CGExprCXX.cpp 90.9 KB
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 1546 1547 1548 1549 1550 1551 1552 1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587 1588 1589 1590 1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611 1612 1613 1614 1615 1616 1617 1618 1619 1620 1621 1622 1623 1624 1625 1626 1627 1628 1629 1630 1631 1632 1633 1634 1635 1636 1637 1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 1648 1649 1650 1651 1652 1653 1654 1655 1656 1657 1658 1659 1660 1661 1662 1663 1664 1665 1666 1667 1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 1678 1679 1680 1681 1682 1683 1684 1685 1686 1687 1688 1689 1690 1691 1692 1693 1694 1695 1696 1697 1698 1699 1700 1701 1702 1703 1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 1715 1716 1717 1718 1719 1720 1721 1722 1723 1724 1725 1726 1727 1728 1729 1730 1731 1732 1733 1734 1735 1736 1737 1738 1739 1740 1741 1742 1743 1744 1745 1746 1747 1748 1749 1750 1751 1752 1753 1754 1755 1756 1757 1758 1759 1760 1761 1762 1763 1764 1765 1766 1767 1768 1769 1770 1771 1772 1773 1774 1775 1776 1777 1778 1779 1780 1781 1782 1783 1784 1785 1786 1787 1788 1789 1790 1791 1792 1793 1794 1795 1796 1797 1798 1799 1800 1801 1802 1803 1804 1805 1806 1807 1808 1809 1810 1811 1812 1813 1814 1815 1816 1817 1818 1819 1820 1821 1822 1823 1824 1825 1826 1827 1828 1829 1830 1831 1832 1833 1834 1835 1836 1837 1838 1839 1840 1841 1842 1843 1844 1845 1846 1847 1848 1849 1850 1851 1852 1853 1854 1855 1856 1857 1858 1859 1860 1861 1862 1863 1864 1865 1866 1867 1868 1869 1870 1871 1872 1873 1874 1875 1876 1877 1878 1879 1880 1881 1882 1883 1884 1885 1886 1887 1888 1889 1890 1891 1892 1893 1894 1895 1896 1897 1898 1899 1900 1901 1902 1903 1904 1905 1906 1907 1908 1909 1910 1911 1912 1913 1914 1915 1916 1917 1918 1919 1920 1921 1922 1923 1924 1925 1926 1927 1928 1929 1930 1931 1932 1933 1934 1935 1936 1937 1938 1939 1940 1941 1942 1943 1944 1945 1946 1947 1948 1949 1950 1951 1952 1953 1954 1955 1956 1957 1958 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036 2037 2038 2039 2040 2041 2042 2043 2044 2045 2046 2047 2048 2049 2050 2051 2052 2053 2054 2055 2056 2057 2058 2059 2060 2061 2062 2063 2064 2065 2066 2067 2068 2069 2070 2071 2072 2073 2074 2075 2076 2077 2078 2079 2080 2081 2082 2083 2084 2085 2086 2087 2088 2089 2090 2091 2092 2093 2094 2095 2096 2097 2098 2099 2100 2101 2102 2103 2104 2105 2106 2107 2108 2109 2110 2111 2112 2113 2114 2115 2116 2117 2118 2119 2120 2121 2122 2123 2124 2125 2126 2127 2128 2129 2130 2131 2132 2133 2134 2135 2136 2137 2138 2139 2140 2141 2142 2143 2144 2145 2146 2147 2148 2149 2150 2151 2152 2153 2154 2155 2156 2157 2158 2159 2160 2161 2162 2163 2164 2165 2166 2167 2168 2169 2170 2171 2172 2173 2174 2175 2176 2177 2178 2179 2180 2181 2182 2183 2184 2185 2186 2187 2188 2189 2190 2191 2192 2193 2194 2195 2196 2197 2198 2199 2200 2201 2202 2203 2204 2205 2206 2207 2208 2209 2210 2211 2212 2213 2214 2215 2216 2217 2218 2219 2220 2221 2222 2223 2224 2225 2226 2227 2228 2229 2230 2231 2232 2233 2234 2235 2236 2237 2238 2239 2240 2241 2242 2243 2244 2245 2246 2247 2248 2249 2250 2251 2252 2253 2254 2255 2256 2257 2258 2259 2260 2261 2262 2263 2264 2265 2266 2267 2268 2269 2270 2271 2272 2273 2274 2275 2276 2277 2278 2279 2280 2281 2282 2283 2284 2285 2286 2287 2288 2289 2290 2291 2292 2293 2294 2295 2296 2297 2298 2299 2300 2301 2302 2303 2304 2305 2306 2307 2308 2309 2310 2311 2312 2313 2314 2315 2316 2317
//===--- CGExprCXX.cpp - Emit LLVM Code for C++ expressions ---------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This contains code dealing with code generation of C++ expressions
//
//===----------------------------------------------------------------------===//

#include "CGCUDARuntime.h"
#include "CGCXXABI.h"
#include "CGDebugInfo.h"
#include "CGObjCRuntime.h"
#include "CodeGenFunction.h"
#include "ConstantEmitter.h"
#include "TargetInfo.h"
#include "clang/Basic/CodeGenOptions.h"
#include "clang/CodeGen/CGFunctionInfo.h"
#include "llvm/IR/Intrinsics.h"

using namespace clang;
using namespace CodeGen;

namespace {
struct MemberCallInfo {
  RequiredArgs ReqArgs;
  // Number of prefix arguments for the call. Ignores the `this` pointer.
  unsigned PrefixSize;
};
}

static MemberCallInfo
commonEmitCXXMemberOrOperatorCall(CodeGenFunction &CGF, const CXXMethodDecl *MD,
                                  llvm::Value *This, llvm::Value *ImplicitParam,
                                  QualType ImplicitParamTy, const CallExpr *CE,
                                  CallArgList &Args, CallArgList *RtlArgs) {
  assert(CE == nullptr || isa<CXXMemberCallExpr>(CE) ||
         isa<CXXOperatorCallExpr>(CE));
  assert(MD->isInstance() &&
         "Trying to emit a member or operator call expr on a static method!");

  // Push the this ptr.
  const CXXRecordDecl *RD =
      CGF.CGM.getCXXABI().getThisArgumentTypeForMethod(MD);
  Args.add(RValue::get(This), CGF.getTypes().DeriveThisType(RD, MD));

  // If there is an implicit parameter (e.g. VTT), emit it.
  if (ImplicitParam) {
    Args.add(RValue::get(ImplicitParam), ImplicitParamTy);
  }

  const FunctionProtoType *FPT = MD->getType()->castAs<FunctionProtoType>();
  RequiredArgs required = RequiredArgs::forPrototypePlus(FPT, Args.size());
  unsigned PrefixSize = Args.size() - 1;

  // And the rest of the call args.
  if (RtlArgs) {
    // Special case: if the caller emitted the arguments right-to-left already
    // (prior to emitting the *this argument), we're done. This happens for
    // assignment operators.
    Args.addFrom(*RtlArgs);
  } else if (CE) {
    // Special case: skip first argument of CXXOperatorCall (it is "this").
    unsigned ArgsToSkip = isa<CXXOperatorCallExpr>(CE) ? 1 : 0;
    CGF.EmitCallArgs(Args, FPT, drop_begin(CE->arguments(), ArgsToSkip),
                     CE->getDirectCallee());
  } else {
    assert(
        FPT->getNumParams() == 0 &&
        "No CallExpr specified for function with non-zero number of arguments");
  }
  return {required, PrefixSize};
}

RValue CodeGenFunction::EmitCXXMemberOrOperatorCall(
    const CXXMethodDecl *MD, const CGCallee &Callee,
    ReturnValueSlot ReturnValue,
    llvm::Value *This, llvm::Value *ImplicitParam, QualType ImplicitParamTy,
    const CallExpr *CE, CallArgList *RtlArgs) {
  const FunctionProtoType *FPT = MD->getType()->castAs<FunctionProtoType>();
  CallArgList Args;
  MemberCallInfo CallInfo = commonEmitCXXMemberOrOperatorCall(
      *this, MD, This, ImplicitParam, ImplicitParamTy, CE, Args, RtlArgs);
  auto &FnInfo = CGM.getTypes().arrangeCXXMethodCall(
      Args, FPT, CallInfo.ReqArgs, CallInfo.PrefixSize);
  return EmitCall(FnInfo, Callee, ReturnValue, Args, nullptr,
                  CE ? CE->getExprLoc() : SourceLocation());
}

RValue CodeGenFunction::EmitCXXDestructorCall(
    GlobalDecl Dtor, const CGCallee &Callee, llvm::Value *This, QualType ThisTy,
    llvm::Value *ImplicitParam, QualType ImplicitParamTy, const CallExpr *CE) {
  const CXXMethodDecl *DtorDecl = cast<CXXMethodDecl>(Dtor.getDecl());

  assert(!ThisTy.isNull());
  assert(ThisTy->getAsCXXRecordDecl() == DtorDecl->getParent() &&
         "Pointer/Object mixup");

  LangAS SrcAS = ThisTy.getAddressSpace();
  LangAS DstAS = DtorDecl->getMethodQualifiers().getAddressSpace();
  if (SrcAS != DstAS) {
    QualType DstTy = DtorDecl->getThisType();
    llvm::Type *NewType = CGM.getTypes().ConvertType(DstTy);
    This = getTargetHooks().performAddrSpaceCast(*this, This, SrcAS, DstAS,
                                                 NewType);
  }

  CallArgList Args;
  commonEmitCXXMemberOrOperatorCall(*this, DtorDecl, This, ImplicitParam,
                                    ImplicitParamTy, CE, Args, nullptr);
  return EmitCall(CGM.getTypes().arrangeCXXStructorDeclaration(Dtor), Callee,
                  ReturnValueSlot(), Args, nullptr,
                  CE ? CE->getExprLoc() : SourceLocation{});
}

RValue CodeGenFunction::EmitCXXPseudoDestructorExpr(
                                            const CXXPseudoDestructorExpr *E) {
  QualType DestroyedType = E->getDestroyedType();
  if (DestroyedType.hasStrongOrWeakObjCLifetime()) {
    // Automatic Reference Counting:
    //   If the pseudo-expression names a retainable object with weak or
    //   strong lifetime, the object shall be released.
    Expr *BaseExpr = E->getBase();
    Address BaseValue = Address::invalid();
    Qualifiers BaseQuals;

    // If this is s.x, emit s as an lvalue. If it is s->x, emit s as a scalar.
    if (E->isArrow()) {
      BaseValue = EmitPointerWithAlignment(BaseExpr);
      const auto *PTy = BaseExpr->getType()->castAs<PointerType>();
      BaseQuals = PTy->getPointeeType().getQualifiers();
    } else {
      LValue BaseLV = EmitLValue(BaseExpr);
      BaseValue = BaseLV.getAddress(*this);
      QualType BaseTy = BaseExpr->getType();
      BaseQuals = BaseTy.getQualifiers();
    }

    switch (DestroyedType.getObjCLifetime()) {
    case Qualifiers::OCL_None:
    case Qualifiers::OCL_ExplicitNone:
    case Qualifiers::OCL_Autoreleasing:
      break;

    case Qualifiers::OCL_Strong:
      EmitARCRelease(Builder.CreateLoad(BaseValue,
                        DestroyedType.isVolatileQualified()),
                     ARCPreciseLifetime);
      break;

    case Qualifiers::OCL_Weak:
      EmitARCDestroyWeak(BaseValue);
      break;
    }
  } else {
    // C++ [expr.pseudo]p1:
    //   The result shall only be used as the operand for the function call
    //   operator (), and the result of such a call has type void. The only
    //   effect is the evaluation of the postfix-expression before the dot or
    //   arrow.
    EmitIgnoredExpr(E->getBase());
  }

  return RValue::get(nullptr);
}

static CXXRecordDecl *getCXXRecord(const Expr *E) {
  QualType T = E->getType();
  if (const PointerType *PTy = T->getAs<PointerType>())
    T = PTy->getPointeeType();
  const RecordType *Ty = T->castAs<RecordType>();
  return cast<CXXRecordDecl>(Ty->getDecl());
}

// Note: This function also emit constructor calls to support a MSVC
// extensions allowing explicit constructor function call.
RValue CodeGenFunction::EmitCXXMemberCallExpr(const CXXMemberCallExpr *CE,
                                              ReturnValueSlot ReturnValue) {
  const Expr *callee = CE->getCallee()->IgnoreParens();

  if (isa<BinaryOperator>(callee))
    return EmitCXXMemberPointerCallExpr(CE, ReturnValue);

  const MemberExpr *ME = cast<MemberExpr>(callee);
  const CXXMethodDecl *MD = cast<CXXMethodDecl>(ME->getMemberDecl());

  if (MD->isStatic()) {
    // The method is static, emit it as we would a regular call.
    CGCallee callee =
        CGCallee::forDirect(CGM.GetAddrOfFunction(MD), GlobalDecl(MD));
    return EmitCall(getContext().getPointerType(MD->getType()), callee, CE,
                    ReturnValue);
  }

  bool HasQualifier = ME->hasQualifier();
  NestedNameSpecifier *Qualifier = HasQualifier ? ME->getQualifier() : nullptr;
  bool IsArrow = ME->isArrow();
  const Expr *Base = ME->getBase();

  return EmitCXXMemberOrOperatorMemberCallExpr(
      CE, MD, ReturnValue, HasQualifier, Qualifier, IsArrow, Base);
}

