summary refs log tree commit diff stats
path: root/compiler/sizealignoffsetimpl.nim
blob: a34383d9f6b04632c03e13bc420e81d5b8544461 (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
74pre { line-height: 125%; }
td.linenos .normal { color: inherit; background-color: transparent; padding-left: 5px; padding-right: 5px; }
span.linenos { color: inherit; background-color: transparent; padding-left: 5px; padding-right: 5px; }
td.linenos .special { color: #000000; background-color: #ffffc0; padding-left: 5px; padding-right: 5px; }
span.linenos.special { color: #000000; background-color: #ffffc0; padding-left: 5px; padding-right: 5px; }
.highlight .hll { background-color: #ffffcc }
.highlight .c { color: #888888 } /* Comment */
.highlight .err { color: #a61717; background-color: #e3d2d2 } /* Error */
.highlight .k { color: #008800; font-weight: bold } /* Keyword */
.highlight .ch { color: #888888 } /* Comment.Hashbang */
.highlight .cm { color: #888888 } /* Comment.Multiline */
.highlight .cp { color: #cc0000; font-weight: bold } /* Comment.Preproc */
.highlight .cpf { color: #888888 } /* Comment.PreprocFile */
.highlight .c1 { color: #888888 } /* Comment.Single */
.highlight .cs { color: #cc0000; font-weight: bold; background-color: #fff0f0 } /* Comment.Special */
.highlight .gd { color: #000000; background-color: #ffdddd } /* Generic.Deleted */
.highlight .ge { font-style: italic } /* Generic.Emph */
.highlight .ges { font-weight: bold; font-style: italic } /* Generic.EmphStrong */
.highlight .gr { color: #aa0000 } /* Generic.Error */
.highlight .gh { color: #333333 } /* Generic.Heading */
.highlight .gi { color: #000000; background-color: #ddffdd } /* Generic.Inserted */
.highlight .go { color: #888888 } /* Generic.Output */
.highlight .gp { color: #555555 } /* Generic.Prompt */
.highlight .gs { font-weight: bold } /* Generic.Strong */
.highlight .gu { color: #666666 } /* Generic.Subheading */
.highlight .gt { color: #aa0000 } /* Generic.Traceback */
.highlight .kc { color: #008800; font-weight: bold } /* Keyword.Constant */
.highlight .kd { color: #008800; font-weight: bold } /* Keyword.Declaration */
.highlight .kn { color: #008800; font-weight: bold } /* Keyword.Namespace */
.highlight .kp { color: #008800 } /* Keyword.Pseudo */
.highlight .kr { color: #008800; font-weight: bold } /* Keyword.Reserved */
.highlight .kt { color: #888888; font-weight: bold } /* Keyword.Type */
.highlight .m { color: #0000DD; font-weight: bold } /* Literal.Number */
.highlight .s { color: #dd2200; background-color: #fff0f0 } /* Literal.String */
.highlight .na { color: #336699 } /* Name.Attribute */
.highlight .nb { color: #003388 } /* Name.Builtin */
.highlight .nc { color: #bb0066; font-weight: bold } /* Name.Class */
.highlight .no { color: #003366; font-weight: bold } /* Name.Constant */
.highlight .nd { color: #555555 } /* Name.Decorator */
.highlight .ne { color: #bb0066; font-weight: bold } /* Name.Exception */
.highlight .nf { color: #0066bb; font-weight: bold } /* Name.Function */
.highlight .nl { color: #336699; font-style: italic } /* Name.Label */
.highlight .nn { color: #bb0066; font-weight: bold } /* Name.Namespace */
.highlight .py { color: #336699; font-weight: bold } /* Name.Property */
.highlight .nt { color: #bb0066; font-weight: bold } /* Name.Tag */
.highlight .nv { color: #336699 } /* Name.Variable */
.highlight .ow { color: #008800 } /* Operator.Word */
.highlight .w { color: #bbbbbb } /* Text.Whitespace */
.highlight .mb { color: #0000DD; font-weight: bold } /* Literal.Number.Bin */
.highlight .mf { color: #0000DD; font-weight: bold } /* Literal.Number.Float */
.highlight .mh { color: #0000DD; font-weight: bold } /* Literal.Number.Hex */
.highlight .mi { color: #0000DD; font-weight: bold } /* Literal.Number.Integer */
.highlight .mo { color: #0000DD; font-weight: bold } /* Literal.Number.Oct */
.highlight .sa { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Affix */
.highlight .sb { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Backtick */
.highlight .sc { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Char */
.highlight .dl { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Delimiter */
.highlight .sd { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Doc */
.highlight .s2 { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Double */
.highlight .se { color: #0044dd; background-color: #fff0f0 } /* Literal.String.Escape */
.highlight .sh { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Heredoc */
.highlight .si { color: #3333bb; background-color: #fff0f0 } /* Literal.String.Interpol */
.highlight .sx { color: #22bb22; background-color: #f0fff0 } /* Literal.String.Other */
.highlight .sr { color: #008800; background-color: #fff0ff } /* Literal.String.Regex */
.highlight .s1 { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Single */
.highlight .ss { color: #aa6600; background-color: #fff0f0 } /* Literal.String.Symbol */
.highlight .bp { color: #003388 } /* Name.Builtin.Pseudo */
.highlight .fm { color: #0066bb; font-weight: bold } /* Name.Function.Magic */
.highlight .vc { color: #336699 } /* Name.Variable.Class */
.highlight .vg { color: #dd7700 } /* Name.Variable.Global */
.highlight .vi { color: #3333bb } /* Name.Variable.Instance */
.highlight .vm { color: #336699 } /* Name.Variable.Magic */
.highlight .il { color: #0000DD; font-weight: bold } /* Literal.Number.Integer.Long */
<!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 - 083scenario_screen_test.mu</title>
<meta name="Generator" content="Vim/7.4">
<meta name="plugin-version" content="vim7.4_v2">
<meta name="syntax" content="none">
<meta name="settings" content="use_css,pre_wrap,no_foldcolumn,expand_tabs,prevent_copy=">
<meta name="colorscheme" content="minimal">
<style type="text/css">
<!--
pre { white-space: pre-wrap; font-family: monospace; color: #eeeeee; background-color: #080808; }
body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color: #080808; }
* { font-size: 12pt; font-size: 1em; }
.Comment { color: #9090ff; }
.Constant { color: #00a0a0; }
.Special { color: #c00000; }
.muScenario { color: #00af00; }
-->
</style>

