summaryrefslogtreecommitdiffstats
path: root/Python/compile.c
blob: 1cf53f95ac615958835f5af27a14715393cfc157 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
2164
2165
2166
2167
2168
2169
2170
2171
2172
2173
2174
2175
2176
2177
2178
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188
2189
2190
2191
2192
2193
2194
2195
2196
2197
2198
2199
2200
2201
2202
2203
2204
2205
2206
2207
2208
2209
2210
2211
2212
2213
2214
2215
2216
2217
2218
2219
2220
2221
2222
2223
2224
2225
2226
2227
2228
2229
2230
2231
2232
2233
2234
2235
2236
2237
2238
2239
2240
2241
2242
2243
2244
2245
2246
2247
2248
2249
2250
2251
2252
2253
2254
2255
2256
2257
2258
2259
2260
2261
2262
2263
2264
2265
2266
2267
2268
2269
2270
2271
2272
2273
2274
2275
2276
2277
2278
2279
2280
2281
2282
2283
2284
2285
2286
2287
2288
2289
2290
2291
2292
2293
2294
2295
2296
2297
2298
2299
2300
2301
2302
2303
2304
2305
2306
2307
2308
2309
2310
2311
2312
2313
2314
2315
2316
2317
2318
2319
2320
2321
2322
2323
2324
2325
2326
2327
2328
2329
2330
2331
2332
2333
2334
2335
2336
2337
2338
2339
2340
2341
2342
2343
2344
2345
2346
2347
2348
2349
2350
2351
2352
2353
2354
2355
2356
2357
2358
2359
2360
2361
2362
2363
2364
2365
2366
2367
2368
2369
2370
2371
2372
2373
2374
2375
2376
2377
2378
2379
2380
2381
2382
2383
2384
2385
2386
2387
2388
2389
2390
2391
2392
2393
2394
2395
2396
2397
2398
2399
2400
2401
2402
2403
2404
2405
2406
2407
2408
2409
2410
2411
2412
2413
2414
2415
2416
2417
2418
2419
2420
2421
2422
2423
2424
2425
2426
2427
2428
2429
2430
2431
2432
2433
2434
2435
2436
2437
2438
2439
2440
2441
2442
2443
2444
2445
2446
2447
2448
2449
2450
2451
2452
2453
2454
2455
2456
2457
2458
2459
2460
2461
2462
2463
2464
2465
2466
2467
2468
2469
2470
2471
2472
2473
2474
2475
2476
2477
2478
2479
2480
2481
2482
2483
2484
2485
2486
2487
2488
2489
2490
2491
2492
2493
2494
2495
2496
2497
2498
2499
2500
2501
2502
2503
2504
2505
2506
2507
2508
2509
2510
2511
2512
2513
2514
2515
2516
2517
2518
2519
2520
2521
2522
2523
2524
2525
2526
2527
2528
2529
2530
2531
2532
2533
2534
2535
2536
2537
2538
2539
2540
2541
2542
2543
2544
2545
2546
2547
2548
2549
2550
2551
2552
2553
2554
2555
2556
2557
2558
2559
2560
2561
2562
2563
2564
2565
2566
2567
2568
2569
2570
2571
2572
2573
2574
2575
2576
2577
2578
2579
2580
2581
2582
2583
2584
2585
2586
2587
2588
2589
2590
2591
2592
2593
2594
2595
2596
2597
2598
2599
2600
2601
2602
2603
2604
2605
2606
2607
2608
2609
2610
2611
2612
2613
2614
2615
2616
2617
2618
2619
2620
2621
2622
2623
2624
2625
2626
2627
2628
2629
2630
2631
2632
2633
2634
2635
2636
2637
2638
2639
2640
2641
2642
2643
2644
2645
2646
2647
2648
2649
2650
2651
2652
2653
2654
2655
2656
2657
2658
2659
2660
2661
2662
2663
2664
2665
2666
2667
2668
2669
2670
2671
2672
2673
2674
2675
2676
2677
2678
2679
2680
2681
2682
2683
2684
2685
2686
2687
2688
2689
2690
2691
2692
2693
2694
2695
2696
2697
2698
2699
2700
2701
2702
2703
2704
2705
2706
2707
2708
2709
2710
2711
2712
2713
2714
2715
2716
2717
2718
2719
2720
2721
2722
2723
2724
2725
2726
2727
2728
2729
2730
2731
2732
2733
2734
2735
2736
2737
2738
2739
2740
2741
2742
2743
2744
2745
2746
2747
2748
2749
2750
2751
2752
2753
2754
2755
2756
2757
2758
2759
2760
2761
2762
2763
2764
2765
2766
2767
2768
2769
2770
2771
2772
2773
2774
2775
2776
2777
2778
2779
2780
2781
2782
2783
2784
2785
2786
2787
2788
2789
2790
2791
2792
2793
2794
2795
2796
2797
2798
2799
2800
2801
2802
2803
2804
2805
2806
2807
2808
2809
2810
2811
2812
2813
2814
2815
2816
2817
2818
2819
2820
2821
2822
2823
2824
2825
2826
2827
2828
2829
2830
2831
2832
2833
2834
2835
2836
2837
2838
2839
2840
2841
2842
2843
2844
2845
2846
2847
2848
2849
2850
2851
2852
2853
2854
2855
2856
2857
2858
2859
2860
2861
2862
2863
2864
2865
2866
2867
2868
2869
2870
2871
2872
2873
2874
2875
2876
2877
2878
2879
2880
2881
2882
2883
2884
2885
2886
2887
2888
2889
2890
2891
2892
2893
2894
2895
2896
2897
2898
2899
2900
2901
2902
2903
2904
2905
2906
2907
2908
2909
2910
2911
2912
2913
2914
2915
2916
2917
2918
2919
2920
2921
2922
2923
2924
2925
2926
2927
2928
2929
2930
2931
2932
2933
2934
2935
2936
2937
2938
2939
2940
2941
2942
2943
2944
2945
2946
2947
2948
2949
2950
2951
2952
2953
2954
2955
2956
2957
2958
2959
2960
2961
2962
2963
2964
2965
2966
2967
2968
2969
2970
2971
2972
2973
2974
2975
2976
2977
2978
2979
2980
2981
2982
2983
2984
2985
2986
2987
2988
2989
2990
2991
2992
2993
2994
2995
2996
2997
2998
2999
3000
3001
3002
3003
3004
3005
3006
3007
3008
3009
3010
3011
3012
3013
3014
3015
3016
3017
3018
3019
3020
3021
3022
3023
3024
3025
3026
3027
3028
3029
3030
3031
3032
3033
3034
3035
3036
3037
3038
3039
3040
3041
3042
3043
3044
3045
3046
3047
3048
3049
3050
3051
3052
3053
3054
3055
3056
3057
3058
3059
3060
3061
3062
3063
3064
3065
3066
3067
3068
3069
3070
3071
3072
3073
3074
3075
3076
3077
3078
3079
3080
3081
3082
3083
3084
3085
3086
3087
3088
3089
3090
3091
3092
3093
3094
3095
3096
3097
3098
3099
3100
3101
3102
3103
3104
3105
3106
3107
3108
3109
3110
3111
3112
3113
3114
3115
3116
3117
3118
3119
3120
3121
3122
3123
3124
3125
3126
3127
3128
3129
3130
3131
3132
3133
3134
3135
3136
3137
3138
3139
3140
3141
3142
3143
3144
3145
3146
3147
3148
3149
3150
3151
3152
3153
3154
3155
3156
3157
3158
3159
3160
3161
3162
3163
3164
3165
3166
3167
3168
3169
3170
3171
3172
3173
3174
3175
3176
3177
3178
3179
3180
3181
3182
3183
3184
3185
3186
3187
3188
3189
3190
3191
3192
3193
3194
3195
3196
3197
3198
3199
3200
3201
3202
3203
3204
3205
3206
3207
3208
3209
3210
3211
3212
3213
3214
3215
3216
3217
3218
3219
3220
3221
3222
3223
3224
3225
3226
3227
3228
3229
3230
3231
3232
3233
3234
3235
3236
3237
3238
3239
3240
3241
3242
3243
3244
3245
3246
3247
3248
3249
3250
3251
3252
3253
3254
3255
3256
3257
3258
3259
3260
3261
3262
3263
3264
3265
3266
3267
3268
3269
3270
3271
3272
3273
3274
3275
3276
3277
3278
3279
3280
3281
3282
3283
3284
3285
3286
3287
3288
3289
3290
3291
3292
3293
3294
3295
3296
3297
3298
3299
3300
3301
3302
3303
3304
3305
3306
3307
3308
3309
3310
3311
3312
3313
3314
3315
3316
3317
3318
3319
3320
3321
3322
3323
3324
3325
3326
3327
3328
3329
3330
3331
3332
3333
3334
3335
3336
3337
3338
3339
3340
3341
3342
3343
3344
3345
3346
3347
3348
3349
3350
3351
3352
3353
3354
3355
3356
3357
3358
3359
3360
3361
3362
3363
3364
3365
3366
3367
3368
3369
3370
3371
3372
3373
3374
3375
3376
3377
3378
3379
3380
3381
3382
3383
3384
3385
3386
3387
3388
3389
3390
3391
3392
3393
3394
3395
3396
3397
3398
3399
3400
3401
3402
3403
3404
3405
3406
3407
3408
3409
3410
3411
3412
3413
3414
3415
3416
3417
3418
3419
3420
3421
3422
3423
3424
3425
3426
3427
3428
3429
3430
3431
3432
3433
3434
3435
3436
3437
3438
3439
3440
3441
3442
3443
3444
3445
3446
3447
3448
3449
3450
3451
3452
3453
3454
3455
3456
3457
3458
3459
3460
3461
3462
3463
3464
3465
3466
3467
3468
3469
3470
3471
3472
3473
3474
3475
3476
3477
3478
3479
3480
3481
3482
3483
3484
3485
3486
3487
3488
3489
3490
3491
3492
3493
3494
3495
3496
3497
3498
3499
3500
3501
3502
3503
3504
3505
3506
3507
3508
3509
3510
3511
3512
3513
3514
3515
3516
3517
3518
3519
3520
3521
3522
3523
3524
3525
3526
3527
3528
3529
3530
3531
3532
3533
3534
3535
3536
3537
3538
3539
3540
3541
3542
3543
3544
3545
3546
3547
3548
3549
3550
3551
3552
3553
3554
3555
3556
3557
3558
3559
3560
3561
3562
3563
3564
3565
3566
3567
3568
3569
3570
3571
3572
3573
3574
3575
3576
3577
3578
3579
3580
3581
3582
3583
3584
3585
3586
3587
3588
3589
3590
3591
3592
3593
3594
3595
3596
3597
3598
3599
3600
3601
3602
3603
3604
3605
3606
3607
3608
3609
3610
3611
3612
3613
3614
3615
3616
3617
3618
3619
3620
3621
3622
3623
3624
3625
3626
3627
3628
3629
3630
3631
3632
3633
3634
3635
3636
3637
3638
3639
3640
3641
3642
3643
3644
3645
3646
3647
3648
3649
3650
3651
3652
3653
3654
3655
3656
3657
3658
3659
3660
3661
3662
3663
3664
3665
3666
3667
3668
3669
3670
3671
3672
3673
3674
3675
3676
3677
3678
3679
3680
3681
3682
3683
3684
3685
3686
3687
3688
3689
3690
3691
3692
3693
3694
3695
3696
3697
3698
3699
3700
3701
3702
3703
3704
3705
3706
3707
3708
3709
3710
3711
3712
3713
3714
3715
3716
3717
3718
3719
3720
3721
3722
3723
3724
3725
3726
3727
3728
3729
3730
3731
3732
3733
3734
3735
3736
3737
3738
3739
3740
3741
3742
3743
3744
3745
3746
3747
3748
3749
3750
3751
3752
3753
3754
3755
3756
3757
3758
3759
3760
3761
3762
3763
3764
3765
3766
3767
3768
3769
3770
3771
3772
3773
3774
3775
3776
3777
3778
3779
3780
3781
3782
3783
3784
3785
3786
3787
3788
3789
3790
3791
3792
3793
3794
3795
3796
3797
3798
3799
3800
3801
3802
3803
3804
3805
3806
3807
3808
3809
3810
3811
3812
3813
3814
3815
3816
3817
3818
3819
3820
3821
3822
3823
3824
3825
3826
3827
3828
3829
3830
3831
3832
3833
3834
3835
3836
3837
3838
3839
3840
3841
3842
3843
3844
3845
3846
3847
3848
3849
3850
3851
3852
3853
3854
3855
3856
3857
3858
3859
3860
3861
3862
3863
3864
3865
3866
3867
3868
3869
3870
3871
3872
3873
3874
3875
3876
3877
3878
3879
3880
3881
3882
3883
3884
3885
3886
3887
3888
3889
3890
3891
3892
3893
3894
3895
3896
3897
3898
3899
3900
3901
3902
3903
3904
3905
3906
3907
3908
3909
3910
3911
3912
3913
3914
3915
3916
3917
3918
3919
3920
3921
3922
3923
3924
3925
3926
3927
3928
3929
3930
3931
3932
3933
3934
3935
3936
3937
3938
3939
3940
3941
3942
3943
3944
3945
3946
3947
3948
3949
3950
3951
3952
3953
3954
3955
3956
3957
3958
3959
3960
3961
3962
3963
3964
3965
3966
3967
3968
3969
3970
3971
3972
3973
3974
3975
3976
3977
3978
3979
3980
3981
3982
3983
3984
3985
3986
3987
3988
3989
3990
3991
3992
3993
3994
3995
3996
3997
3998
3999
4000
4001
4002
4003
4004
/*
 * This file compiles an abstract syntax tree (AST) into Python bytecode.
 *
 * The primary entry point is PyAST_Compile(), which returns a
 * PyCodeObject.  The compiler makes several passes to build the code
 * object:
 *   1. Checks for future statements.  See future.c
 *   2. Builds a symbol table.  See symtable.c.
 *   3. Generate code for basic blocks.  See compiler_mod() in this file.
 *   4. Assemble the basic blocks into final code.  See assemble() in
 *      this file.
 *   5. Optimize the byte code (peephole optimizations).  See peephole.c
 *
 * Note that compiler_mod() suggests module, but the module ast type
 * (mod_ty) has cases for expressions and interactive statements.
 *
 * CAUTION: The VISIT_* macros abort the current function when they
 * encounter a problem. So don't invoke them when there is memory
 * which needs to be released. Code blocks are OK, as the compiler
 * structure takes care of releasing those.  Use the arena to manage
 * objects.
 */

#include "Python.h"

#include "Python-ast.h"
#include "node.h"
#include "pyarena.h"
#include "ast.h"
#include "code.h"
#include "compile.h"
#include "symtable.h"
#include "opcode.h"

int Py_OptimizeFlag = 0;

#define DEFAULT_BLOCK_SIZE 16
#define DEFAULT_BLOCKS 8
#define DEFAULT_CODE_SIZE 128
#define DEFAULT_LNOTAB_SIZE 16

#define COMP_GENEXP   0
#define COMP_SETCOMP  1
#define COMP_DICTCOMP 2

struct instr {
    unsigned i_jabs : 1;
    unsigned i_jrel : 1;
    unsigned i_hasarg : 1;
    unsigned char i_opcode;
    int i_oparg;
    struct basicblock_ *i_target; /* target block (if jump instruction) */
    int i_lineno;
};

typedef struct basicblock_ {
    /* Each basicblock in a compilation unit is linked via b_list in the
       reverse order that the block are allocated.  b_list points to the next
       block, not to be confused with b_next, which is next by control flow. */
    struct basicblock_ *b_list;
    /* number of instructions used */
    int b_iused;
    /* length of instruction array (b_instr) */
    int b_ialloc;
    /* pointer to an array of instructions, initially NULL */
    struct instr *b_instr;
    /* If b_next is non-NULL, it is a pointer to the next
       block reached by normal control flow. */
    struct basicblock_ *b_next;
    /* b_seen is used to perform a DFS of basicblocks. */
    unsigned b_seen : 1;
    /* b_return is true if a RETURN_VALUE opcode is inserted. */
    unsigned b_return : 1;
    /* depth of stack upon entry of block, computed by stackdepth() */
    int b_startdepth;
    /* instruction offset for block, computed by assemble_jump_offsets() */
    int b_offset;
} basicblock;

/* fblockinfo tracks the current frame block.

A frame block is used to handle loops, try/except, and try/finally.
It's called a frame block to distinguish it from a basic block in the
compiler IR.
*/

enum fblocktype { LOOP, EXCEPT, FINALLY_TRY, FINALLY_END };

struct fblockinfo {
    enum fblocktype fb_type;
    basicblock *fb_block;
};

/* The following items change on entry and exit of code blocks.
   They must be saved and restored when returning to a block.
*/
struct compiler_unit {
    PySTEntryObject *u_ste;

    PyObject *u_name;
    /* The following fields are dicts that map objects to
       the index of them in co_XXX.      The index is used as
       the argument for opcodes that refer to those collections.
    */
    PyObject *u_consts;    /* all constants */
    PyObject *u_names;     /* all names */
    PyObject *u_varnames;  /* local variables */
    PyObject *u_cellvars;  /* cell variables */
    PyObject *u_freevars;  /* free variables */

    PyObject *u_private;        /* for private name mangling */

    int u_argcount;        /* number of arguments for block */
    /* Pointer to the most recently allocated block.  By following b_list
       members, you can reach all early allocated blocks. */
    basicblock *u_blocks;
    basicblock *u_curblock; /* pointer to current block */

    int u_nfblocks;
    struct fblockinfo u_fblock[CO_MAXBLOCKS];

    int u_firstlineno; /* the first lineno of the block */
    int u_lineno;          /* the lineno for the current stmt */
    bool u_lineno_set; /* boolean to indicate whether instr
                          has been generated with current lineno */
};

/* This struct captures the global state of a compilation.

