summaryrefslogtreecommitdiff
path: root/gcc/except.c
blob: b25207b4c87e5f64150c156d7e0c36ac3273d47d (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
2164
2165
2166
2167
2168
2169
2170
2171
2172
2173
2174
2175
2176
2177
2178
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188
2189
2190
2191
2192
2193
2194
2195
2196
2197
2198
2199
2200
2201
2202
2203
2204
2205
2206
2207
2208
2209
2210
2211
2212
2213
2214
2215
2216
2217
2218
2219
2220
2221
2222
2223
2224
2225
2226
2227
2228
2229
2230
2231
2232
2233
2234
2235
2236
2237
2238
2239
2240
2241
2242
2243
2244
2245
2246
2247
2248
2249
2250
2251
2252
2253
2254
2255
2256
2257
2258
2259
2260
2261
2262
2263
2264
2265
2266
2267
2268
2269
2270
2271
2272
2273
2274
2275
2276
2277
2278
2279
2280
2281
2282
2283
2284
2285
2286
2287
2288
2289
2290
2291
2292
2293
2294
2295
2296
2297
2298
2299
2300
2301
2302
2303
2304
2305
2306
2307
2308
2309
2310
2311
2312
2313
2314
2315
2316
2317
2318
2319
2320
2321
2322
2323
2324
2325
2326
2327
2328
2329
2330
2331
2332
2333
2334
2335
2336
2337
2338
2339
2340
2341
2342
2343
2344
2345
2346
2347
2348
2349
2350
2351
2352
2353
2354
2355
2356
2357
2358
2359
2360
2361
2362
2363
2364
2365
2366
2367
2368
2369
2370
2371
2372
2373
2374
2375
2376
2377
2378
2379
2380
2381
2382
2383
2384
2385
2386
2387
2388
2389
2390
2391
2392
2393
2394
2395
2396
2397
2398
2399
2400
2401
2402
2403
2404
2405
2406
2407
2408
2409
2410
2411
2412
2413
2414
2415
2416
2417
2418
2419
2420
2421
2422
2423
2424
2425
2426
2427
2428
2429
2430
2431
2432
2433
2434
2435
2436
2437
2438
2439
2440
2441
2442
2443
2444
2445
2446
2447
2448
2449
2450
2451
2452
2453
2454
2455
2456
2457
2458
2459
2460
2461
2462
2463
2464
2465
2466
2467
2468
2469
2470
2471
2472
2473
2474
2475
2476
2477
2478
2479
2480
2481
2482
2483
2484
2485
2486
2487
2488
2489
2490
2491
2492
2493
2494
2495
2496
2497
2498
2499
2500
2501
2502
2503
2504
2505
2506
2507
2508
2509
2510
2511
2512
2513
2514
2515
2516
2517
2518
2519
2520
2521
2522
2523
2524
2525
2526
2527
2528
2529
2530
2531
2532
2533
2534
2535
2536
2537
2538
2539
2540
2541
2542
2543
2544
2545
2546
2547
2548
2549
2550
2551
2552
2553
2554
2555
2556
2557
2558
2559
2560
2561
2562
2563
2564
2565
2566
2567
2568
2569
2570
2571
2572
2573
2574
2575
2576
2577
2578
2579
2580
2581
2582
2583
2584
2585
2586
2587
2588
2589
2590
2591
2592
2593
2594
2595
2596
2597
2598
2599
2600
2601
2602
2603
2604
2605
2606
2607
2608
2609
2610
2611
2612
2613
2614
2615
2616
2617
2618
2619
2620
2621
2622
2623
2624
2625
2626
2627
2628
2629
2630
2631
2632
2633
2634
2635
2636
2637
2638
2639
2640
2641
2642
2643
2644
2645
2646
2647
2648
2649
2650
2651
2652
2653
2654
2655
2656
2657
2658
2659
2660
2661
2662
2663
2664
2665
2666
2667
2668
2669
2670
2671
2672
2673
2674
2675
2676
2677
2678
2679
2680
2681
2682
2683
2684
2685
2686
2687
2688
2689
2690
2691
2692
2693
2694
2695
2696
2697
2698
2699
2700
2701
2702
2703
2704
2705
2706
2707
2708
2709
2710
2711
2712
2713
2714
2715
2716
2717
2718
2719
2720
2721
2722
2723
2724
2725
2726
2727
2728
2729
2730
2731
2732
2733
2734
2735
2736
2737
2738
2739
2740
2741
2742
2743
2744
2745
2746
2747
2748
2749
2750
2751
2752
2753
2754
2755
2756
2757
2758
2759
2760
2761
2762
2763
2764
2765
2766
2767
2768
2769
2770
2771
2772
2773
2774
2775
2776
2777
2778
2779
2780
2781
2782
2783
2784
2785
2786
2787
2788
2789
2790
2791
2792
2793
2794
2795
2796
2797
2798
2799
2800
2801
2802
2803
2804
2805
2806
2807
2808
2809
2810
2811
2812
2813
2814
2815
2816
2817
2818
2819
2820
2821
2822
2823
2824
2825
2826
2827
2828
2829
2830
2831
2832
2833
2834
2835
2836
2837
2838
2839
2840
2841
2842
2843
2844
2845
2846
2847
2848
2849
2850
2851
2852
2853
2854
2855
2856
2857
2858
2859
2860
2861
2862
2863
2864
2865
2866
2867
2868
2869
2870
2871
2872
2873
2874
2875
2876
2877
2878
2879
2880
2881
2882
2883
2884
2885
2886
2887
2888
2889
2890
2891
2892
2893
2894
2895
2896
2897
2898
2899
2900
2901
2902
2903
2904
2905
2906
2907
2908
2909
2910
2911
2912
2913
2914
2915
2916
2917
2918
2919
2920
2921
2922
2923
2924
2925
2926
2927
2928
2929
2930
2931
2932
2933
2934
2935
2936
2937
2938
2939
2940
2941
2942
2943
2944
2945
2946
2947
2948
2949
2950
2951
2952
2953
2954
2955
2956
2957
2958
2959
2960
2961
2962
2963
2964
2965
2966
2967
2968
2969
2970
2971
2972
2973
2974
2975
2976
2977
2978
2979
2980
2981
2982
2983
2984
2985
2986
2987
2988
2989
2990
2991
2992
2993
2994
2995
2996
2997
2998
2999
3000
3001
3002
3003
3004
3005
3006
3007
3008
3009
3010
3011
3012
3013
3014
3015
3016
3017
3018
3019
3020
3021
3022
3023
3024
3025
3026
3027
3028
3029
3030
3031
3032
3033
3034
3035
3036
3037
3038
3039
3040
3041
3042
3043
3044
3045
3046
3047
3048
3049
3050
3051
3052
3053
3054
3055
3056
3057
3058
3059
3060
3061
3062
3063
3064
3065
3066
3067
3068
3069
3070
3071
3072
3073
3074
3075
3076
3077
3078
3079
3080
3081
3082
3083
3084
3085
3086
3087
3088
3089
3090
3091
3092
3093
3094
3095
3096
3097
3098
3099
3100
3101
3102
3103
3104
3105
3106
3107
3108
3109
3110
3111
3112
3113
3114
3115
3116
3117
3118
3119
3120
3121
3122
3123
3124
3125
3126
3127
3128
3129
3130
3131
3132
3133
3134
3135
3136
3137
3138
3139
3140
3141
3142
3143
3144
3145
3146
3147
3148
3149
3150
3151
3152
3153
3154
3155
3156
3157
3158
3159
3160
3161
3162
3163
3164
3165
3166
3167
3168
3169
3170
3171
3172
3173
3174
3175
3176
3177
3178
3179
3180
3181
3182
3183
3184
3185
3186
3187
3188
3189
3190
3191
3192
3193
3194
3195
3196
3197
3198
3199
3200
3201
3202
3203
3204
3205
3206
3207
3208
3209
3210
3211
3212
3213
3214
3215
3216
3217
3218
3219
3220
3221
3222
3223
3224
3225
3226
3227
3228
3229
3230
3231
3232
3233
3234
3235
3236
3237
3238
3239
3240
3241
3242
3243
3244
3245
3246
3247
3248
3249
3250
3251
3252
3253
3254
3255
3256
3257
3258
3259
3260
3261
3262
3263
3264
3265
3266
3267
3268
3269
3270
3271
3272
3273
3274
3275
3276
3277
3278
3279
3280
3281
3282
3283
3284
3285
3286
3287
3288
3289
3290
3291
3292
3293
3294
3295
3296
3297
3298
3299
3300
3301
3302
3303
3304
3305
3306
3307
3308
3309
3310
3311
3312
3313
3314
3315
3316
3317
3318
3319
3320
3321
3322
3323
3324
3325
3326
3327
3328
3329
3330
3331
3332
3333
3334
3335
3336
3337
3338
3339
3340
3341
3342
3343
3344
3345
3346
3347
3348
3349
3350
3351
3352
3353
3354
3355
3356
3357
3358
3359
3360
3361
3362
3363
3364
3365
3366
3367
3368
3369
3370
3371
3372
3373
3374
3375
3376
3377
3378
3379
3380
3381
3382
3383
3384
3385
3386
3387
/* Implements exception handling.
   Copyright (C) 1989-2013 Free Software Foundation, Inc.
   Contributed by Mike Stump <mrs@cygnus.com>.

This file is part of GCC.

GCC 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, or (at your option) any later
version.

GCC 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 GCC; see the file COPYING3.  If not see
<http://www.gnu.org/licenses/>.  */


/* An exception is an event that can be "thrown" from within a
   function.  This event can then be "caught" by the callers of
   the function.

   The representation of exceptions changes several times during
   the compilation process:

   In the beginning, in the front end, we have the GENERIC trees
   TRY_CATCH_EXPR, TRY_FINALLY_EXPR, WITH_CLEANUP_EXPR,
   CLEANUP_POINT_EXPR, CATCH_EXPR, and EH_FILTER_EXPR.

   During initial gimplification (gimplify.c) these are lowered
   to the GIMPLE_TRY, GIMPLE_CATCH, and GIMPLE_EH_FILTER nodes.
   The WITH_CLEANUP_EXPR and CLEANUP_POINT_EXPR nodes are converted
   into GIMPLE_TRY_FINALLY nodes; the others are a more direct 1-1
   conversion.

   During pass_lower_eh (tree-eh.c) we record the nested structure
   of the TRY nodes in EH_REGION nodes in CFUN->EH->REGION_TREE.
   We expand the eh_protect_cleanup_actions langhook into MUST_NOT_THROW
   regions at this time.  We can then flatten the statements within
   the TRY nodes to straight-line code.  Statements that had been within
   TRY nodes that can throw are recorded within CFUN->EH->THROW_STMT_TABLE,
   so that we may remember what action is supposed to be taken if
   a given statement does throw.  During this lowering process,
   we create an EH_LANDING_PAD node for each EH_REGION that has
   some code within the function that needs to be executed if a
   throw does happen.  We also create RESX statements that are
   used to transfer control from an inner EH_REGION to an outer
   EH_REGION.  We also create EH_DISPATCH statements as placeholders
   for a runtime type comparison that should be made in order to
   select the action to perform among different CATCH and EH_FILTER
   regions.

   During pass_lower_eh_dispatch (tree-eh.c), which is run after
   all inlining is complete, we are able to run assign_filter_values,
   which allows us to map the set of types manipulated by all of the
   CATCH and EH_FILTER regions to a set of integers.  This set of integers
   will be how the exception runtime communicates with the code generated
   within the function.  We then expand the GIMPLE_EH_DISPATCH statements
   to a switch or conditional branches that use the argument provided by
   the runtime (__builtin_eh_filter) and the set of integers we computed
   in assign_filter_values.

   During pass_lower_resx (tree-eh.c), which is run near the end
   of optimization, we expand RESX statements.  If the eh region
   that is outer to the RESX statement is a MUST_NOT_THROW, then
   the RESX expands to some form of abort statement.  If the eh
   region that is outer to the RESX statement is within the current
   function, then the RESX expands to a bookkeeping call
   (__builtin_eh_copy_values) and a goto.  Otherwise, the next
   handler for the exception must be within a function somewhere
   up the call chain, so we call back into the exception runtime
   (__builtin_unwind_resume).

   During pass_expand (cfgexpand.c), we generate REG_EH_REGION notes
   that create an rtl to eh_region mapping that corresponds to the
   gimple to eh_region mapping that had been recorded in the
   THROW_STMT_TABLE.

   Then, via finish_eh_generation, we generate the real landing pads
   to which the runtime will actually transfer control.  These new
   landing pads perform whatever bookkeeping is needed by the target
   backend in order to resume execution within the current function.
   Each of these new landing pads falls through into the post_landing_pad
   label which had been used within the CFG up to this point.  All
   exception edges within the CFG are redirected to the new landing pads.
   If the target uses setjmp to implement exceptions, the various extra
   calls into the runtime to register and unregister the current stack
   frame are emitted at this time.

   During pass_convert_to_eh_region_ranges (except.c), we transform
   the REG_EH_REGION notes attached to individual insns into
   non-overlapping ranges of insns bounded by NOTE_INSN_EH_REGION_BEG
   and NOTE_INSN_EH_REGION_END.  Each insn within such ranges has the
   same associated action within the exception region tree, meaning
   that (1) the exception is caught by the same landing pad within the
   current function, (2) the exception is blocked by the runtime with
   a MUST_NOT_THROW region, or (3) the exception is not handled at all
   within the current function.

