wasmtime_environ/fact/trampoline.rs
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
//! Low-level compilation of an fused adapter function.
//!
//! This module is tasked with the top-level `compile` function which creates a
//! single WebAssembly function which will perform the steps of the fused
//! adapter for an `AdapterData` provided. This is the "meat" of compilation
//! where the validation of the canonical ABI or similar all happens to
//! translate arguments from one module to another.
//!
//! ## Traps and their ordering
//!
//! Currently this compiler is pretty "loose" about the ordering of precisely
//! what trap happens where. The main reason for this is that to core wasm all
//! traps are the same and for fused adapters if a trap happens no intermediate
//! side effects are visible (as designed by the canonical ABI itself). For this
//! it's important to note that some of the precise choices of control flow here
//! can be somewhat arbitrary, an intentional decision.
use crate::component::{
CanonicalAbiInfo, ComponentTypesBuilder, FixedEncoding as FE, FlatType, InterfaceType,
StringEncoding, Transcode, TypeEnumIndex, TypeFlagsIndex, TypeListIndex, TypeOptionIndex,
TypeRecordIndex, TypeResourceTableIndex, TypeResultIndex, TypeTupleIndex, TypeVariantIndex,
VariantInfo, FLAG_MAY_ENTER, FLAG_MAY_LEAVE, MAX_FLAT_PARAMS, MAX_FLAT_RESULTS,
};
use crate::fact::signature::Signature;
use crate::fact::transcode::Transcoder;
use crate::fact::traps::Trap;
use crate::fact::{
AdapterData, Body, Context, Function, FunctionId, Helper, HelperLocation, HelperType, Module,
Options,
};
use crate::prelude::*;
use crate::{FuncIndex, GlobalIndex};
use std::collections::HashMap;
use std::mem;
use std::ops::Range;
use wasm_encoder::{BlockType, Encode, Instruction, Instruction::*, MemArg, ValType};
use wasmtime_component_util::{DiscriminantSize, FlagsSize};
const MAX_STRING_BYTE_LENGTH: u32 = 1 << 31;
const UTF16_TAG: u32 = 1 << 31;
/// This value is arbitrarily chosen and should be fine to change at any time,
/// it just seemed like a halfway reasonable starting point.
const INITIAL_FUEL: usize = 1_000;
struct Compiler<'a, 'b> {
types: &'a ComponentTypesBuilder,
module: &'b mut Module<'a>,
result: FunctionId,
/// The encoded WebAssembly function body so far, not including locals.
code: Vec<u8>,
/// Total number of locals generated so far.
nlocals: u32,
/// Locals partitioned by type which are not currently in use.
free_locals: HashMap<ValType, Vec<u32>>,
/// Metadata about all `unreachable` trap instructions in this function and
/// what the trap represents. The offset within `self.code` is recorded as
/// well.
traps: Vec<(usize, Trap)>,
/// A heuristic which is intended to limit the size of a generated function
/// to a certain maximum to avoid generating arbitrarily large functions.
///
/// This fuel counter is decremented each time `translate` is called and
/// when fuel is entirely consumed further translations, if necessary, will
/// be done through calls to other functions in the module. This is intended
/// to be a heuristic to split up the main function into theoretically
/// reusable portions.
fuel: usize,
/// Indicates whether an "enter call" should be emitted in the generated
/// function with a call to `Resource{Enter,Exit}Call` at the beginning and
/// end of the function for tracking of information related to borrowed
/// resources.
emit_resource_call: bool,
}
pub(super) fn compile(module: &mut Module<'_>, adapter: &AdapterData) {
let lower_sig = module.types.signature(&adapter.lower, Context::Lower);
let lift_sig = module.types.signature(&adapter.lift, Context::Lift);
let ty = module
.core_types
.function(&lower_sig.params, &lower_sig.results);
let result = module
.funcs
.push(Function::new(Some(adapter.name.clone()), ty));
// If this type signature contains any borrowed resources then invocations
// of enter/exit call for resource-related metadata tracking must be used.
// It shouldn't matter whether the lower/lift signature is used here as both
// should return the same answer.
let emit_resource_call = module.types.contains_borrow_resource(&adapter.lower);
assert_eq!(
emit_resource_call,
module.types.contains_borrow_resource(&adapter.lift)
);
Compiler {
types: module.types,
module,
code: Vec::new(),
nlocals: lower_sig.params.len() as u32,
free_locals: HashMap::new(),
traps: Vec::new(),
result,
fuel: INITIAL_FUEL,
emit_resource_call,
}
.compile_adapter(adapter, &lower_sig, &lift_sig)
}
/// Compiles a helper function as specified by the `Helper` configuration.
///
/// This function is invoked when the translation process runs out of fuel for
/// some prior function which enqueues a helper to get translated later. This
/// translation function will perform one type translation as specified by
/// `Helper` which can either be in the stack or memory for each side.
pub(super) fn compile_helper(module: &mut Module<'_>, result: FunctionId, helper: Helper) {
let mut nlocals = 0;
let src_flat;
let src = match helper.src.loc {
// If the source is on the stack then it's specified in the parameters
// to the function, so this creates the flattened representation and
// then lists those as the locals with appropriate types for the source
// values.
HelperLocation::Stack => {
src_flat = module
.types
.flatten_types(&helper.src.opts, usize::MAX, [helper.src.ty])
.unwrap()
.iter()
.enumerate()
.map(|(i, ty)| (i as u32, *ty))
.collect::<Vec<_>>();
nlocals += src_flat.len() as u32;
Source::Stack(Stack {
locals: &src_flat,
opts: &helper.src.opts,
})
}
// If the source is in memory then that's just propagated here as the
// first local is the pointer to the source.
HelperLocation::Memory => {
nlocals += 1;
Source::Memory(Memory {
opts: &helper.src.opts,
addr: TempLocal::new(0, helper.src.opts.ptr()),
offset: 0,
})
}
};
let dst_flat;
let dst = match helper.dst.loc {
// This is the same as the stack-based source although `Destination` is
// configured slightly differently.
HelperLocation::Stack => {
dst_flat = module
.types
.flatten_types(&helper.dst.opts, usize::MAX, [helper.dst.ty])
.unwrap();
Destination::Stack(&dst_flat, &helper.dst.opts)
}
// This is the same as a memory-based source but note that the address
// of the destination is passed as the final parameter to the function.
HelperLocation::Memory => {
nlocals += 1;
Destination::Memory(Memory {
opts: &helper.dst.opts,
addr: TempLocal::new(nlocals - 1, helper.dst.opts.ptr()),
offset: 0,
})
}
};
let mut compiler = Compiler {
types: module.types,
module,
code: Vec::new(),
nlocals,
free_locals: HashMap::new(),
traps: Vec::new(),
result,
fuel: INITIAL_FUEL,
// This is a helper function and only the top-level function is
// responsible for emitting these intrinsic calls.
emit_resource_call: false,
};
compiler.translate(&helper.src.ty, &src, &helper.dst.ty, &dst);
compiler.finish();
}
/// Possible ways that a interface value is represented in the core wasm
/// canonical ABI.
enum Source<'a> {
/// This value is stored on the "stack" in wasm locals.
///
/// This could mean that it's inline from the parameters to the function or
/// that after a function call the results were stored in locals and the
/// locals are the inline results.
Stack(Stack<'a>),
/// This value is stored in linear memory described by the `Memory`
/// structure.
Memory(Memory<'a>),
}
/// Same as `Source` but for where values are translated into.
enum Destination<'a> {
/// This value is destined for the WebAssembly stack which means that
/// results are simply pushed as we go along.
///
/// The types listed are the types that are expected to be on the stack at
/// the end of translation.
Stack(&'a [ValType], &'a Options),
/// This value is to be placed in linear memory described by `Memory`.
Memory(Memory<'a>),
}
struct Stack<'a> {
/// The locals that comprise a particular value.
///
/// The length of this list represents the flattened list of types that make
/// up the component value. Each list has the index of the local being
/// accessed as well as the type of the local itself.
locals: &'a [(u32, ValType)],
/// The lifting/lowering options for where this stack of values comes from
opts: &'a Options,
}
/// Representation of where a value is going to be stored in linear memory.
struct Memory<'a> {
/// The lifting/lowering options with memory configuration
opts: &'a Options,
/// The index of the local that contains the base address of where the
/// storage is happening.
addr: TempLocal,
/// A "static" offset that will be baked into wasm instructions for where
/// memory loads/stores happen.
offset: u32,
}
impl Compiler<'_, '_> {
fn compile_adapter(
mut self,
adapter: &AdapterData,
lower_sig: &Signature,
lift_sig: &Signature,
) {
// Check the instance flags required for this trampoline.
//
// This inserts the initial check required by `canon_lower` that the
// caller instance can be left and additionally checks the
// flags on the callee if necessary whether it can be entered.
self.trap_if_not_flag(adapter.lower.flags, FLAG_MAY_LEAVE, Trap::CannotLeave);
if adapter.called_as_export {
self.trap_if_not_flag(adapter.lift.flags, FLAG_MAY_ENTER, Trap::CannotEnter);
self.set_flag(adapter.lift.flags, FLAG_MAY_ENTER, false);
} else if self.module.debug {
self.assert_not_flag(
adapter.lift.flags,
FLAG_MAY_ENTER,
"may_enter should be unset",
);
}
if self.emit_resource_call {
let enter = self.module.import_resource_enter_call();
self.instruction(Call(enter.as_u32()));
}
// Perform the translation of arguments. Note that `FLAG_MAY_LEAVE` is
// cleared around this invocation for the callee as per the
// `canon_lift` definition in the spec. Additionally note that the
// precise ordering of traps here is not required since internal state
// is not visible to either instance and a trap will "lock down" both
// instances to no longer be visible. This means that we're free to
// reorder lifts/lowers and flags and such as is necessary and
// convenient here.
//
// TODO: if translation doesn't actually call any functions in either
// instance then there's no need to set/clear the flag here and that can
// be optimized away.
self.set_flag(adapter.lift.flags, FLAG_MAY_LEAVE, false);
let param_locals = lower_sig
.params
.iter()
.enumerate()
.map(|(i, ty)| (i as u32, *ty))
.collect::<Vec<_>>();
self.translate_params(adapter, ¶m_locals);
self.set_flag(adapter.lift.flags, FLAG_MAY_LEAVE, true);
// With all the arguments on the stack the actual target function is
// now invoked. The core wasm results of the function are then placed
// into locals for result translation afterwards.
self.instruction(Call(adapter.callee.as_u32()));
let mut result_locals = Vec::with_capacity(lift_sig.results.len());
let mut temps = Vec::new();
for ty in lift_sig.results.iter().rev() {
let local = self.local_set_new_tmp(*ty);
result_locals.push((local.idx, *ty));
temps.push(local);
}
result_locals.reverse();
// Like above during the translation of results the caller cannot be
// left (as we might invoke things like `realloc`). Again the precise
// order of everything doesn't matter since intermediate states cannot
// be witnessed, hence the setting of flags here to encapsulate both
// liftings and lowerings.
//
// TODO: like above the management of the `MAY_LEAVE` flag can probably
// be elided here for "simple" results.
self.set_flag(adapter.lower.flags, FLAG_MAY_LEAVE, false);
self.translate_results(adapter, ¶m_locals, &result_locals);
self.set_flag(adapter.lower.flags, FLAG_MAY_LEAVE, true);
// And finally post-return state is handled here once all results/etc
// are all translated.
if let Some(func) = adapter.lift.post_return {
for (result, _) in result_locals.iter() {
self.instruction(LocalGet(*result));
}
self.instruction(Call(func.as_u32()));
}
if adapter.called_as_export {
self.set_flag(adapter.lift.flags, FLAG_MAY_ENTER, true);
}
for tmp in temps {
self.free_temp_local(tmp);
}
if self.emit_resource_call {
let exit = self.module.import_resource_exit_call();
self.instruction(Call(exit.as_u32()));
}
self.finish()
}
fn translate_params(&mut self, adapter: &AdapterData, param_locals: &[(u32, ValType)]) {
let src_tys = self.types[adapter.lower.ty].params;
let src_tys = self.types[src_tys]
.types
.iter()
.copied()
.collect::<Vec<_>>();
let dst_tys = self.types[adapter.lift.ty].params;
let dst_tys = self.types[dst_tys]
.types
.iter()
.copied()
.collect::<Vec<_>>();
let lift_opts = &adapter.lift.options;
let lower_opts = &adapter.lower.options;
// TODO: handle subtyping
assert_eq!(src_tys.len(), dst_tys.len());
let src_flat =
self.types
.flatten_types(lower_opts, MAX_FLAT_PARAMS, src_tys.iter().copied());
let dst_flat =
self.types
.flatten_types(lift_opts, MAX_FLAT_PARAMS, dst_tys.iter().copied());
let src = if let Some(flat) = &src_flat {
Source::Stack(Stack {
locals: ¶m_locals[..flat.len()],
opts: lower_opts,
})
} else {
// If there are too many parameters then that means the parameters
// are actually a tuple stored in linear memory addressed by the
// first parameter local.
let (addr, ty) = param_locals[0];
assert_eq!(ty, lower_opts.ptr());
let align = src_tys
.iter()
.map(|t| self.types.align(lower_opts, t))
.max()
.unwrap_or(1);
Source::Memory(self.memory_operand(lower_opts, TempLocal::new(addr, ty), align))
};
let dst = if let Some(flat) = &dst_flat {
Destination::Stack(flat, lift_opts)
} else {
// If there are too many parameters then space is allocated in the
// destination module for the parameters via its `realloc` function.
