rustc_resolve/diagnostics.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
use rustc_ast::expand::StrippedCfgItem;
use rustc_ast::ptr::P;
use rustc_ast::visit::{self, Visitor};
use rustc_ast::{
self as ast, CRATE_NODE_ID, Crate, ItemKind, MetaItemInner, MetaItemKind, ModKind, NodeId, Path,
};
use rustc_ast_pretty::pprust;
use rustc_data_structures::fx::FxHashSet;
use rustc_errors::codes::*;
use rustc_errors::{
Applicability, Diag, DiagCtxtHandle, ErrorGuaranteed, MultiSpan, SuggestionStyle,
report_ambiguity_error, struct_span_code_err,
};
use rustc_feature::BUILTIN_ATTRIBUTES;
use rustc_hir::PrimTy;
use rustc_hir::def::Namespace::{self, *};
use rustc_hir::def::{self, CtorKind, CtorOf, DefKind, NonMacroAttrKind, PerNS};
use rustc_hir::def_id::{CRATE_DEF_ID, DefId};
use rustc_middle::bug;
use rustc_middle::ty::TyCtxt;
use rustc_session::Session;
use rustc_session::lint::builtin::{
ABSOLUTE_PATHS_NOT_STARTING_WITH_CRATE, AMBIGUOUS_GLOB_IMPORTS,
MACRO_EXPANDED_MACRO_EXPORTS_ACCESSED_BY_ABSOLUTE_PATHS,
};
use rustc_session::lint::{AmbiguityErrorDiag, BuiltinLintDiag};
use rustc_span::edit_distance::find_best_match_for_name;
use rustc_span::edition::Edition;
use rustc_span::hygiene::MacroKind;
use rustc_span::source_map::SourceMap;
use rustc_span::symbol::{Ident, Symbol, kw, sym};
use rustc_span::{BytePos, Span, SyntaxContext};
use thin_vec::{ThinVec, thin_vec};
use tracing::debug;
use crate::errors::{
self, AddedMacroUse, ChangeImportBinding, ChangeImportBindingSuggestion, ConsiderAddingADerive,
ExplicitUnsafeTraits, MacroDefinedLater, MacroSuggMovePosition, MaybeMissingMacroRulesName,
};
use crate::imports::{Import, ImportKind};
use crate::late::{PatternSource, Rib};
use crate::{
AmbiguityError, AmbiguityErrorMisc, AmbiguityKind, BindingError, BindingKey, Finalize,
HasGenericParams, LexicalScopeBinding, MacroRulesScope, Module, ModuleKind,
ModuleOrUniformRoot, NameBinding, NameBindingKind, ParentScope, PathResult, PrivacyError,
ResolutionError, Resolver, Scope, ScopeSet, Segment, UseError, Used, VisResolutionError,
errors as errs, path_names_to_string,
};
type Res = def::Res<ast::NodeId>;
/// A vector of spans and replacements, a message and applicability.
pub(crate) type Suggestion = (Vec<(Span, String)>, String, Applicability);
/// Potential candidate for an undeclared or out-of-scope label - contains the ident of a
/// similarly named label and whether or not it is reachable.
pub(crate) type LabelSuggestion = (Ident, bool);
#[derive(Debug)]
pub(crate) enum SuggestionTarget {
/// The target has a similar name as the name used by the programmer (probably a typo)
SimilarlyNamed,
/// The target is the only valid item that can be used in the corresponding context
SingleItem,
}
#[derive(Debug)]
pub(crate) struct TypoSuggestion {
pub candidate: Symbol,
/// The source location where the name is defined; None if the name is not defined
/// in source e.g. primitives
pub span: Option<Span>,
pub res: Res,
pub target: SuggestionTarget,
}
impl TypoSuggestion {
pub(crate) fn typo_from_ident(ident: Ident, res: Res) -> TypoSuggestion {
Self {
candidate: ident.name,
span: Some(ident.span),
res,
target: SuggestionTarget::SimilarlyNamed,
}
}
pub(crate) fn typo_from_name(candidate: Symbol, res: Res) -> TypoSuggestion {
Self { candidate, span: None, res, target: SuggestionTarget::SimilarlyNamed }
}
pub(crate) fn single_item_from_ident(ident: Ident, res: Res) -> TypoSuggestion {
Self {
candidate: ident.name,
span: Some(ident.span),
res,
target: SuggestionTarget::SingleItem,
}
}
}
/// A free importable items suggested in case of resolution failure.
#[derive(Debug, Clone)]
pub(crate) struct ImportSuggestion {
pub did: Option<DefId>,
pub descr: &'static str,
pub path: Path,
pub accessible: bool,
// false if the path traverses a foreign `#[doc(hidden)]` item.
pub doc_visible: bool,
pub via_import: bool,
/// An extra note that should be issued if this item is suggested
pub note: Option<String>,
}
/// Adjust the impl span so that just the `impl` keyword is taken by removing
/// everything after `<` (`"impl<T> Iterator for A<T> {}" -> "impl"`) and
/// everything after the first whitespace (`"impl Iterator for A" -> "impl"`).
///
/// *Attention*: the method used is very fragile since it essentially duplicates the work of the
/// parser. If you need to use this function or something similar, please consider updating the
/// `source_map` functions and this function to something more robust.
fn reduce_impl_span_to_impl_keyword(sm: &SourceMap, impl_span: Span) -> Span {
let impl_span = sm.span_until_char(impl_span, '<');
sm.span_until_whitespace(impl_span)
}
impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
pub(crate) fn dcx(&self) -> DiagCtxtHandle<'tcx> {
self.tcx.dcx()
}
pub(crate) fn report_errors(&mut self, krate: &Crate) {
self.report_with_use_injections(krate);
for &(span_use, span_def) in &self.macro_expanded_macro_export_errors {
self.lint_buffer.buffer_lint(
MACRO_EXPANDED_MACRO_EXPORTS_ACCESSED_BY_ABSOLUTE_PATHS,
CRATE_NODE_ID,
span_use,
BuiltinLintDiag::MacroExpandedMacroExportsAccessedByAbsolutePaths(span_def),
);
}
for ambiguity_error in &self.ambiguity_errors {
let diag = self.ambiguity_diagnostics(ambiguity_error);
if ambiguity_error.warning {
let NameBindingKind::Import { import, .. } = ambiguity_error.b1.0.kind else {
unreachable!()
};
self.lint_buffer.buffer_lint(
AMBIGUOUS_GLOB_IMPORTS,
import.root_id,
ambiguity_error.ident.span,
BuiltinLintDiag::AmbiguousGlobImports { diag },
);
} else {
let mut err = struct_span_code_err!(self.dcx(), diag.span, E0659, "{}", diag.msg);
report_ambiguity_error(&mut err, diag);
err.emit();
}
}
let mut reported_spans = FxHashSet::default();
for error in std::mem::take(&mut self.privacy_errors) {
if reported_spans.insert(error.dedup_span) {
self.report_privacy_error(&error);
}
}
}
fn report_with_use_injections(&mut self, krate: &Crate) {
for UseError { mut err, candidates, def_id, instead, suggestion, path, is_call } in
self.use_injections.drain(..)
{
let (span, found_use) = if let Some(def_id) = def_id.as_local() {
UsePlacementFinder::check(krate, self.def_id_to_node_id[def_id])
} else {
(None, FoundUse::No)
};
if !candidates.is_empty() {
show_candidates(
self.tcx,
&mut err,
span,
&candidates,
if instead { Instead::Yes } else { Instead::No },
found_use,
DiagMode::Normal,
path,
"",
);
err.emit();
} else if let Some((span, msg, sugg, appl)) = suggestion {
err.span_suggestion_verbose(span, msg, sugg, appl);
err.emit();
} else if let [segment] = path.as_slice()
&& is_call
{
err.stash(segment.ident.span, rustc_errors::StashKey::CallIntoMethod);
} else {
err.emit();
}
}
}
pub(crate) fn report_conflict(
&mut self,
parent: Module<'_>,
ident: Ident,
ns: Namespace,
new_binding: NameBinding<'ra>,
old_binding: NameBinding<'ra>,
) {
// Error on the second of two conflicting names
if old_binding.span.lo() > new_binding.span.lo() {
return self.report_conflict(parent, ident, ns, old_binding, new_binding);
}
let container = match parent.kind {
// Avoid using TyCtxt::def_kind_descr in the resolver, because it
// indirectly *calls* the resolver, and would cause a query cycle.
ModuleKind::Def(kind, _, _) => kind.descr(parent.def_id()),
ModuleKind::Block => "block",
};
let (name, span) =
(ident.name, self.tcx.sess.source_map().guess_head_span(new_binding.span));
if let Some(s) = self.name_already_seen.get(&name) {
if s == &span {
return;
}
}
let old_kind = match (ns, old_binding.module()) {
(ValueNS, _) => "value",
(MacroNS, _) => "macro",
(TypeNS, _) if old_binding.is_extern_crate() => "extern crate",
(TypeNS, Some(module)) if module.is_normal() => "module",
(TypeNS, Some(module)) if module.is_trait() => "trait",
(TypeNS, _) => "type",
};
let code = match (old_binding.is_extern_crate(), new_binding.is_extern_crate()) {
(true, true) => E0259,
(true, _) | (_, true) => match new_binding.is_import() && old_binding.is_import() {
true => E0254,
false => E0260,
},
_ => match (old_binding.is_import_user_facing(), new_binding.is_import_user_facing()) {
(false, false) => E0428,
(true, true) => E0252,
_ => E0255,
},
};
let label = match new_binding.is_import_user_facing() {
true => errors::NameDefinedMultipleTimeLabel::Reimported { span, name },
false => errors::NameDefinedMultipleTimeLabel::Redefined { span, name },
};
let old_binding_label =
(!old_binding.span.is_dummy() && old_binding.span != span).then(|| {
let span = self.tcx.sess.source_map().guess_head_span(old_binding.span);
match old_binding.is_import_user_facing() {
true => errors::NameDefinedMultipleTimeOldBindingLabel::Import {
span,
name,
old_kind,
},
false => errors::NameDefinedMultipleTimeOldBindingLabel::Definition {
span,
name,
old_kind,
},
}
});
let mut err = self
.dcx()
.create_err(errors::NameDefinedMultipleTime {
span,
descr: ns.descr(),
container,
label,
old_binding_label,
})
.with_code(code);
// See https://github.com/rust-lang/rust/issues/32354
use NameBindingKind::Import;
let can_suggest = |binding: NameBinding<'_>, import: self::Import<'_>| {
!binding.span.is_dummy()
&& !matches!(import.kind, ImportKind::MacroUse { .. } | ImportKind::MacroExport)
};
let import = match (&new_binding.kind, &old_binding.kind) {
// If there are two imports where one or both have attributes then prefer removing the
// import without attributes.
(Import { import: new, .. }, Import { import: old, .. })
if {
(new.has_attributes || old.has_attributes)
&& can_suggest(old_binding, *old)
&& can_suggest(new_binding, *new)
} =>
{
if old.has_attributes {
Some((*new, new_binding.span, true))
} else {
Some((*old, old_binding.span, true))
}
}
// Otherwise prioritize the new binding.
(Import { import, .. }, other) if can_suggest(new_binding, *import) => {
Some((*import, new_binding.span, other.is_import()))
}
(other, Import { import, .. }) if can_suggest(old_binding, *import) => {
Some((*import, old_binding.span, other.is_import()))
}
_ => None,
};
// Check if the target of the use for both bindings is the same.
let duplicate = new_binding.res().opt_def_id() == old_binding.res().opt_def_id();
let has_dummy_span = new_binding.span.is_dummy() || old_binding.span.is_dummy();
let from_item =
self.extern_prelude.get(&ident).map_or(true, |entry| entry.introduced_by_item);
// Only suggest removing an import if both bindings are to the same def, if both spans
// aren't dummy spans. Further, if both bindings are imports, then the ident must have
// been introduced by an item.
let should_remove_import = duplicate
&& !has_dummy_span
&& ((new_binding.is_extern_crate() || old_binding.is_extern_crate()) || from_item);
match import {
Some((import, span, true)) if should_remove_import && import.is_nested() => {
self.add_suggestion_for_duplicate_nested_use(&mut err, import, span);
}
Some((import, _, true)) if should_remove_import && !import.is_glob() => {
// Simple case - remove the entire import. Due to the above match arm, this can
// only be a single use so just remove it entirely.
err.subdiagnostic(errors::ToolOnlyRemoveUnnecessaryImport {
span: import.use_span_with_attributes,
});
}
Some((import, span, _)) => {
self.add_suggestion_for_rename_of_use(&mut err, name, import, span);
}
_ => {}
}
err.emit();
self.name_already_seen.insert(name, span);
}
/// This function adds a suggestion to change the binding name of a new import that conflicts
/// with an existing import.
