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
|
------------------------------------------------------------------------------
-- --
-- GNAT COMPILER COMPONENTS --
-- --
-- P A R . C H 4 --
-- --
-- B o d y --
-- --
-- Copyright (C) 1992-2009, 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 3, 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 COPYING3. If not, go to --
-- http://www.gnu.org/licenses for a complete copy of the license. --
-- --
-- GNAT was originally developed by the GNAT team at New York University. --
-- Extensive contributions were provided by Ada Core Technologies Inc. --
-- --
------------------------------------------------------------------------------
pragma Style_Checks (All_Checks);
-- Turn off subprogram body ordering check. Subprograms are in order
-- by RM section rather than alphabetical
with Stringt; use Stringt;
separate (Par)
package body Ch4 is
-- Attributes that cannot have arguments
Is_Parameterless_Attribute : constant Attribute_Class_Array :=
(Attribute_Body_Version => True,
Attribute_External_Tag => True,
Attribute_Img => True,
Attribute_Version => True,
Attribute_Base => True,
Attribute_Class => True,
Attribute_Stub_Type => True,
others => False);
-- This map contains True for parameterless attributes that return a
-- string or a type. For those attributes, a left parenthesis after
-- the attribute should not be analyzed as the beginning of a parameters
-- list because it may denote a slice operation (X'Img (1 .. 2)) or
-- a type conversion (X'Class (Y)).
-- Note that this map designates the minimum set of attributes where a
-- construct in parentheses that is not an argument can appear right
-- after the attribute. For attributes like 'Size, we do not put them
-- in the map. If someone writes X'Size (3), that's illegal in any case,
-- but we get a better error message by parsing the (3) as an illegal
-- argument to the attribute, rather than some meaningless junk that
-- follows the attribute.
-----------------------
-- Local Subprograms --
-----------------------
function P_Aggregate_Or_Paren_Expr return Node_Id;
function P_Allocator return Node_Id;
function P_Record_Or_Array_Component_Association return Node_Id;
function P_Factor return Node_Id;
function P_Primary return Node_Id;
function P_Relation return Node_Id;
function P_Term return Node_Id;
function P_Binary_Adding_Operator return Node_Kind;
function P_Logical_Operator return Node_Kind;
function P_Multiplying_Operator return Node_Kind;
function P_Relational_Operator return Node_Kind;
function P_Unary_Adding_Operator return Node_Kind;
procedure Bad_Range_Attribute (Loc : Source_Ptr);
-- Called to place complaint about bad range attribute at the given
-- source location. Terminates by raising Error_Resync.
function P_Range_Attribute_Reference (Prefix_Node : Node_Id) return Node_Id;
-- Scan a range attribute reference. The caller has scanned out the
-- prefix. The current token is known to be an apostrophe and the
-- following token is known to be RANGE.
procedure Set_Op_Name (Node : Node_Id);
-- Procedure to set name field (Chars) in operator node
-------------------------
-- Bad_Range_Attribute --
-------------------------
procedure Bad_Range_Attribute (Loc : Source_Ptr) is
begin
Error_Msg ("range attribute cannot be used in expression!", Loc);
Resync_Expression;
end Bad_Range_Attribute;
------------------
-- Set_Op_Name --
------------------
procedure Set_Op_Name (Node : Node_Id) is
type Name_Of_Type is array (N_Op) of Name_Id;
Name_Of : constant Name_Of_Type := Name_Of_Type'(
N_Op_And => Name_Op_And,
N_Op_Or => Name_Op_Or,
N_Op_Xor => Name_Op_Xor,
N_Op_Eq => Name_Op_Eq,
N_Op_Ne => Name_Op_Ne,
N_Op_Lt => Name_Op_Lt,
N_Op_Le => Name_Op_Le,
N_Op_Gt => Name_Op_Gt,
N_Op_Ge => Name_Op_Ge,
N_Op_Add => Name_Op_Add,
N_Op_Subtract => Name_Op_Subtract,
N_Op_Concat => Name_Op_Concat,
N_Op_Multiply => Name_Op_Multiply,
N_Op_Divide => Name_Op_Divide,
N_Op_Mod => Name_Op_Mod,
N_Op_Rem => Name_Op_Rem,
N_Op_Expon => Name_Op_Expon,
N_Op_Plus => Name_Op_Add,
N_Op_Minus => Name_Op_Subtract,
N_Op_Abs => Name_Op_Abs,
N_Op_Not => Name_Op_Not,
-- We don't really need these shift operators, since they never
-- appear as operators in the source, but the path of least
-- resistance is to put them in (the aggregate must be complete)
N_Op_Rotate_Left => Name_Rotate_Left,
N_Op_Rotate_Right => Name_Rotate_Right,
N_Op_Shift_Left => Name_Shift_Left,
N_Op_Shift_Right => Name_Shift_Right,
N_Op_Shift_Right_Arithmetic => Name_Shift_Right_Arithmetic);
begin
if Nkind (Node) in N_Op then
Set_Chars (Node, Name_Of (Nkind (Node)));
end if;
end Set_Op_Name;
--------------------------
-- 4.1 Name (also 6.4) --
--------------------------
-- NAME ::=
-- DIRECT_NAME | EXPLICIT_DEREFERENCE
-- | INDEXED_COMPONENT | SLICE
-- | SELECTED_COMPONENT | ATTRIBUTE
-- | TYPE_CONVERSION | FUNCTION_CALL
-- | CHARACTER_LITERAL
-- DIRECT_NAME ::= IDENTIFIER | OPERATOR_SYMBOL
-- PREFIX ::= NAME | IMPLICIT_DEREFERENCE
-- EXPLICIT_DEREFERENCE ::= NAME . all
-- IMPLICIT_DEREFERENCE ::= NAME
-- INDEXED_COMPONENT ::= PREFIX (EXPRESSION {, EXPRESSION})
-- SLICE ::= PREFIX (DISCRETE_RANGE)
-- SELECTED_COMPONENT ::= PREFIX . SELECTOR_NAME
-- SELECTOR_NAME ::= IDENTIFIER | CHARACTER_LITERAL | OPERATOR_SYMBOL
-- ATTRIBUTE_REFERENCE ::= PREFIX ' ATTRIBUTE_DESIGNATOR
-- ATTRIBUTE_DESIGNATOR ::=
-- IDENTIFIER [(static_EXPRESSION)]
-- | access | delta | digits
-- FUNCTION_CALL ::=
-- function_NAME
-- | function_PREFIX ACTUAL_PARAMETER_PART
-- ACTUAL_PARAMETER_PART ::=
-- (PARAMETER_ASSOCIATION {,PARAMETER_ASSOCIATION})
-- PARAMETER_ASSOCIATION ::=
-- [formal_parameter_SELECTOR_NAME =>] EXPLICIT_ACTUAL_PARAMETER
-- EXPLICIT_ACTUAL_PARAMETER ::= EXPRESSION | variable_NAME
-- Note: syntactically a procedure call looks just like a function call,
-- so this routine is in practice used to scan out procedure calls as well.
-- On return, Expr_Form is set to either EF_Name or EF_Simple_Name
-- Error recovery: can raise Error_Resync
-- Note: if on return Token = Tok_Apostrophe, then the apostrophe must be
-- followed by either a left paren (qualified expression case), or by
-- range (range attribute case). All other uses of apostrophe (i.e. all
-- other attributes) are handled in this routine.
-- Error recovery: can raise Error_Resync
function P_Name return Node_Id is
Scan_State : Saved_Scan_State;
Name_Node : Node_Id;
Prefix_Node : Node_Id;
Ident_Node : Node_Id;
Expr_Node : Node_Id;
Range_Node : Node_Id;
Arg_Node : Node_Id;
Arg_List : List_Id := No_List; -- kill junk warning
Attr_Name : Name_Id := No_Name; -- kill junk warning
begin
-- Case of not a name
if Token not in Token_Class_Name then
-- If it looks like start of expression, complain and scan expression
if Token in Token_Class_Literal
or else Token = Tok_Left_Paren
then
Error_Msg_SC ("name expected");
return P_Expression;
-- Otherwise some other junk, not much we can do
else
Error_Msg_AP ("name expected");
raise Error_Resync;
end if;
end if;
-- Loop through designators in qualified name
Name_Node := Token_Node;
loop
Scan; -- past designator
exit when Token /= Tok_Dot;
Save_Scan_State (Scan_State); -- at dot
Scan; -- past dot
-- If we do not have another designator after the dot, then join
-- the normal circuit to handle a dot extension (may be .all or
-- character literal case). Otherwise loop back to scan the next
-- designator.
if Token not in Token_Class_Desig then
goto Scan_Name_Extension_Dot;
else
Prefix_Node := Name_Node;
Name_Node := New_Node (N_Selected_Component, Prev_Token_Ptr);
Set_Prefix (Name_Node, Prefix_Node);
Set_Selector_Name (Name_Node, Token_Node);
end if;
end loop;
-- We have now scanned out a qualified designator. If the last token is
-- an operator symbol, then we certainly do not have the Snam case, so
-- we can just use the normal name extension check circuit
if Prev_Token = Tok_Operator_Symbol then
goto Scan_Name_Extension;
end if;
-- We have scanned out a qualified simple name, check for name extension
-- Note that we know there is no dot here at this stage, so the only
-- possible cases of name extension are apostrophe and left paren.
if Token = Tok_Apostrophe then
Save_Scan_State (Scan_State); -- at apostrophe
Scan; -- past apostrophe
-- If left paren, then this might be a qualified expression, but we
-- are only in the business of scanning out names, so return with
-- Token backed up to point to the apostrophe. The treatment for
-- the range attribute is similar (we do not consider x'range to
-- be a name in this grammar).
if Token = Tok_Left_Paren or else Token = Tok_Range then
Restore_Scan_State (Scan_State); -- to apostrophe
Expr_Form := EF_Simple_Name;
return Name_Node;
-- Otherwise we have the case of a name extended by an attribute
else
goto Scan_Name_Extension_Apostrophe;
end if;
-- Check case of qualified simple name extended by a left parenthesis
elsif Token = Tok_Left_Paren then
Scan; -- past left paren
goto Scan_Name_Extension_Left_Paren;
-- Otherwise the qualified simple name is not extended, so return
else
Expr_Form := EF_Simple_Name;
return Name_Node;
end if;
-- Loop scanning past name extensions. A label is used for control
-- transfer for this loop for ease of interfacing with the finite state
-- machine in the parenthesis scanning circuit, and also to allow for
-- passing in control to the appropriate point from the above code.