let abi = CanonicalAbiInfo::record(dst_tys.iter().map(|t| self.types.canonical_abi(t)));
let (size, align) = if lift_opts.memory64 {
(abi.size64, abi.align64)
} else {
(abi.size32, abi.align32)
};
let size = MallocSize::Const(size);
Destination::Memory(self.malloc(lift_opts, size, align))
};
let srcs = src
.record_field_srcs(self.types, src_tys.iter().copied())
.zip(src_tys.iter());
let dsts = dst
.record_field_dsts(self.types, dst_tys.iter().copied())
.zip(dst_tys.iter());
for ((src, src_ty), (dst, dst_ty)) in srcs.zip(dsts) {
self.translate(&src_ty, &src, &dst_ty, &dst);
}
// If the destination was linear memory instead of the stack then the
// actual parameter that we're passing is the address of the values
// stored, so ensure that's happening in the wasm body here.
if let Destination::Memory(mem) = dst {
self.instruction(LocalGet(mem.addr.idx));
self.free_temp_local(mem.addr);
}
}
fn translate_results(
&mut self,
adapter: &AdapterData,
param_locals: &[(u32, ValType)],
result_locals: &[(u32, ValType)],
) {
let src_tys = self.types[adapter.lift.ty].results;
let src_tys = self.types[src_tys]
.types
.iter()
.copied()
.collect::<Vec<_>>();
let dst_tys = self.types[adapter.lower.ty].results;
let dst_tys = self.types[dst_tys]
.types
.iter()
.copied()
.collect::<Vec<_>>();
let lift_opts = &adapter.lift.options;
let lower_opts = &adapter.lower.options;
let src_flat =
self.types
.flatten_types(lift_opts, MAX_FLAT_RESULTS, src_tys.iter().copied());
let dst_flat =
self.types
.flatten_types(lower_opts, MAX_FLAT_RESULTS, dst_tys.iter().copied());
let src = if src_flat.is_some() {
Source::Stack(Stack {
locals: result_locals,
opts: lift_opts,
})
} else {
// The original results to read from in this case come from the
// return value of the function itself. The imported function will
// return a linear memory address at which the values can be read
// from.
let align = src_tys
.iter()
.map(|t| self.types.align(lift_opts, t))
.max()
.unwrap_or(1);
assert_eq!(result_locals.len(), 1);
let (addr, ty) = result_locals[0];
assert_eq!(ty, lift_opts.ptr());
Source::Memory(self.memory_operand(lift_opts, TempLocal::new(addr, ty), align))
};
let dst = if let Some(flat) = &dst_flat {
Destination::Stack(flat, lower_opts)
} else {
// This is slightly different than `translate_params` where the
// return pointer was provided by the caller of this function
// meaning the last parameter local is a pointer into linear memory.
let align = dst_tys
.iter()
.map(|t| self.types.align(lower_opts, t))
.max()
.unwrap_or(1);
let (addr, ty) = *param_locals.last().expect("no retptr");
assert_eq!(ty, lower_opts.ptr());
Destination::Memory(self.memory_operand(lower_opts, TempLocal::new(addr, ty), align))
};
let srcs = src
.record_field_srcs(self.types, src_tys.iter().copied())
.zip(src_tys.iter());
let dsts = dst
.record_field_dsts(self.types, dst_tys.iter().copied())
.zip(dst_tys.iter());
for ((src, src_ty), (dst, dst_ty)) in srcs.zip(dsts) {
self.translate(&src_ty, &src, &dst_ty, &dst);
}
}
fn translate(
&mut self,
src_ty: &InterfaceType,
src: &Source<'_>,
dst_ty: &InterfaceType,
dst: &Destination,
) {
if let Source::Memory(mem) = src {
self.assert_aligned(src_ty, mem);
}
if let Destination::Memory(mem) = dst {
self.assert_aligned(dst_ty, mem);
}
// Calculate a cost heuristic for what the translation of this specific
// layer of the type is going to incur. The purpose of this cost is that
// we'll deduct it from `self.fuel` and if no fuel is remaining then
// translation is outlined into a separate function rather than being
// translated into this function.
//
// The general goal is to avoid creating an exponentially sized function
// for a linearly sized input (the type section). By outlining helper
// functions there will ideally be a constant set of helper functions
// per type (to accommodate in-memory or on-stack transfers as well as
// src/dst options) which means that each function is at most a certain
// size and we have a linear number of functions which should guarantee
// an overall linear size of the output.
//
// To implement this the current heuristic is that each layer of
// translating a type has a cost associated with it and this cost is
// accounted for in `self.fuel`. Some conversions are considered free as
// they generate basically as much code as the `call` to the translation
// function while other are considered proportionally expensive to the
// size of the type. The hope is that some upper layers are of a type's
// translation are all inlined into one function but bottom layers end
// up getting outlined to separate functions. Theoretically, again this
// is built on hopes and dreams, the outlining can be shared amongst
// tightly-intertwined type hierarchies which will reduce the size of
// the output module due to the helpers being used.
//
// This heuristic of how to split functions has changed a few times in
// the past and this isn't necessarily guaranteed to be the final
// iteration.
let cost = match src_ty {
// These types are all quite simple to load/store and equate to
// basically the same cost of the `call` instruction to call an
// out-of-line translation function, so give them 0 cost.
InterfaceType::Bool
| InterfaceType::U8
| InterfaceType::S8
| InterfaceType::U16
| InterfaceType::S16
| InterfaceType::U32
| InterfaceType::S32
| InterfaceType::U64
| InterfaceType::S64
| InterfaceType::Float32
| InterfaceType::Float64 => 0,
// This has a small amount of validation associated with it, so
// give it a cost of 1.
InterfaceType::Char => 1,
// This has a fair bit of code behind it depending on the
// strings/encodings in play, so arbitrarily assign it this cost.
InterfaceType::String => 40,
// Iteration of a loop is along the lines of the cost of a string
// so give it the same cost
InterfaceType::List(_) => 40,
InterfaceType::Flags(i) => {
let count = self.module.types[*i].names.len();
match FlagsSize::from_count(count) {
FlagsSize::Size0 => 0,
FlagsSize::Size1 | FlagsSize::Size2 => 1,
FlagsSize::Size4Plus(n) => n.into(),
}
}
InterfaceType::Record(i) => self.types[*i].fields.len(),
InterfaceType::Tuple(i) => self.types[*i].types.len(),
InterfaceType::Variant(i) => self.types[*i].cases.len(),
InterfaceType::Enum(i) => self.types[*i].names.len(),
// 2 cases to consider for each of these variants.
InterfaceType::Option(_) | InterfaceType::Result(_) => 2,
// TODO(#6696) - something nonzero, is 1 right?
InterfaceType::Own(_) | InterfaceType::Borrow(_) => 1,
};
match self.fuel.checked_sub(cost) {
// This function has enough fuel to perform the layer of translation
// necessary for this type, so the fuel is updated in-place and
// translation continues. Note that the recursion here is bounded by
// the static recursion limit for all interface types as imposed
// during the translation phase.
Some(n) => {
self.fuel = n;
match src_ty {
InterfaceType::Bool => self.translate_bool(src, dst_ty, dst),
InterfaceType::U8 => self.translate_u8(src, dst_ty, dst),
InterfaceType::S8 => self.translate_s8(src, dst_ty, dst),
InterfaceType::U16 => self.translate_u16(src, dst_ty, dst),
InterfaceType::S16 => self.translate_s16(src, dst_ty, dst),
InterfaceType::U32 => self.translate_u32(src, dst_ty, dst),
InterfaceType::S32 => self.translate_s32(src, dst_ty, dst),
InterfaceType::U64 => self.translate_u64(src, dst_ty, dst),
InterfaceType::S64 => self.translate_s64(src, dst_ty, dst),
InterfaceType::Float32 => self.translate_f32(src, dst_ty, dst),
InterfaceType::Float64 => self.translate_f64(src, dst_ty, dst),
InterfaceType::Char => self.translate_char(src, dst_ty, dst),
InterfaceType::String => self.translate_string(src, dst_ty, dst),
InterfaceType::List(t) => self.translate_list(*t, src, dst_ty, dst),
InterfaceType::Record(t) => self.translate_record(*t, src, dst_ty, dst),
InterfaceType::Flags(f) => self.translate_flags(*f, src, dst_ty, dst),
InterfaceType::Tuple(t) => self.translate_tuple(*t, src, dst_ty, dst),
InterfaceType::Variant(v) => self.translate_variant(*v, src, dst_ty, dst),
InterfaceType::Enum(t) => self.translate_enum(*t, src, dst_ty, dst),
InterfaceType::Option(t) => self.translate_option(*t, src, dst_ty, dst),
InterfaceType::Result(t) => self.translate_result(*t, src, dst_ty, dst),
InterfaceType::Own(t) => self.translate_own(*t, src, dst_ty, dst),
InterfaceType::Borrow(t) => self.translate_borrow(*t, src, dst_ty, dst),
}
}
// This function does not have enough fuel left to perform this
// layer of translation so the translation is deferred to a helper
// function. The actual translation here is then done by marshalling
// the src/dst into the function we're calling and then processing
// the results.
None => {
let src_loc = match src {
// If the source is on the stack then `stack_get` is used to
// convert everything to the appropriate flat representation
// for the source type.
Source::Stack(stack) => {
for (i, ty) in stack
.opts
.flat_types(src_ty, self.types)
.unwrap()
.iter()
.enumerate()
{
let stack = stack.slice(i..i + 1);
self.stack_get(&stack, (*ty).into());
}
HelperLocation::Stack
}
// If the source is in memory then the pointer is passed
// through, but note that the offset must be factored in
// here since the translation function will start from
// offset 0.
Source::Memory(mem) => {
self.push_mem_addr(mem);
HelperLocation::Memory
}
};
let dst_loc = match dst {
Destination::Stack(..) => HelperLocation::Stack,
Destination::Memory(mem) => {
self.push_mem_addr(mem);
HelperLocation::Memory
}
};
// Generate a `FunctionId` corresponding to the `Helper`
// configuration that is necessary here. This will ideally be a
// "cache hit" and use a preexisting helper which represents
// outlining what would otherwise be duplicate code within a
// function to one function.
let helper = self.module.translate_helper(Helper {
src: HelperType {
ty: *src_ty,
opts: *src.opts(),
loc: src_loc,
},
dst: HelperType {
ty: *dst_ty,
opts: *dst.opts(),
loc: dst_loc,
},
});
// Emit a `call` instruction which will get "relocated" to a
// function index once translation has completely finished.
self.flush_code();
self.module.funcs[self.result].body.push(Body::Call(helper));
// If the destination of the translation was on the stack then
// the types on the stack need to be optionally converted to
// different types (e.g. if the result here is part of a variant
// somewhere else).
//
// This translation happens inline here by popping the results
// into new locals and then using those locals to do a
// `stack_set`.
if let Destination::Stack(tys, opts) = dst {
let flat = self
.types
.flatten_types(opts, usize::MAX, [*dst_ty])
.unwrap();
assert_eq!(flat.len(), tys.len());
let locals = flat
.iter()
.rev()
.map(|ty| self.local_set_new_tmp(*ty))
.collect::<Vec<_>>();
for (ty, local) in tys.iter().zip(locals.into_iter().rev()) {
self.instruction(LocalGet(local.idx));
self.stack_set(std::slice::from_ref(ty), local.ty);
self.free_temp_local(local);
}
}
}
}
}
fn push_mem_addr(&mut self, mem: &Memory<'_>) {
self.instruction(LocalGet(mem.addr.idx));
if mem.offset != 0 {
self.ptr_uconst(mem.opts, mem.offset);
self.ptr_add(mem.opts);
}
}
fn translate_bool(&mut self, src: &Source<'_>, dst_ty: &InterfaceType, dst: &Destination) {
// TODO: subtyping
assert!(matches!(dst_ty, InterfaceType::Bool));
self.push_dst_addr(dst);
// Booleans are canonicalized to 0 or 1 as they pass through the
// component boundary, so use a `select` instruction to do so.