RValue CodeGenFunction::EmitCXXMemberOrOperatorMemberCallExpr(
    const CallExpr *CE, const CXXMethodDecl *MD, ReturnValueSlot ReturnValue,
    bool HasQualifier, NestedNameSpecifier *Qualifier, bool IsArrow,
    const Expr *Base) {
  assert(isa<CXXMemberCallExpr>(CE) || isa<CXXOperatorCallExpr>(CE));

  // Compute the object pointer.
  bool CanUseVirtualCall = MD->isVirtual() && !HasQualifier;

  const CXXMethodDecl *DevirtualizedMethod = nullptr;
  if (CanUseVirtualCall &&
      MD->getDevirtualizedMethod(Base, getLangOpts().AppleKext)) {
    const CXXRecordDecl *BestDynamicDecl = Base->getBestDynamicClassType();
    DevirtualizedMethod = MD->getCorrespondingMethodInClass(BestDynamicDecl);
    assert(DevirtualizedMethod);
    const CXXRecordDecl *DevirtualizedClass = DevirtualizedMethod->getParent();
    const Expr *Inner = Base->IgnoreParenBaseCasts();
    if (DevirtualizedMethod->getReturnType().getCanonicalType() !=
        MD->getReturnType().getCanonicalType())
      // If the return types are not the same, this might be a case where more
      // code needs to run to compensate for it. For example, the derived
      // method might return a type that inherits form from the return
      // type of MD and has a prefix.
      // For now we just avoid devirtualizing these covariant cases.
      DevirtualizedMethod = nullptr;
    else if (getCXXRecord(Inner) == DevirtualizedClass)
      // If the class of the Inner expression is where the dynamic method
      // is defined, build the this pointer from it.
      Base = Inner;
    else if (getCXXRecord(Base) != DevirtualizedClass) {
      // If the method is defined in a class that is not the best dynamic
      // one or the one of the full expression, we would have to build
      // a derived-to-base cast to compute the correct this pointer, but
      // we don't have support for that yet, so do a virtual call.
      DevirtualizedMethod = nullptr;
    }
  }

  bool TrivialForCodegen =
      MD->isTrivial() || (MD->isDefaulted() && MD->getParent()->isUnion());
  bool TrivialAssignment =
      TrivialForCodegen &&
      (MD->isCopyAssignmentOperator() || MD->isMoveAssignmentOperator()) &&
      !MD->getParent()->mayInsertExtraPadding();

  // C++17 demands that we evaluate the RHS of a (possibly-compound) assignment
  // operator before the LHS.
  CallArgList RtlArgStorage;
  CallArgList *RtlArgs = nullptr;
  LValue TrivialAssignmentRHS;
  if (auto *OCE = dyn_cast<CXXOperatorCallExpr>(CE)) {
    if (OCE->isAssignmentOp()) {
      if (TrivialAssignment) {
        TrivialAssignmentRHS = EmitLValue(CE->getArg(1));
      } else {
        RtlArgs = &RtlArgStorage;
        EmitCallArgs(*RtlArgs, MD->getType()->castAs<FunctionProtoType>(),
                     drop_begin(CE->arguments(), 1), CE->getDirectCallee(),
                     /*ParamsToSkip*/0, EvaluationOrder::ForceRightToLeft);
      }
    }
  }

  LValue This;
  if (IsArrow) {
    LValueBaseInfo BaseInfo;
    TBAAAccessInfo TBAAInfo;
    Address ThisValue = EmitPointerWithAlignment(Base, &BaseInfo, &TBAAInfo);
    This = MakeAddrLValue(ThisValue, Base->getType(), BaseInfo, TBAAInfo);
  } else {
    This = EmitLValue(Base);
  }

  if (const CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(MD)) {
    // This is the MSVC p->Ctor::Ctor(...) extension. We assume that's
    // constructing a new complete object of type Ctor.
    assert(!RtlArgs);
    assert(ReturnValue.isNull() && "Constructor shouldn't have return value");
    CallArgList Args;
    commonEmitCXXMemberOrOperatorCall(
        *this, Ctor, This.getPointer(*this), /*ImplicitParam=*/nullptr,
        /*ImplicitParamTy=*/QualType(), CE, Args, nullptr);

    EmitCXXConstructorCall(Ctor, Ctor_Complete, /*ForVirtualBase=*/false,
                           /*Delegating=*/false, This.getAddress(*this), Args,
                           AggValueSlot::DoesNotOverlap, CE->getExprLoc(),
                           /*NewPointerIsChecked=*/false);
    return RValue::get(nullptr);
  }

  if (TrivialForCodegen) {
    if (isa<CXXDestructorDecl>(MD))
      return RValue::get(nullptr);

    if (TrivialAssignment) {
      // We don't like to generate the trivial copy/move assignment operator
      // when it isn't necessary; just produce the proper effect here.
      // It's important that we use the result of EmitLValue here rather than
      // emitting call arguments, in order to preserve TBAA information from
      // the RHS.
      LValue RHS = isa<CXXOperatorCallExpr>(CE)
                       ? TrivialAssignmentRHS
                       : EmitLValue(*CE->arg_begin());
      EmitAggregateAssign(This, RHS, CE->getType());
      return RValue::get(This.getPointer(*this));
    }

    assert(MD->getParent()->mayInsertExtraPadding() &&
           "unknown trivial member function");
  }

  // Compute the function type we're calling.
  const CXXMethodDecl *CalleeDecl =
      DevirtualizedMethod ? DevirtualizedMethod : MD;
  const CGFunctionInfo *FInfo = nullptr;
  if (const auto *Dtor = dyn_cast<CXXDestructorDecl>(CalleeDecl))
    FInfo = &CGM.getTypes().arrangeCXXStructorDeclaration(
        GlobalDecl(Dtor, Dtor_Complete));
  else
    FInfo = &CGM.getTypes().arrangeCXXMethodDeclaration(CalleeDecl);

  llvm::FunctionType *Ty = CGM.getTypes().GetFunctionType(*FInfo);

  // C++11 [class.mfct.non-static]p2:
  //   If a non-static member function of a class X is called for an object that
  //   is not of type X, or of a type derived from X, the behavior is undefined.
  SourceLocation CallLoc;
  ASTContext &C = getContext();
  if (CE)
    CallLoc = CE->getExprLoc();

  SanitizerSet SkippedChecks;
  if (const auto *CMCE = dyn_cast<CXXMemberCallExpr>(CE)) {
    auto *IOA = CMCE->getImplicitObjectArgument();
    bool IsImplicitObjectCXXThis = IsWrappedCXXThis(IOA);
    if (IsImplicitObjectCXXThis)
      SkippedChecks.set(SanitizerKind::Alignment, true);
    if (IsImplicitObjectCXXThis || isa<DeclRefExpr>(IOA))
      SkippedChecks.set(SanitizerKind::Null, true);
  }
  EmitTypeCheck(CodeGenFunction::TCK_MemberCall, CallLoc,
                This.getPointer(*this),
                C.getRecordType(CalleeDecl->getParent()),
                /*Alignment=*/CharUnits::Zero(), SkippedChecks);

  // C++ [class.virtual]p12:
  //   Explicit qualification with the scope operator (5.1) suppresses the
  //   virtual call mechanism.
  //
  // We also don't emit a virtual call if the base expression has a record type
  // because then we know what the type is.
  bool UseVirtualCall = CanUseVirtualCall && !DevirtualizedMethod;

  if (const CXXDestructorDecl *Dtor = dyn_cast<CXXDestructorDecl>(CalleeDecl)) {
    assert(CE->arg_begin() == CE->arg_end() &&
           "Destructor shouldn't have explicit parameters");
    assert(ReturnValue.isNull() && "Destructor shouldn't have return value");
    if (UseVirtualCall) {
      CGM.getCXXABI().EmitVirtualDestructorCall(*this, Dtor, Dtor_Complete,
                                                This.getAddress(*this),
                                                cast<CXXMemberCallExpr>(CE));
    } else {
      GlobalDecl GD(Dtor, Dtor_Complete);
      CGCallee Callee;
      if (getLangOpts().AppleKext && Dtor->isVirtual() && HasQualifier)
        Callee = BuildAppleKextVirtualCall(Dtor, Qualifier, Ty);
      else if (!DevirtualizedMethod)
        Callee =
            CGCallee::forDirect(CGM.getAddrOfCXXStructor(GD, FInfo, Ty), GD);
      else {
        Callee = CGCallee::forDirect(CGM.GetAddrOfFunction(GD, Ty), GD);
      }

      QualType ThisTy =
          IsArrow ? Base->getType()->getPointeeType() : Base->getType();
      EmitCXXDestructorCall(GD, Callee, This.getPointer(*this), ThisTy,
                            /*ImplicitParam=*/nullptr,
                            /*ImplicitParamTy=*/QualType(), CE);
    }
    return RValue::get(nullptr);
  }

  // FIXME: Uses of 'MD' past this point need to be audited. We may need to use
  // 'CalleeDecl' instead.

  CGCallee Callee;
  if (UseVirtualCall) {
    Callee = CGCallee::forVirtual(CE, MD, This.getAddress(*this), Ty);
  } else {
    if (SanOpts.has(SanitizerKind::CFINVCall) &&
        MD->getParent()->isDynamicClass()) {
      llvm::Value *VTable;
      const CXXRecordDecl *RD;
      std::tie(VTable, RD) = CGM.getCXXABI().LoadVTablePtr(
          *this, This.getAddress(*this), CalleeDecl->getParent());
      EmitVTablePtrCheckForCall(RD, VTable, CFITCK_NVCall, CE->getBeginLoc());
    }

    if (getLangOpts().AppleKext && MD->isVirtual() && HasQualifier)
      Callee = BuildAppleKextVirtualCall(MD, Qualifier, Ty);
    else if (!DevirtualizedMethod)
      Callee =
          CGCallee::forDirect(CGM.GetAddrOfFunction(MD, Ty), GlobalDecl(MD));
    else {
      Callee =
          CGCallee::forDirect(CGM.GetAddrOfFunction(DevirtualizedMethod, Ty),
                              GlobalDecl(DevirtualizedMethod));
    }
  }

  if (MD->isVirtual()) {
    Address NewThisAddr =
        CGM.getCXXABI().adjustThisArgumentForVirtualFunctionCall(
            *this, CalleeDecl, This.getAddress(*this), UseVirtualCall);
    This.setAddress(NewThisAddr);
  }

  return EmitCXXMemberOrOperatorCall(
      CalleeDecl, Callee, ReturnValue, This.getPointer(*this),
      /*ImplicitParam=*/nullptr, QualType(), CE, RtlArgs);
}

RValue
CodeGenFunction::EmitCXXMemberPointerCallExpr(const CXXMemberCallExpr *E,
                                              ReturnValueSlot ReturnValue) {
  const BinaryOperator *BO =
      cast<BinaryOperator>(E->getCallee()->IgnoreParens());
  const Expr *BaseExpr = BO->getLHS();
  const Expr *MemFnExpr = BO->getRHS();

  const auto *MPT = MemFnExpr->getType()->castAs<MemberPointerType>();
  const auto *FPT = MPT->getPointeeType()->castAs<FunctionProtoType>();
  const auto *RD =
      cast<CXXRecordDecl>(MPT->getClass()->castAs<RecordType>()->getDecl());

  // Emit the 'this' pointer.
  Address This = Address::invalid();
  if (BO->getOpcode() == BO_PtrMemI)
    This = EmitPointerWithAlignment(BaseExpr);
  else
    This = EmitLValue(BaseExpr).getAddress(*this);

  EmitTypeCheck(TCK_MemberCall, E->getExprLoc(), This.getPointer(),
                QualType(MPT->getClass(), 0));

  // Get the member function pointer.
  llvm::Value *MemFnPtr = EmitScalarExpr(MemFnExpr);

  // Ask the ABI to load the callee.  Note that This is modified.
  llvm::Value *ThisPtrForCall = nullptr;
  CGCallee Callee =
    CGM.getCXXABI().EmitLoadOfMemberFunctionPointer(*this, BO, This,
                                             ThisPtrForCall, MemFnPtr, MPT);

  CallArgList Args;

  QualType ThisType =
    getContext().getPointerType(getContext().getTagDeclType(RD));

  // Push the this ptr.
  Args.add(RValue::get(ThisPtrForCall), ThisType);

  RequiredArgs required = RequiredArgs::forPrototypePlus(FPT, 1);

  // And the rest of the call args
  EmitCallArgs(Args, FPT, E->arguments());
  return EmitCall(CGM.getTypes().arrangeCXXMethodCall(Args, FPT, required,
                                                      /*PrefixSize=*/0),
                  Callee, ReturnValue, Args, nullptr, E->getExprLoc());
}