The u pointer points to the current compilation unit, while units
for enclosing blocks are stored in c_stack.     The u and c_stack are
managed by compiler_enter_scope() and compiler_exit_scope().
*/

struct compiler {
    const char *c_filename;
    struct symtable *c_st;
    PyFutureFeatures *c_future; /* pointer to module's __future__ */
    PyCompilerFlags *c_flags;

    int c_interactive;           /* true if in interactive mode */
    int c_nestlevel;

    struct compiler_unit *u; /* compiler state for current block */
    PyObject *c_stack;           /* Python list holding compiler_unit ptrs */
    PyArena *c_arena;            /* pointer to memory allocation arena */
};

static int compiler_enter_scope(struct compiler *, identifier, void *, int);
static void compiler_free(struct compiler *);
static basicblock *compiler_new_block(struct compiler *);
static int compiler_next_instr(struct compiler *, basicblock *);
static int compiler_addop(struct compiler *, int);
static int compiler_addop_o(struct compiler *, int, PyObject *, PyObject *);
static int compiler_addop_i(struct compiler *, int, int);
static int compiler_addop_j(struct compiler *, int, basicblock *, int);
static basicblock *compiler_use_new_block(struct compiler *);
static int compiler_error(struct compiler *, const char *);
static int compiler_nameop(struct compiler *, identifier, expr_context_ty);

static PyCodeObject *compiler_mod(struct compiler *, mod_ty);
static int compiler_visit_stmt(struct compiler *, stmt_ty);
static int compiler_visit_keyword(struct compiler *, keyword_ty);
static int compiler_visit_expr(struct compiler *, expr_ty);
static int compiler_augassign(struct compiler *, stmt_ty);
static int compiler_visit_slice(struct compiler *, slice_ty,
                                expr_context_ty);

static int compiler_push_fblock(struct compiler *, enum fblocktype,
                                basicblock *);
static void compiler_pop_fblock(struct compiler *, enum fblocktype,
                                basicblock *);
/* Returns true if there is a loop on the fblock stack. */
static int compiler_in_loop(struct compiler *);

static int inplace_binop(struct compiler *, operator_ty);
static int expr_constant(expr_ty e);

static int compiler_with(struct compiler *, stmt_ty);

static PyCodeObject *assemble(struct compiler *, int addNone);
static PyObject *__doc__;

#define COMPILER_CAPSULE_NAME_COMPILER_UNIT "compile.c compiler unit"

PyObject *
_Py_Mangle(PyObject *privateobj, PyObject *ident)
{
    /* Name mangling: __private becomes _classname__private.
       This is independent from how the name is used. */
    const char *p, *name = PyString_AsString(ident);
    char *buffer;
    size_t nlen, plen;
    if (privateobj == NULL || !PyString_Check(privateobj) ||
        name == NULL || name[0] != '_' || name[1] != '_') {
        Py_INCREF(ident);
        return ident;
    }
    p = PyString_AsString(privateobj);
    nlen = strlen(name);
    /* Don't mangle __id__ or names with dots.

       The only time a name with a dot can occur is when
       we are compiling an import statement that has a
       package name.

       TODO(jhylton): Decide whether we want to support
       mangling of the module name, e.g. __M.X.
    */
    if ((name[nlen-1] == '_' && name[nlen-2] == '_')
        || strchr(name, '.')) {
        Py_INCREF(ident);
        return ident; /* Don't mangle __whatever__ */
    }
    /* Strip leading underscores from class name */
    while (*p == '_')
        p++;
    if (*p == '\0') {
        Py_INCREF(ident);
        return ident; /* Don't mangle if class is just underscores */
    }
    plen = strlen(p);

    if (plen + nlen >= PY_SSIZE_T_MAX - 1) {
        PyErr_SetString(PyExc_OverflowError,
                        "private identifier too large to be mangled");
        return NULL;
    }

    ident = PyString_FromStringAndSize(NULL, 1 + nlen + plen);
    if (!ident)
        return 0;
    /* ident = "_" + p[:plen] + name # i.e. 1+plen+nlen bytes */
    buffer = PyString_AS_STRING(ident);
    buffer[0] = '_';
    strncpy(buffer+1, p, plen);
    strcpy(buffer+1+plen, name);
    return ident;
}

static int
compiler_init(struct compiler *c)
{
    memset(c, 0, sizeof(struct compiler));

    c->c_stack = PyList_New(0);
    if (!c->c_stack)
        return 0;

    return 1;
}

PyCodeObject *
PyAST_Compile(mod_ty mod, const char *filename, PyCompilerFlags *flags,
              PyArena *arena)
{
    struct compiler c;
    PyCodeObject *co = NULL;
    PyCompilerFlags local_flags;
    int merged;

    if (!__doc__) {
        __doc__ = PyString_InternFromString("__doc__");
        if (!__doc__)
            return NULL;
    }

    if (!compiler_init(&c))
        return NULL;
    c.c_filename = filename;
    c.c_arena = arena;
    c.c_future = PyFuture_FromAST(mod, filename);
    if (c.c_future == NULL)
        goto finally;
    if (!flags) {
        local_flags.cf_flags = 0;
        flags = &local_flags;
    }
    merged = c.c_future->ff_features | flags->cf_flags;
    c.c_future->ff_features = merged;
    flags->cf_flags = merged;
    c.c_flags = flags;
    c.c_nestlevel = 0;

    c.c_st = PySymtable_Build(mod, filename, c.c_future);
    if (c.c_st == NULL) {
        if (!PyErr_Occurred())
            PyErr_SetString(PyExc_SystemError, "no symtable");
        goto finally;
    }

    co = compiler_mod(&c, mod);

 finally:
    compiler_free(&c);
    assert(co || PyErr_Occurred());
    return co;
}

PyCodeObject *
PyNode_Compile(struct _node *n, const char *filename)
{
    PyCodeObject *co = NULL;
    mod_ty mod;
    PyArena *arena = PyArena_New();
    if (!arena)
        return NULL;
    mod = PyAST_FromNode(n, NULL, filename, arena);
    if (mod)
        co = PyAST_Compile(mod, filename, NULL, arena);
    PyArena_Free(arena);
    return co;
}

static void
compiler_free(struct compiler *c)
{
    if (c->c_st)
        PySymtable_Free(c->c_st);
    if (c->c_future)
        PyObject_Free(c->c_future);
    Py_DECREF(c->c_stack);
}

static PyObject *
list2dict(PyObject *list)
{
    Py_ssize_t i, n;
    PyObject *v, *k;
    PyObject *dict = PyDict_New();
    if (!dict) return NULL;

    n = PyList_Size(list);
    for (i = 0; i < n; i++) {
        v = PyInt_FromLong(i);
        if (!v) {
            Py_DECREF(dict);
            return NULL;
        }
        k = PyList_GET_ITEM(list, i);
        k = PyTuple_Pack(2, k, k->ob_type);
        if (k == NULL || PyDict_SetItem(dict, k, v) < 0) {
            Py_XDECREF(k);
            Py_DECREF(v);
            Py_DECREF(dict);
            return NULL;
        }
        Py_DECREF(k);
        Py_DECREF(v);
    }
    return dict;
}

/* Return new dict containing names from src that match scope(s).

src is a symbol table dictionary.  If the scope of a name matches
either scope_type or flag is set, insert it into the new dict.  The
values are integers, starting at offset and increasing by one for
each key.
*/

static PyObject *
dictbytype(PyObject *src, int scope_type, int flag, int offset)
{
    Py_ssize_t i = offset, scope, num_keys, key_i;
    PyObject *k, *v, *dest = PyDict_New();
    PyObject *sorted_keys;

    assert(offset >= 0);
    if (dest == NULL)
        return NULL;

    /* Sort the keys so that we have a deterministic order on the indexes
       saved in the returned dictionary.  These indexes are used as indexes
       into the free and cell var storage.  Therefore if they aren't
       deterministic, then the generated bytecode is not deterministic.
    */
    sorted_keys = PyDict_Keys(src);
    if (sorted_keys == NULL)
        return NULL;
    if (PyList_Sort(sorted_keys) != 0) {
        Py_DECREF(sorted_keys);
        return NULL;
    }
    num_keys = PyList_GET_SIZE(sorted_keys);

    for (key_i = 0; key_i < num_keys; key_i++) {
        k = PyList_GET_ITEM(sorted_keys, key_i);
        v = PyDict_GetItem(src, k);
        /* XXX this should probably be a macro in symtable.h */
        assert(PyInt_Check(v));
        scope = (PyInt_AS_LONG(v) >> SCOPE_OFF) & SCOPE_MASK;

        if (scope == scope_type || PyInt_AS_LONG(v) & flag) {
            PyObject *tuple, *item = PyInt_FromLong(i);
            if (item == NULL) {
                Py_DECREF(sorted_keys);
                Py_DECREF(dest);
                return NULL;
            }
            i++;
            tuple = PyTuple_Pack(2, k, k->ob_type);
            if (!tuple || PyDict_SetItem(dest, tuple, item) < 0) {
                Py_DECREF(sorted_keys);
                Py_DECREF(item);
                Py_DECREF(dest);
                Py_XDECREF(tuple);
                return NULL;
            }
            Py_DECREF(item);
            Py_DECREF(tuple);
        }
    }
    Py_DECREF(sorted_keys);
    return dest;
}

static void
compiler_unit_check(struct compiler_unit *u)
{
    basicblock *block;
    for (block = u->u_blocks; block != NULL; block = block->b_list) {
        assert((void *)block != (void *)0xcbcbcbcb);
        assert((void *)block != (void *)0xfbfbfbfb);
        assert((void *)block != (void *)0xdbdbdbdb);
        if (block->b_instr != NULL) {
            assert(block->b_ialloc > 0);
            assert(block->b_iused > 0);
            assert(block->b_ialloc >= block->b_iused);
        }
        else {
            assert (block->b_iused == 0);
            assert (block->b_ialloc == 0);
        }
    }
}

static void
compiler_unit_free(struct compiler_unit *u)
{
    basicblock *b, *next;

    compiler_unit_check(u);
    b = u->u_blocks;
    while (b != NULL) {
        if (b->b_instr)
            PyObject_Free((void *)b->b_instr);
        next = b->b_list;
        PyObject_Free((void *)b);
        b = next;
    }
    Py_CLEAR(u->u_ste);
    Py_CLEAR(u->u_name);
    Py_CLEAR(u->u_consts);
    Py_CLEAR(u->u_names);
    Py_CLEAR(u->u_varnames);
    Py_CLEAR(u->u_freevars);
    Py_CLEAR(u->u_cellvars);
    Py_CLEAR(u->u_private);
    PyObject_Free(u);
}

static int
compiler_enter_scope(struct compiler *c, identifier name, void *key,
                     int lineno)
{
    struct compiler_unit *u;

    u = (struct compiler_unit *)PyObject_Malloc(sizeof(
                                            struct compiler_unit));
    if (!u) {
        PyErr_NoMemory();
        return 0;
    }
    memset(u, 0, sizeof(struct compiler_unit));
    u->u_argcount = 0;
    u->u_ste = PySymtable_Lookup(c->c_st, key);
    if (!u->u_ste) {
        compiler_unit_free(u);
        return 0;
    }
    Py_INCREF(name);
    u->u_name = name;
    u->u_varnames = list2dict(u->u_ste->ste_varnames);
    u->u_cellvars = dictbytype(u->u_ste->ste_symbols, CELL, 0, 0);
    if (!u->u_varnames || !u->u_cellvars) {
        compiler_unit_free(u);
        return 0;
    }

    u->u_freevars = dictbytype(u->u_ste->ste_symbols, FREE, DEF_FREE_CLASS,
                               PyDict_Size(u->u_cellvars));
    if (!u->u_freevars) {
        compiler_unit_free(u);
        return 0;
    }

    u->u_blocks = NULL;
    u->u_nfblocks = 0;
    u->u_firstlineno = lineno;
    u->u_lineno = 0;
    u->u_lineno_set = false;
    u->u_consts = PyDict_New();
    if (!u->u_consts) {
        compiler_unit_free(u);
        return 0;
    }
    u->u_names = PyDict_New();
    if (!u->u_names) {
        compiler_unit_free(u);
        return 0;
    }

    u->u_private = NULL;

    /* Push the old compiler_unit on the stack. */
    if (c->u) {
        PyObject *capsule = PyCapsule_New(c->u, COMPILER_CAPSULE_NAME_COMPILER_UNIT, NULL);
        if (!capsule || PyList_Append(c->c_stack, capsule) < 0) {
            Py_XDECREF(capsule);
            compiler_unit_free(u);
            return 0;
        }
        Py_DECREF(capsule);
        u->u_private = c->u->u_private;
        Py_XINCREF(u->u_private);
    }
    c->u = u;

    c->c_nestlevel++;
    if (compiler_use_new_block(c) == NULL)
        return 0;

    return 1;
}

static void
compiler_exit_scope(struct compiler *c)
{
    int n;
    PyObject *capsule;

    c->c_nestlevel--;
    compiler_unit_free(c->u);
    /* Restore c->u to the parent unit. */
    n = PyList_GET_SIZE(c->c_stack) - 1;
    if (n >= 0) {
        capsule = PyList_GET_ITEM(c->c_stack, n);
        c->u = (struct compiler_unit *)PyCapsule_GetPointer(capsule, COMPILER_CAPSULE_NAME_COMPILER_UNIT);
        assert(c->u);
        /* we are deleting from a list so this really shouldn't fail */
        if (PySequence_DelItem(c->c_stack, n) < 0)
            Py_FatalError("compiler_exit_scope()");
        compiler_unit_check(c->u);
    }
    else
        c->u = NULL;

}

/* Allocate a new block and return a pointer to it.
   Returns NULL on error.
*/

static basicblock *
compiler_new_block(struct compiler *c)
{
    basicblock *b;
    struct compiler_unit *u;

    u = c->u;
    b = (basicblock *)PyObject_Malloc(sizeof(basicblock));
    if (b == NULL) {
        PyErr_NoMemory();
        return NULL;
    }
    memset((void *)b, 0, sizeof(basicblock));
    /* Extend the singly linked list of blocks with new block. */
    b->b_list = u->u_blocks;
    u->u_blocks = b;
    return b;
}

static basicblock *
compiler_use_new_block(struct compiler *c)
{
    basicblock *block = compiler_new_block(c);
    if (block == NULL)
        return NULL;
    c->u->u_curblock = block;
    return block;
}

static basicblock *
compiler_next_block(struct compiler *c)
{
    basicblock *block = compiler_new_block(c);
    if (block == NULL)
        return NULL;
    c->u->u_curblock->b_next = block;
    c->u->u_curblock = block;
    return block;
}

static basicblock *
compiler_use_next_block(struct compiler *c, basicblock *block)
{
    assert(block != NULL);
    c->u->u_curblock->b_next = block;
    c->u->u_curblock = block;
    return block;
}

/* Returns the offset of the next instruction in the current block's
   b_instr array.  Resizes the b_instr as necessary.
   Returns -1 on failure.
*/

static int
compiler_next_instr(struct compiler *c, basicblock *b)
{
    assert(b != NULL);
    if (b->b_instr == NULL) {
        b->b_instr = (struct instr *)PyObject_Malloc(
                         sizeof(struct instr) * DEFAULT_BLOCK_SIZE);
        if (b->b_instr == NULL) {
            PyErr_NoMemory();
            return -1;
        }
        b->b_ialloc = DEFAULT_BLOCK_SIZE;
        memset((char *)b->b_instr, 0,
               sizeof(struct instr) * DEFAULT_BLOCK_SIZE);
    }
    else if (b->b_iused == b->b_ialloc) {
        struct instr *tmp;
        size_t oldsize, newsize;
        oldsize = b->b_ialloc * sizeof(struct instr);
        newsize = oldsize << 1;

        if (oldsize > (PY_SIZE_MAX >> 1)) {
            PyErr_NoMemory();
            return -1;
        }

        if (newsize == 0) {
            PyErr_NoMemory();
            return -1;
        }
        b->b_ialloc <<= 1;
        tmp = (struct instr *)PyObject_Realloc(
                                        (void *)b->b_instr, newsize);
        if (tmp == NULL) {
            PyErr_NoMemory();
            return -1;
        }
        b->b_instr = tmp;
        memset((char *)b->b_instr + oldsize, 0, newsize - oldsize);
    }
    return b->b_iused++;
}

/* Set the i_lineno member of the instruction at offset off if the
   line number for the current expression/statement has not
   already been set.  If it has been set, the call has no effect.

