aboutsummaryrefslogtreecommitdiffstats
path: root/lib/compiler/doc/src/notes.xml
blob: 0e19642960e84ab77d577a75f2b1cc72ed7c2e94 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
2164
2165
2166
2167
2168
2169
2170
2171
2172
2173
2174
2175
2176
2177
2178
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188
2189
2190
2191
2192
2193
2194
2195
2196
2197
2198
2199
2200
2201
2202
2203
2204
2205
2206
2207
2208
2209
2210
2211
2212
2213
2214
2215
2216
2217
2218
2219
2220
2221
2222
2223
2224
2225
2226
2227
2228
2229
2230
2231
2232
2233
2234
2235
2236
2237
2238
2239
2240
2241
2242
2243
2244
2245
2246
2247
2248
2249
2250
2251
2252
2253
2254
2255
2256
2257
2258
2259
2260
2261
2262
2263
2264
2265
2266
2267
2268
2269
2270
2271
2272
2273
2274
2275
2276
2277
2278
2279
2280
2281
2282
2283
2284
2285
2286
2287
2288
2289
2290
2291
2292
2293
2294
2295
2296
2297
2298
2299
2300
2301
2302
2303
2304
2305
2306
2307
2308
2309
2310
2311
2312
2313
2314
2315
2316
2317
2318
2319
2320
2321
2322
2323
2324
2325
2326
2327
2328
2329
2330
2331
2332
2333
2334
2335
2336
2337
2338
2339
2340
2341
2342
2343
2344
2345
2346
2347
2348
2349
2350
2351
2352
2353
2354
2355
2356
2357
2358
2359
2360
2361
2362
2363
2364
2365
2366
2367
2368
2369
2370
2371
2372
2373
2374
2375
2376
2377
2378
2379
2380
2381
2382
2383
2384
2385
2386
2387
2388
2389
2390
2391
2392
2393
2394
2395
2396
2397
2398
2399
2400
2401
2402
2403
2404
2405
2406
2407
2408
2409
2410
2411
2412
2413
2414
2415
2416
2417
2418
2419
2420
2421
2422
2423
2424
2425
2426
2427
2428
2429
2430
2431
2432
2433
2434
2435
2436
2437
2438
2439
2440
2441
2442
2443
2444
2445
2446
2447
2448
2449
2450
2451
2452
2453
2454
2455
2456
2457
2458
2459
2460
2461
2462
2463
2464
2465
2466
2467
2468
2469
2470
2471
2472
2473
2474
2475
2476
2477
2478
2479
2480
2481
2482
2483
2484
2485
2486
2487
2488
2489
2490
2491
2492
2493
2494
2495
2496
2497
2498
2499
2500
2501
2502
2503
2504
2505
2506
2507
2508
2509
2510
2511
2512
2513
2514
2515
2516
2517
2518
2519
2520
2521
2522
2523
2524
2525
2526
2527
2528
2529
2530
2531
2532
2533
2534
2535
2536
2537
2538
2539
2540
2541
2542
2543
2544
2545
2546
2547
2548
2549
2550
2551
2552
2553
2554
2555
2556
2557
2558
2559
2560
2561
2562
2563
2564
2565
2566
2567
2568
2569
2570
2571
2572
2573
2574
2575
2576
2577
2578
2579
2580
2581
2582
2583
2584
2585
2586
2587
2588
2589
2590
2591
2592
2593
2594
2595
2596
2597
2598
2599
2600
2601
2602
2603
2604
2605
2606
2607
2608
2609
2610
2611
2612
2613
2614
2615
2616
2617
2618
2619
2620
2621
2622
2623
2624
2625
2626
2627
2628
2629
2630
2631
2632
2633
2634
2635
2636
2637
2638
2639
2640
2641
2642
2643
2644
2645
2646
2647
2648
2649
2650
2651
2652
2653
2654
2655
2656
2657
2658
2659
2660
2661
2662
2663
2664
2665
2666
2667
2668
2669
2670
2671
2672
2673
2674
2675
2676
2677
2678
2679
2680
2681
2682
2683
2684
2685
2686
2687
2688
2689
2690
2691
2692
2693
2694
2695
2696
2697
2698
2699
2700
2701
2702
2703
2704
2705
2706
2707
2708
2709
2710
2711
2712
2713
2714
2715
2716
2717
2718
2719
2720
2721
2722
2723
2724
2725
2726
2727
2728
2729
2730
2731
2732
2733
2734
2735
2736
2737
2738
2739
2740
2741
2742
2743
2744
2745
2746
2747
2748
2749
2750
2751
2752
2753
2754
2755
2756
2757
2758
2759
2760
2761
2762
2763
2764
2765
2766
2767
2768
2769
2770
2771
2772
2773
2774
2775
2776
2777
2778
2779
2780
2781
2782
2783
2784
2785
2786
2787
2788
2789
2790
2791
2792
2793
2794
2795
2796
2797
2798
2799
2800
2801
2802
2803
2804
2805
2806
2807
2808
2809
2810
2811
2812
2813
2814
2815
2816
2817
2818
2819
2820
2821
2822
2823
2824
2825
2826
2827
2828
2829
2830
2831
2832
2833
2834
2835
2836
2837
2838
2839
2840
2841
2842
2843
2844
2845
2846
2847
2848
2849
2850
2851
2852
2853
2854
2855
2856
2857
2858
2859
2860
2861
2862
2863
2864
2865
2866
2867
2868
2869
2870
2871
2872
2873
2874
2875
2876
2877
2878
2879
2880
2881
2882
2883
2884
2885
2886
2887
2888
2889
2890
2891
2892
2893
2894
2895
2896
2897
2898
2899
2900
2901
2902
2903
2904
2905
2906
2907
2908
2909
2910
2911
2912
2913
2914
2915
2916
2917
2918
2919
2920
2921
2922
2923
2924
2925
2926
2927
2928
2929
2930
2931
2932
2933
2934
2935
2936
2937
2938
2939
2940
2941
2942
2943
2944
2945
2946
2947
2948
2949
2950
2951
2952
2953
2954
2955
2956
2957
2958
2959
2960
2961
2962
2963
2964
2965
2966
2967
2968
2969
2970
2971
2972
2973
2974
2975
2976
2977
2978
2979
2980
2981
2982
2983
2984
2985
2986
2987
2988
2989
2990
2991
2992
2993
2994
2995
2996
2997
2998
2999
3000
3001
3002
3003
3004
3005
3006
3007
3008
3009
3010
3011
3012
3013
3014
3015
3016
3017
3018
3019
3020
3021
3022
3023
3024
3025
3026
3027
3028
3029
3030
3031
3032
3033
3034
3035
3036
3037
3038
3039
3040
3041
3042
3043
3044
3045
3046
3047
3048
3049
3050
3051
3052
3053
3054
3055
3056
3057
3058
3059
3060
3061
3062
3063
3064
3065
3066
3067
3068
3069
3070
3071
3072
3073
3074
3075
3076
3077
3078
3079
3080
3081
3082
3083
3084
3085
3086
3087
3088
3089
3090
3091
3092
3093
3094
3095
3096
3097
3098
3099
3100
3101
3102
3103
3104
3105
3106
3107
3108
3109
3110
3111
3112
3113
3114
3115
3116
3117
3118
3119
3120
3121
3122
3123
3124
3125
3126
3127
3128
3129
3130
3131
3132
3133
3134
3135
3136
3137
3138
3139
3140
3141
3142
3143
3144
3145
3146
3147
3148
3149
3150
3151
3152
3153
3154
3155
3156
3157
3158
3159
3160
3161
3162
3163
3164
3165
3166
3167
3168
3169
3170
3171
3172
3173
3174
3175
3176
3177
3178
3179
3180
3181
3182
3183
3184
3185
3186
3187
3188
3189
3190
3191
3192
3193
3194
3195
3196
3197
3198
3199
3200
3201
3202
3203
3204
3205
3206
3207
3208
3209
3210
3211
3212
3213
3214
3215
3216
3217
3218
3219
3220
3221
3222
3223
3224
3225
3226
3227
3228
3229
3230
3231
3232
3233
3234
3235
3236
3237
3238
3239
3240
3241
3242
3243
3244
3245
3246
3247
3248
3249
3250
3251
3252
3253
3254
3255
3256
3257
3258
3259
3260
3261
3262
3263
3264
3265
3266
3267
3268
3269
3270
3271
3272
3273
3274
3275
3276
3277
3278
3279
3280
3281
3282
3283
3284
3285
3286
3287
3288
3289
3290
3291
3292
3293
3294
3295
3296
3297
3298
3299
3300
3301
3302
3303
3304
3305
3306
3307
3308
3309
3310
3311
3312
3313
3314
3315
3316
3317
3318
3319
3320
3321
3322
3323
3324
3325
3326
3327
3328
3329
3330
3331
3332
3333
3334
3335
3336
3337
3338
3339
3340
3341
3342
3343
3344
3345
3346
3347
3348
3349
3350
3351
3352
3353
3354
3355
3356
3357
3358
3359
3360
3361
3362
3363
3364
3365
3366
3367
3368
3369
3370
3371
3372
3373
3374
3375
3376
3377
3378
3379
3380
3381
3382
3383
3384
3385
3386
3387
3388
3389
3390
3391
3392
3393
3394
3395
3396
3397
3398
3399
3400
3401
3402
3403
3404
3405
3406
3407
3408
3409
3410
3411
3412
3413
3414
3415
3416
3417
3418
3419
3420
3421
3422
3423
3424
3425
3426
3427
3428
3429
3430
3431
3432
3433
3434
3435
3436
3437
3438
3439
3440
3441
3442
3443
3444
3445
3446
3447
3448
3449
3450
3451
3452
3453
3454
3455
3456
3457
3458
3459
3460
3461
3462
3463
3464
3465
3466
3467
3468
3469
3470
3471
3472
3473
3474
3475
3476
3477
3478
3479
3480
3481
3482
3483
3484
3485
3486
3487
3488
3489
3490
3491
3492
3493
3494
3495
3496
3497
3498
3499
3500
3501
3502
3503
3504
3505
3506
3507
3508
<?xml version="1.0" encoding="utf-8" ?>
<!DOCTYPE chapter SYSTEM "chapter.dtd">

<chapter>
  <header>
    <copyright>
      <year>2004</year><year>2018</year>
      <holder>Ericsson AB. All Rights Reserved.</holder>
    </copyright>
    <legalnotice>
      Licensed under the Apache License, Version 2.0 (the "License");
      you may not use this file except in compliance with the License.
      You may obtain a copy of the License at
 
          http://www.apache.org/licenses/LICENSE-2.0

      Unless required by applicable law or agreed to in writing, software
      distributed under the License is distributed on an "AS IS" BASIS,
      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
      See the License for the specific language governing permissions and
      limitations under the License.

    </legalnotice>

    <title>Compiler Release Notes</title>
    <prepared>otp_appnotes</prepared>
    <docno>nil</docno>
    <date>nil</date>
    <rev>nil</rev>
    <file>notes.xml</file>
  </header>
  <p>This document describes the changes made to the Compiler
    application.</p>

<section><title>Compiler 7.2.3</title>

    <section><title>Fixed Bugs and Malfunctions</title>
      <list>
        <item>
	    <p>Fixed an issue where files compiled with the
	    <c>+deterministic</c> option differed if they were
	    compiled in a different directory but were otherwise
	    identical.</p>
          <p>
	    Own Id: OTP-15204 Aux Id: ERL-679 </p>
        </item>
      </list>
    </section>

</section>

<section><title>Compiler 7.2.2</title>

    <section><title>Fixed Bugs and Malfunctions</title>
      <list>
        <item>
	    <p>In rare cases involving matching of binary literal
	    strings, the compiler could optimize away code that
	    should be executed.</p>
          <p>
	    Own Id: OTP-15156 Aux Id: ERL-655 </p>
        </item>
        <item>
	    <p>There could be an internal consistency check failure
	    when compiling code that called <c>map_get(Key, Map)</c>
	    and then updated the same map.</p>
          <p>
	    Own Id: OTP-15157</p>
        </item>
        <item>
	    <p>In rare circumstances, the compiler could crash in
	    <c>beam_jump</c> when compiling a floating point
	    operation.</p>
          <p>
	    Own Id: OTP-15166 Aux Id: ERL-660 </p>
        </item>
      </list>
    </section>

</section>

<section><title>Compiler 7.2.1</title>

    <section><title>Fixed Bugs and Malfunctions</title>
      <list>
        <item>
	    <p>The could could crash when compiling a complicated
	    function that used the binary syntax.</p>
          <p>
	    Own Id: OTP-15150 Aux Id: ERL-650 </p>
        </item>
      </list>
    </section>

</section>

<section><title>Compiler 7.2</title>

    <section><title>Fixed Bugs and Malfunctions</title>
      <list>
        <item>
	    <p>Fixed an error in an optimization pass that caused
	    impossible tuple matching.</p>
          <p>
	    Own Id: OTP-14855 Aux Id: ERL-549 </p>
        </item>
        <item>
	    <p>The exception thrown when a list comprehension was
	    given a non-list term was not always correct.</p>
          <p>
	    Own Id: OTP-14992 Aux Id: ERL-572 </p>
        </item>
        <item>
	    <p>The compiler could produce incorrect code in rare
	    circumstances when the <c>[{inline,F/A}]</c> option was
	    used.</p>
          <p>
	    Own Id: OTP-15115 Aux Id: PR-1831 </p>
        </item>
      </list>
    </section>


