delphi - 变体递归地使用自身？

Question

我正在尝试构建 rtl140.bpl 的调试版本，以便更轻松地调试带有运行时包的应用程序。我构建了 DPK 并在其上运行 DCC32，它进入了，然后就死掉了。

C:\Program Files (x86)\Embarcadero\RAD Studio\7.0\source\Win32\rtl\sys\Variants.pas(1072) 致命:F2092 程序或单元“变体”递归地使用自身

但是看看 Variants.pas，我不明白如何做到这一点。它仅在interface部分中使用SysUtils和Types，并且它们都不使用Variants，或者使用任何使用Variants的东西。

有人知道为什么会出现这种情况吗？

Answer 1

这是我们(RAD Studio 团队)不建议重建核心 rtl 包的主要原因之一。这需要非常仔细地完成，并且需要以特定顺序在包含部分中列出单元。

变体是一个有点“ SCSS ”的单位。编译器对此有特定的了解，因此当它看到 Variant 类型的使用时，它会自动将 Variant 添加到使用列表中，以确保存在对 Variant 类型的实际 RTL 支持。 System.pas将大部分变体操作都推迟到Variants单元，但是由于System不能使用除SysInit(这也是一个非常特殊的单元)之外的任何其他单元，因此编译器必须介入。

目前，除了尝试重新排列 .dpk 中的包含列表并重试之外，我没有任何具体建议来完成这项工作。这是我们用来构建该包的 rtl.dpk 中的包含列表:

Variants in 'sys\Variants.pas',
VarUtils in 'sys\VarUtils.pas',
SysConst in 'sys\SysConst.pas',
SysUtils in 'sys\SysUtils.pas',
SyncObjs in 'common\SyncObjs.pas',
Types in 'sys\Types.pas',
VCLCom in 'common\VCLCom.pas',
ComConst in 'common\ComConst.pas',
ComObj in 'common\ComObj.pas',
ComObjWrapper in 'common\ComObjWrapper.pas',
RTLConsts in 'common\RTLConsts.pas',
Contnrs in 'common\Contnrs.pas',
ConvUtils in 'common\ConvUtils.pas',
DateUtils in 'common\DateUtils.pas',
IniFiles in 'common\IniFiles.pas',
Masks in 'common\Masks.pas',
Math in 'common\Math.pas',
Registry in 'common\Registry.pas',
StdConvs in 'common\StdConvs.pas',
StdVCL in 'common\StdVCL.pas',
StrUtils in 'common\StrUtils.pas',
TypInfo in 'common\TypInfo.pas',
VarConv in 'common\VarConv.pas',
VarCmplx in 'common\VarCmplx.pas',
Classes in 'common\Classes.pas',
MaskUtils in 'common\MaskUtils.pas',
HelpIntfs in 'common\HelpIntfs.pas',
ScktComp in 'common\ScktComp.pas',
AccCtrl in 'win\AccCtrl.pas',
AclAPI in 'win\AclAPI.pas',
ActiveX in 'win\ActiveX.pas',
ComSvcs in 'win\ComSvcs.pas',
ADOInt in 'win\ADOInt.pas',
AspTlb in 'win\AspTlb.pas',
COMAdmin in 'win\COMAdmin.pas',
CommCtrl in 'win\CommCtrl.pas',
CommDlg in 'win\CommDlg.pas',
Cpl in 'win\Cpl.pas',
DDEml in 'win\DDEml.pas',
Dlgs in 'win\Dlgs.pas',
DwmApi in 'win\DwmApi.pas',
FlatSB in 'win\FlatSB.pas',
ImageHlp in 'win\ImageHlp.pas',
Imm in 'win\Imm.pas',
Isapi in 'win\Isapi.pas',
Isapi2 in 'win\Isapi2.pas',
LZExpand in 'win\LZExpand.pas',
Mapi in 'win\Mapi.pas',
Messages in 'win\Messages.pas',
MMSystem in 'win\MMSystem.pas',
msxml in 'win\msxml.pas',
Mtx in 'win\Mtx.pas',
MultiMon in 'win\MultiMon.pas',
Nb30 in 'win\Nb30.pas',
Ns30Fix in 'win\Ns30Fix.pas',
Ns35Fix in 'win\Ns35Fix.pas',
Ns36Fix in 'win\Ns36Fix.pas',
Nsapi in 'win\Nsapi.pas',
ObjComAuto in 'common\ObjComAuto.pas',
ObjAuto in 'common\ObjAuto.pas',
OleDB in 'win\OleDB.pas',
OleDlg in 'win\OleDlg.pas',
OpenGL in 'win\OpenGL.pas',
oleacc in 'win\oleacc.pas',
Penwin in 'win\Penwin.pas',
PsAPI in 'win\PsAPI.pas',
RegStr in 'win\RegStr.pas',
RichEdit in 'win\RichEdit.pas',
ShellAPI in 'win\ShellAPI.pas',
SHFolder in 'win\SHFolder.pas',
ShlObj in 'win\ShlObj.pas',
ShLwApi in 'win\ShLwApi.pas',
StrHlpr in 'sys\StrHlpr.pas',
TlHelp32 in 'win\TlHelp32.pas',
UrlMon in 'win\UrlMon.pas',
UxTheme in 'win\UxTheme.pas',
VarHlpr in 'sys\VarHlpr.pas',
WideStrings in 'common\WideStrings.pas',
WideStrUtils in 'common\WideStrUtils.pas',
windows in 'win\windows.pas',
winInet in 'win\winInet.pas',
Winsafer in 'win\Winsafer.pas',
WinSock in 'win\WinSock.pas',
winSpool in 'win\winSpool.pas',
winSvc in 'win\winSvc.pas',
CorError in 'win\CorError.pas',
CorHdr in 'win\CorHdr.pas',
Cor in 'win\Cor.pas',
DXTypes in 'win\DXTypes.pas',
DXFile in 'win\DXFile.pas',
DxDiag in 'win\DxDiag.pas',
D3DX8 in 'win\D3DX8.pas',
D3DX9 in 'win\D3DX9.pas',
Direct3D in 'win\Direct3D.pas',
Direct3D8 in 'win\Direct3D8.pas',
DX7toDX8 in 'win\DX7toDX8.pas',
Direct3D9 in 'win\Direct3D9.pas',
DirectDraw in 'win\DirectDraw.pas',
DirectShow9 in 'win\DirectShow9.pas',
DirectInput in 'win\DirectInput.pas',
DirectSound in 'win\DirectSound.pas',
DirectPlay8 in 'win\DirectPlay8.pas',
DirectMusic in 'win\DirectMusic.pas',
WMF9 in 'win\WMF9.pas',
ZLibConst in 'common\ZLibConst.pas',
ZLib in 'common\ZLib.pas',
Character in 'common\Character.pas',
Generics.Defaults in 'common\Generics.Defaults.pas',
Generics.Collections in 'common\Generics.Collections.pas',
Rtti in 'common\Rtti.pas',
TimeSpan in 'common\TimeSpan.pas',
Diagnostics in 'common\Diagnostics.pas',
AnsiStrings in 'common\AnsiStrings.pas',
TpcShrd in 'win\TpcShrd.pas',
RtsCom in 'win\RtsCom.pas',
MsInkAut in 'win\MsInkAut.pas',
MsInkAut15 in 'win\MsInkAut15.pas',
Manipulations in 'win\Manipulations.pas',
IOUtils in 'common\IOUtils.pas',
D2D1 in 'win\D2D1.pas',
DxgiFormat in 'win\DxgiFormat.pas',
Wincodec in 'win\Wincodec.pas',
KnownFolders in 'win\KnownFolders.pas',
ObjectArray in 'win\ObjectArray.pas',
PropSys in 'win\PropSys.pas',
PropKey in 'win\PropKey.pas',
StructuredQuery in 'win\StructuredQuery.pas',
StructuredQueryCondition in 'win\StructuredQueryCondition.pas';