mmo.c 96.2 KB
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
/* BFD back-end for mmo objects (MMIX-specific object-format).
   Copyright 2001, 2002, 2003
   Free Software Foundation, Inc.
   Written by Hans-Peter Nilsson (hp@bitrange.com).
   Infrastructure and other bits originally copied from srec.c and
   binary.c.

This file is part of BFD, the Binary File Descriptor library.

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.

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

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */

/*
SECTION
	mmo backend

	The mmo object format is used exclusively together with Professor
	Donald E.@: Knuth's educational 64-bit processor MMIX.  The simulator
	@command{mmix} which is available at
	@url{http://www-cs-faculty.stanford.edu/~knuth/programs/mmix.tar.gz}
	understands this format.  That package also includes a combined
	assembler and linker called @command{mmixal}.  The mmo format has
	no advantages feature-wise compared to e.g. ELF.  It is a simple
	non-relocatable object format with no support for archives or
	debugging information, except for symbol value information and
	line numbers (which is not yet implemented in BFD).  See
	@url{http://www-cs-faculty.stanford.edu/~knuth/mmix.html} for more
	information about MMIX.  The ELF format is used for intermediate
	object files in the BFD implementation.

@c We want to xref the symbol table node.  A feature in "chew"
@c requires that "commands" do not contain spaces in the
@c arguments.  Hence the hyphen in "Symbol-table".
@menu
@* File layout::
@* Symbol-table::
@* mmo section mapping::
@end menu

INODE
File layout, Symbol-table, mmo, mmo
SUBSECTION
	File layout

	The mmo file contents is not partitioned into named sections as
	with e.g.@: ELF.  Memory areas is formed by specifying the
	location of the data that follows.  Only the memory area
	@samp{0x0000@dots{}00} to @samp{0x01ff@dots{}ff} is executable, so
	it is used for code (and constants) and the area
	@samp{0x2000@dots{}00} to @samp{0x20ff@dots{}ff} is used for
	writable data.  @xref{mmo section mapping}.

	Contents is entered as 32-bit words, xor:ed over previous
	contents, always zero-initialized.  A word that starts with the
	byte @samp{0x98} forms a command called a @samp{lopcode}, where
	the next byte distinguished between the thirteen lopcodes.  The
	two remaining bytes, called the @samp{Y} and @samp{Z} fields, or
	the @samp{YZ} field (a 16-bit big-endian number), are used for
	various purposes different for each lopcode.  As documented in
	@url{http://www-cs-faculty.stanford.edu/~knuth/mmixal-intro.ps.gz},
	the lopcodes are:

	There is provision for specifying ``special data'' of 65536
	different types.  We use type 80 (decimal), arbitrarily chosen the
	same as the ELF <<e_machine>> number for MMIX, filling it with
	section information normally found in ELF objects. @xref{mmo
	section mapping}.

	@table @code
	@item lop_quote
	0x98000001.  The next word is contents, regardless of whether it
	starts with 0x98 or not.

	@item lop_loc
	0x9801YYZZ, where @samp{Z} is 1 or 2.  This is a location
	directive, setting the location for the next data to the next
	32-bit word (for @math{Z = 1}) or 64-bit word (for @math{Z = 2}),
	plus @math{Y * 2^56}.  Normally @samp{Y} is 0 for the text segment
	and 2 for the data segment.

	@item lop_skip
	0x9802YYZZ.  Increase the current location by @samp{YZ} bytes.

	@item lop_fixo
	0x9803YYZZ, where @samp{Z} is 1 or 2.  Store the current location
	as 64 bits into the location pointed to by the next 32-bit
	(@math{Z = 1}) or 64-bit (@math{Z = 2}) word, plus @math{Y *
	2^56}.

	@item lop_fixr
	0x9804YYZZ.  @samp{YZ} is stored into the current location plus
	@math{2 - 4 * YZ}.

	@item lop_fixrx
	0x980500ZZ.  @samp{Z} is 16 or 24.  A value @samp{L} derived from
	the following 32-bit word are used in a manner similar to
	@samp{YZ} in lop_fixr: it is xor:ed into the current location
	minus @math{4 * L}.  The first byte of the word is 0 or 1.  If it
	is 1, then @math{L = (@var{lowest 24 bits of word}) - 2^Z}, if 0,
 	then @math{L = (@var{lowest 24 bits of word})}.

	@item lop_file
	0x9806YYZZ.  @samp{Y} is the file number, @samp{Z} is count of
	32-bit words.  Set the file number to @samp{Y} and the line
	counter to 0.  The next @math{Z * 4} bytes contain the file name,
	padded with zeros if the count is not a multiple of four.  The
	same @samp{Y} may occur multiple times, but @samp{Z} must be 0 for
	all but the first occurrence.

	@item lop_line
	0x9807YYZZ.  @samp{YZ} is the line number.  Together with
	lop_file, it forms the source location for the next 32-bit word.
	Note that for each non-lopcode 32-bit word, line numbers are
	assumed incremented by one.

	@item lop_spec
	0x9808YYZZ.  @samp{YZ} is the type number.  Data until the next
	lopcode other than lop_quote forms special data of type @samp{YZ}.
	@xref{mmo section mapping}.

	Other types than 80, (or type 80 with a content that does not
	parse) is stored in sections named <<.MMIX.spec_data.@var{n}>>
	where @var{n} is the @samp{YZ}-type.  The flags for such a
	sections say not to allocate or load the data.  The vma is 0.
	Contents of multiple occurrences of special data @var{n} is
	concatenated to the data of the previous lop_spec @var{n}s.  The
	location in data or code at which the lop_spec occurred is lost.

	@item lop_pre
	0x980901ZZ.  The first lopcode in a file.  The @samp{Z} field forms the
	length of header information in 32-bit words, where the first word
	tells the time in seconds since @samp{00:00:00 GMT Jan 1 1970}.

	@item lop_post
	0x980a00ZZ.  @math{Z > 32}.  This lopcode follows after all
	content-generating lopcodes in a program.  The @samp{Z} field
	denotes the value of @samp{rG} at the beginning of the program.
	The following @math{256 - Z} big-endian 64-bit words are loaded
	into global registers @samp{$G} @dots{} @samp{$255}.

	@item lop_stab
	0x980b0000.  The next-to-last lopcode in a program.  Must follow
	immediately after the lop_post lopcode and its data.  After this
	lopcode follows all symbols in a compressed format
	(@pxref{Symbol-table}).

	@item lop_end
	0x980cYYZZ.  The last lopcode in a program.  It must follow the
	lop_stab lopcode and its data.  The @samp{YZ} field contains the
	number of 32-bit words of symbol table information after the
	preceding lop_stab lopcode.
	@end table

	Note that the lopcode "fixups"; <<lop_fixr>>, <<lop_fixrx>> and
	<<lop_fixo>> are not generated by BFD, but are handled.  They are
	generated by <<mmixal>>.

EXAMPLE
	This trivial one-label, one-instruction file:

| :Main TRAP 1,2,3

	can be represented this way in mmo:

| 0x98090101 - lop_pre, one 32-bit word with timestamp.
| <timestamp>
| 0x98010002 - lop_loc, text segment, using a 64-bit address.
|              Note that mmixal does not emit this for the file above.
| 0x00000000 - Address, high 32 bits.
| 0x00000000 - Address, low 32 bits.
| 0x98060002 - lop_file, 2 32-bit words for file-name.
| 0x74657374 - "test"
| 0x2e730000 - ".s\0\0"
| 0x98070001 - lop_line, line 1.
| 0x00010203 - TRAP 1,2,3
| 0x980a00ff - lop_post, setting $255 to 0.
| 0x00000000
| 0x00000000
| 0x980b0000 - lop_stab for ":Main" = 0, serial 1.
| 0x203a4040   @xref{Symbol-table}.
| 0x10404020
| 0x4d206120
| 0x69016e00
| 0x81000000
| 0x980c0005 - lop_end; symbol table contained five 32-bit words.  */

#include "bfd.h"
#include "sysdep.h"
#include "libbfd.h"
#include "libiberty.h"
#include "elf/mmix.h"
#include "opcode/mmix.h"

#define LOP 0x98
#define LOP_QUOTE 0
#define LOP_LOC 1
#define LOP_SKIP 2
#define LOP_FIXO 3
#define LOP_FIXR 4
#define LOP_FIXRX 5
#define LOP_FILE 6
#define LOP_LINE 7
#define LOP_SPEC 8
#define LOP_PRE 9
#define LOP_POST 10
#define LOP_STAB 11
#define LOP_END 12

#define LOP_QUOTE_NEXT ((LOP << 24) | (LOP_QUOTE << 16) | 1)
#define SPEC_DATA_SECTION 80
#define LOP_SPEC_SECTION \
 ((LOP << 24) | (LOP_SPEC << 16) | SPEC_DATA_SECTION)

/* Must be a power of two.  If you change this to be >= 64k, you need a
   new test-case; the ld test b-loc64k.d touches chunk-size problem areas.  */
#define MMO_SEC_CONTENTS_CHUNK_SIZE (1 << 15)

/* An arbitrary number for the maximum length section name size.  */
#define MAX_SECTION_NAME_SIZE (1024 * 1024)

/* A quite arbitrary number for the maximum length section size.  */
#define MAX_ARTIFICIAL_SECTION_SIZE (1024 * 1024 * 1024)

#define MMO3_WCHAR 0x80
#define MMO3_LEFT 0x40
#define MMO3_MIDDLE 0x20
#define MMO3_RIGHT 0x10
#define MMO3_TYPEBITS 0xf
#define MMO3_REGQUAL_BITS 0xf
#define MMO3_UNDEF 2
#define MMO3_DATA 8
#define MMO3_SYMBITS 0x2f

/* Put these everywhere in new code.  */
#define FATAL_DEBUG						\
 _bfd_abort (__FILE__, __LINE__,				\
	     "Internal: Non-debugged code (test-case missing)")

#define BAD_CASE(x)				\
 _bfd_abort (__FILE__, __LINE__,		\
	     "bad case for " #x)

enum mmo_sym_type { mmo_reg_sym, mmo_undef_sym, mmo_data_sym, mmo_abs_sym};

/* When scanning the mmo file, a linked list of mmo_symbol
   structures is built to represent the symbol table (if there is
   one).  */

struct mmo_symbol
  {
    struct mmo_symbol *next;
    const char *name;
    bfd_vma value;
    enum mmo_sym_type sym_type;
    unsigned int serno;
  };

struct mmo_data_list_struct
  {
    struct mmo_data_list_struct *next;
    bfd_vma where;
    bfd_size_type size;
    bfd_size_type allocated_size;
    bfd_byte data[1];
  };

typedef struct mmo_data_list_struct mmo_data_list_type;

struct mmo_symbol_trie
  {
    struct mmo_symbol_trie *left;
    struct mmo_symbol_trie *right;
    struct mmo_symbol_trie *middle;

    bfd_byte symchar;

    /* A zero name means there's nothing here.  */
    struct mmo_symbol sym;
  };

/* The mmo tdata information.  */

struct mmo_data_struct
  {
    struct mmo_symbol *symbols;
    struct mmo_symbol *symtail;
    asymbol *csymbols;

    /* File representation of time (NULL) when this file was created.  */
    bfd_byte created[4];

    /* When we're reading bytes recursively, check this occasionally.
       Also holds write errors.  */
    bfd_boolean have_error;

    /* Max symbol length that may appear in the lop_stab table.  Note that
       this table might just hold a subset of symbols for not-really large
       programs, as it can only be 65536 * 4 bytes large.  */
    int max_symbol_length;

    /* Here's the symbol we build in lop_stab.  */
    char *lop_stab_symbol;

    /* Index into lop_stab_symbol for the next character when parsing the
       symbol information.  */
    int symbol_position;

    /* When creating arbitrary sections, we need to count section numbers.  */
    int sec_no;

    /* When writing or reading byte-wise, we need to count the bytes
       within a 32-bit word.  */
    int byte_no;

    /* We also need a buffer to hold the bytes we count reading or writing.  */
    bfd_byte buf[4];
  };

typedef struct mmo_data_struct tdata_type;

struct mmo_section_data_struct
  {
    mmo_data_list_type *head;
    mmo_data_list_type *tail;
  };

#define mmo_section_data(sec) \
  ((struct mmo_section_data_struct *) (sec)->used_by_bfd)

/* These structures are used in bfd_map_over_sections constructs.  */

/* Used when writing out sections; all but the register contents section
   which is stored in reg_section.  */
struct mmo_write_sec_info
  {
    asection *reg_section;
    bfd_boolean retval;
  };

