing on, even in the presence of pragma List (Off).

   procedure Set_Msg_Insertion_Column;
   --  Handle column number insertion (@ insertion character)

   procedure Set_Msg_Insertion_Node;
   --  Handle node (name from node) insertion (& insertion character)

   procedure Set_Msg_Insertion_Type_Reference (Flag : Source_Ptr);
   --  Handle type reference (right brace insertion character). Flag is the
   --  location of the flag, which is provided for the internal call to
   --  Set_Msg_Insertion_Line_Number,

   procedure Set_Msg_Insertion_Unit_Name;
   --  Handle unit name insertion ($ insertion character)

   procedure Set_Msg_Node (Node : Node_Id);
   --  Add the sequence of characters for the name associated with the
   --  given node to the current message.

   procedure Set_Msg_Text (Text : String; Flag : Source_Ptr);
   --  Add a sequence of characters to the current message. The characters may
   --  be one of the special insertion characters (see documentation in spec).
   --  Flag is the location at which the error is to be posted, which is used
   --  to determine whether or not the # insertion needs a file name. The
   --  variables Msg_Buffer, Msglen, Is_Style_Msg, Is_Warning_Msg, and
   --  Is_Unconditional_Msg are set on return.

   procedure Set_Posted (N : Node_Id);
   --  Sets the Error_Posted flag on the given node, and all its parents
   --  that are subexpressions and then on the parent non-subexpression
   --  construct that contains the original expression (this reduces the
   --  number of cascaded messages). Note that this call only has an effect
   --  for a serious error. For a non-serious error, it has no effect.

   procedure Set_Qualification (N : Nat; E : Entity_Id);
   --  Outputs up to N levels of qualification for the given entity. For
   --  example, the entity A.B.C.D will output B.C. if N = 2.

   function Special_Msg_Delete
     (Msg : String;
      N   : Node_Or_Entity_Id;
      E   : Node_Or_Entity_Id) return Boolean;
   --  This function is called from Error_Msg_NEL, passing the message Msg,
   --  node N on which the error is to be posted, and the entity or node E
   --  to be used for an & insertion in the message if any. The job of this
   --  procedure is to test for certain cascaded messages that we would like
   --  to suppress. If the message is to be suppressed then we return True.
   --  If the message should be generated (the normal case) False is returned.

   procedure Unwind_Internal_Type (Ent : in out Entity_Id);
   --  This procedure is given an entity id for an internal type, i.e.
   --  a type with an internal name. It unwinds the type to try to get
   --  to something reasonably printable, generating prefixes like
   --  "subtype of", "access to", etc along the way in the buffer. The
   --  value in Ent on return is the final name to be printed. Hopefully
   --  this is not an internal name, but in some internal name cases, it
   --  is an internal name, and has to be printed anyway (although in this
   --  case the message has been killed if possible). The global variable
   --  Class_Flag is set to True if the resulting entity should have
   --  'Class appended to its name (see Add_Class procedure), and is
   --  otherwise unchanged.

   procedure VMS_Convert;
   --  This procedure has no effect if called when the host is not OpenVMS.
   --  If the host is indeed OpenVMS, then the error message stored in
   --  Msg_Buffer is scanned for appearences of switch names which need
   --  converting to corresponding VMS qualifer names. See Gnames/Vnames
   --  table in Errout spec for precise definition of the conversion that
   --  is performed by this routine in OpenVMS mode.

   -----------------------
   -- Change_Error_Text --
   -----------------------

   procedure Change_Error_Text (Error_Id : Error_Msg_Id; New_Msg : String) is
      Save_Next : Error_Msg_Id;
      Err_Id    : Error_Msg_Id := Error_Id;

   begin
      Set_Msg_Text (New_Msg, Errors.Table (Error_Id).Sptr);
      Errors.Table (Error_Id).Text := new String'(Msg_Buffer (1 .. Msglen));

      --  If in immediate error message mode, output modified error message now
      --  This is just a bit tricky, because we want to output just a single
      --  message, and the messages we modified is already linked in. We solve
      --  this by temporarily resetting its forward pointer to empty.

      if Debug_Flag_OO then
         Save_Next := Errors.Table (Error_Id).Next;
         Errors.Table (Error_Id).Next := No_Error_Msg;
         Write_Eol;
         Output_Source_Line
           (Errors.Table (Error_Id).Line, Errors.Table (Error_Id).Sfile, True);
         Output_Error_Msgs (Err_Id);
         Errors.Table (Error_Id).Next := Save_Next;
      end if;
   end Change_Error_Text;

   ---------------
   -- Error_Msg --
   ---------------

   --  Error_Msg posts a flag at the given location, except that if the
   --  Flag_Location points within a generic template and corresponds
   --  to an instantiation of this generic template, then the actual
   --  message will be posted on the generic instantiation, along with
   --  additional messages referencing the generic declaration.

   procedure Error_Msg (Msg : String; Flag_Location : Source_Ptr) is
      Sindex : Source_File_Index;
      --  Source index for flag location

      Orig_Loc : Source_Ptr;
      --  Original location of Flag_Location (i.e. location in original
      --  template in instantiation case, otherwise unchanged).

   begin
      --  It is a fatal error to issue an error message when scanning from
      --  the internal source buffer (see Sinput for further documentation)

      pragma Assert (Sinput.Source /= Internal_Source_Ptr);

      --  Return if all errors are to be ignored

      if Errors_Must_Be_Ignored then
         return;
      end if;

      --  If we already have messages, and we are trying to place a message
      --  at No_Location or in package Standard, then just ignore the attempt
      --  since we assume that what is happening is some cascaded junk. Note
      --  that this is safe in the sense that proceeding will surely bomb.

      if Flag_Location < First_Source_Ptr
        and then Total_Errors_Detected > 0
      then
         return;
      end if;

      --  Start procesing of new message

      Sindex := Get_Source_File_Index (Flag_Location);
      Test_Style_Warning_Serious_Msg (Msg);
      Orig_Loc := Original_Location (Flag_Location);

      --  If the current location is in an instantiation, the issue arises
      --  of whether to post the message on the template or the instantiation.

      --  The way we decide is to see if we have posted the same message
      --  on the template when we compiled the template (the template is
      --  always compiled before any instantiations). For this purpose,
      --  we use a separate table of messages. The reason we do this is
      --  twofold:

      --     First, the messages can get changed by various processing
      --     including the insertion of tokens etc, making it hard to
      --     do the comparison.

      --     Second, we will suppress a warning on a template if it is
      --     not in the current extended source unit. That's reasonable
      --     and means we don't want the warning on the instantiation
      --     here either, but it does mean that the main error table
      --     would not in any case include the message.

      if Flag_Location = Orig_Loc then
         Non_Instance_Msgs.Append ((new String'(Msg), Flag_Location));
         Warn_On_Instance := False;

      --  Here we have an instance message

      else
         --  Delete if debug flag off, and this message duplicates a
         --  message already posted on the corresponding template

         if not Debug_Flag_GG then
            for J in Non_Instance_Msgs.First .. Non_Instance_Msgs.Last loop
               if Msg = Non_Instance_Msgs.Table (J).Msg.all
                 and then Non_Instance_Msgs.Table (J).Loc = Orig_Loc
               then
                  return;
               end if;
            end loop;
         end if;

         --  No duplicate, so error/warning will be posted on instance

         Warn_On_Instance := Is_Warning_Msg;
      end if;

      --  Ignore warning message that is suppressed. Note that style
      --  checks are not considered warning messages for this purpose

      if Is_Warning_Msg and then Warnings_Suppressed (Orig_Loc) then
         return;
      end if;

      --  The idea at this stage is that we have two kinds of messages.

      --  First, we have those that are to be placed as requested at
      --  Flag_Location. This includes messages that have nothing to
      --  do with generics, and also messages placed on generic templates
      --  that reflect an error in the template itself. For such messages
      --  we simply call Error_Msg_Internal to place the message in the
      --  requested location.

      if Instantiation (Sindex) = No_Location then
         Error_Msg_Internal (Msg, Flag_Location, Flag_Location, False);
         return;
      end if;

      --  If we are trying to flag an error in an instantiation, we may have
      --  a generic contract violation. What we generate in this case is:

      --     instantiation error at ...
      --     original error message

      --  or

      --     warning: in instantiation at
      --     warning: original warning message

      --  All these messages are posted at the location of the top level
      --  instantiation. If there are nested instantiations, then the
      --  instantiation error message can be repeated, pointing to each
      --  of the relevant instantiations.

      --  Note: the instantiation mechanism is also shared for inlining
      --  of subprogram bodies when front end inlining is done. In this
      --  case the messages have the form:

      --     in inlined body at ...
      --     original error message

      --  or

      --     warning: in inlined body at
      --     warning: original warning message

      --  OK, this is the case where we have an instantiation error, and
      --  we need to generate the error on the instantiation, rather than
      --  on the template.

      declare
         Actual_Error_Loc : Source_Ptr;
         --  Location of outer level instantiation in instantiation case, or
         --  just a copy of Flag_Location in the normal case. This is the
         --  location where all error messages will actually be posted.

