summaryrefslogtreecommitdiffstats
path: root/generic/tclNamesp.c
blob: fbbab98500ff17cb2c09a57be6ab2109b7c7e3fd (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
4053
4054
4055
4056
4057
4058
4059
4060
4061
4062
4063
4064
4065
4066
4067
4068
4069
4070
4071
4072
4073
4074
4075
4076
4077
4078
4079
4080
4081
4082
4083
4084
4085
4086
4087
4088
4089
4090
4091
4092
4093
4094
4095
4096
4097
4098
4099
4100
4101
4102
4103
4104
4105
4106
4107
4108
4109
4110
4111
4112
4113
4114
4115
4116
4117
4118
4119
4120
4121
4122
4123
4124
4125
4126
4127
4128
4129
4130
4131
4132
4133
4134
4135
4136
4137
4138
4139
4140
4141
4142
4143
4144
4145
4146
4147
4148
4149
4150
4151
4152
4153
4154
4155
4156
4157
4158
4159
4160
4161
4162
4163
4164
4165
4166
4167
4168
4169
4170
4171
4172
4173
4174
4175
4176
4177
4178
4179
4180
4181
4182
4183
4184
4185
4186
4187
4188
4189
4190
4191
4192
4193
4194
4195
4196
4197
4198
4199
4200
4201
4202
4203
4204
4205
4206
4207
4208
4209
4210
4211
4212
4213
4214
4215
4216
4217
4218
4219
4220
4221
4222
4223
4224
4225
4226
4227
4228
4229
4230
4231
4232
4233
4234
4235
4236
4237
4238
4239
4240
4241
4242
4243
4244
4245
4246
4247
4248
4249
4250
4251
4252
4253
4254
4255
4256
4257
4258
4259
4260
4261
4262
4263
4264
4265
4266
4267
4268
4269
4270
4271
4272
4273
4274
4275
4276
4277
4278
4279
4280
4281
4282
4283
4284
4285
4286
4287
4288
4289
4290
4291
4292
4293
4294
4295
4296
4297
4298
4299
4300
4301
4302
4303
4304
4305
4306
4307
4308
4309
4310
4311
4312
4313
4314
4315
4316
4317
4318
4319
4320
4321
4322
4323
4324
4325
4326
4327
4328
4329
4330
4331
4332
4333
4334
4335
4336
4337
4338
4339
4340
4341
4342
4343
4344
4345
4346
4347
4348
4349
4350
4351
4352
4353
4354
4355
4356
4357
4358
4359
4360
4361
4362
4363
4364
4365
4366
4367
4368
4369
4370
4371
4372
4373
4374
4375
4376
4377
4378
4379
4380
4381
4382
4383
4384
4385
4386
4387
4388
4389
4390
4391
4392
4393
4394
4395
4396
4397
4398
4399
4400
4401
4402
4403
4404
4405
4406
4407
4408
4409
4410
4411
4412
4413
4414
4415
4416
4417
4418
4419
4420
4421
4422
4423
4424
4425
4426
4427
4428
4429
4430
4431
4432
4433
4434
4435
4436
4437
4438
4439
4440
4441
4442
4443
4444
4445
4446
4447
4448
4449
4450
4451
4452
4453
4454
4455
4456
4457
4458
4459
4460
4461
4462
4463
4464
4465
4466
4467
4468
4469
4470
4471
4472
4473
4474
4475
4476
4477
4478
4479
4480
4481
4482
4483
4484
4485
4486
4487
4488
4489
4490
4491
4492
4493
4494
4495
4496
4497
4498
4499
4500
4501
4502
4503
4504
4505
4506
4507
4508
4509
4510
4511
4512
4513
4514
4515
4516
4517
4518
4519
4520
4521
4522
4523
4524
4525
4526
4527
4528
4529
4530
4531
4532
4533
4534
4535
4536
4537
4538
4539
4540
4541
4542
4543
4544
4545
4546
4547
4548
4549
4550
4551
4552
4553
4554
4555
4556
4557
4558
4559
4560
4561
4562
4563
4564
4565
4566
4567
4568
4569
4570
4571
4572
4573
4574
4575
4576
4577
4578
4579
4580
4581
4582
4583
4584
4585
4586
4587
4588
4589
4590
4591
4592
4593
4594
4595
4596
4597
4598
4599
4600
4601
4602
4603
4604
4605
4606
4607
4608
4609
4610
4611
4612
4613
4614
4615
4616
4617
4618
4619
4620
4621
4622
4623
4624
4625
4626
4627
4628
4629
4630
4631
4632
4633
4634
4635
4636
4637
4638
4639
4640
4641
4642
4643
4644
4645
4646
4647
4648
4649
4650
4651
4652
4653
4654
4655
4656
4657
4658
4659
4660
4661
4662
4663
4664
4665
4666
4667
4668
4669
4670
4671
4672
4673
4674
4675
4676
4677
4678
4679
4680
4681
4682
4683
4684
4685
4686
4687
4688
4689
4690
4691
4692
4693
4694
4695
4696
4697
4698
4699
4700
4701
4702
4703
4704
4705
4706
4707
4708
4709
4710
4711
4712
4713
4714
4715
4716
4717
4718
4719
4720
4721
4722
4723
4724
4725
4726
4727
4728
4729
4730
4731
4732
4733
4734
4735
4736
4737
4738
4739
4740
4741
4742
4743
4744
4745
4746
4747
4748
4749
4750
4751
4752
4753
4754
4755
4756
4757
4758
4759
4760
4761
4762
4763
4764
4765
4766
4767
4768
4769
4770
4771
4772
4773
4774
4775
4776
4777
4778
4779
4780
4781
4782
4783
4784
4785
4786
4787
4788
4789
4790
4791
4792
4793
4794
4795
4796
4797
4798
4799
4800
4801
4802
4803
4804
4805
4806
4807
4808
4809
4810
4811
4812
4813
4814
4815
4816
4817
4818
4819
4820
4821
4822
4823
4824
4825
4826
4827
4828
4829
4830
4831
4832
4833
4834
4835
4836
4837
4838
4839
4840
4841
4842
4843
4844
4845
4846
4847
4848
4849
4850
4851
4852
4853
4854
4855
4856
4857
4858
4859
4860
4861
4862
4863
4864
4865
4866
4867
4868
4869
4870
4871
4872
4873
4874
4875
4876
4877
4878
4879
4880
4881
4882
4883
4884
4885
4886
4887
4888
4889
4890
4891
4892
4893
4894
4895
4896
4897
4898
4899
4900
4901
4902
4903
4904
4905
4906
4907
4908
4909
4910
4911
4912
4913
4914
4915
4916
4917
4918
4919
4920
4921
4922
4923
4924
/*
 * tclNamesp.c --
 *
 *	Contains support for namespaces, which provide a separate context of
 *	commands and global variables. The global :: namespace is the
 *	traditional Tcl "global" scope. Other namespaces are created as
 *	children of the global namespace. These other namespaces contain
 *	special-purpose commands and variables for packages. Also includes the
 *	TIP#112 ensemble machinery.
 *
 * Copyright (c) 1993-1997 Lucent Technologies.
 * Copyright (c) 1997 Sun Microsystems, Inc.
 * Copyright (c) 1998-1999 by Scriptics Corporation.
 * Copyright (c) 2002-2005 Donal K. Fellows.
 * Copyright (c) 2006 Neil Madden.
 * Contributions from Don Porter, NIST, 2007. (not subject to US copyright)
 *
 * Originally implemented by
 *   Michael J. McLennan
 *   Bell Labs Innovations for Lucent Technologies
 *   mmclennan@lucent.com
 *
 * See the file "license.terms" for information on usage and redistribution of
 * this file, and for a DISCLAIMER OF ALL WARRANTIES.
 *
 * RCS: @(#) $Id: tclNamesp.c,v 1.200 2010/02/13 18:11:06 dkf Exp $
 */

#include "tclInt.h"
#include "tclCompile.h" /* just for NRCommand */

/*
 * Thread-local storage used to avoid having a global lock on data that is not
 * limited to a single interpreter.
 */

typedef struct ThreadSpecificData {
    long numNsCreated;		/* Count of the number of namespaces created
				 * within the thread. This value is used as a
				 * unique id for each namespace. Cannot be
				 * per-interp because the nsId is used to
				 * distinguish objects which can be passed
				 * around between interps in the same thread,
				 * but does not need to be global because
				 * object internal reps are always per-thread
				 * anyway. */
} ThreadSpecificData;

static Tcl_ThreadDataKey dataKey;

/*
 * This structure contains a cached pointer to a namespace that is the result
 * of resolving the namespace's name in some other namespace. It is the
 * internal representation for a nsName object. It contains the pointer along
 * with some information that is used to check the cached pointer's validity.
 */

typedef struct ResolvedNsName {
    Namespace *nsPtr;		/* A cached pointer to the Namespace that the
				 * name resolved to. */
    Namespace *refNsPtr;	/* Points to the namespace context in which
				 * the name was resolved. NULL if the name is
				 * fully qualified and thus the resolution
				 * does not depend on the context. */
    int refCount;		/* Reference count: 1 for each nsName object
				 * that has a pointer to this ResolvedNsName
				 * structure as its internal rep. This
				 * structure can be freed when refCount
				 * becomes zero. */
} ResolvedNsName;

/*
 * Declarations for functions local to this file:
 */

static void		DeleteImportedCmd(ClientData clientData);
static int		DoImport(Tcl_Interp *interp,
			    Namespace *nsPtr, Tcl_HashEntry *hPtr,
			    const char *cmdName, const char *pattern,
			    Namespace *importNsPtr, int allowOverwrite);
static void		DupNsNameInternalRep(Tcl_Obj *objPtr,Tcl_Obj *copyPtr);
static char *		ErrorCodeRead(ClientData clientData,Tcl_Interp *interp,
			    const char *name1, const char *name2, int flags);
static char *		ErrorInfoRead(ClientData clientData,Tcl_Interp *interp,
			    const char *name1, const char *name2, int flags);
static char *		EstablishErrorCodeTraces(ClientData clientData,
			    Tcl_Interp *interp, const char *name1,
			    const char *name2, int flags);
static char *		EstablishErrorInfoTraces(ClientData clientData,
			    Tcl_Interp *interp, const char *name1,
			    const char *name2, int flags);
static void		FreeNsNameInternalRep(Tcl_Obj *objPtr);
static int		GetNamespaceFromObj(Tcl_Interp *interp,
			    Tcl_Obj *objPtr, Tcl_Namespace **nsPtrPtr);
static int		InvokeImportedCmd(ClientData clientData,
			    Tcl_Interp *interp,int objc,Tcl_Obj *const objv[]);
static int		InvokeImportedNRCmd(ClientData clientData,
			    Tcl_Interp *interp,int objc,Tcl_Obj *const objv[]);
static int		NamespaceChildrenCmd(ClientData dummy,
			    Tcl_Interp *interp,int objc,Tcl_Obj *const objv[]);
static int		NamespaceCodeCmd(ClientData dummy, Tcl_Interp *interp,
			    int objc, Tcl_Obj *const objv[]);
static int		NamespaceCurrentCmd(ClientData dummy,
			    Tcl_Interp *interp,int objc,Tcl_Obj *const objv[]);
static int		NamespaceDeleteCmd(ClientData dummy,Tcl_Interp *interp,
			    int objc, Tcl_Obj *const objv[]);
static int		NamespaceEvalCmd(ClientData dummy, Tcl_Interp *interp,
			    int objc, Tcl_Obj *const objv[]);
static int		NamespaceExistsCmd(ClientData dummy,Tcl_Interp *interp,
			    int objc, Tcl_Obj *const objv[]);
static int		NamespaceExportCmd(ClientData dummy,Tcl_Interp *interp,
			    int objc, Tcl_Obj *const objv[]);
static int		NamespaceForgetCmd(ClientData dummy,Tcl_Interp *interp,
			    int objc, Tcl_Obj *const objv[]);
static void		NamespaceFree(Namespace *nsPtr);
static int		NamespaceImportCmd(ClientData dummy,Tcl_Interp *interp,
			    int objc, Tcl_Obj *const objv[]);
static int		NamespaceInscopeCmd(ClientData dummy,
			    Tcl_Interp *interp,int objc,Tcl_Obj *const objv[]);
static int		NamespaceOriginCmd(ClientData dummy,Tcl_Interp *interp,
			    int objc, Tcl_Obj *const objv[]);
static int		NamespaceParentCmd(ClientData dummy,Tcl_Interp *interp,
			    int objc, Tcl_Obj *const objv[]);
static int		NamespacePathCmd(ClientData dummy, Tcl_Interp *interp,
			    int objc, Tcl_Obj *const objv[]);
static int		NamespaceQualifiersCmd(ClientData dummy,
			    Tcl_Interp *interp,int objc,Tcl_Obj *const objv[]);
static int		NamespaceTailCmd(ClientData dummy, Tcl_Interp *interp,
			    int objc, Tcl_Obj *const objv[]);
static int		NamespaceUpvarCmd(ClientData dummy, Tcl_Interp *interp,
			    int objc, Tcl_Obj *const objv[]);
static int		NamespaceUnknownCmd(ClientData dummy,
			    Tcl_Interp *interp, int objc,
			    Tcl_Obj *const objv[]);
static int		NamespaceWhichCmd(ClientData dummy, Tcl_Interp *interp,
			    int objc, Tcl_Obj *const objv[]);
static int		SetNsNameFromAny(Tcl_Interp *interp, Tcl_Obj *objPtr);
static void		UnlinkNsPath(Namespace *nsPtr);

static Tcl_NRPostProc NsEval_Callback;

/*
 * This structure defines a Tcl object type that contains a namespace
 * reference. It is used in commands that take the name of a namespace as an
 * argument. The namespace reference is resolved, and the result in cached in
 * the object.
 */

static const Tcl_ObjType nsNameType = {
    "nsName",			/* the type's name */
    FreeNsNameInternalRep,	/* freeIntRepProc */
    DupNsNameInternalRep,	/* dupIntRepProc */
    NULL,			/* updateStringProc */
    SetNsNameFromAny		/* setFromAnyProc */
};

/*
 *----------------------------------------------------------------------
 *
 * TclInitNamespaceSubsystem --
 *
 *	This function is called to initialize all the structures that are used
 *	by namespaces on a per-process basis.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

void
TclInitNamespaceSubsystem(void)
{
    /*
     * Does nothing for now.
     */
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_GetCurrentNamespace --
 *
 *	Returns a pointer to an interpreter's currently active namespace.
 *
 * Results:
 *	Returns a pointer to the interpreter's current namespace.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

Tcl_Namespace *
Tcl_GetCurrentNamespace(
    register Tcl_Interp *interp)/* Interpreter whose current namespace is
				 * being queried. */
{
    return TclGetCurrentNamespace(interp);
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_GetGlobalNamespace --
 *
 *	Returns a pointer to an interpreter's global :: namespace.
 *
 * Results:
 *	Returns a pointer to the specified interpreter's global namespace.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

Tcl_Namespace *
Tcl_GetGlobalNamespace(
    register Tcl_Interp *interp)/* Interpreter whose global namespace should
				 * be returned. */
{
    return TclGetGlobalNamespace(interp);
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_PushCallFrame --
 *
 *	Pushes a new call frame onto the interpreter's Tcl call stack. Called
 *	when executing a Tcl procedure or a "namespace eval" or "namespace
 *	inscope" command.
 *
 * Results:
 *	Returns TCL_OK if successful, or TCL_ERROR (along with an error
 *	message in the interpreter's result object) if something goes wrong.
 *
 * Side effects:
 *	Modifies the interpreter's Tcl call stack.
 *
 *----------------------------------------------------------------------
 */

int
Tcl_PushCallFrame(
    Tcl_Interp *interp,		/* Interpreter in which the new call frame is
				 * to be pushed. */
    Tcl_CallFrame *callFramePtr,/* Points to a call frame structure to push.
				 * Storage for this has already been allocated
				 * by the caller; typically this is the
				 * address of a CallFrame structure allocated
				 * on the caller's C stack. The call frame
				 * will be initialized by this function. The
				 * caller can pop the frame later with
				 * Tcl_PopCallFrame, and it is responsible for
				 * freeing the frame's storage. */
    Tcl_Namespace *namespacePtr,/* Points to the namespace in which the frame
				 * will execute. If NULL, the interpreter's
				 * current namespace will be used. */
    int isProcCallFrame)	/* If nonzero, the frame represents a called
				 * Tcl procedure and may have local vars. Vars
				 * will ordinarily be looked up in the frame.
				 * If new variables are created, they will be
				 * created in the frame. If 0, the frame is
				 * for a "namespace eval" or "namespace
				 * inscope" command and var references are
				 * treated as references to namespace
				 * variables. */
{
    Interp *iPtr = (Interp *) interp;
    register CallFrame *framePtr = (CallFrame *) callFramePtr;
    register Namespace *nsPtr;

    if (namespacePtr == NULL) {
	nsPtr = (Namespace *) TclGetCurrentNamespace(interp);
    } else {
	nsPtr = (Namespace *) namespacePtr;

	/*
	 * TODO: Examine whether it would be better to guard based on NS_DYING
	 * or NS_KILLED. It appears that these are not tested because they can
	 * be set in a global interp that has been [namespace delete]d, but
	 * which never really completely goes away because of lingering global
	 * things like ::errorInfo and [::unknown] and hidden commands.
	 * Review of those designs might permit stricter checking here.
	 */

	if (nsPtr->flags & NS_DEAD) {
	    Tcl_Panic("Trying to push call frame for dead namespace");
	    /*NOTREACHED*/
	}
    }

    nsPtr->activationCount++;
    framePtr->nsPtr = nsPtr;
    framePtr->isProcCallFrame = isProcCallFrame;
    framePtr->objc = 0;
    framePtr->objv = NULL;
    framePtr->callerPtr = iPtr->framePtr;
    framePtr->callerVarPtr = iPtr->varFramePtr;
    if (iPtr->varFramePtr != NULL) {
	framePtr->level = (iPtr->varFramePtr->level + 1);
    } else {
	framePtr->level = 0;
    }
    framePtr->procPtr = NULL;		/* no called procedure */
    framePtr->varTablePtr = NULL;	/* and no local variables */
    framePtr->numCompiledLocals = 0;
    framePtr->compiledLocals = NULL;
    framePtr->clientData = NULL;
    framePtr->localCachePtr = NULL;
    framePtr->tailcallPtr = NULL;

    /*
     * Push the new call frame onto the interpreter's stack of procedure call
     * frames making it the current frame.
     */

    iPtr->framePtr = framePtr;
    iPtr->varFramePtr = framePtr;
    return TCL_OK;
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_PopCallFrame --
 *
 *	Removes a call frame from the Tcl call stack for the interpreter.
 *	Called to remove a frame previously pushed by Tcl_PushCallFrame.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	Modifies the call stack of the interpreter. Resets various fields of
 *	the popped call frame. If a namespace has been deleted and has no more
 *	activations on the call stack, the namespace is destroyed.
 *
 *----------------------------------------------------------------------
 */

void
Tcl_PopCallFrame(
    Tcl_Interp *interp)		/* Interpreter with call frame to pop. */
{
    register Interp *iPtr = (Interp *) interp;
    register CallFrame *framePtr = iPtr->framePtr;
    Namespace *nsPtr;

    /*
     * It's important to remove the call frame from the interpreter's stack of
     * call frames before deleting local variables, so that traces invoked by
     * the variable deletion don't see the partially-deleted frame.
     */

    if (framePtr->callerPtr) {
	iPtr->framePtr = framePtr->callerPtr;
	iPtr->varFramePtr = framePtr->callerVarPtr;
    } else {
	/* Tcl_PopCallFrame: trying to pop rootCallFrame! */
    }

    if (framePtr->varTablePtr != NULL) {
	TclDeleteVars(iPtr, framePtr->varTablePtr);
	ckfree((char *) framePtr->varTablePtr);
	framePtr->varTablePtr = NULL;
    }
    if (framePtr->numCompiledLocals > 0) {
	TclDeleteCompiledLocalVars(iPtr, framePtr);
	if (--framePtr->localCachePtr->refCount == 0) {
	    TclFreeLocalCache(interp, framePtr->localCachePtr);
	}
	framePtr->localCachePtr = NULL;
    }

    /*
     * Decrement the namespace's count of active call frames. If the namespace
     * is "dying" and there are no more active call frames, call
     * Tcl_DeleteNamespace to destroy it.
     */

    nsPtr = framePtr->nsPtr;
    nsPtr->activationCount--;
    if ((nsPtr->flags & NS_DYING)
	    && (nsPtr->activationCount - (nsPtr == iPtr->globalNsPtr) == 0)) {
	Tcl_DeleteNamespace((Tcl_Namespace *) nsPtr);
    }
    framePtr->nsPtr = NULL;
}

