<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/118644>118644</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            clang crash on Windows when running pass plugin
        </td>
    </tr>

    <tr>
      <th>Labels</th>
      <td>
            clang
      </td>
    </tr>

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

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

<pre>
    I am attempting to create an example pass plugin on Windows. I have built LLVM from source through the build instructions on https://llvm.org/docs/GettingStartedVS.html using VS 2022. 

Notably, I made a tiny modification to `PassPlugin.h` (`__declspec(dllimport)`) as `llvmGetPassPluginInfo` else was not exported:
```
extern "C" __declspec(dllimport) ::llvm::PassPluginLibraryInfo
    LLVM_ATTRIBUTE_WEAK llvmGetPassPluginInfo();
```

The pass works as intended if tested using opt.exe (` "..\build\MinSizeRel\bin\opt.exe" -load-pass-plugin "C:\Projects\tutorial-llvm-pass\HelloWorld\build\MinSizeRel\Hello.dll" -passes "hello-world" test_hello.ll`). 

clang however crash (`"..\build\MinSizeRel\bin\clang.exe" -fpass-plugin="C:\Projects\tutorial-llvm-pass\HelloWorld\build\MinSizeRel\Hello.dll" -Xclang -disable-O0-optnone test_hello.c`):

```
Stack dump:
0. Program arguments: C:\\Projects\\build\\MinSizeRel\\bin\\clang.exe -cc1 -triple x86_64-pc-windows-msvc19.37.32822 -emit-obj -mincremental-linker-compatible -dumpdir a- -disable-free -clear-ast-before-backend -disable-llvm-verifier -discard-value-names -main-file-name test_hello.c -mrelocation-model pic -pic-level 2 -mframe-pointer=none -relaxed-aliasing -fmath-errno -ffp-contract=on -fno-rounding-math -mconstructor-aliases -fms-volatile -funwind-tables=2 -target-cpu x86-64 -tune-cpu generic -fdebug-compilation-dir=c:\\Projects\\tutorial-llvm-pass -v -fcoverage-compilation-dir=c:\\Projects\\tutorial-llvm-pass -resource-dir C:\\Projects\\build\\MinSizeRel\\lib\\clang\\20 -internal-isystem C:\\Projects\\build\\MinSizeRel\\lib\\clang\\20\\include -internal-isystem "C:\\Program Files\\Microsoft Visual Studio\\2022\\Community\\VC\\Tools\\MSVC\\14.37.32822\\include" -internal-isystem "C:\\Program Files\\Microsoft Visual Studio\\2022\\Community\\VC\\Tools\\MSVC\\14.37.32822\\atlmfc\\include" -internal-isystem "C:\\Program Files (x86)\\Windows Kits\\10\\Include\\10.0.22621.0\\ucrt" -internal-isystem "C:\\Program Files (x86)\\Windows Kits\\10\\Include\\10.0.22621.0\\shared" -internal-isystem "C:\\Program Files (x86)\\Windows Kits\\10\\Include\[test_hello-bce248.zip](https://github.com/user-attachments/files/18009652/test_hello-bce248.zip)
\10.0.22621.0\\um" -internal-isystem "C:\\Program Files (x86)\\Windows Kits\\10\\Include\\10.0.22621.0\\winrt" -internal-isystem "C:\\Program Files (x86)\\Windows Kits\\10\\Include\\10.0.22621.0\\cppwinrt" -ferror-limit 19 -fmessage-length=478 -fno-use-cxa-atexit -fms-extensions -fms-compatibility -fms-compatibility-version=19.37.32822 -fskip-odr-check-in-gmf -fdelayed-template-parsing -fcolor-diagnostics -fpass-plugin=C:\\Projects\\tutorial-llvm-pass\\HelloWorld\\build\\MinSizeRel\\Hello.dll -faddrsig -o C:\\Users\\ADMINI~1\\AppData\\Local\\Temp\\test_hello-ddf9f5.o -x c test_hello.c