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

-->
</script>
</pre { line-height: 125%; }
td.linenos .normal { color: inherit; background-color: transparent; padding-left: 5px; padding-right: 5px; }
span.linenos { color: inherit; background-color: transparent; padding-left: 5px; padding-right: 5px; }
td.linenos .special { color: #000000; background-color: #ffffc0; padding-left: 5px; padding-right: 5px; }
span.linenos.special { color: #000000; background-color: #ffffc0; padding-left: 5px; padding-right: 5px; }
.highlight .hll { background-color: #ffffcc }
.highlight .c { color: #888888 } /* Comment */
.highlight .err { color: #a61717; background-color: #e3d2d2 } /* Error */
.highlight .k { color: #008800; font-weight: bold } /* Keyword */
.highlight .ch { color: #888888 } /* Comment.Hashbang */
.highlight .cm { color: #888888 } /* Comment.Multiline */
.highlight .cp { color: #cc0000; font-weight: bold } /* Comment.Preproc */
.highlight .cpf { color: #888888 } /* Comment.PreprocFile */
.highlight .c1 { color: #888888 } /* Comment.Single */
.highlight .cs { color: #cc0000; font-weight: bold; background-color: #fff0f0 } /* Comment.Special */
.highlight .gd { color: #000000; background-color: #ffdddd } /* Generic.Deleted */
.highlight .ge { font-style: italic } /* Generic.Emph */
.highlight .ges { font-weight: bold; font-style: italic } /* Generic.EmphStrong */
.highlight .gr { color: #aa0000 } /* Generic.Error */
.highlight .gh { color: #333333 } /* Generic.Heading */
.highlight .gi { color: #000000; background-color: #ddffdd } /* Generic.Inserted */
.highlight .go { color: #888888 } /* Generic.Output */
.highlight .gp { color: #555555 } /* Generic.Prompt */
.highlight .gs { font-weight: bold } /* Generic.Strong */
.highlight .gu { color: #666666 } /* Generic.Subheading */
.highlight .gt { color: #aa0000 } /* Generic.Traceback */
.highlight .kc { color: #008800; font-weight: bold } /* Keyword.Constant */
.highlight .kd { color: #008800; font-weight: bold } /* Keyword.Declaration */
.highlight .kn { color: #008800; font-weight: bold } /* Keyword.Namespace */
.highlight .kp { color: #008800 } /* Keyword.Pseudo */
.highlight .kr { color: #008800; font-weight: bold } /* Keyword.Reserved */
.highlight .kt { color: #888888; font-weight: bold } /* Keyword.Type */
.highlight .m { color: #0000DD; font-weight: bold } /* Literal.Number */
.highlight .s { color: #dd2200; background-color: #fff0f0 } /* Literal.String */
.highlight .na { color: #336699 } /* Name.Attribute */
.highlight .nb { color: #003388 } /* Name.Builtin */
.highlight .nc { color: #bb0066; font-weight: bold } /* Name.Class */
.highlight .no { color: #003366; font-weight: bold } /* Name.Constant */
.highlight .nd { color: #555555 } /* Name.Decorator */
.highlight .ne { color: #bb0066; font-weight: bold } /* Name.Exception */
.highlight .nf { color: #0066bb; font-weight: bold } /* Name.Function */
.highlight .nl { color: #336699; font-style: italic } /* Name.Label */
.highlight .nn { color: #bb0066; font-weight: bold } /* Name.Namespace */
.highlight .py { color: #336699; font-weight: bold } /* Name.Property */
.highlight .nt { color: #bb0066; font-weight: bold } /* Name.Tag */
.highlight .nv { color: #336699 } /* Name.Variable */
.highlight .ow { color: #008800 } /* Operator.Word */
.highlight .w { color: #bbbbbb } /* Text.Whitespace */
