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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - DW_AT_call_value location may be clobbered by callee"
href="https://bugs.llvm.org/show_bug.cgi?id=43343">43343</a>
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<th>Summary</th>
<td>DW_AT_call_value location may be clobbered by callee
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<th>Product</th>
<td>libraries
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<th>Version</th>
<td>trunk
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<th>Hardware</th>
<td>PC
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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
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<th>Priority</th>
<td>P
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<th>Component</th>
<td>DebugInfo
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<th>Assignee</th>
<td>unassignedbugs@nondot.org
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<th>Reporter</th>
<td>vsk@apple.com
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<th>CC</th>
<td>jdevlieghere@apple.com, keith.walker@arm.com, llvm-bugs@lists.llvm.org, paul_robinson@playstation.sony.com
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<p>
<div>
<pre>In <a href="https://reviews.llvm.org/D67556">https://reviews.llvm.org/D67556</a>, David Stenberg gives an example of how the
location of a parameter in a caller can escape and be clobbered by the callee.
In this case, the debugger may print a misleading description for the parameter
when stopped in the callee.
The setup is roughly:
```
void caller() {
int local = 0;
escape(&local);
callee(local);
}
void callee(int p) {
cause_arg1_to_be_optimized_out();
*escaped_ptr_to_local = 1;
// print 'p' in the debugger: will show '1' instead of '0'.
}
```</pre>
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