/* Used when trying to find a section corresponding to addr.  */
struct mmo_find_sec_info
  {
    asection *sec;
    bfd_vma addr;
  };

static bfd_boolean mmo_bfd_copy_private_bfd_data
  PARAMS ((bfd *, bfd *));
static void mmo_write_section_unless_reg_contents
 PARAMS ((bfd *, asection *, PTR));
static void mmo_find_sec_w_addr
  PARAMS ((bfd *, asection *, PTR));
static void mmo_find_sec_w_addr_grow
  PARAMS ((bfd *, asection *, PTR));
static asection *mmo_make_section
  PARAMS ((bfd *, const char *));
static void mmo_get_symbol_info
  PARAMS ((bfd *, asymbol *, symbol_info *));
static void mmo_print_symbol
  PARAMS ((bfd *, PTR, asymbol *, bfd_print_symbol_type));
static void mmo_init
  PARAMS ((void));
static bfd_boolean mmo_mkobject
  PARAMS ((bfd *));
static bfd_boolean mmo_scan
  PARAMS ((bfd *));
static asection *mmo_decide_section
  PARAMS ((bfd *, bfd_vma));
static asection *mmo_get_generic_spec_data_section
  PARAMS ((bfd *, int));
static asection *mmo_get_spec_section
  PARAMS ((bfd *, int));
static INLINE bfd_byte *mmo_get_loc
  PARAMS ((asection *, bfd_vma, int));
static void mmo_xore_64
  PARAMS ((asection *, bfd_vma vma, bfd_vma value));
static void mmo_xore_32
  PARAMS ((asection *, bfd_vma vma, unsigned int));
static void mmo_xore_16
  PARAMS ((asection *, bfd_vma vma, unsigned int));
static const bfd_target *mmo_object_p
  PARAMS ((bfd *));
static void mmo_map_set_sizes
  PARAMS ((bfd *, asection *, PTR));
static bfd_boolean mmo_get_symbols
  PARAMS ((bfd *));
static bfd_boolean mmo_create_symbol
  PARAMS ((bfd *, const char *, bfd_vma, enum mmo_sym_type, unsigned int));
static bfd_boolean mmo_get_section_contents
  PARAMS ((bfd *, asection *, PTR, file_ptr, bfd_size_type));
static long mmo_get_symtab_upper_bound
  PARAMS ((bfd *));
static long mmo_get_symtab
  PARAMS ((bfd *, asymbol **));
static void mmo_get_symbol_info
  PARAMS ((bfd *, asymbol *, symbol_info *));
static void mmo_print_symbol
  PARAMS ((bfd *, PTR, asymbol *, bfd_print_symbol_type));
static bfd_boolean mmo_set_section_contents
  PARAMS ((bfd *, sec_ptr, PTR, file_ptr, bfd_size_type));
static int mmo_sizeof_headers
  PARAMS ((bfd *, bfd_boolean));
static long mmo_get_reloc_upper_bound
  PARAMS ((bfd *, asection *));

static bfd_boolean mmo_internal_write_header
  PARAMS ((bfd *));
static bfd_boolean mmo_internal_write_post
  PARAMS ((bfd *, int, asection *));
static bfd_boolean mmo_internal_add_3_sym
  PARAMS ((bfd *, struct mmo_symbol_trie *, const struct mmo_symbol *));
static unsigned int mmo_internal_3_length
  PARAMS ((bfd *, struct mmo_symbol_trie *));
static void mmo_internal_3_dump
  PARAMS ((bfd *, struct mmo_symbol_trie *));
static void mmo_beb128_out
  PARAMS ((bfd *, int, int));
static bfd_boolean mmo_internal_write_section
  PARAMS ((bfd *, asection *));
static void mmo_write_tetra
  PARAMS ((bfd *, unsigned int));
static void mmo_write_tetra_raw
  PARAMS ((bfd *, unsigned int));
static void mmo_write_octa
  PARAMS ((bfd *, bfd_vma));
static void mmo_write_octa_raw
  PARAMS ((bfd *, bfd_vma));
static bfd_boolean mmo_write_chunk
  PARAMS ((bfd *, const bfd_byte *, unsigned int));
static bfd_boolean mmo_flush_chunk
  PARAMS ((bfd *));
static bfd_boolean mmo_write_loc_chunk
  PARAMS ((bfd *, bfd_vma, const bfd_byte *, unsigned int, bfd_vma *));
static bfd_boolean mmo_write_chunk_list
  PARAMS ((bfd *, mmo_data_list_type *));
static bfd_boolean mmo_write_loc_chunk_list
  PARAMS ((bfd *, mmo_data_list_type *));
static bfd_boolean mmo_write_symbols_and_terminator
  PARAMS ((bfd *));
static flagword mmo_sec_flags_from_bfd_flags
  PARAMS ((flagword));
static flagword bfd_sec_flags_from_mmo_flags
  PARAMS ((flagword));
static bfd_byte mmo_get_byte
  PARAMS ((bfd *));
static void mmo_write_byte
  PARAMS ((bfd *, bfd_byte));
static bfd_boolean mmo_new_section_hook
  PARAMS ((bfd *, asection *));
static int mmo_sort_mmo_symbols
  PARAMS ((const PTR, const PTR));
static bfd_boolean mmo_write_object_contents
  PARAMS ((bfd *));
static long mmo_canonicalize_reloc
  PARAMS ((bfd *, sec_ptr, arelent **, asymbol **));

/* Global "const" variables initialized once.  Must not depend on
   particular input or caller; put such things into the bfd or elsewhere.
   Look ma, no static per-invocation data!  */

static unsigned
char valid_mmo_symbol_character_set[/* A-Z a-z (we assume consecutive
				       codes; sorry EBCDIC:ers!).  */
				    + 'Z' - 'A' + 1 + 'z' - 'a' + 1
				    /* Digits.  */
				    + 10
				    /* ':' and '_'.  */
				    + 1 + 1
				    /* Codes higher than 126.  */
				    + 256 - 126
				    /* Ending zero.  */
				    + 1];


/* Get section SECNAME or create one if it doesn't exist.  When creating
   one, new memory for the name is allocated.  */

static asection *
mmo_make_section (abfd, secname)
     bfd *abfd;
     const char *secname;
{
  asection *sec = bfd_get_section_by_name (abfd, secname);

  if (sec == NULL)
    {
      char *newsecname = strdup (secname);

      if (newsecname == NULL)
	{
	  (*_bfd_error_handler)
	    (_("%s: No core to allocate section name %s\n"),
	     bfd_get_filename (abfd), secname);
	  bfd_set_error (bfd_error_system_call);
	  return NULL;
	}
      sec = bfd_make_section (abfd, newsecname);
    }

  return sec;
}

/* Nothing to do, but keep as a placeholder if we need it.
   Note that state that might differ between bfd:s must not be initialized
   here, nor must it be static.  Add it to tdata information instead.  */

static void
mmo_init ()
{
  static bfd_boolean inited = FALSE;
  int i = 0;
  int j = 0;
  static const char letters[]
    = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789:_";

  if (inited)
    return;
  inited = TRUE;

  /* Fill in the set of valid symbol characters.  */
  strcpy (valid_mmo_symbol_character_set, letters);
  i = strlen (letters);

  for (j = 126; j < 256; j++)
    valid_mmo_symbol_character_set[i++] = j;
}

/* Check whether an existing file is an mmo file.  */

static const bfd_target *
mmo_object_p (abfd)
     bfd *abfd;
{
  struct stat statbuf;
  bfd_byte b[4];

  mmo_init ();

  if (bfd_stat (abfd, &statbuf) < 0
      || bfd_seek (abfd, (file_ptr) 0, SEEK_SET) != 0
      || bfd_bread (b, 4, abfd) != 4)
    goto bad_final;

  /* All mmo files are a multiple of four bytes long.
     Only recognize version one.  */
  if ((statbuf.st_size % 4) != 0
      || b[0] != LOP || b[1] != LOP_PRE || b[2] != 1)
    goto bad_format;

  /* Get the last 32-bit word.  */
  if (bfd_seek (abfd, (file_ptr) statbuf.st_size - 4, SEEK_SET) != 0
      || bfd_bread (b, 4, abfd) != 4)
    goto bad_final;

  /* Check if the file ends in a lop_end lopcode. */
  if (b[0] != LOP || b[1] != LOP_END || ! mmo_mkobject (abfd))
    goto bad_format;

  /* Compute an upper bound on the max symbol length.  Not really
     important as all of the symbol information can only be 256k.  */
  abfd->tdata.mmo_data->max_symbol_length = (b[2] * 256 + b[3]) * 4;
  abfd->tdata.mmo_data->lop_stab_symbol
    = bfd_malloc (abfd->tdata.mmo_data->max_symbol_length + 1);

  if (abfd->tdata.mmo_data->lop_stab_symbol == NULL)
    {
      (*_bfd_error_handler)
	(_("%s: No core to allocate a symbol %d bytes long\n"),
	 bfd_get_filename (abfd), abfd->tdata.mmo_data->max_symbol_length);
      goto bad_final;
    }

  /* Read in everything.  */
  if (! mmo_scan (abfd))
    goto bad_format_free;

  if (abfd->symcount > 0)
    abfd->flags |= HAS_SYMS;

  /* You'll have to tweak this if you want to use this format for other
     arches (not recommended due to its small-size limitations).  Look at
     the ELF format for how to make it target-generic.  */
  if (! bfd_default_set_arch_mach (abfd, bfd_arch_mmix, 0))
    goto bad_format_free;

  return abfd->xvec;

 bad_format_free:
  free (abfd->tdata.mmo_data->lop_stab_symbol);
 bad_format:
  bfd_set_error (bfd_error_wrong_format);
 bad_final:
  return NULL;
}

/* Set up the mmo tdata information.  */

static bfd_boolean
mmo_mkobject (abfd)
     bfd *abfd;
{
  mmo_init ();

  if (abfd->tdata.mmo_data == NULL)
    {
      time_t created;

      /* All fields are zero-initialized, so we don't have to explicitly
	 initialize most.  */
      tdata_type *tdata = (tdata_type *) bfd_zmalloc (sizeof (tdata_type));
      if (tdata == NULL)
	return FALSE;

      created = time (NULL);
      bfd_put_32 (abfd, created, tdata->created);

      abfd->tdata.mmo_data = tdata;
    }

  return TRUE;
}

static bfd_boolean
mmo_bfd_copy_private_bfd_data (ibfd, obfd)
     bfd *ibfd;
     bfd *obfd;
{
  if (bfd_get_flavour (ibfd) != bfd_target_mmo_flavour
      || bfd_get_flavour (obfd) != bfd_target_mmo_flavour)
    return TRUE;

  /* Copy the time the copied-from file was created.  If people want the
     time the file was last *modified*, they have that in the normal file
     information.  */
  memcpy (obfd->tdata.mmo_data->created, ibfd->tdata.mmo_data->created,
	  sizeof (obfd->tdata.mmo_data->created));
  return TRUE;
}

/* Helper functions for mmo_decide_section, used through
   bfd_map_over_sections.  */

static void
mmo_find_sec_w_addr (abfd, sec, p)
     bfd *abfd ATTRIBUTE_UNUSED;
     asection *sec;
     PTR p;
{
  struct mmo_find_sec_info *infop = (struct mmo_find_sec_info *) p;
  bfd_vma vma = bfd_get_section_vma (abfd, sec);

  /* Ignore sections that aren't loaded.  */
  if ((bfd_get_section_flags (abfd, sec) & (SEC_LOAD | SEC_ALLOC))
      !=  (SEC_LOAD | SEC_ALLOC))
    return;

  if (infop->addr >= vma && infop->addr < vma + sec->_raw_size)
    infop->sec = sec;
}

static void
mmo_find_sec_w_addr_grow (abfd, sec, p)
     bfd *abfd ATTRIBUTE_UNUSED;
     asection *sec;
     PTR p;
{
  struct mmo_find_sec_info *infop = (struct mmo_find_sec_info *) p;
  bfd_vma vma = bfd_get_section_vma (abfd, sec);

  /* Ignore sections that aren't loaded.  */
  if ((bfd_get_section_flags (abfd, sec) & (SEC_LOAD | SEC_ALLOC))
      !=  (SEC_LOAD | SEC_ALLOC))
    return;

  if (infop->addr >= vma && infop->addr < vma + MAX_ARTIFICIAL_SECTION_SIZE)
    infop->sec = sec;
}

/* Find a section that corresponds to a VMA.  Automatically create .text
   or .data and set current section to it, depending on what vma.  If we
   can't deduce a section, make one up as ".MMIX.sec.N", where N is an
   increasing number.  */

static asection *
mmo_decide_section (abfd, vma)
     bfd *abfd;
     bfd_vma vma;
{
  asection *sec = NULL;
  char sec_name[sizeof (".MMIX.sec.") + 20];
  struct mmo_find_sec_info info;

  info.addr = vma;
  info.sec = NULL;

  /* First see if there's a section that would match exactly.  */
  bfd_map_over_sections (abfd, mmo_find_sec_w_addr, &info);

  if (info.sec != NULL)
    return info.sec;

  /* If there's no such section, try and expand one of the existing ones,
     up to a limit.  Make sure we have .text and .data before we try that;
     create them corresponding to expected addresses and set flags to make
     them match the "loaded and with contents" expectation.  */
  if ((vma >> 56) == 0)
    {
      sec = bfd_make_section_old_way (abfd, MMO_TEXT_SECTION_NAME);

      if (sec == NULL)
	return NULL;

      if (! sec->user_set_vma)
	bfd_set_section_vma (abfd, sec, vma);
      if (! bfd_set_section_flags (abfd, sec,
				   bfd_get_section_flags (abfd, sec)
				   | SEC_CODE | SEC_LOAD | SEC_ALLOC))
	return NULL;
    }
  else if ((vma >> 56) == 0x20)
    {
      sec = bfd_make_section_old_way (abfd, MMO_DATA_SECTION_NAME);

      if (sec == NULL)
	return NULL;

      if (! sec->user_set_vma)
	bfd_set_section_vma (abfd, sec, vma);
      if (! bfd_set_section_flags (abfd, sec,
				   bfd_get_section_flags (abfd, sec)
				   | SEC_LOAD | SEC_ALLOC))
	return NULL;
    }

  bfd_map_over_sections (abfd, mmo_find_sec_w_addr_grow, &info);

  if (info.sec != NULL)
    return info.sec;

  /* If there's still no suitable section, make a new one.  */
  sprintf (sec_name, ".MMIX.sec.%d", abfd->tdata.mmo_data->sec_no++);
  sec = mmo_make_section (abfd, sec_name);
  if (! sec->user_set_vma)
    bfd_set_section_vma (abfd, sec, vma);

  if (! bfd_set_section_flags (abfd, sec,
			       bfd_get_section_flags (abfd, sec)
			       | SEC_LOAD | SEC_ALLOC))
    return NULL;
  return sec;
}

/* Xor in a 64-bit value VALUE at VMA.  */

static INLINE void
mmo_xore_64 (sec, vma, value)
     asection *sec;
     bfd_vma vma;
     bfd_vma value;
{
  bfd_byte *loc = mmo_get_loc (sec, vma, 8);
  bfd_vma prev = bfd_get_64 (sec->owner, loc);

  value ^= prev;
  bfd_put_64 (sec->owner, value, loc);
}

/* Xor in a 32-bit value VALUE at VMA.  */

static INLINE void
mmo_xore_32 (sec, vma, value)
     asection *sec;
     bfd_vma vma;
     unsigned int value;
{
  bfd_byte *loc = mmo_get_loc (sec, vma, 4);
  unsigned int prev = bfd_get_32 (sec->owner, loc);

  value ^= prev;
  bfd_put_32 (sec->owner, value, loc);
}

/* Xor in a 16-bit value VALUE at VMA.  */

static INLINE void
mmo_xore_16 (sec, vma, value)
     asection *sec;
     bfd_vma vma;
     unsigned int value;
{
  bfd_byte *loc = mmo_get_loc (sec, vma, 2);
  unsigned int prev = bfd_get_16 (sec->owner, loc);

  value ^= prev;
  bfd_put_16 (sec->owner, value, loc);
}

/* Write a 32-bit word to output file, no lop_quote generated.  */

static INLINE void
mmo_write_tetra_raw (abfd, value)
     bfd *abfd;
     unsigned int value;
{
  bfd_byte buf[4];

  bfd_put_32 (abfd, value, buf);

  if (bfd_bwrite ((PTR) buf, 4, abfd) != 4)
    abfd->tdata.mmo_data->have_error = TRUE;
}

