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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - [msabi] wrong mangling for auto-typed non-type template parameters"
href="https://bugs.llvm.org/show_bug.cgi?id=44207">44207</a>
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<th>Summary</th>
<td>[msabi] wrong mangling for auto-typed non-type template parameters
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<th>Product</th>
<td>clang
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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>Windows XP
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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>C++17
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<th>Assignee</th>
<td>unassignedclangbugs@nondot.org
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<th>Reporter</th>
<td>richard-llvm@metafoo.co.uk
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<th>CC</th>
<td>blitzrakete@gmail.com, erik.pilkington@gmail.com, llvm-bugs@lists.llvm.org, richard-llvm@metafoo.co.uk, rnk@google.com
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<pre>Clang incorrectly mangles non-type template parameters whose types involve
`auto` when targeting the MS ABI. Testcase:
template<auto *P> struct X {};
int a;
void f(X<&a>) {}
void f(X<(const int*)&a>) {}
MSVC mangles these as:
?f@@YAXU?$X@$MPEAH1?a@@3HA@@@Z
?f@@YAXU?$X@$MPEBH1?a@@3HA@@@Z
Clang wants to mangle them both as:
?f@@YAXU?$X@$1?a@@3HA@@@Z
In practice, Clang rejects both of the above in Sema before getting to
mangling, but commenting out either of the definitions of 'f' results in a
program for which Clang generates wrong manglings under the MS ABI:
<a href="https://godbolt.org/z/xDDuD7">https://godbolt.org/z/xDDuD7</a></pre>
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