aboutsummaryrefslogtreecommitdiff
path: root/gdb/completer.c
blob: f4b5917095d7c993af6bf246dcd02b33192b3513 (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
/* Line completion stuff for GDB, the GNU debugger.
   Copyright (C) 2000-2022 Free Software Foundation, Inc.

   This file is part of GDB.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */

#include "defs.h"
#include "symtab.h"
#include "gdbtypes.h"
#include "expression.h"
#include "filenames.h"		/* For DOSish file names.  */
#include "language.h"
#include "gdbsupport/gdb_signals.h"
#include "target.h"
#include "reggroups.h"
#include "user-regs.h"
#include "arch-utils.h"
#include "location.h"
#include <algorithm>
#include "linespec.h"
#include "cli/cli-decode.h"

/* FIXME: This is needed because of lookup_cmd_1 ().  We should be
   calling a hook instead so we eliminate the CLI dependency.  */
#include "gdbcmd.h"

/* Needed for rl_completer_word_break_characters and for
   rl_filename_completion_function.  */
#include "readline/readline.h"

/* readline defines this.  */
#undef savestring

#include "completer.h"

/* See completer.h.  */

class completion_tracker::completion_hash_entry
{
public:
  /* Constructor.  */
  completion_hash_entry (gdb::unique_xmalloc_ptr<char> name,
			 gdb::unique_xmalloc_ptr<char> lcd)
    : m_name (std::move (name)),
      m_lcd (std::move (lcd))
  {
    /* Nothing.  */
  }

  /* Returns a pointer to the lowest common denominator string.  This
     string will only be valid while this hash entry is still valid as the
     string continues to be owned by this hash entry and will be released
     when this entry is deleted.  */
  char *get_lcd () const
  {
    return m_lcd.get ();
  }

  /* Get, and release the name field from this hash entry.  This can only
     be called once, after which the name field is no longer valid.  This
     should be used to pass ownership of the name to someone else.  */
  char *release_name ()
  {
    return m_name.release ();
  }

  /* Return true of the name in this hash entry is STR.  */
  bool is_name_eq (const char *str) const
  {
    return strcmp (m_name.get (), str) == 0;
  }

  /* Return the hash value based on the name of the entry.  */
  hashval_t hash_name () const
  {
    return htab_hash_string (m_name.get ());
  }

private:

  /* The symbol name stored in this hash entry.  */
  gdb::unique_xmalloc_ptr<char> m_name;

  /* The lowest common denominator string computed for this hash entry.  */
  gdb::unique_xmalloc_ptr<char> m_lcd;
};

/* Misc state that needs to be tracked across several different
   readline completer entry point calls, all related to a single
   completion invocation.  */

struct gdb_completer_state
{
  /* The current completion's completion tracker.  This is a global
     because a tracker can be shared between the handle_brkchars and
     handle_completion phases, which involves different readline
     callbacks.  */
  completion_tracker *tracker = NULL;

  /* Whether the current completion was aborted.  */
  bool aborted = false;
};

/* The current completion state.  */
static gdb_completer_state current_completion;

/* An enumeration of the various things a user might attempt to
   complete for a location.  If you change this, remember to update
   the explicit_options array below too.  */

enum explicit_location_match_type
{
    /* The filename of a source file.  */
    MATCH_SOURCE,

    /* The name of a function or method.  */
    MATCH_FUNCTION,

    /* The fully-qualified name of a function or method.  */
    MATCH_QUALIFIED,

    /* A line number.  */
    MATCH_LINE,

    /* The name of a label.  */
    MATCH_LABEL
};

/* Prototypes for local functions.  */

/* readline uses the word breaks for two things:
   (1) In figuring out where to point the TEXT parameter to the
   rl_completion_entry_function.  Since we don't use TEXT for much,
   it doesn't matter a lot what the word breaks are for this purpose,
   but it does affect how much stuff M-? lists.
   (2) If one of the matches contains a word break character, readline
   will quote it.  That's why we switch between
   current_language->word_break_characters () and
   gdb_completer_command_word_break_characters.  I'm not sure when
   we need this behavior (perhaps for funky characters in C++ 
   symbols?).  */

/* Variables which are necessary for fancy command line editing.  */

/* When completing on command names, we remove '-' and '.' from the list of
   word break characters, since we use it in command names.  If the
   readline library sees one in any of the current completion strings,
   it thinks that the string needs to be quoted and automatically
   supplies a leading quote.  */
static const char gdb_completer_command_word_break_characters[] =
" \t\n!@#$%^&*()+=|~`}{[]\"';:?/><,";

/* When completing on file names, we remove from the list of word
   break characters any characters that are commonly used in file
   names, such as '-', '+', '~', etc.  Otherwise, readline displays
   incorrect completion candidates.  */
/* MS-DOS and MS-Windows use colon as part of the drive spec, and most
   programs support @foo style response files.  */
static const char gdb_completer_file_name_break_characters[] =
#ifdef HAVE_DOS_BASED_FILE_SYSTEM
  " \t\n*|\"';?><@";
#else
  " \t\n*|\"';:?><";
#endif

/* Characters that can be used to quote completion strings.  Note that
   we can't include '"' because the gdb C parser treats such quoted
   sequences as strings.  */
static const char gdb_completer_quote_characters[] = "'";

/* Accessor for some completer data that may interest other files.  */

const char *
get_gdb_completer_quote_characters (void)
{
  return gdb_completer_quote_characters;
}

/* This can be used for functions which don't want to complete on
   symbols but don't want to complete on anything else either.  */

void
noop_completer (struct cmd_list_element *ignore, 
		completion_tracker &tracker,
		const char *text, const char *prefix)
{
}

/* Complete on filenames.  */

void
filename_completer (struct cmd_list_element *ignore,
		    completion_tracker &tracker,
		    const char *text, const char *word)
{
  int subsequent_name;

  subsequent_name = 0;
  while (1)
    {
      gdb::unique_xmalloc_ptr<char> p_rl
	(rl_filename_completion_function (text, subsequent_name));
      if (p_rl == NULL)
	break;
      /* We need to set subsequent_name to a non-zero value before the
	 continue line below, because otherwise, if the first file
	 seen by GDB is a backup file whose name ends in a `~', we
	 will loop indefinitely.  */
      subsequent_name = 1;
      /* Like emacs, don't complete on old versions.  Especially
	 useful in the "source" command.  */
      const char *p = p_rl.get ();
      if (p[strlen (p) - 1] == '~')
	continue;

      tracker.add_completion
	(make_completion_match_str (std::move (p_rl), text, word));
    }
#if 0
  /* There is no way to do this just long enough to affect quote
     inserting without also affecting the next completion.  This
     should be fixed in readline.  FIXME.  */
  /* Ensure that readline does the right thing
     with respect to inserting quotes.  */
  rl_completer_word_break_characters = "";
#endif
}

/* The corresponding completer_handle_brkchars
   implementation.  */

static void
filename_completer_handle_brkchars (struct cmd_list_element *ignore,
				    completion_tracker &tracker,
				    const char *text, const char *word)
{
  set_rl_completer_word_break_characters
    (gdb_completer_file_name_break_characters);
}

/* Find the bounds of the current word for completion purposes, and
   return a pointer to the end of the word.  This mimics (and is a
   modified version of) readline's _rl_find_completion_word internal
   function.

   This function skips quoted substrings (characters between matched
   pairs of characters in rl_completer_quote_characters).  We try to
   find an unclosed quoted substring on which to do matching.  If one
   is not found, we use the word break characters to find the
   boundaries of the current word.  QC, if non-null, is set to the
   opening quote character if we found an unclosed quoted substring,
   '\0' otherwise.  DP, if non-null, is set to the value of the
   delimiter character that caused a word break.  */

struct gdb_rl_completion_word_info
{
  const char *word_break_characters;
  const char *quote_characters;
  const char *basic_quote_characters;
};

static const char *
gdb_rl_find_completion_word (struct gdb_rl_completion_word_info *info,
			     int *qc, int *dp,
			     const char *line_buffer)
{
  int scan, end, delimiter, pass_next, isbrk;
  char quote_char;
  const char *brkchars;
  int point = strlen (line_buffer);

  /* The algorithm below does '--point'.  Avoid buffer underflow with
     the empty string.  */
  if (point == 0)
    {
      if (qc != NULL)
	*qc = '\0';
      if (dp != NULL)
	*dp = '\0';
      return line_buffer;
    }

  end = point;
  delimiter = 0;
  quote_char = '\0';

  brkchars = info->word_break_characters;

  if (info->quote_characters != NULL)
    {
      /* We have a list of characters which can be used in pairs to
	 quote substrings for the completer.  Try to find the start of
	 an unclosed quoted substring.  */
      for (scan = pass_next = 0;
	   scan < end;
	   scan++)
	{
	  if (pass_next)
	    {
	      pass_next = 0;
	      continue;
	    }

	  /* Shell-like semantics for single quotes -- don't allow
	     backslash to quote anything in single quotes, especially
	     not the closing quote.  If you don't like this, take out
	     the check on the value of quote_char.  */
	  if (quote_char != '\'' && line_buffer[scan] == '\\')
	    {
	      pass_next = 1;
	      continue;
	    }

	  if (quote_char != '\0')
	    {
	      /* Ignore everything until the matching close quote
		 char.  */
	      if (line_buffer[scan] == quote_char)
		{
		  /* Found matching close.  Abandon this
		     substring.  */
		  quote_char = '\0';
		  point = end;
		}
	    }
	  else if (strchr (info->quote_characters, line_buffer[scan]))
	    {
	      /* Found start of a quoted substring.  */
	      quote_char = line_buffer[scan];
	      point = scan + 1;
	    }
	}
    }

  if (point == end && quote_char == '\0')
    {
      /* We didn't find an unclosed quoted substring upon which to do
	 completion, so use the word break characters to find the
	 substring on which to complete.  */
      while (--point)
	{
	  scan = line_buffer[point];

	  if (strchr (brkchars, scan) != 0)
	    break;
	}
    }

  /* If we are at an unquoted word break, then advance past it.  */
  scan = line_buffer[point];

  if (scan)
    {
      isbrk = strchr (brkchars, scan) != 0;

      if (isbrk)
	{
	  /* If the character that caused the word break was a quoting
	     character, then remember it as the delimiter.  */
	  if (info->basic_quote_characters
	      && strchr (info->basic_quote_characters, scan)
	      && (end - point) > 1)
	    delimiter = scan;

	  point++;
	}
    }

  if (qc != NULL)
    *qc = quote_char;
  if (dp != NULL)
    *dp = delimiter;

  return line_buffer + point;
}

/* Find the completion word point for TEXT, emulating the algorithm
   readline uses to find the word point, using WORD_BREAK_CHARACTERS
   as word break characters.  */

static const char *
advance_to_completion_word (completion_tracker &tracker,
			    const char *word_break_characters,
			    const char *text)
{
  gdb_rl_completion_word_info info;

  info.word_break_characters = word_break_characters;
  info.quote_characters = gdb_completer_quote_characters;
  info.basic_quote_characters = rl_basic_quote_characters;

  int delimiter;
  const char *start
    = gdb_rl_find_completion_word (&info, NULL, &delimiter, text);

  tracker.advance_custom_word_point_by (start - text);

  if (delimiter)
    {
      tracker.set_quote_char (delimiter);
      tracker.set_suppress_append_ws (true);
    }

  return start;
}

/* See completer.h.  */

const char *
advance_to_expression_complete_word_point (completion_tracker &tracker,
					   const char *text)
{
  const char *brk_chars = current_language->word_break_characters ();
  return advance_to_completion_word (tracker, brk_chars, text);
}