/* Write a 32-bit word to output file; lop_quote if necessary.  */

static INLINE void
mmo_write_tetra (abfd, value)
     bfd *abfd;
     unsigned int value;
{
  if (((value >> 24) & 0xff) == LOP)
    mmo_write_tetra_raw (abfd, LOP_QUOTE_NEXT);

  mmo_write_tetra_raw (abfd, value);
}

/* Write a 64-bit word to output file, perhaps with lop_quoting.  */

static INLINE void
mmo_write_octa (abfd, value)
     bfd *abfd;
     bfd_vma value;
{
  mmo_write_tetra (abfd, (unsigned int) (value >> 32));
  mmo_write_tetra (abfd, (unsigned int) value);
}

/* Write a 64-bit word to output file, without lop_quoting.  */

static INLINE void
mmo_write_octa_raw (abfd, value)
     bfd *abfd;
     bfd_vma value;
{
  mmo_write_tetra_raw (abfd, (unsigned int) (value >> 32));
  mmo_write_tetra_raw (abfd, (unsigned int) value);
}

/* Write quoted contents.  Intended to be called multiple times in
   sequence, followed by a call to mmo_flush_chunk.  */

static INLINE bfd_boolean
mmo_write_chunk (abfd, loc, len)
     bfd *abfd;
     const bfd_byte *loc;
     unsigned int len;
{
  bfd_boolean retval = TRUE;

  /* Fill up a tetra from bytes remaining from a previous chunk.  */
  if (abfd->tdata.mmo_data->byte_no != 0)
    {
      while (abfd->tdata.mmo_data->byte_no < 4 && len != 0)
	{
	  abfd->tdata.mmo_data->buf[abfd->tdata.mmo_data->byte_no++] = *loc++;
	  len--;
	}

      if (abfd->tdata.mmo_data->byte_no == 4)
	{
	  mmo_write_tetra (abfd,
			   bfd_get_32 (abfd, abfd->tdata.mmo_data->buf));
	  abfd->tdata.mmo_data->byte_no = 0;
	}
    }

  while (len >= 4)
    {
      if (loc[0] == LOP)
	mmo_write_tetra_raw (abfd, LOP_QUOTE_NEXT);

      retval = (retval
		&& ! abfd->tdata.mmo_data->have_error
		&& 4 == bfd_bwrite ((PTR) loc, 4, abfd));

      loc += 4;
      len -= 4;
    }

  if (len)
    {
      memcpy (abfd->tdata.mmo_data->buf, loc, len);
      abfd->tdata.mmo_data->byte_no = len;
    }

  if (! retval)
    abfd->tdata.mmo_data->have_error = TRUE;
  return retval;
}

/* Flush remaining bytes, from a previous mmo_write_chunk, zero-padded to
   4 bytes.  */

static INLINE bfd_boolean
mmo_flush_chunk (abfd)
     bfd *abfd;
{
  if (abfd->tdata.mmo_data->byte_no != 0)
    {
      memset (abfd->tdata.mmo_data->buf + abfd->tdata.mmo_data->byte_no,
	      0, 4 - abfd->tdata.mmo_data->byte_no);
      mmo_write_tetra (abfd,
		       bfd_get_32 (abfd, abfd->tdata.mmo_data->buf));
      abfd->tdata.mmo_data->byte_no = 0;
    }

  return ! abfd->tdata.mmo_data->have_error;
}

/* Same, but from a list.  */

static INLINE bfd_boolean
mmo_write_chunk_list (abfd, datap)
     bfd *abfd;
     mmo_data_list_type *datap;
{
  for (; datap != NULL; datap = datap->next)
    if (! mmo_write_chunk (abfd, datap->data, datap->size))
      return FALSE;

  return mmo_flush_chunk (abfd);
}

/* Write a lop_loc and some contents.  A caller needs to call
   mmo_flush_chunk after calling this function.  The location is only
   output if different than *LAST_VMAP, which is updated after this call.  */

static bfd_boolean
mmo_write_loc_chunk (abfd, vma, loc, len, last_vmap)
     bfd *abfd;
     bfd_vma vma;
     const bfd_byte *loc;
     unsigned int len;
     bfd_vma *last_vmap;
{
  /* Find an initial and trailing section of zero tetras; we don't need to
     write out zeros.  FIXME: When we do this, we should emit section size
     and address specifiers, else objcopy can't always perform an identity
     translation.  Only do this if we *don't* have left-over data from a
     previous write or the vma of this chunk is *not* the next address,
     because then data isn't tetrabyte-aligned and we're concatenating to
     that left-over data.  */

  if (abfd->tdata.mmo_data->byte_no == 0 || vma != *last_vmap)
    {
      while (len >= 4 && bfd_get_32 (abfd, loc) == 0)
	{
	  vma += 4;
	  len -= 4;
	  loc += 4;
	}

      while (len >= 4 && bfd_get_32 (abfd, loc + len - 4) == 0)
	len -= 4;
    }

  /* Only write out the location if it's different than the one the caller
     (supposedly) previously handled, accounting for omitted leading zeros.  */
  if (vma != *last_vmap)
    {
      /* We might be in the middle of a sequence.  */
      mmo_flush_chunk (abfd);

      /* We always write the location as 64 bits; no use saving bytes
         here.  */
      mmo_write_tetra_raw (abfd, (LOP << 24) | (LOP_LOC << 16) | 2);
      mmo_write_octa_raw (abfd, vma);
    }

  /* Update to reflect end of this chunk, with trailing zeros omitted.  */
  *last_vmap = vma + len;

  return (! abfd->tdata.mmo_data->have_error
	  && mmo_write_chunk (abfd, loc, len));
}

/* Same, but from a list.  */

static INLINE bfd_boolean
mmo_write_loc_chunk_list (abfd, datap)
     bfd *abfd;
     mmo_data_list_type *datap;
{
  /* Get an address different than the address of the first chunk.  */
  bfd_vma last_vma = datap ? datap->where - 1 : 0;

  for (; datap != NULL; datap = datap->next)
    if (! mmo_write_loc_chunk (abfd, datap->where, datap->data, datap->size,
			       &last_vma))
      return FALSE;

  return mmo_flush_chunk (abfd);
}

/* Make a .MMIX.spec_data.N section.  */

static asection *
mmo_get_generic_spec_data_section (abfd, spec_data_number)
     bfd *abfd;
     int spec_data_number;
{
  asection *sec;
  char secname[sizeof (MMIX_OTHER_SPEC_SECTION_PREFIX) + 20]
    = MMIX_OTHER_SPEC_SECTION_PREFIX;

  sprintf (secname + strlen (MMIX_OTHER_SPEC_SECTION_PREFIX),
	   "%d", spec_data_number);

  sec = mmo_make_section (abfd, secname);

  return sec;
}

/* Make a special section for SPEC_DATA_NUMBER.  If it is the one we use
   ourselves, parse some of its data to get at the section name.  */

static asection *
mmo_get_spec_section (abfd, spec_data_number)
     bfd *abfd;
     int spec_data_number;
{
  bfd_byte *secname;
  asection *sec;
  bfd_byte buf[4];
  unsigned int secname_length;
  unsigned int i;
  bfd_vma section_length;
  bfd_vma section_vma;
  mmo_data_list_type *loc;
  flagword flags;
  long orig_pos;

  /* If this isn't the "special" special data, then make a placeholder
     section.  */
  if (spec_data_number != SPEC_DATA_SECTION)
    return mmo_get_generic_spec_data_section (abfd, spec_data_number);

  /* Seek back to this position if there was a format error.  */
  orig_pos = bfd_tell (abfd);

  /* Read the length (in 32-bit words).  */
  if (bfd_bread (buf, 4, abfd) != 4)
    goto format_error;

  if (buf[0] == LOP)
    {
      if (buf[1] != LOP_QUOTE)
	goto format_error;

      if (bfd_bread (buf, 4, abfd) != 4)
	goto format_error;
    }

  /* We don't care to keep the name length accurate.  It's
     zero-terminated.  */
  secname_length = bfd_get_32 (abfd, buf) * 4;

  /* Check section name length for sanity.  */
  if (secname_length > MAX_SECTION_NAME_SIZE)
    goto format_error;

  /* This should be free'd regardless if a section is created.  */
  secname = bfd_malloc (secname_length + 1);
  secname[secname_length] = 0;

  for (i = 0; i < secname_length / 4; i++)
    {
      if (bfd_bread (secname + i * 4, 4, abfd) != 4)
	goto format_error_free;

      if (secname[i * 4] == LOP)
	{
	  /* A bit of overkill, but we handle char 0x98 in a section name,
	     and recognize misparsing.  */
	  if (secname[i * 4 + 1] != LOP_QUOTE
	      || bfd_bread (secname + i * 4, 4, abfd) != 4)
	    /* Whoops.  We thought this was a name, and now we found a
	       non-lop_quote lopcode before we parsed the whole length of
	       the name.  Signal end-of-file in the same manner.  */
	      goto format_error_free;
	}
    }

  /* Get the section flags.  */
  if (bfd_bread (buf, 4, abfd) != 4
      || (buf[0] == LOP
	  && (buf[1] != LOP_QUOTE || bfd_bread (buf, 4, abfd) != 4)))
    goto format_error_free;

  flags = bfd_get_32 (abfd, buf);

  /* Get the section length.  */
  if (bfd_bread (buf, 4, abfd) != 4
      || (buf[0] == LOP
	  && (buf[1] != LOP_QUOTE || bfd_bread (buf, 4, abfd) != 4)))
    goto format_error_free;

  section_length = (bfd_vma) bfd_get_32 (abfd, buf) << 32;

  /* That's the first, high-part.  Now get the low part.  */

  if (bfd_bread (buf, 4, abfd) != 4
      || (buf[0] == LOP
	  && (buf[1] != LOP_QUOTE || bfd_bread (buf, 4, abfd) != 4)))
    goto format_error_free;

  section_length |= (bfd_vma) bfd_get_32 (abfd, buf);

  /* Check the section length for sanity.  */
  if (section_length > MAX_ARTIFICIAL_SECTION_SIZE)
    goto format_error_free;

  /* Get the section VMA.  */
  if (bfd_bread (buf, 4, abfd) != 4
      || (buf[0] == LOP
	  && (buf[1] != LOP_QUOTE || bfd_bread (buf, 4, abfd) != 4)))
    goto format_error_free;

  section_vma = (bfd_vma) bfd_get_32 (abfd, buf) << 32;

  /* That's the first, high-part.  Now get the low part.  */
  if (bfd_bread (buf, 4, abfd) != 4
      || (buf[0] == LOP
	  && (buf[1] != LOP_QUOTE || bfd_bread (buf, 4, abfd) != 4)))
    goto format_error_free;

  section_vma |= (bfd_vma) bfd_get_32 (abfd, buf);

  sec = mmo_make_section (abfd, secname);
  free (secname);
  if (sec == NULL)
    goto format_error;

  /* We allocate a buffer here for the advertised size, with head room for
     tetrabyte alignment.  */
  loc = bfd_zmalloc (section_length + 3
		     + sizeof (struct mmo_data_list_struct));
  if (loc == NULL)
    goto format_error;

  /* Use a TETRA-rounded size for the allocated buffer; we set the
     "visible" section size below.  */
  loc->size = (section_length + 3) & ~3;

  /* Add in the section flags we found to those bfd entered during this
     process and set the contents.  */
  if (! bfd_set_section_flags (abfd, sec,
			       bfd_sec_flags_from_mmo_flags (flags)
			       | bfd_get_section_flags (abfd, sec)
			       | (section_length != 0 ? SEC_HAS_CONTENTS : 0))
      || ! bfd_set_section_size (abfd, sec,
				 sec->_cooked_size + section_length)
      /* Set VMA only for the first occurrence.  */
      || (! sec->user_set_vma
	  && ! bfd_set_section_vma  (abfd, sec, section_vma)))
    {
      /* If we get an error for any of the calls above, signal more than
	 just a format error for the spec section.  */
      return NULL;
    }

  loc->next = NULL;
  if (mmo_section_data (sec)->tail != NULL)
    mmo_section_data (sec)->tail->next = loc;
  else
    mmo_section_data (sec)->head = loc;
  mmo_section_data (sec)->tail = loc;
  loc->where = section_vma;

  return sec;

 format_error_free:
  free (secname);
 format_error:
  if (bfd_seek (abfd, orig_pos, SEEK_SET) != 0)
    return NULL;

  return mmo_get_generic_spec_data_section (abfd, spec_data_number);
}

/* Read a byte, but read from file in multiples of 32-bit words.  */

static bfd_byte
mmo_get_byte (abfd)
     bfd *abfd;
{
  bfd_byte retval;

  if (abfd->tdata.mmo_data->byte_no == 0)
    {
      if (! abfd->tdata.mmo_data->have_error
	  && bfd_bread (abfd->tdata.mmo_data->buf, 4, abfd) != 4)
	{
	  abfd->tdata.mmo_data->have_error = TRUE;

	  /* A value somewhat safe against tripping on some inconsistency
	     when mopping up after this error.  */
	  return 128;
	}
    }

  retval = abfd->tdata.mmo_data->buf[abfd->tdata.mmo_data->byte_no];
  abfd->tdata.mmo_data->byte_no = (abfd->tdata.mmo_data->byte_no + 1) % 4;

  return retval;
}

/* Write a byte, in multiples of 32-bit words.  */

static void
mmo_write_byte (abfd, value)
     bfd *abfd;
     bfd_byte value;
{
  abfd->tdata.mmo_data->buf[(abfd->tdata.mmo_data->byte_no++ % 4)] = value;
  if ((abfd->tdata.mmo_data->byte_no % 4) == 0)
    {
      if (! abfd->tdata.mmo_data->have_error
	  && bfd_bwrite (abfd->tdata.mmo_data->buf, 4, abfd) != 4)
	abfd->tdata.mmo_data->have_error = TRUE;
    }
}