    <section><title>Improvements and New Features</title>
      <list>
        <item>
	    <p>Changed the default behaviour of <c>.erlang</c>
	    loading: <c>.erlang</c> is no longer loaded from the
	    current directory. <c>c:erlangrc(PathList)</c> can be
	    used to search and load an <c>.erlang</c> file from user
	    specified directories.</p> <p><c>escript</c>,
	    <c>erlc</c>, <c>dialyzer</c> and <c>typer</c> no longer
	    load an <c>.erlang</c> at all.</p>
          <p>
	    *** POTENTIAL INCOMPATIBILITY ***</p>
          <p>
	    Own Id: OTP-14439</p>
        </item>
        <item>
	    <p>Support for "tuple calls" have been removed from the
	    run-time system. Tuple calls was an undocumented and
	    unsupported feature which allowed the module argument for
	    an apply operation to be a tuple: <c>Var = dict:new(),
	    Var:size()</c>. This "feature" frequently caused
	    confusion, especially when such call failed. The
	    stacktrace would point out functions that don't exist in
	    the source code.</p>
	    <p>For legacy code that need to use parameterized modules
	    or tuple calls for some other reason, there is a new
	    compiler option called <c>tuple_calls</c>. When this
	    option is given, the compiler will generate extra code
	    that emulates the old behavior for calls where the module
	    is a variable.</p>
          <p>
	    *** POTENTIAL INCOMPATIBILITY ***</p>
          <p>
	    Own Id: OTP-14497</p>
        </item>
        <item>
	    <p>In code such as <c>example({ok, Val}) -&gt; {ok,
	    Val}.</c> a tuple would be built. The compiler will now
	    automatically rewrite the code to
	    <c>example({ok,Val}=Tuple) -&gt; Tuple.</c> which will
	    reduce code size, execution time, and remove GC
	    pressure.</p>
          <p>
	    Own Id: OTP-14505</p>
        </item>
        <item>
	    <p>The optimization of <c>case</c> expression where only
	    one of the case arms can execute successfully has been
	    improved.</p>
          <p>
	    Own Id: OTP-14525</p>
        </item>
        <item>
	    <p>Some uses of binary matching has been slightly
	    improved, eliminating unnecessary register shuffling.</p>
          <p>
	    Own Id: OTP-14594 Aux Id: ERL-444 </p>
        </item>
        <item>
	    <p>There is a new <c>{compile_info,Info}</c> option for
	    the compiler that allows BEAM-based languages such as
	    Elixir and LFE to add their own compiler versions.</p>
          <p>
	    Own Id: OTP-14615 Aux Id: PR-1558 </p>
        </item>
        <item>
	    <p>Loaded BEAM code in a 64-bit system requires less
	    memory because of better packing of operands for
	    instructions.</p>
	    <p>These memory savings were achieved by major
	    improvements to the <c>beam_makeops</c> scripts used when
	    building the run time system and BEAM compiler. There is
	    also new for documentation for <c>beam_makeops</c> that
	    describes how new BEAM instructions and loader
	    transformations can be implemented. The documentation is
	    found in here in a source directory or git repository:
	    erts/emulator/internal_doc/beam_makeops.md. An online
	    version can be found here:
	    https://github.com/erlang/otp/blob/master/erts/emulator/internal_doc/beam_makeops.md</p>
          <p>
	    Own Id: OTP-14626</p>
        </item>
        <item>
	    <p>Size calculations for binary constructions has been
	    somewhat optimized, producing smaller code.</p>
          <p>
	    Own Id: OTP-14654</p>
        </item>
        <item>
	    <p>When the value returned from a '<c>catch</c>'
	    expression is ignored, no stacktrace will be built if an
	    exception is caught. That will save time and produce less
	    garbage. There are also some minor optimizations of
	    '<c>try</c>/<c>catch</c>' both in the compiler and
	    run-time system.</p>
          <p>
	    Own Id: OTP-14683</p>
        </item>
        <item>
	    <p>There is a new syntax in '<c>try/catch</c>' for
	    retrieving the stacktrace without calling
	    '<c>erlang:get_stacktrace/0</c>'. See the reference
	    manual for a description of the new syntax. The
	    '<c>erlang:get_stacktrace/0</c>' BIF is now
	    deprecated.</p>
          <p>
	    Own Id: OTP-14692</p>
        </item>
        <item>
	    <p>The following is an internal change in the compiler,
	    that is not noticeable for normal use of the compiler:
	    The module <c>v3_life</c> has been removed. Its
	    functionality has been simplified and integrated into
	    <c>v3_codegen</c>.</p>
          <p>
	    Own Id: OTP-14712</p>
        </item>
        <item>
	    <p>The optimization of binary matching that delays
	    creation of sub binaries (see the Efficiency Guide) could
	    be thwarted by the argument order and could be necessary
	    to change the argument order. The compiler has now become
	    smarter and can handle any argument order.</p>
          <p>
	    Own Id: OTP-14774</p>
        </item>
        <item>
	    <p>When the compiler was faced with complex case
	    expressions it would unnecessarily allocate stack
	    elements and shuffle data between x and y registers.
	    Improved code generation to only allocate a stack frame
	    when strictly necessary.</p>
          <p>
	    Own Id: OTP-14808 Aux Id: ERL-514 </p>
        </item>
        <item>
	    <p>There is a new option '<c>makedep_side_effect</c>' for
	    the compiler and <c>-MMD</c> for '<c>erlc</c>' that
	    generates dependencies and continues to compile as
	    normal.</p>
          <p>
	    Own Id: OTP-14830</p>
        </item>
        <item>
	    <p>When compiling modules with huge functions, the
	    compiler would generate a lot of atoms for its internal,
	    sometimes so many that the atom table would overflow. The
	    compiler has been rewritten to generate far less internal
	    atoms to avoid filling the atom table.</p>
          <p>
	    Own Id: OTP-14968 Aux Id: ERL-563 </p>
        </item>
        <item>
	    <p>External funs with literal values for module, name,
	    and arity (e.g. <c>erlang:abs/1</c>) are now treated as
	    literals. That means more efficient code that produces
	    less garbage on the heap.</p>
          <p>
	    Own Id: OTP-15003</p>
        </item>
        <item>
	    <p>Two new guards BIFs operating on maps have been added:
	    <c>map_get/2</c> and <c>is_map_key/2</c>. They do the
	    same as <c>maps:get/2</c> and <c>maps:is_key/2</c>,
	    respectively, except that they are allowed to be used in
	    guards.</p>
          <p>
	    Own Id: OTP-15037 Aux Id: PR-1784, PR-1802 </p>
        </item>
        <item>
	    <p>A call or apply of a literal external fun will be
	    replaced with a direct call.</p>
          <p>
	    Own Id: OTP-15044 Aux Id: ERL-614 </p>
        </item>
        <item>
	    <p>Part of EEP-44 has been implemented.</p>
	    <p>There is a new predefined macro called
	    <c>OTP_RELEASE</c> which is an integer indicating the OTP
	    release number (its value is <c>21</c> in this
	    release).</p>
	    <p>There are new preprocessor directives
	    <c>-if(Condition).</c> and <c>-elif(Condition).</c>. The
	    <c>if/elif</c> supports the builtin function
	    <c>defined(Symbol)</c>.</p>
          <p>
	    Own Id: OTP-15087 Aux Id: PR-1810 </p>
        </item>
      </list>
    </section>

</section>

<section><title>Compiler 7.1.5</title>

    <section><title>Fixed Bugs and Malfunctions</title>
      <list>
        <item>
	    <p>The internal compiler pass (<c>beam_validator</c>)
	    that validates the generated code has been
	    strengthened.</p>
	    <p>When compiling from BEAM assembly code, the
	    <c>beam_type</c> optimizer pass could make the code
	    unsafe. Corrected.</p>
          <p>
	    Own Id: OTP-14863</p>
        </item>
        <item>
	    <p>Corrected optimizations of integers matched out from
	    binaries and used in bit operations.</p>
          <p>
	    Own Id: OTP-14898</p>
        </item>
      </list>
    </section>

</section>

<section><title>Compiler 7.1.4</title>

    <section><title>Fixed Bugs and Malfunctions</title>
      <list>
        <item>
	    <p>The '<c>deterministic</c>' option was not recognized
	    when given in a <c>-compile()</c> attribute in the source
	    code.</p>
          <p>
	    Own Id: OTP-14773 Aux Id: ERL-498 </p>
        </item>
      </list>
    </section>

</section>

<section><title>Compiler 7.1.3</title>

    <section><title>Fixed Bugs and Malfunctions</title>
      <list>
        <item>
	    <p>The compiler could issue an incorrect internal
	    consistency failure diagnostic for some complicated bit
	    syntax maches.</p>
          <p>
	    Own Id: OTP-14640 Aux Id: ERL-490 </p>
        </item>
      </list>
    </section>

</section>

<section><title>Compiler 7.1.2</title>

    <section><title>Fixed Bugs and Malfunctions</title>
      <list>
        <item>
	    <p>Fail labels on guard BIFs weren't taken into account
	    during an optimization pass, and a bug in the validation
	    pass sometimes prevented this from being noticed when a
	    fault occurred.</p>
          <p>
	    Own Id: OTP-14522 Aux Id: ERIERL-48 </p>
        </item>
        <item>
          <p>
	    When compiling from Core Erlang, an 'apply' with a nested
	    apply in the function position would be treated as an
	    invalid call. Corrected. (Thanks to Mikael Pettersson for
	    reporting this bug.)</p>
          <p>
	    Own Id: OTP-14526</p>
        </item>
        <item>
	    <p>Fixed checking of binary matching in the
	    <c>beam_validator</c> module to ensure that potential
	    compiler bugs are found at compile-time instead as
	    emulator crash at run-time.</p>
          <p>
	    Own Id: OTP-14591</p>
        </item>
        <item>
	    <p>There could be false warnings for
	    <c>erlang:get_stacktrace/0</c> being used outside of a
	    <c>try</c> block when using multiple <c>catch</c>
	    clauses.</p>
          <p>
	    Own Id: OTP-14600 Aux Id: ERL-478 </p>
        </item>
      </list>
    </section>


    <section><title>Improvements and New Features</title>
      <list>
        <item>
	    <p> The Erlang code linter no longer checks that the
	    functions mentioned in <c>nowarn_deprecated_function</c>
	    options are declared in the module. </p>
          <p>
	    Own Id: OTP-14378</p>
        </item>
      </list>
    </section>

</section>

<section><title>Compiler 7.1.1</title>

    <section><title>Fixed Bugs and Malfunctions</title>
      <list>
        <item>
	    <p>Fail labels on guard BIFs weren't taken into account
	    during an optimization pass, and a bug in the validation
	    pass sometimes prevented this from being noticed when a
	    fault occurred.</p>
          <p>
	    Own Id: OTP-14522 Aux Id: ERIERL-48 </p>
        </item>
      </list>
    </section>

</section>

<section><title>Compiler 7.1</title>

    <section><title>Fixed Bugs and Malfunctions</title>
      <list>
        <item>
	    <p>For many releases, it has been legal to override a BIF
	    with a local function having the same name. However,
	    calling a local function with the same name as guard BIF
	    as filter in a list comprehension was not allowed.</p>
          <p>
	    Own Id: OTP-13690</p>
        </item>
        <item>
	    <p>compile:forms/2 would not return the module name as
	    documented when one of the options '<c>from_core</c>',
	    '<c>from_asm</c>', or '<c>from_beam</c>' was given. Also,
	    the compiler would crash if one of those options was
	    combined with '<c>native</c>'.</p>
          <p>
	    Own Id: OTP-14408 Aux Id: ERL-417 </p>
        </item>
      </list>
    </section>


    <section><title>Improvements and New Features</title>
      <list>
        <item>
          <p>
	    Optimized test for tuples with an atom as first element.</p>
          <p>
	    Own Id: OTP-12148</p>
        </item>
        <item>
          <p>
	    Compilation of modules with huge literal binary strings
	    is now much faster.</p>
          <p>
	    Own Id: OTP-13794</p>
        </item>
        <item>
	    <p>Replaced usage of deprecated symbolic <seealso
	    marker="erts:erlang#type-time_unit"><c>time
	    unit</c></seealso> representations.</p>
          <p>
	    Own Id: OTP-13831 Aux Id: OTP-13735 </p>
        </item>
        <item>
	    <p>The undocumented and unsupported module
	    <c>sys_pre_expand</c> has been removed. As a partial
	    replacement for the functionality, there is a new
	    function <c>erl_internal:add_predefined_functions/1</c>
	    and <c>erl_expand_records</c> will now add a module
	    prefix to calls to BIFs and imported functions.</p>
          <p>
	    Own Id: OTP-13856</p>
        </item>
        <item>
	    <p>The internal compiler passes now start all generated
	    variables with "@" to avoid any conflicts with variables
	    in languages such as Elixir or LFE.</p>
          <p>
	    Own Id: OTP-13924</p>
        </item>
        <item>
	    <p>The function <c>fmod/2</c> has been added to the
	    <c>math</c> module.</p>
          <p>
	    Own Id: OTP-14000</p>
        </item>
        <item>
	    <p>Code generation for complicated guards have been
	    improved.</p>
          <p>
	    Own Id: OTP-14042</p>
        </item>
        <item>
          <p>
	    The compiler has new warnings for repeated identical map
	    keys.</p>
          <p>
	    A map expression such as,</p>
          <p>
	    <c> #{'a' => 1, 'b' => 2, 'a' => 3}.</c></p>
          <p>
	    will produce a warning for the repeated key 'a'.</p>
          <p>
	    Own Id: OTP-14058</p>
        </item>
        <item>
	    <p>By default, there will now be a warning when
	    <c>export_all</c> is used. The warning can be disabled
	    using <c>nowarn_export_all</c>.</p>
          <p>
	    Own Id: OTP-14071</p>
        </item>
        <item>
          <p>
	    Optimize maps pattern matching by only examining the
	    common keys in each clause first instead of all keys.
	    This will reduce the number of lookups of each key in
	    maps pattern matching.</p>
          <p>
	    Own Id: OTP-14072</p>
        </item>
        <item>
	    <p>There is a new '<c>deterministic</c>' option to omit
	    '<c>source</c>' and '<c>options</c>' tuples in the BEAM
	    file.</p>
          <p>
	    Own Id: OTP-14087</p>
        </item>
        <item>
          <p>
	    Analyzing modules with binary construction with huge
	    strings is now much faster. The compiler also compiles
	    such modules slightly faster.</p>
          <p>
	    Own Id: OTP-14125 Aux Id: ERL-308 </p>
        </item>
        <item>
	    <p>Atoms may now contain arbitrary Unicode
	    characters.</p>
          <p>
	    Own Id: OTP-14178</p>
        </item>
        <item>
	    <p><c>compile:file/2</c> now accepts the option
	    <c>extra_chunks</c> to include extra chunks in the BEAM
	    file.</p>
          <p>
	    Own Id: OTP-14221</p>
        </item>
        <item>
	    <p>The format of debug information that is stored in BEAM
	    files (when <c>debug_info</c> is used) has been changed.
	    The purpose of the change is to better support other
	    BEAM-based languages such as Elixir or LFE.</p>
	    <p>All tools included in OTP (dialyzer, debugger, cover,
	    and so on) will handle both the new format and the
	    previous format. Tools that retrieve the debug
	    information using <c>beam_lib:chunk(Beam,
	    [abstract_code])</c> will continue to work with both the
	    new and old format. Tools that call
	    <c>beam_lib:chunk(Beam, ["Abst"])</c> will not work with
	    the new format.</p>
	    <p>For more information, see the description of
	    <c>debug_info</c> in the documentation for
	    <c>beam_lib</c> and the description of the
	    <c>{debug_info,{Backend,Data}}</c> option in the
	    documentation for <c>compile</c>.</p>
          <p>
	    Own Id: OTP-14369 Aux Id: PR-1367 </p>
        </item>
        <item>
	    <p>In a future release, <c>erlang:get_stacktrace/0</c>
	    will probably only work when called from within a
	    '<c>try</c>' expression (otherwise it will return
	    <c>[]</c>.</p>
	    <p>To help prepare for that change, the compiler will now
	    by default warn if '<c>get_stacktrace/0</c>' is used in a
	    way that will not work in the future. Note that the
	    warning will not be issued if '<c>get_stacktrace/0</c>'
	    is used in a function that uses neither '<c>catch</c>'
	    nor '<c>try</c>' (because that could be a legal use if
	    the function is called from within a '<c>try</c>'.</p>
          <p>
	    Own Id: OTP-14401</p>
        </item>
      </list>
    </section>