/*
 *----------------------------------------------------------------------
 *
 * TclPushStackFrame --
 *
 *	Allocates a new call frame in the interpreter's execution stack, then
 *	pushes it onto the interpreter's Tcl call stack. Called when executing
 *	a Tcl procedure or a "namespace eval" or "namespace inscope" command.
 *
 * Results:
 *	Returns TCL_OK if successful, or TCL_ERROR (along with an error
 *	message in the interpreter's result object) if something goes wrong.
 *
 * Side effects:
 *	Modifies the interpreter's Tcl call stack.
 *
 *----------------------------------------------------------------------
 */

int
TclPushStackFrame(
    Tcl_Interp *interp,		/* Interpreter in which the new call frame is
				 * to be pushed. */
    Tcl_CallFrame **framePtrPtr,/* Place to store a pointer to the stack
				 * allocated call frame. */
    Tcl_Namespace *namespacePtr,/* Points to the namespace in which the frame
				 * will execute. If NULL, the interpreter's
				 * current namespace will be used. */
    int isProcCallFrame)	/* If nonzero, the frame represents a called
				 * Tcl procedure and may have local vars. Vars
				 * will ordinarily be looked up in the frame.
				 * If new variables are created, they will be
				 * created in the frame. If 0, the frame is
				 * for a "namespace eval" or "namespace
				 * inscope" command and var references are
				 * treated as references to namespace
				 * variables. */
{
    *framePtrPtr = (Tcl_CallFrame *) TclStackAlloc(interp, sizeof(CallFrame));
    return Tcl_PushCallFrame(interp, *framePtrPtr, namespacePtr,
	    isProcCallFrame);
}

void
TclPopStackFrame(
    Tcl_Interp *interp)		/* Interpreter with call frame to pop. */
{
    CallFrame *freePtr = ((Interp *) interp)->framePtr;

    Tcl_PopCallFrame(interp);
    TclStackFree(interp, freePtr);
}

/*
 *----------------------------------------------------------------------
 *
 * EstablishErrorCodeTraces --
 *
 *	Creates traces on the ::errorCode variable to keep its value
 *	consistent with the expectations of legacy code.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	Read and unset traces are established on ::errorCode.
 *
 *----------------------------------------------------------------------
 */

static char *
EstablishErrorCodeTraces(
    ClientData clientData,
    Tcl_Interp *interp,
    const char *name1,
    const char *name2,
    int flags)
{
    Tcl_TraceVar(interp, "errorCode", TCL_GLOBAL_ONLY | TCL_TRACE_READS,
	    ErrorCodeRead, NULL);
    Tcl_TraceVar(interp, "errorCode", TCL_GLOBAL_ONLY | TCL_TRACE_UNSETS,
	    EstablishErrorCodeTraces, NULL);
    return NULL;
}

/*
 *----------------------------------------------------------------------
 *
 * ErrorCodeRead --
 *
 *	Called when the ::errorCode variable is read. Copies the current value
 *	of the interp's errorCode field into ::errorCode.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

static char *
ErrorCodeRead(
    ClientData clientData,
    Tcl_Interp *interp,
    const char *name1,
    const char *name2,
    int flags)
{
    Interp *iPtr = (Interp *) interp;

    if (Tcl_InterpDeleted(interp) || !(iPtr->flags & ERR_LEGACY_COPY)) {
	return NULL;
    }
    if (iPtr->errorCode) {
	Tcl_ObjSetVar2(interp, iPtr->ecVar, NULL,
		iPtr->errorCode, TCL_GLOBAL_ONLY);
	return NULL;
    }
    if (NULL == Tcl_ObjGetVar2(interp, iPtr->ecVar, NULL, TCL_GLOBAL_ONLY)) {
	Tcl_ObjSetVar2(interp, iPtr->ecVar, NULL,
		Tcl_NewObj(), TCL_GLOBAL_ONLY);
    }
    return NULL;
}

/*
 *----------------------------------------------------------------------
 *
 * EstablishErrorInfoTraces --
 *
 *	Creates traces on the ::errorInfo variable to keep its value
 *	consistent with the expectations of legacy code.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	Read and unset traces are established on ::errorInfo.
 *
 *----------------------------------------------------------------------
 */

static char *
EstablishErrorInfoTraces(
    ClientData clientData,
    Tcl_Interp *interp,
    const char *name1,
    const char *name2,
    int flags)
{
    Tcl_TraceVar(interp, "errorInfo", TCL_GLOBAL_ONLY | TCL_TRACE_READS,
	    ErrorInfoRead, NULL);
    Tcl_TraceVar(interp, "errorInfo", TCL_GLOBAL_ONLY | TCL_TRACE_UNSETS,
	    EstablishErrorInfoTraces, NULL);
    return NULL;
}

/*
 *----------------------------------------------------------------------
 *
 * ErrorInfoRead --
 *
 *	Called when the ::errorInfo variable is read. Copies the current value
 *	of the interp's errorInfo field into ::errorInfo.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

static char *
ErrorInfoRead(
    ClientData clientData,
    Tcl_Interp *interp,
    const char *name1,
    const char *name2,
    int flags)
{
    Interp *iPtr = (Interp *) interp;

    if (Tcl_InterpDeleted(interp) || !(iPtr->flags & ERR_LEGACY_COPY)) {
	return NULL;
    }
    if (iPtr->errorInfo) {
	Tcl_ObjSetVar2(interp, iPtr->eiVar, NULL,
		iPtr->errorInfo, TCL_GLOBAL_ONLY);
	return NULL;
    }
    if (NULL == Tcl_ObjGetVar2(interp, iPtr->eiVar, NULL, TCL_GLOBAL_ONLY)) {
	Tcl_ObjSetVar2(interp, iPtr->eiVar, NULL,
		Tcl_NewObj(), TCL_GLOBAL_ONLY);
    }
    return NULL;
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_CreateNamespace --
 *
 *	Creates a new namespace with the given name. If there is no active
 *	namespace (i.e., the interpreter is being initialized), the global ::
 *	namespace is created and returned.
 *
 * Results:
 *	Returns a pointer to the new namespace if successful. If the namespace
 *	already exists or if another error occurs, this routine returns NULL,
 *	along with an error message in the interpreter's result object.
 *
 * Side effects:
 *	If the name contains "::" qualifiers and a parent namespace does not
 *	already exist, it is automatically created.
 *
 *----------------------------------------------------------------------
 */

Tcl_Namespace *
Tcl_CreateNamespace(
    Tcl_Interp *interp,		/* Interpreter in which a new namespace is
				 * being created. Also used for error
				 * reporting. */
    const char *name,		/* Name for the new namespace. May be a
				 * qualified name with names of ancestor
				 * namespaces separated by "::"s. */
    ClientData clientData,	/* One-word value to store with namespace. */
    Tcl_NamespaceDeleteProc *deleteProc)
				/* Function called to delete client data when
				 * the namespace is deleted. NULL if no
				 * function should be called. */
{
    Interp *iPtr = (Interp *) interp;
    register Namespace *nsPtr, *ancestorPtr;
    Namespace *parentPtr, *dummy1Ptr, *dummy2Ptr;
    Namespace *globalNsPtr = iPtr->globalNsPtr;
    const char *simpleName;
    Tcl_HashEntry *entryPtr;
    Tcl_DString buffer1, buffer2;
    Tcl_DString *namePtr, *buffPtr;
    int newEntry, nameLen;
    ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);

    /*
     * If there is no active namespace, the interpreter is being initialized.
     */

    if ((globalNsPtr == NULL) && (iPtr->varFramePtr == NULL)) {
	/*
	 * Treat this namespace as the global namespace, and avoid looking for
	 * a parent.
	 */

	parentPtr = NULL;
	simpleName = "";
    } else if (*name == '\0') {
	Tcl_ResetResult(interp);
	Tcl_AppendResult(interp, "can't create namespace \"\": "
		"only global namespace can have empty name", NULL);
	return NULL;
    } else {
	/*
	 * Find the parent for the new namespace.
	 */

	TclGetNamespaceForQualName(interp, name, NULL,
		/*flags*/ (TCL_CREATE_NS_IF_UNKNOWN | TCL_LEAVE_ERR_MSG),
		&parentPtr, &dummy1Ptr, &dummy2Ptr, &simpleName);

	/*
	 * If the unqualified name at the end is empty, there were trailing
	 * "::"s after the namespace's name which we ignore. The new namespace
	 * was already (recursively) created and is pointed to by parentPtr.
	 */

	if (*simpleName == '\0') {
	    return (Tcl_Namespace *) parentPtr;
	}

	/*
	 * Check for a bad namespace name and make sure that the name does not
	 * already exist in the parent namespace.
	 */

	if (
#ifndef BREAK_NAMESPACE_COMPAT
	    Tcl_FindHashEntry(&parentPtr->childTable, simpleName) != NULL
#else
	    parentPtr->childTablePtr != NULL &&
	    Tcl_FindHashEntry(parentPtr->childTablePtr, simpleName) != NULL
#endif
	) {
	    Tcl_AppendResult(interp, "can't create namespace \"", name,
		    "\": already exists", NULL);
	    return NULL;
	}
    }

    /*
     * Create the new namespace and root it in its parent. Increment the count
     * of namespaces created.
     */

    nsPtr = (Namespace *) ckalloc(sizeof(Namespace));
    nsPtr->name = ckalloc((unsigned) (strlen(simpleName)+1));
    strcpy(nsPtr->name, simpleName);
    nsPtr->fullName = NULL;		/* Set below. */
    nsPtr->clientData = clientData;
    nsPtr->deleteProc = deleteProc;
    nsPtr->parentPtr = parentPtr;
#ifndef BREAK_NAMESPACE_COMPAT
    Tcl_InitHashTable(&nsPtr->childTable, TCL_STRING_KEYS);
#else
    nsPtr->childTablePtr = NULL;
#endif
    nsPtr->nsId = ++(tsdPtr->numNsCreated);
    nsPtr->interp = interp;
    nsPtr->flags = 0;
    nsPtr->activationCount = 0;
    nsPtr->refCount = 0;
    Tcl_InitHashTable(&nsPtr->cmdTable, TCL_STRING_KEYS);
    TclInitVarHashTable(&nsPtr->varTable, nsPtr);
    nsPtr->exportArrayPtr = NULL;
    nsPtr->numExportPatterns = 0;
    nsPtr->maxExportPatterns = 0;
    nsPtr->cmdRefEpoch = 0;
    nsPtr->resolverEpoch = 0;
    nsPtr->cmdResProc = NULL;
    nsPtr->varResProc = NULL;
    nsPtr->compiledVarResProc = NULL;
    nsPtr->exportLookupEpoch = 0;
    nsPtr->ensembles = NULL;
    nsPtr->unknownHandlerPtr = NULL;
    nsPtr->commandPathLength = 0;
    nsPtr->commandPathArray = NULL;
    nsPtr->commandPathSourceList = NULL;

    if (parentPtr != NULL) {
	entryPtr = Tcl_CreateHashEntry(
		TclGetNamespaceChildTable((Tcl_Namespace *) parentPtr),
		simpleName, &newEntry);
	Tcl_SetHashValue(entryPtr, nsPtr);
    } else {
	/*
	 * In the global namespace create traces to maintain the ::errorInfo
	 * and ::errorCode variables.
	 */

	iPtr->globalNsPtr = nsPtr;
	EstablishErrorInfoTraces(NULL, interp, NULL, NULL, 0);
	EstablishErrorCodeTraces(NULL, interp, NULL, NULL, 0);
    }

    /*
     * Build the fully qualified name for this namespace.
     */

    Tcl_DStringInit(&buffer1);
    Tcl_DStringInit(&buffer2);
    namePtr = &buffer1;
    buffPtr = &buffer2;
    for (ancestorPtr = nsPtr; ancestorPtr != NULL;
	    ancestorPtr = ancestorPtr->parentPtr) {
	if (ancestorPtr != globalNsPtr) {
	    register Tcl_DString *tempPtr = namePtr;

	    Tcl_DStringAppend(buffPtr, "::", 2);
	    Tcl_DStringAppend(buffPtr, ancestorPtr->name, -1);
	    Tcl_DStringAppend(buffPtr, Tcl_DStringValue(namePtr),
		    Tcl_DStringLength(namePtr));

	    /*
	     * Clear the unwanted buffer or we end up appending to previous
	     * results, making the namespace fullNames of nested namespaces
	     * very wrong (and strange).
	     */

	    Tcl_DStringSetLength(namePtr, 0);

	    /*
	     * Now swap the buffer pointers so that we build in the other
	     * buffer. This is faster than repeated copying back and forth
	     * between buffers.
	     */

	    namePtr = buffPtr;
	    buffPtr = tempPtr;
	}
    }

    name = Tcl_DStringValue(namePtr);
    nameLen = Tcl_DStringLength(namePtr);
    nsPtr->fullName = ckalloc((unsigned) (nameLen+1));
    memcpy(nsPtr->fullName, name, (unsigned) nameLen + 1);

    Tcl_DStringFree(&buffer1);
    Tcl_DStringFree(&buffer2);

    /*
     * If compilation of commands originating from the parent NS is
     * suppressed, suppress it for commands originating in this one too.
     */

    if (nsPtr->parentPtr != NULL &&
	    nsPtr->parentPtr->flags & NS_SUPPRESS_COMPILATION) {
	nsPtr->flags |= NS_SUPPRESS_COMPILATION;
    }

    /*
     * Return a pointer to the new namespace.
     */

    return (Tcl_Namespace *) nsPtr;
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_DeleteNamespace --
 *
 *	Deletes a namespace and all of the commands, variables, and other
 *	namespaces within it.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	When a namespace is deleted, it is automatically removed as a child of
 *	its parent namespace. Also, all its commands, variables and child
 *	namespaces are deleted.
 *
 *----------------------------------------------------------------------
 */

void
Tcl_DeleteNamespace(
    Tcl_Namespace *namespacePtr)/* Points to the namespace to delete. */
{
    register Namespace *nsPtr = (Namespace *) namespacePtr;
    Interp *iPtr = (Interp *) nsPtr->interp;
    Namespace *globalNsPtr = (Namespace *)
	    TclGetGlobalNamespace((Tcl_Interp *) iPtr);
    Tcl_HashEntry *entryPtr;
    Tcl_HashSearch search;
    Command *cmdPtr;

    /*
     * Delete all coroutine commands now: break the circular ref cycle between
     * the namespace and the coroutine command [Bug 2724403]. This code is
     * essentially duplicated in TclTeardownNamespace() for all other
     * commands. Don't optimize to Tcl_NextHashEntry() because of traces.
     *
     * NOTE: we could avoid traversing the ns's command list by keeping a
     * separate list of coros.
     */

    for (entryPtr = Tcl_FirstHashEntry(&nsPtr->cmdTable, &search);
	    entryPtr != NULL;) {
	cmdPtr = (Command *) Tcl_GetHashValue(entryPtr);
	if (cmdPtr->nreProc == NRInterpCoroutine) {
	    Tcl_DeleteCommandFromToken((Tcl_Interp *) iPtr,
		    (Tcl_Command) cmdPtr);
	    entryPtr = Tcl_FirstHashEntry(&nsPtr->cmdTable, &search);
	} else {
	    entryPtr = entryPtr->nextPtr;
	}
    }

    /*
     * If the namespace has associated ensemble commands, delete them first.
     * This leaves the actual contents of the namespace alone (unless they are
     * linked ensemble commands, of course). Note that this code is actually
     * reentrant so command delete traces won't purturb things badly.
     */

    while (nsPtr->ensembles != NULL) {
	EnsembleConfig *ensemblePtr = (EnsembleConfig *) nsPtr->ensembles;

	/*
	 * Splice out and link to indicate that we've already been killed.
	 */

	nsPtr->ensembles = (Tcl_Ensemble *) ensemblePtr->next;
	ensemblePtr->next = ensemblePtr;
	Tcl_DeleteCommandFromToken(nsPtr->interp, ensemblePtr->token);
    }

    /*
     * If the namespace has a registered unknown handler (TIP 181), then free
     * it here.
     */

    if (nsPtr->unknownHandlerPtr != NULL) {
	Tcl_DecrRefCount(nsPtr->unknownHandlerPtr);
	nsPtr->unknownHandlerPtr = NULL;
    }

    /*
     * If the namespace is on the call frame stack, it is marked as "dying"
     * (NS_DYING is OR'd into its flags): the namespace can't be looked up by
     * name but its commands and variables are still usable by those active
     * call frames. When all active call frames referring to the namespace
     * have been popped from the Tcl stack, Tcl_PopCallFrame will call this
     * function again to delete everything in the namespace. If no nsName
     * objects refer to the namespace (i.e., if its refCount is zero), its
     * commands and variables are deleted and the storage for its namespace
     * structure is freed. Otherwise, if its refCount is nonzero, the
     * namespace's commands and variables are deleted but the structure isn't
     * freed. Instead, NS_DEAD is OR'd into the structure's flags to allow the
     * namespace resolution code to recognize that the namespace is "deleted".
     * The structure's storage is freed by FreeNsNameInternalRep when its
     * refCount reaches 0.
     */

    if (nsPtr->activationCount - (nsPtr == globalNsPtr) > 0) {
	nsPtr->flags |= NS_DYING;
	if (nsPtr->parentPtr != NULL) {
	    entryPtr = Tcl_FindHashEntry(
		    TclGetNamespaceChildTable((Tcl_Namespace *)
			    nsPtr->parentPtr), nsPtr->name);
	    if (entryPtr != NULL) {
		Tcl_DeleteHashEntry(entryPtr);
	    }
	}
	nsPtr->parentPtr = NULL;
    } else if (!(nsPtr->flags & NS_KILLED)) {
	/*
	 * Delete the namespace and everything in it. If this is the global
	 * namespace, then clear it but don't free its storage unless the
	 * interpreter is being torn down. Set the NS_KILLED flag to avoid
	 * recursive calls here - if the namespace is really in the process of
	 * being deleted, ignore any second call.
	 */

	nsPtr->flags |= (NS_DYING|NS_KILLED);

	TclTeardownNamespace(nsPtr);

	if ((nsPtr != globalNsPtr) || (iPtr->flags & DELETED)) {
	    /*
	     * If this is the global namespace, then it may have residual
	     * "errorInfo" and "errorCode" variables for errors that occurred
	     * while it was being torn down. Try to clear the variable list
	     * one last time.
	     */

	    TclDeleteNamespaceVars(nsPtr);

#ifndef BREAK_NAMESPACE_COMPAT
	    Tcl_DeleteHashTable(&nsPtr->childTable);
#else
	    if (nsPtr->childTablePtr != NULL) {
		Tcl_DeleteHashTable(nsPtr->childTablePtr);
		ckfree((char *) nsPtr->childTablePtr);
	    }
#endif
	    Tcl_DeleteHashTable(&nsPtr->cmdTable);

	    /*
	     * If the reference count is 0, then discard the namespace.
	     * Otherwise, mark it as "dead" so that it can't be used.
	     */

	    if (nsPtr->refCount == 0) {
		NamespaceFree(nsPtr);
	    } else {
		nsPtr->flags |= NS_DEAD;
	    }
	} else {
	    /*
	     * Restore the ::errorInfo and ::errorCode traces.
	     */

	    EstablishErrorInfoTraces(NULL, nsPtr->interp, NULL, NULL, 0);
	    EstablishErrorCodeTraces(NULL, nsPtr->interp, NULL, NULL, 0);

	    /*
	     * We didn't really kill it, so remove the KILLED marks, so it can
	     * get killed later, avoiding mem leaks.
	     */

	    nsPtr->flags &= ~(NS_DYING|NS_KILLED);
	}
    }
}

/*
 *----------------------------------------------------------------------
 *
 * TclTeardownNamespace --
 *
 *	Used internally to dismantle and unlink a namespace when it is
 *	deleted. Divorces the namespace from its parent, and deletes all
 *	commands, variables, and child namespaces.
 *
 *	This is kept separate from Tcl_DeleteNamespace so that the global
 *	namespace can be handled specially.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	Removes this namespace from its parent's child namespace hashtable.
 *	Deletes all commands, variables and namespaces in this namespace.
 *
 *----------------------------------------------------------------------
 */

void
TclTeardownNamespace(
    register Namespace *nsPtr)	/* Points to the namespace to be dismantled
				 * and unlinked from its parent. */
{
    Interp *iPtr = (Interp *) nsPtr->interp;
    register Tcl_HashEntry *entryPtr;
    Tcl_HashSearch search;
    Tcl_Namespace *childNsPtr;
    Tcl_Command cmd;
    int i;

    /*
     * Start by destroying the namespace's variable table, since variables
     * might trigger traces. Variable table should be cleared but not freed!
     * TclDeleteNamespaceVars frees it, so we reinitialize it afterwards.
     */

    TclDeleteNamespaceVars(nsPtr);
    TclInitVarHashTable(&nsPtr->varTable, nsPtr);

    /*
     * Delete all commands in this namespace. Be careful when traversing the
     * hash table: when each command is deleted, it removes itself from the
     * command table.
     *
     * Don't optimize to Tcl_NextHashEntry() because of traces.
     */

    for (entryPtr = Tcl_FirstHashEntry(&nsPtr->cmdTable, &search);
	    entryPtr != NULL;
	    entryPtr = Tcl_FirstHashEntry(&nsPtr->cmdTable, &search)) {
	cmd = Tcl_GetHashValue(entryPtr);
	Tcl_DeleteCommandFromToken((Tcl_Interp *) iPtr, cmd);
    }
    Tcl_DeleteHashTable(&nsPtr->cmdTable);
    Tcl_InitHashTable(&nsPtr->cmdTable, TCL_STRING_KEYS);