   The line number is reset in the following cases:
   - when entering a new scope
   - on each statement
   - on each expression that start a new line
   - before the "except" clause
   - before the "for" and "while" expressions
*/

static void
compiler_set_lineno(struct compiler *c, int off)
{
    basicblock *b;
    if (c->u->u_lineno_set)
        return;
    c->u->u_lineno_set = true;
    b = c->u->u_curblock;
    b->b_instr[off].i_lineno = c->u->u_lineno;
}

static int
opcode_stack_effect(int opcode, int oparg)
{
    switch (opcode) {
        case POP_TOP:
            return -1;
        case ROT_TWO:
        case ROT_THREE:
            return 0;
        case DUP_TOP:
            return 1;
        case ROT_FOUR:
            return 0;

        case UNARY_POSITIVE:
        case UNARY_NEGATIVE:
        case UNARY_NOT:
        case UNARY_CONVERT:
        case UNARY_INVERT:
            return 0;

        case SET_ADD:
        case LIST_APPEND:
            return -1;

        case MAP_ADD:
            return -2;

        case BINARY_POWER:
        case BINARY_MULTIPLY:
        case BINARY_DIVIDE:
        case BINARY_MODULO:
        case BINARY_ADD:
        case BINARY_SUBTRACT:
        case BINARY_SUBSCR:
        case BINARY_FLOOR_DIVIDE:
        case BINARY_TRUE_DIVIDE:
            return -1;
        case INPLACE_FLOOR_DIVIDE:
        case INPLACE_TRUE_DIVIDE:
            return -1;

        case SLICE+0:
            return 0;
        case SLICE+1:
            return -1;
        case SLICE+2:
            return -1;
        case SLICE+3:
            return -2;

        case STORE_SLICE+0:
            return -2;
        case STORE_SLICE+1:
            return -3;
        case STORE_SLICE+2:
            return -3;
        case STORE_SLICE+3:
            return -4;

        case DELETE_SLICE+0:
            return -1;
        case DELETE_SLICE+1:
            return -2;
        case DELETE_SLICE+2:
            return -2;
        case DELETE_SLICE+3:
            return -3;

        case INPLACE_ADD:
        case INPLACE_SUBTRACT:
        case INPLACE_MULTIPLY:
        case INPLACE_DIVIDE:
        case INPLACE_MODULO:
            return -1;
        case STORE_SUBSCR:
            return -3;
        case STORE_MAP:
            return -2;
        case DELETE_SUBSCR:
            return -2;

        case BINARY_LSHIFT:
        case BINARY_RSHIFT:
        case BINARY_AND:
        case BINARY_XOR:
        case BINARY_OR:
            return -1;
        case INPLACE_POWER:
            return -1;
        case GET_ITER:
            return 0;

        case PRINT_EXPR:
            return -1;
        case PRINT_ITEM:
            return -1;
        case PRINT_NEWLINE:
            return 0;
        case PRINT_ITEM_TO:
            return -2;
        case PRINT_NEWLINE_TO:
            return -1;
        case INPLACE_LSHIFT:
        case INPLACE_RSHIFT:
        case INPLACE_AND:
        case INPLACE_XOR:
        case INPLACE_OR:
            return -1;
        case BREAK_LOOP:
            return 0;
        case SETUP_WITH:
            return 4;
        case WITH_CLEANUP:
            return -1; /* XXX Sometimes more */
        case LOAD_LOCALS:
            return 1;
        case RETURN_VALUE:
            return -1;
        case IMPORT_STAR:
            return -1;
        case EXEC_STMT:
            return -3;
        case YIELD_VALUE:
            return 0;

        case POP_BLOCK:
            return 0;
        case END_FINALLY:
            return -3; /* or -1 or -2 if no exception occurred or
                          return/break/continue */
        case BUILD_CLASS:
            return -2;

        case STORE_NAME:
            return -1;
        case DELETE_NAME:
            return 0;
        case UNPACK_SEQUENCE:
            return oparg-1;
        case FOR_ITER:
            return 1; /* or -1, at end of iterator */

        case STORE_ATTR:
            return -2;
        case DELETE_ATTR:
            return -1;
        case STORE_GLOBAL:
            return -1;
        case DELETE_GLOBAL:
            return 0;
        case DUP_TOPX:
            return oparg;
        case LOAD_CONST:
            return 1;
        case LOAD_NAME:
            return 1;
        case BUILD_TUPLE:
        case BUILD_LIST:
        case BUILD_SET:
            return 1-oparg;
        case BUILD_MAP:
            return 1;
        case LOAD_ATTR:
            return 0;
        case COMPARE_OP:
            return -1;
        case IMPORT_NAME:
            return -1;
        case IMPORT_FROM:
            return 1;

        case JUMP_FORWARD:
        case JUMP_IF_TRUE_OR_POP:  /* -1 if jump not taken */
        case JUMP_IF_FALSE_OR_POP:  /*  "" */
        case JUMP_ABSOLUTE:
            return 0;

        case POP_JUMP_IF_FALSE:
        case POP_JUMP_IF_TRUE:
            return -1;

        case LOAD_GLOBAL:
            return 1;

        case CONTINUE_LOOP:
            return 0;
        case SETUP_LOOP:
        case SETUP_EXCEPT:
        case SETUP_FINALLY:
            return 0;

        case LOAD_FAST:
            return 1;
        case STORE_FAST:
            return -1;
        case DELETE_FAST:
            return 0;

        case RAISE_VARARGS:
            return -oparg;
#define NARGS(o) (((o) % 256) + 2*((o) / 256))
        case CALL_FUNCTION:
            return -NARGS(oparg);
        case CALL_FUNCTION_VAR:
        case CALL_FUNCTION_KW:
            return -NARGS(oparg)-1;
        case CALL_FUNCTION_VAR_KW:
            return -NARGS(oparg)-2;
#undef NARGS
        case MAKE_FUNCTION:
            return -oparg;
        case BUILD_SLICE:
            if (oparg == 3)
                return -2;
            else
                return -1;

        case MAKE_CLOSURE:
            return -oparg-1;
        case LOAD_CLOSURE:
            return 1;
        case LOAD_DEREF:
            return 1;
        case STORE_DEREF:
            return -1;
        default:
            fprintf(stderr, "opcode = %d\n", opcode);
            Py_FatalError("opcode_stack_effect()");

    }
    return 0; /* not reachable */
}

/* Add an opcode with no argument.
   Returns 0 on failure, 1 on success.
*/

static int
compiler_addop(struct compiler *c, int opcode)
{
    basicblock *b;
    struct instr *i;
    int off;
    off = compiler_next_instr(c, c->u->u_curblock);
    if (off < 0)
        return 0;
    b = c->u->u_curblock;
    i = &b->b_instr[off];
    i->i_opcode = opcode;
    i->i_hasarg = 0;
    if (opcode == RETURN_VALUE)
        b->b_return = 1;
    compiler_set_lineno(c, off);
    return 1;
}

static int
compiler_add_o(struct compiler *c, PyObject *dict, PyObject *o)
{
    PyObject *t, *v;
    Py_ssize_t arg;
    double d;

    /* necessary to make sure types aren't coerced (e.g., int and long) */
    /* _and_ to distinguish 0.0 from -0.0 e.g. on IEEE platforms */
    if (PyFloat_Check(o)) {
        d = PyFloat_AS_DOUBLE(o);
        /* all we need is to make the tuple different in either the 0.0
         * or -0.0 case from all others, just to avoid the "coercion".
         */
        if (d == 0.0 && copysign(1.0, d) < 0.0)
            t = PyTuple_Pack(3, o, o->ob_type, Py_None);
        else
            t = PyTuple_Pack(2, o, o->ob_type);
    }
#ifndef WITHOUT_COMPLEX
    else if (PyComplex_Check(o)) {
        Py_complex z;
        int real_negzero, imag_negzero;
        /* For the complex case we must make complex(x, 0.)
           different from complex(x, -0.) and complex(0., y)
           different from complex(-0., y), for any x and y.
           All four complex zeros must be distinguished.*/
        z = PyComplex_AsCComplex(o);
        real_negzero = z.real == 0.0 && copysign(1.0, z.real) < 0.0;
        imag_negzero = z.imag == 0.0 && copysign(1.0, z.imag) < 0.0;
        if (real_negzero && imag_negzero) {
            t = PyTuple_Pack(5, o, o->ob_type,
                             Py_None, Py_None, Py_None);
        }
        else if (imag_negzero) {
            t = PyTuple_Pack(4, o, o->ob_type, Py_None, Py_None);
        }
        else if (real_negzero) {
            t = PyTuple_Pack(3, o, o->ob_type, Py_None);
        }
        else {
            t = PyTuple_Pack(2, o, o->ob_type);
        }
    }
#endif /* WITHOUT_COMPLEX */
    else {
        t = PyTuple_Pack(2, o, o->ob_type);
    }
    if (t == NULL)
        return -1;

    v = PyDict_GetItem(dict, t);
    if (!v) {
        arg = PyDict_Size(dict);
        v = PyInt_FromLong(arg);
        if (!v) {
            Py_DECREF(t);
            return -1;
        }
        if (PyDict_SetItem(dict, t, v) < 0) {
            Py_DECREF(t);
            Py_DECREF(v);
            return -1;
        }
        Py_DECREF(v);
    }
    else
        arg = PyInt_AsLong(v);
    Py_DECREF(t);
    return arg;
}

static int
compiler_addop_o(struct compiler *c, int opcode, PyObject *dict,
                     PyObject *o)
{
    int arg = compiler_add_o(c, dict, o);
    if (arg < 0)
        return 0;
    return compiler_addop_i(c, opcode, arg);
}

static int
compiler_addop_name(struct compiler *c, int opcode, PyObject *dict,
                    PyObject *o)
{
    int arg;
    PyObject *mangled = _Py_Mangle(c->u->u_private, o);
    if (!mangled)
        return 0;
    arg = compiler_add_o(c, dict, mangled);
    Py_DECREF(mangled);
    if (arg < 0)
        return 0;
    return compiler_addop_i(c, opcode, arg);
}

/* Add an opcode with an integer argument.
   Returns 0 on failure, 1 on success.
*/

static int
compiler_addop_i(struct compiler *c, int opcode, int oparg)
{
    struct instr *i;
    int off;
    off = compiler_next_instr(c, c->u->u_curblock);
    if (off < 0)
        return 0;
    i = &c->u->u_curblock->b_instr[off];
    i->i_opcode = opcode;
    i->i_oparg = oparg;
    i->i_hasarg = 1;
    compiler_set_lineno(c, off);
    return 1;
}

static int
compiler_addop_j(struct compiler *c, int opcode, basicblock *b, int absolute)
{
    struct instr *i;
    int off;

    assert(b != NULL);
    off = compiler_next_instr(c, c->u->u_curblock);
    if (off < 0)
        return 0;
    i = &c->u->u_curblock->b_instr[off];
    i->i_opcode = opcode;
    i->i_target = b;
    i->i_hasarg = 1;
    if (absolute)
        i->i_jabs = 1;
    else
        i->i_jrel = 1;
    compiler_set_lineno(c, off);
    return 1;
}

/* The distinction between NEW_BLOCK and NEXT_BLOCK is subtle.  (I'd
   like to find better names.)  NEW_BLOCK() creates a new block and sets
   it as the current block.  NEXT_BLOCK() also creates an implicit jump
   from the current block to the new block.
*/

/* The returns inside these macros make it impossible to decref objects
   created in the local function.  Local objects should use the arena.
*/


#define NEW_BLOCK(C) { \
    if (compiler_use_new_block((C)) == NULL) \
        return 0; \
}

#define NEXT_BLOCK(C) { \
    if (compiler_next_block((C)) == NULL) \
        return 0; \
}

#define ADDOP(C, OP) { \
    if (!compiler_addop((C), (OP))) \
        return 0; \
}

#define ADDOP_IN_SCOPE(C, OP) { \
    if (!compiler_addop((C), (OP))) { \
        compiler_exit_scope(c); \
        return 0; \
    } \
}

#define ADDOP_O(C, OP, O, TYPE) { \
    if (!compiler_addop_o((C), (OP), (C)->u->u_ ## TYPE, (O))) \
        return 0; \
}

#define ADDOP_NAME(C, OP, O, TYPE) { \
    if (!compiler_addop_name((C), (OP), (C)->u->u_ ## TYPE, (O))) \
        return 0; \
}

#define ADDOP_I(C, OP, O) { \
    if (!compiler_addop_i((C), (OP), (O))) \
        return 0; \
}

#define ADDOP_JABS(C, OP, O) { \
    if (!compiler_addop_j((C), (OP), (O), 1)) \
        return 0; \
}

#define ADDOP_JREL(C, OP, O) { \
    if (!compiler_addop_j((C), (OP), (O), 0)) \
        return 0; \
}

/* VISIT and VISIT_SEQ takes an ASDL type as their second argument.  They use
   the ASDL name to synthesize the name of the C type and the visit function.
*/

#define VISIT(C, TYPE, V) {\
    if (!compiler_visit_ ## TYPE((C), (V))) \
        return 0; \
}

#define VISIT_IN_SCOPE(C, TYPE, V) {\
    if (!compiler_visit_ ## TYPE((C), (V))) { \
        compiler_exit_scope(c); \
        return 0; \
    } \
}

#define VISIT_SLICE(C, V, CTX) {\
    if (!compiler_visit_slice((C), (V), (CTX))) \
        return 0; \
}

#define VISIT_SEQ(C, TYPE, SEQ) { \
    int _i; \
    asdl_seq *seq = (SEQ); /* avoid variable capture */ \
    for (_i = 0; _i < asdl_seq_LEN(seq); _i++) { \
        TYPE ## _ty elt = (TYPE ## _ty)asdl_seq_GET(seq, _i); \
        if (!compiler_visit_ ## TYPE((C), elt)) \
            return 0; \
    } \
}

#define VISIT_SEQ_IN_SCOPE(C, TYPE, SEQ) { \
    int _i; \
    asdl_seq *seq = (SEQ); /* avoid variable capture */ \
    for (_i = 0; _i < asdl_seq_LEN(seq); _i++) { \
        TYPE ## _ty elt = (TYPE ## _ty)asdl_seq_GET(seq, _i); \
        if (!compiler_visit_ ## TYPE((C), elt)) { \
            compiler_exit_scope(c); \
            return 0; \
        } \
    } \
}

static int
compiler_isdocstring(stmt_ty s)
{
    if (s->kind != Expr_kind)
        return 0;
    return s->v.Expr.value->kind == Str_kind;
}

/* Compile a sequence of statements, checking for a docstring. */

static int
compiler_body(struct compiler *c, asdl_seq *stmts)
{
    int i = 0;
    stmt_ty st;

    if (!asdl_seq_LEN(stmts))
        return 1;
    st = (stmt_ty)asdl_seq_GET(stmts, 0);
    if (compiler_isdocstring(st) && Py_OptimizeFlag < 2) {
        /* don't generate docstrings if -OO */
        i = 1;
        VISIT(c, expr, st->v.Expr.value);
        if (!compiler_nameop(c, __doc__, Store))
            return 0;
    }
    for (; i < asdl_seq_LEN(stmts); i++)
        VISIT(c, stmt, (stmt_ty)asdl_seq_GET(stmts, i));
    return 1;
}

static PyCodeObject *
compiler_mod(struct compiler *c, mod_ty mod)
{
    PyCodeObject *co;
    int addNone = 1;
    static PyObject *module;
    if (!module) {
        module = PyString_InternFromString("<module>");
        if (!module)
            return NULL;
    }
    /* Use 0 for firstlineno initially, will fixup in assemble(). */
    if (!compiler_enter_scope(c, module, mod, 0))
        return NULL;
    switch (mod->kind) {
    case Module_kind:
        if (!compiler_body(c, mod->v.Module.body)) {
            compiler_exit_scope(c);
            return 0;
        }
        break;
    case Interactive_kind:
        c->c_interactive = 1;
        VISIT_SEQ_IN_SCOPE(c, stmt,
                                mod->v.Interactive.body);
        break;
    case Expression_kind:
        VISIT_IN_SCOPE(c, expr, mod->v.Expression.body);
        addNone = 0;
        break;
    case Suite_kind:
        PyErr_SetString(PyExc_SystemError,
                        "suite should not be possible");
        return 0;
    default:
        PyErr_Format(PyExc_SystemError,
                     "module kind %d should not be possible",
                     mod->kind);
        return 0;
    }
    co = assemble(c, addNone);
    compiler_exit_scope(c);
    return co;
}

