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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW --- - missing check if .gcda file has the expected number of basic blocks for a function"
href="http://llvm.org/bugs/show_bug.cgi?id=17114">17114</a>
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<th>Summary</th>
<td>missing check if .gcda file has the expected number of basic blocks for a function
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<th>Product</th>
<td>compiler-rt
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<th>Version</th>
<td>unspecified
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<th>Hardware</th>
<td>Macintosh
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<th>OS</th>
<td>All
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<th>Status</th>
<td>NEW
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<th>Severity</th>
<td>normal
</td>
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<th>Priority</th>
<td>P
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<th>Component</th>
<td>compiler-rt
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<th>Assignee</th>
<td>unassignedbugs@nondot.org
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<th>Reporter</th>
<td>bob.wilson@apple.com
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<th>CC</th>
<td>llvmbugs@cs.uiuc.edu
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<th>Classification</th>
<td>Unclassified
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<p>
<div>
<pre>According to the gcov man page:
"For each source file compiled with -fprofile-arcs, the profiling code first
attempts to read in an existing .gcda file; if the file doesn't match the
executable (differing number of basic block counts) it will ignore the contents
of the file."
LLVM's implementation seems to be missing that check. If you have a stale
.gcda file that gets read in to have its counts updated, bad things can happen
if the code has changed and there are a different number of basic blocks.
I noticed this by inspection and don't have a test case, but it shouldn't be
hard to make one.</pre>
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