<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/68942>68942</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            Extraneous warning messages with printf format warning in Openmp offload regions
        </td>
    </tr>

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

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

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

<pre>
    If the printf format specifier does not match the variable type, clang can issue a warning message.
If the printf function is inside an OpenMP offload region, a number of extra warning messages can be issued.
It seems to only occur if all the variables in the local scope are used in the offload region.

Example:
```
int main()
  {
      double a = 100;
  #pragma omp target
      {
 printf("target a = %d\n",a);
      }
  }
```
Compiled with: `clang++ -fopenmp -fopenmp-targets=nvptx64 printf_extra_warnings.cpp` will produce the expected
```
printf_extra_warnings.cpp:9:34: warning: format specifies type 'int' but the argument has type 'double' [-Wformat]
 9 |         printf("target a = %d\n",a);
      | ~~    ^
      |                            %f
1 warning generated.
printf_extra_warnings.cpp:9:34: warning: format specifies type 'int' but the argument has type 'double' [-Wformat]
    9 | printf("target a = %d\n",a);
      |                            ~~ ^
      |                            %f
```
And then additional warnings get output:
```
/mnt/prev/home/mdewing/software/llvm/github/usr_main/lib/clang/18/include/__clang_cuda_device_functions.h:38:36: note: used here
   38 | __DEVICE__ void __brkpt(int __a) { __brkpt(); }
      | ^
/mnt/prev/home/mdewing/software/llvm/github/usr_main/lib/clang/18/include/__clang_cuda_device_functions.h:1189:22: note: used here
 1189 |   return __bool2mask(__vseteq2(__a, __b), 16);
 | ^
/mnt/prev/home/mdewing/software/llvm/github/usr_main/lib/clang/18/include/__clang_cuda_device_functions.h:1189:10: note: used here
 1189 |   return __bool2mask(__vseteq2(__a, __b), 16);
 |          ^
 ...
```

If a variable is added to the local scope and is not used in the offload region, the extra warnings do not happen
```
int main()
{
    double a = 100;
    int b;
#pragma omp target
    {
        printf("target a = %d\n",a);
    }
}
```

Use the variable in the offload region, the extra warnings reappear:
```
int main()
{
    double a = 100;
    int b;
#pragma omp target
    {
 printf("target a = %d\n",a);
        b = 1;
 }
}
```

clang version 18.0.0 (https://github.com/llvm/llvm-project.git 6f5b372d593f1d08f6569a32f529b6bd5106237c)

</pre>
<img width="1px" height="1px" alt="" src="http://email.email.llvm.org/o/eJzMV8uOozgXfhpnc1QI7EDIIotKUpF68eufzcwskcEH4mlje2yTVG_q2UeGXCrprlJfNKOyImJ8O5-_c4V7LzuNuCL5muTbGR_C3rhVz91ngUepu1ltxJfVpxbCHsE6qUMLrXE9D-AtNrKV6EAY9KBNgJ6HZj8uPXAnea0QwheLhG6gUVx30HAN0vsBgcOROy11Bz16zztMSLol6eOdqEE3QZq4CaT2UiBwDf-3qP_3G5i2VYYLcNhJo6MQDnroa3RgWsDn4L4S4kcENU4gxFlmAI_YewgGjFZfwDTN4EC2wJW6uU5EMQ4o03AFvjEWgTuEwaM4z93iOsmYnk_PvLcKCTu9kyI9_cZXqSOHUhNaErqcxgDIYn3uxibMEInlQNgWsjQl7DJNKLOOdz0H01sI3HUYXm-9njTxO8qh07rTgYTmguQbTSgldMMjDLa-PWN7Bbb95jU2prdSoYCjDHvCHoEU6ah_QteEruGhNRZ1by-dhwmCJ2yrDzY8F_MTwGrUYnXSok8aa0mRwlEqBdYZMTQ4Uo7PFpuA4ptw3j6KPS4Je2TziPE0Ebt3Bu5HIwZCF1IHQhdQD2GUyl039KgD7Pl1zaSeuIzk64c_p7NIfiZtCWSxgXP7FTVs4OVl7OVP9xPvNELzdlqeXZyjQ42Oh4s_fCjCAE6c_RpX77SXl5_m8M7SHrWI99TAhZAxbnF1pslDBGyGYIfwlvsTuusjYTvr8EDobm96jGNTKCZ0500bjtzFQaUOPaG7Tob9UBO6G7yrptCxUzIOnBxul5WE7qRu1CDivqoaJ6pmELwSeJANVuco65PorayMjyLqVZsQY9UU3fbo8EISK0eSqmr79MenzVNVwcFIAVVVu882EFrGUFZVURkx6ryamNTzOoycGb8o4WPwkGVlNHZK32MiLjqZi8MwOB1vaoyiPfefCS2r6uAx4N907POYpKqqjhzQDWTFja1-XA6y9L_k4OpnF69MkuTbHnOuGfi14pA-uh-KmM2_StVaxPlYq7ydsSOsKam8qiA8CDPu23NrUX93-r5J3u-kboC4u76MvJ_K70qCn08k1xT-Ri6fnr97vC3rfoQ4h5Ey7n6k6vm3afv5ZAJQTzheG-13kTiVwAd0Pla0WZmkSQqElvsQrI_k0N3Fi5PG9FfPjn8P1pm_sAlJJwMUbV6zBRX5krWZSMu2yIslZ7TN6bIuapFnaUHZornwORMrJpZsyWe4yorlIsuLMs1n-5UoyrLMWEY55nnN6zStWVrmNBcU52zRzOSKppRlacbSlBbzPMkWZZk2rM0QF5whJfMUey5VElEmxnWzsbheFeVyTmeK16j8-H1BqcbjVHlHdvPtzK3Gm9VD58k8VdIHfz0lyKBw9RRtSaMZ_Ne1fCwv7z5Kzmvk9JXQ2zsT9bPBqdWPMR5jZgTtCd2Nl_onAAD__7JK484">