///
/// ```text,ignore (diagnostic)
/// help: you can use `as` to change the binding name of the import
/// |
/// LL | use foo::bar as other_bar;
/// | ^^^^^^^^^^^^^^^^^^^^^
/// ```
fn add_suggestion_for_rename_of_use(
&self,
err: &mut Diag<'_>,
name: Symbol,
import: Import<'_>,
binding_span: Span,
) {
let suggested_name = if name.as_str().chars().next().unwrap().is_uppercase() {
format!("Other{name}")
} else {
format!("other_{name}")
};
let mut suggestion = None;
let mut span = binding_span;
match import.kind {
ImportKind::Single { type_ns_only: true, .. } => {
suggestion = Some(format!("self as {suggested_name}"))
}
ImportKind::Single { source, .. } => {
if let Some(pos) =
source.span.hi().0.checked_sub(binding_span.lo().0).map(|pos| pos as usize)
{
if let Ok(snippet) = self.tcx.sess.source_map().span_to_snippet(binding_span) {
if pos <= snippet.len() {
span = binding_span
.with_lo(binding_span.lo() + BytePos(pos as u32))
.with_hi(
binding_span.hi()
- BytePos(if snippet.ends_with(';') { 1 } else { 0 }),
);
suggestion = Some(format!(" as {suggested_name}"));
}
}
}
}
ImportKind::ExternCrate { source, target, .. } => {
suggestion = Some(format!(
"extern crate {} as {};",
source.unwrap_or(target.name),
suggested_name,
))
}
_ => unreachable!(),
}
if let Some(suggestion) = suggestion {
err.subdiagnostic(ChangeImportBindingSuggestion { span, suggestion });
} else {
err.subdiagnostic(ChangeImportBinding { span });
}
}
/// This function adds a suggestion to remove an unnecessary binding from an import that is
/// nested. In the following example, this function will be invoked to remove the `a` binding
/// in the second use statement:
///
/// ```ignore (diagnostic)
/// use issue_52891::a;
/// use issue_52891::{d, a, e};
/// ```
///
/// The following suggestion will be added:
///
/// ```ignore (diagnostic)
/// use issue_52891::{d, a, e};
/// ^-- help: remove unnecessary import
/// ```
///
/// If the nested use contains only one import then the suggestion will remove the entire
/// line.
///
/// It is expected that the provided import is nested - this isn't checked by the
/// function. If this invariant is not upheld, this function's behaviour will be unexpected
/// as characters expected by span manipulations won't be present.
fn add_suggestion_for_duplicate_nested_use(
&self,
err: &mut Diag<'_>,
import: Import<'_>,
binding_span: Span,
) {
assert!(import.is_nested());
// Two examples will be used to illustrate the span manipulations we're doing:
//
// - Given `use issue_52891::{d, a, e};` where `a` is a duplicate then `binding_span` is
// `a` and `import.use_span` is `issue_52891::{d, a, e};`.
// - Given `use issue_52891::{d, e, a};` where `a` is a duplicate then `binding_span` is
// `a` and `import.use_span` is `issue_52891::{d, e, a};`.
let (found_closing_brace, span) =
find_span_of_binding_until_next_binding(self.tcx.sess, binding_span, import.use_span);
// If there was a closing brace then identify the span to remove any trailing commas from
// previous imports.
if found_closing_brace {
if let Some(span) = extend_span_to_previous_binding(self.tcx.sess, span) {
err.subdiagnostic(errors::ToolOnlyRemoveUnnecessaryImport { span });
} else {
// Remove the entire line if we cannot extend the span back, this indicates an
// `issue_52891::{self}` case.
err.subdiagnostic(errors::RemoveUnnecessaryImport {
span: import.use_span_with_attributes,
});
}
return;
}
err.subdiagnostic(errors::RemoveUnnecessaryImport { span });
}
pub(crate) fn lint_if_path_starts_with_module(
&mut self,
finalize: Option<Finalize>,
path: &[Segment],
second_binding: Option<NameBinding<'_>>,
) {
let Some(Finalize { node_id, root_span, .. }) = finalize else {
return;
};
let first_name = match path.get(0) {
// In the 2018 edition this lint is a hard error, so nothing to do
Some(seg) if seg.ident.span.is_rust_2015() && self.tcx.sess.is_rust_2015() => {
seg.ident.name
}
_ => return,
};
// We're only interested in `use` paths which should start with
// `{{root}}` currently.
if first_name != kw::PathRoot {
return;
}
match path.get(1) {
// If this import looks like `crate::...` it's already good
Some(Segment { ident, .. }) if ident.name == kw::Crate => return,
// Otherwise go below to see if it's an extern crate
Some(_) => {}
// If the path has length one (and it's `PathRoot` most likely)
// then we don't know whether we're gonna be importing a crate or an
// item in our crate. Defer this lint to elsewhere
None => return,
}
// If the first element of our path was actually resolved to an
// `ExternCrate` (also used for `crate::...`) then no need to issue a
// warning, this looks all good!
if let Some(binding) = second_binding {
if let NameBindingKind::Import { import, .. } = binding.kind {
// Careful: we still want to rewrite paths from renamed extern crates.
if let ImportKind::ExternCrate { source: None, .. } = import.kind {
return;
}
}
}
let diag = BuiltinLintDiag::AbsPathWithModule(root_span);
self.lint_buffer.buffer_lint(
ABSOLUTE_PATHS_NOT_STARTING_WITH_CRATE,
node_id,
root_span,
diag,
);
}
pub(crate) fn add_module_candidates(
&mut self,
module: Module<'ra>,
names: &mut Vec<TypoSuggestion>,
filter_fn: &impl Fn(Res) -> bool,
ctxt: Option<SyntaxContext>,
) {
for (key, resolution) in self.resolutions(module).borrow().iter() {
if let Some(binding) = resolution.borrow().binding {
let res = binding.res();
if filter_fn(res) && ctxt.map_or(true, |ctxt| ctxt == key.ident.span.ctxt()) {
names.push(TypoSuggestion::typo_from_ident(key.ident, res));
}
}
}
}
/// Combines an error with provided span and emits it.
///
/// This takes the error provided, combines it with the span and any additional spans inside the
/// error and emits it.
pub(crate) fn report_error(
&mut self,
span: Span,
resolution_error: ResolutionError<'ra>,
) -> ErrorGuaranteed {
self.into_struct_error(span, resolution_error).emit()
}
pub(crate) fn into_struct_error(
&mut self,
span: Span,
resolution_error: ResolutionError<'ra>,
) -> Diag<'_> {
match resolution_error {
ResolutionError::GenericParamsFromOuterItem(
outer_res,
has_generic_params,
def_kind,
) => {
use errs::GenericParamsFromOuterItemLabel as Label;
let static_or_const = match def_kind {
DefKind::Static { .. } => {
Some(errs::GenericParamsFromOuterItemStaticOrConst::Static)
}
DefKind::Const => Some(errs::GenericParamsFromOuterItemStaticOrConst::Const),
_ => None,
};
let is_self =
matches!(outer_res, Res::SelfTyParam { .. } | Res::SelfTyAlias { .. });
let mut err = errs::GenericParamsFromOuterItem {
span,
label: None,
refer_to_type_directly: None,
sugg: None,
static_or_const,
is_self,
};
let sm = self.tcx.sess.source_map();
let def_id = match outer_res {
Res::SelfTyParam { .. } => {
err.label = Some(Label::SelfTyParam(span));
return self.dcx().create_err(err);
}
Res::SelfTyAlias { alias_to: def_id, .. } => {
err.label = Some(Label::SelfTyAlias(reduce_impl_span_to_impl_keyword(
sm,
self.def_span(def_id),
)));
err.refer_to_type_directly = Some(span);
return self.dcx().create_err(err);
}
Res::Def(DefKind::TyParam, def_id) => {
err.label = Some(Label::TyParam(self.def_span(def_id)));
def_id
}
Res::Def(DefKind::ConstParam, def_id) => {
err.label = Some(Label::ConstParam(self.def_span(def_id)));
def_id
}
_ => {
bug!(
"GenericParamsFromOuterItem should only be used with \
Res::SelfTyParam, Res::SelfTyAlias, DefKind::TyParam or \
DefKind::ConstParam"
);
}
};
if let HasGenericParams::Yes(span) = has_generic_params {
let name = self.tcx.item_name(def_id);
let (span, snippet) = if span.is_empty() {
let snippet = format!("<{name}>");
(span, snippet)
} else {
let span = sm.span_through_char(span, '<').shrink_to_hi();
let snippet = format!("{name}, ");
(span, snippet)
};
err.sugg = Some(errs::GenericParamsFromOuterItemSugg { span, snippet });
}
self.dcx().create_err(err)
}
ResolutionError::NameAlreadyUsedInParameterList(name, first_use_span) => self
.dcx()
.create_err(errs::NameAlreadyUsedInParameterList { span, first_use_span, name }),
ResolutionError::MethodNotMemberOfTrait(method, trait_, candidate) => {
self.dcx().create_err(errs::MethodNotMemberOfTrait {
span,
method,
trait_,
sub: candidate.map(|c| errs::AssociatedFnWithSimilarNameExists {
span: method.span,
candidate: c,
}),
})
}
ResolutionError::TypeNotMemberOfTrait(type_, trait_, candidate) => {
self.dcx().create_err(errs::TypeNotMemberOfTrait {
span,
type_,
trait_,
sub: candidate.map(|c| errs::AssociatedTypeWithSimilarNameExists {
span: type_.span,
candidate: c,
}),
})
}
ResolutionError::ConstNotMemberOfTrait(const_, trait_, candidate) => {
self.dcx().create_err(errs::ConstNotMemberOfTrait {
span,
const_,
trait_,
sub: candidate.map(|c| errs::AssociatedConstWithSimilarNameExists {
span: const_.span,
candidate: c,
}),
})
}
ResolutionError::VariableNotBoundInPattern(binding_error, parent_scope) => {
let BindingError { name, target, origin, could_be_path } = binding_error;
let target_sp = target.iter().copied().collect::<Vec<_>>();
let origin_sp = origin.iter().copied().collect::<Vec<_>>();
let msp = MultiSpan::from_spans(target_sp.clone());
let mut err = self
.dcx()
.create_err(errors::VariableIsNotBoundInAllPatterns { multispan: msp, name });
for sp in target_sp {
err.subdiagnostic(errors::PatternDoesntBindName { span: sp, name });
}
for sp in origin_sp {
err.subdiagnostic(errors::VariableNotInAllPatterns { span: sp });
}
if could_be_path {
let import_suggestions = self.lookup_import_candidates(
Ident::with_dummy_span(name),
Namespace::ValueNS,
&parent_scope,
&|res: Res| {
matches!(
res,
Res::Def(
DefKind::Ctor(CtorOf::Variant, CtorKind::Const)
| DefKind::Ctor(CtorOf::Struct, CtorKind::Const)
| DefKind::Const
| DefKind::AssocConst,
_,
)
)
},
);
if import_suggestions.is_empty() {
let help_msg = format!(
"if you meant to match on a variant or a `const` item, consider \
making the path in the pattern qualified: `path::to::ModOrType::{name}`",
);
err.span_help(span, help_msg);
}
show_candidates(
self.tcx,
&mut err,
Some(span),
&import_suggestions,
Instead::No,
FoundUse::Yes,
DiagMode::Pattern,
vec![],
"",
);
}
err
}
ResolutionError::VariableBoundWithDifferentMode(variable_name, first_binding_span) => {
self.dcx().create_err(errs::VariableBoundWithDifferentMode {
span,
first_binding_span,
variable_name,
})
}
ResolutionError::IdentifierBoundMoreThanOnceInParameterList(identifier) => self
.dcx()
.create_err(errs::IdentifierBoundMoreThanOnceInParameterList { span, identifier }),
ResolutionError::IdentifierBoundMoreThanOnceInSamePattern(identifier) => self
.dcx()
.create_err(errs::IdentifierBoundMoreThanOnceInSamePattern { span, identifier }),
ResolutionError::UndeclaredLabel { name, suggestion } => {
let ((sub_reachable, sub_reachable_suggestion), sub_unreachable) = match suggestion
{
// A reachable label with a similar name exists.