/* Create a symbol.  */

static bfd_boolean
mmo_create_symbol (abfd, symname, addr, sym_type, serno)
     bfd *abfd;
     const char *symname;
     bfd_vma addr;
     enum mmo_sym_type sym_type;
     unsigned int serno;
{
  struct mmo_symbol *n;

  n = (struct mmo_symbol *) bfd_alloc (abfd, sizeof (struct mmo_symbol));
  if (n == NULL)
    return FALSE;

  n->name = bfd_alloc (abfd, strlen (symname) + 1);
  if (n->name == NULL)
    return FALSE;

  strcpy ((PTR) n->name, symname);

  n->value = addr;
  n->sym_type = sym_type;
  n->serno = serno;

  if (abfd->tdata.mmo_data->symbols == NULL)
    abfd->tdata.mmo_data->symbols = n;
  else
    abfd->tdata.mmo_data->symtail->next = n;
  abfd->tdata.mmo_data->symtail = n;
  n->next = NULL;

  ++abfd->symcount;

  /* Check that :Main equals the last octa of the .MMIX.reg_contents
     section, as it's the one place we're sure to pass when reading a mmo
     object.  For written objects, we do it while setting the symbol
     table.  */
  if (strcmp (symname, MMIX_START_SYMBOL_NAME) == 0
      && bfd_get_start_address (abfd) != addr)
    {
      (*_bfd_error_handler)
	(_("%s: invalid mmo file: initialization value for $255 is not `Main'\n"),
	 bfd_get_filename (abfd));
      bfd_set_error (bfd_error_bad_value);
      return FALSE;
    }

  return TRUE;
}

/* Read in symbols.  */

static bfd_boolean
mmo_get_symbols (abfd)
     bfd *abfd;
{
/*
INODE
Symbol-table, mmo section mapping, File layout, mmo
SUBSECTION
	Symbol table format

	From mmixal.w (or really, the generated mmixal.tex) in
	@url{http://www-cs-faculty.stanford.edu/~knuth/programs/mmix.tar.gz}):
	``Symbols are stored and retrieved by means of a @samp{ternary
	search trie}, following ideas of Bentley and Sedgewick. (See
	ACM--SIAM Symp.@: on Discrete Algorithms @samp{8} (1997), 360--369;
	R.@:Sedgewick, @samp{Algorithms in C} (Reading, Mass.@:
	Addison--Wesley, 1998), @samp{15.4}.)  Each trie node stores a
	character, and there are branches to subtries for the cases where
	a given character is less than, equal to, or greater than the
	character in the trie.  There also is a pointer to a symbol table
	entry if a symbol ends at the current node.''

	So it's a tree encoded as a stream of bytes.  The stream of bytes
	acts on a single virtual global symbol, adding and removing
	characters and signalling complete symbol points.  Here, we read
	the stream and create symbols at the completion points.

	First, there's a control byte <<m>>.  If any of the listed bits
	in <<m>> is nonzero, we execute what stands at the right, in
	the listed order:

| (MMO3_LEFT)
| 0x40 - Traverse left trie.
|        (Read a new command byte and recurse.)
|
| (MMO3_SYMBITS)
| 0x2f - Read the next byte as a character and store it in the
|        current character position; increment character position.
|        Test the bits of <<m>>:
|
|        (MMO3_WCHAR)
|        0x80 - The character is 16-bit (so read another byte,
|               merge into current character.
|
|        (MMO3_TYPEBITS)
|        0xf  - We have a complete symbol; parse the type, value
|               and serial number and do what should be done
|               with a symbol.  The type and length information
|               is in j = (m & 0xf).
|
|               (MMO3_REGQUAL_BITS)
|	        j == 0xf: A register variable.  The following
|                         byte tells which register.
|               j <= 8:   An absolute symbol.  Read j bytes as the
|                         big-endian number the symbol equals.
|                         A j = 2 with two zero bytes denotes an
|                         unknown symbol.
|               j > 8:    As with j <= 8, but add (0x20 << 56)
|                         to the value in the following j - 8
|                         bytes.
|
|               Then comes the serial number, as a variant of
|               uleb128, but better named ubeb128:
|               Read bytes and shift the previous value left 7
|               (multiply by 128).  Add in the new byte, repeat
|               until a byte has bit 7 set.  The serial number
|               is the computed value minus 128.
|
|        (MMO3_MIDDLE)
|        0x20 - Traverse middle trie.  (Read a new command byte
|               and recurse.)  Decrement character position.
|
| (MMO3_RIGHT)
| 0x10 - Traverse right trie.  (Read a new command byte and
|        recurse.)

	Let's look again at the <<lop_stab>> for the trivial file
	(@pxref{File layout}).

| 0x980b0000 - lop_stab for ":Main" = 0, serial 1.
| 0x203a4040
| 0x10404020
| 0x4d206120
| 0x69016e00
| 0x81000000

	This forms the trivial trie (note that the path between ``:'' and
	``M'' is redundant):

| 203a	   ":"
| 40       /
| 40      /
| 10      \
| 40      /
| 40     /
| 204d  "M"
| 2061  "a"
| 2069  "i"
| 016e  "n" is the last character in a full symbol, and
|       with a value represented in one byte.
| 00    The value is 0.
| 81    The serial number is 1.  */

  bfd_byte m = mmo_get_byte (abfd);

  /* Check first if we have a bad hair day.  */
  if (abfd->tdata.mmo_data->have_error)
    return FALSE;

  if (m & MMO3_LEFT)
    /* Traverse left trie. */
    mmo_get_symbols (abfd);

  if (m & MMO3_SYMBITS)
    {
      bfd_byte c = mmo_get_byte (abfd);
      bfd_byte j = m & MMO3_TYPEBITS;
      bfd_vma addr = 0;
      enum mmo_sym_type sym_type;
      unsigned int serno = 0;
      bfd_byte k;

      if (m & MMO3_WCHAR)
	{
	  bfd_byte c2 = mmo_get_byte (abfd);

	  /* A two-byte character.  We can't grok this, but neither can
	     mmotype, for other cases than the second byte being zero.  */

	  if (c != 0)
	    {
	      abfd->tdata.mmo_data->lop_stab_symbol
		[abfd->tdata.mmo_data->symbol_position] = 0;

	      (*_bfd_error_handler)
		(_("%s: unsupported wide character sequence\
 0x%02X 0x%02X after symbol name starting with `%s'\n"),
		 bfd_get_filename (abfd), c, c2,
		 abfd->tdata.mmo_data->lop_stab_symbol);
	      bfd_set_error (bfd_error_bad_value);
	      abfd->tdata.mmo_data->have_error = TRUE;
	      return FALSE;
	    }
	  else
	    c = c2;
	}

      abfd->tdata.mmo_data->lop_stab_symbol[abfd->tdata.mmo_data->symbol_position++] = c;
      abfd->tdata.mmo_data->lop_stab_symbol[abfd->tdata.mmo_data->symbol_position] = 0;

      if (j & MMO3_REGQUAL_BITS)
	{
	  if (j == MMO3_REGQUAL_BITS)
	    {
	      sym_type = mmo_reg_sym;
	      addr = mmo_get_byte (abfd);
	    }
	  else if (j <= 8)
	    {
	      unsigned int i;

	      for (i = 0; i < j; i++)
		addr = (addr << 8) + mmo_get_byte (abfd);

	      if (addr == 0 && j == MMO3_UNDEF)
		sym_type = mmo_undef_sym;
	      else
		sym_type = mmo_abs_sym;
	    }
	  else
	    {
	      unsigned int i;

	      for (i = MMO3_DATA; i < j; i++)
		addr = (addr << 8) + mmo_get_byte (abfd);

	      addr += (bfd_vma) 0x20 << 56;
	      sym_type = mmo_data_sym;
	    }

	  /* Get the serial number.  */
	  do
	    {
	      k = mmo_get_byte (abfd);
	      serno = (serno << 7) + k;
	    }
	  while (k < 128);
	  serno -= 128;

	  /* Got it.  Now enter it.  Skip a leading ":".  */
	  if (! abfd->tdata.mmo_data->have_error
	      && ! mmo_create_symbol (abfd,
				      abfd->tdata.mmo_data->lop_stab_symbol
				      + 1,
				      addr, sym_type, serno))
	    abfd->tdata.mmo_data->have_error = TRUE;
	}

      if (m & MMO3_MIDDLE)
	/* Traverse middle trie. */
	mmo_get_symbols (abfd);

      abfd->tdata.mmo_data->symbol_position--;
    }

  if (m & MMO3_RIGHT)
    /* Traverse right trie.  */
    mmo_get_symbols (abfd);

  return ! abfd->tdata.mmo_data->have_error;
}

/* Get the location of memory area [VMA..VMA + SIZE - 1], which we think
   is in section SEC.  Adjust and reallocate zero-initialized contents.
   If there's new contents, allocate to the next multiple of
   MMO_SEC_CONTENTS_CHUNK_SIZE.  */

static INLINE bfd_byte *
mmo_get_loc (sec, vma, size)
     asection *sec;
     bfd_vma vma;
     int size;
{
  bfd_size_type allocated_size;
  struct mmo_section_data_struct *sdatap = mmo_section_data (sec);
  struct mmo_data_list_struct *datap = sdatap->head;
  struct mmo_data_list_struct *entry;

  /* First search the list to see if we have the requested chunk in one
     piece, or perhaps if we have a suitable chunk with room to fit.  */
  for (; datap != NULL; datap = datap->next)
    {
      if (datap->where <= vma
	  && datap->where + datap->size >= vma + size)
	return datap->data + vma - datap->where;
      else if (datap->where <= vma
	       && datap->where + datap->allocated_size >= vma + size
	       /* Only munch on the "allocated size" if it does not
		  overlap the next chunk.  */
	       && (datap->next == NULL || datap->next->where >= vma + size))
	{
	  /* There was room allocated, but the size wasn't set to include
	     it.  Do that now.  */
	  datap->size += (vma + size) - (datap->where + datap->size);

	  /* Update the section size.  This happens only if we update the
	     32-bit-aligned chunk size.  Callers that have
	     non-32-bit-aligned sections should do all allocation and
	     size-setting by themselves or at least set the section size
	     after the last allocating call to this function.  */
	  if (vma + size > sec->vma + sec->_raw_size)
	    sec->_raw_size += (vma + size) - (sec->vma + sec->_raw_size);

	  return datap->data + vma - datap->where;
	}
    }

  /* Not found; allocate a new block.  First check in case we get a
     request for a size split up over several blocks; we'll have to return
     NULL for those cases, requesting the caller to split up the request.
     Requests with an address aligned on MMO_SEC_CONTENTS_CHUNK_SIZE bytes and
     for no more than MMO_SEC_CONTENTS_CHUNK_SIZE will always get resolved.  */

  for (datap = sdatap->head; datap != NULL; datap = datap->next)
    if ((datap->where <= vma && datap->where + datap->size > vma)
	|| (datap->where < vma + size
	    && datap->where + datap->size >= vma + size))
      return NULL;

  allocated_size
    = (size + MMO_SEC_CONTENTS_CHUNK_SIZE - 1) & ~(MMO_SEC_CONTENTS_CHUNK_SIZE - 1);
  entry = (mmo_data_list_type *)
    bfd_zalloc (sec->owner, sizeof (mmo_data_list_type) + allocated_size);
  if (entry == NULL)
    return NULL;
  entry->where = vma;
  entry->size = size;
  entry->allocated_size = allocated_size;

  datap = sdatap->head;

  /* Sort the records by address.  Optimize for the common case of adding
     a record to the end of the list.  */
  if (sdatap->tail != NULL && entry->where >= sdatap->tail->where)
    {
      sdatap->tail->next = entry;
      entry->next = NULL;
      sdatap->tail = entry;
    }
  else
    {
      mmo_data_list_type **look;
      for (look = &sdatap->head;
	   *look != NULL && (*look)->where < entry->where;
	   look = &(*look)->next)
	;
      entry->next = *look;
      *look = entry;
      if (entry->next == NULL)
	{
	  sdatap->tail = entry;

	  /* We get here for the first time (at other times too) for this
	     section.  Say we have contents.  */
	  if (! bfd_set_section_flags (sec->owner, sec,
				       bfd_get_section_flags (sec->owner, sec)
				       | SEC_HAS_CONTENTS))
	    return NULL;
	}
    }

  /* Update the section size.  This happens only when we add contents and
     re-size as we go.  The section size will then be aligned to 32 bits.  */
  if (vma + size > sec->vma + sec->_raw_size)
    sec->_raw_size += (vma + size) - (sec->vma + sec->_raw_size);
  return entry->data;
}

/* Set sizes once we've read in all sections.  */

static void
mmo_map_set_sizes (abfd, sec, ignored)
     bfd *abfd ATTRIBUTE_UNUSED;
     asection *sec;
     PTR ignored ATTRIBUTE_UNUSED;
{
  sec->_cooked_size = sec->_raw_size;
  sec->lma = sec->vma;
}

/* Read the mmo file and turn it into sections.  */

static bfd_boolean
mmo_scan (abfd)
     bfd *abfd;
{
  unsigned int i;
  unsigned int lineno = 1;
  bfd_boolean error = FALSE;
  bfd_vma vma = 0;
  asection *sec = bfd_make_section_old_way (abfd, MMO_TEXT_SECTION_NAME);
  asection *non_spec_sec = NULL;
  bfd_vma non_spec_vma = 0;
  char *current_filename = NULL;
  bfd_size_type nbytes_read = 0;
  /* Buffer with room to read a 64-bit value.  */
  bfd_byte buf[8];
  long stab_loc = -1;
  char *file_names[256];

  memset (file_names, 0, sizeof (file_names));

  if (bfd_seek (abfd, (file_ptr) 0, SEEK_SET) != 0)
    goto error_return;

  while ((nbytes_read = bfd_bread (buf, 4, abfd)) == 4)
    {
      if (buf[0] == LOP)
	{
	  unsigned int y = bfd_get_8 (abfd, buf + 2);
	  unsigned int z = bfd_get_8 (abfd, buf + 3);

