summary refs log tree commit diff stats
path: root/compiler/ccgexprs.nim
blob: eabcdd66addd21c6c47fa190ca949d8b597c9f0c (plain) (blame)
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
<
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
<html>
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<title>Mu - examples/ex4.subx</title>
<meta name="Generator" content="Vim/8.1">
<meta name="plugin-version" content="vim8.1_v1">
<meta name="syntax" content="none">
<meta name="settings" content="number_lines,use_css,no_foldcolumn,expand_tabs,line_ids,prevent_copy=">
<meta name="colorscheme" content="minimal-light">
<style type="text/css">
<!--
pre { font-family: monospace; color: #000000; background-color: #c6c6c6; }
body { font-size:12pt; font-family: monospace; color: #000000; background-color: #c6c6c6; }
a { color:inherit; }
* { font-size:12pt; font-size: 1em; }
.subxComment { color: #005faf; }
.subxS2Comment { color: #8a8a8a; }
.LineNr { }
.subxS1Comment { color: #0000af; }
.SpecialChar { color: #d70000; }
-->
</style>

<script type='text/javascript'>
<!--

/* function to open any folds containing a jumped-to line before jumping to it */
function JumpToLine()
{
  var lineNum;
  lineNum = window.location.hash;
  lineNum = lineNum.substr(1); /* strip off '#' */

  if (lineNum.indexOf('L') == -1) {
    lineNum = 'L'+lineNum;
  }
  var lineElem = document.getElementById(lineNum);
  /* Always jump to new location even if the line was hidden inside a fold, or
   * we corrected the raw number to a line ID.
   */
  if (lineElem) {
    lineElem.scrollIntoView(true);
  }
  return true;
}
if ('onhashchange' in window) {
  window.onhashchange = JumpToLine;
}

-->
</script>
</head>
<body onload='JumpToLine();'>
<a href='https://github.com/akkartik/mu/blob/master/examples/ex4.subx'>https://github.com/akkartik/mu/blob/master/examples/ex4.subx</a>
<pre id='vimCodeElement'>
<span id="L1" class="LineNr"> 1 </span><span class="subxComment"># Read a character from stdin, save it to a global, write it to stdout.</span>
<span id="L2" class="LineNr"> 2 </span><span class="subxComment">#</span>
<span id="L3" class="LineNr"> 3 </span><span class="subxComment"># To run:</span>
<span id="L4" class="LineNr"> 4 </span><span class="subxComment">#   $ ./subx translate init.linux examples/ex4.subx -o examples/ex4</span>
<span id="L5" class="LineNr"> 5 </span><span class="subxComment">#   $ ./subx run examples/ex4</span>
<span id="L6" class="LineNr"> 6 </span>
<span id="L7" class="LineNr"> 7 </span>== data
<span id="L8" class="LineNr"> 8 </span>
<span id="L9" class="LineNr"> 9 </span><span class="subxComment"># the global variable we save to</span>
<span id="L10" class="LineNr">10 </span><span class="SpecialChar">X</span>:
<span id="L11" class="LineNr">11 </span>    0/imm32  <span class="subxComment"># space for read() to write to</span>
<span id="L12" class="LineNr">12 </span>
<span id="L13" class="LineNr">13 </span>== code
<span id="L14" class="LineNr">14 </span>
<span id="L15" class="LineNr">15 </span><span class="SpecialChar">Entry</span>:
<span id="L16" class="LineNr">16 </span><span class="subxComment"># read(stdin, X, 1)</span>
<span id="L17" class="LineNr">17 </span><span class="subxS1Comment"># . fd = 0 (stdin)</span>
<span id="L18" class="LineNr">18 </span>bb/copy-to-ebx  0/imm32
<span id="L19" class="LineNr">19 </span><span class="subxS1Comment"># . data = X (location to write result to)</span>
<span id="L20" class="LineNr">20 </span>b9/copy-to-ecx  <span class="SpecialChar"><a href='ex4.subx.html#L10'>X</a></span>/imm32
<span id="L21" class="LineNr">21 </span><span class="subxS1Comment"># . size = 1 character</span>
<span id="L22" class="LineNr">22 </span>ba/copy-to-edx  1/imm32
<span id="L23" class="LineNr">23 </span><span class="subxS1Comment"># . syscall</span>
<span id="L24" class="LineNr">24 </span>e8/call  syscall_read/disp32
<span id="L25" class="LineNr">25 </span>
<span id="L26" class="LineNr">26 </span><span class="subxComment"># write(stdout, X, 1)</span>
<span id="L27" class="LineNr">27 </span><span class="subxS1Comment"># . fd = 1 (stdout)</span>
<span id="L28" class="LineNr">28 </span>bb/copy-to-ebx  1/imm32
<span id="L29" class="LineNr">29 </span><span class="subxS1Comment"># . initialize X (location to read from)</span>
<span id="L30" class="LineNr">30 </span>b9/copy-to-ecx  <span class="SpecialChar"><a href='ex4.subx.html#L10'>X</a></span>/imm32
<span id="L31" class="LineNr">31 </span><span class="subxS1Comment"># . size = 1 character</span>
<span id="L32" class="LineNr">32 </span>ba/copy-to-edx  1/imm32
<span id="L33" class="LineNr">33 </span><span class="subxS1Comment"># . syscall</span>
<span id="L34" class="LineNr">34 </span>e8/call  syscall_write/disp32
<span id="L35" class="LineNr">35 </span>
<span id="L36" class="LineNr">36 </span><span class="subxComment"># exit(ebx)</span>
<span id="L37" class="LineNr">37 </span>e8/call  syscall_exit/disp32
<span id="L38" class="LineNr">38 </span>
<span id="L39" class="LineNr">39 </span><span class="subxS2Comment"># . . vim&#0058;nowrap:textwidth=0</span>
</pre>
</body>
</html>
<!-- vim: set foldmethod=manual : -->
195'>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
#
#
#           The Nim Compiler
#        (c) Copyright 2013 Andreas Rumpf
#
#    See the file "copying.txt", included in this
#    distribution, for details about the copyright.
#

# included from cgen.nim

# -------------------------- constant expressions ------------------------

proc int64Literal(i: BiggestInt): Rope =
  if i > low(int64):
    result = rfmt(nil, "IL64($1)", rope(i))
  else:
    result = ~"(IL64(-9223372036854775807) - IL64(1))"

proc uint64Literal(i: uint64): Rope = rope($i & "ULL")

proc intLiteral(i: BiggestInt): Rope =
  if i > low(int32) and i <= high(int32):
    result = rope(i)
  elif i == low(int32):
    # Nim has the same bug for the same reasons :-)
    result = ~"(-2147483647 -1)"
  elif i > low(int64):
    result = rfmt(nil, "IL64($1)", rope(i))
  else:
    result = ~"(IL64(-9223372036854775807) - IL64(1))"

proc getStrLit(m: BModule, s: string): Rope =
  discard cgsym(m, "TGenericSeq")
  result = getTempName(m)
  addf(m.s[cfsData], "STRING_LITERAL($1, $2, $3);$n",
       [result, makeCString(s), rope(len(s))])

proc genLiteral(p: BProc, n: PNode, ty: PType): Rope =
  if ty == nil: internalError(n.info, "genLiteral: ty is nil")
  case n.kind
  of nkCharLit..nkUInt64Lit:
    case skipTypes(ty, abstractVarRange).kind
    of tyChar, tyNil:
      result = intLiteral(n.intVal)
    of tyBool:
      if n.intVal != 0: result = ~"NIM_TRUE"
      else: result = ~"NIM_FALSE"
    of tyInt64: result = int64Literal(n.intVal)
    of tyUInt64: result = uint64Literal(uint64(n.intVal))
    else:
      result = "(($1) $2)" % [getTypeDesc(p.module,
          ty), intLiteral(n.intVal)]
  of nkNilLit:
    let t = skipTypes(ty, abstractVarRange)
    if t.kind == tyProc and t.callConv == ccClosure:
      let id = nodeTableTestOrSet(p.module.dataCache, n, p.module.labels)
      result = p.module.tmpBase & rope(id)
      if id == p.module.labels:
        # not found in cache:
        inc(p.module.labels)
        addf(p.module.s[cfsData],
             "static NIM_CONST $1 $2 = {NIM_NIL,NIM_NIL};$n",
             [getTypeDesc(p.module, ty), result])
    else:
      result = rope("NIM_NIL")
  of nkStrLit..nkTripleStrLit:
    if n.strVal.isNil:
      result = ropecg(p.module, "((#NimStringDesc*) NIM_NIL)", [])
    elif skipTypes(ty, abstractVarRange).kind == tyString:
      let id = nodeTableTestOrSet(p.module.dataCache, n, p.module.labels)
      if id == p.module.labels:
        # string literal not found in the cache:
        result = ropecg(p.module, "((#NimStringDesc*) &$1)",
                        [getStrLit(p.module, n.strVal)])
      else:
        result = ropecg(p.module, "((#NimStringDesc*) &$1$2)",
                        [p.module.tmpBase, rope(id)])
    else:
      result = makeCString(n.strVal)
  of nkFloatLit..nkFloat64Lit:
    result = rope(n.floatVal.toStrMaxPrecision)
  else:
    internalError(n.info, "genLiteral(" & $n.kind & ')')
    result = nil

proc genLiteral(p: BProc, n: PNode): Rope =
  result = genLiteral(p, n, n.typ)

proc bitSetToWord(s: TBitSet, size: int): BiggestInt =
  result = 0
  when true:
    for j in countup(0, size - 1):
      if j < len(s): result = result or `shl`(ze64(s[j]), j * 8)
  else:
    # not needed, too complex thinking:
    if CPU[platform.hostCPU].endian == CPU[targetCPU].endian:
      for j in countup(0, size - 1):
        if j < len(s): result = result or `shl`(Ze64(s[j]), j * 8)
    else:
      for j in countup(0, size - 1):
        if j < len(s): result = result or `shl`(Ze64(s[j]), (Size - 1 - j) * 8)

proc genRawSetData(cs: TBitSet, size: int): Rope =
  var frmt: FormatStr
  if size > 8:
    result = "{$n" % []
    for i in countup(0, size - 1):
      if i < size - 1:
        # not last iteration?
        if (i + 1) mod 8 == 0: frmt = "0x$1,$n"
        else: frmt = "0x$1, "
      else:
        frmt = "0x$1}$n"
      addf(result, frmt, [rope(toHex(ze64(cs[i]), 2))])
  else:
    result = intLiteral(bitSetToWord(cs, size))
    #  result := rope('0x' + ToHex(bitSetToWord(cs, size), size * 2))

proc genSetNode(p: BProc, n: PNode): Rope =
  var cs: TBitSet
  var size = int(getSize(n.typ))
  toBitSet(n, cs)
  if size > 8:
    let id = nodeTableTestOrSet(p.module.dataCache, n, p.module.labels)
    result = p.module.tmpBase & rope(id)
    if id == p.module.labels:
      # not found in cache:
      inc(p.module.labels)
      addf(p.module.s[cfsData], "static NIM_CONST $1 $2 = $3;$n",
           [getTypeDesc(p.module, n.typ), result, genRawSetData(cs, size)])
  else:
    result = genRawSetData(cs, size)

proc getStorageLoc(n: PNode): TStorageLoc =
  case n.kind
  of nkSym:
    case n.sym.kind
    of skParam, skTemp:
      result = OnStack
    of skVar, skForVar, skResult, skLet:
      if sfGlobal in n.sym.flags: result = OnHeap
      else: result = OnStack
    of skConst:
      if sfGlobal in n.sym.flags: result = OnHeap
      else: result = OnUnknown
    else: result = OnUnknown
  of nkDerefExpr, nkHiddenDeref:
    case n.sons[0].typ.kind
    of tyVar: result = OnUnknown
    of tyPtr: result = OnStack
    of tyRef: result = OnHeap
    else: internalError(n.info, "getStorageLoc")
  of nkBracketExpr, nkDotExpr, nkObjDownConv, nkObjUpConv:
    result = getStorageLoc(n.sons[0])
  else: result = OnUnknown

proc genRefAssign(p: BProc, dest, src: TLoc, flags: TAssignmentFlags) =
  if dest.s == OnStack or not usesNativeGC():
    linefmt(p, cpsStmts, "$1 = $2;$n", rdLoc(dest), rdLoc(src))
  elif dest.s == OnHeap:
    # location is on heap
    # now the writer barrier is inlined for performance:
    #
    #    if afSrcIsNotNil in flags:
    #      UseMagic(p.module, 'nimGCref')
    #      lineF(p, cpsStmts, 'nimGCref($1);$n', [rdLoc(src)])
    #    elif afSrcIsNil notin flags:
    #      UseMagic(p.module, 'nimGCref')
    #      lineF(p, cpsStmts, 'if ($1) nimGCref($1);$n', [rdLoc(src)])
    #    if afDestIsNotNil in flags:
    #      UseMagic(p.module, 'nimGCunref')
    #      lineF(p, cpsStmts, 'nimGCunref($1);$n', [rdLoc(dest)])
    #    elif afDestIsNil notin flags:
    #      UseMagic(p.module, 'nimGCunref')
    #      lineF(p, cpsStmts, 'if ($1) nimGCunref($1);$n', [rdLoc(dest)])
    #    lineF(p, cpsStmts, '$1 = $2;$n', [rdLoc(dest), rdLoc(src)])
    if canFormAcycle(dest.t):
      linefmt(p, cpsStmts, "#asgnRef((void**) $1, $2);$n",
              addrLoc(dest), rdLoc(src))
    else:
      linefmt(p, cpsStmts, "#asgnRefNoCycle((void**) $1, $2);$n",
              addrLoc(dest), rdLoc(src))
  else:
    linefmt(p, cpsStmts, "#unsureAsgnRef((void**) $1, $2);$n",
            addrLoc(dest), rdLoc(src))

proc asgnComplexity(n: PNode): int =
  if n != nil:
    case n.kind
    of nkSym: result = 1
    of nkRecCase:
      # 'case objects' are too difficult to inline their assignment operation:
      result = 100
    of nkRecList:
      for t in items(n):
        result += asgnComplexity(t)
    else: discard

proc optAsgnLoc(a: TLoc, t: PType, field: Rope): TLoc =
  assert field != nil
  result.k = locField
  result.s = a.s
  result.t = t
  result.r = rdLoc(a) & "." & field

