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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW --- - [CWG 734] Nonconforming aliasing of block scope objects"
href="https://llvm.org/bugs/show_bug.cgi?id=27443">27443</a>
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<th>Summary</th>
<td>[CWG 734] Nonconforming aliasing of block scope objects
</td>
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<th>Product</th>
<td>clang
</td>
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<th>Version</th>
<td>unspecified
</td>
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<th>Hardware</th>
<td>PC
</td>
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<th>OS</th>
<td>Windows NT
</td>
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<th>Status</th>
<td>NEW
</td>
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<th>Severity</th>
<td>normal
</td>
</tr>
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<th>Priority</th>
<td>P
</td>
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<th>Component</th>
<td>C++
</td>
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<th>Assignee</th>
<td>unassignedclangbugs@nondot.org
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<th>Reporter</th>
<td>frankhb1989@gmail.com
</td>
</tr>
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<th>CC</th>
<td>dgregor@apple.com, llvm-bugs@lists.llvm.org
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<th>Classification</th>
<td>Unclassified
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</tr></table>
<p>
<div>
<pre>Case:
// clang++ -std=c++14 -O0 -pedantic-errors
#include <cstdlib>
void foo(const int* p = {})
{
const int a[] = {1, 2, 3, 4};
if(p == a)
std::abort();
if(!p)
foo(a);
}
int main()
{
foo();
}
As per [intro.object]/5, 'std::abort' should not be called. The rule is
introduced by resolution of CWG 734 and applicable here, though the title of
that issue is about "namespace-scope variables".
However, The program compiled by clang++ with will abort while g++ works well.
The C compilers have similar issues. Not sure for the requirements from ISO C.
Related discussion: <a href="https://gcc.gnu.org/ml/gcc/2016-04/msg00178.html">https://gcc.gnu.org/ml/gcc/2016-04/msg00178.html</a></pre>
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</p>
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