<<Scan_Name_Extension>>
-- Character literal used as name cannot be extended. Also this
-- cannot be a call, since the name for a call must be a designator.
-- Return in these cases, or if there is no name extension
if Token not in Token_Class_Namext
or else Prev_Token = Tok_Char_Literal
then
Expr_Form := EF_Name;
return Name_Node;
end if;
-- Merge here when we know there is a name extension
<<Scan_Name_Extension_OK>>
if Token = Tok_Left_Paren then
Scan; -- past left paren
goto Scan_Name_Extension_Left_Paren;
elsif Token = Tok_Apostrophe then
Save_Scan_State (Scan_State); -- at apostrophe
Scan; -- past apostrophe
goto Scan_Name_Extension_Apostrophe;
else -- Token = Tok_Dot
Save_Scan_State (Scan_State); -- at dot
Scan; -- past dot
goto Scan_Name_Extension_Dot;
end if;
-- Case of name extended by dot (selection), dot is already skipped
-- and the scan state at the point of the dot is saved in Scan_State.
<<Scan_Name_Extension_Dot>>
-- Explicit dereference case
if Token = Tok_All then
Prefix_Node := Name_Node;
Name_Node := New_Node (N_Explicit_Dereference, Token_Ptr);
Set_Prefix (Name_Node, Prefix_Node);
Scan; -- past ALL
goto Scan_Name_Extension;
-- Selected component case
elsif Token in Token_Class_Name then
Prefix_Node := Name_Node;
Name_Node := New_Node (N_Selected_Component, Prev_Token_Ptr);
Set_Prefix (Name_Node, Prefix_Node);
Set_Selector_Name (Name_Node, Token_Node);
Scan; -- past selector
goto Scan_Name_Extension;
-- Reserved identifier as selector
elsif Is_Reserved_Identifier then
Scan_Reserved_Identifier (Force_Msg => False);
Prefix_Node := Name_Node;
Name_Node := New_Node (N_Selected_Component, Prev_Token_Ptr);
Set_Prefix (Name_Node, Prefix_Node);
Set_Selector_Name (Name_Node, Token_Node);
Scan; -- past identifier used as selector
goto Scan_Name_Extension;
-- If dot is at end of line and followed by nothing legal,
-- then assume end of name and quit (dot will be taken as
-- an erroneous form of some other punctuation by our caller).
elsif Token_Is_At_Start_Of_Line then
Restore_Scan_State (Scan_State);
return Name_Node;
-- Here if nothing legal after the dot
else
Error_Msg_AP ("selector expected");
raise Error_Resync;
end if;
-- Here for an apostrophe as name extension. The scan position at the
-- apostrophe has already been saved, and the apostrophe scanned out.
<<Scan_Name_Extension_Apostrophe>>
Scan_Apostrophe : declare
function Apostrophe_Should_Be_Semicolon return Boolean;
-- Checks for case where apostrophe should probably be
-- a semicolon, and if so, gives appropriate message,
-- resets the scan pointer to the apostrophe, changes
-- the current token to Tok_Semicolon, and returns True.
-- Otherwise returns False.
function Apostrophe_Should_Be_Semicolon return Boolean is
begin
if Token_Is_At_Start_Of_Line then
Restore_Scan_State (Scan_State); -- to apostrophe
Error_Msg_SC ("|""''"" should be "";""");
Token := Tok_Semicolon;
return True;
else
return False;
end if;
end Apostrophe_Should_Be_Semicolon;
-- Start of processing for Scan_Apostrophe
begin
-- If range attribute after apostrophe, then return with Token
-- pointing to the apostrophe. Note that in this case the prefix
-- need not be a simple name (cases like A.all'range). Similarly
-- if there is a left paren after the apostrophe, then we also
-- return with Token pointing to the apostrophe (this is the
-- qualified expression case).
if Token = Tok_Range or else Token = Tok_Left_Paren then
Restore_Scan_State (Scan_State); -- to apostrophe
Expr_Form := EF_Name;
return Name_Node;
-- Here for cases where attribute designator is an identifier
elsif Token = Tok_Identifier then
Attr_Name := Token_Name;
if not Is_Attribute_Name (Attr_Name) then
if Apostrophe_Should_Be_Semicolon then
Expr_Form := EF_Name;
return Name_Node;
-- Here for a bad attribute name
else
Signal_Bad_Attribute;
Scan; -- past bad identifier
if Token = Tok_Left_Paren then
Scan; -- past left paren
loop
Discard_Junk_Node (P_Expression_If_OK);
exit when not Comma_Present;
end loop;
T_Right_Paren;
end if;
return Error;
end if;
end if;
if Style_Check then
Style.Check_Attribute_Name (False);
end if;
-- Here for case of attribute designator is not an identifier
else
if Token = Tok_Delta then
Attr_Name := Name_Delta;
elsif Token = Tok_Digits then
Attr_Name := Name_Digits;
elsif Token = Tok_Access then
Attr_Name := Name_Access;
elsif Token = Tok_Mod and then Ada_Version = Ada_05 then
Attr_Name := Name_Mod;
elsif Apostrophe_Should_Be_Semicolon then
Expr_Form := EF_Name;
return Name_Node;
else
Error_Msg_AP ("attribute designator expected");
raise Error_Resync;
end if;
if Style_Check then
Style.Check_Attribute_Name (True);
end if;
end if;
-- We come here with an OK attribute scanned, and the
-- corresponding Attribute identifier node stored in Ident_Node.
Prefix_Node := Name_Node;
Name_Node := New_Node (N_Attribute_Reference, Prev_Token_Ptr);
Scan; -- past attribute designator
Set_Prefix (Name_Node, Prefix_Node);
Set_Attribute_Name (Name_Node, Attr_Name);
-- Scan attribute arguments/designator. We skip this if we know
-- that the attribute cannot have an argument.
if Token = Tok_Left_Paren
and then not
Is_Parameterless_Attribute (Get_Attribute_Id (Attr_Name))
then
Set_Expressions (Name_Node, New_List);
Scan; -- past left paren
loop
declare
Expr : constant Node_Id := P_Expression_If_OK;
begin
if Token = Tok_Arrow then
Error_Msg_SC
("named parameters not permitted for attributes");
Scan; -- past junk arrow
else
Append (Expr, Expressions (Name_Node));
exit when not Comma_Present;
end if;
end;
end loop;
T_Right_Paren;
end if;
goto Scan_Name_Extension;
end Scan_Apostrophe;
-- Here for left parenthesis extending name (left paren skipped)
<<Scan_Name_Extension_Left_Paren>>
-- We now have to scan through a list of items, terminated by a
-- right parenthesis. The scan is handled by a finite state
-- machine. The possibilities are:
-- (discrete_range)
-- This is a slice. This case is handled in LP_State_Init
-- (expression, expression, ..)
-- This is interpreted as an indexed component, i.e. as a
-- case of a name which can be extended in the normal manner.
-- This case is handled by LP_State_Name or LP_State_Expr.
-- Note: conditional expressions (without an extra level of
-- parentheses) are permitted in this context).
-- (..., identifier => expression , ...)
-- If there is at least one occurrence of identifier => (but
-- none of the other cases apply), then we have a call.
-- Test for Id => case
if Token = Tok_Identifier then
Save_Scan_State (Scan_State); -- at Id
Scan; -- past Id
-- Test for => (allow := as an error substitute)
if Token = Tok_Arrow or else Token = Tok_Colon_Equal then
Restore_Scan_State (Scan_State); -- to Id
Arg_List := New_List;
goto LP_State_Call;
else
Restore_Scan_State (Scan_State); -- to Id
end if;
end if;
-- Here we have an expression after all
Expr_Node := P_Expression_Or_Range_Attribute_If_OK;
-- Check cases of discrete range for a slice
-- First possibility: Range_Attribute_Reference
if Expr_Form = EF_Range_Attr then
Range_Node := Expr_Node;
-- Second possibility: Simple_expression .. Simple_expression
elsif Token = Tok_Dot_Dot then
Check_Simple_Expression (Expr_Node);
Range_Node := New_Node (N_Range, Token_Ptr);
Set_Low_Bound (Range_Node, Expr_Node);
Scan; -- past ..
Expr_Node := P_Expression;
Check_Simple_Expression (Expr_Node);
Set_High_Bound (Range_Node, Expr_Node);
-- Third possibility: Type_name range Range
elsif Token = Tok_Range then
if Expr_Form /= EF_Simple_Name then
Error_Msg_SC -- CODEFIX???