/* See completer.h.  */

const char *
advance_to_filename_complete_word_point (completion_tracker &tracker,
					 const char *text)
{
  const char *brk_chars = gdb_completer_file_name_break_characters;
  return advance_to_completion_word (tracker, brk_chars, text);
}

/* See completer.h.  */

bool
completion_tracker::completes_to_completion_word (const char *word)
{
  recompute_lowest_common_denominator ();
  if (m_lowest_common_denominator_unique)
    {
      const char *lcd = m_lowest_common_denominator;

      if (strncmp_iw (word, lcd, strlen (lcd)) == 0)
	{
	  /* Maybe skip the function and complete on keywords.  */
	  size_t wordlen = strlen (word);
	  if (word[wordlen - 1] == ' ')
	    return true;
	}
    }

  return false;
}

/* See completer.h.  */

void
complete_nested_command_line (completion_tracker &tracker, const char *text)
{
  /* Must be called from a custom-word-point completer.  */
  gdb_assert (tracker.use_custom_word_point ());

  /* Disable the custom word point temporarily, because we want to
     probe whether the command we're completing itself uses a custom
     word point.  */
  tracker.set_use_custom_word_point (false);
  size_t save_custom_word_point = tracker.custom_word_point ();

  int quote_char = '\0';
  const char *word = completion_find_completion_word (tracker, text,
						      &quote_char);

  if (tracker.use_custom_word_point ())
    {
      /* The command we're completing uses a custom word point, so the
	 tracker already contains the matches.  We're done.  */
      return;
    }

  /* Restore the custom word point settings.  */
  tracker.set_custom_word_point (save_custom_word_point);
  tracker.set_use_custom_word_point (true);

  /* Run the handle_completions completer phase.  */
  complete_line (tracker, word, text, strlen (text));
}

/* Complete on linespecs, which might be of two possible forms:

       file:line
   or
       symbol+offset

   This is intended to be used in commands that set breakpoints
   etc.  */

static void
complete_files_symbols (completion_tracker &tracker,
			const char *text, const char *word)
{
  completion_list fn_list;
  const char *p;
  int quote_found = 0;
  int quoted = *text == '\'' || *text == '"';
  int quote_char = '\0';
  const char *colon = NULL;
  char *file_to_match = NULL;
  const char *symbol_start = text;
  const char *orig_text = text;

  /* Do we have an unquoted colon, as in "break foo.c:bar"?  */
  for (p = text; *p != '\0'; ++p)
    {
      if (*p == '\\' && p[1] == '\'')
	p++;
      else if (*p == '\'' || *p == '"')
	{
	  quote_found = *p;
	  quote_char = *p++;
	  while (*p != '\0' && *p != quote_found)
	    {
	      if (*p == '\\' && p[1] == quote_found)
		p++;
	      p++;
	    }

	  if (*p == quote_found)
	    quote_found = 0;
	  else
	    break;		/* Hit the end of text.  */
	}
#if HAVE_DOS_BASED_FILE_SYSTEM
      /* If we have a DOS-style absolute file name at the beginning of
	 TEXT, and the colon after the drive letter is the only colon
	 we found, pretend the colon is not there.  */
      else if (p < text + 3 && *p == ':' && p == text + 1 + quoted)
	;
#endif
      else if (*p == ':' && !colon)
	{
	  colon = p;
	  symbol_start = p + 1;
	}
      else if (strchr (current_language->word_break_characters (), *p))
	symbol_start = p + 1;
    }

  if (quoted)
    text++;

  /* Where is the file name?  */
  if (colon)
    {
      char *s;

      file_to_match = (char *) xmalloc (colon - text + 1);
      strncpy (file_to_match, text, colon - text);
      file_to_match[colon - text] = '\0';
      /* Remove trailing colons and quotes from the file name.  */
      for (s = file_to_match + (colon - text);
	   s > file_to_match;
	   s--)
	if (*s == ':' || *s == quote_char)
	  *s = '\0';
    }
  /* If the text includes a colon, they want completion only on a
     symbol name after the colon.  Otherwise, we need to complete on
     symbols as well as on files.  */
  if (colon)
    {
      collect_file_symbol_completion_matches (tracker,
					      complete_symbol_mode::EXPRESSION,
					      symbol_name_match_type::EXPRESSION,
					      symbol_start, word,
					      file_to_match);
      xfree (file_to_match);
    }
  else
    {
      size_t text_len = strlen (text);

      collect_symbol_completion_matches (tracker,
					 complete_symbol_mode::EXPRESSION,
					 symbol_name_match_type::EXPRESSION,
					 symbol_start, word);
      /* If text includes characters which cannot appear in a file
	 name, they cannot be asking for completion on files.  */
      if (strcspn (text,
		   gdb_completer_file_name_break_characters) == text_len)
	fn_list = make_source_files_completion_list (text, text);
    }

  if (!fn_list.empty () && !tracker.have_completions ())
    {
      /* If we only have file names as possible completion, we should
	 bring them in sync with what rl_complete expects.  The
	 problem is that if the user types "break /foo/b TAB", and the
	 possible completions are "/foo/bar" and "/foo/baz"
	 rl_complete expects us to return "bar" and "baz", without the
	 leading directories, as possible completions, because `word'
	 starts at the "b".  But we ignore the value of `word' when we
	 call make_source_files_completion_list above (because that
	 would not DTRT when the completion results in both symbols
	 and file names), so make_source_files_completion_list returns
	 the full "/foo/bar" and "/foo/baz" strings.  This produces
	 wrong results when, e.g., there's only one possible
	 completion, because rl_complete will prepend "/foo/" to each
	 candidate completion.  The loop below removes that leading
	 part.  */
      for (const auto &fn_up: fn_list)
	{
	  char *fn = fn_up.get ();
	  memmove (fn, fn + (word - text), strlen (fn) + 1 - (word - text));
	}
    }

  tracker.add_completions (std::move (fn_list));

  if (!tracker.have_completions ())
    {
      /* No completions at all.  As the final resort, try completing
	 on the entire text as a symbol.  */
      collect_symbol_completion_matches (tracker,
					 complete_symbol_mode::EXPRESSION,
					 symbol_name_match_type::EXPRESSION,
					 orig_text, word);
    }
}

/* See completer.h.  */

completion_list
complete_source_filenames (const char *text)
{
  size_t text_len = strlen (text);

  /* If text includes characters which cannot appear in a file name,
     the user cannot be asking for completion on files.  */
  if (strcspn (text,
	       gdb_completer_file_name_break_characters)
      == text_len)
    return make_source_files_completion_list (text, text);

  return {};
}

/* Complete address and linespec locations.  */

static void
complete_address_and_linespec_locations (completion_tracker &tracker,
					 const char *text,
					 symbol_name_match_type match_type)
{
  if (*text == '*')
    {
      tracker.advance_custom_word_point_by (1);
      text++;
      const char *word
	= advance_to_expression_complete_word_point (tracker, text);
      complete_expression (tracker, text, word);
    }
  else
    {
      linespec_complete (tracker, text, match_type);
    }
}

/* The explicit location options.  Note that indexes into this array
   must match the explicit_location_match_type enumerators.  */

static const char *const explicit_options[] =
  {
    "-source",
    "-function",
    "-qualified",
    "-line",
    "-label",
    NULL
  };

/* The probe modifier options.  These can appear before a location in
   breakpoint commands.  */
static const char *const probe_options[] =
  {
    "-probe",
    "-probe-stap",
    "-probe-dtrace",
    NULL
  };

/* Returns STRING if not NULL, the empty string otherwise.  */

static const char *
string_or_empty (const char *string)
{
  return string != NULL ? string : "";
}

/* A helper function to collect explicit location matches for the given
   LOCATION, which is attempting to match on WORD.  */

static void
collect_explicit_location_matches (completion_tracker &tracker,
				   struct event_location *location,
				   enum explicit_location_match_type what,
				   const char *word,
				   const struct language_defn *language)
{
  const struct explicit_location *explicit_loc
    = get_explicit_location (location);

  /* True if the option expects an argument.  */
  bool needs_arg = true;

  /* Note, in the various MATCH_* below, we complete on
     explicit_loc->foo instead of WORD, because only the former will
     have already skipped past any quote char.  */
  switch (what)
    {
    case MATCH_SOURCE:
      {
	const char *source = string_or_empty (explicit_loc->source_filename);
	completion_list matches
	  = make_source_files_completion_list (source, source);
	tracker.add_completions (std::move (matches));
      }
      break;

    case MATCH_FUNCTION:
      {
	const char *function = string_or_empty (explicit_loc->function_name);
	linespec_complete_function (tracker, function,
				    explicit_loc->func_name_match_type,
				    explicit_loc->source_filename);
      }
      break;

    case MATCH_QUALIFIED:
      needs_arg = false;
      break;
    case MATCH_LINE:
      /* Nothing to offer.  */
      break;

    case MATCH_LABEL:
      {
	const char *label = string_or_empty (explicit_loc->label_name);
	linespec_complete_label (tracker, language,
				 explicit_loc->source_filename,
				 explicit_loc->function_name,
				 explicit_loc->func_name_match_type,
				 label);
      }
      break;

    default:
      gdb_assert_not_reached ("unhandled explicit_location_match_type");
    }

  if (!needs_arg || tracker.completes_to_completion_word (word))
    {
      tracker.discard_completions ();
      tracker.advance_custom_word_point_by (strlen (word));
      complete_on_enum (tracker, explicit_options, "", "");
      complete_on_enum (tracker, linespec_keywords, "", "");
    }
  else if (!tracker.have_completions ())
    {
      /* Maybe we have an unterminated linespec keyword at the tail of
	 the string.  Try completing on that.  */
      size_t wordlen = strlen (word);
      const char *keyword = word + wordlen;

      if (wordlen > 0 && keyword[-1] != ' ')
	{
	  while (keyword > word && *keyword != ' ')
	    keyword--;
	  /* Don't complete on keywords if we'd be completing on the
	     whole explicit linespec option.  E.g., "b -function
	     thr<tab>" should not complete to the "thread"
	     keyword.  */
	  if (keyword != word)
	    {
	      keyword = skip_spaces (keyword);

	      tracker.advance_custom_word_point_by (keyword - word);
	      complete_on_enum (tracker, linespec_keywords, keyword, keyword);
	    }
	}
      else if (wordlen > 0 && keyword[-1] == ' ')
	{
	  /* Assume that we're maybe past the explicit location
	     argument, and we didn't manage to find any match because
	     the user wants to create a pending breakpoint.  Offer the
	     keyword and explicit location options as possible
	     completions.  */
	  tracker.advance_custom_word_point_by (keyword - word);
	  complete_on_enum (tracker, linespec_keywords, keyword, keyword);
	  complete_on_enum (tracker, explicit_options, keyword, keyword);
	}
    }
}

