<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/97983>97983</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            "clang/docs/LibTooling.rst" example code causing crash when invalid paramter given
        </td>
    </tr>

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

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

    <tr>
      <th>Reporter</th>
      <td>
          nickhuang99
      </td>
    </tr>
</table>

<pre>
    For people new to clang like myself, the first tutorial is very essential to learn. That is why those example code from tutorial _clang/docs/LibTooling.rst_ should be very **solid**. Unfortunately a basic error handling always causes core dump which seems scary to a rookie developer. 
The following snippet causes core dump when command line parameter is invalid because **Error** returned from `ExpectedParser.takeError()`  unhandled.

`    auto ExpectedParser = CommonOptionsParser::create(argc, argv, MyToolCategory);`
`    if (!ExpectedParser) {`
`      llvm::errs() << ExpectedParser.takeError();`
`      return 1;`
`    }`
`

A simple fix like this
` toString(ExpectedParser.takeError()); ` 
can fix this because `toString` will call `handleAllErrors` before formatting string result.
It maybe seems trivial, but I believe the **Hello World** is giving very important impression for all new ones to clang.

 
</pre>
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