</section>

<section><title>Compiler 7.0.4.1</title>

    <section><title>Fixed Bugs and Malfunctions</title>
      <list>
        <item>
	    <p>Fail labels on guard BIFs weren't taken into account
	    during an optimization pass, and a bug in the validation
	    pass sometimes prevented this from being noticed when a
	    fault occurred.</p>
          <p>
	    Own Id: OTP-14522 Aux Id: ERIERL-48 </p>
        </item>
      </list>
    </section>

</section>

<section><title>Compiler 7.0.4</title>

    <section><title>Fixed Bugs and Malfunctions</title>
      <list>
        <item>
          <p>
	    Minor internal changes. A typo in the documentation was
	    also fixed.</p>
          <p>
	    Own Id: OTP-14240</p>
        </item>
      </list>
    </section>

</section>

<section><title>Compiler 7.0.3</title>

    <section><title>Fixed Bugs and Malfunctions</title>
      <list>
        <item>
          <p>
	    Fixed a compiler crash when maps were matched.</p>
          <p>
	    Own Id: OTP-13931 Aux Id: ERL-266 </p>
        </item>
        <item>
          <p>
	    Fixed a compiler crash having to with the delayed
	    sub-creation optimization. (Thanks to Jose Valim for
	    reporting this bug.)</p>
          <p>
	    Own Id: OTP-13947 Aux Id: ERL-268 </p>
        </item>
        <item>
	    <p>The compiler option <c>inline_list_funcs</c>
	    accidentally turned off some other optimizations.</p>
          <p>
	    Own Id: OTP-13985</p>
        </item>
        <item>
	    <p>The compiler could sometimes generate spurious
	    warnings when inlining was enabled.</p>
          <p>
	    Own Id: OTP-14040 Aux Id: ERL-301 </p>
        </item>
      </list>
    </section>

</section>

<section><title>Compiler 7.0.2</title>

    <section><title>Fixed Bugs and Malfunctions</title>
      <list>
        <item>
          <p>
	    If the compiler fails to write the BEAM file, it will now
	    report the reason of the error for the write operation.</p>
          <p>
	    Own Id: OTP-13701</p>
        </item>
        <item>
          <p>
	    Fixed an internal compiler error. (Thanks to Svilen
	    Ivanov for reporting this bug.)</p>
          <p>
	    Own Id: OTP-13780 Aux Id: ERL-202 </p>
        </item>
        <item>
          <p>
	    The compiler could crash when trying to compile a
	    complicated expression with multiple catches all on one
	    line . (Thanks to Thomas Arts for reporting this bug.)</p>
          <p>
	    Own Id: OTP-13804 Aux Id: ERL-209 </p>
        </item>
        <item>
          <p>
	    Eliminated a few internal compiler failures.</p>
          <p>
	    Own Id: OTP-13863</p>
        </item>
      </list>
    </section>

</section>

<section><title>Compiler 7.0.1</title>

    <section><title>Fixed Bugs and Malfunctions</title>
      <list>
        <item>
          <p>
	    A literal binary matching regression was introduced in
	    19.0 where a match could fail to resolve to the right
	    clause. This has now been fixed.</p>
          <p>
	    Own Id: OTP-13738</p>
        </item>
      </list>
    </section>

</section>

<section><title>Compiler 7.0</title>

    <section><title>Fixed Bugs and Malfunctions</title>
      <list>
        <item>
	    <p><c>compile:forms/1,2</c> would crash when used in a
	    working directory that had been deleted by another
	    process.</p>
          <p>
	    Own Id: OTP-13430 Aux Id: ERL-113 </p>
        </item>
        <item>
	    <p>Dialyzer no longer crashes when there is an invalid
	    function call such as <c>42(7)</c> in a module being
	    analyzed. The compiler will now warn for invalid function
	    calls such as <c>X = 42, x(7)</c>.</p>
          <p>
	    Own Id: OTP-13552 Aux Id: ERL-138 </p>
        </item>
      </list>
    </section>


    <section><title>Improvements and New Features</title>
      <list>
        <item>
          <p>
	    Optimization of tuple matching has been slightly
	    improved.</p>
          <p>
	    Own Id: OTP-12951</p>
        </item>
        <item>
	    <p>Five deprecated and undocumented functions in the
	    module <c>core_lib</c> have been removed. The functions
	    are: <c>get_anno/{1,2}</c>, <c>is_literal/1</c>,
	    <c>is_literal_list/1</c>, and <c>literal_value</c>. Use
	    the appropriate functions in the <c>cerl</c> module
	    instead.</p>
          <p>
	    Own Id: OTP-12979</p>
        </item>
        <item>
	    <p>The pre-processor can now expand the ?FUNCTION_NAME
	    and ?FUNCTION_ARITY macros.</p>
          <p>
	    Own Id: OTP-13059</p>
        </item>
        <item>
	    <p>The function mapfold/4 has been added to the
	    <c>cerl_trees</c> module.</p>
          <p>
	    Own Id: OTP-13280</p>
        </item>
        <item>
	    <p>Bitstring comprehensions have been generalized to
	    allow arbitrary expressions in the construction part.</p>
          <p>
	    Own Id: OTP-13289</p>
        </item>
        <item>
	    <p>The compiler will now produce warnings for binary
	    patterns that will never match (example:
	    <c>&lt;&lt;-1/unsigned&gt;&gt; = Bin</c>). </p>
          <p>
	    Own Id: OTP-13374 Aux Id: ERL-44 </p>
        </item>
        <item>
	    <p>The compiler will no longer put the compilation date
	    and time into BEAM files. That means that two BEAM files
	    compiled on the same computer from the same source code
	    and compilation options will be identical.</p>
	    <p>Note: If you want to find out whether a BEAM file on
	    disk is different from the loaded code, compared the MD5
	    value obtained from <c>Mod:module_info(md5)</c> with the
	    MD5 value obtained from
	    <c>beam_lib:md5(BeamFileForMod)</c></p>.
          <p>
	    *** POTENTIAL INCOMPATIBILITY ***</p>
          <p>
	    Own Id: OTP-13504</p>
        </item>
        <item>
	    <p>The function <c>compile:env_compiler_options/0</c> has
	    been added to allow tools to pick up the same default
	    compiler options as the compiler itself.</p>
          <p>
	    Own Id: OTP-13654</p>
        </item>
      </list>
    </section>

</section>


<section><title>Compiler 6.0.3.1</title>
    <section><title>Fixed Bugs and Malfunctions</title>
      <list>
        <item>
	    <p>Fail labels on guard BIFs weren't taken into account
	    during an optimization pass, and a bug in the validation
	    pass sometimes prevented this from being noticed when a
	    fault occurred.</p>
          <p>
	    Own Id: OTP-14522 Aux Id: ERIERL-48 </p>
        </item>
      </list>
    </section>
</section>

<section><title>Compiler 6.0.3</title>

    <section><title>Fixed Bugs and Malfunctions</title>
      <list>
        <item>
          <p>
	    An complicated guard expression in a function call could
	    crash the compiler. (Thanks to Thomas Arts for reporting
	    this bug.)</p>
          <p>
	    Own Id: OTP-13208</p>
        </item>
        <item>
	    <p>Constructing a map in a guard in a catch could crash
	    the compiler. (Thanks to Thomas Arts for reporting this
	    bug.)</p>
          <p>
	    Own Id: OTP-13223</p>
        </item>
        <item>
	    <p>Updating a fun as if it were a map would cause the
	    compiler to crash. (Thanks to Thomas Arts for reporting
	    this bug.)</p>
          <p>
	    Own Id: OTP-13231</p>
        </item>
        <item>
          <p>
	    Fix pretty printing of Core Maps</p>
          <p>
	    Literal maps could cause Dialyzer to crash when pretty
	    printing the results.</p>
          <p>
	    Own Id: OTP-13238</p>
        </item>
        <item>
          <p>
	    A complex combination of bit syntax matching operations
	    would cause an internal consistency check failure during
	    compilation. (Thanks to Jose Valim for reporting this
	    bug.)</p>
          <p>
	    Own Id: OTP-13309</p>
        </item>
      </list>
    </section>

</section>

<section><title>Compiler 6.0.2</title>

    <section><title>Fixed Bugs and Malfunctions</title>
      <list>
        <item>
          <p>
	    Fix cerl_trees:label/2 bug with map K/V swap</p>
          <p>
	    Own Id: OTP-13091</p>
        </item>
        <item>
          <p>
	    Warnings produced when the '<c>bin_opt_info</c>' option
	    was given could sometimes lack filenames and line
	    numbers. (Thanks to José Valim for reporting this bug.)</p>
          <p>
	    Own Id: OTP-13113</p>
        </item>
      </list>
    </section>

</section>

<section><title>Compiler 6.0.1</title>

    <section><title>Fixed Bugs and Malfunctions</title>
      <list>
        <item>
          <p>
	    Fix <c>get_map_elements</c> register corruption</p>
          <p>
	    Instruction <c>get_map_elements</c> might destroy target
	    registers when the fail-label is taken. Only seen for
	    patterns with two, and only two, target registers.
	    Specifically if we copy one register and then jump.</p>
          <p>
	    Own Id: OTP-12967</p>
        </item>
      </list>
    </section>

</section>

<section><title>Compiler 6.0</title>

    <section><title>Fixed Bugs and Malfunctions</title>
      <list>
        <item>
          <p>
	    The compiler optimizes away building of terms that are
	    never actually used. As a result, the compiler in OTP 18
	    may produce more warnings for terms that are built but
	    not used than the compiler in OTP 17.</p>
          <p>
	    Own Id: OTP-12453</p>
        </item>
        <item>
          <p>
	    Using a map could incorrectly suppress warnings for
	    unused variables.</p>
          <p>
	    Own Id: OTP-12515</p>
        </item>
        <item>
          <p>
	    The compiler now properly reports unknown parse
	    transforms. That is, <c>undef</c> exceptions coming from
	    the parse transform itself is reported differently from
	    the absence of the parse transform.</p>
          <p>
	    Own Id: OTP-12723</p>
        </item>
        <item>
          <p>
	    Allow for 'creation of sub binary delayed' optimization
	    if maps instructions are in a clause.</p>
          <p>
	    Own Id: OTP-12758</p>
        </item>
      </list>
    </section>


    <section><title>Improvements and New Features</title>
      <list>
        <item>
          <p>
	    The <c>cerl</c> and <c>cerl_trees</c> modules in the
	    Compiler application are now documented.</p>
          <p>
	    Own Id: OTP-11978</p>
        </item>
        <item>
          <p>
	    The deprecated '<c>asm</c>' option has been removed.</p>
          <p>
	    *** POTENTIAL INCOMPATIBILITY ***</p>
          <p>
	    Own Id: OTP-12100</p>
        </item>
        <item>
          <p>
	    Support variables as Map keys in expressions and patterns</p>
	    <p>Erlang will accept any expression as keys in Map
	    expressions and it will accept literals or bound
	    variables as keys in Map patterns.</p>
          <p>
	    Own Id: OTP-12218</p>
        </item>
        <item>
          <p>
	    Infer Map type information in beam_type compiler
	    optimization pass.</p>
          <p>
	    Own Id: OTP-12253</p>
        </item>
        <item>
          <p>
	    Compiler optimizations have been improved.</p>
          <p>
	    Own Id: OTP-12393</p>
        </item>
        <item>
          <p>
	    Five undocumented functions in the module <c>core_lib</c>
	    have been deprecated and will be removed in the next
	    major release. The functions are: <c>get_anno/{1,2}</c>,
	    <c>is_literal/1</c>, <c>is_literal_list/1</c>, and
	    <c>literal_value</c>. Use the appropriate functions in
	    the <c>cerl</c> module instead.</p>
          <p>
	    Own Id: OTP-12497</p>
        </item>
        <item>
          <p>
	    Change some internal data structures to Maps in order to
	    speed up compilation time. Measured speed up is around
	    10%-15%.</p>
          <p>
	    Own Id: OTP-12774</p>
        </item>
        <item>
          <p>
	    Fix beam_bool pass for Maps instruction get_map_elements</p>
          <p>
	    Before beam_split the get_map_elements instruction is
	    still in blocks and the helper function in beam_jump did
	    not reflect this.</p>
          <p>
	    Own Id: OTP-12844 Aux Id: 17 </p>
        </item>
      </list>
    </section>

</section>

<section><title>Compiler 5.0.4</title>

    <section><title>Fixed Bugs and Malfunctions</title>
      <list>
        <item>
          <p>
	    Matching out a map from a record and then updating the
	    record could cause a 'badarg' exception at run-time.
	    (Thanks to Dmitry Aleksandrov for reporting this bug.)</p>
          <p>
	    Own Id: OTP-12402</p>
        </item>
        <item>
	    <p>The compiler would crash when compiling some complex,
	    nonsensical guards such as:</p>
	    <p> ... <c>when {{X}}, -X</c>...</p>
          <p>
	    Own Id: OTP-12410</p>
        </item>
        <item>
          <p>
	    In rare circumstances, using binary pattern in the value
	    part of a map pattern would cause the compiler to crash.</p>
          <p>
	    Own Id: OTP-12414</p>
        </item>
        <item>
	    <p>Case expressions where a map was wrapped in a tuple or
	    list such as:</p>
	    <p><c>case {a,Map} of</c><br/> <c>{a,#{k:=_}}=Tuple -&gt;
	    Tuple</c><br/> <c>end.</c></p>
	    <p>would be unsafely "optimized" to either cause an
	    exception at run-time or would return an empty map.</p>
          <p>
	    Own Id: OTP-12451</p>
        </item>
        <item>
	    <p>When a variable was compared to a literal map using
	    the '<c>==</c>' operator, the compiler would change the
	    operator to '<c>=:=</c>' since it is more efficient.
	    However, this optimization is not safe if the map literal
	    has numeric keys or values. The compiler will now only do
	    the optimization if all keys and values are
	    non-numeric.</p>
          <p>
	    Own Id: OTP-12456</p>
        </item>
      </list>
    </section>

</section>

<section><title>Compiler 5.0.3</title>

    <section><title>Fixed Bugs and Malfunctions</title>
      <list>
        <item>
          <p>
	    Named funs with the same name and arity could get mixed
	    up with each other.</p>
          <p>
	    Own Id: OTP-12262</p>
        </item>
        <item>
          <p>
	    Coalesce map keys in dialyzer mode</p>
          <p>
	    This fixes a regression introduced in commit
	    805f9c89fc01220bc1bb0f27e1b68fd4eca688ba The problem
	    occurred with compounded map keys compiled with dialyzer
	    option turned on, '+dialyzer'.</p>
          <p>
	    Reported by: Ivan Uemlianin</p>
          <p>
	    Own Id: OTP-12347</p>
        </item>
      </list>
    </section>

</section>

<section><title>Compiler 5.0.2</title>

    <section><title>Fixed Bugs and Malfunctions</title>
      <list>
        <item>
          <p>
	    Corrected a bug with incorrect code generation when
	    inlining was turned on.</p>
          <p>
	    Own Id: OTP-12132</p>
        </item>
      </list>
    </section>