proc genOptAsgnTuple(p: BProc, dest, src: TLoc, flags: TAssignmentFlags) =
  let newflags =
    if src.s == OnStatic:
      flags + {needToCopy}
    elif tfShallow in dest.t.flags:
      flags - {needToCopy}
    else:
      flags
  let t = skipTypes(dest.t, abstractInst).getUniqueType()
  for i in 0 .. <t.len:
    let t = t.sons[i]
    let field = "Field$1" % [i.rope]
    genAssignment(p, optAsgnLoc(dest, t, field),
                     optAsgnLoc(src, t, field), newflags)

proc genOptAsgnObject(p: BProc, dest, src: TLoc, flags: TAssignmentFlags,
                      t: PNode) =
  if t == nil: return
  let newflags =
    if src.s == OnStatic:
      flags + {needToCopy}
    elif tfShallow in dest.t.flags:
      flags - {needToCopy}
    else:
      flags
  case t.kind
  of nkSym:
    let field = t.sym
    genAssignment(p, optAsgnLoc(dest, field.typ, field.loc.r),
                     optAsgnLoc(src, field.typ, field.loc.r), newflags)
  of nkRecList:
    for child in items(t): genOptAsgnObject(p, dest, src, newflags, child)
  else: discard

proc genGenericAsgn(p: BProc, dest, src: TLoc, flags: TAssignmentFlags) =
  # Consider:
  # type TMyFastString {.shallow.} = string
  # Due to the implementation of pragmas this would end up to set the
  # tfShallow flag for the built-in string type too! So we check only
  # here for this flag, where it is reasonably safe to do so
  # (for objects, etc.):
  if needToCopy notin flags or
      tfShallow in skipTypes(dest.t, abstractVarRange).flags:
    if dest.s == OnStack or not usesNativeGC():
      useStringh(p.module)
      linefmt(p, cpsStmts,
           "memcpy((void*)$1, (NIM_CONST void*)$2, sizeof($3));$n",
           addrLoc(dest), addrLoc(src), rdLoc(dest))
    else:
      linefmt(p, cpsStmts, "#genericShallowAssign((void*)$1, (void*)$2, $3);$n",
              addrLoc(dest), addrLoc(src), genTypeInfo(p.module, dest.t))
  else:
    linefmt(p, cpsStmts, "#genericAssign((void*)$1, (void*)$2, $3);$n",
            addrLoc(dest), addrLoc(src), genTypeInfo(p.module, dest.t))

proc genAssignment(p: BProc, dest, src: TLoc, flags: TAssignmentFlags) =
  # This function replaces all other methods for generating
  # the assignment operation in C.
  if src.t != nil and src.t.kind == tyPtr:
    # little HACK to support the new 'var T' as return type:
    linefmt(p, cpsStmts, "$1 = $2;$n", rdLoc(dest), rdLoc(src))
    return
  let ty = skipTypes(dest.t, abstractRange)
  case ty.kind
  of tyRef:
    genRefAssign(p, dest, src, flags)
  of tySequence:
    if needToCopy notin flags and src.s != OnStatic:
      genRefAssign(p, dest, src, flags)
    else:
      linefmt(p, cpsStmts, "#genericSeqAssign($1, $2, $3);$n",
              addrLoc(dest), rdLoc(src), genTypeInfo(p.module, dest.t))
  of tyString:
    if needToCopy notin flags and src.s != OnStatic:
      genRefAssign(p, dest, src, flags)
    else:
      if dest.s == OnStack or not usesNativeGC():
        linefmt(p, cpsStmts, "$1 = #copyString($2);$n", dest.rdLoc, src.rdLoc)
      elif dest.s == OnHeap:
        # we use a temporary to care for the dreaded self assignment:
        var tmp: TLoc
        getTemp(p, ty, tmp)
        linefmt(p, cpsStmts, "$3 = $1; $1 = #copyStringRC1($2);$n",
                dest.rdLoc, src.rdLoc, tmp.rdLoc)
        linefmt(p, cpsStmts, "if ($1) #nimGCunrefNoCycle($1);$n", tmp.rdLoc)
      else:
        linefmt(p, cpsStmts, "#unsureAsgnRef((void**) $1, #copyString($2));$n",
               addrLoc(dest), rdLoc(src))
  of tyProc:
    if needsComplexAssignment(dest.t):
      # optimize closure assignment:
      let a = optAsgnLoc(dest, dest.t, "ClEnv".rope)
      let b = optAsgnLoc(src, dest.t, "ClEnv".rope)
      genRefAssign(p, a, b, flags)
      linefmt(p, cpsStmts, "$1.ClPrc = $2.ClPrc;$n", rdLoc(dest), rdLoc(src))
    else:
      linefmt(p, cpsStmts, "$1 = $2;$n", rdLoc(dest), rdLoc(src))
  of tyTuple:
    if needsComplexAssignment(dest.t):
      if dest.t.len <= 4: genOptAsgnTuple(p, dest, src, flags)
      else: genGenericAsgn(p, dest, src, flags)
    else:
      linefmt(p, cpsStmts, "$1 = $2;$n", rdLoc(dest), rdLoc(src))
  of tyObject:
    # XXX: check for subtyping?
    if ty.isImportedCppType:
      linefmt(p, cpsStmts, "$1 = $2;$n", rdLoc(dest), rdLoc(src))
    elif not isObjLackingTypeField(ty):
      genGenericAsgn(p, dest, src, flags)
    elif needsComplexAssignment(ty):
      if ty.sons[0].isNil and asgnComplexity(ty.n) <= 4:
        discard getTypeDesc(p.module, dest.t)
        internalAssert ty.n != nil
        genOptAsgnObject(p, dest, src, flags, ty.n)
      else:
        genGenericAsgn(p, dest, src, flags)
    else:
      linefmt(p, cpsStmts, "$1 = $2;$n", rdLoc(dest), rdLoc(src))
  of tyArray:
    if needsComplexAssignment(dest.t):
      genGenericAsgn(p, dest, src, flags)
    else:
      useStringh(p.module)
      linefmt(p, cpsStmts,
           "memcpy((void*)$1, (NIM_CONST void*)$2, sizeof($3));$n",
           rdLoc(dest), rdLoc(src), getTypeDesc(p.module, dest.t))
  of tyOpenArray, tyVarargs:
    # open arrays are always on the stack - really? What if a sequence is
    # passed to an open array?
    if needsComplexAssignment(dest.t):
      linefmt(p, cpsStmts,     # XXX: is this correct for arrays?
           "#genericAssignOpenArray((void*)$1, (void*)$2, $1Len0, $3);$n",
           addrLoc(dest), addrLoc(src), genTypeInfo(p.module, dest.t))
    else:
      useStringh(p.module)
      linefmt(p, cpsStmts,
           "memcpy((void*)$1, (NIM_CONST void*)$2, sizeof($1[0])*$1Len0);$n",
           rdLoc(dest), rdLoc(src))
  of tySet:
    if mapType(ty) == ctArray:
      useStringh(p.module)
      linefmt(p, cpsStmts, "memcpy((void*)$1, (NIM_CONST void*)$2, $3);$n",
              rdLoc(dest), rdLoc(src), rope(getSize(dest.t)))
    else:
      linefmt(p, cpsStmts, "$1 = $2;$n", rdLoc(dest), rdLoc(src))
  of tyPtr, tyPointer, tyChar, tyBool, tyEnum, tyCString,
     tyInt..tyUInt64, tyRange, tyVar:
    linefmt(p, cpsStmts, "$1 = $2;$n", rdLoc(dest), rdLoc(src))
  else: internalError("genAssignment: " & $ty.kind)

  if optMemTracker in p.options and dest.s in {OnHeap, OnUnknown}:
    #writeStackTrace()
    #echo p.currLineInfo, " requesting"
    linefmt(p, cpsStmts, "#memTrackerWrite((void*)$1, $2, $3, $4);$n",
            addrLoc(dest), rope getSize(dest.t),
            makeCString(p.currLineInfo.toFullPath),
            rope p.currLineInfo.safeLineNm)

proc genDeepCopy(p: BProc; dest, src: TLoc) =
  template addrLocOrTemp(a: TLoc): Rope =
    if a.k == locExpr:
      var tmp: TLoc
      getTemp(p, a.t, tmp)
      genAssignment(p, tmp, a, {})
      addrLoc(tmp)
    else:
      addrLoc(a)

  var ty = skipTypes(dest.t, abstractVarRange)
  case ty.kind
  of tyPtr, tyRef, tyProc, tyTuple, tyObject, tyArray:
    # XXX optimize this
    linefmt(p, cpsStmts, "#genericDeepCopy((void*)$1, (void*)$2, $3);$n",
            addrLoc(dest), addrLocOrTemp(src), genTypeInfo(p.module, dest.t))
  of tySequence, tyString:
    linefmt(p, cpsStmts, "#genericSeqDeepCopy($1, $2, $3);$n",
            addrLoc(dest), rdLoc(src), genTypeInfo(p.module, dest.t))
  of tyOpenArray, tyVarargs:
    linefmt(p, cpsStmts,
         "#genericDeepCopyOpenArray((void*)$1, (void*)$2, $1Len0, $3);$n",
         addrLoc(dest), addrLocOrTemp(src), genTypeInfo(p.module, dest.t))
  of tySet:
    if mapType(ty) == ctArray:
      useStringh(p.module)
      linefmt(p, cpsStmts, "memcpy((void*)$1, (NIM_CONST void*)$2, $3);$n",
              rdLoc(dest), rdLoc(src), rope(getSize(dest.t)))
    else:
      linefmt(p, cpsStmts, "$1 = $2;$n", rdLoc(dest), rdLoc(src))
  of tyPointer, tyChar, tyBool, tyEnum, tyCString,
     tyInt..tyUInt64, tyRange, tyVar:
    linefmt(p, cpsStmts, "$1 = $2;$n", rdLoc(dest), rdLoc(src))
  else: internalError("genDeepCopy: " & $ty.kind)

proc putLocIntoDest(p: BProc, d: var TLoc, s: TLoc) =
  if d.k != locNone:
    if lfNoDeepCopy in d.flags: genAssignment(p, d, s, {})
    else: genAssignment(p, d, s, {needToCopy})
  else:
    d = s # ``d`` is free, so fill it with ``s``

proc putDataIntoDest(p: BProc, d: var TLoc, t: PType, r: Rope) =
  var a: TLoc
  if d.k != locNone:
    # need to generate an assignment here
    initLoc(a, locData, t, OnStatic)
    a.r = r
    if lfNoDeepCopy in d.flags: genAssignment(p, d, a, {})
    else: genAssignment(p, d, a, {needToCopy})
  else:
    # we cannot call initLoc() here as that would overwrite
    # the flags field!
    d.k = locData
    d.t = t
    d.r = r

proc putIntoDest(p: BProc, d: var TLoc, t: PType, r: Rope; s=OnUnknown) =
  var a: TLoc
  if d.k != locNone:
    # need to generate an assignment here
    initLoc(a, locExpr, t, s)
    a.r = r
    if lfNoDeepCopy in d.flags: genAssignment(p, d, a, {})
    else: genAssignment(p, d, a, {needToCopy})
  else:
    # we cannot call initLoc() here as that would overwrite
    # the flags field!
    d.k = locExpr
    d.t = t
    d.r = r

proc binaryStmt(p: BProc, e: PNode, d: var TLoc, frmt: string) =
  var a, b: TLoc
  if d.k != locNone: internalError(e.info, "binaryStmt")
  initLocExpr(p, e.sons[1], a)
  initLocExpr(p, e.sons[2], b)
  lineCg(p, cpsStmts, frmt, rdLoc(a), rdLoc(b))

proc unaryStmt(p: BProc, e: PNode, d: var TLoc, frmt: string) =
  var a: TLoc
  if d.k != locNone: internalError(e.info, "unaryStmt")
  initLocExpr(p, e.sons[1], a)
  lineCg(p, cpsStmts, frmt, [rdLoc(a)])

proc binaryExpr(p: BProc, e: PNode, d: var TLoc, frmt: string) =
  var a, b: TLoc
  assert(e.sons[1].typ != nil)
  assert(e.sons[2].typ != nil)
  initLocExpr(p, e.sons[1], a)
  initLocExpr(p, e.sons[2], b)
  putIntoDest(p, d, e.typ, ropecg(p.module, frmt, [rdLoc(a), rdLoc(b)]))

proc binaryExprChar(p: BProc, e: PNode, d: var TLoc, frmt: string) =
  var a, b: TLoc
  assert(e.sons[1].typ != nil)
  assert(e.sons[2].typ != nil)
  initLocExpr(p, e.sons[1], a)
  initLocExpr(p, e.sons[2], b)
  putIntoDest(p, d, e.typ, ropecg(p.module, frmt, [a.rdCharLoc, b.rdCharLoc]))

proc unaryExpr(p: BProc, e: PNode, d: var TLoc, frmt: string) =
  var a: TLoc
  initLocExpr(p, e.sons[1], a)
  putIntoDest(p, d, e.typ, ropecg(p.module, frmt, [rdLoc(a)]))

proc unaryExprChar(p: BProc, e: PNode, d: var TLoc, frmt: string) =
  var a: TLoc
  initLocExpr(p, e.sons[1], a)
  putIntoDest(p, d, e.typ, ropecg(p.module, frmt, [rdCharLoc(a)]))

proc binaryArithOverflowRaw(p: BProc, t: PType, a, b: TLoc;
                            frmt: string): Rope =
  var size = getSize(t)
  let storage = if size < platform.intSize: rope("NI")
                else: getTypeDesc(p.module, t)
  result = getTempName(p.module)
  linefmt(p, cpsLocals, "$1 $2;$n", storage, result)
  lineCg(p, cpsStmts, frmt, result, rdCharLoc(a), rdCharLoc(b))
  if size < platform.intSize or t.kind in {tyRange, tyEnum}:
    linefmt(p, cpsStmts, "if ($1 < $2 || $1 > $3) #raiseOverflow();$n",
            result, intLiteral(firstOrd(t)), intLiteral(lastOrd(t)))