    /*
     * Remove the namespace from its parent's child hashtable.
     */

    if (nsPtr->parentPtr != NULL) {
	entryPtr = Tcl_FindHashEntry(
		TclGetNamespaceChildTable((Tcl_Namespace *)
			nsPtr->parentPtr), nsPtr->name);
	if (entryPtr != NULL) {
	    Tcl_DeleteHashEntry(entryPtr);
	}
    }
    nsPtr->parentPtr = NULL;

    /*
     * Delete the namespace path if one is installed.
     */

    if (nsPtr->commandPathLength != 0) {
	UnlinkNsPath(nsPtr);
	nsPtr->commandPathLength = 0;
    }
    if (nsPtr->commandPathSourceList != NULL) {
	NamespacePathEntry *nsPathPtr = nsPtr->commandPathSourceList;

	do {
	    if (nsPathPtr->nsPtr != NULL && nsPathPtr->creatorNsPtr != NULL) {
		nsPathPtr->creatorNsPtr->cmdRefEpoch++;
	    }
	    nsPathPtr->nsPtr = NULL;
	    nsPathPtr = nsPathPtr->nextPtr;
	} while (nsPathPtr != NULL);
	nsPtr->commandPathSourceList = NULL;
    }

    /*
     * Delete all the child namespaces.
     *
     * BE CAREFUL: When each child is deleted, it will divorce itself from its
     * parent. You can't traverse a hash table properly if its elements are
     * being deleted. We use only the Tcl_FirstHashEntry function to be safe.
     *
     * Don't optimize to Tcl_NextHashEntry() because of traces.
     */

#ifndef BREAK_NAMESPACE_COMPAT
    for (entryPtr = Tcl_FirstHashEntry(&nsPtr->childTable, &search);
	    entryPtr != NULL;
	    entryPtr = Tcl_FirstHashEntry(&nsPtr->childTable, &search)) {
	childNsPtr = Tcl_GetHashValue(entryPtr);
	Tcl_DeleteNamespace(childNsPtr);
    }
#else
    if (nsPtr->childTablePtr != NULL) {
	for (entryPtr = Tcl_FirstHashEntry(nsPtr->childTablePtr, &search);
		entryPtr != NULL;
		entryPtr = Tcl_FirstHashEntry(nsPtr->childTablePtr,&search)) {
	    childNsPtr = Tcl_GetHashValue(entryPtr);
	    Tcl_DeleteNamespace(childNsPtr);
	}
    }
#endif

    /*
     * Free the namespace's export pattern array.
     */

    if (nsPtr->exportArrayPtr != NULL) {
	for (i = 0;  i < nsPtr->numExportPatterns;  i++) {
	    ckfree(nsPtr->exportArrayPtr[i]);
	}
	ckfree((char *) nsPtr->exportArrayPtr);
	nsPtr->exportArrayPtr = NULL;
	nsPtr->numExportPatterns = 0;
	nsPtr->maxExportPatterns = 0;
    }

    /*
     * Free any client data associated with the namespace.
     */

    if (nsPtr->deleteProc != NULL) {
	nsPtr->deleteProc(nsPtr->clientData);
    }
    nsPtr->deleteProc = NULL;
    nsPtr->clientData = NULL;

    /*
     * Reset the namespace's id field to ensure that this namespace won't be
     * interpreted as valid by, e.g., the cache validation code for cached
     * command references in Tcl_GetCommandFromObj.
     */

    nsPtr->nsId = 0;
}

/*
 *----------------------------------------------------------------------
 *
 * NamespaceFree --
 *
 *	Called after a namespace has been deleted, when its reference count
 *	reaches 0. Frees the data structure representing the namespace.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

static void
NamespaceFree(
    register Namespace *nsPtr)	/* Points to the namespace to free. */
{
    /*
     * Most of the namespace's contents are freed when the namespace is
     * deleted by Tcl_DeleteNamespace. All that remains is to free its names
     * (for error messages), and the structure itself.
     */

    ckfree(nsPtr->name);
    ckfree(nsPtr->fullName);

    ckfree((char *) nsPtr);
}

/*
 *----------------------------------------------------------------------
 *
 * TclNsDecrRefCount --
 *
 *	Drops a reference to a namespace and frees it if the namespace has
 *	been deleted and the last reference has just been dropped.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

void
TclNsDecrRefCount(
    Namespace *nsPtr)
{
    nsPtr->refCount--;
    if ((nsPtr->refCount == 0) && (nsPtr->flags & NS_DEAD)) {
	NamespaceFree(nsPtr);
    }
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_Export --
 *
 *	Makes all the commands matching a pattern available to later be
 *	imported from the namespace specified by namespacePtr (or the current
 *	namespace if namespacePtr is NULL). The specified pattern is appended
 *	onto the namespace's export pattern list, which is optionally cleared
 *	beforehand.
 *
 * Results:
 *	Returns TCL_OK if successful, or TCL_ERROR (along with an error
 *	message in the interpreter's result) if something goes wrong.
 *
 * Side effects:
 *	Appends the export pattern onto the namespace's export list.
 *	Optionally reset the namespace's export pattern list.
 *
 *----------------------------------------------------------------------
 */

int
Tcl_Export(
    Tcl_Interp *interp,		/* Current interpreter. */
    Tcl_Namespace *namespacePtr,/* Points to the namespace from which commands
				 * are to be exported. NULL for the current
				 * namespace. */
    const char *pattern,	/* String pattern indicating which commands to
				 * export. This pattern may not include any
				 * namespace qualifiers; only commands in the
				 * specified namespace may be exported. */
    int resetListFirst)		/* If nonzero, resets the namespace's export
				 * list before appending. */
{
#define INIT_EXPORT_PATTERNS 5
    Namespace *nsPtr, *exportNsPtr, *dummyPtr;
    Namespace *currNsPtr = (Namespace *) TclGetCurrentNamespace(interp);
    const char *simplePattern;
    char *patternCpy;
    int neededElems, len, i;

    /*
     * If the specified namespace is NULL, use the current namespace.
     */

    if (namespacePtr == NULL) {
	nsPtr = (Namespace *) currNsPtr;
    } else {
	nsPtr = (Namespace *) namespacePtr;
    }

    /*
     * If resetListFirst is true (nonzero), clear the namespace's export
     * pattern list.
     */

    if (resetListFirst) {
	if (nsPtr->exportArrayPtr != NULL) {
	    for (i = 0;  i < nsPtr->numExportPatterns;  i++) {
		ckfree(nsPtr->exportArrayPtr[i]);
	    }
	    ckfree((char *) nsPtr->exportArrayPtr);
	    nsPtr->exportArrayPtr = NULL;
	    TclInvalidateNsCmdLookup(nsPtr);
	    nsPtr->numExportPatterns = 0;
	    nsPtr->maxExportPatterns = 0;
	}
    }

    /*
     * Check that the pattern doesn't have namespace qualifiers.
     */

    TclGetNamespaceForQualName(interp, pattern, nsPtr,
	    /*flags*/ (TCL_LEAVE_ERR_MSG | TCL_NAMESPACE_ONLY),
	    &exportNsPtr, &dummyPtr, &dummyPtr, &simplePattern);

    if ((exportNsPtr != nsPtr) || (strcmp(pattern, simplePattern) != 0)) {
	Tcl_AppendResult(interp, "invalid export pattern \"", pattern,
		"\": pattern can't specify a namespace", NULL);
	return TCL_ERROR;
    }

    /*
     * Make sure that we don't already have the pattern in the array
     */

    if (nsPtr->exportArrayPtr != NULL) {
	for (i = 0;  i < nsPtr->numExportPatterns;  i++) {
	    if (strcmp(pattern, nsPtr->exportArrayPtr[i]) == 0) {
		/*
		 * The pattern already exists in the list.
		 */

		return TCL_OK;
	    }
	}
    }

    /*
     * Make sure there is room in the namespace's pattern array for the new
     * pattern.
     */

    neededElems = nsPtr->numExportPatterns + 1;
    if (neededElems > nsPtr->maxExportPatterns) {
	nsPtr->maxExportPatterns = nsPtr->maxExportPatterns ?
		2 * nsPtr->maxExportPatterns : INIT_EXPORT_PATTERNS;
	nsPtr->exportArrayPtr = (char **)
		ckrealloc((char *) nsPtr->exportArrayPtr,
		sizeof(char *) * nsPtr->maxExportPatterns);
    }

    /*
     * Add the pattern to the namespace's array of export patterns.
     */

    len = strlen(pattern);
    patternCpy = ckalloc((unsigned) (len + 1));
    memcpy(patternCpy, pattern, (unsigned) len + 1);

    nsPtr->exportArrayPtr[nsPtr->numExportPatterns] = patternCpy;
    nsPtr->numExportPatterns++;

    /*
     * The list of commands actually exported from the namespace might have
     * changed (probably will have!) However, we do not need to recompute this
     * just yet; next time we need the info will be soon enough.
     */

    TclInvalidateNsCmdLookup(nsPtr);

    return TCL_OK;
#undef INIT_EXPORT_PATTERNS
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_AppendExportList --
 *
 *	Appends onto the argument object the list of export patterns for the
 *	specified namespace.
 *
 * Results:
 *	The return value is normally TCL_OK; in this case the object
 *	referenced by objPtr has each export pattern appended to it. If an
 *	error occurs, TCL_ERROR is returned and the interpreter's result holds
 *	an error message.
 *
 * Side effects:
 *	If necessary, the object referenced by objPtr is converted into a list
 *	object.
 *
 *----------------------------------------------------------------------
 */

int
Tcl_AppendExportList(
    Tcl_Interp *interp,		/* Interpreter used for error reporting. */
    Tcl_Namespace *namespacePtr,/* Points to the namespace whose export
				 * pattern list is appended onto objPtr. NULL
				 * for the current namespace. */
    Tcl_Obj *objPtr)		/* Points to the Tcl object onto which the
				 * export pattern list is appended. */
{
    Namespace *nsPtr;
    int i, result;

    /*
     * If the specified namespace is NULL, use the current namespace.
     */

    if (namespacePtr == NULL) {
	nsPtr = (Namespace *) TclGetCurrentNamespace(interp);
    } else {
	nsPtr = (Namespace *) namespacePtr;
    }

    /*
     * Append the export pattern list onto objPtr.
     */

    for (i = 0;  i < nsPtr->numExportPatterns;  i++) {
	result = Tcl_ListObjAppendElement(interp, objPtr,
		Tcl_NewStringObj(nsPtr->exportArrayPtr[i], -1));
	if (result != TCL_OK) {
	    return result;
	}
    }
    return TCL_OK;
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_Import --
 *
 *	Imports all of the commands matching a pattern into the namespace
 *	specified by namespacePtr (or the current namespace if contextNsPtr is
 *	NULL). This is done by creating a new command (the "imported command")
 *	that points to the real command in its original namespace.
 *
 *	If matching commands are on the autoload path but haven't been loaded
 *	yet, this command forces them to be loaded, then creates the links to
 *	them.
 *
 * Results:
 *	Returns TCL_OK if successful, or TCL_ERROR (along with an error
 *	message in the interpreter's result) if something goes wrong.
 *
 * Side effects:
 *	Creates new commands in the importing namespace. These indirect calls
 *	back to the real command and are deleted if the real commands are
 *	deleted.
 *
 *----------------------------------------------------------------------
 */

int
Tcl_Import(
    Tcl_Interp *interp,		/* Current interpreter. */
    Tcl_Namespace *namespacePtr,/* Points to the namespace into which the
				 * commands are to be imported. NULL for the
				 * current namespace. */
    const char *pattern,	/* String pattern indicating which commands to
				 * import. This pattern should be qualified by
				 * the name of the namespace from which to
				 * import the command(s). */
    int allowOverwrite)		/* If nonzero, allow existing commands to be
				 * overwritten by imported commands. If 0,
				 * return an error if an imported cmd
				 * conflicts with an existing one. */
{
    Namespace *nsPtr, *importNsPtr, *dummyPtr;
    const char *simplePattern;
    register Tcl_HashEntry *hPtr;
    Tcl_HashSearch search;

    /*
     * If the specified namespace is NULL, use the current namespace.
     */

    if (namespacePtr == NULL) {
	nsPtr = (Namespace *) TclGetCurrentNamespace(interp);
    } else {
	nsPtr = (Namespace *) namespacePtr;
    }

    /*
     * First, invoke the "auto_import" command with the pattern being
     * imported. This command is part of the Tcl library. It looks for
     * imported commands in autoloaded libraries and loads them in. That way,
     * they will be found when we try to create links below.
     *
     * Note that we don't just call Tcl_EvalObjv() directly because we do not
     * want absence of the command to be a failure case.
     */

    if (Tcl_FindCommand(interp,"auto_import",NULL,TCL_GLOBAL_ONLY) != NULL) {
	Tcl_Obj *objv[2];
	int result;

	TclNewLiteralStringObj(objv[0], "auto_import");
	objv[1] = Tcl_NewStringObj(pattern, -1);

	Tcl_IncrRefCount(objv[0]);
	Tcl_IncrRefCount(objv[1]);
	result = Tcl_EvalObjv(interp, 2, objv, TCL_GLOBAL_ONLY);
	Tcl_DecrRefCount(objv[0]);
	Tcl_DecrRefCount(objv[1]);

	if (result != TCL_OK) {
	    return TCL_ERROR;
	}
	Tcl_ResetResult(interp);
    }

    /*
     * From the pattern, find the namespace from which we are importing and
     * get the simple pattern (no namespace qualifiers or ::'s) at the end.
     */

    if (strlen(pattern) == 0) {
	Tcl_SetObjResult(interp, Tcl_NewStringObj("empty import pattern",-1));
	return TCL_ERROR;
    }
    TclGetNamespaceForQualName(interp, pattern, nsPtr,
	    /*flags*/ (TCL_LEAVE_ERR_MSG | TCL_NAMESPACE_ONLY),
	    &importNsPtr, &dummyPtr, &dummyPtr, &simplePattern);

    if (importNsPtr == NULL) {
	Tcl_AppendResult(interp, "unknown namespace in import pattern \"",
		pattern, "\"", NULL);
	Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "NAMESPACE", pattern, NULL);
	return TCL_ERROR;
    }
    if (importNsPtr == nsPtr) {
	if (pattern == simplePattern) {
	    Tcl_AppendResult(interp,
		    "no namespace specified in import pattern \"", pattern,
		    "\"", NULL);
	} else {
	    Tcl_AppendResult(interp, "import pattern \"", pattern,
		    "\" tries to import from namespace \"",
		    importNsPtr->name, "\" into itself", NULL);
	}
	return TCL_ERROR;
    }

    /*
     * Scan through the command table in the source namespace and look for
     * exported commands that match the string pattern. Create an "imported
     * command" in the current namespace for each imported command; these
     * commands redirect their invocations to the "real" command.
     */

    if ((simplePattern != NULL) && TclMatchIsTrivial(simplePattern)) {
	hPtr = Tcl_FindHashEntry(&importNsPtr->cmdTable, simplePattern);
	if (hPtr == NULL) {
	    return TCL_OK;
	}
	return DoImport(interp, nsPtr, hPtr, simplePattern, pattern,
		importNsPtr, allowOverwrite);
    }
    for (hPtr = Tcl_FirstHashEntry(&importNsPtr->cmdTable, &search);
	    (hPtr != NULL); hPtr = Tcl_NextHashEntry(&search)) {
	char *cmdName = Tcl_GetHashKey(&importNsPtr->cmdTable, hPtr);

	if (Tcl_StringMatch(cmdName, simplePattern) &&
		DoImport(interp, nsPtr, hPtr, cmdName, pattern, importNsPtr,
		allowOverwrite) == TCL_ERROR) {
	    return TCL_ERROR;
	}
    }
    return TCL_OK;
}

/*
 *----------------------------------------------------------------------
 *
 * DoImport --
 *
 *	Import a particular command from one namespace into another. Helper
 *	for Tcl_Import().
 *
 * Results:
 *	Standard Tcl result code. If TCL_ERROR, appends an error message to
 *	the interpreter result.
 *
 * Side effects:
 *	A new command is created in the target namespace unless this is a
 *	reimport of exactly the same command as before.
 *
 *----------------------------------------------------------------------
 */

static int
DoImport(
    Tcl_Interp *interp,
    Namespace *nsPtr,
    Tcl_HashEntry *hPtr,
    const char *cmdName,
    const char *pattern,
    Namespace *importNsPtr,
    int allowOverwrite)
{
    int i = 0, exported = 0;
    Tcl_HashEntry *found;

    /*
     * The command cmdName in the source namespace matches the pattern. Check
     * whether it was exported. If it wasn't, we ignore it.
     */

    while (!exported && (i < importNsPtr->numExportPatterns)) {
	exported |= Tcl_StringMatch(cmdName,
		importNsPtr->exportArrayPtr[i++]);
    }
    if (!exported) {
	return TCL_OK;
    }

    /*
     * Unless there is a name clash, create an imported command in the current
     * namespace that refers to cmdPtr.
     */

    found = Tcl_FindHashEntry(&nsPtr->cmdTable, cmdName);
    if ((found == NULL) || allowOverwrite) {
	/*
	 * Create the imported command and its client data. To create the new
	 * command in the current namespace, generate a fully qualified name
	 * for it.
	 */

	Tcl_DString ds;
	Tcl_Command importedCmd;
	ImportedCmdData *dataPtr;
	Command *cmdPtr;
	ImportRef *refPtr;

	Tcl_DStringInit(&ds);
	Tcl_DStringAppend(&ds, nsPtr->fullName, -1);
	if (nsPtr != ((Interp *) interp)->globalNsPtr) {
	    Tcl_DStringAppend(&ds, "::", 2);
	}
	Tcl_DStringAppend(&ds, cmdName, -1);

	/*
	 * Check whether creating the new imported command in the current
	 * namespace would create a cycle of imported command references.
	 */

	cmdPtr = Tcl_GetHashValue(hPtr);
	if (found != NULL && cmdPtr->deleteProc == DeleteImportedCmd) {
	    Command *overwrite = Tcl_GetHashValue(found);
	    Command *link = cmdPtr;

	    while (link->deleteProc == DeleteImportedCmd) {
		ImportedCmdData *dataPtr = link->objClientData;

		link = dataPtr->realCmdPtr;
		if (overwrite == link) {
		    Tcl_AppendResult(interp, "import pattern \"", pattern,
			    "\" would create a loop containing command \"",
			    Tcl_DStringValue(&ds), "\"", NULL);
		    Tcl_DStringFree(&ds);
		    return TCL_ERROR;
		}
	    }
	}

	dataPtr = (ImportedCmdData *) ckalloc(sizeof(ImportedCmdData));
	importedCmd = Tcl_NRCreateCommand(interp, Tcl_DStringValue(&ds),
		InvokeImportedCmd, InvokeImportedNRCmd, dataPtr,
		DeleteImportedCmd);
	dataPtr->realCmdPtr = cmdPtr;
	dataPtr->selfPtr = (Command *) importedCmd;
	dataPtr->selfPtr->compileProc = cmdPtr->compileProc;
	Tcl_DStringFree(&ds);

	/*
	 * Create an ImportRef structure describing this new import command
	 * and add it to the import ref list in the "real" command.
	 */

	refPtr = (ImportRef *) ckalloc(sizeof(ImportRef));
	refPtr->importedCmdPtr = (Command *) importedCmd;
	refPtr->nextPtr = cmdPtr->importRefPtr;
	cmdPtr->importRefPtr = refPtr;
    } else {
	Command *overwrite = Tcl_GetHashValue(found);

	if (overwrite->deleteProc == DeleteImportedCmd) {
	    ImportedCmdData *dataPtr = overwrite->objClientData;

	    if (dataPtr->realCmdPtr == Tcl_GetHashValue(hPtr)) {
		/*
		 * Repeated import of same command is acceptable.
		 */

		return TCL_OK;
	    }
	}
	Tcl_AppendResult(interp, "can't import command \"", cmdName,
		"\": already exists", NULL);
	return TCL_ERROR;
    }
    return TCL_OK;
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_ForgetImport --
 *
 *	Deletes commands previously imported into the namespace indicated.
 *	The by namespacePtr, or the current namespace of interp, when
 *	namespacePtr is NULL. The pattern controls which imported commands are
 *	deleted. A simple pattern, one without namespace separators, matches
 *	the current command names of imported commands in the namespace.
 *	Matching imported commands are deleted. A qualified pattern is
 *	interpreted as deletion selection on the basis of where the command is
 *	imported from. The original command and "first link" command for each
 *	imported command are determined, and they are matched against the
 *	pattern. A match leads to deletion of the imported command.
 *
 * Results:
 *	Returns TCL_ERROR and records an error message in the interp result if
 *	a namespace qualified pattern refers to a namespace that does not
 *	exist. Otherwise, returns TCL_OK.
 *
 * Side effects:
 *	May delete commands.
 *
 *----------------------------------------------------------------------
 */

int
Tcl_ForgetImport(
    Tcl_Interp *interp,		/* Current interpreter. */
    Tcl_Namespace *namespacePtr,/* Points to the namespace from which
				 * previously imported commands should be
				 * removed. NULL for current namespace. */
    const char *pattern)	/* String pattern indicating which imported
				 * commands to remove. */
{
    Namespace *nsPtr, *sourceNsPtr, *dummyPtr;
    const char *simplePattern;
    char *cmdName;
    register Tcl_HashEntry *hPtr;
    Tcl_HashSearch search;