   Finally, during assembly generation, we call
   output_function_exception_table (except.c) to emit the tables with
   which the exception runtime can determine if a given stack frame
   handles a given exception, and if so what filter value to provide
   to the function when the non-local control transfer is effected.
   If the target uses dwarf2 unwinding to implement exceptions, then
   output_call_frame_info (dwarf2out.c) emits the required unwind data.  */


#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "tm.h"
#include "rtl.h"
#include "tree.h"
#include "flags.h"
#include "function.h"
#include "expr.h"
#include "libfuncs.h"
#include "insn-config.h"
#include "except.h"
#include "hard-reg-set.h"
#include "basic-block.h"
#include "output.h"
#include "dwarf2asm.h"
#include "dwarf2out.h"
#include "dwarf2.h"
#include "toplev.h"
#include "hash-table.h"
#include "intl.h"
#include "ggc.h"
#include "tm_p.h"
#include "target.h"
#include "common/common-target.h"
#include "langhooks.h"
#include "cgraph.h"
#include "diagnostic.h"
#include "tree-pretty-print.h"
#include "tree-pass.h"
#include "tree-flow.h"
#include "cfgloop.h"

/* Provide defaults for stuff that may not be defined when using
   sjlj exceptions.  */
#ifndef EH_RETURN_DATA_REGNO
#define EH_RETURN_DATA_REGNO(N) INVALID_REGNUM
#endif

static GTY(()) int call_site_base;
static GTY ((param_is (union tree_node)))
  htab_t type_to_runtime_map;

/* Describe the SjLj_Function_Context structure.  */
static GTY(()) tree sjlj_fc_type_node;
static int sjlj_fc_call_site_ofs;
static int sjlj_fc_data_ofs;
static int sjlj_fc_personality_ofs;
static int sjlj_fc_lsda_ofs;
static int sjlj_fc_jbuf_ofs;


struct GTY(()) call_site_record_d
{
  rtx landing_pad;
  int action;
};

/* In the following structure and associated functions,
   we represent entries in the action table as 1-based indices.
   Special cases are:

	 0:	null action record, non-null landing pad; implies cleanups
	-1:	null action record, null landing pad; implies no action
	-2:	no call-site entry; implies must_not_throw
	-3:	we have yet to process outer regions

   Further, no special cases apply to the "next" field of the record.
   For next, 0 means end of list.  */

struct action_record
{
  int offset;
  int filter;
  int next;
};

/* Hashtable helpers.  */

struct action_record_hasher : typed_free_remove <action_record>
{
  typedef action_record value_type;
  typedef action_record compare_type;
  static inline hashval_t hash (const value_type *);
  static inline bool equal (const value_type *, const compare_type *);
};

inline hashval_t
action_record_hasher::hash (const value_type *entry)
{
  return entry->next * 1009 + entry->filter;
}

inline bool
action_record_hasher::equal (const value_type *entry, const compare_type *data)
{
  return entry->filter == data->filter && entry->next == data->next;
}

typedef hash_table <action_record_hasher> action_hash_type;

static bool get_eh_region_and_lp_from_rtx (const_rtx, eh_region *,
					   eh_landing_pad *);

static int t2r_eq (const void *, const void *);
static hashval_t t2r_hash (const void *);

static void dw2_build_landing_pads (void);

static int collect_one_action_chain (action_hash_type, eh_region);
static int add_call_site (rtx, int, int);

static void push_uleb128 (vec<uchar, va_gc> **, unsigned int);
static void push_sleb128 (vec<uchar, va_gc> **, int);
#ifndef HAVE_AS_LEB128
static int dw2_size_of_call_site_table (int);
static int sjlj_size_of_call_site_table (void);
#endif
static void dw2_output_call_site_table (int, int);
static void sjlj_output_call_site_table (void);


void
init_eh (void)
{
  if (! flag_exceptions)
    return;

  type_to_runtime_map = htab_create_ggc (31, t2r_hash, t2r_eq, NULL);

  /* Create the SjLj_Function_Context structure.  This should match
     the definition in unwind-sjlj.c.  */
  if (targetm_common.except_unwind_info (&global_options) == UI_SJLJ)
    {
      tree f_jbuf, f_per, f_lsda, f_prev, f_cs, f_data, tmp;

      sjlj_fc_type_node = lang_hooks.types.make_type (RECORD_TYPE);

      f_prev = build_decl (BUILTINS_LOCATION,
			   FIELD_DECL, get_identifier ("__prev"),
			   build_pointer_type (sjlj_fc_type_node));
      DECL_FIELD_CONTEXT (f_prev) = sjlj_fc_type_node;

      f_cs = build_decl (BUILTINS_LOCATION,
			 FIELD_DECL, get_identifier ("__call_site"),
			 integer_type_node);
      DECL_FIELD_CONTEXT (f_cs) = sjlj_fc_type_node;

      tmp = build_index_type (size_int (4 - 1));
      tmp = build_array_type (lang_hooks.types.type_for_mode
				(targetm.unwind_word_mode (), 1),
			      tmp);
      f_data = build_decl (BUILTINS_LOCATION,
			   FIELD_DECL, get_identifier ("__data"), tmp);
      DECL_FIELD_CONTEXT (f_data) = sjlj_fc_type_node;

      f_per = build_decl (BUILTINS_LOCATION,
			  FIELD_DECL, get_identifier ("__personality"),
			  ptr_type_node);
      DECL_FIELD_CONTEXT (f_per) = sjlj_fc_type_node;

      f_lsda = build_decl (BUILTINS_LOCATION,
			   FIELD_DECL, get_identifier ("__lsda"),
			   ptr_type_node);
      DECL_FIELD_CONTEXT (f_lsda) = sjlj_fc_type_node;

#ifdef DONT_USE_BUILTIN_SETJMP
#ifdef JMP_BUF_SIZE
      tmp = size_int (JMP_BUF_SIZE - 1);
#else
      /* Should be large enough for most systems, if it is not,
	 JMP_BUF_SIZE should be defined with the proper value.  It will
	 also tend to be larger than necessary for most systems, a more
	 optimal port will define JMP_BUF_SIZE.  */
      tmp = size_int (FIRST_PSEUDO_REGISTER + 2 - 1);
#endif
#else
      /* builtin_setjmp takes a pointer to 5 words.  */
      tmp = size_int (5 * BITS_PER_WORD / POINTER_SIZE - 1);
#endif
      tmp = build_index_type (tmp);
      tmp = build_array_type (ptr_type_node, tmp);
      f_jbuf = build_decl (BUILTINS_LOCATION,
			   FIELD_DECL, get_identifier ("__jbuf"), tmp);
#ifdef DONT_USE_BUILTIN_SETJMP
      /* We don't know what the alignment requirements of the
	 runtime's jmp_buf has.  Overestimate.  */
      DECL_ALIGN (f_jbuf) = BIGGEST_ALIGNMENT;
      DECL_USER_ALIGN (f_jbuf) = 1;
#endif
      DECL_FIELD_CONTEXT (f_jbuf) = sjlj_fc_type_node;

      TYPE_FIELDS (sjlj_fc_type_node) = f_prev;
      TREE_CHAIN (f_prev) = f_cs;
      TREE_CHAIN (f_cs) = f_data;
      TREE_CHAIN (f_data) = f_per;
      TREE_CHAIN (f_per) = f_lsda;
      TREE_CHAIN (f_lsda) = f_jbuf;

      layout_type (sjlj_fc_type_node);

      /* Cache the interesting field offsets so that we have
	 easy access from rtl.  */
      sjlj_fc_call_site_ofs
	= (tree_low_cst (DECL_FIELD_OFFSET (f_cs), 1)
	   + tree_low_cst (DECL_FIELD_BIT_OFFSET (f_cs), 1) / BITS_PER_UNIT);
      sjlj_fc_data_ofs
	= (tree_low_cst (DECL_FIELD_OFFSET (f_data), 1)
	   + tree_low_cst (DECL_FIELD_BIT_OFFSET (f_data), 1) / BITS_PER_UNIT);
      sjlj_fc_personality_ofs
	= (tree_low_cst (DECL_FIELD_OFFSET (f_per), 1)
	   + tree_low_cst (DECL_FIELD_BIT_OFFSET (f_per), 1) / BITS_PER_UNIT);
      sjlj_fc_lsda_ofs
	= (tree_low_cst (DECL_FIELD_OFFSET (f_lsda), 1)
	   + tree_low_cst (DECL_FIELD_BIT_OFFSET (f_lsda), 1) / BITS_PER_UNIT);
      sjlj_fc_jbuf_ofs
	= (tree_low_cst (DECL_FIELD_OFFSET (f_jbuf), 1)
	   + tree_low_cst (DECL_FIELD_BIT_OFFSET (f_jbuf), 1) / BITS_PER_UNIT);
    }
}

void
init_eh_for_function (void)
{
  cfun->eh = ggc_alloc_cleared_eh_status ();

  /* Make sure zero'th entries are used.  */
  vec_safe_push (cfun->eh->region_array, (eh_region)0);
  vec_safe_push (cfun->eh->lp_array, (eh_landing_pad)0);
}

/* Routines to generate the exception tree somewhat directly.
   These are used from tree-eh.c when processing exception related
   nodes during tree optimization.  */

static eh_region
gen_eh_region (enum eh_region_type type, eh_region outer)
{
  eh_region new_eh;

  /* Insert a new blank region as a leaf in the tree.  */
  new_eh = ggc_alloc_cleared_eh_region_d ();
  new_eh->type = type;
  new_eh->outer = outer;
  if (outer)
    {
      new_eh->next_peer = outer->inner;
      outer->inner = new_eh;
    }
  else
    {
      new_eh->next_peer = cfun->eh->region_tree;
      cfun->eh->region_tree = new_eh;
    }

  new_eh->index = vec_safe_length (cfun->eh->region_array);
  vec_safe_push (cfun->eh->region_array, new_eh);

  /* Copy the language's notion of whether to use __cxa_end_cleanup.  */
  if (targetm.arm_eabi_unwinder && lang_hooks.eh_use_cxa_end_cleanup)
    new_eh->use_cxa_end_cleanup = true;

  return new_eh;
}

eh_region
gen_eh_region_cleanup (eh_region outer)
{
  return gen_eh_region (ERT_CLEANUP, outer);
}

eh_region
gen_eh_region_try (eh_region outer)
{
  return gen_eh_region (ERT_TRY, outer);
}

eh_catch
gen_eh_region_catch (eh_region t, tree type_or_list)
{
  eh_catch c, l;
  tree type_list, type_node;

  gcc_assert (t->type == ERT_TRY);

  /* Ensure to always end up with a type list to normalize further
     processing, then register each type against the runtime types map.  */
  type_list = type_or_list;
  if (type_or_list)
    {
      if (TREE_CODE (type_or_list) != TREE_LIST)
	type_list = tree_cons (NULL_TREE, type_or_list, NULL_TREE);

      type_node = type_list;
      for (; type_node; type_node = TREE_CHAIN (type_node))
	add_type_for_runtime (TREE_VALUE (type_node));
    }

  c = ggc_alloc_cleared_eh_catch_d ();
  c->type_list = type_list;
  l = t->u.eh_try.last_catch;
  c->prev_catch = l;
  if (l)
    l->next_catch = c;
  else
    t->u.eh_try.first_catch = c;
  t->u.eh_try.last_catch = c;

  return c;
}

eh_region
gen_eh_region_allowed (eh_region outer, tree allowed)
{
  eh_region region = gen_eh_region (ERT_ALLOWED_EXCEPTIONS, outer);
  region->u.allowed.type_list = allowed;

  for (; allowed ; allowed = TREE_CHAIN (allowed))
    add_type_for_runtime (TREE_VALUE (allowed));

  return region;
}

eh_region
gen_eh_region_must_not_throw (eh_region outer)
{
  return gen_eh_region (ERT_MUST_NOT_THROW, outer);
}

eh_landing_pad
gen_eh_landing_pad (eh_region region)
{
  eh_landing_pad lp = ggc_alloc_cleared_eh_landing_pad_d ();

  lp->next_lp = region->landing_pads;
  lp->region = region;
  lp->index = vec_safe_length (cfun->eh->lp_array);
  region->landing_pads = lp;

  vec_safe_push (cfun->eh->lp_array, lp);

  return lp;
}

eh_region
get_eh_region_from_number_fn (struct function *ifun, int i)
{
  return (*ifun->eh->region_array)[i];
}

eh_region
get_eh_region_from_number (int i)
{
  return get_eh_region_from_number_fn (cfun, i);
}

eh_landing_pad
get_eh_landing_pad_from_number_fn (struct function *ifun, int i)
{
  return (*ifun->eh->lp_array)[i];
}

eh_landing_pad
get_eh_landing_pad_from_number (int i)
{
  return get_eh_landing_pad_from_number_fn (cfun, i);
}

eh_region
get_eh_region_from_lp_number_fn (struct function *ifun, int i)
{
  if (i < 0)
    return (*ifun->eh->region_array)[-i];
  else if (i == 0)
    return NULL;
  else
    {
      eh_landing_pad lp;
      lp = (*ifun->eh->lp_array)[i];
      return lp->region;
    }
}

eh_region
get_eh_region_from_lp_number (int i)
{
  return get_eh_region_from_lp_number_fn (cfun, i);
}

/* Returns true if the current function has exception handling regions.  */

bool
current_function_has_exception_handlers (void)
{
  return cfun->eh->region_tree != NULL;
}

/* A subroutine of duplicate_eh_regions.  Copy the eh_region tree at OLD.
   Root it at OUTER, and apply LP_OFFSET to the lp numbers.  */

struct duplicate_eh_regions_data
{
  duplicate_eh_regions_map label_map;
  void *label_map_data;
  struct pointer_map_t *eh_map;
};

static void
duplicate_eh_regions_1 (struct duplicate_eh_regions_data *data,
			eh_region old_r, eh_region outer)
{
  eh_landing_pad old_lp, new_lp;
  eh_region new_r;
  void **slot;

  new_r = gen_eh_region (old_r->type, outer);
  slot = pointer_map_insert (data->eh_map, (void *)old_r);
  gcc_assert (*slot == NULL);
  *slot = (void *)new_r;

  switch (old_r->type)
    {
    case ERT_CLEANUP:
      break;

    case ERT_TRY:
      {
	eh_catch oc, nc;
	for (oc = old_r->u.eh_try.first_catch; oc ; oc = oc->next_catch)
	  {
	    /* We should be doing all our region duplication before and
	       during inlining, which is before filter lists are created.  */
	    gcc_assert (oc->filter_list == NULL);
	    nc = gen_eh_region_catch (new_r, oc->type_list);
	    nc->label = data->label_map (oc->label, data->label_map_data);
	  }
      }
      break;

    case ERT_ALLOWED_EXCEPTIONS:
      new_r->u.allowed.type_list = old_r->u.allowed.type_list;
      if (old_r->u.allowed.label)
	new_r->u.allowed.label
	    = data->label_map (old_r->u.allowed.label, data->label_map_data);
      else
	new_r->u.allowed.label = NULL_TREE;
      break;

    case ERT_MUST_NOT_THROW:
      new_r->u.must_not_throw.failure_loc =
	LOCATION_LOCUS (old_r->u.must_not_throw.failure_loc);
      new_r->u.must_not_throw.failure_decl =
	old_r->u.must_not_throw.failure_decl;
      break;
    }

  for (old_lp = old_r->landing_pads; old_lp ; old_lp = old_lp->next_lp)
    {
      /* Don't bother copying unused landing pads.  */
      if (old_lp->post_landing_pad == NULL)
	continue;

      new_lp = gen_eh_landing_pad (new_r);
      slot = pointer_map_insert (data->eh_map, (void *)old_lp);
      gcc_assert (*slot == NULL);
      *slot = (void *)new_lp;

      new_lp->post_landing_pad
	= data->label_map (old_lp->post_landing_pad, data->label_map_data);
      EH_LANDING_PAD_NR (new_lp->post_landing_pad) = new_lp->index;
    }