("subtype mark must precede RANGE");
raise Error_Resync;
end if;
Range_Node := P_Subtype_Indication (Expr_Node);
-- Otherwise we just have an expression. It is true that we might
-- have a subtype mark without a range constraint but this case
-- is syntactically indistinguishable from the expression case.
else
Arg_List := New_List;
goto LP_State_Expr;
end if;
-- Fall through here with unmistakable Discrete range scanned,
-- which means that we definitely have the case of a slice. The
-- Discrete range is in Range_Node.
if Token = Tok_Comma then
Error_Msg_SC ("slice cannot have more than one dimension");
raise Error_Resync;
elsif Token /= Tok_Right_Paren then
T_Right_Paren;
raise Error_Resync;
else
Scan; -- past right paren
Prefix_Node := Name_Node;
Name_Node := New_Node (N_Slice, Sloc (Prefix_Node));
Set_Prefix (Name_Node, Prefix_Node);
Set_Discrete_Range (Name_Node, Range_Node);
-- An operator node is legal as a prefix to other names,
-- but not for a slice.
if Nkind (Prefix_Node) = N_Operator_Symbol then
Error_Msg_N ("illegal prefix for slice", Prefix_Node);
end if;
-- If we have a name extension, go scan it
if Token in Token_Class_Namext then
goto Scan_Name_Extension_OK;
-- Otherwise return (a slice is a name, but is not a call)
else
Expr_Form := EF_Name;
return Name_Node;
end if;
end if;
-- In LP_State_Expr, we have scanned one or more expressions, and
-- so we have a call or an indexed component which is a name. On
-- entry we have the expression just scanned in Expr_Node and
-- Arg_List contains the list of expressions encountered so far
<<LP_State_Expr>>
Append (Expr_Node, Arg_List);
if Token = Tok_Arrow then
Error_Msg
("expect identifier in parameter association",
Sloc (Expr_Node));
Scan; -- past arrow.
elsif not Comma_Present then
T_Right_Paren;
Prefix_Node := Name_Node;
Name_Node := New_Node (N_Indexed_Component, Sloc (Prefix_Node));
Set_Prefix (Name_Node, Prefix_Node);
Set_Expressions (Name_Node, Arg_List);
goto Scan_Name_Extension;
end if;
-- Comma present (and scanned out), test for identifier => case
-- Test for identifier => case
if Token = Tok_Identifier then
Save_Scan_State (Scan_State); -- at Id
Scan; -- past Id
-- Test for => (allow := as error substitute)
if Token = Tok_Arrow or else Token = Tok_Colon_Equal then
Restore_Scan_State (Scan_State); -- to Id
goto LP_State_Call;
-- Otherwise it's just an expression after all, so backup
else
Restore_Scan_State (Scan_State); -- to Id
end if;
end if;
-- Here we have an expression after all, so stay in this state
Expr_Node := P_Expression_If_OK;
goto LP_State_Expr;
-- LP_State_Call corresponds to the situation in which at least
-- one instance of Id => Expression has been encountered, so we
-- know that we do not have a name, but rather a call. We enter
-- it with the scan pointer pointing to the next argument to scan,
-- and Arg_List containing the list of arguments scanned so far.
<<LP_State_Call>>
-- Test for case of Id => Expression (named parameter)
if Token = Tok_Identifier then
Save_Scan_State (Scan_State); -- at Id
Ident_Node := Token_Node;
Scan; -- past Id
-- Deal with => (allow := as erroneous substitute)
if Token = Tok_Arrow or else Token = Tok_Colon_Equal then
Arg_Node := New_Node (N_Parameter_Association, Prev_Token_Ptr);
Set_Selector_Name (Arg_Node, Ident_Node);
T_Arrow;
Set_Explicit_Actual_Parameter (Arg_Node, P_Expression);
Append (Arg_Node, Arg_List);
-- If a comma follows, go back and scan next entry
if Comma_Present then
goto LP_State_Call;
-- Otherwise we have the end of a call
else
Prefix_Node := Name_Node;
Name_Node := New_Node (N_Function_Call, Sloc (Prefix_Node));
Set_Name (Name_Node, Prefix_Node);
Set_Parameter_Associations (Name_Node, Arg_List);
T_Right_Paren;
if Token in Token_Class_Namext then
goto Scan_Name_Extension_OK;
-- This is a case of a call which cannot be a name
else
Expr_Form := EF_Name;
return Name_Node;
end if;
end if;
-- Not named parameter: Id started an expression after all
else
Restore_Scan_State (Scan_State); -- to Id
end if;
end if;
-- Here if entry did not start with Id => which means that it
-- is a positional parameter, which is not allowed, since we
-- have seen at least one named parameter already.
Error_Msg_SC
("positional parameter association " &
"not allowed after named one");
Expr_Node := P_Expression_If_OK;
-- Leaving the '>' in an association is not unusual, so suggest
-- a possible fix.
if Nkind (Expr_Node) = N_Op_Eq then
Error_Msg_N ("\maybe `='>` was intended", Expr_Node);
end if;
-- We go back to scanning out expressions, so that we do not get
-- multiple error messages when several positional parameters
-- follow a named parameter.
goto LP_State_Expr;
-- End of treatment for name extensions starting with left paren
-- End of loop through name extensions
end P_Name;
-- This function parses a restricted form of Names which are either
-- designators, or designators preceded by a sequence of prefixes
-- that are direct names.
-- Error recovery: cannot raise Error_Resync
function P_Function_Name return Node_Id is
Designator_Node : Node_Id;
Prefix_Node : Node_Id;
Selector_Node : Node_Id;
Dot_Sloc : Source_Ptr := No_Location;
begin
-- Prefix_Node is set to the gathered prefix so far, Empty means that
-- no prefix has been scanned. This allows us to build up the result
-- in the required right recursive manner.
Prefix_Node := Empty;
-- Loop through prefixes
loop
Designator_Node := Token_Node;
if Token not in Token_Class_Desig then
return P_Identifier; -- let P_Identifier issue the error message
else -- Token in Token_Class_Desig
Scan; -- past designator
exit when Token /= Tok_Dot;
end if;
-- Here at a dot, with token just before it in Designator_Node
if No (Prefix_Node) then
Prefix_Node := Designator_Node;
else
Selector_Node := New_Node (N_Selected_Component, Dot_Sloc);
Set_Prefix (Selector_Node, Prefix_Node);
Set_Selector_Name (Selector_Node, Designator_Node);
Prefix_Node := Selector_Node;
end if;
Dot_Sloc := Token_Ptr;
Scan; -- past dot
end loop;
-- Fall out of the loop having just scanned a designator
if No (Prefix_Node) then
return Designator_Node;
else
Selector_Node := New_Node (N_Selected_Component, Dot_Sloc);
Set_Prefix (Selector_Node, Prefix_Node);
Set_Selector_Name (Selector_Node, Designator_Node);
return Selector_Node;
end if;
exception
when Error_Resync =>
return Error;
end P_Function_Name;
-- This function parses a restricted form of Names which are either
-- identifiers, or identifiers preceded by a sequence of prefixes
-- that are direct names.
-- Error recovery: cannot raise Error_Resync
function P_Qualified_Simple_Name return Node_Id is
Designator_Node : Node_Id;
Prefix_Node : Node_Id;
Selector_Node : Node_Id;
Dot_Sloc : Source_Ptr := No_Location;
begin
-- Prefix node is set to the gathered prefix so far, Empty means that
-- no prefix has been scanned. This allows us to build up the result
-- in the required right recursive manner.
Prefix_Node := Empty;
-- Loop through prefixes
loop
Designator_Node := Token_Node;
if Token = Tok_Identifier then
Scan; -- past identifier
exit when Token /= Tok_Dot;
elsif Token not in Token_Class_Desig then
return P_Identifier; -- let P_Identifier issue the error message
else
Scan; -- past designator
if Token /= Tok_Dot then
Error_Msg_SP ("identifier expected");
return Error;
end if;
end if;
-- Here at a dot, with token just before it in Designator_Node
if No (Prefix_Node) then
Prefix_Node := Designator_Node;
else
Selector_Node := New_Node (N_Selected_Component, Dot_Sloc);
Set_Prefix (Selector_Node, Prefix_Node);
Set_Selector_Name (Selector_Node, Designator_Node);
Prefix_Node := Selector_Node;
end if;
Dot_Sloc := Token_Ptr;
Scan; -- past dot
end loop;
-- Fall out of the loop having just scanned an identifier
if No (Prefix_Node) then
return Designator_Node;
else
Selector_Node := New_Node (N_Selected_Component, Dot_Sloc);
Set_Prefix (Selector_Node, Prefix_Node);
Set_Selector_Name (Selector_Node, Designator_Node);
return Selector_Node;
end if;
exception
when Error_Resync =>
return Error;
end P_Qualified_Simple_Name;
-- This procedure differs from P_Qualified_Simple_Name only in that it
-- raises Error_Resync if any error is encountered. It only returns after
-- scanning a valid qualified simple name.
-- Error recovery: can raise Error_Resync
function P_Qualified_Simple_Name_Resync return Node_Id is
Designator_Node : Node_Id;
Prefix_Node : Node_Id;
Selector_Node : Node_Id;
Dot_Sloc : Source_Ptr := No_Location;
begin
Prefix_Node := Empty;
-- Loop through prefixes
loop
Designator_Node := Token_Node;
if Token = Tok_Identifier then
Scan; -- past identifier
exit when Token /= Tok_Dot;
elsif Token not in Token_Class_Desig then
Discard_Junk_Node (P_Identifier); -- to issue the error message
raise Error_Resync;
else
Scan; -- past designator
if Token /= Tok_Dot then
Error_Msg_SP ("identifier expected");
raise Error_Resync;
end if;
end if;
-- Here at a dot, with token just before it in Designator_Node
if No (Prefix_Node) then
Prefix_Node := Designator_Node;
else
Selector_Node := New_Node (N_Selected_Component, Dot_Sloc);
Set_Prefix (Selector_Node, Prefix_Node);
Set_Selector_Name (Selector_Node, Designator_Node);
Prefix_Node := Selector_Node;
end if;
Dot_Sloc := Token_Ptr;
Scan; -- past period
end loop;
-- Fall out of the loop having just scanned an identifier
if No (Prefix_Node) then
return Designator_Node;
else
Selector_Node := New_Node (N_Selected_Component, Dot_Sloc);
Set_Prefix (Selector_Node, Prefix_Node);
Set_Selector_Name (Selector_Node, Designator_Node);
return Selector_Node;
end if;
end P_Qualified_Simple_Name_Resync;
----------------------
-- 4.1 Direct_Name --
----------------------
-- Parsed by P_Name and other functions in section 4.1
-----------------
-- 4.1 Prefix --
-----------------
-- Parsed by P_Name (4.1)
-------------------------------
-- 4.1 Explicit Dereference --
-------------------------------
-- Parsed by P_Name (4.1)
-------------------------------
-- 4.1 Implicit_Dereference --
-------------------------------
-- Parsed by P_Name (4.1)
----------------------------
-- 4.1 Indexed Component --
----------------------------
-- Parsed by P_Name (4.1)
----------------
-- 4.1 Slice --
----------------
-- Parsed by P_Name (4.1)
-----------------------------
-- 4.1 Selected_Component --
-----------------------------
-- Parsed by P_Name (4.1)
------------------------
-- 4.1 Selector Name --
------------------------
-- Parsed by P_Name (4.1)
------------------------------
-- 4.1 Attribute Reference --
------------------------------
-- Parsed by P_Name (4.1)
-------------------------------
-- 4.1 Attribute Designator --
-------------------------------
-- Parsed by P_Name (4.1)
--------------------------------------
-- 4.1.4 Range Attribute Reference --
--------------------------------------
-- RANGE_ATTRIBUTE_REFERENCE ::= PREFIX ' RANGE_ATTRIBUTE_DESIGNATOR
-- RANGE_ATTRIBUTE_DESIGNATOR ::= range [(static_EXPRESSION)]
-- In the grammar, a RANGE attribute is simply a name, but its use is
-- highly restricted, so in the parser, we do not regard it as a name.