    /*
     * If the specified namespace is NULL, use the current namespace.
     */

    if (namespacePtr == NULL) {
	nsPtr = (Namespace *) TclGetCurrentNamespace(interp);
    } else {
	nsPtr = (Namespace *) namespacePtr;
    }

    /*
     * Parse the pattern into its namespace-qualification (if any) and the
     * simple pattern.
     */

    TclGetNamespaceForQualName(interp, pattern, nsPtr,
	    /*flags*/ (TCL_LEAVE_ERR_MSG | TCL_NAMESPACE_ONLY),
	    &sourceNsPtr, &dummyPtr, &dummyPtr, &simplePattern);

    if (sourceNsPtr == NULL) {
	Tcl_AppendResult(interp,
		"unknown namespace in namespace forget pattern \"",
		pattern, "\"", NULL);
	Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "NAMESPACE", pattern, NULL);
	return TCL_ERROR;
    }

    if (strcmp(pattern, simplePattern) == 0) {
	/*
	 * The pattern is simple. Delete any imported commands that match it.
	 */

	if (TclMatchIsTrivial(simplePattern)) {
	    hPtr = Tcl_FindHashEntry(&nsPtr->cmdTable, simplePattern);
	    if (hPtr != NULL) {
		Command *cmdPtr = Tcl_GetHashValue(hPtr);

		if (cmdPtr && (cmdPtr->deleteProc == DeleteImportedCmd)) {
		    Tcl_DeleteCommandFromToken(interp, (Tcl_Command) cmdPtr);
		}
	    }
	    return TCL_OK;
	}
	for (hPtr = Tcl_FirstHashEntry(&nsPtr->cmdTable, &search);
		(hPtr != NULL); hPtr = Tcl_NextHashEntry(&search)) {
	    Command *cmdPtr = Tcl_GetHashValue(hPtr);

	    if (cmdPtr->deleteProc != DeleteImportedCmd) {
		continue;
	    }
	    cmdName = Tcl_GetHashKey(&nsPtr->cmdTable, hPtr);
	    if (Tcl_StringMatch(cmdName, simplePattern)) {
		Tcl_DeleteCommandFromToken(interp, (Tcl_Command) cmdPtr);
	    }
	}
	return TCL_OK;
    }

    /*
     * The pattern was namespace-qualified.
     */

    for (hPtr = Tcl_FirstHashEntry(&nsPtr->cmdTable, &search); (hPtr != NULL);
	    hPtr = Tcl_NextHashEntry(&search)) {
	Tcl_CmdInfo info;
	Tcl_Command token = Tcl_GetHashValue(hPtr);
	Tcl_Command origin = TclGetOriginalCommand(token);

	if (Tcl_GetCommandInfoFromToken(origin, &info) == 0) {
	    continue;			/* Not an imported command. */
	}
	if (info.namespacePtr != (Tcl_Namespace *) sourceNsPtr) {
	    /*
	     * Original not in namespace we're matching. Check the first link
	     * in the import chain.
	     */

	    Command *cmdPtr = (Command *) token;
	    ImportedCmdData *dataPtr = cmdPtr->objClientData;
	    Tcl_Command firstToken = (Tcl_Command) dataPtr->realCmdPtr;

	    if (firstToken == origin) {
		continue;
	    }
	    Tcl_GetCommandInfoFromToken(firstToken, &info);
	    if (info.namespacePtr != (Tcl_Namespace *) sourceNsPtr) {
		continue;
	    }
	    origin = firstToken;
	}
	if (Tcl_StringMatch(Tcl_GetCommandName(NULL, origin), simplePattern)){
	    Tcl_DeleteCommandFromToken(interp, token);
	}
    }
    return TCL_OK;
}

/*
 *----------------------------------------------------------------------
 *
 * TclGetOriginalCommand --
 *
 *	An imported command is created in an namespace when a "real" command
 *	is imported from another namespace. If the specified command is an
 *	imported command, this function returns the original command it refers
 *	to.
 *
 * Results:
 *	If the command was imported into a sequence of namespaces a, b,...,n
 *	where each successive namespace just imports the command from the
 *	previous namespace, this function returns the Tcl_Command token in the
 *	first namespace, a. Otherwise, if the specified command is not an
 *	imported command, the function returns NULL.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

Tcl_Command
TclGetOriginalCommand(
    Tcl_Command command)	/* The imported command for which the original
				 * command should be returned. */
{
    register Command *cmdPtr = (Command *) command;
    ImportedCmdData *dataPtr;

    if (cmdPtr->deleteProc != DeleteImportedCmd) {
	return NULL;
    }

    while (cmdPtr->deleteProc == DeleteImportedCmd) {
	dataPtr = cmdPtr->objClientData;
	cmdPtr = dataPtr->realCmdPtr;
    }
    return (Tcl_Command) cmdPtr;
}

/*
 *----------------------------------------------------------------------
 *
 * InvokeImportedCmd --
 *
 *	Invoked by Tcl whenever the user calls an imported command that was
 *	created by Tcl_Import. Finds the "real" command (in another
 *	namespace), and passes control to it.
 *
 * Results:
 *	Returns TCL_OK if successful, and TCL_ERROR if anything goes wrong.
 *
 * Side effects:
 *	Returns a result in the interpreter's result object. If anything goes
 *	wrong, the result object is set to an error message.
 *
 *----------------------------------------------------------------------
 */

static int
InvokeImportedNRCmd(
    ClientData clientData,	/* Points to the imported command's
				 * ImportedCmdData structure. */
    Tcl_Interp *interp,		/* Current interpreter. */
    int objc,			/* Number of arguments. */
    Tcl_Obj *const objv[])	/* The argument objects. */
{
    ImportedCmdData *dataPtr = clientData;
    Command *realCmdPtr = dataPtr->realCmdPtr;

    ((Interp *) interp)->evalFlags |= TCL_EVAL_REDIRECT;
    return Tcl_NRCmdSwap(interp, (Tcl_Command) realCmdPtr, objc, objv, 0);
}

static int
InvokeImportedCmd(
    ClientData clientData,	/* Points to the imported command's
				 * ImportedCmdData structure. */
    Tcl_Interp *interp,		/* Current interpreter. */
    int objc,			/* Number of arguments. */
    Tcl_Obj *const objv[])	/* The argument objects. */
{
    return Tcl_NRCallObjProc(interp, InvokeImportedNRCmd, clientData,
	    objc, objv);
}

/*
 *----------------------------------------------------------------------
 *
 * DeleteImportedCmd --
 *
 *	Invoked by Tcl whenever an imported command is deleted. The "real"
 *	command keeps a list of all the imported commands that refer to it, so
 *	those imported commands can be deleted when the real command is
 *	deleted. This function removes the imported command reference from the
 *	real command's list, and frees up the memory associated with the
 *	imported command.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	Removes the imported command from the real command's import list.
 *
 *----------------------------------------------------------------------
 */

static void
DeleteImportedCmd(
    ClientData clientData)	/* Points to the imported command's
				 * ImportedCmdData structure. */
{
    ImportedCmdData *dataPtr = clientData;
    Command *realCmdPtr = dataPtr->realCmdPtr;
    Command *selfPtr = dataPtr->selfPtr;
    register ImportRef *refPtr, *prevPtr;

    prevPtr = NULL;
    for (refPtr = realCmdPtr->importRefPtr; refPtr != NULL;
	    refPtr = refPtr->nextPtr) {
	if (refPtr->importedCmdPtr == selfPtr) {
	    /*
	     * Remove *refPtr from real command's list of imported commands
	     * that refer to it.
	     */

	    if (prevPtr == NULL) { /* refPtr is first in list. */
		realCmdPtr->importRefPtr = refPtr->nextPtr;
	    } else {
		prevPtr->nextPtr = refPtr->nextPtr;
	    }
	    ckfree((char *) refPtr);
	    ckfree((char *) dataPtr);
	    return;
	}
	prevPtr = refPtr;
    }

    Tcl_Panic("DeleteImportedCmd: did not find cmd in real cmd's list of import references");
}

/*
 *----------------------------------------------------------------------
 *
 * TclGetNamespaceForQualName --
 *
 *	Given a qualified name specifying a command, variable, or namespace,
 *	and a namespace in which to resolve the name, this function returns a
 *	pointer to the namespace that contains the item. A qualified name
 *	consists of the "simple" name of an item qualified by the names of an
 *	arbitrary number of containing namespace separated by "::"s. If the
 *	qualified name starts with "::", it is interpreted absolutely from the
 *	global namespace. Otherwise, it is interpreted relative to the
 *	namespace specified by cxtNsPtr if it is non-NULL. If cxtNsPtr is
 *	NULL, the name is interpreted relative to the current namespace.
 *
 *	A relative name like "foo::bar::x" can be found starting in either the
 *	current namespace or in the global namespace. So each search usually
 *	follows two tracks, and two possible namespaces are returned. If the
 *	function sets either *nsPtrPtr or *altNsPtrPtr to NULL, then that path
 *	failed.
 *
 *	If "flags" contains TCL_GLOBAL_ONLY, the relative qualified name is
 *	sought only in the global :: namespace. The alternate search (also)
 *	starting from the global namespace is ignored and *altNsPtrPtr is set
 *	NULL.
 *
 *	If "flags" contains TCL_NAMESPACE_ONLY, the relative qualified name is
 *	sought only in the namespace specified by cxtNsPtr. The alternate
 *	search starting from the global namespace is ignored and *altNsPtrPtr
 *	is set NULL. If both TCL_GLOBAL_ONLY and TCL_NAMESPACE_ONLY are
 *	specified, TCL_GLOBAL_ONLY is ignored and the search starts from the
 *	namespace specified by cxtNsPtr.
 *
 *	If "flags" contains TCL_CREATE_NS_IF_UNKNOWN, all namespace components
 *	of the qualified name that cannot be found are automatically created
 *	within their specified parent. This makes sure that functions like
 *	Tcl_CreateCommand always succeed. There is no alternate search path,
 *	so *altNsPtrPtr is set NULL.
 *
 *	If "flags" contains TCL_FIND_ONLY_NS, the qualified name is treated as
 *	a reference to a namespace, and the entire qualified name is followed.
 *	If the name is relative, the namespace is looked up only in the
 *	current namespace. A pointer to the namespace is stored in *nsPtrPtr
 *	and NULL is stored in *simpleNamePtr. Otherwise, if TCL_FIND_ONLY_NS
 *	is not specified, only the leading components are treated as namespace
 *	names, and a pointer to the simple name of the final component is
 *	stored in *simpleNamePtr.
 *
 * Results:
 *	It sets *nsPtrPtr and *altNsPtrPtr to point to the two possible
 *	namespaces which represent the last (containing) namespace in the
 *	qualified name. If the function sets either *nsPtrPtr or *altNsPtrPtr
 *	to NULL, then the search along that path failed. The function also
 *	stores a pointer to the simple name of the final component in
 *	*simpleNamePtr. If the qualified name is "::" or was treated as a
 *	namespace reference (TCL_FIND_ONLY_NS), the function stores a pointer
 *	to the namespace in *nsPtrPtr, NULL in *altNsPtrPtr, and sets
 *	*simpleNamePtr to point to an empty string.
 *
 *	If there is an error, this function returns TCL_ERROR. If "flags"
 *	contains TCL_LEAVE_ERR_MSG, an error message is returned in the
 *	interpreter's result object. Otherwise, the interpreter's result
 *	object is left unchanged.
 *
 *	*actualCxtPtrPtr is set to the actual context namespace. It is set to
 *	the input context namespace pointer in cxtNsPtr. If cxtNsPtr is NULL,
 *	it is set to the current namespace context.
 *
 *	For backwards compatibility with the TclPro byte code loader, this
 *	function always returns TCL_OK.
 *
 * Side effects:
 *	If "flags" contains TCL_CREATE_NS_IF_UNKNOWN, new namespaces may be
 *	created.
 *
 *----------------------------------------------------------------------
 */

int
TclGetNamespaceForQualName(
    Tcl_Interp *interp,		/* Interpreter in which to find the namespace
				 * containing qualName. */
    const char *qualName,	/* A namespace-qualified name of an command,
				 * variable, or namespace. */
    Namespace *cxtNsPtr,	/* The namespace in which to start the search
				 * for qualName's namespace. If NULL start
				 * from the current namespace. Ignored if
				 * TCL_GLOBAL_ONLY is set. */
    int flags,			/* Flags controlling the search: an OR'd
				 * combination of TCL_GLOBAL_ONLY,
				 * TCL_NAMESPACE_ONLY, TCL_FIND_ONLY_NS, and
				 * TCL_CREATE_NS_IF_UNKNOWN. */
    Namespace **nsPtrPtr,	/* Address where function stores a pointer to
				 * containing namespace if qualName is found
				 * starting from *cxtNsPtr or, if
				 * TCL_GLOBAL_ONLY is set, if qualName is
				 * found in the global :: namespace. NULL is
				 * stored otherwise. */
    Namespace **altNsPtrPtr,	/* Address where function stores a pointer to
				 * containing namespace if qualName is found
				 * starting from the global :: namespace.
				 * NULL is stored if qualName isn't found
				 * starting from :: or if the TCL_GLOBAL_ONLY,
				 * TCL_NAMESPACE_ONLY, TCL_FIND_ONLY_NS,
				 * TCL_CREATE_NS_IF_UNKNOWN flag is set. */
    Namespace **actualCxtPtrPtr,/* Address where function stores a pointer to
				 * the actual namespace from which the search
				 * started. This is either cxtNsPtr, the ::
				 * namespace if TCL_GLOBAL_ONLY was specified,
				 * or the current namespace if cxtNsPtr was
				 * NULL. */
    const char **simpleNamePtr) /* Address where function stores the simple
				 * name at end of the qualName, or NULL if
				 * qualName is "::" or the flag
				 * TCL_FIND_ONLY_NS was specified. */
{
    Interp *iPtr = (Interp *) interp;
    Namespace *nsPtr = cxtNsPtr;
    Namespace *altNsPtr;
    Namespace *globalNsPtr = iPtr->globalNsPtr;
    const char *start, *end;
    const char *nsName;
    Tcl_HashEntry *entryPtr;
    Tcl_DString buffer;
    int len;

    /*
     * Determine the context namespace nsPtr in which to start the primary
     * search. If the qualName name starts with a "::" or TCL_GLOBAL_ONLY was
     * specified, search from the global namespace. Otherwise, use the
     * namespace given in cxtNsPtr, or if that is NULL, use the current
     * namespace context. Note that we always treat two or more adjacent ":"s
     * as a namespace separator.
     */

    if (flags & TCL_GLOBAL_ONLY) {
	nsPtr = globalNsPtr;
    } else if (nsPtr == NULL) {
	nsPtr = iPtr->varFramePtr->nsPtr;
    }

    start = qualName;			/* Points to start of qualifying
					 * namespace. */
    if ((*qualName == ':') && (*(qualName+1) == ':')) {
	start = qualName+2;		/* Skip over the initial :: */
	while (*start == ':') {
	    start++;			/* Skip over a subsequent : */
	}
	nsPtr = globalNsPtr;
	if (*start == '\0') {		/* qualName is just two or more
					 * ":"s. */
	    *nsPtrPtr = globalNsPtr;
	    *altNsPtrPtr = NULL;
	    *actualCxtPtrPtr = globalNsPtr;
	    *simpleNamePtr = start;	/* Points to empty string. */
	    return TCL_OK;
	}
    }
    *actualCxtPtrPtr = nsPtr;

    /*
     * Start an alternate search path starting with the global namespace.
     * However, if the starting context is the global namespace, or if the
     * flag is set to search only the namespace *cxtNsPtr, ignore the
     * alternate search path.
     */

    altNsPtr = globalNsPtr;
    if ((nsPtr == globalNsPtr)
	    || (flags & (TCL_NAMESPACE_ONLY | TCL_FIND_ONLY_NS))) {
	altNsPtr = NULL;
    }

    /*
     * Loop to resolve each namespace qualifier in qualName.
     */

    Tcl_DStringInit(&buffer);
    end = start;
    while (*start != '\0') {
	/*
	 * Find the next namespace qualifier (i.e., a name ending in "::") or
	 * the end of the qualified name (i.e., a name ending in "\0"). Set
	 * len to the number of characters, starting from start, in the name;
	 * set end to point after the "::"s or at the "\0".
	 */

	len = 0;
	for (end = start;  *end != '\0';  end++) {
	    if ((*end == ':') && (*(end+1) == ':')) {
		end += 2;		/* Skip over the initial :: */
		while (*end == ':') {
		    end++;		/* Skip over the subsequent : */
		}
		break;			/* Exit for loop; end is after ::'s */
	    }
	    len++;
	}

	if (*end=='\0' && !(end-start>=2 && *(end-1)==':' && *(end-2)==':')) {
	    /*
	     * qualName ended with a simple name at start. If TCL_FIND_ONLY_NS
	     * was specified, look this up as a namespace. Otherwise, start is
	     * the name of a cmd or var and we are done.
	     */

	    if (flags & TCL_FIND_ONLY_NS) {
		nsName = start;
	    } else {
		*nsPtrPtr = nsPtr;
		*altNsPtrPtr = altNsPtr;
		*simpleNamePtr = start;
		Tcl_DStringFree(&buffer);
		return TCL_OK;
	    }
	} else {
	    /*
	     * start points to the beginning of a namespace qualifier ending
	     * in "::". end points to the start of a name in that namespace
	     * that might be empty. Copy the namespace qualifier to a buffer
	     * so it can be null terminated. We can't modify the incoming
	     * qualName since it may be a string constant.
	     */

	    Tcl_DStringSetLength(&buffer, 0);
	    Tcl_DStringAppend(&buffer, start, len);
	    nsName = Tcl_DStringValue(&buffer);
	}

	/*
	 * Look up the namespace qualifier nsName in the current namespace
	 * context. If it isn't found but TCL_CREATE_NS_IF_UNKNOWN is set,
	 * create that qualifying namespace. This is needed for functions like
	 * Tcl_CreateCommand that cannot fail.
	 */

	if (nsPtr != NULL) {
#ifndef BREAK_NAMESPACE_COMPAT
	    entryPtr = Tcl_FindHashEntry(&nsPtr->childTable, nsName);
#else
	    if (nsPtr->childTablePtr == NULL) {
		entryPtr = NULL;
	    } else {
		entryPtr = Tcl_FindHashEntry(nsPtr->childTablePtr, nsName);
	    }
#endif
	    if (entryPtr != NULL) {
		nsPtr = Tcl_GetHashValue(entryPtr);
	    } else if (flags & TCL_CREATE_NS_IF_UNKNOWN) {
		Tcl_CallFrame *framePtr;

		(void) TclPushStackFrame(interp, &framePtr,
			(Tcl_Namespace *) nsPtr, /*isProcCallFrame*/ 0);

		nsPtr = (Namespace *)
			Tcl_CreateNamespace(interp, nsName, NULL, NULL);
		TclPopStackFrame(interp);

		if (nsPtr == NULL) {
		    Tcl_Panic("Could not create namespace '%s'", nsName);
		}
	    } else {			/* Namespace not found and was not
					 * created. */
		nsPtr = NULL;
	    }
	}

	/*
	 * Look up the namespace qualifier in the alternate search path too.
	 */

	if (altNsPtr != NULL) {
#ifndef BREAK_NAMESPACE_COMPAT
	    entryPtr = Tcl_FindHashEntry(&altNsPtr->childTable, nsName);
#else
	    if (altNsPtr->childTablePtr != NULL) {
		entryPtr = Tcl_FindHashEntry(altNsPtr->childTablePtr, nsName);
	    } else {
		entryPtr = NULL;
	    }
#endif
	    if (entryPtr != NULL) {
		altNsPtr = Tcl_GetHashValue(entryPtr);
	    } else {
		altNsPtr = NULL;
	    }
	}

	/*
	 * If both search paths have failed, return NULL results.
	 */

	if ((nsPtr == NULL) && (altNsPtr == NULL)) {
	    *nsPtrPtr = NULL;
	    *altNsPtrPtr = NULL;
	    *simpleNamePtr = NULL;
	    Tcl_DStringFree(&buffer);
	    return TCL_OK;
	}

	start = end;
    }

    /*
     * We ignore trailing "::"s in a namespace name, but in a command or
     * variable name, trailing "::"s refer to the cmd or var named {}.
     */

    if ((flags & TCL_FIND_ONLY_NS) || (end>start && *(end-1)!=':')) {
	*simpleNamePtr = NULL;		/* Found namespace name. */
    } else {
	*simpleNamePtr = end;		/* Found cmd/var: points to empty
					 * string. */
    }

    /*
     * As a special case, if we are looking for a namespace and qualName is ""
     * and the current active namespace (nsPtr) is not the global namespace,
     * return NULL (no namespace was found). This is because namespaces can
     * not have empty names except for the global namespace.
     */

    if ((flags & TCL_FIND_ONLY_NS) && (*qualName == '\0')
	    && (nsPtr != globalNsPtr)) {
	nsPtr = NULL;
    }