  /* Make sure to preserve the original use of __cxa_end_cleanup.  */
  new_r->use_cxa_end_cleanup = old_r->use_cxa_end_cleanup;

  for (old_r = old_r->inner; old_r ; old_r = old_r->next_peer)
    duplicate_eh_regions_1 (data, old_r, new_r);
}

/* Duplicate the EH regions from IFUN rooted at COPY_REGION into
   the current function and root the tree below OUTER_REGION.
   The special case of COPY_REGION of NULL means all regions.
   Remap labels using MAP/MAP_DATA callback.  Return a pointer map
   that allows the caller to remap uses of both EH regions and
   EH landing pads.  */

struct pointer_map_t *
duplicate_eh_regions (struct function *ifun,
		      eh_region copy_region, int outer_lp,
		      duplicate_eh_regions_map map, void *map_data)
{
  struct duplicate_eh_regions_data data;
  eh_region outer_region;

#ifdef ENABLE_CHECKING
  verify_eh_tree (ifun);
#endif

  data.label_map = map;
  data.label_map_data = map_data;
  data.eh_map = pointer_map_create ();

  outer_region = get_eh_region_from_lp_number (outer_lp);

  /* Copy all the regions in the subtree.  */
  if (copy_region)
    duplicate_eh_regions_1 (&data, copy_region, outer_region);
  else
    {
      eh_region r;
      for (r = ifun->eh->region_tree; r ; r = r->next_peer)
	duplicate_eh_regions_1 (&data, r, outer_region);
    }

#ifdef ENABLE_CHECKING
  verify_eh_tree (cfun);
#endif

  return data.eh_map;
}

/* Return the region that is outer to both REGION_A and REGION_B in IFUN.  */

eh_region
eh_region_outermost (struct function *ifun, eh_region region_a,
		     eh_region region_b)
{
  sbitmap b_outer;

  gcc_assert (ifun->eh->region_array);
  gcc_assert (ifun->eh->region_tree);

  b_outer = sbitmap_alloc (ifun->eh->region_array->length());
  bitmap_clear (b_outer);

  do
    {
      bitmap_set_bit (b_outer, region_b->index);
      region_b = region_b->outer;
    }
  while (region_b);

  do
    {
      if (bitmap_bit_p (b_outer, region_a->index))
	break;
      region_a = region_a->outer;
    }
  while (region_a);

  sbitmap_free (b_outer);
  return region_a;
}

static int
t2r_eq (const void *pentry, const void *pdata)
{
  const_tree const entry = (const_tree) pentry;
  const_tree const data = (const_tree) pdata;

  return TREE_PURPOSE (entry) == data;
}

static hashval_t
t2r_hash (const void *pentry)
{
  const_tree const entry = (const_tree) pentry;
  return TREE_HASH (TREE_PURPOSE (entry));
}

void
add_type_for_runtime (tree type)
{
  tree *slot;

  /* If TYPE is NOP_EXPR, it means that it already is a runtime type.  */
  if (TREE_CODE (type) == NOP_EXPR)
    return;

  slot = (tree *) htab_find_slot_with_hash (type_to_runtime_map, type,
					    TREE_HASH (type), INSERT);
  if (*slot == NULL)
    {
      tree runtime = lang_hooks.eh_runtime_type (type);
      *slot = tree_cons (type, runtime, NULL_TREE);
    }
}

tree
lookup_type_for_runtime (tree type)
{
  tree *slot;

  /* If TYPE is NOP_EXPR, it means that it already is a runtime type.  */
  if (TREE_CODE (type) == NOP_EXPR)
    return type;

  slot = (tree *) htab_find_slot_with_hash (type_to_runtime_map, type,
					    TREE_HASH (type), NO_INSERT);

  /* We should have always inserted the data earlier.  */
  return TREE_VALUE (*slot);
}


/* Represent an entry in @TTypes for either catch actions
   or exception filter actions.  */
struct ttypes_filter {
  tree t;
  int filter;
};

/* Helper for ttypes_filter hashing.  */

struct ttypes_filter_hasher : typed_free_remove <ttypes_filter>
{
  typedef ttypes_filter value_type;
  typedef tree_node compare_type;
  static inline hashval_t hash (const value_type *);
  static inline bool equal (const value_type *, const compare_type *);
};

/* Compare ENTRY (a ttypes_filter entry in the hash table) with DATA
   (a tree) for a @TTypes type node we are thinking about adding.  */

inline bool
ttypes_filter_hasher::equal (const value_type *entry, const compare_type *data)
{
  return entry->t == data;
}

inline hashval_t
ttypes_filter_hasher::hash (const value_type *entry)
{
  return TREE_HASH (entry->t);
}

typedef hash_table <ttypes_filter_hasher> ttypes_hash_type;


/* Helper for ehspec hashing.  */

struct ehspec_hasher : typed_free_remove <ttypes_filter>
{
  typedef ttypes_filter value_type;
  typedef ttypes_filter compare_type;
  static inline hashval_t hash (const value_type *);
  static inline bool equal (const value_type *, const compare_type *);
};

/* Compare ENTRY with DATA (both struct ttypes_filter) for a @TTypes
   exception specification list we are thinking about adding.  */
/* ??? Currently we use the type lists in the order given.  Someone
   should put these in some canonical order.  */

inline bool
ehspec_hasher::equal (const value_type *entry, const compare_type *data)
{
  return type_list_equal (entry->t, data->t);
}

/* Hash function for exception specification lists.  */

inline hashval_t
ehspec_hasher::hash (const value_type *entry)
{
  hashval_t h = 0;
  tree list;

  for (list = entry->t; list ; list = TREE_CHAIN (list))
    h = (h << 5) + (h >> 27) + TREE_HASH (TREE_VALUE (list));
  return h;
}

typedef hash_table <ehspec_hasher> ehspec_hash_type;


/* Add TYPE (which may be NULL) to cfun->eh->ttype_data, using TYPES_HASH
   to speed up the search.  Return the filter value to be used.  */

static int
add_ttypes_entry (ttypes_hash_type ttypes_hash, tree type)
{
  struct ttypes_filter **slot, *n;

  slot = ttypes_hash.find_slot_with_hash (type, (hashval_t) TREE_HASH (type),
					  INSERT);

  if ((n = *slot) == NULL)
    {
      /* Filter value is a 1 based table index.  */

      n = XNEW (struct ttypes_filter);
      n->t = type;
      n->filter = vec_safe_length (cfun->eh->ttype_data) + 1;
      *slot = n;

      vec_safe_push (cfun->eh->ttype_data, type);
    }

  return n->filter;
}

/* Add LIST to cfun->eh->ehspec_data, using EHSPEC_HASH and TYPES_HASH
   to speed up the search.  Return the filter value to be used.  */

static int
add_ehspec_entry (ehspec_hash_type ehspec_hash, ttypes_hash_type ttypes_hash,
		  tree list)
{
  struct ttypes_filter **slot, *n;
  struct ttypes_filter dummy;

  dummy.t = list;
  slot = ehspec_hash.find_slot (&dummy, INSERT);

  if ((n = *slot) == NULL)
    {
      int len;

      if (targetm.arm_eabi_unwinder)
	len = vec_safe_length (cfun->eh->ehspec_data.arm_eabi);
      else
	len = vec_safe_length (cfun->eh->ehspec_data.other);

      /* Filter value is a -1 based byte index into a uleb128 buffer.  */

      n = XNEW (struct ttypes_filter);
      n->t = list;
      n->filter = -(len + 1);
      *slot = n;

      /* Generate a 0 terminated list of filter values.  */
      for (; list ; list = TREE_CHAIN (list))
	{
	  if (targetm.arm_eabi_unwinder)
	    vec_safe_push (cfun->eh->ehspec_data.arm_eabi, TREE_VALUE (list));
	  else
	    {
	      /* Look up each type in the list and encode its filter
		 value as a uleb128.  */
	      push_uleb128 (&cfun->eh->ehspec_data.other,
			    add_ttypes_entry (ttypes_hash, TREE_VALUE (list)));
	    }
	}
      if (targetm.arm_eabi_unwinder)
	vec_safe_push (cfun->eh->ehspec_data.arm_eabi, NULL_TREE);
      else
	vec_safe_push (cfun->eh->ehspec_data.other, (uchar)0);
    }

  return n->filter;
}

/* Generate the action filter values to be used for CATCH and
   ALLOWED_EXCEPTIONS regions.  When using dwarf2 exception regions,
   we use lots of landing pads, and so every type or list can share
   the same filter value, which saves table space.  */

void
assign_filter_values (void)
{
  int i;
  ttypes_hash_type ttypes;
  ehspec_hash_type ehspec;
  eh_region r;
  eh_catch c;

  vec_alloc (cfun->eh->ttype_data, 16);
  if (targetm.arm_eabi_unwinder)
    vec_alloc (cfun->eh->ehspec_data.arm_eabi, 64);
  else
    vec_alloc (cfun->eh->ehspec_data.other, 64);

  ttypes.create (31);
  ehspec.create (31);

  for (i = 1; vec_safe_iterate (cfun->eh->region_array, i, &r); ++i)
    {
      if (r == NULL)
	continue;

      switch (r->type)
	{
	case ERT_TRY:
	  for (c = r->u.eh_try.first_catch; c ; c = c->next_catch)
	    {
	      /* Whatever type_list is (NULL or true list), we build a list
		 of filters for the region.  */
	      c->filter_list = NULL_TREE;

	      if (c->type_list != NULL)
		{
		  /* Get a filter value for each of the types caught and store
		     them in the region's dedicated list.  */
		  tree tp_node = c->type_list;

		  for ( ; tp_node; tp_node = TREE_CHAIN (tp_node))
		    {
		      int flt = add_ttypes_entry (ttypes, TREE_VALUE (tp_node));
		      tree flt_node = build_int_cst (integer_type_node, flt);

		      c->filter_list
			= tree_cons (NULL_TREE, flt_node, c->filter_list);
		    }
		}
	      else
		{
		  /* Get a filter value for the NULL list also since it
		     will need an action record anyway.  */
		  int flt = add_ttypes_entry (ttypes, NULL);
		  tree flt_node = build_int_cst (integer_type_node, flt);

		  c->filter_list
		    = tree_cons (NULL_TREE, flt_node, NULL);
		}
	    }
	  break;

	case ERT_ALLOWED_EXCEPTIONS:
	  r->u.allowed.filter
	    = add_ehspec_entry (ehspec, ttypes, r->u.allowed.type_list);
	  break;

	default:
	  break;
	}
    }

  ttypes.dispose ();
  ehspec.dispose ();
}

/* Emit SEQ into basic block just before INSN (that is assumed to be
   first instruction of some existing BB and return the newly
   produced block.  */
static basic_block
emit_to_new_bb_before (rtx seq, rtx insn)
{
  rtx last;
  basic_block bb, prev_bb;
  edge e;
  edge_iterator ei;

  /* If there happens to be a fallthru edge (possibly created by cleanup_cfg
     call), we don't want it to go into newly created landing pad or other EH
     construct.  */
  for (ei = ei_start (BLOCK_FOR_INSN (insn)->preds); (e = ei_safe_edge (ei)); )
    if (e->flags & EDGE_FALLTHRU)
      force_nonfallthru (e);
    else
      ei_next (&ei);
  last = emit_insn_before (seq, insn);
  if (BARRIER_P (last))
    last = PREV_INSN (last);
  prev_bb = BLOCK_FOR_INSN (insn)->prev_bb;
  bb = create_basic_block (seq, last, prev_bb);
  update_bb_for_insn (bb);
  bb->flags |= BB_SUPERBLOCK;
  return bb;
}

/* A subroutine of dw2_build_landing_pads, also used for edge splitting
   at the rtl level.  Emit the code required by the target at a landing
   pad for the given region.  */

void
expand_dw2_landing_pad_for_region (eh_region region)
{
#ifdef HAVE_exception_receiver
  if (HAVE_exception_receiver)
    emit_insn (gen_exception_receiver ());
  else
#endif
#ifdef HAVE_nonlocal_goto_receiver
  if (HAVE_nonlocal_goto_receiver)
    emit_insn (gen_nonlocal_goto_receiver ());
  else
#endif
    { /* Nothing */ }

  if (region->exc_ptr_reg)
    emit_move_insn (region->exc_ptr_reg,
		    gen_rtx_REG (ptr_mode, EH_RETURN_DATA_REGNO (0)));
  if (region->filter_reg)
    emit_move_insn (region->filter_reg,
		    gen_rtx_REG (targetm.eh_return_filter_mode (),
				 EH_RETURN_DATA_REGNO (1)));
}

/* Expand the extra code needed at landing pads for dwarf2 unwinding.  */

static void
dw2_build_landing_pads (void)
{
  int i;
  eh_landing_pad lp;
  int e_flags = EDGE_FALLTHRU;

  /* If we're going to partition blocks, we need to be able to add
     new landing pads later, which means that we need to hold on to
     the post-landing-pad block.  Prevent it from being merged away.
     We'll remove this bit after partitioning.  */
  if (flag_reorder_blocks_and_partition)
    e_flags |= EDGE_PRESERVE;

  for (i = 1; vec_safe_iterate (cfun->eh->lp_array, i, &lp); ++i)
    {
      basic_block bb;
      rtx seq;
      edge e;

      if (lp == NULL || lp->post_landing_pad == NULL)
	continue;

      start_sequence ();

      lp->landing_pad = gen_label_rtx ();
      emit_label (lp->landing_pad);
      LABEL_PRESERVE_P (lp->landing_pad) = 1;

      expand_dw2_landing_pad_for_region (lp->region);

      seq = get_insns ();
      end_sequence ();

      bb = emit_to_new_bb_before (seq, label_rtx (lp->post_landing_pad));
      e = make_edge (bb, bb->next_bb, e_flags);
      e->count = bb->count;
      e->probability = REG_BR_PROB_BASE;
      if (current_loops)
	{
	  struct loop *loop = bb->next_bb->loop_father;
	  /* If we created a pre-header block, add the new block to the
	     outer loop, otherwise to the loop itself.  */
	  if (bb->next_bb == loop->header)
	    add_bb_to_loop (bb, loop_outer (loop));
	  else
	    add_bb_to_loop (bb, loop);
	}
    }
}


static vec<int> sjlj_lp_call_site_index;