.highlight .mb { color: #0000DD; font-weight: bold } /* Literal.Number.Bin */
.highlight .mf { color: #0000DD; font-weight: bold } /* Literal.Number.Float */
.highlight .mh { color: #0000DD; font-weight: bold } /* Literal.Number.Hex */
.highlight .mi { color: #0000DD; font-weight: bold } /* Literal.Number.Integer */
.highlight .mo { color: #0000DD; font-weight: bold } /* Literal.Number.Oct */
.highlight .sa { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Affix */
.highlight .sb { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Backtick */
.highlight .sc { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Char */
.highlight .dl { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Delimiter */
.highlight .sd { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Doc */
.highlight .s2 { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Double */
.highlight .se { color: #0044dd; background-color: #fff0f0 } /* Literal.String.Escape */
.highlight .sh { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Heredoc */
.highlight .si { color: #3333bb; background-color: #fff0f0 } /* Literal.String.Interpol */
.highlight .sx { color: #22bb22; background-color: #f0fff0 } /* Literal.String.Other */
.highlight .sr { color: #008800; background-color: #fff0ff } /* Literal.String.Regex */
.highlight .s1 { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Single */
.highlight .ss { color: #aa6600; background-color: #fff0f0 } /* Literal.String.Symbol */
.highlight .bp { color: #003388 } /* Name.Builtin.Pseudo */
.highlight .fm { color: #0066bb; font-weight: bold } /* Name.Function.Magic */
.highlight .vc { color: #336699 } /* Name.Variable.Class */
.highlight .vg { color: #dd7700 } /* Name.Variable.Global */
.highlight .vi { color: #3333bb } /* Name.Variable.Instance */
.highlight .vm { color: #336699 } /* Name.Variable.Magic */
.highlight .il { color: #0000DD; font-weight: bold } /* Literal.Number.Integer.Long */
#
#
#           The Nim Compiler
#
#    See the file "copying.txt", included in this
#    distribution, for details about the copyright.
#
## code owner: Arne Döring
## e-mail: arne.doering@gmx.net

proc align(address, alignment: BiggestInt): BiggestInt =
  result = (address + (alignment - 1)) and not (alignment - 1)

const
  ## a size is concidered "unknown" when it is an imported type from C
  ## or C++.
  szUnknownSize* = -3
  szIllegalRecursion* = -2
  szUncomputedSize* = -1

proc computeSizeAlign(conf: ConfigRef; typ: PType): void

proc computeSubObjectAlign(conf: ConfigRef; n: PNode): BiggestInt =
  ## returns object alignment
  case n.kind
  of nkRecCase:
    assert(n.sons[0].kind == nkSym)
    result = computeSubObjectAlign(conf, n.sons[0])
    for i in 1 ..< sonsLen(n):
      let child = n.sons[i]
      case child.kind
      of nkOfBranch, nkElse:
        let align = computeSubObjectAlign(conf, child.lastSon)
        if align < 0:
          return align
        result = max(result, align)
      else:
        internalError(conf, "computeSubObjectAlign")
  of nkRecList:
    result = 1
    for i, child in n.sons:
      let align = computeSubObjectAlign(conf, n.sons[i])
      if align < 0:
        return align
      result = max(result, align)
  of nkSym:
    computeSizeAlign(conf, n.sym.typ)
    result = n.sym.typ.align
  else:
    result = 1

