[libcxx-commits] [PATCH] D57761: [libc++] Avoid UB in the no-exceptions mode in a few places

[Duncan P. N. Exon Smith via Phabricator via libcxx-commits]

dexonsmith added inline comments.


================
Comment at: libcxx/src/ios.cpp:271
     if (((state | (__rdbuf_ ? goodbit : badbit)) & __exceptions_) != 0)
-        throw failure("ios_base::clear");
-#endif  // _LIBCPP_NO_EXCEPTIONS
+        __throw_failure("ios_base::clear");
 }
----------------
ldionne wrote:
> Actually, looking at this again, it seems like we probably don't want to abort here, since the stream will report the error with the error flags. So I should not change this one -- @mclow.lists does that seem right to you?
`::abort` seems more consistent to me.  The user has set the exception bit, so I wouldn't expect them to have control flow to handle errors otherwise.  Moreover, the direct user could be templated/inlined header code which doesn't know that `-fno-exceptions` has been passed for this project/TU.

More generally, I think a strict library policy of turning throws into aborts will lead to behaviour that's predictable for users.


Repository:
  rCXX libc++

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D57761/new/

https://reviews.llvm.org/D57761