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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - WebAssembly: libc++abi and clang disagree and width of guard variables in __cxa_guard_acquire/release"
href="https://bugs.llvm.org/show_bug.cgi?id=42680">42680</a>
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<th>Summary</th>
<td>WebAssembly: libc++abi and clang disagree and width of guard variables in __cxa_guard_acquire/release
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<th>Product</th>
<td>libc++abi
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<th>Version</th>
<td>unspecified
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<th>Hardware</th>
<td>PC
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<th>OS</th>
<td>Linux
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<th>Status</th>
<td>NEW
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<th>Severity</th>
<td>enhancement
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<th>Priority</th>
<td>P
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<th>Component</th>
<td>All Bugs
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<th>Assignee</th>
<td>unassignedbugs@nondot.org
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<th>Reporter</th>
<td>sbc@chromium.org
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<th>CC</th>
<td>llvm-bugs@lists.llvm.org, mclow.lists@gmail.com
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<p>
<div>
<pre>In ItaniumCXXABI.cpp we set UseARMGuardVarABI=true for WebAssembly, but in
cxxabi.h we only set the guard type to 32-bit on arm.
This means that clang allocates 4 butes for the guard but libc++abi will assume
it 8 bytes and clobber memory on __cxa_guard_acquire/__cxa_guard_release.
I suggest we simply stop setting UseARMGuardVarABI unless there was a good
reason for doing this?</pre>
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