         Save_Error_Msg_Sloc : constant Source_Ptr := Error_Msg_Sloc;
         --  Save possible location set for caller's message. We need to
         --  use Error_Msg_Sloc for the location of the instantiation error
         --  but we have to preserve a possible original value.

         X : Source_File_Index;

         Msg_Cont_Status : Boolean;
         --  Used to label continuation lines in instantiation case with
         --  proper Msg_Cont status.

      begin
         --  Loop to find highest level instantiation, where all error
         --  messages will be placed.

         X := Sindex;
         loop
            Actual_Error_Loc := Instantiation (X);
            X := Get_Source_File_Index (Actual_Error_Loc);
            exit when Instantiation (X) = No_Location;
         end loop;

         --  Since we are generating the messages at the instantiation
         --  point in any case, we do not want the references to the
         --  bad lines in the instance to be annotated with the location
         --  of the instantiation.

         Suppress_Instance_Location := True;
         Msg_Cont_Status := False;

         --  Loop to generate instantiation messages

         Error_Msg_Sloc := Flag_Location;
         X := Get_Source_File_Index (Flag_Location);

         while Instantiation (X) /= No_Location loop

            --  Suppress instantiation message on continuation lines

            if Msg (Msg'First) /= '\' then

               --  Case of inlined body

               if Inlined_Body (X) then
                  if Is_Warning_Msg then
                     Error_Msg_Internal
                       ("?in inlined body #",
                        Actual_Error_Loc, Flag_Location, Msg_Cont_Status);

                  else
                     Error_Msg_Internal
                       ("error in inlined body #",
                        Actual_Error_Loc, Flag_Location, Msg_Cont_Status);
                  end if;

               --  Case of generic instantiation

               else
                  if Is_Warning_Msg then
                     Error_Msg_Internal
                       ("?in instantiation #",
                        Actual_Error_Loc, Flag_Location, Msg_Cont_Status);

                  else
                     Error_Msg_Internal
                       ("instantiation error #",
                        Actual_Error_Loc, Flag_Location, Msg_Cont_Status);
                  end if;
               end if;
            end if;

            Error_Msg_Sloc := Instantiation (X);
            X := Get_Source_File_Index (Error_Msg_Sloc);
            Msg_Cont_Status := True;
         end loop;

         Suppress_Instance_Location := False;
         Error_Msg_Sloc := Save_Error_Msg_Sloc;

         --  Here we output the original message on the outer instantiation

         Error_Msg_Internal
           (Msg, Actual_Error_Loc, Flag_Location, Msg_Cont_Status);
      end;
   end Error_Msg;

   ------------------
   -- Error_Msg_AP --
   ------------------

   procedure Error_Msg_AP (Msg : String) is
      S1 : Source_Ptr;
      C  : Character;

   begin
      --  If we had saved the Scan_Ptr value after scanning the previous
      --  token, then we would have exactly the right place for putting
      --  the flag immediately at hand. However, that would add at least
      --  two instructions to a Scan call *just* to service the possibility
      --  of an Error_Msg_AP call. So instead we reconstruct that value.

      --  We have two possibilities, start with Prev_Token_Ptr and skip over
      --  the current token, which is made harder by the possibility that this
      --  token may be in error, or start with Token_Ptr and work backwards.
      --  We used to take the second approach, but it's hard because of
      --  comments, and harder still because things that look like comments
      --  can appear inside strings. So now we take the first approach.

      --  Note: in the case where there is no previous token, Prev_Token_Ptr
      --  is set to Source_First, which is a reasonable position for the
      --  error flag in this situation.

      S1 := Prev_Token_Ptr;
      C := Source (S1);

      --  If the previous token is a string literal, we need a special approach
      --  since there may be white space inside the literal and we don't want
      --  to stop on that white space.

      --  Note: since this is an error recovery issue anyway, it is not worth
      --  worrying about special UTF_32 line terminator characters here.

      if Prev_Token = Tok_String_Literal then
         loop
            S1 := S1 + 1;

            if Source (S1) = C then
               S1 := S1 + 1;
               exit when Source (S1) /= C;
            elsif Source (S1) in Line_Terminator then
               exit;
            end if;
         end loop;

      --  Character literal also needs special handling

      elsif Prev_Token = Tok_Char_Literal then
         S1 := S1 + 3;

      --  Otherwise we search forward for the end of the current token, marked
      --  by a line terminator, white space, a comment symbol or if we bump
      --  into the following token (i.e. the current token).

      --  Again, it is not worth worrying about UTF_32 special line terminator
      --  characters in this context, since this is only for error recovery.

      else
         while Source (S1) not in Line_Terminator
           and then Source (S1) /= ' '
           and then Source (S1) /= ASCII.HT
           and then (Source (S1) /= '-' or else Source (S1 + 1) /= '-')
           and then S1 /= Token_Ptr
         loop
            S1 := S1 + 1;
         end loop;
      end if;

      --  S1 is now set to the location for the flag

      Error_Msg (Msg, S1);
   end Error_Msg_AP;

   ------------------
   -- Error_Msg_BC --
   ------------------

   procedure Error_Msg_BC (Msg : String) is
   begin
      --  If we are at end of file, post the flag after the previous token

      if Token = Tok_EOF then
         Error_Msg_AP (Msg);

      --  If we are at start of file, post the flag at the current token

      elsif Token_Ptr = Source_First (Current_Source_File) then
         Error_Msg_SC (Msg);

      --  If the character before the current token is a space or a horizontal
      --  tab, then we place the flag on this character (in the case of a tab
      --  we would really like to place it in the "last" character of the tab
      --  space, but that it too much trouble to worry about).

      elsif Source (Token_Ptr - 1) = ' '
         or else Source (Token_Ptr - 1) = ASCII.HT
      then
         Error_Msg (Msg, Token_Ptr - 1);

      --  If there is no space or tab before the current token, then there is
      --  no room to place the flag before the token, so we place it on the
      --  token instead (this happens for example at the start of a line).

      else
         Error_Msg (Msg, Token_Ptr);
      end if;
   end Error_Msg_BC;

   -------------------
   -- Error_Msg_CRT --
   -------------------

   procedure Error_Msg_CRT (Feature : String; N : Node_Id) is
      CNRT : constant String := " not allowed in no run time mode";
      CCRT : constant String := " not supported by configuration>";

      S : String (1 .. Feature'Length + 1 + CCRT'Length);
      L : Natural;

   begin
      S (1) := '|';
      S (2 .. Feature'Length + 1) := Feature;
      L := Feature'Length + 2;

      if No_Run_Time_Mode then
         S (L .. L + CNRT'Length - 1) := CNRT;
         L := L + CNRT'Length - 1;

      else pragma Assert (Configurable_Run_Time_Mode);
         S (L .. L + CCRT'Length - 1) := CCRT;
         L := L + CCRT'Length - 1;
      end if;

      Error_Msg_N (S (1 .. L), N);
      Configurable_Run_Time_Violations := Configurable_Run_Time_Violations + 1;
   end Error_Msg_CRT;

   -----------------
   -- Error_Msg_F --
   -----------------

   procedure Error_Msg_F (Msg : String; N : Node_Id) is
   begin
      Error_Msg_NEL (Msg, N, N, First_Sloc (N));
   end Error_Msg_F;

   ------------------
   -- Error_Msg_FE --
   ------------------

   procedure Error_Msg_FE
     (Msg : String;
      N   : Node_Id;
      E   : Node_Or_Entity_Id)
   is
   begin
      Error_Msg_NEL (Msg, N, E, Sloc (First_Node (N)));
   end Error_Msg_FE;

   ------------------------
   -- Error_Msg_Internal --
   ------------------------

   procedure Error_Msg_Internal
     (Msg      : String;
      Sptr     : Source_Ptr;
      Optr     : Source_Ptr;
      Msg_Cont : Boolean)
   is
      Next_Msg : Error_Msg_Id;
      --  Pointer to next message at insertion point

      Prev_Msg : Error_Msg_Id;
      --  Pointer to previous message at insertion point

      Temp_Msg : Error_Msg_Id;

      procedure Handle_Serious_Error;
      --  Internal procedure to do all error message handling for a serious
      --  error message, other than bumping the error counts and arranging
      --  for the message to be output.