self.instruction(I32Const(1));
self.instruction(I32Const(0));
match src {
Source::Memory(mem) => self.i32_load8u(mem),
Source::Stack(stack) => self.stack_get(stack, ValType::I32),
}
self.instruction(Select);
match dst {
Destination::Memory(mem) => self.i32_store8(mem),
Destination::Stack(stack, _) => self.stack_set(stack, ValType::I32),
}
}
fn translate_u8(&mut self, src: &Source<'_>, dst_ty: &InterfaceType, dst: &Destination) {
// TODO: subtyping
assert!(matches!(dst_ty, InterfaceType::U8));
self.convert_u8_mask(src, dst, 0xff);
}
fn convert_u8_mask(&mut self, src: &Source<'_>, dst: &Destination<'_>, mask: u8) {
self.push_dst_addr(dst);
let mut needs_mask = true;
match src {
Source::Memory(mem) => {
self.i32_load8u(mem);
needs_mask = mask != 0xff;
}
Source::Stack(stack) => {
self.stack_get(stack, ValType::I32);
}
}
if needs_mask {
self.instruction(I32Const(i32::from(mask)));
self.instruction(I32And);
}
match dst {
Destination::Memory(mem) => self.i32_store8(mem),
Destination::Stack(stack, _) => self.stack_set(stack, ValType::I32),
}
}
fn translate_s8(&mut self, src: &Source<'_>, dst_ty: &InterfaceType, dst: &Destination) {
// TODO: subtyping
assert!(matches!(dst_ty, InterfaceType::S8));
self.push_dst_addr(dst);
match src {
Source::Memory(mem) => self.i32_load8s(mem),
Source::Stack(stack) => {
self.stack_get(stack, ValType::I32);
self.instruction(I32Extend8S);
}
}
match dst {
Destination::Memory(mem) => self.i32_store8(mem),
Destination::Stack(stack, _) => self.stack_set(stack, ValType::I32),
}
}
fn translate_u16(&mut self, src: &Source<'_>, dst_ty: &InterfaceType, dst: &Destination) {
// TODO: subtyping
assert!(matches!(dst_ty, InterfaceType::U16));
self.convert_u16_mask(src, dst, 0xffff);
}
fn convert_u16_mask(&mut self, src: &Source<'_>, dst: &Destination<'_>, mask: u16) {
self.push_dst_addr(dst);
let mut needs_mask = true;
match src {
Source::Memory(mem) => {
self.i32_load16u(mem);
needs_mask = mask != 0xffff;
}
Source::Stack(stack) => {
self.stack_get(stack, ValType::I32);
}
}
if needs_mask {
self.instruction(I32Const(i32::from(mask)));
self.instruction(I32And);
}
match dst {
Destination::Memory(mem) => self.i32_store16(mem),
Destination::Stack(stack, _) => self.stack_set(stack, ValType::I32),
}
}
fn translate_s16(&mut self, src: &Source<'_>, dst_ty: &InterfaceType, dst: &Destination) {
// TODO: subtyping
assert!(matches!(dst_ty, InterfaceType::S16));
self.push_dst_addr(dst);
match src {
Source::Memory(mem) => self.i32_load16s(mem),
Source::Stack(stack) => {
self.stack_get(stack, ValType::I32);
self.instruction(I32Extend16S);
}
}
match dst {
Destination::Memory(mem) => self.i32_store16(mem),
Destination::Stack(stack, _) => self.stack_set(stack, ValType::I32),
}
}
fn translate_u32(&mut self, src: &Source<'_>, dst_ty: &InterfaceType, dst: &Destination) {
// TODO: subtyping
assert!(matches!(dst_ty, InterfaceType::U32));
self.convert_u32_mask(src, dst, 0xffffffff)
}
fn convert_u32_mask(&mut self, src: &Source<'_>, dst: &Destination<'_>, mask: u32) {
self.push_dst_addr(dst);
match src {
Source::Memory(mem) => self.i32_load(mem),
Source::Stack(stack) => self.stack_get(stack, ValType::I32),
}
if mask != 0xffffffff {
self.instruction(I32Const(mask as i32));
self.instruction(I32And);
}
match dst {
Destination::Memory(mem) => self.i32_store(mem),
Destination::Stack(stack, _) => self.stack_set(stack, ValType::I32),
}
}
fn translate_s32(&mut self, src: &Source<'_>, dst_ty: &InterfaceType, dst: &Destination) {
// TODO: subtyping
assert!(matches!(dst_ty, InterfaceType::S32));
self.push_dst_addr(dst);
match src {
Source::Memory(mem) => self.i32_load(mem),
Source::Stack(stack) => self.stack_get(stack, ValType::I32),
}
match dst {
Destination::Memory(mem) => self.i32_store(mem),
Destination::Stack(stack, _) => self.stack_set(stack, ValType::I32),
}
}
fn translate_u64(&mut self, src: &Source<'_>, dst_ty: &InterfaceType, dst: &Destination) {
// TODO: subtyping
assert!(matches!(dst_ty, InterfaceType::U64));
self.push_dst_addr(dst);
match src {
Source::Memory(mem) => self.i64_load(mem),
Source::Stack(stack) => self.stack_get(stack, ValType::I64),
}
match dst {
Destination::Memory(mem) => self.i64_store(mem),
Destination::Stack(stack, _) => self.stack_set(stack, ValType::I64),
}
}
fn translate_s64(&mut self, src: &Source<'_>, dst_ty: &InterfaceType, dst: &Destination) {
// TODO: subtyping
assert!(matches!(dst_ty, InterfaceType::S64));
self.push_dst_addr(dst);
match src {
Source::Memory(mem) => self.i64_load(mem),
Source::Stack(stack) => self.stack_get(stack, ValType::I64),
}
match dst {
Destination::Memory(mem) => self.i64_store(mem),
Destination::Stack(stack, _) => self.stack_set(stack, ValType::I64),
}
}
fn translate_f32(&mut self, src: &Source<'_>, dst_ty: &InterfaceType, dst: &Destination) {
// TODO: subtyping
assert!(matches!(dst_ty, InterfaceType::Float32));
self.push_dst_addr(dst);
match src {
Source::Memory(mem) => self.f32_load(mem),
Source::Stack(stack) => self.stack_get(stack, ValType::F32),
}
match dst {
Destination::Memory(mem) => self.f32_store(mem),
Destination::Stack(stack, _) => self.stack_set(stack, ValType::F32),
}
}
fn translate_f64(&mut self, src: &Source<'_>, dst_ty: &InterfaceType, dst: &Destination) {
// TODO: subtyping
assert!(matches!(dst_ty, InterfaceType::Float64));
self.push_dst_addr(dst);
match src {
Source::Memory(mem) => self.f64_load(mem),
Source::Stack(stack) => self.stack_get(stack, ValType::F64),
}
match dst {
Destination::Memory(mem) => self.f64_store(mem),
Destination::Stack(stack, _) => self.stack_set(stack, ValType::F64),
}
}
fn translate_char(&mut self, src: &Source<'_>, dst_ty: &InterfaceType, dst: &Destination) {
assert!(matches!(dst_ty, InterfaceType::Char));
match src {
Source::Memory(mem) => self.i32_load(mem),
Source::Stack(stack) => self.stack_get(stack, ValType::I32),
}
let local = self.local_set_new_tmp(ValType::I32);
// This sequence is copied from the output of LLVM for:
//
// pub extern "C" fn foo(x: u32) -> char {
// char::try_from(x)
// .unwrap_or_else(|_| std::arch::wasm32::unreachable())
// }
//
// Apparently this does what's required by the canonical ABI:
//
// def i32_to_char(opts, i):
// trap_if(i >= 0x110000)
// trap_if(0xD800 <= i <= 0xDFFF)
// return chr(i)
//
// ... but I don't know how it works other than "well I trust LLVM"
self.instruction(Block(BlockType::Empty));
self.instruction(Block(BlockType::Empty));
self.instruction(LocalGet(local.idx));
self.instruction(I32Const(0xd800));
self.instruction(I32Xor);
self.instruction(I32Const(-0x110000));
self.instruction(I32Add);
self.instruction(I32Const(-0x10f800));
self.instruction(I32LtU);
self.instruction(BrIf(0));
self.instruction(LocalGet(local.idx));
self.instruction(I32Const(0x110000));
self.instruction(I32Ne);
self.instruction(BrIf(1));
self.instruction(End);
self.trap(Trap::InvalidChar);
self.instruction(End);
self.push_dst_addr(dst);
self.instruction(LocalGet(local.idx));
match dst {
Destination::Memory(mem) => {
self.i32_store(mem);
}
Destination::Stack(stack, _) => self.stack_set(stack, ValType::I32),
}
self.free_temp_local(local);
}
fn translate_string(&mut self, src: &Source<'_>, dst_ty: &InterfaceType, dst: &Destination) {
assert!(matches!(dst_ty, InterfaceType::String));
let src_opts = src.opts();
let dst_opts = dst.opts();
// Load the pointer/length of this string into temporary locals. These
// will be referenced a good deal so this just makes it easier to deal
// with them consistently below rather than trying to reload from memory
// for example.
match src {
Source::Stack(s) => {
assert_eq!(s.locals.len(), 2);
self.stack_get(&s.slice(0..1), src_opts.ptr());
self.stack_get(&s.slice(1..2), src_opts.ptr());
}
Source::Memory(mem) => {
self.ptr_load(mem);
self.ptr_load(&mem.bump(src_opts.ptr_size().into()));
}
}
let src_len = self.local_set_new_tmp(src_opts.ptr());
let src_ptr = self.local_set_new_tmp(src_opts.ptr());
let src_str = WasmString {
ptr: src_ptr,
len: src_len,
opts: src_opts,
};
let dst_str = match src_opts.string_encoding {
StringEncoding::Utf8 => match dst_opts.string_encoding {
StringEncoding::Utf8 => self.string_copy(&src_str, FE::Utf8, dst_opts, FE::Utf8),
StringEncoding::Utf16 => self.string_utf8_to_utf16(&src_str, dst_opts),
StringEncoding::CompactUtf16 => {
self.string_to_compact(&src_str, FE::Utf8, dst_opts)
}
},
StringEncoding::Utf16 => {
self.verify_aligned(src_opts, src_str.ptr.idx, 2);
match dst_opts.string_encoding {
StringEncoding::Utf8 => {
self.string_deflate_to_utf8(&src_str, FE::Utf16, dst_opts)
}
StringEncoding::Utf16 => {
self.string_copy(&src_str, FE::Utf16, dst_opts, FE::Utf16)
}
StringEncoding::CompactUtf16 => {
self.string_to_compact(&src_str, FE::Utf16, dst_opts)
}
}
}
StringEncoding::CompactUtf16 => {
self.verify_aligned(src_opts, src_str.ptr.idx, 2);
// Test the tag big to see if this is a utf16 or a latin1 string
// at runtime...
self.instruction(LocalGet(src_str.len.idx));
self.ptr_uconst(src_opts, UTF16_TAG);
self.ptr_and(src_opts);
self.ptr_if(src_opts, BlockType::Empty);
// In the utf16 block unset the upper bit from the length local
// so further calculations have the right value. Afterwards the
// string transcode proceeds assuming utf16.
self.instruction(LocalGet(src_str.len.idx));
self.ptr_uconst(src_opts, UTF16_TAG);
self.ptr_xor(src_opts);
self.instruction(LocalSet(src_str.len.idx));
let s1 = match dst_opts.string_encoding {
StringEncoding::Utf8 => {
self.string_deflate_to_utf8(&src_str, FE::Utf16, dst_opts)
}
StringEncoding::Utf16 => {
self.string_copy(&src_str, FE::Utf16, dst_opts, FE::Utf16)
}
StringEncoding::CompactUtf16 => {
self.string_compact_utf16_to_compact(&src_str, dst_opts)
}
};
self.instruction(Else);
// In the latin1 block the `src_len` local is already the number
// of code units, so the string transcoding is all that needs to
// happen.
let s2 = match dst_opts.string_encoding {
StringEncoding::Utf16 => {
self.string_copy(&src_str, FE::Latin1, dst_opts, FE::Utf16)
}
StringEncoding::Utf8 => {
self.string_deflate_to_utf8(&src_str, FE::Latin1, dst_opts)
}
StringEncoding::CompactUtf16 => {
self.string_copy(&src_str, FE::Latin1, dst_opts, FE::Latin1)
}
};
// Set our `s2` generated locals to the `s2` generated locals
// as the resulting pointer of this transcode.
self.instruction(LocalGet(s2.ptr.idx));
self.instruction(LocalSet(s1.ptr.idx));
self.instruction(LocalGet(s2.len.idx));
self.instruction(LocalSet(s1.len.idx));
self.instruction(End);
self.free_temp_local(s2.ptr);
self.free_temp_local(s2.len);
s1
}
};
// Store the ptr/length in the desired destination
match dst {
Destination::Stack(s, _) => {
self.instruction(LocalGet(dst_str.ptr.idx));
self.stack_set(&s[..1], dst_opts.ptr());
self.instruction(LocalGet(dst_str.len.idx));
self.stack_set(&s[1..], dst_opts.ptr());
}
Destination::Memory(mem) => {
self.instruction(LocalGet(mem.addr.idx));
self.instruction(LocalGet(dst_str.ptr.idx));
self.ptr_store(mem);
self.instruction(LocalGet(mem.addr.idx));
self.instruction(LocalGet(dst_str.len.idx));
self.ptr_store(&mem.bump(dst_opts.ptr_size().into()));
}
}
self.free_temp_local(src_str.ptr);
self.free_temp_local(src_str.len);
self.free_temp_local(dst_str.ptr);
self.free_temp_local(dst_str.len);
}
// Corresponding function for `store_string_copy` in the spec.
//
// This performs a transcoding of the string with a one-pass copy from
// the `src` encoding to the `dst` encoding. This is only possible for
// fixed encodings where the first allocation is guaranteed to be an
// appropriate fit so it's not suitable for all encodings.
//
// Imported host transcoding functions here take the src/dst pointers as
// well as the number of code units in the source (which always matches
// the number of code units in the destination). There is no return
// value from the transcode function since the encoding should always
// work on the first pass.
fn string_copy<'a>(
&mut self,
src: &WasmString<'_>,
src_enc: FE,
dst_opts: &'a Options,
dst_enc: FE,
) -> WasmString<'a> {
assert!(dst_enc.width() >= src_enc.width());
self.validate_string_length(src, dst_enc);
// Calculate the source byte length given the size of each code
// unit. Note that this shouldn't overflow given
// `validate_string_length` above.
let mut src_byte_len_tmp = None;
let src_byte_len = if src_enc.width() == 1 {
src.len.idx
} else {
assert_eq!(src_enc.width(), 2);
self.instruction(LocalGet(src.len.idx));
self.ptr_uconst(src.opts, 1);
self.ptr_shl(src.opts);
let tmp = self.local_set_new_tmp(src.opts.ptr());
let ret = tmp.idx;
src_byte_len_tmp = Some(tmp);
ret
};
// Convert the source code units length to the destination byte
// length type.
self.convert_src_len_to_dst(src.len.idx, src.opts.ptr(), dst_opts.ptr());
let dst_len = self.local_tee_new_tmp(dst_opts.ptr());
if dst_enc.width() > 1 {
assert_eq!(dst_enc.width(), 2);
self.ptr_uconst(dst_opts, 1);
self.ptr_shl(dst_opts);
}
let dst_byte_len = self.local_set_new_tmp(dst_opts.ptr());
// Allocate space in the destination using the calculated byte
// length.
let dst = {
let dst_mem = self.malloc(
dst_opts,
MallocSize::Local(dst_byte_len.idx),
dst_enc.width().into(),
);
WasmString {
ptr: dst_mem.addr,
len: dst_len,
opts: dst_opts,
}
};
// Validate that `src_len + src_ptr` and
// `dst_mem.addr_local + dst_byte_len` are both in-bounds. This
// is done by loading the last byte of the string and if that
// doesn't trap then it's known valid.
self.validate_string_inbounds(src, src_byte_len);
self.validate_string_inbounds(&dst, dst_byte_len.idx);
// If the validations pass then the host `transcode` intrinsic
// is invoked. This will either raise a trap or otherwise succeed
// in which case we're done.
let op = if src_enc == dst_enc {
Transcode::Copy(src_enc)
} else {
assert_eq!(src_enc, FE::Latin1);
assert_eq!(dst_enc, FE::Utf16);
Transcode::Latin1ToUtf16
};
let transcode = self.transcoder(src, &dst, op);
self.instruction(LocalGet(src.ptr.idx));
self.instruction(LocalGet(src.len.idx));
self.instruction(LocalGet(dst.ptr.idx));
self.instruction(Call(transcode.as_u32()));
self.free_temp_local(dst_byte_len);
if let Some(tmp) = src_byte_len_tmp {
self.free_temp_local(tmp);
}
dst
}
// Corresponding function for `store_string_to_utf8` in the spec.