    *nsPtrPtr = nsPtr;
    *altNsPtrPtr = altNsPtr;
    Tcl_DStringFree(&buffer);
    return TCL_OK;
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_FindNamespace --
 *
 *	Searches for a namespace.
 *
 * Results:
 *	Returns a pointer to the namespace if it is found. Otherwise, returns
 *	NULL and leaves an error message in the interpreter's result object if
 *	"flags" contains TCL_LEAVE_ERR_MSG.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

Tcl_Namespace *
Tcl_FindNamespace(
    Tcl_Interp *interp,		/* The interpreter in which to find the
				 * namespace. */
    const char *name,		/* Namespace name. If it starts with "::",
				 * will be looked up in global namespace.
				 * Else, looked up first in contextNsPtr
				 * (current namespace if contextNsPtr is
				 * NULL), then in global namespace. */
    Tcl_Namespace *contextNsPtr,/* Ignored if TCL_GLOBAL_ONLY flag is set or
				 * if the name starts with "::". Otherwise,
				 * points to namespace in which to resolve
				 * name; if NULL, look up name in the current
				 * namespace. */
    register int flags)		/* Flags controlling namespace lookup: an OR'd
				 * combination of TCL_GLOBAL_ONLY and
				 * TCL_LEAVE_ERR_MSG flags. */
{
    Namespace *nsPtr, *dummy1Ptr, *dummy2Ptr;
    const char *dummy;

    /*
     * Find the namespace(s) that contain the specified namespace name. Add
     * the TCL_FIND_ONLY_NS flag to resolve the name all the way down to its
     * last component, a namespace.
     */

    TclGetNamespaceForQualName(interp, name, (Namespace *) contextNsPtr,
	    flags|TCL_FIND_ONLY_NS, &nsPtr, &dummy1Ptr, &dummy2Ptr, &dummy);

    if (nsPtr != NULL) {
	return (Tcl_Namespace *) nsPtr;
    }

    if (flags & TCL_LEAVE_ERR_MSG) {
	Tcl_ResetResult(interp);
	Tcl_AppendResult(interp, "unknown namespace \"", name, "\"", NULL);
	Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "NAMESPACE", name, NULL);
    }
    return NULL;
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_FindCommand --
 *
 *	Searches for a command.
 *
 * Results:
 *	Returns a token for the command if it is found. Otherwise, if it can't
 *	be found or there is an error, returns NULL and leaves an error
 *	message in the interpreter's result object if "flags" contains
 *	TCL_LEAVE_ERR_MSG.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

Tcl_Command
Tcl_FindCommand(
    Tcl_Interp *interp,		/* The interpreter in which to find the
				 * command and to report errors. */
    const char *name,		/* Command's name. If it starts with "::",
				 * will be looked up in global namespace.
				 * Else, looked up first in contextNsPtr
				 * (current namespace if contextNsPtr is
				 * NULL), then in global namespace. */
    Tcl_Namespace *contextNsPtr,/* Ignored if TCL_GLOBAL_ONLY flag set.
				 * Otherwise, points to namespace in which to
				 * resolve name. If NULL, look up name in the
				 * current namespace. */
    int flags)			/* An OR'd combination of flags:
				 * TCL_GLOBAL_ONLY (look up name only in
				 * global namespace), TCL_NAMESPACE_ONLY (look
				 * up only in contextNsPtr, or the current
				 * namespace if contextNsPtr is NULL), and
				 * TCL_LEAVE_ERR_MSG. If both TCL_GLOBAL_ONLY
				 * and TCL_NAMESPACE_ONLY are given,
				 * TCL_GLOBAL_ONLY is ignored. */
{
    Interp *iPtr = (Interp *) interp;
    Namespace *cxtNsPtr;
    register Tcl_HashEntry *entryPtr;
    register Command *cmdPtr;
    const char *simpleName;
    int result;

    /*
     * If this namespace has a command resolver, then give it first crack at
     * the command resolution. If the interpreter has any command resolvers,
     * consult them next. The command resolver functions may return a
     * Tcl_Command value, they may signal to continue onward, or they may
     * signal an error.
     */

    if ((flags & TCL_GLOBAL_ONLY) || !strncmp(name, "::", 2)) {
	cxtNsPtr = (Namespace *) TclGetGlobalNamespace(interp);
    } else if (contextNsPtr != NULL) {
	cxtNsPtr = (Namespace *) contextNsPtr;
    } else {
	cxtNsPtr = (Namespace *) TclGetCurrentNamespace(interp);
    }

    if (cxtNsPtr->cmdResProc != NULL || iPtr->resolverPtr != NULL) {
	ResolverScheme *resPtr = iPtr->resolverPtr;
	Tcl_Command cmd;

	if (cxtNsPtr->cmdResProc) {
	    result = cxtNsPtr->cmdResProc(interp, name,
		    (Tcl_Namespace *) cxtNsPtr, flags, &cmd);
	} else {
	    result = TCL_CONTINUE;
	}

	while (result == TCL_CONTINUE && resPtr) {
	    if (resPtr->cmdResProc) {
		result = resPtr->cmdResProc(interp, name,
			(Tcl_Namespace *) cxtNsPtr, flags, &cmd);
	    }
	    resPtr = resPtr->nextPtr;
	}

	if (result == TCL_OK) {
	    return cmd;
	} else if (result != TCL_CONTINUE) {
	    return NULL;
	}
    }

    /*
     * Find the namespace(s) that contain the command.
     */

    cmdPtr = NULL;
    if (cxtNsPtr->commandPathLength!=0 && strncmp(name, "::", 2)
	    && !(flags & TCL_NAMESPACE_ONLY)) {
	int i;
	Namespace *pathNsPtr, *realNsPtr, *dummyNsPtr;

	(void) TclGetNamespaceForQualName(interp, name, cxtNsPtr,
		TCL_NAMESPACE_ONLY, &realNsPtr, &dummyNsPtr, &dummyNsPtr,
		&simpleName);
	if ((realNsPtr != NULL) && (simpleName != NULL)) {
	    if ((cxtNsPtr == realNsPtr)
		    || !(realNsPtr->flags & NS_DYING)) {
		entryPtr = Tcl_FindHashEntry(&realNsPtr->cmdTable, simpleName);
		if (entryPtr != NULL) {
		    cmdPtr = Tcl_GetHashValue(entryPtr);
		}
	    }
	}

	/*
	 * Next, check along the path.
	 */

	for (i=0 ; i<cxtNsPtr->commandPathLength && cmdPtr==NULL ; i++) {
	    pathNsPtr = cxtNsPtr->commandPathArray[i].nsPtr;
	    if (pathNsPtr == NULL) {
		continue;
	    }
	    (void) TclGetNamespaceForQualName(interp, name, pathNsPtr,
		    TCL_NAMESPACE_ONLY, &realNsPtr, &dummyNsPtr, &dummyNsPtr,
		    &simpleName);
	    if ((realNsPtr != NULL) && (simpleName != NULL)
		    && !(realNsPtr->flags & NS_DYING)) {
		entryPtr = Tcl_FindHashEntry(&realNsPtr->cmdTable, simpleName);
		if (entryPtr != NULL) {
		    cmdPtr = Tcl_GetHashValue(entryPtr);
		}
	    }
	}

	/*
	 * If we've still not found the command, look in the global namespace
	 * as a last resort.
	 */

	if (cmdPtr == NULL) {
	    (void) TclGetNamespaceForQualName(interp, name, NULL,
		    TCL_GLOBAL_ONLY, &realNsPtr, &dummyNsPtr, &dummyNsPtr,
		    &simpleName);
	    if ((realNsPtr != NULL) && (simpleName != NULL)
		    && !(realNsPtr->flags & NS_DYING)) {
		entryPtr = Tcl_FindHashEntry(&realNsPtr->cmdTable, simpleName);
		if (entryPtr != NULL) {
		    cmdPtr = Tcl_GetHashValue(entryPtr);
		}
	    }
	}
    } else {
	Namespace *nsPtr[2];
	register int search;

	TclGetNamespaceForQualName(interp, name, (Namespace *) contextNsPtr,
		flags, &nsPtr[0], &nsPtr[1], &cxtNsPtr, &simpleName);

	/*
	 * Look for the command in the command table of its namespace. Be sure
	 * to check both possible search paths: from the specified namespace
	 * context and from the global namespace.
	 */

	for (search = 0;  (search < 2) && (cmdPtr == NULL);  search++) {
	    if ((nsPtr[search] != NULL) && (simpleName != NULL)) {
		entryPtr = Tcl_FindHashEntry(&nsPtr[search]->cmdTable,
			simpleName);
		if (entryPtr != NULL) {
		    cmdPtr = Tcl_GetHashValue(entryPtr);
		}
	    }
	}
    }

    if (cmdPtr != NULL) {
	return (Tcl_Command) cmdPtr;
    }

    if (flags & TCL_LEAVE_ERR_MSG) {
	Tcl_ResetResult(interp);
	Tcl_AppendResult(interp, "unknown command \"", name, "\"", NULL);
	Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "COMMAND", name, NULL);
    }
    return NULL;
}

/*
 *----------------------------------------------------------------------
 *
 * TclResetShadowedCmdRefs --
 *
 *	Called when a command is added to a namespace to check for existing
 *	command references that the new command may invalidate. Consider the
 *	following cases that could happen when you add a command "foo" to a
 *	namespace "b":
 *	   1. It could shadow a command named "foo" at the global scope. If
 *	      it does, all command references in the namespace "b" are
 *	      suspect.
 *	   2. Suppose the namespace "b" resides in a namespace "a". Then to
 *	      "a" the new command "b::foo" could shadow another command
 *	      "b::foo" in the global namespace. If so, then all command
 *	      references in "a" * are suspect.
 *	The same checks are applied to all parent namespaces, until we reach
 *	the global :: namespace.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	If the new command shadows an existing command, the cmdRefEpoch
 *	counter is incremented in each namespace that sees the shadow. This
 *	invalidates all command references that were previously cached in that
 *	namespace. The next time the commands are used, they are resolved from
 *	scratch.
 *
 *----------------------------------------------------------------------
 */

void
TclResetShadowedCmdRefs(
    Tcl_Interp *interp,		/* Interpreter containing the new command. */
    Command *newCmdPtr)		/* Points to the new command. */
{
    char *cmdName;
    Tcl_HashEntry *hPtr;
    register Namespace *nsPtr;
    Namespace *trailNsPtr, *shadowNsPtr;
    Namespace *globalNsPtr = (Namespace *) TclGetGlobalNamespace(interp);
    int found, i;
    int trailFront = -1;
    int trailSize = 5;		/* Formerly NUM_TRAIL_ELEMS. */
    Namespace **trailPtr = (Namespace **)
	    TclStackAlloc(interp, trailSize * sizeof(Namespace *));

    /*
     * Start at the namespace containing the new command, and work up through
     * the list of parents. Stop just before the global namespace, since the
     * global namespace can't "shadow" its own entries.
     *
     * The namespace "trail" list we build consists of the names of each
     * namespace that encloses the new command, in order from outermost to
     * innermost: for example, "a" then "b". Each iteration of this loop
     * eventually extends the trail upwards by one namespace, nsPtr. We use
     * this trail list to see if nsPtr (e.g. "a" in 2. above) could have
     * now-invalid cached command references. This will happen if nsPtr
     * (e.g. "a") contains a sequence of child namespaces (e.g. "b") such that
     * there is a identically-named sequence of child namespaces starting from
     * :: (e.g. "::b") whose tail namespace contains a command also named
     * cmdName.
     */

    cmdName = Tcl_GetHashKey(newCmdPtr->hPtr->tablePtr, newCmdPtr->hPtr);
    for (nsPtr=newCmdPtr->nsPtr ; (nsPtr!=NULL) && (nsPtr!=globalNsPtr) ;
	    nsPtr=nsPtr->parentPtr) {
	/*
	 * Find the maximal sequence of child namespaces contained in nsPtr
	 * such that there is a identically-named sequence of child namespaces
	 * starting from ::. shadowNsPtr will be the tail of this sequence, or
	 * the deepest namespace under :: that might contain a command now
	 * shadowed by cmdName. We check below if shadowNsPtr actually
	 * contains a command cmdName.
	 */

	found = 1;
	shadowNsPtr = globalNsPtr;

	for (i = trailFront;  i >= 0;  i--) {
	    trailNsPtr = trailPtr[i];
#ifndef BREAK_NAMESPACE_COMPAT
	    hPtr = Tcl_FindHashEntry(&shadowNsPtr->childTable,
		    trailNsPtr->name);
#else
	    if (shadowNsPtr->childTablePtr != NULL) {
		hPtr = Tcl_FindHashEntry(shadowNsPtr->childTablePtr,
			trailNsPtr->name);
	    } else {
		hPtr = NULL;
	    }
#endif
	    if (hPtr != NULL) {
		shadowNsPtr = Tcl_GetHashValue(hPtr);
	    } else {
		found = 0;
		break;
	    }
	}

	/*
	 * If shadowNsPtr contains a command named cmdName, we invalidate all
	 * of the command refs cached in nsPtr. As a boundary case,
	 * shadowNsPtr is initially :: and we check for case 1. above.
	 */

	if (found) {
	    hPtr = Tcl_FindHashEntry(&shadowNsPtr->cmdTable, cmdName);
	    if (hPtr != NULL) {
		nsPtr->cmdRefEpoch++;
		TclInvalidateNsPath(nsPtr);

		/*
		 * If the shadowed command was compiled to bytecodes, we
		 * invalidate all the bytecodes in nsPtr, to force a new
		 * compilation. We use the resolverEpoch to signal the need
		 * for a fresh compilation of every bytecode.
		 */

		if (((Command *)Tcl_GetHashValue(hPtr))->compileProc != NULL){
		    nsPtr->resolverEpoch++;
		}
	    }
	}

	/*
	 * Insert nsPtr at the front of the trail list: i.e., at the end of
	 * the trailPtr array.
	 */

	trailFront++;
	if (trailFront == trailSize) {
	    int newSize = 2 * trailSize;

	    trailPtr = (Namespace **) TclStackRealloc(interp,
		    trailPtr, newSize * sizeof(Namespace *));
	    trailSize = newSize;
	}
	trailPtr[trailFront] = nsPtr;
    }
    TclStackFree(interp, trailPtr);
}

/*
 *----------------------------------------------------------------------
 *
 * TclGetNamespaceFromObj, GetNamespaceFromObj --
 *
 *	Gets the namespace specified by the name in a Tcl_Obj.
 *
 * Results:
 *	Returns TCL_OK if the namespace was resolved successfully, and stores
 *	a pointer to the namespace in the location specified by nsPtrPtr. If
 *	the namespace can't be found, or anything else goes wrong, this
 *	function returns TCL_ERROR and writes an error message to interp,
 *	if non-NULL.
 *
 * Side effects:
 *	May update the internal representation for the object, caching the
 *	namespace reference. The next time this function is called, the
 *	namespace value can be found quickly.
 *
 *----------------------------------------------------------------------
 */

int
TclGetNamespaceFromObj(
    Tcl_Interp *interp,		/* The current interpreter. */
    Tcl_Obj *objPtr,		/* The object to be resolved as the name of a
				 * namespace. */
    Tcl_Namespace **nsPtrPtr)	/* Result namespace pointer goes here. */
{
    if (GetNamespaceFromObj(interp, objPtr, nsPtrPtr) == TCL_ERROR) {
	const char *name = TclGetString(objPtr);

	if ((name[0] == ':') && (name[1] == ':')) {
	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
		    "namespace \"%s\" not found", name));
	} else {
	    /*
	     * Get the current namespace name.
	     */

	    NamespaceCurrentCmd(NULL, interp, 2, NULL);
	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
		    "namespace \"%s\" not found in \"%s\"", name,
		    Tcl_GetStringResult(interp)));
	}
	Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "NAMESPACE", name, NULL);
	return TCL_ERROR;
    }
    return TCL_OK;
}

static int
GetNamespaceFromObj(
    Tcl_Interp *interp,		/* The current interpreter. */
    Tcl_Obj *objPtr,		/* The object to be resolved as the name of a
				 * namespace. */
    Tcl_Namespace **nsPtrPtr)	/* Result namespace pointer goes here. */
{
    ResolvedNsName *resNamePtr;
    Namespace *nsPtr, *refNsPtr;

    if (objPtr->typePtr == &nsNameType) {
	/*
	 * Check that the ResolvedNsName is still valid; avoid letting the ref
	 * cross interps.
	 */

	resNamePtr = (ResolvedNsName *) objPtr->internalRep.twoPtrValue.ptr1;
	nsPtr = resNamePtr->nsPtr;
	refNsPtr = resNamePtr->refNsPtr;
	if (!(nsPtr->flags & NS_DYING) && (interp == nsPtr->interp) &&
		(!refNsPtr || ((interp == refNsPtr->interp) &&
		 (refNsPtr== (Namespace *) Tcl_GetCurrentNamespace(interp))))) {
	    *nsPtrPtr = (Tcl_Namespace *) nsPtr;
	    return TCL_OK;
	}
    }
    if (SetNsNameFromAny(interp, objPtr) == TCL_OK) {
	resNamePtr = (ResolvedNsName *) objPtr->internalRep.twoPtrValue.ptr1;
	*nsPtrPtr = (Tcl_Namespace *) resNamePtr->nsPtr;
	return TCL_OK;
    }
    return TCL_ERROR;
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_NamespaceObjCmd --
 *
 *	Invoked to implement the "namespace" command that creates, deletes, or
 *	manipulates Tcl namespaces. Handles the following syntax:
 *
 *	    namespace children ?name? ?pattern?
 *	    namespace code arg
 *	    namespace current
 *	    namespace delete ?name name...?
 *	    namespace ensemble subcommand ?arg...?
 *	    namespace eval name arg ?arg...?
 *	    namespace exists name
 *	    namespace export ?-clear? ?pattern pattern...?
 *	    namespace forget ?pattern pattern...?
 *	    namespace import ?-force? ?pattern pattern...?
 *	    namespace inscope name arg ?arg...?
 *	    namespace origin name
 *	    namespace parent ?name?
 *	    namespace qualifiers string
 *	    namespace tail string
 *	    namespace which ?-command? ?-variable? name
 *
 * Results:
 *	Returns TCL_OK if the command is successful. Returns TCL_ERROR if
 *	anything goes wrong.
 *
 * Side effects:
 *	Based on the subcommand name (e.g., "import"), this function
 *	dispatches to a corresponding function NamespaceXXXCmd defined
 *	statically in this file. This function's side effects depend on
 *	whatever that subcommand function does. If there is an error, this
 *	function returns an error message in the interpreter's result object.
 *	Otherwise it may return a result in the interpreter's result object.
 *
 *----------------------------------------------------------------------
 */

int
Tcl_NamespaceObjCmd(
    ClientData clientData,	/* Arbitrary value passed to cmd. */
    Tcl_Interp *interp,		/* Current interpreter. */
    int objc,			/* Number of arguments. */
    Tcl_Obj *const objv[])	/* Argument objects. */
{
    return Tcl_NRCallObjProc(interp, TclNRNamespaceObjCmd, clientData, objc,
	    objv);
}

int
TclNRNamespaceObjCmd(
    ClientData clientData,	/* Arbitrary value passed to cmd. */
    Tcl_Interp *interp,		/* Current interpreter. */
    int objc,			/* Number of arguments. */
    Tcl_Obj *const objv[])	/* Argument objects. */
{
    static const char *const subCmds[] = {
	"children", "code", "current", "delete", "ensemble",
	"eval", "exists", "export", "forget", "import",
	"inscope", "origin", "parent", "path", "qualifiers",
	"tail", "unknown", "upvar", "which", NULL
    };
    enum NSSubCmdIdx {
	NSChildrenIdx, NSCodeIdx, NSCurrentIdx, NSDeleteIdx, NSEnsembleIdx,
	NSEvalIdx, NSExistsIdx, NSExportIdx, NSForgetIdx, NSImportIdx,
	NSInscopeIdx, NSOriginIdx, NSParentIdx, NSPathIdx, NSQualifiersIdx,
	NSTailIdx, NSUnknownIdx, NSUpvarIdx, NSWhichIdx
    };
    int index;

    if (objc < 2) {
	Tcl_WrongNumArgs(interp, 1, objv, "subcommand ?arg ...?");
	return TCL_ERROR;
    }