-- Instead, P_Name returns without scanning the 'RANGE part of the
-- attribute, and the caller uses the following function to construct
-- a range attribute in places where it is appropriate.
-- Note that RANGE here is treated essentially as an identifier,
-- rather than a reserved word.
-- The caller has parsed the prefix, i.e. a name, and Token points to
-- the apostrophe. The token after the apostrophe is known to be RANGE
-- at this point. The prefix node becomes the prefix of the attribute.
-- Error_Recovery: Cannot raise Error_Resync
function P_Range_Attribute_Reference
(Prefix_Node : Node_Id)
return Node_Id
is
Attr_Node : Node_Id;
begin
Attr_Node := New_Node (N_Attribute_Reference, Token_Ptr);
Set_Prefix (Attr_Node, Prefix_Node);
Scan; -- past apostrophe
if Style_Check then
Style.Check_Attribute_Name (True);
end if;
Set_Attribute_Name (Attr_Node, Name_Range);
Scan; -- past RANGE
if Token = Tok_Left_Paren then
Scan; -- past left paren
Set_Expressions (Attr_Node, New_List (P_Expression_If_OK));
T_Right_Paren;
end if;
return Attr_Node;
end P_Range_Attribute_Reference;
---------------------------------------
-- 4.1.4 Range Attribute Designator --
---------------------------------------
-- Parsed by P_Range_Attribute_Reference (4.4)
--------------------
-- 4.3 Aggregate --
--------------------
-- AGGREGATE ::= RECORD_AGGREGATE | EXTENSION_AGGREGATE | ARRAY_AGGREGATE
-- Parsed by P_Aggregate_Or_Paren_Expr (4.3), except in the case where
-- an aggregate is known to be required (code statement, extension
-- aggregate), in which cases this routine performs the necessary check
-- that we have an aggregate rather than a parenthesized expression
-- Error recovery: can raise Error_Resync
function P_Aggregate return Node_Id is
Aggr_Sloc : constant Source_Ptr := Token_Ptr;
Aggr_Node : constant Node_Id := P_Aggregate_Or_Paren_Expr;
begin
if Nkind (Aggr_Node) /= N_Aggregate
and then
Nkind (Aggr_Node) /= N_Extension_Aggregate
then
Error_Msg
("aggregate may not have single positional component", Aggr_Sloc);
return Error;
else
return Aggr_Node;
end if;
end P_Aggregate;
------------------------------------------------
-- 4.3 Aggregate or Parenthesized Expression --
------------------------------------------------
-- This procedure parses out either an aggregate or a parenthesized
-- expression (these two constructs are closely related, since a
-- parenthesized expression looks like an aggregate with a single
-- positional component).
-- AGGREGATE ::=
-- RECORD_AGGREGATE | EXTENSION_AGGREGATE | ARRAY_AGGREGATE
-- RECORD_AGGREGATE ::= (RECORD_COMPONENT_ASSOCIATION_LIST)
-- RECORD_COMPONENT_ASSOCIATION_LIST ::=
-- RECORD_COMPONENT_ASSOCIATION {, RECORD_COMPONENT_ASSOCIATION}
-- | null record
-- RECORD_COMPONENT_ASSOCIATION ::=
-- [COMPONENT_CHOICE_LIST =>] EXPRESSION
-- COMPONENT_CHOICE_LIST ::=
-- component_SELECTOR_NAME {| component_SELECTOR_NAME}
-- | others
-- EXTENSION_AGGREGATE ::=
-- (ANCESTOR_PART with RECORD_COMPONENT_ASSOCIATION_LIST)
-- ANCESTOR_PART ::= EXPRESSION | SUBTYPE_MARK
-- ARRAY_AGGREGATE ::=
-- POSITIONAL_ARRAY_AGGREGATE | NAMED_ARRAY_AGGREGATE
-- POSITIONAL_ARRAY_AGGREGATE ::=
-- (EXPRESSION, EXPRESSION {, EXPRESSION})
-- | (EXPRESSION {, EXPRESSION}, others => EXPRESSION)
-- | (EXPRESSION {, EXPRESSION}, others => <>)
-- NAMED_ARRAY_AGGREGATE ::=
-- (ARRAY_COMPONENT_ASSOCIATION {, ARRAY_COMPONENT_ASSOCIATION})
-- PRIMARY ::= (EXPRESSION);
-- Error recovery: can raise Error_Resync
-- Note: POSITIONAL_ARRAY_AGGREGATE rule has been extended to give support
-- to Ada 2005 limited aggregates (AI-287)
function P_Aggregate_Or_Paren_Expr return Node_Id is
Aggregate_Node : Node_Id;
Expr_List : List_Id;
Assoc_List : List_Id;
Expr_Node : Node_Id;
Lparen_Sloc : Source_Ptr;
Scan_State : Saved_Scan_State;
begin
Lparen_Sloc := Token_Ptr;
T_Left_Paren;
-- Conditional expression case
if Token = Tok_If then
Expr_Node := P_Conditional_Expression;
T_Right_Paren;
return Expr_Node;
-- Note: the mechanism used here of rescanning the initial expression
-- is distinctly unpleasant, but it saves a lot of fiddling in scanning
-- out the discrete choice list.
-- Deal with expression and extension aggregate cases first
elsif Token /= Tok_Others then
Save_Scan_State (Scan_State); -- at start of expression
-- Deal with (NULL RECORD) case
if Token = Tok_Null then
Scan; -- past NULL
if Token = Tok_Record then
Aggregate_Node := New_Node (N_Aggregate, Lparen_Sloc);
Set_Null_Record_Present (Aggregate_Node, True);
Scan; -- past RECORD
T_Right_Paren;
return Aggregate_Node;
else
Restore_Scan_State (Scan_State); -- to NULL that must be expr
end if;
end if;
-- Ada 2005 (AI-287): The box notation is allowed only with named
-- notation because positional notation might be error prone. For
-- example, in "(X, <>, Y, <>)", there is no type associated with
-- the boxes, so you might not be leaving out the components you
-- thought you were leaving out.
if Ada_Version >= Ada_05 and then Token = Tok_Box then
Error_Msg_SC ("(Ada 2005) box notation only allowed with "
& "named notation");
Scan; -- past BOX
Aggregate_Node := New_Node (N_Aggregate, Lparen_Sloc);
return Aggregate_Node;
end if;
Expr_Node := P_Expression_Or_Range_Attribute_If_OK;
-- Extension aggregate case
if Token = Tok_With then
if Nkind (Expr_Node) = N_Attribute_Reference
and then Attribute_Name (Expr_Node) = Name_Range
then
Bad_Range_Attribute (Sloc (Expr_Node));
return Error;
end if;
if Ada_Version = Ada_83 then
Error_Msg_SC ("(Ada 83) extension aggregate not allowed");
end if;
Aggregate_Node := New_Node (N_Extension_Aggregate, Lparen_Sloc);
Set_Ancestor_Part (Aggregate_Node, Expr_Node);
Scan; -- past WITH
-- Deal with WITH NULL RECORD case
if Token = Tok_Null then
Save_Scan_State (Scan_State); -- at NULL
Scan; -- past NULL
if Token = Tok_Record then
Scan; -- past RECORD
Set_Null_Record_Present (Aggregate_Node, True);
T_Right_Paren;
return Aggregate_Node;
else
Restore_Scan_State (Scan_State); -- to NULL that must be expr
end if;
end if;
if Token /= Tok_Others then
Save_Scan_State (Scan_State);
Expr_Node := P_Expression;
else
Expr_Node := Empty;
end if;
-- Expression case
elsif Token = Tok_Right_Paren or else Token in Token_Class_Eterm then
if Nkind (Expr_Node) = N_Attribute_Reference
and then Attribute_Name (Expr_Node) = Name_Range
then
Error_Msg
("|parentheses not allowed for range attribute", Lparen_Sloc);
Scan; -- past right paren
return Expr_Node;
end if;
-- Bump paren count of expression
if Expr_Node /= Error then
Set_Paren_Count (Expr_Node, Paren_Count (Expr_Node) + 1);
end if;
T_Right_Paren; -- past right paren (error message if none)
return Expr_Node;
-- Normal aggregate case
else
Aggregate_Node := New_Node (N_Aggregate, Lparen_Sloc);
end if;
-- Others case
else
Aggregate_Node := New_Node (N_Aggregate, Lparen_Sloc);
Expr_Node := Empty;
end if;
-- Prepare to scan list of component associations
Expr_List := No_List; -- don't set yet, maybe all named entries
Assoc_List := No_List; -- don't set yet, maybe all positional entries
-- This loop scans through component associations. On entry to the
-- loop, an expression has been scanned at the start of the current
-- association unless initial token was OTHERS, in which case
-- Expr_Node is set to Empty.
