<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/62711>62711</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            clang-15 crashes on __builtin_va_arg
        </td>
    </tr>

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

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

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

<pre>
    The bug triggering testcase:
```
$ cat small.c
#include <stdarg.h>
#include <stdlib.h>

void vat(va_list param, ...) {
  va_list local;

  __builtin_va_start(local, param);

  if (__builtin_va_arg(global, int) << 1) abort();
}
```

when compile it with clang-15, I got a crash:
```
$ clang-15 small.c
PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace, preprocessed source, and associated run script.
Stack dump:
0. Program arguments: /usr/lib/llvm-15/bin/clang -cc1 -triple x86_64-pc-linux-gnu -emit-obj -mrelax-all --mrelax-relocations -disable-free -clear-ast-before-backend -disable-llvm-verifier -discard-value-names -main-file-name small.c -mrelocation-model pic -pic-level 2 -pic-is-pie -mframe-pointer=all -fmath-errno -ffp-contract=on -fno-rounding-math -mconstructor-aliases -funwind-tables=2 -target-cpu x86-64 -tune-cpu generic -mllvm -treat-scalable-fixed-error-as-warning -debugger-tuning=gdb -fcoverage-compilation-dir=/home/wierton/tmp/hunter -resource-dir /usr/lib/llvm-15/lib/clang/15.0.7 -internal-isystem /usr/lib/llvm-15/lib/clang/15.0.7/include -internal-isystem /usr/local/include -internal-isystem /usr/bin/../lib/gcc/x86_64-linux-gnu/12/../../../../x86_64-linux-gnu/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -fdebug-compilation-dir=/home/wierton/tmp/hunter -ferror-limit 19 -fgnuc-version=4.2.1 -fcolor-diagnostics -faddrsig -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o /tmp/small-835e14.o -x c ./small.c
1. ./small.c:9:41: current parser token ')'
2.      ./small.c:4:30: parsing function body 'vat'
3.      ./small.c:4:30: in compound statement ('{}')
clang: error: unable to execute command: Segmentation fault
clang: error: clang frontend command failed due to signal (use -v to see invocation)
Ubuntu clang version 15.0.7
Target: x86_64-pc-linux-gnu
Thread model: posix
InstalledDir: /usr/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: /tmp/small-29a2d3.c
clang: note: diagnostic msg: /tmp/small-29a2d3.sh
clang: note: diagnostic msg:

********************
```