	  /* Change back to the original section for lopcodes other
	     than LOP_QUOTE that comes after a LOP_SPEC.  */
	  if ((buf[1] != LOP_QUOTE || y != 0 || z != 1)
	      && non_spec_sec != NULL)
	    {
	      sec = non_spec_sec;
	      vma = non_spec_vma;
	      non_spec_sec = NULL;
	    }

	  switch (buf[1])
	    {
	    default:
	      (*_bfd_error_handler)
		(_("%s: invalid mmo file: unsupported lopcode `%d'\n"),
		 bfd_get_filename (abfd), buf[1]);
	      bfd_set_error (bfd_error_bad_value);
	      goto error_return;

	    case LOP_QUOTE:
	      /* Quote the next 32-bit word.  */
	      if (y != 0 || z != 1)
		{
		  (*_bfd_error_handler)
		    (_("%s: invalid mmo file: expected YZ = 1 got YZ = %d for lop_quote\n"),
		     bfd_get_filename (abfd), y*256+z);
		  bfd_set_error (bfd_error_bad_value);
		  goto error_return;
		}
	      if (bfd_bread (buf, 4, abfd) != 4)
		goto error_return;

	      mmo_xore_32 (sec, vma, bfd_get_32 (abfd, buf));
	      vma += 4;
	      vma &= ~3;
	      lineno++;
	      break;

	    case LOP_LOC:
	      /* Set vma (and section).  */
	      vma = (bfd_vma) y << 56;
	      if (z == 1)
		{
		  /* Get a 32-bit value.  */
		  if (bfd_bread (buf, 4, abfd) != 4)
		    goto error_return;

		  vma += bfd_get_32 (abfd, buf);
		}
	      else if (z == 2)
		{
		  /* Get a 64-bit value.  */
		  if (bfd_bread (buf, 8, abfd) != 8)
		    goto error_return;

		  vma += bfd_get_64 (abfd, buf);
		}
	      else
		{
		  (*_bfd_error_handler)
		    (_("%s: invalid mmo file: expected z = 1 or z = 2, got z = %d for lop_loc\n"),
		     bfd_get_filename (abfd), z);
		  bfd_set_error (bfd_error_bad_value);
		  goto error_return;
		}

	      sec = mmo_decide_section (abfd, vma);
	      if (sec == NULL)
		goto error_return;
	      break;

	    case LOP_SKIP:
	      /* Move forward within the same section.  */
	      vma += y * 256 + z;

	      sec = mmo_decide_section (abfd, vma);
	      if (sec == NULL)
		goto error_return;
	      break;

	    case LOP_FIXO:
	      /* A fixup: Store the current vma somewhere.  Position using
		 same format as LOP_LOC.  */
	      {
		bfd_vma p = (bfd_vma) y << 56;
		asection *fixosec;

		if (z == 1)
		  {
		    /* Get a 32-bit value.  */
		    if (bfd_bread (buf, 4, abfd) != 4)
		      goto error_return;

		    p += bfd_get_32 (abfd, buf);
		  }
		else if (z == 2)
		  {
		    /* Get a 64-bit value.  */
		    if (bfd_bread (buf, 8, abfd) != 8)
		      goto error_return;

		    p += bfd_get_64 (abfd, buf);
		  }
		else
		  {
		    (*_bfd_error_handler)
		      (_("%s: invalid mmo file: expected z = 1 or z = 2, got z = %d for lop_fixo\n"),
		       bfd_get_filename (abfd), z);
		    bfd_set_error (bfd_error_bad_value);
		    goto error_return;
		  }

		/* The section where we store this address might be a
		   different one than the current section.  */
		fixosec = mmo_decide_section (abfd, p);
		if (fixosec == NULL)
		  goto error_return;
		mmo_xore_64 (fixosec, p, vma);
	      }
	    break;

	    case LOP_FIXR:
	      /* A fixup: Store YZ of this lopcode into YZ at vma - 4 * yz.  */
	      {
		unsigned int yz = (y * 256 + z);
		bfd_vma p = vma + 2 - 4 * yz;
		asection *fixrsec = mmo_decide_section (abfd, p);
		if (fixrsec == NULL)
		  goto error_return;
		mmo_xore_16 (fixrsec, p, yz);
	      }
	    break;

	    case LOP_FIXRX:
	      /* A fixup, similar to lop_fixr, but taking larger numbers
		 and can change branches into the opposite direction
		 (gasp!).  */
	      {
		bfd_vma delta;
		bfd_vma p;
		asection *fixrsec;

		if (y != 0)
		  {
		    (*_bfd_error_handler)
		      (_("%s: invalid mmo file: expected y = 0, got y = %d for lop_fixrx\n"),
		       bfd_get_filename (abfd), y);
		    bfd_set_error (bfd_error_bad_value);
		    goto error_return;
		  }

		if (z != 16 && z != 24)
		  {
		    (*_bfd_error_handler)
		      (_("%s: invalid mmo file: expected z = 16 or z = 24, got z = %d for lop_fixrx\n"),
		       bfd_get_filename (abfd), z);
		    bfd_set_error (bfd_error_bad_value);
		    goto error_return;
		  }

		/* Get the next 32-bit value.  */
		if (bfd_bread (buf, 4, abfd) != 4)
		  goto error_return;

		delta = bfd_get_32 (abfd, buf);

		/* Do an, ehm, involved calculation for the location of
		   the fixup.  See mmixal documentation for a verbose
		   explanation.  We follow it verbosely here for the
		   readers delight.  */
		if (buf[0] == 0)
		  p = vma - 4 * delta;
		else if (buf[0] == 1)
		  p = vma - 4 * ((delta & 0xffffff) - (1 << z));
		else
		  {
		    (*_bfd_error_handler)
		      (_("%s: invalid mmo file: leading byte of operand word must be 0 or 1, got %d for lop_fixrx\n"),
		       bfd_get_filename (abfd), buf[0]);
		    bfd_set_error (bfd_error_bad_value);
		    goto error_return;
		  }

		fixrsec = mmo_decide_section (abfd, vma);
		if (fixrsec == NULL)
		  goto error_return;
		mmo_xore_32 (fixrsec, p, delta);
	      }
	    break;

	    case LOP_FILE:
	      /* Set current file and perhaps the file name.  Reset line
		 number.  */
	      if (z != 0)
		{
		  char *fname = bfd_malloc (z * 4 + 1);

		  if (fname == NULL)
		    {
		      (*_bfd_error_handler)
			(_("%s: cannot allocate file name for file number %d, %d bytes\n"),
			 bfd_get_filename (abfd), y, z * 4 + 1);
		      bfd_set_error (bfd_error_system_call);
		      goto error_return;
		    }

		  fname[z * 4] = 0;

		  for (i = 0; i < z; i++)
		    {
		      if (bfd_bread (fname + i * 4, 4, abfd) != 4)
			{
			  free (fname);
			  goto error_return;
			}
		    }

		  if (file_names[y] != NULL)
		    {
		      (*_bfd_error_handler)
			(_("%s: invalid mmo file: file number %d `%s',\
 was already entered as `%s'\n"),
			 bfd_get_filename (abfd), y, fname, file_names[y]);
		      bfd_set_error (bfd_error_bad_value);
		      goto error_return;
		    }

		  file_names[y] = fname;
		}

	      if (file_names[y] == NULL)
		{
		  (*_bfd_error_handler)
		    (_("%s: invalid mmo file: file name for number %d\
 was not specified before use\n"),
		     bfd_get_filename (abfd), y);
		  bfd_set_error (bfd_error_bad_value);
		  goto error_return;
		}

	      current_filename = file_names[y];
	      lineno = 0;
	      break;

	    case LOP_LINE:
	      /* Set line number.  */
	      lineno = y * 256 + z;
	      /* FIXME: Create a sequence of mmo-specific line number
		 entries for each section, then translate into canonical
		 format.  */
	      break;

	    case LOP_SPEC:
	      /* Special data follows until the next non-lop_quote
		 lopcode.  */
	      non_spec_sec = sec;
	      non_spec_vma = vma;
	      sec = mmo_get_spec_section (abfd, y * 256 + z);
	      if (sec == NULL)
		goto error_return;

	      vma = sec->vma;
	      break;

	    case LOP_PRE:
	      {
		/* We ignore header information, except we read in the
		   creation time from the first 32-bit word with the time
		   in seconds since era.  */
		if (z >= 1
		    && bfd_bread (abfd->tdata.mmo_data->created, 4,
				 abfd) != 4)
		  goto error_return;

		for (i = 1; i < z; i++)
		  if (bfd_bread (buf, 4, abfd) != 4)
		    goto error_return;
	      }
	      break;

	    case LOP_POST:
	      /* This tells of the contents of registers $Z..$255 at
		 startup.  We make a section out of it, with VMA = Z * 8,
		 but only if Z != 255 or the contents is non-zero.  */
	      {
		asection *rsec;
		bfd_byte *loc;
		bfd_vma first_octa;
		bfd_vma startaddr_octa;

		/* Read first octaword outside loop to simplify logic when
		   excluding the Z == 255, octa == 0 case.  */
		if (bfd_bread (buf, 8, abfd) != 8)
		  goto error_return;

		first_octa = bfd_get_64 (abfd, buf);

		/* Don't emit contents for the trivial case which is
		   always present; $255 pointing to Main.  */
		if (z != 255)
		  {
		    rsec
		      = bfd_make_section_old_way (abfd,
						  MMIX_REG_CONTENTS_SECTION_NAME);
		    rsec->vma = z * 8;
		    loc = mmo_get_loc (rsec, z * 8, (255 - z) * 8);
		    bfd_put_64 (abfd, first_octa, loc);

		    for (i = z + 1; i < 255; i++)
		      {
			if (bfd_bread (loc + (i - z) * 8, 8, abfd) != 8)
			  goto error_return;
		      }

		    /* Read out the last octabyte, and use it to set the
		       start address.  */
		    if (bfd_bread (buf, 8, abfd) != 8)
		      goto error_return;

		    startaddr_octa = bfd_get_64 (abfd, buf);
		  }
		else
		  startaddr_octa = first_octa;

		if (! bfd_set_start_address (abfd, startaddr_octa))
		  {
		    /* Currently this can't fail, but this should handle
		       future failures.  */
		    bfd_set_error (bfd_error_bad_value);
		    goto error_return;
		  }
	      }
	      break;

	    case LOP_STAB:
	      /* We read in the symbols now, not later.  */
	      if (y != 0 || z != 0)
		{
		  (*_bfd_error_handler)
		    (_("%s: invalid mmo file: fields y and z of lop_stab\
 non-zero, y: %d, z: %d\n"),
		     bfd_get_filename (abfd), y, z);
		  bfd_set_error (bfd_error_bad_value);
		  goto error_return;
		}

	      /* Save the location, so we can check that YZ in the LOP_END
		 is correct.  */
	      stab_loc = bfd_tell (abfd);

	      /* It's not said that an MMO can be without symbols (though
		 mmixal will refuse to assemble files without Main), but
		 it seems it would still be a valid mmo-file, so allow it.
		 We detect the absence of a symbol area in that the upper
		 limit is computed (from the lop_end YZ field) as 0.
		 Don't call mmo_get_symbols; it can only detect the end of
		 a valid symbol trie, not the absence of one.  */
	      if (abfd->tdata.mmo_data->max_symbol_length != 0
		  && ! mmo_get_symbols (abfd))
		goto error_return;
	      break;

	    case LOP_END:
	      {
		/* This must be the last 32-bit word in an mmo file.
		   Let's find out.  */
		struct stat statbuf;
		long curpos = bfd_tell (abfd);

		if (bfd_stat (abfd, &statbuf) < 0)
		  goto error_return;

		if (statbuf.st_size != curpos)
		  {
		    (*_bfd_error_handler)
		      (_("%s: invalid mmo file: lop_end not last item in\
 file\n"),
		       bfd_get_filename (abfd));
		    bfd_set_error (bfd_error_bad_value);
		    goto error_return;
		  }

		/* Check that the YZ field is right.  Subtract the size of
		   this LOP_END in the calculation; YZ does not include
		   it.  */
		if ((long) (y * 256 + z) * 4 != (curpos - stab_loc) - 4)
		  {
		    (*_bfd_error_handler)
		      (_("%s: invalid mmo file: YZ of lop_end (%ld)\
 not equal to the number of tetras to the preceding lop_stab (%ld)\n"),
		       bfd_get_filename (abfd), (long) (y * 256 + z),
		       (curpos - stab_loc - 4)/4);
		    bfd_set_error (bfd_error_bad_value);
		    goto error_return;
		  }

		bfd_map_over_sections (abfd, mmo_map_set_sizes, NULL);
		goto done;
	      }
	    }
	}
      else
	{
	  /* This wasn't a lopcode, so store it in the current section.  */
	  mmo_xore_32 (sec, vma & ~3, bfd_get_32 (abfd, buf));
	  vma += 4;
	  vma &= ~3;
	  lineno++;
	}
    }

  /* We know this file is a multiple of four bytes (checked in
     mmo_object_p), so if we got something other than 0, this was a bad
     file (although it's more likely we'll get 0 in that case too).
     If we got end-of-file, then there was no lop_stab, so the file has
     invalid format.  */

  if (nbytes_read != 0)
    bfd_set_error (bfd_error_system_call);
  else
    bfd_set_error (bfd_error_bad_value);

 error_return:
  error = TRUE;
 done:
  /* Mark the .text and .data section with their normal attribute if they
     contain anything.  This is not redundant wrt. mmo_decide_section,
     since that code might never execute, and conversely the alloc+code
     section flags must be set then.  */
  sec = bfd_get_section_by_name (abfd, MMO_TEXT_SECTION_NAME);
  if (sec != NULL
      && (bfd_get_section_flags (abfd, sec) & SEC_HAS_CONTENTS)
      && ! bfd_set_section_flags (abfd, sec,
				  bfd_get_section_flags (abfd, sec)
				  | SEC_ALLOC | SEC_LOAD | SEC_CODE))
    error = TRUE;

  sec = bfd_get_section_by_name (abfd, MMO_DATA_SECTION_NAME);
  if (sec != NULL
      && (bfd_get_section_flags (abfd, sec) & SEC_HAS_CONTENTS)
      && ! bfd_set_section_flags (abfd, sec,
				  bfd_get_section_flags (abfd, sec)
				  | SEC_ALLOC | SEC_LOAD))
    error = TRUE;

  /* Free whatever resources we took.  */
  for (i = 0; i < sizeof (file_names) / sizeof (file_names[0]); i++)
    if (file_names[i])
      free (file_names[i]);
  return ! error;
}

/* A hook to set up object file dependent section information.  For mmo,
   we point out the shape of allocated section contents.  */

static bfd_boolean
mmo_new_section_hook (abfd, newsect)
     bfd *abfd ATTRIBUTE_UNUSED;
     asection *newsect;
{
  /* We zero-fill all fields and assume NULL is represented by an all
     zero-bit pattern.  */
  newsect->used_by_bfd =
    (PTR) bfd_zalloc (abfd, sizeof (struct mmo_section_data_struct));

  if (!newsect->used_by_bfd)
    return FALSE;

