summaryrefslogtreecommitdiff
path: root/gcc/ada/sem_ch13.adb
blob: 69e324b0a7f5584eeca8c8a8be53bf11fe3ee732 (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
2564
2565
2566
2567
2568
2569
2570
2571
2572
2573
2574
2575
2576
2577
2578
2579
2580
2581
2582
2583
2584
2585
2586
2587
2588
2589
2590
2591
2592
2593
2594
2595
2596
2597
2598
2599
2600
2601
2602
2603
2604
2605
2606
2607
2608
2609
2610
2611
2612
2613
2614
2615
2616
2617
2618
2619
2620
2621
2622
2623
2624
2625
2626
2627
2628
2629
2630
2631
2632
2633
2634
2635
2636
2637
2638
2639
2640
2641
2642
2643
2644
2645
2646
2647
2648
2649
2650
2651
2652
2653
2654
2655
2656
2657
2658
2659
2660
2661
2662
2663
2664
2665
2666
2667
2668
2669
2670
2671
2672
2673
2674
2675
2676
2677
2678
2679
2680
2681
2682
2683
2684
2685
2686
2687
2688
2689
2690
2691
2692
2693
2694
2695
2696
2697
2698
2699
2700
2701
2702
2703
2704
2705
2706
2707
2708
2709
2710
2711
2712
2713
2714
2715
2716
2717
2718
2719
2720
2721
2722
2723
2724
2725
2726
2727
2728
2729
2730
2731
2732
2733
2734
2735
2736
2737
2738
2739
2740
2741
2742
2743
2744
2745
2746
2747
2748
2749
2750
2751
2752
2753
2754
2755
2756
2757
2758
2759
2760
2761
2762
2763
2764
2765
2766
2767
2768
2769
2770
2771
2772
2773
2774
2775
2776
2777
2778
2779
2780
2781
2782
2783
2784
2785
2786
2787
2788
2789
2790
2791
2792
2793
2794
2795
2796
2797
2798
2799
2800
2801
2802
2803
2804
2805
2806
2807
2808
2809
2810
2811
2812
2813
2814
2815
2816
2817
2818
2819
2820
2821
2822
2823
2824
2825
2826
2827
2828
2829
2830
2831
2832
2833
2834
2835
2836
2837
2838
2839
2840
2841
2842
2843
2844
2845
2846
2847
2848
2849
2850
2851
2852
2853
2854
2855
2856
2857
2858
2859
2860
2861
2862
2863
2864
2865
2866
2867
2868
2869
2870
2871
2872
2873
2874
2875
2876
2877
2878
2879
2880
2881
2882
2883
2884
2885
2886
2887
2888
2889
2890
2891
2892
2893
2894
2895
2896
2897
2898
2899
2900
2901
2902
2903
2904
2905
2906
2907
2908
2909
2910
2911
2912
2913
2914
2915
2916
2917
2918
2919
2920
2921
2922
2923
2924
2925
2926
2927
2928
2929
2930
2931
2932
2933
2934
2935
2936
2937
2938
2939
2940
2941
2942
2943
2944
2945
2946
2947
2948
2949
2950
2951
2952
2953
2954
2955
2956
2957
2958
2959
2960
2961
2962
2963
2964
2965
2966
2967
2968
2969
2970
2971
2972
2973
2974
2975
2976
2977
2978
2979
2980
2981
2982
2983
2984
2985
2986
2987
2988
2989
2990
2991
2992
2993
2994
2995
2996
2997
2998
2999
3000
3001
3002
3003
3004
3005
3006
3007
3008
3009
3010
3011
3012
3013
3014
3015
3016
3017
3018
3019
3020
3021
3022
3023
3024
3025
3026
3027
3028
3029
3030
3031
3032
3033
3034
3035
3036
3037
3038
3039
3040
3041
3042
3043
3044
3045
3046
3047
3048
3049
3050
3051
3052
3053
3054
3055
3056
3057
3058
3059
3060
3061
3062
3063
3064
3065
3066
3067
3068
3069
3070
3071
3072
3073
3074
3075
3076
3077
3078
3079
3080
3081
3082
3083
3084
3085
3086
3087
3088
3089
3090
3091
3092
3093
3094
3095
3096
3097
3098
3099
3100
3101
3102
3103
3104
3105
3106
3107
3108
3109
3110
3111
3112
3113
3114
3115
3116
3117
3118
3119
3120
3121
3122
3123
3124
3125
3126
3127
3128
3129
3130
3131
3132
3133
3134
3135
3136
3137
3138
3139
3140
3141
3142
3143
3144
3145
3146
3147
3148
3149
3150
3151
3152
3153
3154
3155
3156
3157
3158
3159
3160
3161
3162
3163
3164
3165
3166
3167
3168
3169
3170
3171
3172
3173
3174
3175
3176
3177
3178
3179
3180
3181
3182
3183
3184
3185
3186
3187
3188
3189
3190
3191
3192
3193
3194
3195
3196
3197
3198
3199
3200
3201
3202
3203
3204
3205
3206
3207
3208
3209
3210
3211
3212
3213
3214
3215
3216
3217
3218
3219
3220
3221
3222
3223
3224
3225
3226
3227
3228
3229
3230
3231
3232
3233
3234
3235
3236
3237
3238
3239
3240
3241
3242
3243
3244
3245
3246
3247
3248
3249
3250
3251
3252
3253
3254
3255
3256
3257
3258
3259
3260
3261
3262
3263
3264
3265
3266
3267
3268
3269
3270
3271
3272
3273
3274
3275
3276
3277
3278
3279
3280
3281
3282
3283
3284
3285
3286
3287
3288
3289
3290
3291
3292
3293
3294
3295
3296
3297
3298
3299
3300
3301
3302
3303
3304
3305
3306
3307
3308
3309
3310
3311
3312
3313
3314
3315
3316
3317
3318
3319
3320
3321
3322
3323
3324
3325
3326
3327
3328
3329
3330
3331
3332
3333
3334
3335
3336
3337
3338
3339
3340
3341
3342
3343
3344
3345
3346
3347
3348
3349
3350
3351
3352
3353
3354
3355
3356
3357
3358
3359
3360
3361
3362
3363
3364
3365
3366
3367
3368
3369
3370
3371
3372
3373
3374
3375
3376
3377
3378
3379
3380
3381
3382
3383
3384
3385
3386
3387
3388
3389
3390
3391
3392
3393
3394
3395
3396
3397
3398
3399
3400
3401
3402
3403
3404
3405
3406
3407
3408
3409
3410
3411
3412
3413
3414
3415
3416
3417
3418
3419
3420
3421
3422
3423
3424
3425
3426
3427
3428
3429
3430
3431
3432
3433
3434
3435
3436
3437
3438
3439
3440
3441
3442
3443
3444
3445
3446
3447
3448
3449
3450
3451
3452
3453
3454
3455
3456
3457
3458
3459
3460
3461
3462
3463
3464
3465
3466
3467
3468
3469
3470
3471
3472
3473
3474
3475
3476
3477
3478
3479
3480
3481
3482
3483
3484
3485
3486
3487
3488
3489
3490
3491
3492
3493
3494
3495
3496
3497
3498
3499
3500
3501
3502
3503
3504
3505
3506
3507
3508
3509
3510
3511
3512
3513
3514
3515
3516
3517
3518
3519
3520
3521
3522
3523
3524
3525
3526
3527
3528
3529
3530
3531
3532
3533
3534
3535
3536
3537
3538
3539
3540
3541
3542
3543
3544
3545
3546
3547
3548
3549
3550
3551
3552
3553
3554
3555
3556
3557
3558
3559
3560
3561
3562
3563
3564
3565
3566
3567
3568
3569
3570
3571
3572
3573
3574
3575
3576
3577
3578
3579
3580
3581
3582
3583
3584
3585
3586
3587
3588
3589
3590
3591
3592
3593
3594
3595
3596
3597
3598
3599
3600
3601
3602
3603
3604
3605
3606
3607
3608
3609
3610
3611
3612
3613
3614
3615
3616
3617
3618
3619
3620
3621
3622
3623
3624
3625
3626
3627
3628
3629
3630
3631
3632
3633
3634
3635
3636
3637
3638
3639
3640
3641
3642
3643
3644
3645
3646
3647
3648
3649
3650
3651
3652
3653
3654
3655
3656
3657
3658
3659
3660
3661
3662
3663
3664
3665
3666
3667
3668
3669
3670
3671
3672
3673
3674
3675
3676
3677
3678
3679
3680
3681
3682
3683
3684
3685
3686
3687
3688
3689
3690
3691
3692
3693
3694
3695
3696
3697
3698
3699
3700
3701
3702
3703
3704
3705
3706
3707
3708
3709
3710
3711
3712
3713
3714
3715
3716
3717
3718
3719
3720
3721
3722
3723
3724
3725
3726
3727
3728
3729
3730
3731
3732
3733
3734
3735
3736
3737
3738
3739
3740
3741
3742
3743
3744
3745
3746
3747
3748
3749
3750
3751
3752
3753
3754
3755
3756
3757
3758
3759
3760
3761
3762
3763
3764
3765
3766
3767
3768
3769
3770
3771
3772
3773
3774
3775
3776
3777
3778
3779
3780
3781
3782
3783
3784
3785
3786
3787
3788
3789
3790
3791
3792
3793
3794
3795
3796
3797
3798
3799
3800
3801
3802
3803
3804
3805
3806
3807
3808
3809
3810
3811
3812
3813
3814
3815
3816
3817
3818
3819
3820
3821
3822
3823
3824
3825
3826
3827
3828
3829
3830
3831
3832
3833
3834
3835
3836
3837
3838
3839
3840
3841
3842
3843
3844
3845
3846
3847
3848
3849
3850
3851
3852
3853
3854
3855
3856
3857
3858
3859
3860
3861
3862
3863
3864
3865
3866
3867
3868
3869
3870
3871
3872
3873
3874
3875
3876
3877
3878
3879
3880
3881
3882
3883
3884
3885
3886
3887
3888
3889
3890
3891
3892
3893
3894
3895
3896
3897
3898
3899
3900
3901
3902
3903
3904
3905
3906
3907
3908
3909
3910
3911
3912
3913
3914
3915
3916
3917
3918
3919
3920
3921
3922
3923
3924
3925
3926
3927
3928
3929
3930
3931
3932
3933
3934
3935
3936
3937
3938
3939
3940
3941
3942
3943
3944
3945
3946
3947
3948
3949
3950
3951
3952
3953
3954
3955
3956
3957
3958
3959
3960
3961
3962
3963
3964
3965
3966
3967
3968
3969
3970
3971
3972
3973
3974
3975
3976
3977
3978
3979
3980
3981
3982
3983
3984
3985
3986
3987
3988
3989
3990
3991
3992
3993
3994
3995
3996
3997
3998
3999
4000
4001
4002
4003
4004
4005
4006
4007
4008
4009
4010
4011
4012
4013
4014
4015
4016
4017
4018
4019
4020
4021
4022
4023
4024
4025
4026
4027
4028
4029
4030
4031
4032
4033
4034
4035
4036
4037
4038
4039
4040
4041
4042
4043
4044
4045
4046
4047
4048
4049
4050
4051
4052
------------------------------------------------------------------------------
--                                                                          --
--                         GNAT COMPILER COMPONENTS                         --
--                                                                          --
--                             S E M _ C H 1 3                              --
--                                                                          --
--                                 B o d y                                  --
--                                                                          --
--          Copyright (C) 1992-2004, 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,  59 Temple Place - Suite 330,  Boston, --
-- MA 02111-1307, USA.                                                      --
--                                                                          --
-- GNAT was originally developed  by the GNAT team at  New York University. --
-- Extensive contributions were provided by Ada Core Technologies Inc.      --
--                                                                          --
------------------------------------------------------------------------------

with Atree;    use Atree;
with Checks;   use Checks;
with Einfo;    use Einfo;
with Errout;   use Errout;
with Exp_Tss;  use Exp_Tss;
with Exp_Util; use Exp_Util;
with Lib;      use Lib;
with Nlists;   use Nlists;
with Nmake;    use Nmake;
with Opt;      use Opt;
with Rtsfind;  use Rtsfind;
with Sem;      use Sem;
with Sem_Ch8;  use Sem_Ch8;
with Sem_Eval; use Sem_Eval;
with Sem_Res;  use Sem_Res;
with Sem_Type; use Sem_Type;
with Sem_Util; use Sem_Util;
with Snames;   use Snames;
with Stand;    use Stand;
with Sinfo;    use Sinfo;
with Table;
with Targparm; use Targparm;
with Ttypes;   use Ttypes;
with Tbuild;   use Tbuild;
with Urealp;   use Urealp;

with GNAT.Heap_Sort_A; use GNAT.Heap_Sort_A;

package body Sem_Ch13 is

   SSU : constant Pos := System_Storage_Unit;
   --  Convenient short hand for commonly used constant

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

   procedure Alignment_Check_For_Esize_Change (Typ : Entity_Id);
   --  This routine is called after setting the Esize of type entity Typ.
   --  The purpose is to deal with the situation where an aligment has been
   --  inherited from a derived type that is no longer appropriate for the
   --  new Esize value. In this case, we reset the Alignment to unknown.

   procedure Check_Component_Overlap (C1_Ent, C2_Ent : Entity_Id);
   --  Given two entities for record components or discriminants, checks
   --  if they hav overlapping component clauses and issues errors if so.

   function Get_Alignment_Value (Expr : Node_Id) return Uint;
   --  Given the expression for an alignment value, returns the corresponding
   --  Uint value. If the value is inappropriate, then error messages are
   --  posted as required, and a value of No_Uint is returned.

   function Is_Operational_Item (N : Node_Id) return Boolean;
   --  A specification for a stream attribute is allowed before the full
   --  type is declared, as explained in AI-00137 and the corrigendum.
   --  Attributes that do not specify a representation characteristic are
   --  operational attributes.

   function Address_Aliased_Entity (N : Node_Id) return Entity_Id;
   --  If expression N is of the form E'Address, return E.

   procedure Mark_Aliased_Address_As_Volatile (N : Node_Id);
   --  This is used for processing of an address representation clause. If
   --  the expression N is of the form of K'Address, then the entity that
   --  is associated with K is marked as volatile.

   procedure New_Stream_Function
     (N    : Node_Id;
      Ent  : Entity_Id;
      Subp : Entity_Id;
      Nam  : TSS_Name_Type);
   --  Create a function renaming of a given stream attribute to the
   --  designated subprogram and then in the tagged case, provide this as
   --  a primitive operation, or in the non-tagged case make an appropriate
   --  TSS entry. Used for Input. This is more properly an expansion activity
   --  than just semantics, but the presence of user-defined stream functions
   --  for limited types is a legality check, which is why this takes place
   --  here rather than in exp_ch13, where it was previously. Nam indicates
   --  the name of the TSS function to be generated.
   --
   --  To avoid elaboration anomalies with freeze nodes, for untagged types
   --  we generate both a subprogram declaration and a subprogram renaming
   --  declaration, so that the attribute specification is handled as a
   --  renaming_as_body. For tagged types, the specification is one of the
   --  primitive specs.

   procedure New_Stream_Procedure
     (N     : Node_Id;
      Ent   : Entity_Id;
      Subp  : Entity_Id;
      Nam   : TSS_Name_Type;
      Out_P : Boolean := False);
   --  Create a procedure renaming of a given stream attribute to the
   --  designated subprogram and then in the tagged case, provide this as
   --  a primitive operation, or in the non-tagged case make an appropriate
   --  TSS entry. Used for Read, Output, Write. Nam indicates the name of
   --  the TSS procedure to be generated.

