commit 642080354947e0606992aa091ce5e1b4e1e4179d
author Eric Fiselier <eric@efcs.ca> Sun Jan 06 00:37:31 2019 +0000
committer Eric Fiselier <eric@efcs.ca> Sun Jan 06 00:37:31 2019 +0000
tree f9a10659a20a806a58b146273c3972c6e9eaee7d
parent 936dd3d1fffaa6464d05d5cce70800448c276e09

Fix PR39749 - Headers containing just #error harm __has_include.

This patch changes <experimental/foo> to use #warning instead of
is harmful to common feature detection idioms.

We should also consider only emitting the warning when __DEPRECATED is
defined, like we do in the <ext/foo> headers. Users may want to specify
"-Werror=-W#warnings" while still ignoring the libc++ warnings.

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@350485 91177308-0d34-0410-b5e6-96231b3b80d8