//
// This translation works by possibly performing a number of
// reallocations. First a buffer of size input-code-units is used to try
// to get the transcoding correct on the first try. If that fails the
// maximum worst-case size is used and then that is resized down if it's
// too large.
//
// The host transcoding function imported here will receive src ptr/len
// and dst ptr/len and return how many code units were consumed on both
// sides. The amount of code units consumed in the source dictates which
// branches are taken in this conversion.
fn string_deflate_to_utf8<'a>(
&mut self,
src: &WasmString<'_>,
src_enc: FE,
dst_opts: &'a Options,
) -> WasmString<'a> {
self.validate_string_length(src, src_enc);
// Optimistically assume that the code unit length of the source is
// all that's needed in the destination. Perform that allocation
// here and proceed to transcoding below.
self.convert_src_len_to_dst(src.len.idx, src.opts.ptr(), dst_opts.ptr());
let dst_len = self.local_tee_new_tmp(dst_opts.ptr());
let dst_byte_len = self.local_set_new_tmp(dst_opts.ptr());
let dst = {
let dst_mem = self.malloc(dst_opts, MallocSize::Local(dst_byte_len.idx), 1);
WasmString {
ptr: dst_mem.addr,
len: dst_len,
opts: dst_opts,
}
};
// Ensure buffers are all in-bounds
let mut src_byte_len_tmp = None;
let src_byte_len = match src_enc {
FE::Latin1 => src.len.idx,
FE::Utf16 => {
self.instruction(LocalGet(src.len.idx));
self.ptr_uconst(src.opts, 1);
self.ptr_shl(src.opts);
let tmp = self.local_set_new_tmp(src.opts.ptr());
let ret = tmp.idx;
src_byte_len_tmp = Some(tmp);
ret
}
FE::Utf8 => unreachable!(),
};
self.validate_string_inbounds(src, src_byte_len);
self.validate_string_inbounds(&dst, dst_byte_len.idx);
// Perform the initial transcode
let op = match src_enc {
FE::Latin1 => Transcode::Latin1ToUtf8,
FE::Utf16 => Transcode::Utf16ToUtf8,
FE::Utf8 => unreachable!(),
};
let transcode = self.transcoder(src, &dst, op);
self.instruction(LocalGet(src.ptr.idx));
self.instruction(LocalGet(src.len.idx));
self.instruction(LocalGet(dst.ptr.idx));
self.instruction(LocalGet(dst_byte_len.idx));
self.instruction(Call(transcode.as_u32()));
self.instruction(LocalSet(dst.len.idx));
let src_len_tmp = self.local_set_new_tmp(src.opts.ptr());
// Test if the source was entirely transcoded by comparing
// `src_len_tmp`, the number of code units transcoded from the
// source, with `src_len`, the original number of code units.
self.instruction(LocalGet(src_len_tmp.idx));
self.instruction(LocalGet(src.len.idx));
self.ptr_ne(src.opts);
self.instruction(If(BlockType::Empty));
// Here a worst-case reallocation is performed to grow `dst_mem`.
// In-line a check is also performed that the worst-case byte size
// fits within the maximum size of strings.
self.instruction(LocalGet(dst.ptr.idx)); // old_ptr
self.instruction(LocalGet(dst_byte_len.idx)); // old_size
self.ptr_uconst(dst.opts, 1); // align
let factor = match src_enc {
FE::Latin1 => 2,
FE::Utf16 => 3,
_ => unreachable!(),
};
self.validate_string_length_u8(src, factor);
self.convert_src_len_to_dst(src.len.idx, src.opts.ptr(), dst_opts.ptr());
self.ptr_uconst(dst_opts, factor.into());
self.ptr_mul(dst_opts);
self.instruction(LocalTee(dst_byte_len.idx));
self.instruction(Call(dst_opts.realloc.unwrap().as_u32()));
self.instruction(LocalSet(dst.ptr.idx));
// Verify that the destination is still in-bounds
self.validate_string_inbounds(&dst, dst_byte_len.idx);
// Perform another round of transcoding that should be guaranteed
// to succeed. Note that all the parameters here are offset by the
// results of the first transcoding to only perform the remaining
// transcode on the final units.
self.instruction(LocalGet(src.ptr.idx));
self.instruction(LocalGet(src_len_tmp.idx));
if let FE::Utf16 = src_enc {
self.ptr_uconst(src.opts, 1);
self.ptr_shl(src.opts);
}
self.ptr_add(src.opts);
self.instruction(LocalGet(src.len.idx));
self.instruction(LocalGet(src_len_tmp.idx));
self.ptr_sub(src.opts);
self.instruction(LocalGet(dst.ptr.idx));
self.instruction(LocalGet(dst.len.idx));
self.ptr_add(dst.opts);
self.instruction(LocalGet(dst_byte_len.idx));
self.instruction(LocalGet(dst.len.idx));
self.ptr_sub(dst.opts);
self.instruction(Call(transcode.as_u32()));
// Add the second result, the amount of destination units encoded,
// to `dst_len` so it's an accurate reflection of the final size of
// the destination buffer.
self.instruction(LocalGet(dst.len.idx));
self.ptr_add(dst.opts);
self.instruction(LocalSet(dst.len.idx));
// In debug mode verify the first result consumed the entire string,
// otherwise simply discard it.
if self.module.debug {
self.instruction(LocalGet(src.len.idx));
self.instruction(LocalGet(src_len_tmp.idx));
self.ptr_sub(src.opts);
self.ptr_ne(src.opts);
self.instruction(If(BlockType::Empty));
self.trap(Trap::AssertFailed("should have finished encoding"));
self.instruction(End);
} else {
self.instruction(Drop);
}
// Perform a downsizing if the worst-case size was too large
self.instruction(LocalGet(dst.len.idx));
self.instruction(LocalGet(dst_byte_len.idx));
self.ptr_ne(dst.opts);
self.instruction(If(BlockType::Empty));
self.instruction(LocalGet(dst.ptr.idx)); // old_ptr
self.instruction(LocalGet(dst_byte_len.idx)); // old_size
self.ptr_uconst(dst.opts, 1); // align
self.instruction(LocalGet(dst.len.idx)); // new_size
self.instruction(Call(dst.opts.realloc.unwrap().as_u32()));
self.instruction(LocalSet(dst.ptr.idx));
self.instruction(End);
// If the first transcode was enough then assert that the returned
// amount of destination items written equals the byte size.
if self.module.debug {
self.instruction(Else);
self.instruction(LocalGet(dst.len.idx));
self.instruction(LocalGet(dst_byte_len.idx));
self.ptr_ne(dst_opts);
self.instruction(If(BlockType::Empty));
self.trap(Trap::AssertFailed("should have finished encoding"));
self.instruction(End);
}
self.instruction(End); // end of "first transcode not enough"
self.free_temp_local(src_len_tmp);
self.free_temp_local(dst_byte_len);
if let Some(tmp) = src_byte_len_tmp {
self.free_temp_local(tmp);
}
dst
}
// Corresponds to the `store_utf8_to_utf16` function in the spec.
//
// When converting utf-8 to utf-16 a pessimistic allocation is
// done which is twice the byte length of the utf-8 string.
// The host then transcodes and returns how many code units were
// actually used during the transcoding and if it's beneath the
// pessimistic maximum then the buffer is reallocated down to
// a smaller amount.
//
// The host-imported transcoding function takes the src/dst pointer as
// well as the code unit size of both the source and destination. The
// destination should always be big enough to hold the result of the
// transcode and so the result of the host function is how many code
// units were written to the destination.
fn string_utf8_to_utf16<'a>(
&mut self,
src: &WasmString<'_>,
dst_opts: &'a Options,
) -> WasmString<'a> {
self.validate_string_length(src, FE::Utf16);
self.convert_src_len_to_dst(src.len.idx, src.opts.ptr(), dst_opts.ptr());
let dst_len = self.local_tee_new_tmp(dst_opts.ptr());
self.ptr_uconst(dst_opts, 1);
self.ptr_shl(dst_opts);
let dst_byte_len = self.local_set_new_tmp(dst_opts.ptr());
let dst = {
let dst_mem = self.malloc(dst_opts, MallocSize::Local(dst_byte_len.idx), 2);
WasmString {
ptr: dst_mem.addr,
len: dst_len,
opts: dst_opts,
}
};
self.validate_string_inbounds(src, src.len.idx);
self.validate_string_inbounds(&dst, dst_byte_len.idx);
let transcode = self.transcoder(src, &dst, Transcode::Utf8ToUtf16);
self.instruction(LocalGet(src.ptr.idx));
self.instruction(LocalGet(src.len.idx));
self.instruction(LocalGet(dst.ptr.idx));
self.instruction(Call(transcode.as_u32()));
self.instruction(LocalSet(dst.len.idx));
// If the number of code units returned by transcode is not
// equal to the original number of code units then
// the buffer must be shrunk.
//
// Note that the byte length of the final allocation we
// want is twice the code unit length returned by the
// transcoding function.
self.convert_src_len_to_dst(src.len.idx, src.opts.ptr(), dst.opts.ptr());
self.instruction(LocalGet(dst.len.idx));
self.ptr_ne(dst_opts);
self.instruction(If(BlockType::Empty));
self.instruction(LocalGet(dst.ptr.idx));
self.instruction(LocalGet(dst_byte_len.idx));
self.ptr_uconst(dst.opts, 2);
self.instruction(LocalGet(dst.len.idx));
self.ptr_uconst(dst.opts, 1);
self.ptr_shl(dst.opts);
self.instruction(Call(dst.opts.realloc.unwrap().as_u32()));
self.instruction(LocalSet(dst.ptr.idx));
self.instruction(End); // end of shrink-to-fit
self.free_temp_local(dst_byte_len);
dst
}
// Corresponds to `store_probably_utf16_to_latin1_or_utf16` in the spec.
//
// This will try to transcode the input utf16 string to utf16 in the
// destination. If utf16 isn't needed though and latin1 could be used
// then that's used instead and a reallocation to downsize occurs
// afterwards.
//
// The host transcode function here will take the src/dst pointers as
// well as src length. The destination byte length is twice the src code
// unit length. The return value is the tagged length of the returned
// string. If the upper bit is set then utf16 was used and the
// conversion is done. If the upper bit is not set then latin1 was used
// and a downsizing needs to happen.
fn string_compact_utf16_to_compact<'a>(
&mut self,
src: &WasmString<'_>,
dst_opts: &'a Options,
) -> WasmString<'a> {
self.validate_string_length(src, FE::Utf16);
self.convert_src_len_to_dst(src.len.idx, src.opts.ptr(), dst_opts.ptr());
let dst_len = self.local_tee_new_tmp(dst_opts.ptr());
self.ptr_uconst(dst_opts, 1);
self.ptr_shl(dst_opts);
let dst_byte_len = self.local_set_new_tmp(dst_opts.ptr());
let dst = {
let dst_mem = self.malloc(dst_opts, MallocSize::Local(dst_byte_len.idx), 2);
WasmString {
ptr: dst_mem.addr,
len: dst_len,
opts: dst_opts,
}
};
self.convert_src_len_to_dst(dst_byte_len.idx, dst.opts.ptr(), src.opts.ptr());
let src_byte_len = self.local_set_new_tmp(src.opts.ptr());
self.validate_string_inbounds(src, src_byte_len.idx);
self.validate_string_inbounds(&dst, dst_byte_len.idx);
let transcode = self.transcoder(src, &dst, Transcode::Utf16ToCompactProbablyUtf16);
self.instruction(LocalGet(src.ptr.idx));
self.instruction(LocalGet(src.len.idx));
self.instruction(LocalGet(dst.ptr.idx));
self.instruction(Call(transcode.as_u32()));
self.instruction(LocalSet(dst.len.idx));
// Assert that the untagged code unit length is the same as the
// source code unit length.
if self.module.debug {
self.instruction(LocalGet(dst.len.idx));
self.ptr_uconst(dst.opts, !UTF16_TAG);
self.ptr_and(dst.opts);
self.convert_src_len_to_dst(src.len.idx, src.opts.ptr(), dst.opts.ptr());
self.ptr_ne(dst.opts);
self.instruction(If(BlockType::Empty));
self.trap(Trap::AssertFailed("expected equal code units"));
self.instruction(End);
}
// If the UTF16_TAG is set then utf16 was used and the destination
// should be appropriately sized. Bail out of the "is this string
// empty" block and fall through otherwise to resizing.
self.instruction(LocalGet(dst.len.idx));
self.ptr_uconst(dst.opts, UTF16_TAG);
self.ptr_and(dst.opts);
self.ptr_br_if(dst.opts, 0);
// Here `realloc` is used to downsize the string
self.instruction(LocalGet(dst.ptr.idx)); // old_ptr
self.instruction(LocalGet(dst_byte_len.idx)); // old_size
self.ptr_uconst(dst.opts, 2); // align
self.instruction(LocalGet(dst.len.idx)); // new_size
self.instruction(Call(dst.opts.realloc.unwrap().as_u32()));
self.instruction(LocalSet(dst.ptr.idx));
self.free_temp_local(dst_byte_len);
self.free_temp_local(src_byte_len);
dst
}
// Corresponds to `store_string_to_latin1_or_utf16` in the spec.