   ----------------------------------------------
   -- Table for Validate_Unchecked_Conversions --
   ----------------------------------------------

   --  The following table collects unchecked conversions for validation.
   --  Entries are made by Validate_Unchecked_Conversion and then the
   --  call to Validate_Unchecked_Conversions does the actual error
   --  checking and posting of warnings. The reason for this delayed
   --  processing is to take advantage of back-annotations of size and
   --  alignment values peformed by the back end.

   type UC_Entry is record
      Enode  : Node_Id;   -- node used for posting warnings
      Source : Entity_Id; -- source type for unchecked conversion
      Target : Entity_Id; -- target type for unchecked conversion
   end record;

   package Unchecked_Conversions is new Table.Table (
     Table_Component_Type => UC_Entry,
     Table_Index_Type     => Int,
     Table_Low_Bound      => 1,
     Table_Initial        => 50,
     Table_Increment      => 200,
     Table_Name           => "Unchecked_Conversions");

   ----------------------------
   -- Address_Aliased_Entity --
   ----------------------------

   function Address_Aliased_Entity (N : Node_Id) return Entity_Id is
   begin
      if Nkind (N) = N_Attribute_Reference
        and then Attribute_Name (N) = Name_Address
      then
         declare
            Nam : Node_Id := Prefix (N);
         begin
            while False
              or else Nkind (Nam) = N_Selected_Component
              or else Nkind (Nam) = N_Indexed_Component
            loop
               Nam := Prefix (Nam);
            end loop;

            if Is_Entity_Name (Nam) then
               return Entity (Nam);
            end if;
         end;
      end if;

      return Empty;
   end Address_Aliased_Entity;

   --------------------------------------
   -- Alignment_Check_For_Esize_Change --
   --------------------------------------

   procedure Alignment_Check_For_Esize_Change (Typ : Entity_Id) is
   begin
      --  If the alignment is known, and not set by a rep clause, and is
      --  inconsistent with the size being set, then reset it to unknown,
      --  we assume in this case that the size overrides the inherited
      --  alignment, and that the alignment must be recomputed.

      if Known_Alignment (Typ)
        and then not Has_Alignment_Clause (Typ)
        and then Esize (Typ) mod (Alignment (Typ) * SSU) /= 0
      then
         Init_Alignment (Typ);
      end if;
   end Alignment_Check_For_Esize_Change;

   -----------------------
   -- Analyze_At_Clause --
   -----------------------

   --  An at clause is replaced by the corresponding Address attribute
   --  definition clause that is the preferred approach in Ada 95.

   procedure Analyze_At_Clause (N : Node_Id) is
   begin
      if Warn_On_Obsolescent_Feature then
         Error_Msg_N
           ("at clause is an obsolescent feature ('R'M 'J.7(2))?", N);
         Error_Msg_N
           ("|use address attribute definition clause instead?", N);
      end if;

      Rewrite (N,
        Make_Attribute_Definition_Clause (Sloc (N),
          Name  => Identifier (N),
          Chars => Name_Address,
          Expression => Expression (N)));
      Analyze_Attribute_Definition_Clause (N);
   end Analyze_At_Clause;

   -----------------------------------------
   -- Analyze_Attribute_Definition_Clause --
   -----------------------------------------

   procedure Analyze_Attribute_Definition_Clause (N : Node_Id) is
      Loc   : constant Source_Ptr   := Sloc (N);
      Nam   : constant Node_Id      := Name (N);
      Attr  : constant Name_Id      := Chars (N);
      Expr  : constant Node_Id      := Expression (N);
      Id    : constant Attribute_Id := Get_Attribute_Id (Attr);
      Ent   : Entity_Id;
      U_Ent : Entity_Id;

      FOnly : Boolean := False;
      --  Reset to True for subtype specific attribute (Alignment, Size)
      --  and for stream attributes, i.e. those cases where in the call
      --  to Rep_Item_Too_Late, FOnly is set True so that only the freezing
      --  rules are checked. Note that the case of stream attributes is not
      --  clear from the RM, but see AI95-00137. Also, the RM seems to
      --  disallow Storage_Size for derived task types, but that is also
      --  clearly unintentional.

   begin
      Analyze (Nam);
      Ent := Entity (Nam);

      if Rep_Item_Too_Early (Ent, N) then
         return;
      end if;

      --  Rep clause applies to full view of incomplete type or private type
      --  if we have one (if not, this is a premature use of the type).
      --  However, certain semantic checks need to be done on the specified
      --  entity (i.e. the private view), so we save it in Ent.

      if Is_Private_Type (Ent)
        and then Is_Derived_Type (Ent)
        and then not Is_Tagged_Type (Ent)
        and then No (Full_View (Ent))
      then
         --  If this is a private type whose completion is a derivation
         --  from another private type, there is no full view, and the
         --  attribute belongs to the type itself, not its underlying parent.

         U_Ent := Ent;

      elsif Ekind (Ent) = E_Incomplete_Type then

         --  The attribute applies to the full view, set the entity
         --  of the attribute definition accordingly.

         Ent := Underlying_Type (Ent);
         U_Ent := Ent;
         Set_Entity (Nam, Ent);

      else
         U_Ent := Underlying_Type (Ent);
      end if;

      --  Complete other routine error checks

      if Etype (Nam) = Any_Type then
         return;

      elsif Scope (Ent) /= Current_Scope then
         Error_Msg_N ("entity must be declared in this scope", Nam);
         return;

      elsif No (U_Ent) then
         U_Ent := Ent;

      elsif Is_Type (U_Ent)
        and then not Is_First_Subtype (U_Ent)
        and then Id /= Attribute_Object_Size
        and then Id /= Attribute_Value_Size
        and then not From_At_Mod (N)
      then
         Error_Msg_N ("cannot specify attribute for subtype", Nam);
         return;

      end if;

      --  Switch on particular attribute

      case Id is

         -------------
         -- Address --
         -------------

         --  Address attribute definition clause

         when Attribute_Address => Address : begin
            Analyze_And_Resolve (Expr, RTE (RE_Address));

            if Present (Address_Clause (U_Ent)) then
               Error_Msg_N ("address already given for &", Nam);

            --  Case of address clause for subprogram

            elsif Is_Subprogram (U_Ent) then
               if Has_Homonym (U_Ent) then
                  Error_Msg_N
                    ("address clause cannot be given " &
                     "for overloaded subprogram",
                     Nam);
               end if;

               --  For subprograms, all address clauses are permitted,
               --  and we mark the subprogram as having a deferred freeze
               --  so that Gigi will not elaborate it too soon.

               --  Above needs more comments, what is too soon about???

               Set_Has_Delayed_Freeze (U_Ent);

            --  Case of address clause for entry

            elsif Ekind (U_Ent) = E_Entry then
               if Nkind (Parent (N)) = N_Task_Body then
                  Error_Msg_N
                    ("entry address must be specified in task spec", Nam);
               end if;

               --  For entries, we require a constant address

               Check_Constant_Address_Clause (Expr, U_Ent);

               if Is_Task_Type (Scope (U_Ent))
                 and then Comes_From_Source (Scope (U_Ent))
               then
                  Error_Msg_N
                    ("?entry address declared for entry in task type", N);
                  Error_Msg_N
                    ("\?only one task can be declared of this type", N);
               end if;

               if Warn_On_Obsolescent_Feature then
                  Error_Msg_N
                    ("attaching interrupt to task entry is an " &
                     "obsolescent feature ('R'M 'J.7.1)?", N);
                  Error_Msg_N
                    ("|use interrupt procedure instead?", N);
               end if;

            --  Case of an address clause for a controlled object:
            --  erroneous execution.

            elsif Is_Controlled (Etype (U_Ent)) then
               Error_Msg_NE
                 ("?controlled object& must not be overlaid", Nam, U_Ent);
               Error_Msg_N
                 ("\?Program_Error will be raised at run time", Nam);
               Insert_Action (Declaration_Node (U_Ent),
                 Make_Raise_Program_Error (Loc,
                   Reason => PE_Overlaid_Controlled_Object));

            --  Case of address clause for a (non-controlled) object

            elsif
              Ekind (U_Ent) = E_Variable
                or else
              Ekind (U_Ent) = E_Constant
            then
               declare
                  Expr : constant Node_Id   := Expression (N);
                  Aent : constant Entity_Id := Address_Aliased_Entity (Expr);

               begin
                  --  Exported variables cannot have an address clause,
                  --  because this cancels the effect of the pragma Export

                  if Is_Exported (U_Ent) then
                     Error_Msg_N
                       ("cannot export object with address clause", Nam);

                  --  Overlaying controlled objects is erroneous

                  elsif Present (Aent)
                    and then Is_Controlled (Etype (Aent))
                  then
                     Error_Msg_N
                       ("?controlled object must not be overlaid", Expr);
                     Error_Msg_N
                       ("\?Program_Error will be raised at run time", Expr);
                     Insert_Action (Declaration_Node (U_Ent),
                       Make_Raise_Program_Error (Loc,
                         Reason => PE_Overlaid_Controlled_Object));

                  elsif Present (Aent)
                    and then Ekind (U_Ent) = E_Constant
                    and then Ekind (Aent) /= E_Constant
                  then
                     Error_Msg_N ("constant overlays a variable?", Expr);

                  elsif Present (Renamed_Object (U_Ent)) then
                     Error_Msg_N
                       ("address clause not allowed"
                          & " for a renaming declaration ('R'M 13.1(6))", Nam);

                  --  Imported variables can have an address clause, but then
                  --  the import is pretty meaningless except to suppress
                  --  initializations, so we do not need such variables to
                  --  be statically allocated (and in fact it causes trouble
                  --  if the address clause is a local value).

                  elsif Is_Imported (U_Ent) then
                     Set_Is_Statically_Allocated (U_Ent, False);
                  end if;

                  --  We mark a possible modification of a variable with an
                  --  address clause, since it is likely aliasing is occurring.

                  Note_Possible_Modification (Nam);

                  --  Here we are checking for explicit overlap of one
                  --  variable by another, and if we find this, then we
                  --  mark the overlapped variable as also being aliased.

                  --  First case is where we have an explicit

                  --    for J'Address use K'Address;

                  --  In this case, we mark K as volatile

                  Mark_Aliased_Address_As_Volatile (Expr);

                  --  Second case is where we have a constant whose
                  --  definition is of the form of an adress as in:

                  --     A : constant Address := K'Address;
                  --     ...
                  --     for B'Address use A;

                  --  In this case we also mark K as volatile

                  if Is_Entity_Name (Expr) then
                     declare
                        Ent  : constant Entity_Id := Entity (Expr);
                        Decl : constant Node_Id   := Declaration_Node (Ent);

                     begin
                        if Ekind (Ent) = E_Constant
                          and then Nkind (Decl) = N_Object_Declaration
                          and then Present (Expression (Decl))
                        then
                           Mark_Aliased_Address_As_Volatile
                             (Expression (Decl));
                        end if;
                     end;
                  end if;

                  --  Legality checks on the address clause for initialized
                  --  objects is deferred until the freeze point, because
                  --  a subsequent pragma might indicate that the object is
                  --  imported and thus not initialized.

                  Set_Has_Delayed_Freeze (U_Ent);

                  if Is_Exported (U_Ent) then
                     Error_Msg_N
                       ("& cannot be exported if an address clause is given",
                        Nam);
                     Error_Msg_N
                       ("\define and export a variable " &
                        "that holds its address instead",
                        Nam);
                  end if;

                  --  Entity has delayed freeze, so we will generate
                  --  an alignment check at the freeze point.

                  Set_Check_Address_Alignment
                    (N, not Range_Checks_Suppressed (U_Ent));

                  --  Kill the size check code, since we are not allocating
                  --  the variable, it is somewhere else.

                  Kill_Size_Check_Code (U_Ent);
               end;

            --  Not a valid entity for an address clause

            else
               Error_Msg_N ("address cannot be given for &", Nam);
            end if;
         end Address;

         ---------------
         -- Alignment --
         ---------------

         --  Alignment attribute definition clause

         when Attribute_Alignment => Alignment_Block : declare
            Align : constant Uint := Get_Alignment_Value (Expr);

         begin
            FOnly := True;

            if not Is_Type (U_Ent)
              and then Ekind (U_Ent) /= E_Variable
              and then Ekind (U_Ent) /= E_Constant
            then
               Error_Msg_N ("alignment cannot be given for &", Nam);

            elsif Has_Alignment_Clause (U_Ent) then
               Error_Msg_Sloc := Sloc (Alignment_Clause (U_Ent));
               Error_Msg_N ("alignment clause previously given#", N);

            elsif Align /= No_Uint then
               Set_Has_Alignment_Clause (U_Ent);
               Set_Alignment            (U_Ent, Align);
            end if;
         end Alignment_Block;

         ---------------
         -- Bit_Order --
         ---------------

         --  Bit_Order attribute definition clause

         when Attribute_Bit_Order => Bit_Order : declare
         begin
            if not Is_Record_Type (U_Ent) then
               Error_Msg_N
                 ("Bit_Order can only be defined for record type", Nam);

            else
               Analyze_And_Resolve (Expr, RTE (RE_Bit_Order));

               if Etype (Expr) = Any_Type then
                  return;

               elsif not Is_Static_Expression (Expr) then
                  Flag_Non_Static_Expr
                    ("Bit_Order requires static expression!", Expr);

               else
                  if (Expr_Value (Expr) = 0) /= Bytes_Big_Endian then
                     Set_Reverse_Bit_Order (U_Ent, True);
                  end if;
               end if;
            end if;
         end Bit_Order;

         --------------------
         -- Component_Size --
         --------------------

         --  Component_Size attribute definition clause

         when Attribute_Component_Size => Component_Size_Case : declare
            Csize    : constant Uint := Static_Integer (Expr);
            Btype    : Entity_Id;
            Biased   : Boolean;
            New_Ctyp : Entity_Id;
            Decl     : Node_Id;

         begin
            if not Is_Array_Type (U_Ent) then
               Error_Msg_N ("component size requires array type", Nam);
               return;
            end if;

            Btype := Base_Type (U_Ent);

            if Has_Component_Size_Clause (Btype) then
               Error_Msg_N
                 ("component size clase for& previously given", Nam);

            elsif Csize /= No_Uint then
               Check_Size (Expr, Component_Type (Btype), Csize, Biased);

               if Has_Aliased_Components (Btype)
                 and then Csize < 32
                 and then Csize /= 8
                 and then Csize /= 16
               then
                  Error_Msg_N
                    ("component size incorrect for aliased components", N);
                  return;
               end if;

               --  For the biased case, build a declaration for a subtype
               --  that will be used to represent the biased subtype that
               --  reflects the biased representation of components. We need
               --  this subtype to get proper conversions on referencing
               --  elements of the array.

               if Biased then
                  New_Ctyp :=
                    Make_Defining_Identifier (Loc,
                      Chars => New_External_Name (Chars (U_Ent), 'C', 0, 'T'));

                  Decl :=
                    Make_Subtype_Declaration (Loc,
                      Defining_Identifier => New_Ctyp,
                      Subtype_Indication  =>
                        New_Occurrence_Of (Component_Type (Btype), Loc));

                  Set_Parent (Decl, N);
                  Analyze (Decl, Suppress => All_Checks);

                  Set_Has_Delayed_Freeze        (New_Ctyp, False);
                  Set_Esize                     (New_Ctyp, Csize);
                  Set_RM_Size                   (New_Ctyp, Csize);
                  Init_Alignment                (New_Ctyp);
                  Set_Has_Biased_Representation (New_Ctyp, True);
                  Set_Is_Itype                  (New_Ctyp, True);
                  Set_Associated_Node_For_Itype (New_Ctyp, U_Ent);

                  Set_Component_Type (Btype, New_Ctyp);
               end if;

               Set_Component_Size            (Btype, Csize);
               Set_Has_Component_Size_Clause (Btype, True);
               Set_Has_Non_Standard_Rep      (Btype, True);
            end if;
         end Component_Size_Case;

         ------------------
         -- External_Tag --
         ------------------

         when Attribute_External_Tag => External_Tag :
         begin
            if not Is_Tagged_Type (U_Ent) then
               Error_Msg_N ("should be a tagged type", Nam);
            end if;

            Analyze_And_Resolve (Expr, Standard_String);

            if not Is_Static_Expression (Expr) then
               Flag_Non_Static_Expr
                 ("static string required for tag name!", Nam);
            end if;

            Set_Has_External_Tag_Rep_Clause (U_Ent);
         end External_Tag;

         -----------
         -- Input --
         -----------

         when Attribute_Input => Input : declare
            Subp : Entity_Id := Empty;
            I    : Interp_Index;
            It   : Interp;
            Pnam : Entity_Id;

            function Has_Good_Profile (Subp : Entity_Id) return Boolean;
            --  Return true if the entity is a function with an appropriate
            --  profile for the Input attribute.