proc binaryArithOverflow(p: BProc, e: PNode, d: var TLoc, m: TMagic) =
  const
    prc: array[mAddI..mPred, string] = [
      "$# = #addInt($#, $#);$n", "$# = #subInt($#, $#);$n",
      "$# = #mulInt($#, $#);$n", "$# = #divInt($#, $#);$n",
      "$# = #modInt($#, $#);$n",
      "$# = #addInt($#, $#);$n", "$# = #subInt($#, $#);$n"]
    prc64: array[mAddI..mPred, string] = [
      "$# = #addInt64($#, $#);$n", "$# = #subInt64($#, $#);$n",
      "$# = #mulInt64($#, $#);$n", "$# = #divInt64($#, $#);$n",
      "$# = #modInt64($#, $#);$n",
      "$# = #addInt64($#, $#);$n", "$# = #subInt64($#, $#);$n"]
    opr: array[mAddI..mPred, string] = [
      "($#)($# + $#)", "($#)($# - $#)", "($#)($# * $#)",
      "($#)($# / $#)", "($#)($# % $#)",
      "($#)($# + $#)", "($#)($# - $#)"]
  var a, b: TLoc
  assert(e.sons[1].typ != nil)
  assert(e.sons[2].typ != nil)
  initLocExpr(p, e.sons[1], a)
  initLocExpr(p, e.sons[2], b)
  # skipping 'range' is correct here as we'll generate a proper range check
  # later via 'chckRange'
  let t = e.typ.skipTypes(abstractRange)
  if optOverflowCheck notin p.options:
    let res = opr[m] % [getTypeDesc(p.module, e.typ), rdLoc(a), rdLoc(b)]
    putIntoDest(p, d, e.typ, res)
  else:
    let res = binaryArithOverflowRaw(p, t, a, b,
                                   if t.kind == tyInt64: prc64[m] else: prc[m])
    putIntoDest(p, d, e.typ, "($#)($#)" % [getTypeDesc(p.module, e.typ), res])

proc unaryArithOverflow(p: BProc, e: PNode, d: var TLoc, m: TMagic) =
  const
    opr: array[mUnaryMinusI..mAbsI, string] = [
      mUnaryMinusI: "((NI$2)-($1))",
      mUnaryMinusI64: "-($1)",
      mAbsI: "($1 > 0? ($1) : -($1))"]
  var
    a: TLoc
    t: PType
  assert(e.sons[1].typ != nil)
  initLocExpr(p, e.sons[1], a)
  t = skipTypes(e.typ, abstractRange)
  if optOverflowCheck in p.options:
    linefmt(p, cpsStmts, "if ($1 == $2) #raiseOverflow();$n",
            rdLoc(a), intLiteral(firstOrd(t)))
  putIntoDest(p, d, e.typ, opr[m] % [rdLoc(a), rope(getSize(t) * 8)])

proc binaryArith(p: BProc, e: PNode, d: var TLoc, op: TMagic) =
  const
    binArithTab: array[mAddF64..mXor, string] = [
      "(($4)($1) + ($4)($2))", # AddF64
      "(($4)($1) - ($4)($2))", # SubF64
      "(($4)($1) * ($4)($2))", # MulF64
      "(($4)($1) / ($4)($2))", # DivF64

      "($4)((NU$3)($1) >> (NU$3)($2))", # ShrI
      "($4)((NU$3)($1) << (NU$3)($2))", # ShlI
      "($4)($1 & $2)",      # BitandI
      "($4)($1 | $2)",      # BitorI
      "($4)($1 ^ $2)",      # BitxorI
      "(($1 <= $2) ? $1 : $2)", # MinI
      "(($1 >= $2) ? $1 : $2)", # MaxI
      "(($1 <= $2) ? $1 : $2)", # MinF64
      "(($1 >= $2) ? $1 : $2)", # MaxF64
      "($4)((NU$3)($1) + (NU$3)($2))", # AddU
      "($4)((NU$3)($1) - (NU$3)($2))", # SubU
      "($4)((NU$3)($1) * (NU$3)($2))", # MulU
      "($4)((NU$3)($1) / (NU$3)($2))", # DivU
      "($4)((NU$3)($1) % (NU$3)($2))", # ModU
      "($1 == $2)",           # EqI
      "($1 <= $2)",           # LeI
      "($1 < $2)",            # LtI
      "($1 == $2)",           # EqF64
      "($1 <= $2)",           # LeF64
      "($1 < $2)",            # LtF64
      "((NU$3)($1) <= (NU$3)($2))", # LeU
      "((NU$3)($1) < (NU$3)($2))", # LtU
      "((NU64)($1) <= (NU64)($2))", # LeU64
      "((NU64)($1) < (NU64)($2))", # LtU64
      "($1 == $2)",           # EqEnum
      "($1 <= $2)",           # LeEnum
      "($1 < $2)",            # LtEnum
      "((NU8)($1) == (NU8)($2))", # EqCh
      "((NU8)($1) <= (NU8)($2))", # LeCh
      "((NU8)($1) < (NU8)($2))", # LtCh
      "($1 == $2)",           # EqB
      "($1 <= $2)",           # LeB
      "($1 < $2)",            # LtB
      "($1 == $2)",           # EqRef
      "($1 == $2)",           # EqPtr
      "($1 <= $2)",           # LePtr
      "($1 < $2)",            # LtPtr
      "($1 != $2)"]           # Xor
  var
    a, b: TLoc
    s: BiggestInt
  assert(e.sons[1].typ != nil)
  assert(e.sons[2].typ != nil)
  initLocExpr(p, e.sons[1], a)
  initLocExpr(p, e.sons[2], b)
  # BUGFIX: cannot use result-type here, as it may be a boolean
  s = max(getSize(a.t), getSize(b.t)) * 8
  putIntoDest(p, d, e.typ,
              binArithTab[op] % [rdLoc(a), rdLoc(b), rope(s),
                                      getSimpleTypeDesc(p.module, e.typ)])

proc genEqProc(p: BProc, e: PNode, d: var TLoc) =
  var a, b: TLoc
  assert(e.sons[1].typ != nil)
  assert(e.sons[2].typ != nil)
  initLocExpr(p, e.sons[1], a)
  initLocExpr(p, e.sons[2], b)
  if a.t.skipTypes(abstractInst).callConv == ccClosure:
    putIntoDest(p, d, e.typ,
      "($1.ClPrc == $2.ClPrc && $1.ClEnv == $2.ClEnv)" % [rdLoc(a), rdLoc(b)])
  else:
    putIntoDest(p, d, e.typ, "($1 == $2)" % [rdLoc(a), rdLoc(b)])

proc genIsNil(p: BProc, e: PNode, d: var TLoc) =
  let t = skipTypes(e.sons[1].typ, abstractRange)
  if t.kind == tyProc and t.callConv == ccClosure:
    unaryExpr(p, e, d, "($1.ClPrc == 0)")
  else:
    unaryExpr(p, e, d, "($1 == 0)")

proc unaryArith(p: BProc, e: PNode, d: var TLoc, op: TMagic) =
  const
    unArithTab: array[mNot..mToBiggestInt, string] = ["!($1)", # Not
      "$1",                   # UnaryPlusI
      "($3)((NU$2) ~($1))",   # BitnotI
      "$1",                   # UnaryPlusF64
      "-($1)",                # UnaryMinusF64
      "($1 < 0? -($1) : ($1))", # AbsF64; BUGFIX: fabs() makes problems
                                # for Tiny C, so we don't use it
      "(($3)(NU)(NU8)($1))",  # mZe8ToI
      "(($3)(NU64)(NU8)($1))", # mZe8ToI64
      "(($3)(NU)(NU16)($1))", # mZe16ToI
      "(($3)(NU64)(NU16)($1))", # mZe16ToI64
      "(($3)(NU64)(NU32)($1))", # mZe32ToI64
      "(($3)(NU64)(NU)($1))", # mZeIToI64
      "(($3)(NU8)(NU)($1))", # ToU8
      "(($3)(NU16)(NU)($1))", # ToU16
      "(($3)(NU32)(NU64)($1))", # ToU32
      "((double) ($1))",      # ToFloat
      "((double) ($1))",      # ToBiggestFloat
      "float64ToInt32($1)",   # ToInt
      "float64ToInt64($1)"]   # ToBiggestInt
  var
    a: TLoc
    t: PType
  assert(e.sons[1].typ != nil)
  initLocExpr(p, e.sons[1], a)
  t = skipTypes(e.typ, abstractRange)
  putIntoDest(p, d, e.typ,
              unArithTab[op] % [rdLoc(a), rope(getSize(t) * 8),
                getSimpleTypeDesc(p.module, e.typ)])

proc isCppRef(p: BProc; typ: PType): bool {.inline.} =
  result = p.module.compileToCpp and
      skipTypes(typ, abstractInst).kind == tyVar and
      tfVarIsPtr notin skipTypes(typ, abstractInst).flags

proc genDeref(p: BProc, e: PNode, d: var TLoc; enforceDeref=false) =
  let mt = mapType(e.sons[0].typ)
  if mt in {ctArray, ctPtrToArray} and not enforceDeref:
    # XXX the amount of hacks for C's arrays is incredible, maybe we should
    # simply wrap them in a struct? --> Losing auto vectorization then?
    #if e[0].kind != nkBracketExpr:
    #  message(e.info, warnUser, "CAME HERE " & renderTree(e))
    expr(p, e.sons[0], d)
    if e.sons[0].typ.skipTypes(abstractInst).kind == tyRef:
      d.s = OnHeap
  else:
    var a: TLoc
    let typ = skipTypes(e.sons[0].typ, abstractInst)
    if typ.kind == tyVar and tfVarIsPtr notin typ.flags and p.module.compileToCpp and e.sons[0].kind == nkHiddenAddr:
      initLocExprSingleUse(p, e[0][0], d)
      return
    else:
      initLocExprSingleUse(p, e.sons[0], a)
    if d.k == locNone:
      # dest = *a;  <-- We do not know that 'dest' is on the heap!
      # It is completely wrong to set 'd.s' here, unless it's not yet
      # been assigned to.
      case typ.kind
      of tyRef:
        d.s = OnHeap
      of tyVar:
        d.s = OnUnknown
        if tfVarIsPtr notin typ.flags and p.module.compileToCpp and
            e.kind == nkHiddenDeref:
          putIntoDest(p, d, e.typ, rdLoc(a), a.s)
          return
      of tyPtr:
        d.s = OnUnknown         # BUGFIX!
      else:
        internalError(e.info, "genDeref " & $typ.kind)
    elif p.module.compileToCpp:
      if typ.kind == tyVar and tfVarIsPtr notin typ.flags and
           e.kind == nkHiddenDeref:
        putIntoDest(p, d, e.typ, rdLoc(a), a.s)
        return
    if enforceDeref and mt == ctPtrToArray:
      # we lie about the type for better C interop: 'ptr array[3,T]' is
      # translated to 'ptr T', but for deref'ing this produces wrong code.
      # See tmissingderef. So we get rid of the deref instead. The codegen
      # ends up using 'memcpy' for the array assignment,
      # so the '&' and '*' cancel out:
      putIntoDest(p, d, a.t.sons[0], rdLoc(a), a.s)
    else:
      putIntoDest(p, d, e.typ, "(*$1)" % [rdLoc(a)], a.s)

proc genAddr(p: BProc, e: PNode, d: var TLoc) =
  # careful  'addr(myptrToArray)' needs to get the ampersand:
  if e.sons[0].typ.skipTypes(abstractInst).kind in {tyRef, tyPtr}:
    var a: TLoc
    initLocExpr(p, e.sons[0], a)
    putIntoDest(p, d, e.typ, "&" & a.r, a.s)
    #Message(e.info, warnUser, "HERE NEW &")
  elif mapType(e.sons[0].typ) == ctArray or isCppRef(p, e.sons[0].typ):
    expr(p, e.sons[0], d)
  else:
    var a: TLoc
    initLocExpr(p, e.sons[0], a)
    putIntoDest(p, d, e.typ, addrLoc(a), a.s)

template inheritLocation(d: var TLoc, a: TLoc) =
  if d.k == locNone: d.s = a.s

proc genRecordFieldAux(p: BProc, e: PNode, d, a: var TLoc) =
  initLocExpr(p, e.sons[0], a)
  if e.sons[1].kind != nkSym: internalError(e.info, "genRecordFieldAux")
  d.inheritLocation(a)
  discard getTypeDesc(p.module, a.t) # fill the record's fields.loc

proc genTupleElem(p: BProc, e: PNode, d: var TLoc) =
  var
    a: TLoc
    i: int
  initLocExpr(p, e.sons[0], a)
  let tupType = a.t.skipTypes(abstractInst)
  assert tupType.kind == tyTuple
  d.inheritLocation(a)
  discard getTypeDesc(p.module, a.t) # fill the record's fields.loc
  var r = rdLoc(a)
  case e.sons[1].kind
  of nkIntLit..nkUInt64Lit: i = int(e.sons[1].intVal)
  else: internalError(e.info, "genTupleElem")
  addf(r, ".Field$1", [rope(i)])
  putIntoDest(p, d, tupType.sons[i], r, a.s)

proc lookupFieldAgain(p: BProc, ty: PType; field: PSym; r: var Rope): PSym =
  var ty = ty
  assert r != nil
  while ty != nil:
    ty = ty.skipTypes(skipPtrs)
    assert(ty.kind in {tyTuple, tyObject})
    result = lookupInRecord(ty.n, field.name)
    if result != nil: break
    if not p.module.compileToCpp: add(r, ".Sup")
    ty = ty.sons[0]
  if result == nil: internalError(field.info, "genCheckedRecordField")

proc genRecordField(p: BProc, e: PNode, d: var TLoc) =
  var a: TLoc
  genRecordFieldAux(p, e, d, a)
  var r = rdLoc(a)
  var f = e.sons[1].sym
  let ty = skipTypes(a.t, abstractInst)
  if ty.kind == tyTuple:
    # we found a unique tuple type which lacks field information
    # so we use Field$i
    addf(r, ".Field$1", [rope(f.position)])
    putIntoDest(p, d, f.typ, r, a.s)
  else:
    let field = lookupFieldAgain(p, ty, f, r)
    if field.loc.r == nil: fillObjectFields(p.module, ty)
    if field.loc.r == nil: internalError(e.info, "genRecordField 3 " & typeToString(ty))
    addf(r, ".$1", [field.loc.r])
    putIntoDest(p, d, field.typ, r, a.s)
  #d.s = a.s

proc genInExprAux(p: BProc, e: PNode, a, b, d: var TLoc)

