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<p class="MsoNormal"><span style="mso-fareast-language:EN-US">Agreed with Adrian. The issue boils down to libXml2 not having an official release channel on Windows, and being a pain to compile. Can we maybe provide a .py script as part of LLVM, so that users
can build libXml2 themselves? (based on the solution Petr provided)<o:p></o:p></span></p>
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<p class="MsoNormal"><b><span lang="FR">De :</span></b><span lang="FR"> Adrian McCarthy <amccarth@google.com>
<br>
<b>Envoyé :</b> August 24, 2021 1:22 PM<br>
<b>À :</b> Ben Boeckel <ben.boeckel@kitware.com><br>
<b>Cc :</b> Alexandre Ganea <alexandre.ganea@ubisoft.com>; clang developer list <cfe-dev@lists.llvm.org><br>
<b>Objet :</b> Re: [cfe-dev] Cannot CMake self-hosted clang on Windows for lack of libxml2<o:p></o:p></span></p>
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<p class="MsoNormal">> Could an issue please be filed about this? CMake tries hard to not break<br>
backwards compat, though we're not perfect (and we can't fix what we're<br>
not aware of).<o:p></o:p></p>
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<p class="MsoNormal">I appreciate that, but I don't think this is a CMake bug.<o:p></o:p></p>
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<p class="MsoNormal">In this instance, llvm-mt is supposed to be a cross-platform drop-in alternative for mt.exe. In theory, it shouldn't matter which one CMake selects. And, in fact, the point of a self-hosted build is to use the LLVM tool chain. The fact
that llvm-mt's dependencies aren't met on Windows seems like an LLVM problem, either in the tool itself or in the documentation about how to set up the development environment.<o:p></o:p></p>
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<p class="MsoNormal">[Rant about the near-infinite size of LLVM's "supported" configuration space elided, for now.]<o:p></o:p></p>
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<p class="MsoNormal">On Mon, Aug 23, 2021 at 5:12 PM Ben Boeckel <<a href="mailto:ben.boeckel@kitware.com">ben.boeckel@kitware.com</a>> wrote:<o:p></o:p></p>
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<p class="MsoNormal">On Mon, Aug 23, 2021 at 15:17:21 -0700, Adrian McCarthy via cfe-dev wrote:<br>
> Yikes! Thanks for the heads up.<br>
> <br>
> This is the third time I've bisected to find build configuration problems<br>
> that affect only certain Windows configurations only to learn that it was<br>
> (primarily) a change in our tools that broke things (retroactively). Since<br>
> the bot configurations aren't updated very often, it's easy for these<br>
> problems to go unnoticed for a very long time.<br>
<br>
*Puts on CMake developer hat*<br>
<br>
Could an issue please be filed about this? CMake tries hard to not break<br>
backwards compat, though we're not perfect (and we can't fix what we're<br>
not aware of).<br>
<br>
> It's one thing not to have hermetic builds, but it's quite another to allow<br>
> every developer to choose from a wide range of versions for each of the<br>
> myriad tools necessary to build the product. The builds are so sensitive<br>
> to so many details of the environment, it's rather amazing to me how often<br>
> we manage to succeed.<br>
<br>
Yes, and CMake tries not to be the bump in the road there, but we can<br>
fix this in 3.20.6 and 3.21.2 (maybe 3.21.3, depends on how intricate<br>
the fix is).<br>
<br>
Thanks,<br>
<br>
--Ben<o:p></o:p></p>
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