/* Process all active landing pads.  Assign each one a compact dispatch
   index, and a call-site index.  */

static int
sjlj_assign_call_site_values (void)
{
  action_hash_type ar_hash;
  int i, disp_index;
  eh_landing_pad lp;

  vec_alloc (crtl->eh.action_record_data, 64);
  ar_hash.create (31);

  disp_index = 0;
  call_site_base = 1;
  for (i = 1; vec_safe_iterate (cfun->eh->lp_array, i, &lp); ++i)
    if (lp && lp->post_landing_pad)
      {
	int action, call_site;

	/* First: build the action table.  */
	action = collect_one_action_chain (ar_hash, lp->region);

	/* Next: assign call-site values.  If dwarf2 terms, this would be
	   the region number assigned by convert_to_eh_region_ranges, but
	   handles no-action and must-not-throw differently.  */
	/* Map must-not-throw to otherwise unused call-site index 0.  */
	if (action == -2)
	  call_site = 0;
	/* Map no-action to otherwise unused call-site index -1.  */
	else if (action == -1)
	  call_site = -1;
	/* Otherwise, look it up in the table.  */
	else
	  call_site = add_call_site (GEN_INT (disp_index), action, 0);
	sjlj_lp_call_site_index[i] = call_site;

	disp_index++;
      }

  ar_hash.dispose ();

  return disp_index;
}

/* Emit code to record the current call-site index before every
   insn that can throw.  */

static void
sjlj_mark_call_sites (void)
{
  int last_call_site = -2;
  rtx insn, mem;

  for (insn = get_insns (); insn ; insn = NEXT_INSN (insn))
    {
      eh_landing_pad lp;
      eh_region r;
      bool nothrow;
      int this_call_site;
      rtx before, p;

      /* Reset value tracking at extended basic block boundaries.  */
      if (LABEL_P (insn))
	last_call_site = -2;

      if (! INSN_P (insn))
	continue;

      nothrow = get_eh_region_and_lp_from_rtx (insn, &r, &lp);
      if (nothrow)
	continue;
      if (lp)
	this_call_site = sjlj_lp_call_site_index[lp->index];
      else if (r == NULL)
	{
	  /* Calls (and trapping insns) without notes are outside any
	     exception handling region in this function.  Mark them as
	     no action.  */
	  this_call_site = -1;
	}
      else
	{
	  gcc_assert (r->type == ERT_MUST_NOT_THROW);
	  this_call_site = 0;
	}

      if (this_call_site != -1)
	crtl->uses_eh_lsda = 1;

      if (this_call_site == last_call_site)
	continue;

      /* Don't separate a call from it's argument loads.  */
      before = insn;
      if (CALL_P (insn))
	before = find_first_parameter_load (insn, NULL_RTX);

      start_sequence ();
      mem = adjust_address (crtl->eh.sjlj_fc, TYPE_MODE (integer_type_node),
			    sjlj_fc_call_site_ofs);
      emit_move_insn (mem, GEN_INT (this_call_site));
      p = get_insns ();
      end_sequence ();

      emit_insn_before (p, before);
      last_call_site = this_call_site;
    }
}

/* Construct the SjLj_Function_Context.  */

static void
sjlj_emit_function_enter (rtx dispatch_label)
{
  rtx fn_begin, fc, mem, seq;
  bool fn_begin_outside_block;
  rtx personality = get_personality_function (current_function_decl);

  fc = crtl->eh.sjlj_fc;

  start_sequence ();

  /* We're storing this libcall's address into memory instead of
     calling it directly.  Thus, we must call assemble_external_libcall
     here, as we can not depend on emit_library_call to do it for us.  */
  assemble_external_libcall (personality);
  mem = adjust_address (fc, Pmode, sjlj_fc_personality_ofs);
  emit_move_insn (mem, personality);

  mem = adjust_address (fc, Pmode, sjlj_fc_lsda_ofs);
  if (crtl->uses_eh_lsda)
    {
      char buf[20];
      rtx sym;

      ASM_GENERATE_INTERNAL_LABEL (buf, "LLSDA", current_function_funcdef_no);
      sym = gen_rtx_SYMBOL_REF (Pmode, ggc_strdup (buf));
      SYMBOL_REF_FLAGS (sym) = SYMBOL_FLAG_LOCAL;
      emit_move_insn (mem, sym);
    }
  else
    emit_move_insn (mem, const0_rtx);

  if (dispatch_label)
    {
#ifdef DONT_USE_BUILTIN_SETJMP
      rtx x;
      x = emit_library_call_value (setjmp_libfunc, NULL_RTX, LCT_RETURNS_TWICE,
				   TYPE_MODE (integer_type_node), 1,
				   plus_constant (Pmode, XEXP (fc, 0),
						  sjlj_fc_jbuf_ofs), Pmode);

      emit_cmp_and_jump_insns (x, const0_rtx, NE, 0,
			       TYPE_MODE (integer_type_node), 0,
			       dispatch_label, REG_BR_PROB_BASE / 100);
#else
      expand_builtin_setjmp_setup (plus_constant (Pmode, XEXP (fc, 0),
						  sjlj_fc_jbuf_ofs),
				   dispatch_label);
#endif
    }

  emit_library_call (unwind_sjlj_register_libfunc, LCT_NORMAL, VOIDmode,
		     1, XEXP (fc, 0), Pmode);

  seq = get_insns ();
  end_sequence ();

  /* ??? Instead of doing this at the beginning of the function,
     do this in a block that is at loop level 0 and dominates all
     can_throw_internal instructions.  */

  fn_begin_outside_block = true;
  for (fn_begin = get_insns (); ; fn_begin = NEXT_INSN (fn_begin))
    if (NOTE_P (fn_begin))
      {
	if (NOTE_KIND (fn_begin) == NOTE_INSN_FUNCTION_BEG)
	  break;
	else if (NOTE_INSN_BASIC_BLOCK_P (fn_begin))
	  fn_begin_outside_block = false;
      }

  if (fn_begin_outside_block)
    insert_insn_on_edge (seq, single_succ_edge (ENTRY_BLOCK_PTR));
  else
    emit_insn_after (seq, fn_begin);
}

/* Call back from expand_function_end to know where we should put
   the call to unwind_sjlj_unregister_libfunc if needed.  */

void
sjlj_emit_function_exit_after (rtx after)
{
  crtl->eh.sjlj_exit_after = after;
}

static void
sjlj_emit_function_exit (void)
{
  rtx seq, insn;

  start_sequence ();

  emit_library_call (unwind_sjlj_unregister_libfunc, LCT_NORMAL, VOIDmode,
		     1, XEXP (crtl->eh.sjlj_fc, 0), Pmode);

  seq = get_insns ();
  end_sequence ();

  /* ??? Really this can be done in any block at loop level 0 that
     post-dominates all can_throw_internal instructions.  This is
     the last possible moment.  */

  insn = crtl->eh.sjlj_exit_after;
  if (LABEL_P (insn))
    insn = NEXT_INSN (insn);

  emit_insn_after (seq, insn);
}

static void
sjlj_emit_dispatch_table (rtx dispatch_label, int num_dispatch)
{
  enum machine_mode unwind_word_mode = targetm.unwind_word_mode ();
  enum machine_mode filter_mode = targetm.eh_return_filter_mode ();
  eh_landing_pad lp;
  rtx mem, seq, fc, before, exc_ptr_reg, filter_reg;
  rtx first_reachable_label;
  basic_block bb;
  eh_region r;
  edge e;
  int i, disp_index;
  vec<tree> dispatch_labels = vNULL;

  fc = crtl->eh.sjlj_fc;

  start_sequence ();

  emit_label (dispatch_label);

#ifndef DONT_USE_BUILTIN_SETJMP
  expand_builtin_setjmp_receiver (dispatch_label);

  /* The caller of expand_builtin_setjmp_receiver is responsible for
     making sure that the label doesn't vanish.  The only other caller
     is the expander for __builtin_setjmp_receiver, which places this
     label on the nonlocal_goto_label list.  Since we're modeling these
     CFG edges more exactly, we can use the forced_labels list instead.  */
  LABEL_PRESERVE_P (dispatch_label) = 1;
  forced_labels
    = gen_rtx_EXPR_LIST (VOIDmode, dispatch_label, forced_labels);
#endif

  /* Load up exc_ptr and filter values from the function context.  */
  mem = adjust_address (fc, unwind_word_mode, sjlj_fc_data_ofs);
  if (unwind_word_mode != ptr_mode)
    {
#ifdef POINTERS_EXTEND_UNSIGNED
      mem = convert_memory_address (ptr_mode, mem);
#else
      mem = convert_to_mode (ptr_mode, mem, 0);
#endif
    }
  exc_ptr_reg = force_reg (ptr_mode, mem);

  mem = adjust_address (fc, unwind_word_mode,
			sjlj_fc_data_ofs + GET_MODE_SIZE (unwind_word_mode));
  if (unwind_word_mode != filter_mode)
    mem = convert_to_mode (filter_mode, mem, 0);
  filter_reg = force_reg (filter_mode, mem);

  /* Jump to one of the directly reachable regions.  */

  disp_index = 0;
  first_reachable_label = NULL;

  /* If there's exactly one call site in the function, don't bother
     generating a switch statement.  */
  if (num_dispatch > 1)
    dispatch_labels.create (num_dispatch);

  for (i = 1; vec_safe_iterate (cfun->eh->lp_array, i, &lp); ++i)
    if (lp && lp->post_landing_pad)
      {
	rtx seq2, label;

	start_sequence ();

	lp->landing_pad = dispatch_label;

	if (num_dispatch > 1)
	  {
	    tree t_label, case_elt, t;

	    t_label = create_artificial_label (UNKNOWN_LOCATION);
	    t = build_int_cst (integer_type_node, disp_index);
	    case_elt = build_case_label (t, NULL, t_label);
	    dispatch_labels.quick_push (case_elt);
	    label = label_rtx (t_label);
	  }
	else
	  label = gen_label_rtx ();

	if (disp_index == 0)
	  first_reachable_label = label;
	emit_label (label);

	r = lp->region;
	if (r->exc_ptr_reg)
	  emit_move_insn (r->exc_ptr_reg, exc_ptr_reg);
	if (r->filter_reg)
	  emit_move_insn (r->filter_reg, filter_reg);

	seq2 = get_insns ();
	end_sequence ();

	before = label_rtx (lp->post_landing_pad);
	bb = emit_to_new_bb_before (seq2, before);
	e = make_edge (bb, bb->next_bb, EDGE_FALLTHRU);
	e->count = bb->count;
	e->probability = REG_BR_PROB_BASE;
	if (current_loops)
	  {
	    struct loop *loop = bb->next_bb->loop_father;
	    /* If we created a pre-header block, add the new block to the
	       outer loop, otherwise to the loop itself.  */
	    if (bb->next_bb == loop->header)
	      add_bb_to_loop (bb, loop_outer (loop));
	    else
	      add_bb_to_loop (bb, loop);
	    /* ???  For multiple dispatches we will end up with edges
	       from the loop tree root into this loop, making it a
	       multiple-entry loop.  Discard all affected loops.  */
	    if (num_dispatch > 1)
	      {
		for (loop = bb->loop_father;
		     loop_outer (loop); loop = loop_outer (loop))
		  {
		    loop->header = NULL;
		    loop->latch = NULL;
		  }
	      }
	  }

	disp_index++;
      }
  gcc_assert (disp_index == num_dispatch);

  if (num_dispatch > 1)
    {
      rtx disp = adjust_address (fc, TYPE_MODE (integer_type_node),
				 sjlj_fc_call_site_ofs);
      expand_sjlj_dispatch_table (disp, dispatch_labels);
    }

  seq = get_insns ();
  end_sequence ();

  bb = emit_to_new_bb_before (seq, first_reachable_label);
  if (num_dispatch == 1)
    {
      e = make_edge (bb, bb->next_bb, EDGE_FALLTHRU);
      e->count = bb->count;
      e->probability = REG_BR_PROB_BASE;
      if (current_loops)
	{
	  struct loop *loop = bb->next_bb->loop_father;
	  /* If we created a pre-header block, add the new block to the
	     outer loop, otherwise to the loop itself.  */
	  if (bb->next_bb == loop->header)
	    add_bb_to_loop (bb, loop_outer (loop));
	  else
	    add_bb_to_loop (bb, loop);
	}
    }
  else
    {
      /* We are not wiring up edges here, but as the dispatcher call
         is at function begin simply associate the block with the
	 outermost (non-)loop.  */
      if (current_loops)
	add_bb_to_loop (bb, current_loops->tree_root);
    }
}

static void
sjlj_build_landing_pads (void)
{
  int num_dispatch;

  num_dispatch = vec_safe_length (cfun->eh->lp_array);
  if (num_dispatch == 0)
    return;
  sjlj_lp_call_site_index.safe_grow_cleared (num_dispatch);

  num_dispatch = sjlj_assign_call_site_values ();
  if (num_dispatch > 0)
    {
      rtx dispatch_label = gen_label_rtx ();
      int align = STACK_SLOT_ALIGNMENT (sjlj_fc_type_node,
					TYPE_MODE (sjlj_fc_type_node),
					TYPE_ALIGN (sjlj_fc_type_node));
      crtl->eh.sjlj_fc
	= assign_stack_local (TYPE_MODE (sjlj_fc_type_node),
			      int_size_in_bytes (sjlj_fc_type_node),
			      align);

      sjlj_mark_call_sites ();
      sjlj_emit_function_enter (dispatch_label);
      sjlj_emit_dispatch_table (dispatch_label, num_dispatch);
      sjlj_emit_function_exit ();
    }

  /* If we do not have any landing pads, we may still need to register a
     personality routine and (empty) LSDA to handle must-not-throw regions.  */
  else if (function_needs_eh_personality (cfun) != eh_personality_none)
    {
      int align = STACK_SLOT_ALIGNMENT (sjlj_fc_type_node,
					TYPE_MODE (sjlj_fc_type_node),
					TYPE_ALIGN (sjlj_fc_type_node));
      crtl->eh.sjlj_fc
	= assign_stack_local (TYPE_MODE (sjlj_fc_type_node),
			      int_size_in_bytes (sjlj_fc_type_node),
			      align);

      sjlj_mark_call_sites ();
      sjlj_emit_function_enter (NULL_RTX);
      sjlj_emit_function_exit ();
    }

  sjlj_lp_call_site_index.release ();
}

/* After initial rtl generation, call back to finish generating
   exception support code.  */

void
finish_eh_generation (void)
{
  basic_block bb;