loop
-- Deal with others association first. This is a named association
if No (Expr_Node) then
if No (Assoc_List) then
Assoc_List := New_List;
end if;
Append (P_Record_Or_Array_Component_Association, Assoc_List);
-- Improper use of WITH
elsif Token = Tok_With then
Error_Msg_SC ("WITH must be preceded by single expression in " &
"extension aggregate");
raise Error_Resync;
-- A range attribute can only appear as part of a discrete choice
-- list.
elsif Nkind (Expr_Node) = N_Attribute_Reference
and then Attribute_Name (Expr_Node) = Name_Range
and then Token /= Tok_Arrow
and then Token /= Tok_Vertical_Bar
then
Bad_Range_Attribute (Sloc (Expr_Node));
return Error;
-- Assume positional case if comma, right paren, or literal or
-- identifier or OTHERS follows (the latter cases are missing
-- comma cases). Also assume positional if a semicolon follows,
-- which can happen if there are missing parens
elsif Token = Tok_Comma
or else Token = Tok_Right_Paren
or else Token = Tok_Others
or else Token in Token_Class_Lit_Or_Name
or else Token = Tok_Semicolon
then
if Present (Assoc_List) then
Error_Msg_BC
("""='>"" expected (positional association cannot follow " &
"named association)");
end if;
if No (Expr_List) then
Expr_List := New_List;
end if;
Append (Expr_Node, Expr_List);
-- Anything else is assumed to be a named association
else
Restore_Scan_State (Scan_State); -- to start of expression
if No (Assoc_List) then
Assoc_List := New_List;
end if;
Append (P_Record_Or_Array_Component_Association, Assoc_List);
end if;
exit when not Comma_Present;
-- If we are at an expression terminator, something is seriously
-- wrong, so let's get out now, before we start eating up stuff
-- that doesn't belong to us!
if Token in Token_Class_Eterm then
Error_Msg_AP ("expecting expression or component association");
exit;
end if;
-- Otherwise initiate for reentry to top of loop by scanning an
-- initial expression, unless the first token is OTHERS.
if Token = Tok_Others then
Expr_Node := Empty;
else
Save_Scan_State (Scan_State); -- at start of expression
Expr_Node := P_Expression_Or_Range_Attribute_If_OK;
end if;
end loop;
-- All component associations (positional and named) have been scanned
T_Right_Paren;
Set_Expressions (Aggregate_Node, Expr_List);
Set_Component_Associations (Aggregate_Node, Assoc_List);
return Aggregate_Node;
end P_Aggregate_Or_Paren_Expr;
------------------------------------------------
-- 4.3 Record or Array Component Association --
------------------------------------------------
-- RECORD_COMPONENT_ASSOCIATION ::=
-- [COMPONENT_CHOICE_LIST =>] EXPRESSION
-- | COMPONENT_CHOICE_LIST => <>
-- COMPONENT_CHOICE_LIST =>
-- component_SELECTOR_NAME {| component_SELECTOR_NAME}
-- | others
-- ARRAY_COMPONENT_ASSOCIATION ::=
-- DISCRETE_CHOICE_LIST => EXPRESSION
-- | DISCRETE_CHOICE_LIST => <>
-- Note: this routine only handles the named cases, including others.
-- Cases where the component choice list is not present have already
-- been handled directly.
-- Error recovery: can raise Error_Resync
-- Note: RECORD_COMPONENT_ASSOCIATION and ARRAY_COMPONENT_ASSOCIATION
-- rules have been extended to give support to Ada 2005 limited
-- aggregates (AI-287)
function P_Record_Or_Array_Component_Association return Node_Id is
Assoc_Node : Node_Id;
begin
Assoc_Node := New_Node (N_Component_Association, Token_Ptr);
Set_Choices (Assoc_Node, P_Discrete_Choice_List);
Set_Sloc (Assoc_Node, Token_Ptr);
TF_Arrow;
if Token = Tok_Box then
-- Ada 2005(AI-287): The box notation is used to indicate the
-- default initialization of aggregate components
if Ada_Version < Ada_05 then
Error_Msg_SP
("component association with '<'> is an Ada 2005 extension");
Error_Msg_SP ("\unit must be compiled with -gnat05 switch");
end if;
Set_Box_Present (Assoc_Node);
Scan; -- Past box
else
Set_Expression (Assoc_Node, P_Expression);
end if;
return Assoc_Node;
end P_Record_Or_Array_Component_Association;
-----------------------------
-- 4.3.1 Record Aggregate --
-----------------------------
-- Case of enumeration aggregate is parsed by P_Aggregate (4.3)
-- All other cases are parsed by P_Aggregate_Or_Paren_Expr (4.3)
----------------------------------------------
-- 4.3.1 Record Component Association List --
----------------------------------------------
-- Parsed by P_Aggregate_Or_Paren_Expr (4.3)
----------------------------------
-- 4.3.1 Component Choice List --
----------------------------------
-- Parsed by P_Aggregate_Or_Paren_Expr (4.3)
--------------------------------
-- 4.3.1 Extension Aggregate --
--------------------------------
-- Parsed by P_Aggregate_Or_Paren_Expr (4.3)
--------------------------
-- 4.3.1 Ancestor Part --
--------------------------
-- Parsed by P_Aggregate_Or_Paren_Expr (4.3)
----------------------------
-- 4.3.1 Array Aggregate --
----------------------------
-- Parsed by P_Aggregate_Or_Paren_Expr (4.3)
---------------------------------------
-- 4.3.1 Positional Array Aggregate --
---------------------------------------
-- Parsed by P_Aggregate_Or_Paren_Expr (4.3)
----------------------------------
-- 4.3.1 Named Array Aggregate --
----------------------------------
-- Parsed by P_Aggregate_Or_Paren_Expr (4.3)
----------------------------------------
-- 4.3.1 Array Component Association --
----------------------------------------
-- Parsed by P_Aggregate_Or_Paren_Expr (4.3)
---------------------
-- 4.4 Expression --
---------------------
-- EXPRESSION ::=
-- RELATION {and RELATION} | RELATION {and then RELATION}
-- | RELATION {or RELATION} | RELATION {or else RELATION}
-- | RELATION {xor RELATION}
-- On return, Expr_Form indicates the categorization of the expression
-- EF_Range_Attr is not a possible value (if a range attribute is found,
-- an error message is given, and Error is returned).
-- Error recovery: cannot raise Error_Resync
function P_Expression return Node_Id is
Logical_Op : Node_Kind;
Prev_Logical_Op : Node_Kind;
Op_Location : Source_Ptr;
Node1 : Node_Id;
Node2 : Node_Id;
begin
Node1 := P_Relation;
if Token in Token_Class_Logop then
Prev_Logical_Op := N_Empty;
loop
Op_Location := Token_Ptr;
Logical_Op := P_Logical_Operator;
if Prev_Logical_Op /= N_Empty and then
Logical_Op /= Prev_Logical_Op
then
Error_Msg
("mixed logical operators in expression", Op_Location);
Prev_Logical_Op := N_Empty;
else
Prev_Logical_Op := Logical_Op;
end if;
Node2 := Node1;
Node1 := New_Node (Logical_Op, Op_Location);
Set_Left_Opnd (Node1, Node2);
Set_Right_Opnd (Node1, P_Relation);
Set_Op_Name (Node1);
exit when Token not in Token_Class_Logop;
end loop;
Expr_Form := EF_Non_Simple;
end if;
if Token = Tok_Apostrophe then
Bad_Range_Attribute (Token_Ptr);
return Error;
else
return Node1;
end if;
end P_Expression;
-- This function is identical to the normal P_Expression, except that it
-- also permits the appearence of a conditional expression without the
-- usual surrounding parentheses.
function P_Expression_If_OK return Node_Id is
begin
if Token = Tok_If then
return P_Conditional_Expression;
else
return P_Expression;
end if;
end P_Expression_If_OK;
-- This function is identical to the normal P_Expression, except that it
-- checks that the expression scan did not stop on a right paren. It is
-- called in all contexts where a right parenthesis cannot legitimately
-- follow an expression.
-- Error recovery: can not raise Error_Resync
function P_Expression_No_Right_Paren return Node_Id is
Expr : constant Node_Id := P_Expression;
begin
Ignore (Tok_Right_Paren);
return Expr;
end P_Expression_No_Right_Paren;
----------------------------------------
-- 4.4 Expression_Or_Range_Attribute --
----------------------------------------
-- EXPRESSION ::=
-- RELATION {and RELATION} | RELATION {and then RELATION}
-- | RELATION {or RELATION} | RELATION {or else RELATION}
-- | RELATION {xor RELATION}
-- RANGE_ATTRIBUTE_REFERENCE ::= PREFIX ' RANGE_ATTRIBUTE_DESIGNATOR
-- RANGE_ATTRIBUTE_DESIGNATOR ::= range [(static_EXPRESSION)]
-- On return, Expr_Form indicates the categorization of the expression
-- and EF_Range_Attr is one of the possibilities.
-- Error recovery: cannot raise Error_Resync
-- In the grammar, a RANGE attribute is simply a name, but its use is
-- highly restricted, so in the parser, we do not regard it as a name.