My clang version is:
```
Ubuntu clang version 15.0.7
Target: x86_64-pc-linux-gnu
Thread model: posix
InstalledDir: /usr/bin
Found candidate GCC installation: /usr/bin/../lib/gcc/x86_64-linux-gnu/10
Found candidate GCC installation: /usr/bin/../lib/gcc/x86_64-linux-gnu/11
Found candidate GCC installation: /usr/bin/../lib/gcc/x86_64-linux-gnu/12
Found candidate GCC installation: /usr/bin/../lib/gcc/x86_64-linux-gnu/7
Found candidate GCC installation: /usr/bin/../lib/gcc/x86_64-linux-gnu/7.5.0
Found candidate GCC installation: /usr/bin/../lib/gcc/x86_64-linux-gnu/8
Found candidate GCC installation: /usr/bin/../lib/gcc/x86_64-linux-gnu/9
Selected GCC installation: /usr/bin/../lib/gcc/x86_64-linux-gnu/12
Candidate multilib: .;@m64
Selected multilib: .;@m64
```
</pre>
<img width="1px" height="1px" alt="" src="http://email.email.llvm.org/o/eJzEV1tv27gS_jX0y4CCRMm3Bz-4dtQW6J4WTfbso0FRI5lbijR4cdJ_f0BKdps07W57NtjAUCRy5pvh3Mmdk71G3JD5KzLfz3jwR2M39xKtN3rWmPbz5u6I0IQevJV9j1bqHjw6L7hDUm5Jvif5lizy6Td-sgoE9-AGrlQmLoul1EKFFoGUO-dbbvvsSMqb72wr2Xy9nZ5nI1s4c0_Y6swPSjoPJ275QNgOsiwjbA1k-WqkBbiQKCO4IuWrr5EADocmSOWlPpz5wXluI-pIynYX2PU3bLIDwlaPmLntCVv1yjQjr9Q-aVLuSLmDIr7zxiT8R4jL_fPWS8_7I2oQZjhJhSA93Et_BKG47mkxj1LeQm88cBCWu-MPPTExPXbHh3c329sbcKEZZISJLrZ4MtaDN3D0_uQiKKsJq3vpj6HJhBkIq5U6X_7RkzV_ovCE1dK5gI6wGrhu4eJJf8RRP2i4-OQtF5iMa_FkjUDnsAVngh2XIyd3zgjJPbZggwYnrDz5bFT51nPxCdownK7HzTP4YE1v-QDc9mFA7aPaQFgdnI1qyuaibDRb3UhNWJ1MAlSIAqi38qQQHlaLw6KiJ0GV1OGB9joAxUF6apo_gQ4WFX-gXCmglw-LMVy8NNoBbaXjjULaWUSgQiG3lDtPG-yMRRrPj7r9QpdUOqOVnUSblgW3LT1zFZBqPqADOnCpaSfVuHDx36jMJJkOpkUFJymAnqSgCs-ogI0f0tGTRKBDZ_mA9GSk9mhJuU_H6AbujxSt1QZo152oMDq6yJNybzTQThtqTdCt1D2NtEAHYbTzNghvLOVKchfV7IK-l7qlPh7MkXLPgHpue_RUnEK0LF1UQH3QmBZ61GijwkM0QvQAck-d4Gq0oHzANuoVZTh6z62ORYe22IRYgSKQ1D0p933bAO2EOaPlPdIxW0aztDKek7D6aAYkrJ5KGmG1H05xOURTALU4xl9k-H7UjN8pagiri3mWZ0ugyZqaKyrdZ-dx-Dn-mDRTmvwIaSxIf4d0DO1YBSd5vRCE1VNgX6M6KsAuhE8ez9B-Kxgf4ov4VoGJ9BmcH3P_vAigXYqGX3J5N4aWkrHwFWugXa-DiLnopNGk3FcZy4oUWMpY2krea-O8FDHUedtaJ3ug-8Ph9W53eLP9781h_8f2Y80Ou_rtYXv7Gyn3BVADV8Epb-mqnGNRZQboAwjILuuXelxkj9bK7ZqU26qIxUwEa1GnVufQgjefUANhy9hM2HJkZxmkv8cYFSm3ZR4xIm_Moi5oEa0FsbdHkNRNJ5DyL0Dk2JFiTQDnucdYbyG1tWXsu8v9pFVCG8O93EKyd3wJOiZ47C_4gCJ4jHAD123cvMU-wiVfQseD8t-DGat3Z432saROGNBxqbCFNiQJcbDhKioXHAI9pzVEkPo8lc6ror83QfswwU5hAFOSJoK7VMyi6Ge6xERytMhbSNU42ds4-TBuvdXOc6Ww3Uv7qDfFhH18RG18HKrgS8zB4PovzZ39H7-vZoup92_v7ra7N3D35gbq9-_evf_j7X9eQ_323c0t3L1Py69-fw0fbz68_3h31eHDc7175dKQ873-fSWwmIaxuMv9FfKvj_80l9ias7a8pM4v87vjT9r_n_LCcwPfb5-fRKB035vq_vWArVMJEFy3suUe4fUuTr2Ja0ytp1x_sy_lLwtfvCw8e1H45cuiZ_PsZa2_elH0qZTfokIRy8s_7NPdVd8hKC8jV7mFLN7lqnxYVE-k_4jomsuzdlO263LNZ7gpFquqKJfVKp8dNw1fLBareYFNW66bdZUXPGcLNl-sWbFet-VMbljOynxezPPlfJXnWdNUmFdVzljVoCgEqXIcuFRZHEEzY_tZup9tFmxZFDPFG1Qu3fkZ03gPaZMwRub7md2ksbUJvSNVHu_P7guKl17h5nqhTFc7dGA0PL0Qz4JVm1-_RSZF_xcAAP__qFcthg">