RValue
CodeGenFunction::EmitCXXOperatorMemberCallExpr(const CXXOperatorCallExpr *E,
                                               const CXXMethodDecl *MD,
                                               ReturnValueSlot ReturnValue) {
  assert(MD->isInstance() &&
         "Trying to emit a member call expr on a static method!");
  return EmitCXXMemberOrOperatorMemberCallExpr(
      E, MD, ReturnValue, /*HasQualifier=*/false, /*Qualifier=*/nullptr,
      /*IsArrow=*/false, E->getArg(0));
}

RValue CodeGenFunction::EmitCUDAKernelCallExpr(const CUDAKernelCallExpr *E,
                                               ReturnValueSlot ReturnValue) {
  return CGM.getCUDARuntime().EmitCUDAKernelCallExpr(*this, E, ReturnValue);
}

static void EmitNullBaseClassInitialization(CodeGenFunction &CGF,
                                            Address DestPtr,
                                            const CXXRecordDecl *Base) {
  if (Base->isEmpty())
    return;

  DestPtr = CGF.Builder.CreateElementBitCast(DestPtr, CGF.Int8Ty);

  const ASTRecordLayout &Layout = CGF.getContext().getASTRecordLayout(Base);
  CharUnits NVSize = Layout.getNonVirtualSize();

  // We cannot simply zero-initialize the entire base sub-object if vbptrs are
  // present, they are initialized by the most derived class before calling the
  // constructor.
  SmallVector<std::pair<CharUnits, CharUnits>, 1> Stores;
  Stores.emplace_back(CharUnits::Zero(), NVSize);

  // Each store is split by the existence of a vbptr.
  CharUnits VBPtrWidth = CGF.getPointerSize();
  std::vector<CharUnits> VBPtrOffsets =
      CGF.CGM.getCXXABI().getVBPtrOffsets(Base);
  for (CharUnits VBPtrOffset : VBPtrOffsets) {
    // Stop before we hit any virtual base pointers located in virtual bases.
    if (VBPtrOffset >= NVSize)
      break;
    std::pair<CharUnits, CharUnits> LastStore = Stores.pop_back_val();
    CharUnits LastStoreOffset = LastStore.first;
    CharUnits LastStoreSize = LastStore.second;

    CharUnits SplitBeforeOffset = LastStoreOffset;
    CharUnits SplitBeforeSize = VBPtrOffset - SplitBeforeOffset;
    assert(!SplitBeforeSize.isNegative() && "negative store size!");
    if (!SplitBeforeSize.isZero())
      Stores.emplace_back(SplitBeforeOffset, SplitBeforeSize);

    CharUnits SplitAfterOffset = VBPtrOffset + VBPtrWidth;
    CharUnits SplitAfterSize = LastStoreSize - SplitAfterOffset;
    assert(!SplitAfterSize.isNegative() && "negative store size!");
    if (!SplitAfterSize.isZero())
      Stores.emplace_back(SplitAfterOffset, SplitAfterSize);
  }

  // If the type contains a pointer to data member we can't memset it to zero.
  // Instead, create a null constant and copy it to the destination.
  // TODO: there are other patterns besides zero that we can usefully memset,
  // like -1, which happens to be the pattern used by member-pointers.
  // TODO: isZeroInitializable can be over-conservative in the case where a
  // virtual base contains a member pointer.
  llvm::Constant *NullConstantForBase = CGF.CGM.EmitNullConstantForBase(Base);
  if (!NullConstantForBase->isNullValue()) {
    llvm::GlobalVariable *NullVariable = new llvm::GlobalVariable(
        CGF.CGM.getModule(), NullConstantForBase->getType(),
        /*isConstant=*/true, llvm::GlobalVariable::PrivateLinkage,
        NullConstantForBase, Twine());

    CharUnits Align = std::max(Layout.getNonVirtualAlignment(),
                               DestPtr.getAlignment());
    NullVariable->setAlignment(Align.getAsAlign());

    Address SrcPtr = Address(CGF.EmitCastToVoidPtr(NullVariable), Align);

    // Get and call the appropriate llvm.memcpy overload.
    for (std::pair<CharUnits, CharUnits> Store : Stores) {
      CharUnits StoreOffset = Store.first;
      CharUnits StoreSize = Store.second;
      llvm::Value *StoreSizeVal = CGF.CGM.getSize(StoreSize);
      CGF.Builder.CreateMemCpy(
          CGF.Builder.CreateConstInBoundsByteGEP(DestPtr, StoreOffset),
          CGF.Builder.CreateConstInBoundsByteGEP(SrcPtr, StoreOffset),
          StoreSizeVal);
    }

  // Otherwise, just memset the whole thing to zero.  This is legal
  // because in LLVM, all default initializers (other than the ones we just
  // handled above) are guaranteed to have a bit pattern of all zeros.
  } else {
    for (std::pair<CharUnits, CharUnits> Store : Stores) {
      CharUnits StoreOffset = Store.first;
      CharUnits StoreSize = Store.second;
      llvm::Value *StoreSizeVal = CGF.CGM.getSize(StoreSize);
      CGF.Builder.CreateMemSet(
          CGF.Builder.CreateConstInBoundsByteGEP(DestPtr, StoreOffset),
          CGF.Builder.getInt8(0), StoreSizeVal);
    }
  }
}

void
CodeGenFunction::EmitCXXConstructExpr(const CXXConstructExpr *E,
                                      AggValueSlot Dest) {
  assert(!Dest.isIgnored() && "Must have a destination!");
  const CXXConstructorDecl *CD = E->getConstructor();

  // If we require zero initialization before (or instead of) calling the
  // constructor, as can be the case with a non-user-provided default
  // constructor, emit the zero initialization now, unless destination is
  // already zeroed.
  if (E->requiresZeroInitialization() && !Dest.isZeroed()) {
    switch (E->getConstructionKind()) {
    case CXXConstructExpr::CK_Delegating:
    case CXXConstructExpr::CK_Complete:
      EmitNullInitialization(Dest.getAddress(), E->getType());
      break;
    case CXXConstructExpr::CK_VirtualBase:
    case CXXConstructExpr::CK_NonVirtualBase:
      EmitNullBaseClassInitialization(*this, Dest.getAddress(),
                                      CD->getParent());
      break;
    }
  }

  // If this is a call to a trivial default constructor, do nothing.
  if (CD->isTrivial() && CD->isDefaultConstructor())
    return;

  // Elide the constructor if we're constructing from a temporary.
  // The temporary check is required because Sema sets this on NRVO
  // returns.
  if (getLangOpts().ElideConstructors && E->isElidable()) {
    assert(getContext().hasSameUnqualifiedType(E->getType(),
                                               E->getArg(0)->getType()));
    if (E->getArg(0)->isTemporaryObject(getContext(), CD->getParent())) {
      EmitAggExpr(E->getArg(0), Dest);
      return;
    }
  }

  if (const ArrayType *arrayType
        = getContext().getAsArrayType(E->getType())) {
    EmitCXXAggrConstructorCall(CD, arrayType, Dest.getAddress(), E,
                               Dest.isSanitizerChecked());
  } else {
    CXXCtorType Type = Ctor_Complete;
    bool ForVirtualBase = false;
    bool Delegating = false;

    switch (E->getConstructionKind()) {
     case CXXConstructExpr::CK_Delegating:
      // We should be emitting a constructor; GlobalDecl will assert this
      Type = CurGD.getCtorType();
      Delegating = true;
      break;

     case CXXConstructExpr::CK_Complete:
      Type = Ctor_Complete;
      break;

     case CXXConstructExpr::CK_VirtualBase:
      ForVirtualBase = true;
      LLVM_FALLTHROUGH;

     case CXXConstructExpr::CK_NonVirtualBase:
      Type = Ctor_Base;
     }

     // Call the constructor.
     EmitCXXConstructorCall(CD, Type, ForVirtualBase, Delegating, Dest, E);
  }
}

void CodeGenFunction::EmitSynthesizedCXXCopyCtor(Address Dest, Address Src,
                                                 const Expr *Exp) {
  if (const ExprWithCleanups *E = dyn_cast<ExprWithCleanups>(Exp))
    Exp = E->getSubExpr();
  assert(isa<CXXConstructExpr>(Exp) &&
         "EmitSynthesizedCXXCopyCtor - unknown copy ctor expr");
  const CXXConstructExpr* E = cast<CXXConstructExpr>(Exp);
  const CXXConstructorDecl *CD = E->getConstructor();
  RunCleanupsScope Scope(*this);

  // If we require zero initialization before (or instead of) calling the
  // constructor, as can be the case with a non-user-provided default
  // constructor, emit the zero initialization now.
  // FIXME. Do I still need this for a copy ctor synthesis?
  if (E->requiresZeroInitialization())
    EmitNullInitialization(Dest, E->getType());

  assert(!getContext().getAsConstantArrayType(E->getType())
         && "EmitSynthesizedCXXCopyCtor - Copied-in Array");
  EmitSynthesizedCXXCopyCtorCall(CD, Dest, Src, E);
}

static CharUnits CalculateCookiePadding(CodeGenFunction &CGF,
                                        const CXXNewExpr *E) {
  if (!E->isArray())
    return CharUnits::Zero();

  // No cookie is required if the operator new[] being used is the
  // reserved placement operator new[].
  if (E->getOperatorNew()->isReservedGlobalPlacementOperator())
    return CharUnits::Zero();

  return CGF.CGM.getCXXABI().GetArrayCookieSize(E);
}

static llvm::Value *EmitCXXNewAllocSize(CodeGenFunction &CGF,
                                        const CXXNewExpr *e,
                                        unsigned minElements,
                                        llvm::Value *&numElements,
                                        llvm::Value *&sizeWithoutCookie) {
  QualType type = e->getAllocatedType();

  if (!e->isArray()) {
    CharUnits typeSize = CGF.getContext().getTypeSizeInChars(type);
    sizeWithoutCookie
      = llvm::ConstantInt::get(CGF.SizeTy, typeSize.getQuantity());
    return sizeWithoutCookie;
  }

  // The width of size_t.
  unsigned sizeWidth = CGF.SizeTy->getBitWidth();

  // Figure out the cookie size.
  llvm::APInt cookieSize(sizeWidth,
                         CalculateCookiePadding(CGF, e).getQuantity());

  // Emit the array size expression.
  // We multiply the size of all dimensions for NumElements.
  // e.g for 'int[2][3]', ElemType is 'int' and NumElements is 6.
  numElements =
    ConstantEmitter(CGF).tryEmitAbstract(*e->getArraySize(), e->getType());
  if (!numElements)
    numElements = CGF.EmitScalarExpr(*e->getArraySize());
  assert(isa<llvm::IntegerType>(numElements->getType()));

  // The number of elements can be have an arbitrary integer type;
  // essentially, we need to multiply it by a constant factor, add a
  // cookie size, and verify that the result is representable as a
  // size_t.  That's just a gloss, though, and it's wrong in one
  // important way: if the count is negative, it's an error even if
  // the cookie size would bring the total size >= 0.
  bool isSigned
    = (*e->getArraySize())->getType()->isSignedIntegerOrEnumerationType();
  llvm::IntegerType *numElementsType
    = cast<llvm::IntegerType>(numElements->getType());
  unsigned numElementsWidth = numElementsType->getBitWidth();

  // Compute the constant factor.
  llvm::APInt arraySizeMultiplier(sizeWidth, 1);
  while (const ConstantArrayType *CAT
             = CGF.getContext().getAsConstantArrayType(type)) {
    type = CAT->getElementType();
    arraySizeMultiplier *= CAT->getSize();
  }

  CharUnits typeSize = CGF.getContext().getTypeSizeInChars(type);
  llvm::APInt typeSizeMultiplier(sizeWidth, typeSize.getQuantity());
  typeSizeMultiplier *= arraySizeMultiplier;

  // This will be a size_t.
  llvm::Value *size;

  // If someone is doing 'new int[42]' there is no need to do a dynamic check.
  // Don't bloat the -O0 code.
  if (llvm::ConstantInt *numElementsC =
        dyn_cast<llvm::ConstantInt>(numElements)) {
    const llvm::APInt &count = numElementsC->getValue();

    bool hasAnyOverflow = false;

    // If 'count' was a negative number, it's an overflow.
    if (isSigned && count.isNegative())
      hasAnyOverflow = true;

    // We want to do all this arithmetic in size_t.  If numElements is
    // wider than that, check whether it's already too big, and if so,
    // overflow.
    else if (numElementsWidth > sizeWidth &&
             numElementsWidth - sizeWidth > count.countLeadingZeros())
      hasAnyOverflow = true;

    // Okay, compute a count at the right width.
    llvm::APInt adjustedCount = count.zextOrTrunc(sizeWidth);

    // If there is a brace-initializer, we cannot allocate fewer elements than
    // there are initializers. If we do, that's treated like an overflow.
    if (adjustedCount.ult(minElements))
      hasAnyOverflow = true;