Some((ident, true)) => (
(
Some(errs::LabelWithSimilarNameReachable(ident.span)),
Some(errs::TryUsingSimilarlyNamedLabel {
span,
ident_name: ident.name,
}),
),
None,
),
// An unreachable label with a similar name exists.
Some((ident, false)) => (
(None, None),
Some(errs::UnreachableLabelWithSimilarNameExists {
ident_span: ident.span,
}),
),
// No similarly-named labels exist.
None => ((None, None), None),
};
self.dcx().create_err(errs::UndeclaredLabel {
span,
name,
sub_reachable,
sub_reachable_suggestion,
sub_unreachable,
})
}
ResolutionError::SelfImportsOnlyAllowedWithin { root, span_with_rename } => {
// None of the suggestions below would help with a case like `use self`.
let (suggestion, mpart_suggestion) = if root {
(None, None)
} else {
// use foo::bar::self -> foo::bar
// use foo::bar::self as abc -> foo::bar as abc
let suggestion = errs::SelfImportsOnlyAllowedWithinSuggestion { span };
// use foo::bar::self -> foo::bar::{self}
// use foo::bar::self as abc -> foo::bar::{self as abc}
let mpart_suggestion = errs::SelfImportsOnlyAllowedWithinMultipartSuggestion {
multipart_start: span_with_rename.shrink_to_lo(),
multipart_end: span_with_rename.shrink_to_hi(),
};
(Some(suggestion), Some(mpart_suggestion))
};
self.dcx().create_err(errs::SelfImportsOnlyAllowedWithin {
span,
suggestion,
mpart_suggestion,
})
}
ResolutionError::SelfImportCanOnlyAppearOnceInTheList => {
self.dcx().create_err(errs::SelfImportCanOnlyAppearOnceInTheList { span })
}
ResolutionError::SelfImportOnlyInImportListWithNonEmptyPrefix => {
self.dcx().create_err(errs::SelfImportOnlyInImportListWithNonEmptyPrefix { span })
}
ResolutionError::FailedToResolve { segment, label, suggestion, module } => {
let mut err =
struct_span_code_err!(self.dcx(), span, E0433, "failed to resolve: {label}");
err.span_label(span, label);
if let Some((suggestions, msg, applicability)) = suggestion {
if suggestions.is_empty() {
err.help(msg);
return err;
}
err.multipart_suggestion(msg, suggestions, applicability);
}
if let Some(ModuleOrUniformRoot::Module(module)) = module
&& let Some(module) = module.opt_def_id()
&& let Some(segment) = segment
{
self.find_cfg_stripped(&mut err, &segment, module);
}
err
}
ResolutionError::CannotCaptureDynamicEnvironmentInFnItem => {
self.dcx().create_err(errs::CannotCaptureDynamicEnvironmentInFnItem { span })
}
ResolutionError::AttemptToUseNonConstantValueInConstant {
ident,
suggestion,
current,
type_span,
} => {
// let foo =...
// ^^^ given this Span
// ------- get this Span to have an applicable suggestion
// edit:
// only do this if the const and usage of the non-constant value are on the same line
// the further the two are apart, the higher the chance of the suggestion being wrong
let sp = self
.tcx
.sess
.source_map()
.span_extend_to_prev_str(ident.span, current, true, false);
let ((with, with_label), without) = match sp {
Some(sp) if !self.tcx.sess.source_map().is_multiline(sp) => {
let sp = sp
.with_lo(BytePos(sp.lo().0 - (current.len() as u32)))
.until(ident.span);
(
(Some(errs::AttemptToUseNonConstantValueInConstantWithSuggestion {
span: sp,
suggestion,
current,
type_span,
}), Some(errs::AttemptToUseNonConstantValueInConstantLabelWithSuggestion {span})),
None,
)
}
_ => (
(None, None),
Some(errs::AttemptToUseNonConstantValueInConstantWithoutSuggestion {
ident_span: ident.span,
suggestion,
}),
),
};
self.dcx().create_err(errs::AttemptToUseNonConstantValueInConstant {
span,
with,
with_label,
without,
})
}
ResolutionError::BindingShadowsSomethingUnacceptable {
shadowing_binding,
name,
participle,
article,
shadowed_binding,
shadowed_binding_span,
} => self.dcx().create_err(errs::BindingShadowsSomethingUnacceptable {
span,
shadowing_binding,
shadowed_binding,
article,
sub_suggestion: match (shadowing_binding, shadowed_binding) {
(
PatternSource::Match,
Res::Def(DefKind::Ctor(CtorOf::Variant | CtorOf::Struct, CtorKind::Fn), _),
) => Some(errs::BindingShadowsSomethingUnacceptableSuggestion { span, name }),
_ => None,
},
shadowed_binding_span,
participle,
name,
}),
ResolutionError::ForwardDeclaredGenericParam => {
self.dcx().create_err(errs::ForwardDeclaredGenericParam { span })
}
ResolutionError::ParamInTyOfConstParam { name, param_kind: is_type } => self
.dcx()
.create_err(errs::ParamInTyOfConstParam { span, name, param_kind: is_type }),
ResolutionError::ParamInNonTrivialAnonConst { name, param_kind: is_type } => {
self.dcx().create_err(errs::ParamInNonTrivialAnonConst {
span,
name,
param_kind: is_type,
help: self
.tcx
.sess
.is_nightly_build()
.then_some(errs::ParamInNonTrivialAnonConstHelp),
})
}
ResolutionError::ParamInEnumDiscriminant { name, param_kind: is_type } => self
.dcx()
.create_err(errs::ParamInEnumDiscriminant { span, name, param_kind: is_type }),
ResolutionError::SelfInGenericParamDefault => {
self.dcx().create_err(errs::SelfInGenericParamDefault { span })
}
ResolutionError::UnreachableLabel { name, definition_span, suggestion } => {
let ((sub_suggestion_label, sub_suggestion), sub_unreachable_label) =
match suggestion {
// A reachable label with a similar name exists.
Some((ident, true)) => (
(
Some(errs::UnreachableLabelSubLabel { ident_span: ident.span }),
Some(errs::UnreachableLabelSubSuggestion {
span,
// intentionally taking 'ident.name' instead of 'ident' itself, as this
// could be used in suggestion context
ident_name: ident.name,
}),
),
None,
),
// An unreachable label with a similar name exists.
Some((ident, false)) => (
(None, None),
Some(errs::UnreachableLabelSubLabelUnreachable {
ident_span: ident.span,
}),
),
// No similarly-named labels exist.
None => ((None, None), None),
};
self.dcx().create_err(errs::UnreachableLabel {
span,
name,
definition_span,
sub_suggestion,
sub_suggestion_label,
sub_unreachable_label,
})
}
ResolutionError::TraitImplMismatch {
name,
kind,
code,
trait_item_span,
trait_path,
} => self
.dcx()
.create_err(errors::TraitImplMismatch {
span,
name,
kind,
trait_path,
trait_item_span,
})
.with_code(code),
ResolutionError::TraitImplDuplicate { name, trait_item_span, old_span } => self
.dcx()
.create_err(errs::TraitImplDuplicate { span, name, trait_item_span, old_span }),
ResolutionError::InvalidAsmSym => self.dcx().create_err(errs::InvalidAsmSym { span }),
ResolutionError::LowercaseSelf => self.dcx().create_err(errs::LowercaseSelf { span }),
ResolutionError::BindingInNeverPattern => {
self.dcx().create_err(errs::BindingInNeverPattern { span })
}
}
}
pub(crate) fn report_vis_error(
&mut self,
vis_resolution_error: VisResolutionError<'_>,
) -> ErrorGuaranteed {
match vis_resolution_error {
VisResolutionError::Relative2018(span, path) => {
self.dcx().create_err(errs::Relative2018 {
span,
path_span: path.span,
// intentionally converting to String, as the text would also be used as
// in suggestion context
path_str: pprust::path_to_string(path),
})
}
VisResolutionError::AncestorOnly(span) => {
self.dcx().create_err(errs::AncestorOnly(span))
}
VisResolutionError::FailedToResolve(span, label, suggestion) => {
self.into_struct_error(span, ResolutionError::FailedToResolve {
segment: None,
label,
suggestion,
module: None,
})
}
VisResolutionError::ExpectedFound(span, path_str, res) => {
self.dcx().create_err(errs::ExpectedModuleFound { span, res, path_str })
}
VisResolutionError::Indeterminate(span) => {
self.dcx().create_err(errs::Indeterminate(span))
}
VisResolutionError::ModuleOnly(span) => self.dcx().create_err(errs::ModuleOnly(span)),
}
.emit()
}
/// Lookup typo candidate in scope for a macro or import.
fn early_lookup_typo_candidate(
&mut self,
scope_set: ScopeSet<'ra>,
parent_scope: &ParentScope<'ra>,
ident: Ident,
filter_fn: &impl Fn(Res) -> bool,
) -> Option<TypoSuggestion> {
let mut suggestions = Vec::new();
let ctxt = ident.span.ctxt();
self.visit_scopes(scope_set, parent_scope, ctxt, |this, scope, use_prelude, _| {
match scope {
Scope::DeriveHelpers(expn_id) => {
let res = Res::NonMacroAttr(NonMacroAttrKind::DeriveHelper);
if filter_fn(res) {
suggestions.extend(
this.helper_attrs
.get(&expn_id)
.into_iter()
.flatten()
.map(|(ident, _)| TypoSuggestion::typo_from_ident(*ident, res)),
);
}
}
Scope::DeriveHelpersCompat => {
let res = Res::NonMacroAttr(NonMacroAttrKind::DeriveHelperCompat);
if filter_fn(res) {
for derive in parent_scope.derives {
let parent_scope = &ParentScope { derives: &[], ..*parent_scope };
if let Ok((Some(ext), _)) = this.resolve_macro_path(
derive,
Some(MacroKind::Derive),
parent_scope,
false,
false,
None,
) {
suggestions.extend(
ext.helper_attrs
.iter()
.map(|name| TypoSuggestion::typo_from_name(*name, res)),
);
}
}
}
}
Scope::MacroRules(macro_rules_scope) => {
if let MacroRulesScope::Binding(macro_rules_binding) = macro_rules_scope.get() {
let res = macro_rules_binding.binding.res();
if filter_fn(res) {
suggestions.push(TypoSuggestion::typo_from_ident(
macro_rules_binding.ident,
res,
))
}
}
}
Scope::CrateRoot => {
let root_ident = Ident::new(kw::PathRoot, ident.span);
let root_module = this.resolve_crate_root(root_ident);
this.add_module_candidates(root_module, &mut suggestions, filter_fn, None);
}
Scope::Module(module, _) => {
this.add_module_candidates(module, &mut suggestions, filter_fn, None);
}
Scope::MacroUsePrelude => {
suggestions.extend(this.macro_use_prelude.iter().filter_map(
|(name, binding)| {
let res = binding.res();
filter_fn(res).then_some(TypoSuggestion::typo_from_name(*name, res))
},
));
}
Scope::BuiltinAttrs => {
let res = Res::NonMacroAttr(NonMacroAttrKind::Builtin(kw::Empty));
if filter_fn(res) {
suggestions.extend(
BUILTIN_ATTRIBUTES
.iter()
.map(|attr| TypoSuggestion::typo_from_name(attr.name, res)),
);
}
}
Scope::ExternPrelude => {
suggestions.extend(this.extern_prelude.iter().filter_map(|(ident, _)| {
let res = Res::Def(DefKind::Mod, CRATE_DEF_ID.to_def_id());
filter_fn(res).then_some(TypoSuggestion::typo_from_ident(*ident, res))
}));
}
Scope::ToolPrelude => {
let res = Res::NonMacroAttr(NonMacroAttrKind::Tool);
suggestions.extend(
this.registered_tools
.iter()
.map(|ident| TypoSuggestion::typo_from_ident(*ident, res)),
);
}
Scope::StdLibPrelude => {
if let Some(prelude) = this.prelude {
let mut tmp_suggestions = Vec::new();
this.add_module_candidates(prelude, &mut tmp_suggestions, filter_fn, None);
suggestions.extend(
tmp_suggestions
.into_iter()
.filter(|s| use_prelude.into() || this.is_builtin_macro(s.res)),
);
}
}
Scope::BuiltinTypes => {
suggestions.extend(PrimTy::ALL.iter().filter_map(|prim_ty| {
let res = Res::PrimTy(*prim_ty);
filter_fn(res)
.then_some(TypoSuggestion::typo_from_name(prim_ty.name(), res))
}))
}
}
None::<()>
});
// Make sure error reporting is deterministic.