/* The test for LOCAL must come before the test for FREE in order to
   handle classes where name is both local and free.  The local var is
   a method and the free var is a free var referenced within a method.
*/

static int
get_ref_type(struct compiler *c, PyObject *name)
{
    int scope = PyST_GetScope(c->u->u_ste, name);
    if (scope == 0) {
        char buf[350];
        PyOS_snprintf(buf, sizeof(buf),
                      "unknown scope for %.100s in %.100s(%s) in %s\n"
                      "symbols: %s\nlocals: %s\nglobals: %s",
                      PyString_AS_STRING(name),
                      PyString_AS_STRING(c->u->u_name),
                      PyObject_REPR(c->u->u_ste->ste_id),
                      c->c_filename,
                      PyObject_REPR(c->u->u_ste->ste_symbols),
                      PyObject_REPR(c->u->u_varnames),
                      PyObject_REPR(c->u->u_names)
        );
        Py_FatalError(buf);
    }

    return scope;
}

static int
compiler_lookup_arg(PyObject *dict, PyObject *name)
{
    PyObject *k, *v;
    k = PyTuple_Pack(2, name, name->ob_type);
    if (k == NULL)
        return -1;
    v = PyDict_GetItem(dict, k);
    Py_DECREF(k);
    if (v == NULL)
        return -1;
    return PyInt_AS_LONG(v);
}

static int
compiler_make_closure(struct compiler *c, PyCodeObject *co, int args)
{
    int i, free = PyCode_GetNumFree(co);
    if (free == 0) {
        ADDOP_O(c, LOAD_CONST, (PyObject*)co, consts);
        ADDOP_I(c, MAKE_FUNCTION, args);
        return 1;
    }
    for (i = 0; i < free; ++i) {
        /* Bypass com_addop_varname because it will generate
           LOAD_DEREF but LOAD_CLOSURE is needed.
        */
        PyObject *name = PyTuple_GET_ITEM(co->co_freevars, i);
        int arg, reftype;

        /* Special case: If a class contains a method with a
           free variable that has the same name as a method,
           the name will be considered free *and* local in the
           class.  It should be handled by the closure, as
           well as by the normal name loookup logic.
        */
        reftype = get_ref_type(c, name);
        if (reftype == CELL)
            arg = compiler_lookup_arg(c->u->u_cellvars, name);
        else /* (reftype == FREE) */
            arg = compiler_lookup_arg(c->u->u_freevars, name);
        if (arg == -1) {
            printf("lookup %s in %s %d %d\n"
                "freevars of %s: %s\n",
                PyObject_REPR(name),
                PyString_AS_STRING(c->u->u_name),
                reftype, arg,
                PyString_AS_STRING(co->co_name),
                PyObject_REPR(co->co_freevars));
            Py_FatalError("compiler_make_closure()");
        }
        ADDOP_I(c, LOAD_CLOSURE, arg);
    }
    ADDOP_I(c, BUILD_TUPLE, free);
    ADDOP_O(c, LOAD_CONST, (PyObject*)co, consts);
    ADDOP_I(c, MAKE_CLOSURE, args);
    return 1;
}

static int
compiler_decorators(struct compiler *c, asdl_seq* decos)
{
    int i;

    if (!decos)
        return 1;

    for (i = 0; i < asdl_seq_LEN(decos); i++) {
        VISIT(c, expr, (expr_ty)asdl_seq_GET(decos, i));
    }
    return 1;
}

static int
compiler_arguments(struct compiler *c, arguments_ty args)
{
    int i;
    int n = asdl_seq_LEN(args->args);
    /* Correctly handle nested argument lists */
    for (i = 0; i < n; i++) {
        expr_ty arg = (expr_ty)asdl_seq_GET(args->args, i);
        if (arg->kind == Tuple_kind) {
            PyObject *id = PyString_FromFormat(".%d", i);
            if (id == NULL) {
                return 0;
            }
            if (!compiler_nameop(c, id, Load)) {
                Py_DECREF(id);
                return 0;
            }
            Py_DECREF(id);
            VISIT(c, expr, arg);
        }
    }
    return 1;
}

static int
compiler_function(struct compiler *c, stmt_ty s)
{
    PyCodeObject *co;
    PyObject *first_const = Py_None;
    arguments_ty args = s->v.FunctionDef.args;
    asdl_seq* decos = s->v.FunctionDef.decorator_list;
    stmt_ty st;
    int i, n, docstring;

    assert(s->kind == FunctionDef_kind);

    if (!compiler_decorators(c, decos))
        return 0;
    if (args->defaults)
        VISIT_SEQ(c, expr, args->defaults);
    if (!compiler_enter_scope(c, s->v.FunctionDef.name, (void *)s,
                              s->lineno))
        return 0;

    st = (stmt_ty)asdl_seq_GET(s->v.FunctionDef.body, 0);
    docstring = compiler_isdocstring(st);
    if (docstring && Py_OptimizeFlag < 2)
        first_const = st->v.Expr.value->v.Str.s;
    if (compiler_add_o(c, c->u->u_consts, first_const) < 0)      {
        compiler_exit_scope(c);
        return 0;
    }

    /* unpack nested arguments */
    compiler_arguments(c, args);

    c->u->u_argcount = asdl_seq_LEN(args->args);
    n = asdl_seq_LEN(s->v.FunctionDef.body);
    /* if there was a docstring, we need to skip the first statement */
    for (i = docstring; i < n; i++) {
        st = (stmt_ty)asdl_seq_GET(s->v.FunctionDef.body, i);
        VISIT_IN_SCOPE(c, stmt, st);
    }
    co = assemble(c, 1);
    compiler_exit_scope(c);
    if (co == NULL)
        return 0;

    compiler_make_closure(c, co, asdl_seq_LEN(args->defaults));
    Py_DECREF(co);

    for (i = 0; i < asdl_seq_LEN(decos); i++) {
        ADDOP_I(c, CALL_FUNCTION, 1);
    }

    return compiler_nameop(c, s->v.FunctionDef.name, Store);
}

static int
compiler_class(struct compiler *c, stmt_ty s)
{
    int n, i;
    PyCodeObject *co;
    PyObject *str;
    asdl_seq* decos = s->v.ClassDef.decorator_list;

    if (!compiler_decorators(c, decos))
        return 0;

    /* push class name on stack, needed by BUILD_CLASS */
    ADDOP_O(c, LOAD_CONST, s->v.ClassDef.name, consts);
    /* push the tuple of base classes on the stack */
    n = asdl_seq_LEN(s->v.ClassDef.bases);
    if (n > 0)
        VISIT_SEQ(c, expr, s->v.ClassDef.bases);
    ADDOP_I(c, BUILD_TUPLE, n);
    if (!compiler_enter_scope(c, s->v.ClassDef.name, (void *)s,
                              s->lineno))
        return 0;
    Py_XDECREF(c->u->u_private);
    c->u->u_private = s->v.ClassDef.name;
    Py_INCREF(c->u->u_private);
    str = PyString_InternFromString("__name__");
    if (!str || !compiler_nameop(c, str, Load)) {
        Py_XDECREF(str);
        compiler_exit_scope(c);
        return 0;
    }

    Py_DECREF(str);
    str = PyString_InternFromString("__module__");
    if (!str || !compiler_nameop(c, str, Store)) {
        Py_XDECREF(str);
        compiler_exit_scope(c);
        return 0;
    }
    Py_DECREF(str);

    if (!compiler_body(c, s->v.ClassDef.body)) {
        compiler_exit_scope(c);
        return 0;
    }

    ADDOP_IN_SCOPE(c, LOAD_LOCALS);
    ADDOP_IN_SCOPE(c, RETURN_VALUE);
    co = assemble(c, 1);
    compiler_exit_scope(c);
    if (co == NULL)
        return 0;

    compiler_make_closure(c, co, 0);
    Py_DECREF(co);

    ADDOP_I(c, CALL_FUNCTION, 0);
    ADDOP(c, BUILD_CLASS);
    /* apply decorators */
    for (i = 0; i < asdl_seq_LEN(decos); i++) {
        ADDOP_I(c, CALL_FUNCTION, 1);
    }
    if (!compiler_nameop(c, s->v.ClassDef.name, Store))
        return 0;
    return 1;
}

static int
compiler_ifexp(struct compiler *c, expr_ty e)
{
    basicblock *end, *next;

    assert(e->kind == IfExp_kind);
    end = compiler_new_block(c);
    if (end == NULL)
        return 0;
    next = compiler_new_block(c);
    if (next == NULL)
        return 0;
    VISIT(c, expr, e->v.IfExp.test);
    ADDOP_JABS(c, POP_JUMP_IF_FALSE, next);
    VISIT(c, expr, e->v.IfExp.body);
    ADDOP_JREL(c, JUMP_FORWARD, end);
    compiler_use_next_block(c, next);
    VISIT(c, expr, e->v.IfExp.orelse);
    compiler_use_next_block(c, end);
    return 1;
}

static int
compiler_lambda(struct compiler *c, expr_ty e)
{
    PyCodeObject *co;
    static identifier name;
    arguments_ty args = e->v.Lambda.args;
    assert(e->kind == Lambda_kind);

    if (!name) {
        name = PyString_InternFromString("<lambda>");
        if (!name)
            return 0;
    }

    if (args->defaults)
        VISIT_SEQ(c, expr, args->defaults);
    if (!compiler_enter_scope(c, name, (void *)e, e->lineno))
        return 0;

    /* unpack nested arguments */
    compiler_arguments(c, args);

    /* Make None the first constant, so the lambda can't have a
       docstring. */
    if (compiler_add_o(c, c->u->u_consts, Py_None) < 0)
        return 0;

    c->u->u_argcount = asdl_seq_LEN(args->args);
    VISIT_IN_SCOPE(c, expr, e->v.Lambda.body);
    if (c->u->u_ste->ste_generator) {
        ADDOP_IN_SCOPE(c, POP_TOP);
    }
    else {
        ADDOP_IN_SCOPE(c, RETURN_VALUE);
    }
    co = assemble(c, 1);
    compiler_exit_scope(c);
    if (co == NULL)
        return 0;

    compiler_make_closure(c, co, asdl_seq_LEN(args->defaults));
    Py_DECREF(co);

    return 1;
}

static int
compiler_print(struct compiler *c, stmt_ty s)
{
    int i, n;
    bool dest;

    assert(s->kind == Print_kind);
    n = asdl_seq_LEN(s->v.Print.values);
    dest = false;
    if (s->v.Print.dest) {
        VISIT(c, expr, s->v.Print.dest);
        dest = true;
    }
    for (i = 0; i < n; i++) {
        expr_ty e = (expr_ty)asdl_seq_GET(s->v.Print.values, i);
        if (dest) {
            ADDOP(c, DUP_TOP);
            VISIT(c, expr, e);
            ADDOP(c, ROT_TWO);
            ADDOP(c, PRINT_ITEM_TO);
        }
        else {
            VISIT(c, expr, e);
            ADDOP(c, PRINT_ITEM);
        }
    }
    if (s->v.Print.nl) {
        if (dest)
            ADDOP(c, PRINT_NEWLINE_TO)
        else
            ADDOP(c, PRINT_NEWLINE)
    }
    else if (dest)
        ADDOP(c, POP_TOP);
    return 1;
}

static int
compiler_if(struct compiler *c, stmt_ty s)
{
    basicblock *end, *next;
    int constant;
    assert(s->kind == If_kind);
    end = compiler_new_block(c);
    if (end == NULL)
        return 0;

    constant = expr_constant(s->v.If.test);
    /* constant = 0: "if 0"
     * constant = 1: "if 1", "if 2", ...
     * constant = -1: rest */
    if (constant == 0) {
        if (s->v.If.orelse)
            VISIT_SEQ(c, stmt, s->v.If.orelse);
    } else if (constant == 1) {
        VISIT_SEQ(c, stmt, s->v.If.body);
    } else {
        if (s->v.If.orelse) {
            next = compiler_new_block(c);
            if (next == NULL)
                return 0;
        }
        else
            next = end;
        VISIT(c, expr, s->v.If.test);
        ADDOP_JABS(c, POP_JUMP_IF_FALSE, next);
        VISIT_SEQ(c, stmt, s->v.If.body);
        ADDOP_JREL(c, JUMP_FORWARD, end);
        if (s->v.If.orelse) {
            compiler_use_next_block(c, next);
            VISIT_SEQ(c, stmt, s->v.If.orelse);
        }
    }
    compiler_use_next_block(c, end);
    return 1;
}

static int
compiler_for(struct compiler *c, stmt_ty s)
{
    basicblock *start, *cleanup, *end;

    start = compiler_new_block(c);
    cleanup = compiler_new_block(c);
    end = compiler_new_block(c);
    if (start == NULL || end == NULL || cleanup == NULL)
        return 0;
    ADDOP_JREL(c, SETUP_LOOP, end);
    if (!compiler_push_fblock(c, LOOP, start))
        return 0;
    VISIT(c, expr, s->v.For.iter);
    ADDOP(c, GET_ITER);
    compiler_use_next_block(c, start);
    ADDOP_JREL(c, FOR_ITER, cleanup);
    VISIT(c, expr, s->v.For.target);
    VISIT_SEQ(c, stmt, s->v.For.body);
    ADDOP_JABS(c, JUMP_ABSOLUTE, start);
    compiler_use_next_block(c, cleanup);
    ADDOP(c, POP_BLOCK);
    compiler_pop_fblock(c, LOOP, start);
    VISIT_SEQ(c, stmt, s->v.For.orelse);
    compiler_use_next_block(c, end);
    return 1;
}

static int
compiler_while(struct compiler *c, stmt_ty s)
{
    basicblock *loop, *orelse, *end, *anchor = NULL;
    int constant = expr_constant(s->v.While.test);

    if (constant == 0) {
        if (s->v.While.orelse)
            VISIT_SEQ(c, stmt, s->v.While.orelse);
        return 1;
    }
    loop = compiler_new_block(c);
    end = compiler_new_block(c);
    if (constant == -1) {
        anchor = compiler_new_block(c);
        if (anchor == NULL)
            return 0;
    }
    if (loop == NULL || end == NULL)
        return 0;
    if (s->v.While.orelse) {
        orelse = compiler_new_block(c);
        if (orelse == NULL)
            return 0;
    }
    else
        orelse = NULL;

    ADDOP_JREL(c, SETUP_LOOP, end);
    compiler_use_next_block(c, loop);
    if (!compiler_push_fblock(c, LOOP, loop))
        return 0;
    if (constant == -1) {
        VISIT(c, expr, s->v.While.test);
        ADDOP_JABS(c, POP_JUMP_IF_FALSE, anchor);
    }
    VISIT_SEQ(c, stmt, s->v.While.body);
    ADDOP_JABS(c, JUMP_ABSOLUTE, loop);

    /* XXX should the two POP instructions be in a separate block
       if there is no else clause ?
    */

    if (constant == -1) {
        compiler_use_next_block(c, anchor);
        ADDOP(c, POP_BLOCK);
    }
    compiler_pop_fblock(c, LOOP, loop);
    if (orelse != NULL) /* what if orelse is just pass? */
        VISIT_SEQ(c, stmt, s->v.While.orelse);
    compiler_use_next_block(c, end);

    return 1;
}

static int
compiler_continue(struct compiler *c)
{
    static const char LOOP_ERROR_MSG[] = "'continue' not properly in loop";
    static const char IN_FINALLY_ERROR_MSG[] =
                    "'continue' not supported inside 'finally' clause";
    int i;

    if (!c->u->u_nfblocks)
        return compiler_error(c, LOOP_ERROR_MSG);
    i = c->u->u_nfblocks - 1;
    switch (c->u->u_fblock[i].fb_type) {
    case LOOP:
        ADDOP_JABS(c, JUMP_ABSOLUTE, c->u->u_fblock[i].fb_block);
        break;
    case EXCEPT:
    case FINALLY_TRY:
        while (--i >= 0 && c->u->u_fblock[i].fb_type != LOOP) {
            /* Prevent continue anywhere under a finally
                  even if hidden in a sub-try or except. */
            if (c->u->u_fblock[i].fb_type == FINALLY_END)
                return compiler_error(c, IN_FINALLY_ERROR_MSG);
        }
        if (i == -1)
            return compiler_error(c, LOOP_ERROR_MSG);
        ADDOP_JABS(c, CONTINUE_LOOP, c->u->u_fblock[i].fb_block);
        break;
    case FINALLY_END:
        return compiler_error(c, IN_FINALLY_ERROR_MSG);
    }

    return 1;
}

/* Code generated for "try: <body> finally: <finalbody>" is as follows:

        SETUP_FINALLY           L
        <code for body>
        POP_BLOCK
        LOAD_CONST              <None>
    L:          <code for finalbody>
        END_FINALLY

   The special instructions use the block stack.  Each block
   stack entry contains the instruction that created it (here
   SETUP_FINALLY), the level of the value stack at the time the
   block stack entry was created, and a label (here L).

   SETUP_FINALLY:
    Pushes the current value stack level and the label
    onto the block stack.
   POP_BLOCK:
    Pops en entry from the block stack, and pops the value
    stack until its level is the same as indicated on the
    block stack.  (The label is ignored.)
   END_FINALLY:
    Pops a variable number of entries from the *value* stack
    and re-raises the exception they specify.  The number of
    entries popped depends on the (pseudo) exception type.