1.      <eof> parser at end of file
2.      Optimizer
3. Running pass "function(`anonymous-namespace'::HelloWorld)" on module "test_hello.c"
Exception Code: 0xC0000005
 #0 0x00007ffafa947519 llvmGetPassPluginInfo (C:\Projects\tutorial-llvm-pass\HelloWorld\build\MinSizeRel\Hello.dll+0x7519)
 #1 0x00007ffafa9474f1 llvmGetPassPluginInfo (C:\Projects\tutorial-llvm-pass\HelloWorld\build\MinSizeRel\Hello.dll+0x74f1)
 #2 0x00007ffafa948737 llvmGetPassPluginInfo (C:\Projects\tutorial-llvm-pass\HelloWorld\build\MinSizeRel\Hello.dll+0x8737)
 #3 0x00007ffafa9433ee (C:\Projects\tutorial-llvm-pass\HelloWorld\build\MinSizeRel\Hello.dll+0x33ee)
 #4 0x00007ff614d14b81 (C:\Projects\build\MinSizeRel\bin\clang.exe+0x7d4b81)
 #5 0x00007ff61521855f (C:\Projects\build\MinSizeRel\bin\clang.exe+0xcd855f)
 #6 0x00007ff6152159c7 (C:\Projects\build\MinSizeRel\bin\clang.exe+0xcd59c7)
 #7 0x00007ff61521601f (C:\Projects\build\MinSizeRel\bin\clang.exe+0xcd601f)
 #8 0x00007ff61586877b (C:\Projects\build\MinSizeRel\bin\clang.exe+0x132877b)
 #9 0x00007ff616457f5b (C:\Projects\build\MinSizeRel\bin\clang.exe+0x1f17f5b)
#10 0x00007ff615a43e3d (C:\Projects\build\MinSizeRel\bin\clang.exe+0x1503e3d)
#11 0x00007ff615867621 (C:\Projects\build\MinSizeRel\bin\clang.exe+0x1327621)
#12 0x00007ff615a43cbb (C:\Projects\build\MinSizeRel\bin\clang.exe+0x1503cbb)
#13 0x00007ff615a31f64 (C:\Projects\build\MinSizeRel\bin\clang.exe+0x14f1f64)
#14 0x00007ff615ac283d (C:\Projects\build\MinSizeRel\bin\clang.exe+0x158283d)
#15 0x00007ff6145a1296 (C:\Projects\build\MinSizeRel\bin\clang.exe+0x61296)
#16 0x00007ff61459b87f (C:\Projects\build\MinSizeRel\bin\clang.exe+0x5b87f)
#17 0x00007ff61459c67e (C:\Projects\build\MinSizeRel\bin\clang.exe+0x5c67e)
#18 0x00007ff6145a9d9f (C:\Projects\build\MinSizeRel\bin\clang.exe+0x69d9f)
#19 0x00007ff61722cc18 (C:\Projects\build\MinSizeRel\bin\clang.exe+0x2cecc18)
#20 0x00007ffb32407374 (C:\Windows\System32\KERNEL32.DLL+0x17374)
#21 0x00007ffb32e1cc91 (C:\Windows\SYSTEM32\ntdll.dll+0x4cc91)
clang: error: clang frontend command failed due to signal (use -v to see invocation)
clang version 20.0.0git (https://github.com/llvm/llvm-project.git 83cbb170449b17aa3e1ada514c94d9e9b4f0fca6)
Target: x86_64-pc-windows-msvc
Thread model: posix
InstalledDir: C:\Projects\build\MinSizeRel\bin
clang: note: diagnostic msg:
********************

PLEASE ATTACH THE FOLLOWING FILES TO THE BUG REPORT:
Preprocessed source(s) and associated run script(s) are located at:
clang: note: diagnostic msg: C:\Users\ADMINI~1\AppData\Local\Temp\test_hello-bce248.c
clang: note: diagnostic msg: C:\Users\ADMINI~1\AppData\Local\Temp\test_hello-bce248.sh
clang: note: diagnostic msg:

********************
```
</pre>