  /* Construct the landing pads.  */
  if (targetm_common.except_unwind_info (&global_options) == UI_SJLJ)
    sjlj_build_landing_pads ();
  else
    dw2_build_landing_pads ();
  break_superblocks ();

  if (targetm_common.except_unwind_info (&global_options) == UI_SJLJ
      /* Kludge for Alpha (see alpha_gp_save_rtx).  */
      || single_succ_edge (ENTRY_BLOCK_PTR)->insns.r)
    commit_edge_insertions ();

  /* Redirect all EH edges from the post_landing_pad to the landing pad.  */
  FOR_EACH_BB (bb)
    {
      eh_landing_pad lp;
      edge_iterator ei;
      edge e;

      lp = get_eh_landing_pad_from_rtx (BB_END (bb));

      FOR_EACH_EDGE (e, ei, bb->succs)
	if (e->flags & EDGE_EH)
	  break;

      /* We should not have generated any new throwing insns during this
	 pass, and we should not have lost any EH edges, so we only need
	 to handle two cases here:
	 (1) reachable handler and an existing edge to post-landing-pad,
	 (2) no reachable handler and no edge.  */
      gcc_assert ((lp != NULL) == (e != NULL));
      if (lp != NULL)
	{
	  gcc_assert (BB_HEAD (e->dest) == label_rtx (lp->post_landing_pad));

	  redirect_edge_succ (e, BLOCK_FOR_INSN (lp->landing_pad));
	  e->flags |= (CALL_P (BB_END (bb))
		       ? EDGE_ABNORMAL | EDGE_ABNORMAL_CALL
		       : EDGE_ABNORMAL);
	}
    }
}

/* This section handles removing dead code for flow.  */

void
remove_eh_landing_pad (eh_landing_pad lp)
{
  eh_landing_pad *pp;

  for (pp = &lp->region->landing_pads; *pp != lp; pp = &(*pp)->next_lp)
    continue;
  *pp = lp->next_lp;

  if (lp->post_landing_pad)
    EH_LANDING_PAD_NR (lp->post_landing_pad) = 0;
  (*cfun->eh->lp_array)[lp->index] = NULL;
}

/* Splice the EH region at PP from the region tree.  */

static void
remove_eh_handler_splicer (eh_region *pp)
{
  eh_region region = *pp;
  eh_landing_pad lp;

  for (lp = region->landing_pads; lp ; lp = lp->next_lp)
    {
      if (lp->post_landing_pad)
	EH_LANDING_PAD_NR (lp->post_landing_pad) = 0;
      (*cfun->eh->lp_array)[lp->index] = NULL;
    }

  if (region->inner)
    {
      eh_region p, outer;
      outer = region->outer;

      *pp = p = region->inner;
      do
	{
	  p->outer = outer;
	  pp = &p->next_peer;
	  p = *pp;
	}
      while (p);
    }
  *pp = region->next_peer;

  (*cfun->eh->region_array)[region->index] = NULL;
}

/* Splice a single EH region REGION from the region tree.

   To unlink REGION, we need to find the pointer to it with a relatively
   expensive search in REGION's outer region.  If you are going to
   remove a number of handlers, using remove_unreachable_eh_regions may
   be a better option.  */

void
remove_eh_handler (eh_region region)
{
  eh_region *pp, *pp_start, p, outer;

  outer = region->outer;
  if (outer)
    pp_start = &outer->inner;
  else
    pp_start = &cfun->eh->region_tree;
  for (pp = pp_start, p = *pp; p != region; pp = &p->next_peer, p = *pp)
    continue;

  remove_eh_handler_splicer (pp);
}

/* Worker for remove_unreachable_eh_regions.
   PP is a pointer to the region to start a region tree depth-first
   search from.  R_REACHABLE is the set of regions that have to be
   preserved.  */

static void
remove_unreachable_eh_regions_worker (eh_region *pp, sbitmap r_reachable)
{
  while (*pp)
    {
      eh_region region = *pp;
      remove_unreachable_eh_regions_worker (&region->inner, r_reachable);
      if (!bitmap_bit_p (r_reachable, region->index))
	remove_eh_handler_splicer (pp);
      else
	pp = &region->next_peer;
    }
}

/* Splice all EH regions *not* marked in R_REACHABLE from the region tree.
   Do this by traversing the EH tree top-down and splice out regions that
   are not marked.  By removing regions from the leaves, we avoid costly
   searches in the region tree.  */

void
remove_unreachable_eh_regions (sbitmap r_reachable)
{
  remove_unreachable_eh_regions_worker (&cfun->eh->region_tree, r_reachable);
}

/* Invokes CALLBACK for every exception handler landing pad label.
   Only used by reload hackery; should not be used by new code.  */

void
for_each_eh_label (void (*callback) (rtx))
{
  eh_landing_pad lp;
  int i;

  for (i = 1; vec_safe_iterate (cfun->eh->lp_array, i, &lp); ++i)
    {
      if (lp)
	{
	  rtx lab = lp->landing_pad;
	  if (lab && LABEL_P (lab))
	    (*callback) (lab);
	}
    }
}

/* Create the REG_EH_REGION note for INSN, given its ECF_FLAGS for a
   call insn.

   At the gimple level, we use LP_NR
       > 0 : The statement transfers to landing pad LP_NR
       = 0 : The statement is outside any EH region
       < 0 : The statement is within MUST_NOT_THROW region -LP_NR.

   At the rtl level, we use LP_NR
       > 0 : The insn transfers to landing pad LP_NR
       = 0 : The insn cannot throw
       < 0 : The insn is within MUST_NOT_THROW region -LP_NR
       = INT_MIN : The insn cannot throw or execute a nonlocal-goto.
       missing note: The insn is outside any EH region.

  ??? This difference probably ought to be avoided.  We could stand
  to record nothrow for arbitrary gimple statements, and so avoid
  some moderately complex lookups in stmt_could_throw_p.  Perhaps
  NOTHROW should be mapped on both sides to INT_MIN.  Perhaps the
  no-nonlocal-goto property should be recorded elsewhere as a bit
  on the call_insn directly.  Perhaps we should make more use of
  attaching the trees to call_insns (reachable via symbol_ref in
  direct call cases) and just pull the data out of the trees.  */

void
make_reg_eh_region_note (rtx insn, int ecf_flags, int lp_nr)
{
  rtx value;
  if (ecf_flags & ECF_NOTHROW)
    value = const0_rtx;
  else if (lp_nr != 0)
    value = GEN_INT (lp_nr);
  else
    return;
  add_reg_note (insn, REG_EH_REGION, value);
}

/* Create a REG_EH_REGION note for a CALL_INSN that cannot throw
   nor perform a non-local goto.  Replace the region note if it
   already exists.  */

void
make_reg_eh_region_note_nothrow_nononlocal (rtx insn)
{
  rtx note = find_reg_note (insn, REG_EH_REGION, NULL_RTX);
  rtx intmin = GEN_INT (INT_MIN);

  if (note != 0)
    XEXP (note, 0) = intmin;
  else
    add_reg_note (insn, REG_EH_REGION, intmin);
}

/* Return true if INSN could throw, assuming no REG_EH_REGION note
   to the contrary.  */

bool
insn_could_throw_p (const_rtx insn)
{
  if (!flag_exceptions)
    return false;
  if (CALL_P (insn))
    return true;
  if (INSN_P (insn) && cfun->can_throw_non_call_exceptions)
    return may_trap_p (PATTERN (insn));
  return false;
}

/* Copy an REG_EH_REGION note to each insn that might throw beginning
   at FIRST and ending at LAST.  NOTE_OR_INSN is either the source insn
   to look for a note, or the note itself.  */

void
copy_reg_eh_region_note_forward (rtx note_or_insn, rtx first, rtx last)
{
  rtx insn, note = note_or_insn;

  if (INSN_P (note_or_insn))
    {
      note = find_reg_note (note_or_insn, REG_EH_REGION, NULL_RTX);
      if (note == NULL)
	return;
    }
  note = XEXP (note, 0);

  for (insn = first; insn != last ; insn = NEXT_INSN (insn))
    if (!find_reg_note (insn, REG_EH_REGION, NULL_RTX)
        && insn_could_throw_p (insn))
      add_reg_note (insn, REG_EH_REGION, note);
}

/* Likewise, but iterate backward.  */

void
copy_reg_eh_region_note_backward (rtx note_or_insn, rtx last, rtx first)
{
  rtx insn, note = note_or_insn;

  if (INSN_P (note_or_insn))
    {
      note = find_reg_note (note_or_insn, REG_EH_REGION, NULL_RTX);
      if (note == NULL)
	return;
    }
  note = XEXP (note, 0);

  for (insn = last; insn != first; insn = PREV_INSN (insn))
    if (insn_could_throw_p (insn))
      add_reg_note (insn, REG_EH_REGION, note);
}


/* Extract all EH information from INSN.  Return true if the insn
   was marked NOTHROW.  */

static bool
get_eh_region_and_lp_from_rtx (const_rtx insn, eh_region *pr,
			       eh_landing_pad *plp)
{
  eh_landing_pad lp = NULL;
  eh_region r = NULL;
  bool ret = false;
  rtx note;
  int lp_nr;

  if (! INSN_P (insn))
    goto egress;

  if (NONJUMP_INSN_P (insn)
      && GET_CODE (PATTERN (insn)) == SEQUENCE)
    insn = XVECEXP (PATTERN (insn), 0, 0);

  note = find_reg_note (insn, REG_EH_REGION, NULL_RTX);
  if (!note)
    {
      ret = !insn_could_throw_p (insn);
      goto egress;
    }

  lp_nr = INTVAL (XEXP (note, 0));
  if (lp_nr == 0 || lp_nr == INT_MIN)
    {
      ret = true;
      goto egress;
    }

  if (lp_nr < 0)
    r = (*cfun->eh->region_array)[-lp_nr];
  else
    {
      lp = (*cfun->eh->lp_array)[lp_nr];
      r = lp->region;
    }

 egress:
  *plp = lp;
  *pr = r;
  return ret;
}

/* Return the landing pad to which INSN may go, or NULL if it does not
   have a reachable landing pad within this function.  */

eh_landing_pad
get_eh_landing_pad_from_rtx (const_rtx insn)
{
  eh_landing_pad lp;
  eh_region r;

  get_eh_region_and_lp_from_rtx (insn, &r, &lp);
  return lp;
}

/* Return the region to which INSN may go, or NULL if it does not
   have a reachable region within this function.  */

eh_region
get_eh_region_from_rtx (const_rtx insn)
{
  eh_landing_pad lp;
  eh_region r;

  get_eh_region_and_lp_from_rtx (insn, &r, &lp);
  return r;
}

/* Return true if INSN throws and is caught by something in this function.  */

bool
can_throw_internal (const_rtx insn)
{
  return get_eh_landing_pad_from_rtx (insn) != NULL;
}

/* Return true if INSN throws and escapes from the current function.  */

bool
can_throw_external (const_rtx insn)
{
  eh_landing_pad lp;
  eh_region r;
  bool nothrow;

  if (! INSN_P (insn))
    return false;

  if (NONJUMP_INSN_P (insn)
      && GET_CODE (PATTERN (insn)) == SEQUENCE)
    {
      rtx seq = PATTERN (insn);
      int i, n = XVECLEN (seq, 0);

      for (i = 0; i < n; i++)
	if (can_throw_external (XVECEXP (seq, 0, i)))
	  return true;

      return false;
    }

  nothrow = get_eh_region_and_lp_from_rtx (insn, &r, &lp);

  /* If we can't throw, we obviously can't throw external.  */
  if (nothrow)
    return false;

  /* If we have an internal landing pad, then we're not external.  */
  if (lp != NULL)
    return false;

  /* If we're not within an EH region, then we are external.  */
  if (r == NULL)
    return true;

  /* The only thing that ought to be left is MUST_NOT_THROW regions,
     which don't always have landing pads.  */
  gcc_assert (r->type == ERT_MUST_NOT_THROW);
  return false;
}

/* Return true if INSN cannot throw at all.  */

bool
insn_nothrow_p (const_rtx insn)
{
  eh_landing_pad lp;
  eh_region r;

  if (! INSN_P (insn))
    return true;

  if (NONJUMP_INSN_P (insn)
      && GET_CODE (PATTERN (insn)) == SEQUENCE)
    {
      rtx seq = PATTERN (insn);
      int i, n = XVECLEN (seq, 0);

      for (i = 0; i < n; i++)
	if (!insn_nothrow_p (XVECEXP (seq, 0, i)))
	  return false;

      return true;
    }

  return get_eh_region_and_lp_from_rtx (insn, &r, &lp);
}

/* Return true if INSN can perform a non-local goto.  */
/* ??? This test is here in this file because it (ab)uses REG_EH_REGION.  */

bool
can_nonlocal_goto (const_rtx insn)
{
  if (nonlocal_goto_handler_labels && CALL_P (insn))
    {
      rtx note = find_reg_note (insn, REG_EH_REGION, NULL_RTX);
      if (!note || INTVAL (XEXP (note, 0)) != INT_MIN)
	return true;
    }
  return false;
}

/* Set TREE_NOTHROW and crtl->all_throwers_are_sibcalls.  */

static unsigned int
set_nothrow_function_flags (void)
{
  rtx insn;

  crtl->nothrow = 1;

  /* Assume crtl->all_throwers_are_sibcalls until we encounter
     something that can throw an exception.  We specifically exempt
     CALL_INSNs that are SIBLING_CALL_P, as these are really jumps,
     and can't throw.  Most CALL_INSNs are not SIBLING_CALL_P, so this
     is optimistic.  */

  crtl->all_throwers_are_sibcalls = 1;