   The block stack is unwound when an exception is raised:
   when a SETUP_FINALLY entry is found, the exception is pushed
   onto the value stack (and the exception condition is cleared),
   and the interpreter jumps to the label gotten from the block
   stack.
*/

static int
compiler_try_finally(struct compiler *c, stmt_ty s)
{
    basicblock *body, *end;
    body = compiler_new_block(c);
    end = compiler_new_block(c);
    if (body == NULL || end == NULL)
        return 0;

    ADDOP_JREL(c, SETUP_FINALLY, end);
    compiler_use_next_block(c, body);
    if (!compiler_push_fblock(c, FINALLY_TRY, body))
        return 0;
    VISIT_SEQ(c, stmt, s->v.TryFinally.body);
    ADDOP(c, POP_BLOCK);
    compiler_pop_fblock(c, FINALLY_TRY, body);

    ADDOP_O(c, LOAD_CONST, Py_None, consts);
    compiler_use_next_block(c, end);
    if (!compiler_push_fblock(c, FINALLY_END, end))
        return 0;
    VISIT_SEQ(c, stmt, s->v.TryFinally.finalbody);
    ADDOP(c, END_FINALLY);
    compiler_pop_fblock(c, FINALLY_END, end);

    return 1;
}

/*
   Code generated for "try: S except E1, V1: S1 except E2, V2: S2 ...":
   (The contents of the value stack is shown in [], with the top
   at the right; 'tb' is trace-back info, 'val' the exception's
   associated value, and 'exc' the exception.)

   Value stack          Label   Instruction     Argument
   []                           SETUP_EXCEPT    L1
   []                           <code for S>
   []                           POP_BLOCK
   []                           JUMP_FORWARD    L0

   [tb, val, exc]       L1:     DUP                             )
   [tb, val, exc, exc]          <evaluate E1>                   )
   [tb, val, exc, exc, E1]      COMPARE_OP      EXC_MATCH       ) only if E1
   [tb, val, exc, 1-or-0]       POP_JUMP_IF_FALSE       L2      )
   [tb, val, exc]               POP
   [tb, val]                    <assign to V1>  (or POP if no V1)
   [tb]                         POP
   []                           <code for S1>
                                JUMP_FORWARD    L0

   [tb, val, exc]       L2:     DUP
   .............................etc.......................

   [tb, val, exc]       Ln+1:   END_FINALLY     # re-raise exception

   []                   L0:     <next statement>

   Of course, parts are not generated if Vi or Ei is not present.
*/
static int
compiler_try_except(struct compiler *c, stmt_ty s)
{
    basicblock *body, *orelse, *except, *end;
    int i, n;

    body = compiler_new_block(c);
    except = compiler_new_block(c);
    orelse = compiler_new_block(c);
    end = compiler_new_block(c);
    if (body == NULL || except == NULL || orelse == NULL || end == NULL)
        return 0;
    ADDOP_JREL(c, SETUP_EXCEPT, except);
    compiler_use_next_block(c, body);
    if (!compiler_push_fblock(c, EXCEPT, body))
        return 0;
    VISIT_SEQ(c, stmt, s->v.TryExcept.body);
    ADDOP(c, POP_BLOCK);
    compiler_pop_fblock(c, EXCEPT, body);
    ADDOP_JREL(c, JUMP_FORWARD, orelse);
    n = asdl_seq_LEN(s->v.TryExcept.handlers);
    compiler_use_next_block(c, except);
    for (i = 0; i < n; i++) {
        excepthandler_ty handler = (excepthandler_ty)asdl_seq_GET(
                                        s->v.TryExcept.handlers, i);
        if (!handler->v.ExceptHandler.type && i < n-1)
            return compiler_error(c, "default 'except:' must be last");
        c->u->u_lineno_set = false;
        c->u->u_lineno = handler->lineno;
        except = compiler_new_block(c);
        if (except == NULL)
            return 0;
        if (handler->v.ExceptHandler.type) {
            ADDOP(c, DUP_TOP);
            VISIT(c, expr, handler->v.ExceptHandler.type);
            ADDOP_I(c, COMPARE_OP, PyCmp_EXC_MATCH);
            ADDOP_JABS(c, POP_JUMP_IF_FALSE, except);
        }
        ADDOP(c, POP_TOP);
        if (handler->v.ExceptHandler.name) {
            VISIT(c, expr, handler->v.ExceptHandler.name);
        }
        else {
            ADDOP(c, POP_TOP);
        }
        ADDOP(c, POP_TOP);
        VISIT_SEQ(c, stmt, handler->v.ExceptHandler.body);
        ADDOP_JREL(c, JUMP_FORWARD, end);
        compiler_use_next_block(c, except);
    }
    ADDOP(c, END_FINALLY);
    compiler_use_next_block(c, orelse);
    VISIT_SEQ(c, stmt, s->v.TryExcept.orelse);
    compiler_use_next_block(c, end);
    return 1;
}

static int
compiler_import_as(struct compiler *c, identifier name, identifier asname)
{
    /* The IMPORT_NAME opcode was already generated.  This function
       merely needs to bind the result to a name.

       If there is a dot in name, we need to split it and emit a
       LOAD_ATTR for each name.
    */
    const char *src = PyString_AS_STRING(name);
    const char *dot = strchr(src, '.');
    if (dot) {
        /* Consume the base module name to get the first attribute */
        src = dot + 1;
        while (dot) {
            /* NB src is only defined when dot != NULL */
            PyObject *attr;
            dot = strchr(src, '.');
            attr = PyString_FromStringAndSize(src,
                                dot ? dot - src : strlen(src));
            if (!attr)
                return -1;
            ADDOP_O(c, LOAD_ATTR, attr, names);
            Py_DECREF(attr);
            src = dot + 1;
        }
    }
    return compiler_nameop(c, asname, Store);
}

static int
compiler_import(struct compiler *c, stmt_ty s)
{
    /* The Import node stores a module name like a.b.c as a single
       string.  This is convenient for all cases except
         import a.b.c as d
       where we need to parse that string to extract the individual
       module names.
       XXX Perhaps change the representation to make this case simpler?
     */
    int i, n = asdl_seq_LEN(s->v.Import.names);

    for (i = 0; i < n; i++) {
        alias_ty alias = (alias_ty)asdl_seq_GET(s->v.Import.names, i);
        int r;
        PyObject *level;

        if (c->c_flags && (c->c_flags->cf_flags & CO_FUTURE_ABSOLUTE_IMPORT))
            level = PyInt_FromLong(0);
        else
            level = PyInt_FromLong(-1);

        if (level == NULL)
            return 0;

        ADDOP_O(c, LOAD_CONST, level, consts);
        Py_DECREF(level);
        ADDOP_O(c, LOAD_CONST, Py_None, consts);
        ADDOP_NAME(c, IMPORT_NAME, alias->name, names);

        if (alias->asname) {
            r = compiler_import_as(c, alias->name, alias->asname);
            if (!r)
                return r;
        }
        else {
            identifier tmp = alias->name;
            const char *base = PyString_AS_STRING(alias->name);
            char *dot = strchr(base, '.');
            if (dot)
                tmp = PyString_FromStringAndSize(base,
                                                 dot - base);
            r = compiler_nameop(c, tmp, Store);
            if (dot) {
                Py_DECREF(tmp);
            }
            if (!r)
                return r;
        }
    }
    return 1;
}

static int
compiler_from_import(struct compiler *c, stmt_ty s)
{
    int i, n = asdl_seq_LEN(s->v.ImportFrom.names);

    PyObject *names = PyTuple_New(n);
    PyObject *level;
    static PyObject *empty_string;

    if (!empty_string) {
        empty_string = PyString_FromString("");
        if (!empty_string)
            return 0;
    }

    if (!names)
        return 0;

    if (s->v.ImportFrom.level == 0 && c->c_flags &&
        !(c->c_flags->cf_flags & CO_FUTURE_ABSOLUTE_IMPORT))
        level = PyInt_FromLong(-1);
    else
        level = PyInt_FromLong(s->v.ImportFrom.level);

    if (!level) {
        Py_DECREF(names);
        return 0;
    }

    /* build up the names */
    for (i = 0; i < n; i++) {
        alias_ty alias = (alias_ty)asdl_seq_GET(s->v.ImportFrom.names, i);
        Py_INCREF(alias->name);
        PyTuple_SET_ITEM(names, i, alias->name);
    }

    if (s->lineno > c->c_future->ff_lineno && s->v.ImportFrom.module &&
        !strcmp(PyString_AS_STRING(s->v.ImportFrom.module), "__future__")) {
        Py_DECREF(level);
        Py_DECREF(names);
        return compiler_error(c, "from __future__ imports must occur "
                              "at the beginning of the file");
    }

    ADDOP_O(c, LOAD_CONST, level, consts);
    Py_DECREF(level);
    ADDOP_O(c, LOAD_CONST, names, consts);
    Py_DECREF(names);
    if (s->v.ImportFrom.module) {
        ADDOP_NAME(c, IMPORT_NAME, s->v.ImportFrom.module, names);
    }
    else {
        ADDOP_NAME(c, IMPORT_NAME, empty_string, names);
    }
    for (i = 0; i < n; i++) {
        alias_ty alias = (alias_ty)asdl_seq_GET(s->v.ImportFrom.names, i);
        identifier store_name;

        if (i == 0 && *PyString_AS_STRING(alias->name) == '*') {
            assert(n == 1);
            ADDOP(c, IMPORT_STAR);
            return 1;
        }

        ADDOP_NAME(c, IMPORT_FROM, alias->name, names);
        store_name = alias->name;
        if (alias->asname)
            store_name = alias->asname;

        if (!compiler_nameop(c, store_name, Store)) {
            Py_DECREF(names);
            return 0;
        }
    }
    /* remove imported module */
    ADDOP(c, POP_TOP);
    return 1;
}

static int
compiler_assert(struct compiler *c, stmt_ty s)
{
    static PyObject *assertion_error = NULL;
    basicblock *end;

    if (Py_OptimizeFlag)
        return 1;
    if (assertion_error == NULL) {
        assertion_error = PyString_InternFromString("AssertionError");
        if (assertion_error == NULL)
            return 0;
    }
    if (s->v.Assert.test->kind == Tuple_kind &&
        asdl_seq_LEN(s->v.Assert.test->v.Tuple.elts) > 0) {
        const char* msg =
            "assertion is always true, perhaps remove parentheses?";
        if (PyErr_WarnExplicit(PyExc_SyntaxWarning, msg, c->c_filename,
                               c->u->u_lineno, NULL, NULL) == -1)
            return 0;
    }
    VISIT(c, expr, s->v.Assert.test);
    end = compiler_new_block(c);
    if (end == NULL)
        return 0;
    ADDOP_JABS(c, POP_JUMP_IF_TRUE, end);
    ADDOP_O(c, LOAD_GLOBAL, assertion_error, names);
    if (s->v.Assert.msg) {
        VISIT(c, expr, s->v.Assert.msg);
        ADDOP_I(c, CALL_FUNCTION, 1);
    }
    ADDOP_I(c, RAISE_VARARGS, 1);
    compiler_use_next_block(c, end);
    return 1;
}

static int
compiler_visit_stmt(struct compiler *c, stmt_ty s)
{
    int i, n;

    /* Always assign a lineno to the next instruction for a stmt. */
    c->u->u_lineno = s->lineno;
    c->u->u_lineno_set = false;

    switch (s->kind) {
    case FunctionDef_kind:
        return compiler_function(c, s);
    case ClassDef_kind:
        return compiler_class(c, s);
    case Return_kind:
        if (c->u->u_ste->ste_type != FunctionBlock)
            return compiler_error(c, "'return' outside function");
        if (s->v.Return.value) {
            VISIT(c, expr, s->v.Return.value);
        }
        else
            ADDOP_O(c, LOAD_CONST, Py_None, consts);
        ADDOP(c, RETURN_VALUE);
        break;
    case Delete_kind:
        VISIT_SEQ(c, expr, s->v.Delete.targets)
        break;
    case Assign_kind:
        n = asdl_seq_LEN(s->v.Assign.targets);
        VISIT(c, expr, s->v.Assign.value);
        for (i = 0; i < n; i++) {
            if (i < n - 1)
                ADDOP(c, DUP_TOP);
            VISIT(c, expr,
                  (expr_ty)asdl_seq_GET(s->v.Assign.targets, i));
        }
        break;
    case AugAssign_kind:
        return compiler_augassign(c, s);
    case Print_kind:
        return compiler_print(c, s);
    case For_kind:
        return compiler_for(c, s);
    case While_kind:
        return compiler_while(c, s);
    case If_kind:
        return compiler_if(c, s);
    case Raise_kind:
        n = 0;
        if (s->v.Raise.type) {
            VISIT(c, expr, s->v.Raise.type);
            n++;
            if (s->v.Raise.inst) {
                VISIT(c, expr, s->v.Raise.inst);
                n++;
                if (s->v.Raise.tback) {
                    VISIT(c, expr, s->v.Raise.tback);
                    n++;
                }
            }
        }
        ADDOP_I(c, RAISE_VARARGS, n);
        break;
    case TryExcept_kind:
        return compiler_try_except(c, s);
    case TryFinally_kind:
        return compiler_try_finally(c, s);
    case Assert_kind:
        return compiler_assert(c, s);
    case Import_kind:
        return compiler_import(c, s);
    case ImportFrom_kind:
        return compiler_from_import(c, s);
    case Exec_kind:
        VISIT(c, expr, s->v.Exec.body);
        if (s->v.Exec.globals) {
            VISIT(c, expr, s->v.Exec.globals);
            if (s->v.Exec.locals) {
                VISIT(c, expr, s->v.Exec.locals);
            } else {
                ADDOP(c, DUP_TOP);
            }
        } else {
            ADDOP_O(c, LOAD_CONST, Py_None, consts);
            ADDOP(c, DUP_TOP);
        }
        ADDOP(c, EXEC_STMT);
        break;
    case Global_kind:
        break;
    case Expr_kind:
        if (c->c_interactive && c->c_nestlevel <= 1) {
            VISIT(c, expr, s->v.Expr.value);
            ADDOP(c, PRINT_EXPR);
        }
        else if (s->v.Expr.value->kind != Str_kind &&
                 s->v.Expr.value->kind != Num_kind) {
            VISIT(c, expr, s->v.Expr.value);
            ADDOP(c, POP_TOP);
        }
        break;
    case Pass_kind:
        break;
    case Break_kind:
        if (!compiler_in_loop(c))
            return compiler_error(c, "'break' outside loop");
        ADDOP(c, BREAK_LOOP);
        break;
    case Continue_kind:
        return compiler_continue(c);
    case With_kind:
        return compiler_with(c, s);
    }
    return 1;
}

static int
unaryop(unaryop_ty op)
{
    switch (op) {
    case Invert:
        return UNARY_INVERT;
    case Not:
        return UNARY_NOT;
    case UAdd:
        return UNARY_POSITIVE;
    case USub:
        return UNARY_NEGATIVE;
    default:
        PyErr_Format(PyExc_SystemError,
            "unary op %d should not be possible", op);
        return 0;
    }
}

static int
binop(struct compiler *c, operator_ty op)
{
    switch (op) {
    case Add:
        return BINARY_ADD;
    case Sub:
        return BINARY_SUBTRACT;
    case Mult:
        return BINARY_MULTIPLY;
    case Div:
        if (c->c_flags && c->c_flags->cf_flags & CO_FUTURE_DIVISION)
            return BINARY_TRUE_DIVIDE;
        else
            return BINARY_DIVIDE;
    case Mod:
        return BINARY_MODULO;
    case Pow:
        return BINARY_POWER;
    case LShift:
        return BINARY_LSHIFT;
    case RShift:
        return BINARY_RSHIFT;
    case BitOr:
        return BINARY_OR;
    case BitXor:
        return BINARY_XOR;
    case BitAnd:
        return BINARY_AND;
    case FloorDiv:
        return BINARY_FLOOR_DIVIDE;
    default:
        PyErr_Format(PyExc_SystemError,
            "binary op %d should not be possible", op);
        return 0;
    }
}

static int
cmpop(cmpop_ty op)
{
    switch (op) {
    case Eq:
        return PyCmp_EQ;
    case NotEq:
        return PyCmp_NE;
    case Lt:
        return PyCmp_LT;
    case LtE:
        return PyCmp_LE;
    case Gt:
        return PyCmp_GT;
    case GtE:
        return PyCmp_GE;
    case Is:
        return PyCmp_IS;
    case IsNot:
        return PyCmp_IS_NOT;
    case In:
        return PyCmp_IN;
    case NotIn:
        return PyCmp_NOT_IN;
    default:
        return PyCmp_BAD;
    }
}

static int
inplace_binop(struct compiler *c, operator_ty op)
{
    switch (op) {
    case Add:
        return INPLACE_ADD;
    case Sub:
        return INPLACE_SUBTRACT;
    case Mult:
        return INPLACE_MULTIPLY;
    case Div:
        if (c->c_flags && c->c_flags->cf_flags & CO_FUTURE_DIVISION)
            return INPLACE_TRUE_DIVIDE;
        else
            return INPLACE_DIVIDE;
    case Mod:
        return INPLACE_MODULO;
    case Pow:
        return INPLACE_POWER;
    case LShift:
        return INPLACE_LSHIFT;
    case RShift:
        return INPLACE_RSHIFT;
    case BitOr:
        return INPLACE_OR;
    case BitXor:
        return INPLACE_XOR;
    case BitAnd:
        return INPLACE_AND;
    case FloorDiv:
        return INPLACE_FLOOR_DIVIDE;
    default:
        PyErr_Format(PyExc_SystemError,
            "inplace binary op %d should not be possible", op);
        return 0;
    }
}

static int
compiler_nameop(struct compiler *c, identifier name, expr_context_ty ctx)
{
    int op, scope, arg;
    enum { OP_FAST, OP_GLOBAL, OP_DEREF, OP_NAME } optype;