</section>

<section><title>Compiler 5.0.1</title>

    <section><title>Fixed Bugs and Malfunctions</title>
      <list>
        <item>
          <p>
	    A Dialyzer crash involving analysis of Map types has now
	    been fixed.</p>
          <p>
	    Own Id: OTP-11947</p>
        </item>
        <item>
	    <p>The compiler would fail to compile a file with a
	    latin-1 character in the false branch of an <c>-ifdef</c>
	    or <c>-indef</c>.</p>
          <p>
	    Own Id: OTP-11987</p>
        </item>
      </list>
    </section>

</section>

<section><title>Compiler 5.0</title>

    <section><title>Fixed Bugs and Malfunctions</title>
      <list>
        <item>
          <p>
	    Line numbers would not be correct when a binary
	    construction such as
	    '<c>&lt;&lt;Bin/binary,...&gt;&gt;</c>' fails. (Thanks to
	    Stanislav Seletskiy for reporting this bug.)</p>
          <p>
	    Own Id: OTP-11572</p>
        </item>
        <item>
          <p>
	    The compiler now properly annotates the code in value in
	    the '<c>after</c>' clause for a '<c>try</c>' so that
	    Dialyzer no longer generates a false warning for an
	    unmatched return.</p>
          <p>
	    Own Id: OTP-11580</p>
        </item>
        <item>
          <p>
	    Some case statements where no clause would match could
	    cause an internal error in the compiler. (Thanks to Erik
	    Soe Sorensen for reporting this bug.)</p>
          <p>
	    Own Id: OTP-11610</p>
        </item>
        <item>
          <p>
	    With <c>--Wunmatched_returns</c>, dialyzer will no longer
	    warn when the value of a list comprehension is ignored,
	    provided that the each value in the list would be an
	    atomic value (such as integer or atoms, as opposed to
	    tuples and lists). Example: ignoring '<c>[io:format(...)
	    || ...]</c>' will not cause a warning, while ignoring
	    '<c>[file:close(Fd) || ...]</c>' will.</p>
          <p>
	    Own Id: OTP-11626</p>
        </item>
        <item>
          <p>
	    Matching out a binary and applying the binary as if it
	    were a fun would crash the run-time system. (Thanks to
	    Loïc Hoguin.)</p>
          <p>
	    Own Id: OTP-11672</p>
        </item>
        <item>
          <p>
	    Some local implementations of removing the last element
	    from a list are replaced by <c>lists:droplast/1</c>. Note
	    that this requires at least <c>stdlib-2.0</c>, which is
	    the stdlib version delivered in OTP 17.0. (Thanks to Hans
	    Svensson)</p>
          <p>
	    Own Id: OTP-11678</p>
        </item>
        <item>
          <p>
	    Allow all auto imports to be suppressed at once.
	    Introducing the no_auto_import attribute:
	    -compile(no_auto_import). Useful for code generation
	    tools that always use the qualified function names and
	    want to avoid the auto imported functions clashing with
	    local ones. (Thanks to José Valim.)</p>
          <p>
	    Own Id: OTP-11682</p>
        </item>
        <item>
          <p>
	    Application upgrade (appup) files are corrected for the
	    following applications: </p>
          <p>
	    <c>asn1, common_test, compiler, crypto, debugger,
	    dialyzer, edoc, eldap, erl_docgen, et, eunit, gs, hipe,
	    inets, observer, odbc, os_mon, otp_mibs, parsetools,
	    percept, public_key, reltool, runtime_tools, ssh,
	    syntax_tools, test_server, tools, typer, webtool, wx,
	    xmerl</c></p>
          <p>
	    A new test utility for testing appup files is added to
	    test_server. This is now used by most applications in
	    OTP.</p>
          <p>
	    (Thanks to Tobias Schlager)</p>
          <p>
	    Own Id: OTP-11744</p>
        </item>
        <item>
          <p>
	    Adapt 'asm' deprecation message to new version scheme.
	    (Thanks to Tuncer Ayaz)</p>
          <p>
	    Own Id: OTP-11751</p>
        </item>
        <item>
          <p>
	    A number of compiler errors where unusual or nonsensical
	    code would crash the compiler have been reported by Ulf
	    Norell and corrected by Anthony Ramine.</p>
          <p>
	    Own Id: OTP-11770</p>
        </item>
      </list>
    </section>


    <section><title>Improvements and New Features</title>
      <list>
        <item>
          <p>
	    Compilation times for modules with a huge number for
	    record accesses using the dot operator has been improved.</p>
          <p>
	    Own Id: OTP-10652</p>
        </item>
        <item>
          <p>
	    The compiler can generate somewhat better code by moving
	    let expressions into sequences. (Thanks to Anthony
	    Ramine.)</p>
          <p>
	    Own Id: OTP-11056</p>
        </item>
        <item>
          <p>
	    Forbid unsized fields in patterns of binary generators
	    and simplified v3_core's translation of bit string
	    generators. (Thanks to Anthony Ramine.)</p>
          <p>
	    Own Id: OTP-11186</p>
        </item>
        <item>
          <p>
	    Funs can now be a given a name. Thanks to to Richard
	    O'Keefe for the idea (EEP37) and to Anthony Ramine for
	    the implementation.</p>
          <p>
	    Own Id: OTP-11537</p>
        </item>
        <item>
          <p>
	    Using the <c>from_asm</c> option to produce a BEAM file
	    starting from BEAM assembly code would often fail because
	    early optimization passes would not understand
	    instructions that later optimization passes would
	    introduce. (Thanks to Anthony Ramine.)</p>
          <p>
	    Own Id: OTP-11544</p>
        </item>
        <item>
          <p>
	    The <c>.core</c> and <c>.S</c> extensions are now
	    documented in the <c>erlc</c> documentation, and the
	    '<c>from_core</c>' and '<c>from_asm</c>' options are now
	    documented in the compiler documentation. (Thanks to
	    Tuncer Ayaz.)</p>
          <p>
	    Own Id: OTP-11547</p>
        </item>
        <item>
	    <p>Optimization of case expressions that build tuples or
	    lists have been improved.</p>
          <p>
	    Own Id: OTP-11584</p>
        </item>
        <item>
          <p>
	    EEP43: New data type - Maps</p>
          <p>
	    With Maps you may for instance:</p>
          <taglist>
            <tag/> <item><c>M0 = #{ a =&gt; 1, b =&gt; 2}, % create
	      associations</c></item>
            <tag/><item><c>M1 = M0#{ a := 10 }, % update values</c></item>
            <tag/><item><c>M2 = M1#{ "hi" =&gt;
	      "hello"}, % add new associations</c></item>
            <tag/><item><c>#{ "hi" := V1, a := V2, b := V3} = M2.
               % match keys with values</c></item>
          </taglist>
		<p>
	    For information on how to use Maps please see Map Expressions in the
		<seealso marker="doc/reference_manual:expressions#map_expressions">
			Reference Manual</seealso>.</p>
          <p>
	    The current implementation is without the following
	    features:</p>
          <taglist>
            <tag/><item>No variable keys</item>
	    <tag/><item>No single value access</item>
            <tag/><item>No map comprehensions</item>
          </taglist>
          <p>
	    Note that Maps is <em>experimental</em> during OTP 17.0.</p>
          <p>
	    Own Id: OTP-11616</p>
        </item>
        <item>
          <p>
	    Some function specs are corrected or moved and some edoc
	    comments are corrected in order to allow use of edoc.
	    (Thanks to Pierre Fenoll)</p>
          <p>
	    Own Id: OTP-11702</p>
        </item>
        <item>
          <p>
	    Thanks to Anthony Ramine for several improvements to the
	    optimizations in the BEAM compiler and for cleaning up
	    the code the code that transforms list and binary
	    comprehensions to Core Erlang.</p>
          <p>
	    Own Id: OTP-11720</p>
        </item>
        <item>
          <p>
	    The default encoding for Erlang source files is now
	    UTF-8. As a temporary measure to ease the transition from
	    the old default of latin-1, if the compiler encounters
	    byte sequences that are not valid UTF-8 sequences, the
	    compiler will re-try the compilation in latin-1 mode.
	    This workaround will be removed in a future release.</p>
          <p>
	    Own Id: OTP-11791</p>
        </item>
      </list>
    </section>

</section>

<section><title>Compiler 4.9.4</title>

    <section><title>Fixed Bugs and Malfunctions</title>
      <list>
        <item>
          <p>
	    Typo fix ambigous -&gt; ambiguous. Thanks to Leo Correa.</p>
          <p>
	    Own Id: OTP-11455</p>
        </item>
      </list>
    </section>


    <section><title>Improvements and New Features</title>
      <list>
        <item>
          <p>
	    Lift 'after' blocks to zeroary functions. Thanks to
	    Anthony Ramine.</p>
          <p>
	    Own Id: OTP-11267</p>
        </item>
      </list>
    </section>

</section>

<section><title>Compiler 4.9.3</title>

    <section><title>Fixed Bugs and Malfunctions</title>
      <list>
        <item>
          <p>
	    Expressions such as <c>'B = is_integer(V), if B and B
	    -&gt; ok end'</c> would crash the compiler.</p>
          <p>
	    Own Id: OTP-11240</p>
        </item>
        <item>
          <p>
	    <c>compile:file2/2</c> with the option
	    <c>report_errors</c> could return ErrorInfo tuples with
	    only two elements, while the documentation says that the
	    ErrorInfo tuple always has three elements. Also updated
	    the documentation to add that the first element may be
	    '<c>none</c>' if no line number is applicable.</p>
          <p>
	    Own Id: OTP-11304 Aux Id: seq12412 </p>
        </item>
      </list>
    </section>


    <section><title>Improvements and New Features</title>
      <list>
        <item>
          <p>
	    Fix matching of floating point middle-endian machines.
	    Thanks to Johannes Weissl.</p>
          <p>
	    Own Id: OTP-11201</p>
        </item>
        <item>
          <p>
	    Restrict inlining of local fun references. Thanks to
	    Anthony Ramine.</p>
          <p>
	    Own Id: OTP-11211</p>
        </item>
        <item>
          <p>
	    Silence a misleading warning with some comprehensions.
	    Thanks to Anthony Ramine.</p>
          <p>
	    Own Id: OTP-11212</p>
        </item>
        <item>
          <p>
	    Forbid returning a match context in beam_validator.
	    Thanks to Anthony Ramine.</p>
          <p>
	    Own Id: OTP-11247</p>
        </item>
      </list>
    </section>

</section>

<section><title>Compiler 4.9.2</title>

    <section><title>Fixed Bugs and Malfunctions</title>
      <list>
        <item>
          <p>
	    Compiling functions with complex boolean operations in
	    guards could be very slow. (Thanks to Magnus Muller for
	    reporting this issue.)</p>
          <p>
	    Own Id: OTP-10939</p>
        </item>
        <item>
          <p>
	    Certain guard expressions used in a receive statement
	    could cause the compiler to crash.</p>
          <p>
	    Own Id: OTP-11119 Aux Id: seq12342 </p>
        </item>
      </list>
    </section>


    <section><title>Improvements and New Features</title>
      <list>
        <item>
          <p>
	    Fix optimization of some binary comprehensions. Thanks to
	    Anthony Ramine.</p>
          <p>
	    Own Id: OTP-11005</p>
        </item>
        <item>
          <p>
	    Use a set to store ref registers in beam_receive. Thanks
	    to Anthony Ramine.</p>
          <p>
	    Own Id: OTP-11069</p>
        </item>
        <item>
          <p>
	    Fix renaming of bs_put_string instructions. Thanks to
	    Anthony Ramine.</p>
          <p>
	    Own Id: OTP-11129</p>
        </item>
      </list>
    </section>

</section>

<section><title>Compiler 4.9.1</title>

    <section><title>Fixed Bugs and Malfunctions</title>
      <list>
        <item>
          <p>
	    The compiler would crash attempting to compile
	    expressions such as "element(2, not_tuple)".</p>
          <p>
	    Own Id: OTP-10794</p>
        </item>
        <item>
          <p>
	    Forbid multiple values in Core Erlang sequence arguments.
	    Thanks to José Valim and Anthony Ramine.</p>
          <p>
	    Own Id: OTP-10818</p>
        </item>
        <item>
          <p>
	    An unsafe optimization would cause the compiler to crash
	    with an internal error for certain complex code
	    sequences.</p>
          <p>
	    Own Id: OTP-10825 Aux Id: seq12247 </p>
        </item>
      </list>
    </section>


    <section><title>Improvements and New Features</title>
      <list>
        <item>
	    <p>Integers in expression that will give a floating point
	    result (such as "<c>X / 2</c>" will now be converted to
	    floating point at compile-time. (Suggested by Richard
	    O'Keefe.)</p>
	    <p>Identical floating points constans in a module will
	    now be coalesced to one entry in the constant pool.</p>
          <p>
	    Own Id: OTP-10788</p>
        </item>
      </list>
    </section>

</section>

<section><title>Compiler 4.9</title>

    <section><title>Improvements and New Features</title>
      <list>
        <item>
          <p>
	    The compiler optimizations have been polished, so that
	    the code quality will be slightly better in some cases.</p>
          <p>
	    Own Id: OTP-10193</p>
        </item>
        <item>
	    <p> Support for Unicode has been implemented. </p>
          <p>
	    Own Id: OTP-10302</p>
        </item>
        <item>
	    <p>Where necessary a comment stating encoding has been
	    added to Erlang files. The comment is meant to be removed
	    in Erlang/OTP R17B when UTF-8 becomes the default
	    encoding. </p>
          <p>
	    Own Id: OTP-10630</p>
        </item>
        <item>
          <p>
	    Fix some wrong warnings triggered by the option
	    inline_list_funcs. Thanks to Anthony Ramine.</p>
          <p>
	    Own Id: OTP-10690</p>
        </item>
        <item>
          <p>
	    Forbid local fun variables in Core Erlang guards. Thanks
	    to Anthony Ramine.</p>
          <p>
	    Own Id: OTP-10706</p>
        </item>
        <item>
          <p>
	    Binary syntax matches could cause an internal consistency
	    error in in the compiler. (Thanks to Viktor Sovietov for
	    reporting this bug.)</p>
          <p>
	    Own Id: OTP-10724</p>
        </item>
      </list>
    </section>

