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<base href="http://llvm.org/bugs/" />
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<body><table border="1" cellspacing="0" cellpadding="8">
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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW --- - Analyzer misses potential null dereference"
href="http://llvm.org/bugs/show_bug.cgi?id=15314">15314</a>
</td>
</tr>
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<th>Summary</th>
<td>Analyzer misses potential null dereference
</td>
</tr>
<tr>
<th>Product</th>
<td>clang
</td>
</tr>
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<th>Version</th>
<td>3.2
</td>
</tr>
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<th>Hardware</th>
<td>PC
</td>
</tr>
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<th>OS</th>
<td>All
</td>
</tr>
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<th>Status</th>
<td>NEW
</td>
</tr>
<tr>
<th>Severity</th>
<td>enhancement
</td>
</tr>
<tr>
<th>Priority</th>
<td>P
</td>
</tr>
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<th>Component</th>
<td>Static Analyzer
</td>
</tr>
<tr>
<th>Assignee</th>
<td>kremenek@apple.com
</td>
</tr>
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<th>Reporter</th>
<td>jim.correia@pobox.com
</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=10049" name="attach_10049" title="Sample code which demonstrates the bug.">attachment 10049</a> <a href="attachment.cgi?id=10049&action=edit" title="Sample code which demonstrates the bug.">[details]</a></span>
Sample code which demonstrates the bug.
In the attached sample, the incorrect if on line 52 in -doSomethingElse:
confuses the analyzer. It misses the potential null dereference on line 52,
line 53, and line 59.
===
Build command:
xcrun clang analyzer-null-dereference.m -fobjc-arc --analyze
Details:
Expect 2 "Potential null dereference" warnings to be generated for the
-doSomethingElse: method. None are generated. The erroneous
`if (*error != NULL)` seems to be confusing the analyzer.
Warnings generated:
analyzer-null-dereference.m:45:12: warning: Potential null dereference.
According to coding standards in 'Creating and Returning NSError Objects' the
parameter '' may be null
*error = [NSError errorWithDomain:@"MyErrorDomain" code:1
userInfo:nil];
~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1 warning generated.
(I hit this in production code — this isn't a contrived example.)
Compiler version:
% xcrun clang -v
Apple LLVM version 4.2 (clang-425.0.24) (based on LLVM 3.2svn)
Target: x86_64-apple-darwin12.2.1
Thread model: posix</pre>
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