    PyObject *dict = c->u->u_names;
    PyObject *mangled;
    /* XXX AugStore isn't used anywhere! */

    mangled = _Py_Mangle(c->u->u_private, name);
    if (!mangled)
        return 0;

    op = 0;
    optype = OP_NAME;
    scope = PyST_GetScope(c->u->u_ste, mangled);
    switch (scope) {
    case FREE:
        dict = c->u->u_freevars;
        optype = OP_DEREF;
        break;
    case CELL:
        dict = c->u->u_cellvars;
        optype = OP_DEREF;
        break;
    case LOCAL:
        if (c->u->u_ste->ste_type == FunctionBlock)
            optype = OP_FAST;
        break;
    case GLOBAL_IMPLICIT:
        if (c->u->u_ste->ste_type == FunctionBlock &&
            !c->u->u_ste->ste_unoptimized)
            optype = OP_GLOBAL;
        break;
    case GLOBAL_EXPLICIT:
        optype = OP_GLOBAL;
        break;
    default:
        /* scope can be 0 */
        break;
    }

    /* XXX Leave assert here, but handle __doc__ and the like better */
    assert(scope || PyString_AS_STRING(name)[0] == '_');

    switch (optype) {
    case OP_DEREF:
        switch (ctx) {
        case Load: op = LOAD_DEREF; break;
        case Store: op = STORE_DEREF; break;
        case AugLoad:
        case AugStore:
            break;
        case Del:
            PyErr_Format(PyExc_SyntaxError,
                         "can not delete variable '%s' referenced "
                         "in nested scope",
                         PyString_AS_STRING(name));
            Py_DECREF(mangled);
            return 0;
        case Param:
        default:
            PyErr_SetString(PyExc_SystemError,
                            "param invalid for deref variable");
            return 0;
        }
        break;
    case OP_FAST:
        switch (ctx) {
        case Load: op = LOAD_FAST; break;
        case Store: op = STORE_FAST; break;
        case Del: op = DELETE_FAST; break;
        case AugLoad:
        case AugStore:
            break;
        case Param:
        default:
            PyErr_SetString(PyExc_SystemError,
                            "param invalid for local variable");
            return 0;
        }
        ADDOP_O(c, op, mangled, varnames);
        Py_DECREF(mangled);
        return 1;
    case OP_GLOBAL:
        switch (ctx) {
        case Load: op = LOAD_GLOBAL; break;
        case Store: op = STORE_GLOBAL; break;
        case Del: op = DELETE_GLOBAL; break;
        case AugLoad:
        case AugStore:
            break;
        case Param:
        default:
            PyErr_SetString(PyExc_SystemError,
                            "param invalid for global variable");
            return 0;
        }
        break;
    case OP_NAME:
        switch (ctx) {
        case Load: op = LOAD_NAME; break;
        case Store: op = STORE_NAME; break;
        case Del: op = DELETE_NAME; break;
        case AugLoad:
        case AugStore:
            break;
        case Param:
        default:
            PyErr_SetString(PyExc_SystemError,
                            "param invalid for name variable");
            return 0;
        }
        break;
    }

    assert(op);
    arg = compiler_add_o(c, dict, mangled);
    Py_DECREF(mangled);
    if (arg < 0)
        return 0;
    return compiler_addop_i(c, op, arg);
}

static int
compiler_boolop(struct compiler *c, expr_ty e)
{
    basicblock *end;
    int jumpi, i, n;
    asdl_seq *s;

    assert(e->kind == BoolOp_kind);
    if (e->v.BoolOp.op == And)
        jumpi = JUMP_IF_FALSE_OR_POP;
    else
        jumpi = JUMP_IF_TRUE_OR_POP;
    end = compiler_new_block(c);
    if (end == NULL)
        return 0;
    s = e->v.BoolOp.values;
    n = asdl_seq_LEN(s) - 1;
    assert(n >= 0);
    for (i = 0; i < n; ++i) {
        VISIT(c, expr, (expr_ty)asdl_seq_GET(s, i));
        ADDOP_JABS(c, jumpi, end);
    }
    VISIT(c, expr, (expr_ty)asdl_seq_GET(s, n));
    compiler_use_next_block(c, end);
    return 1;
}

static int
compiler_list(struct compiler *c, expr_ty e)
{
    int n = asdl_seq_LEN(e->v.List.elts);
    if (e->v.List.ctx == Store) {
        ADDOP_I(c, UNPACK_SEQUENCE, n);
    }
    VISIT_SEQ(c, expr, e->v.List.elts);
    if (e->v.List.ctx == Load) {
        ADDOP_I(c, BUILD_LIST, n);
    }
    return 1;
}

static int
compiler_tuple(struct compiler *c, expr_ty e)
{
    int n = asdl_seq_LEN(e->v.Tuple.elts);
    if (e->v.Tuple.ctx == Store) {
        ADDOP_I(c, UNPACK_SEQUENCE, n);
    }
    VISIT_SEQ(c, expr, e->v.Tuple.elts);
    if (e->v.Tuple.ctx == Load) {
        ADDOP_I(c, BUILD_TUPLE, n);
    }
    return 1;
}

static int
compiler_compare(struct compiler *c, expr_ty e)
{
    int i, n;
    basicblock *cleanup = NULL;

    /* XXX the logic can be cleaned up for 1 or multiple comparisons */
    VISIT(c, expr, e->v.Compare.left);
    n = asdl_seq_LEN(e->v.Compare.ops);
    assert(n > 0);
    if (n > 1) {
        cleanup = compiler_new_block(c);
        if (cleanup == NULL)
            return 0;
        VISIT(c, expr,
            (expr_ty)asdl_seq_GET(e->v.Compare.comparators, 0));
    }
    for (i = 1; i < n; i++) {
        ADDOP(c, DUP_TOP);
        ADDOP(c, ROT_THREE);
        ADDOP_I(c, COMPARE_OP,
            cmpop((cmpop_ty)(asdl_seq_GET(
                                      e->v.Compare.ops, i - 1))));
        ADDOP_JABS(c, JUMP_IF_FALSE_OR_POP, cleanup);
        NEXT_BLOCK(c);
        if (i < (n - 1))
            VISIT(c, expr,
                (expr_ty)asdl_seq_GET(e->v.Compare.comparators, i));
    }
    VISIT(c, expr, (expr_ty)asdl_seq_GET(e->v.Compare.comparators, n - 1));
    ADDOP_I(c, COMPARE_OP,
           cmpop((cmpop_ty)(asdl_seq_GET(e->v.Compare.ops, n - 1))));
    if (n > 1) {
        basicblock *end = compiler_new_block(c);
        if (end == NULL)
            return 0;
        ADDOP_JREL(c, JUMP_FORWARD, end);
        compiler_use_next_block(c, cleanup);
        ADDOP(c, ROT_TWO);
        ADDOP(c, POP_TOP);
        compiler_use_next_block(c, end);
    }
    return 1;
}

static int
compiler_call(struct compiler *c, expr_ty e)
{
    int n, code = 0;

    VISIT(c, expr, e->v.Call.func);
    n = asdl_seq_LEN(e->v.Call.args);
    VISIT_SEQ(c, expr, e->v.Call.args);
    if (e->v.Call.keywords) {
        VISIT_SEQ(c, keyword, e->v.Call.keywords);
        n |= asdl_seq_LEN(e->v.Call.keywords) << 8;
    }
    if (e->v.Call.starargs) {
        VISIT(c, expr, e->v.Call.starargs);
        code |= 1;
    }
    if (e->v.Call.kwargs) {
        VISIT(c, expr, e->v.Call.kwargs);
        code |= 2;
    }
    switch (code) {
    case 0:
        ADDOP_I(c, CALL_FUNCTION, n);
        break;
    case 1:
        ADDOP_I(c, CALL_FUNCTION_VAR, n);
        break;
    case 2:
        ADDOP_I(c, CALL_FUNCTION_KW, n);
        break;
    case 3:
        ADDOP_I(c, CALL_FUNCTION_VAR_KW, n);
        break;
    }
    return 1;
}

static int
compiler_listcomp_generator(struct compiler *c, asdl_seq *generators,
                            int gen_index, expr_ty elt)
{
    /* generate code for the iterator, then each of the ifs,
       and then write to the element */

    comprehension_ty l;
    basicblock *start, *anchor, *skip, *if_cleanup;
    int i, n;

    start = compiler_new_block(c);
    skip = compiler_new_block(c);
    if_cleanup = compiler_new_block(c);
    anchor = compiler_new_block(c);

    if (start == NULL || skip == NULL || if_cleanup == NULL ||
        anchor == NULL)
        return 0;

    l = (comprehension_ty)asdl_seq_GET(generators, gen_index);
    VISIT(c, expr, l->iter);
    ADDOP(c, GET_ITER);
    compiler_use_next_block(c, start);
    ADDOP_JREL(c, FOR_ITER, anchor);
    NEXT_BLOCK(c);
    VISIT(c, expr, l->target);

    /* XXX this needs to be cleaned up...a lot! */
    n = asdl_seq_LEN(l->ifs);
    for (i = 0; i < n; i++) {
        expr_ty e = (expr_ty)asdl_seq_GET(l->ifs, i);
        VISIT(c, expr, e);
        ADDOP_JABS(c, POP_JUMP_IF_FALSE, if_cleanup);
        NEXT_BLOCK(c);
    }

    if (++gen_index < asdl_seq_LEN(generators))
        if (!compiler_listcomp_generator(c, generators, gen_index, elt))
        return 0;

    /* only append after the last for generator */
    if (gen_index >= asdl_seq_LEN(generators)) {
        VISIT(c, expr, elt);
        ADDOP_I(c, LIST_APPEND, gen_index+1);

        compiler_use_next_block(c, skip);
    }
    compiler_use_next_block(c, if_cleanup);
    ADDOP_JABS(c, JUMP_ABSOLUTE, start);
    compiler_use_next_block(c, anchor);

    return 1;
}

static int
compiler_listcomp(struct compiler *c, expr_ty e)
{
    assert(e->kind == ListComp_kind);
    ADDOP_I(c, BUILD_LIST, 0);
    return compiler_listcomp_generator(c, e->v.ListComp.generators, 0,
                                       e->v.ListComp.elt);
}

/* Dict and set comprehensions and generator expressions work by creating a
   nested function to perform the actual iteration. This means that the
   iteration variables don't leak into the current scope.
   The defined function is called immediately following its definition, with the
   result of that call being the result of the expression.
   The LC/SC version returns the populated container, while the GE version is
   flagged in symtable.c as a generator, so it returns the generator object
   when the function is called.
   This code *knows* that the loop cannot contain break, continue, or return,
   so it cheats and skips the SETUP_LOOP/POP_BLOCK steps used in normal loops.

   Possible cleanups:
    - iterate over the generator sequence instead of using recursion
*/

static int
compiler_comprehension_generator(struct compiler *c,
                                 asdl_seq *generators, int gen_index,
                                 expr_ty elt, expr_ty val, int type)
{
    /* generate code for the iterator, then each of the ifs,
       and then write to the element */

    comprehension_ty gen;
    basicblock *start, *anchor, *skip, *if_cleanup;
    int i, n;

    start = compiler_new_block(c);
    skip = compiler_new_block(c);
    if_cleanup = compiler_new_block(c);
    anchor = compiler_new_block(c);

    if (start == NULL || skip == NULL || if_cleanup == NULL ||
        anchor == NULL)
        return 0;

    gen = (comprehension_ty)asdl_seq_GET(generators, gen_index);

    if (gen_index == 0) {
        /* Receive outermost iter as an implicit argument */
        c->u->u_argcount = 1;
        ADDOP_I(c, LOAD_FAST, 0);
    }
    else {
        /* Sub-iter - calculate on the fly */
        VISIT(c, expr, gen->iter);
        ADDOP(c, GET_ITER);
    }
    compiler_use_next_block(c, start);
    ADDOP_JREL(c, FOR_ITER, anchor);
    NEXT_BLOCK(c);
    VISIT(c, expr, gen->target);

    /* XXX this needs to be cleaned up...a lot! */
    n = asdl_seq_LEN(gen->ifs);
    for (i = 0; i < n; i++) {
        expr_ty e = (expr_ty)asdl_seq_GET(gen->ifs, i);
        VISIT(c, expr, e);
        ADDOP_JABS(c, POP_JUMP_IF_FALSE, if_cleanup);
        NEXT_BLOCK(c);
    }

    if (++gen_index < asdl_seq_LEN(generators))
        if (!compiler_comprehension_generator(c,
                                              generators, gen_index,
                                              elt, val, type))
        return 0;

    /* only append after the last for generator */
    if (gen_index >= asdl_seq_LEN(generators)) {
        /* comprehension specific code */
        switch (type) {
        case COMP_GENEXP:
            VISIT(c, expr, elt);
            ADDOP(c, YIELD_VALUE);
            ADDOP(c, POP_TOP);
            break;
        case COMP_SETCOMP:
            VISIT(c, expr, elt);
            ADDOP_I(c, SET_ADD, gen_index + 1);
            break;
        case COMP_DICTCOMP:
            /* With 'd[k] = v', v is evaluated before k, so we do
               the same. */
            VISIT(c, expr, val);
            VISIT(c, expr, elt);
            ADDOP_I(c, MAP_ADD, gen_index + 1);
            break;
        default:
            return 0;
        }

        compiler_use_next_block(c, skip);
    }
    compiler_use_next_block(c, if_cleanup);
    ADDOP_JABS(c, JUMP_ABSOLUTE, start);
    compiler_use_next_block(c, anchor);

    return 1;
}

static int
compiler_comprehension(struct compiler *c, expr_ty e, int type, identifier name,
                       asdl_seq *generators, expr_ty elt, expr_ty val)
{
    PyCodeObject *co = NULL;
    expr_ty outermost_iter;

    outermost_iter = ((comprehension_ty)
                      asdl_seq_GET(generators, 0))->iter;

    if (!compiler_enter_scope(c, name, (void *)e, e->lineno))
        goto error;

    if (type != COMP_GENEXP) {
        int op;
        switch (type) {
        case COMP_SETCOMP:
            op = BUILD_SET;
            break;
        case COMP_DICTCOMP:
            op = BUILD_MAP;
            break;
        default:
            PyErr_Format(PyExc_SystemError,
                         "unknown comprehension type %d", type);
            goto error_in_scope;
        }

        ADDOP_I(c, op, 0);
    }

    if (!compiler_comprehension_generator(c, generators, 0, elt,
                                          val, type))
        goto error_in_scope;

    if (type != COMP_GENEXP) {
        ADDOP(c, RETURN_VALUE);
    }

    co = assemble(c, 1);
    compiler_exit_scope(c);
    if (co == NULL)
        goto error;

    if (!compiler_make_closure(c, co, 0))
        goto error;
    Py_DECREF(co);

    VISIT(c, expr, outermost_iter);
    ADDOP(c, GET_ITER);
    ADDOP_I(c, CALL_FUNCTION, 1);
    return 1;
error_in_scope:
    compiler_exit_scope(c);
error:
    Py_XDECREF(co);
    return 0;
}

static int
compiler_genexp(struct compiler *c, expr_ty e)
{
    static identifier name;
    if (!name) {
        name = PyString_FromString("<genexpr>");
        if (!name)
            return 0;
    }
    assert(e->kind == GeneratorExp_kind);
    return compiler_comprehension(c, e, COMP_GENEXP, name,
                                  e->v.GeneratorExp.generators,
                                  e->v.GeneratorExp.elt, NULL);
}

static int
compiler_setcomp(struct compiler *c, expr_ty e)
{
    static identifier name;
    if (!name) {
        name = PyString_FromString("<setcomp>");
        if (!name)
            return 0;
    }
    assert(e->kind == SetComp_kind);
    return compiler_comprehension(c, e, COMP_SETCOMP, name,
                                  e->v.SetComp.generators,
                                  e->v.SetComp.elt, NULL);
}

static int
compiler_dictcomp(struct compiler *c, expr_ty e)
{
    static identifier name;
    if (!name) {
        name = PyString_FromString("<dictcomp>");
        if (!name)
            return 0;
    }
    assert(e->kind == DictComp_kind);
    return compiler_comprehension(c, e, COMP_DICTCOMP, name,
                                  e->v.DictComp.generators,
                                  e->v.DictComp.key, e->v.DictComp.value);
}

static int
compiler_visit_keyword(struct compiler *c, keyword_ty k)
{
    ADDOP_O(c, LOAD_CONST, k->arg, consts);
    VISIT(c, expr, k->value);
    return 1;
}

/* Test whether expression is constant.  For constants, report
   whether they are true or false.

   Return values: 1 for true, 0 for false, -1 for non-constant.
 */

static int
expr_constant(expr_ty e)
{
    switch (e->kind) {
    case Num_kind:
        return PyObject_IsTrue(e->v.Num.n);
    case Str_kind:
        return PyObject_IsTrue(e->v.Str.s);
    case Name_kind:
        /* __debug__ is not assignable, so we can optimize
         * it away in if and while statements */
        if (strcmp(PyString_AS_STRING(e->v.Name.id),
                   "__debug__") == 0)
                   return ! Py_OptimizeFlag;
        /* fall through */
    default:
        return -1;
    }
}

/*
   Implements the with statement from PEP 343.