proc genFieldCheck(p: BProc, e: PNode, obj: Rope, field: PSym;
                   origTy: PType) =
  var test, u, v: TLoc
  for i in countup(1, sonsLen(e) - 1):
    var it = e.sons[i]
    assert(it.kind in nkCallKinds)
    assert(it.sons[0].kind == nkSym)
    let op = it.sons[0].sym
    if op.magic == mNot: it = it.sons[1]
    let disc = it.sons[2].skipConv
    assert(disc.kind == nkSym)
    initLoc(test, locNone, it.typ, OnStack)
    initLocExpr(p, it.sons[1], u)
    var o = obj
    let d = lookupFieldAgain(p, origTy, disc.sym, o)
    initLoc(v, locExpr, d.typ, OnUnknown)
    v.r = o
    v.r.add(".")
    v.r.add(d.loc.r)
    genInExprAux(p, it, u, v, test)
    let id = nodeTableTestOrSet(p.module.dataCache,
                               newStrNode(nkStrLit, field.name.s), p.module.labels)
    let strLit = if id == p.module.labels: getStrLit(p.module, field.name.s)
                 else: p.module.tmpBase & rope(id)
    if op.magic == mNot:
      linefmt(p, cpsStmts,
              "if ($1) #raiseFieldError(((#NimStringDesc*) &$2));$n",
              rdLoc(test), strLit)
    else:
      linefmt(p, cpsStmts,
              "if (!($1)) #raiseFieldError(((#NimStringDesc*) &$2));$n",
              rdLoc(test), strLit)

proc genCheckedRecordField(p: BProc, e: PNode, d: var TLoc) =
  if optFieldCheck in p.options:
    var a: TLoc
    genRecordFieldAux(p, e.sons[0], d, a)
    let ty = skipTypes(a.t, abstractInst)
    var r = rdLoc(a)
    let f = e.sons[0].sons[1].sym
    let field = lookupFieldAgain(p, ty, f, r)
    if field.loc.r == nil: fillObjectFields(p.module, ty)
    if field.loc.r == nil:
      internalError(e.info, "genCheckedRecordField") # generate the checks:
    genFieldCheck(p, e, r, field, ty)
    add(r, rfmt(nil, ".$1", field.loc.r))
    putIntoDest(p, d, field.typ, r, a.s)
  else:
    genRecordField(p, e.sons[0], d)

proc genArrayElem(p: BProc, x, y: PNode, d: var TLoc) =
  var a, b: TLoc
  initLocExpr(p, x, a)
  initLocExpr(p, y, b)
  var ty = skipTypes(skipTypes(a.t, abstractVarRange), abstractPtrs)
  var first = intLiteral(firstOrd(ty))
  # emit range check:
  if optBoundsCheck in p.options and tfUncheckedArray notin ty.flags:
    if not isConstExpr(y):
      # semantic pass has already checked for const index expressions
      if firstOrd(ty) == 0:
        if (firstOrd(b.t) < firstOrd(ty)) or (lastOrd(b.t) > lastOrd(ty)):
          linefmt(p, cpsStmts, "if ((NU)($1) > (NU)($2)) #raiseIndexError();$n",
                  rdCharLoc(b), intLiteral(lastOrd(ty)))
      else:
        linefmt(p, cpsStmts, "if ($1 < $2 || $1 > $3) #raiseIndexError();$n",
                rdCharLoc(b), first, intLiteral(lastOrd(ty)))
    else:
      let idx = getOrdValue(y)
      if idx < firstOrd(ty) or idx > lastOrd(ty):
        localError(x.info, errIndexOutOfBounds)
  d.inheritLocation(a)
  putIntoDest(p, d, elemType(skipTypes(ty, abstractVar)),
              rfmt(nil, "$1[($2)- $3]", rdLoc(a), rdCharLoc(b), first), a.s)

proc genCStringElem(p: BProc, x, y: PNode, d: var TLoc) =
  var a, b: TLoc
  initLocExpr(p, x, a)
  initLocExpr(p, y, b)
  var ty = skipTypes(a.t, abstractVarRange)
  if d.k == locNone: d.s = a.s
  putIntoDest(p, d, elemType(skipTypes(ty, abstractVar)),
              rfmt(nil, "$1[$2]", rdLoc(a), rdCharLoc(b)), a.s)

proc genOpenArrayElem(p: BProc, x, y: PNode, d: var TLoc) =
  var a, b: TLoc
  initLocExpr(p, x, a)
  initLocExpr(p, y, b) # emit range check:
  if optBoundsCheck in p.options:
    linefmt(p, cpsStmts, "if ((NU)($1) >= (NU)($2Len0)) #raiseIndexError();$n",
            rdLoc(b), rdLoc(a)) # BUGFIX: ``>=`` and not ``>``!
  if d.k == locNone: d.s = a.s
  putIntoDest(p, d, elemType(skipTypes(a.t, abstractVar)),
              rfmt(nil, "$1[$2]", rdLoc(a), rdCharLoc(b)), a.s)

proc genSeqElem(p: BProc, x, y: PNode, d: var TLoc) =
  var a, b: TLoc
  initLocExpr(p, x, a)
  initLocExpr(p, y, b)
  var ty = skipTypes(a.t, abstractVarRange)
  if ty.kind in {tyRef, tyPtr}:
    ty = skipTypes(ty.lastSon, abstractVarRange) # emit range check:
  if optBoundsCheck in p.options:
    if ty.kind == tyString:
      linefmt(p, cpsStmts,
           "if ((NU)($1) > (NU)($2->$3)) #raiseIndexError();$n",
           rdLoc(b), rdLoc(a), lenField(p))
    else:
      linefmt(p, cpsStmts,
           "if ((NU)($1) >= (NU)($2->$3)) #raiseIndexError();$n",
           rdLoc(b), rdLoc(a), lenField(p))
  if d.k == locNone: d.s = OnHeap
  if skipTypes(a.t, abstractVar).kind in {tyRef, tyPtr}:
    a.r = rfmt(nil, "(*$1)", a.r)
  putIntoDest(p, d, elemType(skipTypes(a.t, abstractVar)),
              rfmt(nil, "$1->data[$2]", rdLoc(a), rdCharLoc(b)), a.s)

proc genBracketExpr(p: BProc; n: PNode; d: var TLoc) =
  var ty = skipTypes(n.sons[0].typ, abstractVarRange)
  if ty.kind in {tyRef, tyPtr}: ty = skipTypes(ty.lastSon, abstractVarRange)
  case ty.kind
  of tyArray: genArrayElem(p, n.sons[0], n.sons[1], d)
  of tyOpenArray, tyVarargs: genOpenArrayElem(p, n.sons[0], n.sons[1], d)
  of tySequence, tyString: genSeqElem(p, n.sons[0], n.sons[1], d)
  of tyCString: genCStringElem(p, n.sons[0], n.sons[1], d)
  of tyTuple: genTupleElem(p, n, d)
  else: internalError(n.info, "expr(nkBracketExpr, " & $ty.kind & ')')

proc genAndOr(p: BProc, e: PNode, d: var TLoc, m: TMagic) =
  # how to generate code?
  #  'expr1 and expr2' becomes:
  #     result = expr1
  #     fjmp result, end
  #     result = expr2
  #  end:
  #  ... (result computed)
  # BUGFIX:
  #   a = b or a
  # used to generate:
  # a = b
  # if a: goto end
  # a = a
  # end:
  # now it generates:
  # tmp = b
  # if tmp: goto end
  # tmp = a
  # end:
  # a = tmp
  var
    L: TLabel
    tmp: TLoc
  getTemp(p, e.typ, tmp)      # force it into a temp!
  inc p.splitDecls
  expr(p, e.sons[1], tmp)
  L = getLabel(p)
  if m == mOr:
    lineF(p, cpsStmts, "if ($1) goto $2;$n", [rdLoc(tmp), L])
  else:
    lineF(p, cpsStmts, "if (!($1)) goto $2;$n", [rdLoc(tmp), L])
  expr(p, e.sons[2], tmp)
  fixLabel(p, L)
  if d.k == locNone:
    d = tmp
  else:
    genAssignment(p, d, tmp, {}) # no need for deep copying
  dec p.splitDecls

proc genEcho(p: BProc, n: PNode) =
  # this unusal way of implementing it ensures that e.g. ``echo("hallo", 45)``
  # is threadsafe.
  internalAssert n.kind == nkBracket
  discard lists.includeStr(p.module.headerFiles, "<stdio.h>")
  var args: Rope = nil
  var a: TLoc
  for i in countup(0, n.len-1):
    if n.sons[i].skipConv.kind == nkNilLit:
      add(args, ", \"nil\"")
    else:
      initLocExpr(p, n.sons[i], a)
      addf(args, ", $1? ($1)->data:\"nil\"", [rdLoc(a)])
  linefmt(p, cpsStmts, "printf($1$2);$n",
          makeCString(repeat("%s", n.len) & tnl), args)
  linefmt(p, cpsStmts, "fflush(stdout);$n")

proc gcUsage(n: PNode) =
  if gSelectedGC == gcNone: message(n.info, warnGcMem, n.renderTree)

proc genStrConcat(p: BProc, e: PNode, d: var TLoc) =
  #   <Nim code>
  #   s = 'Hello ' & name & ', how do you feel?' & 'z'
  #
  #   <generated C code>
  #  {
  #    string tmp0;
  #    ...
  #    tmp0 = rawNewString(6 + 17 + 1 + s2->len);
  #    // we cannot generate s = rawNewString(...) here, because
  #    // ``s`` may be used on the right side of the expression
  #    appendString(tmp0, strlit_1);
  #    appendString(tmp0, name);
  #    appendString(tmp0, strlit_2);
  #    appendChar(tmp0, 'z');
  #    asgn(s, tmp0);
  #  }
  var a, tmp: TLoc
  getTemp(p, e.typ, tmp)
  var L = 0
  var appends: Rope = nil
  var lens: Rope = nil
  for i in countup(0, sonsLen(e) - 2):
    # compute the length expression:
    initLocExpr(p, e.sons[i + 1], a)
    if skipTypes(e.sons[i + 1].typ, abstractVarRange).kind == tyChar:
      inc(L)
      add(appends, rfmt(p.module, "#appendChar($1, $2);$n", tmp.r, rdLoc(a)))
    else:
      if e.sons[i + 1].kind in {nkStrLit..nkTripleStrLit}:
        inc(L, len(e.sons[i + 1].strVal))
      else:
        addf(lens, "$1->$2 + ", [rdLoc(a), lenField(p)])
      add(appends, rfmt(p.module, "#appendString($1, $2);$n", tmp.r, rdLoc(a)))
  linefmt(p, cpsStmts, "$1 = #rawNewString($2$3);$n", tmp.r, lens, rope(L))
  add(p.s(cpsStmts), appends)
  if d.k == locNone:
    d = tmp
  else:
    genAssignment(p, d, tmp, {}) # no need for deep copying
  gcUsage(e)

proc genStrAppend(p: BProc, e: PNode, d: var TLoc) =
  #  <Nim code>
  #  s &= 'Hello ' & name & ', how do you feel?' & 'z'
  #  // BUG: what if s is on the left side too?
  #  <generated C code>
  #  {
  #    s = resizeString(s, 6 + 17 + 1 + name->len);
  #    appendString(s, strlit_1);
  #    appendString(s, name);
  #    appendString(s, strlit_2);
  #    appendChar(s, 'z');
  #  }
  var
    a, dest: TLoc
    appends, lens: Rope
  assert(d.k == locNone)
  var L = 0
  initLocExpr(p, e.sons[1], dest)
  for i in countup(0, sonsLen(e) - 3):
    # compute the length expression:
    initLocExpr(p, e.sons[i + 2], a)
    if skipTypes(e.sons[i + 2].typ, abstractVarRange).kind == tyChar:
      inc(L)
      add(appends, rfmt(p.module, "#appendChar($1, $2);$n",
                        rdLoc(dest), rdLoc(a)))
    else:
      if e.sons[i + 2].kind in {nkStrLit..nkTripleStrLit}:
        inc(L, len(e.sons[i + 2].strVal))
      else:
        addf(lens, "$1->$2 + ", [rdLoc(a), lenField(p)])
      add(appends, rfmt(p.module, "#appendString($1, $2);$n",
                        rdLoc(dest), rdLoc(a)))
  linefmt(p, cpsStmts, "$1 = #resizeString($1, $2$3);$n",
          rdLoc(dest), lens, rope(L))
  add(p.s(cpsStmts), appends)
  gcUsage(e)

proc genSeqElemAppend(p: BProc, e: PNode, d: var TLoc) =
  # seq &= x  -->
  #    seq = (typeof seq) incrSeq(&seq->Sup, sizeof(x));
  #    seq->data[seq->len-1] = x;
  let seqAppendPattern = if not p.module.compileToCpp:
                           "$1 = ($2) #incrSeqV2(&($1)->Sup, sizeof($3));$n"
                         else:
                           "$1 = ($2) #incrSeqV2($1, sizeof($3));$n"
  var a, b, dest: TLoc
  initLocExpr(p, e.sons[1], a)
  initLocExpr(p, e.sons[2], b)
  let bt = skipTypes(e.sons[2].typ, {tyVar})
  lineCg(p, cpsStmts, seqAppendPattern, [
      rdLoc(a),
      getTypeDesc(p.module, e.sons[1].typ),
      getTypeDesc(p.module, bt)])
  #if bt != b.t:
  #  echo "YES ", e.info, " new: ", typeToString(bt), " old: ", typeToString(b.t)
  initLoc(dest, locExpr, bt, OnHeap)
  dest.r = rfmt(nil, "$1->data[$1->$2]", rdLoc(a), lenField(p))
  genAssignment(p, dest, b, {needToCopy, afDestIsNil})
  lineCg(p, cpsStmts, "++$1->$2;$n", rdLoc(a), lenField(p))
  gcUsage(e)

proc genReset(p: BProc, n: PNode) =
  var a: TLoc
  initLocExpr(p, n.sons[1], a)
  linefmt(p, cpsStmts, "#genericReset((void*)$1, $2);$n",
          addrLoc(a), genTypeInfo(p.module, skipTypes(a.t, {tyVar})))

proc rawGenNew(p: BProc, a: TLoc, sizeExpr: Rope) =
  var sizeExpr = sizeExpr
  let typ = a.t
  var b: TLoc
  initLoc(b, locExpr, a.t, OnHeap)
  let refType = typ.skipTypes(abstractInst)
  assert refType.kind == tyRef
  let bt = refType.lastSon
  if sizeExpr.isNil:
    sizeExpr = "sizeof($1)" %
        [getTypeDesc(p.module, bt)]
  let args = [getTypeDesc(p.module, typ),
              genTypeInfo(p.module, typ),
              sizeExpr]
  if a.s == OnHeap and usesNativeGC():
    # use newObjRC1 as an optimization
    if canFormAcycle(a.t):
      linefmt(p, cpsStmts, "if ($1) #nimGCunref($1);$n", a.rdLoc)
    else:
      linefmt(p, cpsStmts, "if ($1) #nimGCunrefNoCycle($1);$n", a.rdLoc)
    b.r = ropecg(p.module, "($1) #newObjRC1($2, $3)", args)
    linefmt(p, cpsStmts, "$1 = $2;$n", a.rdLoc, b.rdLoc)
  else:
    b.r = ropecg(p.module, "($1) #newObj($2, $3)", args)
    genAssignment(p, a, b, {})  # set the object type:
  genObjectInit(p, cpsStmts, bt, a, false)