-- Instead, P_Name returns without scanning the 'RANGE part of the
-- attribute, and P_Expression_Or_Range_Attribute handles the range
-- attribute reference. In the normal case where a range attribute is
-- not allowed, an error message is issued by P_Expression.
function P_Expression_Or_Range_Attribute return Node_Id is
Logical_Op : Node_Kind;
Prev_Logical_Op : Node_Kind;
Op_Location : Source_Ptr;
Node1 : Node_Id;
Node2 : Node_Id;
Attr_Node : Node_Id;
begin
Node1 := P_Relation;
if Token = Tok_Apostrophe then
Attr_Node := P_Range_Attribute_Reference (Node1);
Expr_Form := EF_Range_Attr;
return Attr_Node;
elsif Token in Token_Class_Logop then
Prev_Logical_Op := N_Empty;
loop
Op_Location := Token_Ptr;
Logical_Op := P_Logical_Operator;
if Prev_Logical_Op /= N_Empty and then
Logical_Op /= Prev_Logical_Op
then
Error_Msg
("mixed logical operators in expression", Op_Location);
Prev_Logical_Op := N_Empty;
else
Prev_Logical_Op := Logical_Op;
end if;
Node2 := Node1;
Node1 := New_Node (Logical_Op, Op_Location);
Set_Left_Opnd (Node1, Node2);
Set_Right_Opnd (Node1, P_Relation);
Set_Op_Name (Node1);
exit when Token not in Token_Class_Logop;
end loop;
Expr_Form := EF_Non_Simple;
end if;
if Token = Tok_Apostrophe then
Bad_Range_Attribute (Token_Ptr);
return Error;
else
return Node1;
end if;
end P_Expression_Or_Range_Attribute;
-- Version that allows a non-parenthesized conditional expression
function P_Expression_Or_Range_Attribute_If_OK return Node_Id is
begin
if Token = Tok_If then
return P_Conditional_Expression;
else
return P_Expression_Or_Range_Attribute;
end if;
end P_Expression_Or_Range_Attribute_If_OK;
-------------------
-- 4.4 Relation --
-------------------
-- RELATION ::=
-- SIMPLE_EXPRESSION [RELATIONAL_OPERATOR SIMPLE_EXPRESSION]
-- | SIMPLE_EXPRESSION [not] in RANGE
-- | SIMPLE_EXPRESSION [not] in SUBTYPE_MARK
-- On return, Expr_Form indicates the categorization of the expression
-- Note: if Token = Tok_Apostrophe on return, then Expr_Form is set to
-- EF_Simple_Name and the following token is RANGE (range attribute case).
-- Error recovery: cannot raise Error_Resync. If an error occurs within an
-- expression, then tokens are scanned until either a non-expression token,
-- a right paren (not matched by a left paren) or a comma, is encountered.
function P_Relation return Node_Id is
Node1, Node2 : Node_Id;
Optok : Source_Ptr;
begin
Node1 := P_Simple_Expression;
if Token not in Token_Class_Relop then
return Node1;
else
-- Here we have a relational operator following. If so then scan it
-- out. Note that the assignment symbol := is treated as a relational
-- operator to improve the error recovery when it is misused for =.
-- P_Relational_Operator also parses the IN and NOT IN operations.
Optok := Token_Ptr;
Node2 := New_Node (P_Relational_Operator, Optok);
Set_Left_Opnd (Node2, Node1);
Set_Op_Name (Node2);
-- Case of IN or NOT IN
if Prev_Token = Tok_In then
Set_Right_Opnd (Node2, P_Range_Or_Subtype_Mark);
-- Case of relational operator (= /= < <= > >=)
else
Set_Right_Opnd (Node2, P_Simple_Expression);
end if;
Expr_Form := EF_Non_Simple;
if Token in Token_Class_Relop then
Error_Msg_SC ("unexpected relational operator");
raise Error_Resync;
end if;
return Node2;
end if;
-- If any error occurs, then scan to the next expression terminator symbol
-- or comma or right paren at the outer (i.e. current) parentheses level.
-- The flags are set to indicate a normal simple expression.
exception
when Error_Resync =>
Resync_Expression;
Expr_Form := EF_Simple;
return Error;
end P_Relation;
----------------------------
-- 4.4 Simple Expression --
----------------------------
-- SIMPLE_EXPRESSION ::=
-- [UNARY_ADDING_OPERATOR] TERM {BINARY_ADDING_OPERATOR TERM}
-- On return, Expr_Form indicates the categorization of the expression
-- Note: if Token = Tok_Apostrophe on return, then Expr_Form is set to
-- EF_Simple_Name and the following token is RANGE (range attribute case).
-- Error recovery: cannot raise Error_Resync. If an error occurs within an
-- expression, then tokens are scanned until either a non-expression token,
-- a right paren (not matched by a left paren) or a comma, is encountered.
-- Note: P_Simple_Expression is called only internally by higher level
-- expression routines. In cases in the grammar where a simple expression
-- is required, the approach is to scan an expression, and then post an
-- appropriate error message if the expression obtained is not simple. This
-- gives better error recovery and treatment.
function P_Simple_Expression return Node_Id is
Scan_State : Saved_Scan_State;
Node1 : Node_Id;
Node2 : Node_Id;
Tokptr : Source_Ptr;
begin
-- Check for cases starting with a name. There are two reasons for
-- special casing. First speed things up by catching a common case
-- without going through several routine layers. Second the caller must
-- be informed via Expr_Form when the simple expression is a name.
if Token in Token_Class_Name then
Node1 := P_Name;
-- Deal with apostrophe cases
if Token = Tok_Apostrophe then
Save_Scan_State (Scan_State); -- at apostrophe
Scan; -- past apostrophe
-- If qualified expression, scan it out and fall through
if Token = Tok_Left_Paren then
Node1 := P_Qualified_Expression (Node1);
Expr_Form := EF_Simple;
-- If range attribute, then we return with Token pointing to the
-- apostrophe. Note: avoid the normal error check on exit. We
-- know that the expression really is complete in this case!
else -- Token = Tok_Range then
Restore_Scan_State (Scan_State); -- to apostrophe
Expr_Form := EF_Simple_Name;
return Node1;
end if;
end if;
-- If an expression terminator follows, the previous processing
-- completely scanned out the expression (a common case), and
-- left Expr_Form set appropriately for returning to our caller.
if Token in Token_Class_Sterm then
null;
-- If we do not have an expression terminator, then complete the
-- scan of a simple expression. This code duplicates the code
-- found in P_Term and P_Factor.
else
if Token = Tok_Double_Asterisk then
if Style_Check then
Style.Check_Exponentiation_Operator;
end if;
Node2 := New_Node (N_Op_Expon, Token_Ptr);
Scan; -- past **
Set_Left_Opnd (Node2, Node1);
Set_Right_Opnd (Node2, P_Primary);
Set_Op_Name (Node2);
Node1 := Node2;
end if;
loop
exit when Token not in Token_Class_Mulop;
Tokptr := Token_Ptr;
Node2 := New_Node (P_Multiplying_Operator, Tokptr);
if Style_Check then
Style.Check_Binary_Operator;
end if;
Scan; -- past operator
Set_Left_Opnd (Node2, Node1);
Set_Right_Opnd (Node2, P_Factor);
Set_Op_Name (Node2);
Node1 := Node2;
end loop;
loop
exit when Token not in Token_Class_Binary_Addop;
Tokptr := Token_Ptr;
Node2 := New_Node (P_Binary_Adding_Operator, Tokptr);
if Style_Check then
Style.Check_Binary_Operator;
end if;
Scan; -- past operator
Set_Left_Opnd (Node2, Node1);
Set_Right_Opnd (Node2, P_Term);
Set_Op_Name (Node2);
Node1 := Node2;
end loop;
Expr_Form := EF_Simple;
end if;
-- Cases where simple expression does not start with a name
else
-- Scan initial sign and initial Term
if Token in Token_Class_Unary_Addop then
Tokptr := Token_Ptr;
Node1 := New_Node (P_Unary_Adding_Operator, Tokptr);
if Style_Check then
Style.Check_Unary_Plus_Or_Minus;
end if;
Scan; -- past operator
Set_Right_Opnd (Node1, P_Term);
Set_Op_Name (Node1);
else
Node1 := P_Term;
end if;
-- In the following, we special-case a sequence of concatenations of
-- string literals, such as "aaa" & "bbb" & ... & "ccc", with nothing
-- else mixed in. For such a sequence, we return a tree representing
-- "" & "aaabbb...ccc" (a single concatenation). This is done only if
-- the number of concatenations is large. If semantic analysis
-- resolves the "&" to a predefined one, then this folding gives the
-- right answer. Otherwise, semantic analysis will complain about a
-- capacity-exceeded error. The purpose of this trick is to avoid
-- creating a deeply nested tree, which would cause deep recursion
-- during semantics, causing stack overflow. This way, we can handle
-- enormous concatenations in the normal case of predefined "&". We
-- first build up the normal tree, and then rewrite it if
-- appropriate.
declare
Num_Concats_Threshold : constant Positive := 1000;
-- Arbitrary threshold value to enable optimization
First_Node : constant Node_Id := Node1;
Is_Strlit_Concat : Boolean;
-- True iff we've parsed a sequence of concatenations of string
-- literals, with nothing else mixed in.
Num_Concats : Natural;
-- Number of "&" operators if Is_Strlit_Concat is True
begin
Is_Strlit_Concat :=
Nkind (Node1) = N_String_Literal
and then Token = Tok_Ampersand;
Num_Concats := 0;
-- Scan out sequence of terms separated by binary adding operators
loop
exit when Token not in Token_Class_Binary_Addop;
Tokptr := Token_Ptr;
Node2 := New_Node (P_Binary_Adding_Operator, Tokptr);
Scan; -- past operator
Set_Left_Opnd (Node2, Node1);
Node1 := P_Term;
Set_Right_Opnd (Node2, Node1);
Set_Op_Name (Node2);
-- Check if we're still concatenating string literals
Is_Strlit_Concat :=
Is_Strlit_Concat
and then Nkind (Node2) = N_Op_Concat
and then Nkind (Node1) = N_String_Literal;
if Is_Strlit_Concat then
Num_Concats := Num_Concats + 1;
end if;
Node1 := Node2;
end loop;
-- If we have an enormous series of concatenations of string
-- literals, rewrite as explained above. The Is_Folded_In_Parser
-- flag tells semantic analysis that if the "&" is not predefined,
-- the folded value is wrong.
if Is_Strlit_Concat
and then Num_Concats >= Num_Concats_Threshold
then
declare
Empty_String_Val : String_Id;
-- String_Id for ""
Strlit_Concat_Val : String_Id;
-- Contains the folded value (which will be correct if the
-- "&" operators are the predefined ones).
Cur_Node : Node_Id;
-- For walking up the tree
New_Node : Node_Id;
-- Folded node to replace Node1
Loc : constant Source_Ptr := Sloc (First_Node);
begin
-- Walk up the tree starting at the leftmost string literal
-- (First_Node), building up the Strlit_Concat_Val as we
-- go. Note that we do not use recursion here -- the whole
-- point is to avoid recursively walking that enormous tree.
