In preparation for switching to the c++11 requirement, I’ve done depends builds on all supported OSs and fixed up any snags along the way.
Note that this does not enable c++11 anywhere, it simply enables c++11 builds to pass.
Once merged, we can begin moving forward with enabling.
This is ugly, but temporary. boost::filesystem will likely be dropped soon
after c++11 is enabled. Otherwise, we could simply roll our own copy_file. I've
fixed this at the buildsystem level for now in order to avoid mixing in
functional changes.
Explanation:
If boost (prior to 1.57) was built without c++11, it emulated scoped enums
using c++98 constructs. Unfortunately, this implementation detail leaked into
the abi. This was fixed in 1.57.
When building against that installed version using c++11, the headers pick up
on the native c++11 scoped enum support and enable it, however it will fail to
link. This can be worked around by disabling c++11 scoped enums if linking will
fail.
Add an autoconf test to determine incompatibility. At build-time, if native
enums are being used (a c++11 build), and force-disabling them causes a
successful link, we can be sure that there's an incompatibility and enable the
work-around.
noexcept is default for destructors as of c++11. By throwing in reverselock's
destructor if it's lock has been tampered with, the likely result is
std::terminate being called. Indeed that happened before this change.
Once reverselock has taken another lock (its ctor didn't throw), it makes no
sense to try to grab or lock the parent lock. That is be broken/undefined
behavior depending on the parent lock's implementation, but it shouldn't cause
the reverselock to fail to re-lock when destroyed.
To avoid those problems, simply swap the parent lock's contents with a dummy
for the duration of the lock. That will ensure that any undefined behavior is
caught at the call-site rather than the reverse lock's destruction.
Barring a failed mutex unlock which would be indicative of a larger problem,
the destructor should now never throw.
c++11ism. This fixes builds against libc++.
atomic_init clashes with
conceptACK, will start testing shortly.
On Wednesday, 6 January 2016, Daniel Cousens notifications@github.com wrote:
utACK
— Reply to this email directly or view it on GitHub #7302 (comment).
minor nits: new configure line output is:
0checking for mismatched boost c++11 scoped enums... ok
Will we use C++11 like we use C++? Ie. capital C? Or is small c ok?
Can you please add a comment to configure.ac (e.g. reuse the commit message) above the new part?
Otherwise ACK Thanks!