//
// This will attempt a first pass of transcoding to latin1 and on
// failure a larger buffer is allocated for utf16 and then utf16 is
// encoded in-place into the buffer. After either latin1 or utf16 the
// buffer is then resized to fit the final string allocation.
fn string_to_compact<'a>(
&mut self,
src: &WasmString<'_>,
src_enc: FE,
dst_opts: &'a Options,
) -> WasmString<'a> {
self.validate_string_length(src, src_enc);
self.convert_src_len_to_dst(src.len.idx, src.opts.ptr(), dst_opts.ptr());
let dst_len = self.local_tee_new_tmp(dst_opts.ptr());
let dst_byte_len = self.local_set_new_tmp(dst_opts.ptr());
let dst = {
let dst_mem = self.malloc(dst_opts, MallocSize::Local(dst_byte_len.idx), 2);
WasmString {
ptr: dst_mem.addr,
len: dst_len,
opts: dst_opts,
}
};
self.validate_string_inbounds(src, src.len.idx);
self.validate_string_inbounds(&dst, dst_byte_len.idx);
// Perform the initial latin1 transcode. This returns the number of
// source code units consumed and the number of destination code
// units (bytes) written.
let (latin1, utf16) = match src_enc {
FE::Utf8 => (Transcode::Utf8ToLatin1, Transcode::Utf8ToCompactUtf16),
FE::Utf16 => (Transcode::Utf16ToLatin1, Transcode::Utf16ToCompactUtf16),
FE::Latin1 => unreachable!(),
};
let transcode_latin1 = self.transcoder(src, &dst, latin1);
let transcode_utf16 = self.transcoder(src, &dst, utf16);
self.instruction(LocalGet(src.ptr.idx));
self.instruction(LocalGet(src.len.idx));
self.instruction(LocalGet(dst.ptr.idx));
self.instruction(Call(transcode_latin1.as_u32()));
self.instruction(LocalSet(dst.len.idx));
let src_len_tmp = self.local_set_new_tmp(src.opts.ptr());
// If the source was entirely consumed then the transcode completed
// and all that's necessary is to optionally shrink the buffer.
self.instruction(LocalGet(src_len_tmp.idx));
self.instruction(LocalGet(src.len.idx));
self.ptr_eq(src.opts);
self.instruction(If(BlockType::Empty)); // if latin1-or-utf16 block
// Test if the original byte length of the allocation is the same as
// the number of written bytes, and if not then shrink the buffer
// with a call to `realloc`.
self.instruction(LocalGet(dst_byte_len.idx));
self.instruction(LocalGet(dst.len.idx));
self.ptr_ne(dst.opts);
self.instruction(If(BlockType::Empty));
self.instruction(LocalGet(dst.ptr.idx)); // old_ptr
self.instruction(LocalGet(dst_byte_len.idx)); // old_size
self.ptr_uconst(dst.opts, 2); // align
self.instruction(LocalGet(dst.len.idx)); // new_size
self.instruction(Call(dst.opts.realloc.unwrap().as_u32()));
self.instruction(LocalSet(dst.ptr.idx));
self.instruction(End);
// In this block the latin1 encoding failed. The host transcode
// returned how many units were consumed from the source and how
// many bytes were written to the destination. Here the buffer is
// inflated and sized and the second utf16 intrinsic is invoked to
// perform the final inflation.
self.instruction(Else); // else latin1-or-utf16 block
// For utf8 validate that the inflated size is still within bounds.
if src_enc.width() == 1 {
self.validate_string_length_u8(src, 2);
}
// Reallocate the buffer with twice the source code units in byte
// size.
self.instruction(LocalGet(dst.ptr.idx)); // old_ptr
self.instruction(LocalGet(dst_byte_len.idx)); // old_size
self.ptr_uconst(dst.opts, 2); // align
self.convert_src_len_to_dst(src.len.idx, src.opts.ptr(), dst.opts.ptr());
self.ptr_uconst(dst.opts, 1);
self.ptr_shl(dst.opts);
self.instruction(LocalTee(dst_byte_len.idx));
self.instruction(Call(dst.opts.realloc.unwrap().as_u32()));
self.instruction(LocalSet(dst.ptr.idx));
// Call the host utf16 transcoding function. This will inflate the
// prior latin1 bytes and then encode the rest of the source string
// as utf16 into the remaining space in the destination buffer.
self.instruction(LocalGet(src.ptr.idx));
self.instruction(LocalGet(src_len_tmp.idx));
if let FE::Utf16 = src_enc {
self.ptr_uconst(src.opts, 1);
self.ptr_shl(src.opts);
}
self.ptr_add(src.opts);
self.instruction(LocalGet(src.len.idx));
self.instruction(LocalGet(src_len_tmp.idx));
self.ptr_sub(src.opts);
self.instruction(LocalGet(dst.ptr.idx));
self.convert_src_len_to_dst(src.len.idx, src.opts.ptr(), dst.opts.ptr());
self.instruction(LocalGet(dst.len.idx));
self.instruction(Call(transcode_utf16.as_u32()));
self.instruction(LocalSet(dst.len.idx));
// If the returned number of code units written to the destination
// is not equal to the size of the allocation then the allocation is
// resized down to the appropriate size.
//
// Note that the byte size desired is `2*dst_len` and the current
// byte buffer size is `2*src_len` so the `2` factor isn't checked
// here, just the lengths.
self.instruction(LocalGet(dst.len.idx));
self.convert_src_len_to_dst(src.len.idx, src.opts.ptr(), dst.opts.ptr());
self.ptr_ne(dst.opts);
self.instruction(If(BlockType::Empty));
self.instruction(LocalGet(dst.ptr.idx)); // old_ptr
self.instruction(LocalGet(dst_byte_len.idx)); // old_size
self.ptr_uconst(dst.opts, 2); // align
self.instruction(LocalGet(dst.len.idx));
self.ptr_uconst(dst.opts, 1);
self.ptr_shl(dst.opts);
self.instruction(Call(dst.opts.realloc.unwrap().as_u32()));
self.instruction(LocalSet(dst.ptr.idx));
self.instruction(End);
// Tag the returned pointer as utf16
self.instruction(LocalGet(dst.len.idx));
self.ptr_uconst(dst.opts, UTF16_TAG);
self.ptr_or(dst.opts);
self.instruction(LocalSet(dst.len.idx));
self.instruction(End); // end latin1-or-utf16 block
self.free_temp_local(src_len_tmp);
self.free_temp_local(dst_byte_len);
dst
}
fn validate_string_length(&mut self, src: &WasmString<'_>, dst: FE) {
self.validate_string_length_u8(src, dst.width())
}
fn validate_string_length_u8(&mut self, s: &WasmString<'_>, dst: u8) {
// Check to see if the source byte length is out of bounds in
// which case a trap is generated.
self.instruction(LocalGet(s.len.idx));
let max = MAX_STRING_BYTE_LENGTH / u32::from(dst);
self.ptr_uconst(s.opts, max);
self.ptr_ge_u(s.opts);
self.instruction(If(BlockType::Empty));
self.trap(Trap::StringLengthTooBig);
self.instruction(End);
}
fn transcoder(
&mut self,
src: &WasmString<'_>,
dst: &WasmString<'_>,
op: Transcode,
) -> FuncIndex {
self.module.import_transcoder(Transcoder {
from_memory: src.opts.memory.unwrap(),
from_memory64: src.opts.memory64,
to_memory: dst.opts.memory.unwrap(),
to_memory64: dst.opts.memory64,
op,
})
}
fn validate_string_inbounds(&mut self, s: &WasmString<'_>, byte_len: u32) {
self.validate_memory_inbounds(s.opts, s.ptr.idx, byte_len, Trap::StringLengthOverflow)
}
fn validate_memory_inbounds(
&mut self,
opts: &Options,
ptr_local: u32,
byte_len_local: u32,
trap: Trap,
) {
let extend_to_64 = |me: &mut Self| {
if !opts.memory64 {
me.instruction(I64ExtendI32U);
}
};
self.instruction(Block(BlockType::Empty));
self.instruction(Block(BlockType::Empty));
// Calculate the full byte size of memory with `memory.size`. Note that
// arithmetic here is done always in 64-bits to accommodate 4G memories.
// Additionally it's assumed that 64-bit memories never fill up
// entirely.
self.instruction(MemorySize(opts.memory.unwrap().as_u32()));
extend_to_64(self);
self.instruction(I64Const(16));
self.instruction(I64Shl);
// Calculate the end address of the string. This is done by adding the
// base pointer to the byte length. For 32-bit memories there's no need
// to check for overflow since everything is extended to 64-bit, but for
// 64-bit memories overflow is checked.
self.instruction(LocalGet(ptr_local));
extend_to_64(self);
self.instruction(LocalGet(byte_len_local));
extend_to_64(self);
self.instruction(I64Add);
if opts.memory64 {
let tmp = self.local_tee_new_tmp(ValType::I64);
self.instruction(LocalGet(ptr_local));
self.ptr_lt_u(opts);
self.instruction(BrIf(0));
self.instruction(LocalGet(tmp.idx));
self.free_temp_local(tmp);
}
// If the byte size of memory is greater than the final address of the
// string then the string is invalid. Note that if it's precisely equal
// then that's ok.
self.instruction(I64GeU);
self.instruction(BrIf(1));
self.instruction(End);
self.trap(trap);
self.instruction(End);
}
fn translate_list(
&mut self,
src_ty: TypeListIndex,
src: &Source<'_>,
dst_ty: &InterfaceType,
dst: &Destination,
) {
let src_element_ty = &self.types[src_ty].element;
let dst_element_ty = match dst_ty {
InterfaceType::List(r) => &self.types[*r].element,
_ => panic!("expected a list"),
};
let src_opts = src.opts();
let dst_opts = dst.opts();
let (src_size, src_align) = self.types.size_align(src_opts, src_element_ty);
let (dst_size, dst_align) = self.types.size_align(dst_opts, dst_element_ty);
// Load the pointer/length of this list into temporary locals. These
// will be referenced a good deal so this just makes it easier to deal
// with them consistently below rather than trying to reload from memory
// for example.
match src {
Source::Stack(s) => {
assert_eq!(s.locals.len(), 2);
self.stack_get(&s.slice(0..1), src_opts.ptr());
self.stack_get(&s.slice(1..2), src_opts.ptr());
}
Source::Memory(mem) => {
self.ptr_load(mem);
self.ptr_load(&mem.bump(src_opts.ptr_size().into()));
}
}
let src_len = self.local_set_new_tmp(src_opts.ptr());
let src_ptr = self.local_set_new_tmp(src_opts.ptr());
// Create a `Memory` operand which will internally assert that the
// `src_ptr` value is properly aligned.
let src_mem = self.memory_operand(src_opts, src_ptr, src_align);
// Calculate the source/destination byte lengths into unique locals.
let src_byte_len = self.calculate_list_byte_len(src_opts, src_len.idx, src_size);
let dst_byte_len = if src_size == dst_size {
self.convert_src_len_to_dst(src_byte_len.idx, src_opts.ptr(), dst_opts.ptr());
self.local_set_new_tmp(dst_opts.ptr())
} else if src_opts.ptr() == dst_opts.ptr() {
self.calculate_list_byte_len(dst_opts, src_len.idx, dst_size)
} else {
self.convert_src_len_to_dst(src_byte_len.idx, src_opts.ptr(), dst_opts.ptr());
let tmp = self.local_set_new_tmp(dst_opts.ptr());
let ret = self.calculate_list_byte_len(dst_opts, tmp.idx, dst_size);
self.free_temp_local(tmp);
ret
};
// Here `realloc` is invoked (in a `malloc`-like fashion) to allocate
// space for the list in the destination memory. This will also
// internally insert checks that the returned pointer is aligned
// correctly for the destination.
let dst_mem = self.malloc(dst_opts, MallocSize::Local(dst_byte_len.idx), dst_align);
// With all the pointers and byte lengths verity that both the source
// and the destination buffers are in-bounds.
self.validate_memory_inbounds(
src_opts,
src_mem.addr.idx,
src_byte_len.idx,
Trap::ListByteLengthOverflow,
);
self.validate_memory_inbounds(
dst_opts,
dst_mem.addr.idx,
dst_byte_len.idx,
Trap::ListByteLengthOverflow,
);
self.free_temp_local(src_byte_len);
self.free_temp_local(dst_byte_len);
// This is the main body of the loop to actually translate list types.