/* If the next word in *TEXT_P is any of the keywords in KEYWORDS,
   then advance both TEXT_P and the word point in the tracker past the
   keyword and return the (0-based) index in the KEYWORDS array that
   matched.  Otherwise, return -1.  */

static int
skip_keyword (completion_tracker &tracker,
	      const char * const *keywords, const char **text_p)
{
  const char *text = *text_p;
  const char *after = skip_to_space (text);
  size_t len = after - text;

  if (text[len] != ' ')
    return -1;

  int found = -1;
  for (int i = 0; keywords[i] != NULL; i++)
    {
      if (strncmp (keywords[i], text, len) == 0)
	{
	  if (found == -1)
	    found = i;
	  else
	    return -1;
	}
    }

  if (found != -1)
    {
      tracker.advance_custom_word_point_by (len + 1);
      text += len + 1;
      *text_p = text;
      return found;
    }

  return -1;
}

/* A completer function for explicit locations.  This function
   completes both options ("-source", "-line", etc) and values.  If
   completing a quoted string, then QUOTED_ARG_START and
   QUOTED_ARG_END point to the quote characters.  LANGUAGE is the
   current language.  */

static void
complete_explicit_location (completion_tracker &tracker,
			    struct event_location *location,
			    const char *text,
			    const language_defn *language,
			    const char *quoted_arg_start,
			    const char *quoted_arg_end)
{
  if (*text != '-')
    return;

  int keyword = skip_keyword (tracker, explicit_options, &text);

  if (keyword == -1)
    {
      complete_on_enum (tracker, explicit_options, text, text);
      /* There are keywords that start with "-".   Include them, too.  */
      complete_on_enum (tracker, linespec_keywords, text, text);
    }
  else
    {
      /* Completing on value.  */
      enum explicit_location_match_type what
	= (explicit_location_match_type) keyword;

      if (quoted_arg_start != NULL && quoted_arg_end != NULL)
	{
	  if (quoted_arg_end[1] == '\0')
	    {
	      /* If completing a quoted string with the cursor right
		 at the terminating quote char, complete the
		 completion word without interpretation, so that
		 readline advances the cursor one whitespace past the
		 quote, even if there's no match.  This makes these
		 cases behave the same:

		   before: "b -function function()"
		   after:  "b -function function() "

		   before: "b -function 'function()'"
		   after:  "b -function 'function()' "

		 and trusts the user in this case:

		   before: "b -function 'not_loaded_function_yet()'"
		   after:  "b -function 'not_loaded_function_yet()' "
	      */
	      tracker.add_completion (make_unique_xstrdup (text));
	    }
	  else if (quoted_arg_end[1] == ' ')
	    {
	      /* We're maybe past the explicit location argument.
		 Skip the argument without interpretation, assuming the
		 user may want to create pending breakpoint.  Offer
		 the keyword and explicit location options as possible
		 completions.  */
	      tracker.advance_custom_word_point_by (strlen (text));
	      complete_on_enum (tracker, linespec_keywords, "", "");
	      complete_on_enum (tracker, explicit_options, "", "");
	    }
	  return;
	}

      /* Now gather matches  */
      collect_explicit_location_matches (tracker, location, what, text,
					 language);
    }
}

/* A completer for locations.  */

void
location_completer (struct cmd_list_element *ignore,
		    completion_tracker &tracker,
		    const char *text, const char * /* word */)
{
  int found_probe_option = -1;

  /* If we have a probe modifier, skip it.  This can only appear as
     first argument.  Until we have a specific completer for probes,
     falling back to the linespec completer for the remainder of the
     line is better than nothing.  */
  if (text[0] == '-' && text[1] == 'p')
    found_probe_option = skip_keyword (tracker, probe_options, &text);

  const char *option_text = text;
  int saved_word_point = tracker.custom_word_point ();

  const char *copy = text;

  explicit_completion_info completion_info;
  event_location_up location
    = string_to_explicit_location (&copy, current_language,
				   &completion_info);
  if (completion_info.quoted_arg_start != NULL
      && completion_info.quoted_arg_end == NULL)
    {
      /* Found an unbalanced quote.  */
      tracker.set_quote_char (*completion_info.quoted_arg_start);
      tracker.advance_custom_word_point_by (1);
    }

  if (completion_info.saw_explicit_location_option)
    {
      if (*copy != '\0')
	{
	  tracker.advance_custom_word_point_by (copy - text);
	  text = copy;

	  /* We found a terminator at the tail end of the string,
	     which means we're past the explicit location options.  We
	     may have a keyword to complete on.  If we have a whole
	     keyword, then complete whatever comes after as an
	     expression.  This is mainly for the "if" keyword.  If the
	     "thread" and "task" keywords gain their own completers,
	     they should be used here.  */
	  int keyword = skip_keyword (tracker, linespec_keywords, &text);

	  if (keyword == -1)
	    {
	      complete_on_enum (tracker, linespec_keywords, text, text);
	    }
	  else
	    {
	      const char *word
		= advance_to_expression_complete_word_point (tracker, text);
	      complete_expression (tracker, text, word);
	    }
	}
      else
	{
	  tracker.advance_custom_word_point_by (completion_info.last_option
						- text);
	  text = completion_info.last_option;

	  complete_explicit_location (tracker, location.get (), text,
				      current_language,
				      completion_info.quoted_arg_start,
				      completion_info.quoted_arg_end);

	}
    }
  /* This is an address or linespec location.  */
  else if (location != NULL)
    {
      /* Handle non-explicit location options.  */

      int keyword = skip_keyword (tracker, explicit_options, &text);
      if (keyword == -1)
	complete_on_enum (tracker, explicit_options, text, text);
      else
	{
	  tracker.advance_custom_word_point_by (copy - text);
	  text = copy;

	  symbol_name_match_type match_type
	    = get_explicit_location (location.get ())->func_name_match_type;
	  complete_address_and_linespec_locations (tracker, text, match_type);
	}
    }
  else
    {
      /* No options.  */
      complete_address_and_linespec_locations (tracker, text,
					       symbol_name_match_type::WILD);
    }

  /* Add matches for option names, if either:

     - Some completer above found some matches, but the word point did
       not advance (e.g., "b <tab>" finds all functions, or "b -<tab>"
       matches all objc selectors), or;

     - Some completer above advanced the word point, but found no
       matches.
  */
  if ((text[0] == '-' || text[0] == '\0')
      && (!tracker.have_completions ()
	  || tracker.custom_word_point () == saved_word_point))
    {
      tracker.set_custom_word_point (saved_word_point);
      text = option_text;

      if (found_probe_option == -1)
	complete_on_enum (tracker, probe_options, text, text);
      complete_on_enum (tracker, explicit_options, text, text);
    }
}

/* The corresponding completer_handle_brkchars
   implementation.  */

static void
location_completer_handle_brkchars (struct cmd_list_element *ignore,
				    completion_tracker &tracker,
				    const char *text,
				    const char *word_ignored)
{
  tracker.set_use_custom_word_point (true);

  location_completer (ignore, tracker, text, NULL);
}

/* See completer.h.  */

void
complete_expression (completion_tracker &tracker,
		     const char *text, const char *word)
{
  expression_up exp;
  std::unique_ptr<expr_completion_base> expr_completer;

  /* Perform a tentative parse of the expression, to see whether a
     field completion is required.  */
  try
    {
      exp = parse_expression_for_completion (text, &expr_completer);
    }
  catch (const gdb_exception_error &except)
    {
      return;
    }

  /* Part of the parse_expression_for_completion contract.  */
  gdb_assert ((exp == nullptr) == (expr_completer == nullptr));
  if (expr_completer != nullptr
      && expr_completer->complete (exp.get (), tracker))
    return;

  complete_files_symbols (tracker, text, word);
}

/* Complete on expressions.  Often this means completing on symbol
   names, but some language parsers also have support for completing
   field names.  */

void
expression_completer (struct cmd_list_element *ignore,
		      completion_tracker &tracker,
		      const char *text, const char *word)
{
  complete_expression (tracker, text, word);
}

/* See definition in completer.h.  */

void
set_rl_completer_word_break_characters (const char *break_chars)
{
  rl_completer_word_break_characters = (char *) break_chars;
}

/* Complete on symbols.  */

void
symbol_completer (struct cmd_list_element *ignore,
		  completion_tracker &tracker,
		  const char *text, const char *word)
{
  collect_symbol_completion_matches (tracker, complete_symbol_mode::EXPRESSION,
				     symbol_name_match_type::EXPRESSION,
				     text, word);
}

/* Here are some useful test cases for completion.  FIXME: These
   should be put in the test suite.  They should be tested with both
   M-? and TAB.

   "show output-" "radix"
   "show output" "-radix"
   "p" ambiguous (commands starting with p--path, print, printf, etc.)
   "p "  ambiguous (all symbols)
   "info t foo" no completions
   "info t " no completions
   "info t" ambiguous ("info target", "info terminal", etc.)
   "info ajksdlfk" no completions
   "info ajksdlfk " no completions
   "info" " "
   "info " ambiguous (all info commands)
   "p \"a" no completions (string constant)
   "p 'a" ambiguous (all symbols starting with a)
   "p b-a" ambiguous (all symbols starting with a)
   "p b-" ambiguous (all symbols)
   "file Make" "file" (word break hard to screw up here)
   "file ../gdb.stabs/we" "ird" (needs to not break word at slash)
 */

enum complete_line_internal_reason
{
  /* Preliminary phase, called by gdb_completion_word_break_characters
     function, is used to either:

     #1 - Determine the set of chars that are word delimiters
	  depending on the current command in line_buffer.