      --------------------------
      -- Handle_Serious_Error --
      --------------------------

      procedure Handle_Serious_Error is
      begin
         --  Turn off code generation if not done already

         if Operating_Mode = Generate_Code then
            Operating_Mode := Check_Semantics;
            Expander_Active := False;
         end if;

         --  Set the fatal error flag in the unit table unless we are
         --  in Try_Semantics mode. This stops the semantics from being
         --  performed if we find a serious error. This is skipped if we
         --  are currently dealing with the configuration pragma file.

         if not Try_Semantics
           and then Current_Source_Unit /= No_Unit
         then
            Set_Fatal_Error (Get_Source_Unit (Sptr));
         end if;
      end Handle_Serious_Error;

   --  Start of processing for Error_Msg_Internal

   begin
      if Raise_Exception_On_Error /= 0 then
         raise Error_Msg_Exception;
      end if;

      Continuation := Msg_Cont;
      Suppress_Message := False;
      Kill_Message := False;
      Set_Msg_Text (Msg, Sptr);

      --  Kill continuation if parent message killed

      if Continuation and Last_Killed then
         return;
      end if;

      --  Return without doing anything if message is suppressed

      if Suppress_Message
        and not All_Errors_Mode
        and not (Msg (Msg'Last) = '!')
      then
         if not Continuation then
            Last_Killed := True;
         end if;

         return;
      end if;

      --  Return without doing anything if message is killed and this
      --  is not the first error message. The philosophy is that if we
      --  get a weird error message and we already have had a message,
      --  then we hope the weird message is a junk cascaded message

      if Kill_Message
        and then not All_Errors_Mode
        and then Total_Errors_Detected /= 0
      then
         if not Continuation then
            Last_Killed := True;
         end if;

         return;
      end if;

      --  Special check for warning message to see if it should be output

      if Is_Warning_Msg then

         --  Immediate return if warning message and warnings are suppressed

         if Warnings_Suppressed (Optr)
           or else Warnings_Suppressed (Sptr)
         then
            Cur_Msg := No_Error_Msg;
            return;
         end if;

         --  If the flag location is in the main extended source unit
         --  then for sure we want the warning since it definitely belongs

         if In_Extended_Main_Source_Unit (Sptr) then
            null;

         --  If the flag location is not in the main extended source
         --  unit then we want to eliminate the warning.

         elsif In_Extended_Main_Code_Unit (Sptr)
           and then Warn_On_Instance
         then
            null;

         --  Keep warning if debug flag G set

         elsif Debug_Flag_GG then
            null;

         --  Here is where we delete a warning from a with'ed unit

         else
            Cur_Msg := No_Error_Msg;
            return;
         end if;
      end if;

      --  If message is to be ignored in special ignore message mode, this is
      --  where we do this special processing, bypassing message output.

      if Ignore_Errors_Enable > 0 then
         if Is_Serious_Error then
            Handle_Serious_Error;
         end if;

         return;
      end if;

      --  Otherwise build error message object for new message

      Errors.Increment_Last;
      Cur_Msg := Errors.Last;
      Errors.Table (Cur_Msg).Text     := new String'(Msg_Buffer (1 .. Msglen));
      Errors.Table (Cur_Msg).Next     := No_Error_Msg;
      Errors.Table (Cur_Msg).Sptr     := Sptr;
      Errors.Table (Cur_Msg).Optr     := Optr;
      Errors.Table (Cur_Msg).Sfile    := Get_Source_File_Index (Sptr);
      Errors.Table (Cur_Msg).Line     := Get_Physical_Line_Number (Sptr);
      Errors.Table (Cur_Msg).Col      := Get_Column_Number (Sptr);
      Errors.Table (Cur_Msg).Warn     := Is_Warning_Msg;
      Errors.Table (Cur_Msg).Style    := Is_Style_Msg;
      Errors.Table (Cur_Msg).Serious  := Is_Serious_Error;
      Errors.Table (Cur_Msg).Uncond   := Is_Unconditional_Msg;
      Errors.Table (Cur_Msg).Msg_Cont := Continuation;
      Errors.Table (Cur_Msg).Deleted  := False;

      --  If immediate errors mode set, output error message now. Also output
      --  now if the -d1 debug flag is set (so node number message comes out
      --  just before actual error message)

      if Debug_Flag_OO or else Debug_Flag_1 then
         Write_Eol;
         Output_Source_Line (Errors.Table (Cur_Msg).Line,
           Errors.Table (Cur_Msg).Sfile, True);
         Temp_Msg := Cur_Msg;
         Output_Error_Msgs (Temp_Msg);

      --  If not in immediate errors mode, then we insert the message in the
      --  error chain for later output by Finalize. The messages are sorted
      --  first by unit (main unit comes first), and within a unit by source
      --  location (earlier flag location first in the chain).

      else
         --  First a quick check, does this belong at the very end of the
         --  chain of error messages. This saves a lot of time in the
         --  normal case if there are lots of messages.

         if Last_Error_Msg /= No_Error_Msg
           and then Errors.Table (Cur_Msg).Sfile =
                    Errors.Table (Last_Error_Msg).Sfile
           and then (Sptr > Errors.Table (Last_Error_Msg).Sptr
                       or else
                          (Sptr = Errors.Table (Last_Error_Msg).Sptr
                             and then
                               Optr > Errors.Table (Last_Error_Msg).Optr))
         then
            Prev_Msg := Last_Error_Msg;
            Next_Msg := No_Error_Msg;

         --  Otherwise do a full sequential search for the insertion point

         else
            Prev_Msg := No_Error_Msg;
            Next_Msg := First_Error_Msg;
            while Next_Msg /= No_Error_Msg loop
               exit when
                 Errors.Table (Cur_Msg).Sfile < Errors.Table (Next_Msg).Sfile;

               if Errors.Table (Cur_Msg).Sfile =
                    Errors.Table (Next_Msg).Sfile
               then
                  exit when Sptr < Errors.Table (Next_Msg).Sptr
                              or else
                                (Sptr = Errors.Table (Next_Msg).Sptr
                                   and then
                                 Optr < Errors.Table (Next_Msg).Optr);
               end if;

               Prev_Msg := Next_Msg;
               Next_Msg := Errors.Table (Next_Msg).Next;
            end loop;
         end if;

         --  Now we insert the new message in the error chain. The insertion
         --  point for the message is after Prev_Msg and before Next_Msg.

         --  The possible insertion point for the new message is after Prev_Msg
         --  and before Next_Msg. However, this is where we do a special check
         --  for redundant parsing messages, defined as messages posted on the
         --  same line. The idea here is that probably such messages are junk
         --  from the parser recovering. In full errors mode, we don't do this
         --  deletion, but otherwise such messages are discarded at this stage.

         if Prev_Msg /= No_Error_Msg
           and then Errors.Table (Prev_Msg).Line =
                                             Errors.Table (Cur_Msg).Line
           and then Errors.Table (Prev_Msg).Sfile =
                                             Errors.Table (Cur_Msg).Sfile
           and then Compiler_State = Parsing
           and then not All_Errors_Mode
         then
            --  Don't delete unconditional messages and at this stage,
            --  don't delete continuation lines (we attempted to delete
            --  those earlier if the parent message was deleted.

            if not Errors.Table (Cur_Msg).Uncond
              and then not Continuation
            then
               --  Don't delete if prev msg is warning and new msg is
               --  an error. This is because we don't want a real error
               --  masked by a warning. In all other cases (that is parse
               --  errors for the same line that are not unconditional)
               --  we do delete the message. This helps to avoid
               --  junk extra messages from cascaded parsing errors

               if not (Errors.Table (Prev_Msg).Warn
                         or
                       Errors.Table (Prev_Msg).Style)
                 or else
                       (Errors.Table (Cur_Msg).Warn
                         or
                        Errors.Table (Cur_Msg).Style)
               then
                  --  All tests passed, delete the message by simply
                  --  returning without any further processing.

                  if not Continuation then
                     Last_Killed := True;
                  end if;

                  return;
               end if;
            end if;
         end if;

         --  Come here if message is to be inserted in the error chain

         if not Continuation then
            Last_Killed := False;
         end if;

         if Prev_Msg = No_Error_Msg then
            First_Error_Msg := Cur_Msg;
         else
            Errors.Table (Prev_Msg).Next := Cur_Msg;
         end if;

         Errors.Table (Cur_Msg).Next := Next_Msg;

         if Next_Msg = No_Error_Msg then
            Last_Error_Msg := Cur_Msg;
         end if;
      end if;

      --  Bump appropriate statistics count

      if Errors.Table (Cur_Msg).Warn
        or else Errors.Table (Cur_Msg).Style
      then
         Warnings_Detected := Warnings_Detected + 1;
      else
         Total_Errors_Detected := Total_Errors_Detected + 1;

         if Errors.Table (Cur_Msg).Serious then
            Serious_Errors_Detected := Serious_Errors_Detected + 1;
            Handle_Serious_Error;
         end if;
      end if;

      --  Terminate if max errors reached

      if Total_Errors_Detected + Warnings_Detected = Maximum_Errors then
         raise Unrecoverable_Error;
      end if;

   end Error_Msg_Internal;

   -----------------
   -- Error_Msg_N --
   -----------------

   procedure Error_Msg_N (Msg : String; N : Node_Or_Entity_Id) is
   begin
      Error_Msg_NEL (Msg, N, N, Sloc (N));
   end Error_Msg_N;

   ------------------
   -- Error_Msg_NE --
   ------------------

   procedure Error_Msg_NE
     (Msg : String;
      N   : Node_Or_Entity_Id;
      E   : Node_Or_Entity_Id)
   is
   begin
      Error_Msg_NEL (Msg, N, E, Sloc (N));
   end Error_Msg_NE;