// Note that if both element sizes are 0 then this won't actually do
// anything so the loop is removed entirely.
if src_size > 0 || dst_size > 0 {
// This block encompasses the entire loop and is use to exit before even
// entering the loop if the list size is zero.
self.instruction(Block(BlockType::Empty));
// Set the `remaining` local and only continue if it's > 0
self.instruction(LocalGet(src_len.idx));
let remaining = self.local_tee_new_tmp(src_opts.ptr());
self.ptr_eqz(src_opts);
self.instruction(BrIf(0));
// Initialize the two destination pointers to their initial values
self.instruction(LocalGet(src_mem.addr.idx));
let cur_src_ptr = self.local_set_new_tmp(src_opts.ptr());
self.instruction(LocalGet(dst_mem.addr.idx));
let cur_dst_ptr = self.local_set_new_tmp(dst_opts.ptr());
self.instruction(Loop(BlockType::Empty));
// Translate the next element in the list
let element_src = Source::Memory(Memory {
opts: src_opts,
offset: 0,
addr: TempLocal::new(cur_src_ptr.idx, cur_src_ptr.ty),
});
let element_dst = Destination::Memory(Memory {
opts: dst_opts,
offset: 0,
addr: TempLocal::new(cur_dst_ptr.idx, cur_dst_ptr.ty),
});
self.translate(src_element_ty, &element_src, dst_element_ty, &element_dst);
// Update the two loop pointers
if src_size > 0 {
self.instruction(LocalGet(cur_src_ptr.idx));
self.ptr_uconst(src_opts, src_size);
self.ptr_add(src_opts);
self.instruction(LocalSet(cur_src_ptr.idx));
}
if dst_size > 0 {
self.instruction(LocalGet(cur_dst_ptr.idx));
self.ptr_uconst(dst_opts, dst_size);
self.ptr_add(dst_opts);
self.instruction(LocalSet(cur_dst_ptr.idx));
}
// Update the remaining count, falling through to break out if it's zero
// now.
self.instruction(LocalGet(remaining.idx));
self.ptr_iconst(src_opts, -1);
self.ptr_add(src_opts);
self.instruction(LocalTee(remaining.idx));
self.ptr_br_if(src_opts, 0);
self.instruction(End); // end of loop
self.instruction(End); // end of block
self.free_temp_local(cur_dst_ptr);
self.free_temp_local(cur_src_ptr);
self.free_temp_local(remaining);
}
// Store the ptr/length in the desired destination
match dst {
Destination::Stack(s, _) => {
self.instruction(LocalGet(dst_mem.addr.idx));
self.stack_set(&s[..1], dst_opts.ptr());
self.convert_src_len_to_dst(src_len.idx, src_opts.ptr(), dst_opts.ptr());
self.stack_set(&s[1..], dst_opts.ptr());
}
Destination::Memory(mem) => {
self.instruction(LocalGet(mem.addr.idx));
self.instruction(LocalGet(dst_mem.addr.idx));
self.ptr_store(mem);
self.instruction(LocalGet(mem.addr.idx));
self.convert_src_len_to_dst(src_len.idx, src_opts.ptr(), dst_opts.ptr());
self.ptr_store(&mem.bump(dst_opts.ptr_size().into()));
}
}
self.free_temp_local(src_len);
self.free_temp_local(src_mem.addr);
self.free_temp_local(dst_mem.addr);
}
fn calculate_list_byte_len(
&mut self,
opts: &Options,
len_local: u32,
elt_size: u32,
) -> TempLocal {
// Zero-size types are easy to handle here because the byte size of the
// destination is always zero.
if elt_size == 0 {
self.ptr_uconst(opts, 0);
return self.local_set_new_tmp(opts.ptr());
}
// For one-byte elements in the destination the check here can be a bit
// more optimal than the general case below. In these situations if the
// source pointer type is 32-bit then we're guaranteed to not overflow,
// so the source length is simply casted to the destination's type.
//
// If the source is 64-bit then all that needs to be checked is to
// ensure that it does not have the upper 32-bits set.
if elt_size == 1 {
if let ValType::I64 = opts.ptr() {
self.instruction(LocalGet(len_local));
self.instruction(I64Const(32));
self.instruction(I64ShrU);
self.instruction(I32WrapI64);
self.instruction(If(BlockType::Empty));
self.trap(Trap::ListByteLengthOverflow);
self.instruction(End);
}
self.instruction(LocalGet(len_local));
return self.local_set_new_tmp(opts.ptr());
}
// The main check implemented by this function is to verify that
// `src_len_local` does not exceed the 32-bit range. Byte sizes for
// lists must always fit in 32-bits to get transferred to 32-bit
// memories.
self.instruction(Block(BlockType::Empty));
self.instruction(Block(BlockType::Empty));
self.instruction(LocalGet(len_local));
match opts.ptr() {
// The source's list length is guaranteed to be less than 32-bits
// so simply extend it up to a 64-bit type for the multiplication
// below.
ValType::I32 => self.instruction(I64ExtendI32U),
// If the source is a 64-bit memory then if the item length doesn't
// fit in 32-bits the byte length definitely won't, so generate a
// branch to our overflow trap here if any of the upper 32-bits are set.
ValType::I64 => {
self.instruction(I64Const(32));
self.instruction(I64ShrU);
self.instruction(I32WrapI64);
self.instruction(BrIf(0));
self.instruction(LocalGet(len_local));
}
_ => unreachable!(),
}
// Next perform a 64-bit multiplication with the element byte size that
// is itself guaranteed to fit in 32-bits. The result is then checked
// to see if we overflowed the 32-bit space. The two input operands to
// the multiplication are guaranteed to be 32-bits at most which means
// that this multiplication shouldn't overflow.
//
// The result of the multiplication is saved into a local as well to
// get the result afterwards.
self.instruction(I64Const(elt_size.into()));
self.instruction(I64Mul);
let tmp = self.local_tee_new_tmp(ValType::I64);
// Branch to success if the upper 32-bits are zero, otherwise
// fall-through to the trap.
self.instruction(I64Const(32));
self.instruction(I64ShrU);
self.instruction(I64Eqz);
self.instruction(BrIf(1));
self.instruction(End);
self.trap(Trap::ListByteLengthOverflow);
self.instruction(End);
// If a fresh local was used to store the result of the multiplication
// then convert it down to 32-bits which should be guaranteed to not
// lose information at this point.
if opts.ptr() == ValType::I64 {
tmp
} else {
self.instruction(LocalGet(tmp.idx));
self.instruction(I32WrapI64);
self.free_temp_local(tmp);
self.local_set_new_tmp(ValType::I32)
}
}
fn convert_src_len_to_dst(
&mut self,
src_len_local: u32,
src_ptr_ty: ValType,
dst_ptr_ty: ValType,
) {
self.instruction(LocalGet(src_len_local));
match (src_ptr_ty, dst_ptr_ty) {
(ValType::I32, ValType::I64) => self.instruction(I64ExtendI32U),
(ValType::I64, ValType::I32) => self.instruction(I32WrapI64),
(src, dst) => assert_eq!(src, dst),
}
}
fn translate_record(
&mut self,
src_ty: TypeRecordIndex,
src: &Source<'_>,
dst_ty: &InterfaceType,
dst: &Destination,
) {
let src_ty = &self.types[src_ty];
let dst_ty = match dst_ty {
InterfaceType::Record(r) => &self.types[*r],
_ => panic!("expected a record"),
};
// TODO: subtyping
assert_eq!(src_ty.fields.len(), dst_ty.fields.len());
// First a map is made of the source fields to where they're coming
// from (e.g. which offset or which locals). This map is keyed by the
// fields' names
let mut src_fields = HashMap::new();
for (i, src) in src
.record_field_srcs(self.types, src_ty.fields.iter().map(|f| f.ty))
.enumerate()
{
let field = &src_ty.fields[i];
src_fields.insert(&field.name, (src, &field.ty));
}
// .. and next translation is performed in the order of the destination
// fields in case the destination is the stack to ensure that the stack
// has the fields all in the right order.
//
// Note that the lookup in `src_fields` is an infallible lookup which
// will panic if the field isn't found.
//
// TODO: should that lookup be fallible with subtyping?
for (i, dst) in dst
.record_field_dsts(self.types, dst_ty.fields.iter().map(|f| f.ty))
.enumerate()
{
let field = &dst_ty.fields[i];
let (src, src_ty) = &src_fields[&field.name];
self.translate(src_ty, src, &field.ty, &dst);
}
}
fn translate_flags(
&mut self,
src_ty: TypeFlagsIndex,
src: &Source<'_>,
dst_ty: &InterfaceType,
dst: &Destination,
) {
let src_ty = &self.types[src_ty];
let dst_ty = match dst_ty {
InterfaceType::Flags(r) => &self.types[*r],
_ => panic!("expected a record"),
};
// TODO: subtyping
//
// Notably this implementation does not support reordering flags from
// the source to the destination nor having more flags in the
// destination. Currently this is a copy from source to destination
// in-bulk. Otherwise reordering indices would have to have some sort of
// fancy bit twiddling tricks or something like that.
assert_eq!(src_ty.names, dst_ty.names);
let cnt = src_ty.names.len();
match FlagsSize::from_count(cnt) {
FlagsSize::Size0 => {}
FlagsSize::Size1 => {
let mask = if cnt == 8 { 0xff } else { (1 << cnt) - 1 };
self.convert_u8_mask(src, dst, mask);
}
FlagsSize::Size2 => {
let mask = if cnt == 16 { 0xffff } else { (1 << cnt) - 1 };
self.convert_u16_mask(src, dst, mask);
}
FlagsSize::Size4Plus(n) => {
let srcs = src.record_field_srcs(self.types, (0..n).map(|_| InterfaceType::U32));
let dsts = dst.record_field_dsts(self.types, (0..n).map(|_| InterfaceType::U32));
let n = usize::from(n);
for (i, (src, dst)) in srcs.zip(dsts).enumerate() {
let mask = if i == n - 1 && (cnt % 32 != 0) {
(1 << (cnt % 32)) - 1
} else {
0xffffffff
};
self.convert_u32_mask(&src, &dst, mask);
}
}
}
}
fn translate_tuple(
&mut self,
src_ty: TypeTupleIndex,
src: &Source<'_>,
dst_ty: &InterfaceType,
dst: &Destination,
) {
let src_ty = &self.types[src_ty];
let dst_ty = match dst_ty {
InterfaceType::Tuple(t) => &self.types[*t],
_ => panic!("expected a tuple"),
};
// TODO: subtyping
assert_eq!(src_ty.types.len(), dst_ty.types.len());
let srcs = src
.record_field_srcs(self.types, src_ty.types.iter().copied())
.zip(src_ty.types.iter());
let dsts = dst
.record_field_dsts(self.types, dst_ty.types.iter().copied())
.zip(dst_ty.types.iter());
for ((src, src_ty), (dst, dst_ty)) in srcs.zip(dsts) {
self.translate(src_ty, &src, dst_ty, &dst);
}
}
fn translate_variant(
&mut self,
src_ty: TypeVariantIndex,
src: &Source<'_>,
dst_ty: &InterfaceType,
dst: &Destination,
) {
let src_ty = &self.types[src_ty];
let dst_ty = match dst_ty {
InterfaceType::Variant(t) => &self.types[*t],
_ => panic!("expected a variant"),
};
let src_info = variant_info(self.types, src_ty.cases.iter().map(|(_, c)| c.as_ref()));
let dst_info = variant_info(self.types, dst_ty.cases.iter().map(|(_, c)| c.as_ref()));
let iter = src_ty
.cases
.iter()
.enumerate()
.map(|(src_i, (src_case, src_case_ty))| {
let dst_i = dst_ty
.cases
.iter()
.position(|(c, _)| c == src_case)
.unwrap();
let dst_case_ty = &dst_ty.cases[dst_i];
let src_i = u32::try_from(src_i).unwrap();
let dst_i = u32::try_from(dst_i).unwrap();
VariantCase {
src_i,
src_ty: src_case_ty.as_ref(),
dst_i,
dst_ty: dst_case_ty.as_ref(),
}
});
self.convert_variant(src, &src_info, dst, &dst_info, iter);
}
fn translate_enum(
&mut self,
src_ty: TypeEnumIndex,
src: &Source<'_>,
dst_ty: &InterfaceType,
dst: &Destination,
) {
let src_ty = &self.types[src_ty];
let dst_ty = match dst_ty {
InterfaceType::Enum(t) => &self.types[*t],
_ => panic!("expected an option"),
};
let src_info = variant_info(self.types, src_ty.names.iter().map(|_| None));
let dst_info = variant_info(self.types, dst_ty.names.iter().map(|_| None));
self.convert_variant(
src,
&src_info,
dst,
&dst_info,
src_ty.names.iter().enumerate().map(|(src_i, src_name)| {
let dst_i = dst_ty.names.iter().position(|n| n == src_name).unwrap();
let src_i = u32::try_from(src_i).unwrap();
let dst_i = u32::try_from(dst_i).unwrap();
VariantCase {
src_i,
dst_i,
src_ty: None,
dst_ty: None,
}
}),
);
}
fn translate_option(
&mut self,
src_ty: TypeOptionIndex,
src: &Source<'_>,
dst_ty: &InterfaceType,
dst: &Destination,
) {
let src_ty = &self.types[src_ty].ty;
let dst_ty = match dst_ty {
InterfaceType::Option(t) => &self.types[*t].ty,
_ => panic!("expected an option"),
};
let src_ty = Some(src_ty);
let dst_ty = Some(dst_ty);
let src_info = variant_info(self.types, [None, src_ty]);
let dst_info = variant_info(self.types, [None, dst_ty]);
self.convert_variant(
src,
&src_info,
dst,
&dst_info,
[
VariantCase {
src_i: 0,
dst_i: 0,
src_ty: None,
dst_ty: None,
},
VariantCase {
src_i: 1,
dst_i: 1,
src_ty,
dst_ty,
},
]
.into_iter(),
);
}
fn translate_result(
&mut self,
src_ty: TypeResultIndex,
src: &Source<'_>,
dst_ty: &InterfaceType,
dst: &Destination,
) {
let src_ty = &self.types[src_ty];
let dst_ty = match dst_ty {
InterfaceType::Result(t) => &self.types[*t],
_ => panic!("expected a result"),
};
let src_info = variant_info(self.types, [src_ty.ok.as_ref(), src_ty.err.as_ref()]);
let dst_info = variant_info(self.types, [dst_ty.ok.as_ref(), dst_ty.err.as_ref()]);
self.convert_variant(
src,
&src_info,
dst,
&dst_info,
[
VariantCase {
src_i: 0,
dst_i: 0,
src_ty: src_ty.ok.as_ref(),
dst_ty: dst_ty.ok.as_ref(),
},
VariantCase {
src_i: 1,
dst_i: 1,
src_ty: src_ty.err.as_ref(),
dst_ty: dst_ty.err.as_ref(),
},
]
.into_iter(),
);
}
fn convert_variant<'a>(
&mut self,
src: &Source<'_>,
src_info: &VariantInfo,
dst: &Destination,
dst_info: &VariantInfo,
src_cases: impl ExactSizeIterator<Item = VariantCase<'a>>,
) {
// The outermost block is special since it has the result type of the
// translation here. That will depend on the `dst`.