  /* If we don't know that this implementation of the function will
     actually be used, then we must not set TREE_NOTHROW, since
     callers must not assume that this function does not throw.  */
  if (TREE_NOTHROW (current_function_decl))
    return 0;

  if (! flag_exceptions)
    return 0;

  for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
    if (can_throw_external (insn))
      {
        crtl->nothrow = 0;

	if (!CALL_P (insn) || !SIBLING_CALL_P (insn))
	  {
	    crtl->all_throwers_are_sibcalls = 0;
	    return 0;
	  }
      }

  if (crtl->nothrow
      && (cgraph_function_body_availability (cgraph_get_node
					     (current_function_decl))
          >= AVAIL_AVAILABLE))
    {
      struct cgraph_node *node = cgraph_get_node (current_function_decl);
      struct cgraph_edge *e;
      for (e = node->callers; e; e = e->next_caller)
        e->can_throw_external = false;
      cgraph_set_nothrow_flag (node, true);

      if (dump_file)
	fprintf (dump_file, "Marking function nothrow: %s\n\n",
		 current_function_name ());
    }
  return 0;
}

struct rtl_opt_pass pass_set_nothrow_function_flags =
{
 {
  RTL_PASS,
  "nothrow",                            /* name */
  OPTGROUP_NONE,                        /* optinfo_flags */
  NULL,                                 /* gate */
  set_nothrow_function_flags,           /* execute */
  NULL,                                 /* sub */
  NULL,                                 /* next */
  0,                                    /* static_pass_number */
  TV_NONE,                              /* tv_id */
  0,                                    /* properties_required */
  0,                                    /* properties_provided */
  0,                                    /* properties_destroyed */
  0,                                    /* todo_flags_start */
  0                                     /* todo_flags_finish */
 }
};


/* Various hooks for unwind library.  */

/* Expand the EH support builtin functions:
   __builtin_eh_pointer and __builtin_eh_filter.  */

static eh_region
expand_builtin_eh_common (tree region_nr_t)
{
  HOST_WIDE_INT region_nr;
  eh_region region;

  gcc_assert (host_integerp (region_nr_t, 0));
  region_nr = tree_low_cst (region_nr_t, 0);

  region = (*cfun->eh->region_array)[region_nr];

  /* ??? We shouldn't have been able to delete a eh region without
     deleting all the code that depended on it.  */
  gcc_assert (region != NULL);

  return region;
}

/* Expand to the exc_ptr value from the given eh region.  */

rtx
expand_builtin_eh_pointer (tree exp)
{
  eh_region region
    = expand_builtin_eh_common (CALL_EXPR_ARG (exp, 0));
  if (region->exc_ptr_reg == NULL)
    region->exc_ptr_reg = gen_reg_rtx (ptr_mode);
  return region->exc_ptr_reg;
}

/* Expand to the filter value from the given eh region.  */

rtx
expand_builtin_eh_filter (tree exp)
{
  eh_region region
    = expand_builtin_eh_common (CALL_EXPR_ARG (exp, 0));
  if (region->filter_reg == NULL)
    region->filter_reg = gen_reg_rtx (targetm.eh_return_filter_mode ());
  return region->filter_reg;
}

/* Copy the exc_ptr and filter values from one landing pad's registers
   to another.  This is used to inline the resx statement.  */

rtx
expand_builtin_eh_copy_values (tree exp)
{
  eh_region dst
    = expand_builtin_eh_common (CALL_EXPR_ARG (exp, 0));
  eh_region src
    = expand_builtin_eh_common (CALL_EXPR_ARG (exp, 1));
  enum machine_mode fmode = targetm.eh_return_filter_mode ();

  if (dst->exc_ptr_reg == NULL)
    dst->exc_ptr_reg = gen_reg_rtx (ptr_mode);
  if (src->exc_ptr_reg == NULL)
    src->exc_ptr_reg = gen_reg_rtx (ptr_mode);

  if (dst->filter_reg == NULL)
    dst->filter_reg = gen_reg_rtx (fmode);
  if (src->filter_reg == NULL)
    src->filter_reg = gen_reg_rtx (fmode);

  emit_move_insn (dst->exc_ptr_reg, src->exc_ptr_reg);
  emit_move_insn (dst->filter_reg, src->filter_reg);

  return const0_rtx;
}

/* Do any necessary initialization to access arbitrary stack frames.
   On the SPARC, this means flushing the register windows.  */

void
expand_builtin_unwind_init (void)
{
  /* Set this so all the registers get saved in our frame; we need to be
     able to copy the saved values for any registers from frames we unwind.  */
  crtl->saves_all_registers = 1;

#ifdef SETUP_FRAME_ADDRESSES
  SETUP_FRAME_ADDRESSES ();
#endif
}

/* Map a non-negative number to an eh return data register number; expands
   to -1 if no return data register is associated with the input number.
   At least the inputs 0 and 1 must be mapped; the target may provide more.  */

rtx
expand_builtin_eh_return_data_regno (tree exp)
{
  tree which = CALL_EXPR_ARG (exp, 0);
  unsigned HOST_WIDE_INT iwhich;

  if (TREE_CODE (which) != INTEGER_CST)
    {
      error ("argument of %<__builtin_eh_return_regno%> must be constant");
      return constm1_rtx;
    }

  iwhich = tree_low_cst (which, 1);
  iwhich = EH_RETURN_DATA_REGNO (iwhich);
  if (iwhich == INVALID_REGNUM)
    return constm1_rtx;

#ifdef DWARF_FRAME_REGNUM
  iwhich = DWARF_FRAME_REGNUM (iwhich);
#else
  iwhich = DBX_REGISTER_NUMBER (iwhich);
#endif

  return GEN_INT (iwhich);
}

/* Given a value extracted from the return address register or stack slot,
   return the actual address encoded in that value.  */

rtx
expand_builtin_extract_return_addr (tree addr_tree)
{
  rtx addr = expand_expr (addr_tree, NULL_RTX, Pmode, EXPAND_NORMAL);

  if (GET_MODE (addr) != Pmode
      && GET_MODE (addr) != VOIDmode)
    {
#ifdef POINTERS_EXTEND_UNSIGNED
      addr = convert_memory_address (Pmode, addr);
#else
      addr = convert_to_mode (Pmode, addr, 0);
#endif
    }

  /* First mask out any unwanted bits.  */
#ifdef MASK_RETURN_ADDR
  expand_and (Pmode, addr, MASK_RETURN_ADDR, addr);
#endif

  /* Then adjust to find the real return address.  */
#if defined (RETURN_ADDR_OFFSET)
  addr = plus_constant (Pmode, addr, RETURN_ADDR_OFFSET);
#endif

  return addr;
}

/* Given an actual address in addr_tree, do any necessary encoding
   and return the value to be stored in the return address register or
   stack slot so the epilogue will return to that address.  */

rtx
expand_builtin_frob_return_addr (tree addr_tree)
{
  rtx addr = expand_expr (addr_tree, NULL_RTX, ptr_mode, EXPAND_NORMAL);

  addr = convert_memory_address (Pmode, addr);

#ifdef RETURN_ADDR_OFFSET
  addr = force_reg (Pmode, addr);
  addr = plus_constant (Pmode, addr, -RETURN_ADDR_OFFSET);
#endif

  return addr;
}

/* Set up the epilogue with the magic bits we'll need to return to the
   exception handler.  */

void
expand_builtin_eh_return (tree stackadj_tree ATTRIBUTE_UNUSED,
			  tree handler_tree)
{
  rtx tmp;

#ifdef EH_RETURN_STACKADJ_RTX
  tmp = expand_expr (stackadj_tree, crtl->eh.ehr_stackadj,
		     VOIDmode, EXPAND_NORMAL);
  tmp = convert_memory_address (Pmode, tmp);
  if (!crtl->eh.ehr_stackadj)
    crtl->eh.ehr_stackadj = copy_to_reg (tmp);
  else if (tmp != crtl->eh.ehr_stackadj)
    emit_move_insn (crtl->eh.ehr_stackadj, tmp);
#endif

  tmp = expand_expr (handler_tree, crtl->eh.ehr_handler,
		     VOIDmode, EXPAND_NORMAL);
  tmp = convert_memory_address (Pmode, tmp);
  if (!crtl->eh.ehr_handler)
    crtl->eh.ehr_handler = copy_to_reg (tmp);
  else if (tmp != crtl->eh.ehr_handler)
    emit_move_insn (crtl->eh.ehr_handler, tmp);

  if (!crtl->eh.ehr_label)
    crtl->eh.ehr_label = gen_label_rtx ();
  emit_jump (crtl->eh.ehr_label);
}

/* Expand __builtin_eh_return.  This exit path from the function loads up
   the eh return data registers, adjusts the stack, and branches to a
   given PC other than the normal return address.  */

void
expand_eh_return (void)
{
  rtx around_label;

  if (! crtl->eh.ehr_label)
    return;

  crtl->calls_eh_return = 1;

#ifdef EH_RETURN_STACKADJ_RTX
  emit_move_insn (EH_RETURN_STACKADJ_RTX, const0_rtx);
#endif

  around_label = gen_label_rtx ();
  emit_jump (around_label);

  emit_label (crtl->eh.ehr_label);
  clobber_return_register ();

#ifdef EH_RETURN_STACKADJ_RTX
  emit_move_insn (EH_RETURN_STACKADJ_RTX, crtl->eh.ehr_stackadj);
#endif

#ifdef HAVE_eh_return
  if (HAVE_eh_return)
    emit_insn (gen_eh_return (crtl->eh.ehr_handler));
  else
#endif
    {
#ifdef EH_RETURN_HANDLER_RTX
      emit_move_insn (EH_RETURN_HANDLER_RTX, crtl->eh.ehr_handler);
#else
      error ("__builtin_eh_return not supported on this target");
#endif
    }

  emit_label (around_label);
}

/* Convert a ptr_mode address ADDR_TREE to a Pmode address controlled by
   POINTERS_EXTEND_UNSIGNED and return it.  */

rtx
expand_builtin_extend_pointer (tree addr_tree)
{
  rtx addr = expand_expr (addr_tree, NULL_RTX, ptr_mode, EXPAND_NORMAL);
  int extend;

#ifdef POINTERS_EXTEND_UNSIGNED
  extend = POINTERS_EXTEND_UNSIGNED;
#else
  /* The previous EH code did an unsigned extend by default, so we do this also
     for consistency.  */
  extend = 1;
#endif

  return convert_modes (targetm.unwind_word_mode (), ptr_mode, addr, extend);
}

static int
add_action_record (action_hash_type ar_hash, int filter, int next)
{
  struct action_record **slot, *new_ar, tmp;

  tmp.filter = filter;
  tmp.next = next;
  slot = ar_hash.find_slot (&tmp, INSERT);

  if ((new_ar = *slot) == NULL)
    {
      new_ar = XNEW (struct action_record);
      new_ar->offset = crtl->eh.action_record_data->length () + 1;
      new_ar->filter = filter;
      new_ar->next = next;
      *slot = new_ar;

      /* The filter value goes in untouched.  The link to the next
	 record is a "self-relative" byte offset, or zero to indicate
	 that there is no next record.  So convert the absolute 1 based
	 indices we've been carrying around into a displacement.  */

      push_sleb128 (&crtl->eh.action_record_data, filter);
      if (next)
	next -= crtl->eh.action_record_data->length () + 1;
      push_sleb128 (&crtl->eh.action_record_data, next);
    }

  return new_ar->offset;
}

static int
collect_one_action_chain (action_hash_type ar_hash, eh_region region)
{
  int next;

  /* If we've reached the top of the region chain, then we have
     no actions, and require no landing pad.  */
  if (region == NULL)
    return -1;

  switch (region->type)
    {
    case ERT_CLEANUP:
      {
	eh_region r;
	/* A cleanup adds a zero filter to the beginning of the chain, but
	   there are special cases to look out for.  If there are *only*
	   cleanups along a path, then it compresses to a zero action.
	   Further, if there are multiple cleanups along a path, we only
	   need to represent one of them, as that is enough to trigger
	   entry to the landing pad at runtime.  */
	next = collect_one_action_chain (ar_hash, region->outer);
	if (next <= 0)
	  return 0;
	for (r = region->outer; r ; r = r->outer)
	  if (r->type == ERT_CLEANUP)
	    return next;
	return add_action_record (ar_hash, 0, next);
      }

    case ERT_TRY:
      {
	eh_catch c;

	/* Process the associated catch regions in reverse order.
	   If there's a catch-all handler, then we don't need to
	   search outer regions.  Use a magic -3 value to record
	   that we haven't done the outer search.  */
	next = -3;
	for (c = region->u.eh_try.last_catch; c ; c = c->prev_catch)
	  {
	    if (c->type_list == NULL)
	      {
		/* Retrieve the filter from the head of the filter list
		   where we have stored it (see assign_filter_values).  */
		int filter = TREE_INT_CST_LOW (TREE_VALUE (c->filter_list));
		next = add_action_record (ar_hash, filter, 0);
	      }
	    else
	      {
		/* Once the outer search is done, trigger an action record for
		   each filter we have.  */
		tree flt_node;

		if (next == -3)
		  {
		    next = collect_one_action_chain (ar_hash, region->outer);

		    /* If there is no next action, terminate the chain.  */
		    if (next == -1)
		      next = 0;
		    /* If all outer actions are cleanups or must_not_throw,
		       we'll have no action record for it, since we had wanted
		       to encode these states in the call-site record directly.
		       Add a cleanup action to the chain to catch these.  */
		    else if (next <= 0)
		      next = add_action_record (ar_hash, 0, 0);
		  }

		flt_node = c->filter_list;
		for (; flt_node; flt_node = TREE_CHAIN (flt_node))
		  {
		    int filter = TREE_INT_CST_LOW (TREE_VALUE (flt_node));
		    next = add_action_record (ar_hash, filter, next);
		  }
	      }
	  }
	return next;
      }

    case ERT_ALLOWED_EXCEPTIONS:
      /* An exception specification adds its filter to the
	 beginning of the chain.  */
      next = collect_one_action_chain (ar_hash, region->outer);

