<html>
    <head>
      <base href="https://llvm.org/bugs/" />
    </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 --- - attribute visibility problems when using operator overloading (new/delete)"
   href="https://llvm.org/bugs/show_bug.cgi?id=25740">25740</a>
          </td>
        </tr>

        <tr>
          <th>Summary</th>
          <td>attribute visibility problems when using operator overloading  (new/delete)
          </td>
        </tr>

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

        <tr>
          <th>Version</th>
          <td>3.7
          </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++
          </td>
        </tr>

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

        <tr>
          <th>Reporter</th>
          <td>kaptain-blaubaer@web.de
          </td>
        </tr>

        <tr>
          <th>CC</th>
          <td>dgregor@apple.com, llvm-bugs@lists.llvm.org
          </td>
        </tr>

        <tr>
          <th>Classification</th>
          <td>Unclassified
          </td>
        </tr></table>
      <p>
        <div>
        <pre>Using this example:

#include <cstdio>
#include <cstdlib>
// replacement of a minimal set of functions:
__attribute__((visibility("hidden")))
void* operator new(std::size_t sz) {
  std::printf("global op new called, size = %zu\n",sz);
  return std::malloc(sz);
}
void operator delete(void* ptr)
{
  std::puts("global op delete called");
  std::free(ptr);
}
int main() {
  int* p1 = new int;
  delete p1;

  int* p2 = new int[10]; // guaranteed to call the replacement in C++11
  delete[] p2;
}


Compilation fails using CLang 3.7.0 and Clang 3.8.0 (trunk):

$ clang  x.cpp -lstdc++
x.cpp:4:16: error: visibility does not match previous declaration
__attribute__((visibility("hidden")))
               ^
note: previous attribute is here
x.cpp:5:7: warning: 'operator new' is missing exception specification
'throw(std::bad_alloc)'
void* operator new(std::size_t sz) {
      ^
                                   throw(std::bad_alloc)
x.cpp:9:6: warning: 'operator delete' is missing exception specification
'throw()'
void operator delete(void* ptr)
     ^
                      throw()
2 warnings and 1 error generated.


But Succeeds using Clang 3.6.2 and 3.5.0:

$ clang  x.cpp -lstdc++
x.cpp:5:7: warning: 'operator new' is missing exception specification
'throw(std::bad_alloc)'
void* operator new(std::size_t sz) {
      ^
                                   throw(std::bad_alloc)
x.cpp:9:6: warning: 'operator delete' is missing exception specification
'throw()'
void operator delete(void* ptr)
     ^
                                throw()
2 warnings generated.</pre>
        </div>
      </p>
      <hr>
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