     #2 - Manually advance RL_POINT to the "word break" point instead
	  of letting readline do it (based on too-simple character
	  matching).

     Simpler completers that just pass a brkchars array to readline
     (#1 above) must defer generating the completions to the main
     phase (below).  No completion list should be generated in this
     phase.

     OTOH, completers that manually advance the word point(#2 above)
     must set "use_custom_word_point" in the tracker and generate
     their completion in this phase.  Note that this is the convenient
     thing to do since they'll be parsing the input line anyway.  */
  handle_brkchars,

  /* Main phase, called by complete_line function, is used to get the
     list of possible completions.  */
  handle_completions,

  /* Special case when completing a 'help' command.  In this case,
     once sub-command completions are exhausted, we simply return
     NULL.  */
  handle_help,
};

/* Helper for complete_line_internal to simplify it.  */

static void
complete_line_internal_normal_command (completion_tracker &tracker,
				       const char *command, const char *word,
				       const char *cmd_args,
				       complete_line_internal_reason reason,
				       struct cmd_list_element *c)
{
  const char *p = cmd_args;

  if (c->completer == filename_completer)
    {
      /* Many commands which want to complete on file names accept
	 several file names, as in "run foo bar >>baz".  So we don't
	 want to complete the entire text after the command, just the
	 last word.  To this end, we need to find the beginning of the
	 file name by starting at `word' and going backwards.  */
      for (p = word;
	   p > command
	     && strchr (gdb_completer_file_name_break_characters,
			p[-1]) == NULL;
	   p--)
	;
    }

  if (reason == handle_brkchars)
    {
      completer_handle_brkchars_ftype *brkchars_fn;

      if (c->completer_handle_brkchars != NULL)
	brkchars_fn = c->completer_handle_brkchars;
      else
	{
	  brkchars_fn
	    = (completer_handle_brkchars_func_for_completer
	       (c->completer));
	}

      brkchars_fn (c, tracker, p, word);
    }

  if (reason != handle_brkchars && c->completer != NULL)
    (*c->completer) (c, tracker, p, word);
}

/* Internal function used to handle completions.


   TEXT is the caller's idea of the "word" we are looking at.

   LINE_BUFFER is available to be looked at; it contains the entire
   text of the line.  POINT is the offset in that line of the cursor.
   You should pretend that the line ends at POINT.

   See complete_line_internal_reason for description of REASON.  */

static void
complete_line_internal_1 (completion_tracker &tracker,
			  const char *text,
			  const char *line_buffer, int point,
			  complete_line_internal_reason reason)
{
  char *tmp_command;
  const char *p;
  int ignore_help_classes;
  /* Pointer within tmp_command which corresponds to text.  */
  const char *word;
  struct cmd_list_element *c, *result_list;

  /* Choose the default set of word break characters to break
     completions.  If we later find out that we are doing completions
     on command strings (as opposed to strings supplied by the
     individual command completer functions, which can be any string)
     then we will switch to the special word break set for command
     strings, which leaves out the '-' and '.' character used in some
     commands.  */
  set_rl_completer_word_break_characters
    (current_language->word_break_characters ());

  /* Decide whether to complete on a list of gdb commands or on
     symbols.  */
  tmp_command = (char *) alloca (point + 1);
  p = tmp_command;

  /* The help command should complete help aliases.  */
  ignore_help_classes = reason != handle_help;

  strncpy (tmp_command, line_buffer, point);
  tmp_command[point] = '\0';
  if (reason == handle_brkchars)
    {
      gdb_assert (text == NULL);
      word = NULL;
    }
  else
    {
      /* Since text always contains some number of characters leading up
	 to point, we can find the equivalent position in tmp_command
	 by subtracting that many characters from the end of tmp_command.  */
      word = tmp_command + point - strlen (text);
    }

  /* Move P up to the start of the command.  */
  p = skip_spaces (p);

  if (*p == '\0')
    {
      /* An empty line is ambiguous; that is, it could be any
	 command.  */
      c = CMD_LIST_AMBIGUOUS;
      result_list = 0;
    }
  else
    c = lookup_cmd_1 (&p, cmdlist, &result_list, NULL, ignore_help_classes,
		      true);

  /* Move p up to the next interesting thing.  */
  while (*p == ' ' || *p == '\t')
    {
      p++;
    }

  tracker.advance_custom_word_point_by (p - tmp_command);

  if (!c)
    {
      /* It is an unrecognized command.  So there are no
	 possible completions.  */
    }
  else if (c == CMD_LIST_AMBIGUOUS)
    {
      const char *q;

      /* lookup_cmd_1 advances p up to the first ambiguous thing, but
	 doesn't advance over that thing itself.  Do so now.  */
      q = p;
      while (valid_cmd_char_p (*q))
	++q;
      if (q != tmp_command + point)
	{
	  /* There is something beyond the ambiguous
	     command, so there are no possible completions.  For
	     example, "info t " or "info t foo" does not complete
	     to anything, because "info t" can be "info target" or
	     "info terminal".  */
	}
      else
	{
	  /* We're trying to complete on the command which was ambiguous.
	     This we can deal with.  */
	  if (result_list)
	    {
	      if (reason != handle_brkchars)
		complete_on_cmdlist (*result_list->subcommands, tracker, p,
				     word, ignore_help_classes);
	    }
	  else
	    {
	      if (reason != handle_brkchars)
		complete_on_cmdlist (cmdlist, tracker, p, word,
				     ignore_help_classes);
	    }
	  /* Ensure that readline does the right thing with respect to
	     inserting quotes.  */
	  set_rl_completer_word_break_characters
	    (gdb_completer_command_word_break_characters);
	}
    }
  else
    {
      /* We've recognized a full command.  */

      if (p == tmp_command + point)
	{
	  /* There is no non-whitespace in the line beyond the
	     command.  */

	  if (p[-1] == ' ' || p[-1] == '\t')
	    {
	      /* The command is followed by whitespace; we need to
		 complete on whatever comes after command.  */
	      if (c->is_prefix ())
		{
		  /* It is a prefix command; what comes after it is
		     a subcommand (e.g. "info ").  */
		  if (reason != handle_brkchars)
		    complete_on_cmdlist (*c->subcommands, tracker, p, word,
					 ignore_help_classes);

		  /* Ensure that readline does the right thing
		     with respect to inserting quotes.  */
		  set_rl_completer_word_break_characters
		    (gdb_completer_command_word_break_characters);
		}
	      else if (reason == handle_help)
		;
	      else if (c->enums)
		{
		  if (reason != handle_brkchars)
		    complete_on_enum (tracker, c->enums, p, word);
		  set_rl_completer_word_break_characters
		    (gdb_completer_command_word_break_characters);
		}
	      else
		{
		  /* It is a normal command; what comes after it is
		     completed by the command's completer function.  */
		  complete_line_internal_normal_command (tracker,
							 tmp_command, word, p,
							 reason, c);
		}
	    }
	  else
	    {
	      /* The command is not followed by whitespace; we need to
		 complete on the command itself, e.g. "p" which is a
		 command itself but also can complete to "print", "ptype"
		 etc.  */
	      const char *q;

	      /* Find the command we are completing on.  */
	      q = p;
	      while (q > tmp_command)
		{
		  if (valid_cmd_char_p (q[-1]))
		    --q;
		  else
		    break;
		}

	      /* Move the custom word point back too.  */
	      tracker.advance_custom_word_point_by (q - p);

	      if (reason != handle_brkchars)
		complete_on_cmdlist (result_list, tracker, q, word,
				     ignore_help_classes);

	      /* Ensure that readline does the right thing
		 with respect to inserting quotes.  */
	      set_rl_completer_word_break_characters
		(gdb_completer_command_word_break_characters);
	    }
	}
      else if (reason == handle_help)
	;
      else
	{
	  /* There is non-whitespace beyond the command.  */

	  if (c->is_prefix () && !c->allow_unknown)
	    {
	      /* It is an unrecognized subcommand of a prefix command,
		 e.g. "info adsfkdj".  */
	    }
	  else if (c->enums)
	    {
	      if (reason != handle_brkchars)
		complete_on_enum (tracker, c->enums, p, word);
	    }
	  else
	    {
	      /* It is a normal command.  */
	      complete_line_internal_normal_command (tracker,
						     tmp_command, word, p,
						     reason, c);
	    }
	}
    }
}

/* Wrapper around complete_line_internal_1 to handle
   MAX_COMPLETIONS_REACHED_ERROR.  */

static void
complete_line_internal (completion_tracker &tracker,
			const char *text,
			const char *line_buffer, int point,
			complete_line_internal_reason reason)
{
  try
    {
      complete_line_internal_1 (tracker, text, line_buffer, point, reason);
    }
  catch (const gdb_exception_error &except)
    {
      if (except.error != MAX_COMPLETIONS_REACHED_ERROR)
	throw;
    }
}

/* See completer.h.  */

int max_completions = 200;

/* Initial size of the table.  It automagically grows from here.  */
#define INITIAL_COMPLETION_HTAB_SIZE 200

/* See completer.h.  */

completion_tracker::completion_tracker ()
{
  discard_completions ();
}

/* See completer.h.  */

void
completion_tracker::discard_completions ()
{
  xfree (m_lowest_common_denominator);
  m_lowest_common_denominator = NULL;

  m_lowest_common_denominator_unique = false;
  m_lowest_common_denominator_valid = false;

  m_entries_hash.reset (nullptr);

  /* A callback used by the hash table to compare new entries with existing
     entries.  We can't use the standard htab_eq_string function here as the
     key to our hash is just a single string, while the values we store in
     the hash are a struct containing multiple strings.  */
  static auto entry_eq_func
    = [] (const void *first, const void *second) -> int
      {
	/* The FIRST argument is the entry already in the hash table, and
	   the SECOND argument is the new item being inserted.  */
	const completion_hash_entry *entry
	  = (const completion_hash_entry *) first;
	const char *name_str = (const char *) second;

	return entry->is_name_eq (name_str);
      };

  /* Callback used by the hash table to compute the hash value for an
     existing entry.  This is needed when expanding the hash table.  */
  static auto entry_hash_func
    = [] (const void *arg) -> hashval_t
      {
	const completion_hash_entry *entry
	  = (const completion_hash_entry *) arg;
	return entry->hash_name ();
      };

  m_entries_hash.reset
    (htab_create_alloc (INITIAL_COMPLETION_HTAB_SIZE,
			entry_hash_func, entry_eq_func,
			htab_delete_entry<completion_hash_entry>,
			xcalloc, xfree));
}