   -------------------
   -- Error_Msg_NEL --
   -------------------

   procedure Error_Msg_NEL
     (Msg           : String;
      N             : Node_Or_Entity_Id;
      E             : Node_Or_Entity_Id;
      Flag_Location : Source_Ptr)
   is
   begin
      if Special_Msg_Delete (Msg, N, E) then
         return;
      end if;

      Test_Style_Warning_Serious_Msg (Msg);

      --  Special handling for warning messages

      if Is_Warning_Msg then

         --  Suppress if no warnings set for either entity or node

         if No_Warnings (N) or else No_Warnings (E) then
            return;
         end if;

         --  Suppress if inside loop that is known to be null

         declare
            P : Node_Id;

         begin
            P := Parent (N);
            while Present (P) loop
               if Nkind (P) = N_Loop_Statement and then Is_Null_Loop (P) then
                  return;
               end if;

               P := Parent (P);
            end loop;
         end;
      end if;

      --  Test for message to be output

      if All_Errors_Mode
        or else Msg (Msg'Last) = '!'
        or else OK_Node (N)
        or else (Msg (Msg'First) = '\' and not Last_Killed)
      then
         Debug_Output (N);
         Error_Msg_Node_1 := E;
         Error_Msg (Msg, Flag_Location);

      else
         Last_Killed := True;
      end if;

      if not Is_Warning_Msg and then not Is_Style_Msg then
         Set_Posted (N);
      end if;
   end Error_Msg_NEL;

   ------------------
   -- Error_Msg_NW --
   ------------------

   procedure Error_Msg_NW
     (Eflag : Boolean;
      Msg   : String;
      N     : Node_Or_Entity_Id)
   is
   begin
      if Eflag
        and then In_Extended_Main_Source_Unit (N)
        and then Comes_From_Source (N)
      then
         Error_Msg_NEL (Msg, N, N, Sloc (N));
      end if;
   end Error_Msg_NW;

   -----------------
   -- Error_Msg_S --
   -----------------

   procedure Error_Msg_S (Msg : String) is
   begin
      Error_Msg (Msg, Scan_Ptr);
   end Error_Msg_S;

   ------------------
   -- Error_Msg_SC --
   ------------------

   procedure Error_Msg_SC (Msg : String) is
   begin
      --  If we are at end of file, post the flag after the previous token

      if Token = Tok_EOF then
         Error_Msg_AP (Msg);

      --  For all other cases the message is posted at the current token
      --  pointer position

      else
         Error_Msg (Msg, Token_Ptr);
      end if;
   end Error_Msg_SC;

   ------------------
   -- Error_Msg_SP --
   ------------------

   procedure Error_Msg_SP (Msg : String) is
   begin
      --  Note: in the case where there is no previous token, Prev_Token_Ptr
      --  is set to Source_First, which is a reasonable position for the
      --  error flag in this situation

      Error_Msg (Msg, Prev_Token_Ptr);
   end Error_Msg_SP;

   --------------
   -- Finalize --
   --------------

   procedure Finalize is
      Cur      : Error_Msg_Id;
      Nxt      : Error_Msg_Id;
      E, F     : Error_Msg_Id;
      Err_Flag : Boolean;

   begin
      --  Reset current error source file if the main unit has a pragma
      --  Source_Reference. This ensures outputting the proper name of
      --  the source file in this situation.

      if Main_Source_File = No_Source_File or else
        Num_SRef_Pragmas (Main_Source_File) /= 0
      then
         Current_Error_Source_File := No_Source_File;
      end if;

      --  Eliminate any duplicated error messages from the list. This is
      --  done after the fact to avoid problems with Change_Error_Text.

      Cur := First_Error_Msg;
      while Cur /= No_Error_Msg loop
         Nxt := Errors.Table (Cur).Next;

         F := Nxt;
         while F /= No_Error_Msg
           and then Errors.Table (F).Sptr = Errors.Table (Cur).Sptr
         loop
            Check_Duplicate_Message (Cur, F);
            F := Errors.Table (F).Next;
         end loop;

         Cur := Nxt;
      end loop;

      --  Brief Error mode

      if Brief_Output or (not Full_List and not Verbose_Mode) then
         E := First_Error_Msg;
         Set_Standard_Error;

         while E /= No_Error_Msg loop
            if not Errors.Table (E).Deleted and then not Debug_Flag_KK then
               if Full_Path_Name_For_Brief_Errors then
                  Write_Name (Full_Ref_Name (Errors.Table (E).Sfile));
               else
                  Write_Name (Reference_Name (Errors.Table (E).Sfile));
               end if;

               Write_Char (':');
               Write_Int (Int (Physical_To_Logical
                                (Errors.Table (E).Line,
                                 Errors.Table (E).Sfile)));
               Write_Char (':');

               if Errors.Table (E).Col < 10 then
                  Write_Char ('0');
               end if;

               Write_Int (Int (Errors.Table (E).Col));
               Write_Str (": ");
               Output_Msg_Text (E);
               Write_Eol;
            end if;

            E := Errors.Table (E).Next;
         end loop;

         Set_Standard_Output;
      end if;

      --  Full source listing case

      if Full_List then
         List_Pragmas_Index := 1;
         List_Pragmas_Mode := True;
         E := First_Error_Msg;
         Write_Eol;

         --  First list initial main source file with its error messages

         for N in 1 .. Last_Source_Line (Main_Source_File) loop
            Err_Flag :=
              E /= No_Error_Msg
                and then Errors.Table (E).Line = N
                and then Errors.Table (E).Sfile = Main_Source_File;

            Output_Source_Line (N, Main_Source_File, Err_Flag);

            if Err_Flag then
               Output_Error_Msgs (E);

               if not Debug_Flag_2 then
                  Write_Eol;
               end if;
            end if;

         end loop;

         --  Then output errors, if any, for subsidiary units

         while E /= No_Error_Msg
           and then Errors.Table (E).Sfile /= Main_Source_File
         loop
            Write_Eol;
            Output_Source_Line
              (Errors.Table (E).Line, Errors.Table (E).Sfile, True);
            Output_Error_Msgs (E);
         end loop;
      end if;

      --  Verbose mode (error lines only with error flags)

      if Verbose_Mode and not Full_List then
         E := First_Error_Msg;

         --  Loop through error lines

         while E /= No_Error_Msg loop
            Write_Eol;
            Output_Source_Line
              (Errors.Table (E).Line, Errors.Table (E).Sfile, True);
            Output_Error_Msgs (E);
         end loop;
      end if;

      --  Output error summary if verbose or full list mode

      if Verbose_Mode or else Full_List then

         --  Extra blank line if error messages or source listing were output

         if Total_Errors_Detected + Warnings_Detected > 0
           or else Full_List
         then
            Write_Eol;
         end if;

         --  Message giving number of lines read and number of errors detected.
         --  This normally goes to Standard_Output. The exception is when brief
         --  mode is not set, verbose mode (or full list mode) is set, and
         --  there are errors. In this case we send the message to standard
         --  error to make sure that *something* appears on standard error in
         --  an error situation.

         --  Formerly, only the "# errors" suffix was sent to stderr, whereas
         --  "# lines:" appeared on stdout. This caused problems on VMS when
         --  the stdout buffer was flushed, giving an extra line feed after
         --  the prefix.

         if Total_Errors_Detected + Warnings_Detected /= 0
           and then not Brief_Output
           and then (Verbose_Mode or Full_List)
         then
            Set_Standard_Error;
         end if;

         --  Message giving total number of lines

         Write_Str (" ");
         Write_Int (Num_Source_Lines (Main_Source_File));

         if Num_Source_Lines (Main_Source_File) = 1 then
            Write_Str (" line: ");
         else
            Write_Str (" lines: ");
         end if;

         if Total_Errors_Detected = 0 then
            Write_Str ("No errors");

         elsif Total_Errors_Detected = 1 then
            Write_Str ("1 error");

         else
            Write_Int (Total_Errors_Detected);
            Write_Str (" errors");
         end if;

         if Warnings_Detected /= 0 then
            Write_Str (", ");
            Write_Int (Warnings_Detected);
            Write_Str (" warning");

            if Warnings_Detected /= 1 then
               Write_Char ('s');
            end if;

            if Warning_Mode = Treat_As_Error then
               Write_Str (" (treated as error");

               if Warnings_Detected /= 1 then
                  Write_Char ('s');
               end if;

               Write_Char (')');
            end if;
         end if;

         Write_Eol;
         Set_Standard_Output;
      end if;

      if Maximum_Errors /= 0
        and then Total_Errors_Detected + Warnings_Detected = Maximum_Errors
      then
         Set_Standard_Error;
         Write_Str ("fatal error: maximum errors reached");
         Write_Eol;
         Set_Standard_Output;
      end if;

      if Warning_Mode = Treat_As_Error then
         Total_Errors_Detected := Total_Errors_Detected + Warnings_Detected;
         Warnings_Detected := 0;
      end if;
   end Finalize;