   The semantics outlined in that PEP are as follows:

   with EXPR as VAR:
       BLOCK

   It is implemented roughly as:

   context = EXPR
   exit = context.__exit__  # not calling it
   value = context.__enter__()
   try:
       VAR = value  # if VAR present in the syntax
       BLOCK
   finally:
       if an exception was raised:
       exc = copy of (exception, instance, traceback)
       else:
       exc = (None, None, None)
       exit(*exc)
 */
static int
compiler_with(struct compiler *c, stmt_ty s)
{
    basicblock *block, *finally;

    assert(s->kind == With_kind);

    block = compiler_new_block(c);
    finally = compiler_new_block(c);
    if (!block || !finally)
        return 0;

    /* Evaluate EXPR */
    VISIT(c, expr, s->v.With.context_expr);
    ADDOP_JREL(c, SETUP_WITH, finally);

    /* SETUP_WITH pushes a finally block. */
    compiler_use_next_block(c, block);
    /* Note that the block is actually called SETUP_WITH in ceval.c, but
       functions the same as SETUP_FINALLY except that exceptions are
       normalized. */
    if (!compiler_push_fblock(c, FINALLY_TRY, block)) {
        return 0;
    }

    if (s->v.With.optional_vars) {
        VISIT(c, expr, s->v.With.optional_vars);
    }
    else {
    /* Discard result from context.__enter__() */
        ADDOP(c, POP_TOP);
    }

    /* BLOCK code */
    VISIT_SEQ(c, stmt, s->v.With.body);

    /* End of try block; start the finally block */
    ADDOP(c, POP_BLOCK);
    compiler_pop_fblock(c, FINALLY_TRY, block);

    ADDOP_O(c, LOAD_CONST, Py_None, consts);
    compiler_use_next_block(c, finally);
    if (!compiler_push_fblock(c, FINALLY_END, finally))
        return 0;

    /* Finally block starts; context.__exit__ is on the stack under
       the exception or return information. Just issue our magic
       opcode. */
    ADDOP(c, WITH_CLEANUP);

    /* Finally block ends. */
    ADDOP(c, END_FINALLY);
    compiler_pop_fblock(c, FINALLY_END, finally);
    return 1;
}

static int
compiler_visit_expr(struct compiler *c, expr_ty e)
{
    int i, n;

    /* If expr e has a different line number than the last expr/stmt,
       set a new line number for the next instruction.
    */
    if (e->lineno > c->u->u_lineno) {
        c->u->u_lineno = e->lineno;
        c->u->u_lineno_set = false;
    }
    switch (e->kind) {
    case BoolOp_kind:
        return compiler_boolop(c, e);
    case BinOp_kind:
        VISIT(c, expr, e->v.BinOp.left);
        VISIT(c, expr, e->v.BinOp.right);
        ADDOP(c, binop(c, e->v.BinOp.op));
        break;
    case UnaryOp_kind:
        VISIT(c, expr, e->v.UnaryOp.operand);
        ADDOP(c, unaryop(e->v.UnaryOp.op));
        break;
    case Lambda_kind:
        return compiler_lambda(c, e);
    case IfExp_kind:
        return compiler_ifexp(c, e);
    case Dict_kind:
        n = asdl_seq_LEN(e->v.Dict.values);
        ADDOP_I(c, BUILD_MAP, (n>0xFFFF ? 0xFFFF : n));
        for (i = 0; i < n; i++) {
            VISIT(c, expr,
                (expr_ty)asdl_seq_GET(e->v.Dict.values, i));
            VISIT(c, expr,
                (expr_ty)asdl_seq_GET(e->v.Dict.keys, i));
            ADDOP(c, STORE_MAP);
        }
        break;
    case Set_kind:
        n = asdl_seq_LEN(e->v.Set.elts);
        VISIT_SEQ(c, expr, e->v.Set.elts);
        ADDOP_I(c, BUILD_SET, n);
        break;
    case ListComp_kind:
        return compiler_listcomp(c, e);
    case SetComp_kind:
        return compiler_setcomp(c, e);
    case DictComp_kind:
        return compiler_dictcomp(c, e);
    case GeneratorExp_kind:
        return compiler_genexp(c, e);
    case Yield_kind:
        if (c->u->u_ste->ste_type != FunctionBlock)
            return compiler_error(c, "'yield' outside function");
        if (e->v.Yield.value) {
            VISIT(c, expr, e->v.Yield.value);
        }
        else {
            ADDOP_O(c, LOAD_CONST, Py_None, consts);
        }
        ADDOP(c, YIELD_VALUE);
        break;
    case Compare_kind:
        return compiler_compare(c, e);
    case Call_kind:
        return compiler_call(c, e);
    case Repr_kind:
        VISIT(c, expr, e->v.Repr.value);
        ADDOP(c, UNARY_CONVERT);
        break;
    case Num_kind:
        ADDOP_O(c, LOAD_CONST, e->v.Num.n, consts);
        break;
    case Str_kind:
        ADDOP_O(c, LOAD_CONST, e->v.Str.s, consts);
        break;
    /* The following exprs can be assignment targets. */
    case Attribute_kind:
        if (e->v.Attribute.ctx != AugStore)
            VISIT(c, expr, e->v.Attribute.value);
        switch (e->v.Attribute.ctx) {
        case AugLoad:
            ADDOP(c, DUP_TOP);
            /* Fall through to load */
        case Load:
            ADDOP_NAME(c, LOAD_ATTR, e->v.Attribute.attr, names);
            break;
        case AugStore:
            ADDOP(c, ROT_TWO);
            /* Fall through to save */
        case Store:
            ADDOP_NAME(c, STORE_ATTR, e->v.Attribute.attr, names);
            break;
        case Del:
            ADDOP_NAME(c, DELETE_ATTR, e->v.Attribute.attr, names);
            break;
        case Param:
        default:
            PyErr_SetString(PyExc_SystemError,
                            "param invalid in attribute expression");
            return 0;
        }
        break;
    case Subscript_kind:
        switch (e->v.Subscript.ctx) {
        case AugLoad:
            VISIT(c, expr, e->v.Subscript.value);
            VISIT_SLICE(c, e->v.Subscript.slice, AugLoad);
            break;
        case Load:
            VISIT(c, expr, e->v.Subscript.value);
            VISIT_SLICE(c, e->v.Subscript.slice, Load);
            break;
        case AugStore:
            VISIT_SLICE(c, e->v.Subscript.slice, AugStore);
            break;
        case Store:
            VISIT(c, expr, e->v.Subscript.value);
            VISIT_SLICE(c, e->v.Subscript.slice, Store);
            break;
        case Del:
            VISIT(c, expr, e->v.Subscript.value);
            VISIT_SLICE(c, e->v.Subscript.slice, Del);
            break;
        case Param:
        default:
            PyErr_SetString(PyExc_SystemError,
                "param invalid in subscript expression");
            return 0;
        }
        break;
    case Name_kind:
        return compiler_nameop(c, e->v.Name.id, e->v.Name.ctx);
    /* child nodes of List and Tuple will have expr_context set */
    case List_kind:
        return compiler_list(c, e);
    case Tuple_kind:
        return compiler_tuple(c, e);
    }
    return 1;
}

static int
compiler_augassign(struct compiler *c, stmt_ty s)
{
    expr_ty e = s->v.AugAssign.target;
    expr_ty auge;

    assert(s->kind == AugAssign_kind);

    switch (e->kind) {
    case Attribute_kind:
        auge = Attribute(e->v.Attribute.value, e->v.Attribute.attr,
                         AugLoad, e->lineno, e->col_offset, c->c_arena);
        if (auge == NULL)
            return 0;
        VISIT(c, expr, auge);
        VISIT(c, expr, s->v.AugAssign.value);
        ADDOP(c, inplace_binop(c, s->v.AugAssign.op));
        auge->v.Attribute.ctx = AugStore;
        VISIT(c, expr, auge);
        break;
    case Subscript_kind:
        auge = Subscript(e->v.Subscript.value, e->v.Subscript.slice,
                         AugLoad, e->lineno, e->col_offset, c->c_arena);
        if (auge == NULL)
            return 0;
        VISIT(c, expr, auge);
        VISIT(c, expr, s->v.AugAssign.value);
        ADDOP(c, inplace_binop(c, s->v.AugAssign.op));
        auge->v.Subscript.ctx = AugStore;
        VISIT(c, expr, auge);
        break;
    case Name_kind:
        if (!compiler_nameop(c, e->v.Name.id, Load))
            return 0;
        VISIT(c, expr, s->v.AugAssign.value);
        ADDOP(c, inplace_binop(c, s->v.AugAssign.op));
        return compiler_nameop(c, e->v.Name.id, Store);
    default:
        PyErr_Format(PyExc_SystemError,
            "invalid node type (%d) for augmented assignment",
            e->kind);
        return 0;
    }
    return 1;
}

static int
compiler_push_fblock(struct compiler *c, enum fblocktype t, basicblock *b)
{
    struct fblockinfo *f;
    if (c->u->u_nfblocks >= CO_MAXBLOCKS) {
        PyErr_SetString(PyExc_SystemError,
                        "too many statically nested blocks");
        return 0;
    }
    f = &c->u->u_fblock[c->u->u_nfblocks++];
    f->fb_type = t;
    f->fb_block = b;
    return 1;
}

static void
compiler_pop_fblock(struct compiler *c, enum fblocktype t, basicblock *b)
{
    struct compiler_unit *u = c->u;
    assert(u->u_nfblocks > 0);
    u->u_nfblocks--;
    assert(u->u_fblock[u->u_nfblocks].fb_type == t);
    assert(u->u_fblock[u->u_nfblocks].fb_block == b);
}

static int
compiler_in_loop(struct compiler *c) {
    int i;
    struct compiler_unit *u = c->u;
    for (i = 0; i < u->u_nfblocks; ++i) {
        if (u->u_fblock[i].fb_type == LOOP)
            return 1;
    }
    return 0;
}
/* Raises a SyntaxError and returns 0.
   If something goes wrong, a different exception may be raised.
*/

static int
compiler_error(struct compiler *c, const char *errstr)
{
    PyObject *loc;
    PyObject *u = NULL, *v = NULL;

    loc = PyErr_ProgramText(c->c_filename, c->u->u_lineno);
    if (!loc) {
        Py_INCREF(Py_None);
        loc = Py_None;
    }
    u = Py_BuildValue("(ziOO)", c->c_filename, c->u->u_lineno,
                      Py_None, loc);
    if (!u)
        goto exit;
    v = Py_BuildValue("(zO)", errstr, u);
    if (!v)
        goto exit;
    PyErr_SetObject(PyExc_SyntaxError, v);
 exit:
    Py_DECREF(loc);
    Py_XDECREF(u);
    Py_XDECREF(v);
    return 0;
}

static int
compiler_handle_subscr(struct compiler *c, const char *kind,
                       expr_context_ty ctx)
{
    int op = 0;

    /* XXX this code is duplicated */
    switch (ctx) {
        case AugLoad: /* fall through to Load */
        case Load:    op = BINARY_SUBSCR; break;
        case AugStore:/* fall through to Store */
        case Store:   op = STORE_SUBSCR; break;
        case Del:     op = DELETE_SUBSCR; break;
        case Param:
            PyErr_Format(PyExc_SystemError,
                         "invalid %s kind %d in subscript\n",
                         kind, ctx);
            return 0;
    }
    if (ctx == AugLoad) {
        ADDOP_I(c, DUP_TOPX, 2);
    }
    else if (ctx == AugStore) {
        ADDOP(c, ROT_THREE);
    }
    ADDOP(c, op);
    return 1;
}

static int
compiler_slice(struct compiler *c, slice_ty s, expr_context_ty ctx)
{
    int n = 2;
    assert(s->kind == Slice_kind);

    /* only handles the cases where BUILD_SLICE is emitted */
    if (s->v.Slice.lower) {
        VISIT(c, expr, s->v.Slice.lower);
    }
    else {
        ADDOP_O(c, LOAD_CONST, Py_None, consts);
    }

    if (s->v.Slice.upper) {
        VISIT(c, expr, s->v.Slice.upper);
    }
    else {
        ADDOP_O(c, LOAD_CONST, Py_None, consts);
    }

    if (s->v.Slice.step) {
        n++;
        VISIT(c, expr, s->v.Slice.step);
    }
    ADDOP_I(c, BUILD_SLICE, n);
    return 1;
}

static int
compiler_simple_slice(struct compiler *c, slice_ty s, expr_context_ty ctx)
{
    int op = 0, slice_offset = 0, stack_count = 0;

    assert(s->v.Slice.step == NULL);
    if (s->v.Slice.lower) {
        slice_offset++;
        stack_count++;
        if (ctx != AugStore)
            VISIT(c, expr, s->v.Slice.lower);
    }
    if (s->v.Slice.upper) {
        slice_offset += 2;
        stack_count++;
        if (ctx != AugStore)
            VISIT(c, expr, s->v.Slice.upper);
    }

    if (ctx == AugLoad) {
        switch (stack_count) {
        case 0: ADDOP(c, DUP_TOP); break;
        case 1: ADDOP_I(c, DUP_TOPX, 2); break;
        case 2: ADDOP_I(c, DUP_TOPX, 3); break;
        }
    }
    else if (ctx == AugStore) {
        switch (stack_count) {
        case 0: ADDOP(c, ROT_TWO); break;
        case 1: ADDOP(c, ROT_THREE); break;
        case 2: ADDOP(c, ROT_FOUR); break;
        }
    }

    switch (ctx) {
    case AugLoad: /* fall through to Load */
    case Load: op = SLICE; break;
    case AugStore:/* fall through to Store */
    case Store: op = STORE_SLICE; break;
    case Del: op = DELETE_SLICE; break;
    case Param:
    default:
        PyErr_SetString(PyExc_SystemError,
                        "param invalid in simple slice");
        return 0;
    }

    ADDOP(c, op + slice_offset);
    return 1;
}

static int
compiler_visit_nested_slice(struct compiler *c, slice_ty s,
                            expr_context_ty ctx)
{
    switch (s->kind) {
    case Ellipsis_kind:
        ADDOP_O(c, LOAD_CONST, Py_Ellipsis, consts);
        break;
    case Slice_kind:
        return compiler_slice(c, s, ctx);
    case Index_kind:
        VISIT(c, expr, s->v.Index.value);
        break;
    case ExtSlice_kind:
    default:
        PyErr_SetString(PyExc_SystemError,
                        "extended slice invalid in nested slice");
        return 0;
    }
    return 1;
}

static int
compiler_visit_slice(struct compiler *c, slice_ty s, expr_context_ty ctx)
{
    char * kindname = NULL;
    switch (s->kind) {
    case Index_kind:
        kindname = "index";
        if (ctx != AugStore) {
            VISIT(c, expr, s->v.Index.value);
        }
        break;
    case Ellipsis_kind:
        kindname = "ellipsis";
        if (ctx != AugStore) {
            ADDOP_O(c, LOAD_CONST, Py_Ellipsis, consts);
        }
        break;
    case Slice_kind:
        kindname = "slice";
        if (!s->v.Slice.step)
            return compiler_simple_slice(c, s, ctx);
        if (ctx != AugStore) {
            if (!compiler_slice(c, s, ctx))
                return 0;
        }
        break;
    case ExtSlice_kind:
        kindname = "extended slice";
        if (ctx != AugStore) {
            int i, n = asdl_seq_LEN(s->v.ExtSlice.dims);
            for (i = 0; i < n; i++) {
                slice_ty sub = (slice_ty)asdl_seq_GET(
                    s->v.ExtSlice.dims, i);
                if (!compiler_visit_nested_slice(c, sub, ctx))
                    return 0;
            }
            ADDOP_I(c, BUILD_TUPLE, n);
        }
        break;
    default:
        PyErr_Format(PyExc_SystemError,
                     "invalid subscript kind %d", s->kind);
        return 0;
    }
    return compiler_handle_subscr(c, kindname, ctx);
}


/* End of the compiler section, beginning of the assembler section */

/* do depth-first search of basic block graph, starting with block.
   post records the block indices in post-order.

