<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/63284>63284</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            Clang with `-pedantic` issues `-Wgnu-line-marker` that it wrote itself in `-frewrite-includes` output
        </td>
    </tr>

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

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

    <tr>
      <th>Reporter</th>
      <td>
          boris-kolpackov
      </td>
    </tr>
</table>

<pre>
    Clang issues the `"this style of line directive is a GNU extension"` warning for line directives that it writes itself in the output produced with `-frewrite-includes`. For example:

```
$ cat <<EOF >test.c
#include <stdlib.h>
EOF

$ clang -pedantic -E -frewrite-includes -o test.i test.c
$ clang -pedantic -c test.i
test.i:1:5: warning: this style of line directive is a GNU extension [-Wgnu-line-marker]
# 1 "<built-in>"
    ^
test.c:4:5: warning: this style of line directive is a GNU extension [-Wgnu-line-marker]
# 1 "test.c"
 ^
test.c:1:5: warning: this style of line directive is a GNU extension [-Wgnu-line-marker]
# 1 "/usr/include/stdlib.h" 1 3 4
 ^
```

This appears to be new behavior starting from Clang 15.
</pre>
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