Start_String;
Store_String_Chars (Strval (First_Node));
Cur_Node := Parent (First_Node);
while Present (Cur_Node) loop
pragma Assert (Nkind (Cur_Node) = N_Op_Concat and then
Nkind (Right_Opnd (Cur_Node)) = N_String_Literal);
Store_String_Chars (Strval (Right_Opnd (Cur_Node)));
Cur_Node := Parent (Cur_Node);
end loop;
Strlit_Concat_Val := End_String;
-- Create new folded node, and rewrite result with a concat-
-- enation of an empty string literal and the folded node.
Start_String;
Empty_String_Val := End_String;
New_Node :=
Make_Op_Concat (Loc,
Make_String_Literal (Loc, Empty_String_Val),
Make_String_Literal (Loc, Strlit_Concat_Val,
Is_Folded_In_Parser => True));
Rewrite (Node1, New_Node);
end;
end if;
end;
-- All done, we clearly do not have name or numeric literal so this
-- is a case of a simple expression which is some other possibility.
Expr_Form := EF_Simple;
end if;
-- Come here at end of simple expression, where we do a couple of
-- special checks to improve error recovery.
-- Special test to improve error recovery. If the current token
-- is a period, then someone is trying to do selection on something
-- that is not a name, e.g. a qualified expression.
if Token = Tok_Dot then
Error_Msg_SC ("prefix for selection is not a name");
raise Error_Resync;
end if;
-- Special test to improve error recovery: If the current token is
-- not the first token on a line (as determined by checking the
-- previous token position with the start of the current line),
-- then we insist that we have an appropriate terminating token.
-- Consider the following two examples:
-- 1) if A nad B then ...
-- 2) A := B
-- C := D
-- In the first example, we would like to issue a binary operator
-- expected message and resynchronize to the then. In the second
-- example, we do not want to issue a binary operator message, so
-- that instead we will get the missing semicolon message. This
-- distinction is of course a heuristic which does not always work,
-- but in practice it is quite effective.
-- Note: the one case in which we do not go through this circuit is
-- when we have scanned a range attribute and want to return with
-- Token pointing to the apostrophe. The apostrophe is not normally
-- an expression terminator, and is not in Token_Class_Sterm, but
-- in this special case we know that the expression is complete.
if not Token_Is_At_Start_Of_Line
and then Token not in Token_Class_Sterm
then
Error_Msg_AP ("binary operator expected");
raise Error_Resync;
else
return Node1;
end if;
-- If any error occurs, then scan to next expression terminator symbol
-- or comma, right paren or vertical bar at the outer (i.e. current) paren
-- level. Expr_Form is set to indicate a normal simple expression.
exception
when Error_Resync =>
Resync_Expression;
Expr_Form := EF_Simple;
return Error;
end P_Simple_Expression;
-----------------------------------------------
-- 4.4 Simple Expression or Range Attribute --
-----------------------------------------------
-- SIMPLE_EXPRESSION ::=
-- [UNARY_ADDING_OPERATOR] TERM {BINARY_ADDING_OPERATOR TERM}
-- RANGE_ATTRIBUTE_REFERENCE ::= PREFIX ' RANGE_ATTRIBUTE_DESIGNATOR
-- RANGE_ATTRIBUTE_DESIGNATOR ::= range [(static_EXPRESSION)]
-- Error recovery: cannot raise Error_Resync
function P_Simple_Expression_Or_Range_Attribute return Node_Id is
Sexpr : Node_Id;
Attr_Node : Node_Id;
begin
-- We don't just want to roar ahead and call P_Simple_Expression
-- here, since we want to handle the case of a parenthesized range
-- attribute cleanly.
if Token = Tok_Left_Paren then
declare
Lptr : constant Source_Ptr := Token_Ptr;
Scan_State : Saved_Scan_State;
begin
Save_Scan_State (Scan_State);
Scan; -- past left paren
Sexpr := P_Simple_Expression;
if Token = Tok_Apostrophe then
Attr_Node := P_Range_Attribute_Reference (Sexpr);
Expr_Form := EF_Range_Attr;
if Token = Tok_Right_Paren then
Scan; -- scan past right paren if present
end if;
Error_Msg ("parentheses not allowed for range attribute", Lptr);
return Attr_Node;
end if;
Restore_Scan_State (Scan_State);
end;
end if;
-- Here after dealing with parenthesized range attribute
Sexpr := P_Simple_Expression;
if Token = Tok_Apostrophe then
Attr_Node := P_Range_Attribute_Reference (Sexpr);
Expr_Form := EF_Range_Attr;
return Attr_Node;
else
return Sexpr;
end if;
end P_Simple_Expression_Or_Range_Attribute;
---------------
-- 4.4 Term --
---------------
-- TERM ::= FACTOR {MULTIPLYING_OPERATOR FACTOR}
-- Error recovery: can raise Error_Resync
function P_Term return Node_Id is
Node1, Node2 : Node_Id;
Tokptr : Source_Ptr;
begin
Node1 := P_Factor;
loop
exit when Token not in Token_Class_Mulop;
Tokptr := Token_Ptr;
Node2 := New_Node (P_Multiplying_Operator, Tokptr);
Scan; -- past operator
Set_Left_Opnd (Node2, Node1);
Set_Right_Opnd (Node2, P_Factor);
Set_Op_Name (Node2);
Node1 := Node2;
end loop;
return Node1;
end P_Term;
-----------------
-- 4.4 Factor --
-----------------
-- FACTOR ::= PRIMARY [** PRIMARY] | abs PRIMARY | not PRIMARY
-- Error recovery: can raise Error_Resync
function P_Factor return Node_Id is
Node1 : Node_Id;
Node2 : Node_Id;
begin
if Token = Tok_Abs then
Node1 := New_Node (N_Op_Abs, Token_Ptr);
if Style_Check then
Style.Check_Abs_Not;
end if;
Scan; -- past ABS
Set_Right_Opnd (Node1, P_Primary);
Set_Op_Name (Node1);
return Node1;
elsif Token = Tok_Not then
Node1 := New_Node (N_Op_Not, Token_Ptr);
if Style_Check then
Style.Check_Abs_Not;
end if;
Scan; -- past NOT
Set_Right_Opnd (Node1, P_Primary);
Set_Op_Name (Node1);
return Node1;
else
Node1 := P_Primary;
if Token = Tok_Double_Asterisk then
Node2 := New_Node (N_Op_Expon, Token_Ptr);
Scan; -- past **
Set_Left_Opnd (Node2, Node1);
Set_Right_Opnd (Node2, P_Primary);
Set_Op_Name (Node2);
return Node2;
else
return Node1;
end if;
end if;
end P_Factor;
------------------
-- 4.4 Primary --
------------------
-- PRIMARY ::=
-- NUMERIC_LITERAL | null
-- | STRING_LITERAL | AGGREGATE
-- | NAME | QUALIFIED_EXPRESSION
-- | ALLOCATOR | (EXPRESSION)
-- Error recovery: can raise Error_Resync
function P_Primary return Node_Id is
Scan_State : Saved_Scan_State;
Node1 : Node_Id;
begin
-- The loop runs more than once only if misplaced pragmas are found
loop
case Token is
-- Name token can start a name, call or qualified expression, all
-- of which are acceptable possibilities for primary. Note also
-- that string literal is included in name (as operator symbol)
-- and type conversion is included in name (as indexed component).
when Tok_Char_Literal | Tok_Operator_Symbol | Tok_Identifier =>
Node1 := P_Name;
-- All done unless apostrophe follows
if Token /= Tok_Apostrophe then
return Node1;
-- Apostrophe following means that we have either just parsed
-- the subtype mark of a qualified expression, or the prefix
-- or a range attribute.
else -- Token = Tok_Apostrophe
Save_Scan_State (Scan_State); -- at apostrophe
Scan; -- past apostrophe
-- If range attribute, then this is always an error, since
-- the only legitimate case (where the scanned expression is
-- a qualified simple name) is handled at the level of the
-- Simple_Expression processing. This case corresponds to a
-- usage such as 3 + A'Range, which is always illegal.
if Token = Tok_Range then
Restore_Scan_State (Scan_State); -- to apostrophe
Bad_Range_Attribute (Token_Ptr);
return Error;
-- If left paren, then we have a qualified expression.
-- Note that P_Name guarantees that in this case, where
-- Token = Tok_Apostrophe on return, the only two possible
-- tokens following the apostrophe are left paren and
-- RANGE, so we know we have a left paren here.
else -- Token = Tok_Left_Paren
return P_Qualified_Expression (Node1);
end if;
end if;
-- Numeric or string literal
when Tok_Integer_Literal |
Tok_Real_Literal |
Tok_String_Literal =>
Node1 := Token_Node;
Scan; -- past number
return Node1;
-- Left paren, starts aggregate or parenthesized expression
when Tok_Left_Paren =>
declare
Expr : constant Node_Id := P_Aggregate_Or_Paren_Expr;
begin
if Nkind (Expr) = N_Attribute_Reference
and then Attribute_Name (Expr) = Name_Range
then
Bad_Range_Attribute (Sloc (Expr));
end if;
return Expr;
end;
-- Allocator
when Tok_New =>
return P_Allocator;
-- Null
when Tok_Null =>
Scan; -- past NULL
return New_Node (N_Null, Prev_Token_Ptr);
-- Pragma, not allowed here, so just skip past it
when Tok_Pragma =>
P_Pragmas_Misplaced;
-- Deal with IF (possible unparenthesized conditional expression)
when Tok_If =>
-- If this looks like a real if, defined as an IF appearing at
-- the start of a new line, then we consider we have a missing
-- operand.
if Token_Is_At_Start_Of_Line then
Error_Msg_AP ("missing operand");
return Error;
-- If this looks like a conditional expression, then treat it
-- that way with an error messasge.
elsif Extensions_Allowed then
Error_Msg_SC
("conditional expression must be parenthesized");
return P_Conditional_Expression;
-- Otherwise treat as misused identifier
else
return P_Identifier;
end if;
-- Anything else is illegal as the first token of a primary, but
-- we test for a reserved identifier so that it is treated nicely
when others =>
if Is_Reserved_Identifier then
return P_Identifier;
elsif Prev_Token = Tok_Comma then
Error_Msg_SP ("|extra "","" ignored");
raise Error_Resync;
else
Error_Msg_AP ("missing operand");
raise Error_Resync;
end if;
end case;
end loop;
end P_Primary;
---------------------------
-- 4.5 Logical Operator --
---------------------------
-- LOGICAL_OPERATOR ::= and | or | xor
-- Note: AND THEN and OR ELSE are also treated as logical operators
-- by the parser (even though they are not operators semantically)
-- The value returned is the appropriate Node_Kind code for the operator
-- On return, Token points to the token following the scanned operator.
