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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW --- - [ms] clang-cl emits scalar deleting ctor and vtable for templates with dllimported instantiation declaration"
href="https://llvm.org/bugs/show_bug.cgi?id=27811">27811</a>
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<th>Summary</th>
<td>[ms] clang-cl emits scalar deleting ctor and vtable for templates with dllimported instantiation declaration
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<th>Product</th>
<td>clang
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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>Windows NT
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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++
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<th>Assignee</th>
<td>unassignedclangbugs@nondot.org
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<th>Reporter</th>
<td>nicolasweber@gmx.de
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<th>CC</th>
<td>dgregor@apple.com, llvm-bugs@lists.llvm.org
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<th>Classification</th>
<td>Unclassified
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<p>
<div>
<pre>Somewhat similar to <a class="bz_bug_link
bz_status_NEW "
title="NEW --- - [ms] clang-cl emits definitions for methods of inner classes of template classes of the template has a dllimported instantiation declaration"
href="show_bug.cgi?id=27810">bug 27810</a>, but I'm less sure that it's wrong -- I vaguely
remember that we emit some members more often than cl on purpose.
Anyhow...consider:
template <class T>
struct codecvt {
virtual ~codecvt() {
}
};
template class __declspec(dllimport) codecvt<char>;
clang-cl emits a whole lot of stuff for this. cl emits nothing. Regular
non-windows clang also emits nothing if this is converted to an `extern
template class codecvt<char>`.
This too causes us to emit many functions (order of 60) into every TU including
MS C++ headers. Other than <a class="bz_bug_link
bz_status_NEW "
title="NEW --- - [ms] clang-cl emits definitions for methods of inner classes of template classes of the template has a dllimported instantiation declaration"
href="show_bug.cgi?id=27810">bug 27810</a>, these functions disappear after -O2, but
it'd probably be much faster to not emit them in the first place, instead of
relying on the optimizer to clean them up.</pre>
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