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    <head>
      <base href="https://bugs.llvm.org/">
    </head>
    <body><table border="1" cellspacing="0" cellpadding="8">
        <tr>
          <th>Bug ID</th>
          <td><a class="bz_bug_link 
          bz_status_NEW "
   title="NEW - clang-format using over 5GB of RAM on a C file with many arrays"
   href="https://bugs.llvm.org/show_bug.cgi?id=48363">48363</a>
          </td>
        </tr>

        <tr>
          <th>Summary</th>
          <td>clang-format using over 5GB of RAM on a C file with many arrays
          </td>
        </tr>

        <tr>
          <th>Product</th>
          <td>clang
          </td>
        </tr>

        <tr>
          <th>Version</th>
          <td>unspecified
          </td>
        </tr>

        <tr>
          <th>Hardware</th>
          <td>PC
          </td>
        </tr>

        <tr>
          <th>OS</th>
          <td>Linux
          </td>
        </tr>

        <tr>
          <th>Status</th>
          <td>NEW
          </td>
        </tr>

        <tr>
          <th>Severity</th>
          <td>enhancement
          </td>
        </tr>

        <tr>
          <th>Priority</th>
          <td>P
          </td>
        </tr>

        <tr>
          <th>Component</th>
          <td>Formatter
          </td>
        </tr>

        <tr>
          <th>Assignee</th>
          <td>unassignedclangbugs@nondot.org
          </td>
        </tr>

        <tr>
          <th>Reporter</th>
          <td>tmatth@videolan.org
          </td>
        </tr>

        <tr>
          <th>CC</th>
          <td>djasper@google.com, klimek@google.com, llvm-bugs@lists.llvm.org
          </td>
        </tr></table>
      <p>
        <div>
        <pre>Created <span class=""><a href="attachment.cgi?id=24228" name="attach_24228" title="Problematic source file">attachment 24228</a> <a href="attachment.cgi?id=24228&action=edit" title="Problematic source file">[details]</a></span>
Problematic source file

I noticed that clang-format was running out of memory on a system with only
3.75GB available. It turns out that for a specific file
(<a href="https://aomedia.googlesource.com/aom/+/c15883a29b9dc3c28caa03e22b7368ed8355d834/av1/common/quant_common.c">https://aomedia.googlesource.com/aom/+/c15883a29b9dc3c28caa03e22b7368ed8355d834/av1/common/quant_common.c</a>)
it is using over 5GB when invoked as follows:

/usr/bin/time -v clang-format -i --style=file aom/av1/common/quant_common.c
        Command being timed: "clang-format -i --style=file
aom/av1/common/quant_common.c"
        User time (seconds): 17.59
        System time (seconds): 1.49
        Percent of CPU this job got: 99%
        Elapsed (wall clock) time (h:mm:ss or m:ss): 0:19.14
        Average shared text size (kbytes): 0
        Average unshared data size (kbytes): 0
        Average stack size (kbytes): 0
        Average total size (kbytes): 0
        Maximum resident set size (kbytes): 5479164        <----------------
        Average resident set size (kbytes): 0
        Major (requiring I/O) page faults: 0
        Minor (reclaiming a frame) page faults: 1375531
        Voluntary context switches: 2
        Involuntary context switches: 136
        Swaps: 0
        File system inputs: 0
        File system outputs: 0
        Socket messages sent: 0
        Socket messages received: 0
        Signals delivered: 0
        Page size (bytes): 4096
        Exit status: 0


The file in question is 12875 lines, and does contain a number of arrays, but
this still seems like it shouldn't be quite so memory intensive. I've seen the
same behavior with both clang 10 and 12.</pre>
        </div>
      </p>


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