<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/56693>56693</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            Clang: Test failures due to "LLVM ERROR: picking up libstdc++ headers is unimplemented on AIX"
        </td>
    </tr>

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

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

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

<pre>
    I'm building clang with `-DCLANG_DEFAULT_CXX_STDLIB:STRING=libstdc++` and `-DCLANG_DEFAULT_RTLIB:STRING=libgcc` and get the following test failures:
```
  Clang :: Driver/cxa-atexit.cpp
  Clang :: Driver/ignore-xcoff-visibility.cpp
  Clang :: Driver/openbsd.cpp
  Clang :: Driver/ppc-crbits.cpp
  Clang :: Driver/ppc-isa-features.cpp
  Clang-Unit :: Interpreter/ExceptionTests/./ClangReplInterpreterExceptionTests/0/1
  Clang-Unit :: StaticAnalyzer/./StaticAnalysisTests/1/45
  Clang-Unit :: StaticAnalyzer/./StaticAnalysisTests/13/45
  Clang-Unit :: StaticAnalyzer/./StaticAnalysisTests/14/45
  Clang-Unit :: StaticAnalyzer/./StaticAnalysisTests/16/45
  Clang-Unit :: StaticAnalyzer/./StaticAnalysisTests/17/45
  Clang-Unit :: StaticAnalyzer/./StaticAnalysisTests/19/45
  Clang-Unit :: StaticAnalyzer/./StaticAnalysisTests/2/45
  Clang-Unit :: StaticAnalyzer/./StaticAnalysisTests/20/45
  Clang-Unit :: StaticAnalyzer/./StaticAnalysisTests/22/45
  Clang-Unit :: StaticAnalyzer/./StaticAnalysisTests/23/45
  Clang-Unit :: StaticAnalyzer/./StaticAnalysisTests/34/45
  Clang-Unit :: StaticAnalyzer/./StaticAnalysisTests/35/45
  Clang-Unit :: StaticAnalyzer/./StaticAnalysisTests/37/45
  Clang-Unit :: StaticAnalyzer/./StaticAnalysisTests/38/45
  Clang-Unit :: StaticAnalyzer/./StaticAnalysisTests/40/45
  Clang-Unit :: StaticAnalyzer/./StaticAnalysisTests/41/45
  Clang-Unit :: StaticAnalyzer/./StaticAnalysisTests/43/45
  Clang-Unit :: StaticAnalyzer/./StaticAnalysisTests/44/45
```
mostly due to clang/LLVM throwing the following error and bailing out:
```
LLVM ERROR: picking up libstdc++ headers is unimplemented on AIX
```
for example:
```
Command Output (stderr):
--
/var/tmp/paludis/build/dev-lang-clang-scm/work/llvm-project/clang/test/Driver/cxa-atexit.cpp:29:15: error: CHECK-AIX: expected string not found i
n input
// CHECK-AIX: "-fno-use-cxa-atexit"
              ^
<stdin>:1:1: note: scanning from here
clang version 15.0.0 (/var/cache/paludis/distfiles/scm/llvm-project b33aeee3e3766191ba7ffe2f7b60016ba1fddff2)
^
<stdin>:8:191: note: possible intended match here
0. Program arguments: /var/tmp/paludis/build/dev-lang-clang-scm/work/build/bin/clang -### -target powerpc-ibm-aix-xcoff -c /var/tmp/paludis/build
/dev-lang-clang-scm/work/llvm-project/clang/test/Driver/cxa-atexit.cpp -o /dev/null
                                                                                                                                                                                              ^

Input file: <stdin>
Check file: /var/tmp/paludis/build/dev-lang-clang-scm/work/llvm-project/clang/test/Driver/cxa-atexit.cpp

-dump-input=help explains the following input dump.

Input was:
<<<<<<
            1: clang version 15.0.0 (/var/cache/paludis/distfiles/scm/llvm-project b33aeee3e3766191ba7ffe2f7b60016ba1fddff2)
check:29'0     X~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ error: no match fou
nd
            2: Target: powerpc-ibm-aix-xcoff
check:29'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
            3: Thread model: posix
check:29'0     ~~~~~~~~~~~~~~~~~~~~
            4: InstalledDir: /var/tmp/paludis/build/dev-lang-clang-scm/work/build/bin
check:29'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
            5: LLVM ERROR: picking up libstdc++ headers is unimplemented on AIX
check:29'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
            6: PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace, [...]
```