</section>

<section><title>Compiler 4.8.2</title>

    <section><title>Fixed Bugs and Malfunctions</title>
      <list>
        <item>
          <p>
	    Modules with very many functions would compile very
	    slowly.</p>
          <p>
	    Own Id: OTP-10123</p>
        </item>
        <item>
          <p>
	    <c>compile:forms/2</c> will now use a
	    {source,SourceFilePath} to set the source returned by
	    <c>module_info(compile)</c> (Thanks to José Valim)</p>
          <p>
	    Own Id: OTP-10150</p>
        </item>
        <item>
          <p>
	    A process which had enabled trap_exit would receive EXIT
	    messages after calling the compiler. (Thanks to Jeremy
	    Heater.)</p>
          <p>
	    Own Id: OTP-10171</p>
        </item>
        <item>
          <p>
	    Fix messages ordering with column numbers</p>
          <p>
	    Own Id: OTP-10183</p>
        </item>
        <item>
          <p>
	    sys_pre_expand: Fix BASE never being set</p>
          <p>
	    Commit a612e99fb5aaa934fe5a8591db0f083d7fa0b20a turned
	    module attributes from 2-tuples to 3-tuples but forgot to
	    update get_base/1, breaking BASE for parametric modules.</p>
          <p>
	    Own Id: OTP-10184</p>
        </item>
        <item>
          <p>
	    The compiler will now issue a warning if literal tuple
	    funs are used. For example, {erlang,is_tuple}(X) will now
	    generate a warning.</p>
          <p>
	    Own Id: OTP-10185</p>
        </item>
        <item>
          <p>
	    The compiler will now warn for illegal sizes for segments
	    in binary construction. For example,
	    &lt;&lt;X:(2.5)&gt;&gt; will now cause the compiler to
	    issue a warning.</p>
          <p>
	    Own Id: OTP-10197</p>
        </item>
        <item>
          <p>
	    Fix the erlc -MP flag</p>
          <p>
	    Because of a copy-and-paste error in erlc.c, the -MP flag
	    had the same effect as -MG. As a workaround, you had to
	    pass +makedep_phony to enable the MP option. This patch
	    makes -MP work as intended.</p>
          <p>
	    Own Id: OTP-10211</p>
        </item>
      </list>
    </section>

</section>

<section><title>Compiler 4.8.1</title>

    <section><title>Fixed Bugs and Malfunctions</title>
      <list>
        <item>
          <p>
	    In rare circumstance, the compiler could crash when
	    compiling a case statement. (Thanks to Hakan Mattsson.)</p>
          <p>
	    Own Id: OTP-9842</p>
        </item>
        <item>
	    <p>Calling a guard test (such as is_list/1) from the
	    top-level in a guard, would cause a compiler crash if
	    there was a local definition with the same name.
	    Corrected to reject the program with an error
	    message.</p>
          <p>
	    Own Id: OTP-9866</p>
        </item>
        <item>
	    <p>Using <c>get/1</c> in a <c>try</c> block could in some
	    cases cause an internal compiler error. (Thanks to Eric
	    Merritt.)</p>
          <p>
	    Own Id: OTP-9867</p>
        </item>
        <item>
          <p>
	    An unexported on_load function would not get run if the
	    module was compiled with the <c>inline</c> option.
	    (Thanks to Yiannis Tsiouris.)</p>
          <p>
	    Own Id: OTP-9910</p>
        </item>
        <item>
          <p>
	    Fixed a discrepancy in compile_info</p>
          <p>
	    The BEAM disassembler used the atom 'none' to signify the
	    absence of a compile_info chunk in a .beam file. This
	    clashed with the type declaration of the compile_info
	    field of a #beam_file{} record as containing a list. Now
	    [] signifies the absence of this chunk. This simplifies
	    the code and avoids a dialyzer warning.</p>
          <p>
	    Own Id: OTP-9917</p>
        </item>
        <item>
          <p>
	    Fix typo in `compile' doc: unmatched parenthesis (Thanks
	    to Ricardo Catalinas Jiménez)</p>
          <p>
	    Own Id: OTP-9919</p>
        </item>
        <item>
	    <p>In a <c>try</c>...<c>catch</c> statement that always
	    returned <c>false</c>, the compiler would remove calls to
	    BIFs that could not cause an exception (such as
	    <c>put/2</c>). Example of such code: <c>try put(K, V),
	    false catch _:_ -&gt; false end.</c></p>
          <p>
	    Own Id: OTP-9982</p>
        </item>
      </list>
    </section>

</section>

<section><title>Compiler 4.8</title>

    <section><title>Fixed Bugs and Malfunctions</title>
      <list>
        <item>
          <p>
	    Add '-callback' attributes in stdlib's behaviours</p>
          <p>
	    Replace the behaviour_info(callbacks) export in stdlib's
	    behaviours with -callback' attributes for all the
	    callbacks. Update the documentation with information on
	    the callback attribute Automatically generate
	    'behaviour_info' function from '-callback' attributes</p>
          <p>
	    'behaviour_info(callbacks)' is a special function that is
	    defined in a module which describes a behaviour and
	    returns a list of its callbacks.</p>
          <p>
	    This function is now automatically generated using the
	    '-callback' specs. An error is returned by lint if user
	    defines both '-callback' attributes and the
	    behaviour_info/1 function. If no type info is needed for
	    a callback use a generic spec for it. Add '-callback'
	    attribute to language syntax</p>
          <p>
	    Behaviours may define specs for their callbacks using the
	    familiar spec syntax, replacing the '-spec' keyword with
	    '-callback'. Simple lint checks are performed to ensure
	    that no callbacks are defined twice and all types
	    referred are declared.</p>
          <p>
	    These attributes can be then used by tools to provide
	    documentation to the behaviour or find discrepancies in
	    the callback definitions in the callback module.</p>
          <p>
	    Add callback specs into 'application' module in kernel
	    Add callback specs to tftp module following internet
	    documentation Add callback specs to inets_service module
	    following possibly deprecated comments</p>
          <p>
	    Own Id: OTP-9621</p>
        </item>
        <item>
          <p>
	    The calculation of the 'uniq' value for a fun (see
	    <c>erlang:fun_info/1</c>) was too weak and has been
	    strengthened. It used to be based on the only the code
	    for the fun body, but it is now based on the MD5 of the
	    BEAM code for the module.</p>
          <p>
	    Own Id: OTP-9667</p>
        </item>
      </list>
    </section>


    <section><title>Improvements and New Features</title>
      <list>
        <item>
	    <p>Variables are now now allowed in '<c>fun M:F/A</c>' as
	    suggested by Richard O'Keefe in EEP-23.</p>
	    <p>The representation of '<c>fun M:F/A</c>' in the
	    abstract format has been changed in an incompatible way.
	    Tools that directly read or manipulate the abstract
	    format (such as parse transforms) may need to be updated.
	    The compiler can handle both the new and the old format
	    (i.e. extracting the abstract format from a pre-R15 BEAM
	    file and compiling it using compile:forms/1,2 will work).
	    The <c>syntax_tools</c> application can also handle both
	    formats.</p>
          <p>
	    *** POTENTIAL INCOMPATIBILITY ***</p>
          <p>
	    Own Id: OTP-9643</p>
        </item>
        <item>
          <p>
	    <c>filename:find_src/1,2</c> will now work on stripped
	    BEAM files (reported by Per Hedeland). The HiPE compiler
	    will also work on stripped BEAM files. The BEAM compiler
	    will no longer include compilation options given in the
	    source code itself in <c>M:module_info(compile)</c>
	    (because those options will be applied anyway if the
	    module is re-compiled).</p>
          <p>
	    Own Id: OTP-9752</p>
        </item>
        <item>
	    <p>Inlining binary matching could cause an internal
	    compiler error. (Thanks to Rene Kijewski for reporting
	    this bug.)</p>
          <p>
	    Own Id: OTP-9770</p>
        </item>
      </list>
    </section>

</section>

<section><title>Compiler 4.7.5</title>

    <section><title>Fixed Bugs and Malfunctions</title>
      <list>
        <item>
          <p>
	    Compiler options given in the source code using a
	    <c>-compile()</c> attribute used to be included twice in
	    <c>Mod:module_info(compile)</c>. They are now only
	    included once at the beginning of the list of options.</p>
          <p>
	    Own Id: OTP-9534</p>
        </item>
        <item>
          <p>
	    beam_disasm: Handle stripped BEAM files</p>
          <p>
	    beam_disasm:file/1 would crash if asked to disassemble a
	    stripped BEAM file without an "Attr" chunk. (Thanks to
	    Haitao Li)</p>
          <p>
	    Own Id: OTP-9571</p>
        </item>
      </list>
    </section>

</section>

<section><title>Compiler 4.7.4</title>

    <section><title>Fixed Bugs and Malfunctions</title>
      <list>
        <item>
          <p>
	    If a variable is matched out in binary matching and used
	    as the size for a binary element, it would seem to be
	    unbound if used in a subsequent match operation. (Thanks
	    to Bernard Duggan.)</p>
          <p>
	    Own Id: OTP-9134</p>
        </item>
        <item>
	    <p>Eliminate incorrect warning in
	    <c>sys_core_fold</c></p>
          <p>
	    Own Id: OTP-9152</p>
        </item>
      </list>
    </section>

</section>

<section><title>Compiler 4.7.3</title>

    <section><title>Fixed Bugs and Malfunctions</title>
      <list>
        <item>
          <p>
	    The <c>-export_type()</c> directive is no longer included
	    among the attributes.</p>
          <p>
	    Own Id: OTP-8998</p>
        </item>
      </list>
    </section>


    <section><title>Improvements and New Features</title>
      <list>
        <item>
          <p>
	    The maximum number of allowed arguments for an Erlang
	    function has been lowered from 256 to 255, so that the
	    number of arguments can now fit in a byte.</p>
          <p>
	    Own Id: OTP-9049</p>
        </item>
        <item>
          <p>
	    Dependency generation for Makefiles has been added to the
	    compiler and erlc. See the manual pages for
	    <c>compile</c> and <c>erlc</c>. (Thanks to Jean-Sebastien
	    Pedron.)</p>
          <p>
	    Own Id: OTP-9065</p>
        </item>
      </list>
    </section>

</section>

<section><title>Compiler 4.7.2</title>

    <section><title>Fixed Bugs and Malfunctions</title>
      <list>
        <item>
          <p>
	    Two compiler bugs (that would cause the compiler to
	    terminate) reported by Christopher Williams have been
	    fixed.</p>
          <p>
	    Own Id: OTP-8949</p>
        </item>
      </list>
    </section>


    <section><title>Improvements and New Features</title>
      <list>
        <item>
	    <p>The compiler would translate binary comprehensions
	    containing tail segments in a way that would would
	    confuse Dialyzer. For instance:</p>
	    <p><c>[42 || &lt;&lt;_:8/integer, _/bits&gt;&gt; &lt;=
	    Bits]</c></p>
          <p>
	    would produce a Dialyzer warning.</p>
          <p>
	    Own Id: OTP-8864</p>
        </item>
        <item>
          <p>
	    Code such as <c>foo(A) -&gt; &lt;&lt;A:0&gt;&gt;</c>
	    would crash the compiler.</p>
          <p>
	    Own Id: OTP-8865</p>
        </item>
        <item>
          <p>
	    The compiler could fail with an internal error when
	    variables were exported from a receive block but the
	    return value of the receive block were not used. (Thanks
	    to Jim Engquist for reporting this error.)</p>
          <p>
	    Own Id: OTP-8888</p>
        </item>
      </list>
    </section>

</section>

<section><title>Compiler 4.7.1</title>

    <section><title>Improvements and New Features</title>
      <list>
        <item>
          <p>
	    Eliminated warnings for auto-imported BIF clashes.</p>
          <p>
	    Own Id: OTP-8840</p>
        </item>
      </list>
    </section>

</section>

<section><title>Compiler 4.7</title>

    <section><title>Fixed Bugs and Malfunctions</title>
      <list>
        <item>
          <p>
	    Several problems in the inliner have been fixed.</p>
          <p>
	    Own Id: OTP-8552</p>
        </item>
      </list>
    </section>


    <section><title>Improvements and New Features</title>
      <list>
        <item>
          <p>
	    The module binary from EEP31 (and EEP9) is implemented.</p>
          <p>
	    Own Id: OTP-8217</p>
        </item>
        <item>
	    <p>Local and imported functions now override the
	    auto-imported BIFs when the names clash. The pre R14
	    behaviour was that auto-imported BIFs would override
	    local functions. To avoid that old programs change
	    behaviour, the following will generate an error:</p>
	    <list><item><p>Doing a call without explicit module name
	    to a local function having a name clashing with the name
	    of an auto-imported BIF that was present (and
	    auto-imported) before OTP R14A</p></item>
	    <item><p>Explicitly importing a function having a name
	    clashing with the name of an autoimported BIF that was
	    present (and autoimported) before OTP R14A</p></item>
	    <item><p>Using any form of the old compiler directive
	    <c>nowarn_bif_clash</c></p></item> </list> <p>If the BIF
	    was added or auto-imported in OTP R14A or later,
	    overriding it with an import or a local function will
	    only result in a warning,</p> <p>To resolve clashes, you
	    can either use the explicit module name <c>erlang</c> to
	    call the BIF, or you can remove the auto-import of that
	    specific BIF by using the new compiler directive
	    <c>-compile({no_auto_import,[F/A]}).</c>, which makes all
	    calls to the local or imported function without explicit
	    module name pass without warnings or errors.</p> <p>The
	    change makes it possible to add auto-imported BIFs
	    without breaking or silently changing old code in the
	    future. However some current code ingeniously utilizing
	    the old behaviour or the <c>nowarn_bif_clash</c> compiler
	    directive, might need changing to be accepted by the
	    compiler.</p>
          <p>
	    *** POTENTIAL INCOMPATIBILITY ***</p>
          <p>
	    Own Id: OTP-8579</p>
        </item>
        <item>
	    <p>The undocumented, unsupport, and deprecated function
	    <c>lists:flat_length/1</c> has been removed.</p>
          <p>
	    Own Id: OTP-8584</p>
        </item>
        <item>
	    <p>Nested records can now be accessed without
	    parenthesis. See the Reference Manual for examples.
	    (Thanks to YAMASHINA Hio and Tuncer Ayaz.)</p>
          <p>
	    Own Id: OTP-8597</p>
        </item>
        <item>
	    <p>It is now possible to suppress the warning in code
	    such as "<c>list_to_integer(S), ok</c>" by assigning the
	    ignored value "_" like this: "<c>_ = list_to_integer(S),
	    ok</c>".</p>
          <p>
	    Own Id: OTP-8602</p>
        </item>
        <item>
	    <p><c>receive</c> statements that can only read out a
	    newly created reference are now specially optimized so
	    that it will execute in constant time regardless of the
	    number of messages in the receive queue for the process.
	    That optimization will benefit calls to
	    <c>gen_server:call()</c>. (See <c>gen:do_call/4</c> for
	    an example of a receive statement that will be
	    optimized.)</p>
          <p>
	    Own Id: OTP-8623</p>
        </item>
        <item>
	    <p>The compiler optimizes record operations better.</p>
          <p>
	    Own Id: OTP-8668</p>
        </item>
      </list>
    </section>

</section>

<section><title>Compiler 4.6.5</title>

    <section><title>Fixed Bugs and Malfunctions</title>
      <list>
        <item>
          <p>
	    Using complex boolean expressions in ifs could cause the
	    compiler to either crash or teminate with an internal
	    error. (Thanks to Simon Cornish.)</p>
          <p>
	    Own Id: OTP-8338</p>
        </item>
        <item>
	    <p>Bit string comprehensions can now be used in
	    parameterized modules. (Thanks to Jebu Ittiachen.)</p>
          <p>
	    Own Id: OTP-8447</p>
        </item>
      </list>
    </section>