  /* Always align to at least 32-bit words.  */
  newsect->alignment_power = 2;
  return TRUE;
}

/* We already have section contents loaded for sections that have
   contents.  */

static bfd_boolean
mmo_get_section_contents (abfd, sec, location, offset, bytes_to_do)
     bfd *abfd ATTRIBUTE_UNUSED;
     asection *sec ATTRIBUTE_UNUSED;
     PTR location ATTRIBUTE_UNUSED;
     file_ptr offset ATTRIBUTE_UNUSED;
     bfd_size_type bytes_to_do ATTRIBUTE_UNUSED;
{
  /* Iterate over diminishing chunk sizes, copying contents, like
     mmo_set_section_contents.  */
  while (bytes_to_do)
    {
      /* A minor song-and-dance to make sure we're not bitten by the
	 distant possibility of the cast from bfd_vma to int making the
	 chunk zero-sized.  */
      int chunk_size
	= (int) bytes_to_do != 0 ? bytes_to_do : MMO_SEC_CONTENTS_CHUNK_SIZE;
      bfd_byte *loc;

      do
	loc = mmo_get_loc (sec, sec->vma + offset, chunk_size);
      while (loc == NULL && (chunk_size /= 2) != 0);

      if (chunk_size == 0)
	return FALSE;

      memcpy (location, loc, chunk_size);

      location += chunk_size;
      bytes_to_do -= chunk_size;
      offset += chunk_size;
    }
  return TRUE;
}

/* Return the amount of memory needed to read the symbol table.  */

static long
mmo_get_symtab_upper_bound (abfd)
     bfd *abfd ATTRIBUTE_UNUSED;
{
  return (abfd->symcount + 1) * sizeof (asymbol *);
}

/* Sort mmo symbols by serial number.  */

static int
mmo_sort_mmo_symbols (arg1, arg2)
     const PTR arg1;
     const PTR arg2;
{
  const struct mmo_symbol *sym1 = *(const struct mmo_symbol **) arg1;
  const struct mmo_symbol *sym2 = *(const struct mmo_symbol **) arg2;

  /* Sort by serial number first.  */
  if (sym1->serno < sym2->serno)
    return -1;
  else if (sym1->serno > sym2->serno)
    return 1;

  /* Then sort by address of the table entries.  */
  return ((const char *) arg1 - (const char *) arg2);
}

/* Translate the symbol table.  */

static long
mmo_get_symtab (abfd, alocation)
     bfd *abfd;
     asymbol **alocation;
{
  unsigned int symcount = bfd_get_symcount (abfd);
  asymbol *csymbols;
  unsigned int i;

  csymbols = abfd->tdata.mmo_data->csymbols;
  if (csymbols == NULL)
    {
      asymbol *c;
      struct mmo_symbol *s;
      struct mmo_symbol **msp;

      /* First we store the symbols into the table we'll return, then we
	 qsort it on the serial number, with secondary on the address of
	 the symbol, to preserve order if there would be non-unique serial
	 numbers.  */
      for (s = abfd->tdata.mmo_data->symbols,
	     msp = (struct mmo_symbol **) alocation;
	   s != NULL;
	   s = s->next, ++msp)
	*msp = s;

      *msp = NULL;

      qsort (alocation, symcount, sizeof (struct mmo_symbol *),
	     mmo_sort_mmo_symbols);

      csymbols = (asymbol *) bfd_alloc (abfd, symcount * sizeof (asymbol));
      if (csymbols == NULL && symcount != 0)
	return FALSE;
      abfd->tdata.mmo_data->csymbols = csymbols;

      for (msp = (struct mmo_symbol **) alocation, c = csymbols;
	   *msp != NULL;
	   msp++, ++c)
	{
	  s = *msp;
	  c->the_bfd = abfd;
	  c->name = s->name;
	  c->value = s->value;
	  c->flags = BSF_GLOBAL;

	  if (s->sym_type == mmo_data_sym)
	    {
	      c->section
		= bfd_get_section_by_name (abfd, MMO_DATA_SECTION_NAME);

	      if (c->section == NULL)
		c->section = bfd_abs_section_ptr;
	      else
		c->value -= c->section->vma;
	    }
	  else if (s->sym_type == mmo_undef_sym)
	    c->section = bfd_und_section_ptr;
	  else if (s->sym_type == mmo_reg_sym)
	    {
	      c->section
		= bfd_make_section_old_way (abfd, MMIX_REG_SECTION_NAME);
	    }
	  else
	    {
	      asection *textsec
		= bfd_get_section_by_name (abfd, MMO_TEXT_SECTION_NAME);

	      if (textsec != NULL
		  && c->value >= textsec->vma
		  && c->value <= textsec->vma + textsec->_cooked_size)
		{
		  c->section = textsec;
		  c->value -= c->section->vma;
		}
	      else
		c->section = bfd_abs_section_ptr;
	    }

	  c->udata.p = NULL;
	}
    }

  /* Last, overwrite the incoming table with the right-type entries.  */
  for (i = 0; i < symcount; i++)
    *alocation++ = csymbols++;
  *alocation = NULL;

  return symcount;
}

/* Get information about a symbol.  */

static void
mmo_get_symbol_info (ignore_abfd, symbol, ret)
     bfd *ignore_abfd ATTRIBUTE_UNUSED;
     asymbol *symbol;
     symbol_info *ret;
{
  bfd_symbol_info (symbol, ret);
}

static void
mmo_print_symbol (abfd, afile, symbol, how)
     bfd *abfd;
     PTR afile;
     asymbol *symbol;
     bfd_print_symbol_type how;
{
  FILE *file = (FILE *) afile;

  switch (how)
    {
    case bfd_print_symbol_name:
      fprintf (file, "%s", symbol->name);
      break;
    default:
      bfd_print_symbol_vandf (abfd, (PTR) file, symbol);

      fprintf (file, " %-5s %s",
	       symbol->section->name,
	       symbol->name);
    }
}

/* We can't map a file directly into executable code, so the
   size of header information is irrelevant.  */

static int
mmo_sizeof_headers (abfd, exec)
     bfd *abfd ATTRIBUTE_UNUSED;
     bfd_boolean exec ATTRIBUTE_UNUSED;
{
  return 0;
}

/* Write the (section-neutral) file preamble.  */

static bfd_boolean
mmo_internal_write_header (abfd)
     bfd *abfd;
{
  const char lop_pre_bfd[] = { LOP, LOP_PRE, 1, 1};

  if (bfd_bwrite (lop_pre_bfd, 4, abfd) != 4)
    return FALSE;

  /* Copy creation time of original file.  */
  if (bfd_bwrite (abfd->tdata.mmo_data->created, 4, abfd) != 4)
    return FALSE;

  return TRUE;
}

/* Write the LOP_POST record, with global register initializations.
   Z is the Z field of the LOP_POST, corresponding to 255 - number of
   registers at DATA.  The Z = 255 field is filled in with the
   start-address.  */

static bfd_boolean
mmo_internal_write_post (abfd, z, sec)
     bfd *abfd;
     int z;
     asection *sec;
{
  int i;
  bfd_byte buf[8];
  mmo_write_tetra_raw (abfd, (LOP << 24) | (LOP_POST << 16) | z);

  for (i = z; i < 255; i++)
    {
      bfd_byte *data = mmo_get_loc (sec, i * 8, 8);

      if (bfd_bwrite (data, 8, abfd) != 8)
	return FALSE;
    }

  /* For Z == $255, we always emit the start location; supposedly Main,
     but we have it handy at bfd_get_start_address.  If we're called with
     Z == 255, don't assume DATA is valid.  */
  bfd_put_64 (abfd, bfd_get_start_address (abfd), buf);

  return ! abfd->tdata.mmo_data->have_error && bfd_bwrite (buf, 8, abfd) == 8;
}

/* Translate to and from BFD flags.  This is to make sure that we don't
   get bitten by BFD flag number changes.  */

static flagword
mmo_sec_flags_from_bfd_flags (flags)
     flagword flags;
{
  flagword oflags = 0;

  if (flags & SEC_ALLOC)
    oflags |= MMO_SEC_ALLOC;
  if (flags & SEC_LOAD)
    oflags |= MMO_SEC_LOAD;
  if (flags & SEC_RELOC)
    oflags |= MMO_SEC_RELOC;
  if (flags & SEC_READONLY)
    oflags |= MMO_SEC_READONLY;
  if (flags & SEC_CODE)
    oflags |= MMO_SEC_CODE;
  if (flags & SEC_DATA)
    oflags |= MMO_SEC_DATA;
  if (flags & SEC_NEVER_LOAD)
    oflags |= MMO_SEC_NEVER_LOAD;
  if (flags & SEC_IS_COMMON)
    oflags |= MMO_SEC_IS_COMMON;
  if (flags & SEC_DEBUGGING)
    oflags |= MMO_SEC_DEBUGGING;

  return oflags;
}

static flagword
bfd_sec_flags_from_mmo_flags (flags)
     flagword flags;
{
  flagword oflags = 0;

  if (flags & MMO_SEC_ALLOC)
    oflags |= SEC_ALLOC;
  if (flags & MMO_SEC_LOAD)
    oflags |= SEC_LOAD;
  if (flags & MMO_SEC_RELOC)
    oflags |= SEC_RELOC;
  if (flags & MMO_SEC_READONLY)
    oflags |= SEC_READONLY;
  if (flags & MMO_SEC_CODE)
    oflags |= SEC_CODE;
  if (flags & MMO_SEC_DATA)
    oflags |= SEC_DATA;
  if (flags & MMO_SEC_NEVER_LOAD)
    oflags |= SEC_NEVER_LOAD;
  if (flags & MMO_SEC_IS_COMMON)
    oflags |= SEC_IS_COMMON;
  if (flags & MMO_SEC_DEBUGGING)
    oflags |= SEC_DEBUGGING;

  return oflags;
}

/* Write a section.  */

static bfd_boolean
mmo_internal_write_section (abfd, sec)
     bfd *abfd;
     asection *sec;
{
  /* We do it differently depending on what section this is:

   ".text": Output, prepended by information about the first source file
   (not yet implemented.)

   ".data": Output.

   (".MMIX.reg_contents": Not handled here.)

   Anything else: Output inside a lop_spec 80, in the format described
   above.  */

  if (strcmp (sec->name, MMO_TEXT_SECTION_NAME) == 0)
    /* FIXME: Output source file name and line number.  */
    return mmo_write_loc_chunk_list (abfd, mmo_section_data (sec)->head);
  else if (strcmp (sec->name, MMO_DATA_SECTION_NAME) == 0)
    return mmo_write_loc_chunk_list (abfd, mmo_section_data (sec)->head);
  else if (strcmp (sec->name, MMIX_REG_CONTENTS_SECTION_NAME) == 0)
    /* Not handled here.  */
    {
      /* This would normally be an abort call since this can't happen, but
         we don't do that.  */
      bfd_set_error (bfd_error_bad_value);
      return FALSE;
    }
  else if (strncmp (sec->name, MMIX_OTHER_SPEC_SECTION_PREFIX,
		    strlen (MMIX_OTHER_SPEC_SECTION_PREFIX)) == 0)
    {
      int n = atoi (sec->name + strlen (MMIX_OTHER_SPEC_SECTION_PREFIX));
      mmo_write_tetra_raw (abfd, (LOP << 24) | (LOP_SPEC << 16) | n);
      return (! abfd->tdata.mmo_data->have_error
	      && mmo_write_chunk_list (abfd, mmo_section_data (sec)->head));
    }
  /* Ignore sections that are just allocated or empty; we write out
     _contents_ here.  */
  else if ((bfd_get_section_flags (abfd, sec) & SEC_HAS_CONTENTS) != 0
	   && sec->_raw_size != 0)
    {
      /* Keep the document-comment formatted the way it is.  */
/*
INODE
mmo section mapping, , Symbol-table, mmo
SUBSECTION
	mmo section mapping

	The implementation in BFD uses special data type 80 (decimal) to
	encapsulate and describe named sections, containing e.g.@: debug
	information.  If needed, any datum in the encapsulation will be
	quoted using lop_quote.  First comes a 32-bit word holding the
	number of 32-bit words containing the zero-terminated zero-padded
	segment name.  After the name there's a 32-bit word holding flags
	describing the section type.  Then comes a 64-bit big-endian word
	with the section length (in bytes), then another with the section
	start address.  Depending on the type of section, the contents
	might follow, zero-padded to 32-bit boundary.  For a loadable
	section (such as data or code), the contents might follow at some
	later point, not necessarily immediately, as a lop_loc with the
	same start address as in the section description, followed by the
	contents.  This in effect forms a descriptor that must be emitted
	before the actual contents.  Sections described this way must not
	overlap.

	For areas that don't have such descriptors, synthetic sections are
	formed by BFD.  Consecutive contents in the two memory areas
	@samp{0x0000@dots{}00} to @samp{0x01ff@dots{}ff} and
	@samp{0x2000@dots{}00} to @samp{0x20ff@dots{}ff} are entered in
	sections named <<.text>> and <<.data>> respectively.  If an area
	is not otherwise described, but would together with a neighboring
	lower area be less than @samp{0x40000000} bytes long, it is joined
	with the lower area and the gap is zero-filled.  For other cases,
	a new section is formed, named <<.MMIX.sec.@var{n}>>.  Here,
	@var{n} is a number, a running count through the mmo file,
	starting at 0.

EXAMPLE
	A loadable section specified as:

| .section secname,"ax"
| TETRA 1,2,3,4,-1,-2009
| BYTE 80

	and linked to address @samp{0x4}, is represented by the sequence:

| 0x98080050 - lop_spec 80
| 0x00000002 - two 32-bit words for the section name
| 0x7365636e - "secn"
| 0x616d6500 - "ame\0"
| 0x00000033 - flags CODE, READONLY, LOAD, ALLOC
| 0x00000000 - high 32 bits of section length
| 0x0000001c - section length is 28 bytes; 6 * 4 + 1 + alignment to 32 bits
| 0x00000000 - high 32 bits of section address
| 0x00000004 - section address is 4
| 0x98010002 - 64 bits with address of following data
| 0x00000000 - high 32 bits of address
| 0x00000004 - low 32 bits: data starts at address 4
| 0x00000001 - 1
| 0x00000002 - 2
| 0x00000003 - 3
| 0x00000004 - 4
| 0xffffffff - -1
| 0xfffff827 - -2009
| 0x50000000 - 80 as a byte, padded with zeros.