    /*
     * Return an index reflecting the particular subcommand.
     */

    if (Tcl_GetIndexFromObj(interp, objv[1], subCmds, "option", /*flags*/ 0,
	    (int *) &index) != TCL_OK) {
	return TCL_ERROR;
    }

    switch (index) {
    case NSChildrenIdx:
	return NamespaceChildrenCmd(clientData, interp, objc, objv);
    case NSCodeIdx:
	return NamespaceCodeCmd(clientData, interp, objc, objv);
    case NSCurrentIdx:
	return NamespaceCurrentCmd(clientData, interp, objc, objv);
    case NSDeleteIdx:
	return NamespaceDeleteCmd(clientData, interp, objc, objv);
    case NSEnsembleIdx:
	return TclNamespaceEnsembleCmd(clientData, interp, objc, objv);
    case NSEvalIdx:
	return NamespaceEvalCmd(clientData, interp, objc, objv);
    case NSExistsIdx:
	return NamespaceExistsCmd(clientData, interp, objc, objv);
    case NSExportIdx:
	return NamespaceExportCmd(clientData, interp, objc, objv);
    case NSForgetIdx:
	return NamespaceForgetCmd(clientData, interp, objc, objv);
    case NSImportIdx:
	return NamespaceImportCmd(clientData, interp, objc, objv);
    case NSInscopeIdx:
	return NamespaceInscopeCmd(clientData, interp, objc, objv);
    case NSOriginIdx:
	return NamespaceOriginCmd(clientData, interp, objc, objv);
    case NSParentIdx:
	return NamespaceParentCmd(clientData, interp, objc, objv);
    case NSPathIdx:
	return NamespacePathCmd(clientData, interp, objc, objv);
    case NSQualifiersIdx:
	return NamespaceQualifiersCmd(clientData, interp, objc, objv);
    case NSTailIdx:
	return NamespaceTailCmd(clientData, interp, objc, objv);
    case NSUpvarIdx:
	return NamespaceUpvarCmd(clientData, interp, objc, objv);
    case NSUnknownIdx:
	return NamespaceUnknownCmd(clientData, interp, objc, objv);
    case NSWhichIdx:
	return NamespaceWhichCmd(clientData, interp, objc, objv);
    default:
	Tcl_Panic("unhandled namespace subcommand");
    }
    return TCL_ERROR;
}

/*
 *----------------------------------------------------------------------
 *
 * NamespaceChildrenCmd --
 *
 *	Invoked to implement the "namespace children" command that returns a
 *	list containing the fully-qualified names of the child namespaces of a
 *	given namespace. Handles the following syntax:
 *
 *	    namespace children ?name? ?pattern?
 *
 * Results:
 *	Returns TCL_OK if successful, and TCL_ERROR if anything goes wrong.
 *
 * Side effects:
 *	Returns a result in the interpreter's result object. If anything goes
 *	wrong, the result is an error message.
 *
 *----------------------------------------------------------------------
 */

static int
NamespaceChildrenCmd(
    ClientData dummy,		/* Not used. */
    Tcl_Interp *interp,		/* Current interpreter. */
    int objc,			/* Number of arguments. */
    Tcl_Obj *const objv[])	/* Argument objects. */
{
    Tcl_Namespace *namespacePtr;
    Namespace *nsPtr, *childNsPtr;
    Namespace *globalNsPtr = (Namespace *) TclGetGlobalNamespace(interp);
    const char *pattern = NULL;
    Tcl_DString buffer;
    register Tcl_HashEntry *entryPtr;
    Tcl_HashSearch search;
    Tcl_Obj *listPtr, *elemPtr;

    /*
     * Get a pointer to the specified namespace, or the current namespace.
     */

    if (objc == 2) {
	nsPtr = (Namespace *) TclGetCurrentNamespace(interp);
    } else if ((objc == 3) || (objc == 4)) {
	if (TclGetNamespaceFromObj(interp, objv[2], &namespacePtr) != TCL_OK){
	    return TCL_ERROR;
	}
	nsPtr = (Namespace *) namespacePtr;
    } else {
	Tcl_WrongNumArgs(interp, 2, objv, "?name? ?pattern?");
	return TCL_ERROR;
    }

    /*
     * Get the glob-style pattern, if any, used to narrow the search.
     */

    Tcl_DStringInit(&buffer);
    if (objc == 4) {
	const char *name = TclGetString(objv[3]);

	if ((*name == ':') && (*(name+1) == ':')) {
	    pattern = name;
	} else {
	    Tcl_DStringAppend(&buffer, nsPtr->fullName, -1);
	    if (nsPtr != globalNsPtr) {
		Tcl_DStringAppend(&buffer, "::", 2);
	    }
	    Tcl_DStringAppend(&buffer, name, -1);
	    pattern = Tcl_DStringValue(&buffer);
	}
    }

    /*
     * Create a list containing the full names of all child namespaces whose
     * names match the specified pattern, if any.
     */

    listPtr = Tcl_NewListObj(0, NULL);
    if ((pattern != NULL) && TclMatchIsTrivial(pattern)) {
	unsigned int length = strlen(nsPtr->fullName);

	if (strncmp(pattern, nsPtr->fullName, length) != 0) {
	    goto searchDone;
	}
	if (
#ifndef BREAK_NAMESPACE_COMPAT
	    Tcl_FindHashEntry(&nsPtr->childTable, pattern+length) != NULL
#else
	    nsPtr->childTablePtr != NULL &&
	    Tcl_FindHashEntry(nsPtr->childTablePtr, pattern+length) != NULL
#endif
	) {
	    Tcl_ListObjAppendElement(interp, listPtr,
		    Tcl_NewStringObj(pattern, -1));
	}
	goto searchDone;
    }
#ifndef BREAK_NAMESPACE_COMPAT
    entryPtr = Tcl_FirstHashEntry(&nsPtr->childTable, &search);
#else
    if (nsPtr->childTablePtr == NULL) {
	goto searchDone;
    }
    entryPtr = Tcl_FirstHashEntry(nsPtr->childTablePtr, &search);
#endif
    while (entryPtr != NULL) {
	childNsPtr = Tcl_GetHashValue(entryPtr);
	if ((pattern == NULL)
		|| Tcl_StringMatch(childNsPtr->fullName, pattern)) {
	    elemPtr = Tcl_NewStringObj(childNsPtr->fullName, -1);
	    Tcl_ListObjAppendElement(interp, listPtr, elemPtr);
	}
	entryPtr = Tcl_NextHashEntry(&search);
    }

  searchDone:
    Tcl_SetObjResult(interp, listPtr);
    Tcl_DStringFree(&buffer);
    return TCL_OK;
}

/*
 *----------------------------------------------------------------------
 *
 * NamespaceCodeCmd --
 *
 *	Invoked to implement the "namespace code" command to capture the
 *	namespace context of a command. Handles the following syntax:
 *
 *	    namespace code arg
 *
 *	Here "arg" can be a list. "namespace code arg" produces a result
 *	equivalent to that produced by the command
 *
 *	    list ::namespace inscope [namespace current] $arg
 *
 *	However, if "arg" is itself a scoped value starting with "::namespace
 *	inscope", then the result is just "arg".
 *
 * Results:
 *	Returns TCL_OK if successful, and TCL_ERROR if anything goes wrong.
 *
 * Side effects:
 *	If anything goes wrong, this function returns an error message as the
 *	result in the interpreter's result object.
 *
 *----------------------------------------------------------------------
 */

static int
NamespaceCodeCmd(
    ClientData dummy,		/* Not used. */
    Tcl_Interp *interp,		/* Current interpreter. */
    int objc,			/* Number of arguments. */
    Tcl_Obj *const objv[])	/* Argument objects. */
{
    Namespace *currNsPtr;
    Tcl_Obj *listPtr, *objPtr;
    register const char *arg, *p;
    int length;

    if (objc != 3) {
	Tcl_WrongNumArgs(interp, 2, objv, "arg");
	return TCL_ERROR;
    }

    /*
     * If "arg" is already a scoped value, then return it directly.
     */

    arg = TclGetStringFromObj(objv[2], &length);
    while (*arg == ':') {
	arg++;
	length--;
    }
    if (*arg=='n' && length>17 && strncmp(arg, "namespace", 9)==0) {
	for (p=arg+9 ; isspace(UCHAR(*p)) ; p++) {
	    /* empty body: skip over whitespace */
	}
	if (*p=='i' && (p+7 <= arg+length) && strncmp(p, "inscope", 7)==0) {
	    Tcl_SetObjResult(interp, objv[2]);
	    return TCL_OK;
	}
    }

    /*
     * Otherwise, construct a scoped command by building a list with
     * "namespace inscope", the full name of the current namespace, and the
     * argument "arg". By constructing a list, we ensure that scoped commands
     * are interpreted properly when they are executed later, by the
     * "namespace inscope" command.
     */

    TclNewObj(listPtr);
    TclNewLiteralStringObj(objPtr, "::namespace");
    Tcl_ListObjAppendElement(interp, listPtr, objPtr);
    TclNewLiteralStringObj(objPtr, "inscope");
    Tcl_ListObjAppendElement(interp, listPtr, objPtr);

    currNsPtr = (Namespace *) TclGetCurrentNamespace(interp);
    if (currNsPtr == (Namespace *) TclGetGlobalNamespace(interp)) {
	TclNewLiteralStringObj(objPtr, "::");
    } else {
	objPtr = Tcl_NewStringObj(currNsPtr->fullName, -1);
    }
    Tcl_ListObjAppendElement(interp, listPtr, objPtr);

    Tcl_ListObjAppendElement(interp, listPtr, objv[2]);

    Tcl_SetObjResult(interp, listPtr);
    return TCL_OK;
}

/*
 *----------------------------------------------------------------------
 *
 * NamespaceCurrentCmd --
 *
 *	Invoked to implement the "namespace current" command which returns the
 *	fully-qualified name of the current namespace. Handles the following
 *	syntax:
 *
 *	    namespace current
 *
 * Results:
 *	Returns TCL_OK if successful, and TCL_ERROR if anything goes wrong.
 *
 * Side effects:
 *	Returns a result in the interpreter's result object. If anything goes
 *	wrong, the result is an error message.
 *
 *----------------------------------------------------------------------
 */

static int
NamespaceCurrentCmd(
    ClientData dummy,		/* Not used. */
    Tcl_Interp *interp,		/* Current interpreter. */
    int objc,			/* Number of arguments. */
    Tcl_Obj *const objv[])	/* Argument objects. */
{
    register Namespace *currNsPtr;

    if (objc != 2) {
	Tcl_WrongNumArgs(interp, 2, objv, NULL);
	return TCL_ERROR;
    }

    /*
     * The "real" name of the global namespace ("::") is the null string, but
     * we return "::" for it as a convenience to programmers. Note that "" and
     * "::" are treated as synonyms by the namespace code so that it is still
     * easy to do things like:
     *
     *    namespace [namespace current]::bar { ... }
     */

    currNsPtr = (Namespace *) TclGetCurrentNamespace(interp);
    if (currNsPtr == (Namespace *) TclGetGlobalNamespace(interp)) {
	Tcl_SetObjResult(interp, Tcl_NewStringObj("::", 2));
    } else {
	Tcl_SetObjResult(interp, Tcl_NewStringObj(currNsPtr->fullName, -1));
    }
    return TCL_OK;
}

/*
 *----------------------------------------------------------------------
 *
 * NamespaceDeleteCmd --
 *
 *	Invoked to implement the "namespace delete" command to delete
 *	namespace(s). Handles the following syntax:
 *
 *	    namespace delete ?name name...?
 *
 *	Each name identifies a namespace. It may include a sequence of
 *	namespace qualifiers separated by "::"s. If a namespace is found, it
 *	is deleted: all variables and procedures contained in that namespace
 *	are deleted. If that namespace is being used on the call stack, it is
 *	kept alive (but logically deleted) until it is removed from the call
 *	stack: that is, it can no longer be referenced by name but any
 *	currently executing procedure that refers to it is allowed to do so
 *	until the procedure returns. If the namespace can't be found, this
 *	function returns an error. If no namespaces are specified, this
 *	command does nothing.
 *
 * Results:
 *	Returns TCL_OK if successful, and TCL_ERROR if anything goes wrong.
 *
 * Side effects:
 *	Deletes the specified namespaces. If anything goes wrong, this
 *	function returns an error message in the interpreter's result object.
 *
 *----------------------------------------------------------------------
 */

static int
NamespaceDeleteCmd(
    ClientData dummy,		/* Not used. */
    Tcl_Interp *interp,		/* Current interpreter. */
    int objc,			/* Number of arguments. */
    Tcl_Obj *const objv[])	/* Argument objects. */
{
    Tcl_Namespace *namespacePtr;
    const char *name;
    register int i;

    if (objc < 2) {
	Tcl_WrongNumArgs(interp, 2, objv, "?name name...?");
	return TCL_ERROR;
    }

    /*
     * Destroying one namespace may cause another to be destroyed. Break this
     * into two passes: first check to make sure that all namespaces on the
     * command line are valid, and report any errors.
     */

    for (i = 2;  i < objc;  i++) {
	name = TclGetString(objv[i]);
	namespacePtr = Tcl_FindNamespace(interp, name, NULL, /*flags*/ 0);
	if ((namespacePtr == NULL)
		|| (((Namespace *) namespacePtr)->flags & NS_KILLED)) {
	    Tcl_AppendResult(interp, "unknown namespace \"",
		    TclGetString(objv[i]),
		    "\" in namespace delete command", NULL);
	    Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "NAMESPACE",
		    TclGetString(objv[i]), NULL);
	    return TCL_ERROR;
	}
    }

    /*
     * Okay, now delete each namespace.
     */

    for (i = 2;  i < objc;  i++) {
	name = TclGetString(objv[i]);
	namespacePtr = Tcl_FindNamespace(interp, name, NULL, /* flags */ 0);
	if (namespacePtr) {
	    Tcl_DeleteNamespace(namespacePtr);
	}
    }
    return TCL_OK;
}

/*
 *----------------------------------------------------------------------
 *
 * NamespaceEvalCmd --
 *
 *	Invoked to implement the "namespace eval" command. Executes commands
 *	in a namespace. If the namespace does not already exist, it is
 *	created. Handles the following syntax:
 *
 *	    namespace eval name arg ?arg...?
 *
 *	If more than one arg argument is specified, the command that is
 *	executed is the result of concatenating the arguments together with a
 *	space between each argument.
 *
 * Results:
 *	Returns TCL_OK if the namespace is found and the commands are executed
 *	successfully. Returns TCL_ERROR if anything goes wrong.
 *
 * Side effects:
 *	Returns the result of the command in the interpreter's result object.
 *	If anything goes wrong, this function returns an error message as the
 *	result.
 *
 *----------------------------------------------------------------------
 */

static int
NamespaceEvalCmd(
    ClientData dummy,		/* Not used. */
    Tcl_Interp *interp,		/* Current interpreter. */
    int objc,			/* Number of arguments. */
    Tcl_Obj *const objv[])	/* Argument objects. */
{
    Interp *iPtr = (Interp *) interp;
    CmdFrame *invoker;
    int word;
    Tcl_Namespace *namespacePtr;
    CallFrame *framePtr, **framePtrPtr;
    Tcl_Obj *objPtr;
    int result;

    if (objc < 4) {
	Tcl_WrongNumArgs(interp, 2, objv, "name arg ?arg...?");
	return TCL_ERROR;
    }

    /*
     * Try to resolve the namespace reference, caching the result in the
     * namespace object along the way.
     */

    result = GetNamespaceFromObj(interp, objv[2], &namespacePtr);

    /*
     * If the namespace wasn't found, try to create it.
     */

    if (result == TCL_ERROR) {
	const char *name = TclGetString(objv[2]);

	namespacePtr = Tcl_CreateNamespace(interp, name, NULL, NULL);
	if (namespacePtr == NULL) {
	    return TCL_ERROR;
	}
    }

    /*
     * Make the specified namespace the current namespace and evaluate the
     * command(s).
     */

    /* This is needed to satisfy GCC 3.3's strict aliasing rules */
    framePtrPtr = &framePtr;
    result = TclPushStackFrame(interp, (Tcl_CallFrame **) framePtrPtr,
	    namespacePtr, /*isProcCallFrame*/ 0);
    if (result != TCL_OK) {
	return TCL_ERROR;
    }

    framePtr->objc = objc;
    framePtr->objv = objv;

    if (objc == 4) {
	/*
	 * TIP #280: Make actual argument location available to eval'd script.
	 */

	objPtr = objv[3];
	invoker = iPtr->cmdFramePtr;
	word = 3;
	TclArgumentGet(interp, objPtr, &invoker, &word);
    } else {
	/*
	 * More than one argument: concatenate them together with spaces
	 * between, then evaluate the result. Tcl_EvalObjEx will delete the
	 * object when it decrements its refcount after eval'ing it.
	 */

	objPtr = Tcl_ConcatObj(objc-3, objv+3);
	invoker = NULL;
	word = 0;
    }

    /*
     * TIP #280: Make invoking context available to eval'd script.
     */

    TclNRAddCallback(interp, NsEval_Callback, namespacePtr, "eval",
	    NULL, NULL);
    return TclNREvalObjEx(interp, objPtr, 0, invoker, word);
}

static int
NsEval_Callback(
    ClientData data[],
    Tcl_Interp *interp,
    int result)
{
    Tcl_Namespace *namespacePtr = data[0];

    if (result == TCL_ERROR) {
	int length = strlen(namespacePtr->fullName);
	int limit = 200;
	int overflow = (length > limit);
	char *cmd = data[1];

	Tcl_AppendObjToErrorInfo(interp, Tcl_ObjPrintf(
		"\n    (in namespace %s \"%.*s%s\" script line %d)",
		cmd,
		(overflow ? limit : length), namespacePtr->fullName,
		(overflow ? "..." : ""), Tcl_GetErrorLine(interp)));
    }

    /*
     * Restore the previous "current" namespace.
     */

    TclPopStackFrame(interp);
    return result;
}

/*
 *----------------------------------------------------------------------
 *
 * NamespaceExistsCmd --
 *
 *	Invoked to implement the "namespace exists" command that returns true
 *	if the given namespace currently exists, and false otherwise. Handles
 *	the following syntax:
 *
 *	    namespace exists name
 *
 * Results:
 *	Returns TCL_OK if successful, and TCL_ERROR if anything goes wrong.
 *
 * Side effects:
 *	Returns a result in the interpreter's result object. If anything goes
 *	wrong, the result is an error message.
 *
 *----------------------------------------------------------------------
 */

static int
NamespaceExistsCmd(
    ClientData dummy,		/* Not used. */
    Tcl_Interp *interp,		/* Current interpreter. */
    int objc,			/* Number of arguments. */
    Tcl_Obj *const objv[])	/* Argument objects. */
{
    Tcl_Namespace *namespacePtr;

    if (objc != 3) {
	Tcl_WrongNumArgs(interp, 2, objv, "name");
	return TCL_ERROR;
    }

    Tcl_SetObjResult(interp, Tcl_NewBooleanObj(
	    GetNamespaceFromObj(interp, objv[2], &namespacePtr) == TCL_OK));
    return TCL_OK;
}

/*
 *----------------------------------------------------------------------
 *
 * NamespaceExportCmd --
 *
 *	Invoked to implement the "namespace export" command that specifies
 *	which commands are exported from a namespace. The exported commands
 *	are those that can be imported into another namespace using "namespace
 *	import". Both commands defined in a namespace and commands the
 *	namespace has imported can be exported by a namespace. This command
 *	has the following syntax:
 *
 *	    namespace export ?-clear? ?pattern pattern...?
 *
 *	Each pattern may contain "string match"-style pattern matching special
 *	characters, but the pattern may not include any namespace qualifiers:
 *	that is, the pattern must specify commands in the current (exporting)
 *	namespace. The specified patterns are appended onto the namespace's
 *	list of export patterns.
 *
 *	To reset the namespace's export pattern list, specify the "-clear"
 *	flag.
 *
 *	If there are no export patterns and the "-clear" flag isn't given,
 *	this command returns the namespace's current export list.
 *
 * Results:
 *	Returns TCL_OK if successful, and TCL_ERROR if anything goes wrong.
 *
 * Side effects:
 *	Returns a result in the interpreter's result object. If anything goes
 *	wrong, the result is an error message.
 *
 *----------------------------------------------------------------------
 */

static int
NamespaceExportCmd(
    ClientData dummy,		/* Not used. */
    Tcl_Interp *interp,		/* Current interpreter. */
    int objc,			/* Number of arguments. */
    Tcl_Obj *const objv[])	/* Argument objects. */
{
    Namespace *currNsPtr = (Namespace *) TclGetCurrentNamespace(interp);
    const char *pattern, *string;
    int resetListFirst = 0;
    int firstArg, patternCt, i, result;

    if (objc < 2) {
	Tcl_WrongNumArgs(interp, 2, objv, "?-clear? ?pattern pattern...?");
	return TCL_ERROR;
    }

    /*
     * Process the optional "-clear" argument.
     */

    firstArg = 2;
    if (firstArg < objc) {
	string = TclGetString(objv[firstArg]);
	if (strcmp(string, "-clear") == 0) {
	    resetListFirst = 1;
	    firstArg++;
	}
    }

    /*
     * If no pattern arguments are given, and "-clear" isn't specified, return
     * the namespace's current export pattern list.
     */

    patternCt = (objc - firstArg);
    if (patternCt == 0) {
	if (firstArg > 2) {
	    return TCL_OK;
	} else {
	    /*
	     * Create list with export patterns.
	     */

	    Tcl_Obj *listPtr = Tcl_NewListObj(0, NULL);

	    result = Tcl_AppendExportList(interp, (Tcl_Namespace *) currNsPtr,
		    listPtr);
	    if (result != TCL_OK) {
		return result;
	    }
	    Tcl_SetObjResult(interp, listPtr);
	    return TCL_OK;
	}
    }