   XXX must handle implicit jumps from one block to next
*/

struct assembler {
    PyObject *a_bytecode;  /* string containing bytecode */
    int a_offset;              /* offset into bytecode */
    int a_nblocks;             /* number of reachable blocks */
    basicblock **a_postorder; /* list of blocks in dfs postorder */
    PyObject *a_lnotab;    /* string containing lnotab */
    int a_lnotab_off;      /* offset into lnotab */
    int a_lineno;              /* last lineno of emitted instruction */
    int a_lineno_off;      /* bytecode offset of last lineno */
};

static void
dfs(struct compiler *c, basicblock *b, struct assembler *a)
{
    int i;
    struct instr *instr = NULL;

    if (b->b_seen)
        return;
    b->b_seen = 1;
    if (b->b_next != NULL)
        dfs(c, b->b_next, a);
    for (i = 0; i < b->b_iused; i++) {
        instr = &b->b_instr[i];
        if (instr->i_jrel || instr->i_jabs)
            dfs(c, instr->i_target, a);
    }
    a->a_postorder[a->a_nblocks++] = b;
}

static int
stackdepth_walk(struct compiler *c, basicblock *b, int depth, int maxdepth)
{
    int i, target_depth;
    struct instr *instr;
    if (b->b_seen || b->b_startdepth >= depth)
        return maxdepth;
    b->b_seen = 1;
    b->b_startdepth = depth;
    for (i = 0; i < b->b_iused; i++) {
        instr = &b->b_instr[i];
        depth += opcode_stack_effect(instr->i_opcode, instr->i_oparg);
        if (depth > maxdepth)
            maxdepth = depth;
        assert(depth >= 0); /* invalid code or bug in stackdepth() */
        if (instr->i_jrel || instr->i_jabs) {
            target_depth = depth;
            if (instr->i_opcode == FOR_ITER) {
                target_depth = depth-2;
            }
            else if (instr->i_opcode == SETUP_FINALLY ||
                     instr->i_opcode == SETUP_EXCEPT) {
                target_depth = depth+3;
                if (target_depth > maxdepth)
                    maxdepth = target_depth;
            }
            else if (instr->i_opcode == JUMP_IF_TRUE_OR_POP ||
                     instr->i_opcode == JUMP_IF_FALSE_OR_POP)
                depth = depth - 1;
            maxdepth = stackdepth_walk(c, instr->i_target,
                                       target_depth, maxdepth);
            if (instr->i_opcode == JUMP_ABSOLUTE ||
                instr->i_opcode == JUMP_FORWARD) {
                goto out; /* remaining code is dead */
            }
        }
    }
    if (b->b_next)
        maxdepth = stackdepth_walk(c, b->b_next, depth, maxdepth);
out:
    b->b_seen = 0;
    return maxdepth;
}

/* Find the flow path that needs the largest stack.  We assume that
 * cycles in the flow graph have no net effect on the stack depth.
 */
static int
stackdepth(struct compiler *c)
{
    basicblock *b, *entryblock;
    entryblock = NULL;
    for (b = c->u->u_blocks; b != NULL; b = b->b_list) {
        b->b_seen = 0;
        b->b_startdepth = INT_MIN;
        entryblock = b;
    }
    if (!entryblock)
        return 0;
    return stackdepth_walk(c, entryblock, 0, 0);
}

static int
assemble_init(struct assembler *a, int nblocks, int firstlineno)
{
    memset(a, 0, sizeof(struct assembler));
    a->a_lineno = firstlineno;
    a->a_bytecode = PyString_FromStringAndSize(NULL, DEFAULT_CODE_SIZE);
    if (!a->a_bytecode)
        return 0;
    a->a_lnotab = PyString_FromStringAndSize(NULL, DEFAULT_LNOTAB_SIZE);
    if (!a->a_lnotab)
        return 0;
    if (nblocks > PY_SIZE_MAX / sizeof(basicblock *)) {
        PyErr_NoMemory();
        return 0;
    }
    a->a_postorder = (basicblock **)PyObject_Malloc(
                                        sizeof(basicblock *) * nblocks);
    if (!a->a_postorder) {
        PyErr_NoMemory();
        return 0;
    }
    return 1;
}

static void
assemble_free(struct assembler *a)
{
    Py_XDECREF(a->a_bytecode);
    Py_XDECREF(a->a_lnotab);
    if (a->a_postorder)
        PyObject_Free(a->a_postorder);
}

/* Return the size of a basic block in bytes. */

static int
instrsize(struct instr *instr)
{
    if (!instr->i_hasarg)
        return 1;               /* 1 byte for the opcode*/
    if (instr->i_oparg > 0xffff)
        return 6;               /* 1 (opcode) + 1 (EXTENDED_ARG opcode) + 2 (oparg) + 2(oparg extended) */
    return 3;                   /* 1 (opcode) + 2 (oparg) */
}

static int
blocksize(basicblock *b)
{
    int i;
    int size = 0;

    for (i = 0; i < b->b_iused; i++)
        size += instrsize(&b->b_instr[i]);
    return size;
}

/* Appends a pair to the end of the line number table, a_lnotab, representing
   the instruction's bytecode offset and line number.  See
   Objects/lnotab_notes.txt for the description of the line number table. */

static int
assemble_lnotab(struct assembler *a, struct instr *i)
{
    int d_bytecode, d_lineno;
    int len;
    unsigned char *lnotab;

    d_bytecode = a->a_offset - a->a_lineno_off;
    d_lineno = i->i_lineno - a->a_lineno;

    assert(d_bytecode >= 0);
    assert(d_lineno >= 0);

    if(d_bytecode == 0 && d_lineno == 0)
        return 1;

    if (d_bytecode > 255) {
        int j, nbytes, ncodes = d_bytecode / 255;
        nbytes = a->a_lnotab_off + 2 * ncodes;
        len = PyString_GET_SIZE(a->a_lnotab);
        if (nbytes >= len) {
            if ((len <= INT_MAX / 2) && (len * 2 < nbytes))
                len = nbytes;
            else if (len <= INT_MAX / 2)
                len *= 2;
            else {
                PyErr_NoMemory();
                return 0;
            }
            if (_PyString_Resize(&a->a_lnotab, len) < 0)
                return 0;
        }
        lnotab = (unsigned char *)
                   PyString_AS_STRING(a->a_lnotab) + a->a_lnotab_off;
        for (j = 0; j < ncodes; j++) {
            *lnotab++ = 255;
            *lnotab++ = 0;
        }
        d_bytecode -= ncodes * 255;
        a->a_lnotab_off += ncodes * 2;
    }
    assert(d_bytecode <= 255);
    if (d_lineno > 255) {
        int j, nbytes, ncodes = d_lineno / 255;
        nbytes = a->a_lnotab_off + 2 * ncodes;
        len = PyString_GET_SIZE(a->a_lnotab);
        if (nbytes >= len) {
            if ((len <= INT_MAX / 2) && len * 2 < nbytes)
                len = nbytes;
            else if (len <= INT_MAX / 2)
                len *= 2;
            else {
                PyErr_NoMemory();
                return 0;
            }
            if (_PyString_Resize(&a->a_lnotab, len) < 0)
                return 0;
        }
        lnotab = (unsigned char *)
                   PyString_AS_STRING(a->a_lnotab) + a->a_lnotab_off;
        *lnotab++ = d_bytecode;
        *lnotab++ = 255;
        d_bytecode = 0;
        for (j = 1; j < ncodes; j++) {
            *lnotab++ = 0;
            *lnotab++ = 255;
        }
        d_lineno -= ncodes * 255;
        a->a_lnotab_off += ncodes * 2;
    }

    len = PyString_GET_SIZE(a->a_lnotab);
    if (a->a_lnotab_off + 2 >= len) {
        if (_PyString_Resize(&a->a_lnotab, len * 2) < 0)
            return 0;
    }
    lnotab = (unsigned char *)
                    PyString_AS_STRING(a->a_lnotab) + a->a_lnotab_off;

    a->a_lnotab_off += 2;
    if (d_bytecode) {
        *lnotab++ = d_bytecode;
        *lnotab++ = d_lineno;
    }
    else {      /* First line of a block; def stmt, etc. */
        *lnotab++ = 0;
        *lnotab++ = d_lineno;
    }
    a->a_lineno = i->i_lineno;
    a->a_lineno_off = a->a_offset;
    return 1;
}

/* assemble_emit()
   Extend the bytecode with a new instruction.
   Update lnotab if necessary.
*/

static int
assemble_emit(struct assembler *a, struct instr *i)
{
    int size, arg = 0, ext = 0;
    Py_ssize_t len = PyString_GET_SIZE(a->a_bytecode);
    char *code;

    size = instrsize(i);
    if (i->i_hasarg) {
        arg = i->i_oparg;
        ext = arg >> 16;
    }
    if (i->i_lineno && !assemble_lnotab(a, i))
        return 0;
    if (a->a_offset + size >= len) {
        if (len > PY_SSIZE_T_MAX / 2)
            return 0;
        if (_PyString_Resize(&a->a_bytecode, len * 2) < 0)
            return 0;
    }
    code = PyString_AS_STRING(a->a_bytecode) + a->a_offset;
    a->a_offset += size;
    if (size == 6) {
        assert(i->i_hasarg);
        *code++ = (char)EXTENDED_ARG;
        *code++ = ext & 0xff;
        *code++ = ext >> 8;
        arg &= 0xffff;
    }
    *code++ = i->i_opcode;
    if (i->i_hasarg) {
        assert(size == 3 || size == 6);
        *code++ = arg & 0xff;
        *code++ = arg >> 8;
    }
    return 1;
}

static void
assemble_jump_offsets(struct assembler *a, struct compiler *c)
{
    basicblock *b;
    int bsize, totsize, extended_arg_count = 0, last_extended_arg_count;
    int i;

    /* Compute the size of each block and fixup jump args.
       Replace block pointer with position in bytecode. */
    do {
        totsize = 0;
        for (i = a->a_nblocks - 1; i >= 0; i--) {
            b = a->a_postorder[i];
            bsize = blocksize(b);
            b->b_offset = totsize;
            totsize += bsize;
        }
        last_extended_arg_count = extended_arg_count;
        extended_arg_count = 0;
        for (b = c->u->u_blocks; b != NULL; b = b->b_list) {
            bsize = b->b_offset;
            for (i = 0; i < b->b_iused; i++) {
                struct instr *instr = &b->b_instr[i];
                /* Relative jumps are computed relative to
                   the instruction pointer after fetching
                   the jump instruction.
                */
                bsize += instrsize(instr);
                if (instr->i_jabs)
                    instr->i_oparg = instr->i_target->b_offset;
                else if (instr->i_jrel) {
                    int delta = instr->i_target->b_offset - bsize;
                    instr->i_oparg = delta;
                }
                else
                    continue;
                if (instr->i_oparg > 0xffff)
                    extended_arg_count++;
            }
        }

    /* XXX: This is an awful hack that could hurt performance, but
        on the bright side it should work until we come up
        with a better solution.

        The issue is that in the first loop blocksize() is called
        which calls instrsize() which requires i_oparg be set
        appropriately.          There is a bootstrap problem because
        i_oparg is calculated in the second loop above.

        So we loop until we stop seeing new EXTENDED_ARGs.
        The only EXTENDED_ARGs that could be popping up are
        ones in jump instructions.  So this should converge
        fairly quickly.
    */
    } while (last_extended_arg_count != extended_arg_count);
}

static PyObject *
dict_keys_inorder(PyObject *dict, int offset)
{
    PyObject *tuple, *k, *v;
    Py_ssize_t i, pos = 0, size = PyDict_Size(dict);

    tuple = PyTuple_New(size);
    if (tuple == NULL)
        return NULL;
    while (PyDict_Next(dict, &pos, &k, &v)) {
        i = PyInt_AS_LONG(v);
        /* The keys of the dictionary are tuples. (see compiler_add_o)
           The object we want is always first, though. */
        k = PyTuple_GET_ITEM(k, 0);
        Py_INCREF(k);
        assert((i - offset) < size);
        assert((i - offset) >= 0);
        PyTuple_SET_ITEM(tuple, i - offset, k);
    }
    return tuple;
}

static int
compute_code_flags(struct compiler *c)
{
    PySTEntryObject *ste = c->u->u_ste;
    int flags = 0, n;
    if (ste->ste_type != ModuleBlock)
        flags |= CO_NEWLOCALS;
    if (ste->ste_type == FunctionBlock) {
        if (!ste->ste_unoptimized)
            flags |= CO_OPTIMIZED;
        if (ste->ste_nested)
            flags |= CO_NESTED;
        if (ste->ste_generator)
            flags |= CO_GENERATOR;
        if (ste->ste_varargs)
            flags |= CO_VARARGS;
        if (ste->ste_varkeywords)
            flags |= CO_VARKEYWORDS;
    }

    /* (Only) inherit compilerflags in PyCF_MASK */
    flags |= (c->c_flags->cf_flags & PyCF_MASK);

    n = PyDict_Size(c->u->u_freevars);
    if (n < 0)
        return -1;
    if (n == 0) {
        n = PyDict_Size(c->u->u_cellvars);
        if (n < 0)
        return -1;
        if (n == 0) {
        flags |= CO_NOFREE;
        }
    }

    return flags;
}

static PyCodeObject *
makecode(struct compiler *c, struct assembler *a)
{
    PyObject *tmp;
    PyCodeObject *co = NULL;
    PyObject *consts = NULL;
    PyObject *names = NULL;
    PyObject *varnames = NULL;
    PyObject *filename = NULL;
    PyObject *name = NULL;
    PyObject *freevars = NULL;
    PyObject *cellvars = NULL;
    PyObject *bytecode = NULL;
    int nlocals, flags;

    tmp = dict_keys_inorder(c->u->u_consts, 0);
    if (!tmp)
        goto error;
    consts = PySequence_List(tmp); /* optimize_code requires a list */
    Py_DECREF(tmp);

    names = dict_keys_inorder(c->u->u_names, 0);
    varnames = dict_keys_inorder(c->u->u_varnames, 0);
    if (!consts || !names || !varnames)
        goto error;

    cellvars = dict_keys_inorder(c->u->u_cellvars, 0);
    if (!cellvars)
        goto error;
    freevars = dict_keys_inorder(c->u->u_freevars, PyTuple_Size(cellvars));
    if (!freevars)
        goto error;
    filename = PyString_FromString(c->c_filename);
    if (!filename)
        goto error;

    nlocals = PyDict_Size(c->u->u_varnames);
    flags = compute_code_flags(c);
    if (flags < 0)
        goto error;

    bytecode = PyCode_Optimize(a->a_bytecode, consts, names, a->a_lnotab);
    if (!bytecode)
        goto error;

    tmp = PyList_AsTuple(consts); /* PyCode_New requires a tuple */
    if (!tmp)
        goto error;
    Py_DECREF(consts);
    consts = tmp;

    co = PyCode_New(c->u->u_argcount, nlocals, stackdepth(c), flags,
                    bytecode, consts, names, varnames,
                    freevars, cellvars,
                    filename, c->u->u_name,
                    c->u->u_firstlineno,
                    a->a_lnotab);
 error:
    Py_XDECREF(consts);
    Py_XDECREF(names);
    Py_XDECREF(varnames);
    Py_XDECREF(filename);
    Py_XDECREF(name);
    Py_XDECREF(freevars);
    Py_XDECREF(cellvars);
    Py_XDECREF(bytecode);
    return co;
}


/* For debugging purposes only */
#if 0
static void
dump_instr(const struct instr *i)
{
    const char *jrel = i->i_jrel ? "jrel " : "";
    const char *jabs = i->i_jabs ? "jabs " : "";
    char arg[128];

    *arg = '\0';
    if (i->i_hasarg)
        sprintf(arg, "arg: %d ", i->i_oparg);

    fprintf(stderr, "line: %d, opcode: %d %s%s%s\n",
                    i->i_lineno, i->i_opcode, arg, jabs, jrel);
}

static void
dump_basicblock(const basicblock *b)
{
    const char *seen = b->b_seen ? "seen " : "";
    const char *b_return = b->b_return ? "return " : "";
    fprintf(stderr, "used: %d, depth: %d, offset: %d %s%s\n",
        b->b_iused, b->b_startdepth, b->b_offset, seen, b_return);
    if (b->b_instr) {
        int i;
        for (i = 0; i < b->b_iused; i++) {
            fprintf(stderr, "  [%02d] ", i);
            dump_instr(b->b_instr + i);
        }
    }
}
#endif

static PyCodeObject *
assemble(struct compiler *c, int addNone)
{
    basicblock *b, *entryblock;
    struct assembler a;
    int i, j, nblocks;
    PyCodeObject *co = NULL;

    /* Make sure every block that falls off the end returns None.
       XXX NEXT_BLOCK() isn't quite right, because if the last
       block ends with a jump or return b_next shouldn't set.
     */
    if (!c->u->u_curblock->b_return) {
        NEXT_BLOCK(c);
        if (addNone)
            ADDOP_O(c, LOAD_CONST, Py_None, consts);
        ADDOP(c, RETURN_VALUE);
    }

    nblocks = 0;
    entryblock = NULL;
    for (b = c->u->u_blocks; b != NULL; b = b->b_list) {
        nblocks++;
        entryblock = b;
    }

    /* Set firstlineno if it wasn't explicitly set. */
    if (!c->u->u_firstlineno) {
        if (entryblock && entryblock->b_instr)
            c->u->u_firstlineno = entryblock->b_instr->i_lineno;
        else
            c->u->u_firstlineno = 1;
    }
    if (!assemble_init(&a, nblocks, c->u->u_firstlineno))
        goto error;
    dfs(c, entryblock, &a);

    /* Can't modify the bytecode after computing jump offsets. */
    assemble_jump_offsets(&a, c);

    /* Emit code in reverse postorder from dfs. */
    for (i = a.a_nblocks - 1; i >= 0; i--) {
        b = a.a_postorder[i];
        for (j = 0; j < b->b_iused; j++)
            if (!assemble_emit(&a, &b->b_instr[j]))
                goto error;
    }

    if (_PyString_Resize(&a.a_lnotab, a.a_lnotab_off) < 0)
        goto error;
    if (_PyString_Resize(&a.a_bytecode, a.a_offset) < 0)
        goto error;

    co = makecode(c, &a);
 error:
    assemble_free(&a);
    return co;
}