proc computeObjectOffsetsFoldFunction(conf: ConfigRef; n: PNode, initialOffset: BiggestInt): tuple[offset, align: BiggestInt] =
  ## ``offset`` is the offset within the object, after the node has been written, no padding bytes added
  ## ``align`` maximum alignment from all sub nodes
  assert n != nil
  if n.typ != nil and n.typ.size == szIllegalRecursion:
    result.offset = szIllegalRecursion
    result.align  = szIllegalRecursion
    return

  result.align = 1
  case n.kind
  of nkRecCase:
    assert(n.sons[0].kind == nkSym)
    let (kindOffset, kindAlign) = computeObjectOffsetsFoldFunction(conf, n.sons[0], initialOffset)

    var maxChildAlign: BiggestInt = 0
    for i in 1 ..< sonsLen(n):
      let child = n.sons[i]
      case child.kind
      of nkOfBranch, nkElse:
        # offset parameter cannot be known yet, it needs to know the alignment first
        let align = computeSubObjectAlign(conf, n.sons[i].lastSon)

        if align == szIllegalRecursion:
          result.offset  = szIllegalRecursion
          result.align = szIllegalRecursion
          return

        if align == szUnknownSize or maxChildAlign == szUnknownSize:
          maxChildAlign = szUnknownSize
        else:
          maxChildAlign = max(maxChildAlign, align)
      else:
        internalError(conf, "computeObjectOffsetsFoldFunction(record case branch)")

    if maxChildAlign == szUnknownSize:
      result.align  = szUnknownSize
      result.offset = szUnknownSize
    else:
      # the union neds to be aligned first, before the offsets can be assigned
      let kindUnionOffset = align(kindOffset, maxChildAlign)

      var maxChildOffset: BiggestInt = 0
      for i in 1 ..< sonsLen(n):
        let (offset, align) = computeObjectOffsetsFoldFunction(conf, n.sons[i].lastSon, kindUnionOffset)
        maxChildOffset = max(maxChildOffset, offset)

      result.align = max(kindAlign, maxChildAlign)
      result.offset = maxChildOffset


  of nkRecList:
    result.align = 1 # maximum of all member alignments
    var offset = initialOffset

    for i, child in n.sons:
      let (new_offset, align) = computeObjectOffsetsFoldFunction(conf, child, offset)

      if new_offset == szIllegalRecursion:
        result.offset = szIllegalRecursion
        result.align = szIllegalRecursion
        return

      elif new_offset == szUnknownSize or offset == szUnknownSize:
        # if anything is unknown, the rest becomes unknown as well
        offset = szUnknownSize
        result.align = szUnknownSize

      else:
        offset = new_offset
        result.align = max(result.align, align)

    # final alignment
    if offset == szUnknownSize:
      result.offset = szUnknownSize
    else:
      result.offset = align(offset, result.align)

  of nkSym:
    var size = szUnknownSize
    var align = szUnknownSize

    if n.sym.bitsize == 0: # 0 represents bitsize not set
      computeSizeAlign(conf, n.sym.typ)
      size = n.sym.typ.size.int
      align = n.sym.typ.align.int

    result.align = align
    if initialOffset == szUnknownSize or size == szUnknownSize:
      n.sym.offset = szUnknownSize
      result.offset = szUnknownSize
    else:
      n.sym.offset = align(initialOffset, align).int
      result.offset = n.sym.offset + n.sym.typ.size
  else:
    result.align = szUnknownSize
    result.offset = szUnknownSize

proc computePackedObjectOffsetsFoldFunction(conf: ConfigRef; n: PNode, initialOffset: BiggestInt, debug: bool): BiggestInt =
  ## ``result`` is the offset within the object, after the node has been written, no padding bytes added
  case n.kind
  of nkRecCase:
    assert(n.sons[0].kind == nkSym)
    let kindOffset = computePackedObjectOffsetsFoldFunction(conf, n.sons[0], initialOffset, debug)
    # the union neds to be aligned first, before the offsets can be assigned
    let kindUnionOffset = kindOffset

