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      <base href="http://llvm.org/bugs/" />
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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 --- - With -std=c++11, setjmp and sigsetjmp lose returns_twice attribute"
   href="http://llvm.org/bugs/show_bug.cgi?id=19207">19207</a>
          </td>
        </tr>

        <tr>
          <th>Summary</th>
          <td>With -std=c++11, setjmp and sigsetjmp lose returns_twice attribute
          </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>normal
          </td>
        </tr>

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

        <tr>
          <th>Component</th>
          <td>C++11
          </td>
        </tr>

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

        <tr>
          <th>Reporter</th>
          <td>eugeni.stepanov@gmail.com
          </td>
        </tr>

        <tr>
          <th>CC</th>
          <td>dgregor@apple.com, llvmbugs@cs.uiuc.edu
          </td>
        </tr>

        <tr>
          <th>Classification</th>
          <td>Unclassified
          </td>
        </tr></table>
      <p>
        <div>
        <pre>This results in rare miscompilations and is causing the current failure on
lab.llvm.org:8011/builders/sanitizer-x86_64-linux (android tests). Observed
both on arm-android and x86_64-linux.

$ cat 1.cc
#include <setjmp.h>
void f() {
  jmp_buf a;
  sigjmp_buf b;
  setjmp(a);
  sigsetjmp(b, true);
}

# clang++ 1.cc -S -emit-llvm -o -
...
; Function Attrs: nounwind returns_twice
declare i32 @_setjmp(%struct.__jmp_buf_tag*) #1

; Function Attrs: nounwind returns_twice
declare i32 @__sigsetjmp(%struct.__jmp_buf_tag*, i32) #1
...

# clang++ 1.cc -S -emit-llvm -std=c++11 -o -
...
; Function Attrs: nounwind
declare i32 @_setjmp(%struct.__jmp_buf_tag*) #1

; Function Attrs: nounwind
declare i32 @__sigsetjmp(%struct.__jmp_buf_tag*, i32) #1
...</pre>
        </div>
      </p>
      <hr>
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