proc genNew(p: BProc, e: PNode) =
  var a: TLoc
  initLocExpr(p, e.sons[1], a)
  # 'genNew' also handles 'unsafeNew':
  if e.len == 3:
    var se: TLoc
    initLocExpr(p, e.sons[2], se)
    rawGenNew(p, a, se.rdLoc)
  else:
    rawGenNew(p, a, nil)
  gcUsage(e)

proc genNewSeqAux(p: BProc, dest: TLoc, length: Rope) =
  let seqtype = skipTypes(dest.t, abstractVarRange)
  let args = [getTypeDesc(p.module, seqtype),
              genTypeInfo(p.module, seqtype), length]
  var call: TLoc
  initLoc(call, locExpr, dest.t, OnHeap)
  if dest.s == OnHeap and usesNativeGC():
    if canFormAcycle(dest.t):
      linefmt(p, cpsStmts, "if ($1) #nimGCunref($1);$n", dest.rdLoc)
    else:
      linefmt(p, cpsStmts, "if ($1) #nimGCunrefNoCycle($1);$n", dest.rdLoc)
    call.r = ropecg(p.module, "($1) #newSeqRC1($2, $3)", args)
    linefmt(p, cpsStmts, "$1 = $2;$n", dest.rdLoc, call.rdLoc)
  else:
    call.r = ropecg(p.module, "($1) #newSeq($2, $3)", args)
    genAssignment(p, dest, call, {})

proc genNewSeq(p: BProc, e: PNode) =
  var a, b: TLoc
  initLocExpr(p, e.sons[1], a)
  initLocExpr(p, e.sons[2], b)
  genNewSeqAux(p, a, b.rdLoc)
  gcUsage(e)

proc genNewSeqOfCap(p: BProc; e: PNode; d: var TLoc) =
  let seqtype = skipTypes(e.typ, abstractVarRange)
  var a: TLoc
  initLocExpr(p, e.sons[1], a)
  putIntoDest(p, d, e.typ, ropecg(p.module,
              "($1)#nimNewSeqOfCap($2, $3)", [
              getTypeDesc(p.module, seqtype),
              genTypeInfo(p.module, seqtype), a.rdLoc]))
  gcUsage(e)

proc genConstExpr(p: BProc, n: PNode): Rope
proc handleConstExpr(p: BProc, n: PNode, d: var TLoc): bool =
  if d.k == locNone and n.len > ord(n.kind == nkObjConstr) and n.isDeepConstExpr:
    let t = n.typ
    discard getTypeDesc(p.module, t) # so that any fields are initialized
    let id = nodeTableTestOrSet(p.module.dataCache, n, p.module.labels)
    fillLoc(d, locData, t, p.module.tmpBase & rope(id), OnStatic)
    if id == p.module.labels:
      # expression not found in the cache:
      inc(p.module.labels)
      addf(p.module.s[cfsData], "NIM_CONST $1 $2 = $3;$n",
           [getTypeDesc(p.module, t), d.r, genConstExpr(p, n)])
    result = true
  else:
    result = false

proc genObjConstr(p: BProc, e: PNode, d: var TLoc) =
  #echo rendertree e, " ", e.isDeepConstExpr
  if handleConstExpr(p, e, d): return
  var tmp: TLoc
  var t = e.typ.skipTypes(abstractInst)
  getTemp(p, t, tmp)
  let isRef = t.kind == tyRef
  var r = rdLoc(tmp)
  if isRef:
    rawGenNew(p, tmp, nil)
    t = t.lastSon.skipTypes(abstractInst)
    r = "(*$1)" % [r]
    gcUsage(e)
  else:
    constructLoc(p, tmp)
  discard getTypeDesc(p.module, t)
  let ty = getUniqueType(t)
  for i in 1 .. <e.len:
    let it = e.sons[i]
    var tmp2: TLoc
    tmp2.r = r
    let field = lookupFieldAgain(p, ty, it.sons[0].sym, tmp2.r)
    if field.loc.r == nil: fillObjectFields(p.module, ty)
    if field.loc.r == nil: internalError(e.info, "genObjConstr")
    if it.len == 3 and optFieldCheck in p.options:
      genFieldCheck(p, it.sons[2], r, field, ty)
    add(tmp2.r, ".")
    add(tmp2.r, field.loc.r)
    tmp2.k = locTemp
    tmp2.t = field.loc.t
    tmp2.s = if isRef: OnHeap else: OnStack
    expr(p, it.sons[1], tmp2)

  if d.k == locNone:
    d = tmp
  else:
    genAssignment(p, d, tmp, {})

proc genSeqConstr(p: BProc, t: PNode, d: var TLoc) =
  var arr: TLoc
  if d.k == locNone:
    getTemp(p, t.typ, d)
  # generate call to newSeq before adding the elements per hand:
  genNewSeqAux(p, d, intLiteral(sonsLen(t)))
  for i in countup(0, sonsLen(t) - 1):
    initLoc(arr, locExpr, elemType(skipTypes(t.typ, typedescInst)), OnHeap)
    arr.r = rfmt(nil, "$1->data[$2]", rdLoc(d), intLiteral(i))
    arr.s = OnHeap            # we know that sequences are on the heap
    expr(p, t.sons[i], arr)
  gcUsage(t)

proc genArrToSeq(p: BProc, t: PNode, d: var TLoc) =
  var elem, a, arr: TLoc
  if t.kind == nkBracket:
    t.sons[1].typ = t.typ
    genSeqConstr(p, t.sons[1], d)
    return
  if d.k == locNone:
    getTemp(p, t.typ, d)
  # generate call to newSeq before adding the elements per hand:
  var L = int(lengthOrd(t.sons[1].typ))

  genNewSeqAux(p, d, intLiteral(L))
  initLocExpr(p, t.sons[1], a)
  for i in countup(0, L - 1):
    initLoc(elem, locExpr, elemType(skipTypes(t.typ, abstractInst)), OnHeap)
    elem.r = rfmt(nil, "$1->data[$2]", rdLoc(d), intLiteral(i))
    elem.s = OnHeap # we know that sequences are on the heap
    initLoc(arr, locExpr, elemType(skipTypes(t.sons[1].typ, abstractInst)), a.s)
    arr.r = rfmt(nil, "$1[$2]", rdLoc(a), intLiteral(i))
    genAssignment(p, elem, arr, {afDestIsNil, needToCopy})

proc genNewFinalize(p: BProc, e: PNode) =
  var
    a, b, f: TLoc
    refType, bt: PType
    ti: Rope
  refType = skipTypes(e.sons[1].typ, abstractVarRange)
  initLocExpr(p, e.sons[1], a)
  initLocExpr(p, e.sons[2], f)
  initLoc(b, locExpr, a.t, OnHeap)
  ti = genTypeInfo(p.module, refType)
  addf(p.module.s[cfsTypeInit3], "$1->finalizer = (void*)$2;$n", [ti, rdLoc(f)])
  b.r = ropecg(p.module, "($1) #newObj($2, sizeof($3))", [
      getTypeDesc(p.module, refType),
      ti, getTypeDesc(p.module, skipTypes(refType.lastSon, abstractRange))])
  genAssignment(p, a, b, {})  # set the object type:
  bt = skipTypes(refType.lastSon, abstractRange)
  genObjectInit(p, cpsStmts, bt, a, false)
  gcUsage(e)

proc genOfHelper(p: BProc; dest: PType; a: Rope): Rope =
  # unfortunately 'genTypeInfo' sets tfObjHasKids as a side effect, so we
  # have to call it here first:
  let ti = genTypeInfo(p.module, dest)
  if tfFinal in dest.flags or (objHasKidsValid in p.module.flags and
                               tfObjHasKids notin dest.flags):
    result = "$1.m_type == $2" % [a, ti]
  else:
    discard cgsym(p.module, "TNimType")
    inc p.module.labels
    let cache = "Nim_OfCheck_CACHE" & p.module.labels.rope
    addf(p.module.s[cfsVars], "static TNimType* $#[2];$n", [cache])
    result = rfmt(p.module, "#isObjWithCache($#.m_type, $#, $#)", a, ti, cache)
  when false:
    # former version:
    result = rfmt(p.module, "#isObj($1.m_type, $2)",
                  a, genTypeInfo(p.module, dest))

proc genOf(p: BProc, x: PNode, typ: PType, d: var TLoc) =
  var a: TLoc
  initLocExpr(p, x, a)
  var dest = skipTypes(typ, typedescPtrs)
  var r = rdLoc(a)
  var nilCheck: Rope = nil
  var t = skipTypes(a.t, abstractInst)
  while t.kind in {tyVar, tyPtr, tyRef}:
    if t.kind != tyVar: nilCheck = r
    if t.kind != tyVar or not p.module.compileToCpp:
      r = rfmt(nil, "(*$1)", r)
    t = skipTypes(t.lastSon, typedescInst)
  if not p.module.compileToCpp:
    while t.kind == tyObject and t.sons[0] != nil:
      add(r, ~".Sup")
      t = skipTypes(t.sons[0], skipPtrs)
  if isObjLackingTypeField(t):
    globalError(x.info, errGenerated,
      "no 'of' operator available for pure objects")
  if nilCheck != nil:
    r = rfmt(p.module, "(($1) && ($2))", nilCheck, genOfHelper(p, dest, r))
  else:
    r = rfmt(p.module, "($1)", genOfHelper(p, dest, r))
  putIntoDest(p, d, getSysType(tyBool), r, a.s)

proc genOf(p: BProc, n: PNode, d: var TLoc) =
  genOf(p, n.sons[1], n.sons[2].typ, d)

proc genRepr(p: BProc, e: PNode, d: var TLoc) =
  var a: TLoc
  initLocExpr(p, e.sons[1], a)
  var t = skipTypes(e.sons[1].typ, abstractVarRange)
  case t.kind
  of tyInt..tyInt64, tyUInt..tyUInt64:
    putIntoDest(p, d, e.typ,
                ropecg(p.module, "#reprInt((NI64)$1)", [rdLoc(a)]), a.s)
  of tyFloat..tyFloat128:
    putIntoDest(p, d, e.typ, ropecg(p.module, "#reprFloat($1)", [rdLoc(a)]), a.s)
  of tyBool:
    putIntoDest(p, d, e.typ, ropecg(p.module, "#reprBool($1)", [rdLoc(a)]), a.s)
  of tyChar:
    putIntoDest(p, d, e.typ, ropecg(p.module, "#reprChar($1)", [rdLoc(a)]), a.s)
  of tyEnum, tyOrdinal:
    putIntoDest(p, d, e.typ,
                ropecg(p.module, "#reprEnum((NI)$1, $2)", [
                rdLoc(a), genTypeInfo(p.module, t)]), a.s)
  of tyString:
    putIntoDest(p, d, e.typ, ropecg(p.module, "#reprStr($1)", [rdLoc(a)]), a.s)
  of tySet:
    putIntoDest(p, d, e.typ, ropecg(p.module, "#reprSet($1, $2)", [
                addrLoc(a), genTypeInfo(p.module, t)]), a.s)
  of tyOpenArray, tyVarargs:
    var b: TLoc
    case a.t.kind
    of tyOpenArray, tyVarargs:
      putIntoDest(p, b, e.typ, "$1, $1Len0" % [rdLoc(a)], a.s)
    of tyString, tySequence:
      putIntoDest(p, b, e.typ,
                  "$1->data, $1->$2" % [rdLoc(a), lenField(p)], a.s)
    of tyArray:
      putIntoDest(p, b, e.typ,
                  "$1, $2" % [rdLoc(a), rope(lengthOrd(a.t))], a.s)
    else: internalError(e.sons[0].info, "genRepr()")
    putIntoDest(p, d, e.typ,
        ropecg(p.module, "#reprOpenArray($1, $2)", [rdLoc(b),
        genTypeInfo(p.module, elemType(t))]), a.s)
  of tyCString, tyArray, tyRef, tyPtr, tyPointer, tyNil, tySequence:
    putIntoDest(p, d, e.typ,
                ropecg(p.module, "#reprAny($1, $2)", [
                rdLoc(a), genTypeInfo(p.module, t)]), a.s)
  of tyEmpty, tyVoid:
    localError(e.info, "'repr' doesn't support 'void' type")
  else:
    putIntoDest(p, d, e.typ, ropecg(p.module, "#reprAny($1, $2)",
                                   [addrLoc(a), genTypeInfo(p.module, t)]), a.s)
  gcUsage(e)

proc genGetTypeInfo(p: BProc, e: PNode, d: var TLoc) =
  let t = e.sons[1].typ
  putIntoDest(p, d, e.typ, genTypeInfo(p.module, t))

proc genDollar(p: BProc, n: PNode, d: var TLoc, frmt: string) =
  var a: TLoc
  initLocExpr(p, n.sons[1], a)
  a.r = ropecg(p.module, frmt, [rdLoc(a)])
  if d.k == locNone: getTemp(p, n.typ, d)
  genAssignment(p, d, a, {})
  gcUsage(n)

proc genArrayLen(p: BProc, e: PNode, d: var TLoc, op: TMagic) =
  var a = e.sons[1]
  if a.kind == nkHiddenAddr: a = a.sons[0]
  let typ = skipTypes(a.typ, abstractVar)
  case typ.kind
  of tyOpenArray, tyVarargs:
    if op == mHigh: unaryExpr(p, e, d, "($1Len0-1)")
    else: unaryExpr(p, e, d, "$1Len0")
  of tyCString:
    useStringh(p.module)
    if op == mHigh: unaryExpr(p, e, d, "($1 ? (strlen($1)-1) : -1)")
    else: unaryExpr(p, e, d, "($1 ? strlen($1) : 0)")
  of tyString, tySequence:
    if not p.module.compileToCpp:
      if op == mHigh: unaryExpr(p, e, d, "($1 ? ($1->Sup.len-1) : -1)")
      else: unaryExpr(p, e, d, "($1 ? $1->Sup.len : 0)")
    else:
      if op == mHigh: unaryExpr(p, e, d, "($1 ? ($1->len-1) : -1)")
      else: unaryExpr(p, e, d, "($1 ? $1->len : 0)")
  of tyArray:
    # YYY: length(sideeffect) is optimized away incorrectly?
    if op == mHigh: putIntoDest(p, d, e.typ, rope(lastOrd(typ)))
    else: putIntoDest(p, d, e.typ, rope(lengthOrd(typ)))
  else: internalError(e.info, "genArrayLen()")