    var maxChildOffset: BiggestInt = kindUnionOffset
    for i in 1 ..< sonsLen(n):
      let offset = computePackedObjectOffsetsFoldFunction(conf, n.sons[i].lastSon, kindUnionOffset, debug)
      maxChildOffset = max(maxChildOffset, offset)
    result = maxChildOffset
  of nkRecList:
    result = initialOffset
    for i, child in n.sons:
      result = computePackedObjectOffsetsFoldFunction(conf, child, result, debug)
      if result == szIllegalRecursion:
        break
  of nkSym:
    computeSizeAlign(conf, n.sym.typ)
    n.sym.offset = initialOffset.int
    result = n.sym.offset + n.sym.typ.size
  else:
    result = szUnknownSize

# TODO this one needs an alignment map of the individual types

proc computeSizeAlign(conf: ConfigRef; typ: PType) =
  ## computes and sets ``size`` and ``align`` members of ``typ``
  assert typ != nil
  let hasSize = typ.size != szUncomputedSize
  let hasAlign = typ.align != szUncomputedSize

  if hasSize and hasAlign:
    # nothing to do, size and align already computed
    return

  # This function can only calculate both, size and align at the same time.
  # If one of them is already set this value is stored here and reapplied
  let revertSize = typ.size
  let revertAlign = typ.align
  defer:
    if hasSize:
      typ.size = revertSize
    if hasAlign:
      typ.align = revertAlign

  if typ.size == szIllegalRecursion or typ.align == szIllegalRecursion:
    # we are already computing the size of the type
    # --> illegal recursion in type
    return

  # mark computation in progress
  typ.size = szIllegalRecursion
  typ.align = szIllegalRecursion

  var maxAlign, sizeAccum, length: BiggestInt

  var tk = typ.kind
  case tk
  of tyProc:
    if typ.callConv == ccClosure:
      typ.size = 2 * conf.target.ptrSize
    else:
      typ.size = conf.target.ptrSize
    typ.align = int16(conf.target.ptrSize)

  of tyNil:
    typ.size = conf.target.ptrSize
    typ.align = int16(conf.target.ptrSize)

  of tyString:
    if conf.selectedGC == gcDestructors:
      typ.size = conf.target.ptrSize * 2
    else:
      typ.size = conf.target.ptrSize
    typ.align = int16(conf.target.ptrSize)

  of tyCString, tySequence, tyPtr, tyRef, tyVar, tyLent, tyOpenArray:
    let base = typ.lastSon
    if base == typ:
      # this is not the correct location to detect ``type A = ptr A``
      typ.size = szIllegalRecursion
      typ.align = szIllegalRecursion
      return

    # recursive tuplers are not allowed and should be detected in the frontend
    if base.kind == tyTuple:
      computeSizeAlign(conf, base)
      if base.size < 0:
        typ.size = base.size
        typ.align = base.align
        return

    typ.align = int16(conf.target.ptrSize)
    if typ.kind == tySequence and conf.selectedGC == gcDestructors:
      typ.size = conf.target.ptrSize * 2
    else:
      typ.size = conf.target.ptrSize

  of tyArray:
    computeSizeAlign(conf, typ.sons[1])
    let elemSize = typ.sons[1].size
    if elemSize < 0:
      typ.size = elemSize
      typ.align = int16(elemSize)
    else:
      typ.size = lengthOrd(conf, typ.sons[0]) * elemSize
      typ.align = typ.sons[1].align