    // Scale numElements by that.  This might overflow, but we don't
    // care because it only overflows if allocationSize does, too, and
    // if that overflows then we shouldn't use this.
    numElements = llvm::ConstantInt::get(CGF.SizeTy,
                                         adjustedCount * arraySizeMultiplier);

    // Compute the size before cookie, and track whether it overflowed.
    bool overflow;
    llvm::APInt allocationSize
      = adjustedCount.umul_ov(typeSizeMultiplier, overflow);
    hasAnyOverflow |= overflow;

    // Add in the cookie, and check whether it's overflowed.
    if (cookieSize != 0) {
      // Save the current size without a cookie.  This shouldn't be
      // used if there was overflow.
      sizeWithoutCookie = llvm::ConstantInt::get(CGF.SizeTy, allocationSize);

      allocationSize = allocationSize.uadd_ov(cookieSize, overflow);
      hasAnyOverflow |= overflow;
    }

    // On overflow, produce a -1 so operator new will fail.
    if (hasAnyOverflow) {
      size = llvm::Constant::getAllOnesValue(CGF.SizeTy);
    } else {
      size = llvm::ConstantInt::get(CGF.SizeTy, allocationSize);
    }

  // Otherwise, we might need to use the overflow intrinsics.
  } else {
    // There are up to five conditions we need to test for:
    // 1) if isSigned, we need to check whether numElements is negative;
    // 2) if numElementsWidth > sizeWidth, we need to check whether
    //   numElements is larger than something representable in size_t;
    // 3) if minElements > 0, we need to check whether numElements is smaller
    //    than that.
    // 4) we need to compute
    //      sizeWithoutCookie := numElements * typeSizeMultiplier
    //    and check whether it overflows; and
    // 5) if we need a cookie, we need to compute
    //      size := sizeWithoutCookie + cookieSize
    //    and check whether it overflows.

    llvm::Value *hasOverflow = nullptr;

    // If numElementsWidth > sizeWidth, then one way or another, we're
    // going to have to do a comparison for (2), and this happens to
    // take care of (1), too.
    if (numElementsWidth > sizeWidth) {
      llvm::APInt threshold(numElementsWidth, 1);
      threshold <<= sizeWidth;

      llvm::Value *thresholdV
        = llvm::ConstantInt::get(numElementsType, threshold);

      hasOverflow = CGF.Builder.CreateICmpUGE(numElements, thresholdV);
      numElements = CGF.Builder.CreateTrunc(numElements, CGF.SizeTy);

    // Otherwise, if we're signed, we want to sext up to size_t.
    } else if (isSigned) {
      if (numElementsWidth < sizeWidth)
        numElements = CGF.Builder.CreateSExt(numElements, CGF.SizeTy);

      // If there's a non-1 type size multiplier, then we can do the
      // signedness check at the same time as we do the multiply
      // because a negative number times anything will cause an
      // unsigned overflow.  Otherwise, we have to do it here. But at least
      // in this case, we can subsume the >= minElements check.
      if (typeSizeMultiplier == 1)
        hasOverflow = CGF.Builder.CreateICmpSLT(numElements,
                              llvm::ConstantInt::get(CGF.SizeTy, minElements));

    // Otherwise, zext up to size_t if necessary.
    } else if (numElementsWidth < sizeWidth) {
      numElements = CGF.Builder.CreateZExt(numElements, CGF.SizeTy);
    }

    assert(numElements->getType() == CGF.SizeTy);

    if (minElements) {
      // Don't allow allocation of fewer elements than we have initializers.
      if (!hasOverflow) {
        hasOverflow = CGF.Builder.CreateICmpULT(numElements,
                              llvm::ConstantInt::get(CGF.SizeTy, minElements));
      } else if (numElementsWidth > sizeWidth) {
        // The other existing overflow subsumes this check.
        // We do an unsigned comparison, since any signed value < -1 is
        // taken care of either above or below.
        hasOverflow = CGF.Builder.CreateOr(hasOverflow,
                          CGF.Builder.CreateICmpULT(numElements,
                              llvm::ConstantInt::get(CGF.SizeTy, minElements)));
      }
    }

    size = numElements;

    // Multiply by the type size if necessary.  This multiplier
    // includes all the factors for nested arrays.
    //
    // This step also causes numElements to be scaled up by the
    // nested-array factor if necessary.  Overflow on this computation
    // can be ignored because the result shouldn't be used if
    // allocation fails.
    if (typeSizeMultiplier != 1) {
      llvm::Function *umul_with_overflow
        = CGF.CGM.getIntrinsic(llvm::Intrinsic::umul_with_overflow, CGF.SizeTy);

      llvm::Value *tsmV =
        llvm::ConstantInt::get(CGF.SizeTy, typeSizeMultiplier);
      llvm::Value *result =
          CGF.Builder.CreateCall(umul_with_overflow, {size, tsmV});

      llvm::Value *overflowed = CGF.Builder.CreateExtractValue(result, 1);
      if (hasOverflow)
        hasOverflow = CGF.Builder.CreateOr(hasOverflow, overflowed);
      else
        hasOverflow = overflowed;

      size = CGF.Builder.CreateExtractValue(result, 0);

      // Also scale up numElements by the array size multiplier.
      if (arraySizeMultiplier != 1) {
        // If the base element type size is 1, then we can re-use the
        // multiply we just did.
        if (typeSize.isOne()) {
          assert(arraySizeMultiplier == typeSizeMultiplier);
          numElements = size;

        // Otherwise we need a separate multiply.
        } else {
          llvm::Value *asmV =
            llvm::ConstantInt::get(CGF.SizeTy, arraySizeMultiplier);
          numElements = CGF.Builder.CreateMul(numElements, asmV);
        }
      }
    } else {
      // numElements doesn't need to be scaled.
      assert(arraySizeMultiplier == 1);
    }

    // Add in the cookie size if necessary.
    if (cookieSize != 0) {
      sizeWithoutCookie = size;

      llvm::Function *uadd_with_overflow
        = CGF.CGM.getIntrinsic(llvm::Intrinsic::uadd_with_overflow, CGF.SizeTy);

      llvm::Value *cookieSizeV = llvm::ConstantInt::get(CGF.SizeTy, cookieSize);
      llvm::Value *result =
          CGF.Builder.CreateCall(uadd_with_overflow, {size, cookieSizeV});

      llvm::Value *overflowed = CGF.Builder.CreateExtractValue(result, 1);
      if (hasOverflow)
        hasOverflow = CGF.Builder.CreateOr(hasOverflow, overflowed);
      else
        hasOverflow = overflowed;

      size = CGF.Builder.CreateExtractValue(result, 0);
    }

    // If we had any possibility of dynamic overflow, make a select to
    // overwrite 'size' with an all-ones value, which should cause
    // operator new to throw.
    if (hasOverflow)
      size = CGF.Builder.CreateSelect(hasOverflow,
                                 llvm::Constant::getAllOnesValue(CGF.SizeTy),
                                      size);
  }

  if (cookieSize == 0)
    sizeWithoutCookie = size;
  else
    assert(sizeWithoutCookie && "didn't set sizeWithoutCookie?");

  return size;
}

static void StoreAnyExprIntoOneUnit(CodeGenFunction &CGF, const Expr *Init,
                                    QualType AllocType, Address NewPtr,
                                    AggValueSlot::Overlap_t MayOverlap) {
  // FIXME: Refactor with EmitExprAsInit.
  switch (CGF.getEvaluationKind(AllocType)) {
  case TEK_Scalar:
    CGF.EmitScalarInit(Init, nullptr,
                       CGF.MakeAddrLValue(NewPtr, AllocType), false);
    return;
  case TEK_Complex:
    CGF.EmitComplexExprIntoLValue(Init, CGF.MakeAddrLValue(NewPtr, AllocType),
                                  /*isInit*/ true);
    return;
  case TEK_Aggregate: {
    AggValueSlot Slot
      = AggValueSlot::forAddr(NewPtr, AllocType.getQualifiers(),
                              AggValueSlot::IsDestructed,
                              AggValueSlot::DoesNotNeedGCBarriers,
                              AggValueSlot::IsNotAliased,
                              MayOverlap, AggValueSlot::IsNotZeroed,
                              AggValueSlot::IsSanitizerChecked);
    CGF.EmitAggExpr(Init, Slot);
    return;
  }
  }
  llvm_unreachable("bad evaluation kind");
}

void CodeGenFunction::EmitNewArrayInitializer(
    const CXXNewExpr *E, QualType ElementType, llvm::Type *ElementTy,
    Address BeginPtr, llvm::Value *NumElements,
    llvm::Value *AllocSizeWithoutCookie) {
  // If we have a type with trivial initialization and no initializer,
  // there's nothing to do.
  if (!E->hasInitializer())
    return;

  Address CurPtr = BeginPtr;

  unsigned InitListElements = 0;

  const Expr *Init = E->getInitializer();
  Address EndOfInit = Address::invalid();
  QualType::DestructionKind DtorKind = ElementType.isDestructedType();
  EHScopeStack::stable_iterator Cleanup;
  llvm::Instruction *CleanupDominator = nullptr;

  CharUnits ElementSize = getContext().getTypeSizeInChars(ElementType);
  CharUnits ElementAlign =
    BeginPtr.getAlignment().alignmentOfArrayElement(ElementSize);

  // Attempt to perform zero-initialization using memset.
  auto TryMemsetInitialization = [&]() -> bool {
    // FIXME: If the type is a pointer-to-data-member under the Itanium ABI,
    // we can initialize with a memset to -1.
    if (!CGM.getTypes().isZeroInitializable(ElementType))
      return false;

    // Optimization: since zero initialization will just set the memory
    // to all zeroes, generate a single memset to do it in one shot.

    // Subtract out the size of any elements we've already initialized.
    auto *RemainingSize = AllocSizeWithoutCookie;
    if (InitListElements) {
      // We know this can't overflow; we check this when doing the allocation.
      auto *InitializedSize = llvm::ConstantInt::get(
          RemainingSize->getType(),
          getContext().getTypeSizeInChars(ElementType).getQuantity() *
              InitListElements);
      RemainingSize = Builder.CreateSub(RemainingSize, InitializedSize);
    }

    // Create the memset.
    Builder.CreateMemSet(CurPtr, Builder.getInt8(0), RemainingSize, false);
    return true;
  };

  // If the initializer is an initializer list, first do the explicit elements.
  if (const InitListExpr *ILE = dyn_cast<InitListExpr>(Init)) {
    // Initializing from a (braced) string literal is a special case; the init
    // list element does not initialize a (single) array element.
    if (ILE->isStringLiteralInit()) {
      // Initialize the initial portion of length equal to that of the string
      // literal. The allocation must be for at least this much; we emitted a
      // check for that earlier.
      AggValueSlot Slot =
          AggValueSlot::forAddr(CurPtr, ElementType.getQualifiers(),
                                AggValueSlot::IsDestructed,
                                AggValueSlot::DoesNotNeedGCBarriers,
                                AggValueSlot::IsNotAliased,
                                AggValueSlot::DoesNotOverlap,
                                AggValueSlot::IsNotZeroed,
                                AggValueSlot::IsSanitizerChecked);
      EmitAggExpr(ILE->getInit(0), Slot);

      // Move past these elements.
      InitListElements =
          cast<ConstantArrayType>(ILE->getType()->getAsArrayTypeUnsafe())
              ->getSize().getZExtValue();
      CurPtr =
          Address(Builder.CreateInBoundsGEP(CurPtr.getPointer(),
                                            Builder.getSize(InitListElements),
                                            "string.init.end"),
                  CurPtr.getAlignment().alignmentAtOffset(InitListElements *
                                                          ElementSize));

      // Zero out the rest, if any remain.
      llvm::ConstantInt *ConstNum = dyn_cast<llvm::ConstantInt>(NumElements);
      if (!ConstNum || !ConstNum->equalsInt(InitListElements)) {
        bool OK = TryMemsetInitialization();
        (void)OK;
        assert(OK && "couldn't memset character type?");
      }
      return;
    }

    InitListElements = ILE->getNumInits();

    // If this is a multi-dimensional array new, we will initialize multiple
    // elements with each init list element.
    QualType AllocType = E->getAllocatedType();
    if (const ConstantArrayType *CAT = dyn_cast_or_null<ConstantArrayType>(
            AllocType->getAsArrayTypeUnsafe())) {
      ElementTy = ConvertTypeForMem(AllocType);
      CurPtr = Builder.CreateElementBitCast(CurPtr, ElementTy);
      InitListElements *= getContext().getConstantArrayElementCount(CAT);
    }

    // Enter a partial-destruction Cleanup if necessary.
    if (needsEHCleanup(DtorKind)) {
      // In principle we could tell the Cleanup where we are more
      // directly, but the control flow can get so varied here that it
      // would actually be quite complex.  Therefore we go through an
      // alloca.
      EndOfInit = CreateTempAlloca(BeginPtr.getType(), getPointerAlign(),
                                   "array.init.end");
      CleanupDominator = Builder.CreateStore(BeginPtr.getPointer(), EndOfInit);
      pushIrregularPartialArrayCleanup(BeginPtr.getPointer(), EndOfInit,
                                       ElementType, ElementAlign,
                                       getDestroyer(DtorKind));
      Cleanup = EHStack.stable_begin();
    }