            ----------------------
            -- Has_Good_Profile --
            ----------------------

            function Has_Good_Profile (Subp : Entity_Id) return Boolean is
               F  : Entity_Id;
               Ok : Boolean := False;

            begin
               if Ekind (Subp) = E_Function then
                  F := First_Formal (Subp);

                  if Present (F) and then No (Next_Formal (F)) then
                     if Ekind (Etype (F)) = E_Anonymous_Access_Type
                       and then
                         Designated_Type (Etype (F)) =
                           Class_Wide_Type (RTE (RE_Root_Stream_Type))
                     then
                        Ok := Base_Type (Etype (Subp)) = Base_Type (Ent);
                     end if;
                  end if;
               end if;

               return Ok;
            end Has_Good_Profile;

         --  Start of processing for Input attribute definition

         begin
            FOnly := True;

            if not Is_Type (U_Ent) then
               Error_Msg_N ("local name must be a subtype", Nam);
               return;

            else
               Pnam := TSS (Base_Type (U_Ent), TSS_Stream_Input);

               if Present (Pnam)
                 and then Base_Type (Etype (Pnam)) = Base_Type (U_Ent)
               then
                  Error_Msg_Sloc := Sloc (Pnam);
                  Error_Msg_N ("input attribute already defined #", Nam);
                  return;
               end if;
            end if;

            Analyze (Expr);

            if Is_Entity_Name (Expr) then
               if not Is_Overloaded (Expr) then
                  if Has_Good_Profile (Entity (Expr)) then
                     Subp := Entity (Expr);
                  end if;

               else
                  Get_First_Interp (Expr, I, It);

                  while Present (It.Nam) loop
                     if Has_Good_Profile (It.Nam) then
                        Subp := It.Nam;
                        exit;
                     end if;

                     Get_Next_Interp (I, It);
                  end loop;
               end if;
            end if;

            if Present (Subp) then
               Set_Entity (Expr, Subp);
               Set_Etype (Expr, Etype (Subp));
               New_Stream_Function (N, U_Ent, Subp,  TSS_Stream_Input);
            else
               Error_Msg_N ("incorrect expression for input attribute", Expr);
               return;
            end if;
         end Input;

         -------------------
         -- Machine_Radix --
         -------------------

         --  Machine radix attribute definition clause

         when Attribute_Machine_Radix => Machine_Radix : declare
            Radix : constant Uint := Static_Integer (Expr);

         begin
            if not Is_Decimal_Fixed_Point_Type (U_Ent) then
               Error_Msg_N ("decimal fixed-point type expected for &", Nam);

            elsif Has_Machine_Radix_Clause (U_Ent) then
               Error_Msg_Sloc := Sloc (Alignment_Clause (U_Ent));
               Error_Msg_N ("machine radix clause previously given#", N);

            elsif Radix /= No_Uint then
               Set_Has_Machine_Radix_Clause (U_Ent);
               Set_Has_Non_Standard_Rep (Base_Type (U_Ent));

               if Radix = 2 then
                  null;
               elsif Radix = 10 then
                  Set_Machine_Radix_10 (U_Ent);
               else
                  Error_Msg_N ("machine radix value must be 2 or 10", Expr);
               end if;
            end if;
         end Machine_Radix;

         -----------------
         -- Object_Size --
         -----------------

         --  Object_Size attribute definition clause

         when Attribute_Object_Size => Object_Size : declare
            Size   : constant Uint := Static_Integer (Expr);
            Biased : Boolean;

         begin
            if not Is_Type (U_Ent) then
               Error_Msg_N ("Object_Size cannot be given for &", Nam);

            elsif Has_Object_Size_Clause (U_Ent) then
               Error_Msg_N ("Object_Size already given for &", Nam);

            else
               Check_Size (Expr, U_Ent, Size, Biased);

               if Size /= 8
                    and then
                  Size /= 16
                    and then
                  Size /= 32
                    and then
                  UI_Mod (Size, 64) /= 0
               then
                  Error_Msg_N
                    ("Object_Size must be 8, 16, 32, or multiple of 64",
                     Expr);
               end if;

               Set_Esize (U_Ent, Size);
               Set_Has_Object_Size_Clause (U_Ent);
               Alignment_Check_For_Esize_Change (U_Ent);
            end if;
         end Object_Size;

         ------------
         -- Output --
         ------------

         when Attribute_Output => Output : declare
            Subp : Entity_Id := Empty;
            I    : Interp_Index;
            It   : Interp;
            Pnam : Entity_Id;

            function Has_Good_Profile (Subp : Entity_Id) return Boolean;
            --  Return true if the entity is a procedure with an
            --  appropriate profile for the output attribute.

            ----------------------
            -- Has_Good_Profile --
            ----------------------

            function Has_Good_Profile (Subp : Entity_Id) return Boolean is
               F  : Entity_Id;
               Ok : Boolean := False;

            begin
               if Ekind (Subp) = E_Procedure then
                  F := First_Formal (Subp);

                  if Present (F) then
                     if Ekind (Etype (F)) = E_Anonymous_Access_Type
                       and then
                         Designated_Type (Etype (F)) =
                           Class_Wide_Type (RTE (RE_Root_Stream_Type))
                     then
                        Next_Formal (F);
                        Ok :=  Present (F)
                          and then Parameter_Mode (F) = E_In_Parameter
                          and then Base_Type (Etype (F)) = Base_Type (Ent)
                          and then No (Next_Formal (F));
                     end if;
                  end if;
               end if;

               return Ok;
            end Has_Good_Profile;

         --  Start of processing for Output attribute definition

         begin
            FOnly := True;

            if not Is_Type (U_Ent) then
               Error_Msg_N ("local name must be a subtype", Nam);
               return;

            else
               Pnam := TSS (Base_Type (U_Ent), TSS_Stream_Output);

               if Present (Pnam)
                 and then
                   Base_Type (Etype (Next_Formal (First_Formal (Pnam))))
                                                        = Base_Type (U_Ent)
               then
                  Error_Msg_Sloc := Sloc (Pnam);
                  Error_Msg_N ("output attribute already defined #", Nam);
                  return;
               end if;
            end if;

            Analyze (Expr);

            if Is_Entity_Name (Expr) then
               if not Is_Overloaded (Expr) then
                  if Has_Good_Profile (Entity (Expr)) then
                     Subp := Entity (Expr);
                  end if;

               else
                  Get_First_Interp (Expr, I, It);

                  while Present (It.Nam) loop
                     if Has_Good_Profile (It.Nam) then
                        Subp := It.Nam;
                        exit;
                     end if;

                     Get_Next_Interp (I, It);
                  end loop;
               end if;
            end if;

            if Present (Subp) then
               Set_Entity (Expr, Subp);
               Set_Etype (Expr, Etype (Subp));
               New_Stream_Procedure (N, U_Ent, Subp, TSS_Stream_Output);
            else
               Error_Msg_N ("incorrect expression for output attribute", Expr);
               return;
            end if;
         end Output;

         ----------
         -- Read --
         ----------

         when Attribute_Read => Read : declare
            Subp : Entity_Id := Empty;
            I    : Interp_Index;
            It   : Interp;
            Pnam : Entity_Id;

            function Has_Good_Profile (Subp : Entity_Id) return Boolean;
            --  Return true if the entity is a procedure with an appropriate
            --  profile for the Read attribute.

            ----------------------
            -- Has_Good_Profile --
            ----------------------

            function Has_Good_Profile (Subp : Entity_Id) return Boolean is
               F     : Entity_Id;
               Ok    : Boolean := False;

            begin
               if Ekind (Subp) = E_Procedure then
                  F := First_Formal (Subp);

                  if Present (F) then
                     if Ekind (Etype (F)) = E_Anonymous_Access_Type
                       and then
                         Designated_Type (Etype (F)) =
                           Class_Wide_Type (RTE (RE_Root_Stream_Type))
                     then
                        Next_Formal (F);
                        Ok :=  Present (F)
                          and then Parameter_Mode (F) = E_Out_Parameter
                          and then Base_Type (Etype (F)) = Base_Type (Ent)
                          and then No (Next_Formal (F));
                     end if;
                  end if;
               end if;

               return Ok;
            end Has_Good_Profile;

         --  Start of processing for Read attribute definition

         begin
            FOnly := True;

            if not Is_Type (U_Ent) then
               Error_Msg_N ("local name must be a subtype", Nam);
               return;

            else
               Pnam := TSS (Base_Type (U_Ent), TSS_Stream_Read);

               if Present (Pnam)
                 and then Base_Type (Etype (Next_Formal (First_Formal (Pnam))))
                   = Base_Type (U_Ent)
               then
                  Error_Msg_Sloc := Sloc (Pnam);
                  Error_Msg_N ("read attribute already defined #", Nam);
                  return;
               end if;
            end if;

            Analyze (Expr);

            if Is_Entity_Name (Expr) then
               if not Is_Overloaded (Expr) then
                  if Has_Good_Profile (Entity (Expr)) then
                     Subp := Entity (Expr);
                  end if;

               else
                  Get_First_Interp (Expr, I, It);

                  while Present (It.Nam) loop
                     if Has_Good_Profile (It.Nam) then
                        Subp := It.Nam;
                        exit;
                     end if;

                     Get_Next_Interp (I, It);
                  end loop;
               end if;
            end if;

            if Present (Subp) then
               Set_Entity (Expr, Subp);
               Set_Etype (Expr, Etype (Subp));
               New_Stream_Procedure (N, U_Ent, Subp, TSS_Stream_Read, True);
            else
               Error_Msg_N ("incorrect expression for read attribute", Expr);
               return;
            end if;
         end Read;

         ----------
         -- Size --
         ----------

         --  Size attribute definition clause

         when Attribute_Size => Size : declare
            Size   : constant Uint := Static_Integer (Expr);
            Etyp   : Entity_Id;
            Biased : Boolean;

         begin
            FOnly := True;

            if Has_Size_Clause (U_Ent) then
               Error_Msg_N ("size already given for &", Nam);

            elsif not Is_Type (U_Ent)
              and then Ekind (U_Ent) /= E_Variable
              and then Ekind (U_Ent) /= E_Constant
            then
               Error_Msg_N ("size cannot be given for &", Nam);

            elsif Is_Array_Type (U_Ent)
              and then not Is_Constrained (U_Ent)
            then
               Error_Msg_N
                 ("size cannot be given for unconstrained array", Nam);

            elsif Size /= No_Uint then
               if Is_Type (U_Ent) then
                  Etyp := U_Ent;
               else
                  Etyp := Etype (U_Ent);
               end if;

               --  Check size, note that Gigi is in charge of checking
               --  that the size of an array or record type is OK. Also
               --  we do not check the size in the ordinary fixed-point
               --  case, since it is too early to do so (there may be a
               --  subsequent small clause that affects the size). We can
               --  check the size if a small clause has already been given.

               if not Is_Ordinary_Fixed_Point_Type (U_Ent)
                 or else Has_Small_Clause (U_Ent)
               then
                  Check_Size (Expr, Etyp, Size, Biased);
                  Set_Has_Biased_Representation (U_Ent, Biased);
               end if;

               --  For types set RM_Size and Esize if possible

               if Is_Type (U_Ent) then
                  Set_RM_Size (U_Ent, Size);

                  --  For scalar types, increase Object_Size to power of 2,
                  --  but not less than a storage unit in any case (i.e.,
                  --  normally this means it will be byte addressable).

                  if Is_Scalar_Type (U_Ent) then
                     if Size <= System_Storage_Unit then
                        Init_Esize (U_Ent, System_Storage_Unit);
                     elsif Size <= 16 then
                        Init_Esize (U_Ent, 16);
                     elsif Size <= 32 then
                        Init_Esize (U_Ent, 32);
                     else
                        Set_Esize  (U_Ent, (Size + 63) / 64 * 64);
                     end if;

                  --  For all other types, object size = value size. The
                  --  backend will adjust as needed.

                  else
                     Set_Esize (U_Ent, Size);
                  end if;

                  Alignment_Check_For_Esize_Change (U_Ent);

               --  For objects, set Esize only

               else
                  if Is_Elementary_Type (Etyp) then
                     if Size /= System_Storage_Unit
                          and then
                        Size /= System_Storage_Unit * 2
                          and then
                        Size /= System_Storage_Unit * 4
                           and then
                        Size /= System_Storage_Unit * 8
                     then
                        Error_Msg_N
                          ("size for primitive object must be power of 2", N);
                     end if;
                  end if;

                  Set_Esize (U_Ent, Size);
               end if;

               Set_Has_Size_Clause (U_Ent);
            end if;
         end Size;

         -----------
         -- Small --
         -----------

         --  Small attribute definition clause

         when Attribute_Small => Small : declare
            Implicit_Base : constant Entity_Id := Base_Type (U_Ent);
            Small         : Ureal;

         begin
            Analyze_And_Resolve (Expr, Any_Real);

            if Etype (Expr) = Any_Type then
               return;

            elsif not Is_Static_Expression (Expr) then
               Flag_Non_Static_Expr
                 ("small requires static expression!", Expr);
               return;

            else
               Small := Expr_Value_R (Expr);

               if Small <= Ureal_0 then
                  Error_Msg_N ("small value must be greater than zero", Expr);
                  return;
               end if;

            end if;

            if not Is_Ordinary_Fixed_Point_Type (U_Ent) then
               Error_Msg_N
                 ("small requires an ordinary fixed point type", Nam);

            elsif Has_Small_Clause (U_Ent) then
               Error_Msg_N ("small already given for &", Nam);

            elsif Small > Delta_Value (U_Ent) then
               Error_Msg_N
                 ("small value must not be greater then delta value", Nam);

            else
               Set_Small_Value (U_Ent, Small);
               Set_Small_Value (Implicit_Base, Small);
               Set_Has_Small_Clause (U_Ent);
               Set_Has_Small_Clause (Implicit_Base);
               Set_Has_Non_Standard_Rep (Implicit_Base);
            end if;
         end Small;

         ------------------
         -- Storage_Size --
         ------------------

         --  Storage_Size attribute definition clause

         when Attribute_Storage_Size => Storage_Size : declare
            Btype : constant Entity_Id := Base_Type (U_Ent);
            Sprag : Node_Id;

         begin
            if Is_Task_Type (U_Ent) then
               if Warn_On_Obsolescent_Feature then
                  Error_Msg_N
                    ("storage size clause for task is an " &
                     "obsolescent feature ('R'M 'J.9)?", N);
                  Error_Msg_N
                    ("|use Storage_Size pragma instead?", N);
               end if;

               FOnly := True;
            end if;

            if not Is_Access_Type (U_Ent)
              and then Ekind (U_Ent) /= E_Task_Type
            then
               Error_Msg_N ("storage size cannot be given for &", Nam);

            elsif Is_Access_Type (U_Ent) and Is_Derived_Type (U_Ent) then
               Error_Msg_N
                 ("storage size cannot be given for a derived access type",
                  Nam);

            elsif Has_Storage_Size_Clause (Btype) then
               Error_Msg_N ("storage size already given for &", Nam);

            else
               Analyze_And_Resolve (Expr, Any_Integer);

               if Is_Access_Type (U_Ent) then

                  if Present (Associated_Storage_Pool (U_Ent)) then
                     Error_Msg_N ("storage pool already given for &", Nam);
                     return;
                  end if;

                  if Compile_Time_Known_Value (Expr)
                    and then Expr_Value (Expr) = 0
                  then
                     Set_No_Pool_Assigned (Btype);
                  end if;

               else -- Is_Task_Type (U_Ent)
                  Sprag := Get_Rep_Pragma (Btype, Name_Storage_Size);

                  if Present (Sprag) then
                     Error_Msg_Sloc := Sloc (Sprag);
                     Error_Msg_N
                       ("Storage_Size already specified#", Nam);
                     return;
                  end if;
               end if;

               Set_Has_Storage_Size_Clause (Btype);
            end if;
         end Storage_Size;

         ------------------
         -- Storage_Pool --
         ------------------

         --  Storage_Pool attribute definition clause

         when Attribute_Storage_Pool => Storage_Pool : declare
            Pool : Entity_Id;

         begin
            if Ekind (U_Ent) /= E_Access_Type
              and then Ekind (U_Ent) /= E_General_Access_Type
            then
               Error_Msg_N (
                 "storage pool can only be given for access types", Nam);
               return;

            elsif Is_Derived_Type (U_Ent) then
               Error_Msg_N
                 ("storage pool cannot be given for a derived access type",
                  Nam);

            elsif Has_Storage_Size_Clause (U_Ent) then
               Error_Msg_N ("storage size already given for &", Nam);
               return;

            elsif Present (Associated_Storage_Pool (U_Ent)) then
               Error_Msg_N ("storage pool already given for &", Nam);
               return;
            end if;