      /* If there is no next action, terminate the chain.  */
      if (next == -1)
	next = 0;
      /* If all outer actions are cleanups or must_not_throw,
	 we'll have no action record for it, since we had wanted
	 to encode these states in the call-site record directly.
	 Add a cleanup action to the chain to catch these.  */
      else if (next <= 0)
	next = add_action_record (ar_hash, 0, 0);

      return add_action_record (ar_hash, region->u.allowed.filter, next);

    case ERT_MUST_NOT_THROW:
      /* A must-not-throw region with no inner handlers or cleanups
	 requires no call-site entry.  Note that this differs from
	 the no handler or cleanup case in that we do require an lsda
	 to be generated.  Return a magic -2 value to record this.  */
      return -2;
    }

  gcc_unreachable ();
}

static int
add_call_site (rtx landing_pad, int action, int section)
{
  call_site_record record;

  record = ggc_alloc_call_site_record_d ();
  record->landing_pad = landing_pad;
  record->action = action;

  vec_safe_push (crtl->eh.call_site_record_v[section], record);

  return call_site_base + crtl->eh.call_site_record_v[section]->length () - 1;
}

/* Turn REG_EH_REGION notes back into NOTE_INSN_EH_REGION notes.
   The new note numbers will not refer to region numbers, but
   instead to call site entries.  */

static unsigned int
convert_to_eh_region_ranges (void)
{
  rtx insn, iter, note;
  action_hash_type ar_hash;
  int last_action = -3;
  rtx last_action_insn = NULL_RTX;
  rtx last_landing_pad = NULL_RTX;
  rtx first_no_action_insn = NULL_RTX;
  int call_site = 0;
  int cur_sec = 0;
  rtx section_switch_note = NULL_RTX;
  rtx first_no_action_insn_before_switch = NULL_RTX;
  rtx last_no_action_insn_before_switch = NULL_RTX;
  int saved_call_site_base = call_site_base;

  vec_alloc (crtl->eh.action_record_data, 64);

  ar_hash.create (31);

  for (iter = get_insns (); iter ; iter = NEXT_INSN (iter))
    if (INSN_P (iter))
      {
	eh_landing_pad lp;
	eh_region region;
	bool nothrow;
	int this_action;
	rtx this_landing_pad;

	insn = iter;
	if (NONJUMP_INSN_P (insn)
	    && GET_CODE (PATTERN (insn)) == SEQUENCE)
	  insn = XVECEXP (PATTERN (insn), 0, 0);

	nothrow = get_eh_region_and_lp_from_rtx (insn, &region, &lp);
	if (nothrow)
	  continue;
	if (region)
	  this_action = collect_one_action_chain (ar_hash, region);
	else
	  this_action = -1;

	/* Existence of catch handlers, or must-not-throw regions
	   implies that an lsda is needed (even if empty).  */
	if (this_action != -1)
	  crtl->uses_eh_lsda = 1;

	/* Delay creation of region notes for no-action regions
	   until we're sure that an lsda will be required.  */
	else if (last_action == -3)
	  {
	    first_no_action_insn = iter;
	    last_action = -1;
	  }

	if (this_action >= 0)
	  this_landing_pad = lp->landing_pad;
	else
	  this_landing_pad = NULL_RTX;

	/* Differing actions or landing pads implies a change in call-site
	   info, which implies some EH_REGION note should be emitted.  */
	if (last_action != this_action
	    || last_landing_pad != this_landing_pad)
	  {
	    /* If there is a queued no-action region in the other section
	       with hot/cold partitioning, emit it now.  */
	    if (first_no_action_insn_before_switch)
	      {
		gcc_assert (this_action != -1
			    && last_action == (first_no_action_insn
					       ? -1 : -3));
		call_site = add_call_site (NULL_RTX, 0, 0);
		note = emit_note_before (NOTE_INSN_EH_REGION_BEG,
					 first_no_action_insn_before_switch);
		NOTE_EH_HANDLER (note) = call_site;
		note = emit_note_after (NOTE_INSN_EH_REGION_END,
					last_no_action_insn_before_switch);
		NOTE_EH_HANDLER (note) = call_site;
		gcc_assert (last_action != -3
			    || (last_action_insn
				== last_no_action_insn_before_switch));
		first_no_action_insn_before_switch = NULL_RTX;
		last_no_action_insn_before_switch = NULL_RTX;
		call_site_base++;
	      }
	    /* If we'd not seen a previous action (-3) or the previous
	       action was must-not-throw (-2), then we do not need an
	       end note.  */
	    if (last_action >= -1)
	      {
		/* If we delayed the creation of the begin, do it now.  */
		if (first_no_action_insn)
		  {
		    call_site = add_call_site (NULL_RTX, 0, cur_sec);
		    note = emit_note_before (NOTE_INSN_EH_REGION_BEG,
					     first_no_action_insn);
		    NOTE_EH_HANDLER (note) = call_site;
		    first_no_action_insn = NULL_RTX;
		  }

		note = emit_note_after (NOTE_INSN_EH_REGION_END,
					last_action_insn);
		NOTE_EH_HANDLER (note) = call_site;
	      }

	    /* If the new action is must-not-throw, then no region notes
	       are created.  */
	    if (this_action >= -1)
	      {
		call_site = add_call_site (this_landing_pad,
					   this_action < 0 ? 0 : this_action,
					   cur_sec);
		note = emit_note_before (NOTE_INSN_EH_REGION_BEG, iter);
		NOTE_EH_HANDLER (note) = call_site;
	      }

	    last_action = this_action;
	    last_landing_pad = this_landing_pad;
	  }
	last_action_insn = iter;
      }
    else if (NOTE_P (iter)
	     && NOTE_KIND (iter) == NOTE_INSN_SWITCH_TEXT_SECTIONS)
      {
	gcc_assert (section_switch_note == NULL_RTX);
	gcc_assert (flag_reorder_blocks_and_partition);
	section_switch_note = iter;
	if (first_no_action_insn)
	  {
	    first_no_action_insn_before_switch = first_no_action_insn;
	    last_no_action_insn_before_switch = last_action_insn;
	    first_no_action_insn = NULL_RTX;
	    gcc_assert (last_action == -1);
	    last_action = -3;
	  }
	/* Force closing of current EH region before section switch and
	   opening a new one afterwards.  */
	else if (last_action != -3)
	  last_landing_pad = pc_rtx;
	if (crtl->eh.call_site_record_v[cur_sec])
	  call_site_base += crtl->eh.call_site_record_v[cur_sec]->length ();
	cur_sec++;
	gcc_assert (crtl->eh.call_site_record_v[cur_sec] == NULL);
	vec_alloc (crtl->eh.call_site_record_v[cur_sec], 10);
      }

  if (last_action >= -1 && ! first_no_action_insn)
    {
      note = emit_note_after (NOTE_INSN_EH_REGION_END, last_action_insn);
      NOTE_EH_HANDLER (note) = call_site;
    }

  call_site_base = saved_call_site_base;

  ar_hash.dispose ();
  return 0;
}

static bool
gate_convert_to_eh_region_ranges (void)
{
  /* Nothing to do for SJLJ exceptions or if no regions created.  */
  if (cfun->eh->region_tree == NULL)
    return false;
  if (targetm_common.except_unwind_info (&global_options) == UI_SJLJ)
    return false;
  return true;
}

struct rtl_opt_pass pass_convert_to_eh_region_ranges =
{
 {
  RTL_PASS,
  "eh_ranges",                          /* name */
  OPTGROUP_NONE,                        /* optinfo_flags */
  gate_convert_to_eh_region_ranges,	/* gate */
  convert_to_eh_region_ranges,          /* execute */
  NULL,                                 /* sub */
  NULL,                                 /* next */
  0,                                    /* static_pass_number */
  TV_NONE,                              /* tv_id */
  0,                                    /* properties_required */
  0,                                    /* properties_provided */
  0,                                    /* properties_destroyed */
  0,                                    /* todo_flags_start */
  0              			/* todo_flags_finish */
 }
};

static void
push_uleb128 (vec<uchar, va_gc> **data_area, unsigned int value)
{
  do
    {
      unsigned char byte = value & 0x7f;
      value >>= 7;
      if (value)
	byte |= 0x80;
      vec_safe_push (*data_area, byte);
    }
  while (value);
}

static void
push_sleb128 (vec<uchar, va_gc> **data_area, int value)
{
  unsigned char byte;
  int more;

  do
    {
      byte = value & 0x7f;
      value >>= 7;
      more = ! ((value == 0 && (byte & 0x40) == 0)
		|| (value == -1 && (byte & 0x40) != 0));
      if (more)
	byte |= 0x80;
      vec_safe_push (*data_area, byte);
    }
  while (more);
}


#ifndef HAVE_AS_LEB128
static int
dw2_size_of_call_site_table (int section)
{
  int n = vec_safe_length (crtl->eh.call_site_record_v[section]);
  int size = n * (4 + 4 + 4);
  int i;

  for (i = 0; i < n; ++i)
    {
      struct call_site_record_d *cs =
	(*crtl->eh.call_site_record_v[section])[i];
      size += size_of_uleb128 (cs->action);
    }

  return size;
}

static int
sjlj_size_of_call_site_table (void)
{
  int n = vec_safe_length (crtl->eh.call_site_record_v[0]);
  int size = 0;
  int i;

  for (i = 0; i < n; ++i)
    {
      struct call_site_record_d *cs =
	(*crtl->eh.call_site_record_v[0])[i];
      size += size_of_uleb128 (INTVAL (cs->landing_pad));
      size += size_of_uleb128 (cs->action);
    }

  return size;
}
#endif

static void
dw2_output_call_site_table (int cs_format, int section)
{
  int n = vec_safe_length (crtl->eh.call_site_record_v[section]);
  int i;
  const char *begin;

  if (section == 0)
    begin = current_function_func_begin_label;
  else if (first_function_block_is_cold)
    begin = crtl->subsections.hot_section_label;
  else
    begin = crtl->subsections.cold_section_label;

  for (i = 0; i < n; ++i)
    {
      struct call_site_record_d *cs = (*crtl->eh.call_site_record_v[section])[i];
      char reg_start_lab[32];
      char reg_end_lab[32];
      char landing_pad_lab[32];

      ASM_GENERATE_INTERNAL_LABEL (reg_start_lab, "LEHB", call_site_base + i);
      ASM_GENERATE_INTERNAL_LABEL (reg_end_lab, "LEHE", call_site_base + i);

      if (cs->landing_pad)
	ASM_GENERATE_INTERNAL_LABEL (landing_pad_lab, "L",
				     CODE_LABEL_NUMBER (cs->landing_pad));

      /* ??? Perhaps use insn length scaling if the assembler supports
	 generic arithmetic.  */
      /* ??? Perhaps use attr_length to choose data1 or data2 instead of
	 data4 if the function is small enough.  */
      if (cs_format == DW_EH_PE_uleb128)
	{
	  dw2_asm_output_delta_uleb128 (reg_start_lab, begin,
					"region %d start", i);
	  dw2_asm_output_delta_uleb128 (reg_end_lab, reg_start_lab,
					"length");
	  if (cs->landing_pad)
	    dw2_asm_output_delta_uleb128 (landing_pad_lab, begin,
					  "landing pad");
	  else
	    dw2_asm_output_data_uleb128 (0, "landing pad");
	}
      else
	{
	  dw2_asm_output_delta (4, reg_start_lab, begin,
				"region %d start", i);
	  dw2_asm_output_delta (4, reg_end_lab, reg_start_lab, "length");
	  if (cs->landing_pad)
	    dw2_asm_output_delta (4, landing_pad_lab, begin,
				  "landing pad");
	  else
	    dw2_asm_output_data (4, 0, "landing pad");
	}
      dw2_asm_output_data_uleb128 (cs->action, "action");
    }

  call_site_base += n;
}

static void
sjlj_output_call_site_table (void)
{
  int n = vec_safe_length (crtl->eh.call_site_record_v[0]);
  int i;

  for (i = 0; i < n; ++i)
    {
      struct call_site_record_d *cs = (*crtl->eh.call_site_record_v[0])[i];

      dw2_asm_output_data_uleb128 (INTVAL (cs->landing_pad),
				   "region %d landing pad", i);
      dw2_asm_output_data_uleb128 (cs->action, "action");
    }

  call_site_base += n;
}

/* Switch to the section that should be used for exception tables.  */

static void
switch_to_exception_section (const char * ARG_UNUSED (fnname))
{
  section *s;

  if (exception_section)
    s = exception_section;
  else
    {
      /* Compute the section and cache it into exception_section,
	 unless it depends on the function name.  */
      if (targetm_common.have_named_sections)
	{
	  int flags;

	  if (EH_TABLES_CAN_BE_READ_ONLY)
	    {
	      int tt_format =
		ASM_PREFERRED_EH_DATA_FORMAT (/*code=*/0, /*global=*/1);
	      flags = ((! flag_pic
			|| ((tt_format & 0x70) != DW_EH_PE_absptr
			    && (tt_format & 0x70) != DW_EH_PE_aligned))
		       ? 0 : SECTION_WRITE);
	    }
	  else
	    flags = SECTION_WRITE;

#ifdef HAVE_LD_EH_GC_SECTIONS
	  if (flag_function_sections
	      || (DECL_ONE_ONLY (current_function_decl) && HAVE_COMDAT_GROUP))
	    {
	      char *section_name = XNEWVEC (char, strlen (fnname) + 32);
	      /* The EH table must match the code section, so only mark
		 it linkonce if we have COMDAT groups to tie them together.  */
	      if (DECL_ONE_ONLY (current_function_decl) && HAVE_COMDAT_GROUP)
		flags |= SECTION_LINKONCE;
	      sprintf (section_name, ".gcc_except_table.%s", fnname);
	      s = get_section (section_name, flags, current_function_decl);
	      free (section_name);
	    }
	  else
#endif
	    exception_section
	      = s = get_section (".gcc_except_table", flags, NULL);
	}
      else
	exception_section
	  = s = flag_pic ? data_section : readonly_data_section;
    }

  switch_to_section (s);
}


/* Output a reference from an exception table to the type_info object TYPE.
   TT_FORMAT and TT_FORMAT_SIZE describe the DWARF encoding method used for
   the value.  */

static void
output_ttype (tree type, int tt_format, int tt_format_size)
{
  rtx value;
  bool is_public = true;

  if (type == NULL_TREE)
    value = const0_rtx;
  else
    {
      /* FIXME lto.  pass_ipa_free_lang_data changes all types to
	 runtime types so TYPE should already be a runtime type
	 reference.  When pass_ipa_free_lang data is made a default
	 pass, we can then remove the call to lookup_type_for_runtime
	 below.  */
      if (TYPE_P (type))
	type = lookup_type_for_runtime (type);

      value = expand_expr (type, NULL_RTX, VOIDmode, EXPAND_INITIALIZER);

      /* Let cgraph know that the rtti decl is used.  Not all of the
	 paths below go through assemble_integer, which would take
	 care of this for us.  */
      STRIP_NOPS (type);
      if (TREE_CODE (type) == ADDR_EXPR)
	{
	  type = TREE_OPERAND (type, 0);
	  if (TREE_CODE (type) == VAR_DECL)
	    is_public = TREE_PUBLIC (type);
	}
      else
	gcc_assert (TREE_CODE (type) == INTEGER_CST);
    }

