<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/77042>77042</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            Missing install prefix in llvm/cmake config cmake files
        </td>
    </tr>

    <tr>
      <th>Labels</th>
      <td>
            new issue
      </td>
    </tr>

    <tr>
      <th>Assignees</th>
      <td>
      </td>
    </tr>

    <tr>
      <th>Reporter</th>
      <td>
          rezso
      </td>
    </tr>
</table>

<pre>
    I tried to compile Qt 6.6.1 with llvm 17.0.6 release, but failed:

`CMake Error in qttools/src/linguist/lupdate/CMakeLists.txt:
  Imported target "WrapLibClang::WrapLibClang" includes non-existent path

 "//include"

  in its INTERFACE_INCLUDE_DIRECTORIES.  Possible reasons include:

  * The path was deleted, renamed, or moved to another location.

  * An install or uninstall procedure did not complete successfully.

  * The installation package was faulty and references files it does not
  provide.`
(and same error for qttools/src/qdoc/qdoc/CMakeLists.txt)

Yes, "//include" really nonexistent directory, but where is the "usr" from the include path?
I looked into ClangConfig.cmake and LLVMConfig.cmake files. In these files the include path definition is ${CLANG_INSTALL_PREFIX}/include and ${LLVM_INSTALL_PREFIX}/include, but I don' found any definition for CLANG_INSTALL_PREFIX and LLVM_INSTALL_PREFIX.
As a quick workaround, I added
set(CLANG_INSTALL_PREFIX "@CMAKE_INSTALL_PREFIX@") and 
set(LLVM_INSTALL_PREFIX "@CMAKE_INSTALL_PREFIX@")
to *Config.cmake.in files, and recompiled the llvm.
After this the qt compilation was successful.
But why happened this? This is a bug, or I missed anything?
</pre>
<img width="1px" height="1px" alt="" src="http://email.email.llvm.org/o/eJyMVV1z6jYQ_TXiZed6bGEgPPDABdzxlKS3uenXU0ZYa1uNkBxpnYT--o5kk3CTTKcvYMm7Zz_O2bXwXjUGccVmX9lsOxE9tdatHP7j7eRg5WlVAjmFEshCZY-d0gi_EsyTeZLBs6IWtH46QrZI0mQODjUKj4xv4NAT1EJplGy6ZumWpeffebq5Fg8IO-esA2Xgkcha7RkvvKsYL7QyTa88hce-k4KQ8SL67JUnn9ALvWIClMfOOgoZCtcgAeP8Dye6vTpstDBNsJyuf7jhHJSpdC_Rg7HmC74oT2gIOkHtZaoBi_GC8WK0D-fL9yF7RR7Km7vdbbHe7O7Lm83-t-3uflve7jZ3v9yWu-8JwDfrvTpoBIfCW-PP8d-1BoDxNdy1GDOBZ-FBokZCGTrq0Ijj8GgdHO3TwIowllp0oG0lSFmTfERcG1DGk9A6ePbmfOicrVD2DkEqCcZSpDgEBN9XFXpf91qfPkEMOY4oMSh0onoQDcaca9FrOoEwEhzW6NBU6KFWGj0oAmlj3-mM1zn7pCQmbJ6OgfhV8PXiiIBRJLV1H1TyKO3F3zt58OVlzn-hD137hM1AiNanIINXFUjlsCLrTmcZP7foEJQHajGA9N4F19rZY7wa4Qb5TIshZgna2geUoAxZiMLbWFOrJqmOQf2hwv3-9-sfLmOPEihNwPXj-UMMkFgro2LflQfGc7b4utmvb366L2--3633-_tvt7ui_JMttm_VxoiDbYj7X6bnwkuQ1jC-gNr2RoIwp8vQgZTPor6W9u5-lNHag4DHXlUP8Gzdg3ABO0QsQUiJcrDySIxffQofaMzTzfX65937IvI0crwcar0A-iSd_4MzQJANmr8kKlFm4CbkPeh8XI4yshV24rncmtABtaN8Hmlco8PYhHF5G7XR5WvU3Ala0XVoIqTybFrAXUBRoX-Hvhn3QAlH5T1GdqhVYeEVE7mayuV0KSa4yhZpnvPF1TybtKtUVtnVIpUHrEV6VWVznmMu8zzPFvM6w-VErXjK8zRLZ2meZWmWzGeYTqv8MBNLOZ2LKctTPAqlk1iidc1Eed_jarFIcz7R4oDax48J5wafIb4MvZxtJ24VfL4c-sazPNVxVl9RSJHG1bXyXpkG3hYU1uolbNlgyHgxjEkVqYCLmZn0Tq9aos6HlRqHvFHU9oekssFvdI8JdM7-jVX4usTswkaJ2f8bAAD__7WXQP8">