This is important for two reasons:
1. A compiler might warn about a class that has a virtual member
function but no virtual destructor. We don't want to treat the feature
as incomplete in this case.
2. MSVC10 supports the override identifier except on destructors. In
this case, the feature really is incomplete and we want to detect it as
such.
Turn the feature check for cxx11_unordered_map into a function such that
we can use it for other features as well. Drop the 11 suffix, as we may
want to check features from other standards.
Run the `Utilities/Scripts/clang-format.bash` script to update
all our C++ code to a new style defined by `.clang-format`.
Use `clang-format` version 3.8.
* If you reached this commit for a line in `git blame`, re-run the blame
operation starting at the parent of this commit to see older history
for the content.
* See the parent commit for instructions to rebase a change across this
style transition commit.
Support for C11's _Thread_local was introduced in GCC in the 4.9 series,
even though we make the C11 compiler flags available in CMake with GCC
>= 4.6.
FreeBSD's runetype.h uses _Thread_local, which causes CMake's own build
to fail when using GCC < 4.9 and -std=gnu11:
/usr/include/runetype.h:92:22: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'const'
extern _Thread_local const _RuneLocale *_ThreadRuneLocale;
Add a test for _Thread_local support and only build CMake itself with
C11 support if it works.
Bug: http://www.cmake.org/Bug/view.php?id=15741
The GNU 4.8 standard library's cstdio header is not aware that C++14
honors C11's removal of "gets" from stdio.h and results in an error:
/.../include/c++/4.8/cstdio:120:11: error: no member named 'gets' in the global namespace
Detect this problematic case and default to using C++11 instead of
C++14 for building CMake itself.