proc genSetLengthSeq(p: BProc, e: PNode, d: var TLoc) =
  var a, b: TLoc
  assert(d.k == locNone)
  initLocExpr(p, e.sons[1], a)
  initLocExpr(p, e.sons[2], b)
  let t = skipTypes(e.sons[1].typ, {tyVar})
  let setLenPattern = if not p.module.compileToCpp:
      "$1 = ($3) #setLengthSeq(&($1)->Sup, sizeof($4), $2);$n"
    else:
      "$1 = ($3) #setLengthSeq($1, sizeof($4), $2);$n"

  lineCg(p, cpsStmts, setLenPattern, [
      rdLoc(a), rdLoc(b), getTypeDesc(p.module, t),
      getTypeDesc(p.module, t.skipTypes(abstractInst).sons[0])])
  gcUsage(e)

proc genSetLengthStr(p: BProc, e: PNode, d: var TLoc) =
  binaryStmt(p, e, d, "$1 = #setLengthStr($1, $2);$n")
  gcUsage(e)

proc genSwap(p: BProc, e: PNode, d: var TLoc) =
  # swap(a, b) -->
  # temp = a
  # a = b
  # b = temp
  var a, b, tmp: TLoc
  getTemp(p, skipTypes(e.sons[1].typ, abstractVar), tmp)
  initLocExpr(p, e.sons[1], a) # eval a
  initLocExpr(p, e.sons[2], b) # eval b
  genAssignment(p, tmp, a, {})
  genAssignment(p, a, b, {})
  genAssignment(p, b, tmp, {})

proc rdSetElemLoc(a: TLoc, setType: PType): Rope =
  # read a location of an set element; it may need a subtraction operation
  # before the set operation
  result = rdCharLoc(a)
  assert(setType.kind == tySet)
  if firstOrd(setType) != 0:
    result = "($1- $2)" % [result, rope(firstOrd(setType))]

proc fewCmps(s: PNode): bool =
  # this function estimates whether it is better to emit code
  # for constructing the set or generating a bunch of comparisons directly
  if s.kind != nkCurly: internalError(s.info, "fewCmps")
  if (getSize(s.typ) <= platform.intSize) and (nfAllConst in s.flags):
    result = false            # it is better to emit the set generation code
  elif elemType(s.typ).kind in {tyInt, tyInt16..tyInt64}:
    result = true             # better not emit the set if int is basetype!
  else:
    result = sonsLen(s) <= 8  # 8 seems to be a good value

proc binaryExprIn(p: BProc, e: PNode, a, b, d: var TLoc, frmt: string) =
  putIntoDest(p, d, e.typ, frmt % [rdLoc(a), rdSetElemLoc(b, a.t)])

proc genInExprAux(p: BProc, e: PNode, a, b, d: var TLoc) =
  case int(getSize(skipTypes(e.sons[1].typ, abstractVar)))
  of 1: binaryExprIn(p, e, a, b, d, "(($1 &(1U<<((NU)($2)&7U)))!=0)")
  of 2: binaryExprIn(p, e, a, b, d, "(($1 &(1U<<((NU)($2)&15U)))!=0)")
  of 4: binaryExprIn(p, e, a, b, d, "(($1 &(1U<<((NU)($2)&31U)))!=0)")
  of 8: binaryExprIn(p, e, a, b, d, "(($1 &((NU64)1<<((NU)($2)&63U)))!=0)")
  else: binaryExprIn(p, e, a, b, d, "(($1[(NU)($2)>>3] &(1U<<((NU)($2)&7U)))!=0)")

proc binaryStmtInExcl(p: BProc, e: PNode, d: var TLoc, frmt: string) =
  var a, b: TLoc
  assert(d.k == locNone)
  initLocExpr(p, e.sons[1], a)
  initLocExpr(p, e.sons[2], b)
  lineF(p, cpsStmts, frmt, [rdLoc(a), rdSetElemLoc(b, a.t)])

proc genInOp(p: BProc, e: PNode, d: var TLoc) =
  var a, b, x, y: TLoc
  if (e.sons[1].kind == nkCurly) and fewCmps(e.sons[1]):
    # a set constructor but not a constant set:
    # do not emit the set, but generate a bunch of comparisons; and if we do
    # so, we skip the unnecessary range check: This is a semantical extension
    # that code now relies on. :-/ XXX
    let ea = if e.sons[2].kind in {nkChckRange, nkChckRange64}:
               e.sons[2].sons[0]
             else:
               e.sons[2]
    initLocExpr(p, ea, a)
    initLoc(b, locExpr, e.typ, OnUnknown)
    b.r = rope("(")
    var length = sonsLen(e.sons[1])
    for i in countup(0, length - 1):
      if e.sons[1].sons[i].kind == nkRange:
        initLocExpr(p, e.sons[1].sons[i].sons[0], x)
        initLocExpr(p, e.sons[1].sons[i].sons[1], y)
        addf(b.r, "$1 >= $2 && $1 <= $3",
             [rdCharLoc(a), rdCharLoc(x), rdCharLoc(y)])
      else:
        initLocExpr(p, e.sons[1].sons[i], x)
        addf(b.r, "$1 == $2", [rdCharLoc(a), rdCharLoc(x)])
      if i < length - 1: add(b.r, " || ")
    add(b.r, ")")
    putIntoDest(p, d, e.typ, b.r)
  else:
    assert(e.sons[1].typ != nil)
    assert(e.sons[2].typ != nil)
    initLocExpr(p, e.sons[1], a)
    initLocExpr(p, e.sons[2], b)
    genInExprAux(p, e, a, b, d)

proc genSetOp(p: BProc, e: PNode, d: var TLoc, op: TMagic) =
  const
    lookupOpr: array[mLeSet..mSymDiffSet, string] = [
      "for ($1 = 0; $1 < $2; $1++) { $n" &
        "  $3 = (($4[$1] & ~ $5[$1]) == 0);$n" &
        "  if (!$3) break;}$n", "for ($1 = 0; $1 < $2; $1++) { $n" &
        "  $3 = (($4[$1] & ~ $5[$1]) == 0);$n" & "  if (!$3) break;}$n" &
        "if ($3) $3 = (memcmp($4, $5, $2) != 0);$n",
      "&", "|", "& ~", "^"]
  var a, b, i: TLoc
  var setType = skipTypes(e.sons[1].typ, abstractVar)
  var size = int(getSize(setType))
  case size
  of 1, 2, 4, 8:
    case op
    of mIncl:
      var ts = "NU" & $(size * 8)
      binaryStmtInExcl(p, e, d,
          "$1 |= ((" & ts & ")1)<<(($2)%(sizeof(" & ts & ")*8));$n")
    of mExcl:
      var ts = "NU" & $(size * 8)
      binaryStmtInExcl(p, e, d, "$1 &= ~(((" & ts & ")1) << (($2) % (sizeof(" &
          ts & ")*8)));$n")
    of mCard:
      if size <= 4: unaryExprChar(p, e, d, "#countBits32($1)")
      else: unaryExprChar(p, e, d, "#countBits64($1)")
    of mLtSet: binaryExprChar(p, e, d, "(($1 & ~ $2 ==0)&&($1 != $2))")
    of mLeSet: binaryExprChar(p, e, d, "(($1 & ~ $2)==0)")
    of mEqSet: binaryExpr(p, e, d, "($1 == $2)")
    of mMulSet: binaryExpr(p, e, d, "($1 & $2)")
    of mPlusSet: binaryExpr(p, e, d, "($1 | $2)")
    of mMinusSet: binaryExpr(p, e, d, "($1 & ~ $2)")
    of mSymDiffSet: binaryExpr(p, e, d, "($1 ^ $2)")
    of mInSet:
      genInOp(p, e, d)
    else: internalError(e.info, "genSetOp()")
  else:
    case op
    of mIncl: binaryStmtInExcl(p, e, d, "$1[(NU)($2)>>3] |=(1U<<($2&7U));$n")
    of mExcl: binaryStmtInExcl(p, e, d, "$1[(NU)($2)>>3] &= ~(1U<<($2&7U));$n")
    of mCard: unaryExprChar(p, e, d, "#cardSet($1, " & $size & ')')
    of mLtSet, mLeSet:
      getTemp(p, getSysType(tyInt), i) # our counter
      initLocExpr(p, e.sons[1], a)
      initLocExpr(p, e.sons[2], b)
      if d.k == locNone: getTemp(p, getSysType(tyBool), d)
      lineF(p, cpsStmts, lookupOpr[op],
           [rdLoc(i), rope(size), rdLoc(d), rdLoc(a), rdLoc(b)])
    of mEqSet:
      useStringh(p.module)
      binaryExprChar(p, e, d, "(memcmp($1, $2, " & $(size) & ")==0)")
    of mMulSet, mPlusSet, mMinusSet, mSymDiffSet:
      # we inline the simple for loop for better code generation:
      getTemp(p, getSysType(tyInt), i) # our counter
      initLocExpr(p, e.sons[1], a)
      initLocExpr(p, e.sons[2], b)
      if d.k == locNone: getTemp(p, a.t, d)
      lineF(p, cpsStmts,
           "for ($1 = 0; $1 < $2; $1++) $n" &
           "  $3[$1] = $4[$1] $6 $5[$1];$n", [
          rdLoc(i), rope(size), rdLoc(d), rdLoc(a), rdLoc(b),
          rope(lookupOpr[op])])
    of mInSet: genInOp(p, e, d)
    else: internalError(e.info, "genSetOp")

proc genOrd(p: BProc, e: PNode, d: var TLoc) =
  unaryExprChar(p, e, d, "$1")

proc genSomeCast(p: BProc, e: PNode, d: var TLoc) =
  const
    ValueTypes = {tyTuple, tyObject, tyArray, tyOpenArray, tyVarargs}
  # we use whatever C gives us. Except if we have a value-type, we need to go
  # through its address:
  var a: TLoc
  initLocExpr(p, e.sons[1], a)
  let etyp = skipTypes(e.typ, abstractRange)
  if etyp.kind in ValueTypes and lfIndirect notin a.flags:
    putIntoDest(p, d, e.typ, "(*($1*) ($2))" %
        [getTypeDesc(p.module, e.typ), addrLoc(a)], a.s)
  elif etyp.kind == tyProc and etyp.callConv == ccClosure:
    putIntoDest(p, d, e.typ, "(($1) ($2))" %
        [getClosureType(p.module, etyp, clHalfWithEnv), rdCharLoc(a)], a.s)
  else:
    putIntoDest(p, d, e.typ, "(($1) ($2))" %
        [getTypeDesc(p.module, e.typ), rdCharLoc(a)], a.s)

proc genCast(p: BProc, e: PNode, d: var TLoc) =
  const ValueTypes = {tyFloat..tyFloat128, tyTuple, tyObject, tyArray}
  let
    destt = skipTypes(e.typ, abstractRange)
    srct = skipTypes(e.sons[1].typ, abstractRange)
  if destt.kind in ValueTypes or srct.kind in ValueTypes:
    # 'cast' and some float type involved? --> use a union.
    inc(p.labels)
    var lbl = p.labels.rope
    var tmp: TLoc
    tmp.r = "LOC$1.source" % [lbl]
    linefmt(p, cpsLocals, "union { $1 source; $2 dest; } LOC$3;$n",
      getTypeDesc(p.module, e.sons[1].typ), getTypeDesc(p.module, e.typ), lbl)
    tmp.k = locExpr
    tmp.t = srct
    tmp.s = OnStack
    tmp.flags = {}
    expr(p, e.sons[1], tmp)
    putIntoDest(p, d, e.typ, "LOC$#.dest" % [lbl], tmp.s)
  else:
    # I prefer the shorter cast version for pointer types -> generate less
    # C code; plus it's the right thing to do for closures:
    genSomeCast(p, e, d)

proc genRangeChck(p: BProc, n: PNode, d: var TLoc, magic: string) =
  var a: TLoc
  var dest = skipTypes(n.typ, abstractVar)
  # range checks for unsigned turned out to be buggy and annoying:
  if optRangeCheck notin p.options or dest.skipTypes({tyRange}).kind in
                                             {tyUInt..tyUInt64}:
    initLocExpr(p, n.sons[0], a)
    putIntoDest(p, d, n.typ, "(($1) ($2))" %
        [getTypeDesc(p.module, dest), rdCharLoc(a)], a.s)
  else:
    initLocExpr(p, n.sons[0], a)
    putIntoDest(p, d, dest, ropecg(p.module, "(($1)#$5($2, $3, $4))", [
        getTypeDesc(p.module, dest), rdCharLoc(a),
        genLiteral(p, n.sons[1], dest), genLiteral(p, n.sons[2], dest),
        rope(magic)]), a.s)

proc genConv(p: BProc, e: PNode, d: var TLoc) =
  let destType = e.typ.skipTypes({tyVar, tyGenericInst, tyAlias})
  if compareTypes(destType, e.sons[1].typ, dcEqIgnoreDistinct):
    expr(p, e.sons[1], d)
  else:
    genSomeCast(p, e, d)

proc convStrToCStr(p: BProc, n: PNode, d: var TLoc) =
  var a: TLoc
  initLocExpr(p, n.sons[0], a)
  putIntoDest(p, d, skipTypes(n.typ, abstractVar), "$1->data" % [rdLoc(a)], a.s)

proc convCStrToStr(p: BProc, n: PNode, d: var TLoc) =
  var a: TLoc
  initLocExpr(p, n.sons[0], a)
  putIntoDest(p, d, skipTypes(n.typ, abstractVar),
              ropecg(p.module, "#cstrToNimstr($1)", [rdLoc(a)]), a.s)
  gcUsage(n)

proc genStrEquals(p: BProc, e: PNode, d: var TLoc) =
  var x: TLoc
  var a = e.sons[1]
  var b = e.sons[2]
  if (a.kind == nkNilLit) or (b.kind == nkNilLit):
    binaryExpr(p, e, d, "($1 == $2)")
  elif (a.kind in {nkStrLit..nkTripleStrLit}) and (a.strVal == ""):
    initLocExpr(p, e.sons[2], x)
    putIntoDest(p, d, e.typ,
      rfmt(nil, "(($1) && ($1)->$2 == 0)", rdLoc(x), lenField(p)))
  elif (b.kind in {nkStrLit..nkTripleStrLit}) and (b.strVal == ""):
    initLocExpr(p, e.sons[1], x)
    putIntoDest(p, d, e.typ,
      rfmt(nil, "(($1) && ($1)->$2 == 0)", rdLoc(x), lenField(p)))
  else:
    binaryExpr(p, e, d, "#eqStrings($1, $2)")

