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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif"">I'm curious how this could work.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif""><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif"">I have two classes.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif"">TargetData and DataLayout.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif""><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif"">I want to point all uses of TargetData at DataLayout.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif""><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif"">typedef won't work not just because of forward declarations, but also because of static functions.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif""><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif"">So, I could define DataLayout as a subclass of TargetData, but once I want to move to DataLayout, how do I define TargetData in a way that won't require changes to many many
locations.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif""><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif"">Micah<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif""><o:p> </o:p></span></p>
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<p class="MsoNormal"><b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">From:</span></b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif""> Kim Gräsman [mailto:kim.grasman@gmail.com]
<br>
<b>Sent:</b> Thursday, October 04, 2012 1:33 PM<br>
<b>To:</b> Villmow, Micah<br>
<b>Cc:</b> Chris Lattner; Evan Cheng; llvm-commits@cs.uiuc.edu LLVM; cfe-commits@cs.uiuc.edu cfe; Nadav Rotem<br>
<b>Subject:</b> Re: [cfe-commits] [llvm-commits] [Patch] Move TargetData from Target to Support/VMCore<o:p></o:p></span></p>
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<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">HI Micah,<br>
<br>
On Thursday, October 4, 2012, Villmow, Micah wrote:<o:p></o:p></p>
<p class="MsoNormal">Chris, the problem with steps #2/#3 is that plenty of clients have forward declarations of TargetData and the typedef won't work in this case, so I need to update the clients anyways.<o:p></o:p></p>
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<p class="MsoNormal"> <o:p></o:p></p>
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<p class="MsoNormal">One trick I've used as an alternative to typedefs is to just derive from the old class, e.g.<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal"> class NewName : public TargetData {};<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">This is forward-declarable just as well as TargetData itself.<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">FWIW,<o:p></o:p></p>
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<p class="MsoNormal">- Kim<o:p></o:p></p>
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