    CharUnits StartAlign = CurPtr.getAlignment();
    for (unsigned i = 0, e = ILE->getNumInits(); i != e; ++i) {
      // Tell the cleanup that it needs to destroy up to this
      // element.  TODO: some of these stores can be trivially
      // observed to be unnecessary.
      if (EndOfInit.isValid()) {
        auto FinishedPtr =
          Builder.CreateBitCast(CurPtr.getPointer(), BeginPtr.getType());
        Builder.CreateStore(FinishedPtr, EndOfInit);
      }
      // FIXME: If the last initializer is an incomplete initializer list for
      // an array, and we have an array filler, we can fold together the two
      // initialization loops.
      StoreAnyExprIntoOneUnit(*this, ILE->getInit(i),
                              ILE->getInit(i)->getType(), CurPtr,
                              AggValueSlot::DoesNotOverlap);
      CurPtr = Address(Builder.CreateInBoundsGEP(CurPtr.getPointer(),
                                                 Builder.getSize(1),
                                                 "array.exp.next"),
                       StartAlign.alignmentAtOffset((i + 1) * ElementSize));
    }

    // The remaining elements are filled with the array filler expression.
    Init = ILE->getArrayFiller();

    // Extract the initializer for the individual array elements by pulling
    // out the array filler from all the nested initializer lists. This avoids
    // generating a nested loop for the initialization.
    while (Init && Init->getType()->isConstantArrayType()) {
      auto *SubILE = dyn_cast<InitListExpr>(Init);
      if (!SubILE)
        break;
      assert(SubILE->getNumInits() == 0 && "explicit inits in array filler?");
      Init = SubILE->getArrayFiller();
    }

    // Switch back to initializing one base element at a time.
    CurPtr = Builder.CreateBitCast(CurPtr, BeginPtr.getType());
  }

  // If all elements have already been initialized, skip any further
  // initialization.
  llvm::ConstantInt *ConstNum = dyn_cast<llvm::ConstantInt>(NumElements);
  if (ConstNum && ConstNum->getZExtValue() <= InitListElements) {
    // If there was a Cleanup, deactivate it.
    if (CleanupDominator)
      DeactivateCleanupBlock(Cleanup, CleanupDominator);
    return;
  }

  assert(Init && "have trailing elements to initialize but no initializer");

  // If this is a constructor call, try to optimize it out, and failing that
  // emit a single loop to initialize all remaining elements.
  if (const CXXConstructExpr *CCE = dyn_cast<CXXConstructExpr>(Init)) {
    CXXConstructorDecl *Ctor = CCE->getConstructor();
    if (Ctor->isTrivial()) {
      // If new expression did not specify value-initialization, then there
      // is no initialization.
      if (!CCE->requiresZeroInitialization() || Ctor->getParent()->isEmpty())
        return;

      if (TryMemsetInitialization())
        return;
    }

    // Store the new Cleanup position for irregular Cleanups.
    //
    // FIXME: Share this cleanup with the constructor call emission rather than
    // having it create a cleanup of its own.
    if (EndOfInit.isValid())
      Builder.CreateStore(CurPtr.getPointer(), EndOfInit);

    // Emit a constructor call loop to initialize the remaining elements.
    if (InitListElements)
      NumElements = Builder.CreateSub(
          NumElements,
          llvm::ConstantInt::get(NumElements->getType(), InitListElements));
    EmitCXXAggrConstructorCall(Ctor, NumElements, CurPtr, CCE,
                               /*NewPointerIsChecked*/true,
                               CCE->requiresZeroInitialization());
    return;
  }

  // If this is value-initialization, we can usually use memset.
  ImplicitValueInitExpr IVIE(ElementType);
  if (isa<ImplicitValueInitExpr>(Init)) {
    if (TryMemsetInitialization())
      return;

    // Switch to an ImplicitValueInitExpr for the element type. This handles
    // only one case: multidimensional array new of pointers to members. In
    // all other cases, we already have an initializer for the array element.
    Init = &IVIE;
  }

  // At this point we should have found an initializer for the individual
  // elements of the array.
  assert(getContext().hasSameUnqualifiedType(ElementType, Init->getType()) &&
         "got wrong type of element to initialize");

  // If we have an empty initializer list, we can usually use memset.
  if (auto *ILE = dyn_cast<InitListExpr>(Init))
    if (ILE->getNumInits() == 0 && TryMemsetInitialization())
      return;

  // If we have a struct whose every field is value-initialized, we can
  // usually use memset.
  if (auto *ILE = dyn_cast<InitListExpr>(Init)) {
    if (const RecordType *RType = ILE->getType()->getAs<RecordType>()) {
      if (RType->getDecl()->isStruct()) {
        unsigned NumElements = 0;
        if (auto *CXXRD = dyn_cast<CXXRecordDecl>(RType->getDecl()))
          NumElements = CXXRD->getNumBases();
        for (auto *Field : RType->getDecl()->fields())
          if (!Field->isUnnamedBitfield())
            ++NumElements;
        // FIXME: Recurse into nested InitListExprs.
        if (ILE->getNumInits() == NumElements)
          for (unsigned i = 0, e = ILE->getNumInits(); i != e; ++i)
            if (!isa<ImplicitValueInitExpr>(ILE->getInit(i)))
              --NumElements;
        if (ILE->getNumInits() == NumElements && TryMemsetInitialization())
          return;
      }
    }
  }

  // Create the loop blocks.
  llvm::BasicBlock *EntryBB = Builder.GetInsertBlock();
  llvm::BasicBlock *LoopBB = createBasicBlock("new.loop");
  llvm::BasicBlock *ContBB = createBasicBlock("new.loop.end");

  // Find the end of the array, hoisted out of the loop.
  llvm::Value *EndPtr =
    Builder.CreateInBoundsGEP(BeginPtr.getPointer(), NumElements, "array.end");

  // If the number of elements isn't constant, we have to now check if there is
  // anything left to initialize.
  if (!ConstNum) {
    llvm::Value *IsEmpty =
      Builder.CreateICmpEQ(CurPtr.getPointer(), EndPtr, "array.isempty");
    Builder.CreateCondBr(IsEmpty, ContBB, LoopBB);
  }

  // Enter the loop.
  EmitBlock(LoopBB);

  // Set up the current-element phi.
  llvm::PHINode *CurPtrPhi =
    Builder.CreatePHI(CurPtr.getType(), 2, "array.cur");
  CurPtrPhi->addIncoming(CurPtr.getPointer(), EntryBB);

  CurPtr = Address(CurPtrPhi, ElementAlign);

  // Store the new Cleanup position for irregular Cleanups.
  if (EndOfInit.isValid())
    Builder.CreateStore(CurPtr.getPointer(), EndOfInit);

  // Enter a partial-destruction Cleanup if necessary.
  if (!CleanupDominator && needsEHCleanup(DtorKind)) {
    pushRegularPartialArrayCleanup(BeginPtr.getPointer(), CurPtr.getPointer(),
                                   ElementType, ElementAlign,
                                   getDestroyer(DtorKind));
    Cleanup = EHStack.stable_begin();
    CleanupDominator = Builder.CreateUnreachable();
  }

  // Emit the initializer into this element.
  StoreAnyExprIntoOneUnit(*this, Init, Init->getType(), CurPtr,
                          AggValueSlot::DoesNotOverlap);

  // Leave the Cleanup if we entered one.
  if (CleanupDominator) {
    DeactivateCleanupBlock(Cleanup, CleanupDominator);
    CleanupDominator->eraseFromParent();
  }

  // Advance to the next element by adjusting the pointer type as necessary.
  llvm::Value *NextPtr =
    Builder.CreateConstInBoundsGEP1_32(ElementTy, CurPtr.getPointer(), 1,
                                       "array.next");

  // Check whether we've gotten to the end of the array and, if so,
  // exit the loop.
  llvm::Value *IsEnd = Builder.CreateICmpEQ(NextPtr, EndPtr, "array.atend");
  Builder.CreateCondBr(IsEnd, ContBB, LoopBB);
  CurPtrPhi->addIncoming(NextPtr, Builder.GetInsertBlock());

  EmitBlock(ContBB);
}

static void EmitNewInitializer(CodeGenFunction &CGF, const CXXNewExpr *E,
                               QualType ElementType, llvm::Type *ElementTy,
                               Address NewPtr, llvm::Value *NumElements,
                               llvm::Value *AllocSizeWithoutCookie) {
  ApplyDebugLocation DL(CGF, E);
  if (E->isArray())
    CGF.EmitNewArrayInitializer(E, ElementType, ElementTy, NewPtr, NumElements,
                                AllocSizeWithoutCookie);
  else if (const Expr *Init = E->getInitializer())
    StoreAnyExprIntoOneUnit(CGF, Init, E->getAllocatedType(), NewPtr,
                            AggValueSlot::DoesNotOverlap);
}

/// Emit a call to an operator new or operator delete function, as implicitly
/// created by new-expressions and delete-expressions.
static RValue EmitNewDeleteCall(CodeGenFunction &CGF,
                                const FunctionDecl *CalleeDecl,
                                const FunctionProtoType *CalleeType,
                                const CallArgList &Args) {
  llvm::CallBase *CallOrInvoke;
  llvm::Constant *CalleePtr = CGF.CGM.GetAddrOfFunction(CalleeDecl);
  CGCallee Callee = CGCallee::forDirect(CalleePtr, GlobalDecl(CalleeDecl));
  RValue RV =
      CGF.EmitCall(CGF.CGM.getTypes().arrangeFreeFunctionCall(
                       Args, CalleeType, /*ChainCall=*/false),
                   Callee, ReturnValueSlot(), Args, &CallOrInvoke);

  /// C++1y [expr.new]p10:
  ///   [In a new-expression,] an implementation is allowed to omit a call
  ///   to a replaceable global allocation function.
  ///
  /// We model such elidable calls with the 'builtin' attribute.
  llvm::Function *Fn = dyn_cast<llvm::Function>(CalleePtr);
  if (CalleeDecl->isReplaceableGlobalAllocationFunction() &&
      Fn && Fn->hasFnAttribute(llvm::Attribute::NoBuiltin)) {
    CallOrInvoke->addAttribute(llvm::AttributeList::FunctionIndex,
                               llvm::Attribute::Builtin);
  }

  return RV;
}

RValue CodeGenFunction::EmitBuiltinNewDeleteCall(const FunctionProtoType *Type,
                                                 const CallExpr *TheCall,
                                                 bool IsDelete) {
  CallArgList Args;
  EmitCallArgs(Args, Type->getParamTypes(), TheCall->arguments());
  // Find the allocation or deallocation function that we're calling.
  ASTContext &Ctx = getContext();
  DeclarationName Name = Ctx.DeclarationNames
      .getCXXOperatorName(IsDelete ? OO_Delete : OO_New);

  for (auto *Decl : Ctx.getTranslationUnitDecl()->lookup(Name))
    if (auto *FD = dyn_cast<FunctionDecl>(Decl))
      if (Ctx.hasSameType(FD->getType(), QualType(Type, 0)))
        return EmitNewDeleteCall(*this, FD, Type, Args);
  llvm_unreachable("predeclared global operator new/delete is missing");
}

namespace {
/// The parameters to pass to a usual operator delete.
struct UsualDeleteParams {
  bool DestroyingDelete = false;
  bool Size = false;
  bool Alignment = false;
};
}

static UsualDeleteParams getUsualDeleteParams(const FunctionDecl *FD) {
  UsualDeleteParams Params;

  const FunctionProtoType *FPT = FD->getType()->castAs<FunctionProtoType>();
  auto AI = FPT->param_type_begin(), AE = FPT->param_type_end();

  // The first argument is always a void*.
  ++AI;

  // The next parameter may be a std::destroying_delete_t.
  if (FD->isDestroyingOperatorDelete()) {
    Params.DestroyingDelete = true;
    assert(AI != AE);
    ++AI;
  }

  // Figure out what other parameters we should be implicitly passing.
  if (AI != AE && (*AI)->isIntegerType()) {
    Params.Size = true;
    ++AI;
  }

  if (AI != AE && (*AI)->isAlignValT()) {
    Params.Alignment = true;
    ++AI;
  }

  assert(AI == AE && "unexpected usual deallocation function parameter");
  return Params;
}

namespace {
  /// A cleanup to call the given 'operator delete' function upon abnormal
  /// exit from a new expression. Templated on a traits type that deals with
  /// ensuring that the arguments dominate the cleanup if necessary.
  template<typename Traits>
  class CallDeleteDuringNew final : public EHScopeStack::Cleanup {
    /// Type used to hold llvm::Value*s.
    typedef typename Traits::ValueTy ValueTy;
    /// Type used to hold RValues.
    typedef typename Traits::RValueTy RValueTy;
    struct PlacementArg {
      RValueTy ArgValue;
      QualType ArgType;
    };

    unsigned NumPlacementArgs : 31;
    unsigned PassAlignmentToPlacementDelete : 1;
    const FunctionDecl *OperatorDelete;
    ValueTy Ptr;
    ValueTy AllocSize;
    CharUnits AllocAlign;