proc binaryFloatArith(p: BProc, e: PNode, d: var TLoc, m: TMagic) =
  if {optNaNCheck, optInfCheck} * p.options != {}:
    const opr: array[mAddF64..mDivF64, string] = ["+", "-", "*", "/"]
    var a, b: TLoc
    assert(e.sons[1].typ != nil)
    assert(e.sons[2].typ != nil)
    initLocExpr(p, e.sons[1], a)
    initLocExpr(p, e.sons[2], b)
    putIntoDest(p, d, e.typ, rfmt(nil, "(($4)($2) $1 ($4)($3))",
                                  rope(opr[m]), rdLoc(a), rdLoc(b),
                                  getSimpleTypeDesc(p.module, e[1].typ)))
    if optNaNCheck in p.options:
      linefmt(p, cpsStmts, "#nanCheck($1);$n", rdLoc(d))
    if optInfCheck in p.options:
      linefmt(p, cpsStmts, "#infCheck($1);$n", rdLoc(d))
  else:
    binaryArith(p, e, d, m)

proc genMagicExpr(p: BProc, e: PNode, d: var TLoc, op: TMagic) =
  case op
  of mOr, mAnd: genAndOr(p, e, d, op)
  of mNot..mToBiggestInt: unaryArith(p, e, d, op)
  of mUnaryMinusI..mAbsI: unaryArithOverflow(p, e, d, op)
  of mAddF64..mDivF64: binaryFloatArith(p, e, d, op)
  of mShrI..mXor: binaryArith(p, e, d, op)
  of mEqProc: genEqProc(p, e, d)
  of mAddI..mPred: binaryArithOverflow(p, e, d, op)
  of mRepr: genRepr(p, e, d)
  of mGetTypeInfo: genGetTypeInfo(p, e, d)
  of mSwap: genSwap(p, e, d)
  of mUnaryLt:
    if optOverflowCheck notin p.options: unaryExpr(p, e, d, "($1 - 1)")
    else: unaryExpr(p, e, d, "#subInt($1, 1)")
  of mInc, mDec:
    const opr: array[mInc..mDec, string] = ["$1 += $2;$n", "$1 -= $2;$n"]
    const fun64: array[mInc..mDec, string] = ["$# = #addInt64($#, $#);$n",
                                               "$# = #subInt64($#, $#);$n"]
    const fun: array[mInc..mDec, string] = ["$# = #addInt($#, $#);$n",
                                             "$# = #subInt($#, $#);$n"]
    let underlying = skipTypes(e.sons[1].typ, {tyGenericInst, tyAlias, tyVar, tyRange})
    if optOverflowCheck notin p.options or underlying.kind in {tyUInt..tyUInt64}:
      binaryStmt(p, e, d, opr[op])
    else:
      var a, b: TLoc
      assert(e.sons[1].typ != nil)
      assert(e.sons[2].typ != nil)
      initLocExpr(p, e.sons[1], a)
      initLocExpr(p, e.sons[2], b)

      let ranged = skipTypes(e.sons[1].typ, {tyGenericInst, tyAlias, tyVar})
      let res = binaryArithOverflowRaw(p, ranged, a, b,
        if underlying.kind == tyInt64: fun64[op] else: fun[op])
      putIntoDest(p, a, ranged, "($#)($#)" % [
        getTypeDesc(p.module, ranged), res])

  of mConStrStr: genStrConcat(p, e, d)
  of mAppendStrCh: binaryStmt(p, e, d, "$1 = #addChar($1, $2);$n")
  of mAppendStrStr: genStrAppend(p, e, d)
  of mAppendSeqElem: genSeqElemAppend(p, e, d)
  of mEqStr: genStrEquals(p, e, d)
  of mLeStr: binaryExpr(p, e, d, "(#cmpStrings($1, $2) <= 0)")
  of mLtStr: binaryExpr(p, e, d, "(#cmpStrings($1, $2) < 0)")
  of mIsNil: genIsNil(p, e, d)
  of mIntToStr: genDollar(p, e, d, "#nimIntToStr($1)")
  of mInt64ToStr: genDollar(p, e, d, "#nimInt64ToStr($1)")
  of mBoolToStr: genDollar(p, e, d, "#nimBoolToStr($1)")
  of mCharToStr: genDollar(p, e, d, "#nimCharToStr($1)")
  of mFloatToStr: genDollar(p, e, d, "#nimFloatToStr($1)")
  of mCStrToStr: genDollar(p, e, d, "#cstrToNimstr($1)")
  of mStrToStr: expr(p, e.sons[1], d)
  of mEnumToStr: genRepr(p, e, d)
  of mOf: genOf(p, e, d)
  of mNew: genNew(p, e)
  of mNewFinalize: genNewFinalize(p, e)
  of mNewSeq: genNewSeq(p, e)
  of mNewSeqOfCap: genNewSeqOfCap(p, e, d)
  of mSizeOf:
    let t = e.sons[1].typ.skipTypes({tyTypeDesc})
    putIntoDest(p, d, e.typ, "((NI)sizeof($1))" % [getTypeDesc(p.module, t)])
  of mChr: genSomeCast(p, e, d)
  of mOrd: genOrd(p, e, d)
  of mLengthArray, mHigh, mLengthStr, mLengthSeq, mLengthOpenArray:
    genArrayLen(p, e, d, op)
  of mXLenStr, mXLenSeq:
    if not p.module.compileToCpp:
      unaryExpr(p, e, d, "($1->Sup.len)")
    else:
      unaryExpr(p, e, d, "$1->len")
  of mGCref: unaryStmt(p, e, d, "#nimGCref($1);$n")
  of mGCunref: unaryStmt(p, e, d, "#nimGCunref($1);$n")
  of mSetLengthStr: genSetLengthStr(p, e, d)
  of mSetLengthSeq: genSetLengthSeq(p, e, d)
  of mIncl, mExcl, mCard, mLtSet, mLeSet, mEqSet, mMulSet, mPlusSet, mMinusSet,
     mInSet:
    genSetOp(p, e, d, op)
  of mNewString, mNewStringOfCap, mCopyStr, mCopyStrLast, mExit,
      mParseBiggestFloat:
    var opr = e.sons[0].sym
    if lfNoDecl notin opr.loc.flags:
      discard cgsym(p.module, $opr.loc.r)
    genCall(p, e, d)
  of mReset: genReset(p, e)
  of mEcho: genEcho(p, e[1].skipConv)
  of mArrToSeq: genArrToSeq(p, e, d)
  of mNLen..mNError, mSlurp..mQuoteAst:
    localError(e.info, errXMustBeCompileTime, e.sons[0].sym.name.s)
  of mSpawn:
    let n = lowerings.wrapProcForSpawn(p.module.module, e, e.typ, nil, nil)
    expr(p, n, d)
  of mParallel:
    let n = semparallel.liftParallel(p.module.module, e)
    expr(p, n, d)
  of mDeepCopy:
    var a, b: TLoc
    let x = if e[1].kind in {nkAddr, nkHiddenAddr}: e[1][0] else: e[1]
    initLocExpr(p, x, a)
    initLocExpr(p, e.sons[2], b)
    genDeepCopy(p, a, b)
  of mDotDot, mEqCString: genCall(p, e, d)
  else: internalError(e.info, "genMagicExpr: " & $op)

proc genSetConstr(p: BProc, e: PNode, d: var TLoc) =
  # example: { a..b, c, d, e, f..g }
  # we have to emit an expression of the form:
  # memset(tmp, 0, sizeof(tmp)); inclRange(tmp, a, b); incl(tmp, c);
  # incl(tmp, d); incl(tmp, e); inclRange(tmp, f, g);
  var
    a, b, idx: TLoc
  if nfAllConst in e.flags:
    putIntoDest(p, d, e.typ, genSetNode(p, e))
  else:
    if d.k == locNone: getTemp(p, e.typ, d)
    if getSize(e.typ) > 8:
      # big set:
      useStringh(p.module)
      lineF(p, cpsStmts, "memset($1, 0, sizeof($1));$n", [rdLoc(d)])
      for i in countup(0, sonsLen(e) - 1):
        if e.sons[i].kind == nkRange:
          getTemp(p, getSysType(tyInt), idx) # our counter
          initLocExpr(p, e.sons[i].sons[0], a)
          initLocExpr(p, e.sons[i].sons[1], b)
          lineF(p, cpsStmts, "for ($1 = $3; $1 <= $4; $1++) $n" &
              "$2[(NU)($1)>>3] |=(1U<<((NU)($1)&7U));$n", [rdLoc(idx), rdLoc(d),
              rdSetElemLoc(a, e.typ), rdSetElemLoc(b, e.typ)])
        else:
          initLocExpr(p, e.sons[i], a)
          lineF(p, cpsStmts, "$1[(NU)($2)>>3] |=(1U<<((NU)($2)&7U));$n",
               [rdLoc(d), rdSetElemLoc(a, e.typ)])
    else:
      # small set
      var ts = "NU" & $(getSize(e.typ) * 8)
      lineF(p, cpsStmts, "$1 = 0;$n", [rdLoc(d)])
      for i in countup(0, sonsLen(e) - 1):
        if e.sons[i].kind == nkRange:
          getTemp(p, getSysType(tyInt), idx) # our counter
          initLocExpr(p, e.sons[i].sons[0], a)
          initLocExpr(p, e.sons[i].sons[1], b)
          lineF(p, cpsStmts, "for ($1 = $3; $1 <= $4; $1++) $n" &
              "$2 |=((" & ts & ")(1)<<(($1)%(sizeof(" & ts & ")*8)));$n", [
              rdLoc(idx), rdLoc(d), rdSetElemLoc(a, e.typ),
              rdSetElemLoc(b, e.typ)])
        else:
          initLocExpr(p, e.sons[i], a)
          lineF(p, cpsStmts,
               "$1 |=((" & ts & ")(1)<<(($2)%(sizeof(" & ts & ")*8)));$n",
               [rdLoc(d), rdSetElemLoc(a, e.typ)])

proc genTupleConstr(p: BProc, n: PNode, d: var TLoc) =
  var rec: TLoc
  if not handleConstExpr(p, n, d):
    let t = n.typ
    discard getTypeDesc(p.module, t) # so that any fields are initialized
    if d.k == locNone: getTemp(p, t, d)
    for i in countup(0, sonsLen(n) - 1):
      var it = n.sons[i]
      if it.kind == nkExprColonExpr: it = it.sons[1]
      initLoc(rec, locExpr, it.typ, d.s)
      rec.r = "$1.Field$2" % [rdLoc(d), rope(i)]
      expr(p, it, rec)

proc isConstClosure(n: PNode): bool {.inline.} =
  result = n.sons[0].kind == nkSym and isRoutine(n.sons[0].sym) and
      n.sons[1].kind == nkNilLit

proc genClosure(p: BProc, n: PNode, d: var TLoc) =
  assert n.kind == nkClosure

  if isConstClosure(n):
    inc(p.module.labels)
    var tmp = "CNSTCLOSURE" & rope(p.module.labels)
    addf(p.module.s[cfsData], "static NIM_CONST $1 $2 = $3;$n",
        [getTypeDesc(p.module, n.typ), tmp, genConstExpr(p, n)])
    putIntoDest(p, d, n.typ, tmp, OnStatic)
  else:
    var tmp, a, b: TLoc
    initLocExpr(p, n.sons[0], a)
    initLocExpr(p, n.sons[1], b)
    if n.sons[0].skipConv.kind == nkClosure:
      internalError(n.info, "closure to closure created")
    # tasyncawait.nim breaks with this optimization:
    when false:
      if d.k != locNone:
        linefmt(p, cpsStmts, "$1.ClPrc = $2; $1.ClEnv = $3;$n",
                d.rdLoc, a.rdLoc, b.rdLoc)
    else:
      getTemp(p, n.typ, tmp)
      linefmt(p, cpsStmts, "$1.ClPrc = $2; $1.ClEnv = $3;$n",
              tmp.rdLoc, a.rdLoc, b.rdLoc)
      putLocIntoDest(p, d, tmp)

proc genArrayConstr(p: BProc, n: PNode, d: var TLoc) =
  var arr: TLoc
  if not handleConstExpr(p, n, d):
    if d.k == locNone: getTemp(p, n.typ, d)
    for i in countup(0, sonsLen(n) - 1):
      initLoc(arr, locExpr, elemType(skipTypes(n.typ, abstractInst)), d.s)
      arr.r = "$1[$2]" % [rdLoc(d), intLiteral(i)]
      expr(p, n.sons[i], arr)

proc genComplexConst(p: BProc, sym: PSym, d: var TLoc) =
  requestConstImpl(p, sym)
  assert((sym.loc.r != nil) and (sym.loc.t != nil))
  putLocIntoDest(p, d, sym.loc)

proc genStmtListExpr(p: BProc, n: PNode, d: var TLoc) =
  var length = sonsLen(n)
  for i in countup(0, length - 2): genStmts(p, n.sons[i])
  if length > 0: expr(p, n.sons[length - 1], d)

proc upConv(p: BProc, n: PNode, d: var TLoc) =
  var a: TLoc
  initLocExpr(p, n.sons[0], a)
  let dest = skipTypes(n.typ, abstractPtrs)
  if optObjCheck in p.options and not isObjLackingTypeField(dest):
    var r = rdLoc(a)
    var nilCheck: Rope = nil
    var t = skipTypes(a.t, abstractInst)
    while t.kind in {tyVar, tyPtr, tyRef}:
      if t.kind != tyVar: nilCheck = r
      if t.kind != tyVar or not p.module.compileToCpp:
        r = "(*$1)" % [r]
      t = skipTypes(t.lastSon, abstractInst)
    if not p.module.compileToCpp:
      while t.kind == tyObject and t.sons[0] != nil:
        add(r, ".Sup")
        t = skipTypes(t.sons[0], skipPtrs)
    if nilCheck != nil:
      linefmt(p, cpsStmts, "if ($1) #chckObj($2.m_type, $3);$n",
              nilCheck, r, genTypeInfo(p.module, dest))
    else:
      linefmt(p, cpsStmts, "#chckObj($1.m_type, $2);$n",
              r, genTypeInfo(p.module, dest))
  if n.sons[0].typ.kind != tyObject:
    putIntoDest(p, d, n.typ,
                "(($1) ($2))" % [getTypeDesc(p.module, n.typ), rdLoc(a)], a.s)
  else:
    putIntoDest(p, d, n.typ, "(*($1*) ($2))" %
                             [getTypeDesc(p.module, dest), addrLoc(a)], a.s)