suggestions.sort_by(|a, b| a.candidate.as_str().partial_cmp(b.candidate.as_str()).unwrap());
match find_best_match_for_name(
&suggestions.iter().map(|suggestion| suggestion.candidate).collect::<Vec<Symbol>>(),
ident.name,
None,
) {
Some(found) if found != ident.name => {
suggestions.into_iter().find(|suggestion| suggestion.candidate == found)
}
_ => None,
}
}
fn lookup_import_candidates_from_module<FilterFn>(
&mut self,
lookup_ident: Ident,
namespace: Namespace,
parent_scope: &ParentScope<'ra>,
start_module: Module<'ra>,
crate_path: ThinVec<ast::PathSegment>,
filter_fn: FilterFn,
) -> Vec<ImportSuggestion>
where
FilterFn: Fn(Res) -> bool,
{
let mut candidates = Vec::new();
let mut seen_modules = FxHashSet::default();
let start_did = start_module.def_id();
let mut worklist = vec![(
start_module,
ThinVec::<ast::PathSegment>::new(),
true,
start_did.is_local() || !self.tcx.is_doc_hidden(start_did),
)];
let mut worklist_via_import = vec![];
while let Some((in_module, path_segments, accessible, doc_visible)) = match worklist.pop() {
None => worklist_via_import.pop(),
Some(x) => Some(x),
} {
let in_module_is_extern = !in_module.def_id().is_local();
in_module.for_each_child(self, |this, ident, ns, name_binding| {
// avoid non-importable candidates
if !name_binding.is_importable() {
return;
}
if ident.name == kw::Underscore {
return;
}
let child_accessible =
accessible && this.is_accessible_from(name_binding.vis, parent_scope.module);
// do not venture inside inaccessible items of other crates
if in_module_is_extern && !child_accessible {
return;
}
let via_import = name_binding.is_import() && !name_binding.is_extern_crate();
// There is an assumption elsewhere that paths of variants are in the enum's
// declaration and not imported. With this assumption, the variant component is
// chopped and the rest of the path is assumed to be the enum's own path. For
// errors where a variant is used as the type instead of the enum, this causes
// funny looking invalid suggestions, i.e `foo` instead of `foo::MyEnum`.
if via_import && name_binding.is_possibly_imported_variant() {
return;
}
// #90113: Do not count an inaccessible reexported item as a candidate.
if let NameBindingKind::Import { binding, .. } = name_binding.kind {
if this.is_accessible_from(binding.vis, parent_scope.module)
&& !this.is_accessible_from(name_binding.vis, parent_scope.module)
{
return;
}
}
let res = name_binding.res();
let did = match res {
Res::Def(DefKind::Ctor(..), did) => this.tcx.opt_parent(did),
_ => res.opt_def_id(),
};
let child_doc_visible = doc_visible
&& (did.map_or(true, |did| did.is_local() || !this.tcx.is_doc_hidden(did)));
// collect results based on the filter function
// avoid suggesting anything from the same module in which we are resolving
// avoid suggesting anything with a hygienic name
if ident.name == lookup_ident.name
&& ns == namespace
&& in_module != parent_scope.module
&& !ident.span.normalize_to_macros_2_0().from_expansion()
&& filter_fn(res)
{
// create the path
let mut segms = if lookup_ident.span.at_least_rust_2018() {
// crate-local absolute paths start with `crate::` in edition 2018
// FIXME: may also be stabilized for Rust 2015 (Issues #45477, #44660)
crate_path.clone()
} else {
ThinVec::new()
};
segms.append(&mut path_segments.clone());
segms.push(ast::PathSegment::from_ident(ident));
let path = Path { span: name_binding.span, segments: segms, tokens: None };
if child_accessible {
// Remove invisible match if exists
if let Some(idx) = candidates
.iter()
.position(|v: &ImportSuggestion| v.did == did && !v.accessible)
{
candidates.remove(idx);
}
}
if candidates.iter().all(|v: &ImportSuggestion| v.did != did) {
// See if we're recommending TryFrom, TryInto, or FromIterator and add
// a note about editions
let note = if let Some(did) = did {
let requires_note = !did.is_local()
&& this.tcx.get_attrs(did, sym::rustc_diagnostic_item).any(
|attr| {
[sym::TryInto, sym::TryFrom, sym::FromIterator]
.map(|x| Some(x))
.contains(&attr.value_str())
},
);
requires_note.then(|| {
format!(
"'{}' is included in the prelude starting in Edition 2021",
path_names_to_string(&path)
)
})
} else {
None
};
candidates.push(ImportSuggestion {
did,
descr: res.descr(),
path,
accessible: child_accessible,
doc_visible: child_doc_visible,
note,
via_import,
});
}
}
// collect submodules to explore
if let Some(module) = name_binding.module() {
// form the path
let mut path_segments = path_segments.clone();
path_segments.push(ast::PathSegment::from_ident(ident));
let alias_import = if let NameBindingKind::Import { import, .. } =
name_binding.kind
&& let ImportKind::ExternCrate { source: Some(_), .. } = import.kind
&& import.parent_scope.expansion == parent_scope.expansion
{
true
} else {
false
};
let is_extern_crate_that_also_appears_in_prelude =
name_binding.is_extern_crate() && lookup_ident.span.at_least_rust_2018();
if !is_extern_crate_that_also_appears_in_prelude || alias_import {
// add the module to the lookup
if seen_modules.insert(module.def_id()) {
if via_import { &mut worklist_via_import } else { &mut worklist }
.push((module, path_segments, child_accessible, child_doc_visible));
}
}
}
})
}
// If only some candidates are accessible, take just them
if !candidates.iter().all(|v: &ImportSuggestion| !v.accessible) {
candidates.retain(|x| x.accessible)
}
candidates
}
/// When name resolution fails, this method can be used to look up candidate
/// entities with the expected name. It allows filtering them using the
/// supplied predicate (which should be used to only accept the types of
/// definitions expected, e.g., traits). The lookup spans across all crates.
///
/// N.B., the method does not look into imports, but this is not a problem,
/// since we report the definitions (thus, the de-aliased imports).
pub(crate) fn lookup_import_candidates<FilterFn>(
&mut self,
lookup_ident: Ident,
namespace: Namespace,
parent_scope: &ParentScope<'ra>,
filter_fn: FilterFn,
) -> Vec<ImportSuggestion>
where
FilterFn: Fn(Res) -> bool,
{
let crate_path = thin_vec![ast::PathSegment::from_ident(Ident::with_dummy_span(kw::Crate))];
let mut suggestions = self.lookup_import_candidates_from_module(
lookup_ident,
namespace,
parent_scope,
self.graph_root,
crate_path,
&filter_fn,
);
if lookup_ident.span.at_least_rust_2018() {
for ident in self.extern_prelude.clone().into_keys() {
if ident.span.from_expansion() {
// Idents are adjusted to the root context before being
// resolved in the extern prelude, so reporting this to the
// user is no help. This skips the injected
// `extern crate std` in the 2018 edition, which would
// otherwise cause duplicate suggestions.
continue;
}
let crate_id = self.crate_loader(|c| c.maybe_process_path_extern(ident.name));
if let Some(crate_id) = crate_id {
let crate_def_id = crate_id.as_def_id();
let crate_root = self.expect_module(crate_def_id);
// Check if there's already an item in scope with the same name as the crate.
// If so, we have to disambiguate the potential import suggestions by making
// the paths *global* (i.e., by prefixing them with `::`).
let needs_disambiguation =
self.resolutions(parent_scope.module).borrow().iter().any(
|(key, name_resolution)| {
if key.ns == TypeNS
&& key.ident == ident
&& let Some(binding) = name_resolution.borrow().binding
{
match binding.res() {
// No disambiguation needed if the identically named item we
// found in scope actually refers to the crate in question.
Res::Def(_, def_id) => def_id != crate_def_id,
Res::PrimTy(_) => true,
_ => false,
}
} else {
false
}
},
);
let mut crate_path = ThinVec::new();
if needs_disambiguation {
crate_path.push(ast::PathSegment::path_root(rustc_span::DUMMY_SP));
}
crate_path.push(ast::PathSegment::from_ident(ident));
suggestions.extend(self.lookup_import_candidates_from_module(
lookup_ident,
namespace,
parent_scope,
crate_root,
crate_path,
&filter_fn,
));
}
}
}
suggestions
}
pub(crate) fn unresolved_macro_suggestions(
&mut self,
err: &mut Diag<'_>,
macro_kind: MacroKind,
parent_scope: &ParentScope<'ra>,
ident: Ident,
krate: &Crate,
) {
let is_expected = &|res: Res| res.macro_kind() == Some(macro_kind);
let suggestion = self.early_lookup_typo_candidate(
ScopeSet::Macro(macro_kind),
parent_scope,
ident,
is_expected,
);
self.add_typo_suggestion(err, suggestion, ident.span);
let import_suggestions =
self.lookup_import_candidates(ident, Namespace::MacroNS, parent_scope, is_expected);
let (span, found_use) = match parent_scope.module.nearest_parent_mod().as_local() {
Some(def_id) => UsePlacementFinder::check(krate, self.def_id_to_node_id[def_id]),
None => (None, FoundUse::No),
};
show_candidates(
self.tcx,
err,
span,
&import_suggestions,
Instead::No,
found_use,
DiagMode::Normal,
vec![],
"",
);
if macro_kind == MacroKind::Bang && ident.name == sym::macro_rules {
let label_span = ident.span.shrink_to_hi();
let mut spans = MultiSpan::from_span(label_span);
spans.push_span_label(label_span, "put a macro name here");
err.subdiagnostic(MaybeMissingMacroRulesName { spans });
return;
}
if macro_kind == MacroKind::Derive && (ident.name == sym::Send || ident.name == sym::Sync) {
err.subdiagnostic(ExplicitUnsafeTraits { span: ident.span, ident });
return;
}
let unused_macro = self.unused_macros.iter().find_map(|(def_id, (_, unused_ident))| {
if unused_ident.name == ident.name { Some((def_id, unused_ident)) } else { None }
});
if let Some((def_id, unused_ident)) = unused_macro {
let scope = self.local_macro_def_scopes[&def_id];
let parent_nearest = parent_scope.module.nearest_parent_mod();
if Some(parent_nearest) == scope.opt_def_id() {
err.subdiagnostic(MacroDefinedLater { span: unused_ident.span });
err.subdiagnostic(MacroSuggMovePosition { span: ident.span, ident });
return;
}
}
if self.macro_names.contains(&ident.normalize_to_macros_2_0()) {
err.subdiagnostic(AddedMacroUse);
return;
}
if ident.name == kw::Default
&& let ModuleKind::Def(DefKind::Enum, def_id, _) = parent_scope.module.kind
{
let span = self.def_span(def_id);
let source_map = self.tcx.sess.source_map();
let head_span = source_map.guess_head_span(span);
err.subdiagnostic(ConsiderAddingADerive {
span: head_span.shrink_to_lo(),
suggestion: "#[derive(Default)]\n".to_string(),
});
}
for ns in [Namespace::MacroNS, Namespace::TypeNS, Namespace::ValueNS] {
if let Ok(binding) = self.early_resolve_ident_in_lexical_scope(
ident,
ScopeSet::All(ns),
parent_scope,
None,
false,
None,
None,
) {
let desc = match binding.res() {
Res::Def(DefKind::Macro(MacroKind::Bang), _) => {
"a function-like macro".to_string()
}
Res::Def(DefKind::Macro(MacroKind::Attr), _) | Res::NonMacroAttr(..) => {
format!("an attribute: `#[{ident}]`")
}
Res::Def(DefKind::Macro(MacroKind::Derive), _) => {
format!("a derive macro: `#[derive({ident})]`")
}
Res::ToolMod => {
// Don't confuse the user with tool modules.
continue;
}
Res::Def(DefKind::Trait, _) if macro_kind == MacroKind::Derive => {
"only a trait, without a derive macro".to_string()
}
res => format!(
"{} {}, not {} {}",
res.article(),
res.descr(),
macro_kind.article(),
macro_kind.descr_expected(),
),
};
if let crate::NameBindingKind::Import { import, .. } = binding.kind {
if !import.span.is_dummy() {
let note = errors::IdentImporterHereButItIsDesc {
span: import.span,
imported_ident: ident,
imported_ident_desc: &desc,
};
err.subdiagnostic(note);
// Silence the 'unused import' warning we might get,
// since this diagnostic already covers that import.
self.record_use(ident, binding, Used::Other);
return;
}
}
let note = errors::IdentInScopeButItIsDesc {
imported_ident: ident,
imported_ident_desc: &desc,
};
err.subdiagnostic(note);
return;
}
}
}
pub(crate) fn add_typo_suggestion(
&self,
err: &mut Diag<'_>,
suggestion: Option<TypoSuggestion>,
span: Span,
) -> bool {
let suggestion = match suggestion {
None => return false,
// We shouldn't suggest underscore.