/* See completer.h.  */

completion_tracker::~completion_tracker ()
{
  xfree (m_lowest_common_denominator);
}

/* See completer.h.  */

bool
completion_tracker::maybe_add_completion
  (gdb::unique_xmalloc_ptr<char> name,
   completion_match_for_lcd *match_for_lcd,
   const char *text, const char *word)
{
  void **slot;

  if (max_completions == 0)
    return false;

  if (htab_elements (m_entries_hash.get ()) >= max_completions)
    return false;

  hashval_t hash = htab_hash_string (name.get ());
  slot = htab_find_slot_with_hash (m_entries_hash.get (), name.get (),
				   hash, INSERT);
  if (*slot == HTAB_EMPTY_ENTRY)
    {
      const char *match_for_lcd_str = NULL;

      if (match_for_lcd != NULL)
	match_for_lcd_str = match_for_lcd->finish ();

      if (match_for_lcd_str == NULL)
	match_for_lcd_str = name.get ();

      gdb::unique_xmalloc_ptr<char> lcd
	= make_completion_match_str (match_for_lcd_str, text, word);

      size_t lcd_len = strlen (lcd.get ());
      *slot = new completion_hash_entry (std::move (name), std::move (lcd));

      m_lowest_common_denominator_valid = false;
      m_lowest_common_denominator_max_length
	= std::max (m_lowest_common_denominator_max_length, lcd_len);
    }

  return true;
}

/* See completer.h.  */

void
completion_tracker::add_completion (gdb::unique_xmalloc_ptr<char> name,
				    completion_match_for_lcd *match_for_lcd,
				    const char *text, const char *word)
{
  if (!maybe_add_completion (std::move (name), match_for_lcd, text, word))
    throw_error (MAX_COMPLETIONS_REACHED_ERROR, _("Max completions reached."));
}

/* See completer.h.  */

void
completion_tracker::add_completions (completion_list &&list)
{
  for (auto &candidate : list)
    add_completion (std::move (candidate));
}

/* See completer.h.  */

void
completion_tracker::remove_completion (const char *name)
{
  hashval_t hash = htab_hash_string (name);
  if (htab_find_slot_with_hash (m_entries_hash.get (), name, hash, NO_INSERT)
      != NULL)
    {
      htab_remove_elt_with_hash (m_entries_hash.get (), name, hash);
      m_lowest_common_denominator_valid = false;
    }
}

/* Helper for the make_completion_match_str overloads.  Returns NULL
   as an indication that we want MATCH_NAME exactly.  It is up to the
   caller to xstrdup that string if desired.  */

static char *
make_completion_match_str_1 (const char *match_name,
			     const char *text, const char *word)
{
  char *newobj;

  if (word == text)
    {
      /* Return NULL as an indication that we want MATCH_NAME
	 exactly.  */
      return NULL;
    }
  else if (word > text)
    {
      /* Return some portion of MATCH_NAME.  */
      newobj = xstrdup (match_name + (word - text));
    }
  else
    {
      /* Return some of WORD plus MATCH_NAME.  */
      size_t len = strlen (match_name);
      newobj = (char *) xmalloc (text - word + len + 1);
      memcpy (newobj, word, text - word);
      memcpy (newobj + (text - word), match_name, len + 1);
    }

  return newobj;
}

/* See completer.h.  */

gdb::unique_xmalloc_ptr<char>
make_completion_match_str (const char *match_name,
			   const char *text, const char *word)
{
  char *newobj = make_completion_match_str_1 (match_name, text, word);
  if (newobj == NULL)
    newobj = xstrdup (match_name);
  return gdb::unique_xmalloc_ptr<char> (newobj);
}

/* See completer.h.  */

gdb::unique_xmalloc_ptr<char>
make_completion_match_str (gdb::unique_xmalloc_ptr<char> &&match_name,
			   const char *text, const char *word)
{
  char *newobj = make_completion_match_str_1 (match_name.get (), text, word);
  if (newobj == NULL)
    return std::move (match_name);
  return gdb::unique_xmalloc_ptr<char> (newobj);
}

/* See complete.h.  */

completion_result
complete (const char *line, char const **word, int *quote_char)
{
  completion_tracker tracker_handle_brkchars;
  completion_tracker tracker_handle_completions;
  completion_tracker *tracker;

  /* The WORD should be set to the end of word to complete.  We initialize
     to the completion point which is assumed to be at the end of LINE.
     This leaves WORD to be initialized to a sensible value in cases
     completion_find_completion_word() fails i.e., throws an exception.
     See bug 24587. */
  *word = line + strlen (line);

  try
    {
      *word = completion_find_completion_word (tracker_handle_brkchars,
					      line, quote_char);

      /* Completers that provide a custom word point in the
	 handle_brkchars phase also compute their completions then.
	 Completers that leave the completion word handling to readline
	 must be called twice.  */
      if (tracker_handle_brkchars.use_custom_word_point ())
	tracker = &tracker_handle_brkchars;
      else
	{
	  complete_line (tracker_handle_completions, *word, line, strlen (line));
	  tracker = &tracker_handle_completions;
	}
    }
  catch (const gdb_exception &ex)
    {
      return {};
    }

  return tracker->build_completion_result (*word, *word - line, strlen (line));
}


/* Generate completions all at once.  Does nothing if max_completions
   is 0.  If max_completions is non-negative, this will collect at
   most max_completions strings.

   TEXT is the caller's idea of the "word" we are looking at.

   LINE_BUFFER is available to be looked at; it contains the entire
   text of the line.

   POINT is the offset in that line of the cursor.  You
   should pretend that the line ends at POINT.  */

void
complete_line (completion_tracker &tracker,
	       const char *text, const char *line_buffer, int point)
{
  if (max_completions == 0)
    return;
  complete_line_internal (tracker, text, line_buffer, point,
			  handle_completions);
}

/* Complete on command names.  Used by "help".  */

void
command_completer (struct cmd_list_element *ignore, 
		   completion_tracker &tracker,
		   const char *text, const char *word)
{
  complete_line_internal (tracker, word, text,
			  strlen (text), handle_help);
}

/* The corresponding completer_handle_brkchars implementation.  */

static void
command_completer_handle_brkchars (struct cmd_list_element *ignore,
				   completion_tracker &tracker,
				   const char *text, const char *word)
{
  set_rl_completer_word_break_characters
    (gdb_completer_command_word_break_characters);
}

/* Complete on signals.  */

void
signal_completer (struct cmd_list_element *ignore,
		  completion_tracker &tracker,
		  const char *text, const char *word)
{
  size_t len = strlen (word);
  int signum;
  const char *signame;

  for (signum = GDB_SIGNAL_FIRST; signum != GDB_SIGNAL_LAST; ++signum)
    {
      /* Can't handle this, so skip it.  */
      if (signum == GDB_SIGNAL_0)
	continue;

      signame = gdb_signal_to_name ((enum gdb_signal) signum);

      /* Ignore the unknown signal case.  */
      if (!signame || strcmp (signame, "?") == 0)
	continue;

      if (strncasecmp (signame, word, len) == 0)
	tracker.add_completion (make_unique_xstrdup (signame));
    }
}

/* Bit-flags for selecting what the register and/or register-group
   completer should complete on.  */

enum reg_completer_target
  {
    complete_register_names = 0x1,
    complete_reggroup_names = 0x2
  };
DEF_ENUM_FLAGS_TYPE (enum reg_completer_target, reg_completer_targets);

/* Complete register names and/or reggroup names based on the value passed
   in TARGETS.  At least one bit in TARGETS must be set.  */

static void
reg_or_group_completer_1 (completion_tracker &tracker,
			  const char *text, const char *word,
			  reg_completer_targets targets)
{
  size_t len = strlen (word);
  struct gdbarch *gdbarch;
  const char *name;

  gdb_assert ((targets & (complete_register_names
			  | complete_reggroup_names)) != 0);
  gdbarch = get_current_arch ();

  if ((targets & complete_register_names) != 0)
    {
      int i;

      for (i = 0;
	   (name = user_reg_map_regnum_to_name (gdbarch, i)) != NULL;
	   i++)
	{
	  if (*name != '\0' && strncmp (word, name, len) == 0)
	    tracker.add_completion (make_unique_xstrdup (name));
	}
    }

  if ((targets & complete_reggroup_names) != 0)
    {
      for (const struct reggroup *group : gdbarch_reggroups (gdbarch))
	{
	  name = reggroup_name (group);
	  if (strncmp (word, name, len) == 0)
	    tracker.add_completion (make_unique_xstrdup (name));
	}
    }
}

/* Perform completion on register and reggroup names.  */

void
reg_or_group_completer (struct cmd_list_element *ignore,
			completion_tracker &tracker,
			const char *text, const char *word)
{
  reg_or_group_completer_1 (tracker, text, word,
			    (complete_register_names
			     | complete_reggroup_names));
}

/* Perform completion on reggroup names.  */

void
reggroup_completer (struct cmd_list_element *ignore,
		    completion_tracker &tracker,
		    const char *text, const char *word)
{
  reg_or_group_completer_1 (tracker, text, word,
			    complete_reggroup_names);
}

/* The default completer_handle_brkchars implementation.  */

static void
default_completer_handle_brkchars (struct cmd_list_element *ignore,
				   completion_tracker &tracker,
				   const char *text, const char *word)
{
  set_rl_completer_word_break_characters
    (current_language->word_break_characters ());
}

/* See definition in completer.h.  */

completer_handle_brkchars_ftype *
completer_handle_brkchars_func_for_completer (completer_ftype *fn)
{
  if (fn == filename_completer)
    return filename_completer_handle_brkchars;

  if (fn == location_completer)
    return location_completer_handle_brkchars;

  if (fn == command_completer)
    return command_completer_handle_brkchars;

  return default_completer_handle_brkchars;
}

/* Used as brkchars when we want to tell readline we have a custom
   word point.  We do that by making our rl_completion_word_break_hook
   set RL_POINT to the desired word point, and return the character at
   the word break point as the break char.  This is two bytes in order
   to fit one break character plus the terminating null.  */
static char gdb_custom_word_point_brkchars[2];

/* Since rl_basic_quote_characters is not completer-specific, we save
   its original value here, in order to be able to restore it in
   gdb_rl_attempted_completion_function.  */
static const char *gdb_org_rl_basic_quote_characters = rl_basic_quote_characters;