	Note that the lop_spec wrapping does not include the section
	contents.  Compare this to a non-loaded section specified as:

| .section thirdsec
| TETRA 200001,100002
| BYTE 38,40

	This, when linked to address @samp{0x200000000000001c}, is
	represented by:

| 0x98080050 - lop_spec 80
| 0x00000002 - two 32-bit words for the section name
| 0x7365636e - "thir"
| 0x616d6500 - "dsec"
| 0x00000010 - flag READONLY
| 0x00000000 - high 32 bits of section length
| 0x0000000c - section length is 12 bytes; 2 * 4 + 2 + alignment to 32 bits
| 0x20000000 - high 32 bits of address
| 0x0000001c - low 32 bits of address 0x200000000000001c
| 0x00030d41 - 200001
| 0x000186a2 - 100002
| 0x26280000 - 38, 40 as bytes, padded with zeros

	For the latter example, the section contents must not be
	loaded in memory, and is therefore specified as part of the
	special data.  The address is usually unimportant but might
	provide information for e.g.@: the DWARF 2 debugging format.  */

      mmo_write_tetra_raw (abfd, LOP_SPEC_SECTION);
      mmo_write_tetra (abfd, (strlen (sec->name) + 3) / 4);
      mmo_write_chunk (abfd, sec->name, strlen (sec->name));
      mmo_flush_chunk (abfd);
      /* FIXME: We can get debug sections (.debug_line & Co.) with a
	 section flag still having SEC_RELOC set.  Investigate.  This
	 might be true for all alien sections; perhaps mmo.em should clear
	 that flag.  Might be related to weak references.  */
      mmo_write_tetra (abfd,
		       mmo_sec_flags_from_bfd_flags
		       (bfd_get_section_flags (abfd, sec)));
      mmo_write_octa (abfd, sec->_raw_size);
      mmo_write_octa (abfd, bfd_get_section_vma (abfd, sec));

      /* Writing a LOP_LOC ends the LOP_SPEC data, and makes data actually
	 loaded.  */
      if (bfd_get_section_flags (abfd, sec) & SEC_LOAD)
	return (! abfd->tdata.mmo_data->have_error
		&& mmo_write_loc_chunk_list (abfd,
					     mmo_section_data (sec)->head));
      return (! abfd->tdata.mmo_data->have_error
	      && mmo_write_chunk_list (abfd, mmo_section_data (sec)->head));
    }
  return TRUE;
}

/* We save up all data before output.  */

static bfd_boolean
mmo_set_section_contents (abfd, sec, location, offset, bytes_to_do)
     bfd *abfd ATTRIBUTE_UNUSED;
     sec_ptr sec;
     PTR location;
     file_ptr offset;
     bfd_size_type bytes_to_do;
{
  /* Iterate over diminishing chunk sizes, copying contents.  */
  while (bytes_to_do)
    {
      /* A minor song-and-dance to make sure we're not bitten by the
	 distant possibility of the cast from bfd_vma to int making the
	 chunk zero-sized.  */
      int chunk_size
	= (int) bytes_to_do != 0 ? bytes_to_do : MMO_SEC_CONTENTS_CHUNK_SIZE;
      bfd_byte *loc;

      do
	loc = mmo_get_loc (sec, sec->vma + offset, chunk_size);
      while (loc == NULL && (chunk_size /= 2) != 0);

      if (chunk_size == 0)
	return FALSE;

      memcpy (loc, location, chunk_size);

      location += chunk_size;
      bytes_to_do -= chunk_size;
      offset += chunk_size;
    }
  return TRUE;
}

/* Add a symbol to a trie-tree.  */

static bfd_boolean
mmo_internal_add_3_sym (abfd, rootp, symp)
     bfd *abfd;
     struct mmo_symbol_trie *rootp;
     const struct mmo_symbol *symp;
{
  const char *name = symp->name;
  struct mmo_symbol_trie *trie = rootp;
  struct mmo_symbol_trie **triep = NULL;

  while (*name && trie != NULL)
    {
      if (*name < trie->symchar)
	{
	  triep = &trie->left;
	  trie = trie->left;
	}
      else if (*name > trie->symchar)
	{
	  triep = &trie->right;
	  trie = trie->right;
	}
      else if (*name == trie->symchar)
	{
	  triep = &trie->middle;
	  name++;

	  /* Make sure "trie" points to where we should fill in the
	     current symbol whenever we've iterated through "name".  We
	     would lose the right position if we encounter "foobar" then
	     "foo".  */
	  if (*name)
	    trie = trie->middle;
	}
    }

  while (*name != 0)
    {
      /* Create middle branches for the rest of the characters.  */
      trie = bfd_zalloc (abfd, sizeof (struct mmo_symbol_trie));
      *triep = trie;
      trie->symchar = *name++;
      triep = &trie->middle;
    }

  /* We discover a duplicate symbol rather late in the process, but still;
     we discover it and bail out.  */
  if (trie->sym.name != NULL)
    {
      (*_bfd_error_handler)
	(_("%s: invalid symbol table: duplicate symbol `%s'\n"),
	 bfd_get_filename (abfd), trie->sym.name);
      bfd_set_error (bfd_error_bad_value);
      return FALSE;
    }

  memcpy (&trie->sym, symp, sizeof *symp);
  return TRUE;
}

/* Find out the length of the serialized version of a trie in bytes.  */

static unsigned int
mmo_internal_3_length (abfd, trie)
     bfd *abfd;
     struct mmo_symbol_trie *trie;
{
  /* First, one for the control byte.  */
  unsigned int length = 1;

  if (trie == NULL)
    return 0;

  /* Add in the recursion to the left.  */
  length += mmo_internal_3_length (abfd, trie->left);

  /* Add in the middle trie and the character.  */
  length += 1 + mmo_internal_3_length (abfd, trie->middle);

  /* Add in the recursion to the right.  */
  length += mmo_internal_3_length (abfd, trie->right);

  /* Add in bytes for the symbol (if this is an endnode). */
  if (trie->sym.name != NULL)
    {
      unsigned int serno = trie->sym.serno;

      /* First what it takes to encode the value. */
      if (trie->sym.sym_type == mmo_reg_sym)
	length++;
      else if (trie->sym.sym_type == mmo_undef_sym)
	length += 2;
      else
	{
	  bfd_vma value = trie->sym.value;

	  /* Coded in one to eight following bytes.  */
	  if (trie->sym.sym_type == mmo_data_sym)
	    value -= (bfd_vma) 0x20 << 56;

	  do
	    {
	      value >>= 8;
	      length++;
	    }
	  while (value != 0);
	}

      /* Find out what it takes to encode the serial number.  */
      do
	{
	  serno >>= 7;
	  length++;
	}
      while (serno != 0);
    }

  return length;
}

/* Helper function for outputting the serial number of a symbol, output as
   a variant of leb128 (see dwarf2 documentation) which could be called
   beb128.  Using a helper function and recursion simplifies debugging.  */

static void
mmo_beb128_out (abfd, serno, marker)
     bfd *abfd;
     int serno;
     int marker;
{
  if (serno & ~0x7f)
    mmo_beb128_out (abfd, serno >> 7, 0);
  mmo_write_byte (abfd, marker | (serno & 0x7f));
}

/* Serialize a trie.  */

static void
mmo_internal_3_dump (abfd, trie)
     bfd *abfd;
     struct mmo_symbol_trie *trie;
{
  bfd_byte control = 0;

  if (trie == NULL)
    return;

  if (trie->left)
    control |= MMO3_LEFT;

  if (trie->middle)
    control |= MMO3_MIDDLE;

  if (trie->right)
    control |= MMO3_RIGHT;

  if (trie->sym.name != NULL)
    {
      /* Encode the symbol type and length of value bytes.  */
      if (trie->sym.sym_type == mmo_reg_sym)
	control |= MMO3_REGQUAL_BITS;
      else if (trie->sym.sym_type == mmo_undef_sym)
	control |= MMO3_UNDEF;
      else
	{
	  bfd_vma value = trie->sym.value;

	  /* Coded in 1..8 following bytes.  */
	  if (trie->sym.sym_type == mmo_data_sym)
	    {
	      control |= MMO3_DATA;
	      value -= (bfd_vma) 0x20 << 56;
	    }

	  do
	    {
	      value >>= 8;
	      control++;
	    }
	  while (value != 0);
	}
    }

  /* The control byte is output before recursing.  */
  mmo_write_byte (abfd, control);

  mmo_internal_3_dump (abfd, trie->left);

  if (control & MMO3_SYMBITS)
    {
      mmo_write_byte (abfd, trie->symchar);

      if (trie->sym.name != NULL)
	{
	  if (trie->sym.sym_type == mmo_reg_sym)
	    mmo_write_byte (abfd, trie->sym.value);
	  else if (trie->sym.sym_type == mmo_undef_sym)
	    {
	      mmo_write_byte (abfd, 0);
	      mmo_write_byte (abfd, 0);
	    }
	  else
	    {
	      bfd_vma value = trie->sym.value;

	      bfd_byte byte_n = control & 15;

	      /* Coded in 1..8 following bytes.  Note that the value is
		 shifted out big-endian.  */
	      if (trie->sym.sym_type == mmo_data_sym)
		{
		  value -= (bfd_vma) 0x20 << 56;
		  byte_n -= 8;
		}

	      do
		{
		  mmo_write_byte (abfd, (value >> ((byte_n - 1) * 8)) & 0xff);
		  byte_n--;
		}
	      while (byte_n != 0);
	    }

	  mmo_beb128_out (abfd, trie->sym.serno, 128);
	}
      mmo_internal_3_dump (abfd, trie->middle);
    }
  mmo_internal_3_dump (abfd, trie->right);
}

/* Write symbols in mmo format.  Also write the lop_end terminator.  */

static bfd_boolean
mmo_write_symbols_and_terminator (abfd)
     bfd *abfd;
{
  int count = bfd_get_symcount (abfd);
  asymbol *maintable[2];
  asymbol **table;
  asymbol **orig_table = bfd_get_outsymbols (abfd);
  int serno;
  struct mmo_symbol_trie root;
  int trie_len;
  int i;
  bfd_byte buf[4];

  /* Create a symbol for "Main".  */
  asymbol *fakemain = bfd_make_empty_symbol (abfd);

  fakemain->flags = BSF_GLOBAL;
  fakemain->value = bfd_get_start_address (abfd);
  fakemain->name = MMIX_START_SYMBOL_NAME;
  fakemain->section = bfd_abs_section_ptr;
  maintable[0] = fakemain;
  maintable[1] = NULL;

  memset (&root, 0, sizeof (root));

  /* Make all symbols take a left turn.  */
  root.symchar = 0xff;

  /* There must always be a ":Main", so we'll add one if there are no
     symbols.  Make sure we have room for it.  */
  table = bfd_alloc (abfd, (count + 1) * sizeof (asymbol *));
  if (table == NULL)
    return FALSE;

  memcpy (table, orig_table, count * sizeof (asymbol *));

  /* Move :Main (if there is one) to the first position.  This is
     necessary to get the same layout of the trie-tree when linking as
     when objcopying the result as in the objcopy.exp test "simple objcopy
     of executable".  It also automatically takes care of assigning serial
     number 1 to :Main (as is mandatory).  */
  for (i = 0; i < count; i++)
    if (table[i] != NULL
	&& strcmp (table[i]->name, MMIX_START_SYMBOL_NAME) == 0
	&& (table[i]->flags & (BSF_DEBUGGING|BSF_GLOBAL)) == BSF_GLOBAL)
      {
	asymbol *mainsym = table[i];
	memcpy (table + 1, orig_table, i * sizeof (asymbol *));
	table[0] = mainsym;

	/* Check that the value assigned to :Main is the same as the entry
	   address.  The default linker script asserts this.  This is as
	   good a place as any to check this consistency. */
	if ((mainsym->value
	     + mainsym->section->output_section->vma
	     + mainsym->section->output_offset)
	    != bfd_get_start_address (abfd))
	  {
	    /* Arbitrary buffer to hold the printable representation of a
	       vma.  */
	    char vmas_main[40];
	    char vmas_start[40];
	    bfd_vma vma_start = bfd_get_start_address (abfd);

	    sprintf_vma (vmas_main, mainsym->value);
	    sprintf_vma (vmas_start, vma_start);

	    (*_bfd_error_handler)
	      (_("%s: Bad symbol definition: `Main' set to %s rather\
 than the start address %s\n"),
	       bfd_get_filename (abfd), vmas_main, vmas_start);
	    bfd_set_error (bfd_error_bad_value);
	    return FALSE;
	  }
	break;
      }
  if (i == count && count != 0)
    {
      /* When there are symbols, there must be a :Main.  There was no
	 :Main, so we need to add it manually.  */
      memcpy (table + 1, orig_table, count * sizeof (asymbol *));
      table[0] = fakemain;
      count++;
    }

  for (i = 0, serno = 1; i < count && table[i] != NULL; i++)
    {
      asymbol *s = table[i];

      /* It's not enough to consult bfd_is_local_label, since it does not
	 mean "local" in the sense of linkable-and-observable-after-link.
	 Let's just check the BSF_GLOBAL flag.

