<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/63287>63287</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            The llvm-cov is unable to generate coverage reports for fuzzer target
        </td>
    </tr>

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

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

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

<pre>
    Background:
I want to generate a coverage report for my fuzzer target code, but when I run llvm-cov, I get an error saying "No coverage data found". 

Step:
1. build fuzzer target. eg: demo_fuzzer , use -fprofile-instr-generate, -fcoverage-mapping, -fsanitize=fuzzer, -fsanitize=fuzzer-no-link
2.  run ./demo_fuzzer --max_total_time=10
3. llvm-profdata merge -sparse default.profraw -o default.profdata [success]
4. llvm-cov show ./demo_fuzzer --instr-profile=default.profdata [error： ./demo_fuzzer No coverage data found]

It's even more confusing that this issue only happens on Linux, as I was able to successfully generate a coverage report with llvm-cov on my Mac after copying the complete default.profdata file generated on Linux.

System Info: Debian GNU/Linux 10 (buster) Linux 5.4.143.bsk.8-amd64 x86_64

</pre>
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