            Analyze_And_Resolve
              (Expr, Class_Wide_Type (RTE (RE_Root_Storage_Pool)));

            --  If the argument is a name that is not an entity name, then
            --  we construct a renaming operation to define an entity of
            --  type storage pool.

            if not Is_Entity_Name (Expr)
              and then Is_Object_Reference (Expr)
            then
               Pool :=
                 Make_Defining_Identifier (Loc,
                   Chars => New_Internal_Name ('P'));

               declare
                  Rnode : constant Node_Id :=
                            Make_Object_Renaming_Declaration (Loc,
                              Defining_Identifier => Pool,
                              Subtype_Mark        =>
                                New_Occurrence_Of (Etype (Expr), Loc),
                              Name => Expr);

               begin
                  Insert_Before (N, Rnode);
                  Analyze (Rnode);
                  Set_Associated_Storage_Pool (U_Ent, Pool);
               end;

            elsif Is_Entity_Name (Expr) then
               Pool := Entity (Expr);

               --  If pool is a renamed object, get original one. This can
               --  happen with an explicit renaming, and within instances.

               while Present (Renamed_Object (Pool))
                 and then Is_Entity_Name (Renamed_Object (Pool))
               loop
                  Pool := Entity (Renamed_Object (Pool));
               end loop;

               if Present (Renamed_Object (Pool))
                 and then Nkind (Renamed_Object (Pool)) = N_Type_Conversion
                 and then Is_Entity_Name (Expression (Renamed_Object (Pool)))
               then
                  Pool := Entity (Expression (Renamed_Object (Pool)));
               end if;

               if Present (Etype (Pool))
                 and then Etype (Pool) /= RTE (RE_Stack_Bounded_Pool)
                 and then Etype (Pool) /= RTE (RE_Unbounded_Reclaim_Pool)
               then
                  Set_Associated_Storage_Pool (U_Ent, Pool);
               else
                  Error_Msg_N ("Non sharable GNAT Pool", Expr);
               end if;

            --  The pool may be specified as the Storage_Pool of some other
            --  type. It is rewritten as a class_wide conversion of the
            --  corresponding pool entity.

            elsif Nkind (Expr) = N_Type_Conversion
              and then Is_Entity_Name (Expression (Expr))
              and then Nkind (Original_Node (Expr)) = N_Attribute_Reference
            then
               Pool := Entity (Expression (Expr));

               if Present (Etype (Pool))
                 and then Etype (Pool) /= RTE (RE_Stack_Bounded_Pool)
                 and then Etype (Pool) /= RTE (RE_Unbounded_Reclaim_Pool)
               then
                  Set_Associated_Storage_Pool (U_Ent, Pool);
               else
                  Error_Msg_N ("Non sharable GNAT Pool", Expr);
               end if;

            else
               Error_Msg_N ("incorrect reference to a Storage Pool", Expr);
               return;
            end if;
         end Storage_Pool;

         ----------------
         -- Value_Size --
         ----------------

         --  Value_Size attribute definition clause

         when Attribute_Value_Size => Value_Size : declare
            Size   : constant Uint := Static_Integer (Expr);
            Biased : Boolean;

         begin
            if not Is_Type (U_Ent) then
               Error_Msg_N ("Value_Size cannot be given for &", Nam);

            elsif Present
                   (Get_Attribute_Definition_Clause
                     (U_Ent, Attribute_Value_Size))
            then
               Error_Msg_N ("Value_Size already given for &", Nam);

            else
               if Is_Elementary_Type (U_Ent) then
                  Check_Size (Expr, U_Ent, Size, Biased);
                  Set_Has_Biased_Representation (U_Ent, Biased);
               end if;

               Set_RM_Size (U_Ent, Size);
            end if;
         end Value_Size;

         -----------
         -- Write --
         -----------

         --  Write attribute definition clause
         --  check for class-wide case will be performed later

         when Attribute_Write => Write : declare
            Subp : Entity_Id := Empty;
            I    : Interp_Index;
            It   : Interp;
            Pnam : Entity_Id;

            function Has_Good_Profile (Subp : Entity_Id) return Boolean;
            --  Return true if the entity is a procedure with an
            --  appropriate profile for the write attribute.

            ----------------------
            -- Has_Good_Profile --
            ----------------------

            function Has_Good_Profile (Subp : Entity_Id) return Boolean is
               F     : Entity_Id;
               Ok    : Boolean := False;

            begin
               if Ekind (Subp) = E_Procedure then
                  F := First_Formal (Subp);

                  if Present (F) then
                     if Ekind (Etype (F)) = E_Anonymous_Access_Type
                       and then
                         Designated_Type (Etype (F)) =
                           Class_Wide_Type (RTE (RE_Root_Stream_Type))
                     then
                        Next_Formal (F);
                        Ok :=  Present (F)
                          and then Parameter_Mode (F) = E_In_Parameter
                          and then Base_Type (Etype (F)) = Base_Type (Ent)
                          and then No (Next_Formal (F));
                     end if;
                  end if;
               end if;

               return Ok;
            end Has_Good_Profile;

         --  Start of processing for Write attribute definition

         begin
            FOnly := True;

            if not Is_Type (U_Ent) then
               Error_Msg_N ("local name must be a subtype", Nam);
               return;
            end if;

            Pnam := TSS (Base_Type (U_Ent), TSS_Stream_Write);

            if Present (Pnam)
              and then Base_Type (Etype (Next_Formal (First_Formal (Pnam))))
                = Base_Type (U_Ent)
            then
               Error_Msg_Sloc := Sloc (Pnam);
               Error_Msg_N ("write attribute already defined #", Nam);
               return;
            end if;

            Analyze (Expr);

            if Is_Entity_Name (Expr) then
               if not Is_Overloaded (Expr) then
                  if Has_Good_Profile (Entity (Expr)) then
                     Subp := Entity (Expr);
                  end if;

               else
                  Get_First_Interp (Expr, I, It);

                  while Present (It.Nam) loop
                     if Has_Good_Profile (It.Nam) then
                        Subp := It.Nam;
                        exit;
                     end if;

                     Get_Next_Interp (I, It);
                  end loop;
               end if;
            end if;

            if Present (Subp) then
               Set_Entity (Expr, Subp);
               Set_Etype (Expr, Etype (Subp));
               New_Stream_Procedure (N, U_Ent, Subp, TSS_Stream_Write);
            else
               Error_Msg_N ("incorrect expression for write attribute", Expr);
               return;
            end if;
         end Write;

         --  All other attributes cannot be set

         when others =>
            Error_Msg_N
              ("attribute& cannot be set with definition clause", N);

      end case;

      --  The test for the type being frozen must be performed after
      --  any expression the clause has been analyzed since the expression
      --  itself might cause freezing that makes the clause illegal.

      if Rep_Item_Too_Late (U_Ent, N, FOnly) then
         return;
      end if;
   end Analyze_Attribute_Definition_Clause;

   ----------------------------
   -- Analyze_Code_Statement --
   ----------------------------

   procedure Analyze_Code_Statement (N : Node_Id) is
      HSS   : constant Node_Id   := Parent (N);
      SBody : constant Node_Id   := Parent (HSS);
      Subp  : constant Entity_Id := Current_Scope;
      Stmt  : Node_Id;
      Decl  : Node_Id;
      StmtO : Node_Id;
      DeclO : Node_Id;

   begin
      --  Analyze and check we get right type, note that this implements the
      --  requirement (RM 13.8(1)) that Machine_Code be with'ed, since that
      --  is the only way that Asm_Insn could possibly be visible.

      Analyze_And_Resolve (Expression (N));

      if Etype (Expression (N)) = Any_Type then
         return;
      elsif Etype (Expression (N)) /= RTE (RE_Asm_Insn) then
         Error_Msg_N ("incorrect type for code statement", N);
         return;
      end if;

      --  Make sure we appear in the handled statement sequence of a
      --  subprogram (RM 13.8(3)).

      if Nkind (HSS) /= N_Handled_Sequence_Of_Statements
        or else Nkind (SBody) /= N_Subprogram_Body
      then
         Error_Msg_N
           ("code statement can only appear in body of subprogram", N);
         return;
      end if;

      --  Do remaining checks (RM 13.8(3)) if not already done

      if not Is_Machine_Code_Subprogram (Subp) then
         Set_Is_Machine_Code_Subprogram (Subp);

         --  No exception handlers allowed

         if Present (Exception_Handlers (HSS)) then
            Error_Msg_N
              ("exception handlers not permitted in machine code subprogram",
               First (Exception_Handlers (HSS)));
         end if;

         --  No declarations other than use clauses and pragmas (we allow
         --  certain internally generated declarations as well).

         Decl := First (Declarations (SBody));
         while Present (Decl) loop
            DeclO := Original_Node (Decl);
            if Comes_From_Source (DeclO)
              and then Nkind (DeclO) /= N_Pragma
              and then Nkind (DeclO) /= N_Use_Package_Clause
              and then Nkind (DeclO) /= N_Use_Type_Clause
              and then Nkind (DeclO) /= N_Implicit_Label_Declaration
            then
               Error_Msg_N
                 ("this declaration not allowed in machine code subprogram",
                  DeclO);
            end if;

            Next (Decl);
         end loop;

         --  No statements other than code statements, pragmas, and labels.
         --  Again we allow certain internally generated statements.

         Stmt := First (Statements (HSS));
         while Present (Stmt) loop
            StmtO := Original_Node (Stmt);
            if Comes_From_Source (StmtO)
              and then Nkind (StmtO) /= N_Pragma
              and then Nkind (StmtO) /= N_Label
              and then Nkind (StmtO) /= N_Code_Statement
            then
               Error_Msg_N
                 ("this statement is not allowed in machine code subprogram",
                  StmtO);
            end if;

            Next (Stmt);
         end loop;
      end if;
   end Analyze_Code_Statement;

   -----------------------------------------------
   -- Analyze_Enumeration_Representation_Clause --
   -----------------------------------------------

   procedure Analyze_Enumeration_Representation_Clause (N : Node_Id) is
      Ident    : constant Node_Id    := Identifier (N);
      Aggr     : constant Node_Id    := Array_Aggregate (N);
      Enumtype : Entity_Id;
      Elit     : Entity_Id;
      Expr     : Node_Id;
      Assoc    : Node_Id;
      Choice   : Node_Id;
      Val      : Uint;
      Err      : Boolean := False;

      Lo  : constant Uint := Expr_Value (Type_Low_Bound (Universal_Integer));
      Hi  : constant Uint := Expr_Value (Type_High_Bound (Universal_Integer));
      Min : Uint;
      Max : Uint;

   begin
      --  First some basic error checks

      Find_Type (Ident);
      Enumtype := Entity (Ident);

      if Enumtype = Any_Type
        or else Rep_Item_Too_Early (Enumtype, N)
      then
         return;
      else
         Enumtype := Underlying_Type (Enumtype);
      end if;

      if not Is_Enumeration_Type (Enumtype) then
         Error_Msg_NE
           ("enumeration type required, found}",
            Ident, First_Subtype (Enumtype));
         return;
      end if;

      --  Ignore rep clause on generic actual type. This will already have
      --  been flagged on the template as an error, and this is the safest
      --  way to ensure we don't get a junk cascaded message in the instance.

      if Is_Generic_Actual_Type (Enumtype) then
         return;

      --  Type must be in current scope

      elsif Scope (Enumtype) /= Current_Scope then
         Error_Msg_N ("type must be declared in this scope", Ident);
         return;

      --  Type must be a first subtype

      elsif not Is_First_Subtype (Enumtype) then
         Error_Msg_N ("cannot give enumeration rep clause for subtype", N);
         return;

      --  Ignore duplicate rep clause

      elsif Has_Enumeration_Rep_Clause (Enumtype) then
         Error_Msg_N ("duplicate enumeration rep clause ignored", N);
         return;

      --  Don't allow rep clause if root type is standard [wide_]character

      elsif Root_Type (Enumtype) = Standard_Character
        or else Root_Type (Enumtype) = Standard_Wide_Character
      then
         Error_Msg_N ("enumeration rep clause not allowed for this type", N);
         return;

      --  All tests passed, so set rep clause in place

      else
         Set_Has_Enumeration_Rep_Clause (Enumtype);
         Set_Has_Enumeration_Rep_Clause (Base_Type (Enumtype));
      end if;

      --  Now we process the aggregate. Note that we don't use the normal
      --  aggregate code for this purpose, because we don't want any of the
      --  normal expansion activities, and a number of special semantic
      --  rules apply (including the component type being any integer type)

      --  Badent signals that we found some incorrect entries processing
      --  the list. The final checks for completeness and ordering are
      --  skipped in this case.

      Elit := First_Literal (Enumtype);

      --  First the positional entries if any

      if Present (Expressions (Aggr)) then
         Expr := First (Expressions (Aggr));
         while Present (Expr) loop
            if No (Elit) then
               Error_Msg_N ("too many entries in aggregate", Expr);
               return;
            end if;

            Val := Static_Integer (Expr);

            if Val = No_Uint then
               Err := True;

            elsif Val < Lo or else Hi < Val then
               Error_Msg_N ("value outside permitted range", Expr);
               Err := True;
            end if;

            Set_Enumeration_Rep (Elit, Val);
            Set_Enumeration_Rep_Expr (Elit, Expr);
            Next (Expr);
            Next (Elit);
         end loop;
      end if;

      --  Now process the named entries if present

      if Present (Component_Associations (Aggr)) then
         Assoc := First (Component_Associations (Aggr));
         while Present (Assoc) loop
            Choice := First (Choices (Assoc));

            if Present (Next (Choice)) then
               Error_Msg_N
                 ("multiple choice not allowed here", Next (Choice));
               Err := True;
            end if;

            if Nkind (Choice) = N_Others_Choice then
               Error_Msg_N ("others choice not allowed here", Choice);
               Err := True;

            elsif Nkind (Choice) = N_Range then
               --  ??? should allow zero/one element range here
               Error_Msg_N ("range not allowed here", Choice);
               Err := True;

            else
               Analyze_And_Resolve (Choice, Enumtype);

               if Is_Entity_Name (Choice)
                 and then Is_Type (Entity (Choice))
               then
                  Error_Msg_N ("subtype name not allowed here", Choice);
                  Err := True;
                  --  ??? should allow static subtype with zero/one entry

               elsif Etype (Choice) = Base_Type (Enumtype) then
                  if not Is_Static_Expression (Choice) then
                     Flag_Non_Static_Expr
                       ("non-static expression used for choice!", Choice);
                     Err := True;

                  else
                     Elit := Expr_Value_E (Choice);

                     if Present (Enumeration_Rep_Expr (Elit)) then
                        Error_Msg_Sloc := Sloc (Enumeration_Rep_Expr (Elit));
                        Error_Msg_NE
                          ("representation for& previously given#",
                           Choice, Elit);
                        Err := True;
                     end if;

                     Set_Enumeration_Rep_Expr (Elit, Choice);

                     Expr := Expression (Assoc);
                     Val := Static_Integer (Expr);

                     if Val = No_Uint then
                        Err := True;

                     elsif Val < Lo or else Hi < Val then
                        Error_Msg_N ("value outside permitted range", Expr);
                        Err := True;
                     end if;

                     Set_Enumeration_Rep (Elit, Val);
                  end if;
               end if;
            end if;

            Next (Assoc);
         end loop;
      end if;

      --  Aggregate is fully processed. Now we check that a full set of
      --  representations was given, and that they are in range and in order.
      --  These checks are only done if no other errors occurred.

      if not Err then
         Min  := No_Uint;
         Max  := No_Uint;

         Elit := First_Literal (Enumtype);
         while Present (Elit) loop
            if No (Enumeration_Rep_Expr (Elit)) then
               Error_Msg_NE ("missing representation for&!", N, Elit);

            else
               Val := Enumeration_Rep (Elit);

               if Min = No_Uint then
                  Min := Val;
               end if;

               if Val /= No_Uint then
                  if Max /= No_Uint and then Val <= Max then
                     Error_Msg_NE
                       ("enumeration value for& not ordered!",
                                       Enumeration_Rep_Expr (Elit), Elit);
                  end if;

                  Max := Val;
               end if;

               --  If there is at least one literal whose representation
               --  is not equal to the Pos value, then note that this
               --  enumeration type has a non-standard representation.

               if Val /= Enumeration_Pos (Elit) then
                  Set_Has_Non_Standard_Rep (Base_Type (Enumtype));
               end if;
            end if;

            Next (Elit);
         end loop;

         --  Now set proper size information

         declare
            Minsize : Uint := UI_From_Int (Minimum_Size (Enumtype));

         begin
            if Has_Size_Clause (Enumtype) then
               if Esize (Enumtype) >= Minsize then
                  null;

               else
                  Minsize :=
                    UI_From_Int (Minimum_Size (Enumtype, Biased => True));

                  if Esize (Enumtype) < Minsize then
                     Error_Msg_N ("previously given size is too small", N);

                  else
                     Set_Has_Biased_Representation (Enumtype);
                  end if;
               end if;

            else
               Set_RM_Size    (Enumtype, Minsize);
               Set_Enum_Esize (Enumtype);
            end if;

            Set_RM_Size   (Base_Type (Enumtype), RM_Size   (Enumtype));
            Set_Esize     (Base_Type (Enumtype), Esize     (Enumtype));
            Set_Alignment (Base_Type (Enumtype), Alignment (Enumtype));
         end;
      end if;

      --  We repeat the too late test in case it froze itself!

      if Rep_Item_Too_Late (Enumtype, N) then
         null;
      end if;
   end Analyze_Enumeration_Representation_Clause;

   ----------------------------
   -- Analyze_Free_Statement --
   ----------------------------

   procedure Analyze_Free_Statement (N : Node_Id) is
   begin
      Analyze (Expression (N));
   end Analyze_Free_Statement;

   ------------------------------------------
   -- Analyze_Record_Representation_Clause --
   ------------------------------------------

   procedure Analyze_Record_Representation_Clause (N : Node_Id) is
      Loc     : constant Source_Ptr := Sloc (N);
      Ident   : constant Node_Id    := Identifier (N);
      Rectype : Entity_Id;
      Fent    : Entity_Id;
      CC      : Node_Id;
      Posit   : Uint;
      Fbit    : Uint;
      Lbit    : Uint;
      Hbit    : Uint := Uint_0;
      Comp    : Entity_Id;
      Ocomp   : Entity_Id;
      Biased  : Boolean;

      Max_Bit_So_Far : Uint;
      --  Records the maximum bit position so far. If all field positions
      --  are monotonically increasing, then we can skip the circuit for
      --  checking for overlap, since no overlap is possible.