   ----------------
   -- First_Node --
   ----------------

   function First_Node (C : Node_Id) return Node_Id is
      L        : constant Source_Ptr        := Sloc (C);
      Sfile    : constant Source_File_Index := Get_Source_File_Index (L);
      Earliest : Node_Id;
      Eloc     : Source_Ptr;
      Discard  : Traverse_Result;

      pragma Warnings (Off, Discard);

      function Test_Earlier (N : Node_Id) return Traverse_Result;
      --  Function applied to every node in the construct

      function Search_Tree_First is new Traverse_Func (Test_Earlier);
      --  Create traversal function

      ------------------
      -- Test_Earlier --
      ------------------

      function Test_Earlier (N : Node_Id) return Traverse_Result is
         Loc : constant Source_Ptr := Sloc (N);

      begin
         --  Check for earlier. The tests for being in the same file ensures
         --  against strange cases of foreign code somehow being present. We
         --  don't want wild placement of messages if that happens, so it is
         --  best to just ignore this situation.

         if Loc < Eloc
           and then Get_Source_File_Index (Loc) = Sfile
         then
            Earliest := N;
            Eloc     := Loc;
         end if;

         return OK_Orig;
      end Test_Earlier;

   --  Start of processing for First_Node

   begin
      Earliest := Original_Node (C);
      Eloc := Sloc (Earliest);
      Discard := Search_Tree_First (Original_Node (C));
      return Earliest;
   end First_Node;

   ----------------
   -- First_Sloc --
   ----------------

   function First_Sloc (N : Node_Id) return Source_Ptr is
      SI : constant Source_File_Index := Source_Index (Get_Source_Unit (N));
      SF : constant Source_Ptr        := Source_First (SI);
      F  : Node_Id;
      S  : Source_Ptr;

   begin
      F := First_Node (N);
      S := Sloc (F);

      --  The following circuit is a bit subtle. When we have parenthesized
      --  expressions, then the Sloc will not record the location of the
      --  paren, but we would like to post the flag on the paren. So what
      --  we do is to crawl up the tree from the First_Node, adjusting the
      --  Sloc value for any parentheses we know are present. Yes, we know
      --  this circuit is not 100% reliable (e.g. because we don't record
      --  all possible paren level valoues), but this is only for an error
      --  message so it is good enough.

      Node_Loop : loop
         Paren_Loop : for J in 1 .. Paren_Count (F) loop

            --  We don't look more than 12 characters behind the current
            --  location, and in any case not past the front of the source.

            Search_Loop : for K in 1 .. 12 loop
               exit Search_Loop when S = SF;

               if Source_Text (SI) (S - 1) = '(' then
                  S := S - 1;
                  exit Search_Loop;

               elsif Source_Text (SI) (S - 1) <= ' ' then
                  S := S - 1;

               else
                  exit Search_Loop;
               end if;
            end loop Search_Loop;
         end loop Paren_Loop;

         exit Node_Loop when F = N;
         F := Parent (F);
         exit Node_Loop when Nkind (F) not in N_Subexpr;
      end loop Node_Loop;

      return S;
   end First_Sloc;

   ----------------
   -- Initialize --
   ----------------

   procedure Initialize is
   begin
      Errors.Init;
      First_Error_Msg := No_Error_Msg;
      Last_Error_Msg := No_Error_Msg;
      Serious_Errors_Detected := 0;
      Total_Errors_Detected := 0;
      Warnings_Detected := 0;
      Cur_Msg := No_Error_Msg;
      List_Pragmas.Init;

      --  Initialize warnings table, if all warnings are suppressed, supply
      --  an initial dummy entry covering all possible source locations.

      Warnings.Init;

      if Warning_Mode = Suppress then
         Warnings.Increment_Last;
         Warnings.Table (Warnings.Last).Start := Source_Ptr'First;
         Warnings.Table (Warnings.Last).Stop  := Source_Ptr'Last;
      end if;

      --  Set the error nodes to Empty to avoid uninitialized variable
      --  references for saves/restores/moves.

      Error_Msg_Node_1 := Empty;
      Error_Msg_Node_2 := Empty;
   end Initialize;

   -----------------
   -- No_Warnings --
   -----------------

   function No_Warnings (N : Node_Or_Entity_Id) return Boolean is
   begin
      if Error_Posted (N) then
         return True;

      elsif Nkind (N) in N_Entity and then Warnings_Off (N) then
         return True;

      elsif Is_Entity_Name (N)
        and then Present (Entity (N))
        and then Warnings_Off (Entity (N))
      then
         return True;

      else
         return False;
      end if;
   end No_Warnings;

   -------------
   -- OK_Node --
   -------------

   function OK_Node (N : Node_Id) return Boolean is
      K : constant Node_Kind := Nkind (N);

   begin
      if Error_Posted (N) then
         return False;

      elsif K in N_Has_Etype
        and then Present (Etype (N))
        and then Error_Posted (Etype (N))
      then
         return False;

      elsif (K in N_Op
              or else K = N_Attribute_Reference
              or else K = N_Character_Literal
              or else K = N_Expanded_Name
              or else K = N_Identifier
              or else K = N_Operator_Symbol)
        and then Present (Entity (N))
        and then Error_Posted (Entity (N))
      then
         return False;
      else
         return True;
      end if;
   end OK_Node;

   ------------------------
   -- Output_Source_Line --
   ------------------------

   procedure Output_Source_Line
     (L     : Physical_Line_Number;
      Sfile : Source_File_Index;
      Errs  : Boolean)
   is
      S : Source_Ptr;
      C : Character;

      Line_Number_Output : Boolean := False;
      --  Set True once line number is output

   begin
      if Sfile /= Current_Error_Source_File then
         Write_Str ("==============Error messages for ");

         case Sinput.File_Type (Sfile) is
            when Sinput.Src =>
               Write_Str ("source");

            when Sinput.Config =>
               Write_Str ("configuration pragmas");

            when Sinput.Def =>
               Write_Str ("symbol definition");

            when Sinput.Preproc =>
               Write_Str ("preprocessing data");
         end case;

         Write_Str (" file: ");
         Write_Name (Full_File_Name (Sfile));
         Write_Eol;

         if Num_SRef_Pragmas (Sfile) > 0 then
            Write_Str ("--------------Line numbers from file: ");
            Write_Name (Full_Ref_Name (Sfile));
            Write_Str (" (starting at line ");
            Write_Int (Int (First_Mapped_Line (Sfile)));
            Write_Char (')');
            Write_Eol;
         end if;

         Current_Error_Source_File := Sfile;
      end if;

      if Errs or List_Pragmas_Mode then
         Output_Line_Number (Physical_To_Logical (L, Sfile));
         Line_Number_Output := True;
      end if;

      S := Line_Start (L, Sfile);

      loop
         C := Source_Text (Sfile) (S);
         exit when C = ASCII.LF or else C = ASCII.CR or else C = EOF;

         --  Deal with matching entry in List_Pragmas table

         if Full_List
           and then List_Pragmas_Index <= List_Pragmas.Last
           and then S = List_Pragmas.Table (List_Pragmas_Index).Ploc
         then
            case List_Pragmas.Table (List_Pragmas_Index).Ptyp is
               when Page =>
                  Write_Char (C);

                  --  Ignore if on line with errors so that error flags
                  --  get properly listed with the error line .

                  if not Errs then
                     Write_Char (ASCII.FF);
                  end if;

               when List_On =>
                  List_Pragmas_Mode := True;

                  if not Line_Number_Output then
                     Output_Line_Number (Physical_To_Logical (L, Sfile));
                     Line_Number_Output := True;
                  end if;

                  Write_Char (C);

               when List_Off =>
                  Write_Char (C);
                  List_Pragmas_Mode := False;
            end case;

            List_Pragmas_Index := List_Pragmas_Index + 1;

         --  Normal case (no matching entry in List_Pragmas table)

         else
            if Errs or List_Pragmas_Mode then
               Write_Char (C);
            end if;
         end if;

         S := S + 1;
      end loop;

      if Line_Number_Output then
         Write_Eol;
      end if;
   end Output_Source_Line;

   -----------------------------
   -- Remove_Warning_Messages --
   -----------------------------

   procedure Remove_Warning_Messages (N : Node_Id) is

      function Check_For_Warning (N : Node_Id) return Traverse_Result;
      --  This function checks one node for a possible warning message.

      function Check_All_Warnings is new
        Traverse_Func (Check_For_Warning);
      --  This defines the traversal operation

      -----------------------
      -- Check_For_Warning --
      -----------------------

      function Check_For_Warning (N : Node_Id) return Traverse_Result is
         Loc : constant Source_Ptr := Sloc (N);
         E   : Error_Msg_Id;

         function To_Be_Removed (E : Error_Msg_Id) return Boolean;
         --  Returns True for a message that is to be removed. Also adjusts
         --  warning count appropriately.

