Local class + function pointer template argument + noexcept = SEGFAULT

[Quuxplusone]

Bugzilla Link	PR28340
Status	NEW
Importance	P normal
Reported by	Mark (turck11@hotmail.com)
Reported on	2016-06-28 02:44:57 -0700
Last modified on	2016-06-28 18:16:44 -0700
Version	trunk
Hardware	All All
CC	llvm-bugs@lists.llvm.org
Fixed by commit(s)
Attachments	test2-2d7555.sh (2067 bytes, application/octet-stream)
Blocks
Blocked by
See also

Created attachment 16646
Run script. Couldn't figure out how to add a 2nd attachment, but the
preprocessed output is boring/probably not helpful anyway.

Minimal repro:

template<typename T>
void isNothrowCallableFunPtr() {
  struct NothrowCallableTest {
    T fun;
    NothrowCallableTest() noexcept(noexcept(fun())) {}
  };
}

int main() {
  isNothrowCallableFunPtr<void(*)()>();
  return 0;
}

See it live on the trunk version of clang here, including the output:
http://melpon.org/wandbox/permlink/dZw6IKrnMY1VbKM8

This repros on 3.8, 3.7, 3.6... maybe more. Also on Apple LLVM version 7.3.0
(clang-703.0.31), which is what I attached the preprocessed source and
associated run script from.

[Quuxplusone]

Attached test2-2d7555.sh (2067 bytes, application/octet-stream): Run script. Couldn't figure out how to add a 2nd attachment, but the preprocessed output is boring/probably not helpful anyway.

[Quuxplusone]

FWIW: just realized that the repro/what I was trying to do doesn't actually make sense until C++17 when this paper is implemented: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/p0012r1.html

In particular, a function pointer does not know whether or not it is noexcept.