/* Get the list of chars that are considered as word breaks
   for the current command.  */

static char *
gdb_completion_word_break_characters_throw ()
{
  /* New completion starting.  Get rid of the previous tracker and
     start afresh.  */
  delete current_completion.tracker;
  current_completion.tracker = new completion_tracker ();

  completion_tracker &tracker = *current_completion.tracker;

  complete_line_internal (tracker, NULL, rl_line_buffer,
			  rl_point, handle_brkchars);

  if (tracker.use_custom_word_point ())
    {
      gdb_assert (tracker.custom_word_point () > 0);
      rl_point = tracker.custom_word_point () - 1;

      gdb_assert (rl_point >= 0 && rl_point < strlen (rl_line_buffer));

      gdb_custom_word_point_brkchars[0] = rl_line_buffer[rl_point];
      rl_completer_word_break_characters = gdb_custom_word_point_brkchars;
      rl_completer_quote_characters = NULL;

      /* Clear this too, so that if we're completing a quoted string,
	 readline doesn't consider the quote character a delimiter.
	 If we didn't do this, readline would auto-complete {b
	 'fun<tab>} to {'b 'function()'}, i.e., add the terminating
	 \', but, it wouldn't append the separator space either, which
	 is not desirable.  So instead we take care of appending the
	 quote character to the LCD ourselves, in
	 gdb_rl_attempted_completion_function.  Since this global is
	 not just completer-specific, we'll restore it back to the
	 default in gdb_rl_attempted_completion_function.  */
      rl_basic_quote_characters = NULL;
    }

  return (char *) rl_completer_word_break_characters;
}

char *
gdb_completion_word_break_characters ()
{
  /* New completion starting.  */
  current_completion.aborted = false;

  try
    {
      return gdb_completion_word_break_characters_throw ();
    }
  catch (const gdb_exception &ex)
    {
      /* Set this to that gdb_rl_attempted_completion_function knows
	 to abort early.  */
      current_completion.aborted = true;
    }

  return NULL;
}

/* See completer.h.  */

const char *
completion_find_completion_word (completion_tracker &tracker, const char *text,
				 int *quote_char)
{
  size_t point = strlen (text);

  complete_line_internal (tracker, NULL, text, point, handle_brkchars);

  if (tracker.use_custom_word_point ())
    {
      gdb_assert (tracker.custom_word_point () > 0);
      *quote_char = tracker.quote_char ();
      return text + tracker.custom_word_point ();
    }

  gdb_rl_completion_word_info info;

  info.word_break_characters = rl_completer_word_break_characters;
  info.quote_characters = gdb_completer_quote_characters;
  info.basic_quote_characters = rl_basic_quote_characters;

  return gdb_rl_find_completion_word (&info, quote_char, NULL, text);
}

/* See completer.h.  */

void
completion_tracker::recompute_lcd_visitor (completion_hash_entry *entry)
{
  if (!m_lowest_common_denominator_valid)
    {
      /* This is the first lowest common denominator that we are
	 considering, just copy it in.  */
      strcpy (m_lowest_common_denominator, entry->get_lcd ());
      m_lowest_common_denominator_unique = true;
      m_lowest_common_denominator_valid = true;
    }
  else
    {
      /* Find the common denominator between the currently-known lowest
	 common denominator and NEW_MATCH_UP.  That becomes the new lowest
	 common denominator.  */
      size_t i;
      const char *new_match = entry->get_lcd ();

      for (i = 0;
	   (new_match[i] != '\0'
	    && new_match[i] == m_lowest_common_denominator[i]);
	   i++)
	;
      if (m_lowest_common_denominator[i] != new_match[i])
	{
	  m_lowest_common_denominator[i] = '\0';
	  m_lowest_common_denominator_unique = false;
	}
    }
}

/* See completer.h.  */

void
completion_tracker::recompute_lowest_common_denominator ()
{
  /* We've already done this.  */
  if (m_lowest_common_denominator_valid)
    return;

  /* Resize the storage to ensure we have enough space, the plus one gives
     us space for the trailing null terminator we will include.  */
  m_lowest_common_denominator
    = (char *) xrealloc (m_lowest_common_denominator,
			 m_lowest_common_denominator_max_length + 1);

  /* Callback used to visit each entry in the m_entries_hash.  */
  auto visitor_func
    = [] (void **slot, void *info) -> int
      {
	completion_tracker *obj = (completion_tracker *) info;
	completion_hash_entry *entry = (completion_hash_entry *) *slot;
	obj->recompute_lcd_visitor (entry);
	return 1;
      };

  htab_traverse (m_entries_hash.get (), visitor_func, this);
  m_lowest_common_denominator_valid = true;
}

/* See completer.h.  */

void
completion_tracker::advance_custom_word_point_by (int len)
{
  m_custom_word_point += len;
}

/* Build a new C string that is a copy of LCD with the whitespace of
   ORIG/ORIG_LEN preserved.

   Say the user is completing a symbol name, with spaces, like:

     "foo ( i"

   and the resulting completion match is:

     "foo(int)"

   we want to end up with an input line like:

     "foo ( int)"
      ^^^^^^^      => text from LCD [1], whitespace from ORIG preserved.
	     ^^	   => new text from LCD

   [1] - We must take characters from the LCD instead of the original
   text, since some completions want to change upper/lowercase.  E.g.:

     "handle sig<>"

   completes to:

     "handle SIG[QUIT|etc.]"
*/

static char *
expand_preserving_ws (const char *orig, size_t orig_len,
		      const char *lcd)
{
  const char *p_orig = orig;
  const char *orig_end = orig + orig_len;
  const char *p_lcd = lcd;
  std::string res;

  while (p_orig < orig_end)
    {
      if (*p_orig == ' ')
	{
	  while (p_orig < orig_end && *p_orig == ' ')
	    res += *p_orig++;
	  p_lcd = skip_spaces (p_lcd);
	}
      else
	{
	  /* Take characters from the LCD instead of the original
	     text, since some completions change upper/lowercase.
	     E.g.:
	       "handle sig<>"
	     completes to:
	       "handle SIG[QUIT|etc.]"
	  */
	  res += *p_lcd;
	  p_orig++;
	  p_lcd++;
	}
    }

  while (*p_lcd != '\0')
    res += *p_lcd++;

  return xstrdup (res.c_str ());
}

/* See completer.h.  */

completion_result
completion_tracker::build_completion_result (const char *text,
					     int start, int end)
{
  size_t element_count = htab_elements (m_entries_hash.get ());

  if (element_count == 0)
    return {};

  /* +1 for the LCD, and +1 for NULL termination.  */
  char **match_list = XNEWVEC (char *, 1 + element_count + 1);

  /* Build replacement word, based on the LCD.  */

  recompute_lowest_common_denominator ();
  match_list[0]
    = expand_preserving_ws (text, end - start,
			    m_lowest_common_denominator);

  if (m_lowest_common_denominator_unique)
    {
      /* We don't rely on readline appending the quote char as
	 delimiter as then readline wouldn't append the ' ' after the
	 completion.  */
      char buf[2] = { (char) quote_char () };

      match_list[0] = reconcat (match_list[0], match_list[0],
				buf, (char *) NULL);
      match_list[1] = NULL;

      /* If the tracker wants to, or we already have a space at the
	 end of the match, tell readline to skip appending
	 another.  */
      char *match = match_list[0];
      bool completion_suppress_append
	= (suppress_append_ws ()
	   || (match[0] != '\0'
	       && match[strlen (match) - 1] == ' '));

      return completion_result (match_list, 1, completion_suppress_append);
    }
  else
    {
      /* State object used while building the completion list.  */
      struct list_builder
      {
	list_builder (char **ml)
	  : match_list (ml),
	    index (1)
	{ /* Nothing.  */ }

	/* The list we are filling.  */
	char **match_list;

	/* The next index in the list to write to.  */
	int index;
      };
      list_builder builder (match_list);

      /* Visit each entry in m_entries_hash and add it to the completion
	 list, updating the builder state object.  */
      auto func
	= [] (void **slot, void *info) -> int
	  {
	    completion_hash_entry *entry = (completion_hash_entry *) *slot;
	    list_builder *state = (list_builder *) info;

	    state->match_list[state->index] = entry->release_name ();
	    state->index++;
	    return 1;
	  };

      /* Build the completion list and add a null at the end.  */
      htab_traverse_noresize (m_entries_hash.get (), func, &builder);
      match_list[builder.index] = NULL;

      return completion_result (match_list, builder.index - 1, false);
    }
}

/* See completer.h  */

completion_result::completion_result ()
  : match_list (NULL), number_matches (0),
    completion_suppress_append (false)
{}

/* See completer.h  */

completion_result::completion_result (char **match_list_,
				      size_t number_matches_,
				      bool completion_suppress_append_)
  : match_list (match_list_),
    number_matches (number_matches_),
    completion_suppress_append (completion_suppress_append_)
{}

/* See completer.h  */

completion_result::~completion_result ()
{
  reset_match_list ();
}

/* See completer.h  */

completion_result::completion_result (completion_result &&rhs) noexcept
  : match_list (rhs.match_list),
    number_matches (rhs.number_matches)
{
  rhs.match_list = NULL;
  rhs.number_matches = 0;
}

/* See completer.h  */

char **
completion_result::release_match_list ()
{
  char **ret = match_list;
  match_list = NULL;
  return ret;
}

/* See completer.h  */

void
completion_result::sort_match_list ()
{
  if (number_matches > 1)
    {
      /* Element 0 is special (it's the common prefix), leave it
	 be.  */
      std::sort (&match_list[1],
		 &match_list[number_matches + 1],
		 compare_cstrings);
    }
}

/* See completer.h  */

void
completion_result::reset_match_list ()
{
  if (match_list != NULL)
    {
      for (char **p = match_list; *p != NULL; p++)
	xfree (*p);
      xfree (match_list);
      match_list = NULL;
    }
}

/* Helper for gdb_rl_attempted_completion_function, which does most of
   the work.  This is called by readline to build the match list array
   and to determine the lowest common denominator.  The real matches
   list starts at match[1], while match[0] is the slot holding
   readline's idea of the lowest common denominator of all matches,
   which is what readline replaces the completion "word" with.

   TEXT is the caller's idea of the "word" we are looking at, as
   computed in the handle_brkchars phase.

   START is the offset from RL_LINE_BUFFER where TEXT starts.  END is
   the offset from RL_LINE_BUFFER where TEXT ends (i.e., where
   rl_point is).

   You should thus pretend that the line ends at END (relative to
   RL_LINE_BUFFER).

   RL_LINE_BUFFER contains the entire text of the line.  RL_POINT is
   the offset in that line of the cursor.  You should pretend that the
   line ends at POINT.