         -------------------
         -- To_Be_Removed --
         -------------------

         function To_Be_Removed (E : Error_Msg_Id) return Boolean is
         begin
            if E /= No_Error_Msg
              and then Errors.Table (E).Optr = Loc
              and then (Errors.Table (E).Warn or Errors.Table (E).Style)
            then
               Warnings_Detected := Warnings_Detected - 1;
               return True;
            else
               return False;
            end if;
         end To_Be_Removed;

      --  Start of processing for Check_For_Warnings

      begin
         while To_Be_Removed (First_Error_Msg) loop
            First_Error_Msg := Errors.Table (First_Error_Msg).Next;
         end loop;

         if First_Error_Msg = No_Error_Msg then
            Last_Error_Msg := No_Error_Msg;
         end if;

         E := First_Error_Msg;
         while E /= No_Error_Msg loop
            while To_Be_Removed (Errors.Table (E).Next) loop
               Errors.Table (E).Next :=
                 Errors.Table (Errors.Table (E).Next).Next;

               if Errors.Table (E).Next = No_Error_Msg then
                  Last_Error_Msg := E;
               end if;
            end loop;

            E := Errors.Table (E).Next;
         end loop;

         if Nkind (N) = N_Raise_Constraint_Error
           and then Original_Node (N) /= N
           and then No (Condition (N))
         then
            --  Warnings may have been posted on subexpressions of
            --  the original tree. We place the original node back
            --  on the tree to remove those warnings, whose sloc
            --  do not match those of any node in the current tree.
            --  Given that we are in unreachable code, this modification
            --  to the tree is harmless.

            declare
               Status : Traverse_Result;

            begin
               if Is_List_Member (N) then
                  Set_Condition (N, Original_Node (N));
                  Status := Check_All_Warnings (Condition (N));
               else
                  Rewrite (N, Original_Node (N));
                  Status := Check_All_Warnings (N);
               end if;

               return Status;
            end;

         else
            return OK;
         end if;
      end Check_For_Warning;

   --  Start of processing for Remove_Warning_Messages

   begin
      if Warnings_Detected /= 0 then
         declare
            Discard : Traverse_Result;
            pragma Warnings (Off, Discard);

         begin
            Discard := Check_All_Warnings (N);
         end;
      end if;
   end Remove_Warning_Messages;

   procedure Remove_Warning_Messages (L : List_Id) is
      Stat : Node_Id;
   begin
      if Is_Non_Empty_List (L) then
         Stat := First (L);

         while Present (Stat) loop
            Remove_Warning_Messages (Stat);
            Next (Stat);
         end loop;
      end if;
   end Remove_Warning_Messages;

   ---------------------------
   -- Set_Identifier_Casing --
   ---------------------------

   procedure Set_Identifier_Casing
     (Identifier_Name : System.Address;
      File_Name       : System.Address)
   is
      type Big_String is array (Positive) of Character;
      type Big_String_Ptr is access all Big_String;

      function To_Big_String_Ptr is new Unchecked_Conversion
        (System.Address, Big_String_Ptr);

      Ident : constant Big_String_Ptr := To_Big_String_Ptr (Identifier_Name);
      File  : constant Big_String_Ptr := To_Big_String_Ptr (File_Name);
      Flen  : Natural;

      Desired_Case : Casing_Type := Mixed_Case;
      --  Casing required for result. Default value of Mixed_Case is used if
      --  for some reason we cannot find the right file name in the table.

   begin
      --  Get length of file name

      Flen := 0;
      while File (Flen + 1) /= ASCII.NUL loop
         Flen := Flen + 1;
      end loop;

      --  Loop through file names to find matching one. This is a bit slow,
      --  but we only do it in error situations so it is not so terrible.
      --  Note that if the loop does not exit, then the desired case will
      --  be left set to Mixed_Case, this can happen if the name was not
      --  in canonical form, and gets canonicalized on VMS. Possibly we
      --  could fix this by unconditinally canonicalizing these names ???

      for J in 1 .. Last_Source_File loop
         Get_Name_String (Full_Debug_Name (J));

         if Name_Len = Flen
           and then Name_Buffer (1 .. Name_Len) = String (File (1 .. Flen))
         then
            Desired_Case := Identifier_Casing (J);
            exit;
         end if;
      end loop;

      --  Copy identifier as given to Name_Buffer

      for J in Name_Buffer'Range loop
         Name_Buffer (J) := Ident (J);

         if Name_Buffer (J) = ASCII.Nul then
            Name_Len := J - 1;
            exit;
         end if;
      end loop;

      Set_Casing (Desired_Case);
   end Set_Identifier_Casing;

   -----------------------
   -- Set_Ignore_Errors --
   -----------------------

   procedure Set_Ignore_Errors (To : Boolean) is
   begin
      Errors_Must_Be_Ignored := To;
   end Set_Ignore_Errors;

   ------------------------------
   -- Set_Msg_Insertion_Column --
   ------------------------------

   procedure Set_Msg_Insertion_Column is
   begin
      if Style.RM_Column_Check then
         Set_Msg_Str (" in column ");
         Set_Msg_Int (Int (Error_Msg_Col) + 1);
      end if;
   end Set_Msg_Insertion_Column;

   ----------------------------
   -- Set_Msg_Insertion_Node --
   ----------------------------

   procedure Set_Msg_Insertion_Node is
      K : Node_Kind;

   begin
      Suppress_Message :=
        Error_Msg_Node_1 = Error
          or else Error_Msg_Node_1 = Any_Type;

      if Error_Msg_Node_1 = Empty then
         Set_Msg_Blank_Conditional;
         Set_Msg_Str ("<empty>");

      elsif Error_Msg_Node_1 = Error then
         Set_Msg_Blank;
         Set_Msg_Str ("<error>");

      elsif Error_Msg_Node_1 = Standard_Void_Type then
         Set_Msg_Blank;
         Set_Msg_Str ("procedure name");

      else
         Set_Msg_Blank_Conditional;

         --  Output name

         K := Nkind (Error_Msg_Node_1);

         --  If we have operator case, skip quotes since name of operator
         --  itself will supply the required quotations. An operator can be
         --  an applied use in an expression or an explicit operator symbol,
         --  or an identifier whose name indicates it is an operator.

         if K in N_Op
           or else K = N_Operator_Symbol
           or else K = N_Defining_Operator_Symbol
           or else ((K = N_Identifier or else K = N_Defining_Identifier)
                       and then Is_Operator_Name (Chars (Error_Msg_Node_1)))
         then
            Set_Msg_Node (Error_Msg_Node_1);

         --  Normal case, not an operator, surround with quotes

         else
            Set_Msg_Quote;
            Set_Qualification (Error_Msg_Qual_Level, Error_Msg_Node_1);
            Set_Msg_Node (Error_Msg_Node_1);
            Set_Msg_Quote;
         end if;
      end if;

      --  The following assignment ensures that a second ampersand insertion
      --  character will correspond to the Error_Msg_Node_2 parameter.

      Error_Msg_Node_1 := Error_Msg_Node_2;
   end Set_Msg_Insertion_Node;

   --------------------------------------
   -- Set_Msg_Insertion_Type_Reference --
   --------------------------------------

   procedure Set_Msg_Insertion_Type_Reference (Flag : Source_Ptr) is
      Ent : Entity_Id;

   begin
      Set_Msg_Blank;

      if Error_Msg_Node_1 = Standard_Void_Type then
         Set_Msg_Str ("package or procedure name");
         return;

      elsif Error_Msg_Node_1 = Standard_Exception_Type then
         Set_Msg_Str ("exception name");
         return;

      elsif     Error_Msg_Node_1 = Any_Access
        or else Error_Msg_Node_1 = Any_Array
        or else Error_Msg_Node_1 = Any_Boolean
        or else Error_Msg_Node_1 = Any_Character
        or else Error_Msg_Node_1 = Any_Composite
        or else Error_Msg_Node_1 = Any_Discrete
        or else Error_Msg_Node_1 = Any_Fixed
        or else Error_Msg_Node_1 = Any_Integer
        or else Error_Msg_Node_1 = Any_Modular
        or else Error_Msg_Node_1 = Any_Numeric
        or else Error_Msg_Node_1 = Any_Real
        or else Error_Msg_Node_1 = Any_Scalar
        or else Error_Msg_Node_1 = Any_String
      then
         Get_Unqualified_Decoded_Name_String (Chars (Error_Msg_Node_1));
         Set_Msg_Name_Buffer;
         return;

      elsif Error_Msg_Node_1 = Universal_Real then
         Set_Msg_Str ("type universal real");
         return;

      elsif Error_Msg_Node_1 = Universal_Integer then
         Set_Msg_Str ("type universal integer");
         return;

      elsif Error_Msg_Node_1 = Universal_Fixed then
         Set_Msg_Str ("type universal fixed");
         return;
      end if;

      --  Special case of anonymous array

      if Nkind (Error_Msg_Node_1) in N_Entity
        and then Is_Array_Type (Error_Msg_Node_1)
        and then Present (Related_Array_Object (Error_Msg_Node_1))
      then
         Set_Msg_Str ("type of ");
         Set_Msg_Node (Related_Array_Object (Error_Msg_Node_1));
         Set_Msg_Str (" declared");
         Set_Msg_Insertion_Line_Number
           (Sloc (Related_Array_Object (Error_Msg_Node_1)), Flag);
         return;
      end if;