What's the proper way to fix this? Should the tests even be executed when `clang` is configure to use `libstdc++` headers by default? Or should the tests make sure that `libc++` headers are picked up? Any help with this is appreciated
</pre>
<img width="1px" height="1px" alt="" src="http://email.email.llvm.org/o/eJztWN9z4jYQ_mvMi8aMbYEJDzxwQK6Zpnc3Sa7N240sr7Ea2fJIMpD-9V3JcCGB9Do9X6_tNCMbIu8vfVrvtyJT-ePsKkgmFclaIXNRrwmXDO9bYUsSpFG4XFzP3739tFxdzj9e331a3N9_ur1bXl-9Cej89u7m6t3bgC6lyIzNeZC8cSONCKvzc9o3d6eKa84PGmuwxJZACiWl2rpgLBhLCiZkq8GgYhAtg2iO8vvh_yVk4WN2z-mcLLXYgA6SS75jIbOwE3bIm-aPZcW6VhrCHVdFEW6EEZmQwj5-WVE1UGcm_7Jg0_CQ60xY8-dkhWFhAcy6lZ9ohB9rYQ9qV7UF3WiwXne149BYoeo7xM7gxBAvr3QDjTySPRGM8Ipfd3NrmRV8XjP5-Jv35AwfTRphDpZivEbjfkzRHm2NerSV9mhr0qOtaX-2kh5NRT3a6jOuHtOL9phedNyjrR7Ti170Z2vUY06Meiw5ox5zYnScEy94q1LGykeSt0Cs6ngXha-vf_4JWVDvCfAZHYLWSnuqzJAT3Yxq7Wu06A2tbm7e37iYG8EfnELbkGdsTUpgOWhDhCFtLapGQgVIEjlRNZlf3Z81XWAUsGNO-DXvC1VVLtD3rW1aRC65QJ8Yf5BMP6uE4V41udwwh6OtGsd-TLa5cOj5pgQ_c9iEfhc8SKHhFU5ulX7ADyk3Vdho9Stw60h_D6PrHPDjtWaAzn0c8dhh42F1XxY_rBY_hm7VbnbXoEkEwljtkKsVtiKqxTWJLuyaiBrX9nkNOJ5bCJIkLGoVtgbCJ_84e0it479gvNpboguEStQBXbkI95dz78AmhrO6dvEUWlW4exo6ta5vw8UapHQSj4fRMHKwfwaXM17CM3jxbgshwX3vMD0Gk2SUMgCgQCdpGk_jjE2KApJikqVRFKcZi4s8L4rEbWkX-fklXLglTJ8tolEGWywJiKCFOkeQK2Z5ebScaEg-aLXWrCJMr1uXk6bD9Cty5SCTYWj7VCFh4DjADRJadIU9aKO22CRhC5ZVIRO7riskIf-S80Mi9J6uJFSks4v3upXyXAL92_6essXfr9y7RFw6-m0-yqCunpTAH54e__0V4yjUMG-rJuxefrosQTauWEgmavOiYHsZ4sSHp2vdsqMjDV28HCdb7N-gf8Brzt1WdBU0mUQ-tPtgsvp_fP14oqJa7UsiUs6ebvLTlEic6J2vWl1ZPVO4Xt20b7iSk0CpD7TU2GyQSuUg9ywgdt8mvJMARt1J2VgmJeRLoXslk-8A8XccJ-D6LqrPfvM_CuUJcKmD6sP1an67IqbNKjxjMJK1a6KhUdq6c0FpbeN5wjeYa2HLNhtydSjjp3wmjGl9rfcHBVFzTGrwvMQ1MyUeHfiD1YwjSSyQhN8Mh8NgvDzbxHf3X0qGdicdt6GfBjRy16MLrhA7nMVXhl6S21K1MvdCjkoNgQ3UJAPkRuCt2-FtiRNovGPcNHI5wFVdiHWr_RkIG2X3_OTnxEPOZHhagoK10jqH7zUxL31W7AEQSWcOo94bO2OJoYRLUYyqbZyxef1IPJP7Xz7dmlx0rGk0cIFtQD6AWZyOL9KLKU1Hg3xG8ymdsoEVVsLMnxF9iTv-wfJwtMOOv6eXI0kGrZazv54T4zSd0kE5GyPfX_AoK6JoQjmNxzkdZTCKxwUt4rhIBpJlIM0M8wOd1rAl3oQ7u4yXAzFLoiSJJskonkbJKBkmxTRLp4hOSpNpFCXBKIIKURi6OIZKrwd65kPC3Db4UGJLYp4eMjwNrGsA7w7ts9aWSs8qpjcD73fm4_4dQpSLVA">