    /*
     * Add each pattern to the namespace's export pattern list.
     */

    for (i = firstArg;  i < objc;  i++) {
	pattern = TclGetString(objv[i]);
	result = Tcl_Export(interp, (Tcl_Namespace *) currNsPtr, pattern,
		((i == firstArg)? resetListFirst : 0));
	if (result != TCL_OK) {
	    return result;
	}
    }
    return TCL_OK;
}

/*
 *----------------------------------------------------------------------
 *
 * NamespaceForgetCmd --
 *
 *	Invoked to implement the "namespace forget" command to remove imported
 *	commands from a namespace. Handles the following syntax:
 *
 *	    namespace forget ?pattern pattern...?
 *
 *	Each pattern is a name like "foo::*" or "a::b::x*". That is, the
 *	pattern may include the special pattern matching characters recognized
 *	by the "string match" command, but only in the command name at the end
 *	of the qualified name; the special pattern characters may not appear
 *	in a namespace name. All of the commands that match that pattern are
 *	checked to see if they have an imported command in the current
 *	namespace that refers to the matched command. If there is an alias, it
 *	is removed.
 *
 * Results:
 *	Returns TCL_OK if successful, and TCL_ERROR if anything goes wrong.
 *
 * Side effects:
 *	Imported commands are removed from the current namespace. If anything
 *	goes wrong, this function returns an error message in the
 *	interpreter's result object.
 *
 *----------------------------------------------------------------------
 */

static int
NamespaceForgetCmd(
    ClientData dummy,		/* Not used. */
    Tcl_Interp *interp,		/* Current interpreter. */
    int objc,			/* Number of arguments. */
    Tcl_Obj *const objv[])	/* Argument objects. */
{
    const char *pattern;
    register int i, result;

    if (objc < 2) {
	Tcl_WrongNumArgs(interp, 2, objv, "?pattern pattern...?");
	return TCL_ERROR;
    }

    for (i = 2;  i < objc;  i++) {
	pattern = TclGetString(objv[i]);
	result = Tcl_ForgetImport(interp, NULL, pattern);
	if (result != TCL_OK) {
	    return result;
	}
    }
    return TCL_OK;
}

/*
 *----------------------------------------------------------------------
 *
 * NamespaceImportCmd --
 *
 *	Invoked to implement the "namespace import" command that imports
 *	commands into a namespace. Handles the following syntax:
 *
 *	    namespace import ?-force? ?pattern pattern...?
 *
 *	Each pattern is a namespace-qualified name like "foo::*", "a::b::x*",
 *	or "bar::p". That is, the pattern may include the special pattern
 *	matching characters recognized by the "string match" command, but only
 *	in the command name at the end of the qualified name; the special
 *	pattern characters may not appear in a namespace name. All of the
 *	commands that match the pattern and which are exported from their
 *	namespace are made accessible from the current namespace context. This
 *	is done by creating a new "imported command" in the current namespace
 *	that points to the real command in its original namespace; when the
 *	imported command is called, it invokes the real command.
 *
 *	If an imported command conflicts with an existing command, it is
 *	treated as an error. But if the "-force" option is included, then
 *	existing commands are overwritten by the imported commands.
 *
 *	If there are no pattern arguments and the "-force" flag isn't given,
 *	this command returns the list of commands currently imported in
 *	the current namespace.
 *
 * Results:
 *	Returns TCL_OK if successful, and TCL_ERROR if anything goes wrong.
 *
 * Side effects:
 *	Adds imported commands to the current namespace. If anything goes
 *	wrong, this function returns an error message in the interpreter's
 *	result object.
 *
 *----------------------------------------------------------------------
 */

static int
NamespaceImportCmd(
    ClientData dummy,		/* Not used. */
    Tcl_Interp *interp,		/* Current interpreter. */
    int objc,			/* Number of arguments. */
    Tcl_Obj *const objv[])	/* Argument objects. */
{
    int allowOverwrite = 0;
    const char *string, *pattern;
    register int i, result;
    int firstArg;

    if (objc < 2) {
	Tcl_WrongNumArgs(interp, 2, objv, "?-force? ?pattern pattern...?");
	return TCL_ERROR;
    }

    /*
     * Skip over the optional "-force" as the first argument.
     */

    firstArg = 2;
    if (firstArg < objc) {
	string = TclGetString(objv[firstArg]);
	if ((*string == '-') && (strcmp(string, "-force") == 0)) {
	    allowOverwrite = 1;
	    firstArg++;
	}
    } else {
	/*
	 * When objc == 2, command is just [namespace import]. Introspection
	 * form to return list of imported commands.
	 */

	Tcl_HashEntry *hPtr;
	Tcl_HashSearch search;
	Namespace *nsPtr = (Namespace *) TclGetCurrentNamespace(interp);
	Tcl_Obj *listPtr;

	TclNewObj(listPtr);
	for (hPtr = Tcl_FirstHashEntry(&nsPtr->cmdTable, &search);
		hPtr != NULL; hPtr = Tcl_NextHashEntry(&search)) {
	    Command *cmdPtr = Tcl_GetHashValue(hPtr);

	    if (cmdPtr->deleteProc == DeleteImportedCmd) {
		Tcl_ListObjAppendElement(NULL, listPtr, Tcl_NewStringObj(
			Tcl_GetHashKey(&nsPtr->cmdTable, hPtr) ,-1));
	    }
	}
	Tcl_SetObjResult(interp, listPtr);
	return TCL_OK;
    }

    /*
     * Handle the imports for each of the patterns.
     */

    for (i = firstArg;  i < objc;  i++) {
	pattern = TclGetString(objv[i]);
	result = Tcl_Import(interp, NULL, pattern, allowOverwrite);
	if (result != TCL_OK) {
	    return result;
	}
    }
    return TCL_OK;
}

/*
 *----------------------------------------------------------------------
 *
 * NamespaceInscopeCmd --
 *
 *	Invoked to implement the "namespace inscope" command that executes a
 *	script in the context of a particular namespace. This command is not
 *	expected to be used directly by programmers; calls to it are generated
 *	implicitly when programs use "namespace code" commands to register
 *	callback scripts. Handles the following syntax:
 *
 *	    namespace inscope name arg ?arg...?
 *
 *	The "namespace inscope" command is much like the "namespace eval"
 *	command except that it has lappend semantics and the namespace must
 *	already exist. It treats the first argument as a list, and appends any
 *	arguments after the first onto the end as proper list elements. For
 *	example,
 *
 *	    namespace inscope ::foo {a b} c d e
 *
 *	is equivalent to
 *
 *	    namespace eval ::foo [concat {a b} [list c d e]]
 *
 *	This lappend semantics is important because many callback scripts are
 *	actually prefixes.
 *
 * Results:
 *	Returns TCL_OK to indicate success, or TCL_ERROR to indicate failure.
 *
 * Side effects:
 *	Returns a result in the Tcl interpreter's result object.
 *
 *----------------------------------------------------------------------
 */

static int
NamespaceInscopeCmd(
    ClientData dummy,		/* Not used. */
    Tcl_Interp *interp,		/* Current interpreter. */
    int objc,			/* Number of arguments. */
    Tcl_Obj *const objv[])	/* Argument objects. */
{
    Tcl_Namespace *namespacePtr;
    CallFrame *framePtr, **framePtrPtr;
    int i, result;
    Tcl_Obj *cmdObjPtr;

    if (objc < 4) {
	Tcl_WrongNumArgs(interp, 2, objv, "name arg ?arg...?");
	return TCL_ERROR;
    }

    /*
     * Resolve the namespace reference.
     */

    if (TclGetNamespaceFromObj(interp, objv[2], &namespacePtr) != TCL_OK) {
	return TCL_ERROR;
    }

    /*
     * Make the specified namespace the current namespace.
     */

    framePtrPtr = &framePtr;		/* This is needed to satisfy GCC's
					 * strict aliasing rules. */
    result = TclPushStackFrame(interp, (Tcl_CallFrame **) framePtrPtr,
	    namespacePtr, /*isProcCallFrame*/ 0);
    if (result != TCL_OK) {
	return result;
    }

    framePtr->objc = objc;
    framePtr->objv = objv;

    /*
     * Execute the command. If there is just one argument, just treat it as a
     * script and evaluate it. Otherwise, create a list from the arguments
     * after the first one, then concatenate the first argument and the list
     * of extra arguments to form the command to evaluate.
     */

    if (objc == 4) {
	cmdObjPtr = objv[3];
    } else {
	Tcl_Obj *concatObjv[2];
	register Tcl_Obj *listPtr;

	listPtr = Tcl_NewListObj(0, NULL);
	for (i = 4;  i < objc;  i++) {
	    if (Tcl_ListObjAppendElement(interp, listPtr, objv[i]) != TCL_OK){
		Tcl_DecrRefCount(listPtr);	/* Free unneeded obj. */
		return TCL_ERROR;
	    }
	}

	concatObjv[0] = objv[3];
	concatObjv[1] = listPtr;
	cmdObjPtr = Tcl_ConcatObj(2, concatObjv);
	Tcl_DecrRefCount(listPtr);    /* We're done with the list object. */
    }

    TclNRAddCallback(interp, NsEval_Callback, namespacePtr, "inscope",
	    NULL, NULL);
    return TclNREvalObjEx(interp, cmdObjPtr, 0, NULL, 0);
}

/*
 *----------------------------------------------------------------------
 *
 * NamespaceOriginCmd --
 *
 *	Invoked to implement the "namespace origin" command to return the
 *	fully-qualified name of the "real" command to which the specified
 *	"imported command" refers. Handles the following syntax:
 *
 *	    namespace origin name
 *
 * Results:
 *	An imported command is created in an namespace when that namespace
 *	imports a command from another namespace. If a command is imported
 *	into a sequence of namespaces a, b,...,n where each successive
 *	namespace just imports the command from the previous namespace, this
 *	command returns the fully-qualified name of the original command in
 *	the first namespace, a. If "name" does not refer to an alias, its
 *	fully-qualified name is returned. The returned name is stored in the
 *	interpreter's result object. This function returns TCL_OK if
 *	successful, and TCL_ERROR if anything goes wrong.
 *
 * Side effects:
 *	If anything goes wrong, this function returns an error message in the
 *	interpreter's result object.
 *
 *----------------------------------------------------------------------
 */

static int
NamespaceOriginCmd(
    ClientData dummy,		/* Not used. */
    Tcl_Interp *interp,		/* Current interpreter. */
    int objc,			/* Number of arguments. */
    Tcl_Obj *const objv[])	/* Argument objects. */
{
    Tcl_Command command, origCommand;
    Tcl_Obj *resultPtr;

    if (objc != 3) {
	Tcl_WrongNumArgs(interp, 2, objv, "name");
	return TCL_ERROR;
    }

    command = Tcl_GetCommandFromObj(interp, objv[2]);
    if (command == NULL) {
	Tcl_AppendResult(interp, "invalid command name \"",
		TclGetString(objv[2]), "\"", NULL);
	Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "COMMAND",
		TclGetString(objv[2]), NULL);
	return TCL_ERROR;
    }
    origCommand = TclGetOriginalCommand(command);
    TclNewObj(resultPtr);
    if (origCommand == NULL) {
	/*
	 * The specified command isn't an imported command. Return the
	 * command's name qualified by the full name of the namespace it was
	 * defined in.
	 */

	Tcl_GetCommandFullName(interp, command, resultPtr);
    } else {
	Tcl_GetCommandFullName(interp, origCommand, resultPtr);
    }
    Tcl_SetObjResult(interp, resultPtr);
    return TCL_OK;
}

/*
 *----------------------------------------------------------------------
 *
 * NamespaceParentCmd --
 *
 *	Invoked to implement the "namespace parent" command that returns the
 *	fully-qualified name of the parent namespace for a specified
 *	namespace. Handles the following syntax:
 *
 *	    namespace parent ?name?
 *
 * Results:
 *	Returns TCL_OK if successful, and TCL_ERROR if anything goes wrong.
 *
 * Side effects:
 *	Returns a result in the interpreter's result object. If anything goes
 *	wrong, the result is an error message.
 *
 *----------------------------------------------------------------------
 */

static int
NamespaceParentCmd(
    ClientData dummy,		/* Not used. */
    Tcl_Interp *interp,		/* Current interpreter. */
    int objc,			/* Number of arguments. */
    Tcl_Obj *const objv[])	/* Argument objects. */
{
    Tcl_Namespace *nsPtr;

    if (objc == 2) {
	nsPtr = TclGetCurrentNamespace(interp);
    } else if (objc == 3) {
	if (TclGetNamespaceFromObj(interp, objv[2], &nsPtr) != TCL_OK) {
	    return TCL_ERROR;
	}
    } else {
	Tcl_WrongNumArgs(interp, 2, objv, "?name?");
	return TCL_ERROR;
    }

    /*
     * Report the parent of the specified namespace.
     */

    if (nsPtr->parentPtr != NULL) {
	Tcl_SetObjResult(interp, Tcl_NewStringObj(
		nsPtr->parentPtr->fullName, -1));
    }
    return TCL_OK;
}

/*
 *----------------------------------------------------------------------
 *
 * NamespacePathCmd --
 *
 *	Invoked to implement the "namespace path" command that reads and
 *	writes the current namespace's command resolution path. Has one
 *	optional argument: if present, it is a list of named namespaces to set
 *	the path to, and if absent, the current path should be returned.
 *	Handles the following syntax:
 *
 *	    namespace path ?nsList?
 *
 * Results:
 *	Returns TCL_OK if successful, and TCL_ERROR if anything goes wrong
 *	(most notably if the namespace list contains the name of something
 *	other than a namespace). In the successful-exit case, may set the
 *	interpreter result to the list of names of the namespaces on the
 *	current namespace's path.
 *
 * Side effects:
 *	May update the namespace path (triggering a recomputing of all command
 *	names that depend on the namespace for resolution).
 *
 *----------------------------------------------------------------------
 */

static int
NamespacePathCmd(
    ClientData dummy,		/* Not used. */
    Tcl_Interp *interp,		/* Current interpreter. */
    int objc,			/* Number of arguments. */
    Tcl_Obj *const objv[])	/* Argument objects. */
{
    Namespace *nsPtr = (Namespace *) TclGetCurrentNamespace(interp);
    int i, nsObjc, result = TCL_ERROR;
    Tcl_Obj **nsObjv;
    Tcl_Namespace **namespaceList = NULL;

    if (objc > 3) {
	Tcl_WrongNumArgs(interp, 2, objv, "?pathList?");
	return TCL_ERROR;
    }

    /*
     * If no path is given, return the current path.
     */

    if (objc == 2) {
	/*
	 * Not a very fast way to compute this, but easy to get right.
	 */

	for (i=0 ; i<nsPtr->commandPathLength ; i++) {
	    if (nsPtr->commandPathArray[i].nsPtr != NULL) {
		Tcl_AppendElement(interp,
			nsPtr->commandPathArray[i].nsPtr->fullName);
	    }
	}
	return TCL_OK;
    }

    /*
     * There is a path given, so parse it into an array of namespace pointers.
     */

    if (TclListObjGetElements(interp, objv[2], &nsObjc, &nsObjv) != TCL_OK) {
	goto badNamespace;
    }
    if (nsObjc != 0) {
	namespaceList = (Tcl_Namespace **)
		TclStackAlloc(interp, sizeof(Tcl_Namespace *) * nsObjc);

	for (i=0 ; i<nsObjc ; i++) {
	    if (TclGetNamespaceFromObj(interp, nsObjv[i],
		    &namespaceList[i]) != TCL_OK) {
		goto badNamespace;
	    }
	}
    }

    /*
     * Now we have the list of valid namespaces, install it as the path.
     */

    TclSetNsPath(nsPtr, nsObjc, namespaceList);

    result = TCL_OK;
  badNamespace:
    if (namespaceList != NULL) {
	TclStackFree(interp, namespaceList);
    }
    return result;
}

/*
 *----------------------------------------------------------------------
 *
 * TclSetNsPath --
 *
 *	Sets the namespace command name resolution path to the given list of
 *	namespaces. If the list is empty (of zero length) the path is set to
 *	empty and the default old-style behaviour of command name resolution
 *	is used.
 *
 * Results:
 *	nothing
 *
 * Side effects:
 *	Invalidates the command name resolution caches for any command
 *	resolved in the given namespace.
 *
 *----------------------------------------------------------------------
 */

void
TclSetNsPath(
    Namespace *nsPtr,		/* Namespace whose path is to be set. */
    int pathLength,		/* Length of pathAry. */
    Tcl_Namespace *pathAry[])	/* Array of namespaces that are the path. */
{
    if (pathLength != 0) {
	NamespacePathEntry *tmpPathArray = (NamespacePathEntry *)
		ckalloc(sizeof(NamespacePathEntry) * pathLength);
	int i;

	for (i=0 ; i<pathLength ; i++) {
	    tmpPathArray[i].nsPtr = (Namespace *) pathAry[i];
	    tmpPathArray[i].creatorNsPtr = nsPtr;
	    tmpPathArray[i].prevPtr = NULL;
	    tmpPathArray[i].nextPtr =
		    tmpPathArray[i].nsPtr->commandPathSourceList;
	    if (tmpPathArray[i].nextPtr != NULL) {
		tmpPathArray[i].nextPtr->prevPtr = &tmpPathArray[i];
	    }
	    tmpPathArray[i].nsPtr->commandPathSourceList = &tmpPathArray[i];
	}
	if (nsPtr->commandPathLength != 0) {
	    UnlinkNsPath(nsPtr);
	}
	nsPtr->commandPathArray = tmpPathArray;
    } else {
	if (nsPtr->commandPathLength != 0) {
	    UnlinkNsPath(nsPtr);
	}
    }

    nsPtr->commandPathLength = pathLength;
    nsPtr->cmdRefEpoch++;
    nsPtr->resolverEpoch++;
}

/*
 *----------------------------------------------------------------------
 *
 * UnlinkNsPath --
 *
 *	Delete the given namespace's command name resolution path. Only call
 *	if the path is non-empty. Caller must reset the counter containing the
 *	path size.
 *
 * Results:
 *	nothing
 *
 * Side effects:
 *	Deletes the array of path entries and unlinks those path entries from
 *	the target namespace's list of interested namespaces.
 *
 *----------------------------------------------------------------------
 */

static void
UnlinkNsPath(
    Namespace *nsPtr)
{
    int i;
    for (i=0 ; i<nsPtr->commandPathLength ; i++) {
	NamespacePathEntry *nsPathPtr = &nsPtr->commandPathArray[i];

	if (nsPathPtr->prevPtr != NULL) {
	    nsPathPtr->prevPtr->nextPtr = nsPathPtr->nextPtr;
	}
	if (nsPathPtr->nextPtr != NULL) {
	    nsPathPtr->nextPtr->prevPtr = nsPathPtr->prevPtr;
	}
	if (nsPathPtr->nsPtr != NULL) {
	    if (nsPathPtr->nsPtr->commandPathSourceList == nsPathPtr) {
		nsPathPtr->nsPtr->commandPathSourceList = nsPathPtr->nextPtr;
	    }
	}
    }
    ckfree((char *) nsPtr->commandPathArray);
}

/*
 *----------------------------------------------------------------------
 *
 * TclInvalidateNsPath --
 *
 *	Invalidate the name resolution caches for all names looked up in
 *	namespaces whose name path includes the given namespace.
 *
 * Results:
 *	nothing
 *
 * Side effects:
 *	Increments the command reference epoch in each namespace whose path
 *	includes the given namespace. This causes any cached resolved names
 *	whose root cacheing context starts at that namespace to be recomputed
 *	the next time they are used.
 *
 *----------------------------------------------------------------------
 */

void
TclInvalidateNsPath(
    Namespace *nsPtr)
{
    NamespacePathEntry *nsPathPtr = nsPtr->commandPathSourceList;

    while (nsPathPtr != NULL) {
	if (nsPathPtr->nsPtr != NULL) {
	    nsPathPtr->creatorNsPtr->cmdRefEpoch++;
	}
	nsPathPtr = nsPathPtr->nextPtr;
    }
}

/*
 *----------------------------------------------------------------------
 *
 * NamespaceQualifiersCmd --
 *
 *	Invoked to implement the "namespace qualifiers" command that returns
 *	any leading namespace qualifiers in a string. These qualifiers are
 *	namespace names separated by "::"s. For example, for "::foo::p" this
 *	command returns "::foo", and for "::" it returns "". This command is
 *	the complement of the "namespace tail" command. Note that this command
 *	does not check whether the "namespace" names are, in fact, the names
 *	of currently defined namespaces. Handles the following syntax:
 *
 *	    namespace qualifiers string
 *
 * Results:
 *	Returns TCL_OK if successful, and TCL_ERROR if anything goes wrong.
 *
 * Side effects:
 *	Returns a result in the interpreter's result object. If anything goes
 *	wrong, the result is an error message.
 *
 *----------------------------------------------------------------------
 */

static int
NamespaceQualifiersCmd(
    ClientData dummy,		/* Not used. */
    Tcl_Interp *interp,		/* Current interpreter. */
    int objc,			/* Number of arguments. */
    Tcl_Obj *const objv[])	/* Argument objects. */
{
    register const char *name, *p;
    int length;

    if (objc != 3) {
	Tcl_WrongNumArgs(interp, 2, objv, "string");
	return TCL_ERROR;
    }