Some(suggestion) if suggestion.candidate == kw::Underscore => return false,
Some(suggestion) => suggestion,
};
let mut did_label_def_span = false;
if let Some(def_span) = suggestion.res.opt_def_id().map(|def_id| self.def_span(def_id)) {
if span.overlaps(def_span) {
// Don't suggest typo suggestion for itself like in the following:
// error[E0423]: expected function, tuple struct or tuple variant, found struct `X`
// --> $DIR/issue-64792-bad-unicode-ctor.rs:3:14
// |
// LL | struct X {}
// | ----------- `X` defined here
// LL |
// LL | const Y: X = X("ö");
// | -------------^^^^^^- similarly named constant `Y` defined here
// |
// help: use struct literal syntax instead
// |
// LL | const Y: X = X {};
// | ^^^^
// help: a constant with a similar name exists
// |
// LL | const Y: X = Y("ö");
// | ^
return false;
}
let span = self.tcx.sess.source_map().guess_head_span(def_span);
let candidate_descr = suggestion.res.descr();
let candidate = suggestion.candidate;
let label = match suggestion.target {
SuggestionTarget::SimilarlyNamed => {
errors::DefinedHere::SimilarlyNamed { span, candidate_descr, candidate }
}
SuggestionTarget::SingleItem => {
errors::DefinedHere::SingleItem { span, candidate_descr, candidate }
}
};
did_label_def_span = true;
err.subdiagnostic(label);
}
let (span, msg, sugg) = if let SuggestionTarget::SimilarlyNamed = suggestion.target
&& let Ok(snippet) = self.tcx.sess.source_map().span_to_snippet(span)
&& let Some(span) = suggestion.span
&& let Some(candidate) = suggestion.candidate.as_str().strip_prefix('_')
&& snippet == candidate
{
let candidate = suggestion.candidate;
// When the suggested binding change would be from `x` to `_x`, suggest changing the
// original binding definition instead. (#60164)
let msg = format!(
"the leading underscore in `{candidate}` marks it as unused, consider renaming it to `{snippet}`"
);
if !did_label_def_span {
err.span_label(span, format!("`{candidate}` defined here"));
}
(span, msg, snippet)
} else {
let msg = match suggestion.target {
SuggestionTarget::SimilarlyNamed => format!(
"{} {} with a similar name exists",
suggestion.res.article(),
suggestion.res.descr()
),
SuggestionTarget::SingleItem => {
format!("maybe you meant this {}", suggestion.res.descr())
}
};
(span, msg, suggestion.candidate.to_ident_string())
};
err.span_suggestion(span, msg, sugg, Applicability::MaybeIncorrect);
true
}
fn binding_description(&self, b: NameBinding<'_>, ident: Ident, from_prelude: bool) -> String {
let res = b.res();
if b.span.is_dummy() || !self.tcx.sess.source_map().is_span_accessible(b.span) {
// These already contain the "built-in" prefix or look bad with it.
let add_built_in =
!matches!(b.res(), Res::NonMacroAttr(..) | Res::PrimTy(..) | Res::ToolMod);
let (built_in, from) = if from_prelude {
("", " from prelude")
} else if b.is_extern_crate()
&& !b.is_import()
&& self.tcx.sess.opts.externs.get(ident.as_str()).is_some()
{
("", " passed with `--extern`")
} else if add_built_in {
(" built-in", "")
} else {
("", "")
};
let a = if built_in.is_empty() { res.article() } else { "a" };
format!("{a}{built_in} {thing}{from}", thing = res.descr())
} else {
let introduced = if b.is_import_user_facing() { "imported" } else { "defined" };
format!("the {thing} {introduced} here", thing = res.descr())
}
}
fn ambiguity_diagnostics(&self, ambiguity_error: &AmbiguityError<'_>) -> AmbiguityErrorDiag {
let AmbiguityError { kind, ident, b1, b2, misc1, misc2, .. } = *ambiguity_error;
let (b1, b2, misc1, misc2, swapped) = if b2.span.is_dummy() && !b1.span.is_dummy() {
// We have to print the span-less alternative first, otherwise formatting looks bad.
(b2, b1, misc2, misc1, true)
} else {
(b1, b2, misc1, misc2, false)
};
let could_refer_to = |b: NameBinding<'_>, misc: AmbiguityErrorMisc, also: &str| {
let what = self.binding_description(b, ident, misc == AmbiguityErrorMisc::FromPrelude);
let note_msg = format!("`{ident}` could{also} refer to {what}");
let thing = b.res().descr();
let mut help_msgs = Vec::new();
if b.is_glob_import()
&& (kind == AmbiguityKind::GlobVsGlob
|| kind == AmbiguityKind::GlobVsExpanded
|| kind == AmbiguityKind::GlobVsOuter && swapped != also.is_empty())
{
help_msgs.push(format!(
"consider adding an explicit import of `{ident}` to disambiguate"
))
}
if b.is_extern_crate() && ident.span.at_least_rust_2018() {
help_msgs.push(format!("use `::{ident}` to refer to this {thing} unambiguously"))
}
match misc {
AmbiguityErrorMisc::SuggestCrate => help_msgs
.push(format!("use `crate::{ident}` to refer to this {thing} unambiguously")),
AmbiguityErrorMisc::SuggestSelf => help_msgs
.push(format!("use `self::{ident}` to refer to this {thing} unambiguously")),
AmbiguityErrorMisc::FromPrelude | AmbiguityErrorMisc::None => {}
}
(
b.span,
note_msg,
help_msgs
.iter()
.enumerate()
.map(|(i, help_msg)| {
let or = if i == 0 { "" } else { "or " };
format!("{or}{help_msg}")
})
.collect::<Vec<_>>(),
)
};
let (b1_span, b1_note_msg, b1_help_msgs) = could_refer_to(b1, misc1, "");
let (b2_span, b2_note_msg, b2_help_msgs) = could_refer_to(b2, misc2, " also");
AmbiguityErrorDiag {
msg: format!("`{ident}` is ambiguous"),
span: ident.span,
label_span: ident.span,
label_msg: "ambiguous name".to_string(),
note_msg: format!("ambiguous because of {}", kind.descr()),
b1_span,
b1_note_msg,
b1_help_msgs,
b2_span,
b2_note_msg,
b2_help_msgs,
}
}
/// If the binding refers to a tuple struct constructor with fields,
/// returns the span of its fields.
fn ctor_fields_span(&self, binding: NameBinding<'_>) -> Option<Span> {
if let NameBindingKind::Res(Res::Def(
DefKind::Ctor(CtorOf::Struct, CtorKind::Fn),
ctor_def_id,
)) = binding.kind
{
let def_id = self.tcx.parent(ctor_def_id);
return self.field_idents(def_id)?.iter().map(|&f| f.span).reduce(Span::to); // None for `struct Foo()`
}
None
}
fn report_privacy_error(&mut self, privacy_error: &PrivacyError<'ra>) {
let PrivacyError { ident, binding, outermost_res, parent_scope, single_nested, dedup_span } =
*privacy_error;
let res = binding.res();
let ctor_fields_span = self.ctor_fields_span(binding);
let plain_descr = res.descr().to_string();
let nonimport_descr =
if ctor_fields_span.is_some() { plain_descr + " constructor" } else { plain_descr };
let import_descr = nonimport_descr.clone() + " import";
let get_descr =
|b: NameBinding<'_>| if b.is_import() { &import_descr } else { &nonimport_descr };
// Print the primary message.
let ident_descr = get_descr(binding);
let mut err =
self.dcx().create_err(errors::IsPrivate { span: ident.span, ident_descr, ident });
let mut not_publicly_reexported = false;
if let Some((this_res, outer_ident)) = outermost_res {
let import_suggestions = self.lookup_import_candidates(
outer_ident,
this_res.ns().unwrap_or(Namespace::TypeNS),
&parent_scope,
&|res: Res| res == this_res,
);
let point_to_def = !show_candidates(
self.tcx,
&mut err,
Some(dedup_span.until(outer_ident.span.shrink_to_hi())),
&import_suggestions,
Instead::Yes,
FoundUse::Yes,
DiagMode::Import { append: single_nested },
vec![],
"",
);
// If we suggest importing a public re-export, don't point at the definition.
if point_to_def && ident.span != outer_ident.span {
not_publicly_reexported = true;
let label = errors::OuterIdentIsNotPubliclyReexported {
span: outer_ident.span,
outer_ident_descr: this_res.descr(),
outer_ident,
};
err.subdiagnostic(label);
}
}
let mut non_exhaustive = None;
// If an ADT is foreign and marked as `non_exhaustive`, then that's
// probably why we have the privacy error.
// Otherwise, point out if the struct has any private fields.
if let Some(def_id) = res.opt_def_id()
&& !def_id.is_local()
&& let Some(attr) = self.tcx.get_attr(def_id, sym::non_exhaustive)
{
non_exhaustive = Some(attr.span);
} else if let Some(span) = ctor_fields_span {
let label = errors::ConstructorPrivateIfAnyFieldPrivate { span };
err.subdiagnostic(label);
if let Res::Def(_, d) = res
&& let Some(fields) = self.field_visibility_spans.get(&d)
{
let spans = fields.iter().map(|span| *span).collect();
let sugg =
errors::ConsiderMakingTheFieldPublic { spans, number_of_fields: fields.len() };
err.subdiagnostic(sugg);
}
}
let mut sugg_paths = vec![];
if let Some(mut def_id) = res.opt_def_id() {
// We can't use `def_path_str` in resolve.
let mut path = vec![def_id];
while let Some(parent) = self.tcx.opt_parent(def_id) {
def_id = parent;
if !def_id.is_top_level_module() {
path.push(def_id);
} else {
break;
}
}
// We will only suggest importing directly if it is accessible through that path.
let path_names: Option<Vec<String>> = path
.iter()
.rev()
.map(|def_id| {
self.tcx.opt_item_name(*def_id).map(|n| {
if def_id.is_top_level_module() {
"crate".to_string()
} else {
n.to_string()
}
})
})
.collect();
if let Some(def_id) = path.get(0)
&& let Some(path) = path_names
{
if let Some(def_id) = def_id.as_local() {
if self.effective_visibilities.is_directly_public(def_id) {
sugg_paths.push((path, false));
}
} else if self.is_accessible_from(self.tcx.visibility(def_id), parent_scope.module)
{
sugg_paths.push((path, false));
}
}
}
// Print the whole import chain to make it easier to see what happens.