    PlacementArg *getPlacementArgs() {
      return reinterpret_cast<PlacementArg *>(this + 1);
    }

  public:
    static size_t getExtraSize(size_t NumPlacementArgs) {
      return NumPlacementArgs * sizeof(PlacementArg);
    }

    CallDeleteDuringNew(size_t NumPlacementArgs,
                        const FunctionDecl *OperatorDelete, ValueTy Ptr,
                        ValueTy AllocSize, bool PassAlignmentToPlacementDelete,
                        CharUnits AllocAlign)
      : NumPlacementArgs(NumPlacementArgs),
        PassAlignmentToPlacementDelete(PassAlignmentToPlacementDelete),
        OperatorDelete(OperatorDelete), Ptr(Ptr), AllocSize(AllocSize),
        AllocAlign(AllocAlign) {}

    void setPlacementArg(unsigned I, RValueTy Arg, QualType Type) {
      assert(I < NumPlacementArgs && "index out of range");
      getPlacementArgs()[I] = {Arg, Type};
    }

    void Emit(CodeGenFunction &CGF, Flags flags) override {
      const auto *FPT = OperatorDelete->getType()->castAs<FunctionProtoType>();
      CallArgList DeleteArgs;

      // The first argument is always a void* (or C* for a destroying operator
      // delete for class type C).
      DeleteArgs.add(Traits::get(CGF, Ptr), FPT->getParamType(0));

      // Figure out what other parameters we should be implicitly passing.
      UsualDeleteParams Params;
      if (NumPlacementArgs) {
        // A placement deallocation function is implicitly passed an alignment
        // if the placement allocation function was, but is never passed a size.
        Params.Alignment = PassAlignmentToPlacementDelete;
      } else {
        // For a non-placement new-expression, 'operator delete' can take a
        // size and/or an alignment if it has the right parameters.
        Params = getUsualDeleteParams(OperatorDelete);
      }

      assert(!Params.DestroyingDelete &&
             "should not call destroying delete in a new-expression");

      // The second argument can be a std::size_t (for non-placement delete).
      if (Params.Size)
        DeleteArgs.add(Traits::get(CGF, AllocSize),
                       CGF.getContext().getSizeType());

      // The next (second or third) argument can be a std::align_val_t, which
      // is an enum whose underlying type is std::size_t.
      // FIXME: Use the right type as the parameter type. Note that in a call
      // to operator delete(size_t, ...), we may not have it available.
      if (Params.Alignment)
        DeleteArgs.add(RValue::get(llvm::ConstantInt::get(
                           CGF.SizeTy, AllocAlign.getQuantity())),
                       CGF.getContext().getSizeType());

      // Pass the rest of the arguments, which must match exactly.
      for (unsigned I = 0; I != NumPlacementArgs; ++I) {
        auto Arg = getPlacementArgs()[I];
        DeleteArgs.add(Traits::get(CGF, Arg.ArgValue), Arg.ArgType);
      }

      // Call 'operator delete'.
      EmitNewDeleteCall(CGF, OperatorDelete, FPT, DeleteArgs);
    }
  };
}

/// Enter a cleanup to call 'operator delete' if the initializer in a
/// new-expression throws.
static void EnterNewDeleteCleanup(CodeGenFunction &CGF,
                                  const CXXNewExpr *E,
                                  Address NewPtr,
                                  llvm::Value *AllocSize,
                                  CharUnits AllocAlign,
                                  const CallArgList &NewArgs) {
  unsigned NumNonPlacementArgs = E->passAlignment() ? 2 : 1;

  // If we're not inside a conditional branch, then the cleanup will
  // dominate and we can do the easier (and more efficient) thing.
  if (!CGF.isInConditionalBranch()) {
    struct DirectCleanupTraits {
      typedef llvm::Value *ValueTy;
      typedef RValue RValueTy;
      static RValue get(CodeGenFunction &, ValueTy V) { return RValue::get(V); }
      static RValue get(CodeGenFunction &, RValueTy V) { return V; }
    };

    typedef CallDeleteDuringNew<DirectCleanupTraits> DirectCleanup;

    DirectCleanup *Cleanup = CGF.EHStack
      .pushCleanupWithExtra<DirectCleanup>(EHCleanup,
                                           E->getNumPlacementArgs(),
                                           E->getOperatorDelete(),
                                           NewPtr.getPointer(),
                                           AllocSize,
                                           E->passAlignment(),
                                           AllocAlign);
    for (unsigned I = 0, N = E->getNumPlacementArgs(); I != N; ++I) {
      auto &Arg = NewArgs[I + NumNonPlacementArgs];
      Cleanup->setPlacementArg(I, Arg.getRValue(CGF), Arg.Ty);
    }

    return;
  }

  // Otherwise, we need to save all this stuff.
  DominatingValue<RValue>::saved_type SavedNewPtr =
    DominatingValue<RValue>::save(CGF, RValue::get(NewPtr.getPointer()));
  DominatingValue<RValue>::saved_type SavedAllocSize =
    DominatingValue<RValue>::save(CGF, RValue::get(AllocSize));

  struct ConditionalCleanupTraits {
    typedef DominatingValue<RValue>::saved_type ValueTy;
    typedef DominatingValue<RValue>::saved_type RValueTy;
    static RValue get(CodeGenFunction &CGF, ValueTy V) {
      return V.restore(CGF);
    }
  };
  typedef CallDeleteDuringNew<ConditionalCleanupTraits> ConditionalCleanup;

  ConditionalCleanup *Cleanup = CGF.EHStack
    .pushCleanupWithExtra<ConditionalCleanup>(EHCleanup,
                                              E->getNumPlacementArgs(),
                                              E->getOperatorDelete(),
                                              SavedNewPtr,
                                              SavedAllocSize,
                                              E->passAlignment(),
                                              AllocAlign);
  for (unsigned I = 0, N = E->getNumPlacementArgs(); I != N; ++I) {
    auto &Arg = NewArgs[I + NumNonPlacementArgs];
    Cleanup->setPlacementArg(
        I, DominatingValue<RValue>::save(CGF, Arg.getRValue(CGF)), Arg.Ty);
  }

  CGF.initFullExprCleanup();
}

llvm::Value *CodeGenFunction::EmitCXXNewExpr(const CXXNewExpr *E) {
  // The element type being allocated.
  QualType allocType = getContext().getBaseElementType(E->getAllocatedType());

  // 1. Build a call to the allocation function.
  FunctionDecl *allocator = E->getOperatorNew();

  // If there is a brace-initializer, cannot allocate fewer elements than inits.
  unsigned minElements = 0;
  if (E->isArray() && E->hasInitializer()) {
    const InitListExpr *ILE = dyn_cast<InitListExpr>(E->getInitializer());
    if (ILE && ILE->isStringLiteralInit())
      minElements =
          cast<ConstantArrayType>(ILE->getType()->getAsArrayTypeUnsafe())
              ->getSize().getZExtValue();
    else if (ILE)
      minElements = ILE->getNumInits();
  }

  llvm::Value *numElements = nullptr;
  llvm::Value *allocSizeWithoutCookie = nullptr;
  llvm::Value *allocSize =
    EmitCXXNewAllocSize(*this, E, minElements, numElements,
                        allocSizeWithoutCookie);
  CharUnits allocAlign = getContext().getPreferredTypeAlignInChars(allocType);

  // Emit the allocation call.  If the allocator is a global placement
  // operator, just "inline" it directly.
  Address allocation = Address::invalid();
  CallArgList allocatorArgs;
  if (allocator->isReservedGlobalPlacementOperator()) {
    assert(E->getNumPlacementArgs() == 1);
    const Expr *arg = *E->placement_arguments().begin();

    LValueBaseInfo BaseInfo;
    allocation = EmitPointerWithAlignment(arg, &BaseInfo);

    // The pointer expression will, in many cases, be an opaque void*.
    // In these cases, discard the computed alignment and use the
    // formal alignment of the allocated type.
    if (BaseInfo.getAlignmentSource() != AlignmentSource::Decl)
      allocation = Address(allocation.getPointer(), allocAlign);

    // Set up allocatorArgs for the call to operator delete if it's not
    // the reserved global operator.
    if (E->getOperatorDelete() &&
        !E->getOperatorDelete()->isReservedGlobalPlacementOperator()) {
      allocatorArgs.add(RValue::get(allocSize), getContext().getSizeType());
      allocatorArgs.add(RValue::get(allocation.getPointer()), arg->getType());
    }

  } else {
    const FunctionProtoType *allocatorType =
      allocator->getType()->castAs<FunctionProtoType>();
    unsigned ParamsToSkip = 0;

    // The allocation size is the first argument.
    QualType sizeType = getContext().getSizeType();
    allocatorArgs.add(RValue::get(allocSize), sizeType);
    ++ParamsToSkip;

    if (allocSize != allocSizeWithoutCookie) {
      CharUnits cookieAlign = getSizeAlign(); // FIXME: Ask the ABI.
      allocAlign = std::max(allocAlign, cookieAlign);
    }

    // The allocation alignment may be passed as the second argument.
    if (E->passAlignment()) {
      QualType AlignValT = sizeType;
      if (allocatorType->getNumParams() > 1) {
        AlignValT = allocatorType->getParamType(1);
        assert(getContext().hasSameUnqualifiedType(
                   AlignValT->castAs<EnumType>()->getDecl()->getIntegerType(),
                   sizeType) &&
               "wrong type for alignment parameter");
        ++ParamsToSkip;
      } else {
        // Corner case, passing alignment to 'operator new(size_t, ...)'.
        assert(allocator->isVariadic() && "can't pass alignment to allocator");
      }
      allocatorArgs.add(
          RValue::get(llvm::ConstantInt::get(SizeTy, allocAlign.getQuantity())),
          AlignValT);
    }

    // FIXME: Why do we not pass a CalleeDecl here?
    EmitCallArgs(allocatorArgs, allocatorType, E->placement_arguments(),
                 /*AC*/AbstractCallee(), /*ParamsToSkip*/ParamsToSkip);

    RValue RV =
      EmitNewDeleteCall(*this, allocator, allocatorType, allocatorArgs);

    // Set !heapallocsite metadata on the call to operator new.
    if (getDebugInfo())
      if (auto *newCall = dyn_cast<llvm::CallBase>(RV.getScalarVal()))
        getDebugInfo()->addHeapAllocSiteMetadata(newCall, allocType,
                                                 E->getExprLoc());

    // If this was a call to a global replaceable allocation function that does
    // not take an alignment argument, the allocator is known to produce
    // storage that's suitably aligned for any object that fits, up to a known
    // threshold. Otherwise assume it's suitably aligned for the allocated type.
    CharUnits allocationAlign = allocAlign;
    if (!E->passAlignment() &&
        allocator->isReplaceableGlobalAllocationFunction()) {
      unsigned AllocatorAlign = llvm::PowerOf2Floor(std::min<uint64_t>(
          Target.getNewAlign(), getContext().getTypeSize(allocType)));
      allocationAlign = std::max(
          allocationAlign, getContext().toCharUnitsFromBits(AllocatorAlign));
    }

    allocation = Address(RV.getScalarVal(), allocationAlign);
  }

  // Emit a null check on the allocation result if the allocation
  // function is allowed to return null (because it has a non-throwing
  // exception spec or is the reserved placement new) and we have an
  // interesting initializer will be running sanitizers on the initialization.
  bool nullCheck = E->shouldNullCheckAllocation() &&
                   (!allocType.isPODType(getContext()) || E->hasInitializer() ||
                    sanitizePerformTypeCheck());

  llvm::BasicBlock *nullCheckBB = nullptr;
  llvm::BasicBlock *contBB = nullptr;

  // The null-check means that the initializer is conditionally
  // evaluated.
  ConditionalEvaluation conditional(*this);

  if (nullCheck) {
    conditional.begin(*this);

    nullCheckBB = Builder.GetInsertBlock();
    llvm::BasicBlock *notNullBB = createBasicBlock("new.notnull");
    contBB = createBasicBlock("new.cont");

    llvm::Value *isNull =
      Builder.CreateIsNull(allocation.getPointer(), "new.isnull");
    Builder.CreateCondBr(isNull, contBB, notNullBB);
    EmitBlock(notNullBB);
  }

  // If there's an operator delete, enter a cleanup to call it if an
  // exception is thrown.
  EHScopeStack::stable_iterator operatorDeleteCleanup;
  llvm::Instruction *cleanupDominator = nullptr;
  if (E->getOperatorDelete() &&
      !E->getOperatorDelete()->isReservedGlobalPlacementOperator()) {
    EnterNewDeleteCleanup(*this, E, allocation, allocSize, allocAlign,
                          allocatorArgs);
    operatorDeleteCleanup = EHStack.stable_begin();
    cleanupDominator = Builder.CreateUnreachable();
  }

  assert((allocSize == allocSizeWithoutCookie) ==
         CalculateCookiePadding(*this, E).isZero());
  if (allocSize != allocSizeWithoutCookie) {
    assert(E->isArray());
    allocation = CGM.getCXXABI().InitializeArrayCookie(*this, allocation,
                                                       numElements,
                                                       E, allocType);
  }

  llvm::Type *elementTy = ConvertTypeForMem(allocType);
  Address result = Builder.CreateElementBitCast(allocation, elementTy);