      --  If we fall through, it is not a special case, so first output
      --  the name of the type, preceded by private for a private type

      if Is_Private_Type (Error_Msg_Node_1) then
         Set_Msg_Str ("private type ");
      else
         Set_Msg_Str ("type ");
      end if;

      Ent := Error_Msg_Node_1;

      if Is_Internal_Name (Chars (Ent)) then
         Unwind_Internal_Type (Ent);
      end if;

      --  Types in Standard are displayed as "Standard.name"

      if Sloc (Ent) <= Standard_Location then
         Set_Msg_Quote;
         Set_Msg_Str ("Standard.");
         Set_Msg_Node (Ent);
         Add_Class;
         Set_Msg_Quote;

      --  Types in other language defined units are displayed as
      --  "package-name.type-name"

      elsif
        Is_Predefined_File_Name (Unit_File_Name (Get_Source_Unit (Ent)))
      then
         Get_Unqualified_Decoded_Name_String
           (Unit_Name (Get_Source_Unit (Ent)));
         Name_Len := Name_Len - 2;
         Set_Msg_Quote;
         Set_Casing (Mixed_Case);
         Set_Msg_Name_Buffer;
         Set_Msg_Char ('.');
         Set_Casing (Mixed_Case);
         Set_Msg_Node (Ent);
         Add_Class;
         Set_Msg_Quote;

      --  All other types display as "type name" defined at line xxx
      --  possibly qualified if qualification is requested.

      else
         Set_Msg_Quote;
         Set_Qualification (Error_Msg_Qual_Level, Ent);
         Set_Msg_Node (Ent);
         Add_Class;
         Set_Msg_Quote;
      end if;

      --  If the original type did not come from a predefined
      --  file, add the location where the type was defined.

      if Sloc (Error_Msg_Node_1) > Standard_Location
        and then
          not Is_Predefined_File_Name
                (Unit_File_Name (Get_Source_Unit (Error_Msg_Node_1)))
      then
         Set_Msg_Str (" defined");
         Set_Msg_Insertion_Line_Number (Sloc (Error_Msg_Node_1), Flag);

      --  If it did come from a predefined file, deal with the case where
      --  this was a file with a generic instantiation from elsewhere.

      else
         if Sloc (Error_Msg_Node_1) > Standard_Location then
            declare
               Iloc : constant Source_Ptr :=
                        Instantiation_Location (Sloc (Error_Msg_Node_1));

            begin
               if Iloc /= No_Location
                 and then not Suppress_Instance_Location
               then
                  Set_Msg_Str (" from instance");
                  Set_Msg_Insertion_Line_Number (Iloc, Flag);
               end if;
            end;
         end if;
      end if;
   end Set_Msg_Insertion_Type_Reference;

   ---------------------------------
   -- Set_Msg_Insertion_Unit_Name --
   ---------------------------------

   procedure Set_Msg_Insertion_Unit_Name is
   begin
      if Error_Msg_Unit_1 = No_Name then
         null;

      elsif Error_Msg_Unit_1 = Error_Name then
         Set_Msg_Blank;
         Set_Msg_Str ("<error>");

      else
         Get_Unit_Name_String (Error_Msg_Unit_1);
         Set_Msg_Blank;
         Set_Msg_Quote;
         Set_Msg_Name_Buffer;
         Set_Msg_Quote;
      end if;

      --  The following assignment ensures that a second percent insertion
      --  character will correspond to the Error_Msg_Unit_2 parameter.

      Error_Msg_Unit_1 := Error_Msg_Unit_2;
   end Set_Msg_Insertion_Unit_Name;

   ------------------
   -- Set_Msg_Node --
   ------------------

   procedure Set_Msg_Node (Node : Node_Id) is
      Ent : Entity_Id;
      Nam : Name_Id;

   begin
      if Nkind (Node) = N_Designator then
         Set_Msg_Node (Name (Node));
         Set_Msg_Char ('.');
         Set_Msg_Node (Identifier (Node));
         return;

      elsif Nkind (Node) = N_Defining_Program_Unit_Name then
         Set_Msg_Node (Name (Node));
         Set_Msg_Char ('.');
         Set_Msg_Node (Defining_Identifier (Node));
         return;

      elsif Nkind (Node) = N_Selected_Component then
         Set_Msg_Node (Prefix (Node));
         Set_Msg_Char ('.');
         Set_Msg_Node (Selector_Name (Node));
         return;
      end if;

      --  The only remaining possibilities are identifiers, defining
      --  identifiers, pragmas, and pragma argument associations, i.e.
      --  nodes that have a Chars field.

      --  Internal names generally represent something gone wrong. An exception
      --  is the case of internal type names, where we try to find a reasonable
      --  external representation for the external name

      if Is_Internal_Name (Chars (Node))
        and then
          ((Is_Entity_Name (Node)
                          and then Present (Entity (Node))
                          and then Is_Type (Entity (Node)))
              or else
           (Nkind (Node) = N_Defining_Identifier and then Is_Type (Node)))
      then
         if Nkind (Node) = N_Identifier then
            Ent := Entity (Node);
         else
            Ent := Node;
         end if;

         Unwind_Internal_Type (Ent);
         Nam := Chars (Ent);

      else
         Nam := Chars (Node);
      end if;

      --  At this stage, the name to output is in Nam

      Get_Unqualified_Decoded_Name_String (Nam);

      --  Remove trailing upper case letters from the name (useful for
      --  dealing with some cases of internal names.

      while Name_Len > 1 and then Name_Buffer (Name_Len) in 'A' .. 'Z' loop
         Name_Len := Name_Len  - 1;
      end loop;

      --  If we have any of the names from standard that start with the
      --  characters "any " (e.g. Any_Type), then kill the message since
      --  almost certainly it is a junk cascaded message.

      if Name_Len > 4
        and then Name_Buffer (1 .. 4) = "any "
      then
         Kill_Message := True;
      end if;

      --  Now we have to set the proper case. If we have a source location
      --  then do a check to see if the name in the source is the same name
      --  as the name in the Names table, except for possible differences
      --  in case, which is the case when we can copy from the source.

      declare
         Src_Loc : constant Source_Ptr := Sloc (Error_Msg_Node_1);
         Sbuffer : Source_Buffer_Ptr;
         Ref_Ptr : Integer;
         Src_Ptr : Source_Ptr;

      begin
         Ref_Ptr := 1;
         Src_Ptr := Src_Loc;

         --  For standard locations, always use mixed case

         if Src_Loc <= No_Location
           or else Sloc (Node) <= No_Location
         then
            Set_Casing (Mixed_Case);

         else
            --  Determine if the reference we are dealing with corresponds
            --  to text at the point of the error reference. This will often
            --  be the case for simple identifier references, and is the case
            --  where we can copy the spelling from the source.

            Sbuffer := Source_Text (Get_Source_File_Index (Src_Loc));

            while Ref_Ptr <= Name_Len loop
               exit when
                 Fold_Lower (Sbuffer (Src_Ptr)) /=
                 Fold_Lower (Name_Buffer (Ref_Ptr));
               Ref_Ptr := Ref_Ptr + 1;
               Src_Ptr := Src_Ptr + 1;
            end loop;

            --  If we get through the loop without a mismatch, then output
            --  the name the way it is spelled in the source program

            if Ref_Ptr > Name_Len then
               Src_Ptr := Src_Loc;

               for J in 1 .. Name_Len loop
                  Name_Buffer (J) := Sbuffer (Src_Ptr);
                  Src_Ptr := Src_Ptr + 1;
               end loop;

            --  Otherwise set the casing using the default identifier casing

            else
               Set_Casing (Identifier_Casing (Flag_Source), Mixed_Case);
            end if;
         end if;
      end;

      Set_Msg_Name_Buffer;
      Add_Class;
   end Set_Msg_Node;

   ------------------
   -- Set_Msg_Text --
   ------------------

   procedure Set_Msg_Text (Text : String; Flag : Source_Ptr) is
      C : Character;         -- Current character
      P : Natural;           -- Current index;

   begin
      Manual_Quote_Mode := False;
      Is_Unconditional_Msg := False;
      Msglen := 0;
      Flag_Source := Get_Source_File_Index (Flag);
      P := Text'First;

      while P <= Text'Last loop
         C := Text (P);
         P := P + 1;

         --  Check for insertion character

         case C is
            when '%' =>
               Set_Msg_Insertion_Name;

            when '$' =>
               Set_Msg_Insertion_Unit_Name;

            when '{' =>
               Set_Msg_Insertion_File_Name;

            when '}' =>
               Set_Msg_Insertion_Type_Reference (Flag);

            when '*' =>
               Set_Msg_Insertion_Reserved_Name;

            when '&' =>
               Set_Msg_Insertion_Node;

            when '#' =>
               Set_Msg_Insertion_Line_Number (Error_Msg_Sloc, Flag);

            when '\' =>
               Continuation := True;

            when '@' =>
               Set_Msg_Insertion_Column;

            when '>' =>
               Set_Msg_Insertion_Run_Time_Name;

            when '^' =>
               Set_Msg_Insertion_Uint;

            when '`' =>
               Manual_Quote_Mode := not Manual_Quote_Mode;
               Set_Msg_Char ('"');

            when '!' =>
               Is_Unconditional_Msg := True;

            when '?' =>
               null; -- already dealt with

            when '|' =>
               null; -- already dealt with

            when ''' =>
               Set_Msg_Char (Text (P));
               P := P + 1;