    <section><title>Improvements and New Features</title>
      <list>
        <item>
          <p>
	    The expected return value for an on_load function has
	    been changed. (See the section about code loading in the
	    Reference manual.)</p>
          <p>
	    *** POTENTIAL INCOMPATIBILITY ***</p>
          <p>
	    Own Id: OTP-8339</p>
        </item>
        <item>
          <p>
	    In rare circumstances when using garbaging collecting
	    guard BIFs, the validation pass (beam_validator) would
	    signal that the code was unsafe, when it in fact was
	    correct. (Thanks to Kiran Khaladkar.)</p>
          <p>
	    Own Id: OTP-8378</p>
        </item>
        <item>
          <p>
	    The <c>-Werror</c> option for <c>erlc</c> and the
	    compiler option <c>warnings_as_errors</c> will cause
	    warnings to be treated as errors. (Thanks to Christopher
	    Faulet.)</p>
          <p>
	    Own Id: OTP-8382</p>
        </item>
        <item>
	    <p>Macros overloading has been implemented. (Thanks to
	    Christopher Faulet.)</p>
          <p>
	    Own Id: OTP-8388</p>
        </item>
      </list>
    </section>

</section>

<section><title>Compiler 4.6.4</title>

    <section><title>Fixed Bugs and Malfunctions</title>
      <list>
        <item>
	    <p>The compiler's 'E' option now works with modules with
	    types and specifications.</p>
          <p>
	    Own Id: OTP-8238 Aux Id: OTP-8150 </p>
        </item>
        <item>
          <p>
	    Certain uses of binary matching in a
	    <c>begin</c>-<c>end</c> in a list comprehension could
	    cause the compiler to crash or generate incorrect code.</p>
          <p>
	    Own Id: OTP-8271</p>
        </item>
      </list>
    </section>


    <section><title>Improvements and New Features</title>
      <list>
        <item>
          <p>
	    The documentation is now built with open source tools
	    (xsltproc and fop) that exists on most platforms. One
	    visible change is that the frames are removed.</p>
          <p>
	    Own Id: OTP-8201</p>
        </item>
        <item>
          <p>
	    The compiler could crash if invalid calls to is_record/2
	    was used in (for example) a list comprehension. (Thanks
	    to Tobias Lindahl.)</p>
          <p>
	    Own Id: OTP-8269</p>
        </item>
        <item>
	    <p>The -on_load() directive can be used to run a function
	    when a module is loaded. It is documented in the section
	    about code loading in the Reference Manual.</p>
          <p>
	    Own Id: OTP-8295</p>
        </item>
      </list>
    </section>

</section>

<section><title>Compiler 4.6.3</title>

    <section><title>Improvements and New Features</title>
      <list>
        <item>
	    <p>Corrected liveness optimization to eliminate a
	    compiler crash that could occur when compiling bit syntax
	    construction code. (Thanks to Mikage Sawatari.)</p>
	    <p>Calling BIFs such as <c>length/1</c> in guard context
	    in a try/catch block could cause a compiler crash.
	    (Thanks to Paul Fisher.)</p>
	    <p>Using filter expressions containing <c>andalso</c> or
	    <c>orelse</c> in a list comprehension could cause a
	    compiler crash. (Thanks to Martin Engström.)</p>
          <p>
	    Own Id: OTP-8054</p>
        </item>
        <item>
          <p>
	    A guard with nested 'not' operators could cause the
	    compiler to crash. (Thanks to Tuncer Ayaz.)</p>
          <p>
	    Own Id: OTP-8131</p>
        </item>
      </list>
    </section>

</section>

<section><title>Compiler 4.6.2</title>

    <section><title>Fixed Bugs and Malfunctions</title>
      <list>
        <item>
          <p>
	    The compiler would crash while compiling certain complex
	    function bodies containing <c>receive after</c> due to a
	    bug in the jump optimizer (a label that had only had
	    backward references could still be removed). (Thanks to
	    Vincent de Phily.)</p>
          <p>
	    Own Id: OTP-7980</p>
        </item>
      </list>
    </section>

</section>

<section><title>Compiler 4.6.1</title>

    <section><title>Fixed Bugs and Malfunctions</title>
      <list>
        <item>
          <p>
	    Miscellaneous minor bugs fixed.</p>
          <p>
	    Own Id: OTP-7937</p>
        </item>
      </list>
    </section>


    <section><title>Improvements and New Features</title>
      <list>
        <item>
          <p>
	    There will be more efficient code if there is a clause
	    that matches the empty binary and no other clauses that
	    matches non-empty binaries.</p>
          <p>
	    Own Id: OTP-7924</p>
        </item>
        <item>
	    <p>There is new option to allow a module to have a module
	    name other than the filename. Do not use it unless you
	    know what you are doing.</p>
          <p>
	    Own Id: OTP-7927</p>
        </item>
      </list>
    </section>

</section>

<section><title>Compiler 4.6.0.1</title>

    <section><title>Fixed Bugs and Malfunctions</title>
      <list>
        <item>
            <p>Using <c>andalso</c>/<c>orelse</c> or record access in
            a <c>try</c>...<c>catch</c> could cause a compiler
            crash.</p>
            <p>Som large and complex functions could require
            extremely long compilation times (hours or days).</p>
          <p>
            Own Id: OTP-7905</p>
        </item>
      </list>
    </section>

</section>

<section><title>Compiler 4.6</title>

    <section><title>Fixed Bugs and Malfunctions</title>
      <list>
        <item>
          <p>
	    For some complex guards which used
	    <c>andalso</c>/<c>orelse</c>, the compiler would crash.
	    (Thanks to Hunter Morris.)</p>
          <p>
	    Own Id: OTP-7679</p>
        </item>
        <item>
          <p>
	    Code that (incorrectly) used the the value of nested
	    applications of <c>setelement/3</c> in bit syntax
	    construction could crash the compiler.</p>
          <p>
	    Own Id: OTP-7690</p>
        </item>
        <item>
	    <p>Modules containing huge integers (consisting of
	    several hundreds of thousands of digits or more) could be
	    slow to compile. This problem has been corrected.</p>
          <p>
	    Own Id: OTP-7707 Aux Id: seq11129 </p>
        </item>
        <item>
	    <p>If the generator in a list comprehension is given a
	    non-list term, there will now be <c>function_clause</c>
	    exception instead of a <c>case_clause</c> exception (as
	    it was in all releases before R12B).</p>
          <p>
	    Own Id: OTP-7844</p>
        </item>
      </list>
    </section>


    <section><title>Improvements and New Features</title>
      <list>
        <item>
          <p>
	    The compiler could crash if the size for a binary segment
	    in matching was a complex literal such as binary or
	    tuple.</p>
          <p>
	    Own Id: OTP-7650</p>
        </item>
        <item>
          <p>
	    The compiler generates more compact and faster code for
	    matching of complex constants (such as constant lists and
	    tuples).</p>
          <p>
	    Own Id: OTP-7655</p>
        </item>
        <item>
          <p>
	    The undocumented, unsupported, and deprecated guard BIF
	    <c>is_constant/1</c> has been removed.</p>
          <p>
	    *** INCOMPATIBILITY with R12B ***</p>
          <p>
	    Own Id: OTP-7673</p>
        </item>
        <item>
	    <p>The compiler generates better code for many guard
	    expressions, and especially for guards that use
	    <c>andalso</c>/<c>orelse</c> or record fields.</p>
	    <p>(In technical terms, <c>andalso</c>/<c>orelse</c> in a
	    guard would case the creation of a stack frame and saving
	    of all x registers that could potentially be alive after
	    the guard and restoring all x registers before leaving
	    the guard. For certain guards, far too many x registers
	    were saved and subsequently restored. In this version of
	    the compiler, no stack frame is created and no x
	    registers are saved and restored.)</p>
          <p>
	    Own Id: OTP-7718</p>
        </item>
        <item>
	    <p>The default size for the resulting binary created by a
	    binary comprehension was 64Kb in R12B (it would grow if
	    needed). This was often far too much. In this release,
	    the default is changed to 256 bytes. Furthermore, for
	    most binary comprehensions without filters, the exact
	    size of the resulting binary can be calculated beforehand
	    and the compiler now generates code that does that
	    calculation.</p>
          <p>
	    Own Id: OTP-7737</p>
        </item>
        <item>
	    <p>The short-circuit operators <c>andalso</c> and
	    <c>orelse</c> no longer guarantees that their second
	    argument is either <c>true</c> or <c>false</c>. As a
	    consequence, <c>andalso</c>/<c>orelse</c> are now
	    tail-recursive.</p>
          <p>
	    *** POTENTIAL INCOMPATIBILITY ***</p>
          <p>
	    Own Id: OTP-7748</p>
        </item>
        <item>
	    <p>The compiler will refuse to a compile file where the
	    module name in the file differs from the output file
	    name.</p>
	    <p>When compiling using <c>erlc</c>, the current working
	    directory will no be included in the code path (unless
	    explicitly added using "-pa .").</p>
          <p>
	    *** POTENTIAL INCOMPATIBILITY ***</p>
          <p>
	    Own Id: OTP-7793</p>
        </item>
        <item>
	    <p>There will no longer be any warnings for list
	    comprehensions without generators, as such list
	    comprehension have turned out to be useful.</p>
          <p>
	    Own Id: OTP-7846</p>
        </item>
        <item>
	    <p>Warnings for obsolete guard tests are now turned on.
	    (That is, writing <c>list(L)</c> in a guard instead of
	    <c>is_list(L)</c> will generate a warning.)</p>
	    <p>The warnings can be turned off using the
	    <c>nowarn_obsolete_guard</c> option.</p>
          <p>
	    Own Id: OTP-7850</p>
        </item>
        <item>
	    <p>The copyright notices have been updated.</p>
          <p>
	    Own Id: OTP-7851</p>
        </item>
        <item>
	    <p>If a module contains an exported function with the
	    same name as an auto-imported BIF (such as
	    <c>length/1</c>), any calls to the BIF must have an
	    explicit <c>erlang:</c> prefix, or there will be a
	    compilation error (such calls would only generate a
	    warning in previous releases).</p>
	    <p>(The reason for the change is to avoid breaking code
	    in a future major release, R14 or R15, in which we plan
	    to make calls without a module prefix always call the
	    local function in the same module even if there is an
	    auto-imported BIF with the same name.)</p>
          <p>
	    *** POTENTIAL INCOMPATIBILITY ***</p>
          <p>
	    Own Id: OTP-7873</p>
        </item>
      </list>
    </section>

</section>

<section><title>Compiler 4.5.5</title>

    <section><title>Fixed Bugs and Malfunctions</title>
      <list>
        <item>
	    <p>Matching on a zero-width segment in the bit syntax
	    would crash the compiler. (Thanks to Will.)</p>
          <p>
	    Own Id: OTP-7591</p>
        </item>
      </list>
    </section>


    <section><title>Improvements and New Features</title>
      <list>
        <item>
          <p>
	    In bit syntax expressions which started with a binary
	    segment, and was followed by at least two segments of
	    variable size, too little space could be allocated for
	    the binary, leading to memory corruption.</p>
          <p>
	    Own Id: OTP-7556</p>
        </item>
        <item>
	    <p>In user-defined attributes, <c>Name/Arity</c> is now
	    allowed and will be translated to <c>{Name,Arity}</c>.
	    (An implementation of EEP-24 by Richard O'Keefe.)</p>
	    <p>The <c>module_info/{0,1}</c> functions automatically
	    inserted into each compiled modules are now documented in
	    the Modules section in the Reference Manual.</p>
          <p>
	    Own Id: OTP-7586</p>
        </item>
      </list>
    </section>

</section>

<section><title>Compiler 4.5.4</title>

    <section><title>Improvements and New Features</title>
      <list>
        <item>
          <p>
	    Certain complex bit syntax matching operations matching
	    out binaries and having several clauses could give
	    incorrect results (the matched out binaries were too
	    short). (Thanks to Christian von Roques for bug report
	    and correction.)</p>
          <p>
	    Own Id: OTP-7498</p>
        </item>
      </list>
    </section>

</section>

<section><title>Compiler 4.5.3</title>

    <section><title>Improvements and New Features</title>
      <list>
        <item>
          <p>
	    New option <c>warn_export_all</c> to warn for a module
	    using <c>export_all</c>. (Thanks to Richard Carlsson.)</p>
          <p>
	    Own Id: OTP-7392</p>
        </item>
      </list>
    </section>

</section>

<section><title>Compiler 4.5.2.1</title>

    <section><title>Fixed Bugs and Malfunctions</title>
      <list>
        <item>
          <p>
            In rare circumstances, the length/1 BIF (and a few other
            guard BIFs) would seem to return an incorrect value (of
            any type).</p>
          <p>
            Own Id: OTP-7345 Aux Id: seq10962 </p>
        </item>
      </list>
    </section>

</section>
<section><title>Compiler 4.5.2</title>

    <section><title>Fixed Bugs and Malfunctions</title>
      <list>
        <item>
	    <p>A bug in the old inliner has been fixed. Some
	    undocumented functionality has been removed.</p>
          <p>
	    Own Id: OTP-7223</p>
        </item>
        <item>
	    <p>Matching several binary patterns in parallel using the
	    '=' operator is not allowed (an implementation
	    limitation), but the compiler did not reject all such
	    attempts (depending on the patterns, the generated code
	    might or might not work correctly). Now the compiler
	    rejects all binary patterns joined by '='.</p>
          <p>
	    Own Id: OTP-7227</p>
        </item>
        <item>
	    <p>Complex combinations of record operations and binary
	    matching could cause the compiler to crash. (Thanks to
	    Vladimir Klebansky.)</p>
          <p>
	    Own Id: OTP-7233</p>
        </item>
        <item>
          <p>
	    In rare circumstances, mixing binary matching clauses
	    with clauses matching other data types, the compiler
	    could crash.</p>
          <p>
	    Own Id: OTP-7240 Aux Id: seq10916 </p>
        </item>
      </list>
    </section>

</section>

<section><title>Compiler 4.5.1.1</title>

    <section><title>Fixed Bugs and Malfunctions</title>
      <list>
        <item>
          <p>
	    Corrected a compiler bug that could cause a complex
	    binary matching operation to fail when it shouldn't.
	    (Thanks to Tomas Stejskal.)</p>
          <p>
	    Own Id: OTP-7188</p>
        </item>
        <item>
          <p>
	    In unusual circumstances, the environment for a fun could
	    bind wrong values.</p>
          <p>
	    Own Id: OTP-7202 Aux Id: seq10887 </p>
        </item>
        <item>
	    <p>Long sequences of list comprehensions without
	    generators joined by the '++' operator would cause a code
	    expansion explosion, which could cause the compiler to
	    run out of memory. To resolve this problem, in
	    '<c>[...||...]++Expr</c>', <c>Expr</c> is now evaluated
	    before the list comprehension. This change <em>is</em>
	    backwards compatible (see the following note about
	    evaluation order if you have doubts).</p>
	    <p>Note about evaluation order: The Reference manual says
	    that subexpressions are evaluated <em>in any order</em>
	    before the expression itself. Therefore, in an expression
	    such as '<c>LeftExpr++RightExpr</c>', you should not
	    depend on <c>LeftExpr</c> being evaluated before
	    <c>RightExpr</c> or vice versa. The evaluation order is
	    only important if the expressions contains and/or depends
	    on operations with side-effects, such as message passing
	    or ETS operations.</p>
          <p>
	    Own Id: OTP-7206</p>
        </item>
      </list>
    </section>

