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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW --- - GlobalOpt::CleanupPointerRootUsers could pass nullptr to dyn_cast"
href="http://llvm.org/bugs/show_bug.cgi?id=21592">21592</a>
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<tr>
<th>Summary</th>
<td>GlobalOpt::CleanupPointerRootUsers could pass nullptr to dyn_cast
</td>
</tr>
<tr>
<th>Product</th>
<td>libraries
</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>
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<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>Interprocedural Optimizations
</td>
</tr>
<tr>
<th>Assignee</th>
<td>unassignedbugs@nondot.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>vedun@ispras.ru
</td>
</tr>
<tr>
<th>CC</th>
<td>llvmbugs@cs.uiuc.edu
</td>
</tr>
<tr>
<th>Classification</th>
<td>Unclassified
</td>
</tr></table>
<p>
<div>
<pre>Created <span class=""><a href="attachment.cgi?id=13358" name="attach_13358" title="Proposed patch">attachment 13358</a> <a href="attachment.cgi?id=13358&action=edit" title="Proposed patch">[details]</a></span>
Proposed patch
<a href="https://github.com/llvm-mirror/llvm/blob/master/lib/Transforms/IPO/GlobalOpt.cpp#L222">https://github.com/llvm-mirror/llvm/blob/master/lib/Transforms/IPO/GlobalOpt.cpp#L222</a>
:
222: GlobalVariable *MemSrc = dyn_cast<GlobalVariable>(MTI->getSource());
223: if (MemSrc && MemSrc->isConstant()) {
224: Changed = true;
225: MTI->eraseFromParent();
226: } else if (Instruction *I = dyn_cast<Instruction>(MemSrc)) {
227: if (I->hasOneUse())
228: Dead.push_back(std::make_pair(I, MTI));
229: }
if MTI->getSource() is an Instruction, dyn_cast(222) returns nullptr, so the
condition (223) would be false, and dyn_cast (226) would fail due to MemSrc
being null.
Probably, the author meant that dyn_cast (226) should use the return of
MTI->getSource(). In this case, the attached patch fixes the issue.</pre>
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