let first_binding = binding;
let mut next_binding = Some(binding);
let mut next_ident = ident;
let mut path = vec![];
while let Some(binding) = next_binding {
let name = next_ident;
next_binding = match binding.kind {
_ if res == Res::Err => None,
NameBindingKind::Import { binding, import, .. } => match import.kind {
_ if binding.span.is_dummy() => None,
ImportKind::Single { source, .. } => {
next_ident = source;
Some(binding)
}
ImportKind::Glob { .. }
| ImportKind::MacroUse { .. }
| ImportKind::MacroExport => Some(binding),
ImportKind::ExternCrate { .. } => None,
},
_ => None,
};
match binding.kind {
NameBindingKind::Import { import, .. } => {
for segment in import.module_path.iter().skip(1) {
path.push(segment.ident.to_string());
}
sugg_paths.push((
path.iter()
.cloned()
.chain(vec![ident.to_string()].into_iter())
.collect::<Vec<_>>(),
true, // re-export
));
}
NameBindingKind::Res(_) | NameBindingKind::Module(_) => {}
}
let first = binding == first_binding;
let def_span = self.tcx.sess.source_map().guess_head_span(binding.span);
let mut note_span = MultiSpan::from_span(def_span);
if !first && binding.vis.is_public() {
let desc = match binding.kind {
NameBindingKind::Import { .. } => "re-export",
_ => "directly",
};
note_span.push_span_label(def_span, format!("you could import this {desc}"));
}
// Final step in the import chain, point out if the ADT is `non_exhaustive`
// which is probably why this privacy violation occurred.
if next_binding.is_none()
&& let Some(span) = non_exhaustive
{
note_span.push_span_label(
span,
"cannot be constructed because it is `#[non_exhaustive]`",
);
}
let note = errors::NoteAndRefersToTheItemDefinedHere {
span: note_span,
binding_descr: get_descr(binding),
binding_name: name,
first,
dots: next_binding.is_some(),
};
err.subdiagnostic(note);
}
// We prioritize shorter paths, non-core imports and direct imports over the alternatives.
sugg_paths.sort_by_key(|(p, reexport)| (p.len(), p[0] == "core", *reexport));
for (sugg, reexport) in sugg_paths {
if not_publicly_reexported {
break;
}
if sugg.len() <= 1 {
// A single path segment suggestion is wrong. This happens on circular imports.
// `tests/ui/imports/issue-55884-2.rs`
continue;
}
let path = sugg.join("::");
let sugg = if reexport {
errors::ImportIdent::ThroughReExport { span: dedup_span, ident, path }
} else {
errors::ImportIdent::Directly { span: dedup_span, ident, path }
};
err.subdiagnostic(sugg);
break;
}
err.emit();
}
pub(crate) fn find_similarly_named_module_or_crate(
&mut self,
ident: Symbol,
current_module: Module<'ra>,
) -> Option<Symbol> {
let mut candidates = self
.extern_prelude
.keys()
.map(|ident| ident.name)
.chain(
self.module_map
.iter()
.filter(|(_, module)| {
current_module.is_ancestor_of(**module) && current_module != **module
})
.flat_map(|(_, module)| module.kind.name()),
)
.filter(|c| !c.to_string().is_empty())
.collect::<Vec<_>>();
candidates.sort();
candidates.dedup();
match find_best_match_for_name(&candidates, ident, None) {
Some(sugg) if sugg == ident => None,
sugg => sugg,
}
}
pub(crate) fn report_path_resolution_error(
&mut self,
path: &[Segment],
opt_ns: Option<Namespace>, // `None` indicates a module path in import
parent_scope: &ParentScope<'ra>,
ribs: Option<&PerNS<Vec<Rib<'ra>>>>,
ignore_binding: Option<NameBinding<'ra>>,
ignore_import: Option<Import<'ra>>,
module: Option<ModuleOrUniformRoot<'ra>>,
failed_segment_idx: usize,
ident: Ident,
) -> (String, Option<Suggestion>) {
let is_last = failed_segment_idx == path.len() - 1;
let ns = if is_last { opt_ns.unwrap_or(TypeNS) } else { TypeNS };
let module_res = match module {
Some(ModuleOrUniformRoot::Module(module)) => module.res(),
_ => None,
};
if module_res == self.graph_root.res() {
let is_mod = |res| matches!(res, Res::Def(DefKind::Mod, _));
let mut candidates = self.lookup_import_candidates(ident, TypeNS, parent_scope, is_mod);
candidates
.sort_by_cached_key(|c| (c.path.segments.len(), pprust::path_to_string(&c.path)));
if let Some(candidate) = candidates.get(0) {
let path = {
// remove the possible common prefix of the path
let len = candidate.path.segments.len();
let start_index = (0..=failed_segment_idx.min(len - 1))
.find(|&i| path[i].ident.name != candidate.path.segments[i].ident.name)
.unwrap_or_default();
let segments =
(start_index..len).map(|s| candidate.path.segments[s].clone()).collect();
Path { segments, span: Span::default(), tokens: None }
};
(
String::from("unresolved import"),
Some((
vec![(ident.span, pprust::path_to_string(&path))],
String::from("a similar path exists"),
Applicability::MaybeIncorrect,
)),
)
} else if ident.name == sym::core {
(
format!("you might be missing crate `{ident}`"),
Some((
vec![(ident.span, "std".to_string())],
"try using `std` instead of `core`".to_string(),
Applicability::MaybeIncorrect,
)),
)
} else if ident.name == kw::Underscore {
(format!("`_` is not a valid crate or module name"), None)
} else if self.tcx.sess.is_rust_2015() {
(
format!("you might be missing crate `{ident}`"),
Some((
vec![(
self.current_crate_outer_attr_insert_span,
format!("extern crate {ident};\n"),
)],
format!("consider importing the `{ident}` crate"),
Applicability::MaybeIncorrect,
)),
)
} else {
(format!("could not find `{ident}` in the crate root"), None)
}
} else if failed_segment_idx > 0 {
let parent = path[failed_segment_idx - 1].ident.name;
let parent = match parent {
// ::foo is mounted at the crate root for 2015, and is the extern
// prelude for 2018+
kw::PathRoot if self.tcx.sess.edition() > Edition::Edition2015 => {
"the list of imported crates".to_owned()
}
kw::PathRoot | kw::Crate => "the crate root".to_owned(),
_ => format!("`{parent}`"),
};
let mut msg = format!("could not find `{ident}` in {parent}");
if ns == TypeNS || ns == ValueNS {
let ns_to_try = if ns == TypeNS { ValueNS } else { TypeNS };
let binding = if let Some(module) = module {
self.resolve_ident_in_module(
module,
ident,
ns_to_try,
parent_scope,
None,
ignore_binding,
ignore_import,
)
.ok()
} else if let Some(ribs) = ribs
&& let Some(TypeNS | ValueNS) = opt_ns
{
assert!(ignore_import.is_none());
match self.resolve_ident_in_lexical_scope(
ident,
ns_to_try,
parent_scope,
None,
&ribs[ns_to_try],
ignore_binding,
) {
// we found a locally-imported or available item/module
Some(LexicalScopeBinding::Item(binding)) => Some(binding),
_ => None,
}
} else {
self.early_resolve_ident_in_lexical_scope(
ident,
ScopeSet::All(ns_to_try),
parent_scope,
None,
false,
ignore_binding,
ignore_import,
)
.ok()
};
if let Some(binding) = binding {
let mut found = |what| {
msg = format!(
"expected {}, found {} `{}` in {}",
ns.descr(),
what,
ident,
parent
)
};
if binding.module().is_some() {
found("module")
} else {
match binding.res() {
// Avoid using TyCtxt::def_kind_descr in the resolver, because it
// indirectly *calls* the resolver, and would cause a query cycle.
Res::Def(kind, id) => found(kind.descr(id)),
_ => found(ns_to_try.descr()),
}
}
};
}
(msg, None)
} else if ident.name == kw::SelfUpper {
// As mentioned above, `opt_ns` being `None` indicates a module path in import.
// We can use this to improve a confusing error for, e.g. `use Self::Variant` in an
// impl
if opt_ns.is_none() {
("`Self` cannot be used in imports".to_string(), None)
} else {
(
"`Self` is only available in impls, traits, and type definitions".to_string(),
None,
)
}
} else if ident.name.as_str().chars().next().is_some_and(|c| c.is_ascii_uppercase()) {
// Check whether the name refers to an item in the value namespace.
let binding = if let Some(ribs) = ribs {
assert!(ignore_import.is_none());
self.resolve_ident_in_lexical_scope(
ident,
ValueNS,
parent_scope,
None,
&ribs[ValueNS],
ignore_binding,
)
} else {
None
};
let match_span = match binding {
// Name matches a local variable. For example:
// ```
// fn f() {
// let Foo: &str = "";
// println!("{}", Foo::Bar); // Name refers to local
// // variable `Foo`.
// }
// ```
Some(LexicalScopeBinding::Res(Res::Local(id))) => {
Some(*self.pat_span_map.get(&id).unwrap())
}
// Name matches item from a local name binding
// created by `use` declaration. For example:
// ```
// pub Foo: &str = "";
//
// mod submod {
// use super::Foo;
// println!("{}", Foo::Bar); // Name refers to local
// // binding `Foo`.
// }
// ```
Some(LexicalScopeBinding::Item(name_binding)) => Some(name_binding.span),
_ => None,
};
let suggestion = match_span.map(|span| {
(
vec![(span, String::from(""))],
format!("`{ident}` is defined here, but is not a type"),
Applicability::MaybeIncorrect,
)
});
(format!("use of undeclared type `{ident}`"), suggestion)
} else {
let mut suggestion = None;
if ident.name == sym::alloc {
suggestion = Some((
vec![],
String::from("add `extern crate alloc` to use the `alloc` crate"),
Applicability::MaybeIncorrect,
))
}
suggestion = suggestion.or_else(|| {
self.find_similarly_named_module_or_crate(ident.name, parent_scope.module).map(
|sugg| {
(
vec![(ident.span, sugg.to_string())],
String::from("there is a crate or module with a similar name"),
Applicability::MaybeIncorrect,
)
},
)
});
if let Ok(binding) = self.early_resolve_ident_in_lexical_scope(
ident,
ScopeSet::All(ValueNS),
parent_scope,
None,
false,
ignore_binding,
ignore_import,
) {
let descr = binding.res().descr();
(format!("{descr} `{ident}` is not a crate or module"), suggestion)
} else {
(format!("use of undeclared crate or module `{ident}`"), suggestion)
}
}
}
/// Adds suggestions for a path that cannot be resolved.
pub(crate) fn make_path_suggestion(
&mut self,
span: Span,
mut path: Vec<Segment>,
parent_scope: &ParentScope<'ra>,
) -> Option<(Vec<Segment>, Option<String>)> {
debug!("make_path_suggestion: span={:?} path={:?}", span, path);
match (path.get(0), path.get(1)) {
// `{{root}}::ident::...` on both editions.
// On 2015 `{{root}}` is usually added implicitly.
(Some(fst), Some(snd))
if fst.ident.name == kw::PathRoot && !snd.ident.is_path_segment_keyword() => {}
// `ident::...` on 2018.
(Some(fst), _)
if fst.ident.span.at_least_rust_2018() && !fst.ident.is_path_segment_keyword() =>
{
// Insert a placeholder that's later replaced by `self`/`super`/etc.
path.insert(0, Segment::from_ident(Ident::empty()));
}
_ => return None,
}
self.make_missing_self_suggestion(path.clone(), parent_scope)
.or_else(|| self.make_missing_crate_suggestion(path.clone(), parent_scope))
.or_else(|| self.make_missing_super_suggestion(path.clone(), parent_scope))
.or_else(|| self.make_external_crate_suggestion(path, parent_scope))
}
/// Suggest a missing `self::` if that resolves to an correct module.
///
/// ```text
/// |
/// LL | use foo::Bar;
/// | ^^^ did you mean `self::foo`?
/// ```
fn make_missing_self_suggestion(
&mut self,
mut path: Vec<Segment>,
parent_scope: &ParentScope<'ra>,
) -> Option<(Vec<Segment>, Option<String>)> {
// Replace first ident with `self` and check if that is valid.
path[0].ident.name = kw::SelfLower;
let result = self.maybe_resolve_path(&path, None, parent_scope, None);
debug!("make_missing_self_suggestion: path={:?} result={:?}", path, result);
if let PathResult::Module(..) = result { Some((path, None)) } else { None }
}
/// Suggests a missing `crate::` if that resolves to an correct module.