  of tyUncheckedArray:
    let base = typ.lastSon
    computeSizeAlign(conf, base)
    typ.size = szUnknownSize
    typ.align = base.align
  of tyEnum:
    if firstOrd(conf, typ) < 0:
      typ.size = 4              # use signed int32
      typ.align = 4
    else:
      length = lastOrd(conf, typ)   # BUGFIX: use lastOrd!
      if length + 1 < `shl`(1, 8):
        typ.size = 1
        typ.align = 1
      elif length + 1 < `shl`(1, 16):
        typ.size = 2
        typ.align = 2
      elif length + 1 < `shl`(BiggestInt(1), 32):
        typ.size = 4
        typ.align = 4
      else:
        typ.size = 8
        typ.align = 8
  of tySet:
    if typ.sons[0].kind == tyGenericParam:
      typ.size = szUncomputedSize
      typ.align = szUncomputedSize # in original version this was 1
    else:
      length = lengthOrd(conf, typ.sons[0])
      if length <= 8:
        typ.size = 1
      elif length <= 16:
        typ.size = 2
      elif length <= 32:
        typ.size = 4
      elif length <= 64:
        typ.size = 8
      elif align(length, 8) mod 8 == 0:
        typ.size = align(length, 8) div 8
      else:
        typ.size = align(length, 8) div 8 + 1
    typ.align = int16(typ.size)
  of tyRange:
    computeSizeAlign(conf, typ.sons[0])
    typ.size = typ.sons[0].size
    typ.align = typ.sons[0].align
  of tyTuple:
    maxAlign = 1
    sizeAccum = 0
    for i in countup(0, sonsLen(typ) - 1):
      let child = typ.sons[i]
      computeSizeAlign(conf, child)
      if child.size < 0:
        typ.size = child.size
        typ.align = child.align
        return
      maxAlign = max(maxAlign, child.align)
      sizeAccum = align(sizeAccum, child.align) + child.size
    typ.size = align(sizeAccum, maxAlign)
    typ.align = int16(maxAlign)
  of tyObject:
    var headerSize: BiggestInt
    var headerAlign: int16
    if typ.sons[0] != nil:
      # compute header size

      if conf.cmd == cmdCompileToCpp:
        # if the target is C++ the members of this type are written
        # into the padding byets at the end of the parent type. At the
        # moment it is not supported to calculate that.
        headerSize = szUnknownSize
        headerAlign = szUncomputedSize
      else:
        var st = typ.sons[0]
        while st.kind in skipPtrs:
          st = st.sons[^1]
        computeSizeAlign(conf, st)
        if st.size == szIllegalRecursion:
          typ.size = st.size
          typ.align = st.align
          return
        headerSize = st.size
        headerAlign = st.align
    elif isObjectWithTypeFieldPredicate(typ):
      # this branch is taken for RootObj
      headerSize = conf.target.intSize
      headerAlign = conf.target.intSize.int16
    else:
      headerSize = 0
      headerAlign = 1
    let (offset, align) =
      if tfPacked in typ.flags:
        (computePackedObjectOffsetsFoldFunction(conf, typ.n, headerSize, false), BiggestInt(1))
      else:
        computeObjectOffsetsFoldFunction(conf, typ.n, headerSize)
    if offset == szIllegalRecursion:
      typ.size = szIllegalRecursion
      typ.align = szIllegalRecursion
      return
    if offset == szUnknownSize or (
        typ.sym != nil and
        typ.sym.flags * {sfCompilerProc, sfImportc} == {sfImportc}):
      typ.size = szUnknownSize
      typ.align = szUnknownSize
      return

    # header size is already in size from computeObjectOffsetsFoldFunction
    # maxAlign is probably not changed at all from headerAlign
    if tfPacked in typ.flags:
      typ.size = offset
      typ.align = 1
    else:
      typ.align = int16(max(align, headerAlign))
      typ.size = align(offset, typ.align)

  of tyInferred:
    if typ.len > 1:
      computeSizeAlign(conf, typ.lastSon)
      typ.size = typ.lastSon.size
      typ.align = typ.lastSon.align

  of tyGenericInst, tyDistinct, tyGenericBody, tyAlias, tySink:
    computeSizeAlign(conf, typ.lastSon)
    typ.size = typ.lastSon.size
    typ.align = typ.lastSon.align

  of tyTypeClasses:
    if typ.isResolvedUserTypeClass:
      computeSizeAlign(conf, typ.lastSon)
      typ.size = typ.lastSon.size
      typ.align = typ.lastSon.align
    else:
      typ.size = szUncomputedSize
      typ.align = szUncomputedSize

  of tyTypeDesc:
    computeSizeAlign(conf, typ.base)
    typ.size = typ.base.size
    typ.align = typ.base.align

  of tyForward:
    # is this really illegal recursion, or maybe just unknown?
    typ.size = szIllegalRecursion
    typ.align = szIllegalRecursion

  of tyStatic:
    if typ.n != nil:
      computeSizeAlign(conf, typ.lastSon)
      typ.size = typ.lastSon.size
      typ.align = typ.lastSon.align
    else:
      typ.size = szUncomputedSize
      typ.align = szUncomputedSize
  else:
    typ.size = szUncomputedSize
    typ.align = szUncomputedSize