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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - static analyzer false positive: non-null value is believed to be null [clang-analyzer-core.uninitialized.UndefReturn]"
href="https://bugs.llvm.org/show_bug.cgi?id=42815">42815</a>
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<th>Summary</th>
<td>static analyzer false positive: non-null value is believed to be null [clang-analyzer-core.uninitialized.UndefReturn]
</td>
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<th>Product</th>
<td>clang
</td>
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<th>Version</th>
<td>trunk
</td>
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<th>Hardware</th>
<td>PC
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<th>OS</th>
<td>Linux
</td>
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<th>Status</th>
<td>NEW
</td>
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<th>Severity</th>
<td>enhancement
</td>
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<th>Priority</th>
<td>P
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<th>Component</th>
<td>Static Analyzer
</td>
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<th>Assignee</th>
<td>dcoughlin@apple.com
</td>
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<th>Reporter</th>
<td>raffael@casagrande.ch
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<th>CC</th>
<td>dcoughlin@apple.com, llvm-bugs@lists.llvm.org
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<div>
<pre>Overview:
Under some circumstances, the static analyer believes that a null reference is
being returned when it is clearly not.
Steps to Reproduce
1) run scan-build g++ main.cc
Actual Results:
In file included from main.cc:1:
In file included from ./Eigen/Eigen:2:
In file included from ./Eigen/Sparse:26:
In file included from ./Eigen/SparseCore:39:
./Eigen/src/SparseCore/CompressedStorage.h:121:80: warning: Returning null
reference
inline StorageIndex& index(Index i) { eigen_internal_assert(m_indices!=0);
return m_indices[i]; }
^~~~~~~~~~~~~~~~~~~
1 warning generated.
scan-build: 1 bug found.
Expected Results:
No bug should be found.
Build information:
The bug appears on the latest trunk build (git hash
89fb9e8ce151d48b56a6bc25de62e93743e0d6c1), pulled on July 29th 2019. The bug
was first encountered on clang-tidy-8.
Additional Information:
- The attached example code illustrates the issue. I've reduced it as much as
possible, but I couldn't get rid of the Eigen dependency in reasonable time,
therefore I've just included it.
- By uncommenting line 18 in main.cc the warning disappears, but this is of
course not practical.</pre>
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