      Overlap_Check_Required : Boolean;
      --  Used to keep track of whether or not an overlap check is required

      Ccount : Natural := 0;
      --  Number of component clauses in record rep clause

   begin
      Find_Type (Ident);
      Rectype := Entity (Ident);

      if Rectype = Any_Type
        or else Rep_Item_Too_Early (Rectype, N)
      then
         return;
      else
         Rectype := Underlying_Type (Rectype);
      end if;

      --  First some basic error checks

      if not Is_Record_Type (Rectype) then
         Error_Msg_NE
           ("record type required, found}", Ident, First_Subtype (Rectype));
         return;

      elsif Is_Unchecked_Union (Rectype) then
         Error_Msg_N
           ("record rep clause not allowed for Unchecked_Union", N);

      elsif Scope (Rectype) /= Current_Scope then
         Error_Msg_N ("type must be declared in this scope", N);
         return;

      elsif not Is_First_Subtype (Rectype) then
         Error_Msg_N ("cannot give record rep clause for subtype", N);
         return;

      elsif Has_Record_Rep_Clause (Rectype) then
         Error_Msg_N ("duplicate record rep clause ignored", N);
         return;

      elsif Rep_Item_Too_Late (Rectype, N) then
         return;
      end if;

      if Present (Mod_Clause (N)) then
         declare
            Loc     : constant Source_Ptr := Sloc (N);
            M       : constant Node_Id := Mod_Clause (N);
            P       : constant List_Id := Pragmas_Before (M);
            AtM_Nod : Node_Id;

            Mod_Val : Uint;
            pragma Warnings (Off, Mod_Val);

         begin
            if Warn_On_Obsolescent_Feature then
               Error_Msg_N
                 ("mod clause is an obsolescent feature ('R'M 'J.8)?", N);
               Error_Msg_N
                 ("|use alignment attribute definition clause instead?", N);
            end if;

            if Present (P) then
               Analyze_List (P);
            end if;

            --  In ASIS_Mode mode, expansion is disabled, but we must
            --  convert the Mod clause into an alignment clause anyway, so
            --  that the back-end can compute and back-annotate properly the
            --  size and alignment of types that may include this record.

            if Operating_Mode = Check_Semantics
              and then ASIS_Mode
            then
               AtM_Nod :=
                 Make_Attribute_Definition_Clause (Loc,
                   Name       => New_Reference_To (Base_Type (Rectype), Loc),
                   Chars      => Name_Alignment,
                   Expression => Relocate_Node (Expression (M)));

               Set_From_At_Mod (AtM_Nod);
               Insert_After (N, AtM_Nod);
               Mod_Val := Get_Alignment_Value (Expression (AtM_Nod));
               Set_Mod_Clause (N, Empty);

            else
               --  Get the alignment value to perform error checking

               Mod_Val := Get_Alignment_Value (Expression (M));

            end if;
         end;
      end if;

      --  Clear any existing component clauses for the type (this happens
      --  with derived types, where we are now overriding the original)

      Fent := First_Entity (Rectype);

      Comp := Fent;
      while Present (Comp) loop
         if Ekind (Comp) = E_Component
           or else Ekind (Comp) = E_Discriminant
         then
            Set_Component_Clause (Comp, Empty);
         end if;

         Next_Entity (Comp);
      end loop;

      --  All done if no component clauses

      CC := First (Component_Clauses (N));

      if No (CC) then
         return;
      end if;

      --  If a tag is present, then create a component clause that places
      --  it at the start of the record (otherwise gigi may place it after
      --  other fields that have rep clauses).

      if Nkind (Fent) = N_Defining_Identifier
        and then Chars (Fent) = Name_uTag
      then
         Set_Component_Bit_Offset    (Fent, Uint_0);
         Set_Normalized_Position     (Fent, Uint_0);
         Set_Normalized_First_Bit    (Fent, Uint_0);
         Set_Normalized_Position_Max (Fent, Uint_0);
         Init_Esize                  (Fent, System_Address_Size);

         Set_Component_Clause    (Fent,
           Make_Component_Clause (Loc,
             Component_Name =>
               Make_Identifier (Loc,
                 Chars => Name_uTag),

             Position  =>
               Make_Integer_Literal (Loc,
                 Intval => Uint_0),

             First_Bit =>
               Make_Integer_Literal (Loc,
                 Intval => Uint_0),

             Last_Bit  =>
               Make_Integer_Literal (Loc,
                 UI_From_Int (System_Address_Size))));

         Ccount := Ccount + 1;
      end if;

      --  A representation like this applies to the base type

      Set_Has_Record_Rep_Clause (Base_Type (Rectype));
      Set_Has_Non_Standard_Rep  (Base_Type (Rectype));
      Set_Has_Specified_Layout  (Base_Type (Rectype));

      Max_Bit_So_Far := Uint_Minus_1;
      Overlap_Check_Required := False;

      --  Process the component clauses

      while Present (CC) loop

         --  If pragma, just analyze it

         if Nkind (CC) = N_Pragma then
            Analyze (CC);

         --  Processing for real component clause

         else
            Ccount := Ccount + 1;
            Posit := Static_Integer (Position  (CC));
            Fbit  := Static_Integer (First_Bit (CC));
            Lbit  := Static_Integer (Last_Bit  (CC));

            if Posit /= No_Uint
              and then Fbit /= No_Uint
              and then Lbit /= No_Uint
            then
               if Posit < 0 then
                  Error_Msg_N
                    ("position cannot be negative", Position (CC));

               elsif Fbit < 0 then
                  Error_Msg_N
                    ("first bit cannot be negative", First_Bit (CC));

               --  Values look OK, so find the corresponding record component
               --  Even though the syntax allows an attribute reference for
               --  implementation-defined components, GNAT does not allow the
               --  tag to get an explicit position.

               elsif Nkind (Component_Name (CC)) = N_Attribute_Reference then

                  if Attribute_Name (Component_Name (CC)) = Name_Tag then
                     Error_Msg_N ("position of tag cannot be specified", CC);
                  else
                     Error_Msg_N ("illegal component name", CC);
                  end if;

               else
                  Comp := First_Entity (Rectype);
                  while Present (Comp) loop
                     exit when Chars (Comp) = Chars (Component_Name (CC));
                     Next_Entity (Comp);
                  end loop;

                  if No (Comp) then

                     --  Maybe component of base type that is absent from
                     --  statically constrained first subtype.

                     Comp := First_Entity (Base_Type (Rectype));
                     while Present (Comp) loop
                        exit when Chars (Comp) = Chars (Component_Name (CC));
                        Next_Entity (Comp);
                     end loop;
                  end if;

                  if No (Comp) then
                     Error_Msg_N
                       ("component clause is for non-existent field", CC);

                  elsif Present (Component_Clause (Comp)) then
                     Error_Msg_Sloc := Sloc (Component_Clause (Comp));
                     Error_Msg_N
                       ("component clause previously given#", CC);

                  else
                     --  Update Fbit and Lbit to the actual bit number.

                     Fbit := Fbit + UI_From_Int (SSU) * Posit;
                     Lbit := Lbit + UI_From_Int (SSU) * Posit;

                     if Fbit <= Max_Bit_So_Far then
                        Overlap_Check_Required := True;
                     else
                        Max_Bit_So_Far := Lbit;
                     end if;

                     if Has_Size_Clause (Rectype)
                       and then Esize (Rectype) <= Lbit
                     then
                        Error_Msg_N
                          ("bit number out of range of specified size",
                           Last_Bit (CC));
                     else
                        Set_Component_Clause     (Comp, CC);
                        Set_Component_Bit_Offset (Comp, Fbit);
                        Set_Esize                (Comp, 1 + (Lbit - Fbit));
                        Set_Normalized_First_Bit (Comp, Fbit mod SSU);
                        Set_Normalized_Position  (Comp, Fbit / SSU);

                        Set_Normalized_Position_Max
                          (Fent, Normalized_Position (Fent));

                        if Is_Tagged_Type (Rectype)
                          and then Fbit < System_Address_Size
                        then
                           Error_Msg_NE
                             ("component overlaps tag field of&",
                              CC, Rectype);
                        end if;

                        --  This information is also set in the corresponding
                        --  component of the base type, found by accessing the
                        --  Original_Record_Component link if it is present.

                        Ocomp := Original_Record_Component (Comp);

                        if Hbit < Lbit then
                           Hbit := Lbit;
                        end if;

                        Check_Size
                          (Component_Name (CC),
                           Etype (Comp),
                           Esize (Comp),
                           Biased);

                        Set_Has_Biased_Representation (Comp, Biased);

                        if Present (Ocomp) then
                           Set_Component_Clause     (Ocomp, CC);
                           Set_Component_Bit_Offset (Ocomp, Fbit);
                           Set_Normalized_First_Bit (Ocomp, Fbit mod SSU);
                           Set_Normalized_Position  (Ocomp, Fbit / SSU);
                           Set_Esize                (Ocomp, 1 + (Lbit - Fbit));

                           Set_Normalized_Position_Max
                             (Ocomp, Normalized_Position (Ocomp));

                           Set_Has_Biased_Representation
                             (Ocomp, Has_Biased_Representation (Comp));
                        end if;

                        if Esize (Comp) < 0 then
                           Error_Msg_N ("component size is negative", CC);
                        end if;
                     end if;
                  end if;
               end if;
            end if;
         end if;

         Next (CC);
      end loop;

      --  Now that we have processed all the component clauses, check for
      --  overlap. We have to leave this till last, since the components
      --  can appear in any arbitrary order in the representation clause.

      --  We do not need this check if all specified ranges were monotonic,
      --  as recorded by Overlap_Check_Required being False at this stage.

      --  This first section checks if there are any overlapping entries
      --  at all. It does this by sorting all entries and then seeing if
      --  there are any overlaps. If there are none, then that is decisive,
      --  but if there are overlaps, they may still be OK (they may result
      --  from fields in different variants).

      if Overlap_Check_Required then
         Overlap_Check1 : declare

            OC_Fbit : array (0 .. Ccount) of Uint;
            --  First-bit values for component clauses, the value is the
            --  offset of the first bit of the field from start of record.
            --  The zero entry is for use in sorting.

            OC_Lbit : array (0 .. Ccount) of Uint;
            --  Last-bit values for component clauses, the value is the
            --  offset of the last bit of the field from start of record.
            --  The zero entry is for use in sorting.

            OC_Count : Natural := 0;
            --  Count of entries in OC_Fbit and OC_Lbit

            function OC_Lt (Op1, Op2 : Natural) return Boolean;
            --  Compare routine for Sort (See GNAT.Heap_Sort_A)

            procedure OC_Move (From : Natural; To : Natural);
            --  Move routine for Sort (see GNAT.Heap_Sort_A)

            function OC_Lt (Op1, Op2 : Natural) return Boolean is
            begin
               return OC_Fbit (Op1) < OC_Fbit (Op2);
            end OC_Lt;

            procedure OC_Move (From : Natural; To : Natural) is
            begin
               OC_Fbit (To) := OC_Fbit (From);
               OC_Lbit (To) := OC_Lbit (From);
            end OC_Move;

         begin
            CC := First (Component_Clauses (N));
            while Present (CC) loop
               if Nkind (CC) /= N_Pragma then
                  Posit := Static_Integer (Position  (CC));
                  Fbit  := Static_Integer (First_Bit (CC));
                  Lbit  := Static_Integer (Last_Bit  (CC));

                  if Posit /= No_Uint
                    and then Fbit /= No_Uint
                    and then Lbit /= No_Uint
                  then
                     OC_Count := OC_Count + 1;
                     Posit := Posit * SSU;
                     OC_Fbit (OC_Count) := Fbit + Posit;
                     OC_Lbit (OC_Count) := Lbit + Posit;
                  end if;
               end if;

               Next (CC);
            end loop;

            Sort
              (OC_Count,
               OC_Move'Unrestricted_Access,
               OC_Lt'Unrestricted_Access);

            Overlap_Check_Required := False;
            for J in 1 .. OC_Count - 1 loop
               if OC_Lbit (J) >= OC_Fbit (J + 1) then
                  Overlap_Check_Required := True;
                  exit;
               end if;
            end loop;
         end Overlap_Check1;
      end if;

      --  If Overlap_Check_Required is still True, then we have to do
      --  the full scale overlap check, since we have at least two fields
      --  that do overlap, and we need to know if that is OK since they
      --  are in the same variant, or whether we have a definite problem

      if Overlap_Check_Required then
         Overlap_Check2 : declare
            C1_Ent, C2_Ent : Entity_Id;
            --  Entities of components being checked for overlap

            Clist : Node_Id;
            --  Component_List node whose Component_Items are being checked

            Citem : Node_Id;
            --  Component declaration for component being checked

         begin
            C1_Ent := First_Entity (Base_Type (Rectype));

            --  Loop through all components in record. For each component check
            --  for overlap with any of the preceding elements on the component
            --  list containing the component, and also, if the component is in
            --  a variant, check against components outside the case structure.
            --  This latter test is repeated recursively up the variant tree.

            Main_Component_Loop : while Present (C1_Ent) loop
               if Ekind (C1_Ent) /= E_Component
                 and then Ekind (C1_Ent) /= E_Discriminant
               then
                  goto Continue_Main_Component_Loop;
               end if;

               --  Skip overlap check if entity has no declaration node. This
               --  happens with discriminants in constrained derived types.
               --  Probably we are missing some checks as a result, but that
               --  does not seem terribly serious ???

               if No (Declaration_Node (C1_Ent)) then
                  goto Continue_Main_Component_Loop;
               end if;

               Clist := Parent (List_Containing (Declaration_Node (C1_Ent)));

               --  Loop through component lists that need checking. Check the
               --  current component list and all lists in variants above us.