<img width="1px" height="1px" alt="" src="http://email.email.llvm.org/o/eJzMWVFz27iu_jXMC4YeiZIs-SEPrpO0mU3bTJNt733q0CRkc0uRGpJynH24v_0OJSWys-menuPd7slkxhZNfh8AAiBAce_VxiCek-INKS7OeBe21p1foVH7d2drKx_Pr4E3wEPApg3KbCBYEA55QOAGcM-bViO03HtodbdRBqyBL8pI--BncA1bvkNYd0oHuLn5_B5qZxvwtnMCIWyd7TZbCNthigRlfHCdCMoaH4G2IbSeZEvCrgi70nrXzKzbEHYlrfCEXb3FEIW6C9wFlJ_vZtvQaOh8FPTzHbCEsRmQZEmS5Qcb-Fo_EraCa2i4ROAQlHmExkpVK8EjadSOzJNb7v1tr81sS-YJEFaRefL1q0ShfYuCsEpqrZrWukDYgswTwhbAfVwbhXyLYYK4NrWNIKg9wgP3YGwA3Me1KKNuyTICDP_JEvcBnQHC2IowBt8lhbg0W0a64dvEeKPWjrvHnjhZAkBv-q_L-_tP129-vb_8-uVy-Qu8LiirokLZmxdSkWR5vx33-cG6bz5qq0xAI1GCqiGgDyhH09s2zHCPo92iLrMZKVb9HpNi9V6ZO_U7fkIdB5UhxWpcETWm2nJJIxMdPaq3RbYkxerW2d9QBE-KVeiCdYprGvXop5Ni9Q61tl-s62lepetnzKTWPVVchj4SbOM4feiXMtar87Ufm2k97O-TIwnNzQa29gF36EA47rejoj-gZ7_4WdP6QEuSXfx9ev7PIDSVyvO1RvoxobYNxho81FQMio4-eewAd4GLbyC7ph1-TmZw6-zGxeTgNl2DJsRAhVGBYx0OhHwp57NlDo0DVIgUaHAqJpd9Nf86z2kr6MOQV2jjdyJdzLJylrEq6oeNCtSufwPaKCMcRnGiyZT5ho4K27Q8qLVGoFEDqRxwOlmjdhgpNXJHuQ90jbV1SNdcfEMjp3n9DuzQqVqh64cFd5LuuO6QGt6gB9pwZWit9DBwZF2gjUNth0xDGytRQ6sE0FYJqnGHGhjQpna8QdraGF2OZBf9LlGHmu9RUq4V72OM1g0PW4rOGQu0rlsqrAmOi0CyC2uA1sZSZzsjldnQOBdoI-yYYK0bkKLIdePpzmoeVDRQ3ZloZhqzJXqSXTCggbsNBiraLm4GnedAQ2ewH9igQRe1qCWuu01vbKUHHaWKCojvuMQfPRvoDmgt7A4d3-CJUA6HYyYu_U_cUqv1gVsOX1kCtN8XwzVV_tEHbP467OFTGaE7ia8QTflh4Oqj70rFbRpZhLPe1gE-K99xDXehk8o-wTM2fFvZpumMCo_D4-fV8HlvrX4CunsaTPPnKDuSrs8q_5UC8qCbWpwkbEzn-2oeU2H_41jOwC_qaWvTca-uR4JxcJbMGJuzdDb-3Il4VP9D5H7LHcqfQ_9mynN0LZDl1ex31ZLigrDquIbbqLDt1jNhG8KuOo-O8hC42A4HCLuqe29hV2mVJIt5wQi7eh2bLeIJ9arVm3_M5g_K_IM7Ltp2EqBG56yjWjUqQLqIaR69j2lVo9mELcku8rIajonOIxV7TnnAvQrDiRDrUOP7Qrx_fjpElVbh8ZWheDDG6SS7ODqaa_9NtdRKR8UWxTeqDN00dX9caP6IksbOQvOAtOVuPNmE1dZRqfjGWB-U8H8olb6Xc1-tll4WTH-em58rJ6A1l9J5tQFqD7L8rx7dCLu8eH_94fr_0vGpbS944MPDjRV8RLzHph3Fm1xZynpRFzMLdA_iuApLlukM-j-SrdDWJLuEaBx0wAPEksTWEAOFJEs2zvzYBtWo39GRZJnN4FNnTLRlfxQSxurO9F3VUKhyY81jYzs_VC0tF0hYObQRB5Zii-hJ1sQWqdOxnGdHcjJGkuXlXmDb904rKzGWgMl-lfR_Rew-CMsSSPbxuaxrXvNFXhbp4vX2I4bC31ECv0n2kXRIGlGk9KVIeZ3-fJHyOp1EYi9Eqsqs_OkiRdJJpOyFSFmG-DeSR_iJPJ_I52ku03xdpa-T_1i_FQ0uI8hEURxSFCytiqI-kULICDJRzF9QFAtRnkwRQSaK8gXFPElP1yKCTBTVEUU1r8pyfSJFmrGIMnEsDjnmeVHWxckcdRpRxlqBZWlypAfPM8zkqRxFElEmjvSFrco5O9Vv04xFlImDvdRDrE-2VZFElIkjO-bI0nqen8qR1xFl4siPOQSr_oL9qCLKxHEU5HnBU7aYn8gxjxgTw_yYYbGuylMDsIgYE0P5gkHMy-8k4h9niBgTQ_XCSgu5OFWHecSYGI7iu2RMiLQ6kYEJjCjPHOwgvtcZy5MyKw99dqysSbG664vyLPaMv1x--nB5k7HZxc3N4EFx1YSZHmFiKsQifR3zf-_uL9_3mCZIrZ_PtTwuGQCHfj9bQl-dxy_DzVztbH-ZCsI2DTcSaq40SpAdQrDg1cZwHVk7j0B3_RgiKLMb75MO4GGsxIHFDiHZqAB_3ob1d8jDB22HbZjFVVVMCGmZ5PlinZacZ5hyyYs0F4tcLnCxzuukFnyMhPv-kiiq9PqFXX-F7JBL6K--4sTWerUnyfLa-MC1Rnmh3MEl4o-4xIFJjQ19_Tn1DdD4zXibyU747y9Db28ul3eXsLy_X67ewf27S7j6eHPz8cv1h7dwdX1zeQf3H_vhN7--hU-Xtx8_3Q_Utw5bZwV6j3J880FY5fs3BkYC994KxQNKcJ0BL5xqw_MEh9DfGKIEHga8f63vk_2eGpWDLmVqUZ76k7E5-WOTLX4il9_-8EaevpdPt9pn8jyTi2zBz_A8LbMsY6zIk7PteZnnrCizOZsXokK-lsjrPEsyVpYlFmlxps5ZwvKUJXmas6qYzzCtBSKvqiJdZFkhSJ5gw5WePb2yOlPed3ieptU8z880X6P2_Us3xga1GSPFxZk774Nw3W08yROtfPATRFBB4_kQ4sNrh-lVGzxs0UQHmrq-oVc-65w-__din7CrXtr-GmYQeHfO_j8AAP__0WOpEg">