    /*
     * Find the end of the string, then work backward and find the start of
     * the last "::" qualifier.
     */

    name = TclGetString(objv[2]);
    for (p = name;  *p != '\0';  p++) {
	/* empty body */
    }
    while (--p >= name) {
	if ((*p == ':') && (p > name) && (*(p-1) == ':')) {
	    p -= 2;			/* Back up over the :: */
	    while ((p >= name) && (*p == ':')) {
		p--;			/* Back up over the preceeding : */
	    }
	    break;
	}
    }

    if (p >= name) {
	length = p-name+1;
	Tcl_SetObjResult(interp, Tcl_NewStringObj(name, length));
    }
    return TCL_OK;
}

/*
 *----------------------------------------------------------------------
 *
 * NamespaceUnknownCmd --
 *
 *	Invoked to implement the "namespace unknown" command (TIP 181) that
 *	sets or queries a per-namespace unknown command handler. This handler
 *	is called when command lookup fails (current and global ns). The
 *	default handler for the global namespace is ::unknown. The default
 *	handler for other namespaces is to call the global namespace unknown
 *	handler. Passing an empty list results in resetting the handler to its
 *	default.
 *
 *	    namespace unknown ?handler?
 *
 * Results:
 *	Returns TCL_OK if successful, and TCL_ERROR if anything goes wrong.
 *
 * Side effects:
 *	If no handler is specified, returns a result in the interpreter's
 *	result object, otherwise it sets the unknown handler pointer in the
 *	current namespace to the script fragment provided. If anything goes
 *	wrong, the result is an error message.
 *
 *----------------------------------------------------------------------
 */

static int
NamespaceUnknownCmd(
    ClientData dummy,		/* Not used. */
    Tcl_Interp *interp,		/* Current interpreter. */
    int objc,			/* Number of arguments. */
    Tcl_Obj *const objv[])	/* Argument objects. */
{
    Tcl_Namespace *currNsPtr;
    Tcl_Obj *resultPtr;
    int rc;

    if (objc > 3) {
	Tcl_WrongNumArgs(interp, 2, objv, "?script?");
	return TCL_ERROR;
    }

    currNsPtr = TclGetCurrentNamespace(interp);

    if (objc == 2) {
	/*
	 * Introspection - return the current namespace handler.
	 */

	resultPtr = Tcl_GetNamespaceUnknownHandler(interp, currNsPtr);
	if (resultPtr == NULL) {
	    TclNewObj(resultPtr);
	}
	Tcl_SetObjResult(interp, resultPtr);
    } else {
	rc = Tcl_SetNamespaceUnknownHandler(interp, currNsPtr, objv[2]);
	if (rc == TCL_OK) {
	    Tcl_SetObjResult(interp, objv[2]);
	}
	return rc;
    }
    return TCL_OK;
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_GetNamespaceUnknownHandler --
 *
 *	Returns the unknown command handler registered for the given
 *	namespace.
 *
 * Results:
 *	Returns the current unknown command handler, or NULL if none exists
 *	for the namespace.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

Tcl_Obj *
Tcl_GetNamespaceUnknownHandler(
    Tcl_Interp *interp,		/* The interpreter in which the namespace
				 * exists. */
    Tcl_Namespace *nsPtr)	/* The namespace. */
{
    Namespace *currNsPtr = (Namespace *) nsPtr;

    if (currNsPtr->unknownHandlerPtr == NULL &&
	    currNsPtr == ((Interp *) interp)->globalNsPtr) {
	/*
	 * Default handler for global namespace is "::unknown". For all other
	 * namespaces, it is NULL (which falls back on the global unknown
	 * handler).
	 */

	TclNewLiteralStringObj(currNsPtr->unknownHandlerPtr, "::unknown");
	Tcl_IncrRefCount(currNsPtr->unknownHandlerPtr);
    }
    return currNsPtr->unknownHandlerPtr;
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_SetNamespaceUnknownHandler --
 *
 *	Sets the unknown command handler for the given namespace to the
 *	command prefix passed.
 *
 * Results:
 *	Returns TCL_OK if successful, and TCL_ERROR if anything goes wrong.
 *
 * Side effects:
 *	Sets the namespace unknown command handler. If the passed in handler
 *	is NULL or an empty list, then the handler is reset to its default. If
 *	an error occurs, then an error message is left in the interpreter
 *	result.
 *
 *----------------------------------------------------------------------
 */

int
Tcl_SetNamespaceUnknownHandler(
    Tcl_Interp *interp,		/* Interpreter in which the namespace
				 * exists. */
    Tcl_Namespace *nsPtr,	/* Namespace which is being updated. */
    Tcl_Obj *handlerPtr)	/* The new handler, or NULL to reset. */
{
    int lstlen = 0;
    Namespace *currNsPtr = (Namespace *) nsPtr;

    /*
     * Ensure that we check for errors *first* before we change anything.
     */

    if (handlerPtr != NULL) {
	if (TclListObjLength(interp, handlerPtr, &lstlen) != TCL_OK) {
	    /*
	     * Not a list.
	     */

	    return TCL_ERROR;
	}
	if (lstlen > 0) {
	    /*
	     * We are going to be saving this handler. Increment the reference
	     * count before decrementing the refcount on the previous handler,
	     * so that nothing strange can happen if we are told to set the
	     * handler to the previous value.
	     */

	    Tcl_IncrRefCount(handlerPtr);
	}
    }

    /*
     * Remove old handler next.
     */

    if (currNsPtr->unknownHandlerPtr != NULL) {
	Tcl_DecrRefCount(currNsPtr->unknownHandlerPtr);
    }

    /*
     * Install the new handler.
     */

    if (lstlen > 0) {
	/*
	 * Just store the handler. It already has the correct reference count.
	 */

	currNsPtr->unknownHandlerPtr = handlerPtr;
    } else {
	/*
	 * If NULL or an empty list is passed, this resets to the default
	 * handler.
	 */

	currNsPtr->unknownHandlerPtr = NULL;
    }
    return TCL_OK;
}

/*
 *----------------------------------------------------------------------
 *
 * NamespaceTailCmd --
 *
 *	Invoked to implement the "namespace tail" command that returns the
 *	trailing name at the end of a string with "::" namespace qualifiers.
 *	These qualifiers are namespace names separated by "::"s. For example,
 *	for "::foo::p" this command returns "p", and for "::" it returns "".
 *	This command is the complement of the "namespace qualifiers" command.
 *	Note that this command does not check whether the "namespace" names
 *	are, in fact, the names of currently defined namespaces. Handles the
 *	following syntax:
 *
 *	    namespace tail string
 *
 * Results:
 *	Returns TCL_OK if successful, and TCL_ERROR if anything goes wrong.
 *
 * Side effects:
 *	Returns a result in the interpreter's result object. If anything goes
 *	wrong, the result is an error message.
 *
 *----------------------------------------------------------------------
 */

static int
NamespaceTailCmd(
    ClientData dummy,		/* Not used. */
    Tcl_Interp *interp,		/* Current interpreter. */
    int objc,			/* Number of arguments. */
    Tcl_Obj *const objv[])	/* Argument objects. */
{
    register const char *name, *p;

    if (objc != 3) {
	Tcl_WrongNumArgs(interp, 2, objv, "string");
	return TCL_ERROR;
    }

    /*
     * Find the end of the string, then work backward and find the last "::"
     * qualifier.
     */

    name = TclGetString(objv[2]);
    for (p = name;  *p != '\0';  p++) {
	/* empty body */
    }
    while (--p > name) {
	if ((*p == ':') && (*(p-1) == ':')) {
	    p++;			/* Just after the last "::" */
	    break;
	}
    }

    if (p >= name) {
	Tcl_SetObjResult(interp, Tcl_NewStringObj(p, -1));
    }
    return TCL_OK;
}

/*
 *----------------------------------------------------------------------
 *
 * NamespaceUpvarCmd --
 *
 *	Invoked to implement the "namespace upvar" command, that creates
 *	variables in the current scope linked to variables in another
 *	namespace. Handles the following syntax:
 *
 *	    namespace upvar ns otherVar myVar ?otherVar myVar ...?
 *
 * Results:
 *	Returns TCL_OK if successful, and TCL_ERROR if anything goes wrong.
 *
 * Side effects:
 *	Creates new variables in the current scope, linked to the
 *	corresponding variables in the stipulated nmamespace. If anything goes
 *	wrong, the result is an error message.
 *
 *----------------------------------------------------------------------
 */

static int
NamespaceUpvarCmd(
    ClientData dummy,		/* Not used. */
    Tcl_Interp *interp,		/* Current interpreter. */
    int objc,			/* Number of arguments. */
    Tcl_Obj *const objv[])	/* Argument objects. */
{
    Interp *iPtr = (Interp *) interp;
    Tcl_Namespace *nsPtr, *savedNsPtr;
    Var *otherPtr, *arrayPtr;
    const char *myName;

    if (objc < 3 || !(objc & 1)) {
	Tcl_WrongNumArgs(interp, 2, objv, "ns ?otherVar myVar ...?");
	return TCL_ERROR;
    }

    if (TclGetNamespaceFromObj(interp, objv[2], &nsPtr) != TCL_OK) {
	return TCL_ERROR;
    }

    objc -= 3;
    objv += 3;

    for (; objc>0 ; objc-=2, objv+=2) {
	/*
	 * Locate the other variable.
	 */

	savedNsPtr = (Tcl_Namespace *) iPtr->varFramePtr->nsPtr;
	iPtr->varFramePtr->nsPtr = (Namespace *) nsPtr;
	otherPtr = TclObjLookupVarEx(interp, objv[0], NULL,
		(TCL_NAMESPACE_ONLY | TCL_LEAVE_ERR_MSG), "access",
		/*createPart1*/ 1, /*createPart2*/ 1, &arrayPtr);
	iPtr->varFramePtr->nsPtr = (Namespace *) savedNsPtr;
	if (otherPtr == NULL) {
	    return TCL_ERROR;
	}

	/*
	 * Create the new variable and link it to otherPtr.
	 */

	myName = TclGetString(objv[1]);
	if (TclPtrMakeUpvar(interp, otherPtr, myName, 0, -1) != TCL_OK) {
	    return TCL_ERROR;
	}
    }

    return TCL_OK;
}

/*
 *----------------------------------------------------------------------
 *
 * NamespaceWhichCmd --
 *
 *	Invoked to implement the "namespace which" command that returns the
 *	fully-qualified name of a command or variable. If the specified
 *	command or variable does not exist, it returns "". Handles the
 *	following syntax:
 *
 *	    namespace which ?-command? ?-variable? name
 *
 * Results:
 *	Returns TCL_OK if successful, and TCL_ERROR if anything goes wrong.
 *
 * Side effects:
 *	Returns a result in the interpreter's result object. If anything goes
 *	wrong, the result is an error message.
 *
 *----------------------------------------------------------------------
 */

static int
NamespaceWhichCmd(
    ClientData dummy,		/* Not used. */
    Tcl_Interp *interp,		/* Current interpreter. */
    int objc,			/* Number of arguments. */
    Tcl_Obj *const objv[])	/* Argument objects. */
{
    static const char *const opts[] = {
	"-command", "-variable", NULL
    };
    int lookupType = 0;
    Tcl_Obj *resultPtr;

    if (objc < 3 || objc > 4) {
    badArgs:
	Tcl_WrongNumArgs(interp, 2, objv, "?-command? ?-variable? name");
	return TCL_ERROR;
    } else if (objc == 4) {
	/*
	 * Look for a flag controlling the lookup.
	 */

	if (Tcl_GetIndexFromObj(interp, objv[2], opts, "option", 0,
		&lookupType) != TCL_OK) {
	    /*
	     * Preserve old style of error message!
	     */

	    Tcl_ResetResult(interp);
	    goto badArgs;
	}
    }

    TclNewObj(resultPtr);
    switch (lookupType) {
    case 0: {				/* -command */
	Tcl_Command cmd = Tcl_GetCommandFromObj(interp, objv[objc-1]);

	if (cmd != NULL) {
	    Tcl_GetCommandFullName(interp, cmd, resultPtr);
	}
	break;
    }
    case 1: {				/* -variable */
	Tcl_Var var = Tcl_FindNamespaceVar(interp,
		TclGetString(objv[objc-1]), NULL, /*flags*/ 0);

	if (var != NULL) {
	    Tcl_GetVariableFullName(interp, var, resultPtr);
	}
	break;
    }
    }
    Tcl_SetObjResult(interp, resultPtr);
    return TCL_OK;
}

/*
 *----------------------------------------------------------------------
 *
 * FreeNsNameInternalRep --
 *
 *	Frees the resources associated with a nsName object's internal
 *	representation.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	Decrements the ref count of any Namespace structure pointed to by the
 *	nsName's internal representation. If there are no more references to
 *	the namespace, it's structure will be freed.
 *
 *----------------------------------------------------------------------
 */

static void
FreeNsNameInternalRep(
    register Tcl_Obj *objPtr)	/* nsName object with internal representation
				 * to free. */
{
    ResolvedNsName *resNamePtr = objPtr->internalRep.twoPtrValue.ptr1;

    /*
     * Decrement the reference count of the namespace. If there are no more
     * references, free it up.
     */

    resNamePtr->refCount--;
    if (resNamePtr->refCount == 0) {
	/*
	 * Decrement the reference count for the cached namespace. If the
	 * namespace is dead, and there are no more references to it, free
	 * it.
	 */

	TclNsDecrRefCount(resNamePtr->nsPtr);
	ckfree((char *) resNamePtr);
    }
    objPtr->typePtr = NULL;
}

/*
 *----------------------------------------------------------------------
 *
 * DupNsNameInternalRep --
 *
 *	Initializes the internal representation of a nsName object to a copy
 *	of the internal representation of another nsName object.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	copyPtr's internal rep is set to refer to the same namespace
 *	referenced by srcPtr's internal rep. Increments the ref count of the
 *	ResolvedNsName structure used to hold the namespace reference.
 *
 *----------------------------------------------------------------------
 */

static void
DupNsNameInternalRep(
    Tcl_Obj *srcPtr,		/* Object with internal rep to copy. */
    register Tcl_Obj *copyPtr)	/* Object with internal rep to set. */
{
    ResolvedNsName *resNamePtr = srcPtr->internalRep.twoPtrValue.ptr1;

    copyPtr->internalRep.twoPtrValue.ptr1 = resNamePtr;
    resNamePtr->refCount++;
    copyPtr->typePtr = &nsNameType;
}

/*
 *----------------------------------------------------------------------
 *
 * SetNsNameFromAny --
 *
 *	Attempt to generate a nsName internal representation for a Tcl object.
 *
 * Results:
 *	Returns TCL_OK if the value could be converted to a proper namespace
 *	reference. Otherwise, it returns TCL_ERROR, along with an error
 *	message in the interpreter's result object.
 *
 * Side effects:
 *	If successful, the object is made a nsName object. Its internal rep is
 *	set to point to a ResolvedNsName, which contains a cached pointer to
 *	the Namespace. Reference counts are kept on both the ResolvedNsName
 *	and the Namespace, so we can keep track of their usage and free them
 *	when appropriate.
 *
 *----------------------------------------------------------------------
 */

static int
SetNsNameFromAny(
    Tcl_Interp *interp,		/* Points to the namespace in which to resolve
				 * name. Also used for error reporting if not
				 * NULL. */
    register Tcl_Obj *objPtr)	/* The object to convert. */
{
    const char *dummy;
    Namespace *nsPtr, *dummy1Ptr, *dummy2Ptr;
    register ResolvedNsName *resNamePtr;
    const char *name = TclGetString(objPtr);

    TclGetNamespaceForQualName(interp, name, NULL, TCL_FIND_ONLY_NS,
	     &nsPtr, &dummy1Ptr, &dummy2Ptr, &dummy);

    /*
     * If we found a namespace, then create a new ResolvedNsName structure
     * that holds a reference to it.
     */

    if ((nsPtr == NULL) || (nsPtr->flags & NS_DYING)) {
	/*
	 * Our failed lookup proves any previously cached nsName intrep is no
	 * longer valid. Get rid of it so we no longer waste memory storing
	 * it, nor time determining its invalidity again and again.
	 */

	if (objPtr->typePtr == &nsNameType) {
	    TclFreeIntRep(objPtr);
	    objPtr->typePtr = NULL;
	}
	return TCL_ERROR;
    }

    nsPtr->refCount++;
    resNamePtr = (ResolvedNsName *) ckalloc(sizeof(ResolvedNsName));
    resNamePtr->nsPtr = nsPtr;
    if ((name[0] == ':') && (name[1] == ':')) {
	resNamePtr->refNsPtr = NULL;
    } else {
	resNamePtr->refNsPtr = (Namespace *) Tcl_GetCurrentNamespace(interp);
    }
    resNamePtr->refCount = 1;
    TclFreeIntRep(objPtr);
    objPtr->internalRep.twoPtrValue.ptr1 = resNamePtr;
    objPtr->typePtr = &nsNameType;
    return TCL_OK;
}

/*
 *----------------------------------------------------------------------
 *
 * TclGetNamespaceCommandTable --
 *
 *	Returns the hash table of commands.
 *
 * Results:
 *	Pointer to the hash table.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

Tcl_HashTable *
TclGetNamespaceCommandTable(
    Tcl_Namespace *nsPtr)
{
    return &((Namespace *) nsPtr)->cmdTable;
}

/*
 *----------------------------------------------------------------------
 *
 * TclGetNamespaceChildTable --
 *
 *	Returns the hash table of child namespaces.
 *
 * Results:
 *	Pointer to the hash table.
 *
 * Side effects:
 *	Might allocate memory.
 *
 *----------------------------------------------------------------------
 */

Tcl_HashTable *
TclGetNamespaceChildTable(
    Tcl_Namespace *nsPtr)
{
    Namespace *nPtr = (Namespace *) nsPtr;
#ifndef BREAK_NAMESPACE_COMPAT
    return &nPtr->childTable;
#else
    if (nPtr->childTablePtr == NULL) {
	nPtr->childTablePtr = (Tcl_HashTable*) ckalloc(sizeof(Tcl_HashTable));
	Tcl_InitHashTable(nPtr->childTablePtr, TCL_STRING_KEYS);
    }
    return nPtr->childTablePtr;
#endif
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_LogCommandInfo --
 *
 *	This function is invoked after an error occurs in an interpreter. It
 *	adds information to iPtr->errorInfo field to describe the command that
 *	was being executed when the error occurred.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	Information about the command is added to errorInfo and the line
 *	number stored internally in the interpreter is set.
 *
 *----------------------------------------------------------------------
 */

void
Tcl_LogCommandInfo(
    Tcl_Interp *interp,		/* Interpreter in which to log information. */
    const char *script,		/* First character in script containing
				 * command (must be <= command). */
    const char *command,	/* First character in command that generated
				 * the error. */
    int length)			/* Number of bytes in command (-1 means use
				 * all bytes up to first null byte). */
{
    register const char *p;
    Interp *iPtr = (Interp *) interp;
    int overflow, limit = 150;
    Var *varPtr, *arrayPtr;

    if (iPtr->flags & ERR_ALREADY_LOGGED) {
	/*
	 * Someone else has already logged error information for this command;
	 * we shouldn't add anything more.
	 */

	return;
    }

    /*
     * Compute the line number where the error occurred.
     */

    iPtr->errorLine = 1;
    for (p = script; p != command; p++) {
	if (*p == '\n') {
	    iPtr->errorLine++;
	}
    }

    if (length < 0) {
	length = strlen(command);
    }
    overflow = (length > limit);
    Tcl_AppendObjToErrorInfo(interp, Tcl_ObjPrintf(
	    "\n    %s\n\"%.*s%s\"", ((iPtr->errorInfo == NULL)
	    ? "while executing" : "invoked from within"),
	    (overflow ? limit : length), command, (overflow ? "..." : "")));

    varPtr = TclObjLookupVarEx(interp, iPtr->eiVar, NULL, TCL_GLOBAL_ONLY,
	    NULL, 0, 0, &arrayPtr);
    if ((varPtr == NULL) || !TclIsVarTraced(varPtr)) {
	/*
	 * Should not happen.
	 */

	return;
    } else {
	Tcl_HashEntry *hPtr = Tcl_FindHashEntry(&iPtr->varTraces,
		(char *) varPtr);
	VarTrace *tracePtr = Tcl_GetHashValue(hPtr);

	if (tracePtr->traceProc != EstablishErrorInfoTraces) {
	    /*
	     * The most recent trace set on ::errorInfo is not the one the
	     * core itself puts on last. This means some other code is tracing
	     * the variable, and the additional trace(s) might be write traces
	     * that expect the timing of writes to ::errorInfo that existed
	     * Tcl releases before 8.5. To satisfy that compatibility need, we
	     * write the current -errorinfo value to the ::errorInfo variable.
	     */

	    Tcl_ObjSetVar2(interp, iPtr->eiVar, NULL, iPtr->errorInfo,
		    TCL_GLOBAL_ONLY);
	}
    }
}

/*
 * Local Variables:
 * mode: c
 * c-basic-offset: 4
 * fill-column: 78
 * End:
 */