This upstreams a Google-internal change.
Original CL description:
The C++ standard says that function pointers are not implicitly
convertible to object pointers. Visual Studio disregards that and allows
implicit conversion between function pointers and object points, and
enough code relies on this that clang follows suit in
Microsoft-compatibility mode.
However, clang emits a -Wmicrosoft-cast warning when such a conversion
is done:
E:\b\c\b\win_clang\src\sandbox\win\src\sync_dispatcher.cc(42,7):
warning: implicit conversion between pointer-to-function and
pointer-to-object is a Microsoft extension [-Wmicrosoft-cast]
This change fixes this warning in gtest, while hopefully not changing
any behavior. The change does two things:
1. It replaces the if in DefaultPrintTo with SFINAE
2. In C++11 mode, it uses enable_if<is_function<>> instead of
ImplicitlyConvertible<T*, const void*> to check if the
explicit cast is needed.
With this change, functions will use the branch with the reintpret_casts
with Visual Studio and clang/win, and clang no longer needs to warn
that it implicitly converts a function pointer to a void pointer.
Fixes the following errors:
hash_map(17): error C2338: <hash_map> is deprecated and will be REMOVED. Please use <unordered_map>. You can define _SILENCE_STDEXT_HASH_DEPRECATION_WARNINGS to acknowledge that you have received this warning. [googlemock\gtest\gtest-printers_test.vcxproj]
hash_set(17): error C2338: <hash_set> is deprecated and will be REMOVED. Please use <unordered_set>. You can define _SILENCE_STDEXT_HASH_DEPRECATION_WARNINGS to acknowledge that you have received this warning. [googlemock\gtest\gtest-printers_test.vcxproj]
googletest\test\gtest_catch_exceptions_test_.cc(152): error C2220: warning treated as error - no 'object' file generated
googletest\test\gtest_catch_exceptions_test_.cc(152): warning C4297: 'CxxExceptionInDestructorTest::~CxxExceptionInDestructorTest': function assumed not to throw an exception but does
googletest\test\gtest_catch_exceptions_test_.cc(152): note: destructor or deallocator has a (possibly implicit) non-throwing exception specification
There were already some checks for _MSC_VER in the code, so this commit
continues in that vein.
If REGISTER_TYPED_TEST_CASE_P is included in a header file, but
the .cc file does not declare INSTANTIATE_TYPED_TEST_CASE_P, an
unused-variable warning may be raised by the compiler.
googletest doesn't currently build with clang's very aggressive
-Wformat-nonliteral warning. It requires that all non-literal format
strings come from the argument of a function annotated with a compatible
format attribute.
Fixing that reports that ColoredPrintf's callers weren't passing the
normal -Wformat warning. Some messages were passed directly into the
format string rather than via "%s".
Adds instructions for how to add gtest and gmock to
another CMake project directly. Downloading of the
googletest sources happens as configure time, allowing
it to be added to the main build directly via the
add_subdirectory() command. This ensures googletest is
built with the same compiler settings, etc. and will
typically result in a more robust and more convenient
build arrangement.