            --  Upper case letter

            when 'A' .. 'Z' =>

               --  Start of reserved word if two or more

               if P <= Text'Last and then Text (P) in 'A' .. 'Z' then
                  P := P - 1;
                  Set_Msg_Insertion_Reserved_Word (Text, P);

               --  Single upper case letter is just inserted

               else
                  Set_Msg_Char (C);
               end if;

            --  Normal character with no special treatment

            when others =>
               Set_Msg_Char (C);
         end case;
      end loop;

      VMS_Convert;
   end Set_Msg_Text;

   ----------------
   -- Set_Posted --
   ----------------

   procedure Set_Posted (N : Node_Id) is
      P : Node_Id;

   begin
      if Is_Serious_Error then

         --  We always set Error_Posted on the node itself

         Set_Error_Posted (N);

         --  If it is a subexpression, then set Error_Posted on parents
         --  up to and including the first non-subexpression construct. This
         --  helps avoid cascaded error messages within a single expression.

         P := N;
         loop
            P := Parent (P);
            exit when No (P);
            Set_Error_Posted (P);
            exit when Nkind (P) not in N_Subexpr;
         end loop;

         --  A special check, if we just posted an error on an attribute
         --  definition clause, then also set the entity involved as posted.
         --  For example, this stops complaining about the alignment after
         --  complaining about the size, which is likely to be useless.

         if Nkind (P) = N_Attribute_Definition_Clause then
            if Is_Entity_Name (Name (P)) then
               Set_Error_Posted (Entity (Name (P)));
            end if;
         end if;
      end if;
   end Set_Posted;

   -----------------------
   -- Set_Qualification --
   -----------------------

   procedure Set_Qualification (N : Nat; E : Entity_Id) is
   begin
      if N /= 0 and then Scope (E) /= Standard_Standard then
         Set_Qualification (N - 1, Scope (E));
         Set_Msg_Node (Scope (E));
         Set_Msg_Char ('.');
      end if;
   end Set_Qualification;

   ------------------------
   -- Special_Msg_Delete --
   ------------------------

   function Special_Msg_Delete
     (Msg : String;
      N   : Node_Or_Entity_Id;
      E   : Node_Or_Entity_Id) return Boolean
   is
   begin
      --  Never delete messages in -gnatdO mode

      if Debug_Flag_OO then
         return False;

      --  When an atomic object refers to a non-atomic type in the same
      --  scope, we implicitly make the type atomic. In the non-error
      --  case this is surely safe (and in fact prevents an error from
      --  occurring if the type is not atomic by default). But if the
      --  object cannot be made atomic, then we introduce an extra junk
      --  message by this manipulation, which we get rid of here.

      --  We identify this case by the fact that it references a type for
      --  which Is_Atomic is set, but there is no Atomic pragma setting it.

      elsif Msg = "atomic access to & cannot be guaranteed"
        and then Is_Type (E)
        and then Is_Atomic (E)
        and then No (Get_Rep_Pragma (E, Name_Atomic))
      then
         return True;

      --  When a size is wrong for a frozen type there is no explicit
      --  size clause, and other errors have occurred, suppress the
      --  message, since it is likely that this size error is a cascaded
      --  result of other errors. The reason we eliminate unfrozen types
      --  is that messages issued before the freeze type are for sure OK.

      elsif Msg = "size for& too small, minimum allowed is ^"
        and then Is_Frozen (E)
        and then Serious_Errors_Detected > 0
        and then Nkind (N) /= N_Component_Clause
        and then Nkind (Parent (N)) /= N_Component_Clause
        and then
          No (Get_Attribute_Definition_Clause (E, Attribute_Size))
        and then
          No (Get_Attribute_Definition_Clause (E, Attribute_Object_Size))
        and then
          No (Get_Attribute_Definition_Clause (E, Attribute_Value_Size))
      then
         return True;

      --  All special tests complete, so go ahead with message

      else
         return False;
      end if;
   end Special_Msg_Delete;

   --------------------------
   -- Unwind_Internal_Type --
   --------------------------

   procedure Unwind_Internal_Type (Ent : in out Entity_Id) is
      Derived : Boolean := False;
      Mchar   : Character;
      Old_Ent : Entity_Id;

   begin
      --  Undo placement of a quote, since we will put it back later

      Mchar := Msg_Buffer (Msglen);

      if Mchar = '"' then
         Msglen := Msglen - 1;
      end if;

      --  The loop here deals with recursive types, we are trying to
      --  find a related entity that is not an implicit type. Note
      --  that the check with Old_Ent stops us from getting "stuck".
      --  Also, we don't output the "type derived from" message more
      --  than once in the case where we climb up multiple levels.

      loop
         Old_Ent := Ent;

         --  Implicit access type, use directly designated type

         if Is_Access_Type (Ent) then
            Set_Msg_Str ("access to ");
            Ent := Directly_Designated_Type (Ent);

         --  Classwide type

         elsif Is_Class_Wide_Type (Ent) then
            Class_Flag := True;
            Ent := Root_Type (Ent);

         --  Use base type if this is a subtype

         elsif Ent /= Base_Type (Ent) then
            Buffer_Remove ("type ");

            --  Avoid duplication "subtype of subtype of", and also replace
            --  "derived from subtype of" simply by "derived from"

            if not Buffer_Ends_With ("subtype of ")
              and then not Buffer_Ends_With ("derived from ")
            then
               Set_Msg_Str ("subtype of ");
            end if;

            Ent := Base_Type (Ent);

         --  If this is a base type with a first named subtype, use the
         --  first named subtype instead. This is not quite accurate in
         --  all cases, but it makes too much noise to be accurate and
         --  add 'Base in all cases. Note that we only do this is the
         --  first named subtype is not itself an internal name. This
         --  avoids the obvious loop (subtype->basetype->subtype) which
         --  would otherwise occur!)

         elsif Present (Freeze_Node (Ent))
           and then Present (First_Subtype_Link (Freeze_Node (Ent)))
           and then
             not Is_Internal_Name
                   (Chars (First_Subtype_Link (Freeze_Node (Ent))))
         then
            Ent := First_Subtype_Link (Freeze_Node (Ent));

         --  Otherwise use root type

         else
            if not Derived then
               Buffer_Remove ("type ");

               --  Test for "subtype of type derived from" which seems
               --  excessive and is replaced by simply "type derived from"

               Buffer_Remove ("subtype of");

               --  Avoid duplication "type derived from type derived from"

               if not Buffer_Ends_With ("type derived from ") then
                  Set_Msg_Str ("type derived from ");
               end if;

               Derived := True;
            end if;

            Ent := Etype (Ent);
         end if;

         --  If we are stuck in a loop, get out and settle for the internal
         --  name after all. In this case we set to kill the message if it
         --  is not the first error message (we really try hard not to show
         --  the dirty laundry of the implementation to the poor user!)

         if Ent = Old_Ent then
            Kill_Message := True;
            exit;
         end if;

         --  Get out if we finally found a non-internal name to use

         exit when not Is_Internal_Name (Chars (Ent));
      end loop;

      if Mchar = '"' then
         Set_Msg_Char ('"');
      end if;
   end Unwind_Internal_Type;

   -----------------
   -- VMS_Convert --
   -----------------

   procedure VMS_Convert is
      P : Natural;
      L : Natural;
      N : Natural;

   begin
      if not OpenVMS then
         return;
      end if;

      P := Msg_Buffer'First;
      loop
         if P >= Msglen then
            return;
         end if;

         if Msg_Buffer (P) = '-' then
            for G in Gnames'Range loop
               L := Gnames (G)'Length;

               --  See if we have "-ggg switch", where ggg is Gnames entry

               if P + L + 7 <= Msglen
                 and then Msg_Buffer (P + 1 .. P + L) = Gnames (G).all
                 and then Msg_Buffer (P + L + 1 .. P + L + 7) = " switch"
               then
                  --  Replace by "/vvv qualifier", where vvv is Vnames entry

                  N := Vnames (G)'Length;
                  Msg_Buffer (P + N + 11 .. Msglen + N - L + 3) :=
                    Msg_Buffer (P + L + 8 .. Msglen);
                  Msg_Buffer (P) := '/';
                  Msg_Buffer (P + 1 .. P + N) := Vnames (G).all;
                  Msg_Buffer (P + N + 1 .. P + N + 10) := " qualifier";
                  P := P + N + 10;
                  Msglen := Msglen + N - L + 3;
                  exit;
               end if;
            end loop;
         end if;

         P := P + 1;
      end loop;
   end VMS_Convert;

end Errout;