-- The caller has checked that the first token is a legitimate logical
-- operator token (i.e. is either XOR, AND, OR).
-- Error recovery: cannot raise Error_Resync
function P_Logical_Operator return Node_Kind is
begin
if Token = Tok_And then
if Style_Check then
Style.Check_Binary_Operator;
end if;
Scan; -- past AND
if Token = Tok_Then then
Scan; -- past THEN
return N_And_Then;
else
return N_Op_And;
end if;
elsif Token = Tok_Or then
if Style_Check then
Style.Check_Binary_Operator;
end if;
Scan; -- past OR
if Token = Tok_Else then
Scan; -- past ELSE
return N_Or_Else;
else
return N_Op_Or;
end if;
else -- Token = Tok_Xor
if Style_Check then
Style.Check_Binary_Operator;
end if;
Scan; -- past XOR
return N_Op_Xor;
end if;
end P_Logical_Operator;
------------------------------
-- 4.5 Relational Operator --
------------------------------
-- RELATIONAL_OPERATOR ::= = | /= | < | <= | > | >=
-- The value returned is the appropriate Node_Kind code for the operator.
-- On return, Token points to the operator token, NOT past it.
-- The caller has checked that the first token is a legitimate relational
-- operator token (i.e. is one of the operator tokens listed above).
-- Error recovery: cannot raise Error_Resync
function P_Relational_Operator return Node_Kind is
Op_Kind : Node_Kind;
Relop_Node : constant array (Token_Class_Relop) of Node_Kind :=
(Tok_Less => N_Op_Lt,
Tok_Equal => N_Op_Eq,
Tok_Greater => N_Op_Gt,
Tok_Not_Equal => N_Op_Ne,
Tok_Greater_Equal => N_Op_Ge,
Tok_Less_Equal => N_Op_Le,
Tok_In => N_In,
Tok_Not => N_Not_In,
Tok_Box => N_Op_Ne);
begin
if Token = Tok_Box then
Error_Msg_SC ("|""'<'>"" should be ""/=""");
end if;
Op_Kind := Relop_Node (Token);
if Style_Check then
Style.Check_Binary_Operator;
end if;
Scan; -- past operator token
if Prev_Token = Tok_Not then
T_In;
end if;
return Op_Kind;
end P_Relational_Operator;
---------------------------------
-- 4.5 Binary Adding Operator --
---------------------------------
-- BINARY_ADDING_OPERATOR ::= + | - | &
-- The value returned is the appropriate Node_Kind code for the operator.
-- On return, Token points to the operator token (NOT past it).
-- The caller has checked that the first token is a legitimate adding
-- operator token (i.e. is one of the operator tokens listed above).
-- Error recovery: cannot raise Error_Resync
function P_Binary_Adding_Operator return Node_Kind is
Addop_Node : constant array (Token_Class_Binary_Addop) of Node_Kind :=
(Tok_Ampersand => N_Op_Concat,
Tok_Minus => N_Op_Subtract,
Tok_Plus => N_Op_Add);
begin
return Addop_Node (Token);
end P_Binary_Adding_Operator;
--------------------------------
-- 4.5 Unary Adding Operator --
--------------------------------
-- UNARY_ADDING_OPERATOR ::= + | -
-- The value returned is the appropriate Node_Kind code for the operator.
-- On return, Token points to the operator token (NOT past it).
-- The caller has checked that the first token is a legitimate adding
-- operator token (i.e. is one of the operator tokens listed above).
-- Error recovery: cannot raise Error_Resync
function P_Unary_Adding_Operator return Node_Kind is
Addop_Node : constant array (Token_Class_Unary_Addop) of Node_Kind :=
(Tok_Minus => N_Op_Minus,
Tok_Plus => N_Op_Plus);
begin
return Addop_Node (Token);
end P_Unary_Adding_Operator;
-------------------------------
-- 4.5 Multiplying Operator --
-------------------------------
-- MULTIPLYING_OPERATOR ::= * | / | mod | rem
-- The value returned is the appropriate Node_Kind code for the operator.
-- On return, Token points to the operator token (NOT past it).
-- The caller has checked that the first token is a legitimate multiplying
-- operator token (i.e. is one of the operator tokens listed above).
-- Error recovery: cannot raise Error_Resync
function P_Multiplying_Operator return Node_Kind is
Mulop_Node : constant array (Token_Class_Mulop) of Node_Kind :=
(Tok_Asterisk => N_Op_Multiply,
Tok_Mod => N_Op_Mod,
Tok_Rem => N_Op_Rem,
Tok_Slash => N_Op_Divide);
begin
return Mulop_Node (Token);
end P_Multiplying_Operator;
--------------------------------------
-- 4.5 Highest Precedence Operator --
--------------------------------------
-- Parsed by P_Factor (4.4)
-- Note: this rule is not in fact used by the grammar at any point!
--------------------------
-- 4.6 Type Conversion --
--------------------------
-- Parsed by P_Primary as a Name (4.1)
-------------------------------
-- 4.7 Qualified Expression --
-------------------------------
-- QUALIFIED_EXPRESSION ::=
-- SUBTYPE_MARK ' (EXPRESSION) | SUBTYPE_MARK ' AGGREGATE
-- The caller has scanned the name which is the Subtype_Mark parameter
-- and scanned past the single quote following the subtype mark. The
-- caller has not checked that this name is in fact appropriate for
-- a subtype mark name (i.e. it is a selected component or identifier).
-- Error_Recovery: cannot raise Error_Resync
function P_Qualified_Expression (Subtype_Mark : Node_Id) return Node_Id is
Qual_Node : Node_Id;
begin
Qual_Node := New_Node (N_Qualified_Expression, Prev_Token_Ptr);
Set_Subtype_Mark (Qual_Node, Check_Subtype_Mark (Subtype_Mark));
Set_Expression (Qual_Node, P_Aggregate_Or_Paren_Expr);
return Qual_Node;
end P_Qualified_Expression;
--------------------
-- 4.8 Allocator --
--------------------
-- ALLOCATOR ::=
-- new [NULL_EXCLUSION] SUBTYPE_INDICATION | new QUALIFIED_EXPRESSION
-- The caller has checked that the initial token is NEW
-- Error recovery: can raise Error_Resync
function P_Allocator return Node_Id is
Alloc_Node : Node_Id;
Type_Node : Node_Id;
Null_Exclusion_Present : Boolean;
begin
Alloc_Node := New_Node (N_Allocator, Token_Ptr);
T_New;
-- Scan Null_Exclusion if present (Ada 2005 (AI-231))
Null_Exclusion_Present := P_Null_Exclusion;
Set_Null_Exclusion_Present (Alloc_Node, Null_Exclusion_Present);
Type_Node := P_Subtype_Mark_Resync;
if Token = Tok_Apostrophe then
Scan; -- past apostrophe
Set_Expression (Alloc_Node, P_Qualified_Expression (Type_Node));
else
Set_Expression
(Alloc_Node,
P_Subtype_Indication (Type_Node, Null_Exclusion_Present));
end if;
return Alloc_Node;
end P_Allocator;
------------------------------
-- P_Conditional_Expression --
------------------------------
function P_Conditional_Expression return Node_Id is
Exprs : constant List_Id := New_List;
Loc : constant Source_Ptr := Token_Ptr;
Expr : Node_Id;
State : Saved_Scan_State;
begin
Inside_Conditional_Expression := Inside_Conditional_Expression + 1;
if Token = Tok_If and then not Extensions_Allowed then
Error_Msg_SC ("|conditional expression is an Ada extension");
Error_Msg_SC ("\|use -gnatX switch to compile this unit");
end if;
Scan; -- past IF or ELSIF
Append_To (Exprs, P_Expression_No_Right_Paren);
TF_Then;
Append_To (Exprs, P_Expression);
-- We now have scanned out IF expr THEN expr
-- Check for common error of semicolon before the ELSE
if Token = Tok_Semicolon then
Save_Scan_State (State);
Scan; -- past semicolon
if Token = Tok_Else or else Token = Tok_Elsif then
Error_Msg_SP ("|extra "";"" ignored");
else
Restore_Scan_State (State);
end if;
end if;
-- Scan out ELSIF sequence if present
if Token = Tok_Elsif then
Expr := P_Conditional_Expression;
Set_Is_Elsif (Expr);
Append_To (Exprs, Expr);
-- Scan out ELSE phrase if present
elsif Token = Tok_Else then
-- Scan out ELSE expression
Scan; -- Past ELSE
Append_To (Exprs, P_Expression);
-- Two expression case (implied True, filled in during semantics)
else
null;
end if;
-- If we have an END IF, diagnose as not needed
if Token = Tok_End then
Error_Msg_SC
("`END IF` not allowed at end of conditional expression");
Scan; -- past END
if Token = Tok_If then
Scan; -- past IF;
end if;
end if;
Inside_Conditional_Expression := Inside_Conditional_Expression - 1;
-- Return the Conditional_Expression node
return
Make_Conditional_Expression (Loc,
Expressions => Exprs);
end P_Conditional_Expression;
end Ch4;
|