               Component_List_Loop : loop

                  --  If derived type definition, go to full declaration
                  --  If at outer level, check discriminants if there are any

                  if Nkind (Clist) = N_Derived_Type_Definition then
                     Clist := Parent (Clist);
                  end if;

                  --  Outer level of record definition, check discriminants

                  if Nkind (Clist) = N_Full_Type_Declaration
                    or else Nkind (Clist) = N_Private_Type_Declaration
                  then
                     if Has_Discriminants (Defining_Identifier (Clist)) then
                        C2_Ent :=
                          First_Discriminant (Defining_Identifier (Clist));

                        while Present (C2_Ent) loop
                           exit when C1_Ent = C2_Ent;
                           Check_Component_Overlap (C1_Ent, C2_Ent);
                           Next_Discriminant (C2_Ent);
                        end loop;
                     end if;

                  --  Record extension case

                  elsif Nkind (Clist) = N_Derived_Type_Definition then
                     Clist := Empty;

                  --  Otherwise check one component list

                  else
                     Citem := First (Component_Items (Clist));

                     while Present (Citem) loop
                        if Nkind (Citem) = N_Component_Declaration then
                           C2_Ent := Defining_Identifier (Citem);
                           exit when C1_Ent = C2_Ent;
                           Check_Component_Overlap (C1_Ent, C2_Ent);
                        end if;

                        Next (Citem);
                     end loop;
                  end if;

                  --  Check for variants above us (the parent of the Clist can
                  --  be a variant, in which case its parent is a variant part,
                  --  and the parent of the variant part is a component list
                  --  whose components must all be checked against the current
                  --  component for overlap.

                  if Nkind (Parent (Clist)) = N_Variant then
                     Clist := Parent (Parent (Parent (Clist)));

                  --  Check for possible discriminant part in record, this is
                  --  treated essentially as another level in the recursion.
                  --  For this case we have the parent of the component list
                  --  is the record definition, and its parent is the full
                  --  type declaration which contains the discriminant
                  --  specifications.

                  elsif Nkind (Parent (Clist)) = N_Record_Definition then
                     Clist := Parent (Parent ((Clist)));

                  --  If neither of these two cases, we are at the top of
                  --  the tree

                  else
                     exit Component_List_Loop;
                  end if;
               end loop Component_List_Loop;

               <<Continue_Main_Component_Loop>>
                  Next_Entity (C1_Ent);

            end loop Main_Component_Loop;
         end Overlap_Check2;
      end if;

      --  For records that have component clauses for all components, and
      --  whose size is less than or equal to 32, we need to know the size
      --  in the front end to activate possible packed array processing
      --  where the component type is a record.

      --  At this stage Hbit + 1 represents the first unused bit from all
      --  the component clauses processed, so if the component clauses are
      --  complete, then this is the length of the record.

      --  For records longer than System.Storage_Unit, and for those where
      --  not all components have component clauses, the back end determines
      --  the length (it may for example be appopriate to round up the size
      --  to some convenient boundary, based on alignment considerations etc).

      if Unknown_RM_Size (Rectype)
        and then Hbit + 1 <= 32
      then
         --  Nothing to do if at least one component with no component clause

         Comp := First_Entity (Rectype);
         while Present (Comp) loop
            if Ekind (Comp) = E_Component
              or else Ekind (Comp) = E_Discriminant
            then
               if No (Component_Clause (Comp)) then
                  return;
               end if;
            end if;

            Next_Entity (Comp);
         end loop;

         --  If we fall out of loop, all components have component clauses
         --  and so we can set the size to the maximum value.

         Set_RM_Size (Rectype, Hbit + 1);
      end if;
   end Analyze_Record_Representation_Clause;

   -----------------------------
   -- Check_Component_Overlap --
   -----------------------------

   procedure Check_Component_Overlap (C1_Ent, C2_Ent : Entity_Id) is
   begin
      if Present (Component_Clause (C1_Ent))
        and then Present (Component_Clause (C2_Ent))
      then
         --  Exclude odd case where we have two tag fields in the same
         --  record, both at location zero. This seems a bit strange,
         --  but it seems to happen in some circumstances ???

         if Chars (C1_Ent) = Name_uTag
           and then Chars (C2_Ent) = Name_uTag
         then
            return;
         end if;

         --  Here we check if the two fields overlap

         declare
            S1 : constant Uint := Component_Bit_Offset (C1_Ent);
            S2 : constant Uint := Component_Bit_Offset (C2_Ent);
            E1 : constant Uint := S1 + Esize (C1_Ent);
            E2 : constant Uint := S2 + Esize (C2_Ent);

         begin
            if E2 <= S1 or else E1 <= S2 then
               null;
            else
               Error_Msg_Node_2 :=
                 Component_Name (Component_Clause (C2_Ent));
               Error_Msg_Sloc := Sloc (Error_Msg_Node_2);
               Error_Msg_Node_1 :=
                 Component_Name (Component_Clause (C1_Ent));
               Error_Msg_N
                 ("component& overlaps & #",
                  Component_Name (Component_Clause (C1_Ent)));
            end if;
         end;
      end if;
   end Check_Component_Overlap;

   -----------------------------------
   -- Check_Constant_Address_Clause --
   -----------------------------------

   procedure Check_Constant_Address_Clause
     (Expr  : Node_Id;
      U_Ent : Entity_Id)
   is
      procedure Check_At_Constant_Address (Nod : Node_Id);
      --  Checks that the given node N represents a name whose 'Address
      --  is constant (in the same sense as OK_Constant_Address_Clause,
      --  i.e. the address value is the same at the point of declaration
      --  of U_Ent and at the time of elaboration of the address clause.

      procedure Check_Expr_Constants (Nod : Node_Id);
      --  Checks that Nod meets the requirements for a constant address
      --  clause in the sense of the enclosing procedure.

      procedure Check_List_Constants (Lst : List_Id);
      --  Check that all elements of list Lst meet the requirements for a
      --  constant address clause in the sense of the enclosing procedure.

      -------------------------------
      -- Check_At_Constant_Address --
      -------------------------------

      procedure Check_At_Constant_Address (Nod : Node_Id) is
      begin
         if Is_Entity_Name (Nod) then
            if Present (Address_Clause (Entity ((Nod)))) then
               Error_Msg_NE
                 ("invalid address clause for initialized object &!",
                           Nod, U_Ent);
               Error_Msg_NE
                 ("address for& cannot" &
                    " depend on another address clause! ('R'M 13.1(22))!",
                  Nod, U_Ent);

            elsif In_Same_Source_Unit (Entity (Nod), U_Ent)
              and then Sloc (U_Ent) < Sloc (Entity (Nod))
            then
               Error_Msg_NE
                 ("invalid address clause for initialized object &!",
                  Nod, U_Ent);
               Error_Msg_Name_1 := Chars (Entity (Nod));
               Error_Msg_Name_2 := Chars (U_Ent);
               Error_Msg_N
                 ("\% must be defined before % ('R'M 13.1(22))!",
                  Nod);
            end if;

         elsif Nkind (Nod) = N_Selected_Component then
            declare
               T : constant Entity_Id := Etype (Prefix (Nod));

            begin
               if (Is_Record_Type (T)
                    and then Has_Discriminants (T))
                 or else
                  (Is_Access_Type (T)
                     and then Is_Record_Type (Designated_Type (T))
                     and then Has_Discriminants (Designated_Type (T)))
               then
                  Error_Msg_NE
                    ("invalid address clause for initialized object &!",
                     Nod, U_Ent);
                  Error_Msg_N
                    ("\address cannot depend on component" &
                     " of discriminated record ('R'M 13.1(22))!",
                     Nod);
               else
                  Check_At_Constant_Address (Prefix (Nod));
               end if;
            end;

         elsif Nkind (Nod) = N_Indexed_Component then
            Check_At_Constant_Address (Prefix (Nod));
            Check_List_Constants (Expressions (Nod));

         else
            Check_Expr_Constants (Nod);
         end if;
      end Check_At_Constant_Address;

      --------------------------
      -- Check_Expr_Constants --
      --------------------------

      procedure Check_Expr_Constants (Nod : Node_Id) is
         Loc_U_Ent : constant Source_Ptr := Sloc (U_Ent);
         Ent       : Entity_Id           := Empty;

      begin
         if Nkind (Nod) in N_Has_Etype
           and then Etype (Nod) = Any_Type
         then
            return;
         end if;

         case Nkind (Nod) is
            when N_Empty | N_Error =>
               return;

            when N_Identifier | N_Expanded_Name =>
               Ent := Entity (Nod);

               --  We need to look at the original node if it is different
               --  from the node, since we may have rewritten things and
               --  substituted an identifier representing the rewrite.

               if Original_Node (Nod) /= Nod then
                  Check_Expr_Constants (Original_Node (Nod));

                  --  If the node is an object declaration without initial
                  --  value, some code has been expanded, and the expression
                  --  is not constant, even if the constituents might be
                  --  acceptable, as in  A'Address + offset.

                  if Ekind (Ent) = E_Variable
                    and then Nkind (Declaration_Node (Ent))
                      = N_Object_Declaration
                    and then
                      No (Expression (Declaration_Node (Ent)))
                  then
                     Error_Msg_NE
                       ("invalid address clause for initialized object &!",
                        Nod, U_Ent);

                  --  If entity is constant, it may be the result of expanding
                  --  a check. We must verify that its declaration appears
                  --  before the object in question, else we also reject the
                  --  address clause.

                  elsif Ekind (Ent) = E_Constant
                    and then In_Same_Source_Unit (Ent, U_Ent)
                    and then Sloc (Ent) > Loc_U_Ent
                  then
                     Error_Msg_NE
                       ("invalid address clause for initialized object &!",
                        Nod, U_Ent);
                  end if;

                  return;
               end if;

               --  Otherwise look at the identifier and see if it is OK.

               if Ekind (Ent) = E_Named_Integer
                    or else
                  Ekind (Ent) = E_Named_Real
                    or else
                  Is_Type (Ent)
               then
                  return;

               elsif
                  Ekind (Ent) = E_Constant
                    or else
                  Ekind (Ent) = E_In_Parameter
               then
                  --  This is the case where we must have Ent defined
                  --  before U_Ent. Clearly if they are in different
                  --  units this requirement is met since the unit
                  --  containing Ent is already processed.

                  if not In_Same_Source_Unit (Ent, U_Ent) then
                     return;

                  --  Otherwise location of Ent must be before the
                  --  location of U_Ent, that's what prior defined means.

                  elsif Sloc (Ent) < Loc_U_Ent then
                     return;

                  else
                     Error_Msg_NE
                       ("invalid address clause for initialized object &!",
                        Nod, U_Ent);
                     Error_Msg_Name_1 := Chars (Ent);
                     Error_Msg_Name_2 := Chars (U_Ent);
                     Error_Msg_N
                       ("\% must be defined before % ('R'M 13.1(22))!",
                        Nod);
                  end if;

               elsif Nkind (Original_Node (Nod)) = N_Function_Call then
                  Check_Expr_Constants (Original_Node (Nod));

               else
                  Error_Msg_NE
                    ("invalid address clause for initialized object &!",
                     Nod, U_Ent);

                  if Comes_From_Source (Ent) then
                     Error_Msg_Name_1 := Chars (Ent);
                     Error_Msg_N
                       ("\reference to variable% not allowed"
                          & " ('R'M 13.1(22))!", Nod);
                  else
                     Error_Msg_N
                       ("non-static expression not allowed"
                          & " ('R'M 13.1(22))!", Nod);
                  end if;
               end if;

            when N_Integer_Literal   =>

               --  If this is a rewritten unchecked conversion, in a system
               --  where Address is an integer type, always use the base type
               --  for a literal value. This is user-friendly and prevents
               --  order-of-elaboration issues with instances of unchecked
               --  conversion.

               if Nkind (Original_Node (Nod)) = N_Function_Call then
                  Set_Etype (Nod, Base_Type (Etype (Nod)));
               end if;

            when N_Real_Literal      |
                 N_String_Literal    |
                 N_Character_Literal =>
               return;

            when N_Range =>
               Check_Expr_Constants (Low_Bound (Nod));
               Check_Expr_Constants (High_Bound (Nod));

            when N_Explicit_Dereference =>
               Check_Expr_Constants (Prefix (Nod));

            when N_Indexed_Component =>
               Check_Expr_Constants (Prefix (Nod));
               Check_List_Constants (Expressions (Nod));

            when N_Slice =>
               Check_Expr_Constants (Prefix (Nod));
               Check_Expr_Constants (Discrete_Range (Nod));

            when N_Selected_Component =>
               Check_Expr_Constants (Prefix (Nod));

            when N_Attribute_Reference =>

               if Attribute_Name (Nod) = Name_Address
                   or else
                  Attribute_Name (Nod) = Name_Access
                    or else
                  Attribute_Name (Nod) = Name_Unchecked_Access
                    or else
                  Attribute_Name (Nod) = Name_Unrestricted_Access
               then
                  Check_At_Constant_Address (Prefix (Nod));

               else
                  Check_Expr_Constants (Prefix (Nod));
                  Check_List_Constants (Expressions (Nod));
               end if;

            when N_Aggregate =>
               Check_List_Constants (Component_Associations (Nod));
               Check_List_Constants (Expressions (Nod));

            when N_Component_Association =>
               Check_Expr_Constants (Expression (Nod));

            when N_Extension_Aggregate =>
               Check_Expr_Constants (Ancestor_Part (Nod));
               Check_List_Constants (Component_Associations (Nod));
               Check_List_Constants (Expressions (Nod));

            when N_Null =>
               return;

            when N_Binary_Op | N_And_Then | N_Or_Else | N_In | N_Not_In =>
               Check_Expr_Constants (Left_Opnd (Nod));
               Check_Expr_Constants (Right_Opnd (Nod));

            when N_Unary_Op =>
               Check_Expr_Constants (Right_Opnd (Nod));

            when N_Type_Conversion           |
                 N_Qualified_Expression      |
                 N_Allocator                 =>
               Check_Expr_Constants (Expression (Nod));

            when N_Unchecked_Type_Conversion =>
               Check_Expr_Constants (Expression (Nod));

               --  If this is a rewritten unchecked conversion, subtypes
               --  in this node are those created within the instance.
               --  To avoid order of elaboration issues, replace them
               --  with their base types. Note that address clauses can
               --  cause order of elaboration problems because they are
               --  elaborated by the back-end at the point of definition,
               --  and may mention entities declared in between (as long
               --  as everything is static). It is user-friendly to allow
               --  unchecked conversions in this context.

               if Nkind (Original_Node (Nod)) = N_Function_Call then
                  Set_Etype (Expression (Nod),
                    Base_Type (Etype (Expression (Nod))));
                  Set_Etype (Nod, Base_Type (Etype (Nod)));
               end if;

            when N_Function_Call =>
               if not Is_Pure (Entity (Name (Nod))) then
                  Error_Msg_NE
                    ("invalid address clause for initialized object &!",
                     Nod, U_Ent);

                  Error_Msg_NE
                    ("\function & is not pure ('R'M 13.1(22))!",
                     Nod, Entity (Name (Nod)));

               else
                  Check_List_Constants (Parameter_Associations (Nod));
               end if;

            when N_Parameter_Association =>
               Check_Expr_Constants (Explicit_Actual_Parameter (Nod));

            when others =>
               Error_Msg_NE
                 ("invalid address clause for initialized object &!",
                  Nod, U_Ent);
               Error_Msg_NE
                 ("\must be constant defined before& ('R'M 13.1(22))!",
                  Nod, U_Ent);
         end case;
      end Check_Expr_Constants;

      --------------------------
      -- Check_List_Constants --
      --------------------------

      procedure Check_List_Constants (Lst : List_Id) is
         Nod1 : Node_Id;

      begin
         if Present (Lst) then
            Nod1 := First (Lst);
            while Present (Nod1) loop
               Check_Expr_Constants (Nod1);
               Next (Nod1);
            end loop;
         end if;
      end Check_List_Constants;

   --  Start of processing for Check_Constant_Address_Clause

   begin
      Check_Expr_Constants (Expr);
   end Check_Constant_Address_Clause;

   ----------------
   -- Check_Size --
   ----------------

   procedure Check_Size
     (N      : Node_Id;
      T      : Entity_Id;
      Siz    : Uint;
      Biased : out Boolean)
   is
      UT : constant Entity_Id := Underlying_Type (T);
      M  : Uint;

   begin
      Biased := False;

      --  Dismiss cases for generic types or types with previous errors

      if No (UT)
        or else UT = Any_Type
        or else Is_Generic_Type (UT)
        or else Is_Generic_Type (Root_Type (UT))
      then
         return;

