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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 --- - -Wold-style-cast should be suppressed in the expansion of system header macros"
   href="http://llvm.org/bugs/show_bug.cgi?id=18147">18147</a>
          </td>
        </tr>

        <tr>
          <th>Summary</th>
          <td>-Wold-style-cast should be suppressed in the expansion of system header macros
          </td>
        </tr>

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

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

        <tr>
          <th>Hardware</th>
          <td>All
          </td>
        </tr>

        <tr>
          <th>OS</th>
          <td>All
          </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>jonathan.sauer@gmx.de
          </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>The following code (which includes itself as a system header) produces a
warning when compiled with clang r196506 and -Wold-style-cast:

#ifdef IS_INCLUDE_FILE
#pragma clang system_header

#define FOO(a) ((int*) (a))

#else
#define IS_INCLUDE_FILE
#include __FILE__

int main()
{
    int* i = FOO(0);
}
#endif


This results in:

% ~/LLVM/build/Release+Asserts/bin/clang++ -c -Wold-style-cast clang.cpp  
clang.cpp:12:14: warning: use of old-style cast [-Wold-style-cast]
    int* i = FOO(0);
             ^~~~~~
clang.cpp:4:24: note: expanded from macro 'FOO'
#define FOO(a) ((int*) (a))
                ~~~~~~ ^
1 warning generated.


While -Wold-style-cast already is suppressed inside function definitions in
system headers, it should also be suppressed when a macro defined in a system
header is expanded outside of a system header.

(real-life examples are found in the SSE headers shipped with clang such as
emmintrin.h)</pre>
        </div>
      </p>
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