</section>


<section><title>Compiler 4.5.1</title>

    <section><title>Fixed Bugs and Malfunctions</title>
      <list>
        <item>
          <p>
	    A match expression inside a function call could cause a
	    false "a term is constructed but never used" warning.</p>
          <p>
	    Own Id: OTP-7018 Aux Id: seq10824 </p>
        </item>
        <item>
	    <p>The compiler could crash if a binary tail was matched
	    out, and then used in a binary append operation. (Thanks
	    to Oleg Avdeev.)</p>
	    <p>Similarly, the compiler could crash if a binary tail
	    was matched out, and then used (incorrectly) in binary
	    construction in an integer field. (Thanks to Fredrik
	    Svahn.) Or was incorrectly used in a float field. Or was
	    used in a binary field with a given length. (Thanks to
	    Chih - Wei Yu.) </p>
          <p>
	    Own Id: OTP-7022</p>
        </item>
        <item>
          <p>
	    Matching an empty binary in a record and then using the
	    same record again could cause a compiler crash. (Thanks
	    to Fredrik Thulin.)</p>
          <p>
	    Own Id: OTP-7029</p>
        </item>
        <item>
	    <p>In rare circumstances, constants containing floating
	    points and integers could be confused. Example:</p>
	    <p><c>f(a) -> [1]; f(b) -> [1.0].</c></p>
	    <p>Both <c>f(a)</c> and <c>f(b)</c> would return
	    <c>[1]</c>.</p>
          <p>
	    Own Id: OTP-7073</p>
        </item>
        <item>
	    <p>Some bit syntax code such as</p>
	    <p><c>matching d(_,&lt;$lt;$gt;$gt;) -> one; d(0,&lt;$lt;D$gt;$gt;)
	    ->two.</c></p>
	    <p>could crash the compiler. (Thanks to Simon
	    Cornish.)</p>
          <p>
	    Own Id: OTP-7094</p>
        </item>
        <item>
          <p>
	    In unusual circumstances, a call to a fun could fail due
	    to an unsafe optimization. (Thanks to Simon Cornish.)</p>
          <p>
	    Own Id: OTP-7102</p>
        </item>
        <item>
          <p>
	    Bit syntax matching with a guard containing two or more
	    uses of andalso/orelse could cause the compiler to crash.
	    (Thanks to Mateusz Berezecki.)</p>
          <p>
	    Own Id: OTP-7113</p>
        </item>
        <item>
          <p>
	    This was only a problem if you generated or wrote your
	    own Core Erlang code: The Core Erlang optimizer code
	    could move nested calls such as
	    <c>erlang:'$lt;'(erlang:length(L), 2)</c> as case expression
	    into a guard, which would change the semantics. (Thanks
	    to Robert Virding.)</p>
          <p>
	    Own Id: OTP-7117</p>
        </item>
      </list>
    </section>


    <section><title>Improvements and New Features</title>
      <list>
        <item>
          <p>
	    The compiler could generate suboptimal code for record
	    updates if the record update code consisted of multiple
	    source code lines.</p>
          <p>
	    Own Id: OTP-7101</p>
        </item>
      </list>
    </section>

</section>

<section><title>Compiler 4.5</title>

    <section><title>Fixed Bugs and Malfunctions</title>
      <list>
        <item>
	    <p>The compiler used to allow that a binary field without
	    size could be used in other positions than at the end in
	    bit syntax pattern. For instance,
	    <c><![CDATA[<<B/binary,EmptyBinary/binary>> = Bin]]></c>
	    used to compile, but now the compilation will fail with
	    an an error message.</p>
	    <p>Also, it is now longer permitted to give a literal
	    string in a binary pattern a type or a size; for
	    instance, <c><![CDATA[<<"abc"/binary>> = Bin]]></c> will
	    no longer compile. (In previous releases, there would
	    always be a <c>badmatch</c> exception at run-time.)</p>
          <p>
	    Own Id: OTP-6885</p>
        </item>
      </list>
    </section>


    <section><title>Improvements and New Features</title>
      <list>
        <item>
          <p>
	    Bitstrings (bit-level) binaries and binary comprehensions
	    are now part of the language. See the Reference Manual.</p>
          <p>
	    Own Id: OTP-6558</p>
        </item>
        <item>
          <p>
	    The '<c>compressed</c>' option for the compiler has been
	    documented.</p>
          <p>
	    Own Id: OTP-6801</p>
        </item>
        <item>
	    <p>If the value of a list comprehension is not used, such
	    as in '<c>[do_something(X) || X &lt;- List], ok</c>', a
	    result list will no longer be built. For more details,
	    see the Efficiency Guide.</p>
	    <p>If the value of an expression is not used, and the
	    expression has no side effects except for possibly
	    throwing an exception, a warning will be generated.
	    Examples: '<c>self(),ok</c>' and
	    '<c>{error,Reason},ok</c>'.</p>
          <p>
	    Own Id: OTP-6824</p>
        </item>
        <item>
          <p>
	    Three new functions have been added to the <c>compile</c>
	    module: <c>noenv_file/2</c>, <c>noenv_forms/2</c>, and
	    <c>noenv_output_generated/1</c>.</p>
          <p>
	    Own Id: OTP-6829</p>
        </item>
        <item>
	    <p>Many bit syntax operations, both construction and
	    matching, are faster. For further information, see the
	    Efficiency Guide.</p>
          <p>
	    Own Id: OTP-6838</p>
        </item>
        <item>
	    <p>Literal lists, tuples, and binaries are no longer
	    constructed at run-time as they used to be, but are
	    stored in a per-module constant pool. Literals that are
	    used more than once are stored only once.</p>
	    <p>This is not a change to the language, only in the
	    details of its implementation. Therefore, the
	    implications of this change is described in the
	    Efficiency Guide.</p>
	    <p>Example 1: In the expression <c>element(BitNum-1,
	    {1,2,4,8,16,32,64,128})</c>, the tuple used to be
	    constructed every time the expression was executed, which
	    could be detrimental to performance in two ways if the
	    expression was executed in a loop: the time to build the
	    tuple itself and the time spent in garbage collections
	    because the heap filled up with garbage faster.</p>
	    <p>Example 2: Literal strings, such as <c>"abc"</c>, used
	    to be stored in the compiled code compactly as a byte
	    string and expanded to a list at run-time. Now all
	    strings will be stored expanded to lists (such as
	    <c>[$a,$b,$c]</c>) in the constant pool. That means that
	    the string will be faster to use at run-time, but that it
	    will require more space even when not used. If space is
	    an issue, you might want to use binary literals (that is,
	    <c>&lt;&lt;"abc"&lt;&lt;</c>) instead of string literals for
	    infrequently used long strings (such as error
	    messages).</p>
          <p>
	    Own Id: OTP-6850</p>
        </item>
        <item>
          <p>
	    Recursive calls now usually consume less stack than in
	    R11B. See the Efficiency Guide.</p>
          <p>
	    Own Id: OTP-6862 Aux Id: seq10746 </p>
        </item>
        <item>
	    <p>Two new guard BIFs have been introduced as a
	    recommended replacement for <c>size/1</c>. (The
	    <c>size/1</c> BIF will be removed no earlier than in
	    R14B.) The BIFs are <c>tuple_size/1</c> to calculate the
	    size of a tuple and <c>byte_size/1</c> to calculate the
	    number of bytes needed for the contents of the binary or
	    bitstring (rounded up to the nearest number of bytes if
	    necessary).</p>
	    <p>There is also a new <c>bit_size/1</c> BIF that returns
	    the exact number of bits that a binary or bitstring
	    contains.</p>
          <p>
	    Own Id: OTP-6902</p>
        </item>
        <item>
          <p>
	    The two internal functions <c>erl_bifs:is_bif/3</c> and
	    <c>erl_bifs:is_guard/3</c> have been removed. They were
	    unsupported, undocumented, and unmaintained.</p>
          <p>
	    Own Id: OTP-6966</p>
        </item>
      </list>
    </section>

</section>

  <section>
    <title>Compiler 4.4.5</title>

    <section>
      <title>Fixed Bugs and Malfunctions</title>
      <list type="bulleted">
        <item>
          <p>The compiler would crash if you tried to combine to
            non-list literals with '<c><![CDATA[++]]></c>' (for instance,
            <c><![CDATA[an_atom++"string"]]></c>).</p>
          <p>Own Id: OTP-6630 Aux Id: seq10635 </p>
        </item>
      </list>
    </section>

    <section>
      <title>Improvements and New Features</title>
      <list type="bulleted">
        <item>
          <p>Minor Makefile changes.</p>
          <p>Own Id: OTP-6689</p>
        </item>
      </list>
    </section>
  </section>

  <section>
    <title>Compiler 4.4.4</title>

    <section>
      <title>Fixed Bugs and Malfunctions</title>
      <list type="bulleted">
        <item>
          <p>Incorrect code could be generated for bit syntax matching
            if the old inliner was used with aggressive settings.</p>
          <p>Own Id: OTP-6461</p>
        </item>
      </list>
    </section>
  </section>

  <section>
    <title>Compiler 4.4.3</title>

    <section>
      <title>Fixed Bugs and Malfunctions</title>
      <list type="bulleted">
        <item>
          <p>The R10B compiler could generate unsafe
            <c><![CDATA[bs_save/bs_restore]]></c> instructions that could cause
            memory corruption. (The R11B compiler does not have that
            problem.) The erlang emulator will now refuse to load
            R10B-compiled modules that contain such unsafe
            <c><![CDATA[bs_save/bs_restore]]></c> instructions. In addition, the
            beam_validator module in the compiler will also reject
            such instructions (in case it is used to validate R10B
            code). (Thanks to Matthew Reilly.)</p>
          <p>Own Id: OTP-6386</p>
        </item>
      </list>
    </section>

    <section>
      <title>Improvements and New Features</title>
      <list type="bulleted">
        <item>
          <p>Directives for parse transforms that have been run are
            now removed from the abstract code stored when the
            debug_info option is given, to prevent the parse
            transforms to be run again.</p>
          <p>Own Id: OTP-5344</p>
        </item>
        <item>
          <p>Minor improvements in code generation for some guards
            expression involving boolean expressions.</p>
          <p>Own Id: OTP-6347</p>
        </item>
      </list>
    </section>
  </section>

  <section>
    <title>Compiler 4.4.2.1</title>

    <section>
      <title>Fixed Bugs and Malfunctions</title>
      <list type="bulleted">
        <item>
          <p>The compiler could generate incorrect code for bit syntax
            matching consisting of several clauses.</p>
          <p>Own Id: OTP-6392 Aux Id: seq10539 </p>
        </item>
      </list>
    </section>
  </section>

  <section>
    <title>Compiler 4.4.2</title>

    <section>
      <title>Fixed Bugs and Malfunctions</title>
      <list type="bulleted">
        <item>
          <p>Defining a fun itself containing a fun in an
            <c><![CDATA[after]]></c> block of a <c><![CDATA[try]]></c> would cause the
            compiler to crash or generate incorrect code. (Thanks to
            Tim Rath.)</p>
          <p>Shorter compilation times for modules containing with
            an extreme number of functions (10000 functions or more).</p>
          <p>(The compiled could generate deprecated instructions
            for certain bit syntax matching operations.)</p>
          <p>Own Id: OTP-6212 Aux Id: seq10446 </p>
        </item>
        <item>
          <p>Fixed several bugs that would cause warnings to be shown
            without file name and line number.</p>
          <p>Own Id: OTP-6260 Aux Id: seq10461 </p>
        </item>
      </list>
    </section>

    <section>
      <title>Improvements and New Features</title>
      <list type="bulleted">
        <item>
          <p>The <c><![CDATA[strict_record_tests]]></c> option is now default;
            that is, reading a field from a record using the
            <c><![CDATA[Record#record_tag.field]]></c> syntax will fail if
            <c><![CDATA[Record]]></c> is not a record of the correct type.</p>
          <p>If necessary, the record tests can be turned off by
            giving the <c><![CDATA[no_strict_record_tests]]></c> option. To avoid
            editing Makefiles, the environment variable
            <c><![CDATA[ERL_COMPILER_OPTIONS]]></c> can be set to
            "<c><![CDATA[no_strict_record_tests]]></c>".</p>
          <p>The <c><![CDATA[no_strict_record_tests]]></c> option will probably
            be removed in the R12B release.</p>
          <p>*** POTENTIAL INCOMPATIBILITY ***</p>
          <p>Own Id: OTP-6294</p>
        </item>
      </list>
    </section>
  </section>

  <section>
    <title>Compiler 4.4.1</title>

    <section>
      <title>Fixed Bugs and Malfunctions</title>
      <list type="bulleted">
        <item>
          <p>The compiler used to crash if a module contained code
            similar to '<c><![CDATA[fun(1=0) -> ok end]]></c>'. (Thanks to
            Richard Carlsson.)</p>
          <p>The compiler would spend really long time compiling
            bit syntax expressions such as
            '<c><![CDATA[<<1:(50*1024*1024)>>]]></c>' and produce a huge .beam
            file. Corrected.</p>
          <p>The compiler would compile list comprehensions with
            many generators really, really slow. (Thanks to Thomas
            Raes.)</p>
          <p>Module attributes would be stored in reverse order
            compared to the order in the source code. (Thus,
            <c><![CDATA[M:module_info(attributes)]]></c> would also return the
            attributes in reversed order.)</p>
          <p>Defining a fun in an <c><![CDATA[after]]></c> block of a
            <c><![CDATA[try]]></c> would cause the compiler to crash or generate
            incorrect code. (Thanks to Martin Bjorklund.)</p>
          <p>The combination of binary pattern and a guard with
            andalso/orelse could cause the compiler to crash.</p>
          <p>Own Id: OTP-6121 Aux Id: seq10400 </p>
        </item>
      </list>
    </section>
  </section>

  <section>
    <title>Compiler 4.4</title>

    <section>
      <title>Fixed Bugs and Malfunctions</title>
      <list type="bulleted">
        <item>
          <p>When a <c><![CDATA[.hrl]]></c> file is included using
            <c><![CDATA[-include_lib]]></c>, the include path is temporarily
            updated to include the directory the <c><![CDATA[.hrl]]></c> file was
            found in, which will allow that <c><![CDATA[.hrl]]></c> file to itself
            include files from the same directory using
            <c><![CDATA[-include]]></c>. (Thanks to Richard Carlsson.)</p>
          <p>Own Id: OTP-5944</p>
        </item>
      </list>
    </section>