   Returns NULL if there are no completions.  */

static char **
gdb_rl_attempted_completion_function_throw (const char *text, int start, int end)
{
  /* Completers that provide a custom word point in the
     handle_brkchars phase also compute their completions then.
     Completers that leave the completion word handling to readline
     must be called twice.  If rl_point (i.e., END) is at column 0,
     then readline skips the handle_brkchars phase, and so we create a
     tracker now in that case too.  */
  if (end == 0 || !current_completion.tracker->use_custom_word_point ())
    {
      delete current_completion.tracker;
      current_completion.tracker = new completion_tracker ();

      complete_line (*current_completion.tracker, text,
		     rl_line_buffer, rl_point);
    }

  completion_tracker &tracker = *current_completion.tracker;

  completion_result result
    = tracker.build_completion_result (text, start, end);

  rl_completion_suppress_append = result.completion_suppress_append;
  return result.release_match_list ();
}

/* Function installed as "rl_attempted_completion_function" readline
   hook.  Wrapper around gdb_rl_attempted_completion_function_throw
   that catches C++ exceptions, which can't cross readline.  */

char **
gdb_rl_attempted_completion_function (const char *text, int start, int end)
{
  /* Restore globals that might have been tweaked in
     gdb_completion_word_break_characters.  */
  rl_basic_quote_characters = gdb_org_rl_basic_quote_characters;

  /* If we end up returning NULL, either on error, or simple because
     there are no matches, inhibit readline's default filename
     completer.  */
  rl_attempted_completion_over = 1;

  /* If the handle_brkchars phase was aborted, don't try
     completing.  */
  if (current_completion.aborted)
    return NULL;

  try
    {
      return gdb_rl_attempted_completion_function_throw (text, start, end);
    }
  catch (const gdb_exception &ex)
    {
    }

  return NULL;
}

/* Skip over the possibly quoted word STR (as defined by the quote
   characters QUOTECHARS and the word break characters BREAKCHARS).
   Returns pointer to the location after the "word".  If either
   QUOTECHARS or BREAKCHARS is NULL, use the same values used by the
   completer.  */

const char *
skip_quoted_chars (const char *str, const char *quotechars,
		   const char *breakchars)
{
  char quote_char = '\0';
  const char *scan;

  if (quotechars == NULL)
    quotechars = gdb_completer_quote_characters;

  if (breakchars == NULL)
    breakchars = current_language->word_break_characters ();

  for (scan = str; *scan != '\0'; scan++)
    {
      if (quote_char != '\0')
	{
	  /* Ignore everything until the matching close quote char.  */
	  if (*scan == quote_char)
	    {
	      /* Found matching close quote.  */
	      scan++;
	      break;
	    }
	}
      else if (strchr (quotechars, *scan))
	{
	  /* Found start of a quoted string.  */
	  quote_char = *scan;
	}
      else if (strchr (breakchars, *scan))
	{
	  break;
	}
    }

  return (scan);
}

/* Skip over the possibly quoted word STR (as defined by the quote
   characters and word break characters used by the completer).
   Returns pointer to the location after the "word".  */

const char *
skip_quoted (const char *str)
{
  return skip_quoted_chars (str, NULL, NULL);
}

/* Return a message indicating that the maximum number of completions
   has been reached and that there may be more.  */

const char *
get_max_completions_reached_message (void)
{
  return _("*** List may be truncated, max-completions reached. ***");
}

/* GDB replacement for rl_display_match_list.
   Readline doesn't provide a clean interface for TUI(curses).
   A hack previously used was to send readline's rl_outstream through a pipe
   and read it from the event loop.  Bleah.  IWBN if readline abstracted
   away all the necessary bits, and this is what this code does.  It
   replicates the parts of readline we need and then adds an abstraction
   layer, currently implemented as struct match_list_displayer, so that both
   CLI and TUI can use it.  We copy all this readline code to minimize
   GDB-specific mods to readline.  Once this code performs as desired then
   we can submit it to the readline maintainers.

   N.B. A lot of the code is the way it is in order to minimize differences
   from readline's copy.  */

/* Not supported here.  */
#undef VISIBLE_STATS

#if defined (HANDLE_MULTIBYTE)
#define MB_INVALIDCH(x) ((x) == (size_t)-1 || (x) == (size_t)-2)
#define MB_NULLWCH(x)   ((x) == 0)
#endif

#define ELLIPSIS_LEN	3

/* gdb version of readline/complete.c:get_y_or_n.
   'y' -> returns 1, and 'n' -> returns 0.
   Also supported: space == 'y', RUBOUT == 'n', ctrl-g == start over.
   If FOR_PAGER is non-zero, then also supported are:
   NEWLINE or RETURN -> returns 2, and 'q' -> returns 0.  */

static int
gdb_get_y_or_n (int for_pager, const struct match_list_displayer *displayer)
{
  int c;

  for (;;)
    {
      RL_SETSTATE (RL_STATE_MOREINPUT);
      c = displayer->read_key (displayer);
      RL_UNSETSTATE (RL_STATE_MOREINPUT);

      if (c == 'y' || c == 'Y' || c == ' ')
	return 1;
      if (c == 'n' || c == 'N' || c == RUBOUT)
	return 0;
      if (c == ABORT_CHAR || c < 0)
	{
	  /* Readline doesn't erase_entire_line here, but without it the
	     --More-- prompt isn't erased and neither is the text entered
	     thus far redisplayed.  */
	  displayer->erase_entire_line (displayer);
	  /* Note: The arguments to rl_abort are ignored.  */
	  rl_abort (0, 0);
	}
      if (for_pager && (c == NEWLINE || c == RETURN))
	return 2;
      if (for_pager && (c == 'q' || c == 'Q'))
	return 0;
      displayer->beep (displayer);
    }
}

/* Pager function for tab-completion.
   This is based on readline/complete.c:_rl_internal_pager.
   LINES is the number of lines of output displayed thus far.
   Returns:
   -1 -> user pressed 'n' or equivalent,
   0 -> user pressed 'y' or equivalent,
   N -> user pressed NEWLINE or equivalent and N is LINES - 1.  */

static int
gdb_display_match_list_pager (int lines,
			      const struct match_list_displayer *displayer)
{
  int i;

  displayer->puts (displayer, "--More--");
  displayer->flush (displayer);
  i = gdb_get_y_or_n (1, displayer);
  displayer->erase_entire_line (displayer);
  if (i == 0)
    return -1;
  else if (i == 2)
    return (lines - 1);
  else
    return 0;
}

/* Return non-zero if FILENAME is a directory.
   Based on readline/complete.c:path_isdir.  */

static int
gdb_path_isdir (const char *filename)
{
  struct stat finfo;

  return (stat (filename, &finfo) == 0 && S_ISDIR (finfo.st_mode));
}

/* Return the portion of PATHNAME that should be output when listing
   possible completions.  If we are hacking filename completion, we
   are only interested in the basename, the portion following the
   final slash.  Otherwise, we return what we were passed.  Since
   printing empty strings is not very informative, if we're doing
   filename completion, and the basename is the empty string, we look
   for the previous slash and return the portion following that.  If
   there's no previous slash, we just return what we were passed.

   Based on readline/complete.c:printable_part.  */

static char *
gdb_printable_part (char *pathname)
{
  char *temp, *x;

  if (rl_filename_completion_desired == 0)	/* don't need to do anything */
    return (pathname);

  temp = strrchr (pathname, '/');
#if defined (__MSDOS__)
  if (temp == 0 && ISALPHA ((unsigned char)pathname[0]) && pathname[1] == ':')
    temp = pathname + 1;
#endif

  if (temp == 0 || *temp == '\0')
    return (pathname);
  /* If the basename is NULL, we might have a pathname like '/usr/src/'.
     Look for a previous slash and, if one is found, return the portion
     following that slash.  If there's no previous slash, just return the
     pathname we were passed. */
  else if (temp[1] == '\0')
    {
      for (x = temp - 1; x > pathname; x--)
	if (*x == '/')
	  break;
      return ((*x == '/') ? x + 1 : pathname);
    }
  else
    return ++temp;
}

/* Compute width of STRING when displayed on screen by print_filename.
   Based on readline/complete.c:fnwidth.  */

static int
gdb_fnwidth (const char *string)
{
  int width, pos;
#if defined (HANDLE_MULTIBYTE)
  mbstate_t ps;
  int left, w;
  size_t clen;
  wchar_t wc;

  left = strlen (string) + 1;
  memset (&ps, 0, sizeof (mbstate_t));
#endif

  width = pos = 0;
  while (string[pos])
    {
      if (CTRL_CHAR (string[pos]) || string[pos] == RUBOUT)
	{
	  width += 2;
	  pos++;
	}
      else
	{
#if defined (HANDLE_MULTIBYTE)
	  clen = mbrtowc (&wc, string + pos, left - pos, &ps);
	  if (MB_INVALIDCH (clen))
	    {
	      width++;
	      pos++;
	      memset (&ps, 0, sizeof (mbstate_t));
	    }
	  else if (MB_NULLWCH (clen))
	    break;
	  else
	    {
	      pos += clen;
	      w = wcwidth (wc);
	      width += (w >= 0) ? w : 1;
	    }
#else
	  width++;
	  pos++;
#endif
	}
    }

  return width;
}

/* Print TO_PRINT, one matching completion.
   PREFIX_BYTES is number of common prefix bytes.
   Based on readline/complete.c:fnprint.  */

static int
gdb_fnprint (const char *to_print, int prefix_bytes,
	     const struct match_list_displayer *displayer)
{
  int printed_len, w;
  const char *s;
#if defined (HANDLE_MULTIBYTE)
  mbstate_t ps;
  const char *end;
  size_t tlen;
  int width;
  wchar_t wc;

  end = to_print + strlen (to_print) + 1;
  memset (&ps, 0, sizeof (mbstate_t));
#endif

  printed_len = 0;