  /* Allow the target to override the type table entry format.  */
  if (targetm.asm_out.ttype (value))
    return;

  if (tt_format == DW_EH_PE_absptr || tt_format == DW_EH_PE_aligned)
    assemble_integer (value, tt_format_size,
		      tt_format_size * BITS_PER_UNIT, 1);
  else
    dw2_asm_output_encoded_addr_rtx (tt_format, value, is_public, NULL);
}

static void
output_one_function_exception_table (int section)
{
  int tt_format, cs_format, lp_format, i;
#ifdef HAVE_AS_LEB128
  char ttype_label[32];
  char cs_after_size_label[32];
  char cs_end_label[32];
#else
  int call_site_len;
#endif
  int have_tt_data;
  int tt_format_size = 0;

  have_tt_data = (vec_safe_length (cfun->eh->ttype_data)
		  || (targetm.arm_eabi_unwinder
		      ? vec_safe_length (cfun->eh->ehspec_data.arm_eabi)
		      : vec_safe_length (cfun->eh->ehspec_data.other)));

  /* Indicate the format of the @TType entries.  */
  if (! have_tt_data)
    tt_format = DW_EH_PE_omit;
  else
    {
      tt_format = ASM_PREFERRED_EH_DATA_FORMAT (/*code=*/0, /*global=*/1);
#ifdef HAVE_AS_LEB128
      ASM_GENERATE_INTERNAL_LABEL (ttype_label,
				   section ? "LLSDATTC" : "LLSDATT",
				   current_function_funcdef_no);
#endif
      tt_format_size = size_of_encoded_value (tt_format);

      assemble_align (tt_format_size * BITS_PER_UNIT);
    }

  targetm.asm_out.internal_label (asm_out_file, section ? "LLSDAC" : "LLSDA",
				  current_function_funcdef_no);

  /* The LSDA header.  */

  /* Indicate the format of the landing pad start pointer.  An omitted
     field implies @LPStart == @Start.  */
  /* Currently we always put @LPStart == @Start.  This field would
     be most useful in moving the landing pads completely out of
     line to another section, but it could also be used to minimize
     the size of uleb128 landing pad offsets.  */
  lp_format = DW_EH_PE_omit;
  dw2_asm_output_data (1, lp_format, "@LPStart format (%s)",
		       eh_data_format_name (lp_format));

  /* @LPStart pointer would go here.  */

  dw2_asm_output_data (1, tt_format, "@TType format (%s)",
		       eh_data_format_name (tt_format));

#ifndef HAVE_AS_LEB128
  if (targetm_common.except_unwind_info (&global_options) == UI_SJLJ)
    call_site_len = sjlj_size_of_call_site_table ();
  else
    call_site_len = dw2_size_of_call_site_table (section);
#endif

  /* A pc-relative 4-byte displacement to the @TType data.  */
  if (have_tt_data)
    {
#ifdef HAVE_AS_LEB128
      char ttype_after_disp_label[32];
      ASM_GENERATE_INTERNAL_LABEL (ttype_after_disp_label,
				   section ? "LLSDATTDC" : "LLSDATTD",
				   current_function_funcdef_no);
      dw2_asm_output_delta_uleb128 (ttype_label, ttype_after_disp_label,
				    "@TType base offset");
      ASM_OUTPUT_LABEL (asm_out_file, ttype_after_disp_label);
#else
      /* Ug.  Alignment queers things.  */
      unsigned int before_disp, after_disp, last_disp, disp;

      before_disp = 1 + 1;
      after_disp = (1 + size_of_uleb128 (call_site_len)
		    + call_site_len
		    + vec_safe_length (crtl->eh.action_record_data)
		    + (vec_safe_length (cfun->eh->ttype_data)
		       * tt_format_size));

      disp = after_disp;
      do
	{
	  unsigned int disp_size, pad;

	  last_disp = disp;
	  disp_size = size_of_uleb128 (disp);
	  pad = before_disp + disp_size + after_disp;
	  if (pad % tt_format_size)
	    pad = tt_format_size - (pad % tt_format_size);
	  else
	    pad = 0;
	  disp = after_disp + pad;
	}
      while (disp != last_disp);

      dw2_asm_output_data_uleb128 (disp, "@TType base offset");
#endif
    }

  /* Indicate the format of the call-site offsets.  */
#ifdef HAVE_AS_LEB128
  cs_format = DW_EH_PE_uleb128;
#else
  cs_format = DW_EH_PE_udata4;
#endif
  dw2_asm_output_data (1, cs_format, "call-site format (%s)",
		       eh_data_format_name (cs_format));

#ifdef HAVE_AS_LEB128
  ASM_GENERATE_INTERNAL_LABEL (cs_after_size_label,
			       section ? "LLSDACSBC" : "LLSDACSB",
			       current_function_funcdef_no);
  ASM_GENERATE_INTERNAL_LABEL (cs_end_label,
			       section ? "LLSDACSEC" : "LLSDACSE",
			       current_function_funcdef_no);
  dw2_asm_output_delta_uleb128 (cs_end_label, cs_after_size_label,
				"Call-site table length");
  ASM_OUTPUT_LABEL (asm_out_file, cs_after_size_label);
  if (targetm_common.except_unwind_info (&global_options) == UI_SJLJ)
    sjlj_output_call_site_table ();
  else
    dw2_output_call_site_table (cs_format, section);
  ASM_OUTPUT_LABEL (asm_out_file, cs_end_label);
#else
  dw2_asm_output_data_uleb128 (call_site_len, "Call-site table length");
  if (targetm_common.except_unwind_info (&global_options) == UI_SJLJ)
    sjlj_output_call_site_table ();
  else
    dw2_output_call_site_table (cs_format, section);
#endif

  /* ??? Decode and interpret the data for flag_debug_asm.  */
  {
    uchar uc;
    FOR_EACH_VEC_ELT (*crtl->eh.action_record_data, i, uc)
      dw2_asm_output_data (1, uc, i ? NULL : "Action record table");
  }

  if (have_tt_data)
    assemble_align (tt_format_size * BITS_PER_UNIT);

  i = vec_safe_length (cfun->eh->ttype_data);
  while (i-- > 0)
    {
      tree type = (*cfun->eh->ttype_data)[i];
      output_ttype (type, tt_format, tt_format_size);
    }

#ifdef HAVE_AS_LEB128
  if (have_tt_data)
      ASM_OUTPUT_LABEL (asm_out_file, ttype_label);
#endif

  /* ??? Decode and interpret the data for flag_debug_asm.  */
  if (targetm.arm_eabi_unwinder)
    {
      tree type;
      for (i = 0;
	   vec_safe_iterate (cfun->eh->ehspec_data.arm_eabi, i, &type); ++i)
	output_ttype (type, tt_format, tt_format_size);
    }
  else
    {
      uchar uc;
      for (i = 0;
	   vec_safe_iterate (cfun->eh->ehspec_data.other, i, &uc); ++i)
	dw2_asm_output_data (1, uc,
			     i ? NULL : "Exception specification table");
    }
}

void
output_function_exception_table (const char *fnname)
{
  rtx personality = get_personality_function (current_function_decl);

  /* Not all functions need anything.  */
  if (! crtl->uses_eh_lsda)
    return;

  if (personality)
    {
      assemble_external_libcall (personality);

      if (targetm.asm_out.emit_except_personality)
	targetm.asm_out.emit_except_personality (personality);
    }

  switch_to_exception_section (fnname);

  /* If the target wants a label to begin the table, emit it here.  */
  targetm.asm_out.emit_except_table_label (asm_out_file);

  output_one_function_exception_table (0);
  if (crtl->eh.call_site_record_v[1])
    output_one_function_exception_table (1);

  switch_to_section (current_function_section ());
}

void
set_eh_throw_stmt_table (struct function *fun, struct htab *table)
{
  fun->eh->throw_stmt_table = table;
}

htab_t
get_eh_throw_stmt_table (struct function *fun)
{
  return fun->eh->throw_stmt_table;
}

/* Determine if the function needs an EH personality function.  */

enum eh_personality_kind
function_needs_eh_personality (struct function *fn)
{
  enum eh_personality_kind kind = eh_personality_none;
  eh_region i;

  FOR_ALL_EH_REGION_FN (i, fn)
    {
      switch (i->type)
	{
	case ERT_CLEANUP:
	  /* Can do with any personality including the generic C one.  */
	  kind = eh_personality_any;
	  break;

	case ERT_TRY:
	case ERT_ALLOWED_EXCEPTIONS:
	  /* Always needs a EH personality function.  The generic C
	     personality doesn't handle these even for empty type lists.  */
	  return eh_personality_lang;

	case ERT_MUST_NOT_THROW:
	  /* Always needs a EH personality function.  The language may specify
	     what abort routine that must be used, e.g. std::terminate.  */
	  return eh_personality_lang;
	}
    }

  return kind;
}

/* Dump EH information to OUT.  */

void
dump_eh_tree (FILE * out, struct function *fun)
{
  eh_region i;
  int depth = 0;
  static const char *const type_name[] = {
    "cleanup", "try", "allowed_exceptions", "must_not_throw"
  };

  i = fun->eh->region_tree;
  if (!i)
    return;

  fprintf (out, "Eh tree:\n");
  while (1)
    {
      fprintf (out, "  %*s %i %s", depth * 2, "",
	       i->index, type_name[(int) i->type]);

      if (i->landing_pads)
	{
	  eh_landing_pad lp;

	  fprintf (out, " land:");
	  if (current_ir_type () == IR_GIMPLE)
	    {
	      for (lp = i->landing_pads; lp ; lp = lp->next_lp)
		{
		  fprintf (out, "{%i,", lp->index);
		  print_generic_expr (out, lp->post_landing_pad, 0);
		  fputc ('}', out);
		  if (lp->next_lp)
		    fputc (',', out);
		}
	    }
	  else
	    {
	      for (lp = i->landing_pads; lp ; lp = lp->next_lp)
		{
		  fprintf (out, "{%i,", lp->index);
		  if (lp->landing_pad)
		    fprintf (out, "%i%s,", INSN_UID (lp->landing_pad),
			     NOTE_P (lp->landing_pad) ? "(del)" : "");
		  else
		    fprintf (out, "(nil),");
		  if (lp->post_landing_pad)
		    {
		      rtx lab = label_rtx (lp->post_landing_pad);
		      fprintf (out, "%i%s}", INSN_UID (lab),
			       NOTE_P (lab) ? "(del)" : "");
		    }
		  else
		    fprintf (out, "(nil)}");
		  if (lp->next_lp)
		    fputc (',', out);
		}
	    }
	}

      switch (i->type)
	{
	case ERT_CLEANUP:
	case ERT_MUST_NOT_THROW:
	  break;

	case ERT_TRY:
	  {
	    eh_catch c;
	    fprintf (out, " catch:");
	    for (c = i->u.eh_try.first_catch; c; c = c->next_catch)
	      {
		fputc ('{', out);
		if (c->label)
		  {
		    fprintf (out, "lab:");
		    print_generic_expr (out, c->label, 0);
		    fputc (';', out);
		  }
		print_generic_expr (out, c->type_list, 0);
		fputc ('}', out);
		if (c->next_catch)
		  fputc (',', out);
	      }
	  }
	  break;

	case ERT_ALLOWED_EXCEPTIONS:
	  fprintf (out, " filter :%i types:", i->u.allowed.filter);
	  print_generic_expr (out, i->u.allowed.type_list, 0);
	  break;
	}
      fputc ('\n', out);

      /* If there are sub-regions, process them.  */
      if (i->inner)
	i = i->inner, depth++;
      /* If there are peers, process them.  */
      else if (i->next_peer)
	i = i->next_peer;
      /* Otherwise, step back up the tree to the next peer.  */
      else
	{
	  do
	    {
	      i = i->outer;
	      depth--;
	      if (i == NULL)
		return;
	    }
	  while (i->next_peer == NULL);
	  i = i->next_peer;
	}
    }
}

/* Dump the EH tree for FN on stderr.  */

DEBUG_FUNCTION void
debug_eh_tree (struct function *fn)
{
  dump_eh_tree (stderr, fn);
}

/* Verify invariants on EH datastructures.  */

DEBUG_FUNCTION void
verify_eh_tree (struct function *fun)
{
  eh_region r, outer;
  int nvisited_lp, nvisited_r;
  int count_lp, count_r, depth, i;
  eh_landing_pad lp;
  bool err = false;

  if (!fun->eh->region_tree)
    return;

  count_r = 0;
  for (i = 1; vec_safe_iterate (fun->eh->region_array, i, &r); ++i)
    if (r)
      {
	if (r->index == i)
	  count_r++;
	else
	  {
	    error ("region_array is corrupted for region %i", r->index);
	    err = true;
	  }
      }

  count_lp = 0;
  for (i = 1; vec_safe_iterate (fun->eh->lp_array, i, &lp); ++i)
    if (lp)
      {
	if (lp->index == i)
	  count_lp++;
	else
	  {
	    error ("lp_array is corrupted for lp %i", lp->index);
	    err = true;
	  }
      }

  depth = nvisited_lp = nvisited_r = 0;
  outer = NULL;
  r = fun->eh->region_tree;
  while (1)
    {
      if ((*fun->eh->region_array)[r->index] != r)
	{
	  error ("region_array is corrupted for region %i", r->index);
	  err = true;
	}
      if (r->outer != outer)
	{
	  error ("outer block of region %i is wrong", r->index);
	  err = true;
	}
      if (depth < 0)
	{
	  error ("negative nesting depth of region %i", r->index);
	  err = true;
	}
      nvisited_r++;

      for (lp = r->landing_pads; lp ; lp = lp->next_lp)
	{
	  if ((*fun->eh->lp_array)[lp->index] != lp)
	    {
	      error ("lp_array is corrupted for lp %i", lp->index);
	      err = true;
	    }
	  if (lp->region != r)
	    {
	      error ("region of lp %i is wrong", lp->index);
	      err = true;
	    }
	  nvisited_lp++;
	}

      if (r->inner)
	outer = r, r = r->inner, depth++;
      else if (r->next_peer)
	r = r->next_peer;
      else
	{
	  do
	    {
	      r = r->outer;
	      if (r == NULL)
		goto region_done;
	      depth--;
	      outer = r->outer;
	    }
	  while (r->next_peer == NULL);
	  r = r->next_peer;
	}
    }
 region_done:
  if (depth != 0)
    {
      error ("tree list ends on depth %i", depth);
      err = true;
    }
  if (count_r != nvisited_r)
    {
      error ("region_array does not match region_tree");
      err = true;
    }
  if (count_lp != nvisited_lp)
    {
      error ("lp_array does not match region_tree");
      err = true;
    }

  if (err)
    {
      dump_eh_tree (stderr, fun);
      internal_error ("verify_eh_tree failed");
    }
}

#include "gt-except.h"