    <section>
      <title>Improvements and New Features</title>
      <list type="bulleted">
        <item>
          <p>The <c><![CDATA[andalso]]></c> and <c><![CDATA[orelse]]></c> operators are
            now allowed to be used in guards. That also applies to
            match specifications.</p>
          <p>Own Id: OTP-5894 Aux Id: OTP-5149 </p>
        </item>
        <item>
          <p>When given the new option
            <c><![CDATA[strict_record_tests]]></c>, the compiler will generate
            code that verifies the record type for
            <c><![CDATA[R#record.field]]></c> operations in guards. Code that
            verifies record types in bodies has already been
            generated since R10B, but in this release there will be a
            <c><![CDATA[{badrecord,RecordTag}]]></c> instead of a
            <c><![CDATA[badmatch]]></c> if the record verification test fails.
            See <c><![CDATA[compile(3)]]></c> for more information.</p>
          <p>The Erlang shell always applies strict record tests.</p>
          <p>Own Id: OTP-5915 Aux Id: OTP-5714 </p>
        </item>
        <item>
          <p>The BIF <c><![CDATA[is_record/3]]></c> can now be used in guards.
            Also, <c><![CDATA[is_record/3]]></c> can now be called without an
            <c><![CDATA[erlang:]]></c> module prefix for consistency with the other
            <c><![CDATA[is_*]]></c> functions.</p>
          <p>Own Id: OTP-5916</p>
        </item>
        <item>
          <p>The compiler options <c><![CDATA[ignore_try]]></c> and
            <c><![CDATA[ignore_cond]]></c>, which allowed code that used
            unquoted <c><![CDATA[try]]></c> or <c><![CDATA[cond]]></c> as atoms or record
            tags, has been removed. Old code that depended on the
            options need to be revised to have occurrences of
            <c><![CDATA[try]]></c> or <c><![CDATA[cond]]></c> as atom or record tags
            single-quoted. (Note: Although <c><![CDATA[cond]]></c> is a reserved
            keyword, there is no <c><![CDATA[cond]]></c> statement. It might be
            introduced in a future release.)</p>
          <p>*** POTENTIAL INCOMPATIBILITY ***</p>
          <p>Own Id: OTP-6058</p>
        </item>
      </list>
    </section>
  </section>

  <section>
    <title>Compiler 4.3.12</title>

    <section>
      <title>Improvements and New Features</title>
      <list type="bulleted">
        <item>
          <p>The following code would crash the compiler: <c><![CDATA[case T of #r{s = ""} -> T #r{s = "x"} end]]></c>. (Thanks to
            Richard Carlsson.)</p>
          <p>The compiler could crash if binaries were constructed
            in certain guards involving boolean operators (including
            semicolon). (Thanks to Torbjorn Tornkvist.)</p>
          <p>Own Id: OTP-5872</p>
        </item>
        <item>
          <p>The compiler will now warn that the
            <c><![CDATA[megaco:format_versions/1]]></c> function is deprecated.</p>
          <p>Own Id: OTP-5976</p>
        </item>
      </list>
    </section>
  </section>

  <section>
    <title>Compiler 4.3.11</title>

    <section>
      <title>Improvements and New Features</title>
      <list type="bulleted">
        <item>
          <p>The compiler would assume that some patterns with
            aliases ('=') would not match if they were split into
            several lines. (Thanks to Peter Nagy/Mats Cronqvist.)</p>
          <p>Minor cleanups to eliminate Dialyzer warnings.</p>
          <p>Own Id: OTP-5791 Aux Id: seq10141 </p>
        </item>
      </list>
    </section>
  </section>

  <section>
    <title>Compiler 4.3.10</title>

    <section>
      <title>Fixed Bugs and Malfunctions</title>
      <list type="bulleted">
        <item>
          <p>When given the new option
            <c><![CDATA[strict_record_tests]]></c>, the compiler will generate
            code that verifies the record type for
            <c><![CDATA[R#record.field]]></c> operations (in body context only,
            not in guards). See the documentation for the
            <c><![CDATA[compile]]></c> module for more information.</p>
          <p>The beam validator pass of the compiler could crash
            given in rare circumstances when given certain
            combinations of catches and record operations. (Thanks to
            Mats Cronqvist.)</p>
          <p>Attributes containing binaries (such as -a(&lt;&lt;1,2,3&gt;&gt;))
            would crash the compiler. (Thanks to Roger Price.)</p>
          <p>Multiple behaviours in the same module will no longer
            generate a warning, unless one or more callbacks for the
            behaviours overlap. For instance, using both the
            <c><![CDATA[application]]></c> and <c><![CDATA[supervisor]]></c> behaviours
            in the same module will NOT generate any warning, but
            using <c><![CDATA[gen_server]]></c> and <c><![CDATA[gen_fsm]]></c> will.</p>
          <p>Own Id: OTP-5714 Aux Id: seq10073 </p>
        </item>
        <item>
          <p>The pre-processor used to complain that the macro
            definition <c><![CDATA[-define(S(S), ??S).]]></c> was circular,
            which it isn't. (Thanks to Richard Carlsson.)</p>
          <p>Own Id: OTP-5777</p>
        </item>
      </list>
    </section>
  </section>

  <section>
    <title>Compiler 4.3.9</title>

    <section>
      <title>Fixed Bugs and Malfunctions</title>
      <list type="bulleted">
        <item>
          <p>Updating at least two fields of a record with a literal
            string could cause the compiler to generate dangerous
            code that could cause a crash at run-time (e.g.
            <c><![CDATA[R#r{a="abc",b=1}]]></c>). (Thanks to Mikael Karlsson.)</p>
          <p>Unecessary tests (such as a 'case' with two case
            branches that were identical) could cause the compiler to
            crash. (Thanks to Fredrik Thulin.)</p>
          <p>The validation pass of the compiler could generate an
            error for correct code when floating point operations
            were used in try/catch statements.</p>
          <p>In bit syntax construction, any field following a
            binary field would always be marked as "aligned" (which
            may or may not be correct). That would cause the hipe
            native compiler to generate incorrect code if the field
            was in fact unaligned. (Thanks to Per Gustafsson.)</p>
          <p>Some complex guard expressions (such as <c><![CDATA[A#a.b==""; A#a.b==undefined]]></c>) would crash the compiler. (Thanks
            to Sean Hinde.)</p>
          <p>Compilation speed has been increased for modules with
            many functions and/or atoms (such as modules generated by
            the Asn1 application or other code generators).</p>
          <p>Own Id: OTP-5632 Aux Id: seq10057 </p>
        </item>
      </list>
    </section>
  </section>

  <section>
    <title>Compiler 4.3.8</title>

    <section>
      <title>Fixed Bugs and Malfunctions</title>
      <list type="bulleted">
        <item>
          <p>In some circumstances, having two try/catch constructs
            following each in a function body, would cause an
            internal error to be generated (when in fact the
            generated code was correct). (Thanks to Fredrik Thulin.)</p>
          <p>Incorrect calls such as <c><![CDATA[M:42()]]></c> would crash the
            compiler. The compiler now generates a warning. (Thanks
            to Ulf Wiger.)</p>
          <p>Own Id: OTP-5553</p>
        </item>
      </list>
    </section>

    <section>
      <title>Improvements and New Features</title>
      <list type="bulleted">
        <item>
          <p>The new <c><![CDATA[fun M:F/A]]></c> construct creates a fun that
            refers to the latest version of <c><![CDATA[M:F/A]]></c>. This syntax is
            meant to replace tuple funs <c><![CDATA[{M,F}]]></c> which have many
            problems.</p>
          <p>The new type test <c><![CDATA[is_function(Fun, A)]]></c> (which may be
            used in guards) test whether <c><![CDATA[Fun]]></c> is a fun that can be
            applied with <c><![CDATA[A]]></c> arguments. (Currently, <c><![CDATA[Fun]]></c> can
            also be a tuple fun.)</p>
          <p>Own Id: OTP-5584</p>
        </item>
      </list>
    </section>
  </section>

  <section>
    <title>Compiler 4.3.7</title>

    <section>
      <title>Improvements and New Features</title>
      <list type="bulleted">
        <item>
          <p>Further improvements of encrypted debug info: New option
            <c><![CDATA[encrypt_debug_info]]></c> for compiler.</p>
          <p>Own Id: OTP-5541 Aux Id: seq9837 </p>
        </item>
      </list>
    </section>
  </section>

  <section>
    <title>Compiler 4.3.6</title>

    <section>
      <title>Fixed Bugs and Malfunctions</title>
      <list type="bulleted">
        <item>
          <p>Fixed a bug in the validator of the generated code
            (beam_validator) which caused an internal compiler error
            even though the generated code was indeed correct.</p>
          <p>Own Id: OTP-5481 Aux Id: seq9798 </p>
        </item>
      </list>
    </section>

    <section>
      <title>Improvements and New Features</title>
      <list type="bulleted">
        <item>
          <p>It is now possible to encrypt the debug information in
            Beam files, to help keep the source code secret. See the
            documentation for <c><![CDATA[compile]]></c> on how to provide the key
            for encrypting, and the documentation for <c><![CDATA[beam_lib]]></c>
            on how to provide the key for decryption so that tools such
            as the Debugger, Xref, or Cover can be used.</p>
          <p>The <c><![CDATA[beam_lib:chunks/2]]></c> functions now accepts an
            additional chunk type <c><![CDATA[compile_info]]></c> to retrieve
            the compilation information directly as a term. (Thanks
            to Tobias Lindahl.)</p>
          <p>Own Id: OTP-5460 Aux Id: seq9787 </p>
        </item>
      </list>
    </section>
  </section>

  <section>
    <title>Compiler 4.3.5</title>

    <section>
      <title>Fixed Bugs and Malfunctions</title>
      <list type="bulleted">
        <item>
          <p>Complex functions could cause the internal validator in
            the compiler to generate an internal error even though
            the generated code was correct.</p>
          <p>Own Id: OTP-5436 Aux Id: seq9781 </p>
        </item>
      </list>
    </section>
  </section>

  <section>
    <title>Compiler 4.3.4</title>

    <section>
      <title>Fixed Bugs and Malfunctions</title>
      <list type="bulleted">
        <item>
          <p>In rare circumstances, incorrect code for record or
            tuple access could be generated. The incorrect code would
            either trigger an internal error in the compiler or cause
            an exception at run time. (Thanks to Martin Bjorklund.)</p>
          <p>Corrected a bug in in bit syntax matching where
            clauses could match in the wrong order. (Thanks to Ulf
            Wiger.)</p>
          <p>Own Id: OTP-5404 Aux Id: seq9767 </p>
        </item>
      </list>
    </section>
  </section>

  <section>
    <title>Compiler 4.3.3</title>

    <section>
      <title>Improvements and New Features</title>
      <list type="bulleted">
        <item>
          <p>Given bit syntax construction in certain complex
            contexts involving a catch, the compiler would either
            crash or terminate due to failure in an internal
            consistency check. (Thanks to Fredrik Thulin.)</p>
          <p>Matches such as
            <c><![CDATA[<<103133:64/float>> = <<103133:64/float>>]]></c>
            used to fail. Now they succeed.</p>
          <p>Shadowing of variables in bit syntax matches in fun heads
            such as in
            <c><![CDATA[L = 8, F = fun(<<L:L,B:L>>) -> B end]]></c> was
            handled incorrectly by the compiler. The fun used to be
            compiled as if it was written
            '<c><![CDATA[>fun(<<8:8,B:8>>)]]></c>, while it should be
            compiled in the same way as <c><![CDATA[fun(<<L:8,B:L>>)]]></c>.</p>
          <p>A bug in the validation pass has been corrected. It
            sometimes occurred when the compiler optimized by reusing
            code for causing an exception when the reused code was
            called from within catch or try-catch statements. Then the
            validator refused to approve the code and complained about
            <c><![CDATA[fun(<<L:L,B:L>>) -> B end]]></c> was handled
            incorrectly by the in the same way as
            <c><![CDATA[fun(<<L:8,B:L>>)]]></c>.</p>
          <p>A bug in the unknown_catch_try_state.</p>
          <p>Corrected a bug in the optimizer that would cause
            the compiler to crash. (Thanks to Peter-Henry Mander.)</p>
          <p>There are now warnings generated if a bit syntax
            construction will fail at run-time because of a type
            mismatch (e.g. <c><![CDATA[<<an_atom:8>>]]></c>).</p>
          <p>Own Id: OTP-5342 Aux Id: OTP-5118, OTP-5270, OTP-5323 </p>
        </item>
        <item>
          <p>Binary pattern matching such as
            <c><![CDATA[t(<<A:8>> = <<A:8>)]]></c> used to silently
            fail at runtime (i.e. never match). The compiler now
            generates an error for any such patterns.</p>
          <p>Own Id: OTP-5371</p>
        </item>
      </list>
    </section>
  </section>

  <section>
    <title>Compiler 4.3.2</title>

    <section>
      <title>Fixed Bugs and Malfunctions</title>
      <list type="bulleted">
        <item>
          <p>In rare cases, the code compiler code generate code
            for a tuple match that could crash the emulator if passed
            a term that was not a tuple.</p>
          <p>If a bit syntax construction failed within a catch,
            previously assigned variables could get the wrong value.</p>
          <p>The compiler now runs a validation pass on the
            generated code and aborts before writing a Beam file if
            any suspect code is found. In particular, the validation
            pass checks for incorrect code that may cause emulator
            crashes or other strange symptoms in the emulator.</p>
          <p>Some corrections to the unsupported feature
            parameterized modules by Richard Carlsson (HiPE).</p>
          <p>Own Id: OTP-5247 Aux Id: OTP-5235 </p>
        </item>
      </list>
    </section>
  </section>

  <section>
    <title>Compiler 4.3.1</title>

    <section>
      <title>Fixed Bugs and Malfunctions</title>
      <list type="bulleted">
        <item>
          <p>Corrected the release note regarding <c><![CDATA[try/catch]]></c> below.
            <c><![CDATA[try/catch]]></c> DOES work in the initial R10B release.</p>
          <p>A few minor issues code generation issues were corrected.
            Although the generated code was correct, it was slightly
            slower and larger than it needed to be.</p>
          <p>A debug printout (that could be seen in rare
            circumstances) has been removed.</p>
          <p><c><![CDATA[not record_test(not_a_tuple, RecordTag)]]></c> and
            similar expressions in a guard would fail.</p>
          <p>New options <c><![CDATA[basic_validation]]></c> and
            <c><![CDATA[strong_validation]]></c> to do a quick check of the code
            of a module.</p>
          <p>The <c><![CDATA[inline]]></c> option was not recognized if it
            appeared in a <c><![CDATA[-compile()]]></c> directive inside the
            module.</p>
          <p>Corrected some bugs in the undocumented feature
            "parameterized modules".</p>
          <p>Own Id: OTP-5198</p>
        </item>
        <item>
          <p>When the undocumented feature "parameterized modules" was
            used, the <c><![CDATA[?MODULE]]></c> macro did not work correctly.</p>
          <p>Own Id: OTP-5224</p>
        </item>
      </list>
    </section>
  </section>
</chapter>