Commit Graph

5 Commits

Author SHA1 Message Date
Richard Smith 82da19ddb3 [c++1z] P0003R5: Removing dynamic exception specifications.
We continue to support dynamic exception specifications in C++1z as an
extension, but produce an error-by-default warning when we encounter one. This
allows users to opt back into the feature with a warning flag, and implicitly
opts system headers back into the feature should they happen to use it.

There is one semantic change implied by P0003R5 but not implemented here:
violating a throw() exception specification should now call std::terminate
directly instead of calling std::unexpected(), but since P0003R5 also removes
std::unexpected() and std::set_unexpected, and the default unexpected handler
calls std::terminate(), a conforming C++1z program cannot tell that we are
still calling it. The upside of this strategy is perfect backwards
compatibility; the downside is that we don't get the more efficient 'noexcept'
codegen for 'throw()'.

llvm-svn: 289019
2016-12-08 02:49:07 +00:00
Richard Smith 1be59c5106 [c++1z] P0012R1: Implement a few remaining pieces: downgrade diagnostic for
mismatched dynamic exception specifications in expressions from an error to a
warning, since this is no longer ill-formed in C++1z.

Allow reference binding of a reference-to-non-noexcept function to a noexcept
function lvalue. As defect resolutions, also allow a conditional between
noexcept and non-noexcept function lvalues to produce a non-noexcept function
lvalue (rather than decaying to a function pointer), and allow function
template argument deduction to deduce a reference to non-noexcept function when
binding to a noexcept function type.

llvm-svn: 284905
2016-10-22 01:32:19 +00:00
Richard Smith eb7ef2e1ca Re-commit r284753, reverted in r284778, with a fix for PR30749.
Original commit message:

[c++1z] Teach composite pointer type computation how to compute the composite
pointer type of two function pointers with different noexcept specifications.
While I'm here, also teach it how to merge dynamic exception specifications.

llvm-svn: 284785
2016-10-20 21:53:09 +00:00
Hans Wennborg 2b81f42a76 Revert r284753 "[c++1z] Teach composite pointer type computation how to compute the composite"
It caused PR30749.

llvm-svn: 284778
2016-10-20 20:54:32 +00:00
Richard Smith 9c37e66c31 [c++1z] Teach composite pointer type computation how to compute the composite
pointer type of two function pointers with different noexcept specifications.
While I'm here, also teach it how to merge dynamic exception specifications.

llvm-svn: 284753
2016-10-20 17:57:33 +00:00