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<base href="https://llvm.org/bugs/" />
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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW " title="NEW --- - Warning when -fsanitize-coverage= is followed by -fno-sanitize=all" href="https://urldefense.proofpoint.com/v2/url?u=https-3A__llvm.org_bugs_show-5Fbug.cgi-3Fid-3D23604&d=AwMBaQ&c=8hUWFZcy2Z-Za5rBPlktOQ&r=pF93YEPyB-J_PERP4DUZOJDzFVX5ZQ57vQk33wu0vio&m=KclujQOb29VDz0WPP2RbBwcXaCLqT_U-b5i9-T-9DSY&s=awoIaXLXjSw4HdhFdk_NW067FesAsnlsw3Ick3ZdIgQ&e=">23604</a>
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<th>Summary</th>
<td>Warning when -fsanitize-coverage= is followed by -fno-sanitize=all
</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
</td>
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<th>OS</th>
<td>All
</td>
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<th>Status</th>
<td>NEW
</td>
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<th>Severity</th>
<td>normal
</td>
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<th>Priority</th>
<td>P
</td>
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<th>Component</th>
<td>Driver
</td>
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<th>Assignee</th>
<td>unassignedclangbugs@nondot.org
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<th>Reporter</th>
<td>llvm-bugs@justinbogner.com
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<th>CC</th>
<td>llvmbugs@cs.uiuc.edu
</td>
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<th>Classification</th>
<td>Unclassified
</td>
</tr></table>
<p>
<div>
<pre>If sanitizers are turned off using -fno-sanitize=all, but -fsanitize-coverage=
flags were specified, we get a warning about an unused argument:
% clang++ -fsanitize=address,undefined
-fsanitize-coverage=edge,indirect-calls,8bit-counters,trace-cmp
-fno-sanitize=all -x c++ -c /dev/null -o /dev/null
clang-3.7: warning: argument unused during compilation:
'-fsanitize-coverage=edge,indirect-calls,8bit-counters,trace-cmp'
This is poor behaviour since the -fsanitize-coverage flag was valid where it
was used, and it makes it difficult to disable sanitizers in a makefile using
-fno-sanitize=all.
You'll hit this issue if you build llvm using a cmake invocation including
"-DLLVM_USE_SANITIZER=Address;Undefined -DLLVM_USE_SANITIZE_COVERAGE=ON
-DLLVM_ENABLE_WERROR=ON".</pre>
</div>
</p>
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