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    <body><table border="1" cellspacing="0" cellpadding="8">
        <tr>
          <th>Bug ID</th>
          <td><a class="bz_bug_link 
          bz_status_NEW "
   title="NEW - Does not complains about loop bound variable not being shared"
   href="https://bugs.llvm.org/show_bug.cgi?id=39372">39372</a>
          </td>
        </tr>

        <tr>
          <th>Summary</th>
          <td>Does not complains about loop bound variable not being shared
          </td>
        </tr>

        <tr>
          <th>Product</th>
          <td>OpenMP
          </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>Clang Compiler Support
          </td>
        </tr>

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

        <tr>
          <th>Reporter</th>
          <td>lebedev.ri@gmail.com
          </td>
        </tr>

        <tr>
          <th>CC</th>
          <td>llvm-bugs@lists.llvm.org
          </td>
        </tr></table>
      <p>
        <div>
        <pre>Originally reported as <a href="https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87668">https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87668</a>

<a href="https://godbolt.org/z/05Zgdd">https://godbolt.org/z/05Zgdd</a>

#include <vector>
struct b {};
void c() {
  std::vector<b> d;
#ifdef _OPENMP
#pragma omp parallel default(none)
#pragma omp for
#endif
  for (auto f = d.begin(); f < d.end(); ++f)
    ;
}

#ifndef _OPENMP
Yes, there is OMP.
#endif


GCC output:

<source>: In function 'void c()':
<source>:9:25: error: 'd' not specified in enclosing 'parallel'
   for (auto f = d.begin(); f < d.end(); ++f)
                         ^
<source>:6:9: error: enclosing 'parallel'
 #pragma omp parallel default(none)
         ^~~
Compiler returned: 1

Clang is perfectly happy with that code.


Jakub Jelinek 2018-10-21 10:22:10 UTC
GCC is correct here.
Even with the recent 5.0 clarifications, those expressions are to be evaluated
before the worksharing-loop construct, but still inside of the parallel region,
so with default(none) d needs to be specified on the parallel (e.g. shared or
firstprivate).</pre>
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