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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 - Reparse leads to extra diagnostic and removes skipped ranges"
   href="https://bugs.llvm.org/show_bug.cgi?id=34570">34570</a>
          </td>
        </tr>

        <tr>
          <th>Summary</th>
          <td>Reparse leads to extra diagnostic and removes skipped ranges
          </td>
        </tr>

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

        <tr>
          <th>Version</th>
          <td>trunk
          </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>libclang
          </td>
        </tr>

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

        <tr>
          <th>Reporter</th>
          <td>nikolai.kosjar@qt.io
          </td>
        </tr>

        <tr>
          <th>CC</th>
          <td>klimek@google.com, llvm-bugs@lists.llvm.org
          </td>
        </tr></table>
      <p>
        <div>
        <pre>The following code outlines the problems in the comments:

    #ifdef MYCPLUSPLUS
    extern "C" { // On parse this is skipped as expected. On reparse, this is
surprisingly not skipped anymore.
    #endif

    #ifdef MYCPLUSPLUS
    }
    #endif

    int main()
    {
        return 0;
    } // On reparse a diagnostic is added here: "expected '}' to match this '{'
(line 2)"

Here are some c-index-test invocations for this to make this
testable/reproducible ($FILE does not contain the above comments):

Do a parse and save the tokens:

    % ./c-index-test -test-annotate-tokens=$FILE:1:1:7:1 $FILE > /tmp/1

No diagnostics are emitted as expected.

Do a parse and reparse and save also the tokens:

    % CINDEXTEST_EDITING=1 ./c-index-test -test-annotate-tokens=$FILE:1:1:7:1
$FILE > /tmp/2
    $FILE:12:2: error: expected '}'
    Number FIX-ITs = 0
    $FILE:2:12: note: to match this '{'
    Number FIX-ITs = 0

Note that a new diagnostic is emitted on reparse at the bottom of the file
(issue1).
Also, the first skipped source range is not skipped anymore on reparse
(issue2):

    % diff -u /tmp/{1,2}
    --- /tmp/1  2017-09-12 09:33:42.210204021 +0200
    +++ /tmp/2  2017-09-12 09:33:51.458334870 +0200
    @@ -1,4 +1,3 @@
    -Skipping: [1:2 - 3:7]
     Skipping: [5:2 - 7:7]
     Punctuation: "#" [1:1 - 1:2] preprocessing directive=
     Identifier: "ifdef" [1:2 - 1:7] preprocessing directive=</pre>
        </div>
      </p>


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