  // Passing pointer through launder.invariant.group to avoid propagation of
  // vptrs information which may be included in previous type.
  // To not break LTO with different optimizations levels, we do it regardless
  // of optimization level.
  if (CGM.getCodeGenOpts().StrictVTablePointers &&
      allocator->isReservedGlobalPlacementOperator())
    result = Address(Builder.CreateLaunderInvariantGroup(result.getPointer()),
                     result.getAlignment());

  // Emit sanitizer checks for pointer value now, so that in the case of an
  // array it was checked only once and not at each constructor call. We may
  // have already checked that the pointer is non-null.
  // FIXME: If we have an array cookie and a potentially-throwing allocator,
  // we'll null check the wrong pointer here.
  SanitizerSet SkippedChecks;
  SkippedChecks.set(SanitizerKind::Null, nullCheck);
  EmitTypeCheck(CodeGenFunction::TCK_ConstructorCall,
                E->getAllocatedTypeSourceInfo()->getTypeLoc().getBeginLoc(),
                result.getPointer(), allocType, result.getAlignment(),
                SkippedChecks, numElements);

  EmitNewInitializer(*this, E, allocType, elementTy, result, numElements,
                     allocSizeWithoutCookie);
  if (E->isArray()) {
    // NewPtr is a pointer to the base element type.  If we're
    // allocating an array of arrays, we'll need to cast back to the
    // array pointer type.
    llvm::Type *resultType = ConvertTypeForMem(E->getType());
    if (result.getType() != resultType)
      result = Builder.CreateBitCast(result, resultType);
  }

  // Deactivate the 'operator delete' cleanup if we finished
  // initialization.
  if (operatorDeleteCleanup.isValid()) {
    DeactivateCleanupBlock(operatorDeleteCleanup, cleanupDominator);
    cleanupDominator->eraseFromParent();
  }

  llvm::Value *resultPtr = result.getPointer();
  if (nullCheck) {
    conditional.end(*this);

    llvm::BasicBlock *notNullBB = Builder.GetInsertBlock();
    EmitBlock(contBB);

    llvm::PHINode *PHI = Builder.CreatePHI(resultPtr->getType(), 2);
    PHI->addIncoming(resultPtr, notNullBB);
    PHI->addIncoming(llvm::Constant::getNullValue(resultPtr->getType()),
                     nullCheckBB);

    resultPtr = PHI;
  }

  return resultPtr;
}

void CodeGenFunction::EmitDeleteCall(const FunctionDecl *DeleteFD,
                                     llvm::Value *Ptr, QualType DeleteTy,
                                     llvm::Value *NumElements,
                                     CharUnits CookieSize) {
  assert((!NumElements && CookieSize.isZero()) ||
         DeleteFD->getOverloadedOperator() == OO_Array_Delete);

  const auto *DeleteFTy = DeleteFD->getType()->castAs<FunctionProtoType>();
  CallArgList DeleteArgs;

  auto Params = getUsualDeleteParams(DeleteFD);
  auto ParamTypeIt = DeleteFTy->param_type_begin();

  // Pass the pointer itself.
  QualType ArgTy = *ParamTypeIt++;
  llvm::Value *DeletePtr = Builder.CreateBitCast(Ptr, ConvertType(ArgTy));
  DeleteArgs.add(RValue::get(DeletePtr), ArgTy);

  // Pass the std::destroying_delete tag if present.
  llvm::AllocaInst *DestroyingDeleteTag = nullptr;
  if (Params.DestroyingDelete) {
    QualType DDTag = *ParamTypeIt++;
    llvm::Type *Ty = getTypes().ConvertType(DDTag);
    CharUnits Align = CGM.getNaturalTypeAlignment(DDTag);
    DestroyingDeleteTag = CreateTempAlloca(Ty, "destroying.delete.tag");
    DestroyingDeleteTag->setAlignment(Align.getAsAlign());
    DeleteArgs.add(RValue::getAggregate(Address(DestroyingDeleteTag, Align)), DDTag);
  }

  // Pass the size if the delete function has a size_t parameter.
  if (Params.Size) {
    QualType SizeType = *ParamTypeIt++;
    CharUnits DeleteTypeSize = getContext().getTypeSizeInChars(DeleteTy);
    llvm::Value *Size = llvm::ConstantInt::get(ConvertType(SizeType),
                                               DeleteTypeSize.getQuantity());

    // For array new, multiply by the number of elements.
    if (NumElements)
      Size = Builder.CreateMul(Size, NumElements);

    // If there is a cookie, add the cookie size.
    if (!CookieSize.isZero())
      Size = Builder.CreateAdd(
          Size, llvm::ConstantInt::get(SizeTy, CookieSize.getQuantity()));

    DeleteArgs.add(RValue::get(Size), SizeType);
  }

  // Pass the alignment if the delete function has an align_val_t parameter.
  if (Params.Alignment) {
    QualType AlignValType = *ParamTypeIt++;
    CharUnits DeleteTypeAlign =
        getContext().toCharUnitsFromBits(getContext().getTypeAlignIfKnown(
            DeleteTy, true /* NeedsPreferredAlignment */));
    llvm::Value *Align = llvm::ConstantInt::get(ConvertType(AlignValType),
                                                DeleteTypeAlign.getQuantity());
    DeleteArgs.add(RValue::get(Align), AlignValType);
  }

  assert(ParamTypeIt == DeleteFTy->param_type_end() &&
         "unknown parameter to usual delete function");

  // Emit the call to delete.
  EmitNewDeleteCall(*this, DeleteFD, DeleteFTy, DeleteArgs);

  // If call argument lowering didn't use the destroying_delete_t alloca,
  // remove it again.
  if (DestroyingDeleteTag && DestroyingDeleteTag->use_empty())
    DestroyingDeleteTag->eraseFromParent();
}

namespace {
  /// Calls the given 'operator delete' on a single object.
  struct CallObjectDelete final : EHScopeStack::Cleanup {
    llvm::Value *Ptr;
    const FunctionDecl *OperatorDelete;
    QualType ElementType;

    CallObjectDelete(llvm::Value *Ptr,
                     const FunctionDecl *OperatorDelete,
                     QualType ElementType)
      : Ptr(Ptr), OperatorDelete(OperatorDelete), ElementType(ElementType) {}

    void Emit(CodeGenFunction &CGF, Flags flags) override {
      CGF.EmitDeleteCall(OperatorDelete, Ptr, ElementType);
    }
  };
}

void
CodeGenFunction::pushCallObjectDeleteCleanup(const FunctionDecl *OperatorDelete,
                                             llvm::Value *CompletePtr,
                                             QualType ElementType) {
  EHStack.pushCleanup<CallObjectDelete>(NormalAndEHCleanup, CompletePtr,
                                        OperatorDelete, ElementType);
}

/// Emit the code for deleting a single object with a destroying operator
/// delete. If the element type has a non-virtual destructor, Ptr has already
/// been converted to the type of the parameter of 'operator delete'. Otherwise
/// Ptr points to an object of the static type.
static void EmitDestroyingObjectDelete(CodeGenFunction &CGF,
                                       const CXXDeleteExpr *DE, Address Ptr,
                                       QualType ElementType) {
  auto *Dtor = ElementType->getAsCXXRecordDecl()->getDestructor();
  if (Dtor && Dtor->isVirtual())
    CGF.CGM.getCXXABI().emitVirtualObjectDelete(CGF, DE, Ptr, ElementType,
                                                Dtor);
  else
    CGF.EmitDeleteCall(DE->getOperatorDelete(), Ptr.getPointer(), ElementType);
}

/// Emit the code for deleting a single object.
/// \return \c true if we started emitting UnconditionalDeleteBlock, \c false
/// if not.
static bool EmitObjectDelete(CodeGenFunction &CGF,
                             const CXXDeleteExpr *DE,
                             Address Ptr,
                             QualType ElementType,
                             llvm::BasicBlock *UnconditionalDeleteBlock) {
  // C++11 [expr.delete]p3:
  //   If the static type of the object to be deleted is different from its
  //   dynamic type, the static type shall be a base class of the dynamic type
  //   of the object to be deleted and the static type shall have a virtual
  //   destructor or the behavior is undefined.
  CGF.EmitTypeCheck(CodeGenFunction::TCK_MemberCall,
                    DE->getExprLoc(), Ptr.getPointer(),
                    ElementType);

  const FunctionDecl *OperatorDelete = DE->getOperatorDelete();
  assert(!OperatorDelete->isDestroyingOperatorDelete());

  // Find the destructor for the type, if applicable.  If the
  // destructor is virtual, we'll just emit the vcall and return.
  const CXXDestructorDecl *Dtor = nullptr;
  if (const RecordType *RT = ElementType->getAs<RecordType>()) {
    CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl());
    if (RD->hasDefinition() && !RD->hasTrivialDestructor()) {
      Dtor = RD->getDestructor();

      if (Dtor->isVirtual()) {
        bool UseVirtualCall = true;
        const Expr *Base = DE->getArgument();
        if (auto *DevirtualizedDtor =
                dyn_cast_or_null<const CXXDestructorDecl>(
                    Dtor->getDevirtualizedMethod(
                        Base, CGF.CGM.getLangOpts().AppleKext))) {
          UseVirtualCall = false;
          const CXXRecordDecl *DevirtualizedClass =
              DevirtualizedDtor->getParent();
          if (declaresSameEntity(getCXXRecord(Base), DevirtualizedClass)) {
            // Devirtualized to the class of the base type (the type of the
            // whole expression).
            Dtor = DevirtualizedDtor;
          } else {
            // Devirtualized to some other type. Would need to cast the this
            // pointer to that type but we don't have support for that yet, so
            // do a virtual call. FIXME: handle the case where it is
            // devirtualized to the derived type (the type of the inner
            // expression) as in EmitCXXMemberOrOperatorMemberCallExpr.
            UseVirtualCall = true;
          }
        }
        if (UseVirtualCall) {
          CGF.CGM.getCXXABI().emitVirtualObjectDelete(CGF, DE, Ptr, ElementType,
                                                      Dtor);
          return false;
        }
      }
    }
  }

  // Make sure that we call delete even if the dtor throws.
  // This doesn't have to a conditional cleanup because we're going
  // to pop it off in a second.
  CGF.EHStack.pushCleanup<CallObjectDelete>(NormalAndEHCleanup,
                                            Ptr.getPointer(),
                                            OperatorDelete, ElementType);

  if (Dtor)
    CGF.EmitCXXDestructorCall(Dtor, Dtor_Complete,
                              /*ForVirtualBase=*/false,
                              /*Delegating=*/false,
                              Ptr, ElementType);
  else if (auto Lifetime = ElementType.getObjCLifetime()) {
    switch (Lifetime) {
    case Qualifiers::OCL_None:
    case Qualifiers::OCL_ExplicitNone:
    case Qualifiers::OCL_Autoreleasing:
      break;

    case Qualifiers::OCL_Strong:
      CGF.EmitARCDestroyStrong(Ptr, ARCPreciseLifetime);
      break;

    case Qualifiers::OCL_Weak:
      CGF.EmitARCDestroyWeak(Ptr);
      break;
    }
  }

  // When optimizing for size, call 'operator delete' unconditionally.
  if (CGF.CGM.getCodeGenOpts().OptimizeSize > 1) {
    CGF.EmitBlock(UnconditionalDeleteBlock);
    CGF.PopCleanupBlock();
    return true;
  }

  CGF.PopCleanupBlock();
  return false;
}

namespace {
  /// Calls the given 'operator delete' on an array of objects.
  struct CallArrayDelete final : EHScopeStack::Cleanup {
    llvm::Value *Ptr;
    const FunctionDecl *OperatorDelete;
    llvm::Value *NumElements;
    QualType ElementType;
    CharUnits CookieSize;

    CallArrayDelete(llvm::Value *Ptr,
                    const FunctionDecl *OperatorDelete,
                    llvm::Value *NumElements,
                    QualType ElementType,
                    CharUnits CookieSize)
      : Ptr(Ptr), OperatorDelete(OperatorDelete), NumElements(NumElements),
        ElementType(ElementType), CookieSize(CookieSize) {}

    void Emit(CodeGenFunction &CGF, Flags flags) override {
      CGF.EmitDeleteCall(OperatorDelete, Ptr, ElementType, NumElements,
                         CookieSize);
    }
  };
}

/// Emit the code for deleting an array of objects.
static void EmitArrayDelete(CodeGenFunction &CGF,
                            const CXXDeleteExpr *E,
                            Address deletedPtr,
                            QualType elementType) {
  llvm::Value *numElements = nullptr;
  llvm::Value *allocatedPtr = nullptr;
  CharUnits cookieSize;
  CGF.CGM.getCXXABI().ReadArrayCookie(CGF, deletedPtr, E, elementType,
                                      numElements, allocatedPtr, cookieSize);

  assert(allocatedPtr && "ReadArrayCookie didn't set allocated pointer");

