<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/102937>102937</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            [clang-format] Unstable output with AllowShortFunctionsOnASingleLine=inline
        </td>
    </tr>

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

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

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

<pre>
    Somewhat minified test case:
```cpp
auto f() {
#define M(x)     \
  case x: {      \
    return {#x}; \
  }
}
```
Formatting it with `clang-format-18 -Werror --style='{AllowShortFunctionsOnASingleLine: Inline}'` results in oscillating outputs - original code produces output 1, it produces output 2, which produces output 1, and so on.
Output 1:
```cpp
auto f() {
#define M(x) \
  case x: { \
    return { \
      #x \
    }; \
 }
}
```
Output 2:
```cpp
auto f() {
#define M(x) \
  case x: { \
 return {#x}; \
  }
}
```

It is a regression in clang-format-18, 17 works fine. Issue is still present in clang-format-19, did not check with trunk.
</pre>
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