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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - Analyzer crashes (Unexpected CFG element at front of block) with widen-loops=true"
href="https://bugs.llvm.org/show_bug.cgi?id=37861">37861</a>
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<th>Summary</th>
<td>Analyzer crashes (Unexpected CFG element at front of block) with widen-loops=true
</td>
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<th>Product</th>
<td>clang
</td>
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<th>Version</th>
<td>trunk
</td>
</tr>
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<th>Hardware</th>
<td>PC
</td>
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<th>OS</th>
<td>All
</td>
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<th>Status</th>
<td>NEW
</td>
</tr>
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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>Static Analyzer
</td>
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<th>Assignee</th>
<td>dcoughlin@apple.com
</td>
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<th>Reporter</th>
<td>warren_ristow@playstation.sony.com
</td>
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<th>CC</th>
<td>llvm-bugs@lists.llvm.org
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<p>
<div>
<pre>The following test-case crashes in the Static Analyzer with an UNREACHABLE:
Unexpected CFG element at front of block
when widen-loops=true.
$ cat t.cpp
//////////////// "t.cpp" ///////////////
class A {
public:
void m_fn1();
};
bool g;
void fn1() {
A a;
A *b = &a;
for (;;) {
g = !b;
b->m_fn1();
}
}
////////////////////////////////////////
$ clang --analyze -Xanalyzer -analyzer-config -Xanalyzer widen-loops=true t.cpp
Unexpected CFG element at front of block
UNREACHABLE executed at clang/lib/StaticAnalyzer/Core/PathDiagnostic.cpp:740!
Stack dump:
...
clang: error: clang frontend command failed due to signal ...
clang version 7.0.0 (trunk 335000)
Target: x86_64-unknown-linux-gnu
...
$
As an aside, prior to r319333 it crashed with a different UNREACHABLE, but in
the same area of "StaticAnalyzer/Core/PathDiagnostic.cpp":
Unexpected ProgramPoint
That "Unexpected ProgramPoint" crash was reported with a different test-case,
as <a class="bz_bug_link
bz_status_RESOLVED bz_closed"
title="RESOLVED WORKSFORME - Assertion UNREACHABLE: "Unexpected ProgramPoint" with widen-loops=true"
href="show_bug.cgi?id=25609">bug 25609</a>. Just cross-referencing here, since they may be related.</pre>
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