  // Make sure that we call delete even if one of the dtors throws.
  const FunctionDecl *operatorDelete = E->getOperatorDelete();
  CGF.EHStack.pushCleanup<CallArrayDelete>(NormalAndEHCleanup,
                                           allocatedPtr, operatorDelete,
                                           numElements, elementType,
                                           cookieSize);

  // Destroy the elements.
  if (QualType::DestructionKind dtorKind = elementType.isDestructedType()) {
    assert(numElements && "no element count for a type with a destructor!");

    CharUnits elementSize = CGF.getContext().getTypeSizeInChars(elementType);
    CharUnits elementAlign =
      deletedPtr.getAlignment().alignmentOfArrayElement(elementSize);

    llvm::Value *arrayBegin = deletedPtr.getPointer();
    llvm::Value *arrayEnd =
      CGF.Builder.CreateInBoundsGEP(arrayBegin, numElements, "delete.end");

    // Note that it is legal to allocate a zero-length array, and we
    // can never fold the check away because the length should always
    // come from a cookie.
    CGF.emitArrayDestroy(arrayBegin, arrayEnd, elementType, elementAlign,
                         CGF.getDestroyer(dtorKind),
                         /*checkZeroLength*/ true,
                         CGF.needsEHCleanup(dtorKind));
  }

  // Pop the cleanup block.
  CGF.PopCleanupBlock();
}

void CodeGenFunction::EmitCXXDeleteExpr(const CXXDeleteExpr *E) {
  const Expr *Arg = E->getArgument();
  Address Ptr = EmitPointerWithAlignment(Arg);

  // Null check the pointer.
  //
  // We could avoid this null check if we can determine that the object
  // destruction is trivial and doesn't require an array cookie; we can
  // unconditionally perform the operator delete call in that case. For now, we
  // assume that deleted pointers are null rarely enough that it's better to
  // keep the branch. This might be worth revisiting for a -O0 code size win.
  llvm::BasicBlock *DeleteNotNull = createBasicBlock("delete.notnull");
  llvm::BasicBlock *DeleteEnd = createBasicBlock("delete.end");

  llvm::Value *IsNull = Builder.CreateIsNull(Ptr.getPointer(), "isnull");

  Builder.CreateCondBr(IsNull, DeleteEnd, DeleteNotNull);
  EmitBlock(DeleteNotNull);

  QualType DeleteTy = E->getDestroyedType();

  // A destroying operator delete overrides the entire operation of the
  // delete expression.
  if (E->getOperatorDelete()->isDestroyingOperatorDelete()) {
    EmitDestroyingObjectDelete(*this, E, Ptr, DeleteTy);
    EmitBlock(DeleteEnd);
    return;
  }

  // We might be deleting a pointer to array.  If so, GEP down to the
  // first non-array element.
  // (this assumes that A(*)[3][7] is converted to [3 x [7 x %A]]*)
  if (DeleteTy->isConstantArrayType()) {
    llvm::Value *Zero = Builder.getInt32(0);
    SmallVector<llvm::Value*,8> GEP;

    GEP.push_back(Zero); // point at the outermost array

    // For each layer of array type we're pointing at:
    while (const ConstantArrayType *Arr
             = getContext().getAsConstantArrayType(DeleteTy)) {
      // 1. Unpeel the array type.
      DeleteTy = Arr->getElementType();

      // 2. GEP to the first element of the array.
      GEP.push_back(Zero);
    }

    Ptr = Address(Builder.CreateInBoundsGEP(Ptr.getPointer(), GEP, "del.first"),
                  Ptr.getAlignment());
  }

  assert(ConvertTypeForMem(DeleteTy) == Ptr.getElementType());

  if (E->isArrayForm()) {
    EmitArrayDelete(*this, E, Ptr, DeleteTy);
    EmitBlock(DeleteEnd);
  } else {
    if (!EmitObjectDelete(*this, E, Ptr, DeleteTy, DeleteEnd))
      EmitBlock(DeleteEnd);
  }
}

static bool isGLValueFromPointerDeref(const Expr *E) {
  E = E->IgnoreParens();

  if (const auto *CE = dyn_cast<CastExpr>(E)) {
    if (!CE->getSubExpr()->isGLValue())
      return false;
    return isGLValueFromPointerDeref(CE->getSubExpr());
  }

  if (const auto *OVE = dyn_cast<OpaqueValueExpr>(E))
    return isGLValueFromPointerDeref(OVE->getSourceExpr());

  if (const auto *BO = dyn_cast<BinaryOperator>(E))
    if (BO->getOpcode() == BO_Comma)
      return isGLValueFromPointerDeref(BO->getRHS());

  if (const auto *ACO = dyn_cast<AbstractConditionalOperator>(E))
    return isGLValueFromPointerDeref(ACO->getTrueExpr()) ||
           isGLValueFromPointerDeref(ACO->getFalseExpr());

  // C++11 [expr.sub]p1:
  //   The expression E1[E2] is identical (by definition) to *((E1)+(E2))
  if (isa<ArraySubscriptExpr>(E))
    return true;

  if (const auto *UO = dyn_cast<UnaryOperator>(E))
    if (UO->getOpcode() == UO_Deref)
      return true;

  return false;
}

static llvm::Value *EmitTypeidFromVTable(CodeGenFunction &CGF, const Expr *E,
                                         llvm::Type *StdTypeInfoPtrTy) {
  // Get the vtable pointer.
  Address ThisPtr = CGF.EmitLValue(E).getAddress(CGF);

  QualType SrcRecordTy = E->getType();

  // C++ [class.cdtor]p4:
  //   If the operand of typeid refers to the object under construction or
  //   destruction and the static type of the operand is neither the constructor
  //   or destructor’s class nor one of its bases, the behavior is undefined.
  CGF.EmitTypeCheck(CodeGenFunction::TCK_DynamicOperation, E->getExprLoc(),
                    ThisPtr.getPointer(), SrcRecordTy);

  // C++ [expr.typeid]p2:
  //   If the glvalue expression is obtained by applying the unary * operator to
  //   a pointer and the pointer is a null pointer value, the typeid expression
  //   throws the std::bad_typeid exception.
  //
  // However, this paragraph's intent is not clear.  We choose a very generous
  // interpretation which implores us to consider comma operators, conditional
  // operators, parentheses and other such constructs.
  if (CGF.CGM.getCXXABI().shouldTypeidBeNullChecked(
          isGLValueFromPointerDeref(E), SrcRecordTy)) {
    llvm::BasicBlock *BadTypeidBlock =
        CGF.createBasicBlock("typeid.bad_typeid");
    llvm::BasicBlock *EndBlock = CGF.createBasicBlock("typeid.end");

    llvm::Value *IsNull = CGF.Builder.CreateIsNull(ThisPtr.getPointer());
    CGF.Builder.CreateCondBr(IsNull, BadTypeidBlock, EndBlock);

    CGF.EmitBlock(BadTypeidBlock);
    CGF.CGM.getCXXABI().EmitBadTypeidCall(CGF);
    CGF.EmitBlock(EndBlock);
  }

  return CGF.CGM.getCXXABI().EmitTypeid(CGF, SrcRecordTy, ThisPtr,
                                        StdTypeInfoPtrTy);
}

llvm::Value *CodeGenFunction::EmitCXXTypeidExpr(const CXXTypeidExpr *E) {
  llvm::Type *StdTypeInfoPtrTy =
    ConvertType(E->getType())->getPointerTo();

  if (E->isTypeOperand()) {
    llvm::Constant *TypeInfo =
        CGM.GetAddrOfRTTIDescriptor(E->getTypeOperand(getContext()));
    return Builder.CreateBitCast(TypeInfo, StdTypeInfoPtrTy);
  }

  // C++ [expr.typeid]p2:
  //   When typeid is applied to a glvalue expression whose type is a
  //   polymorphic class type, the result refers to a std::type_info object
  //   representing the type of the most derived object (that is, the dynamic
  //   type) to which the glvalue refers.
  // If the operand is already most derived object, no need to look up vtable.
  if (E->isPotentiallyEvaluated() && !E->isMostDerived(getContext()))
    return EmitTypeidFromVTable(*this, E->getExprOperand(),
                                StdTypeInfoPtrTy);

  QualType OperandTy = E->getExprOperand()->getType();
  return Builder.CreateBitCast(CGM.GetAddrOfRTTIDescriptor(OperandTy),
                               StdTypeInfoPtrTy);
}

static llvm::Value *EmitDynamicCastToNull(CodeGenFunction &CGF,
                                          QualType DestTy) {
  llvm::Type *DestLTy = CGF.ConvertType(DestTy);
  if (DestTy->isPointerType())
    return llvm::Constant::getNullValue(DestLTy);

  /// C++ [expr.dynamic.cast]p9:
  ///   A failed cast to reference type throws std::bad_cast
  if (!CGF.CGM.getCXXABI().EmitBadCastCall(CGF))
    return nullptr;

  CGF.EmitBlock(CGF.createBasicBlock("dynamic_cast.end"));
  return llvm::UndefValue::get(DestLTy);
}

llvm::Value *CodeGenFunction::EmitDynamicCast(Address ThisAddr,
                                              const CXXDynamicCastExpr *DCE) {
  CGM.EmitExplicitCastExprType(DCE, this);
  QualType DestTy = DCE->getTypeAsWritten();

  QualType SrcTy = DCE->getSubExpr()->getType();

  // C++ [expr.dynamic.cast]p7:
  //   If T is "pointer to cv void," then the result is a pointer to the most
  //   derived object pointed to by v.
  const PointerType *DestPTy = DestTy->getAs<PointerType>();

  bool isDynamicCastToVoid;
  QualType SrcRecordTy;
  QualType DestRecordTy;
  if (DestPTy) {
    isDynamicCastToVoid = DestPTy->getPointeeType()->isVoidType();
    SrcRecordTy = SrcTy->castAs<PointerType>()->getPointeeType();
    DestRecordTy = DestPTy->getPointeeType();
  } else {
    isDynamicCastToVoid = false;
    SrcRecordTy = SrcTy;
    DestRecordTy = DestTy->castAs<ReferenceType>()->getPointeeType();
  }

  // C++ [class.cdtor]p5:
  //   If the operand of the dynamic_cast refers to the object under
  //   construction or destruction and the static type of the operand is not a
  //   pointer to or object of the constructor or destructor’s own class or one
  //   of its bases, the dynamic_cast results in undefined behavior.
  EmitTypeCheck(TCK_DynamicOperation, DCE->getExprLoc(), ThisAddr.getPointer(),
                SrcRecordTy);

  if (DCE->isAlwaysNull())
    if (llvm::Value *T = EmitDynamicCastToNull(*this, DestTy))
      return T;

  assert(SrcRecordTy->isRecordType() && "source type must be a record type!");

  // C++ [expr.dynamic.cast]p4:
  //   If the value of v is a null pointer value in the pointer case, the result
  //   is the null pointer value of type T.
  bool ShouldNullCheckSrcValue =
      CGM.getCXXABI().shouldDynamicCastCallBeNullChecked(SrcTy->isPointerType(),
                                                         SrcRecordTy);

  llvm::BasicBlock *CastNull = nullptr;
  llvm::BasicBlock *CastNotNull = nullptr;
  llvm::BasicBlock *CastEnd = createBasicBlock("dynamic_cast.end");

  if (ShouldNullCheckSrcValue) {
    CastNull = createBasicBlock("dynamic_cast.null");
    CastNotNull = createBasicBlock("dynamic_cast.notnull");

    llvm::Value *IsNull = Builder.CreateIsNull(ThisAddr.getPointer());
    Builder.CreateCondBr(IsNull, CastNull, CastNotNull);
    EmitBlock(CastNotNull);
  }

  llvm::Value *Value;
  if (isDynamicCastToVoid) {
    Value = CGM.getCXXABI().EmitDynamicCastToVoid(*this, ThisAddr, SrcRecordTy,
                                                  DestTy);
  } else {
    assert(DestRecordTy->isRecordType() &&
           "destination type must be a record type!");
    Value = CGM.getCXXABI().EmitDynamicCastCall(*this, ThisAddr, SrcRecordTy,
                                                DestTy, DestRecordTy, CastEnd);
    CastNotNull = Builder.GetInsertBlock();
  }

  if (ShouldNullCheckSrcValue) {
    EmitBranch(CastEnd);

    EmitBlock(CastNull);
    EmitBranch(CastEnd);
  }

  EmitBlock(CastEnd);

  if (ShouldNullCheckSrcValue) {
    llvm::PHINode *PHI = Builder.CreatePHI(Value->getType(), 2);
    PHI->addIncoming(Value, CastNotNull);
    PHI->addIncoming(llvm::Constant::getNullValue(Value->getType()), CastNull);

    Value = PHI;
  }

  return Value;
}