proc downConv(p: BProc, n: PNode, d: var TLoc) =
  if p.module.compileToCpp:
    expr(p, n.sons[0], d)     # downcast does C++ for us
  else:
    var dest = skipTypes(n.typ, abstractPtrs)

    var arg = n.sons[0]
    while arg.kind == nkObjDownConv: arg = arg.sons[0]

    var src = skipTypes(arg.typ, abstractPtrs)
    var a: TLoc
    initLocExpr(p, arg, a)
    var r = rdLoc(a)
    let isRef = skipTypes(arg.typ, abstractInst).kind in {tyRef, tyPtr, tyVar}
    if isRef:
      add(r, "->Sup")
    else:
      add(r, ".Sup")
    for i in countup(2, abs(inheritanceDiff(dest, src))): add(r, ".Sup")
    if isRef:
      # it can happen that we end up generating '&&x->Sup' here, so we pack
      # the '&x->Sup' into a temporary and then those address is taken
      # (see bug #837). However sometimes using a temporary is not correct:
      # init(TFigure(my)) # where it is passed to a 'var TFigure'. We test
      # this by ensuring the destination is also a pointer:
      if d.k == locNone and skipTypes(n.typ, abstractInst).kind in {tyRef, tyPtr, tyVar}:
        getTemp(p, n.typ, d)
        linefmt(p, cpsStmts, "$1 = &$2;$n", rdLoc(d), r)
      else:
        r = "&" & r
        putIntoDest(p, d, n.typ, r, a.s)
    else:
      putIntoDest(p, d, n.typ, r, a.s)

proc exprComplexConst(p: BProc, n: PNode, d: var TLoc) =
  let t = n.typ
  discard getTypeDesc(p.module, t) # so that any fields are initialized
  let id = nodeTableTestOrSet(p.module.dataCache, n, p.module.labels)
  let tmp = p.module.tmpBase & rope(id)

  if id == p.module.labels:
    # expression not found in the cache:
    inc(p.module.labels)
    addf(p.module.s[cfsData], "NIM_CONST $1 $2 = $3;$n",
         [getTypeDesc(p.module, t), tmp, genConstExpr(p, n)])

  if d.k == locNone:
    fillLoc(d, locData, t, tmp, OnStatic)
  else:
    putDataIntoDest(p, d, t, tmp)
    # This fixes bug #4551, but we really need better dataflow
    # analysis to make this 100% safe.
    if t.kind notin {tySequence, tyString}:
      d.s = OnStatic

proc expr(p: BProc, n: PNode, d: var TLoc) =
  p.currLineInfo = n.info
  case n.kind
  of nkSym:
    var sym = n.sym
    case sym.kind
    of skMethod:
      if {sfDispatcher, sfForward} * sym.flags != {}:
        # we cannot produce code for the dispatcher yet:
        fillProcLoc(p.module, sym)
        genProcPrototype(p.module, sym)
      else:
        genProc(p.module, sym)
      putLocIntoDest(p, d, sym.loc)
    of skProc, skConverter, skIterator:
      #if sym.kind == skIterator:
      #  echo renderTree(sym.getBody, {renderIds})
      if sfCompileTime in sym.flags:
        localError(n.info, "request to generate code for .compileTime proc: " &
           sym.name.s)
      genProc(p.module, sym)
      if sym.loc.r == nil or sym.loc.t == nil:
        internalError(n.info, "expr: proc not init " & sym.name.s)
      putLocIntoDest(p, d, sym.loc)
    of skConst:
      if isSimpleConst(sym.typ):
        putIntoDest(p, d, n.typ, genLiteral(p, sym.ast, sym.typ), OnStatic)
      else:
        genComplexConst(p, sym, d)
    of skEnumField:
      putIntoDest(p, d, n.typ, rope(sym.position))
    of skVar, skForVar, skResult, skLet:
      if {sfGlobal, sfThread} * sym.flags != {}:
        genVarPrototype(p.module, sym)
      if sym.loc.r == nil or sym.loc.t == nil:
        #echo "FAILED FOR PRCO ", p.prc.name.s
        #echo renderTree(p.prc.ast, {renderIds})
        internalError n.info, "expr: var not init " & sym.name.s & "_" & $sym.id
      if sfThread in sym.flags:
        accessThreadLocalVar(p, sym)
        if emulatedThreadVars():
          putIntoDest(p, d, sym.loc.t, "NimTV->" & sym.loc.r)
        else:
          putLocIntoDest(p, d, sym.loc)
      else:
        putLocIntoDest(p, d, sym.loc)
    of skTemp:
      if sym.loc.r == nil or sym.loc.t == nil:
        #echo "FAILED FOR PRCO ", p.prc.name.s
        #echo renderTree(p.prc.ast, {renderIds})
        internalError(n.info, "expr: temp not init " & sym.name.s & "_" & $sym.id)
      putLocIntoDest(p, d, sym.loc)
    of skParam:
      if sym.loc.r == nil or sym.loc.t == nil:
        # echo "FAILED FOR PRCO ", p.prc.name.s
        # debug p.prc.typ.n
        # echo renderTree(p.prc.ast, {renderIds})
        internalError(n.info, "expr: param not init " & sym.name.s & "_" & $sym.id)
      putLocIntoDest(p, d, sym.loc)
    else: internalError(n.info, "expr(" & $sym.kind & "); unknown symbol")
  of nkNilLit:
    if not isEmptyType(n.typ):
      putIntoDest(p, d, n.typ, genLiteral(p, n))
  of nkStrLit..nkTripleStrLit:
    putDataIntoDest(p, d, n.typ, genLiteral(p, n))
  of nkIntLit..nkUInt64Lit,
     nkFloatLit..nkFloat128Lit, nkCharLit:
    putIntoDest(p, d, n.typ, genLiteral(p, n))
  of nkCall, nkHiddenCallConv, nkInfix, nkPrefix, nkPostfix, nkCommand,
     nkCallStrLit:
    genLineDir(p, n)
    let op = n.sons[0]
    if n.typ.isNil:
      # discard the value:
      var a: TLoc
      if op.kind == nkSym and op.sym.magic != mNone:
        genMagicExpr(p, n, a, op.sym.magic)
      else:
        genCall(p, n, a)
    else:
      # load it into 'd':
      if op.kind == nkSym and op.sym.magic != mNone:
        genMagicExpr(p, n, d, op.sym.magic)
      else:
        genCall(p, n, d)
  of nkCurly:
    if isDeepConstExpr(n) and n.len != 0:
      putIntoDest(p, d, n.typ, genSetNode(p, n))
    else:
      genSetConstr(p, n, d)
  of nkBracket:
    if isDeepConstExpr(n) and n.len != 0:
      exprComplexConst(p, n, d)
    elif skipTypes(n.typ, abstractVarRange).kind == tySequence:
      genSeqConstr(p, n, d)
    else:
      genArrayConstr(p, n, d)
  of nkPar:
    if isDeepConstExpr(n) and n.len != 0:
      exprComplexConst(p, n, d)
    else:
      genTupleConstr(p, n, d)
  of nkObjConstr: genObjConstr(p, n, d)
  of nkCast: genCast(p, n, d)
  of nkHiddenStdConv, nkHiddenSubConv, nkConv: genConv(p, n, d)
  of nkHiddenAddr, nkAddr: genAddr(p, n, d)
  of nkBracketExpr: genBracketExpr(p, n, d)
  of nkDerefExpr, nkHiddenDeref: genDeref(p, n, d)
  of nkDotExpr: genRecordField(p, n, d)
  of nkCheckedFieldExpr: genCheckedRecordField(p, n, d)
  of nkBlockExpr, nkBlockStmt: genBlock(p, n, d)
  of nkStmtListExpr: genStmtListExpr(p, n, d)
  of nkStmtList:
    for i in countup(0, sonsLen(n) - 1): genStmts(p, n.sons[i])
  of nkIfExpr, nkIfStmt: genIf(p, n, d)
  of nkWhen:
    # This should be a "when nimvm" node.
    expr(p, n.sons[1].sons[0], d)
  of nkObjDownConv: downConv(p, n, d)
  of nkObjUpConv: upConv(p, n, d)
  of nkChckRangeF: genRangeChck(p, n, d, "chckRangeF")
  of nkChckRange64: genRangeChck(p, n, d, "chckRange64")
  of nkChckRange: genRangeChck(p, n, d, "chckRange")
  of nkStringToCString: convStrToCStr(p, n, d)
  of nkCStringToString: convCStrToStr(p, n, d)
  of nkLambdaKinds:
    var sym = n.sons[namePos].sym
    genProc(p.module, sym)
    if sym.loc.r == nil or sym.loc.t == nil:
      internalError(n.info, "expr: proc not init " & sym.name.s)
    putLocIntoDest(p, d, sym.loc)
  of nkClosure: genClosure(p, n, d)

  of nkEmpty: discard
  of nkWhileStmt: genWhileStmt(p, n)
  of nkVarSection, nkLetSection: genVarStmt(p, n)
  of nkConstSection: genConstStmt(p, n)
  of nkForStmt: internalError(n.info, "for statement not eliminated")
  of nkCaseStmt: genCase(p, n, d)
  of nkReturnStmt: genReturnStmt(p, n)
  of nkBreakStmt: genBreakStmt(p, n)
  of nkAsgn:
    if nfPreventCg notin n.flags:
      genAsgn(p, n, fastAsgn=false)
  of nkFastAsgn:
    if nfPreventCg notin n.flags:
      # transf is overly aggressive with 'nkFastAsgn', so we work around here.
      # See tests/run/tcnstseq3 for an example that would fail otherwise.
      genAsgn(p, n, fastAsgn=p.prc != nil)
  of nkDiscardStmt:
    if n.sons[0].kind != nkEmpty:
      genLineDir(p, n)
      var a: TLoc
      initLocExpr(p, n.sons[0], a)
  of nkAsmStmt: genAsmStmt(p, n)
  of nkTryStmt:
    if p.module.compileToCpp and optNoCppExceptions notin gGlobalOptions:
      genTryCpp(p, n, d)
    else:
      genTry(p, n, d)
  of nkRaiseStmt: genRaiseStmt(p, n)
  of nkTypeSection:
    # we have to emit the type information for object types here to support
    # separate compilation:
    genTypeSection(p.module, n)
  of nkCommentStmt, nkIteratorDef, nkIncludeStmt,
     nkImportStmt, nkImportExceptStmt, nkExportStmt, nkExportExceptStmt,
     nkFromStmt, nkTemplateDef, nkMacroDef:
    discard
  of nkPragma: genPragma(p, n)
  of nkPragmaBlock: expr(p, n.lastSon, d)
  of nkProcDef, nkMethodDef, nkConverterDef:
    if n.sons[genericParamsPos].kind == nkEmpty:
      var prc = n.sons[namePos].sym
      # due to a bug/limitation in the lambda lifting, unused inner procs
      # are not transformed correctly. We work around this issue (#411) here
      # by ensuring it's no inner proc (owner is a module):
      if prc.skipGenericOwner.kind == skModule and sfCompileTime notin prc.flags:
        if (optDeadCodeElim notin gGlobalOptions and
            sfDeadCodeElim notin getModule(prc).flags) or
            ({sfExportc, sfCompilerProc} * prc.flags == {sfExportc}) or
            (sfExportc in prc.flags and lfExportLib in prc.loc.flags) or
            (prc.kind == skMethod):
          # we have not only the header:
          if prc.getBody.kind != nkEmpty or lfDynamicLib in prc.loc.flags:
            genProc(p.module, prc)
  of nkParForStmt: genParForStmt(p, n)
  of nkState: genState(p, n)
  of nkGotoState: genGotoState(p, n)
  of nkBreakState: genBreakState(p, n)
  else: internalError(n.info, "expr(" & $n.kind & "); unknown node kind")

proc genNamedConstExpr(p: BProc, n: PNode): Rope =
  if n.kind == nkExprColonExpr: result = genConstExpr(p, n.sons[1])
  else: result = genConstExpr(p, n)

proc genConstSimpleList(p: BProc, n: PNode): Rope =
  var length = sonsLen(n)
  result = rope("{")
  let t = n.typ.skipTypes(abstractInst)
  if n.kind == nkObjConstr and not isObjLackingTypeField(t) and
      not p.module.compileToCpp:
    addf(result, "{$1}", [genTypeInfo(p.module, t)])
    if n.len > 1: add(result, ",")
  for i in countup(ord(n.kind == nkObjConstr), length - 2):
    addf(result, "$1,$n", [genNamedConstExpr(p, n.sons[i])])
  if length > ord(n.kind == nkObjConstr):
    add(result, genNamedConstExpr(p, n.sons[length - 1]))
  addf(result, "}$n", [])

proc genConstSeq(p: BProc, n: PNode, t: PType): Rope =
  var data = "{{$1, $1}" % [n.len.rope]
  if n.len > 0:
    # array part needs extra curlies:
    data.add(", {")
    for i in countup(0, n.len - 1):
      if i > 0: data.addf(",$n", [])
      data.add genConstExpr(p, n.sons[i])
    data.add("}")
  data.add("}")

  result = getTempName(p.module)
  let base = t.skipTypes(abstractInst).sons[0]

  appcg(p.module, cfsData,
        "NIM_CONST struct {$n" &
        "  #TGenericSeq Sup;$n" &
        "  $1 data[$2];$n" &
        "} $3 = $4;$n", [
        getTypeDesc(p.module, base), n.len.rope, result, data])

  result = "(($1)&$2)" % [getTypeDesc(p.module, t), result]

proc genConstExpr(p: BProc, n: PNode): Rope =
  case n.kind
  of nkHiddenStdConv, nkHiddenSubConv:
    result = genConstExpr(p, n.sons[1])
  of nkCurly:
    var cs: TBitSet
    toBitSet(n, cs)
    result = genRawSetData(cs, int(getSize(n.typ)))
  of nkBracket, nkPar, nkClosure, nkObjConstr:
    var t = skipTypes(n.typ, abstractInst)
    if t.kind == tySequence:
      result = genConstSeq(p, n, n.typ)
    else:
      result = genConstSimpleList(p, n)
  else:
    var d: TLoc
    initLocExpr(p, n, d)
    result = rdLoc(d)