<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/64033>64033</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            [clang-tidy] modernize-use-std-print misbehaves when arguments must be re-ordered and casts added or c_str() removed
        </td>
    </tr>

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

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

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

<pre>
    The newly-added _modernize-use-std-print_ check gets confused if it has to re-order arguments at the same time as adding casts or removing calls to `c_str()`. For example applying the check with _StrictMode_ enabled to:
```c++
printf("%*s=%*d\n", 4, s.c_str(), 3, ui);
```
yields:
```c++
std::println("{:>{}}={:{}}", s.c_str(), s4, ui, static_cast<int>(3));
```
rather than the expected:
```c++
std::println("{:>{}}={:{}}", s, 4, static_cast<int>(ui), 3);
```
I attempted to fix this by:

1. Doing the argument re-ordering first in `FormatStringConverter::applyFixes`.
2. Storing the argument index in `FormatStringConverter::ArgFixes` rather than the `Expr *` for the argument, and changing the index as required during re-ordering.

This meant that the cast was being applied to the correct argument, but since there was already a replacement pending for that argument functions like `getBeginLoc()` don't report the right position and the cast ends up in the wrong place resulting in:
```c++
std::println("{:>{}}={:{}}", s.c_str(), 4s, uistatic_cast<int>(), 3);
```
Note that I hadn't even attempted to fix the `c_str()` removal at this point. I've no idea where to even start with that since `FormatStringConverter::ArgCstrRemovals` contains the matched nodes rather than an index.

Is there a good way to have fixes built upon earlier fixes within the same `DiagnosticBuilder` instance, or do I need to handle all the possible combinations myself and generate a single combined fix for each?

An alternative would be to leave the arguments where they are and use argument indices in the format string, e.g.:
```c++
std::println("{2:>{1}}={4:{3}}", 4, s, 3, static_cast<int>(ui));
```
However, if argument indices are used then they must be used in the entire format satring and I wouldn't necessarily know whether they needed to be used until I'd already started rewriting earlier arguments which makes even this rather messy.

Any advice gratefully received.
</pre>
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