      --  Check case of bit packed array

      elsif Is_Array_Type (UT)
        and then Known_Static_Component_Size (UT)
        and then Is_Bit_Packed_Array (UT)
      then
         declare
            Asiz : Uint;
            Indx : Node_Id;
            Ityp : Entity_Id;

         begin
            Asiz := Component_Size (UT);
            Indx := First_Index (UT);
            loop
               Ityp := Etype (Indx);

               --  If non-static bound, then we are not in the business of
               --  trying to check the length, and indeed an error will be
               --  issued elsewhere, since sizes of non-static array types
               --  cannot be set implicitly or explicitly.

               if not Is_Static_Subtype (Ityp) then
                  return;
               end if;

               --  Otherwise accumulate next dimension

               Asiz := Asiz * (Expr_Value (Type_High_Bound (Ityp)) -
                               Expr_Value (Type_Low_Bound  (Ityp)) +
                               Uint_1);

               Next_Index (Indx);
               exit when No (Indx);
            end loop;

            if Asiz <= Siz then
               return;
            else
               Error_Msg_Uint_1 := Asiz;
               Error_Msg_NE
                 ("size for& too small, minimum allowed is ^", N, T);
               Set_Esize   (T, Asiz);
               Set_RM_Size (T, Asiz);
            end if;
         end;

      --  All other composite types are ignored

      elsif Is_Composite_Type (UT) then
         return;

      --  For fixed-point types, don't check minimum if type is not frozen,
      --  since we don't know all the characteristics of the type that can
      --  affect the size (e.g. a specified small) till freeze time.

      elsif Is_Fixed_Point_Type (UT)
        and then not Is_Frozen (UT)
      then
         null;

      --  Cases for which a minimum check is required

      else
         --  Ignore if specified size is correct for the type

         if Known_Esize (UT) and then Siz = Esize (UT) then
            return;
         end if;

         --  Otherwise get minimum size

         M := UI_From_Int (Minimum_Size (UT));

         if Siz < M then

            --  Size is less than minimum size, but one possibility remains
            --  that we can manage with the new size if we bias the type

            M := UI_From_Int (Minimum_Size (UT, Biased => True));

            if Siz < M then
               Error_Msg_Uint_1 := M;
               Error_Msg_NE
                 ("size for& too small, minimum allowed is ^", N, T);
               Set_Esize (T, M);
               Set_RM_Size (T, M);
            else
               Biased := True;
            end if;
         end if;
      end if;
   end Check_Size;

   -------------------------
   -- Get_Alignment_Value --
   -------------------------

   function Get_Alignment_Value (Expr : Node_Id) return Uint is
      Align : constant Uint := Static_Integer (Expr);

   begin
      if Align = No_Uint then
         return No_Uint;

      elsif Align <= 0 then
         Error_Msg_N ("alignment value must be positive", Expr);
         return No_Uint;

      else
         for J in Int range 0 .. 64 loop
            declare
               M : constant Uint := Uint_2 ** J;

            begin
               exit when M = Align;

               if M > Align then
                  Error_Msg_N
                    ("alignment value must be power of 2", Expr);
                  return No_Uint;
               end if;
            end;
         end loop;

         return Align;
      end if;
   end Get_Alignment_Value;

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

   procedure Initialize is
   begin
      Unchecked_Conversions.Init;
   end Initialize;

   -------------------------
   -- Is_Operational_Item --
   -------------------------

   function Is_Operational_Item (N : Node_Id) return Boolean is
   begin
      if Nkind (N) /= N_Attribute_Definition_Clause then
         return False;
      else
         declare
            Id    : constant Attribute_Id := Get_Attribute_Id (Chars (N));

         begin
            return Id = Attribute_Input
              or else Id = Attribute_Output
              or else Id = Attribute_Read
              or else Id = Attribute_Write
              or else Id = Attribute_External_Tag;
         end;
      end if;
   end Is_Operational_Item;

   --------------------------------------
   -- Mark_Aliased_Address_As_Volatile --
   --------------------------------------

   procedure Mark_Aliased_Address_As_Volatile (N : Node_Id) is
      Ent : constant Entity_Id := Address_Aliased_Entity (N);

   begin
      if Present (Ent) then
         Set_Treat_As_Volatile (Ent);
      end if;
   end Mark_Aliased_Address_As_Volatile;

   ------------------
   -- Minimum_Size --
   ------------------

   function Minimum_Size
     (T      : Entity_Id;
      Biased : Boolean := False) return Nat
   is
      Lo     : Uint    := No_Uint;
      Hi     : Uint    := No_Uint;
      LoR    : Ureal   := No_Ureal;
      HiR    : Ureal   := No_Ureal;
      LoSet  : Boolean := False;
      HiSet  : Boolean := False;
      B      : Uint;
      S      : Nat;
      Ancest : Entity_Id;
      R_Typ  : constant Entity_Id := Root_Type (T);

   begin
      --  If bad type, return 0

      if T = Any_Type then
         return 0;

      --  For generic types, just return zero. There cannot be any legitimate
      --  need to know such a size, but this routine may be called with a
      --  generic type as part of normal processing.

      elsif Is_Generic_Type (R_Typ)
        or else R_Typ = Any_Type
      then
         return 0;

         --  Access types. Normally an access type cannot have a size smaller
         --  than the size of System.Address. The exception is on VMS, where
         --  we have short and long addresses, and it is possible for an access
         --  type to have a short address size (and thus be less than the size
         --  of System.Address itself). We simply skip the check for VMS, and
         --  leave the back end to do the check.

      elsif Is_Access_Type (T) then
         if OpenVMS_On_Target then
            return 0;
         else
            return System_Address_Size;
         end if;

      --  Floating-point types

      elsif Is_Floating_Point_Type (T) then
         return UI_To_Int (Esize (R_Typ));

      --  Discrete types

      elsif Is_Discrete_Type (T) then

         --  The following loop is looking for the nearest compile time
         --  known bounds following the ancestor subtype chain. The idea
         --  is to find the most restrictive known bounds information.

         Ancest := T;
         loop
            if Ancest = Any_Type or else Etype (Ancest) = Any_Type then
               return 0;
            end if;

            if not LoSet then
               if Compile_Time_Known_Value (Type_Low_Bound (Ancest)) then
                  Lo := Expr_Rep_Value (Type_Low_Bound (Ancest));
                  LoSet := True;
                  exit when HiSet;
               end if;
            end if;

            if not HiSet then
               if Compile_Time_Known_Value (Type_High_Bound (Ancest)) then
                  Hi := Expr_Rep_Value (Type_High_Bound (Ancest));
                  HiSet := True;
                  exit when LoSet;
               end if;
            end if;

            Ancest := Ancestor_Subtype (Ancest);

            if No (Ancest) then
               Ancest := Base_Type (T);

               if Is_Generic_Type (Ancest) then
                  return 0;
               end if;
            end if;
         end loop;

      --  Fixed-point types. We can't simply use Expr_Value to get the
      --  Corresponding_Integer_Value values of the bounds, since these
      --  do not get set till the type is frozen, and this routine can
      --  be called before the type is frozen. Similarly the test for
      --  bounds being static needs to include the case where we have
      --  unanalyzed real literals for the same reason.

      elsif Is_Fixed_Point_Type (T) then

         --  The following loop is looking for the nearest compile time
         --  known bounds following the ancestor subtype chain. The idea
         --  is to find the most restrictive known bounds information.

         Ancest := T;
         loop
            if Ancest = Any_Type or else Etype (Ancest) = Any_Type then
               return 0;
            end if;

            if not LoSet then
               if Nkind (Type_Low_Bound (Ancest)) = N_Real_Literal
                 or else Compile_Time_Known_Value (Type_Low_Bound (Ancest))
               then
                  LoR := Expr_Value_R (Type_Low_Bound (Ancest));
                  LoSet := True;
                  exit when HiSet;
               end if;
            end if;

            if not HiSet then
               if Nkind (Type_High_Bound (Ancest)) = N_Real_Literal
                 or else Compile_Time_Known_Value (Type_High_Bound (Ancest))
               then
                  HiR := Expr_Value_R (Type_High_Bound (Ancest));
                  HiSet := True;
                  exit when LoSet;
               end if;
            end if;

            Ancest := Ancestor_Subtype (Ancest);

            if No (Ancest) then
               Ancest := Base_Type (T);

               if Is_Generic_Type (Ancest) then
                  return 0;
               end if;
            end if;
         end loop;

         Lo := UR_To_Uint (LoR / Small_Value (T));
         Hi := UR_To_Uint (HiR / Small_Value (T));

      --  No other types allowed

      else
         raise Program_Error;
      end if;

      --  Fall through with Hi and Lo set. Deal with biased case.

      if (Biased and then not Is_Fixed_Point_Type (T))
        or else Has_Biased_Representation (T)
      then
         Hi := Hi - Lo;
         Lo := Uint_0;
      end if;

      --  Signed case. Note that we consider types like range 1 .. -1 to be
      --  signed for the purpose of computing the size, since the bounds
      --  have to be accomodated in the base type.

      if Lo < 0 or else Hi < 0 then
         S := 1;
         B := Uint_1;

         --  S = size, B = 2 ** (size - 1) (can accommodate -B .. +(B - 1))
         --  Note that we accommodate the case where the bounds cross. This
         --  can happen either because of the way the bounds are declared
         --  or because of the algorithm in Freeze_Fixed_Point_Type.

         while Lo < -B
           or else Hi < -B
           or else Lo >= B
           or else Hi >= B
         loop
            B := Uint_2 ** S;
            S := S + 1;
         end loop;

      --  Unsigned case

      else
         --  If both bounds are positive, make sure that both are represen-
         --  table in the case where the bounds are crossed. This can happen
         --  either because of the way the bounds are declared, or because of
         --  the algorithm in Freeze_Fixed_Point_Type.

         if Lo > Hi then
            Hi := Lo;
         end if;

         --  S = size, (can accommodate 0 .. (2**size - 1))

         S := 0;
         while Hi >= Uint_2 ** S loop
            S := S + 1;
         end loop;
      end if;

      return S;
   end Minimum_Size;

   -------------------------
   -- New_Stream_Function --
   -------------------------

   procedure New_Stream_Function
     (N    : Node_Id;
      Ent  : Entity_Id;
      Subp : Entity_Id;
      Nam  : TSS_Name_Type)
   is
      Loc       : constant Source_Ptr := Sloc (N);
      Sname     : constant Name_Id    := Make_TSS_Name (Base_Type (Ent), Nam);
      Subp_Id   : Entity_Id;
      Subp_Decl : Node_Id;
      F         : Entity_Id;
      Etyp      : Entity_Id;

      function Build_Spec return Node_Id;
      --  Used for declaration and renaming declaration, so that this is
      --  treated as a renaming_as_body.

      ----------------
      -- Build_Spec --
      ----------------

      function Build_Spec return Node_Id is
      begin
         Subp_Id := Make_Defining_Identifier (Loc, Sname);

         return
           Make_Function_Specification (Loc,
             Defining_Unit_Name => Subp_Id,
             Parameter_Specifications =>
               New_List (
                 Make_Parameter_Specification (Loc,
                   Defining_Identifier =>
                     Make_Defining_Identifier (Loc, Name_S),
                   Parameter_Type =>
                     Make_Access_Definition (Loc,
                       Subtype_Mark =>
                         New_Reference_To (
                           Designated_Type (Etype (F)), Loc)))),

             Subtype_Mark =>
               New_Reference_To (Etyp, Loc));
      end Build_Spec;

   --  Start of processing for New_Stream_Function

   begin
      F    := First_Formal (Subp);
      Etyp := Etype (Subp);

      if not Is_Tagged_Type (Ent) then
         Subp_Decl :=
           Make_Subprogram_Declaration (Loc,
             Specification => Build_Spec);
         Insert_Action (N, Subp_Decl);
      end if;

      Subp_Decl :=
        Make_Subprogram_Renaming_Declaration (Loc,
          Specification => Build_Spec,
          Name => New_Reference_To (Subp, Loc));

      if Is_Tagged_Type (Ent) and then not Is_Limited_Type (Ent) then
         Set_TSS (Base_Type (Ent), Subp_Id);
      else
         Insert_Action (N, Subp_Decl);
         Copy_TSS (Subp_Id, Base_Type (Ent));
      end if;
   end New_Stream_Function;

   --------------------------
   -- New_Stream_Procedure --
   --------------------------

   procedure New_Stream_Procedure
     (N     : Node_Id;
      Ent   : Entity_Id;
      Subp  : Entity_Id;
      Nam   : TSS_Name_Type;
      Out_P : Boolean := False)
   is
      Loc       : constant Source_Ptr := Sloc (N);
      Sname     : constant Name_Id    := Make_TSS_Name (Base_Type (Ent), Nam);
      Subp_Id   : Entity_Id;
      Subp_Decl : Node_Id;
      F         : Entity_Id;
      Etyp      : Entity_Id;

      function Build_Spec return Node_Id;
      --  Used for declaration and renaming declaration, so that this is
      --  treated as a renaming_as_body.

      ----------------
      -- Build_Spec --
      ----------------

      function Build_Spec return Node_Id is
      begin
         Subp_Id := Make_Defining_Identifier (Loc, Sname);

         return
           Make_Procedure_Specification (Loc,
             Defining_Unit_Name => Subp_Id,
             Parameter_Specifications =>
               New_List (
                 Make_Parameter_Specification (Loc,
                   Defining_Identifier =>
                     Make_Defining_Identifier (Loc, Name_S),
                   Parameter_Type =>
                     Make_Access_Definition (Loc,
                       Subtype_Mark =>
                         New_Reference_To (
                           Designated_Type (Etype (F)), Loc))),

                 Make_Parameter_Specification (Loc,
                   Defining_Identifier =>
                     Make_Defining_Identifier (Loc, Name_V),
                   Out_Present => Out_P,
                   Parameter_Type =>
                     New_Reference_To (Etyp, Loc))));
      end Build_Spec;

      --  Start of processing for New_Stream_Procedure

   begin
      F        := First_Formal (Subp);
      Etyp     := Etype (Next_Formal (F));

      if not Is_Tagged_Type (Ent) then
         Subp_Decl :=
           Make_Subprogram_Declaration (Loc,
             Specification => Build_Spec);
         Insert_Action (N, Subp_Decl);
      end if;

      Subp_Decl :=
        Make_Subprogram_Renaming_Declaration (Loc,
          Specification => Build_Spec,
          Name => New_Reference_To (Subp, Loc));

      if Is_Tagged_Type (Ent) and then not Is_Limited_Type (Ent) then
         Set_TSS (Base_Type (Ent), Subp_Id);
      else
         Insert_Action (N, Subp_Decl);
         Copy_TSS (Subp_Id, Base_Type (Ent));
      end if;
   end New_Stream_Procedure;

   ---------------------
   -- Record_Rep_Item --
   ---------------------

   procedure Record_Rep_Item (T : Entity_Id; N : Node_Id) is
   begin
      Set_Next_Rep_Item (N, First_Rep_Item (T));
      Set_First_Rep_Item (T, N);
   end Record_Rep_Item;

   ------------------------
   -- Rep_Item_Too_Early --
   ------------------------

   function Rep_Item_Too_Early
     (T : Entity_Id;
      N : Node_Id) return Boolean
   is
   begin
      --  Cannot apply rep items that are not operational items
      --  to generic types

      if Is_Operational_Item (N) then
         return False;

      elsif Is_Type (T)
        and then Is_Generic_Type (Root_Type (T))
      then
         Error_Msg_N
           ("representation item not allowed for generic type", N);
         return True;
      end if;

      --  Otherwise check for incompleted type

      if Is_Incomplete_Or_Private_Type (T)
        and then No (Underlying_Type (T))
      then
         Error_Msg_N
           ("representation item must be after full type declaration", N);
         return True;

      --  If the type has incompleted components, a representation clause is
      --  illegal but stream attributes and Convention pragmas are correct.

      elsif Has_Private_Component (T) then
         if Nkind (N) = N_Pragma then
            return False;
         else
            Error_Msg_N
              ("representation item must appear after type is fully defined",
                N);
            return True;
         end if;
      else
         return False;
      end if;
   end Rep_Item_Too_Early;

