Google Test has recently (02/09/2018) switched the default death test
style from "fast" to "threadsafe" in
ec7faa943d
Threadsafe death tests have been used internally for a while, and are
proven to be a better default.
However, adopting this better default can be challenging for large
projects with a significant investment in custom infrastructure built on
top of Google Test. The same custom infrastructure can make it difficult
for large projects to switch back to the old default by passing in
--gtest_death_test_style=fast.
For the reasons above, the default switch is considered too disruptive,
and this CL reverts it. This CL also introduces the
GTEST_DEFAULT_DEATH_TEST_STYLE preprocesor macro, which replaces the
hard-coded default. The macro can be defined in
gtest/internal/custom/gtest-port.h by projects that are ready to migrate
to thread-safe death tests.
_HAS_EXCEPTIONS is specific to the MSVC STL and defining it to 0 causes
problems with libc++, so libc++ users may leave it undefined. This can
cause GTEST_HAS_EXCEPTIONS to be defined incorrectly if the user has
disabled exceptions via the compiler, which can lead to build errors.
_CPPUNWIND is a builtin macro provided by the compiler so it should
work with both STLs.
clang-cl is clang for Windows running in MSVC mode. Chromium uses it for
Windows builds. clang-cl is weird in that it defines __clang__ and
_MSC_VER, but *NOT* __GNUC__. This is vaguely analogous to how normal
clang defines __clang__ (what it is) and __GNUC__ (what it is compatible
with).
However, clang-cl still implements most GCC extensions, being clang.
Notably, the way to control -Wformat-literal is still with
__attribute__((__format__)). For better error-checking and strict
-Wformatl-literal compatibility (see
53c478d639b8eebd2942e88266610ebc79c541f6), define
GTEST_ATTRIBUTE_PRINTF_ in clang-cl too.
This makes it easier to use GTest in projects that build with the
-Wmissing-declarations warning. This fixes the warning in headers and
source files, though not GTest's own tests as it is rather noisy there.
On platforms with std::tuple and not std::tr1::tuple, GTEST_HAS_COMBINE
gets turned off when it works fine (due to GTEST_TUPLE_NAMESPACE_).
Elsewhere in the project, several GTEST_HAS_TR1_TUPLE checks
additionally check GTEST_HAS_STD_TUPLE_, so use that formulation.
(The ones that don't are specific to std::tr1::tuple and are followed by
an identical GTEST_HAS_STD_TUPLE_ version underneath it.)
In particular, this fixes testing::Combine on MSVC 2017, which regressed
here:
https://github.com/google/googletest/pull/1348#issuecomment-353879010