	 Also, don't export symbols with characters not in the allowed set.  */
      if ((s->flags & (BSF_DEBUGGING|BSF_GLOBAL)) == BSF_GLOBAL
	  && strspn (s->name,
		     valid_mmo_symbol_character_set) == strlen (s->name))
	{
	  struct mmo_symbol sym;
	  memset (&sym, 0, sizeof (sym));

	  sym.name = s->name;
	  sym.value =
	    s->value
	    + s->section->output_section->vma
	    + s->section->output_offset;

	  if (bfd_is_und_section (s->section))
	    sym.sym_type = mmo_undef_sym;
	  else if (strcmp (s->section->name, MMO_DATA_SECTION_NAME) == 0
		   /* The encoding of data symbols require that the "rest"
		      of the value fits in 6 bytes, so the upper two bytes
		      must be 0x2000.  All other symbols get to be the
		      absolute type.  */
		   && (sym.value >> 48) == 0x2000)
	    sym.sym_type = mmo_data_sym;
	  else if (strcmp (s->section->name, MMIX_REG_SECTION_NAME) == 0)
	    sym.sym_type = mmo_reg_sym;
	  else if (strcmp (s->section->name,
			   MMIX_REG_CONTENTS_SECTION_NAME) == 0)
	    {
	      sym.sym_type = mmo_reg_sym;
	      sym.value /= 8;
	    }
	  else
	    sym.sym_type = mmo_abs_sym;

	  /* FIXME: We assume the order of the received symbols is an
	     ordered mapping of the serial numbers.  This is not
	     necessarily true if we e.g. objcopy a mmo file to another and
	     there are gaps in the numbering.  Not sure if this can
	     happen.  Not sure what to do.  */
	  sym.serno = serno++;

	  if (! mmo_internal_add_3_sym (abfd, &root, &sym))
	    return FALSE;
	}
    }

  /* Change the root node to be a ":"-prefix.  */
  root.symchar = ':';
  root.middle = root.left;
  root.right = NULL;
  root.left = NULL;

  /* We have to find out if we can fit the whole symbol table in the mmo
     symtab.  It would be bad to assume we can always fit it in 262144
     bytes.  If we can't, just leave the Main symbol.  */
  trie_len = (mmo_internal_3_length (abfd, &root) + 3)/4;

  if (trie_len > 0xffff)
    {
      /* Test this code by using a lower limit in the test above and check
	 that the single "Main" symbol is emitted and handled properly.
	 There's no specific test-case.  */
      struct mmo_symbol sym;

      (*_bfd_error_handler)
	(_("%s: warning: symbol table too large for mmo, larger than 65535\
 32-bit words: %d.  Only `Main' will be emitted.\n"),
	 bfd_get_filename (abfd), trie_len);

      memset (&sym, 0, sizeof (sym));
      sym.sym_type = mmo_abs_sym;
      sym.name = MMIX_START_SYMBOL_NAME;
      sym.serno = 1;
      sym.value = bfd_get_start_address (abfd);

      /* Then patch up a symbol table to be just the ":Main" symbol.  */
      memset (&root, 0, sizeof (root));
      root.left = root.middle;
      root.symchar = 0xff;
      root.middle = NULL;
      root.right = NULL;

      if (! mmo_internal_add_3_sym (abfd, &root, &sym))
	return FALSE;

      root.symchar = ':';
      root.middle = root.left;
      root.right = NULL;
      root.left = NULL;

      trie_len = (mmo_internal_3_length (abfd, &root) + 3)/4;
    }

  /* Reset the written-bytes counter.  */
  abfd->tdata.mmo_data->byte_no = 0;

  /* Put out the lop_stab mark.  */
  bfd_put_32 (abfd, (LOP << 24) | (LOP_STAB << 16), buf);
  if (bfd_bwrite (buf, 4, abfd) != 4)
    return FALSE;

  /* Dump out symbols.  */
  mmo_internal_3_dump (abfd, &root);

  if (trie_len != (abfd->tdata.mmo_data->byte_no + 3)/4)
    {
      /* I haven't seen this trig.  It seems no use claiming this case
	 isn't debugged and abort if we get here.  Instead emit a
	 diagnostic and fail "normally".  */
      (*_bfd_error_handler)
	(_("%s: internal error, symbol table changed size from %d to %d\
 words\n"),
	 bfd_get_filename (abfd), trie_len,
	 (abfd->tdata.mmo_data->byte_no + 3)/4);
      bfd_set_error (bfd_error_bad_value);
      return FALSE;
    }

  /* Dump out remaining bytes in the buffer and handle I/O errors by
     propagating errors.  */
  if ((abfd->tdata.mmo_data->byte_no % 4) != 0
      || abfd->tdata.mmo_data->have_error)
    {
      memset (abfd->tdata.mmo_data->buf + (abfd->tdata.mmo_data->byte_no % 4),
	      0, 4 - (abfd->tdata.mmo_data->byte_no % 4));

      if (abfd->tdata.mmo_data->have_error
	  || bfd_bwrite (abfd->tdata.mmo_data->buf, 4, abfd) != 4)
	return FALSE;
    }

  bfd_put_32 (abfd, (LOP << 24) | (LOP_END << 16) | trie_len, buf);
  return bfd_bwrite (buf, 4, abfd) == 4;
}

/* Write section unless it is the register contents section.  For that, we
   instead store the section in the supplied pointer.  This function is
   used through bfd_map_over_sections.  */

static void
mmo_write_section_unless_reg_contents (abfd, sec, p)
     bfd *abfd;
     asection *sec;
     PTR p;
{
  struct mmo_write_sec_info *infop = (struct mmo_write_sec_info *) p;

  if (! infop->retval)
    return;

  if (strcmp (sec->name, MMIX_REG_CONTENTS_SECTION_NAME) == 0)
    {
      infop->reg_section = sec;
      return;
    }

  /* Exclude the convenience register section.  */
  if (strcmp (sec->name, MMIX_REG_SECTION_NAME) == 0)
    {
      if (bfd_get_section_flags (abfd, sec) & SEC_HAS_CONTENTS)
	{
	  /* Make sure it hasn't got contents.  It seems impossible to
	     make it carry contents, so we don't have a test-case for
	     this.  */
	  (*_bfd_error_handler)
	    (_("%s: internal error, internal register section %s had\
 contents\n"),
	     bfd_get_filename (abfd), sec->name);
	  bfd_set_error (bfd_error_bad_value);
	  infop->retval = FALSE;
	  return;
	}

      return;
    }

  infop->retval = mmo_internal_write_section (abfd, sec);
}

/* Do the actual output of a file.  Assumes mmo_set_section_contents is
   already called. */

static bfd_boolean
mmo_write_object_contents (abfd)
     bfd *abfd;
{
  struct mmo_write_sec_info wsecinfo;

  /* First, there are a few words of preamble.  */
  if (! mmo_internal_write_header (abfd))
    return FALSE;

  wsecinfo.reg_section = NULL;
  wsecinfo.retval = TRUE;

  bfd_map_over_sections (abfd, mmo_write_section_unless_reg_contents,
			 (PTR) &wsecinfo);

  if (! wsecinfo.retval)
    return FALSE;

  if (wsecinfo.reg_section != NULL)
    {
      asection *sec = wsecinfo.reg_section;
      unsigned int z = (unsigned int) (sec->vma / 8);

      /* Registers 0..31 must not be global.  Do sanity check on the "vma"
	 of the register contents section and check that it corresponds to
	 the length of the section.  */
      if (z < 32 || z >= 255 || (sec->vma & 7) != 0
	  || sec->vma != 256 * 8 - sec->_raw_size - 8)
	{
	  bfd_set_error (bfd_error_bad_value);

	  if (sec->_raw_size == 0)
	    /* There must always be at least one such register.  */
	    (*_bfd_error_handler)
	      (_("%s: no initialized registers; section length 0\n"),
	       bfd_get_filename (abfd));
	  else if (sec->vma > (256 - 32) * 8)
	    /* Provide better error message for the case of too many
	       global registers.  */
	    (*_bfd_error_handler)
	      (_("%s: too many initialized registers; section length %ld\n"),
	       bfd_get_filename (abfd),
	       (long) sec->_raw_size);
	  else
	    (*_bfd_error_handler)
	      (_("%s: invalid start address for initialized registers of\
 length %ld: 0x%lx%08lx\n"),
	       bfd_get_filename (abfd),
	       (long) sec->_raw_size,
	       (unsigned long) (sec->vma >> 32), (unsigned long) (sec->vma));

	  return FALSE;
	}

      if (! mmo_internal_write_post (abfd, z, sec))
	return FALSE;
    }
  else
    if (! mmo_internal_write_post (abfd, 255, NULL))
      return FALSE;

  return mmo_write_symbols_and_terminator (abfd);
}

/* Return the size of a NULL pointer, so we support linking in an mmo
   object.  */

static long
mmo_get_reloc_upper_bound (abfd, sec)
     bfd *abfd ATTRIBUTE_UNUSED;
     asection *sec ATTRIBUTE_UNUSED;
{
  return sizeof (PTR);
}

/* Similarly canonicalize relocs to empty, filling in the terminating NULL
   pointer.  */

long
mmo_canonicalize_reloc (abfd, section, relptr, symbols)
     bfd *abfd ATTRIBUTE_UNUSED;
     sec_ptr section ATTRIBUTE_UNUSED;
     arelent **relptr;
     asymbol **symbols ATTRIBUTE_UNUSED;
{
  *relptr = NULL;
  return 0;
}

/* If there's anything in particular in a mmo bfd that we want to free,
   make this a real function.  Only do this if you see major memory
   thrashing; zealous free:ing will cause unwanted behavior, especially if
   you "free" memory allocated with "bfd_alloc", or even "bfd_release" a
   block allocated with "bfd_alloc"; they're really allocated from an
   obstack, and we don't know what was allocated there since this
   particular allocation.  */

#define	mmo_close_and_cleanup _bfd_generic_close_and_cleanup
#define mmo_bfd_free_cached_info _bfd_generic_bfd_free_cached_info

/* Perhaps we need to adjust this one; mmo labels (originally) without a
   leading ':' might more appropriately be called local.  */
#define mmo_bfd_is_local_label_name bfd_generic_is_local_label_name

/* Is this one really used or defined by anyone?  */
#define mmo_get_lineno _bfd_nosymbols_get_lineno

/* FIXME: We can do better on this one, if we have a dwarf2 .debug_line
   section or if MMO line numbers are implemented.  */
#define mmo_find_nearest_line _bfd_nosymbols_find_nearest_line
#define mmo_make_empty_symbol _bfd_generic_make_empty_symbol
#define mmo_bfd_make_debug_symbol _bfd_nosymbols_bfd_make_debug_symbol
#define mmo_read_minisymbols _bfd_generic_read_minisymbols
#define mmo_minisymbol_to_symbol _bfd_generic_minisymbol_to_symbol

#define mmo_get_section_contents_in_window \
  _bfd_generic_get_section_contents_in_window
#define mmo_bfd_get_relocated_section_contents \
  bfd_generic_get_relocated_section_contents
#define mmo_bfd_gc_sections bfd_generic_gc_sections
#define mmo_bfd_link_hash_table_create _bfd_generic_link_hash_table_create
#define mmo_bfd_link_hash_table_free _bfd_generic_link_hash_table_free
#define mmo_bfd_link_add_symbols _bfd_generic_link_add_symbols
#define mmo_bfd_link_just_syms _bfd_generic_link_just_syms
#define mmo_bfd_final_link _bfd_generic_final_link
#define mmo_bfd_link_split_section _bfd_generic_link_split_section

/* Strictly speaking, only MMIX uses this restricted format, but let's not
   stop anybody from shooting themselves in the foot.  */
#define mmo_set_arch_mach bfd_default_set_arch_mach
#define mmo_bfd_relax_section bfd_generic_relax_section
#define mmo_bfd_merge_sections bfd_generic_merge_sections
#define mmo_bfd_discard_group bfd_generic_discard_group

/* objcopy will be upset if we return -1 from bfd_get_reloc_upper_bound by
   using BFD_JUMP_TABLE_RELOCS (_bfd_norelocs) rather than 0.  FIXME: Most
   likely a bug in the _bfd_norelocs definition.

   On the other hand, we smuggle in an mmo object (because setting up ELF
   is too cumbersome) when linking (from other formats, presumably ELF) to
   represent the g255 entry.  We need to link that object, so need to say
   it has no relocs.  Upper bound for the size of the relocation table is
   the size of a NULL pointer, and we support "canonicalization" for that
   pointer.  */
#define mmo_bfd_reloc_type_lookup _bfd_norelocs_bfd_reloc_type_lookup

/* We want to copy time of creation, otherwise we'd use
   BFD_JUMP_TABLE_COPY (_bfd_generic).  */
#define mmo_bfd_merge_private_bfd_data _bfd_generic_bfd_merge_private_bfd_data
#define mmo_bfd_copy_private_section_data _bfd_generic_bfd_copy_private_section_data
#define mmo_bfd_copy_private_symbol_data _bfd_generic_bfd_copy_private_symbol_data
#define mmo_bfd_set_private_flags _bfd_generic_bfd_set_private_flags
#define mmo_bfd_print_private_bfd_data _bfd_generic_bfd_print_private_bfd_data

const bfd_target bfd_mmo_vec =
{
  "mmo",			/* name */
  bfd_target_mmo_flavour,
  BFD_ENDIAN_BIG,		/* target byte order */
  BFD_ENDIAN_BIG,		/* target headers byte order */

  /* FIXME: Might need adjustments.  */
  (HAS_RELOC | EXEC_P |		/* object flags */
   HAS_LINENO | HAS_DEBUG |
   HAS_SYMS | HAS_LOCALS | WP_TEXT),

  /* FIXME: Might need adjustments.  */
  (SEC_CODE | SEC_DATA | SEC_HAS_CONTENTS | SEC_ALLOC | SEC_LOAD
   | SEC_READONLY | SEC_EXCLUDE | SEC_DEBUGGING | SEC_IN_MEMORY),
				/* section flags */
  0,				/* leading underscore */
  ' ',				/* ar_pad_char */
  16,				/* ar_max_namelen */
  bfd_getb64, bfd_getb_signed_64, bfd_putb64,
  bfd_getb32, bfd_getb_signed_32, bfd_putb32,
  bfd_getb16, bfd_getb_signed_16, bfd_putb16,	/* data */
  bfd_getb64, bfd_getb_signed_64, bfd_putb64,
  bfd_getb32, bfd_getb_signed_32, bfd_putb32,
  bfd_getb16, bfd_getb_signed_16, bfd_putb16,	/* hdrs */

  {
    _bfd_dummy_target,
    mmo_object_p,		/* bfd_check_format */
    _bfd_dummy_target,
    _bfd_dummy_target,
  },
  {
    bfd_false,
    mmo_mkobject,
    bfd_false,
    bfd_false,
  },
  {				/* bfd_write_contents */
    bfd_false,
    mmo_write_object_contents,
    bfd_false,
    bfd_false,
  },

  BFD_JUMP_TABLE_GENERIC (mmo),
  BFD_JUMP_TABLE_COPY (mmo),
  BFD_JUMP_TABLE_CORE (_bfd_nocore),
  BFD_JUMP_TABLE_ARCHIVE (_bfd_noarchive),
  BFD_JUMP_TABLE_SYMBOLS (mmo),
  /* We have to provide a valid method for getting relocs, returning zero,
     so we can't say BFD_JUMP_TABLE_RELOCS (_bfd_norelocs).  */
  BFD_JUMP_TABLE_RELOCS (mmo),
  BFD_JUMP_TABLE_WRITE (mmo),
  BFD_JUMP_TABLE_LINK (mmo),
  BFD_JUMP_TABLE_DYNAMIC (_bfd_nodynamic),

  NULL,

  NULL
};