   -----------------------
   -- Rep_Item_Too_Late --
   -----------------------

   function Rep_Item_Too_Late
     (T     : Entity_Id;
      N     : Node_Id;
      FOnly : Boolean := False) return Boolean
   is
      S           : Entity_Id;
      Parent_Type : Entity_Id;

      procedure Too_Late;
      --  Output the too late message

      procedure Too_Late is
      begin
         Error_Msg_N ("representation item appears too late!", N);
      end Too_Late;

   --  Start of processing for Rep_Item_Too_Late

   begin
      --  First make sure entity is not frozen (RM 13.1(9)). Exclude imported
      --  types, which may be frozen if they appear in a representation clause
      --  for a local type.

      if Is_Frozen (T)
        and then not From_With_Type (T)
      then
         Too_Late;
         S := First_Subtype (T);

         if Present (Freeze_Node (S)) then
            Error_Msg_NE
              ("?no more representation items for }!", Freeze_Node (S), S);
         end if;

         return True;

      --  Check for case of non-tagged derived type whose parent either has
      --  primitive operations, or is a by reference type (RM 13.1(10)).

      elsif Is_Type (T)
        and then not FOnly
        and then Is_Derived_Type (T)
        and then not Is_Tagged_Type (T)
      then
         Parent_Type := Etype (Base_Type (T));

         if Has_Primitive_Operations (Parent_Type) then
            Too_Late;
            Error_Msg_NE
              ("primitive operations already defined for&!", N, Parent_Type);
            return True;

         elsif Is_By_Reference_Type (Parent_Type) then
            Too_Late;
            Error_Msg_NE
              ("parent type & is a by reference type!", N, Parent_Type);
            return True;
         end if;
      end if;

      --  No error, link item into head of chain of rep items for the entity

      Record_Rep_Item (T, N);
      return False;
   end Rep_Item_Too_Late;

   -------------------------
   -- Same_Representation --
   -------------------------

   function Same_Representation (Typ1, Typ2 : Entity_Id) return Boolean is
      T1 : constant Entity_Id := Underlying_Type (Typ1);
      T2 : constant Entity_Id := Underlying_Type (Typ2);

   begin
      --  A quick check, if base types are the same, then we definitely have
      --  the same representation, because the subtype specific representation
      --  attributes (Size and Alignment) do not affect representation from
      --  the point of view of this test.

      if Base_Type (T1) = Base_Type (T2) then
         return True;

      elsif Is_Private_Type (Base_Type (T2))
        and then Base_Type (T1) = Full_View (Base_Type (T2))
      then
         return True;
      end if;

      --  Tagged types never have differing representations

      if Is_Tagged_Type (T1) then
         return True;
      end if;

      --  Representations are definitely different if conventions differ

      if Convention (T1) /= Convention (T2) then
         return False;
      end if;

      --  Representations are different if component alignments differ

      if (Is_Record_Type (T1) or else Is_Array_Type (T1))
        and then
         (Is_Record_Type (T2) or else Is_Array_Type (T2))
        and then Component_Alignment (T1) /= Component_Alignment (T2)
      then
         return False;
      end if;

      --  For arrays, the only real issue is component size. If we know the
      --  component size for both arrays, and it is the same, then that's
      --  good enough to know we don't have a change of representation.

      if Is_Array_Type (T1) then
         if Known_Component_Size (T1)
           and then Known_Component_Size (T2)
           and then Component_Size (T1) = Component_Size (T2)
         then
            return True;
         end if;
      end if;

      --  Types definitely have same representation if neither has non-standard
      --  representation since default representations are always consistent.
      --  If only one has non-standard representation, and the other does not,
      --  then we consider that they do not have the same representation. They
      --  might, but there is no way of telling early enough.

      if Has_Non_Standard_Rep (T1) then
         if not Has_Non_Standard_Rep (T2) then
            return False;
         end if;
      else
         return not Has_Non_Standard_Rep (T2);
      end if;

      --  Here the two types both have non-standard representation, and we
      --  need to determine if they have the same non-standard representation

      --  For arrays, we simply need to test if the component sizes are the
      --  same. Pragma Pack is reflected in modified component sizes, so this
      --  check also deals with pragma Pack.

      if Is_Array_Type (T1) then
         return Component_Size (T1) = Component_Size (T2);

      --  Tagged types always have the same representation, because it is not
      --  possible to specify different representations for common fields.

      elsif Is_Tagged_Type (T1) then
         return True;

      --  Case of record types

      elsif Is_Record_Type (T1) then

         --  Packed status must conform

         if Is_Packed (T1) /= Is_Packed (T2) then
            return False;

         --  Otherwise we must check components. Typ2 maybe a constrained
         --  subtype with fewer components, so we compare the components
         --  of the base types.

         else
            Record_Case : declare
               CD1, CD2 : Entity_Id;

               function Same_Rep return Boolean;
               --  CD1 and CD2 are either components or discriminants. This
               --  function tests whether the two have the same representation

               function Same_Rep return Boolean is
               begin
                  if No (Component_Clause (CD1)) then
                     return No (Component_Clause (CD2));

                  else
                     return
                        Present (Component_Clause (CD2))
                          and then
                        Component_Bit_Offset (CD1) = Component_Bit_Offset (CD2)
                          and then
                        Esize (CD1) = Esize (CD2);
                  end if;
               end Same_Rep;

            --  Start processing for Record_Case

            begin
               if Has_Discriminants (T1) then
                  CD1 := First_Discriminant (T1);
                  CD2 := First_Discriminant (T2);

                  --  The number of discriminants may be different if the
                  --  derived type has fewer (constrained by values). The
                  --  invisible discriminants retain the representation of
                  --  the original, so the discrepancy does not per se
                  --  indicate a different representation.

                  while Present (CD1)
                    and then Present (CD2)
                  loop
                     if not Same_Rep then
                        return False;
                     else
                        Next_Discriminant (CD1);
                        Next_Discriminant (CD2);
                     end if;
                  end loop;
               end if;

               CD1 := First_Component (Underlying_Type (Base_Type (T1)));
               CD2 := First_Component (Underlying_Type (Base_Type (T2)));

               while Present (CD1) loop
                  if not Same_Rep then
                     return False;
                  else
                     Next_Component (CD1);
                     Next_Component (CD2);
                  end if;
               end loop;

               return True;
            end Record_Case;
         end if;

      --  For enumeration types, we must check each literal to see if the
      --  representation is the same. Note that we do not permit enumeration
      --  reprsentation clauses for Character and Wide_Character, so these
      --  cases were already dealt with.

      elsif Is_Enumeration_Type (T1) then

         Enumeration_Case : declare
            L1, L2 : Entity_Id;

         begin
            L1 := First_Literal (T1);
            L2 := First_Literal (T2);

            while Present (L1) loop
               if Enumeration_Rep (L1) /= Enumeration_Rep (L2) then
                  return False;
               else
                  Next_Literal (L1);
                  Next_Literal (L2);
               end if;
            end loop;

            return True;

         end Enumeration_Case;

      --  Any other types have the same representation for these purposes

      else
         return True;
      end if;
   end Same_Representation;

   --------------------
   -- Set_Enum_Esize --
   --------------------

   procedure Set_Enum_Esize (T : Entity_Id) is
      Lo : Uint;
      Hi : Uint;
      Sz : Nat;

   begin
      Init_Alignment (T);

      --  Find the minimum standard size (8,16,32,64) that fits

      Lo := Enumeration_Rep (Entity (Type_Low_Bound (T)));
      Hi := Enumeration_Rep (Entity (Type_High_Bound (T)));

      if Lo < 0 then
         if Lo >= -Uint_2**07 and then Hi < Uint_2**07 then
            Sz := Standard_Character_Size;  -- May be > 8 on some targets

         elsif Lo >= -Uint_2**15 and then Hi < Uint_2**15 then
            Sz := 16;

         elsif Lo >= -Uint_2**31 and then Hi < Uint_2**31 then
            Sz := 32;

         else pragma Assert (Lo >= -Uint_2**63 and then Hi < Uint_2**63);
            Sz := 64;
         end if;

      else
         if Hi < Uint_2**08 then
            Sz := Standard_Character_Size;  -- May be > 8 on some targets

         elsif Hi < Uint_2**16 then
            Sz := 16;

         elsif Hi < Uint_2**32 then
            Sz := 32;

         else pragma Assert (Hi < Uint_2**63);
            Sz := 64;
         end if;
      end if;

      --  That minimum is the proper size unless we have a foreign convention
      --  and the size required is 32 or less, in which case we bump the size
      --  up to 32. This is required for C and C++ and seems reasonable for
      --  all other foreign conventions.

      if Has_Foreign_Convention (T)
        and then Esize (T) < Standard_Integer_Size
      then
         Init_Esize (T, Standard_Integer_Size);

      else
         Init_Esize (T, Sz);
      end if;
   end Set_Enum_Esize;

   -----------------------------------
   -- Validate_Unchecked_Conversion --
   -----------------------------------

   procedure Validate_Unchecked_Conversion
     (N        : Node_Id;
      Act_Unit : Entity_Id)
   is
      Source : Entity_Id;
      Target : Entity_Id;
      Vnode  : Node_Id;

   begin
      --  Obtain source and target types. Note that we call Ancestor_Subtype
      --  here because the processing for generic instantiation always makes
      --  subtypes, and we want the original frozen actual types.

      --  If we are dealing with private types, then do the check on their
      --  fully declared counterparts if the full declarations have been
      --  encountered (they don't have to be visible, but they must exist!)

      Source := Ancestor_Subtype (Etype (First_Formal (Act_Unit)));

      if Is_Private_Type (Source)
        and then Present (Underlying_Type (Source))
      then
         Source := Underlying_Type (Source);
      end if;

      Target := Ancestor_Subtype (Etype (Act_Unit));

      --  If either type is generic, the instantiation happens within a
      --  generic unit, and there is nothing to check. The proper check
      --  will happen when the enclosing generic is instantiated.

      if Is_Generic_Type (Source) or else Is_Generic_Type (Target) then
         return;
      end if;

      if Is_Private_Type (Target)
        and then Present (Underlying_Type (Target))
      then
         Target := Underlying_Type (Target);
      end if;

      --  Source may be unconstrained array, but not target

      if Is_Array_Type (Target)
        and then not Is_Constrained (Target)
      then
         Error_Msg_N
           ("unchecked conversion to unconstrained array not allowed", N);
         return;
      end if;

      --  Make entry in unchecked conversion table for later processing
      --  by Validate_Unchecked_Conversions, which will check sizes and
      --  alignments (using values set by the back-end where possible).
      --  This is only done if the appropriate warning is active

      if Warn_On_Unchecked_Conversion then
         Unchecked_Conversions.Append
           (New_Val => UC_Entry'
              (Enode  => N,
               Source => Source,
               Target => Target));

         --  If both sizes are known statically now, then back end annotation
         --  is not required to do a proper check but if either size is not
         --  known statically, then we need the annotation.

         if Known_Static_RM_Size (Source)
           and then Known_Static_RM_Size (Target)
         then
            null;
         else
            Back_Annotate_Rep_Info := True;
         end if;
      end if;

      --  If unchecked conversion to access type, and access type is
      --  declared in the same unit as the unchecked conversion, then
      --  set the No_Strict_Aliasing flag (no strict aliasing is
      --  implicit in this situation).

      if Is_Access_Type (Target) and then
        In_Same_Source_Unit (Target, N)
      then
         Set_No_Strict_Aliasing (Implementation_Base_Type (Target));
      end if;

      --  Generate N_Validate_Unchecked_Conversion node for back end in
      --  case the back end needs to perform special validation checks.

      --  Shouldn't this be in exp_ch13, since the check only gets done
      --  if we have full expansion and the back end is called ???

      Vnode :=
        Make_Validate_Unchecked_Conversion (Sloc (N));
      Set_Source_Type (Vnode, Source);
      Set_Target_Type (Vnode, Target);

      --  If the unchecked conversion node is in a list, just insert before
      --  it. If not we have some strange case, not worth bothering about.

      if Is_List_Member (N) then
         Insert_After (N, Vnode);
      end if;
   end Validate_Unchecked_Conversion;

   ------------------------------------
   -- Validate_Unchecked_Conversions --
   ------------------------------------

   procedure Validate_Unchecked_Conversions is
   begin
      for N in Unchecked_Conversions.First .. Unchecked_Conversions.Last loop
         declare
            T : UC_Entry renames Unchecked_Conversions.Table (N);

            Enode  : constant Node_Id   := T.Enode;
            Source : constant Entity_Id := T.Source;
            Target : constant Entity_Id := T.Target;

            Source_Siz    : Uint;
            Target_Siz    : Uint;

         begin
            --  This validation check, which warns if we have unequal sizes
            --  for unchecked conversion, and thus potentially implementation
            --  dependent semantics, is one of the few occasions on which we
            --  use the official RM size instead of Esize. See description
            --  in Einfo "Handling of Type'Size Values" for details.

            if Serious_Errors_Detected = 0
              and then Known_Static_RM_Size (Source)
              and then Known_Static_RM_Size (Target)
            then
               Source_Siz := RM_Size (Source);
               Target_Siz := RM_Size (Target);

               if Source_Siz /= Target_Siz then
                  Error_Msg_N
                    ("types for unchecked conversion have different sizes?",
                     Enode);

                  if All_Errors_Mode then
                     Error_Msg_Name_1 := Chars (Source);
                     Error_Msg_Uint_1 := Source_Siz;
                     Error_Msg_Name_2 := Chars (Target);
                     Error_Msg_Uint_2 := Target_Siz;
                     Error_Msg_N
                       ("\size of % is ^, size of % is ^?", Enode);

                     Error_Msg_Uint_1 := UI_Abs (Source_Siz - Target_Siz);

                     if Is_Discrete_Type (Source)
                       and then Is_Discrete_Type (Target)
                     then
                        if Source_Siz > Target_Siz then
                           Error_Msg_N
                             ("\^ high order bits of source will be ignored?",
                              Enode);

                        elsif Is_Unsigned_Type (Source) then
                           Error_Msg_N
                             ("\source will be extended with ^ high order " &
                              "zero bits?", Enode);

                        else
                           Error_Msg_N
                             ("\source will be extended with ^ high order " &
                              "sign bits?",
                              Enode);
                        end if;

                     elsif Source_Siz < Target_Siz then
                        if Is_Discrete_Type (Target) then
                           if Bytes_Big_Endian then
                              Error_Msg_N
                                ("\target value will include ^ undefined " &
                                 "low order bits?",
                                 Enode);
                           else
                              Error_Msg_N
                                ("\target value will include ^ undefined " &
                                 "high order bits?",
                                 Enode);
                           end if;

                        else
                           Error_Msg_N
                             ("\^ trailing bits of target value will be " &
                              "undefined?", Enode);
                        end if;

                     else pragma Assert (Source_Siz > Target_Siz);
                        Error_Msg_N
                          ("\^ trailing bits of source will be ignored?",
                           Enode);
                     end if;
                  end if;
               end if;
            end if;

            --  If both types are access types, we need to check the alignment.
            --  If the alignment of both is specified, we can do it here.

            if Serious_Errors_Detected = 0
              and then Ekind (Source) in Access_Kind
              and then Ekind (Target) in Access_Kind
              and then Target_Strict_Alignment
              and then Present (Designated_Type (Source))
              and then Present (Designated_Type (Target))
            then
               declare
                  D_Source : constant Entity_Id := Designated_Type (Source);
                  D_Target : constant Entity_Id := Designated_Type (Target);

               begin
                  if Known_Alignment (D_Source)
                    and then Known_Alignment (D_Target)
                  then
                     declare
                        Source_Align : constant Uint := Alignment (D_Source);
                        Target_Align : constant Uint := Alignment (D_Target);

                     begin
                        if Source_Align < Target_Align
                          and then not Is_Tagged_Type (D_Source)
                        then
                           Error_Msg_Uint_1 := Target_Align;
                           Error_Msg_Uint_2 := Source_Align;
                           Error_Msg_Node_2 := D_Source;
                           Error_Msg_NE
                             ("alignment of & (^) is stricter than " &
                              "alignment of & (^)?", Enode, D_Target);

                           if All_Errors_Mode then
                              Error_Msg_N
                                ("\resulting access value may have invalid " &
                                 "alignment?", Enode);
                           end if;
                        end if;
                     end;
                  end if;
               end;
            end if;
         end;
      end loop;
   end Validate_Unchecked_Conversions;

end Sem_Ch13;