  /* Don't print only the ellipsis if the common prefix is one of the
     possible completions */
  if (to_print[prefix_bytes] == '\0')
    prefix_bytes = 0;

  if (prefix_bytes)
    {
      char ellipsis;

      ellipsis = (to_print[prefix_bytes] == '.') ? '_' : '.';
      for (w = 0; w < ELLIPSIS_LEN; w++)
	displayer->putch (displayer, ellipsis);
      printed_len = ELLIPSIS_LEN;
    }

  s = to_print + prefix_bytes;
  while (*s)
    {
      if (CTRL_CHAR (*s))
	{
	  displayer->putch (displayer, '^');
	  displayer->putch (displayer, UNCTRL (*s));
	  printed_len += 2;
	  s++;
#if defined (HANDLE_MULTIBYTE)
	  memset (&ps, 0, sizeof (mbstate_t));
#endif
	}
      else if (*s == RUBOUT)
	{
	  displayer->putch (displayer, '^');
	  displayer->putch (displayer, '?');
	  printed_len += 2;
	  s++;
#if defined (HANDLE_MULTIBYTE)
	  memset (&ps, 0, sizeof (mbstate_t));
#endif
	}
      else
	{
#if defined (HANDLE_MULTIBYTE)
	  tlen = mbrtowc (&wc, s, end - s, &ps);
	  if (MB_INVALIDCH (tlen))
	    {
	      tlen = 1;
	      width = 1;
	      memset (&ps, 0, sizeof (mbstate_t));
	    }
	  else if (MB_NULLWCH (tlen))
	    break;
	  else
	    {
	      w = wcwidth (wc);
	      width = (w >= 0) ? w : 1;
	    }
	  for (w = 0; w < tlen; ++w)
	    displayer->putch (displayer, s[w]);
	  s += tlen;
	  printed_len += width;
#else
	  displayer->putch (displayer, *s);
	  s++;
	  printed_len++;
#endif
	}
    }

  return printed_len;
}

/* Output TO_PRINT to rl_outstream.  If VISIBLE_STATS is defined and we
   are using it, check for and output a single character for `special'
   filenames.  Return the number of characters we output.
   Based on readline/complete.c:print_filename.  */

static int
gdb_print_filename (char *to_print, char *full_pathname, int prefix_bytes,
		    const struct match_list_displayer *displayer)
{
  int printed_len, extension_char, slen, tlen;
  char *s, c, *new_full_pathname;
  const char *dn;
  extern int _rl_complete_mark_directories;

  extension_char = 0;
  printed_len = gdb_fnprint (to_print, prefix_bytes, displayer);

#if defined (VISIBLE_STATS)
 if (rl_filename_completion_desired && (rl_visible_stats || _rl_complete_mark_directories))
#else
 if (rl_filename_completion_desired && _rl_complete_mark_directories)
#endif
    {
      /* If to_print != full_pathname, to_print is the basename of the
	 path passed.  In this case, we try to expand the directory
	 name before checking for the stat character. */
      if (to_print != full_pathname)
	{
	  /* Terminate the directory name. */
	  c = to_print[-1];
	  to_print[-1] = '\0';

	  /* If setting the last slash in full_pathname to a NUL results in
	     full_pathname being the empty string, we are trying to complete
	     files in the root directory.  If we pass a null string to the
	     bash directory completion hook, for example, it will expand it
	     to the current directory.  We just want the `/'. */
	  if (full_pathname == 0 || *full_pathname == 0)
	    dn = "/";
	  else if (full_pathname[0] != '/')
	    dn = full_pathname;
	  else if (full_pathname[1] == 0)
	    dn = "//";		/* restore trailing slash to `//' */
	  else if (full_pathname[1] == '/' && full_pathname[2] == 0)
	    dn = "/";		/* don't turn /// into // */
	  else
	    dn = full_pathname;
	  s = tilde_expand (dn);
	  if (rl_directory_completion_hook)
	    (*rl_directory_completion_hook) (&s);

	  slen = strlen (s);
	  tlen = strlen (to_print);
	  new_full_pathname = (char *)xmalloc (slen + tlen + 2);
	  strcpy (new_full_pathname, s);
	  if (s[slen - 1] == '/')
	    slen--;
	  else
	    new_full_pathname[slen] = '/';
	  new_full_pathname[slen] = '/';
	  strcpy (new_full_pathname + slen + 1, to_print);

#if defined (VISIBLE_STATS)
	  if (rl_visible_stats)
	    extension_char = stat_char (new_full_pathname);
	  else
#endif
	  if (gdb_path_isdir (new_full_pathname))
	    extension_char = '/';

	  xfree (new_full_pathname);
	  to_print[-1] = c;
	}
      else
	{
	  s = tilde_expand (full_pathname);
#if defined (VISIBLE_STATS)
	  if (rl_visible_stats)
	    extension_char = stat_char (s);
	  else
#endif
	    if (gdb_path_isdir (s))
	      extension_char = '/';
	}

      xfree (s);
      if (extension_char)
	{
	  displayer->putch (displayer, extension_char);
	  printed_len++;
	}
    }

  return printed_len;
}

/* GDB version of readline/complete.c:complete_get_screenwidth.  */

static int
gdb_complete_get_screenwidth (const struct match_list_displayer *displayer)
{
  /* Readline has other stuff here which it's not clear we need.  */
  return displayer->width;
}

extern int _rl_completion_prefix_display_length;
extern int _rl_print_completions_horizontally;

EXTERN_C int _rl_qsort_string_compare (const void *, const void *);
typedef int QSFUNC (const void *, const void *);

/* GDB version of readline/complete.c:rl_display_match_list.
   See gdb_display_match_list for a description of MATCHES, LEN, MAX.
   Returns non-zero if all matches are displayed.  */

static int
gdb_display_match_list_1 (char **matches, int len, int max,
			  const struct match_list_displayer *displayer)
{
  int count, limit, printed_len, lines, cols;
  int i, j, k, l, common_length, sind;
  char *temp, *t;
  int page_completions = displayer->height != INT_MAX && pagination_enabled;

  /* Find the length of the prefix common to all items: length as displayed
     characters (common_length) and as a byte index into the matches (sind) */
  common_length = sind = 0;
  if (_rl_completion_prefix_display_length > 0)
    {
      t = gdb_printable_part (matches[0]);
      temp = strrchr (t, '/');
      common_length = temp ? gdb_fnwidth (temp) : gdb_fnwidth (t);
      sind = temp ? strlen (temp) : strlen (t);

      if (common_length > _rl_completion_prefix_display_length && common_length > ELLIPSIS_LEN)
	max -= common_length - ELLIPSIS_LEN;
      else
	common_length = sind = 0;
    }

  /* How many items of MAX length can we fit in the screen window? */
  cols = gdb_complete_get_screenwidth (displayer);
  max += 2;
  limit = cols / max;
  if (limit != 1 && (limit * max == cols))
    limit--;

  /* If cols == 0, limit will end up -1 */
  if (cols < displayer->width && limit < 0)
    limit = 1;

  /* Avoid a possible floating exception.  If max > cols,
     limit will be 0 and a divide-by-zero fault will result. */
  if (limit == 0)
    limit = 1;

  /* How many iterations of the printing loop? */
  count = (len + (limit - 1)) / limit;

  /* Watch out for special case.  If LEN is less than LIMIT, then
     just do the inner printing loop.
	   0 < len <= limit  implies  count = 1. */

  /* Sort the items if they are not already sorted. */
  if (rl_ignore_completion_duplicates == 0 && rl_sort_completion_matches)
    qsort (matches + 1, len, sizeof (char *), (QSFUNC *)_rl_qsort_string_compare);

  displayer->crlf (displayer);

  lines = 0;
  if (_rl_print_completions_horizontally == 0)
    {
      /* Print the sorted items, up-and-down alphabetically, like ls. */
      for (i = 1; i <= count; i++)
	{
	  for (j = 0, l = i; j < limit; j++)
	    {
	      if (l > len || matches[l] == 0)
		break;
	      else
		{
		  temp = gdb_printable_part (matches[l]);
		  printed_len = gdb_print_filename (temp, matches[l], sind,
						    displayer);

		  if (j + 1 < limit)
		    for (k = 0; k < max - printed_len; k++)
		      displayer->putch (displayer, ' ');
		}
	      l += count;
	    }
	  displayer->crlf (displayer);
	  lines++;
	  if (page_completions && lines >= (displayer->height - 1) && i < count)
	    {
	      lines = gdb_display_match_list_pager (lines, displayer);
	      if (lines < 0)
		return 0;
	    }
	}
    }
  else
    {
      /* Print the sorted items, across alphabetically, like ls -x. */
      for (i = 1; matches[i]; i++)
	{
	  temp = gdb_printable_part (matches[i]);
	  printed_len = gdb_print_filename (temp, matches[i], sind, displayer);
	  /* Have we reached the end of this line? */
	  if (matches[i+1])
	    {
	      if (i && (limit > 1) && (i % limit) == 0)
		{
		  displayer->crlf (displayer);
		  lines++;
		  if (page_completions && lines >= displayer->height - 1)
		    {
		      lines = gdb_display_match_list_pager (lines, displayer);
		      if (lines < 0)
			return 0;
		    }
		}
	      else
		for (k = 0; k < max - printed_len; k++)
		  displayer->putch (displayer, ' ');
	    }
	}
      displayer->crlf (displayer);
    }

  return 1;
}

/* Utility for displaying completion list matches, used by both CLI and TUI.

   MATCHES is the list of strings, in argv format, LEN is the number of
   strings in MATCHES, and MAX is the length of the longest string in
   MATCHES.  */

void
gdb_display_match_list (char **matches, int len, int max,
			const struct match_list_displayer *displayer)
{
  /* Readline will never call this if complete_line returned NULL.  */
  gdb_assert (max_completions != 0);

  /* complete_line will never return more than this.  */
  if (max_completions > 0)
    gdb_assert (len <= max_completions);

  if (rl_completion_query_items > 0 && len >= rl_completion_query_items)
    {
      char msg[100];

      /* We can't use *query here because they wait for <RET> which is
	 wrong here.  This follows the readline version as closely as possible
	 for compatibility's sake.  See readline/complete.c.  */

      displayer->crlf (displayer);

      xsnprintf (msg, sizeof (msg),
		 "Display all %d possibilities? (y or n)", len);
      displayer->puts (displayer, msg);
      displayer->flush (displayer);

      if (gdb_get_y_or_n (0, displayer) == 0)
	{
	  displayer->crlf (displayer);
	  return;
	}
    }

  if (gdb_display_match_list_1 (matches, len, max, displayer))
    {
      /* Note: MAX_COMPLETIONS may be -1 or zero, but LEN is always > 0.  */
      if (len == max_completions)
	{
	  /* The maximum number of completions has been reached.  Warn the user
	     that there may be more.  */
	  const char *message = get_max_completions_reached_message ();

	  displayer->puts (displayer, message);
	  displayer->crlf (displayer);
	}
    }
}

void _initialize_completer ();
void
_initialize_completer ()
{
  add_setshow_zuinteger_unlimited_cmd ("max-completions", no_class,
				       &max_completions, _("\
Set maximum number of completion candidates."), _("\
Show maximum number of completion candidates."), _("\
Use this to limit the number of candidates considered\n\
during completion.  Specifying \"unlimited\" or -1\n\
disables limiting.  Note that setting either no limit or\n\
a very large limit can make completion slow."),
				       NULL, NULL, &setlist, &showlist);
}