///
/// ```text
/// |
/// LL | use foo::Bar;
/// | ^^^ did you mean `crate::foo`?
/// ```
fn make_missing_crate_suggestion(
&mut self,
mut path: Vec<Segment>,
parent_scope: &ParentScope<'ra>,
) -> Option<(Vec<Segment>, Option<String>)> {
// Replace first ident with `crate` and check if that is valid.
path[0].ident.name = kw::Crate;
let result = self.maybe_resolve_path(&path, None, parent_scope, None);
debug!("make_missing_crate_suggestion: path={:?} result={:?}", path, result);
if let PathResult::Module(..) = result {
Some((
path,
Some(
"`use` statements changed in Rust 2018; read more at \
<https://doc.rust-lang.org/edition-guide/rust-2018/module-system/path-\
clarity.html>"
.to_string(),
),
))
} else {
None
}
}
/// Suggests a missing `super::` if that resolves to an correct module.
///
/// ```text
/// |
/// LL | use foo::Bar;
/// | ^^^ did you mean `super::foo`?
/// ```
fn make_missing_super_suggestion(
&mut self,
mut path: Vec<Segment>,
parent_scope: &ParentScope<'ra>,
) -> Option<(Vec<Segment>, Option<String>)> {
// Replace first ident with `crate` and check if that is valid.
path[0].ident.name = kw::Super;
let result = self.maybe_resolve_path(&path, None, parent_scope, None);
debug!("make_missing_super_suggestion: path={:?} result={:?}", path, result);
if let PathResult::Module(..) = result { Some((path, None)) } else { None }
}
/// Suggests a missing external crate name if that resolves to an correct module.
///
/// ```text
/// |
/// LL | use foobar::Baz;
/// | ^^^^^^ did you mean `baz::foobar`?
/// ```
///
/// Used when importing a submodule of an external crate but missing that crate's
/// name as the first part of path.
fn make_external_crate_suggestion(
&mut self,
mut path: Vec<Segment>,
parent_scope: &ParentScope<'ra>,
) -> Option<(Vec<Segment>, Option<String>)> {
if path[1].ident.span.is_rust_2015() {
return None;
}
// Sort extern crate names in *reverse* order to get
// 1) some consistent ordering for emitted diagnostics, and
// 2) `std` suggestions before `core` suggestions.
let mut extern_crate_names =
self.extern_prelude.keys().map(|ident| ident.name).collect::<Vec<_>>();
extern_crate_names.sort_by(|a, b| b.as_str().partial_cmp(a.as_str()).unwrap());
for name in extern_crate_names.into_iter() {
// Replace first ident with a crate name and check if that is valid.
path[0].ident.name = name;
let result = self.maybe_resolve_path(&path, None, parent_scope, None);
debug!(
"make_external_crate_suggestion: name={:?} path={:?} result={:?}",
name, path, result
);
if let PathResult::Module(..) = result {
return Some((path, None));
}
}
None
}
/// Suggests importing a macro from the root of the crate rather than a module within
/// the crate.
///
/// ```text
/// help: a macro with this name exists at the root of the crate
/// |
/// LL | use issue_59764::makro;
/// | ^^^^^^^^^^^^^^^^^^
/// |
/// = note: this could be because a macro annotated with `#[macro_export]` will be exported
/// at the root of the crate instead of the module where it is defined
/// ```
pub(crate) fn check_for_module_export_macro(
&mut self,
import: Import<'ra>,
module: ModuleOrUniformRoot<'ra>,
ident: Ident,
) -> Option<(Option<Suggestion>, Option<String>)> {
let ModuleOrUniformRoot::Module(mut crate_module) = module else {
return None;
};
while let Some(parent) = crate_module.parent {
crate_module = parent;
}
if module == ModuleOrUniformRoot::Module(crate_module) {
// Don't make a suggestion if the import was already from the root of the crate.
return None;
}
let resolutions = self.resolutions(crate_module).borrow();
let binding_key = BindingKey::new(ident, MacroNS);
let resolution = resolutions.get(&binding_key)?;
let binding = resolution.borrow().binding()?;
if let Res::Def(DefKind::Macro(MacroKind::Bang), _) = binding.res() {
let module_name = crate_module.kind.name().unwrap();
let import_snippet = match import.kind {
ImportKind::Single { source, target, .. } if source != target => {
format!("{source} as {target}")
}
_ => format!("{ident}"),
};
let mut corrections: Vec<(Span, String)> = Vec::new();
if !import.is_nested() {
// Assume this is the easy case of `use issue_59764::foo::makro;` and just remove
// intermediate segments.
corrections.push((import.span, format!("{module_name}::{import_snippet}")));
} else {
// Find the binding span (and any trailing commas and spaces).
// ie. `use a::b::{c, d, e};`
// ^^^
let (found_closing_brace, binding_span) = find_span_of_binding_until_next_binding(
self.tcx.sess,
import.span,
import.use_span,
);
debug!(
"check_for_module_export_macro: found_closing_brace={:?} binding_span={:?}",
found_closing_brace, binding_span
);
let mut removal_span = binding_span;
if found_closing_brace {
// If the binding span ended with a closing brace, as in the below example:
// ie. `use a::b::{c, d};`
// ^
// Then expand the span of characters to remove to include the previous
// binding's trailing comma.
// ie. `use a::b::{c, d};`
// ^^^
if let Some(previous_span) =
extend_span_to_previous_binding(self.tcx.sess, binding_span)
{
debug!("check_for_module_export_macro: previous_span={:?}", previous_span);
removal_span = removal_span.with_lo(previous_span.lo());
}
}
debug!("check_for_module_export_macro: removal_span={:?}", removal_span);
// Remove the `removal_span`.
corrections.push((removal_span, "".to_string()));
// Find the span after the crate name and if it has nested imports immediately
// after the crate name already.
// ie. `use a::b::{c, d};`
// ^^^^^^^^^
// or `use a::{b, c, d}};`
// ^^^^^^^^^^^
let (has_nested, after_crate_name) = find_span_immediately_after_crate_name(
self.tcx.sess,
module_name,
import.use_span,
);
debug!(
"check_for_module_export_macro: has_nested={:?} after_crate_name={:?}",
has_nested, after_crate_name
);
let source_map = self.tcx.sess.source_map();
// Make sure this is actually crate-relative.
let is_definitely_crate = import
.module_path
.first()
.is_some_and(|f| f.ident.name != kw::SelfLower && f.ident.name != kw::Super);
// Add the import to the start, with a `{` if required.
let start_point = source_map.start_point(after_crate_name);
if is_definitely_crate
&& let Ok(start_snippet) = source_map.span_to_snippet(start_point)
{
corrections.push((
start_point,
if has_nested {
// In this case, `start_snippet` must equal '{'.
format!("{start_snippet}{import_snippet}, ")
} else {
// In this case, add a `{`, then the moved import, then whatever
// was there before.
format!("{{{import_snippet}, {start_snippet}")
},
));
// Add a `};` to the end if nested, matching the `{` added at the start.
if !has_nested {
corrections
.push((source_map.end_point(after_crate_name), "};".to_string()));
}
} else {
// If the root import is module-relative, add the import separately
corrections.push((
import.use_span.shrink_to_lo(),
format!("use {module_name}::{import_snippet};\n"),
));
}
}
let suggestion = Some((
corrections,
String::from("a macro with this name exists at the root of the crate"),
Applicability::MaybeIncorrect,
));
Some((suggestion, Some("this could be because a macro annotated with `#[macro_export]` will be exported \
at the root of the crate instead of the module where it is defined"
.to_string())))
} else {
None
}
}
/// Finds a cfg-ed out item inside `module` with the matching name.
pub(crate) fn find_cfg_stripped(&self, err: &mut Diag<'_>, segment: &Symbol, module: DefId) {
let local_items;
let symbols = if module.is_local() {
local_items = self
.stripped_cfg_items
.iter()
.filter_map(|item| {
let parent_module = self.opt_local_def_id(item.parent_module)?.to_def_id();
Some(StrippedCfgItem { parent_module, name: item.name, cfg: item.cfg.clone() })
})
.collect::<Vec<_>>();
local_items.as_slice()
} else {
self.tcx.stripped_cfg_items(module.krate)
};
for &StrippedCfgItem { parent_module, name, ref cfg } in symbols {
if parent_module != module || name.name != *segment {
continue;
}
let note = errors::FoundItemConfigureOut { span: name.span };
err.subdiagnostic(note);
if let MetaItemKind::List(nested) = &cfg.kind
&& let MetaItemInner::MetaItem(meta_item) = &nested[0]
&& let MetaItemKind::NameValue(feature_name) = &meta_item.kind
{
let note = errors::ItemWasBehindFeature {
feature: feature_name.symbol,
span: meta_item.span,
};
err.subdiagnostic(note);
} else {
let note = errors::ItemWasCfgOut { span: cfg.span };
err.subdiagnostic(note);
}
}
}
}
/// Given a `binding_span` of a binding within a use statement:
///
/// ```ignore (illustrative)
/// use foo::{a, b, c};
/// // ^
/// ```
///
/// then return the span until the next binding or the end of the statement:
///
/// ```ignore (illustrative)
/// use foo::{a, b, c};
/// // ^^^
/// ```
fn find_span_of_binding_until_next_binding(
sess: &Session,
binding_span: Span,
use_span: Span,
) -> (bool, Span) {
let source_map = sess.source_map();
// Find the span of everything after the binding.
// ie. `a, e};` or `a};`
let binding_until_end = binding_span.with_hi(use_span.hi());
// Find everything after the binding but not including the binding.
// ie. `, e};` or `};`
let after_binding_until_end = binding_until_end.with_lo(binding_span.hi());
// Keep characters in the span until we encounter something that isn't a comma or
// whitespace.
// ie. `, ` or ``.
//
// Also note whether a closing brace character was encountered. If there
// was, then later go backwards to remove any trailing commas that are left.
let mut found_closing_brace = false;
let after_binding_until_next_binding =
source_map.span_take_while(after_binding_until_end, |&ch| {
if ch == '}' {
found_closing_brace = true;
}
ch == ' ' || ch == ','
});
// Combine the two spans.
// ie. `a, ` or `a`.
//
// Removing these would leave `issue_52891::{d, e};` or `issue_52891::{d, e, };`
let span = binding_span.with_hi(after_binding_until_next_binding.hi());
(found_closing_brace, span)
}
/// Given a `binding_span`, return the span through to the comma or opening brace of the previous
/// binding.
///
/// ```ignore (illustrative)
/// use foo::a::{a, b, c};
/// // ^^--- binding span
/// // |
/// // returned span
///
/// use foo::{a, b, c};
/// // --- binding span
/// ```
fn extend_span_to_previous_binding(sess: &Session, binding_span: Span) -> Option<Span> {
let source_map = sess.source_map();
// `prev_source` will contain all of the source that came before the span.
// Then split based on a command and take the first (ie. closest to our span)
// snippet. In the example, this is a space.
let prev_source = source_map.span_to_prev_source(binding_span).ok()?;
let prev_comma = prev_source.rsplit(',').collect::<Vec<_>>();
let prev_starting_brace = prev_source.rsplit('{').collect::<Vec<_>>();
if prev_comma.len() <= 1 || prev_starting_brace.len() <= 1 {
return None;
}
let prev_comma = prev_comma.first().unwrap();
let prev_starting_brace = prev_starting_brace.first().unwrap();
// If the amount of source code before the comma is greater than
// the amount of source code before the starting brace then we've only
// got one item in the nested item (eg. `issue_52891::{self}`).
if prev_comma.len() > prev_starting_brace.len() {
return None;
}
Some(binding_span.with_lo(BytePos(
// Take away the number of bytes for the characters we've found and an
// extra for the comma.
binding_span.lo().0 - (prev_comma.as_bytes().len() as u32) - 1,
)))
}
/// Given a `use_span` of a binding within a use statement, returns the highlighted span and if
/// it is a nested use tree.
