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<base href="https://bugs.llvm.org/">
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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - Clang can not detect binding to null pointer"
href="https://bugs.llvm.org/show_bug.cgi?id=46089">46089</a>
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<tr>
<th>Summary</th>
<td>Clang can not detect binding to null pointer
</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>enhancement
</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>haoxintu@gmail.com
</td>
</tr>
<tr>
<th>CC</th>
<td>blitzrakete@gmail.com, dgregor@apple.com, erik.pilkington@gmail.com, llvm-bugs@lists.llvm.org, richard-llvm@metafoo.co.uk
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<p>
<div>
<pre>This simple case test.cc
#include<iostream>
int main(){
int &x = *(int *)nullptr; // Error: null reference
std::cout << "ok" << std::endl;
return 0;
}
In clang-trunk, clang-10, clang-9 can not detect runtime error, while clang-8
and lower version does.
$clang++-trunk -fsanitize=null test.cc ; ./a.out
test.cc:4:14: warning: binding dereferenced null pointer to reference has
undefined behavior [-Wnull-dereference]
int &x = *(int *)nullptr;
^~~~~~~~~~~~~~~
1 warning generated.
ok
$clang++-8 -w -fsanitize=null test.cc ; ./a.out
test.cc:4:14: warning: binding dereferenced null pointer to reference has
undefined behavior [-Wnull-dereference]
int &x = *(int *)nullptr;
^~~~~~~~~~~~~~~
1 warning generated.
test.cc:4:14: runtime error: reference binding to null pointer of type 'int'
ok
My clang-trunk version is
$clang++-trunk --version
clang version 11.0.0 (<a href="https://github.com/llvm/llvm-project">https://github.com/llvm/llvm-project</a>
210616bd38d589020b45f8cbbf9f9ef1296f2729)
Target: x86_64-unknown-linux-gnu
Thread model: posix
InstalledDir: /home/haoxin/compilers/llvm-clang/llvm-project/build/bin
Is clang delete runtime error message when "-fsanitize=null" is used in new
recent versions after clang-8? If not, I think there something wrong with the
above case.</pre>
</div>
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