let outer_block_ty = match dst {
Destination::Stack(dst_flat, _) => match dst_flat.len() {
0 => BlockType::Empty,
1 => BlockType::Result(dst_flat[0]),
_ => {
let ty = self.module.core_types.function(&[], &dst_flat);
BlockType::FunctionType(ty)
}
},
Destination::Memory(_) => BlockType::Empty,
};
self.instruction(Block(outer_block_ty));
// After the outermost block generate a new block for each of the
// remaining cases.
let src_cases_len = src_cases.len();
for _ in 0..src_cases_len - 1 {
self.instruction(Block(BlockType::Empty));
}
// Generate a block for an invalid variant discriminant
self.instruction(Block(BlockType::Empty));
// And generate one final block that we'll be jumping out of with the
// `br_table`
self.instruction(Block(BlockType::Empty));
// Load the discriminant
match src {
Source::Stack(s) => self.stack_get(&s.slice(0..1), ValType::I32),
Source::Memory(mem) => match src_info.size {
DiscriminantSize::Size1 => self.i32_load8u(mem),
DiscriminantSize::Size2 => self.i32_load16u(mem),
DiscriminantSize::Size4 => self.i32_load(mem),
},
}
// Generate the `br_table` for the discriminant. Each case has an
// offset of 1 to skip the trapping block.
let mut targets = Vec::new();
for i in 0..src_cases_len {
targets.push((i + 1) as u32);
}
self.instruction(BrTable(targets[..].into(), 0));
self.instruction(End); // end the `br_table` block
self.trap(Trap::InvalidDiscriminant);
self.instruction(End); // end the "invalid discriminant" block
// Translate each case individually within its own block. Note that the
// iteration order here places the first case in the innermost block
// and the last case in the outermost block. This matches the order
// of the jump targets in the `br_table` instruction.
let src_cases_len = u32::try_from(src_cases_len).unwrap();
for case in src_cases {
let VariantCase {
src_i,
src_ty,
dst_i,
dst_ty,
} = case;
// Translate the discriminant here, noting that `dst_i` may be
// different than `src_i`.
self.push_dst_addr(dst);
self.instruction(I32Const(dst_i as i32));
match dst {
Destination::Stack(stack, _) => self.stack_set(&stack[..1], ValType::I32),
Destination::Memory(mem) => match dst_info.size {
DiscriminantSize::Size1 => self.i32_store8(mem),
DiscriminantSize::Size2 => self.i32_store16(mem),
DiscriminantSize::Size4 => self.i32_store(mem),
},
}
let src_payload = src.payload_src(self.types, src_info, src_ty);
let dst_payload = dst.payload_dst(self.types, dst_info, dst_ty);
// Translate the payload of this case using the various types from
// the dst/src.
match (src_ty, dst_ty) {
(Some(src_ty), Some(dst_ty)) => {
self.translate(src_ty, &src_payload, dst_ty, &dst_payload);
}
(None, None) => {}
_ => unimplemented!(),
}
// If the results of this translation were placed on the stack then
// the stack values may need to be padded with more zeros due to
// this particular case being possibly smaller than the entire
// variant. That's handled here by pushing remaining zeros after
// accounting for the discriminant pushed as well as the results of
// this individual payload.
if let Destination::Stack(payload_results, _) = dst_payload {
if let Destination::Stack(dst_results, _) = dst {
let remaining = &dst_results[1..][payload_results.len()..];
for ty in remaining {
match ty {
ValType::I32 => self.instruction(I32Const(0)),
ValType::I64 => self.instruction(I64Const(0)),
ValType::F32 => self.instruction(F32Const(0.0)),
ValType::F64 => self.instruction(F64Const(0.0)),
_ => unreachable!(),
}
}
}
}
// Branch to the outermost block. Note that this isn't needed for
// the outermost case since it simply falls through.
if src_i != src_cases_len - 1 {
self.instruction(Br(src_cases_len - src_i - 1));
}
self.instruction(End); // end this case's block
}
}
fn translate_own(
&mut self,
src_ty: TypeResourceTableIndex,
src: &Source<'_>,
dst_ty: &InterfaceType,
dst: &Destination,
) {
let dst_ty = match dst_ty {
InterfaceType::Own(t) => *t,
_ => panic!("expected an `Own`"),
};
let transfer = self.module.import_resource_transfer_own();
self.translate_resource(src_ty, src, dst_ty, dst, transfer);
}
fn translate_borrow(
&mut self,
src_ty: TypeResourceTableIndex,
src: &Source<'_>,
dst_ty: &InterfaceType,
dst: &Destination,
) {
let dst_ty = match dst_ty {
InterfaceType::Borrow(t) => *t,
_ => panic!("expected an `Borrow`"),
};
let transfer = self.module.import_resource_transfer_borrow();
self.translate_resource(src_ty, src, dst_ty, dst, transfer);
}
/// Translates the index `src`, which resides in the table `src_ty`, into
/// and index within `dst_ty` and is stored at `dst`.
///
/// Actual translation of the index happens in a wasmtime libcall, which a
/// cranelift-generated trampoline to satisfy this import will call. The
/// `transfer` function is an imported function which takes the src, src_ty,
/// and dst_ty, and returns the dst index.
fn translate_resource(
&mut self,
src_ty: TypeResourceTableIndex,
src: &Source<'_>,
dst_ty: TypeResourceTableIndex,
dst: &Destination,
transfer: FuncIndex,
) {
self.push_dst_addr(dst);
match src {
Source::Memory(mem) => self.i32_load(mem),
Source::Stack(stack) => self.stack_get(stack, ValType::I32),
}
self.instruction(I32Const(src_ty.as_u32() as i32));
self.instruction(I32Const(dst_ty.as_u32() as i32));
self.instruction(Call(transfer.as_u32()));
match dst {
Destination::Memory(mem) => self.i32_store(mem),
Destination::Stack(stack, _) => self.stack_set(stack, ValType::I32),
}
}
fn trap_if_not_flag(&mut self, flags_global: GlobalIndex, flag_to_test: i32, trap: Trap) {
self.instruction(GlobalGet(flags_global.as_u32()));
self.instruction(I32Const(flag_to_test));
self.instruction(I32And);
self.instruction(I32Eqz);
self.instruction(If(BlockType::Empty));
self.trap(trap);
self.instruction(End);
}
fn assert_not_flag(&mut self, flags_global: GlobalIndex, flag_to_test: i32, msg: &'static str) {
self.instruction(GlobalGet(flags_global.as_u32()));
self.instruction(I32Const(flag_to_test));
self.instruction(I32And);
self.instruction(If(BlockType::Empty));
self.trap(Trap::AssertFailed(msg));
self.instruction(End);
}
fn set_flag(&mut self, flags_global: GlobalIndex, flag_to_set: i32, value: bool) {
self.instruction(GlobalGet(flags_global.as_u32()));
if value {
self.instruction(I32Const(flag_to_set));
self.instruction(I32Or);
} else {
self.instruction(I32Const(!flag_to_set));
self.instruction(I32And);
}
self.instruction(GlobalSet(flags_global.as_u32()));
}
fn verify_aligned(&mut self, opts: &Options, addr_local: u32, align: u32) {
// If the alignment is 1 then everything is trivially aligned and the
// check can be omitted.
if align == 1 {
return;
}
self.instruction(LocalGet(addr_local));
assert!(align.is_power_of_two());
self.ptr_uconst(opts, align - 1);
self.ptr_and(opts);
self.ptr_if(opts, BlockType::Empty);
self.trap(Trap::UnalignedPointer);
self.instruction(End);
}
fn assert_aligned(&mut self, ty: &InterfaceType, mem: &Memory) {
if !self.module.debug {
return;
}
let align = self.types.align(mem.opts, ty);
if align == 1 {
return;
}
assert!(align.is_power_of_two());
self.instruction(LocalGet(mem.addr.idx));
self.ptr_uconst(mem.opts, mem.offset);
self.ptr_add(mem.opts);
self.ptr_uconst(mem.opts, align - 1);
self.ptr_and(mem.opts);
self.ptr_if(mem.opts, BlockType::Empty);
self.trap(Trap::AssertFailed("pointer not aligned"));
self.instruction(End);
}
fn malloc<'a>(&mut self, opts: &'a Options, size: MallocSize, align: u32) -> Memory<'a> {
let realloc = opts.realloc.unwrap();
self.ptr_uconst(opts, 0);
self.ptr_uconst(opts, 0);
self.ptr_uconst(opts, align);
match size {
MallocSize::Const(size) => self.ptr_uconst(opts, size),
MallocSize::Local(idx) => self.instruction(LocalGet(idx)),
}
self.instruction(Call(realloc.as_u32()));
let addr = self.local_set_new_tmp(opts.ptr());
self.memory_operand(opts, addr, align)
}
fn memory_operand<'a>(&mut self, opts: &'a Options, addr: TempLocal, align: u32) -> Memory<'a> {
let ret = Memory {
addr,
offset: 0,
opts,
};
self.verify_aligned(opts, ret.addr.idx, align);
ret
}
/// Generates a new local in this function of the `ty` specified,
/// initializing it with the top value on the current wasm stack.
///
/// The returned `TempLocal` must be freed after it is finished with
/// `free_temp_local`.
fn local_tee_new_tmp(&mut self, ty: ValType) -> TempLocal {
self.gen_temp_local(ty, LocalTee)
}
/// Same as `local_tee_new_tmp` but initializes the local with `LocalSet`
/// instead of `LocalTee`.
fn local_set_new_tmp(&mut self, ty: ValType) -> TempLocal {
self.gen_temp_local(ty, LocalSet)
}
fn gen_temp_local(&mut self, ty: ValType, insn: fn(u32) -> Instruction<'static>) -> TempLocal {
// First check to see if any locals are available in this function which
// were previously generated but are no longer in use.
if let Some(idx) = self.free_locals.get_mut(&ty).and_then(|v| v.pop()) {
self.instruction(insn(idx));
return TempLocal {
ty,
idx,
needs_free: true,
};
}
// Failing that generate a fresh new local.
let locals = &mut self.module.funcs[self.result].locals;
match locals.last_mut() {
Some((cnt, prev_ty)) if ty == *prev_ty => *cnt += 1,
_ => locals.push((1, ty)),
}
self.nlocals += 1;
let idx = self.nlocals - 1;
self.instruction(insn(idx));
TempLocal {
ty,
idx,
needs_free: true,
}
}
/// Used to release a `TempLocal` from a particular lexical scope to allow
/// its possible reuse in later scopes.
fn free_temp_local(&mut self, mut local: TempLocal) {
assert!(local.needs_free);
self.free_locals
.entry(local.ty)
.or_insert(Vec::new())
.push(local.idx);
local.needs_free = false;
}
fn instruction(&mut self, instr: Instruction) {
instr.encode(&mut self.code);
}
fn trap(&mut self, trap: Trap) {
self.traps.push((self.code.len(), trap));
self.instruction(Unreachable);
}
/// Flushes out the current `code` instructions (and `traps` if there are
/// any) into the destination function.
///
/// This is a noop if no instructions have been encoded yet.
fn flush_code(&mut self) {
if self.code.is_empty() {
return;
}
self.module.funcs[self.result].body.push(Body::Raw(
mem::take(&mut self.code),
mem::take(&mut self.traps),
));
}
fn finish(mut self) {
// Append the final `end` instruction which all functions require, and
// then empty out the temporary buffer in `Compiler`.
self.instruction(End);
self.flush_code();
// Flag the function as "done" which helps with an assert later on in
// emission that everything was eventually finished.
self.module.funcs[self.result].filled_in = true;
}
/// Fetches the value contained with the local specified by `stack` and
/// converts it to `dst_ty`.