///
/// ```ignore (illustrative)
/// use foo::a::{b, c};
/// // ^^^^^^^^^^ -- false
///
/// use foo::{a, b, c};
/// // ^^^^^^^^^^ -- true
///
/// use foo::{a, b::{c, d}};
/// // ^^^^^^^^^^^^^^^ -- true
/// ```
fn find_span_immediately_after_crate_name(
sess: &Session,
module_name: Symbol,
use_span: Span,
) -> (bool, Span) {
debug!(
"find_span_immediately_after_crate_name: module_name={:?} use_span={:?}",
module_name, use_span
);
let source_map = sess.source_map();
// Using `use issue_59764::foo::{baz, makro};` as an example throughout..
let mut num_colons = 0;
// Find second colon.. `use issue_59764:`
let until_second_colon = source_map.span_take_while(use_span, |c| {
if *c == ':' {
num_colons += 1;
}
!matches!(c, ':' if num_colons == 2)
});
// Find everything after the second colon.. `foo::{baz, makro};`
let from_second_colon = use_span.with_lo(until_second_colon.hi() + BytePos(1));
let mut found_a_non_whitespace_character = false;
// Find the first non-whitespace character in `from_second_colon`.. `f`
let after_second_colon = source_map.span_take_while(from_second_colon, |c| {
if found_a_non_whitespace_character {
return false;
}
if !c.is_whitespace() {
found_a_non_whitespace_character = true;
}
true
});
// Find the first `{` in from_second_colon.. `foo::{`
let next_left_bracket = source_map.span_through_char(from_second_colon, '{');
(next_left_bracket == after_second_colon, from_second_colon)
}
/// A suggestion has already been emitted, change the wording slightly to clarify that both are
/// independent options.
enum Instead {
Yes,
No,
}
/// Whether an existing place with an `use` item was found.
enum FoundUse {
Yes,
No,
}
/// Whether a binding is part of a pattern or a use statement. Used for diagnostics.
pub(crate) enum DiagMode {
Normal,
/// The binding is part of a pattern
Pattern,
/// The binding is part of a use statement
Import {
/// `true` mean add the tips afterward for case `use a::{b,c}`,
/// rather than replacing within.
append: bool,
},
}
pub(crate) fn import_candidates(
tcx: TyCtxt<'_>,
err: &mut Diag<'_>,
// This is `None` if all placement locations are inside expansions
use_placement_span: Option<Span>,
candidates: &[ImportSuggestion],
mode: DiagMode,
append: &str,
) {
show_candidates(
tcx,
err,
use_placement_span,
candidates,
Instead::Yes,
FoundUse::Yes,
mode,
vec![],
append,
);
}
type PathString<'a> = (String, &'a str, Option<Span>, &'a Option<String>, bool);
/// When an entity with a given name is not available in scope, we search for
/// entities with that name in all crates. This method allows outputting the
/// results of this search in a programmer-friendly way. If any entities are
/// found and suggested, returns `true`, otherwise returns `false`.
fn show_candidates(
tcx: TyCtxt<'_>,
err: &mut Diag<'_>,
// This is `None` if all placement locations are inside expansions
use_placement_span: Option<Span>,
candidates: &[ImportSuggestion],
instead: Instead,
found_use: FoundUse,
mode: DiagMode,
path: Vec<Segment>,
append: &str,
) -> bool {
if candidates.is_empty() {
return false;
}
let mut accessible_path_strings: Vec<PathString<'_>> = Vec::new();
let mut inaccessible_path_strings: Vec<PathString<'_>> = Vec::new();
candidates.iter().for_each(|c| {
if c.accessible {
// Don't suggest `#[doc(hidden)]` items from other crates
if c.doc_visible {
accessible_path_strings.push((
pprust::path_to_string(&c.path),
c.descr,
c.did.and_then(|did| Some(tcx.source_span(did.as_local()?))),
&c.note,
c.via_import,
))
}
} else {
inaccessible_path_strings.push((
pprust::path_to_string(&c.path),
c.descr,
c.did.and_then(|did| Some(tcx.source_span(did.as_local()?))),
&c.note,
c.via_import,
))
}
});
// we want consistent results across executions, but candidates are produced
// by iterating through a hash map, so make sure they are ordered:
for path_strings in [&mut accessible_path_strings, &mut inaccessible_path_strings] {
path_strings.sort_by(|a, b| a.0.cmp(&b.0));
path_strings.dedup_by(|a, b| a.0 == b.0);
let core_path_strings =
path_strings.extract_if(|p| p.0.starts_with("core::")).collect::<Vec<_>>();
let std_path_strings =
path_strings.extract_if(|p| p.0.starts_with("std::")).collect::<Vec<_>>();
let foreign_crate_path_strings =
path_strings.extract_if(|p| !p.0.starts_with("crate::")).collect::<Vec<_>>();
// We list the `crate` local paths first.
// Then we list the `std`/`core` paths.
if std_path_strings.len() == core_path_strings.len() {
// Do not list `core::` paths if we are already listing the `std::` ones.
path_strings.extend(std_path_strings);
} else {
path_strings.extend(std_path_strings);
path_strings.extend(core_path_strings);
}
// List all paths from foreign crates last.
path_strings.extend(foreign_crate_path_strings);
}
if !accessible_path_strings.is_empty() {
let (determiner, kind, s, name, through) =
if let [(name, descr, _, _, via_import)] = &accessible_path_strings[..] {
(
"this",
*descr,
"",
format!(" `{name}`"),
if *via_import { " through its public re-export" } else { "" },
)
} else {
// Get the unique item kinds and if there's only one, we use the right kind name
// instead of the more generic "items".
let mut kinds = accessible_path_strings
.iter()
.map(|(_, descr, _, _, _)| *descr)
.collect::<FxHashSet<&str>>()
.into_iter();
let kind = if let Some(kind) = kinds.next()
&& let None = kinds.next()
{
kind
} else {
"item"
};
let s = if kind.ends_with('s') { "es" } else { "s" };
("one of these", kind, s, String::new(), "")
};
let instead = if let Instead::Yes = instead { " instead" } else { "" };
let mut msg = if let DiagMode::Pattern = mode {
format!(
"if you meant to match on {kind}{s}{instead}{name}, use the full path in the \
pattern",
)
} else {
format!("consider importing {determiner} {kind}{s}{through}{instead}")
};
for note in accessible_path_strings.iter().flat_map(|cand| cand.3.as_ref()) {
err.note(note.clone());
}
let append_candidates = |msg: &mut String, accessible_path_strings: Vec<PathString<'_>>| {
msg.push(':');
for candidate in accessible_path_strings {
msg.push('\n');
msg.push_str(&candidate.0);
}
};
if let Some(span) = use_placement_span {
let (add_use, trailing) = match mode {
DiagMode::Pattern => {
err.span_suggestions(
span,
msg,
accessible_path_strings.into_iter().map(|a| a.0),
Applicability::MaybeIncorrect,
);
return true;
}
DiagMode::Import { .. } => ("", ""),
DiagMode::Normal => ("use ", ";\n"),
};
for candidate in &mut accessible_path_strings {
// produce an additional newline to separate the new use statement
// from the directly following item.
let additional_newline = if let FoundUse::No = found_use
&& let DiagMode::Normal = mode
{
"\n"
} else {
""
};
candidate.0 =
format!("{add_use}{}{append}{trailing}{additional_newline}", candidate.0);
}
match mode {
DiagMode::Import { append: true, .. } => {
append_candidates(&mut msg, accessible_path_strings);
err.span_help(span, msg);
}
_ => {
err.span_suggestions_with_style(
span,
msg,
accessible_path_strings.into_iter().map(|a| a.0),
Applicability::MaybeIncorrect,
SuggestionStyle::ShowAlways,
);
}
}
if let [first, .., last] = &path[..] {
let sp = first.ident.span.until(last.ident.span);
// Our suggestion is empty, so make sure the span is not empty (or we'd ICE).
// Can happen for derive-generated spans.
if sp.can_be_used_for_suggestions() && !sp.is_empty() {
err.span_suggestion_verbose(
sp,
format!("if you import `{}`, refer to it directly", last.ident),
"",
Applicability::Unspecified,
);
}
}
} else {
append_candidates(&mut msg, accessible_path_strings);
err.help(msg);
}
true
} else if !(inaccessible_path_strings.is_empty() || matches!(mode, DiagMode::Import { .. })) {
let prefix =
if let DiagMode::Pattern = mode { "you might have meant to match on " } else { "" };
if let [(name, descr, source_span, note, _)] = &inaccessible_path_strings[..] {
let msg = format!(
"{prefix}{descr} `{name}`{} exists but is inaccessible",
if let DiagMode::Pattern = mode { ", which" } else { "" }
);
if let Some(source_span) = source_span {
let span = tcx.sess.source_map().guess_head_span(*source_span);
let mut multi_span = MultiSpan::from_span(span);
multi_span.push_span_label(span, "not accessible");
err.span_note(multi_span, msg);
} else {
err.note(msg);
}
if let Some(note) = (*note).as_deref() {
err.note(note.to_string());
}
} else {
let (_, descr_first, _, _, _) = &inaccessible_path_strings[0];
let descr = if inaccessible_path_strings
.iter()
.skip(1)
.all(|(_, descr, _, _, _)| descr == descr_first)
{
descr_first
} else {
"item"
};
let plural_descr =
if descr.ends_with('s') { format!("{descr}es") } else { format!("{descr}s") };
let mut msg = format!("{prefix}these {plural_descr} exist but are inaccessible");
let mut has_colon = false;
let mut spans = Vec::new();
for (name, _, source_span, _, _) in &inaccessible_path_strings {
if let Some(source_span) = source_span {
let span = tcx.sess.source_map().guess_head_span(*source_span);
spans.push((name, span));
} else {
if !has_colon {
msg.push(':');
has_colon = true;
}
msg.push('\n');
msg.push_str(name);
}
}
let mut multi_span = MultiSpan::from_spans(spans.iter().map(|(_, sp)| *sp).collect());
for (name, span) in spans {
multi_span.push_span_label(span, format!("`{name}`: not accessible"));
}
for note in inaccessible_path_strings.iter().flat_map(|cand| cand.3.as_ref()) {
err.note(note.clone());
}
err.span_note(multi_span, msg);
}
true
} else {
false
}
}
#[derive(Debug)]
struct UsePlacementFinder {
target_module: NodeId,
first_legal_span: Option<Span>,
first_use_span: Option<Span>,
}
impl UsePlacementFinder {
fn check(krate: &Crate, target_module: NodeId) -> (Option<Span>, FoundUse) {
let mut finder =
UsePlacementFinder { target_module, first_legal_span: None, first_use_span: None };
finder.visit_crate(krate);
if let Some(use_span) = finder.first_use_span {
(Some(use_span), FoundUse::Yes)
} else {
(finder.first_legal_span, FoundUse::No)
}
}
}
impl<'tcx> visit::Visitor<'tcx> for UsePlacementFinder {
fn visit_crate(&mut self, c: &Crate) {
if self.target_module == CRATE_NODE_ID {
let inject = c.spans.inject_use_span;
if is_span_suitable_for_use_injection(inject) {
self.first_legal_span = Some(inject);
}
self.first_use_span = search_for_any_use_in_items(&c.items);
return;
} else {
visit::walk_crate(self, c);
}
}
fn visit_item(&mut self, item: &'tcx ast::Item) {
if self.target_module == item.id {
if let ItemKind::Mod(_, ModKind::Loaded(items, _inline, mod_spans)) = &item.kind {
let inject = mod_spans.inject_use_span;
if is_span_suitable_for_use_injection(inject) {
self.first_legal_span = Some(inject);
}
self.first_use_span = search_for_any_use_in_items(items);
return;
}
} else {
visit::walk_item(self, item);
}
}
}
fn search_for_any_use_in_items(items: &[P<ast::Item>]) -> Option<Span> {
for item in items {
if let ItemKind::Use(..) = item.kind {
if is_span_suitable_for_use_injection(item.span) {
let mut lo = item.span.lo();
for attr in &item.attrs {
if attr.span.eq_ctxt(item.span) {
lo = std::cmp::min(lo, attr.span.lo());
}
}
return Some(Span::new(lo, lo, item.span.ctxt(), item.span.parent()));
}
}
}
None
}
fn is_span_suitable_for_use_injection(s: Span) -> bool {
// don't suggest placing a use before the prelude
// import or other generated ones
!s.from_expansion()
}