///
/// This is only intended for use in primitive operations where `stack` is
/// guaranteed to have only one local. The type of the local on the stack is
/// then converted to `dst_ty` appropriately. Note that the types may be
/// different due to the "flattening" of variant types.
fn stack_get(&mut self, stack: &Stack<'_>, dst_ty: ValType) {
assert_eq!(stack.locals.len(), 1);
let (idx, src_ty) = stack.locals[0];
self.instruction(LocalGet(idx));
match (src_ty, dst_ty) {
(ValType::I32, ValType::I32)
| (ValType::I64, ValType::I64)
| (ValType::F32, ValType::F32)
| (ValType::F64, ValType::F64) => {}
(ValType::I32, ValType::F32) => self.instruction(F32ReinterpretI32),
(ValType::I64, ValType::I32) => {
self.assert_i64_upper_bits_not_set(idx);
self.instruction(I32WrapI64);
}
(ValType::I64, ValType::F64) => self.instruction(F64ReinterpretI64),
(ValType::I64, ValType::F32) => {
self.assert_i64_upper_bits_not_set(idx);
self.instruction(I32WrapI64);
self.instruction(F32ReinterpretI32);
}
// should not be possible given the `join` function for variants
(ValType::I32, ValType::I64)
| (ValType::I32, ValType::F64)
| (ValType::F32, ValType::I32)
| (ValType::F32, ValType::I64)
| (ValType::F32, ValType::F64)
| (ValType::F64, ValType::I32)
| (ValType::F64, ValType::I64)
| (ValType::F64, ValType::F32)
// not used in the component model
| (ValType::Ref(_), _)
| (_, ValType::Ref(_))
| (ValType::V128, _)
| (_, ValType::V128) => {
panic!("cannot get {dst_ty:?} from {src_ty:?} local");
}
}
}
fn assert_i64_upper_bits_not_set(&mut self, local: u32) {
if !self.module.debug {
return;
}
self.instruction(LocalGet(local));
self.instruction(I64Const(32));
self.instruction(I64ShrU);
self.instruction(I32WrapI64);
self.instruction(If(BlockType::Empty));
self.trap(Trap::AssertFailed("upper bits are unexpectedly set"));
self.instruction(End);
}
/// Converts the top value on the WebAssembly stack which has type
/// `src_ty` to `dst_tys[0]`.
///
/// This is only intended for conversion of primitives where the `dst_tys`
/// list is known to be of length 1.
fn stack_set(&mut self, dst_tys: &[ValType], src_ty: ValType) {
assert_eq!(dst_tys.len(), 1);
let dst_ty = dst_tys[0];
match (src_ty, dst_ty) {
(ValType::I32, ValType::I32)
| (ValType::I64, ValType::I64)
| (ValType::F32, ValType::F32)
| (ValType::F64, ValType::F64) => {}
(ValType::F32, ValType::I32) => self.instruction(I32ReinterpretF32),
(ValType::I32, ValType::I64) => self.instruction(I64ExtendI32U),
(ValType::F64, ValType::I64) => self.instruction(I64ReinterpretF64),
(ValType::F32, ValType::I64) => {
self.instruction(I32ReinterpretF32);
self.instruction(I64ExtendI32U);
}
// should not be possible given the `join` function for variants
(ValType::I64, ValType::I32)
| (ValType::F64, ValType::I32)
| (ValType::I32, ValType::F32)
| (ValType::I64, ValType::F32)
| (ValType::F64, ValType::F32)
| (ValType::I32, ValType::F64)
| (ValType::I64, ValType::F64)
| (ValType::F32, ValType::F64)
// not used in the component model
| (ValType::Ref(_), _)
| (_, ValType::Ref(_))
| (ValType::V128, _)
| (_, ValType::V128) => {
panic!("cannot get {dst_ty:?} from {src_ty:?} local");
}
}
}
fn i32_load8u(&mut self, mem: &Memory) {
self.instruction(LocalGet(mem.addr.idx));
self.instruction(I32Load8U(mem.memarg(0)));
}
fn i32_load8s(&mut self, mem: &Memory) {
self.instruction(LocalGet(mem.addr.idx));
self.instruction(I32Load8S(mem.memarg(0)));
}
fn i32_load16u(&mut self, mem: &Memory) {
self.instruction(LocalGet(mem.addr.idx));
self.instruction(I32Load16U(mem.memarg(1)));
}
fn i32_load16s(&mut self, mem: &Memory) {
self.instruction(LocalGet(mem.addr.idx));
self.instruction(I32Load16S(mem.memarg(1)));
}
fn i32_load(&mut self, mem: &Memory) {
self.instruction(LocalGet(mem.addr.idx));
self.instruction(I32Load(mem.memarg(2)));
}
fn i64_load(&mut self, mem: &Memory) {
self.instruction(LocalGet(mem.addr.idx));
self.instruction(I64Load(mem.memarg(3)));
}
fn ptr_load(&mut self, mem: &Memory) {
if mem.opts.memory64 {
self.i64_load(mem);
} else {
self.i32_load(mem);
}
}
fn ptr_add(&mut self, opts: &Options) {
if opts.memory64 {
self.instruction(I64Add);
} else {
self.instruction(I32Add);
}
}
fn ptr_sub(&mut self, opts: &Options) {
if opts.memory64 {
self.instruction(I64Sub);
} else {
self.instruction(I32Sub);
}
}
fn ptr_mul(&mut self, opts: &Options) {
if opts.memory64 {
self.instruction(I64Mul);
} else {
self.instruction(I32Mul);
}
}
fn ptr_ge_u(&mut self, opts: &Options) {
if opts.memory64 {
self.instruction(I64GeU);
} else {
self.instruction(I32GeU);
}
}
fn ptr_lt_u(&mut self, opts: &Options) {
if opts.memory64 {
self.instruction(I64LtU);
} else {
self.instruction(I32LtU);
}
}
fn ptr_shl(&mut self, opts: &Options) {
if opts.memory64 {
self.instruction(I64Shl);
} else {
self.instruction(I32Shl);
}
}
fn ptr_eqz(&mut self, opts: &Options) {
if opts.memory64 {
self.instruction(I64Eqz);
} else {
self.instruction(I32Eqz);
}
}
fn ptr_uconst(&mut self, opts: &Options, val: u32) {
if opts.memory64 {
self.instruction(I64Const(val.into()));
} else {
self.instruction(I32Const(val as i32));
}
}
fn ptr_iconst(&mut self, opts: &Options, val: i32) {
if opts.memory64 {
self.instruction(I64Const(val.into()));
} else {
self.instruction(I32Const(val));
}
}
fn ptr_eq(&mut self, opts: &Options) {
if opts.memory64 {
self.instruction(I64Eq);
} else {
self.instruction(I32Eq);
}
}
fn ptr_ne(&mut self, opts: &Options) {
if opts.memory64 {
self.instruction(I64Ne);
} else {
self.instruction(I32Ne);
}
}
fn ptr_and(&mut self, opts: &Options) {
if opts.memory64 {
self.instruction(I64And);
} else {
self.instruction(I32And);
}
}
fn ptr_or(&mut self, opts: &Options) {
if opts.memory64 {
self.instruction(I64Or);
} else {
self.instruction(I32Or);
}
}
fn ptr_xor(&mut self, opts: &Options) {
if opts.memory64 {
self.instruction(I64Xor);
} else {
self.instruction(I32Xor);
}
}
fn ptr_if(&mut self, opts: &Options, ty: BlockType) {
if opts.memory64 {
self.instruction(I64Const(0));
self.instruction(I64Ne);
}
self.instruction(If(ty));
}
fn ptr_br_if(&mut self, opts: &Options, depth: u32) {
if opts.memory64 {
self.instruction(I64Const(0));
self.instruction(I64Ne);
}
self.instruction(BrIf(depth));
}
fn f32_load(&mut self, mem: &Memory) {
self.instruction(LocalGet(mem.addr.idx));
self.instruction(F32Load(mem.memarg(2)));
}
fn f64_load(&mut self, mem: &Memory) {
self.instruction(LocalGet(mem.addr.idx));
self.instruction(F64Load(mem.memarg(3)));
}
fn push_dst_addr(&mut self, dst: &Destination) {
if let Destination::Memory(mem) = dst {
self.instruction(LocalGet(mem.addr.idx));
}
}
fn i32_store8(&mut self, mem: &Memory) {
self.instruction(I32Store8(mem.memarg(0)));
}
fn i32_store16(&mut self, mem: &Memory) {
self.instruction(I32Store16(mem.memarg(1)));
}
fn i32_store(&mut self, mem: &Memory) {
self.instruction(I32Store(mem.memarg(2)));
}
fn i64_store(&mut self, mem: &Memory) {
self.instruction(I64Store(mem.memarg(3)));
}
fn ptr_store(&mut self, mem: &Memory) {
if mem.opts.memory64 {
self.i64_store(mem);
} else {
self.i32_store(mem);
}
}
fn f32_store(&mut self, mem: &Memory) {
self.instruction(F32Store(mem.memarg(2)));
}
fn f64_store(&mut self, mem: &Memory) {
self.instruction(F64Store(mem.memarg(3)));
}
}
impl<'a> Source<'a> {
/// Given this `Source` returns an iterator over the `Source` for each of
/// the component `fields` specified.
///
/// This will automatically slice stack-based locals to the appropriate
/// width for each component type and additionally calculate the appropriate
/// offset for each memory-based type.
fn record_field_srcs<'b>(
&'b self,
types: &'b ComponentTypesBuilder,
fields: impl IntoIterator<Item = InterfaceType> + 'b,
) -> impl Iterator<Item = Source<'a>> + 'b
where
'a: 'b,
{
let mut offset = 0;
fields.into_iter().map(move |ty| match self {
Source::Memory(mem) => {
let mem = next_field_offset(&mut offset, types, &ty, mem);
Source::Memory(mem)
}
Source::Stack(stack) => {
let cnt = types.flat_types(&ty).unwrap().len() as u32;
offset += cnt;
Source::Stack(stack.slice((offset - cnt) as usize..offset as usize))
}
})
}
/// Returns the corresponding discriminant source and payload source f
fn payload_src(
&self,
types: &ComponentTypesBuilder,
info: &VariantInfo,
case: Option<&InterfaceType>,
) -> Source<'a> {
match self {
Source::Stack(s) => {
let flat_len = match case {
Some(case) => types.flat_types(case).unwrap().len(),
None => 0,
};
Source::Stack(s.slice(1..s.locals.len()).slice(0..flat_len))
}
Source::Memory(mem) => {
let mem = if mem.opts.memory64 {
mem.bump(info.payload_offset64)
} else {
mem.bump(info.payload_offset32)
};
Source::Memory(mem)
}
}
}
fn opts(&self) -> &'a Options {
match self {
Source::Stack(s) => s.opts,
Source::Memory(mem) => mem.opts,
}
}
}
impl<'a> Destination<'a> {
/// Same as `Source::record_field_srcs` but for destinations.
fn record_field_dsts<'b>(
&'b self,
types: &'b ComponentTypesBuilder,
fields: impl IntoIterator<Item = InterfaceType> + 'b,
) -> impl Iterator<Item = Destination<'b>> + 'b
where
'a: 'b,
{
let mut offset = 0;
fields.into_iter().map(move |ty| match self {
Destination::Memory(mem) => {
let mem = next_field_offset(&mut offset, types, &ty, mem);
Destination::Memory(mem)
}
Destination::Stack(s, opts) => {
let cnt = types.flat_types(&ty).unwrap().len() as u32;
offset += cnt;
Destination::Stack(&s[(offset - cnt) as usize..offset as usize], opts)
}
})
}
/// Returns the corresponding discriminant source and payload source f
fn payload_dst(
&self,
types: &ComponentTypesBuilder,
info: &VariantInfo,
case: Option<&InterfaceType>,
) -> Destination {
match self {
Destination::Stack(s, opts) => {
let flat_len = match case {
Some(case) => types.flat_types(case).unwrap().len(),
None => 0,
};
Destination::Stack(&s[1..][..flat_len], opts)
}
Destination::Memory(mem) => {
let mem = if mem.opts.memory64 {
mem.bump(info.payload_offset64)
} else {
mem.bump(info.payload_offset32)
};
Destination::Memory(mem)
}
}
}
fn opts(&self) -> &'a Options {
match self {
Destination::Stack(_, opts) => opts,
Destination::Memory(mem) => mem.opts,
}
}
}
fn next_field_offset<'a>(
offset: &mut u32,
types: &ComponentTypesBuilder,
field: &InterfaceType,
mem: &Memory<'a>,
) -> Memory<'a> {
let abi = types.canonical_abi(field);
let offset = if mem.opts.memory64 {
abi.next_field64(offset)
} else {
abi.next_field32(offset)
};
mem.bump(offset)
}
impl<'a> Memory<'a> {
fn memarg(&self, align: u32) -> MemArg {
MemArg {
offset: u64::from(self.offset),
align,
memory_index: self.opts.memory.unwrap().as_u32(),
}
}
fn bump(&self, offset: u32) -> Memory<'a> {
Memory {
opts: self.opts,
addr: TempLocal::new(self.addr.idx, self.addr.ty),
offset: self.offset + offset,
}
}
}
impl<'a> Stack<'a> {
fn slice(&self, range: Range<usize>) -> Stack<'a> {
Stack {
locals: &self.locals[range],
opts: self.opts,
}
}
}
struct VariantCase<'a> {
src_i: u32,
src_ty: Option<&'a InterfaceType>,
dst_i: u32,
dst_ty: Option<&'a InterfaceType>,
}
fn variant_info<'a, I>(types: &ComponentTypesBuilder, cases: I) -> VariantInfo
where
I: IntoIterator<Item = Option<&'a InterfaceType>>,
I::IntoIter: ExactSizeIterator,
{
VariantInfo::new(
cases
.into_iter()
.map(|ty| ty.map(|ty| types.canonical_abi(ty))),
)
.0
}
enum MallocSize {
Const(u32),
Local(u32),
}
struct WasmString<'a> {
ptr: TempLocal,
len: TempLocal,
opts: &'a Options,
}
struct TempLocal {
idx: u32,
ty: ValType,
needs_free: bool,
}
impl TempLocal {
fn new(idx: u32, ty: ValType) -> TempLocal {
TempLocal {
idx,
ty,
needs_free: false,
}
}
}
impl std::ops::Drop for TempLocal {
fn drop(&mut self) {
if self.needs_free {
panic!("temporary local not free'd");
}
}
}
impl From<FlatType> for ValType {
fn from(ty: FlatType) -> ValType {
match ty {
FlatType::I32 => ValType::I32,
FlatType::I64 => ValType::I64,
FlatType::F32 => ValType::F32,
FlatType::F64 => ValType::F64,
}
}
}